Flat-blade-shaped cutting blade

Abstract

In a longitudinal cross-section extending in both a thickness direction orthogonal to the extension direction and the extension direction, the outer shape of the first blade portion has: a first inclined surface inclined with respect to the center line so as to be thinned further away from the base portion in the extension direction; in a longitudinal cross-section, the outer shape of the second blade section has a second inclined surface that is inclined linearly so as to be more gentle than the slope of the first inclined surface with respect to the center line and that is in contact with the first inclined surface, and in a longitudinal cross-section, the outer shape of the third blade section has a concave curved surface that is in contact with the second inclined surface and that is in contact with the third inclined surface. And a concave curved surface that is curved so as to be concave toward the center line side and that is in contact with the second inclined surface, the length of the second blade being greater than or equal to the length of the first blade in the extension direction.

Description

Technical Field

[0001] The present disclosure relates to a flat-blade cutting edge. This application claims priority based on Japanese Patent Application No. 2022-208048, filed on December 26, 2022. The entire contents of the Japanese Patent Application are incorporated herein by reference. Background Art

[0002] Currently, flat-edged cutting edges are disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-158016 (Patent Document 1) and International Publication No. 2020 / 130092 (Patent Document 2).

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-158016

[0004] Patent Document 2: International Publication No. 2020 / 130092 Summary of the Invention

[0005] The flat-blade cutting edge disclosed in the present invention is a flat-blade cutting edge as follows, that is, it has: a flat base extending along a center line; and a blade extending from the end of the base in the extension direction, which is composed of a WC-Co or WC-Ni super-hard alloy, and the blade includes: a first blade, which is located at a position farthest from the base in the extension direction; a second blade, which is located at a position adjacent to the first blade on the base side in the extension direction; and a third blade, which is located between the second blade and the base in the extension direction, and in a longitudinal section extending in two directions, the thickness direction orthogonal to the extension direction and the extension direction, the third blade The outer shape of the first blade portion has a first inclined surface and a tip portion serving as a blade tip, the first inclined surface being inclined relative to the center line in a manner that becomes thinner as it moves away from the base in the extension direction, the outer shape of the second blade portion having a second inclined surface in the longitudinal section, the second inclined surface being linearly inclined relative to the center line in a manner that is more gentle than the slope of the first inclined surface and being connected to the first inclined surface, the outer shape of the third blade portion having a concave curved surface in the longitudinal section, the concave curved surface being concavely curved toward the center line side and being connected to the second inclined surface, and the length of the second blade portion in the extension direction is greater than or equal to the length of the first blade portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a perspective view showing a state in which a sheet-like object 1 is press-cut and cut by the flat-edged cutting blade 100 according to the first embodiment.

[0007] Figure 2 Observed from the direction of arrow II Figure 1A side view of a flat cutting edge 100.

[0008] Figure 3 It is an enlarged representation Figure 2 A side view of the III portion of the flat-edged cutting edge 100.

[0009] Figure 4 This is a side view of the flat-edged cutting edge 100 according to the second embodiment.

[0010] Figure 5 It is an enlarged representation Figure 4 A side view of the V portion of the flat-edged cutting edge 100.

[0011] Figure 6 This is a perspective view of a device for explaining a cutting test.

[0012] Figure 7 It is along Figure 6 Cross-sectional view along line VII-VII in FIG.

[0013] Figure 8 This is a diagram of the object 1 after cutting, shown to explain a method for evaluating the cut surface 1 b. DETAILED DESCRIPTION

[0014] [Problems to be Solved by the Present Disclosure]

[0015] Conventional flat-edged cutting edges have a problem in that the cut surface of the object being cut becomes inclined.

[0016] Patent Document 2 proposes a cutting technique for large MLCC (Multi-Layer Ceramic Capacitor) in which the second blade is shorter than the first blade.

[0017] The thickness of the portion is extremely thin, and the cutting resistance is reduced. However, there is a problem that, although the blade tip becomes sharp, the rigidity is reduced, and the perpendicularity of the surface parallel to the moving direction of the blade in the workpiece cross section is reduced.

[0018] Demand has been growing in new markets such as 5G communications equipment, robots, xEVs (electric vehicles), and self-driving cars in recent years. Consequently, high-density stacking technology for larger MLCCs has been developed. To achieve high capacity, materials with higher relative dielectric constants are being selected, thinner dielectrics are being used, and the number of stacking layers is being increased. While green sheet hardness is increasing, there is also a trend toward narrowing the stacking between electrodes, which deteriorates vertical cutting performance when cutting workpieces.

[0019] Multilayer ceramic capacitors have a structure in which dielectric layers and internal electrodes are stacked in multiple layers. The capacitance is increased by thinning the dielectric layers to narrow the distance between electrodes or by increasing the number of stacked layers to increase the total electrode area.

[0020] The raw sheets are stacked in layers greater than or equal to 100 to 1000 layers, and pressure is applied to form an integral body. The integrally formed stacked sheets are cut into a specified size to realize chip formation. For the stacked sheets, the following situations can be cited: as the density and hardness are achieved through thin-layer technology and multi-layer technology, the material becomes a hard material, so that the tip of the cutting blade and the base material are bent. When cutting the cutting object, if the cutting resistance (intrusion volume) is large, the tip of the cutting blade and the base material are bent, the chip cross section is tilted, and the vertical cutting performance is deteriorated. The present disclosure is proposed in view of the above-mentioned problems, and its purpose is to provide a flat-blade cutting blade that can reduce the bending of the blade tip and improve the vertical cutting performance.

[0021] The flat-blade cutting blade disclosed herein has: a flat base extending along a center line; and a blade extending from the end of the base in the extension direction, which is made of a WC-Co or WC-Ni superhard alloy. The blade includes: a first blade located at a position farthest from the base in the extension direction; a second blade located adjacent to the first blade on the base side in the extension direction; and a third blade located between the second blade and the base in the extension direction. In a longitudinal section extending in both a thickness direction orthogonal to the extension direction and in the extension direction, the outer shape of the first blade has: a first inclined surface inclined relative to the center line in a manner that becomes thinner as it moves away from the base in the extension direction; and a tip portion serving as a blade tip.

[0022] In the longitudinal section, the outer shape of the second blade portion has a second inclined surface, which is linearly inclined relative to the center line in a manner that is gentler than the slope of the first inclined surface and is connected to the first inclined surface. In the longitudinal section, the outer shape of the third blade portion has a concave curved surface, which is concavely curved toward the center line side and is connected to the second inclined surface. In the extension direction, the length of the second blade portion is greater than or equal to the length of the first blade portion.

[0023] With the flat-edged cutting edge thus configured, the length of the second blade portion is equal to or greater than the length of the first blade portion, and thus deflection of the second blade portion can be suppressed, thereby enabling the object to be cut to be cut perpendicularly.

[0024] Preferably, in the longitudinal section, the first inclined surface includes either a convexly curved surface that curves convexly toward a side away from the center line and contacts the second inclined surface, or a surface that is linearly inclined.

[0025] A key characteristic required of a cutting edge is sharpness (no damage to the chip cross-section). To improve sharpness, the shape of the tip is particularly important, preferably with a small (sharp) tip angle. However, the thinner the tip, the lower the strength, and the inevitable inclination of the chip cross-section caused by the deflection of the tip and the substrate is unavoidable.

[0026] In addition, the thicker the tip of the blade is, the greater the cutting resistance (penetration volume) is, and it is inevitable that the chip cross-section will be damaged.

[0027] The present disclosure provides a flat cutting blade having good perpendicularity (i.e., cross-section cutting performance) and suitable blade tip rigidity, with the cut surface of the object being perpendicular to the surface of the object being cut. By reducing blade tip deflection, it has been confirmed that perpendicularity is improved when cutting multilayer ceramic capacitors.

[0028] (Implementation Method 1)

[0029] Hereinafter, a flat-edged cutting edge according to a first embodiment of the present invention will be described with reference to the accompanying drawings. In the following description of the embodiment, the same or corresponding parts in the drawings are denoted by the same reference numerals, and their description will not be repeated.

[0030] Figure 1 1 is a perspective view showing a state in which a sheet-shaped cutting object 1 is pressed and cut by the flat-edged cutting blade 100 according to the first embodiment. Figure 1 As shown, the flat-edged cutting blade 100 according to the first embodiment moves in the vertical direction to press-cut a sheet-shaped object 1. The flat-edged cutting blade 100 includes a base portion 110 and a blade portion 120.

[0031] The sheet-like object to be cut 1 is, for example, a ceramic green sheet before sintering of a multilayer capacitor or a multilayer inductor, a metal foil, or a hard resin.

[0032] Figure 2 Observed from the direction of arrow II Figure 1 A side view of a flat cutting edge 100. Figure 3 It is an enlarged representation Figure 2 A side view of the III portion of the flat blade-shaped cutting edge 100. Figure 1 and Figure 2As shown, the base 110 of the flat-edged cutting blade 100 according to the first embodiment is flat and extends along the center line C. The extending direction of the base 110 is the Z direction, the thickness direction perpendicular to the extending direction of the base 110 is the Y direction, and the width direction perpendicular to the extending direction and the thickness direction of the base 110 is the X direction.

[0033] The blade 120 extends from the end portion in the extension direction (Z direction) of the base 110. In the present embodiment, the blade 120 extends symmetrically about the center line C. However, the blade 120 may extend asymmetrically about the center line C.

[0034] If the Y-direction dimension of the object 1 is significantly smaller on one side relative to the cutting position of the flat-edged cutting blade 100, that is, if the Y-direction dimension of the object 1 is significantly smaller, when the flat-edged cutting blade 100 is used to press-cut the sheet-like object 1, the object with the smaller Y-direction dimension may be cut obliquely along the slope of the tip of the blade 120. To prevent such oblique cutting of the object, the tip of the blade 120 may be shaped so that the slope on the side contacting the smaller Y-direction object is smaller than the slope on the side opposite to the centerline C. In this case, the blade 120 extends asymmetrically with respect to the centerline C.

[0035] like Figure 2 As shown, the blade portion 120 includes a first blade portion 121, a second blade portion 122, and a third blade portion 123. The first blade portion 121 is located farthest from the base portion 110 in the extension direction (Z direction). The second blade portion 122 is located adjacent to the first blade portion 121 on the base portion 110 side in the extension direction (Z direction). The third blade portion 123 is located between the second blade portion 122 and the base portion 110 in the extension direction (Z direction). Furthermore, the blade portion 120 may further include one or more blade portions located between the third blade portion 123 and the base portion 110 in the extension direction (Z direction).

[0036] The thickness of the base 110 is preferably greater than or equal to 0.1 mm and less than or equal to 1 mm. By setting this range, when the chip to be cut is thick (greater than or equal to 1 mm), the thickness of the flat-edged cutting edge 100 itself is greater. This increases the rigidity of the base 110, which can suppress deflection of the substrate during cutting.

[0037] In a longitudinal cross-section extending in both the thickness direction (Y direction) and the extension direction (Z direction), the first blade portion 121 has a linearly inclined surface 121s with respect to the centerline C, decreasing in thickness as it moves away from the base portion 110 in the extension direction (Z direction), and a tip portion 121t, which serves as the blade tip. In this embodiment, the first inclined surface 121s and the tip portion 121t are symmetrically arranged about the centerline C. The thickness of the first blade portion 121 is greatest at the end on the base portion 110 side in the extension direction (Z direction).

[0038] In this embodiment, in the longitudinal section ( Figure 2 ), the tip portion 121t extends in a straight line. However, in the above-mentioned longitudinal section, the tip portion 121t may extend in a convex curved shape toward the side opposite to the base portion 110 side.

[0039] In this embodiment, in the longitudinal cross-section, the internal angle between the first inclined surfaces 121s is preferably θ1, and preferably 16° ≤ θ1 ≤ 40°. The length of the first cutting edge 121 in the extension direction (Z direction) is L1. A smaller θ1 reduces the intrusion volume, but the blade tip of the flat-edged cutting edge 100 is more susceptible to damage during cutting, and the first cutting edge 121 lacks sufficient rigidity, making it more susceptible to blade tip deflection.

[0040] In the longitudinal section, the outer shape of the second blade portion 122 includes a second inclined surface 122s that is linearly inclined with respect to the center line C at a more gradual inclination than the first inclined surface 121s and that is in contact with the first inclined surface 121s. In this embodiment, the second inclined surface 122s is symmetrically arranged with respect to the center line C.

[0041] The length of the second blade portion 122 in the extending direction (Z direction) is L2. In the extending direction (Z direction), the length L2 of the second blade portion 122 is greater than or equal to the length L1 of the first blade portion 121.

[0042] like Figure 3 As shown, the second inclination angle formed by the line CP parallel to the center line C and the second inclined surface 122s is set to θ2. It can be seen that if θ2 increases, it is easy to produce inclination (irregular shape, crushing) and damage in the chip cross section. It is preferred that the blade tip angle θ2 is greater than or equal to 3° and less than or equal to 18°, and θ2 is less than or equal to θ1. It can be seen that if θ2 is smaller, the intrusion volume can be further reduced, but it is easy to bend. In addition, it can be seen that if θ2 increases, it is easy to produce inclination (irregular shape, crushing) and damage in the chip cross section.

[0043] Furthermore, when the surface roughness (Sa) of the second blade portion exceeds 0.6 μm, there is a possibility that a chip cross section may be scratched, resulting in a poor appearance inspection.

[0044] like Figure 2 As shown in the longitudinal section, the third blade portion 123 has a concave curved surface 123s that is concavely curved toward the center line C and in contact with the second inclined surface 122s. The length of the third blade portion 123 in the extending direction (Z direction) is L3.

[0045] The flat-edged cutting edge 100 of the first embodiment is made of a rigid super-hard alloy. Specifically, it is made of a WC-Co or WC-Ni super-hard alloy. However, the material of the flat-edged cutting edge 100 is not limited to super-hard alloy and may also be steel, depending on the object to be cut.

[0046] The flat-edged cutting edge 100 according to the first embodiment of the present invention can be formed by grinding with a grinding wheel. The radius of curvature of the concave curved surface is substantially the same as the radius of the grinding wheel.

[0047] Here, the measurement method of each dimension is described.

[0048] The length of each blade in the extension direction (Z direction) was measured using a measuring microscope. Specifically, a 10x eyepiece and a 20x objective lens were attached to an Olympus Corporation measuring microscope (STM6-LM) for measurement. The length of each blade in the extension direction (Z direction) was the average of the measured values ​​of the YZ cross-sections at intervals of 10 mm in the X direction.

[0049] Regarding the inner angle θ1, the second inclination angle θ2, and the curvature radius of the concave curved surface held together by the first inclined surfaces 121s, the longitudinal section is photographed using a SEM (Scanning Electron Microscope) and measured based on the photographed image. Specifically, the longitudinal section is photographed at a high magnification using an electric field emission scanning electron microscope (S-4200) manufactured by Hitachi, Ltd. Regarding the inner angle θ1 and the second inclination angle θ2 held together by the first inclined surfaces 121s, the curvature radius of the concave curved surface is measured based on the photographed image using a protractor or the like. The curvature radius of the concave curved surface is set to the radius of the approximate circle of the concave curved surface obtained by the least squares method or the like based on the photographed image.

[0050] (Implementation Method 2)

[0051] Figure 4 This is a side view of the flat-edged cutting edge 100 according to the second embodiment. Figure 5 It is enlarged to show Figure 4The flat-edged cutting edge 100 according to the second embodiment is different from the flat-edged cutting edge 100 according to the first embodiment in which the first inclined surface 121s of the first blade portion 121 is linear in that the first inclined surface 1121s of the first blade portion 121 is convex.

[0052] When the internal angle (θ1) of the cutting blade tip is small, cutting resistance is reduced, but defects are more likely to occur. To address this problem, the convexly curved first inclined surface 1121s is formed, which also increases the thickness of the blade and prevents defects. The internal angle (θ1) formed by the two first inclined surfaces 1121s is referred to as the angle formed by the two straight lines 2121 at the tip 121t.

[0053] The straight line 2121 is a straight line connecting the boundary between the tip portion 121 t , the first blade portion 121 , and the second blade portion 122 .

[0054] (Example)

[0055] Samples No. 1 to 13 ( Figure 1-3 ) and sample numbers 21 to 30 ( Figure 4 、 5 ) flat-edged cutting edges. Each sample had a width of 40 mm in the X direction, a thickness of 0.4 mm in the Y direction, and a length of 20 mm in the Z direction. The third cutting edge 123 had a thickness of 0.1 mm at its thinnest portion in the Y direction. The blade shapes of the flat-edged cutting edges for Samples 1 to 13 and 21 to 30 are shown in Tables 1 and 2.

[0056] [Table 1]

[0057]

[0058] [Table 2]

[0059]

[0060] The "height of the convex portion" in Table 2 refers to Figure 5 The height t of the convex portion 121st is shown. The height t is the distance from the straight line 2121 to the convex portion 121st farthest therefrom.

[0061] Figure 6 This is a perspective view of a device for explaining a cutting test. Figure 7 It is along Figure 6 Cross-sectional view along line VII-VII in FIG.

[0062] like Figure 6 and Figure 7 As shown in the cutting evaluation method, a Kistler cutting dynamometer 9255 (hereinafter referred to as cutting dynamometer 2003) was placed on stage 2004 of a Makino Frame V55 machining center. A 10 mm thick acrylic plate 2002, a 1 mm thick double-sided adhesive sheet 2001, and an object 1 to be cut were placed in this order from the bottom. The object 1 was a vinyl chloride sheet 2 mm thick, 290 mm wide, and 30 mm long. The flat-edged cutting edge 100 was placed on supports 3001 and 3002 so that its length was 40 mm and the 5 mm portions at each end of the flat-edged cutting edge 100 did not act on the object 1. Furthermore, the angle (the angle in the XZ plane) between the tip 121t and the top surface 1a of the object 1 was set within a range of ±0.5°. The cutting conditions are set as cutting speed 300mm / s, cutting interval 12mm, and press depth 2.05mm. Figure 6 A total of 24 cuts in the Y direction are considered one step. The first, second, 23rd, and 24th cuts are excluded from evaluation. Twenty-five cut products (pieces of the cut object 1 after cutting) can be produced in one step. Repeating one step five times yields a total of 100 cut products (pieces of the cut object 1 after cutting).

[0063] (Vertical cutting performance evaluation)

[0064] The vertical cutting property was evaluated by observing the cut pieces of the cutting object 1 after the above-mentioned cutting test.

[0065] Figure 8 This figure shows the cut object 1 after cutting to illustrate the evaluation method of the cut surface 1b. Regarding the method for measuring the vertical cutting property, an Olympus measuring microscope (STM6-LM) is used, equipped with a 50x eyepiece and a 20x objective lens, with 1a of the cut object 1 as the top surface and the cut surface 1b on the left.

[0066] It should be noted that Figure 8 The point at which the tip 121t of the measuring device first enters the object 1 is defined as point 2b, and the measuring stage is parallel to the upper surface 1a. A point on the lower surface 1f that moves in the Z-axis direction from point 2b is defined as point 2a. With the measuring device focusing on point 2b, the distance from point 2a on the lower surface 1f in the Z-axis direction is measured, and this distance is defined as L11.

[0067] The point on the lower surface 1f of the cut surface 1b that the tip 121t finally contacts is defined as point 2c. The distance from point 2a to point 2c in the Y-axis direction is measured and defined as L12. tanθ4 = L11 / L12, so θ4 = tan -1 θ4 is calculated by calculating (L11 / L12). θ4 is the angle formed by the straight line 1e passing through the points 2b and 2c and the upper surface 1a.

[0068] The cuts were performed 24 times in one step. The cut surfaces 1b from the 1st, 2nd, 23rd, and 24th cuts were not evaluated. Therefore, 20 cut surfaces 1b were evaluated in one step, and 80 cut surfaces 1b were evaluated in four steps. The number of cut surfaces with θ4 within the range of 90° ± 2° was set to n, and the value n / 80 was set to the pass rate. A pass rate of 99% or greater was rated "A," a pass rate of 80% or greater but less than 99% was rated "B," and a pass rate of less than 80% was rated "C."

[0069] (Surface roughness evaluation of the second inclined surface)

[0070] The surface roughness (Sa) of the second inclined surface 122s was measured using a non-contact surface roughness measuring device using a laser. Specifically, a non-contact three-dimensional roughness measuring device (NewView7300) manufactured by Zygo Corporation was used, and the measurement range of the above-mentioned longitudinal section was set to 0.15 mm in the X direction and 0.05 mm in the Z direction. Regarding the measurement field of view, the magnification of the zoom lens was set to 1 times, and the magnification of the objective lens was set to 50 times. Regarding the measurement correction, a robust type bandpass filter was used, and the wavelength of the cutoff frequency on the lower side was set to 250 μm, and the wavelength of the cutoff frequency on the upper side was set to 2.5 μm.

[0071] Tables 1 and 2 show the above results.

[0072] According to Table 1 and Table 2, regarding Sample Nos. 1 to 12 and 21 to 29 in which the length L1 was equal to or greater than the length L2 , results equal to or greater than the evaluation B were obtained.

[0073] Furthermore, Tables 1 and 2 confirm that if length L2 is greater than or equal to length L1 and greater than or equal to 100 μm and less than or equal to 2000 μm, θ1 satisfies 16° ≤ θ1 ≤ 40°, and θ2 satisfies 3° ≤ θ2 ≤ 18°, then a rating of A is obtained. If length L2 is less than length L1, then a rating of C is obtained.

[0074] The embodiments and examples disclosed this time are illustrative in all aspects and should not be construed as restrictive.

[0075] The scope of the present invention is indicated by the claims, not the above description, and is intended to include all modifications within the scope of the claims and equivalents thereof. Furthermore, in the above embodiment, the cross-sectional shape of the flat-blade cutting edge is described as being symmetrical about the center line C. However, in order to achieve a perpendicular cutting effect, the cross-sectional shape of the flat-blade cutting edge may not be symmetrical about the center line C.

[0076] Description of the label

[0077] 1 object to be cut, 1a upper surface, 1b cut surface, 1e, 2121 straight line, 1f lower surface, 2a, 2b, 2c point, 100 flat cutting edge, 110 base, 120 blade portion, 121 first blade portion, 121s, 1121s first inclined surface, 121st convex portion, 121t tip portion, 122 second blade portion, 122s second inclined surface, 123 third blade portion, 123s concave curved surface, 2001 double-sided adhesive sheet, 2002 acrylic plate, 2003 cutting dynamometer, 2004 stage.

Claims

1. A flat-edged cutting blade comprising a flat base extending along a center line and a blade extending from an end portion of the base in an extending direction, the blade being made of a WC-Co or WC-Ni superhard alloy, wherein: The blade portion comprises: a first blade portion located farthest from the base portion in the extending direction; a second blade portion located adjacent to the first blade portion on the base side in the extending direction; as well as a third blade portion located between the second blade portion and the base portion in the extending direction; In a longitudinal section extending in both a thickness direction orthogonal to the extending direction and the extending direction, the outer shape of the first blade portion includes a first inclined surface and a tip portion serving as a blade tip, the first inclined surface being inclined relative to the center line so as to become thinner as it moves away from the base portion in the extending direction. In the longitudinal section, the outer shape of the second blade portion has a second inclined surface, which is linearly inclined relative to the center line in a manner that is gentler than the slope of the first inclined surface and is connected to the first inclined surface. In the longitudinal section, the outer shape of the third blade portion has a concave curved surface, which is concavely curved toward the center line side and is connected to the second inclined surface. In the extension direction, the length of the second blade portion is greater than or equal to the length of the first blade portion.

2. The flat cutting edge according to claim 1, wherein: In the longitudinal section, the first inclined surface includes either a convexly curved surface that curves convexly toward a side away from the center line and contacts the second inclined surface, or a linearly inclined surface.

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