JP7144641B2 - Cemented carbide cutting blade - Google Patents

Description

The present disclosure relates to cemented carbide cutting blades. This application claims priority from Japanese Patent Application No. 2020-105771 filed on June 19, 2020. All the contents described in the Japanese patent application are incorporated herein by reference.

Conventionally, cutting blades, for example, JP-A-10-217181 (Patent Document 1), JP-A-2001-158016 (Patent Document 2), International Publication No. 2014/050883 (Patent Document 3), International Publication No. 2014 /050884 (Patent Document 4), JP-A-2017-42911 (Patent Document 5) and JP-A-2004-17444 (Patent Document 6).

JP-A-10-217181 Japanese Patent Application Laid-Open No. 2001-158016 WO2014/050883 WO2014/050884 JP 2017-42911 A JP-A-2004-17444

The cemented carbide cutting blade of the present disclosure includes a base and a blade having a shape that is provided on an extension of the base and has a shape that decreases in thickness toward the cutting edge, which is the most distal part. The thickness of the blade at a position of 3 μm is 0.26 μm or more and 7.00 μm or less, and the thickness of the blade at a position of X μm (X is an integer from 3 to 25) from the blade edge to the base is TX, from the blade edge to the base When the thickness of the blade portion at the position of X + 1 μm toward the blade is TX1, the blade thickness change amount TX1-TX is 0.08 μm or more and 1.85 μm or less for all integers from 3 to 25, and is orthogonal to the blade length direction. In the longitudinal section, the outer shape of the blade has an inward concave portion in a range of 25 μm from the cutting edge toward the base, and the concave portion is inside a straight line connecting the cutting edge and a position of 25 μm from the cutting edge toward the base. To position.

FIG. 1 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 1. FIG. FIG. 2 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 2. As shown in FIG. FIG. 3 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 3. As shown in FIG. FIG. 4 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 4. As shown in FIG. FIG. 5 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 5. As shown in FIG. FIG. 6 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 6. As shown in FIG. FIG. 7 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 7. As shown in FIG. FIG. 8 is a perspective view of an apparatus for explaining the cutting test. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. FIG.

[Problems to be Solved by the Present Disclosure]
A general blade with a straight blade face has a large contact area with the cut object and a large cutting resistance, so there is a problem of poor cutting straightness (how straight the cut object can be cut) and easy to cause cross-section roughness. rice field.

[Description of Embodiments of the Present Disclosure]
First, the embodiments of the present disclosure are listed and described.

[Details of Embodiments of the Present Disclosure]
(Material)
The material used for the cutting blade is a cemented carbide containing tungsten carbide and cobalt as main components. The content of cobalt used in cemented carbide is in the range of 3-25% by weight. The cobalt content is preferably in the range of 5-20%.

The hardness of cemented carbide is in the range of 82-95 in HRA (Rockwell hardness). The composition of the elements constituting the cemented carbide is specified by ICP emission spectroscopic analysis and Co titration. In the cemented carbide in the present disclosure, the main components are tungsten carbide and cobalt. In addition, elements such as chromium, vanadium, tantalum, and niobium may be included in order to adjust characteristics such as grain size.

Preferably, the size of the tungsten carbide crystals in the cemented carbide is between 0.1 μm and 4 μm. More preferably, the crystal size is 2 μm or less.

In addition, a compound containing tantalum as a main component may be contained in order to control crystal grains of tungsten carbide and suppress crystal grain growth. Its content is preferably 0.1 to 2% by mass. The additive for suppressing grain growth may be a vanadium-based compound or a chromium-based compound. The content of each of the compound containing tantalum as the main component, the compound containing vanadium as the main component, and the compound containing chromium as the main component is 0.1 to 2% by mass.

(shape)
The shape of the cutting blade is basically a rectangular plate shape. The thickness is the shortest side of the board.

The cemented carbide cutting blade includes a base and a cutting edge that is provided on an extension of the base and has a shape that decreases in thickness toward the cutting edge, which is the most distal portion.

Preferably, the thickness of the base is constant. The base has a thickness of 50 to 1000 μm, and the required thickness varies depending on the size of the cut product. A blade for cutting is formed on one side extending from the base. The dimension of the blade portion in the direction from the base toward the blade portion is expressed as the width of the blade portion (Z-axis direction). The length in the direction of blade length (X-axis direction) and the dimension in the direction perpendicular to the width direction of the blade portion are represented as the thickness of the blade portion (Y-axis direction).

In many cases, when used as a cutting blade, the length in the blade span direction is often 30 mm to 500 mm, and the width is often 10 to 30 mm.

The blade has a thickness of 0.26 μm or more and 7.00 μm or less at a position of 3 μm from the blade edge toward the base. If the thickness of the blade portion at this position is less than 0.26 μm, it becomes difficult to maintain the strength of the blade portion. Or it is too thin and cannot be manufactured. If the thickness of the blade portion at this position exceeds 7.00 μm, the cutting resistance increases.

When the thickness of the blade at a position X μm (X is an integer from 3 to 25) from the cutting edge toward the base is TX, and the thickness of the blade at a position X + 1 μm from the cutting edge toward the base is TX1, the amount of change in blade thickness. TX1-TX is 0.08 μm or more and 1.85 μm or less where X is an integer of 3 to 25. If the amount of change in blade thickness is less than 0.08 μm, sufficient strength of the blade portion cannot be obtained, resulting in chipping. If the blade thickness variation exceeds 1.85 μm, the cutting resistance increases.

In a longitudinal section perpendicular to the blade extension direction, the cutting edge has an inwardly concave portion within a range of 25 μm from the cutting edge, and the concave portion is located inside a straight line connecting the cutting edge and a position 25 μm from the cutting edge. Due to the presence of the concave portion, the contact area with the object to be cut is smaller compared to a straight cutting blade that does not have a concave portion, and the cutting resistance is reduced. .

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 1. FIG. As shown in FIG. 1, the cemented carbide cutting blade 1 has a cutting edge 121t extending in the blade span direction. FIG. 1 is a cross section in a direction orthogonal to the blade extension direction.

The cemented carbide cutting blade 1 has a base portion 110 and a blade portion 120 connected to the base portion 110 . Blade 120 has a first portion 121 . The tip portion of the first portion 121 is the cutting edge 121t.

The thickness (Y-axis direction) of the blade portion 120 gradually decreases from the base portion 110 toward the blade edge 121t. The thickness at a point 203 having a dimension of 3 μm in the length direction (Z-axis direction) from the cutting edge 121t is T1. The thickness at point 225, which is 25 μm in length from the cutting edge 121t, is T2. The thickness at a point 20X having a lengthwise dimension of X μm from the cutting edge 121t is TX. The thickness at the point 20X1, which is X+1 μm in the length direction from the cutting edge 121t, is TX1.

The recess 120u is located inside the straight line S connecting the point 225 and the cutting edge 121t. The recess 120u is provided on the outer surface 121s. A straight line 325 is drawn on the outer surface 121s at the point 225, and the angle formed by the two straight lines 325 is θ. The slope of the straight line 325 is half the blade thickness variation at the point 225 . The direction perpendicular to the Y-axis and Z-axis directions is the blade length direction.

The outer surface 121s has a curved shape. The amount of change in blade thickness in the blade portion 120 becomes smaller as it approaches the blade tip 121t. 121 s of outer surfaces are bilaterally symmetrical with respect to the centerline C in this embodiment. However, the outer surface 121s may be asymmetrical with respect to the centerline C.

The outer surface 121 s is gently curved to connect the cutting edge 121 t and the base 110 . The angle between the outer surface 121s and the center line C decreases as the cutting edge 121t is approached. The blade portion 120 may be curved only in the range of 3 to 25 μm in the Z-axis direction, and the base portion 110 side of the curved portion may be linear.

The cutting object of the cemented carbide cutting blade 1 is, for example, unfired ceramics or glass such as laminated capacitors or laminated inductors, metal green sheets, metal foils, paper, fibers, or hard resins.

The cemented carbide cutting blade 1 includes a base portion 110 and a blade portion 120 which is provided on an extension line of the base portion 110 and has a shape whose thickness decreases toward a cutting edge 121t which is the most distal portion. A thickness T1 of the blade portion 120 at a position of 3 μm from the blade edge 121t toward the base portion 110 is 0.26 μm or more and 7.00 μm or less. When the thickness of the blade portion at a position of X μm (X is an integer from 3 to 25) from the cutting edge 121 t toward the base portion 110 is TX, and the thickness of the blade portion 120 at a position of X + 1 μm from the blade edge 121 t toward the base portion 110 is TX1. , and the blade thickness change amount TX1-TX is 0.08 μm or more and 1.85 μm or less where X is an integer of 3 to 25. In a longitudinal section perpendicular to the blade length direction, the outer shape of the blade portion 120 has a concave portion inward in a range of 25 μm from the cutting edge 121t, and the concave portion 120u is from the straight line S connecting the cutting edge 121t and a position 25 μm from the cutting edge 121t. is also inside.

More preferably, the amount of change in blade thickness when X is 3 is 0.26 μm or more and 0.93 μm or less.

(Embodiment 2)
FIG. 2 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 2. As shown in FIG. As shown in FIG. 2, in the cemented carbide cutting blade 1 according to Embodiment 2, the outer surface 121s is curved in that the outer surfaces 121s, 122s, and 123s have a three-step shape. It differs from the cemented carbide cutting blade 1 according to the first embodiment. All of the outer surfaces 121s, 122s, and 123s of the three-stage blade portion 120 are linear. The angle formed by the outer surfaces 121s, 122s, and 123s with respect to the center line C is the largest at the portion near the outer surface 122s and the smallest at the outer surface 123s or the outer surface 121s near the cutting edge 121t.

A point 225 at a distance of 25 μm from the cutting edge 121 t in the Z-axis direction exists on the first portion 121 . Although the recesses 120u are rectangular in this embodiment, the recesses 120u may be curved.

(Embodiment 3)
FIG. 3 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 3. As shown in FIG. As shown in FIG. 3, in the cemented carbide cutting blade 1 according to Embodiment 3, the outer surfaces 121s, 122s, 123s are three steps in that the outer surfaces 121s, 122s are two steps. It differs from the cemented carbide cutting blade 1 according to the second embodiment.

The blade portion 120 has a first portion 121 and a second portion 122 from the tip side. The outer surface 121s has a recess 120u. The recess 120u is located inside the straight line S. The angle formed by the outer surface 121s with respect to the center line C is the smallest near the cutting edge 121t.

(Embodiment 4)
FIG. 4 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 4. As shown in FIG. As shown in FIG. 4, in the cemented carbide cutting blade 1 according to Embodiment 4, the outer surface 122s has a concave shape, unlike Embodiment 3 in which the outer surface 122s has a linear shape. It differs from the cemented carbide cutting blade 1 according to this. A point 225 at a distance of 25 μm from the cutting edge 121 t in the Z-axis direction exists on the first portion 121 .

The blade portion 120 has a first portion 121 and a second portion 122 from the tip side. A recess 120u is present in the first portion 121 . The recess 120u is located inside the straight line S.

The outer surface 122s of the second portion 122 of the blade portion 120 is curved so that the angle formed with the center line C decreases as it approaches the blade tip 121t.

(Embodiment 5)
FIG. 5 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 5. As shown in FIG. As shown in FIG. 5, the cemented carbide cutting blade 1 according to Embodiment 5 differs from the cemented carbide cutting blade 1 according to Embodiment 1 in that the cutting edge 121t has a flat shape. different. The flat surface forming the cutting edge 121t may be perpendicular to the center line C or may be inclined with respect to the center line C.

(Embodiment 6)
FIG. 6 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 6. As shown in FIG. As shown in FIG. 6, in the cemented carbide cutting blade 1 according to Embodiment 6, the cutting edge 121t is sharp in that the cutting edge 121t is rounded. It is different from the manufacturing cutting blade 1. The cutting edge 121t may have a single radius of curvature, or may have a plurality of curvature radii to form a so-called compound R shape.

(Embodiment 7)
FIG. 7 is a longitudinal sectional view of a cemented carbide cutting blade 1 according to Embodiment 7. As shown in FIG. As shown in FIG. 7, in the cemented carbide cutting blade 1 according to Embodiment 7, the outer surface 121s of the first portion 121 in the vicinity of the cutting edge 121t has an inwardly concave shape, and the outer surface 121s of the first portion 121 near the cutting edge 121t has a concave shape. The second portion 122 has a concave outer surface 122s. A point 225 at a distance of 25 μm from the cutting edge 121 t in the Z-axis direction exists on the first portion 121 .

(Example 1)
Using a cemented carbide cutting blade 1 having a base portion 110 of 100 μm in thickness, 20 mm in width, and 40 mm in length in the blade length direction, the characteristics thereof were confirmed.

<Material>
The sintered body used for the cutting blade is a cemented carbide containing tungsten carbide and cobalt as main components. The cobalt content used in the cemented carbide is 10% by weight. The hardness of cemented carbide is 92 in HRA (Rockwell hardness).

<Grinding>
The produced sintered body was cut into a plate shape of 100 μm in thickness, 20 mm in width and 40 mm in length by a grinder using a diamond whetstone, and was used as a material for processing the cutting edge.

<Sharpening>
Subsequently, the cutting edge was formed using the above material. In the forming process, a dedicated grinder with a diamond cylindrical grindstone was used, and the material was fixed to a dedicated work rest with an adjustable angle. When the blade has two stages, the first blade has the tip angle that is the most tip with respect to one side in the direction of the long side length of 40 mm of the material, and the tip angle that is connected to it and continues to the base 110. Blades with different tip angles of the second blades were formed on both sides.

<Forming concave curved outer surface>
In order to form the outer surface 121s, which is a concavely curved surface as shown in FIG. 1, a cylindrical grindstone having a convexly curved surface was used to apply concave processing to both surfaces of the distal end portion. Since the formation of the concave shape is a very precise process, it is very important to set the grinding conditions such as the depth of cut and the work rest angle.

<Flat outer surface molding>
In order to form the flat outer surface 121s as shown in FIG. 3, a cylindrical grindstone was used to apply concave shape processing to the distal end portion on both sides. In the case of a three-stage blade as shown in FIG. 2, a third portion 123 is provided at the time of sharpening.

<Forming concave curved outer surface>
In order to form the outer surface 122s, which is a concavely curved surface as shown in FIG. 4, a cylindrical grindstone having a convexly curved surface was used to apply concave processing to both sides of the leading end.

<Confirmation of cross section>
The cross-section was confirmed using a JEOL Schottky field emission scanning electron microscope JSM-7900F at 3,000 times. , . . . , the blade thickness (thickness of the blade portion 120) at a portion of 26 μm was measured. From the blade thickness, the amount of change in blade thickness was calculated. The results are shown in Tables 1-5.

In Table 1, etc., "25 μm angle [°]" means that in the longitudinal section shown in FIG. , refers to the angle formed by two straight lines 325 . The slope of straight line 325 is half the blade thickness variation at point 225 . "3 μm angle [°]" means that, in the longitudinal section shown in FIG. It means the angle to make. The slope of the two straight lines is the blade thickness variation at point 203 . "N" in the "inner concave" column means that the outer surface 121s does not have a concave 120u recessed inward from the straight line S. "Y" in the "inner concave" column means that the outer surface 121s has a concave 120u recessed inward from the straight line S. In the "blade thickness change amount [μm]", the "3 μm point" is a value obtained by subtracting the blade thickness at a point 3 μm from the blade edge 121t from the blade thickness at a point 4 μm from the blade edge 121t. “A portion of 25 μm” is a value obtained by subtracting the blade thickness of a portion of 25 μm from the blade edge 121t from the blade thickness of a portion of 26 μm from the blade edge 121t. "Figure" indicates a drawing corresponding to the shape of each sample. “max/min” indicates the maximum value and minimum value of the blade thickness change amount on the outer surface 121s in the range from 3 μm to 25 μm away from the blade edge 121t in the Z-axis direction.

<Cutting test>
In addition, in order to confirm the effect of using the cemented carbide cutting blade created here, press cutting was performed on a commercially available vinyl chloride plate and the cross-sectional cutting quality and cutting straightness of the cut piece were observed. The effect of the alloy cutting blade was confirmed. FIG. 8 is a perspective view of the device for explaining the cutting test. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. FIG. As shown in FIGS. 8 and 9, chucks 3001 and 3002 held the cemented carbide cutting blade 1 .

Conditions of this test (Fig. 8 and Fig. 9)
Work material: PVC plate 100, thickness 0.5 mm, width 290 mm, length 30 mm
Test equipment: Machining center V55 (stage 2004) manufactured by Makino Milling Machine Co., Ltd. and Kistler's cutting dynamometer 9255 (cutting dynamometer 2003) set. A vinyl chloride plate 100 as a work was laminated.

Cutting conditions: Cutting speed 300mm/s, push amount 0.55mm, longitudinal workpiece and blade angle ±0.1°, workpiece and blade cross section angle 90°±0.1°, number of cuts 100 times, cutting interval (pitch ) 2.5 mm
Items to be checked: Cutting straightness of cut pieces, cross-section quality (cross-section roughness)
Tables 1 to 5 show the results of repeated cutting tests for each sample number.

Regarding cutting straightness, cross sections of five randomly selected cut pieces were observed with a microscope VHX5000 manufactured by Keyence. From the observation results, the absolute values of differences A1 to A5 between 90° and the angles formed by the five cut surfaces and the upper and lower surfaces of the workpiece (whichever is acceptable) were determined. An average value of these five absolute values was calculated and described as "angle [°]" of "cutting straightness" in the table. If the "angle [°]" was less than 2°, the evaluation was A; if the angle was 2° or more and less than 4°, the evaluation was B;

Regarding cross-sectional roughness, if the cross-sectional surface roughness Sa (arithmetic mean height ISO25178) is 0.05 μm or less, the evaluation is A, and if the cross-sectional surface roughness Sa is greater than 0.05 μm and 0.15 μm or less, the evaluation is B. , the evaluation was C if the surface roughness Sa exceeded 0.15 μm. The surface roughness Sa is measured using a non-contact surface roughness measuring device using a white interferometer. Specifically, it was measured using a non-contact three-dimensional roughness measuring device (Nexview (registered trademark)) manufactured by Zygo Corporation.

Regarding the overall evaluation, if the evaluation was A for both cutting straightness and cross-sectional quality, the overall evaluation was A. If either the straightness of cutting or the quality of the cross section was evaluated as C, or if the product was not manufacturable, the overall evaluation was set as C. Other evaluation was set to B.

As shown in Tables 1 to 5, the thickness of the blade portion at the position of 3 μm is 0.26 μm or more and 7.00 μm or less, and the blade thickness change amount from 3 μm to 25 μm is 0.08 μm or more and 1.85 μm or less. It can be seen that the overall evaluation is A or B if there is a recess 120u.

Furthermore, if the amount of change in blade thickness at the position of 3 μm (X=3 μm) is 0.26 μm or more and 0.93 μm or less, the overall evaluation is A, which is more preferable.

(Example 2)
Cutting blades (sample numbers 97-100, 109-112, 121-124, 133-136) having the shapes shown in Figures 1, 2, 4 and 7 were produced. These cutting blades and the cutting blade manufactured in Example 1 above were additionally processed as follows to the cutting edge of the cutting blade to prepare a cutting blade. A cutting blade was fixed on a fixed table, and a flat diamond whetstone with a grain size of #10000 was used so that the tip angle was perpendicular to the base portion 110 . The cross section confirmation method was the same as in Example 1. Cemented carbide cutting blades of sample numbers 89-92, 101-104, 113-116, 125-128, and 137-140 were thus prepared.

Using the same material as in Example 1, a grindstone with a grain size of #10000 was grooved with a radius of 0.25 μm, and the groove was used to round the tip of the cutting blade. Alternatively, fine diamond or tungsten carbide particles (recommended 1 μm or less) are suspended in a liquid such as water, and the suspension is adjusted to the blade by adjusting the flow rate, injection angle and time, and R processing is performed. . The cross-sectional confirmation was the same as in Example 1. Cemented carbide cutting blades of sample numbers 93-96, 105-108, 117-120, 129-132, and 141-144 were thus prepared. These details are shown in Tables 6-10.

The cemented carbide cutting blades in Tables 6-10 were evaluated in the same manner as in Example 1. The results are shown in Table 6-10.

In the "figure" of Table 6, etc., "3, 5" indicates that the cutting edge 121t of the cemented carbide cutting blade 1 of FIG. 3 is flattened as shown in FIG. "1,5", "2,5", "4,5", and "7,5" are also similar to the cutting edge 121t of the cemented carbide cutting blade 1 shown in FIGS. is flattened.

"3, 6" indicates that the cutting edge 121t of the cemented carbide alloy cutting blade 1 shown in FIG. 3 is rounded as shown in FIG. "1,6", "2,6", "4,6", and "7,6" are also similar to the cutting edge 121t of the cemented carbide cutting blade 1 shown in FIGS. is rounded. It can be seen that Tables 6 to 10 show the same tendency as Tables 1 to 5.

The embodiments and examples disclosed this time are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all changes within the scope and meaning equivalent to the scope of the claims.

1 alloy cutting blade, 100 vinyl chloride plate, 110 base, 120 blade, 120u concave, 121 first portion, 121s, 122s, 123s outer surface, 121t cutting edge, 122 second portion, 203, 225 points, 325 tangent line, 2001 Double-sided adhesive sheet, 2002 acrylic plate, 2003 cutting dynamometer, 2004 stage, 3001, 3002 chuck.

Claims (2)

a base;
A blade portion provided on an extension of the base portion and having a shape in which the thickness decreases toward the cutting edge, which is the most distal portion,
The thickness of the blade portion at a position of 3 μm from the blade edge toward the base portion is 0.26 μm or more and 7.00 μm or less,
The thickness of the blade portion at a position of X μm (X is an integer from 3 to 25) from the blade edge toward the base is TX, and the thickness of the blade portion at a position of X + 1 μm from the blade edge toward the base is TX1. when the amount of change in blade thickness TX1-TX is 0.08 μm or more and 1.85 μm or less where X is an integer of 3 to 25,
In a longitudinal section perpendicular to the blade length direction, the outer shape of the blade has an inwardly concave portion in a range of 25 μm from the blade edge toward the base, and the concave portion extends from the blade edge and from the blade edge to the base. Cemented carbide cutting blade located inside the straight line connecting the 25 μm points. 2. The cemented carbide cutting blade according to claim 1, wherein said blade thickness change amount when said X is 3 is 0.26 [mu]m or more and 0.93 [mu]m or less.

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