JP2006271959A - Ceramic knife - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress chipping of the blade tip of a ceramic knife without spoiling the original function and the usability of the kitchen knife. <P>SOLUTION: This ceramic knife comprises a handle section and a blade section made of the ceramic which is attached to the handle section. The blade section has a cutting blade ridge, a back surface ridge having a relationship as a back surface with the cutting blade ridge to each other, and an arc-like end ridge which is provided on the end part of the blade section, continues from the cutting blade ridge, and has a specified radius of curvature. At least one side surface of the blade section is composed of a large blade surface which tilts from the back surface ridge toward the cutting blade ridge, and a small blade surface which tilts from the large blade surface over the cutting blade ridge at a larger angle than the large blade surface. The small blade surface is formed at least at a position from the cutting blade ridge to the end of the arc of the ridge by passing through the arc-like end ridge. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ceramic blade such as a kitchen knife having a blade made of ceramics.

  In general, kitchen knives widely used are made of metal such as steel and stainless steel.

  Steel knives are generally easy to manufacture and inexpensive, but the sharpness of the cutting edge is reduced due to wear of the cutting edge during use, and rust is likely to occur, so that the sharpness is further improved. Often worse. Therefore, frequent sharpening is necessary. Moreover, after use, it is necessary to wipe off moisture and to give rust prevention. Furthermore, since the iron component of the kitchen knife is easily transferred to food, there is a drawback that the smell of gold adheres and the taste of the dish is impaired. In order to avoid the inconvenience of such steel knives, the ones made of stainless steel that is hard to rust are also cheap and often used, but because the hardness is lower than steel, the cutting edge is easy to dull and the sharpness is immediately It tends to deteriorate. In addition, knives made of special stainless alloy steel containing molybdenum, tungsten, etc., which are hard to rust and have high hardness, are also commercially available, but their sharpness is not good for the price.

  Thus, since the conventional metal knife has low hardness, the sharpness deteriorates quickly and frequent sharpening is required. In addition, there is a problem that it is easily rusted, food is gold-like, and it is weak against acids and alkalis and easily corrodes.

  In order to improve these problems of metal knives, ceramic knives represented by zirconia ceramics have been put into practical use (see Patent Documents 1 and 2).

  These conventional ceramic knives 11 include a handle portion 12 and a blade portion attached to the handle portion 12 as shown in a side view of FIG. 4A and a partially enlarged sectional view of the blade portion 13 of FIG. 13, and the blade portion 13 has a cutting edge ridge edge 14, a narrow back ridge edge 15 that is in a back relationship with the cutting edge ridge edge 14, and a cutting edge from the back ridge edge 15. A large blade portion 16 continuously inclined toward the ridge side 14 and an arcuate tip ridge side 17 having a predetermined radius of curvature at the tip are provided, and a large portion extends from the cutting edge ridge side 14 to the arcuate tip ridge side 17. It has the rough surface part 18 which roughened the blade edge surface.

In the case of a blade having a metal blade, there is a blade that has a sharp tip to maintain the sharpness even at the tip of the blade, but in the case of a ceramic knife, the blade is sharp. Since it is easy to generate a chip and a crack when the shape is the same, as shown in FIG. 4A, an arc shape is proposed.
JP 58-71095 A JP-A-62-275057

  However, by forming the tip of the blade in an arc shape, it is possible to suppress chipping and cracking at the tip of the blade, but since the ceramic blade has lower toughness than metal, the tip of the blade Regardless, the fact that there are many chippings at the blade edge portion still remained a problem. In a conventional ceramic blade, in order to improve the sharpness, only the large blade is formed to make the tip of the blade edge have an acute shape. Therefore, although the sharpness is excellent, there is a problem that a lot of chipping occurs at the blade edge portion.

  Also, some metal blades have an arc tip at the tip of the blade, but this is for safety reasons, and the tip is not attached to the tip of the blade. The original functions of knives such as decorative cutting and hidden knives could not be used.

  The present invention has been devised in view of the above-described problems, and an object of the present invention is to suppress the occurrence of chipping of the cutting edge of a ceramic knife without impairing the original function and usability of the knife.

  In view of the above, the present invention comprises a handle portion and a ceramic blade portion attached to the handle portion, the blade portion being in a relationship between the cutting edge and the cutting edge. It is a ceramic blade having a certain back ridge and an arcuate tip ridge that is provided at the tip of the blade and is continuous with the cutting edge and has a predetermined radius of curvature, and at least one side surface of the blade is A large blade surface inclined from the back ridge to the cutting edge ridge, and a small blade surface inclined from the large blade surface to the cutting edge by a larger angle than the large blade surface. The blade surface is a ceramic blade formed at least from the ridge edge of the cutting blade through the arcuate tip ridge edge to a position where the arc of the ridge edge ends.

  Furthermore, the small blade surface is provided in a range of 3.0 mm or less from the cutting edge ridge.

  Furthermore, the said large blade surface is provided with a rough surface part from the cutting-edge ridge edge to the circular-arc-shaped front-end ridge edge on the surface of the blade edge | tip part of this large blade surface, It is characterized by the above-mentioned.

  Furthermore, the angle of the large blade surface is 0.1 to 15 °, and the angle of the small blade surface is 20 to 55 °.

  Furthermore, the angle of the large blade surface is 1 to 5 °, and the angle of the small blade surface is 30 to 45 °.

  Furthermore, the large blade surface and the small blade surface are formed on both side surfaces of the blade portion.

  Further, the large blade surface is formed by a curved surface having a curvature radius (R) of 400 to 800 mm in a vertical cross section at a central portion in a cutting edge ridge side direction.

  Furthermore, the blade portion is made of zirconia ceramic.

  The ceramic blade of the present invention forms a small blade continuously from the edge of the cutting edge to the point where the curvature of the arcuate tip edge ends, and increases the angle of the blade edge portion by increasing the angle of the blade edge portion. Chipping can be greatly suppressed. In addition, a small blade angle that does not impair the sharpness is set, so that the original function and usability of the knife are not impaired, and chipping of the cutting edge of the ceramic blade can be suppressed.

  FIG. 1 is a side view showing a kitchen knife 1 which is an embodiment of the ceramic blade of the present invention.

  The ceramic knife 1 of the present invention comprises a handle portion 2 and a ceramic blade portion 3 attached to the handle portion 2, and a cutting edge ridge 4 and the cutting edge 4 on the blade 3. And the narrow back edge 5 that is in the back relation to each other, the large blade 6 that is continuously inclined from the back edge 5 to the cutting edge 4 and the cutting edge 4 at the tip. The cutting edge of the large blade 6 has a rough surface portion 8 whose surface is roughened from the cutting edge ridge edge 4 to the arcuate tip ridge edge 7, which is continuous and has an arcuate tip ridge edge 7 having a predetermined radius of curvature. Is. The rough surface portion 8 preferably has an arithmetic average surface roughness of 1 to 100 μm, so that the object can be cut without slipping.

  FIG. 2 (a) is a partially enlarged side view of the blade tip portion of the blade portion 3 of the ceramic knife of the present invention, and FIGS. 2 (b) and 2 (c) are sectional views thereof.

  Here, in the ceramic knife 1 of the present invention, the small blade 10 is formed continuously to the large blade 6 from at least the point 9 at which the curvature of the arcuate tip ridge side 7 ends from the cutting edge ridge 4. is important.

  Conventionally, there is no small blade 10 provided up to the arcuate tip ridge side 7, and the cutting edge of the arcuate tip ridge side 7 is provided by providing the small blade 10 continuous to the large blade 6 up to the arcuate tip ridge side 7. An angle becomes large and the chip | tip in the circular arc-shaped front-end | tip ridge side 7 can be suppressed significantly. Moreover, by setting the angle of the blade 10 that does not impair the sharpness, the original function and usability of the knife are not impaired. Also, since the arcuate tip edge 7, that is, the cutting edge of the knife edge can be used as a cutting blade, it is easy to use, and it is easy to realize where the ingredients are actually cut when cutting the ingredients at the tip of the knife, Fine work such as decorative cutting can be performed easily and reliably.

  The large blade 6 and the small blade 10 are preferably provided on both side surfaces, but may be provided only on one side surface.

  Moreover, although the large blade 6 may be formed in a plane, as shown in FIG. 2 (c), in order to have the strength of the blade body and prevent the cut food and the like from sticking to the blade, R400 to R800mm It is preferable to form with a curved surface.

  Furthermore, the small blade 10 may be provided at least from the cutting edge ridge 4 to the point 9 where the curvature of the arcuate tip ridge 7 ends, but may be formed beyond the point 9 where the curvature ends. .

  Furthermore, the angle of the large blade 6 is preferably set to 1 to 5 degrees.

  When this angle is smaller than 1 degree, the strength of the blade part 3 is remarkably lowered, and there is a possibility that chipping and breaking occur frequently. Moreover, when an angle is larger than 5 degree | times, the load at the time of cutting | disconnection of a foodstuff etc. becomes large, and sharpness deteriorates.

  The angle of the small blade 10 is preferably set to 20 to 45 degrees. When the angle of the small blade is smaller than 20 degrees, the strength of the blade edge is remarkably lowered, and the chip of the blade edge may frequently occur. On the other hand, when the angle is larger than 45 degrees, sharpness is remarkably deteriorated.

  Further, the small blade 10 is preferably provided on both side surfaces of the blade, but may be provided only on one side surface.

  In order to produce the ceramic knife 1 having such a small blade 10, first, an acrylic, wax-based or PEG-based binder is added to zirconia powder containing 1.5 to 3 mol% of yttria powder. Add 10 mass% to produce granules with an average particle size of 10-150 microns. Next, this granule is molded into a predetermined shape as shown in FIG. 3 at a molding pressure of 700 to 2000 kg / cm @ 2 with a mold, and then fired at 1300 to 1500 DEG C. to obtain a zirconia sintered body. Thereafter, the blade is attached by a known method. The method of attaching a small blade to the arcuate tip is to attach the blade by rotating around the tip when it comes to the tip while continuously forming the blade at the cutting edge as usual. To.

  As a molding method of the molded body, in addition to the above, a known molding method such as a casting method, a plastic molding method (for example, an injection molding method), a rubber press method, a hot press method, or the like may be used. The so-called HIP method in which the obtained zirconia sintered body is sintered at 1300 to 1500 ° C. and held at a pressure of 1500 to 2500 Kg / cm 2 for 2 to 5 hours can also be used.

  Next, examples of the present invention will be described.

  First, the angle of the large blade was set to 0.5 to 10 degrees, the angle of the small blade was set to 25 to 50 degrees, and a knife made of zirconia ceramic was produced by the above-described manufacturing method. The impact resistance test of the blade edge in the obtained kitchen knife was performed.

  As a comparative example, a similar test was performed on a conventional product in which a small blade was not formed.

  FIG. 3 shows the impact resistance test method. Set one of the 1.4m-long bars as the center of rotation, and set it at a height of 24cm so that it can move smoothly. Fix the kitchen knife to the other end, lift the kitchen knife to a height of 50 cm, gently release your hand and let it collide with natural fall. Place a porcelain dish in the collision area. By setting as described above, the center or tip of the blade body collides with the porcelain dish. The impact test was repeated 30 times, and the state of the blade edge after the test was determined as “◯: no change (occurrence of chipping smaller than 0.3 mm)”, “Δ: generation of chipping of 0.3 to 1.0 mm”, “× : Chipping larger than 1.0 mm ”.

  In addition, the sharpness of these knives was evaluated by a monitor. We asked 10 housewives to evaluate as a monitor. The results were evaluated according to “○: 9 or more people judged that sharpness was good”, “△: 5-8 people judged that sharpness was good”, “×: 4 or less people judged that sharpness was good”. .

  Table 1 shows the results of the impact test and the sharpness test. From the impact test results, it can be confirmed that the impact resistance decreases when the large blade angle is smaller than 1 degree or when the small blade angle is smaller than 30 degrees. In addition, from the sharpness test result, it can be confirmed that the sharpness deteriorates when the large blade angle is larger than 5 degrees or when the small blade angle is larger than 45 degrees.

From the above results, it can be seen that both impact resistance and sharpness can be obtained by setting the large blade angle to 1 to 5 degrees and the small blade angle to 30 to 45 degrees, respectively.

It is a side view which shows one Embodiment of the knife which is the ceramic blade of this invention. (A) is a partial expanded side view of the front-end | tip part of the ceramic knife in FIG. 1, (b), (c) is sectional drawing which shows the various examples of the blade part of the figure (a). It is a schematic explanatory drawing of the impact test in an Example. (A) is a side view of the conventional ceramic knife, (b) is the blade part sectional drawing.

Explanation of symbols

1. ・ Ceramic knife 2 ・ ・ Handle 3 ・ ・ Blade 4 ・ ・ Cutter edge 5 ・ ・ Rear edge 6 ・ ・ Large blade 7 ・ ・ Arc-shaped tip edge 8 ・ ・ Rough surface 9 · · End point of curvature 10 · · Small blade 11 · · Ceramic knife 12 · · Handle 13 · · Blade 14 · · Cutting edge 15 · · Back edge 16 · · Large blade 17 · · Arc tip Ridge 18 ... Rough surface of large blade

Claims (8)

The blade portion includes a handle portion and a ceramic blade portion attached to the handle portion, and the blade portion includes a cutting edge ridge, a back edge and a cutting edge corresponding to the back of the cutting edge. Is a ceramic blade having an arcuate tip ridge that is continuous with the cutting edge and has a predetermined radius of curvature, and at least one side surface of the blade is cut from the back edge. A large blade surface inclined toward the ridge, and a small blade surface inclined at an angle larger than the large blade surface from the large blade surface to the cutting blade ridge, and the small blade surface is at least the cutting blade ridge A ceramic blade characterized by being formed from a side to a position where an arc of the ridge side ends through an arcuate tip ridge side. The ceramic blade according to claim 1, wherein the small blade surface is provided in a range of 3.0 mm or less from the edge of the cutting blade. 3. The ceramic blade according to claim 1, wherein the large blade surface includes a rough surface portion extending from a cutting edge ridge side to an arcuate tip ridge side on a surface of a cutting edge portion of the large blade surface. The ceramic blade according to any one of claims 1 to 3, wherein the angle of the large blade surface is 0.1 to 15 °, and the angle of the small blade surface is 20 to 55 °. The ceramic blade according to claim 4, wherein the angle of the large blade surface is 1 to 5 °, and the angle of the small blade surface is 30 to 45 °. The ceramic blade according to any one of claims 1 to 5, wherein the large blade surface and the small blade surface are formed on both side surfaces of the blade portion. The said large blade surface is formed in the vertical cross section in the center part of a cutting-edge ridge side direction, and the curvature radius (R) is formed by the curved surface of 400-800 mm. The ceramic blade as described. The ceramic blade according to any one of claims 1 to 7, wherein the blade portion is made of zirconia ceramic.

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