TW201433430A - Flat cutting blade and green sheet cutting blade - Google Patents

Abstract

An object of the invention is to provide a cutting blade which satisfies both stable shape accuracy and workability and which is capable of preventing oblique cutting. A cutting blade 1 of a flat-blade type according to the present invention has a base portion 5 and a blade edge portion 7 as a cutting executing part. The blade edge portion 7 has left and right blade faces 9a and 9b inclined from left and right surfaces of the base portion 5 towards each other, and a blade tip 11 having a convex curved surface connecting the left and the right blade faces 9a and 9b. A shortest distance between the blade tip 11 and an intersection point of two straight lines 13a and 13b extending along the left and the right blade faces 9a and 9b is not smaller than 1 μ m and is not greater than 10 μ m. The blade tip 11 has different lengths on left and right sides with respect to a center line 21. The difference between the lengths is not smaller than 1 μ m and is not greater than 20 μ m, and an inner angle formed by two lines along the left and right blade faces 9a and 9b is not smaller than 4 degrees and is not greater than 60 degrees.

Description

Flat blade cutting edge and green sheet cutting edge

The present invention relates to a flat blade cutting edge and a green sheet cutting edge.

As a method of manufacturing a laminated ceramic capacitor, a laminated varistor, a laminated coil, a laminated piezoelectric actuator, or the like, a laminate of a paste-like plate containing a mixture of a dielectric ceramic powder and a binder (referred to as a green sheet) is cut. After forming the shape of each product, bake and mount the electrodes on both ends.

Here, in recent years, in order to cope with a small-sized machine represented by a smart phone, the capacitor has been required to have a small size, and therefore, a high degree of shape accuracy is required. In order to realize such a small-sized ceramic capacitor, it is necessary to pay attention to forming a vertical cutting surface as much as possible, or not to damage the cutting surface.

As a method of cutting a green sheet, there is a method of cutting by a circular blade called a cutting method, and a cutting method using a flat blade-shaped cutting edge.

Although the cutting method is higher in cutting precision than the cutting method, because the chip is generated, the material yield rate is worse than the cutting method, and the cutting speed difference is also disadvantageous. Therefore, the smaller the size of the green sheet after cutting, the more advantageous the cutting method is. .

Here, the flat blade-shaped cutting edge has a shape of a blade tip portion and a base portion (also referred to as a shank), and the blade tip portion is a cutting execution portion that facilitates cutting, and the base portion has a structure for fixing the cutting blade to the cutting device. Parallel faces.

In the flat blade-shaped cutting edge, it is desirable to have sharpness (small shear resistance during cutting), wear resistance, weld resistance to the object to be cut, strength to buckling, and long life (herein referred to herein) The term "lifetime" means a point at which a scratch occurs in the cross-sectional shape of the object to be cut due to chips, and in the case of a cutting edge for a laminated capacitor, when the laminated film is peeled off, the cutting edge is finished.

For example, Patent Document 1 discloses a structure in which a vertical cutting surface can be formed by providing a step shape of an arrow shape in a cross-sectional shape of a blade edge (Patent Document 1).

On the other hand, regarding the shear resistance, especially the shape of the blade tip, it is particularly important to consider the damage to the object to be cut, and the angle of the thin blade and the tip end of the blade is preferably small. However, the thinner the blade, the worse the strength is unavoidable. Therefore, the cutting edge used nowadays is made to increase the angle of the tip end of the foremost end by adding an angle of one or more segments from the tip to the base.

For example, Patent Document 2 discloses a structure in which the blade tip portion is formed by a plurality of concave curved surfaces to reduce the shear resistance and increase the buckling strength (Patent Document 2).

[Prior patent documents] [Patent Literature]

[Patent Document 1] Unexamined Japanese Patent Publication No. SHO63-197089

[Patent Document 2] Japanese Patent Laid-Open No. Hei 10-217181

However, even in the case of using the blade tip of Patent Document 2, it is difficult to ensure the strength of the tip end.

Further, the flat blade-shaped cutting blade is made of a hard material such as a superhard alloy in addition to stainless steel. In particular, when the material is a hard material, it is rigid, but it is a hard-to-cut material and has low toughness and is prone to cracking. Further, in the case where the thickness of the blade is thin, even in the case of a hard material, the blade may be detached due to the pressing of the grindstone during the processing of the tip end portion of the blade tip. Therefore, a shape excellent in workability is required. However, in the structures of Patent Documents 1 and 2, it is not easy to have high precision processing, and there is a problem in practicality.

Further, at the time of cutting, since the size of the cut object is different around the cutting edge, when the product size is remarkably smaller than that of the green sheet, the left and right cut objects are relatively small in size and are easily deformed during cutting. Therefore, it is necessary to control the so-called oblique cutting caused by "running away".

However, the structures of Patent Documents 1 and 2 have a problem that the structure of the oblique cut cannot be suppressed.

The present invention has been made in view of the above problems, and an object of the invention is to provide a cutting edge which can satisfy stable shape accuracy and workability while suppressing oblique cutting.

In order to solve this problem, the inventors have examined whether it is possible to suppress the oblique cutting while ensuring the blade tip strength and reducing the cutting resistance at the time of cutting.

As a result, it has been found that by making the shape of the tip end of the blade tip, the blade tip shape is intentionally made to be left-right asymmetrical, and the cutting resistance at the time of cutting can be reduced without suppressing the strength of the tip end, and the oblique cutting can be suppressed. Therefore, the present invention has been proposed.

That is, the first aspect of the present invention is a flat blade-shaped cutting blade, which comprises The base portion of the flat plate; the left and right blade faces are inclined from each other to be close to each other; and the tip end of the blade is formed by connecting the left and right blade faces and has a convex curved surface; and the feature is: In the cross-sectional shape in the thickness direction, the shortest distance between the intersection of the two straight lines along the left and right blade faces and the tip end is 1 μm or more and 10 μm or less; and the length of the tip end portion of the convex curved surface in the center line direction The center line of the base portion is different from left to right, and the difference is 1 μm or more and 20 μm or less. Further, the internal angle of the intersection angle of the two straight lines along the left and right blade faces is 4 degrees or more and 60 degrees or less.

According to a second aspect of the invention, there is provided a cutting blade of a green sheet having a flat blade-shaped cutting edge according to the first aspect.

According to the present invention, it is possible to provide a cutting edge which satisfies stable shape accuracy and cutting performance while suppressing oblique cutting.

1‧‧‧ flat blade cutting edge

3‧‧‧ Cutting device fixing department

5‧‧‧ base

5a‧‧‧Fixed Department

5b‧‧‧Connecting Department

7‧‧‧Edge Tip

9a‧‧‧left face

9b‧‧‧Right face

11‧‧‧ Tip tip

15‧‧‧Connecting Department

21‧‧‧ center line

31‧‧‧ film

100‧‧‧cuts

201‧‧‧solution

203‧‧‧ container

205‧‧‧ solid matter

X‧‧‧ shortest distance

Y1‧‧‧ distance

Y2‧‧‧ distance

Θ‧‧‧ inside corner

Fig. 1 is a schematic side view showing the shape of the flat blade-shaped cutting edge 1.

Fig. 2 is a perspective view of Fig. 1.

Fig. 3 is a cross-sectional view showing the tip shape of the flat blade-shaped cutting edge 1.

Fig. 4 is an enlarged view of the vicinity of the connecting portion 15 of Fig. 3.

Figure 5 is a cross-sectional view for explaining oblique cutting.

Figure 6 is a cross-sectional view showing oblique cutting.

Fig. 7 is a schematic view showing a method of processing the tip end of the flat blade-shaped cutting edge 1.

Figure 8 is a diagram showing the processing method of the tip end of the flat blade-shaped cutting edge 1. Figure.

Fig. 9 is a schematic view showing a processing method of the tip end of the flat blade-shaped cutting edge 1.

Hereinafter, embodiments suitable for the present invention will be described in detail with reference to the drawings.

First, the shape of the flat blade-shaped cutting edge 1 according to the embodiment of the present invention will be described with reference to Figs. 1 to 6 .

Here, as the flat blade-shaped cutting edge 1, a green sheet cutting blade is exemplified.

As shown in Fig. 1, the flat blade-shaped cutting edge 1 has a flat base portion 5 having a rectangular planar shape, and a blade edge portion 7 provided on one of the long sides of the base portion 5 for cutting the object to be cut 100. Cutting the execution unit.

The base portion 5 is a fixing portion 3 of the cutting device, and has a fixed portion 5a having a parallel straight portion as shown in the drawing, and a connecting portion 5b that connects the fixed portion 5a and the blade edge portion 7.

In addition, in the first figure and the second figure, the length of the long side of the flat blade-shaped cutting edge 1 is denoted by L, the length of the short side is denoted by H, and the height of the tip end portion 7 is denoted by H1. The thickness of the cutting edge 1 is denoted by T.

Further, as shown in Fig. 3, the blade edge portion 7 has a left blade surface 9a and a right blade surface 9b which are inclined from the left and right sides of the base portion 5 so as to be close to each other, and a blade tip end portion 11 for connecting the left blade surface 9a. Formed with the right blade surface 9b.

Here, as shown in Fig. 3, the cross-sectional shape of the blade edge portion 7 in the thickness direction is along the two straight lines 13a, 13b of the left blade face 9a and the right blade face 9b. The shortest distance X between the intersection point and the tip end tip 11 is preferably 1 μm or more and 10 μm or less.

When the value is less than 1 μm, cracks are likely to occur at the tip of the blade. On the other hand, in the case of exceeding 10 μm, a large cutting resistance is generated when the blade edge enters the object 100 to be cut. Furthermore, it is easy to shorten the life due to friction. More preferably, it is 1.5 μm or more and 5 μm or less.

Further, as shown in Fig. 3, the flat blade-shaped cutting edge 1 has a convex curved surface in advance at the tip end tip 11. The convex curved surface is intended to point to the curved shape of the outer side. By adopting a configuration in which the tip end tip 11 has a convex curved surface, the blade tip strength and the low cutting resistance can be set. Further, as shown in Fig. 4, when the cross-sectional shape of the connecting portion 15 of the left blade surface 9a, the right blade surface 9b, and the blade tip end 11 in the thickness direction is formed by a curved line, it is preferable to have a low cutting resistance.

Further, the cross-sectional shape of the blade tip end 11 in the thickness direction is such that the length of the blade tip end 11 is different from the center line 21 (the line passing through the center of the thickness direction of the base portion 5 and parallel in the short side direction). That is, the cross-sectional shape of the blade tip end 11 in the thickness direction is asymmetric with respect to the center line 21 left and right.

Specifically, in Fig. 3, the shortest distance Y1 from the tip end portion 17 to the left blade surface 9a side of the connecting portion 15 and the shortest distance Y2 on the right blade surface 9b side are different from the center line 21 The difference (the absolute value of Y1-Y2) is 1 μm or more and 20 μm or less.

Explain the reason for making this shape.

As described above, when cutting with the flat-blade cutting edge 1, since the size of the cut object is different around the cutting edge, it is difficult to cut vertically, especially when the size of the left and right cut objects is relatively small. Easy to deform, need to suppress The so-called "running off" caused by the oblique cutting.

Specifically, for example, as shown in Fig. 5, in the case where the object to be cut 100 is cut by the left and right symmetrical blades, the right side region 101 (product side) is flat blade-like in comparison with the left side region 103 (plate side) of the cutting portion. The length of the cutting edge 1 in the horizontal direction is relatively short.

In this case, since the left side region 103 is hard to be plastically deformed at the time of cutting (difficult to deform in the direction of A in FIG. 5), the cut surface is difficult to be obliquely cut, but the right side region 101 is short in the horizontal direction, and has The degree of freedom of movement is deformed in the direction of the arrow B shown in Fig. 5 at the time of cutting, since it is possible to run away from the blade edge, so that the cutting surface of the right right region 101 is easier to be the same as the left region 103 as shown in Fig. 5. The oblique cut shown. Although this is also related to the state of the object to be cut and the size of the product cut from the object to be cut, the smaller the size of the object to be cut (the direction in the left-right direction of Fig. 5), the more likely it is to occur.

Therefore, in the present embodiment, the cross-sectional shape in the thickness direction of the blade tip end 11 is different in the left and right, and the "runaway" is absorbed to prevent the oblique cutting.

In this case, as shown in Fig. 6, comparing Y1 and Y2, the length in the horizontal direction toward the object to be cut is relatively short in the comparatively long (here, the left blade face 9a side) (the right side region in Fig. 1) 101) Post cutting.

In addition, when the difference (the absolute value of Y1-Y2) is less than 1 μm, since the left and right blade faces are almost bilaterally symmetrical, it is difficult to obtain an effect of oblique cutting when the product to be cut is small.

On the other hand, if the difference exceeds 20 μm, it is not preferable because it has the possibility of becoming a reverse oblique cut.

Further, the difference (the absolute value of Y1 - Y2) is preferably 2 μm or less and 10 μm or less.

Further, the shape of the tip end tip 11 is preferably 4 degrees or more and 60 degrees or less along the internal angle θ of the intersection angle of the two straight lines 13a and 13b of the left blade surface 9a and the right blade surface 9b.

This is because the cutting resistance becomes small when θ is less than 4 degrees, but the cutting edge is liable to generate chips, which has a bad influence on the cut surface, or the life of the cutting edge becomes short.

Further, when θ exceeds 60 degrees, a large load is generated when the blade edge enters the workpiece 100, and buckling resistance or wear resistance is deteriorated. Further, in this case, the amount of plastic deformation of the workpiece 100 is increased, and scratches are likely to occur on the surface of the workpiece 100, so that the cut surface does not become vertical, and it tends to become inclined, and the cutting resistance is increased.

Further, from the viewpoint of ensuring the strength of the blade tip and the low cutting resistance, the angle θ is preferably 10 degrees or more and 30 degrees or less.

The above is a description of the shape of the flat blade-shaped cutting edge 1.

In addition, the material constituting the flat blade-shaped cutting edge 1 is appropriately selected depending on the object to be cut, and specific examples thereof include carbon tool steel or WC-Co superhard alloy.

Next, a method of processing the blade tip portion 7 of the flat blade-shaped cutting edge 1 will be described with reference to Figs. 7 to 9 .

The method of processing the blade tip portion 7 of the flat blade-shaped cutting edge 1 is not particularly limited as long as it can process the blade tip shape described above, and examples thereof include the following methods.

First, the tip end (long side) of the connecting portion 5b of the base portion 5 is linearly processed to form a left blade surface 9a, a right blade surface 9b, and straight lines 13a and 13b.

This linear processing is performed, for example, by grinding of a grindstone or the like.

Next, the blade tip portion 7 is subjected to processing for forming the tip end tip 11.

As described above, since the shape of the tip end tip 11 has a convex curved surface, the press working of the grindstone in the case of forming the left blade face 9a and the right blade face 9b is processed because the blade tip is too thin. When the blade tip is easy to run away from the grindstone, stable processing is not easy.

Therefore, the cutting edge tip 11 is processed by: (1) a method of forming the tip end tip 11 in a solution having abrasive grains, or (2) using a mixed abrasive grain or other hard material, that is, metal powder or ceramic powder. The solid matter forms a method of the tip end 11 and the like.

Hereinafter, a specific processing method will be described.

First, the method of (1) is as shown in Fig. 7, in a suitable container 203, filled with a solution 201 having a hard material, and only the tip end portion 7 of the flat-blade cutting edge 1 is immersed in the solution 201, Further, a method of forming the blade tip end 11 by bringing the hard material in the solution 201 into contact with the blade edge portion 7 and rotating it in the blade length direction for a fixed period of time.

Here, as a specific example of the hard material, since the processing time of the diamond particles having high hardness can be short, it is preferable, but other metal powder or ceramic powder may be used.

Further, the solvent of the solution 201 is, for example, water.

Secondly, the method of (2) is as shown in Fig. 8, by means of a flat blade The cutting blade 1 cuts the solid matter 205 in which the hard material powder has been mixed, and the hard material in the solid material 205 is brought into contact with the blade edge portion 7 to be processed, and the blade tip end 11 is formed on the blade tip portion 7.

Here, as the solid material 205, for example, a clay material is cited.

Further, examples of the hard material include powders of diamond, W, Mo, WC, Al ₂ O ₃ , TiO ₂ , TiC, TiCN, SiC, Si ₃ N ₄ , and BN.

The average particle diameter of the secondary particle of the powder particle diameter of these hard materials is preferably 1 μm or less in Fsss (Fisher Sub-Sieve Sizer) particle size. This is because when it exceeds 1 μm, the surface of the blade tip is processed, and there is a possibility of occurrence of cracks. Further, the finer the particles, the better the shape accuracy of the flat blade-shaped cutting edge. However, since the processing is time-consuming, the particles of a size close to 1 μm are initially processed in this range, and the finishing is performed to be finer. Hard material particles having a size of 1 μm are more preferably processed. By uniformly dispersing the particles, uniform edge processing can be achieved.

Here, as described above, the cross-sectional shape of the blade tip end 11 of the flat blade-shaped cutting edge 1 in the thickness direction differs from the blade tip end portion 17 to the connecting portion 15 in the right and left directions with respect to the center line 21, and therefore, In the case of using any of the methods (1) and (2), it is necessary to form a cross-sectional shape in the thickness direction to be different from left to right.

As an example of such processing, there is a method of performing film processing on one side of the tip end 11 as shown in Fig. 9 between the processing and the final processing. In other words, as shown in Fig. 9, when the film is processed on one side and the film 31 is formed, the hardness of the left and right surfaces of the tip end 11 is different. Therefore, when machining is performed in this state, the difference in hardness is caused by the difference in the amount of left and right machining (polishing amount), so that the cross-sectional shape in the thickness direction can be processed in the left and right phase. different.

Here, as a method of the film processing, for example, a method of forming a film from the next μm to several μm according to a sputtering method which is one of PVD (Physical Vapor Depositon) is used.

At this time, it can be achieved by shielding the surface on which the film is not to be processed or the arrangement of the cutting edge before the film (for example, on the opposite side of the target).

Further, the type of the film is not particularly limited, and may be Ti-based, Fe-based, or non-metallic, as long as the hardness is lower than that of the flat-blade cutting edge 1.

By coating the film on only one side, for example, in the processing of the abrasive particle solution, the cross section of the tip end portion can be processed into a left-right asymmetric shape, and the degree of asymmetry (Y1 and Y2) can be based on the film. The film thickness is adjusted. In addition, the film is removed by processing and finally being ground.

Further, the order of the film treatment is not necessarily the case where the blade faces 13a and 13b are formed on both sides, and the film may be processed after only one side of the material of the flat blade-shaped cutting edge 1 is sharpened, and then the remaining The other side of the next side is sharpened. The flat-blade cutting edge 1 having the above-described shape can be finished by processing the flat-blade cutting edge 1 which has been subjected to the film treatment on one side in a solution having, for example, a hard material.

The above is an explanation of an example of a processing method of the blade tip portion 7 of the flat blade-shaped cutting edge 1.

In this manner, according to the present embodiment, the blade edge portion 7 of the blade edge cutting blade 1 has a blade edge portion 7 having a left blade surface 9a and a right blade surface 9b. The two sides of the base 5 are inclined to be close to each other; and the tip end 11 is formed by connecting the left blade face 9a and the right blade face 9b, and has a convex curved face; along the left blade face 9a and the right edge The shortest distance between the intersection of the two straight lines 13a and 13b of the surface 9b and the tip end point 11 is 1 μm or more and 10 μm or less, and the length of the tip end point 11 is different from the center line 21 in the left and right directions, and the difference is 1 μm or more and 20 μm. In addition, since the internal angle of the intersection angle of the two straight lines along the left and right blade faces is 4 degrees or more and 60 degrees or less, the flat blade-shaped cutting edge 1 can simultaneously satisfy stable shape accuracy and cutting performance.

Example

Hereinafter, the present invention will be described in more detail based on examples.

(First embodiment)

The cutting test was performed using the flat-blade cutting edge 1 manufactured according to the method of forming the tip end tip 11 in the solution having the abrasive grains, and the chipping property, the abrasion property and the influence on the cutting surface of the shape of the tip end tip 11 were evaluated. . The specific steps are as follows.

<Processing of flat blade cutting edge 1>

First, the length L of the blade length direction is 100 mm, the length H in the short-side direction is 20 mm, the thickness T is 0.1 mm (see FIG. 2), and the material is made of a superhard alloy FM10K made by Allied Material Co., Ltd. The plate material is subjected to a grinding process on one of the long sides by a technique using a grindstone, and is formed to be bilaterally symmetrical with respect to the cross section in the thickness direction, and the left blade faces 9a and 13a and the right blade faces 9b and 13b are formed.

Then, on one side, according to the use of NEC Aneluva shares limited The company's SPF-332 sputtering method forms a TiN film having a thickness of 2 μm from the tip end to a position of 1 mm.

Next, the blade edge of the flat blade-shaped cutting edge 1 is immersed only in the solution 201 having a hard material as shown in Fig. 7, and is reciprocally slid in the blade length direction for a fixed time to form a blade edge. Tip 11.

As a solution having a hard material, a diamond slurry PC-1-W (Fsss particle size: 1 μm) manufactured by Wada Trading Co., Ltd. was used, and as a finishing, PC-N100-W (particle size: 0.1 μm) was used.

Further, although not shown, the solution 201 (aqueous solution) should be noted so as not to affect the cutting edge processing, and while sliding to a uniform concentration, the sliding time is adjusted, and the tip end tip 11 having the tip shown in FIG. 3 is obtained. Flat blade cutting edge 1. Here, the connecting portion 15 of Fig. 4 is a curved line.

<Evaluation of Flat Edge Cutting Edge 1>

Next, the flat blade-shaped cutting edge 1 was evaluated in accordance with the following procedure.

First, prepare the material to be cut.

Here, as described above, the flat-blade cutting edge 1 is mainly a cutting edge for a green sheet, but as a cut object, in order to perform an acceleration test, a metal powder and an oil clay are prepared to be mixed. This is because the difference between the properties of the products (the mechanical strength such as shear resistance) of the green sheets of the product is large, and it is difficult to select a green sheet having representative characteristics, and it is also easy to evaluate.

Further, as the material corresponding to the ceramic powder in the metal powder system and the green sheet, the oil clay is a material corresponding to the binder in the green sheet.

The specific method of manufacturing the cut object and the steps of the cutting test are as follows.

First, for the oil-making clay POPPY of the Central Electromagnetic Industry Co., Ltd., the W powder having a Fsss particle size of 1 μm was formed to have a weight ratio of 100:20, and mixed into a uniform by a mortar.

Next, the mixture was molded to a thickness of 1 mm at a pressing pressure of 10 kg/cm ² to serve as a cut object.

Then, as shown in Fig. 1, the flat blade-shaped cutting edge 1 was placed in a cutting device, and the cutting speed of the cutting blade was set to 10 mm/s, and the object to be cut was continuously cut. Here, in the case of continuous cutting, in order to prevent the cut object from being cut twice at the same horizontal position, it is possible to move in the horizontal direction every time the flat blade-shaped cutting edge 1 rises. Further, the dimension of the object to be cut in the width direction was set to 1 mm. A diagram is shown in Fig. 8.

Further, in order to completely cut the object to be cut, in the lower portion of the object to be cut, a hardness lower than that of the object to be cut is required, and the filter paper grade No. 1 of Toyo Filter Paper Co., Ltd. is laid.

The first table shows the state of the blade tip before cutting and 1000 times of the cutting.

In the first table, the shortest distance between the intersection of the two straight lines 13a and 13b of the left blade surface 9a and the right blade surface 9b and the blade tip end 11 is described as "X (μm)".

As a confirmation of the evaluation, the presence or absence of the chip at the tip of the blade, the degree of wear of the blade tip, the state of the cut surface of the object to be cut, and the presence or absence of the oblique cut were evaluated.

Specifically, the presence or absence of the chip is obtained by magnifying the entire surface in the longitudinal direction of the blade, and the crack is not observed, or the crack having a thickness of less than 5 μm is judged as "○", and the crack having 5 μm and less than 10 μm is formed. The situation is judged as "△". The case of having a crack of 10 μm or more was judged as "x". The observation system was observed at a magnification of 200 times in an Olympus microscope STM6-LM.

In addition, the degree of wear of the blade edge is determined to be "○" when the distance of H1 in the second drawing of the microscope is shorter than 5 μm or less before starting the cutting, and the case where the shortening distance is more than 5 μm and not more than 10 μm is determined as "△". The case where the shortening distance exceeds 10 μm is judged as "x".

The state of the cut surface of the cut object was also observed under a microscope, and the flaw of the cut surface of the 1000th time was judged as "○" when the flaw having a width of less than 5 μm was observed, and 5 μm or more and less than 10 μm were observed. In the case of the flaw, it was judged as "△", and the case where the flaw of 10 μm or more was observed was judged as "x".

In addition, the evaluation of the presence or absence of the oblique cutting was performed by observing the cut surface of the cut product having a thickness of 1 mm and a cutting width of 2 mm by an optical microscope, and confirming whether or not the cut surface was cut vertically. The angle of the cut surface of the cut object is judged as "◎" in the case of 89 to 90 degrees, and "○" in the case of less than 89 degrees and 88 degrees or more, and is less than 88 degrees and 87 degrees or more. The case is judged as "△", and the case where the degree is less than 87 degrees is judged as "x".

[Table 1]

From the first table, the sample having the shortest distance X of 1 to 10 μm and the absolute value of Y1 to Y2 of 1 μm or more and 20 μm or less (test piece No. 1st to 8th, 25th to 52nd embodiments) The presence or absence of the chip tip, the degree of wear of the blade tip, the state of the cut surface of the cut object, and the oblique cut are all evaluated as "△", "○" or "◎".

On the other hand, in the test piece in which the shortest distance X is outside this range (test piece No. 1 to 2, and the sixth to ninth to ninth comparative examples), the presence or absence of chips at the edge of the blade, the degree of wear of the blade tip, and the object to be cut are Any (or all) of the state of the cut surface is evaluated as "x".

In addition, the oblique cutting has a tendency to increase the blade tip angle, and the oblique cutting is larger, and particularly the first comparative example in which the blade edge angle is 4 degrees with respect to the left and right symmetrical blades (first, sixth, and eighth comparative examples). The state in which the oblique cutting is performed is "○", but the sixth comparative example in which the cutting edge angle is 30 degrees is "△", and the state in which the cutting edge angle is 60 degrees is the sixth comparative example. ×", apparently becomes a diagonal cut.

On the other hand, in the third comparative example in which the blade tip angle is 3 degrees, the presence or absence of the chip edge, the degree of wear of the blade tip, and the state of the cut surface of the object to be cut are all "x". Further, in the tenth comparative example in which the blade tip angle is 65 degrees, the degree of wear of the blade tip, the state of the cut surface of the cut object, and the oblique cutting state are "x".

(Second embodiment)

In the second embodiment, as a process for forming the tip end 11, a blade tip 11 is formed by a method of forming a tip end 11 using a solid material, and a cutting test is performed. The specific steps are as follows.

First, the same material as in the first embodiment is prepared, and the cross-section in the thickness direction is symmetrical with respect to the conventional method using the grindstone to form the left blade faces 9a and 13a and the right blade faces 9b and 13b.

Then, on one side, a TiN film having a thickness of 2 μm was formed from the tip end of the blade tip to a position of about 1 mm by sputtering under the same conditions as in the first embodiment.

Then, as a solid material used for the processing of the cutting edge, the oil-making clay POPPY of the Central Electromagnetic Industry Co., Ltd. is prepared, and the F3 grade titanium oxide powder produced by Showa Denko Co., Ltd. is made to have a weight ratio of 100:50, and Grind it into a uniform. The mixture was shaped to a thickness of 1 mm at a pressing pressure of 10 kg/cm ² .

Here, the specific surface area BET (Brunauer, Emmet and Teller) value of titanium oxide is 36 m ² /g, which is observed by a scanning electron microscope using a Hitachi HighTechonologies field emission type scanning electron microscope S-420, and the primary particle system is less than 0.1 μm. .

As the object to be cut, as shown in Fig. 1, the flat blade-shaped cutting edge 1 was placed in a cutting device, and the cutting speed of the cutting blade was set to 5 mm/s, and the cutting was continuously performed. Here, in the case of continuous cutting, in order to prevent the object to be cut from being cut twice at the same horizontal position, it is possible to move in the horizontal direction every time the flat blade-shaped cutting edge 1 rises (refer to Fig. 8). The number of cuts was adjusted, and the tip end tip 11 was adjusted to have the shape shown in Table 2.

Here, the connecting portion 15 of Fig. 4 is a curve.

Then, the same material as that of the first embodiment was cut in the same manner as in the first embodiment, and the presence or absence of chips at the tip, the degree of wear of the blade tip, and the object to be cut were confirmed in the same manner as in the first embodiment. The state of the cut surface and the presence or absence of oblique cutting.

The results are shown in the second table.

[Table 2]

It is known from the second table that the shortest distance X is 1 to 10 μm, the absolute value of Y1 to Y2 is 1 μm or more, and the test piece of 20 μm or less (test piece No. 9 to 24) is a blade tip chip. The presence or absence, the degree of wear of the blade tip, the state of the cut surface of the cut object, and the oblique cut were all evaluated as "○" or more, and the same results as in the first example were obtained.

(Third embodiment)

The flat blade-shaped cutting edge 1 which is the same as the test pieces No. 1 to 8 of the first embodiment was produced, and the size of the object to be cut in the width direction was set to 0.5 mm, and the cutting test was performed.

The result is shown in the third table.

As is apparent from the third table, even in the case of the same blade as in the first embodiment, the evaluation of the oblique cut is small in size, and tends to be slightly deteriorated. Based on this result, it was found that the small-sized product is more prone to oblique cutting.

[Industrial Applicability]

The present invention has been described above based on the embodiments and examples, but the present invention is not limited to the above embodiments.

It is a matter of course that various modifications or improvements can be made without departing from the scope of the invention.

7‧‧‧Edge Tip

9a‧‧‧left face

9b‧‧‧Right face

11‧‧‧ Tip tip

13a‧‧‧ Straight line

13b‧‧‧ Straight line

15‧‧‧Connecting Department

17‧‧‧ tip

21‧‧‧ center line

Y1‧‧‧ distance

Y2‧‧‧ distance

X‧‧‧ shortest distance

Θ‧‧‧ inside corner

Claims (6)

A flat blade-shaped cutting edge comprising: a flat base; the left and right blade faces are inclined from each other on both sides of the base; and the tip end is formed by connecting the left and right blade faces and has a convex shape a curved surface; the cross-sectional shape in the thickness direction; the shortest distance between the intersection of the two straight lines along the left and right blade faces and the tip end of the blade tip is 1 μm or more and 10 μm or less; and the length of the tip end portion is opposite to the The center line of the base portion is different from left to right, and the difference is 1 μm or more and 20 μm or less. Further, the internal angle of the intersection angle of the two straight lines along the left and right blade faces is 4 degrees or more and 60 degrees or less. The flat blade-shaped cutting edge according to claim 1, wherein the length of the tip end is different from the center line of the base in the left and right blade faces, and the difference is 2 μm or more and 10 μm or less. A flat blade-shaped cutting edge according to claim 1 or 2, wherein at least the cross-sectional shape of the connection portion between the left and right blade faces and the tip end is curved. The flat blade-shaped cutting edge according to any one of claims 1 to 3, wherein a shortest distance between the intersection of the two straight lines along the left and right blade faces and the tip end of the blade tip is 1.5 μm or more and 5 μm or less. The flat blade-shaped cutting edge according to any one of claims 1 to 4, wherein the inner angle of the intersection angle of the two straight lines along the left and right blade faces is 10 degrees or more and 30 degrees or less. A green sheet cutting edge characterized by having a flat blade-shaped cutting edge according to any one of claims 1 to 5.