JP6087363B2 - Green sheet cutting blade - Google Patents

Description

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

  As a method of manufacturing multilayer ceramic capacitors, multilayer varistors, multilayer coils, multilayer piezoelectric actuators, etc., a laminate of paste-like sheets containing a mixture of dielectric ceramic powder and binder (called a green sheet) is made into individual product shapes. After cutting, there is a method of firing and attaching electrodes to both ends.

  Here, in recent years, there is an increasing demand for capacitors to be reduced in size in order to be compatible with small machines such as smartphones, and therefore, high shape accuracy is required. In order to realize such a small-sized ceramic capacitor, it is necessary to pay attention to forming a cut surface as vertical as possible and not damaging the cut surface when cutting the green sheet. .

  As a cutting method of the green sheet, there are a method of cutting with a rotating round blade called a dicing method and a guillotine method of cutting with a flat blade-like cutting blade.

  Although the cutting accuracy of the dicing method is higher than that of the guillotine method, the material yield is worse than the guillotine method due to the generation of cutting waste, and the cutting speed is also inferior, so the size of the green sheet after cutting becomes smaller. The guillotine method is useful.

  Here, the flat blade-shaped cutting blade has a shape having a cutting execution portion that contributes to cutting, that is, a blade tip portion and a base portion (also referred to as a shank) having parallel surfaces to fix the cutting blade to the cutting device.

  Flat-blade cutting blades are sharp (low shear resistance during cutting), wear resistant, weld resistant to the workpiece, strong against buckling, and long life ("Life" as used herein refers to the point in time when the cross-sectional shape of the workpiece is damaged by chipping, and in the case of a multilayer capacitor cutting blade, peeling of the multilayer film occurs. And cutting blade life).

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

  On the other hand, regarding the shear resistance, the shape of the cutting edge is particularly important. Considering damage to the workpiece, it is preferable that the blade has a thin blade and has a small tip angle. However, the strength becomes inevitable as the blade becomes thinner. Therefore, the cutting blade currently used is devised such as increasing the cutting edge angle of the cutting edge by providing one or more angles between the cutting edge and the base.

  For example, Patent Document 2 discloses a structure in which the cutting edge portion is formed with a plurality of concave curved surfaces, thereby reducing the shear resistance and increasing the buckling strength (Patent Document 2).

Japanese Utility Model Publication No. 63-197089 JP-A-10-217181

  However, even when the blade edge as in Patent Document 2 is used, it is difficult to ensure the strength of the edge of the blade edge.

  In addition, for example, hard materials such as cemented carbide other than stainless steel are used for the flat blade-shaped cutting blade. Especially, when the material is a hard material, it is hard to cut but has low toughness. Easy to chip. Further, when the blade thickness is thin, even if it is a hard material, a shape excellent in workability is required because the blade tends to escape by pressing of a grindstone during processing, especially at the tip of the blade tip. However, in the structures of Patent Documents 1 and 2, accurate processing is not easy, and there is a problem in terms of practicality.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a cutting blade that satisfies both stable shape accuracy and cutting performance.

  In order to solve the above-described problems, the present inventor has examined whether it is possible to achieve both the securing of the strength of the blade tip and the reduction of the shear resistance during cutting.

  As a result, it has been found that by devising the shape of the tip of the blade tip, the shear resistance at the time of cutting can be reduced without reducing the strength of the tip of the blade tip, leading to the present invention.

That is, one aspect of the present invention is a WC-Co-based cemented carbide alloy, a flat base portion, and a cutting edge portion formed at the end portion of the base portion (a coating layer on the cutting edge portion). The cutting edge portion is formed so as to connect the left and right blade surfaces inclined so as to approach each other from the left and right surfaces of the base portion , and has a convex curved surface. The blade tip portion has no chipping of 10 μm or more in the spanning direction, and the cross-sectional shape in the plate thickness direction of the blade tip portion is the intersection of two straight lines along the left and right blade surfaces and the blade tip It is a green sheet cutting blade having a flat blade-shaped cutting blade whose shortest distance at the tip is 1 μm or more and 10 μm or less.

  According to the present invention, it is possible to provide a cutting blade that satisfies both stable shape accuracy and cutting performance.

It is a side view which shows the outline of the shape of the flat blade-shaped cutting blade 1. FIG. 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 blade 1. FIG. 4 is an enlarged view of the vicinity of a connecting portion 15 in FIG. 3. FIG. 3 is a schematic diagram showing a method for processing the tip of the flat blade-shaped cutting blade 1. FIG. 3 is a schematic diagram showing a method for processing the tip of the flat blade-shaped cutting blade 1.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments suitable for the invention will be described in detail with reference to the drawings.

  First, the shape of the flat cutting blade 1 according to the embodiment of the present invention will be described with reference to FIGS.

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

  As shown in FIGS. 1 and 2, the flat blade-shaped cutting blade 1 is provided on a flat plate-like base portion 5 having a rectangular planar shape and one long side (one end portion) of the base portion 5. It has a flat blade-shaped cutting edge portion 7 which is a cutting execution portion for cutting.

  The base 5 has a fixed portion 5a having a straight linear portion parallel to the fixing portion 3 of the cutting device, and a connecting portion 5b for connecting the fixed portion 5a and the blade edge portion 7 as shown in the figure.

  1 and 2, the length of the long side of the flat blade-shaped cutting blade 1 is L, the length of the short side is H, the height of the blade edge portion 7 is H1, and the thickness of the flat blade-shaped cutting blade 1 is shown. Is described as T.

  Further, as shown in FIG. 3, the blade edge portion 7 includes a left blade surface 9a, a right blade surface 9b, and a left blade surface 9b that are inclined so as to approach each other (in the plate thickness direction) from the left and right surfaces (both flat surfaces) of the base 5. It has a blade tip 11 formed so as to connect the blade surface 9a and the right blade surface 9b.

  Here, as shown in FIG. 3, the cross-sectional shape of the blade edge portion 7 in the plate thickness direction is such that the intersection of the two straight lines 13a and 13b along the left blade surface 9a and the right blade surface 9b and the shortest of the blade edge tip 11 are shown. It is desirable that the distance X is 1 μm or more and 10 μm or less.

  When the above value is less than 1 μm, the cutting edge tends to be chipped. On the other hand, when it exceeds 10 μm, a large cutting resistance is generated when the cutting edge enters the workpiece 100. Furthermore, it tends to have a short life due to wear. More preferably, it is 1.5 μm or more and 5 μm or less.

Further, as shown in FIG. 3, flat blade-shaped cutting blade 1 has previously rounded edge destination end 1 1. In other words, the cutting edge destination end 1 1 has a convex curved surface. Here, the convex curved surface means a curved shape that swells outward. Thus, by a structure having a rounded cutting edge destination end 1 1, it is possible to achieve both strength and low cutting resistance of the cutting edge. Moreover, as shown in FIG. 4, if the cross-sectional shape in the plate thickness direction of the connection part 15 of the left blade surface 9a, the right blade surface 9b, and the blade edge | tip tip 11 has a curve, it will become low cutting resistance, but it consists of two straight lines. It may be in shape.

Further, the left blade surface 9a and the right blade surface 9b are bilaterally symmetric. Specifically, as shown in FIG. 3, the tip angle of the blade edge portion is two along the left blade surface 9a and the right blade surface 9b. When the angles α ₁ and α ₂ between the straight lines 13a and 13b and the center line 21 in the plate thickness direction (straight line passing through the center in the plate thickness direction and parallel to the short side direction) are measured, the angle difference is ± 0 It is desirable to be within 3 degrees.

  This is because when the shape is asymmetrical, the direction must be taken into account when cutting, which affects workability.

Furthermore, it is desirable that the internal angle θ (that is, α ₁ + α ₂ ) of the intersection angle between the two straight lines 13a and 13b along the left blade surface 9a and the right blade surface 9b is 4 degrees or more and 60 degrees or less.

  This is because when θ is less than 4 degrees, the cutting resistance is reduced, but chipping of the cutting edge is liable to occur, and the cut surface is adversely affected or the life is deteriorated.

  When θ exceeds 60 degrees, a large load is generated when the cutting edge enters the workpiece 100, and the buckling resistance and the wear resistance are inferior. Further, in such a case, the amount of plastic deformation of the workpiece 100 is increased, the surface of the workpiece 100 is likely to be scratched, and the cut surface is more likely to be inclined rather than vertical, This is because the cutting resistance increases.

  In addition, it is more desirable that the angle θ is 10 degrees or more and 30 degrees or less from the viewpoint of ensuring the strength of the blade edge and low cutting resistance.

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

  In addition, although the material which comprises the flat blade-shaped cutting blade 1 is suitably selected according to a to-be-cut object, as a specific material, carbon tool steel, a WC-Co type cemented carbide, etc. are mentioned, for example. Is mentioned.

  Next, the processing method of the blade edge | tip part 7 of the flat blade-shaped cutting blade 1 is demonstrated.

  Although the processing method of the blade edge | tip part 7 of the flat blade-shaped cutting blade 1 will not be specifically limited if the above-mentioned cutting edge shape processing is possible, The following methods can be illustrated.

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

  This linear processing is performed by, for example, polishing with a grindstone.

  Next, the process for forming the blade edge | tip tip 11 in the blade edge | tip part 7 is performed.

  As described above, the shape of the tip 11 of the cutting edge has a curved shape, so that the cutting edge is too thin in the press working with a grindstone as in the case of forming the left blade surface 9a and the right blade surface 9b. The cutting edge easily escapes from the grindstone during processing, and stable processing is not easy.

  Therefore, the cutting edge tip 11 is processed by (1) a method of forming the cutting edge tip 11 in a solution containing abrasive grains (hard material), or (2) abrasive grains or other hard materials, that is, metal powder or ceramic powder. There is a method of forming the blade tip 11 using a mixed solid material.

  Hereinafter, a specific processing method will be described.

  First, as shown in FIG. 5, the method (1) is a method in which a suitable container 203 is filled with a solution 201 having a hard material as abrasive grains, and the edge of the flat blade-shaped cutting blade 1 is put into the solution 201. In this method, only the portion 7 is immersed and reciprocated in the blade spanning direction for a predetermined time to perform processing by bringing the hard material in the solution 201 into contact with the blade edge portion 7 to form the blade tip 11.

  Here, as a specific example of the hard material, high hardness diamond grains are preferable because a short processing time is required, but other metal powders and ceramic powders may be used.

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

  Next, the method of (2) is, as shown in FIG. 6, by cutting the solid material 205 mixed with the hard material powder with the flat blade-shaped cutting blade 1, the hard material in the solid material 205 and the cutting edge portion. 7 is a method of forming a cutting edge tip 11 on the cutting edge portion 7 by performing processing by bringing the cutting edge 7 into contact.

  Here, as the solid material 205, for example, a clay-like material may be mentioned.

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

  As for the powder particle size of these hard materials, the average particle size of secondary particles is preferably 1 μm or less in terms of Fsss (Fisher Sub-Sieve Sizer) particle size. This is because if it exceeds 1 μm, chipping may occur in the processing of the blade edge surface. Further, the finer the particle, the better the shape accuracy of the flat blade-shaped cutting blade. However, it takes time to process, so in this range, it is initially processed with particles of a size close to 1 μm, and the finish is smaller than 1 μm. It is more preferable to process with hard material particles of a size. A uniform cutting edge is possible because the particles are uniformly dispersed.

  The above is description of the example of a processing method of the blade edge | tip part 7 of the flat blade-shaped cutting blade 1. FIG.

  Thus, according to the present embodiment, the blade edge portion 7 that is the cutting execution portion of the flat blade-shaped cutting blade 1 includes the left blade surface 9 a and the right blade surface 9 b that are inclined so as to approach each other from the left and right surfaces of the base 5. The blade edge tip 11 is formed so as to connect the left blade surface 9a and the right blade surface 9b, the intersection of the two straight lines 13a and 13b along the left blade surface 9a and the right blade surface 9b, and the blade edge tip 11 The shortest distance is 1 μm or more and 10 μm or less.

  Therefore, the flat blade-shaped cutting blade 1 can satisfy both stable shape accuracy and cutting performance.

  Hereinafter, based on an Example, this invention is demonstrated in detail.

Example 1
A cutting test using the flat blade-shaped cutting blade 1 manufactured by the method of forming the blade tip 11 in a solution having abrasive grains is performed, and the effect of the shape of the blade tip 11 on the chipping property, wear resistance and cutting surface is examined. evaluated. The specific procedure is as follows.

<Processing of flat cutting blade 1>
First, the length L in the blade direction is 100 mm, the length H in the short side direction is 20 mm, the thickness T is 0.1 mm (see FIGS. 1 and 2), and the material is a flat plate made of cemented carbide FM10K manufactured by Allied Material Co., Ltd. A plate material is prepared, and with the existing technique using a grindstone, polishing is performed on one of the long sides so as to be bilaterally symmetric with respect to the cross section in the thickness direction. Blade surfaces 9b and 13b were formed. At this time, the blade surfaces 9a, 13a and 9b, 13b form an angle θ.

  Next, as shown in FIG. 5, the flat blade-shaped cutting blade 1 is immersed in the solution 201 having a hard material as abrasive grains, and only the blade edge portion 7 is slid back and forth in the spanning direction for a predetermined time, and the blade edge tip 11 is moved. Formed.

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

  Although not shown, the solution 201 (aqueous solution) is slid while stirring so as to have a uniform concentration so as not to affect the cutting edge processing, and the slide time is adjusted. A flat blade-shaped cutting blade 1 having a blade tip 11 shown in FIG.

<Evaluation of flat blade-shaped cutting blade 1>
Next, the flat blade-shaped cutting blade 1 was evaluated according to the following procedure.

  First, a material to be cut was prepared.

  Here, as described above, the flat blade-shaped cutting blade 1 is mainly a cutting blade for green sheets, but as an object to be cut, a mixture of metal powder and oil clay is prepared for an accelerated test. did. This is because the green sheets of the product have large differences in properties (mechanical strength such as shear resistance) for each product, and it is difficult to select a green sheet with typical characteristics as an object to be cut. It is also to do.

  The metal powder was a material corresponding to the ceramic powder in the green sheet, and the oil clay was regarded as a material corresponding to the binder in the green sheet.

  The specific manufacturing method of the object to be cut and the procedure of the cutting test are as follows.

  First, W powder having an Fsss particle size of 1 μm was mixed with the Chubu Denki Kogyo Co., Ltd. oil-grown clay poppy so as to be uniform in a mortar at a weight ratio of 100: 20.

Next, this mixture was molded to a thickness of 1 mm at a press pressure of 10 kg / cm ² to obtain a workpiece.

  Next, as shown in FIG. 1, the object to be cut was continuously cut by incorporating the flat blade-shaped cutting blade 1 into the cutting device and setting the lowering speed of the cutting blade to 10 mm / second. Here, when continuously cutting, the flat blade-shaped cutting blade 1 can be moved 5 mm in the horizontal direction every time the flat blade-shaped cutting blade 1 is lifted so that the workpiece is not cut twice at the same horizontal position. A schematic diagram is shown in FIG.

  In addition, in order to cut | disconnect a to-be-cut object completely, the lower thing of hardness than a to-be-cut object is required for the lower part of a to-be-cut object, and Toyo Filter Paper Co., Ltd. qualitative filter paper grade No. 1 was spread | laid.

  The shortest distance X before cutting (the intersection of the two straight lines 13a and 13b along the left blade surface 9a and the right blade surface 9b and the shortest distance between the blade tip 11) and the cutting edge after 1000 times of the above cutting The state is shown in Table 1.

  As confirmation of the evaluation, the presence or absence of chipping of the blade edge after cutting 1000 times, the degree of wear of the blade edge, and the state of the cut surface of the workpiece were confirmed.

  Specifically, the presence / absence of chipping is observed by enlarging the entire surface in the direction of the cutting edge, and when no chipping is observed, or when there is a chip of less than 5 μm, “◯”, and when there is a chip of 5 μm or more and less than 10 μm. “C” was judged as “x” when there was a chip of 10 μm or more. The observation was performed with an Olympus microscope STM6-LM at a magnification of 200 times.

  Further, the degree of wear of the blade edge is “◯” when the distance of H1 in FIG. 2 is shortened by 5 μm or less compared to before the start of cutting with the microscope, “△”, and when “5 μm is shortened by 10 μm or less” The case where it shortened exceeding 10 micrometers was judged as "x". The state of the cut surface of the cut product was also observed with a microscope, and regarding the scratch on the 1000th cut surface, a case where a scratch having a width of 5 μm or more was seen was judged as “X”, and the others were judged as “◯”.

  As is clear from Table 1, the samples having the shortest distance X of 1 to 10 μm (Examples 1 to 16) are all “△” in the presence or absence of chipping of the blade edge, the degree of wear of the blade edge, and the state of the cut surface of the workpiece. Or it was evaluation of "(circle)".

  On the other hand, samples (Comparative Examples 1 to 4) in which at least one of the shortest distance X1 to 10 μm and the blade edge angle 4 to 60 degrees is out of this range are the presence or absence of chipping of the blade edge, the wear degree of the blade edge, and the cut surface of the workpiece. Any (or all) of the states of was rated as “x”.

  Further, in the samples of Comparative Examples 3 and 4, although the state of the cut surface of the cut object was good, the cut angle of the object to be cut was less than 87 degrees and was not cut vertically (this is “oblique” in Table 1). Described). This occurs because X is out of the above range and the blade edge angle is large (60 degrees or more), so that the cutting blade is forced to spread when entering the workpiece. It was considered. In addition, as a result of observing the cross section of the cutting blade before the evaluation of the example and the comparative example, the angle difference with respect to the center line of the left and right blade surfaces is within ± 0.3 degrees, and the connecting portion 15 in FIG. 4 has a curve. It was.

(Example 2)
In Example 2, as a process for forming the blade tip 11, the blade tip 11 was formed using a method of forming the blade tip 11 using a solid material, and a cutting test was performed. The specific procedure is as follows.

  First, the same plate material as in Example 1 is polished by a conventional technique using a grindstone so as to be bilaterally symmetric with respect to the cross section in the thickness direction, and the left blade surfaces 9a, 13a and right formed by straight lines are polished. Blade surfaces 9b and 13b were formed. At this time, the left blade surfaces 9a and 13a and the right blade surfaces 9b and 13b form an angle θ.

Next, as a solid material used for cutting edge processing, Chubu Denki Kogyo Co., Ltd. oil clay poppy, F3 grade titanium oxide powder made by Showa Denko Co., Ltd. in a mortar with a weight ratio of 100: 50 What was mixed so that it might become uniform was prepared. This mixture was molded to a thickness of 1 mm at a press 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, and scanning electron microscope at 20,000 times using Hitachi High-Technologies Field Emission Scanning Electron Microscope S-420. In observation, the primary particles were less than 0.1 μm.

  With this solid material to be cut, a flat blade-shaped cutting blade 1 was incorporated into a cutting apparatus as shown in FIG. 1, and the cutting blade was continuously cut at a descending speed of 5 mm / second. Here, when cutting continuously, each time the flat blade-shaped cutting blade 1 is raised, the workpiece can be moved in the horizontal direction so that the workpiece is not cut twice at the same horizontal position (see FIG. 6). . The cutting edge number 11 was adjusted to adjust the blade tip 11 to the shape shown in Table 2.

  Next, with the obtained flat blade-shaped cutting blade 1, the same material as in Example 1 was cut, and as in Example 1, the presence or absence of chipping of the blade edge, the degree of wear of the blade edge, the cutting surface of the workpiece to be cut The state was confirmed.

The results are shown in Table 2.

  As is clear from Table 2, the samples having the shortest distance X of 1 to 10 μm (Examples 17 to 24) are all “△” in the presence or absence of chipping of the blade edge, the degree of wear of the blade edge, and the state of the cut surface of the workpiece. Or it was evaluation of "(circle)" and the result similar to Example 1 was obtained. In addition, as a result of observing the cross section of the cutting blade before the evaluation of the example and the comparative example, the angle difference with respect to the center line of the left and right blade surfaces is within ± 0.3 degrees, and the connecting portion 15 in FIG. 4 has a curve. It was.

  As mentioned above, although this invention was demonstrated based on embodiment and an Example, this invention is not limited to above-described embodiment.

  It is natural for those skilled in the art to come up with various modifications and improvements within the scope of the present invention, and it is understood that these also belong to the scope of the present invention.

1: Flat blade-shaped cutting blade 3: Cutting device fixing portion 5: Base portion 5a: Fixed portion 5b: Connection portion 7: Blade edge portion 9a: Left blade surface 9b: Right blade surface 11: Cutting edge tip 15: Connection portion 21: Center line 100: object to be cut 201: solution 203: container 205: solid X: the shortest distance alpha _1: angle alpha _2: angle theta: internal angle

Claims (4)

Consists of WC-Co based cemented carbide,
A flat base, and
A blade edge portion (excluding those having a coating layer on the blade edge portion) which is a cutting execution portion formed at an end portion of the base portion, and
The cutting edge portion is
Left and right blade surfaces inclined so as to approach each other from both left and right sides of the base,
A cutting edge tip formed to tie the left and right blade surfaces and having a convex curved surface;
There is no chip of 10 μm or more in the blade span direction in the blade edge part,
The cross-sectional shape in the plate thickness direction of the blade edge portion is such that the shortest distance between the intersection of two straight lines along the left and right blade surfaces and the tip of the blade edge is 1 μm or more and 10 μm or less .
A green sheet cutting blade having a flat cutting blade. The shortest distance between the intersection of two straight lines along the left and right blade surfaces and the tip of the blade edge is 1.5 μm or more and 5 μm or less .
A green sheet cutting blade having the flat blade-shaped cutting blade according to claim 1 . The internal angle of the intersection angle of the two straight lines along the left and right blade surfaces is 4 degrees or more and 60 degrees or less .
The green sheet cutting blade which has the flat blade-shaped cutting blade of Claim 1 or 2 . The internal angle of the intersection angle of two straight lines along the left and right blade surfaces is 10 degrees or more and 30 degrees or less .
The green sheet cutting blade which has the flat blade-shaped cutting blade as described in any one of Claims 1-3 .

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