JP2015123574A - Cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutter equipped with a cutting blade having excellent durability.SOLUTION: A cutter 10 has plural cutting blades 22 which are provided on an outer periphery of a base metal 12 at intervals in a circumferential direction, and so cuts a work-piece as to form a V-shaped groove in the work-piece by the cutting blades 22 of which set angles δ of both side faces 24, 24 are so set as to be negative. In the cutting blades 22, a rank angle (α) at a position where an outer diameter of the cutter becomes maximum is so set as to be 0° or a negative degree. Further, in the cutting blades 22, a lead angle is so set that one side edge of a rake face 28 constitutes a dominant blade 32.

Description

  The present invention relates to a cutter for cutting a V-shaped groove.

  A chip saw in which a chip is brazed to the outer peripheral edge of a disk-shaped base metal is used to cut a V-shaped groove on a printed circuit board which is a plate material such as resin, aluminum or copper (for example, (See Patent Document 1). The chip 50 (refer to FIG. 6) of Patent Document 1 is formed in a mountain shape that is inclined (set angle <0 °) so that both side surfaces 52, 52 approach each other as they go radially outward. And the chip | tip 50 cuts the printed circuit board (workpiece | work) W with the dominant edge set to the side edge of the rake face 54 set to the positive rake angle (alpha) of the range of 10 degrees-20 degrees. Yes.

JP 2012-86353 A

  As shown in FIG. 6, in the tip saw, when the rake face 54 of the tip 50 is set at a positive angle, the tip (blade edge) 50a of the tip 50 that has entered the workpiece W during cutting precedes the front side in the rotational direction. As a result, a load is applied to the tip 50a of the chip 50. As described above, since the tip 50a of the chip 50 is pointed in a mountain shape to form the V-shaped groove Wa, there is a difficulty in that the tip 50a is easily chipped when a load is applied to the tip 50a. Improvement of the durability of the chip 50 is required.

  That is, the present invention has been proposed to solve these problems in view of the problems inherent in the prior art, and it is an object of the present invention to provide a cutter provided with a cutting blade having excellent durability. .

In order to overcome the above-mentioned problems and achieve the intended object, the cutter of the invention according to claim 1 of the present application,
In a cutter that has a plurality of cutting blades provided at intervals in the circumferential direction on the outer periphery of the disk body, and cuts a V-shaped groove with a cutting blade whose clam angle on both side surfaces is set to be negative,
The gist of the cutting blade is that the rake angle at the position where the outer diameter of the cutter is maximum is set to 0 ° or a negative angle.
According to the invention which concerns on Claim 1, the load to the front-end | tip of a cutting blade can be reduced by setting a cutting blade by 0 degree or a negative rake angle. Therefore, chipping at the tip of the cutting blade can be suppressed and the life of the cutting blade can be improved.

In the invention according to claim 2, the cutting blade has a rake face lead angle set at a positive angle so that one side edge of the rake face is a dominant edge.
The gist is that the cutting blades adjacent to each other in the circumferential direction have different lead directions.
According to the invention which concerns on Claim 2, by setting a lead angle so that the side edge of one side of a rake face may become a dominant edge in a cutting blade, generation | occurrence | production of a burr | flash can be suppressed when a work material is cut. . In addition, since the cutting blades adjacent to each other in the rotation direction have different lead directions, the cutter can suppress the vibration of the cutter and stably cut the work material.

In the invention which concerns on Claim 3, the outer periphery of the said disc body is provided with two or more stepping parts to which the chip | tip with which the said cutting blade was provided is joined, spaced apart in the circumferential direction with the same shape,
The gist of the chip is that the base side face and the rake face of the chip cross each other at an angle, and that the base side face and the side face of the disc body are aligned.
According to the invention which concerns on Claim 3, since it has comprised so that the base side surface of a chip | tip and the side surface of a disc body may align, positioning of the rotating shaft direction of a cutter becomes easy when joining a chip | tip. Further, since the chip is bonded to the stepped portion provided in the disc body, the bonding area of the chip can be ensured.

In the invention according to claim 4, the cutting blade is connected to the first outer peripheral flank face connected to the position where the outer diameter of the cutter is maximum, and to the rear side in the rotational direction of the first outer peripheral flank face. The gist of the present invention is to provide a second outer peripheral flank having a larger outer peripheral flank angle than the first outer peripheral flank.
According to the invention according to claim 4, by configuring the outer peripheral flank with the first outer flank and the second outer flank having a larger outer flank angle than the first outer flank, It becomes possible to set the outer peripheral clearance angle of the first outer peripheral clearance surface small. Thereby, since the rigidity of the front-end | tip of a cutting blade can be improved, the chip | tip of the front-end | tip of a cutting blade can be suppressed more suitably.

  The cutter according to the present invention is excellent in the durability of the cutting blade.

It is a side view which shows the cutter which concerns on the suitable Example of this invention. It is a side view which expands and shows the principal part of the cutter of an Example. (a) is a view from arrow A in FIG. 2, (b) is a view from arrow B in FIG. 2, and (c) is a view from arrow C in FIG. (a) is a view on arrow D in FIG. 2, and (b) is a view on arrow E in FIG. It is a schematic diagram which shows the cutting condition of the workpiece | work by the cutter of an Example by a side view. It is a schematic diagram which shows the cutting condition of the workpiece | work by the conventional chip saw in a side view.

  Next, a preferred embodiment of the cutter according to the present invention will be described below with reference to the accompanying drawings. The cutter according to the present invention is suitably used for cutting to form a V-shaped groove Wa on a work (work material) W (see FIG. 5) such as a printed circuit board made of a plate material such as resin, aluminum, or copper. It is something that can be done.

  As shown in FIG. 1, the cutter 10 according to the embodiment has a plurality of chips 20 provided on the outer periphery of a substantially disk-shaped base metal (disk body) 12 at intervals in the circumferential direction. The cutter 10 is set in a processing apparatus by fitting a support shaft (not shown) in a shaft hole 12 a formed through the center of the base metal 12. Then, the cutter 10 is rotated in one direction with a virtual axis passing through the center in the thickness direction (rotation axis direction) of the base metal 12 as the rotation center O, and the cutter 10 is provided with a cutting blade 22 provided on the chip 20. W is cut (see FIG. 5). In the cutter 10 of the embodiment, the tip 20 is disposed on each of the tooth bodies 14 formed on the outer periphery of the base metal 12.

  The said base metal 12 is comprised with steel, such as carbon tool steel and alloy tool steel. On the outer peripheral portion of the base metal 12, a plurality of tooth bodies 14 formed to extend outward in the radial direction are spaced apart from each other at regular intervals in the rotation direction. Further, a tooth bag 16 capable of accommodating cutting waste of the workpiece W generated when cutting with the tip 20 is formed between the tooth bodies 14 and 14 adjacent to each other in the rotation direction on the front side in the rotation direction of each tip 20. ing. Each tooth body 14 has a stepped portion 14a formed in a step shape on the front side in the rotational direction. The chip 20 is accommodated in the stepped portion 14a, and the chip 20 and the base metal 12 are joined by brazing. Is done. In the cutter 10 of the embodiment, the plurality of tooth bodies 14 are formed in the same shape, and the stepped portions 14a of the plurality of tooth bodies 14 are formed in the same shape. In the cutter 10 of the embodiment, the plurality of chips 20 are basically formed in the same shape except for the inclination direction (lead direction) of the lead angle β described later, and all the tooth bags 16 have the same shape. It has become.

  The chip 20 is made of cemented carbide, cermet, CBN (cubic boron nitride), polycrystalline diamond (PCD), or the like. Further, the chip 20 may form a film on the outer surface. The coating may have a single layer structure or a multilayer structure in which the same or different ones are stacked, and a metal, nitride, carbide, one or more elements such as chromium, titanium, aluminum, etc. Mention may be made of layers of carbonitrides, oxides, oxynitrides and the like. The chip 20 of the embodiment is a composite material in which PCD is laminated on the surface layer of a base layer made of a cemented carbide, and the rake face 28 of the cutting blade 22 is formed by the PCD constituting the front surface in the rotational direction of the chip 20. (See FIG. 2). In addition, in FIGS. 1-5, the boundary line of a base layer and a surface layer is abbreviate | omitting illustration. Further, the chip 20 is cut out so that the root side face 25 and the rake face 28 in the chip 20 are obliquely crossed in order to give a lead angle β to the rake face 28, and then a base layer made of a cemented carbide. Is formed according to the lead angle β. Thus, the back surface of the chip 20 to be joined to the vertical wall surface of the stepped portion 14a and the root side surface 25 of the chip 20 are orthogonal to each other, and the root side surface 25 and the rake face 28 are inclined. Further, the chip 20 is formed such that the base side surface 25 is flush with the side surface of the base metal 12 when bonded to the stepped portion 14 a. That is, the chip 20 is set so that the width between the base side surfaces is the same as the thickness of the base metal 12.

  The chip 20 has a back surface extending rearward in the rotational direction joined to the vertical wall surface of the stepped portion 14a, and a bottom surface extending radially inward of the base metal 12 joined to the bottom wall surface of the stepped portion 14a. (See FIG. 2). As shown in FIGS. 2 to 4, the cutting blade 22 provided on the tip 20 has a pair of side surfaces 24, 24 facing in the width direction (rotational axis direction) of the tip 20, and facing the radially outer side of the tip. The outer peripheral flank 26 and the rake face 28 formed so as to face the tooth bag 16 and facing the front side in the rotational direction are basically constituted. In addition, since the outer peripheral flank 26 has a short blade length (width in the rotation axis direction of the cutter 10), it is indicated by a line rather than a plane in FIG. In the cutting blade 22, the ridge formed by the outer peripheral flank face 26 and the rake face 28 is the cutting edge 30 (the position where the outer diameter of the cutter is maximized) located on the outermost radial direction of the cutting blade 22. As will be described later, a cutting edge 30 is set at the pointed tip of the tip 20. In addition, the blade edge | tip 30 of an Example is a straight blade with a blade length of 0.02 mm-0.1 mm.

  As shown in FIG. 4, the cutting blade 22 is formed such that the radially outer tip portion of the tip 20 becomes thinner (thinner) in the rotation axis direction from the radially inner side toward the radially outer side. As a result, the cutting edge 22 has a set angle δ of each side surface 24 that is negative (δ) with respect to a virtual reference line Lc that connects points that are V-shaped vertices of the chip 20 perpendicularly from the rotation axis. <0 °). On the other hand, the root side surface 25 of the chip 20 has a set angle of 0 °, and the base side surface 25 of the chip 20 is aligned with the side surface of the base metal 12. In the embodiment, the set angle δ of both the side surfaces 24 and 24 is set to be the same, and both the side surfaces 24 and 24 are symmetrical with the reference line Lc sandwiched in the rotation axis direction.

  As shown in FIG. 2, the outer peripheral flank 26 has a radius from the cutting edge 30 toward the rear side in the rotation direction with respect to a plane orthogonal to a virtual center line Lo connecting the rotation center O and the cutting edge 30 with a straight line. It is formed so as to tilt inward. In addition, the cutting blade 22 in which the negative set angle δ is set on both side surfaces 24, 24 is formed in a sharp ridge shape in which the outer peripheral flank 26 is continuous in the rotation direction. The cutting blade 22 has a plurality of outer peripheral flank surfaces 26. The cutting blade 22 according to the embodiment includes an outer peripheral flank (referred to as a first outer peripheral flank 26A) that constitutes the cutting edge 30 connected to a position where the outer diameter of the cutter 10 is maximized in the cutting blade 22, and the first. An outer peripheral flank face (referred to as a second outer peripheral flank face 26B) formed continuously to the rear side in the rotational direction of the outer peripheral flank face 26A. The first outer clearance angle γ1 of the first outer peripheral clearance surface 26A is set in the range of 1 ° to 5 °. The relationship between the extending length of the first outer circumferential flank 26A in the rotational direction and the first outer circumferential flank angle γ1 is that the first outer circumferential flank 26A does not protrude radially outward from the rotation locus R of the cutting edge 30; 26 A of 1st outer peripheral flank is set so that it may extend with the inclination angle approximated to the radial inside of this rotation locus R. The second outer peripheral flank 26B is set to have an outer peripheral flank angle γ2 larger than that of the first outer peripheral flank 26A. Here, the second outer peripheral clearance surface 26B is set such that the second outer peripheral clearance angle γ2 with respect to the tangent to the blade edge 30 is in the range of 10 ° to 15 °.

  As shown in FIG. 2, in the cutting blade 22, the rake angle α of the rake face 28 of the cutting edge 30 at which the outer diameter of the cutter 10 is maximized is 0 ° or a negative angle (α <0 °). Is set. The rake face 28 of the embodiment is formed as a flat plane over the entire radial direction and width direction, and is set so that the rake angle α with respect to the center line Lo becomes a negative angle. That is, the rake face 28 is formed so as to incline forward in the rotational direction as it goes from the radially outer side to the inner side. The rake angle α is set in a range of −15 ° to 0 °, and preferably −15 °.

  As shown in FIGS. 3B and 3C, the cutting blade 22 has a positive lead angle β of the rake face 28 so that one side edge of the rake face 28 becomes a dominant edge 32. Is set. In the cutting blade 22, the dominant edge 32 formed by a ridge line formed by one side edge of the rake face 28 and one side face 24 connected to the one side edge is located on the front side in the rotational direction with respect to the other side edge of the rake face 28. It is extended. The lead angle β is set in the range of 10 ° to 20 °.

  The cutting blades 22 and 22 adjacent to each other in the rotational direction (circumferential direction) are set so that the dominant blades 32 are provided on different side edges of the rake faces 28 and 28 and the lead directions are different from each other. In other words, in the cutter 10, the side edges of the rake face 28 on which the dominant edge 32 is provided are set alternately in the plurality of cutting blades 22 arranged in the rotation direction (see FIGS. 1 and 2). More specifically, with respect to the cutting blade 22 with the lead angle β inclined to the rear side in the rotational direction from the right edge toward the left edge so that the dominant edge 32 is formed on the right edge of the rake face 28, the rotational direction The cutting blades 22 adjacent to each other are provided with a lead angle β that inclines toward the rear in the rotational direction from the left edge toward the right edge so that a dominant edge 32 is formed on the left edge of the rake face 28.

(Effects of Example)
Next, the operation of the cutter 10 according to the embodiment will be described. Since the cutter 10 sets the rake face 28 of the cutting blade 22 at 0 ° or a negative rake angle, when the V-shaped groove Wa is cut in the workpiece W as shown in FIG. The intermediate portion of the rake face 28 in the cutting blade 22 that has entered the head comes to the front in the rotational direction. That is, in the cutting blade 22, the cutting edge 30 is delayed behind the intermediate portion of the rake face 28 in the rotational direction, so that the load on the cutting edge 30 when cutting the workpiece W can be reduced. On the other hand, the intermediate portion of the rake face 28 that precedes the front side in the rotation direction when the workpiece W is cut has rigidity than the tapered cutting edge 30. Therefore, damage such as chipping of the cutting edge 30 of the cutting blade 22 can be suppressed, the cutting edge 22 can be kept long, and the life of the cutting blade 22 can be improved.

  The cutting blade 22 is configured by configuring the outer peripheral flank with a first outer flank 26A and a second outer flank 26B having a larger outer flank angle γ than the first outer flank 26A. The first outer clearance angle γ1 of the first outer clearance surface 26A can be set small. That is, by configuring the outer peripheral flank 26 in two stages, the extending length in the rotation direction of the first outer flank 26A is shortened so that the first outer flank 26A becomes the rotation locus R of the cutting edge 30. It can be set with an approximate slope. Thereby, since the rigidity of the blade edge | tip 30 of the cutting blade 22 can be improved, the chip | tip of the blade edge | tip 30 can be suppressed more suitably.

  In the cutter 10, the lead angle β is set so that the side edge on one side of the rake face 28 in the cutting blade 22 becomes the dominant edge 32, so that generation of burrs when the workpiece W is cut can be suppressed. Further, as described above, the cutting blade 22 is set so that the rake face 28 is set at 0 ° or a negative rake angle α and the intermediate portion of the rake face 28 precedes the front side in the rotation direction when the workpiece W is cut. The dominant blade 32 formed on the side edge on one side of the surface 28 appropriately hits the workpiece W, and the workpiece W can be suitably cut by the sharpness of the dominant blade 32. Further, since the cutter 10 is set so that the cutting blades 22 and 22 adjacent to each other in the rotation direction have different lead directions, it is possible to stably cut the workpiece W while suppressing the vibration of the cutter 10. it can.

  Since the cutter 10 is configured such that the base side surface 25 of the chip 20 and the side surface of the base metal 12 are aligned, it is easy to position the cutter 10 in the rotation axis direction when the chip 20 is joined to the base metal 12. become. Further, since the chip 20 is bonded to the stepped portion 14 a provided on the base metal 12, the bonding area of the chip 20 can be ensured.

(Test example)
About the cutter 10 of the example and the cutter of the comparative example, a test for actually cutting a V-shaped groove Wa having a depth of 0.5 mm is performed on a work (printed substrate made of an alumina-containing glass epoxy material) W. The durability of both was compared. The cutter 10 of the example and the cutter of the comparative example have an outer diameter (diameter) of 120 mm, the number of teeth is set to 24, and teeth provided on the outer peripheral portion of the base metal 12 made of carbon tool steel having a thickness of 2 mm. This is also called a chip saw in which the chips 20 and 50 are joined to each of the bodies 14. The chip 20 of the example and the chip 50 of the comparative example are composite materials in which a surface layer made of polycrystalline diamond (PCD: mixed particles of 40 μm + 16 μm) is laminated on a base layer made of cemented carbide. In the cutting blade 22 provided on the tip 20 of the embodiment, the set angle of each dominant blade 32 is 17.5 ° (V angle of the tip: 35 °), and the rake angle of the rake face 28 constituting the cutting edge 30 is − At 15 °, the lead angle of the rake face 28 is set to 10 °. In the cutting blade 22 of the embodiment, the outer peripheral flank 26 is formed in two stages, the extending length of the first outer flank 26A constituting the cutting edge 30 is 0.2 mm, and the outer flank angle γ1 is In addition to being set to 1 °, the outer peripheral clearance angle γ2 of the second outer peripheral clearance surface 26B connected to the first outer peripheral clearance surface 26A is set to 10 °. The tip 50 (see FIG. 6) of the comparative example has a set angle of 17.5 ° on each side surface 52 (V angle of the tip: 35 °), and a rake angle of the rake face 54 constituting the cutting edge is + 5 °. The lead angle of the rake face 54 is set to 0 °. That is, the lead of the chip 50 of the comparative example is not set. The tip 50 of the comparative example has an outer peripheral flank 56 formed in a single stage, and the outer peripheral flank angle of the outer peripheral flank 56 constituting the cutting edge is set to 10 °. When the cutter 10 of the example and the cutter of the comparative example were respectively set in the processing apparatus, the processing conditions such as the number of rotations were set to be the same, and the V-shaped groove Wa was cut into the workpiece W, the cutter of the example 10 was confirmed to be 10 times more durable than the cutter of the comparative example.

(Change example)
The present invention is not limited to the above-described configuration, and can be modified as follows, for example.
(1) The rake face and the flank face may be one step or three or more steps.
(2) The second rake face when the second rake face is formed radially inward from the rake face connected to the position where the outer diameter of the cutter is the largest (the first rake face is referred to when distinguished). It is preferable that the rake angle be larger than the rake angle of the first rake face on the positive side. If the first rake face is 0 ° or a negative rake angle α, another rake face (second rake face) connected radially inward of this rake face is set to a positive rake angle. May be.
(3) The cutting edge of the side edge that does not become the dominant edge may be changed from the set angle of the side edge that becomes the dominant edge so that the side edge that does not become the dominant edge does not directly participate in cutting. Further, the outer diameter of the side edge that does not become the dominant blade may be smaller (inward in the radial direction) than the outer diameter of the side edge that becomes the dominant blade. By setting in this way, the sharpness of the dominant blade can be ensured.
(4) The cutting edge of the cutting blade is not limited to a straight blade, and the side edge between the side surfaces may be formed in a tapered shape or a curved shape, or the entire cutting edge may be formed in a curved shape.
(5) The chip may be formed so that the base side surface is parallel to the side surface of the base metal (disk body) when joined to the stepped portion. Moreover, you may set the chip | tip to the width dimension between base side surfaces smaller than the thickness of a base metal.

12 base metal (disc body), 14a stepped part, 22 cutting blade, 24 side surface, 25 root side surface,
26 outer peripheral flank, 26A first outer flank, 26B second outer flank,
28 rake face, 32 dominant edge, α rake angle, β lead angle, γ outer clearance angle,
δ Clam angle

Claims (4)

A cutting blade having a plurality of cutting blades (22) provided on the outer periphery of the disc body (12) at intervals in the circumferential direction, and the set angle (δ) of both side surfaces (24, 24) being set negative. In the cutter that cuts the V-shaped groove according to (22),
The cutting blade (22) is characterized in that the rake angle (α) at the position where the outer diameter of the cutter is maximum is set to 0 ° or a negative angle. The cutting blade (22) is set with a positive angle of the lead angle (β) of the rake face (28) so that one side edge of the rake face (28) becomes a dominant edge (32),
The cutter according to claim 1, wherein the cutting blades (22, 22) adjacent in the circumferential direction have different lead directions. On the outer periphery of the disc body (12), a plurality of stepped portions (14a) to which the tip (20) provided with the cutting blade (22) is joined are provided in the same shape and spaced apart in the circumferential direction. ,
In the tip (20), the base side surface (25) and the rake face (28) of the tip (20) obliquely intersect with each other, and the base side surface (25) and the side surface of the disc body (12) are The cutter according to claim 1 or 2 formed so as to be aligned.   The cutting blade (22) is connected to the first outer peripheral flank (26A) connected to the position where the outer diameter of the cutter is maximum, and to the rear side in the rotational direction of the first outer peripheral flank (26A). The cutter according to any one of claims 1 to 3, further comprising a second outer peripheral flank (26B) having an outer peripheral flank angle (γ) set larger than the first outer flank face (26A).

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