JP7810085B2 - Trolley wire manufacturing method and trolley wire manufacturing device - Google Patents

Description

The present invention relates to a method and apparatus for manufacturing trolley wire.

Traditionally, copper and copper alloys have been the primary materials used for electric train wires (trolley wires) that supply power to trains via pantographs and other devices. While ordinary copper wire is made by cold drawing copper wire rods with a diameter of 8 mm or more through wire drawing dies, trolley wire is manufactured by cold drawing copper wire rods with a diameter of 20 mm or more. Because the strength of trolley wire is directly linked to its lifespan, there is a strong demand for both lower costs and improved strength. As a result, various initiatives are being undertaken by various manufacturers.

For example, there are manufacturers that manufacture trolley wires that achieve low costs by limiting the alloying elements added to the copper base material to only one inexpensive solid-solution strengthening element, and manufacturers that manufacture high-performance trolley wires with tensile strengths exceeding 500 MPa by adding multiple precipitation-strengthening elements to the copper base material and then heat treating it. As shown in Patent Documents 1 and 2, the applicant provides high-strength, low-cost trolley wires by adding tin and indium, which are solid-solution strengthening elements, to the copper base material and by devising manufacturing methods for copper wire rods.

For typical trolley wire, the wire drawing equipment mainly used is a single-head wire drawing machine, which has only one die on the wire drawing line and repeatedly draws and rewinds the wire, or a continuous wire drawing machine, which has multiple dies on the wire drawing line. A known method of manufacturing trolley wire using a continuous wire drawing machine involves three wire drawing processes and one groove processing process, as shown in Patent Document 3, for example.

When continuously drawing contact wire, the heat generated during the process can cause a decrease in strength, so cooling during the process is important, especially when manufacturing contact wire that requires high strength. In general copper wire processing equipment, room temperature processing oil is applied to or immersed in the dies, capstans, and copper wire for cooling. Known examples of immersion cooling and wire drawing of general copper wire in processing oil include those described in Patent Document 4.

Japanese Patent Application Laid-Open No. 2004-137551 JP 2007-56370 A Japanese Patent Application Laid-Open No. 2010-201478 Japanese Patent Application Laid-Open No. 2008-290121

However, because contact wires have a large diameter, they generate a lot of processing heat during the wiredrawing process, and there is a concern that room-temperature processing oil will not be able to fully reduce the processing heat, resulting in a decrease in strength. Furthermore, because the same wiredrawing oil is used repeatedly in a single wiredrawing process, the temperature of the wiredrawing oil rises, which could result in incomplete reduction of processing heat. Furthermore, the processing oil used for contact wires has a high viscosity due to the balance with the wiredrawing load, making it unsuitable for cooling.

The present invention therefore aims to provide a trolley wire manufacturing method and manufacturing device that can produce high-strength trolley wire while keeping costs down.

In order to solve the above-mentioned problems, the present invention provides a method for manufacturing a trolley wire made of a copper base material containing 0.25% or more by weight of tin, which includes a processing step in which the wire is drawn and grooved using multiple dies while being transported by multiple transport devices. The method successively performs the wiredrawing and grooved processes while cooling using a first cooling mechanism that sprays cooling water inside the transport devices, a second cooling mechanism that cools the dies by immersing or applying wiredrawing oil, and a third cooling mechanism that applies an aqueous lubricant to the wire and stores the water-based lubricant in a cover that houses the transport devices, thereby immersing the wire in the water-based lubricant.

In order to solve the above-mentioned problems, the present invention also provides a trolley wire manufacturing device that includes a supply device that supplies wire made of a copper base material containing 0.25% or more by weight of tin, multiple transfer devices that transfer the wire, multiple dies that perform wire drawing and grooving on the wire, a first cooling mechanism that sprays cooling water into the interior of the transfer devices, a second cooling mechanism that cools the dies by immersing or applying wire drawing oil, and a third cooling mechanism that applies a water-based lubricant to the wire and stores the water-based lubricant in a cover that houses the transfer devices, thereby immersing the wire in the water-based lubricant.

The trolley wire manufacturing method and manufacturing device of the present invention make it possible to manufacture high-strength trolley wire while keeping costs down.

2 is a flowchart illustrating an example of steps in a method for manufacturing a trolley wire according to an embodiment of the present invention. 1 is a schematic diagram showing a configuration example of a trolley wire manufacturing device according to an embodiment of the present invention. 1A to 1F are cross-sectional views of a wire rod, a drawn wire material, a stripped material, a first grooved material, a second grooved material, and a trolley wire. FIG. 2 is a cross-sectional view showing an example of a first cooling mechanism. FIG. 10 is a cross-sectional view showing an example of a second cooling mechanism. FIG. 10 is a cross-sectional view showing an example of a third cooling mechanism.

[Embodiment]
Fig. 1 is a flowchart showing an example of a method for manufacturing a trolley wire 100 according to an embodiment of the present invention. Fig. 2 is a schematic diagram showing an example of the configuration of a manufacturing apparatus 1 for the trolley wire 100 according to the present embodiment. Figs. 3(a) to 3(f) are cross-sectional views of a wire rod 11, a drawn wire material 12, a stripping material 13, a first grooved material 14, a second grooved material 15, and the finished trolley wire 100. Figs. 4 to 6 are cross-sectional views showing the configurations of first to third cooling mechanisms 6 to 8 of the manufacturing apparatus 1.

As shown in Figure 3(f), the trolley wire 100 is formed with a pair of suspension grooves 101 for stringing the trolley wire 100 and a pair of holding grooves 102 for holding an optical fiber 90 as a detection wire for detecting when the wear amount of the trolley wire 100 reaches a predetermined value, which extend longitudinally along the entire length of the trolley wire 100. The trolley wire 100 is suspended above the track of the railway vehicle by metal fittings with claws that clamp the pair of suspension grooves 101. When the optical fiber 90 breaks, it is detected that the wear amount of the trolley wire 100 has reached a predetermined value.

The roughly drawn wire 11, the drawn wire material 12, the stripping material 13, the first grooved material 14, and the second grooved material 15 are linear bodies in the process of processing the trolley wire 100. In the following description, the roughly drawn wire 11, the drawn wire material 12, the stripping material 13, the first grooved material 14, and the second grooved material 15 are collectively referred to as wire material 10. The first grooved material 14 and the second grooved material 15 are respectively formed with suspension grooves 141, 151 that become the suspension groove 101 of the trolley wire 100, and holding grooves 142, 152 that become the holding groove 102 of the trolley wire 100.

As shown in Figure 1, the manufacturing method of the trolley wire 100 according to this embodiment includes a wiredrawing process (F1) in which the rough wire 11 is drawn into a circular shape to produce the drawn wire material 12; a stripping process (F2) in which the copper oxide layer 121 is removed from the surface of the drawn wire material 12 to produce the stripped material 13; a grooving process (F3) in which the stripped material 13 is grooved to sequentially produce the first grooved material 14 and the second grooved material 15; a finishing process (F4) in which the second grooved material 15 is finished to give it the final shape as the trolley wire 100; and a winding process (F5) in which the trolley wire 100 is wound onto the wire storage machine 4.

In this embodiment, a pair of suspension grooves 101 and holding grooves 102 are formed by two groove processes on the wire 10. The first grooved material 14 is a linear body after the first groove process, and the second grooved material 15 is a linear body after the second groove process. The finishing process in the finishing step (F4) includes accommodating the optical fibers 90 in each of the pair of holding grooves 152 of the second grooved material 15 and then closing the pair of holding grooves 152.

The wire drawing process (F1), skinning process (F2), groove forming process (F3), finishing process (F4), and winding process (F5) are carried out continuously, i.e., as a series of processes, without interrupting the flow of the wire rod 10 and trolley wire 100 at each stage from when the rough wire 11 is unwound until the trolley wire 100 is wound onto the wire storage machine 4. The trolley wire 100 is then rewound from the wire storage machine 4 onto the winding drum 51 and shipped.

As shown in FIG. 2, the manufacturing apparatus 1 includes a wire rod payout machine 2 that pays out a wire rod 11 wound into a coil, first through fifth processing machines 3A-3E (hereinafter collectively referred to as "processing machines 3"), a wire storage machine 4 that stores the trolley wire 100 produced by the first through fifth processing machines 3A-3E, and a drum winding machine 5 that winds the trolley wire 100 paid out from the wire storage machine 4 onto a winding drum 51. The wire rod payout machine 2 is an example of a supply device of the present invention. The wire storage machine 4 is an example of a winding device of the present invention.

The manufacturing apparatus 1 also has each of the first to third cooling mechanisms 6-8 shown in Figures 4 to 6 in at least one of the first to fifth processing machines 3A-3E. The first to third cooling mechanisms 6-8 cool the wire 10 so that the pre-processing temperature of the wire 10 immediately before each of the wire drawing, skinning, grooving, and finishing processes is 30°C or less, and the post-processing temperature of the wire 10 immediately after each of these processes is 100°C or less.

The wire rod payout machine 2 pays out the wire rod 11, which is produced by casting and hot-rolling molten pure copper or copper alloy, from the coil 21 at a constant speed. The wire rod 11 is made of a copper base material containing 0.25% or more by weight of tin. The copper base material may contain other additive elements (e.g., indium) in addition to tin. In this case, the total content of the additive elements, including tin and other additive elements, may be, for example, 0.15% or more by weight and 0.8% or less by weight.

The first to fifth processing machines 3A to 3E each have dies 31A to 31E (collectively referred to as "dies 31") that shape the wire rod 10, and first to fifth capstans 32A to 32E (collectively referred to as "capstans 32") that transfer the wire rod 10 to subsequent processes. The first to fifth capstans 32A to 32E are arranged adjacent to and downstream of the dies 31A to 31E in the direction of travel of the wire rod 10. The rough wire rod 11 is shaped by passing sequentially through the dies 31A to 31E of the first to fifth processing machines 3A to 3E, and its cross-sectional shape and size gradually become closer to that of the trolley wire 100. The capstans 32 are an example of a transfer device of the present invention.

The manufacturing apparatus 1 uses a round-hole wire drawing die (die 31A) of the first processing machine 3A to draw the rough wire 11 to produce the drawn wire material 12; a stripping die (die 31B) of the second processing machine 3B to strip the surface of the drawn wire material 12 to produce the stripped material 13; grooved dies (dies 31C, 31D) of irregular holes (die 31C, 31D) of the third processing machine 3C and the fourth processing machine 3D to groove the wire in two separate steps to produce the second grooved material 15; and a finishing die (die 31E) of the fifth processing machine 3E to produce the final shape of the trolley wire 100. Here, the second processing machine 3B, which performs the stripping process, is an example of the stripping device of the present invention. Optical fiber 90 is supplied to the fifth processing machine 3E from the detection wire payout machine 9.

The manufacturing apparatus 1 includes a wire drawing payout machine 2, a die 31A (wire drawing die), a first capstan 32A, a die 31B (skinning die), a second capstan 32B, a die 31C (irregular hole die), a third capstan 32C, a die 31D (irregular hole die), a fourth capstan 32D, a die 31E (finishing die), a fifth capstan 32E, and a wire storage machine 4, all arranged in series, so that the manufacturing process can be performed continuously from the payout of the wire drawing 11 to the winding of the trolley wire 100. The manufacturing apparatus 1 also includes a wire speed control unit that controls the rotational speed of each of the multiple capstans 32 so that the wire speed of the wire 10 in the first through fifth processing machines 3A-3E is constant. Each capstan 32 applies a predetermined tension to the wire 10 while transporting it.

The wire storage machine 4 has a cylindrical winding body 41 and continuously winds the trolley wire 100 produced by the first to fifth processing machines 3A to 3E onto the winding body 41 from its starting end to its terminal end. The drum winding machine 5 does not operate until the wire storage machine 4 winds up the terminal end of the trolley wire 100, and after the wire storage machine 4 winds up the terminal end of the trolley wire 100, it winds the trolley wire 100 unwound from the wire storage machine 4 onto a winding drum 51.

Figure 4 is a cross-sectional view showing an example of a first cooling mechanism 6 for cooling the capstan 32. This first cooling mechanism 6 is provided in at least one of the first through fifth processing machines 3A-3E. The capstan 32 becomes hot due to heat transferred from the shaped wire 10. For this reason, the first cooling mechanism 6 sprays cooling water 60 inside the capstan 32 to suppress the temperature rise of the capstan 32 during at least one of the wire drawing process (F1), skinning process (F2), grooving process (F3), and finishing process (F4).

The first cooling mechanism 6 includes a rotary joint 61, a portion of which is located inside the capstan 32, a cooling water tank 62 that stores cooling water 60, a cooling water device 63 that lowers the temperature of the cooling water 60 and supplies it to the cooling water tank 62, and a pump 64 that transports the cooling water 60 in the cooling water tank 62 to the inside of the rotary joint 61 and sprays the cooling water 60 inside the capstan 32. In Figure 4, 62a, 62b, 63a, and 63b are pipes that transport the cooling water 60.

The rotary joint 61 has a pipe 611 that passes through it. A pump 64 transports cooling water 60 through the pipe 611 into the capstan 32 and sprays it. The cooling water 60 sprayed inside the capstan 32 cools it. The cooling water 60 sprayed inside the capstan 32 also flows inside the capstan 32, passes from inside the capstan 32 back through the rotary joint 61, and is collected in the cooling water tank 62. The cooling water device 63 draws cooling water from the cooling water tank 62, cools it, and returns the cooled cooling water 60 to the cooling water tank 62.

Figure 5 is a cross-sectional view showing an example of a second cooling mechanism 7 for cooling the die 31. This second cooling mechanism 7 is provided in at least one of the first to fifth processing machines 3A to 3E. The temperature of the die 31 rises due to processing heat generated when shaping the wire rod 10. Furthermore, in order to shape the wire rod 10 with a small load, it is necessary to supply wire drawing oil to the die 31. For this reason, the second cooling mechanism 7 cools the die 31 by immersing it in or applying wire drawing oil 70 during at least one of the wire drawing process (F1), skinning process (F2), grooving process (F3), and finishing process (F4), thereby suppressing the temperature rise of the die 31.

The second cooling mechanism 7 has a die box 71 that houses a guide die 711 that guides the wire 10, a first die holder 712 that holds the guide die 711, and a second die holder 713 that holds the die 31. The die box 71 is filled with wire drawing oil 70 to the extent that at least a portion of the guide die 711, the first die holder 712, the die 31, and the second die holder 713 are immersed.

The second cooling mechanism 7 includes an oil tank 72 that collects wiredrawing oil 70 in the die box 71, an oil filter 73 located on the supply pipe 72a of the oil tank 72 and that collects copper powder and other particles generated during processing, a pump 74, a heat exchanger 75, a cooling water unit 76, and an oil supply nozzle 77 that supplies wiredrawing oil 70 into the die box 71. The pump 74 pumps the wiredrawing oil 70 that has passed through the oil filter 73 to the heat exchanger 75. The cooling water unit 76 supplies cooling water to the heat exchanger 75 to cool the wiredrawing oil 70. The heat exchanger 75 exchanges heat between the wiredrawing oil 70 and the cooling water from the cooling water unit 76. In FIG. 4, 72a, 72b, and 75a are pipes that transport wiredrawing oil 70. 76a and 76b are pipes that transport cooling water between the heat exchanger 75 and the cooling water unit 76.

The wire drawing oil 70 is drawn into the pump 74 from the oil tank 72 and discharged from the pump 74. After its temperature is lowered through the heat exchanger 75, it is supplied to the die box 71 through the oil supply nozzle 77, cooling the die 31. Instead of using the oil supply nozzle 77, the wire drawing oil 70 may be applied to the die 31 with a paintbrush or brush.

Figure 6 is a cross-sectional view showing an example of a third cooling mechanism 8 that performs both direct cooling at the capstan 32 and emulsion immersion cooling. This third cooling mechanism 8 is provided in at least one of the first through fifth processing machines 3A-3E. The third cooling mechanism 8 applies emulsion 80 to the wire 10 during at least one of the wire drawing process (F1), skinning process (F2), grooving process (F3), and finishing process (F4), and then immerses the wire 10 in the emulsion 80 by storing the emulsion 80 in a capstan cover 81. In other words, to further cool the wire 10 whose processing heat has been alleviated by applying the emulsion 80, the emulsion 80 applied to the wire 10 from the emulsion nozzle 82 is stored and the wire 10 is immersed in it. Here, the emulsion 80 is an example of a water-based lubricant.

The third cooling mechanism 8 includes a capstan cover 81 that houses the capstan 32, an emulsion nozzle 82 that applies emulsion 80 to the wire 10, an emulsion tank 83 that houses the emulsion 80, a pump 84 that pressurizes the emulsion 80 in the emulsion tank 83, a heat exchanger 85, and a cooling water device 86 that supplies cooling water to the heat exchanger 85. The heat exchanger 85 exchanges heat between the emulsion 80 and the cooling water from the cooling water device 86. In Figure 5, 83a, 83b, and 85a are pipes that transport the emulsion 80. 86a and 86b are pipes that transport cooling water between the heat exchanger 85 and the cooling water device 86.

The emulsion 80 applied to the wire 10 is stored in a depth of approximately 20 cm inside the capstan cover 81, and the wire 10 is further cooled by immersing it in the emulsion 80. The emulsion 80 stored in the capstan cover 81 is collected in the emulsion tank 83. The collected emulsion 80 has its temperature lowered by the heat exchanger 85, and is then applied again to the wire 10 by the emulsion nozzle 82. The emulsion 80 applied to the wire 10 is blown away by a blower. This prevents the emulsion 80 from mixing with the wire drawing oil 70.

(Modification)
In the above embodiment, the wire drawing process is performed in one step, but the wire drawing process may be performed in multiple steps. In the above embodiment, the grooving process is performed in two steps, but the number of times the grooving process is performed may be one step or three or more steps. In the first cooling mechanism 6, emulsion may be used instead of the cooling water 60, and the emulsion may be collected in an emulsion tank. In the first cooling mechanism 6, other refrigerants such as gas may be used instead of the cooling water 60.

(Example)
To verify the strength-enhancing effect of this embodiment, the tensile strength of each contact wire was investigated using a single-head wire drawing machine, a continuous wire drawing machine without cooling reinforcement, and a continuous wire drawing machine with cooling reinforcement corresponding to the above embodiment. The contact wires (samples) used were a 110 ^mm² cross-sectional area contact wire (Cu-Sn contact wire 110SQ) containing 0.3 wt% tin, a 110 mm² ^cross -sectional area contact wire (Cu-Sn-In contact wire 110SQ) containing 0.3 wt% tin and 0.1 wt% indium, and a 170 ^mm² cross-sectional area contact wire (Cu-Sn-In contact wire 170SQ) containing 0.3 wt% tin and 0.1 wt% indium. The tensile strength and elongation of the contact wires were measured in accordance with JIS C3002 (Test Methods for Electrical Copper Wires and Aluminum Wires). Table 1 shows the tensile load, tensile strength, and elongation of the contact wires. Tensile strength is the tensile load divided by the nominal cross-sectional area.

As shown in Table 1, the single-head wire drawing machine and the continuous wire drawing machine without cooling reinforcement have roughly the same tensile load and tensile strength of the contact wire, and it can be seen that, depending on the product type, the continuous wire drawing machine without cooling reinforcement has a lower tensile load and tensile strength of the contact wire. On the other hand, the continuous wire drawing machine with cooling reinforcement has a tensile strength that is about 3 to 4% higher than that of the single-head wire drawing machine, and about 6 to 7% higher than that of the continuous wire drawing machine without cooling reinforcement, achieving a tensile strength of 430 MPa or more. Therefore, it can be seen that the strength of the contact wire can be increased by performing the cooling reinforcement according to the above embodiment. Furthermore, with general metal materials, elongation decreases as tensile strength increases, but it can be seen that the elongation of the contact wire manufactured in this example maintains the same level of elongation as that of the single-head wire drawing machine.

(Effects of the embodiment)
As described above, according to this embodiment, the wire rod 10 can be supplied to each die 31 in a sufficiently cooled state during shaping of the wire rod 10, and the temperature of the wire rod 10 can be kept low during and after processing, thereby making it possible to manufacture a high-strength trolley wire 100. Furthermore, since the strength of the trolley wire 100 and the life of the trolley wire 100 are proportional to each other, by increasing the strength of the trolley wire 100, it is possible to extend the life of the trolley wire 100 while keeping costs down.

(Summary of the embodiment)
Next, the technical ideas grasped from the above-described embodiments will be described by using the reference numerals and the like in the embodiments. However, the reference numerals in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiments.

[1] A method for manufacturing a trolley wire (100) made of a copper base material containing 0.25% or more by weight of tin, comprising a processing step of drawing and grooving a wire (10) using a plurality of dies (31) while transferring the wire using a plurality of transfer devices (capstans 32), and the wire drawing and grooving are continuously performed while cooling is performed using a first cooling mechanism (6) that sprays cooling water (60) inside the transfer devices (32), a second cooling mechanism (7) that cools the dies by immersing or applying wire drawing oil (70), and a third cooling mechanism (8) that applies an aqueous lubricant (emulsion 80) to the wire (10) and stores the aqueous lubricant (80) in a cover (capstan cover 81) that houses the transfer devices (32), thereby immersing the wire (10) in the aqueous lubricant (80).

[2] The method for manufacturing a trolley wire described in [1] above, wherein the cooling is performed so that the pre-processing temperature of the wire (10) before the wire drawing and the groove forming is 30°C or less, and the post-processing temperature of the wire (10) after the wire drawing and the groove forming is 100°C or less.

[3] The method for manufacturing a trolley wire described in [1] above, wherein the grooving process is a process for forming grooves (141, 142, 151, 152) in the wire rod (10) using a special-hole die (31C, 31D).

[4] The method for manufacturing a trolley wire described in [1] above, wherein the processing step further includes a skinning process for skinning the surface of the wire (10), and in the processing step, the wire drawing process, the skinning process, and the grooving process are performed consecutively while cooling is performed by the first to third cooling mechanisms (6 to 8).

[5] A method for manufacturing a trolley wire according to any one of [1] to [4] above, wherein the tensile strength of the trolley wire (100) processed in the processing step is 430 MPa or more.

[6] A trolley wire manufacturing apparatus (1) comprising: a supply device (rough wire drawing payout machine 2) that supplies wire (10) made of a copper base material containing 0.25% or more by weight of tin; a plurality of transfer devices (32) that transfer the wire (10); a plurality of dies (31) that perform wire drawing and grooving on the wire (10); a first cooling mechanism (6) that sprays cooling water (60) into the inside of the transfer device (32); a second cooling mechanism (7) that cools the dies (31) by immersing or applying wire drawing oil (70); and a third cooling mechanism (8) that applies an aqueous lubricant (80) to the wire (10) and stores the aqueous lubricant (80) in a cover (81) that houses the transfer device (32), thereby immersing the wire (10) in the aqueous lubricant (80).

[7] The trolley wire manufacturing apparatus (1) described in [6] above, further comprising a skinning device (second processing machine 3B) that skins the surface of the wire (10) that has been subjected to the wire drawing process.

The above describes embodiments of the present invention, but the above-described embodiments do not limit the scope of the invention as defined in the claims. It should also be noted that not all combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention.

1... Manufacturing device 10... Wire rod 100... Trolley wire 2... Rough wire payout machine (supply device)
3...Processing machine 31, 31A to 31E...Dies 32...Capstan (transfer device) 32A to 32E...First to fifth capstans 3A to 3E...First to fifth processing machines 6...First cooling mechanism 60...Cooling water 7...Second cooling mechanism 70...Wire drawing oil 8...Third cooling mechanism 80...Emulsion (water-based lubricant) 81...Capstan cover (cover)

Claims (7)

A method for manufacturing a trolley wire made of a copper base material containing 0.25% by weight or more of tin,
a processing step in which wire drawing and grooving are performed using a plurality of dies while the wire is being transferred using a plurality of transfer devices;
The wire drawing and the grooving are performed successively while cooling is performed by a first cooling mechanism that sprays cooling water into the inside of the transfer device, a second cooling mechanism that cools the die by immersing or applying wire drawing oil, and a third cooling mechanism that applies an aqueous lubricant to the wire and stores the aqueous lubricant in a cover that houses the transfer device, thereby immersing the wire in the aqueous lubricant.
Method of manufacturing contact wire. The cooling is performed so that the pre-processing temperature of the wire rod before the wiredrawing and the grooving is 30°C or less, and the post-processing temperature of the wire rod after the wiredrawing and the grooving is 100°C or less.
The method for manufacturing a trolley wire according to claim 1. The grooving process is a process of forming a groove in the wire using a special hole die.
The method for manufacturing a trolley wire according to claim 1. The processing step further includes a skinning process for skinning the surface of the wire,
In the processing step, the wire drawing, the skinning, and the grooving are successively performed while cooling is performed by the first to third cooling mechanisms.
The method for manufacturing a trolley wire according to claim 1. The tensile strength of the trolley wire processed in the processing step is 430 MPa or more.
A method for manufacturing a trolley wire according to any one of claims 1 to 4. a supply device for supplying a wire made of a copper base material containing 0.25 wt % or more of tin;
a plurality of transfer devices for transferring the wire;
a plurality of dies for drawing and grooving the wire;
a first cooling mechanism that sprays cooling water into the inside of the transfer device;
a second cooling mechanism that cools the die by immersing it in or applying wire drawing oil;
a third cooling mechanism that applies a water-based lubricant to the wire and stores the water-based lubricant in a cover that houses the transfer device, thereby immersing the wire in the water-based lubricant;
A contact wire manufacturing device equipped with the above. The wire drawing method further includes a stripping device for stripping the surface of the wire that has been subjected to the wire drawing process.
7. The apparatus for manufacturing a trolley wire according to claim 6.