rotary tools

Abstract

An object of the present invention is to provide a rotary tool that reduces cutting resistance and allows chips to be smoothly discharged from the grooves. [Solution] The rotary tool 1 of the present invention comprises a disk-shaped main body 10 having an outer peripheral surface of a predetermined width, a plurality of cutting edge portions 20 formed at predetermined intervals circumferentially on the outer peripheral surface of the main body 10, and a plurality of chip discharge groove portions 30 formed between the cutting edge portions 20, the cutting edge portions 20 being inclined at a predetermined twist angle with respect to the rotation axis of the main body 10, and cutting edge portions 20 with positive twist angles and cutting edge portions 20 with negative twist angles being arranged alternately, and the chip discharge groove portions 30 have curved groove surfaces 31 of a predetermined width formed on the rake faces of the cutting edge portions 20.

Description

[Technical Field]

[0001] The present invention relates to a disk-shaped rotary tool such as a metal saw used for cutting a workpiece made of a metal material. [Background technology]

[0002] Rotary tools such as metal saws have traditionally been used to perform cutting processes such as cutting and grooving on workpieces made of metal materials. These rotary tools have a disk-shaped main body with multiple cutting edges arranged on the outer periphery, and can efficiently perform cutting and grooving by pressing the cutting edges against the workpiece while rotating the main body at high speed around the central axis.

[0003] For example, Patent Document 1 describes a method for reducing cutting torque by setting alternate helix angles for multiple cutting edges formed around the periphery of a metal saw. Also, Patent Document 2 describes a method for forming the rake face of a cutting part formed on the outer periphery of a disk by connecting a first rake face having a positive rake angle and a second rake face having a negative rake angle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 53-1186 [Patent Document 2] Patent No. 3105866 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, multiple cutting edges are set at alternating helix angles so that they are inclined relative to the rotation axis of the metal saw, and the distance between both ends of adjacent cutting edges is set so that one end is narrow and the other is wide. As a result, the grooves between adjacent cutting edges are formed so that one end is narrow and the other end is wide, which poses a problem in that chips generated by the cutting edges cannot be discharged smoothly and tend to accumulate in the grooves, easily becoming clogged.

[0006] In Patent Document 2, the cutting edges of the blades formed on the outer periphery of the disk are set in a straight line along the rotation axis, which causes line contact between the workpiece and the cutting edges, increasing the load. Also, the grooves formed between adjacent blades are formed with a predetermined width along the rotation axis, which creates an issue in that chips generated by the blades are difficult to discharge from both ends of the grooves and are prone to clogging.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a rotary tool that reduces cutting resistance and allows chips to be smoothly discharged from the grooves. [Means for solving the problem]

[0008] The rotary tool according to the present invention is a rotary tool including a disk-shaped main body portion having an outer peripheral surface of a predetermined width, a plurality of cutting edges formed at predetermined intervals on the outer peripheral surface of the main body portion, and chip discharge groove portions formed between the cutting edges along the outer peripheral surface of the main body portion, wherein the cutting edges are inclined at a predetermined helix angle with respect to the rotation axis of the main body portion, and the cutting edges with positive helix angles and the cutting edges with negative helix angles are alternately arranged, and the chip discharge groove portions have curved groove surfaces of a predetermined width connected to the rake faces of the cutting edges. Crate The chip discharge groove portion is formed to coincide with a virtual spiral groove of a predetermined width set around the axis at a predetermined twist angle on the outer surface of a virtual cylinder that has the same diameter as the main body and is set with an axis that coincides with the rotation axis, and the cutting edge portion is formed to coincide with a virtual outer cutting edge that is set along the virtual spiral groove. [Effects of the Invention]

[0009] In the present invention, by setting the helix angle of the cutting edge portion relative to the rotation axis, the cutting edge makes point contact with the workpiece, causing chips to curl spirally, thereby reducing cutting resistance. Furthermore, the chip discharge groove portion has a curved groove surface of a predetermined width connected to the rake face of the cutting edge portion, so that curled chips are smoothly discharged along the curved groove surface. Furthermore, because cutting edge portions with positive helix angles and cutting edge portions with negative helix angles are alternately arranged, chips are discharged alternately from one end or the other of the chip discharge groove portion, allowing chips to be efficiently discharged to the outside without accumulating.

[0010] The chip discharge groove portion is formed to match a virtual spiral groove of a predetermined width that is set around the axis at a predetermined twist angle on the outer surface of a virtual cylinder that has the same diameter as the main body and is set with an axis that coincides with the rotation axis, and the cutting edge portion is formed to match a virtual outer cutting edge that is set along the virtual spiral groove, making it possible to achieve cutting processing functions similar to those of an end mill. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a front view of a rotary tool according to an embodiment of the present invention, viewed from a direction of a rotation axis. [Figure 2] 2 is a partially enlarged photograph of the cutting edge of the rotary tool shown in FIG. 1. [Figure 3] 10A and 10B are a partially enlarged view and a partially enlarged front view of the cutting edge portion and the chip discharge groove portion as viewed from the radial direction of the main body portion. [Figure 4] 10A and 10B are explanatory diagrams relating to the shape setting of a cutting edge portion and a chip discharge groove portion. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail. Note that the embodiments described below are preferred examples for carrying out the present invention, and therefore various technical limitations are imposed thereon, but the present invention is not limited to these embodiments unless otherwise specified in the following description to limit the present invention.

[0013] FIG. 1 is a front view of a rotary tool 1 according to an embodiment of the present invention, as viewed from the direction of the rotation axis, and FIG. 2 is a partially enlarged photograph of the cutting edge portion of the rotary tool shown in FIG.

[0014] The rotary tool 1 comprises a disk-shaped main body 10 having an outer peripheral surface of a predetermined width, a plurality of cutting edge portions 20 formed at predetermined intervals along the circumferential direction on the outer peripheral surface of the main body 10, and a plurality of chip discharge groove portions 30 formed between the cutting edge portions 20 along the circumferential direction on the outer peripheral surface of the main body 10.

[0015] The main body 10 is formed in a disk shape using a known metal material for cutting tools, such as high-speed tool steel or cemented carbide, and has a mounting hole 11 drilled in the center for mounting to a rotating shaft. The main body 10 has a predetermined thickness for use in groove machining and cutting, and the outer circumferential surface on which the cutting edge 20 is formed is set to a predetermined width in accordance with the machining shape.

[0016] The cutting edges 20 are arranged at equal intervals in the circumferential direction on the outer peripheral surface of the main body 10, and the cutting edges of the cutting edges 20 are formed along the outer peripheral surface. In this example, the outer peripheral surface of the main body 10 is set to follow the peripheral surface of an imaginary cylinder centered on the central axis of rotation. The chip discharge grooves 30 are formed and arranged at equal intervals between adjacent cutting edges 20.

[0017] 3A and 3B are a partially enlarged view (FIG. 3A) and a partially enlarged front view (FIG. 3B) of the cutting edge portion 20 and the chip discharge groove portion 30 as viewed from the radial direction of the main body. In FIG. 3A, the portion corresponding to the flank of the cutting edge portion 20 is indicated by hatching.

[0018] The cutting edge 21 of the cutting edge portion 20 is formed by the intersection of a rake face 22 and a flank face 23, and as will be described later, is formed to be slightly concavely curved along an imaginary spiral groove. The cutting edge 21 is set to be inclined at a helix angle α with respect to the rotation axis O of the main body 10, and adjacent cutting edge portions 20 are arranged so that the helix angles of the cutting edges 21 alternate between a positive helix angle +α and a negative helix angle -α.

[0019] In this example, the flank 23 is set to be inclined at a predetermined clearance angle with respect to the outer peripheral surface passing through the cutting edge 21 .

[0020] The chip discharge groove portion 30 has a curved groove surface 31 formed adjacent to the rake face 22, and the groove surface 31 is formed with a predetermined width d along the cutting edge 21. As will be described later, the chip discharge groove portion 30 is formed along an imaginary spiral groove and is set at an angle with respect to the rotation axis O of the main body portion 10. Similar to the twist angle of the cutting edge 21 of the cutting edge portion 20, adjacent chip discharge groove portions 30 are arranged so that the inclination angles with respect to the rotation axis O are alternately positive and negative.

[0021] When the main body 10 rotates in the rotation direction R, the cutting edge 21 is set at an angle relative to the rotation direction R, so that the cutting edge 21 cuts the workpiece from the tip side relative to the rotation direction R, thereby reducing the cutting resistance and suppressing heat generation during cutting processing.

[0022] Furthermore, the chips tend to curl spirally along the rake face 22, and are generated while curling from the front end to the rear end of the cutting edge 21, and are then discharged into the chip discharge groove 30. The groove surface 31 of the chip discharge groove 30 is formed with a predetermined width so as to follow the cutting edge 21, and is also formed in a curved shape connected to the rake face 22, so that the chips discharged into the chip discharge groove 30 move within the groove surface 31 in the discharge direction S, which is the opposite direction to the rotation direction R, and are then smoothly discharged to the outside.

[0023] Furthermore, since the cutting edge portions 20 are arranged alternately with positive and negative twist angles and the chip discharge groove portions 30 are arranged so as to be alternately inclined in accordance with the twist angles of the cutting edge portions 20, the chips are discharged alternately to both sides of the main body portion 10, and are efficiently discharged to the outside without accumulating, making it possible to perform cutting processing at high speeds.

[0024] 4A and 4B are explanatory diagrams illustrating the configuration of the cutting edge portion 20 and the chip discharge groove portion 30. As shown in FIG. 4A, a virtual cylinder C is set up, which has the same diameter as the main body 10 and an axis coincident with the rotation axis O. On the outer circumferential surface of the cylinder C, a virtual spiral groove G1 of a predetermined width is set up around the axis with a positive helix angle, and a virtual spiral groove G2 of a predetermined width is set up around the axis with a negative helix angle. A virtual peripheral cutting edge L1 is set up at one side end of the virtual spiral groove G1, and a virtual peripheral cutting edge L2 is set up at one side end of the virtual spiral groove G2.

[0025] As shown in Figure 4(b), on the outer surface of the main body 10, the shapes of the cutting edge portion 20 and the chip discharge groove portion 30 are set with a positive twist angle so that they coincide with the imaginary outer cutting edge L1 and the imaginary spiral groove G1, respectively, and the shapes of the cutting edge portion 20 and the chip discharge groove portion 30 are set with a negative twist angle so that they coincide with the imaginary outer cutting edge L2 and the imaginary spiral groove G2, respectively.

[0026] The shapes of the cutting edge portions 20 and chip discharge groove portions 30 are set by alternately arranging cutting edge portions 20 and chip discharge groove portions 30 set at a positive twist angle and cutting edge portions 20 and chip discharge groove portions 30 set at a negative twist angle at equal intervals on the outer peripheral surface of the main body portion 10.

[0027] The virtual spiral groove and virtual peripheral cutting edge formed on the outer peripheral surface of the virtual cylinder are set to have the same shapes as the chip discharge groove and peripheral cutting edge of an end mill, for example. The cutting edge portion 20 and chip discharge groove portion 30 formed on the outer peripheral surface of the main body portion 10 have the same shapes as the peripheral cutting edge and chip discharge groove obtained by slicing the end mill into a ring of a predetermined thickness in a direction perpendicular to the rotation axis, making it possible to achieve cutting functions similar to those of an end mill.

[0028] Cylindrical end mills are attached to machine tools such as machining centers or milling machines and are used for a variety of cutting operations, including groove machining, side machining, and finish machining. The spiral peripheral cutting edge of the end mill reduces cutting resistance while cutting, and chips generated by cutting can be efficiently discharged to the outside along the spiral chip discharge groove.

[0029] Therefore, the cutting edge portion 20 and chip discharge groove portion 30 formed on the outer peripheral surface of the main body portion 10 can reduce cutting resistance and efficiently discharge chips, making it possible to achieve high-speed cutting processing.

[0030] Therefore, the rotary tool 1 can stably cut metal materials such as iron and aluminum, and can also cut heat-resistant alloys such as titanium alloys and Inconel, making it possible to process a wide range of metal materials. [Explanation of symbols]

[0031] C···Cylinder, G1, G2···Spiral grooves, L1, L2···Peripheral cutting edge, 1···Rotary tool, 10···Main body, 11···Mounting hole, 20···Cutting edge, 21···Cutting edge, 22···Rake face, 23···Flank face, 30···Chip discharge groove, 31···Groove surface

Claims

[Claim 1] a rotary tool comprising: a disk-shaped main body portion having an outer peripheral surface of a predetermined width; a plurality of cutting edge portions formed at predetermined intervals in the circumferential direction on the outer peripheral surface of the main body portion; and a plurality of chip discharge groove portions formed circumferentially on the outer peripheral surface of the main body portion between the cutting edge portions, wherein the cutting edge portions are set so as to be inclined at a predetermined twist angle with respect to the rotation axis of the main body portion, and the cutting edge portions with positive twist angles and the cutting edge portions with negative twist angles are arranged alternately, and the chip discharge groove portions have curved groove surfaces of a predetermined width connected to the rake faces of the cutting edge portions, and the chip discharge groove portions are formed to coincide with a virtual spiral groove of a predetermined width that is set around the axis at a predetermined twist angle on the outer peripheral surface of a virtual cylinder that has the same diameter as the main body portion and is set with an axis that coincides with the rotation axis, and the cutting edge portions are formed to coincide with a virtual peripheral cutting edge that is set along the virtual spiral groove.

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