Knives

Abstract

A cutting tool has a blade, the blade having a base portion and a blade tip portion arranged along the end of the base portion, wherein the base portion is composed of a hollow body formed by sintering a first constituent material powder, and the blade tip portion is composed of a solid body formed by sintering a second constituent material powder, and a reinforcing wall is provided in the hollow body of at least the front end portion of the cutting tool of the base portion.

Description

Technical Field

[0001] The present invention relates to cutting tools such as kitchen knives. Background Art

[0002] In the past, kitchen knives made of materials with metal materials as the main component were used. Among them, in recent years, kitchen knives made of stainless steel with nickel and chromium as components are also used (see Patent Document 1). In addition, ceramic kitchen knives with zirconium oxide as the main component are also known (see Patent Document 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-189682

[0006] Patent Document 2: International Publication No. 2016 / 190343 Summary of the invention

[0007] Problems to be solved by the invention

[0008] The knife of the present invention has a blade body, which includes a base part and a blade tip part arranged along the end of the base part. The base part is composed of a hollow body, and the blade tip part is composed of a solid body. A reinforcing wall is arranged in the hollow body of at least the front end of the knife of the base part. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a side view showing a state where a shank is attached to the tool according to one embodiment of the present invention.

[0010] Figure 2 yes Figure 1 The tool is shown in a cross-sectional view as viewed from the side.

[0011] Figure 3 yes Figure 1 The XX line section view of the tool is shown.

[0012] Figure 4 (a) and (b) are a side view and a top view, respectively, of a tool showing another embodiment of the present invention. DETAILED DESCRIPTION

[0013] Hereinafter, a tool according to an embodiment of the present invention will be described with reference to the drawings. It should be noted that the drawings used in the following description are schematic, and the dimensional ratios and the like in the drawings are not necessarily consistent with the actual dimensional ratios and the like.

[0014] like Figure 1 as well as Figure 2As shown, the knife 1 of the present invention includes a blade 2 and a handle 3 connected to the blade 2. The blade 2 includes a base portion 21 and a blade tip portion 22 arranged along the end of the base portion 21.

[0015] The blade 2 is set to a shape and size that suits the purpose of the knife 1. When the knife 1 is a kitchen knife, the shape of the blade 2 includes, for example, the shape of a Japanese kitchen knife such as a thick-bladed kitchen knife, a Santoku kitchen knife, a sashimi kitchen knife, a Western kitchen knife such as a beef knife, or a Chinese kitchen knife. When the knife 1 is used for purposes other than kitchen knives, such as a knife or a surgical instrument, it may be any shape as long as it suits its purpose.

[0016] The handle 3 connected to the blade 2 is used for a person to hold the knife 1 by hand, and is set to a shape and size that matches the purpose of the knife 1, similar to the blade 2. The handle 3 includes wood, resin, ceramic or metal material.

[0017] The blade 2 and the handle 3 may be formed integrally or separately. In the present embodiment, the blade 2 and the handle 3 are formed separately, and a part of the blade 2, namely the handle portion 23, is inserted into the interior of the handle 3 and fixed relative to the handle 3 by the insertion portion. The handle portion 23 is sometimes also called a tang.

[0018] The cutter 1 may have any size, but an example of the size of the cutter 1 is shown for reference. Figure 1 The total length Ht1 shown can also be set to be greater than 5 cm and less than 40 cm. The length Ht3 of the width direction of the blade 2 in a direction perpendicular to the total length Ht1 can also be set to be greater than 10 mm and less than 150 mm. The blade length (the length of the edged portion) Ht2 of the blade 2 can be appropriately set according to the purpose. When used as a normal kitchen knife, for example, it can be set to be greater than 5 cm and less than 35 cm.

[0019] The thickness of blade 2 can also be set to more than 1mm and below 5mm at the part with the thickest thickness, for example. In addition, the length and thickness of handle 3 can be set appropriately, and for example the thickness of handle 3 can also be set to more than 5mm and below 3cm.

[0020] A handle portion 23 is integrally formed on the base portion 21 of the blade 2. A hole portion 4 is provided in the handle portion 23. The hole portion 4 may be provided with only one or more holes. The hole portion 4 is used to fix the blade 2 to the handle 3, but as described later, when the tool 1 is manufactured, it also has a function as a discharge hole for discharging powder in the tool 1. The hole portion 4 is formed, for example, in a circular shape with a radius of 0.5 mm or more and 3 mm or less.

[0021] It should be noted that the handle 3 may not be used, and the handle portion 23 may be used as a handle.

[0022] like Figure 2 As shown in the figure, the base part 21 is a hollow body formed by sintering or melting the powder of the first constituent material, and the blade tip part 22 is a solid body formed by sintering or melting the powder of the second constituent material. Such a base part 21 and the blade tip part 22 can be manufactured by a 3D printer, for example, as described later. Like the base part 21, the handle part 23 is also a hollow body, and the base part 21 and the handle part 23 form a hollow body that is connected to each other. Therefore, the hole 4 formed in the handle part 23 is connected to the hollow body (the internal space of the hollow body) in the base part 21.

[0023] It should be noted that in the following description, when the base portion 21 is referred to, the handle portion 23 is included.

[0024] In the present invention, the blade tip 22 refers to a solid area having a cutting edge ridge 22a. Figure 3 As shown, the base portion 21 includes both side surface portions 21a, 21a and a back portion 21b, and the hollow body has a space 5 formed by the back portion 22b of the blade tip portion 22, the both side surface portions 21a, 21a and the back portion 21b.

[0025] like Figure 2 As shown in FIG. 2 , a plurality of reinforcing walls 6 are provided in the hollow body of the front end portion 2a of the tool. Figure 3 As shown, the reinforcing wall 6 is provided between the two side surface portions 21a, 21a. The reinforcing wall 6 is used to reinforce the hollow base portion 21. Here, the tool tip portion 2a refers to a region that is 20% or more and 40% or less of the total length of the base portion 21 excluding the handle portion 23.

[0026] The front end of the reinforcing wall 6 may or may not be connected to the inner surface of the tool front end 2a1. Figure 2 The state where the front end of the reinforcing wall 6 is not connected to the inner surface of the tool front end 2a1 is shown. In addition, the reason why the reinforcing wall 6 is provided at the tool front end 2a is that the tool front end 2a is the part that is most subjected to impact force when the tool 1 is used. Therefore, the reinforcing wall 6 may be formed not only at the tool front end 2a but also within the range of the total length of the base 21 or the total length of the base 21 excluding the handle portion 23.

[0027] Multiple reinforcement walls 6 such as Figure 2 In this case, each reinforcing wall 6 may be parallel or non-parallel. In the present embodiment, the reinforcing wall 6 is formed in a downwardly extending shape from the front end 2a1 of the tool in a manner that follows the shape of the base portion 21 and the interval between each reinforcing wall 6 increases as it moves away from the front end 2a1 of the tool.

[0028] A plurality of blade portions 61 are formed at predetermined intervals on the inner surface of the reinforcing wall 6 of the front end portion 2a of the tool, the back portion 22b of the blade tip, and the back portion 21b of the base portion 21, and are perpendicular to the long side direction of the reinforcing wall 6. The blade portions 61 are provided between the two side surfaces 21a, 21a in the same manner as the reinforcing wall 6. By forming a plurality of blade portions 61 on the reinforcing wall 6, the reinforcing effect of the front end portion 2a of the tool is further improved. The blade portions 61 are formed simultaneously with the reinforcing wall 6.

[0029] The hollow body as the base portion 21 is formed by sintering or melting the first constituent material powder, and the solid body as the blade tip portion 22 is formed by sintering or melting the second constituent material powder.

[0030] The first constituent material powder and the second constituent material powder may be the same or different powders, and metal powder or ceramic material powder that can be sintered or melted is used.

[0031] As metal powder, for example, ferritic stainless steel, austenitic stainless steel, nickel-based alloys such as Inconel (registered trademark), titanium alloys, nickel-cobalt alloys, cobalt alloys, cobalt-chromium-tungsten alloys such as Stellite (registered trademark), CCM alloys (cobalt-chromium-molybdenum alloys), etc. can be used. In addition, as ceramic powder, for example, oxide ceramics such as zirconium oxide (zirconia), or carbide ceramics such as tungsten carbide, titanium carbide, and vanadium carbide can be used.

[0032] On the basis of integrally and firmly joining the base portion 21 and the blade tip portion 22, it is preferred that the same powder be used for the first constituent material powder and the second constituent material powder; however, as long as the base portion 21 and the blade tip portion 22 can be firmly joined, the first constituent material powder and the second constituent material powder may also be different material powders.

[0033] The particle size of the first constituent material powder and the second constituent material powder can be appropriately determined according to the material, etc., but is generally preferably 40 μm or more and 120 μm or less. The particle size can be adjusted by mechanical methods such as ball mills or mesh passes, or spray methods such as gas atomization or water atomization.

[0034] Next, the manufacturing method of the tool of the present invention is described. In order to sinter the first constituent material powder to form a hollow body and sinter the second constituent material powder to form a solid body, for example, a powder sintering layered modeling method is preferably used, and a powder sintering 3D printer can be used for this purpose.

[0035] Powder sintering layered modeling methods include, for example, laser sintering (SLS), direct metal laser sintering (DMLS), etc. In addition, laser melting (SLM), electron beam melting (EBM), laser direct layering, laser metal deposition (LMD), etc. can also be used.

[0036] Laser sintering is a method of forming a modeling table by covering it with material powder and irradiating it with a laser beam such as a carbon dioxide laser. The material powder adjusted to a specified particle size is supplied from a powder supply unit to the modeling table while gradually being formed. When the forming of one layer is completed, the modeling table is lowered a section and the forming of the next layer begins. In this way, in the laser sintering method, the object is formed in the powdered material irradiated with a laser beam. According to the laser sintering method, it is possible to achieve material properties (strength, hardness, toughness, wear resistance, etc.) that are close to the original material of the material powder used.

[0037] In order to prevent oxidation of the material, the material powder used in the laser sintering method generally uses metal powder or ceramic material powder coated with a water-soluble resin such as polyvinyl alcohol (PVA).

[0038] Direct metal laser sintering differs from laser sintering, which mainly uses a carbon dioxide gas laser, in that it uses an ytterbium laser. The ytterbium laser has the advantage of excellent output stability and can stably maintain the same size. Uncoated single-material metal powder and ceramic material powder are used as material powder.

[0039] The laser melting method is the same as the laser sintering method and the direct metal laser sintering method in that it uses a laser beam for irradiation, but instead of sintering, a modeling object is made by melting and solidifying a material powder (metal powder or ceramic material powder). The material uses the same metal powder as mentioned above. In modeling, the 3DCAD data of the STL library is sliced ​​and a laser beam is irradiated for each layer. The following operation is repeated: when one layer is fixed, the metal powder that becomes the next layer is covered from above with a powder bed, and fixed by irradiating the laser here. The laser uses a high-output ytterbium laser like the direct metal sintering method, but it becomes a high-output compared to the direct metal sintering method.

[0040] Electron beam melting is a lamination method using electron beams, and similar to the laser sintering method, it is a mechanism of melting metal powder by irradiating it with electron beams. Electron beams irradiated in a high vacuum are higher in output and higher in speed than laser beams, and can accurately 3D print precision metal parts. Specifically, in electron beam melting (EBM), after the metal powder is heated to a certain temperature as a whole in a vacuum, an electron beam with a high melting point is irradiated to the molded part. Here, the electron beam refers to a beam of electrons emitted by a heating filament controlled and irradiated by an electromagnetic coil in a high vacuum. In the electron beam melting method, ceramic material powder can also be used.

[0041] Laser direct lamination is different from the mechanism of irradiating laser to metal powder. It is a method of gradually laminating metal powder by dropping it into a molten pool from a nozzle and sintering it with laser. This method has the following advantages: it can achieve smooth processing, the molding speed is also fast, and the material cost can be suppressed to nearly half. Ceramic material powder can also be used in the laser direct lamination method.

[0042] Next, the steps of using a 3D printer to make the blade 2 of the tool 1 are described. First, 3D data of the design drawing of the blade 2 of the tool 1 is prepared. For this purpose, modeling is performed using 3D CAD software. As 3D CAD software, various commercial products can be used without particular limitation.

[0043] In the present invention, 3D data is prepared for each of the base portion 21 which is a hollow body and the blade tip portion 22 which is a solid body. At this time, topology optimization software can also be used.

[0044] The 3D data produced by 3DCAD software is converted into 3D data in STL format. After the physical compatibility of the STL data is checked using an STL verification tool, the STL data of the object is converted into data actually used for output control of a 3D printer. That is, the 3D data is sliced ​​for each layer and converted into modeling tool path data (G code, etc.) for operating a 3D printer. The conversion software is generally called slicing software.

[0045] After the STL data is converted into modeling tool path data, the tool path data is read into the 3D printer and modeling using the 3D printer begins. At this time, support design and thermal stress calculation are performed as necessary to appropriately optimize the molding conditions.

[0046] In the present invention, the base portion 21 is composed of a hollow body and the blade tip portion 22 is composed of a solid body, so it is better to first shape one of the base portion 21 and the blade tip portion 22 by a 3D printer and then change the control conditions to shape the other.

[0047] The blade tip 22 is preferably of higher hardness than the base 21. To this end, the conditions of laser irradiation can be appropriately adjusted. In addition, for example, titanium carbide powder with a particle size of about 2 to 5 μm can be added to the titanium alloy powder at about 0.1 to 0.3 mass%, and heterogeneous solidification nucleus particles can be added to form fine equiaxed crystals. In addition, it is also possible to increase the cooling rate without preheating using SLM to form fine crystals. In addition, according to LMD, cooling is faster, so it is easy to form fine crystals. In addition, in EBM and LMD, if the phase changes from liquid phase to solid phase parallel to the stacking direction, columnar crystals extend in a direction parallel to the stacking direction. Therefore, columnar crystals are formed in the same direction 90 degrees different from the layer above it, and the columnar crystals are alternately and repeatedly stacked, so that crystal growth of different directions overlaps. In this way, hardness can also be improved. In addition, according to the cooling conditions, a dense metal and ceramic or carbon structure appears, which can also achieve high toughness and high hardness. After the blade 2 is molded, the material powder in the blade 2 is discharged from the hole 4 of the handle portion 23. It should be noted that when the base portion 21 is molded, the reinforcing wall 6 is also molded at the same time.

[0048] In addition, the blade 2 of the knife 1 with high toughness can also be manufactured by controlling the structure. For example, by adjusting the conditions of laser irradiation, the toughness of the blade 2 can be improved with the same effect as quenching.

[0049] As for the joining of the blade tip 22 and the base 21, since the two are continuously formed in the same molding process, there is no need for a process of joining the two. That is, the blade tip 22 and the base 21 are molded integrally. Thus, high strength can be obtained even at the part regarded as the joining part of the two.

[0050] By grinding the blade 2 thus produced, a blade tip 22 can be formed. When grinding the blade 2, in order to process at a small blade angle of 20 to 40°, it is preferred to use a grinding material such as aluminum oxide, silicon carbide, or diamond. After grinding, the blade 2 is mounted on the handle 3 at the handle portion 23.

[0051] The obtained knife 1 is lightweight because the base body 21 is a hollow body, and has excellent strength because the blade tip 22 is a solid body, thereby achieving high sharpness.

[0052] Figure 4 (a) and Figure 4 (b) is a diagram showing another embodiment of the present invention, the blade 2 'as shown in the Figure 4 As shown in (b), the tool 1 has a wavy meandering shape, and the two side surfaces 21a, 21a are formed with concave and convex portions 7. Therefore, when used, the cutting properties of the tool 1 are improved. The rest is the same as the above-mentioned embodiment, so the same reference numerals are marked on the same components and the description is omitted.

[0053] The above is a description of the embodiment of the tool of the present invention, but the present invention is not limited to the above embodiment, and various changes and improvements can be made. For example, in the above embodiment, the base part 21 including the handle part 23 and the blade tip part 22 are manufactured by a 3D printer, but the blade tip part 22 as a solid body can also be manufactured by other methods, and the base part 21 including the handle part 23 is manufactured on the blade tip part 22 by a 3D printer and the base part 21 is joined by a 3D printer.

[0054] Description of Reference Numerals

[0055] 1 Knife

[0056] 2, 2′ blade

[0057] 2a Tool front end

[0058] 2a1 Tool front end

[0059] 3 handles

[0060] 4 holes

[0061] 5. Space

[0062] 6 Strengthening wall

[0063] 61 Blade

[0064] 7 Concavoconvex part

[0065] 21 Base part

[0066] 21a Side view

[0067] 21b Back

[0068] 22 Blade tip

[0069] 22a Blade tip ridge

[0070] 22b Back side of blade tip

[0071] 23 Handle portion.

Claims

1. A knife having a blade, wherein the blade has a base portion and a blade tip portion arranged along an end portion of the base portion, wherein: The base part is composed of a hollow body, and the blade tip part is composed of a solid body. A reinforcing wall is provided in the hollow body at least at the front end of the tool, The base portion has a handle portion in which a hole portion communicating with the inner space of the hollow body is formed.

2. The tool according to claim 1, wherein: The base portion includes two side surfaces and a back portion, the hollow body includes a space formed by a back portion of the blade tip portion, the two side surfaces, and the back portion, and the reinforcing wall is provided between the two side surfaces.

3. The tool according to claim 1 or 2, wherein: The reinforcing wall is arranged in a lattice shape.

4. The tool according to claim 1 or 2, wherein: The base portion is composed of a hollow body formed by sintering a first constituent material powder, and the blade tip portion is composed of a solid body formed by sintering a second constituent material powder.

5. The tool according to claim 4, wherein: The first constituent material powder and the second constituent material powder are the same or different powders and are metal powders selected from the group consisting of ferritic stainless steel, austenitic stainless steel, nickel-based alloys, titanium alloys, nickel-cobalt alloys, cobalt alloys, cobalt-chromium-tungsten alloys and cobalt-chromium-molybdenum alloys.

6. The tool according to claim 4, wherein: The first constituent material powder and the second constituent material powder are the same or different powders and are ceramic material powders containing at least one selected from the group consisting of tungsten carbide, titanium carbide, vanadium carbide, and zirconium oxide as a main component.

7. The tool according to claim 1 or 2, wherein: The blade tip portion has a higher hardness than the base portion.

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