Manufacturing method of blade for ice skating, and product of the blade

Abstract

To solve the problems that since a conventional metallic blade for ice skating has a pedestal and a blade which are joined / manufactured by soldering, welding or caulking technique, there is a large variation in shape quality and the strength of a joint part, which increases the physical / mental burden on a competitor, and a construction method of manufacturing an integral type blade from rolled steel by whole cutting is announced, but a yield of a product weight relative to a material weight is as low as 2-3% due to direct cutting from a rolled square bar, and a product becomes greatly expensive.SOLUTION: A manufacturing method of a blade for ice skating includes, after selecting a material for a metallic blade and cutting it to have a proper individual weight: 1. molding a rough shape by cold or hot forging; 2. executing refining heat treatment so as to satisfy the requirement characteristics of a product and adjust the rigidity and structure to be optimum for machining; 3. removing an oxide on the forged / heat treated material surface by shot blast; 4. obtaining a final shape by machining; and 5. applying surface treatment to the product to give corrosion resistance and abrasion resistance.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a high-strength, inexpensive metal blade that is attached to ice skates (Figure 4), and to the product itself. [Background technology]

[0002] Traditionally, metal ice skate blades (Figure 5) are typically manufactured by separately punching out three pieces from rolled thin steel plate: two bases for attaching to the skates (one heel piece and one toe piece) and one blade piece for skating. These are then finished and then joined into a T-shape by brazing, welding, or crimping, as shown in Figure 1. Recently, a method has been announced in which blades for advanced skaters are entirely cut from rolled steel. However, because the blades are cut directly from rolled lumber, the product weight yield rate is low at 2-3% compared to the material weight, making the product very expensive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US20090206562 A1 [Non-patent literature]

[0004] [Non-Patent Document 1] URL for Yamaichi Hagane's "YS BLADES" https: / / yamaichi-hagane.jp / ysblades / Summary of the Invention [Problem to be solved by the invention]

[0005] Blades made by conventional techniques such as soldering, welding, or crimping inevitably have slight differences in each product, even when made by a skilled craftsman. Therefore, even products of the same model from the same manufacturer have variations in shape and quality. For this reason, skaters have had to adjust their senses and get used to the variations in shape and quality that occur every time they replace their blades. In addition, there is a large variation in the strength of the joints in blades made by brazing, welding, or crimping techniques, and there have been cases where the joints could not withstand the large impact of jumping in figure skating, and bent or broke. This could lead to serious accidents that could endanger the life of the athlete, so a safe and secure blade was desperately needed. Therefore, instead of joining rolled thin plates by brazing or welding, a method has been proposed in which the joint part of the blade material, which is a rolled thin plate, to the base is extended, the extended part is bent at right angles to the left and right, and the bent part is directly screwed to the base, as shown in [Patent Document 1]. However, with this method, the connecting cross-sectional area between the base and the blade is halved to begin with, so ultimately only the same bending strength as the welding method can be expected. Also, as in [Non-Patent Document 1], a technology was announced in which blades are cut directly from rolled steel metal, which is the blade material. This method certainly makes it possible to obtain safe and secure blades with no quality variations. However, with this method, for example, if the material is ferrous, it is necessary to cut out about 300g of blade products from square steel that weighs more than 10kg, which results in 97% to 98% of the scrap being discarded, making the product very expensive. [Means for solving the problem]

[0006] The present invention has been proposed in consideration of the above-mentioned circumstances, and provides safe and secure metal ice skate blades with stable shape quality at low cost by the following manufacturing method (Figure 2). First, select the material for the metal blade and cut it to the appropriate unit weight. ▲1▼ Cold or hot forging is used to form the rough shape. 2. To achieve the required product characteristics and the optimum hardness and structure for cutting processing Normalizing · Carry out refining heat treatment ▲3▼Oxides and other substances on the surface of the forged and heat-treated material are removed by shot blasting. ▲4▼ The final shape is obtained by cutting 5. Surface treatment is applied to further improve corrosion resistance and wear resistance. Effect of the Invention

[0007] This invention makes it possible to manufacture metal ice skating blades that are molded and constructed as a single unit without joining the base and blade by brazing, welding, crimping, etc. This means skaters no longer have to worry about variations in shape quality that occur every time they replace the blade, and they no longer have to worry about the joint between the base and the blade bending or breaking even during attempts that involve large impacts such as jumps, allowing them to concentrate on their competition safely and securely. Furthermore, one-piece metal ice skates that combine forging and cutting have a higher product yield than those made by cutting the blades directly from the metal steel block that forms the blade material, and can be provided to athletes at a lower cost. [Brief description of the drawings]

[0008] [Figure 4] Figure ice skates: Shoe and blade joined together [Diagram 5] Same blade: The base and blade are joined in a T-shape [Figure 1] State Blade Diagram [Diagram 2] Flowchart of the manufacturing process of the present invention [Diagram 3] Forging process diagram and grain flow direction by forging method (A) When T-shaped material is formed along the rolling direction (B) When T-shaped material is formed perpendicular to the rolling direction DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Metallic materials suitable for ice skating blades include ferrous metals such as carbon steel, spring steel, nitriding steel, carburizing steel, tool steel, maraging steel, stainless steel, and other special steels. In addition, Ni-based alloys, Co-based alloys, and Ti alloys, which have corrosion and wear resistance, as well as lightweight materials such as Al alloys and Mg alloys, are also applicable.

[0010] The rolled steel bar material selected from the above materials is cut to an appropriate unit weight (approximately 2 to 3 kg, since the target is about 10 times the product weight), and a thin-walled T-shaped intermediate material is obtained by cold or hot forging. The forging method can be either free forging with a hammer or die forging. At this time, if the T-shaped material is formed along the rolling direction as shown in Figure 3(A), the grain flow line will appear overlapping with the rolling direction of the T-shaped material. On the other hand, if the T-shaped material is formed perpendicular to the rolling direction as shown in Figure 3(B), although the material weight will increase slightly, a continuous grain flow line will appear from the flange part (future base part) to the web part (future blade part) of the T-shaped material. Note that while Figure 3(B) shows the material formed on a circular arc, it is also possible to design and forge the base of the heel part and the base of the toe part to be flat as reference parts when processing into the final product.

[0011] Since the metal structure and hardness of the thin-walled T-shaped material after forging are not uniform, each material is tempered to obtain the structure and hardness that are optimal for the required characteristics of the product and for subsequent cutting processing. For example, when tempering ferrous metals, the material is heated to above the A3 transformation point to completely transform it into an austenitic structure, and then rapidly cooled (quenched) to generate a martensite structure. In addition, the distortion after quenching is removed, and the material is tempered at a temperature below the A1 transformation point to adjust the hardness to the optimum for cutting processing. At this time, by adjusting the tempering temperature, it is possible to adjust the optimal hardness for each material according to the required characteristics of the final product, for example, high-temperature tempering makes it soft, and low-temperature tempering makes it hard.

[0012] After tempering, the material has an oxide film on its surface, which makes cutting difficult, so it is necessary to remove the oxide film by shot blasting. In this case, since the only purpose is to remove the oxide film, care must be taken to avoid generating residual stress in the metal surface layer.

[0013] The material, which has been shot blasted to clean its surface, is then machined into the required product shape. However, it is important that the blade shape is designed with strength for each appropriately selected material against a preset load stress based on actual measurement data, and that the product shape is preferably verified by structural analysis. Furthermore, cutting is performed using NC machine tools such as 3-axis or 5-axis machines. However, because a certain degree of thin-walled structure is formed in advance by forging, it is necessary to place appropriate jigs, etc. depending on the machining area to minimize material deformation during machining.

[0014] The boundary between the T-shaped flange and web sections, which are formed by the blade base and cutting edge after cutting, is the area where bending stress is greatest, so it is important to give the boundary section a sufficiently safe R radius and it is also effective to shot blast the boundary surface after cutting to improve its impact resistance and fatigue strength.

[0015] If necessary, the blade after cutting can be subjected to surface treatment such as plating, anodizing, vapor deposition, painting, etc., for the purpose of improving corrosion resistance and wear resistance. In addition, a surface hardening treatment such as nitriding can be performed. However, since the cutting edge of the blade (the part in contact with the ice) is constantly polished to ensure ice-gliding performance, it is necessary to apply a treatment to the material so that a width of 1 to several mm from the tip of the blade edge, which is the part in contact with the ice, is not surface treated or surface hardened. EXAMPLES

[0016] High-strength spring steel (SUP11AM) was selected as the material for ice skate blades, and a φ60mm×315mm (7kg) blank was cut out from rolled round steel of the material. It was heated to 1200℃ as shown in Figure 3(A) and hot die forged (upsetting (P-1) → forming (P-2) → trimming (P-3)). Furthermore, this product was subjected to normalizing treatment, and then thermal refining treatment (quenching at 850°C, tempering at 580°C) was carried out to refine it to a hardness of HRC31. By refining to this hardness, it is possible to produce a material with sufficient strength, a uniform structure, and excellent workability. The material obtained by the above treatment was put into a φ0.8mm steel ball shot blasting machine to remove oxides on the surface, and then cut using a 5-axis processing machine to produce skate blades of the specified shape. Furthermore, since the cutter is very susceptible to rust, it is chrome plated. However, by masking the entire length of the cutting edge with a width of 5 mm and intentionally leaving non-plated areas, it is possible to polish the cutting edge and ensure its gliding performance.

[0017] High-strength spring steel (SUP11AM) was selected as the material for ice skate blades, and a φ60mm×315mm (7kg) blank was cut out from the rolled round steel of the material. It was heated to 1200℃-1260℃ as shown in Figure 3(A) and hammer forged (forming (P-2) → trimming (P-3)). Furthermore, this product was subjected to normalizing treatment, and then thermal refining treatment (quenching at 850°C, tempering at 580°C) was carried out to refine it to a hardness of HRC31. By refining it to this hardness, it is possible to create a material with sufficient strength, a uniform structure, and excellent workability. The material obtained by the above treatment was put into a φ0.8mm steel ball shot blasting machine to remove oxides on the surface, and then cut using a 5-axis processing machine to create a scale of the specified shape. We manufactured a 300mm diameter carbide blade. Furthermore, since the cutter is very susceptible to rust, it is chrome plated. However, by masking the entire length of the cutting edge with a width of 5 mm and intentionally leaving non-plated areas, it is possible to polish the cutting edge and ensure its gliding performance.

[0018] High-strength spring steel (SUP11AM) was selected as the material for ice skate blades, and two pieces of φ90mm x 100mm (5kg) were cut out from rolled round steel of the material. As shown in Figure 3(B), these were heated to 1200℃ and hot forged (upsetting (P-1) → forming (P-2) → trimming and dividing (P-3)), and then each piece (piece) was forged (P-4) to adjust the angle between the base (heel and toe) and the squareness to obtain a T-shape with the blade. Furthermore, after normalizing the divided products, they were subjected to thermal refining treatment (quenching at 850°C, tempering at 580°C) to refine the hardness to HRC 31. By refining to this hardness, it is possible to create a material with sufficient strength, a uniform structure, and excellent workability. The material obtained by the above treatment was shot blasted with a φ0.8 mm steel ball to remove oxides and other impurities from the surface, and then machined using a 5-axis machining center to produce skate blades of the desired shape. Furthermore, since the cutter is very susceptible to rust, it is chrome plated. However, by masking the entire length of the cutting edge with a width of 5 mm and intentionally leaving non-plated areas, it is possible to polish the cutting edge and ensure its gliding performance. [Industrial Applicability]

[0019] By combining forging and cutting methods, it is possible to manufacture thin, T-shaped and other complex shaped products, such as skate blades, inexpensively while maintaining high strength and in one piece, without using joining techniques such as brazing, welding or crimping.

Claims

1. A method for manufacturing an ice skating blade, in which a base for fastening the blade to the skate with screws and a metal blade that contacts the ice are molded and constructed as a single unit by combining a forging process and a cutting process.

2. 2. A one-piece metal ice skate blade having a uniform metal structure without joints between the base and the blade, which is produced by combining the forging method and cutting process described in claim 1.

3. A method for manufacturing a metal ice skate blade according to claim 1, the method being designed to improve impact resistance and fatigue strength by forming continuous grain flows from the base to the blade during forging.

4. 4. The one-piece metal ice skate blade according to claim 3, in which a continuous grain flow is formed from the base portion to the blade portion.

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