JPH03149075A - Knife and manufacture thereof - Google Patents

Abstract

PURPOSE:To impart a wide range of cutting edge having both hardness and good appearance to the knife body by applying the constitution wherein a narrow plate- shaped core material and an outer material of high hardness covering the core material form the same plane or curved surface at both ends of the cutter body, and a cutting edge comprises the aforesaid outer layer material. CONSTITUTION:A knife is constituted with a core material 4 and an outer layer material 5 forming a cutting edge 2, and an edged point 3 having the cutting edge 2 so formed is provided. As a method for manufacturing the knife, a Japanese sword is severed into a plurality of small pieces 9 and the knife is formed via a polishing process, using all the pieces 9 as material. The core material 4 is made of relatively soft metal. For example, mild steel of 56 degrees or less Rockwell hardness C scale after hardened, or the like corresponds to the core material 4. The outer layer material 5 covering the core material 4 is made of material having relatively high hardness. For example, high carbon steel subjected to heat treatment of 56 degrees or more to Rockwell hardness C scale, a sintered alloy, and fine ceramics as nonmetal correspond to the outer layer material 5. According to the aforesaid construction, it is possible to expect the knife to have characteristics pertaining to a Japanese sword such as freedom from a fracture or bending for a cutter body of high hardness and sharp edge.

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to a small sword used as stationery or a tool.Furthermore, the present invention relates to a small sword used as stationery or a tool.Furthermore, the Japanese sword, which has been traditionally used as an art craft, has new uses and applications as a material for daily necessities. This is related to the addition of a method.

(Prior Art) Conventionally, Japanese-style razors, cut-out knives, and the like have been made using a forging method to have a two-layer structure as shown in FIG.

In other words, a manufacturing method in which the outer layer material 5 made of mild steel forms most of the external shape of the blade body 1, and the core material 4 is enclosed in the outer layer material and a part of it protrudes outside to form the blade edge. It is.

In contrast, Japanese swords use mild steel for the core material 4 called shingane, and hard steel for the outer layer material 5 called kawagane, as shown in Figure 10. The edge of the blade is made of gold.

Actual Japanese swords are often made from M iron sand using craft techniques, so there are differences in the material for each Japanese sword, but the core metal has a carbon concentration of about 0.4% and is compatible with general structural mild steel. Conventional measurements have shown that the alloy has a carbon concentration of about 0.7% and corresponds to high carbon hard steel.

-Therefore, the materials will be simply referred to as mild steel and hard steel.

As shown in Fig. 11, conventionally, as a method of shortening the length of a Japanese sword, a new part 6 (hereinafter referred to as the stem) that is inserted into the handle is added to the rear of the blade 11. There was a processing method that involved cutting and polishing (hereinafter referred to as polishing). The newly formed stem 6 is called a polished stem.

(Problem that the invention seeks to solve) These had the following problems.

(a) The area of the blade of a small sword made by cutting is small compared to the proportion of the entire blade, and the boundary with the soft iron is 10
is exposed along the blade edge 2.

Compared to Japanese swords, there is a pattern caused by hardening of the edge of the blade! (hereinafter referred to as habun) 8 had the problem of lacking in aesthetic appearance.

(b) Kozuka, small sword, and tosu as everyday items that have the same manufacturing method and structure as Japanese swords.
existed. Although it has a good appearance, it has the problem that the manufacturing process is more complicated and the price is higher than that of short swords.

(When making a small sword by maraging a c1 Japanese sword, the soft steel mandrel is exposed inside the fractured surface. 3), we used only the cut piece at the tip of the blade 11 that has the unpolished tip 3.The unpolished part including the stem 6 is discarded during processing, or It was only used as a substitute for a machete.In other words, even when the blade is broken or a part of it is damaged, only the part that includes the traditional tip 3 is used for reuse. It could not be played.

If the cutting edge 3 was reduced due to use and the mandrel was exposed, it could not be regenerated.

Furthermore, in Japan, it is sometimes difficult to re-register a Japanese sword that has been polished after being registered as an art sword due to artistic values. Even if only one part of the broken FJJ piece 9 was long enough, it was either discarded or used only as reference material.

The problem here was that the reuse of the blade 11 of the Japanese sword, which is not only excellent in engineering but also historically and artistically valuable, was extremely inefficient.

The present invention has been made to solve this problem.

(Means for solving the problem) (A) A small knife has a core material 4 and an outer layer material 5 that forms the edge 2 of tR.
Make the tR precepts even better. Furthermore, a cutting tip 3 whose blade edge 2 is made of an outer layer material 5 is provided.

(8) As a manufacturing method, the Japanese sword is divided into a plurality of small cut pieces 9, and all the small cut pieces 9 are polished to form the short sword of the present invention as described in (A). .

(Example) Examples of the present invention will be explained below.

FIGS. 1 and 2 show a knife having the structure described in claim 2 of the present invention.

The knife shown in FIG. 1 has a core material 4 exposed on both end surfaces of the blade 11, which is made up of a straight edge flcl and a stem 6, as is clear from the cross-sectional view of FIG. 2(A).

In the present invention, the core material 4 is made of a relatively soft metal material. For example, the practical quenching hardness is Rock Urchin T.
This includes mild steel with a hardness of 56 degrees or less on the IP-hardness C scale. The outer layer material 5 enclosing the core material 4 is made of a relatively hard material. For example, high carbon so-called, sintered alloys that have been heat treated to a temperature of 56 degrees or higher on the Rockwell hardness C scale,
Fine ceramics, which are non-metals, fall under this category.

In this embodiment, since the blades i & 2 belonging to the cutting edge 3 are composed only of the outer layer material 5 with high hardness, the core material 4 is cut with only one of both sides of the blade so that it does not touch the blade edge 2. Ahead 3
It has a blade body structure that forms a blade edge 2. The side of the cutting edge can be selected depending on the user's purpose and dominant arm. In FIG. 1, the most extreme point of the cutting edge 3 is centered in the direction of the blade edge 2 other than the cutting edge 3 from the central axis of the core material 4, so the present invention also satisfies Clause 3 of the scope of Article 1. There is.

FIG. 3 shows a knife having the structure described in claim 3 of the present invention. FIG. 4 shows its cross-sectional view.

In this embodiment, it is further clearly seen that the core material 4 is exposed on both end faces of the blade 11, which is composed of the blade l and the stem 6. In order to avoid forming the tip of the cutting edge 3 with the core material 4, which has a lower hardness than the outer layer material 5, a cut is made in the area between the outer edge of the core material 4 on the blade edge side and the blade edge 2 of the outer layer material 5. It forms the most advanced point of the previous three.

FIG. 5 shows a method for manufacturing a small knife according to claim 4 of the present invention.

Figure 5 (A) shows the Japanese sword used as the material. If the blade 11 is broken or a portion of the blade is severely damaged, its value as a work of art will be lost and its registration as an art sword will be cancelled. In the manufacturing method of the present invention, the purpose of adding new practical value to such a Japanese sword and effectively reusing most parts of the blade 11 is to use it for a new purpose as a material.

Figure 5 (B) shows a state in which a Japanese sword is divided into a plurality of small pieces 9 of the length necessary to process it into a small knife.If a rotating disc type diamond cutter is used in this process, the cutting heat will Hamon 8 never disappears.

FIG. 5(C) shows a state in which each cut piece 9 is formed into a knife by grinding. In this step, the rough outline is formed using a rotating disk type or cloth belt type grinder. Here, all the small cut pieces 9 other than the conventional small cut pieces including the cutting edge 3 before processing have the mild steel core material 4 exposed at the tip of the blade, so that the scope of claims M1 to 3 of the present invention is It is formed into the structure of the short sword described in the section. Mekugi holes 7 for fixing the blade body 1 to the external device 2 are drilled using a carbide drill or after annealing only the stem 6 portion to lower its hardness.

The external shape is polished using a small rotary whetstone or by hand (V-craft) using a file, whetstone, or sandpaper.

Application examples of the present invention are shown below.

Figures 6(A) and 6(B) show the outer device 2 for the knife of the present invention.
This is an example with . In this embodiment, the short sword of this vehicle has an exterior similar to a Japanese sword. Of course, the blade 11 may be used by gripping the stem 6 of the blade 11 without attaching the outer device 2 like a normal short sword.

FIG. 7 and FIG. 8 are examples of application of the knife according to claim 2 of the present invention.

Fig. 7 is the same as No. 1 tJ in that the blade edge 2 of the cutting tip 3 is made up of only the outer layer material 5 on either side, but in this configuration, the most extreme point of the cutting tip 3 is made of the core material 5. It is formed in the direction opposite to the conventional blade edge 2 from the central axis of the blade, and in the jump region from the outer edge of the core material 4 to the outer edge of the outer layer material 5.

FIG. 8 is a sectional view of this application example.

In this structure, which is made from a Japanese sword's small-cut fragment 9, the cutting edge 3 formed is near the tip (back side) of the blade 11, and the core material 4
Although the hardness is higher than that of the conventional blade edge 2, the hardness may be slightly lower than that of the conventional blade edge 2.

Therefore, as an application example of the method for manufacturing a short knife according to claim 4 of the present invention, only the most extreme point portion is subjected to induction hardening.

Further, although not shown, as another application example of the method for manufacturing a small knife of the present invention, the whole or a part of the material is annealed to reduce the hardness and then processed. It includes those formed in any of the four configurations described above.

In addition, the martensitic structure that makes up the blade pattern 8 is annealed by heat treatment before machining and cutting heat, resulting in a low hardness.
In the case where the blade pattern 8 disappears due to transformation into 1a, the blade body 1 is hardened again after being formed into a configuration that falls under any one of claims 1 to 3 of claim 1 of the present invention. The process of forming the blade pattern 8 is also an example of application of the manufacturing method of the present invention.

(Effect of the invention) The effects of the present invention are summarized below.

The invention! The length of the Kai's short sword is 8. For short swords that use hard steel for the outer layer material, hamons that combine hardness and beauty can be set on a wide range of blade bodies.

b- Since the knife can be formed by cutting the material of the knife consisting of the core material and the outer layer material to any length, it can be adapted to the user's needs. The manufacturing process is also simple.

The shape of the C-cutting tip can also be selected within the range described in the examples according to the intended use. Furthermore, the cutting edge of this configuration can be remade many times as long as the length of the blade continues. This is an effect that traditional Japanese swords and short swords did not have.

Next, regarding the method for manufacturing a short sword of the present invention, d. Most parts of the blade of a Japanese sword that is broken or scratched can be used without wasting it.

e. Multiple small swords can be formed from one blade.

f. It is possible to form an aesthetically pleasing small sword that makes use of the traditional blade patterns and unique patterns created by forging in the Japanese swords used as materials. This is not only a work of art or aesthetic excellence, but also has documentary value.

g. The manufacturing process is reduced compared to the case where the short sword is manufactured from the beginning. Mass production is possible.

b- The forged pattern on the cross section of the blade body and the shape of the mandrel, which did not appear on the blade body in conventional Japanese swords, are exposed on the cutting edge. This also has a beautiful appearance and material value.

Furthermore, the short sword of the present invention has a highly hard blade and can be expected to have properties unique to Japanese swords, such as not breaking or bending even though it is sharp.

Specifically, when an unreasonable impact force is applied to the blade edge during use and a fracture surface (crack) occurs on the blade edge, the fracture surface will be soft unless the impact is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a knife according to claim 2 of the present invention. FIG. 2 is a sectional view thereof. FIG. 3 is a knife according to claim 3 of the present invention. FIG. 4 is a sectional view thereof. FIG. 5 shows a method for manufacturing a small knife according to claim 4 of the present invention. Figures 6 and 7 show an embodiment of the pond. FIG. 8 is a sectional view of FIG. 7. Figures 9, 10, and 11 show conventional examples 21--Blade body 11-Blade 2--Blade edge 12--Exterior 3--Tip 4--Heart material 5-- Outer layer material row - Stem (Nakago) Fu - Ichimoku nail hole 8 - Hamon 9 - Small cut fragment 10 - Boundary by interruption (patent applicant Yuro Iba) tt) r'7 6 no, no. Figure 2 l Figure 3 δ′ F C2呵CA)
99 1P%18im no\ (to) / \1 (L-≠=Long O (convex) r

Claims (4)

[Claims] (1) In a blade consisting of a thin plate-shaped core made of a metal material and an outer layer made of a material that encloses the core and has a harder part than the core, the core and the outer layer are located at both ends of the blade. A short sword characterized by having the same plane or the same curved surface at the tip of the blade, and the entire edge of the blade is made of an outer layer of material. (2) The knife according to claim 1, wherein the edge of the tip of the blade is formed from only one of the outer surfaces on both sides of the blade body made of an outer layer material. (3) Claim 1, characterized in that the most extreme point of the blade is eccentric in the direction of the blade edge with respect to the center line of the included core material.
The short sword mentioned in the section. (4) A Japanese sword whose blade is made of core material and outer layer material is divided into a plurality of small pieces each having a fractured surface at both ends or one side, and each small piece is formed by polishing to form a small sword. A method for manufacturing a short sword according to claim 1, characterized in that: