JPH05192060A - Fishing gear for longline fishing - Google Patents

Abstract

PURPOSE:To provide a fishing gear for longline fishing high in biting ratio of target fishes such as tuna to bait and excellent in durability and operability. CONSTITUTION:In the objective fishing gear for longline fishing having a fishhook base wire for connecting a fishhook 26 to branch line part 20, the fishhook base wire 11 contains 0.68-1.00wt.% carbon and is formed by together twisting plural steel wires having 180-400kgf/mm<2> tensile strength and plating these steel wires with zinc aluminum alloy so as to attach the alloy to these steel wires in a plating amount of 40-100g/m<2>.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fishing line, and more particularly to a fishing tackle for longline fishing provided with a fishing wire used for tuna longline fishing.

[0002]

2. Description of the Related Art In tuna longline fishing, buoy lights are dropped from the stern from about 1 to 2 hours before sunrise, while the main ropes are fed out one by one, while the bait of the branch line is fed with saury, squid, sardines, etc. Alternatively, feed the simulated bait and throw it in the sea. The number of pots to be used depends on the size of the fishing boat, but the maximum number of pots to be used per day is about 550 to 600, generally 4
It will be about 100 to 500 bowls. The trunk rope is thrown with a certain amount of slack, but if one bowl is about 300 m long and about 20% of the slack is 450 bowls, the total length is 100 km or more.

In such a longline operation, it takes about 4 hours even if the rope is cast at a full speed of 10 to 12 knots. Until recently, most of the lanyards relied on manual work, but since the advent of automatic lanyards the work has been reduced. The main rope is unwound by an automatic lanyard, and in the process, it is laid at a predetermined trunk position, and floats are attached in order with special clips.

By the way, the portion of the branch rope to which the fishing hook is directly attached is called a fishing wire, and the biting condition of the tuna is considerably different depending on the selection of the material used for this fishing wire, which greatly affects the catch. It is known. Generally, the fishing wire is made of Tegsu or braid, but these have sufficient strength against the violent rotation of the tuna, and none of them are thin enough to be noticed by the tuna.

[0005]

[Problems to be Solved by the Invention] Under these circumstances,
It has been proposed to use steel wire as the fishing wire. The steel wire can further reduce the diameter of the fishing wire while satisfying the desired tensile strength. The use of a small diameter fishing wire makes it difficult for the tuna to be noticed and is lightweight, so that the movement of the bait is activated and it is expected that the tuna bites well.

However, since the fishing wire is used by immersing it in the sea, it will be corroded in a short period of time. Therefore, in order to use the fishing wire stably for a long period of time, it is necessary to apply corrosion-resistant plating to the steel wire with a sufficient thickness. However, if the plating layer is thickened, the life can be extended, but since the plating layer is brittle, the fatigue resistance is reduced, and in addition, the fishing wire becomes thick and the tuna biting rate is reduced.

Further, in the conventional fishing wire, if the tensile strength of the wire is increased, the fatigue resistance of the wire is lowered, and a brittle alloy layer is formed between the base metal and the plating, and the fatigue resistance is further increased. It lowers and breaks in a short time. Especially, in tuna longline fishing, which is operated daily for a long time,
Use stability is required.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide a fishing tackle for longline fishing, which has a high biting rate with respect to the feed of target fish such as tuna and has excellent durability and operability. To aim.

[0009]

In the fishing tackle for longline fishing according to the present invention, the fishing wire for connecting the fishing hook to the branch rope portion contains carbon in an amount of 0.68 to 1.00% by weight, and has a wire tensile strength. 180 to 400 kgf / mm ² Of a plurality of steel wires, and these steel wires are zinc-aluminum alloy plated, and the zinc-aluminum alloy plating deposition amount is 40 to 100 grams per square meter. To do.

The reason why the material of the wire of the fishing wire is selected in the above composition range is that the strength of the wire is 180 to 400 kgf / mm ² for the purpose of achieving high tensile strength. This is because it is necessary to include at least 0.68% by weight or more of carbon in the steel wire in order to improve the steel wire to a certain level. On the other hand, if the carbon content is too high, the fatigue resistance of the cable deteriorates, so the upper limit of the carbon content was set to 1.00% by weight in consideration of the influence of the plating treatment and the like. Further, when chromium is arbitrarily added to strengthen the steel wire, the upper limit of the chromium content is set to 0.4% by weight for the same reason.

The reason why the lower limit of the aluminum content of the Zn-Al alloy plating is set to 4% by weight is that the desired corrosion resistance cannot be obtained with an aluminum content below this value.

On the other hand, the reason why the upper limit of the aluminum content of Zn-Al alloy plating is set to 6% by weight is that the desired fatigue resistance cannot be obtained with an aluminum content exceeding this value.

Further, by setting the Al content in the alloy to 4 to 6% by weight, the fluidity of the molten metal in the bath becomes good, so that the plating surface becomes beautiful, and Zn-
Since the melting point of the Al alloy is low, it is suitable for plating steel wire as a strength member, can suppress erosion in the bath of equipment tools for immersion, and can reduce the occurrence of dross. There are advantages.

The lower limit of the zinc-aluminum coating amount is 40 grams per square meter. When the coating amount is less than this, the plating thickness tends to be non-uniform, and the thin portion of the plating is rusted. This is because the corrosion resistance and durability are deteriorated.

On the other hand, the upper limit of the amount of zinc aluminum plating deposited is 100 grams per square meter.
Since a brittle intermetallic compound layer is generated at the interface between the substrate and the plating, if the plating adhesion amount exceeds this, fatigue cracks will occur in the intermetallic compound layer near the interface due to repeated bending or vibration of the wire or wire twisted wire. The reason is that the wire will be broken in a short time.

The reason why the zinc aluminum plating is formed by a so-called "one bath method" in which a twisted wire or a steel wire forming the twisted wire is immersed and passed through a single molten metal bath is as follows. Secondly, in order to prevent the brittle intermetallic compound layer from growing and developing at the boundary with the plating layer, secondly, to improve the surface characteristics of the plating. The first reason is that the intermetallic compound at the boundary between the wire base metal and the plating layer has the property of being hard and brittle. Therefore, when this intermetallic compound layer grows and develops to a thickness that cannot be ignored, this causes fatigue cracking. This is because the fatigue resistance of the fishing wire is remarkably reduced from the starting point. Also, the second
The reason is that the plating formed by the one-bath method has less uneven thickness and has a smooth surface, so that it is excellent in operability and has improved corrosion resistance and fatigue resistance.

Further, by controlling the cooling conditions immediately after plating to a desired rate and temperature, the pearlite phase in which the granulation has progressed is present in the gap of the dendrite structure of α phase or β phase in the plating layer. Can be mixed tissue. Such a dendrite / pearlite phase mixed structure is particularly excellent in fatigue resistance, and contributes greatly to the improvement of the durability of the fishing wire.

On the other hand, in the pearlite structure in which the α-phase and β-phase thin plate-like layers are alternately arranged, fatigue cracks are easily propagated along the grain boundaries and the fatigue resistance is poor. In particular, in the sharp pearlite structure in which the crystal grain boundaries are directly connected to the substrate, fatigue cracks propagate to the surface along the crystal grain boundaries of the thin plate-like structure, leading to fatigue fracture in a short time.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 2, trunk ropes 30 are successively cast from the longline fishing boat 70.

The trunk line 30 is a main part of a long line and has a total length of 100 km or more. Floating ropes 40 are attached to the trunk ropes 30 at substantially equal intervals by clips (not shown).
0 does not sink to the sea floor. Each float 40
A float 51 and a flag pole 60 are attached to the upper ends of the main ropes 30, and a desired buoyancy is applied to the trunk rope 30 through the plurality of float ropes 40. It should be noted that the buoy lamps 50 are provided together with the floats 51 at appropriate intervals so that they can be seen even at night.

As the floating rope 40, a rope having almost the same thickness as the trunk rope 30 is used, but since it does not receive a strong force unlike the trunk rope 30, the floating rope 40 may have a slightly smaller diameter. Incidentally, the length of the floating rope 40 is about 40 m.

A large number of branch ropes 20 are suspended from the trunk ropes 30. The mutual distance between the branch rope portions 20 is about 50.
m. Fishing hooks 26 are attached to the lower ends of the branch rope portions 20, and baits are attached to the fishing hooks 26. Here, the space between the floating rope 40 and the next floating rope 40 is called one pot. As shown in FIG. 3, in the case of tuna longline fishing, the lengths of the branch lines 20 provided in one bowl are almost the same. Next, the branch rope portion 20 will be described with reference to FIG.

The branch rope portion 20 is roughly composed of three portions. That is, the upper branch rope 22, the Sekiyama 24, and the fishing wire 11 are bound in order from the trunk rope binding portion 31. The branch rope portion 20 has the fishing hook 26 attached to the fishing wire 11 at the lower end, and thus serves as a line thread in the case of a fishing rod. In particular, fishermen use nerves for the fishing wire 11 because the material and the condition of the fishing wire 11 affect the feeding of the tuna.

The length of the upper branch rope 22 depends on the swimming layer in which the target fish inhabits, but in the case of tuna fishing, it is 15 to 20.
It is about m. Sekiyama 24 following the upper branch rope 22 is 9
It is a wire in which No. 26 to No. 29 wires are twisted and wound with a silk thread or a thread having a thickness of vinylon 210D, and is connected to a branch line 22 by a "pot", and the lower end thereof is also the fishing wire 11 Connected to.

As shown in FIG. 4, the upper branch rope 22 is bound to the trunk rope 30 by the binding portion 31. As shown in FIG. 5, the Sekiyama 24 is connected to the upper branch rope 22 by a salcan 23. The sulcan 23 has a more reversing role. As shown in FIG. 6, the fishing wire 11 is joined to the Sekiyama 24 by the joining portion 25. As shown in FIG. 7, a fishing hook 26 is attached to the lower end of the fishing wire 11. The fishing wire 11 is formed by twisting seven wires of Nos. 25 to 30 and has a length of about 2 m. Fishhook 2
6 has a size of 105 to 115 mm. As shown in FIG. 8, the flagpole 60 has a floating rope 40, two floats 51,
A red and white flag 61 and a weight 62 are tied together. Next, a case of manufacturing the fishing wire 11 will be described. [Heat treatment of steel wire]

Carbon content is 0.62% by weight,
0.68% by weight, 0.86% by weight, 0.92% by weight,
Five kinds of 1.42 mm diameter piano wire rods containing 0.90% by weight of hypereutectoid steel and 0.20% by weight of chromium were heated in the austenite region and then passed through the A ₁ transformation point from the maximum heating temperature. The structure of each wire is transformed from austenite to pearlite by accelerating cooling at such a rate that the time until the heating becomes 0.8 seconds or less.

In this heat treatment step, care must be taken so that initial cementite does not form and the structure does not become coarse. This is because if coarse cementite precipitates, subsequent wire drawing becomes difficult and the fatigue resistance of the wire decreases. [Steel wire plating]

The steel wire plating process will be described with reference to FIG. The steel wire 11a heat-treated as described above is dipped and passed in a molten lead bath (about 420 to 440 ° C.) not shown, and further dipped and passed in a water cooling tank, a hydrochloric acid tank, and a water washing tank (neither is shown). Degrease and wash. After the degreasing cleaning treatment, a predetermined amount of flux is attached to the steel wire 11a in the flux tank 2 and dried in the hot air drying furnace 3. After drying, the steel wire 11a is dipped and passed through the plating bath 4. The plating bath 4 contains a molten zinc aluminum alloy.

A roll box 5 is provided at a position where the steel wire 11a is transferred from horizontal to vertical by a roll 5 in the bath and the steel wire 11a is pulled up from the bath 4. A non-oxidizing gas 7 is introduced into the seal box 6, and excess zinc aluminum alloy adhering to the steel wire 11a is squeezed out under a non-oxidizing atmosphere to adjust the plating layer to an appropriate thickness. Further, the water cooling nozzle 8 allows the steel wire 11a.
Water is sprayed onto the steel wire 11a to cool it. Cooling water 45 ±
The temperature is adjusted to 2 ° C. and the steel wire 11a is cooled at a desired cooling rate. The zinc-aluminum alloy plating deposition amount was variously changed within the range of 30 to 120 grams per square meter of the wire surface area, and various samples shown in Table 1 were prepared.

Separately, for comparison, a wire having a carbon content of 0.62% by weight was galvanized to prepare another sample (Comparative Examples 1 to 5). In this case, the galvanized amount is 8 per square meter of wire surface area.
Various changes were made in the range of 0 to 160 grams. [Drawing]

After the plating treatment, the steel wire 11a was reduced in area by 96.
Wire drawing was performed at 5%. At this time, it is necessary to reduce the surface tensile residual stress of the wire generated during wire drawing for the purpose of ensuring the workability for obtaining the desired strength. That is, in the middle of wire drawing, the steel wire 11a is passed through a so-called leveling roll in which a plurality of small-diameter rollers are arranged in a zigzag manner, and a small bending strain is applied to the steel wire 11a to improve the twisting value. As in this example, since the surface properties of the plating formed by the one-bath method are good, the effect of wire drawing on the fatigue resistance is not recognized. [Twisted] Plating coverage is 1m ² A case where the wire 11 is manufactured by twisting together about 80 grams of the steel wire 11a will be described.

Steel wire 11 from seven bobbins of the tubular stranded wire machine
The rotor was rotated while supplying a toward each voice, and 1 × 7 wire ropes 11 having a cross section as shown in FIG. 10 were manufactured. The twist pitch at this time was 28 to 30 mm.

As shown in Table 1, the wire ropes of Examples 1 to 16 and Comparative Examples 1 to 19 were manufactured through the above steps. Here, the wire rope 11 is set to 1
× 7 strands were used, but the number is not limited to this, and 3 of FIG.
× 7 twisted rope, 1 × (3 + 9) twisted rope in FIG.
Alternatively, a 4 × 3 twist rope of FIG. 13 may be used. next,
The fatigue test of the rope 11 will be described with reference to FIG. [Durability test]

One end of the sample rope 11 is fixed to the member 81 of the fatigue testing machine, and the weight 82 is hung from the other end through the supporting roll 83, and the roll 80 is set in groups of three. Thus, tensile and compressive bending stress was repeatedly applied to the sample rope 11. The diameter of each roll 80 is 1 inch, and three rolls 80 are simultaneously reciprocated in the horizontal direction. The weight of the weight 82 corresponds to 10% of the breaking load of the rope 11.

In this case, the test condition is a stroke amount of 2
A reciprocating vibration of 5 mm was applied to the rope 11 about 80,000 times.
The acceptance / rejection of the durability test was determined by the presence / absence of wire breakage. As shown in Table 1, Examples 1 to 1
All 16 test results were good. On the other hand, the results of Comparative Examples 3 to 5, 11, 13, 15, 15, 17 and 19 were poor. [Corrosion resistance test]

In order to evaluate the corrosion resistance of each sample rope, a salt spray test was conducted. Salt water was sprayed onto the rope at room temperature, and the time until red rust was generated on the surface was examined. Those with a red rust generation time of more than 200 hours are regarded as acceptable.

As shown in Table 1, the test results of Examples 1 to 16 were all excellent, with the result that the red rust generation time significantly exceeded 200 hours. On the other hand, Comparative Example 1,
The results of 2, 6, 12, 14, 16, 18 were clearly inferior to this. In addition, in the other comparative examples, the red rust generation time was 220 hours, which was relatively good.

The steps of cold drawing (drawing) of the rope and plating may be replaced with each other.
That is, in the above embodiment, the case where the wire drawing process is performed after the plating process has been described, but the plating process may be performed after the wire drawing process.

In addition, in the above embodiment, an example of tuna longline fishing has been described, but the present invention is not limited to this.
As shown in FIG. 15, the fishing wire 11 may be adopted as a dragonfly rope having branch rope portions 20 having different lengths in one pot. Further, as shown in FIG. 16, the present invention can also be applied to a bluefin tuna rope having only one branch rope 20 in one pot.

[0040]

[Table 1]

[0041]

According to the present invention, it is possible to provide a fishing gear which is excellent in durability and operability and has high tensile strength and light weight. In particular, when the cooling rate is controlled during the wire plating treatment, the growth and development of the intermetallic compound layer at the boundary between the strand base material and the plating layer is small, and a plating structure excellent in fatigue resistance can be obtained. For this reason, it is possible to obtain a fishing gear that is compact and light, and that has a fishing wire that is hard to break.

Further, by increasing the tensile strength of the strand, the strand diameter can be reduced, the amount of zinc aluminum alloy deposited can be increased, and the corrosion resistance can be improved. In particular, in zinc-aluminum alloy plating as compared with zinc plating, it is possible to improve the corrosion resistance by a factor of 2 to 3 when the amount of adhesion is the same. Furthermore, in the fishing gear of the present invention, the diameter of the fishing wire is 20 to 25% as compared with the conventional Tegsu product.
Since it can be made thin, the biting rate of tuna is significantly improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a mechanism of a fishing gear according to an embodiment of the present invention.

[Figure 2] Schematic diagram of tuna longline fishing.

FIG. 3 is a view showing the mechanism of one longline between the float and the float.

FIG. 4 is an enlarged view of a portion where a branch rope is connected to a trunk rope.

FIG. 5 is an enlarged view showing a connecting portion between the twisting (sarkan) and Sekiyama.

FIG. 6 is an enlarged view showing a connecting portion between Sekiyama and a fishing wire.

FIG. 7 is an enlarged view showing a fishing hook connected to a fishing wire.

FIG. 8 is an enlarged view showing a flagpole.

FIG. 9 is a schematic configuration diagram showing a part of a plating apparatus.

FIG. 10 is a cross-sectional view of the fishing wire according to the embodiment of the present invention.

FIG. 11 is a transverse cross-sectional view of a fishing wire according to another embodiment.

FIG. 12 is a cross-sectional view of a fishing wire according to another embodiment.

FIG. 13 is a cross-sectional view of a fishing wire according to another embodiment.

FIG. 14 is a schematic configuration diagram showing a part of a fatigue resistance test apparatus.

FIG. 15 is a schematic view of a dragonfly rope.

FIG. 16 is a schematic diagram of a bluefin tuna rope.

[Explanation of symbols]

11: fishing wire, 20: branch line parts 21, 25; coupling part, 22: upper branch line, 23;
24; Sekiyama, 26; Fishing hook, 30; Trunk line, 31; Snap, 40; Float, 50; Buoy light, 51; Float, 60;
Flagpole

Claims (3)

[Claims] 1. A fishing tackle for longline fishing, comprising a fishing wire for connecting a fishing hook to a branch line portion, wherein the fishing wire is 0.6
Contains 8 to 1.00% by weight of carbon and has a wire tensile strength of 180
~ 400 kgf / mm ² Formed by twisting multiple steel wires of
A fishing tackle for longline fishing, characterized in that these steel wires are zinc-aluminum alloy plated, and the zinc-aluminum alloy plating deposition amount is 40 to 100 grams per square meter. 2. The fishing tackle for longline fishing according to claim 1, wherein the plating mainly comprises a Zn--Al alloy layer containing 4 to 6% by weight of aluminum. 3. The plating is made of a Zn--Al alloy mainly composed of a mixed structure in which a pearlite phase in which granulation has progressed exists in the interstices of the dendrite structure of the α phase or β phase. The fishing gear for longline fishing according to claim 1.