JPH0649111B2 - Zirconia ceramic knife - Google Patents

Description

TECHNICAL FIELD The present invention relates to a knife, particularly a knife used for cooking.

[Prior art and its problems]

Many kitchen knives widely used in homes, restaurants, restaurants, etc. are made of steel. However, although such steel knives are relatively easy to manufacture and have the characteristics of being inexpensive, the initial good sharpness is deteriorated due to wear of the cutting edge due to use, and rust is likely to occur. The sharpness often deteriorates.

Therefore, it is necessary to sharpen the blade before use, and after use, it is necessary to wipe off water and prevent rust. Moreover, since the iron component of the kitchen knife is easily transferred to food, there is a drawback that a golden odor adheres and the taste of the dish cannot be fully enjoyed.

In order to avoid the inconvenience of such steel knives, many things made of stainless steel that is hard to rust have been used, but since the hardness is smaller than steel, the cutting edge is apt to be blunt and sharp It tended to get worse. Further, a knife made of alloy steel containing molybdenum, tungsten, etc., which is hard to rust and has high hardness, is also on the market, but the sharpness is not long-lasting for the price.

As described above, the conventional metal knives have problems that the cutting edge is worn for a short period of time to deteriorate the sharpness, rust is likely to occur, and "food scraps" are attached to the food.

Further, as shown in Japanese Patent Laid-Open No. 58-71095, there is a knife formed of zirconia ceramic, but there is a problem that the cutting edge is easily chipped.

[Means for Solving the Problems]

Therefore, in the present invention, in a knife made of zirconia ceramic, at least one side of a plate-shaped body having a wall thickness of 1 to 8 mm is provided with a two-step shaped cutting edge having a taper angle and a cutting edge angle of 10 to 45 ° continuous to this. The cutting edge is formed to have a thickness of 0.1 to 2 mm.

〔Example〕

 Examples of the present invention will be described below.

As shown in the side view of FIG. 1 and the sectional view of FIG. 2, the blade portion of the willow blade sashimi knife H has a partially stabilized zirconia (ZrO ₂ ) ceramic with a toughness of 130 kg / mm ² in bending strength. Due to (hereinafter simply referred to as zirconia), the wall thickness T is 2.5 m
It was formed as m and 210 mm in total length.

Further, by forming a two-step-shaped blade edge having a taper angle a and a blade edge angle b of 10 to 45 ° continuous to the blade portion, and setting the blade edge thickness c within the range of 0.1 to 2 mm, It is designed to prevent chipping of the cutting edge and to obtain excellent sharpness.

The shape of the cutting edge is shown in Figs. 2 (a) to (d).
As shown in, the taper angle a and the edge angle b can be formed on one side or both sides of the blade, respectively.

Here, with respect to the kitchen knives H having the shapes shown in FIGS. 2 (a) to 2 (d), various tests were carried out to measure the sharpness and the edge strength by changing the angle and the dimension in various ways.

As a device for performing a sharpness evaluation test, a knife H is held by an arm A as shown in FIG. 3, a weight E is mounted on the other end of the arm A, and a predetermined load is applied to the cutting edge of the knife H. Use the one that can be added. Then, the cutting edge of the knife H was pressed against the paper P to be cut, and the sharpness was evaluated by the number of cut pieces when the paper P was moved at a predetermined speed.

The conditions of this sharpness evaluation device were as follows.

Load: 2500g Paper moving speed: 4.5mm / sec Time: 40 seconds Paper used: 30 × 120 × 0.03mm (Product name: Ginmine) In addition, using the device shown in FIG. The weight of the holder was added to set to 2500 g, and the test was performed by dropping the blade edge of the knife H from the height of 300 mm onto the oak tree K (30 × 60 × 30 mm) placed below.

The experimental results for the knife-shaped knife H shown in FIGS. 2A to 2D are as shown in Tables 1 to 4, respectively.

In each table, the number in parentheses for sharpness evaluation is
It is the result of conducting the same sharpness evaluation test again after cooking fish (hamachi) for 200 people. In addition, the evaluation of the strength of the cutting edge was classified as follows according to the depth of the chip generated in the cutting edge after the experiment.

Depth of chip ○: 0.1 mm or less △: 0.1 to 0.5 mm ×: 0.5 mm or more Based on the above experimental results, the shape of each cutting edge shown in FIG. 2 was evaluated, and the results were as follows.

<Shape of Figure (a)> If the taper angle a is less than 7 °, it is very difficult to carry out cutting, and if the taper angle a is in the range of 7 to 11 °, the cutting edge angle b is 30.
A material with a blade edge thickness c of -10 ° and a blade edge thickness c of 0.1 to 2.0 mm has some problems in terms of strength, but is less susceptible to aging compared to metal knives and can be sufficiently used.

Furthermore, the optimum condition for this cutting edge shape is the taper angle a = 12 ~
14 °, the blade edge angle b = 10 to 30 °, and the blade edge thickness c = 0.1 to 1.0 mm.

The taper angle a = 14 to 15 °, the blade edge angle b = 10 to 30 °, and the blade edge thickness c = 2 mm or less cannot be used for sashimi and meat cutting, but for cutting fruits and vegetables. Can be used for

<Shape of Figure (b)> The taper angle a is 7 to 10 °, and the cutting edge angles b ₁ and b ₂ are 10 to 30 °,
When the blade edge thicknesses c ₁ and c ₂ are 0.1 to 0.2 mm, although the strength is somewhat problematic, the sharpness is better than that of a metal knife and it can be used sufficiently. If the taper angle a is less than 7 °, it is difficult to process as in the case of FIG.

Further, the range of forming the optimum shape is a taper angle a = 12 to 13 °, a blade edge angle b ₁ and b ₂ = 15 to 25 °, and a blade edge thickness c ₁ and c ₂ = 0.1 to 0.5 mm.

Further, the taper angle a = 13 to 15 °, the blade edge angles b ₁ and b ₂ = 10 to 30
The cutting edge thicknesses c ₁ and c ₂ = 0.1 to 2.0 mm are sufficient for cutting fruits and vegetables.

<Shape of (c) and (d)> Since it has a double-edged shape, it is not suitable for sashimi and meat cutting, but when evaluated under the same conditions, the overall sharpness was good. However, in terms of strength, the taper angles a ₁ , a ₂ =
1 to 14 ° is the range that can be used as a blade.

Further, in the zirconia knife of the present invention, the wall thickness T is 1
If it is less than 8 mm, the strength becomes unreasonable, and if it is more than 8 mm, it causes problems in sharpness and weight. Therefore, the wall thickness T is preferably in the range of 1 to 8 mm.

〔The invention's effect〕

As described above, according to the present invention, in a knife made of zirconia ceramic, a plate-shaped body having a wall thickness of 1 to 8 mm has a taper angle and a blade edge angle of 10 to 45 ° continuous to the taper angle. Stepped blade edge is formed, and the blade edge thickness is 0.1 to 2 m.
By using m, it is possible to provide a kitchen knife whose blade edge is less likely to be damaged and which has excellent long-lasting sharpness.

[Brief description of drawings]

FIG. 1 is a side view of a zirconia ceramic kitchen knife according to an embodiment of the present invention, and FIGS. 2 (a) to 2 (d) are views showing various embodiments of a cross section taken along line XX in FIG. FIG. 3 is a schematic view showing an apparatus for testing the sharpness of the kitchen knife of the present invention, and FIG. 4 is a schematic sectional view of the apparatus for testing the strength of the kitchen knife of the present invention. H: Kitchen knife T: Wall thickness a, a ₁ , a ₂ : Tapering angle b, b ₁ , b ₂ : Blade edge angle c, c ₁ , c ₂ : Blade edge thickness

Claims (1)

[Claims] 1. A zirconia ceramic having a wall thickness of 1
At least one side of a plate-shaped body of ~ 8 mm is formed with a two-step cutting edge having a taper angle and a cutting edge angle of 10-45 ° continuous to this, and the cutting edge thickness is 0.1-2 mm. A zirconia ceramic knife.