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(11) | EP 3 037 138 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 153(4) EPC |
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| (54) | HIGH-RESILIENCE DART AND PROCESSING TECHNOLOGY THEREOF |
BACKGROUND
Technical Field
[0001] The present invention relates to dart products, and in particular, to a high-resilience dart and a processing technology thereof.
Related Art
[0002] A dart generally includes a dart rod, a dart cylinder, a dart needle connected to the front end of the dart cylinder, and a dart wing located at the tail end of the dart rod. According to different materials of the front ends of darts, current darts are mainly classified into: rigid needle darts (the material of the dart needle is rigid metal) and flexible needle darts (the material of the dart needle is plastic). The rigid needle darts are used for projecting a hemp target and a paper target, and the flexible needle darts are used for projecting a plastic target and an electronic target.
[0003] The dart needle of a conventional rigid needle dart generally has the diameter of 2.35 mm, and is made of carbon steel or stainless steel.
[0004] Practices in dart sports prove that, a finer dart needle is easier to be inserted into the dart target, and the depth of the dart needle entering into the dart target is deeper; therefore, the dart is less likely to fall from the dart target. As a result, projected darts can all be inserted into the dart target regardless of whether the dart target is too hard or too soft, thereby ensuring the scoring. In addition, the finer dart needle is less likely to hit metal screen wires on the surface of the dart target, thereby greatly reducing the probability that the dart is rebounded to fall due to hitting the metal screen wire; therefore, the scoring probability of the dart players is improved, and the dart and the dart targets are better protected from being damaged.
[0005] Practices in dart sports also prove that, finer and more flexible dart needles are more convenient for a dart player to hit multiple darts at the same time in the same high scoring area having a small area on a dart target, thereby improving the scoring probability of the dart player. After one dart hits a high scoring area, when other one or two darts are aimed and projected to the high scoring area and hit the former dart, the dart needle of the former dart bends and leaves some room because of the small diameter and the flexibility thereof, and therefore, the subsequent dart can smoothly hit the same area, thereby reducing the probability of changing the flying path and hitting another area due to collision with the former dart.
[0006] However, a finer dart needle has a higher requirement on the material quality of the dart needle. If the commonly used carbon steel having large rigidity is adopted, and the dart needle is made to have a smaller diameter, during use, once the dart falls to the ground or hits a hard object, the dart needle is easily broken, so that the dart is scrapped. If a material having low rigidity, for example, stainless steel or iron, is used, during use, after the dart needle is bent and deformed after being hit, the dart needle cannot be straightened and cannot be used continuously either, which not only causes waste of material but also increases the use cost of the dart.
SUMMARY
[0007] To overcome the defects of the prior art, an objective of the present invention is to provide a high-resilience dart, which has high hardness and high resilience, can resist wear and corrosion, prolongs the service life to the dart, and reduces the use cost of dart fans.
[0008] Another objective of the present invention is to provide a high-resilience dart and a processing technology thereof, and a high-resilience dart is obtained through the technology, so as to prolong the service life of the dart, and reduce the use cost of dart fans.
[0009] To solve the above problems, a technical solution adopted in the present invention is described as follows.
[0010] A high-resilience dart includes a dart rod, a dart cylinder, a dart wing connected to the tail end of the dart rod, and a dart needle connected to the front end of the dart cylinder; where the dart needle is made of a nickel-titanium alloy material, and the maximum diameter of the dart needle is 1-1.5 mm.
[0011] In the above solution, the nickel-titanium alloy material comprises the following elements by weight percentage:
nickel 48-55%,
titanium 43.5-50%,
chromium 0.8-1.5%,
carbon 0.005-0.01%,
oxygen 0.01-0.05%,
hydrogen ≤0.001%,
nitrogen ≤0.0015%, and
the residual being impurities.
[0013] As a preferred solution of the present invention, on the basis of the above solution, the dart rod is made of a nickel-titanium alloy material.
[0014] As a preferred solution of the present invention, on the basis of the above solution, the nickel-titanium alloy material further includes ≤0.1% copper by weight percentage.
[0015] As a preferred solution of the present invention, on the basis of the above solution, the nickel-titanium alloy material further includes ≤0.05% zirconium by weight percentage.
[0016] A processing technology of a high-resilience dart includes the following steps:
smelting: evenly stirring titanium powder and nickel powder in proportion, and smelting into an ingot;
polishing away the skin: cutting a base of the ingot, and polishing away a surface oxide skin;
rolling into a square shape: rolling the ingot into a rectangular shape;
polishing away the skin: polishing away a surface oxide skin of the rectangular ingot;
rolling into wires: rolling the rectangular ingot into cylindrical wire;
performing rotary forging: performing rotary forging on the cylindrical wire to form a wire material having the diameter of 4-7mm;
drawing: fractionally drawing the wire material into wires having the diameter of 1-1.5mm;
straightening: performing heat treatment on the wires and straightening;
forming: cutting the straightened wire into the length of a dart needle, and forging it into a dart needle according to the shape of the dart needle; and
assembling: assembling the dart needle with a dart rod, a dart cylinder and a dart wing assembling to form a dart.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
- 1. The high-resilience dart of the present invention has high hardness and high resilience, can resist wear and corrosion, prolongs the service life to the dart, and reduces the use cost of dart fans.
- 2. The dart needle of the high-resilience dart of the present invention is finer than the conventional dart needle, and therefore, the dart needle more easily enters a dart target and the dart needle is firmly fixed on the dart target; moreover, the probability that the dart needle hits a metal screen wire on a dart target surface is reduced, thereby protecting the dart and the dart target from being damaged easily. Moreover, the nickel-titanium alloy material used by the dart needle has high hardness and high resilience, the probability that multiple darts hit the highest scoring area at the same time may be improved, thereby improving the scoring probability of dart players.
[0018] The present invention is further described in detail through the following specific implementation manners.
DETAILED DESCRIPTION
Embodiment 1
[0019] A high-resilience dart of the present invention includes a dart rod, a dart cylinder, a dart wing connected to the tail end of the dart rod, and a dart needle connected to the front end of the dart cylinder, where the dart needle is made of a nickel-titanium alloy material, and the maximum diameter of the dart needle is 1 mm. The dart needle is manufactured using the following method:
smelting: evenly stirring titanium powder and nickel powder in proportion, and smelting into an ingot;
polishing away the skin: cutting a base of the ingot, and polishing away a surface oxide skin;
rolling into a square shape: rolling the ingot into a rectangular shape;
polishing away the skin: polishing away a surface oxide skin of the rectangular ingot;
rolling into wires: rolling the rectangular ingot into cylindrical wire;
performing rotary forging: performing rotary forging on the cylindrical wire to form a wire material having the diameter of 4 mm;
drawing: fractionally drawing the wire material into wires having the diameter of 1 mm;
straightening: performing heat treatment on the wires and straightening;
forming: cutting the straightened wire into the length of a dart needle, and forging it into a dart needle according to the shape of the dart needle; and
finally, assembling the dart needle with a dart rod, a dart cylinder and a dart wing assembling to form a dart.
[0020] The nickel-titanium alloy material includes the following elements by weight percentage:
nickel 55%, titanium 43.5%, chromium 1.4%, carbon 0.005%, oxygen 0.018%, hydrogen 0.001%, nitrogen 0.001%, and the residual being impurities.
Embodiment 2
[0021] A high-resilience dart of the present invention includes a dart rod, a dart cylinder, a dart wing connected to the tail end of the dart rod, and a dart needle connected to the front end of the dart cylinder, where the dart needle is made of a nickel-titanium alloy material, and the maximum diameter of the dart needle is 1.2 mm. The dart needle is manufactured using the following method:
smelting: evenly stirring titanium powder and nickel powder in proportion, and smelting into an ingot;
polishing away the skin: cutting a base of the ingot, and polishing away a surface oxide skin;
rolling into a square shape: rolling the ingot into a rectangular shape;
polishing away the skin: polishing away a surface oxide skin of the rectangular ingot;
rolling into wires: rolling the rectangular ingot into cylindrical wire;
performing rotary forging: performing rotary forging on the cylindrical wire to form a wire material having the diameter of 5 mm;
drawing: fractionally drawing the wire material into wires having the diameter of 1.2 mm;
straightening: performing heat treatment on the wires and straightening;
forming: cutting the straightened wire into the length of a dart needle, and forging it into a dart needle according to the shape of the dart needle; and
finally, assembling the dart needle with a dart rod, a dart cylinder and a dart wing assembling to form a dart.
[0022] The nickel-titanium alloy material includes the following elements by weight percentage:
nickel 50.85%, titanium 48.09%, chromium 1.003%, carbon 0.007%, oxygen 0.041%, hydrogen 0.0009%, nitrogen 0.0014%, and the residual being impurities.
Embodiment 3
[0023] A high-resilience dart of the present invention includes a dart rod, a dart cylinder, a dart wing connected to the tail end of the dart rod, and a dart needle connected to the front end of the dart cylinder, where the dart needle is made of a nickel-titanium alloy material, and the maximum diameter of the dart needle is 1.5 mm. The dart needle is manufactured using the following method:
smelting: evenly stirring titanium powder and nickel powder in proportion, and smelting into an ingot;
polishing away the skin: cutting a base of the ingot, and polishing away a surface oxide skin;
rolling into a square shape: rolling the ingot into a rectangular shape;
polishing away the skin: polishing away a surface oxide skin of the rectangular ingot;
rolling into wires: rolling the rectangular ingot into cylindrical wire;
performing rotary forging: performing rotary forging on the cylindrical wire to form a wire material having the diameter of 7 mm;
drawing: fractionally drawing the wire material into wires having the diameter of 1.5 mm;
straightening: performing heat treatment on the wires and straightening;
forming: cutting the straightened wire into the length of a dart needle, and forging it into a dart needle according to the shape of the dart needle; and
finally, assembling the dart needle with a dart rod, a dart cylinder and a dart wing assembling to form a dart.
[0024] The nickel-titanium alloy material includes the following elements by weight percentage:
nickel 48%, titanium 50%, chromium 0.8%, carbon 0.01%, oxygen 0.05%, hydrogen 0.001%, nitrogen 0.0012%, and the residual being impurities.
Performance detection
[0025] Performances of the dart needles in Embodiments 1-3 are detected, and detection results are shown in Table 1.
| Item | Embodiment 1 | Embodiment 2 | Embodiment 3 |
| Bending strength (MPa) | 1577 | 1621 | 1589 |
| Elasticity modulus (104MPa) | 9.46 | 10.34 | 10.18 |
| Density (g/cm3) | 4.52 | 4.73 | 4.65 |
[0026] The implementation manners are merely preferred implementation manners of the present invention, and are not intended to limit the scope of the present invention. Any insubstantial variation and replacement made by a person skilled in the art on the basis of the present invention shall fall within the protection scope of the present invention.
nickel 48-55%,
titanium 43.5-50%,
chromium 0.8-1.5%,
carbon 0.005-0.01%,
oxygen 0.01-0.05%,
hydrogen ≤0.001%,
nitrogen ≤0.0015%, and
the residual being impurities.
smelting: evenly stirring titanium powder and nickel powder in proportion, and smelting into an ingot;
polishing away the skin: cutting a base of the ingot, and polishing away a surface oxide skin;
rolling into a square shape: rolling the ingot into a rectangular shape;
polishing away the skin: polishing away a surface oxide skin of the rectangular ingot;
rolling into wires: rolling the rectangular ingot into cylindrical wire;
performing rotary forging: performing rotary forging on the cylindrical wire to form a wire material having the diameter of 4-7 mm;
drawing: fractionally drawing the wire material into wires having the diameter of 1-1.5 mm;
straightening: performing heat treatment on the wires and straightening;
forming: cutting the straightened wire into the length of a dart needle, and forging it into a dart needle according to the shape of the dart needle; and
assembling: assembling the dart needle with a dart rod, a dart cylinder and a dart wing assembling to form a dart.