WIRE DRAWING DEVICE AND METHOD FOR MANUFACTURING WIRE

Abstract

Included are a wire supply part, a wire pulling part, a first capstan mechanism part and a second capstan mechanism part. The first capstan mechanism part includes a plurality of first capstans, a first rotation drive source and a first rotation transmission mechanism part that transmits the rotation drive force of the first rotation drive source to the respective first capstans, and the second capstan mechanism part includes a plurality of second capstans and a plurality of second rotation drive sources that rotatively drive the respective second capstans in an individually manner. Dies are provided between ones of the respective first capstans and the respective second capstans.

Description

TECHNICAL FIELD

The present invention relates to the technology of drawing a wire.

BACKGROUND ART

The conventional technologies of drawing wires are disclosed in Patent Document 1 and Patent Document 2.

In Patent Document 1, a plurality of intermediate drawing capstans are divided into two or more blocks such that some of them are accommodated in one block, and the plurality of intermediate drawing capstans are driven by one motor per block.

In Patent Document 2, a plurality of wire drawing units including a drive capstan and a capstan drive motor are disposed between unwinding means and winding means.

In the wire drawing machines as described above, the degree of diameter reducing deformation is set correspondingly to the intervals between the capstans, which are configured such that a wire is gradually subjected to diameter reducing deformation through a plurality of diameter reducing deformation processes. Specifically, dies are disposed between the capstans correspondingly to the degree of diameter reducing deformation. Further, the drawing speed ratio of capstans disposed so as to sandwich each die is set correspondingly to the degree of diameter reducing deformation by the die.

PRIOR ART DOCUMENTS

Patent Documents

Patent Document 1: Japanese Patent Application Laid-Open No. 11-47821 (1999)

Patent Document 2: Japanese Patent Application Laid-Open No. 2005-103623

DISCLOSURE OF INVENTION

Problems to be Solved by the Invention

In the case of drawing a wire, it is necessary to appropriately set or change the degree of diameter reducing deformation of a wire in accordance with a material of a base wire to be processed, a target finished wire diameter or the like.

In the technology disclosed in Patent Document 1, however, a plurality of intermediate drawing capstans are rotatively driven by one drive motor per block, which makes it difficult to change the setting of the degree of diameter reducing deformation of a wire.

Meanwhile, in the technology disclosed in Patent Document 2, all capstans are rotatively driven by a motor in an individual manner, which complicates maintenance tasks.

Therefore, an object of the present invention enables easy response to, for example, adjustment or change of the degree of diameter reducing deformation of a wire in accordance with a material of a base wire, a target finished wire diameter or the like while simplifying maintenance tasks.

Means to Solve the Problems

In order to solve the above-mentioned problems, a first aspect relates to a wire drawing machine drawing a wire, which includes: a wire supply part supplying a wire; a wire pulling part pulling the wire; a first capstan mechanism part provided between the wire supply part and the wire pulling part on a side closer to the wire supply part, which includes a plurality of first capstans, a first rotation drive source, and a first rotation transmission mechanism part transmitting a rotation drive force of the first rotation drive source to the plurality of first capstans; a second capstan mechanism part provided between the wire supply part and the wire pulling part on a side closer to the wire pulling part than the first capstan mechanism part, which includes a plurality of second capstans, and a plurality of second rotation drive sources rotatively driving the plurality of second capstans in an individual manner; and a plurality of dies disposed between ones of the plurality of first capstans and the plurality of second capstans.

According to a second aspect, in the wire drawing machine according to the first aspect, drawing speed ratios between adjacent ones of the plurality of second capstans are set so that a wire that has passed through all of the plurality of second capstans has a smallest finished wire diameter among a plurality of types of finished wire diameters to be manufactured and that a wire that has passed through part of the plurality of second capstans has one finished wire diameter among the plurality of types of finished wire diameters to be manufactured.

According to a third aspect, in the wire drawing machine according to the first or second aspect, drawing speed ratios between adjacent ones of the plurality of second capstans are set so as to gradually decrease toward the wire pulling part.

According to a fourth aspect, in the wire drawing machine according to any one of the first to third aspects, a wire subjected to a wire drawing process is an aluminum wire or an aluminum alloy wire, and drawing speed ratios between ones of the plurality of first capstans are set so that the wire whose diameter has been reduced to 0.5 mm or smaller is subjected to the wire drawing process while the wire is drawn by the second capstan.

According to a fifth aspect, the wire drawing machine according to any one of the first to fourth aspects further includes a finishing capstan mechanism part provided between the wire supply part and the wire pulling part on a side closer to the wire pulling part than the second capstan mechanism part, which includes at least one finishing capstan, a finishing rotation drive source, and a finishing transmission mechanism part transmitting a rotation drive force of the finishing rotation drive source to the finishing capstan.

A sixth aspect relates to a strand manufacturing method of manufacturing a strand by drawing a wire with a wire drawing machine including: a wire supply part supplying a wire; a wire pulling part pulling the wire; a first capstan mechanism part provided between the wire supply part and the wire pulling part on a side closer to the wire supply part, which includes a plurality of first capstans, a first rotation drive source, and a first rotation transmission mechanism part transmitting a rotation drive force of the first rotation drive source to the plurality of first capstans; a second capstan mechanism part provided between the wire supply part and the wire pulling part on a side closer to the wire pulling part, which includes a plurality of second capstans, and a plurality of second rotation drive sources rotatively driving the plurality of second capstans in an individual manner; and a plurality of dies disposed between ones of the plurality of first capstans and the plurality of second capstans, the method including: setting rotational speeds of the plurality of second capstans so that a wire that has passed through all of the plurality of second capstans has a smallest finished wire diameter among a plurality of types of finished wire diameters to be manufactured and that a wire that has passed through part of the plurality of second capstans has one finished wire diameter among the plurality of types of finished wire diameters to be manufactured; and changing targets of the plurality of second capstans through which the wire passes to all or part thereof, to thereby manufacture strands having the plurality of types of finished wire diameters.

Effects of the Invention

According to the wire drawing machine of the first aspect, in the first capstan mechanism, the rotation drive force of one first rotation drive source is transmitted to a plurality of first capstans via the first rotation transmission mechanism part, which simplifies maintenance tasks. In the second capstan mechanism, the rotational speeds of a plurality of second rotation drive sources are individually adjusted so as to change the rotational speeds of the plurality of second capstans, which changes the drawing speed ratios between adjacent ones of the respective second capstans. This enables an easy response to adjustment or change of the degree of diameter reducing deformation of a wire in accordance with the material of a base wire, a target finished wire diameter or the like.

According to the second aspect, strands having a small diameter can be manufactured by performing the wire drawing process with all of the plurality of second capstans. Further, wire drawing performed by part of a plurality of second capstans enables to manufacture a strand having one of a plurality of types of finished wire diameters to be manufactured. Accordingly, once the drawing speed ratios between adjacent ones of the second capstans are set, the strands having a plurality of types of finished wire diameters can be easily manufactured without changing the setting.

According to the third aspect, the drawing speed ratios between adjacent ones become smaller as the diameter of the wire becomes smaller, which prevents cutting of the wire more reliably.

Generally, an aluminum wire or aluminum alloy wire is difficult to cut when having a diameter larger than 0.50 mm and is easy to cut when having a diameter smaller than 0.50 mm in the wire drawing process. Therefore, as in the fourth aspect, the wire drawing process is performed by the first capstan mechanism part to an extent that the diameter is reduced to approximately 0.50 mm, which enables efficient wire drawing at a fixed delivery speed ratio. Meanwhile, a wire whose diameter has been reduced to 0.50 mm or smaller is subjected to the wire drawing process by drawing of the second capstans, which enables the wire drawing process in which the drawing speeds are adjusted so as to make it difficult to cut an aluminum wire or aluminum alloy wire.

According to the fifth aspect, the wire drawing process is performed at a relatively large degree of diameter reducing deformation by the first capstan mechanism part, and the wire drawing process is performed at a degree of diameter reducing deformation that is adjusted in accordance with a material or the like by the second capstan mechanism part, which enables the wire drawing process at a degree of diameter reducing deformation suitable for finishing by a plurality of finishing capstans.

According to the sixth aspect, the strands having a plurality of types of finished wire diameters can be easily manufactured without changing the rotational speeds of the second capstans.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic plan view showing a wire drawing machine according to an embodiment.

FIG. 2 is a schematic side view showing the wire drawing machine.

FIG. 3 is a figure showing examples of setting of percentage of area reduction.

FIG. 4 is a figure showing spots at which a wire is broken and factors of breaking.

FIG. 5 is an explanatory view showing an example of performing a wire drawing process with the use of part of second capstans.

FIG. 6 is a schematic plan view showing a wire drawing machine according to a modification.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, a wire drawing machine and a strand manufacturing method according to an embodiment are described. FIG. 1 is a schematic plan view showing a wire drawing machine 20 according to the embodiment, and FIG. 2 is a schematic side view showing the wire drawing machine 20.

The wire drawing machine 20 is an apparatus that draws a wire so as to reduce diameters of wires 10, and includes a wire supply part 22, a wire pulling part 26, a first capstan mechanism part 30, a second capstan mechanism part 40 and a plurality of dies 60. Note that the wires 10 generally refer to all wires including those before, after and during a wire drawing process, and in some cases, discrimination is made such that ones before the process are base wires 10a and drawn ones after the process are strands 10b. The strands 10b are used as, for example, cores of electric wires in a single manner or in a twisted manner.

The wire supply part 22 is configured so as to supply the base wires 10a. More specifically, the wire supply part 22 is configured to accommodate the base wires 10a that are wound around a reel-like member. The wire supply part 22 is rotatively supported on the upstream side of a predetermined wire drawing process line L such that the base wires 10a can be drawn from this wire supply part 22.

The wire pulling part 26 is configured so as to pull the strands 10b. More specifically, in the wire pulling part 26, a reel-like member capable of accommodating the strands 10b in a wound manner is supported to be rotatively driven by a rotation drive source such as a motor. The wire pulling part 26 is disposed on the downstream side of the wire drawing process line L such that the strands 10b processed to have a finished wire diameter are pulled by and accommodated in this wire pulling part 26.

In the present embodiment, a plurality of (in this case, seven) wire supply parts 22 and a plurality of (in this case, seven) wire pulling parts 26 are provided so that a plurality of (in this case, seven) base wires 10a can be subjected to the wire drawing process. Needless to say, a twisting mechanism part that twists a plurality of strands 10b may be provided on the downstream side of the second capstan mechanism part 40. In this case, only one wire pulling part that pulls only one twisted wire may be provided.

The first capstan mechanism part 30 is provided between the wire supply part 22 and the wire puling part 26 on the side closer to the wire supply part 22, and includes a plurality of (in this case, eight) first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8), one first rotation drive source 34 and a first rotation transmission mechanism part 36.

Each of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) is formed approximately in a disc shape or cylindrical shape, and a circumferential groove around which the wire 10 can be wound is formed on an outer circumference thereof. The circumferential grooves are formed in accordance with the number of wires 10 to be processed, and in this case, seven circumferential grooves are formed. The respective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) are disposed so as to be lined at intervals along the wire drawing process line L from the upstream side toward the downstream side and supported so as to rotate about the rotation axis approximately in a horizontal direction almost perpendicular to the wire drawing process line L. The respective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) are rotatively driven in the state in which the wires 10 are wound around the circumferential grooves of the respective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8), so that the wires 10 are drawn at the drawing speed corresponding to the rotational speed.

Note that the rotation axis of each of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) may be an axis along an approximately perpendicular direction or a direction oblique to the approximately perpendicular direction.

The first rotation drive source 34 is a motor such as an AC motor and is configured so as to generate a rotation drive force.

The first rotation transmission mechanism part 36 is configured so as to transmit the rotation drive force of the one first rotation drive source 34 to the respective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8). More specifically, the first rotation transmission mechanism part 36 includes drive shafts 36a that are respectively connected to the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) and speed change mechanisms 36b that change and transmit the speed of a rotation movement between the drive shafts 36a and so on. The speed change mechanism 36b is composed of various mechanisms such as a plurality of gears, a pulley and a transmission belt wound around the pulley, and is configured to transmit the rotation movement at a predetermined speed change ratio by appropriating setting a gear diameter, the number of teeth of the gear, a pulley diameter or the like. In this case, the rotation movement of the first rotation drive source 34 is transmitted to the first capstan 32(8) on the downstream side at the rotational speed without change, and is transmitted from the downstream side to the first capstans 32(7), 32(6), . . . , 32(2) and 32(1) on the upstream side at a gradually increasing speed. Accordingly, the rotational speeds of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) have values determined in accordance with the rotational speed of the first rotation drive source 34, and the rotational speed ratio of the respective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) is constant between ones of the upstream side and downstream side of the wire drawing process line L (in some case, simply referred to as between adjacent ones). In the present embodiment, description is given assuming that the respective capstans have the same diameter, and thus the constant rotational speed ratio between before adjacent ones means the constant drawing speed ratio between adjacent ones. In this case, in the respective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8), the drawing speed ratios between adjacent ones thereof are set to be a given fixed value. A more specific setting example of the drawing speed ratio is described below.

The second capstan mechanism part 40 includes a plurality of (in this case, seven) second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) and a plurality of second rotation drive sources 44, and is provided between the wire supply part 22 and the wire puling part 26 on the side closer to the wire pulling part 26 than the first capstan mechanism part 30. The second capstan 42(15) on the most downstream side of the wire supply line among the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) is referred to as a finishing capstan in some cases.

Similarly to the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8), each of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) is formed approximately in a disc shape or cylindrical shape, and a circumferential groove around which the wire 10 can be wound is formed on an outer circumference thereof. The respective second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are rotatively disposed and supported so as to be lined at intervals along the wire drawing process line L from the upstream side toward the downstream side in this order. The second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are rotatively driven in the state in which the wires 10 are wound around the circumferential grooves of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15), so that the wires 10 are drawn at the drawing speed corresponding to the rotational speed.

The second rotation drive source 44 is a motor capable of adjusting a rotational speed, such as an AC motor, and a plurality of (in this case, six) second rotation drive sources 44 are provided correspondingly to the respective second capstans 42(9), 42 (10), . . . , 42(13), 42(14) and 42(15). The respective second rotation drive sources 44 are individually connected to the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15), and the respective second rotation drive sources 44 are configured so as to rotatively drive the second capstans in an individual manner. Accordingly, the rotational speeds of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) have values determined in accordance with the rotational speeds of the respective second rotation drive sources 44, and the rotational speed ratios between adjacent ones of the respective second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) can be adjusted by the adjustment of the rotational speeds of the respective second rotation drive sources 44. In the present embodiment, description is given assuming that the respective capstans have the same diameter, and thus the fact that the rotational speed ration between adjacent ones can be adjusted means that the drawing speed ratio between adjacent ones can be adjusted. In this case, the drawing speed ratios between adjacent ones of the respective second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are set so as to gradually decrease from the upstream side toward the downstream side of the wire drawing process line L (that is, are set such that the speed difference gradually decreases). A specific adjustment setting example of each drawing speed ratio is described below.

The configuration is made so as to include the first capstan mechanism part 30 and the second capstan mechanism part 40 as described above, with the result that the process region in which the drawing speed ratio is constant can be provided between adjacent ones of only the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) and that the process region in which the drawing speed ratio is variable can be provided between adjacent ones (that is, including the relation between the first capstan 32(8) and the second capstan 42(9)) of the capstans including the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15).

Provided between the second capstan mechanism part 40 and the wire pulling part 26 is a wire speed difference absorbing mechanism part 70 including a pair of rollers 72a and 72b. The wire speed difference absorbing mechanism part 70 is also referred to as, for example, a so-called dancer roller, and is configured such that the movable side roller 72b is supported so as to move close to and apart from the fixed roller 72a. The distance between both rollers 72a and 72b is adjusted in accordance with the wire speed difference between the second capstan 42(15) and the wire pulling part 26, whereby, for example, the slackness of the wire 10 between the second capstan mechanism part 40 and the wire pulling part 26 and the action by the excessive pulling force of the wire 10 are suppressed.

A plurality of dies 60 are processing tools for processing the wire 10 to have reduced diameter and deformed, and are detachably disposed between ones of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) and the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15). More specifically, the dies 60 are members formed of metal or the like, in which a reduced diameter processing hole for allowing the wire 10 to pass therethrough is formed. In this case, a plurality of (in this case, seven) reduced diameter processing holes are formed in a parallel manner in accordance with the number of the wires 10 to be processed. The reduced diameter processing holes are formed into a through-hole shape whose diameter subsequently decreases from the upstream side toward the downstream side along the process line L. The aperture diameter on the upstream side of the reduced diameter processing hole is approximately identical to the diameter of the wire 10 guided by the die 60, and the aperture diameter on the downstream side of the diameter reduced processing hole is approximately identical to a target diameter of one to be processed by the die 60. In a case where the aperture area on the upstream side and the aperture area on the downstream side of the reduced diameter processing hole in the die 60 are represented by S1 and S2, respectively, a percentage of reduction of the aperture area ((S1-S2)/S1) is referred to as a percentage of area reduction. The percentage of area reduction is set in accordance with a target degree of diameter reducing process in the die 60. A guide hole for guiding the wire 10 to the reduced diameter processing hole may be formed on the upstream side of the reduced diameter processing hole. Note that the respective dies 60 are detachably disposed for detachment, change, maintenance or the like of the dies 60. In particular, in a case where the drawing speed ratio between adjacent ones is adjusted along with a change of the speeds of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15), it is necessary to replace the dies 60 with ones having a corresponding percentage of area reduction.

The relationship between the percentage of area reduction and the drawing speed ratio is now described. That is, when the wire 10 is processed to have a reduced diameter by the die 60, the wire 10 is elongated to be long. Therefore, the speed of drawing the wire 10 needs to be made larger on the downstream side of the die 60 compared with the upstream side thereof. Further, the wire 10 is elongated more as the degree of diameter reducing process (percentage of area reduction) of the wire 10 by the die 60 becomes larger, and accordingly the ratio of the drawing speed on the downstream side to the drawing speed on the upstream side in the die 60 needs to be large. From the relationship of the cross-sectional area of the wire 10, for example, in a case where the percentage of area reduction by the die 60 is “r”, it suffices that the ratio of the drawing speed difference to the drawing speed on the downstream side with the die 60 being sandwiched between the upstream side and the downstream side (that is, (V2-V1)/V2) in the case where the drawing speed on the upstream side is V1 and the drawing speed on the downstream side is V2) is set to “r”. That is, when a study is made so as to perform processing in each capstan portion at a predetermined degree of diameter reducing deformation, the percentage of area reduction in the die 60 is determined as one type in terms of design. Correspondingly to this, the drawing speed ratio between adjacent capstans is determined as one type as well. That is, the setting and adjustment of the degree of diameter reducing deformation by each die 60 are synonymous with the setting and adjustment of the percentage of area reduction by a die and the setting and adjustment of the drawing speed ratio between adjacent capstans. The following description is given on that assumption.

Further, the wire drawing machine 20 includes a control unit 68. The control unit 68 is a typical microcomputer including a CPU, ROM, RAM and the like. The control unit 68 receives, via an input part 68a such as a switch, on/off commands for the first rotation drive source 34 and each second rotation drive source 44 and a rotational speed command for each second rotation drive source 44. Moreover, the control unit 68 controls on/off operation of the first rotation drive source 34 and each second rotation drive source 44 in accordance with the command and controls the rotational speed of each second rotation drive source 44. Alternatively, the rotational speed of each second rotation drive source 44 may be adjusted by individual setting for each second rotation drive source 44.

Hereinafter, the operation of the wire drawing machine 20 is described with reference to specific percentages of area reduction (%) of aluminum wire or aluminum alloy wire. FIG. 3 is a figure showing examples of setting of the percentage of area reduction. Here, examples in which the base wire 10a that is made of an aluminum alloy and has a diameter of 1.100 mm is used as a base wire are assumed. In FIG. 3, the left column shows the numbers of brackets of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) and the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) (that is, order of capstans disposed from the upstream side toward the downstream side in the wire drawing process line L), the center column shows the diameter of the wire 10 wound around and drawn by each capstan, and the right column shows the percentages of area reduction by the die 60 located on the upstream side of each capstan. As described above, the percentage of area reduction represents the degree of diameter reducing deformation by the die 60 and also indirectly represents the drawing speed ratio between the adjacent capstans with the die 60 being sandwiched therebetween.

As shown in this figure, the percentage of area reduction is set to a given fixed value, 20% between ones of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) in the first capstan mechanism part 30. That is, one configured to have a speed change ratio of that percentage of area reduction (drawing speed ratio) is used as the first rotation transmission mechanism part 36. Note that the above-mentioned percentage of area reduction is a setting value that is obtained by considering that the wire drawing process for the wire 10 whose diameter has been reduced to 0.5 mm or smaller can be performed while drawing the wire 10 by the second capstan 42 (9). Accordingly, the base wire 10a having a diameter of 1.10 mm is deformed to have a reduced diameter in stages, from 0.98 mm to 0.87 mm, 0.78 mm, 0.70 mm, 0.62 mm, 0.56 mm and 0.50 mm. Then, the wire 10 whose diameter has been reduced to 0.50 mm is processed so as to be drawn by the die 60 between the capstan 32(8) and the capstan 42(9) while being drawn by the following second capstan 42(9).

Description is now given of the reason why the wire drawing process is allowed for the wire 10 reduced to be 0.5 mm or smaller while drawing the wire 10 by the second capstan 42(9).

FIG. 4 is a figure showing the spots in which a wire is broken in a case where the inventors have tried wire drawing process under various conditions, with various aluminum alloy wires as the base wires. The target wires herein include so-called 1000 series aluminum alloys (in particular, such as 1050 to 1080), 5000 series aluminum alloys (in particular, such as 5154 to 5454), and other aluminum alloys such as Al—Fe alloy, Al—Fe—Mg alloy and Al—Mg alloy in the JIS. As shown in this figure, wire breaking has occurred almost in the die portions processed in which a diameter is reduced to 0.5 mm or smaller. It is conceivable that an increased percentage of area reduction increases a possibility that wire breaking may be caused by factors such as an increase of drawing resistance and frictional heat due to improvements in speed. Therefore, the wire drawing process in the stage in which the wire 10 has a relatively large diameter is performed at the percentage of area reduction of a given fixed value by the respective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) in the first capstan mechanism part 30. On the other hand, the wire drawing process at the time when the wire 10 has a relatively small diameter (0.50 mm or smaller) is performed in the drawing process by the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) capable of, for example, changing setting of the percentage of area reduction. As a result, the wire 10 can be manufactured by adjusting the percentage of area reduction so as to make it difficult to cause wire breaking.

Between adjacent ones of the respective second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15), the percentages of area reduction are set to be smaller than the percentages of area reduction between ones of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) in the first capstan mechanism part 30 and are also set to gradually decrease toward the wire pulling part 26. That is, setting is made such that the drawing speed ratios corresponding thereto gradually decrease toward the wire pulling part 26. To what extent the percentage of area reduction is set or at what rate the percentage of area reduction is gradually decreased is experimentally determined in accordance with the material of the wire 10, a target diameter thereof or the like. That is, it is preferable to set the percentage of area reduction as large as possible for processing with a minimum number of dies 60. On the contrary, wire breaking is apt to occur when the percentage of area reduction is large. Whether wire breaking is apt to occur depends on the material of a wire, a process diameter thereof or the like, and thus the percentage of area reduction is experimentally determined so as to be set as large as possible within the range of a frequency causing no problem.

In this case, the respective percentages of area reduction are set such that in a case where the wire drawing process is performed via all of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15), the wire 10 has the smallest finished wire diameter among a plurality of types of finished wire diameters to be manufactured. Moreover, the percentage of area reduction is set such that in a case where the wire drawing process is performed via part of a plurality of second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) (that is, the wire is not wound around the remaining capstans, and corresponding dies are omitted), the wire 10 has one finished wire diameter among a plurality of types of finished wire diameters to be manufactured. In this case, a suitable speed command value is provided to the control unit 68 through the input part 68a and the speed command value is set and stored in the control unit 60 so as to obtain the above-mentioned drawing speed ratio, and the control unit 60 controls driving of the respective second rotation drive sources 44 in accordance with the control command value.

It is assumed here that the finished wire diameters of the strands 10b to be manufactured are 0.42 mm, 0.36 mm, 0.34 mm, 0.32 mm and 0.30 mm on the assumption of the case where those are used as the cores of the electric wires to be manufactured.

The percentage of area reduction between the first capstan 32(8) and the second capstan 42(9) is set to 16%, the percentage of area reduction between the second capstans 42(9) and 42(10) is set to 15%, the percentage of area reduction between the second capstans 42(10) and 42(11) is set to 14%, the percentage of area reduction between the second capstans 42(11) and 42(12) is set to 13%, the percentage of area reduction between the second capstans 42(12) and 42(13) is set to 12%, the percentage of area reduction between the second capstans 42(13) and 42(14) is set to 11%, and the percentage of area reduction between the second capstans 42(14) and 42(15) is set to 10%. Then, the diameter of the wire 10 is 0.45 mm at the time of being drawn by the second capstan 42(9), is 0.42 mm at the time of being drawn by the second capstan 42(10), is 0.39 mm at the time of being drawn by the second capstan 42(11), is 0.36 mm at the time of being drawn by the second capstan 42(12), is 0.34 mm at the time of being drawn by the second capstan 42(13), is 0.32 mm at the time of being drawn by the second capstan 42(14), and is 0.30 mm at the time of being drawn by the second capstan 42(15). Accordingly, the strand 10b having the smallest diameter of 0.30 mm can be obtained in the case where the wire drawing process is performed via all of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15). Alternatively, through the processes via ones up to the second capstan 42(10), ones up to the second capstan 42(12), ones up to the second capstan 42(13), ones up to the second capstan 42(14) and ones up to the second capstan 42(15), it is possible to obtain the strands 10b having diameters of 0.42 mm, 0.36 mm, 0.34 mm and 0.32 mm to be manufactured.

That is, in the case of manufacturing the strand 10b having a diameter of 0.30, as shown in FIG. 1 and FIG. 2, the wire 10 is wound around all of the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) and all of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15). The dies 60 are disposed between ones among all of them, and the wires 10 are inserted through the all dies 60. In this state, then, the respective first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) and the respective second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are rotated at rotational speeds so as to obtain the drawing speed ratios corresponding to the above-mentioned percentages of area reduction. Any one of rotational speeds is determined, whereby each of the actual rotational speeds is determined based on the determined one in accordance with the above-mentioned drawing speed ratio. Generally, a speed as high as possible is selected within the range where breaking of the wire 10 does not occur at a predetermined frequency or more on the most downstream side on which the wire speed becomes the highest. As a result, the wire 10 is sequentially processed through compression and deformation, whereby the strand 10b having the smallest diameter of 0.30 mm is manufactured.

For example, in the case of manufacturing a strand having a diameter of 0.32 mm, as shown in FIG. 5, part of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) and part of the dies 60 are omitted. More specifically, the wire 10 is caused to pass through without being around the second capstan 42(14). In addition, the die 60 disposed between the second capstans 42(14) and 42(15) is removed, and the die 60 that has been disposed between the second capstans 42(13) and 42(14) is provided in that location. Not the second capstan 42(15) on the most downstream side but the preceding second capstan 42(14) is omitted because a motor having relatively large torque is selected as a finishing capstan in the second capstan 42(15) on the most downstream side.

Also in the case of manufacturing the strand 10b having the other diameter of 0.42 mm, 0.36 mm or 0.34 mm, it can be manufactured in a similar manner to the above by omitting one or a plurality of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15).

Accordingly, once the drawing speeds of a plurality of second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are set in accordance with the material of the wire 10, a target diameter thereof or the like, it is possible to easily manufacture the strands 10 having a plurality of types of finished wire diameters depending on whether all of or part of a plurality of second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) is used.

Needless to say, the rotational speeds of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) may be changed or adjusted, or the dies 60 may be replaced in accordance with a finished wire diameter.

According to the wire drawing machine 20 configured as described above, in the first capstan mechanism part 30, one first rotation drive source 34 is transmitted to a plurality of first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8) via the first rotation transmission mechanism part 36, with the result that maintenance tasks can be simplified compared with the case of individually driving those by motors. In addition, in the second capstan mechanism part 40, the rotational speeds of a plurality of second rotation drive sources 44 are individually adjusted and the rotational speeds of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are individually changed, with the result that the drawing speed ratio of the wire 10 can be changed between adjacent ones of the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15). This enables an easy response to the adjustment or change of the degree of diameter reducing deformation of the wire 10 in accordance with the material of the wire 10, a target finished wire diameter or the like.

In the first capstan mechanism part 30, the percentage of area reduction is set to a relatively large fixed value, and thus the wire drawing process can be performed with efficiency in the stage where the wire 10 has a relatively large diameter, resulting in a reduction of the number of the whole dies 60. This contributes to reduction of a device size, cost or the like.

The drawing speed ratios between adjacent ones of the respective second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) are set so as to gradually decrease toward the downstream, that is, as the diameter of the wire 10 becomes smaller. That is, setting is made such that the degree of diameter reducing deformation by one die 60 becomes smaller as the diameter of the wire 10 becomes smaller. This prevents cutting of the wire 10 more reliably.

FIG. 6 is a schematic plan view showing a wire drawing machine 120 according to a modification. Similar components to those described in the embodiment above are denoted by the same reference numerals and description thereof is omitted, and differences are mainly described.

In the present modification, description is given of an example in which a finishing capstan located on the most downstream side is set to have a fixed drawing speed. The wire drawing machine 120 includes the wire supply part 22, the wire pulling part 26, a first capstan mechanism part 130, a second capstan mechanism part 140, a finishing capstan mechanism part 180 and the dies 60.

Similarly to the first capstan mechanism part 30, the first capstan mechanism part 130 is provided between the wire supply part 22 and the wire pulling part 26 on the side closer to the wire supply part 22 and includes a plurality of (in this case, three) first capstans 132(1), 132(2) and 132(3) corresponding to the first capstans 32(1), 32(2), . . . , 32(6), 32(7) and 32(8), a first rotation drive source 134 corresponding to the first rotation drive source 34 and a first rotation transmission mechanism part 136 corresponding to the first rotation transmission mechanism part 36. That is, this first capstan mechanism part 130 has a similar configuration to that of the first capstan mechanism part 30 except for a different number of first capstans 132(1), 132(2) and 132(3) and a different number of rotation drive force transmission targets of the first rotation transmission mechanism part 136.

Similarly to the second capstan mechanism part 40, the second capstan mechanism part 140 is provided between the wire supply part 22 and the wire pulling part 26 on the side closer to the wire pulling part 26 than the first capstan mechanism part 130 and includes a plurality of (in this case, three) second capstans 142(4), 142(5) and 142(6) corresponding to the second capstans 42(9), 42(10), . . . , 42(13), 42(14) and 42(15) and a plurality of (in this case, four) second rotation drive sources 144 corresponding to the second rotation drive sources 44. That is, this second capstan mechanism part 140 has a similar configuration to that of the second capstan mechanism part 40 except for a different number of second capstans 142(4), 142(5) and 142(6) and a different number of second rotation drive sources 144.

The finishing capstan mechanism part 180 serves to draw the wire 10 at a constant drawing speed, is provided between the wire supply part 22 and the wire pulling part 26 on the side closer to the wire pulling part 26 than the second capstan mechanism part 140, and includes a plurality of (in this case, three) finishing capstans 182(7), 182(8) and 182(9), one finishing rotation drive source 182, and a finishing transmission mechanism part 184 that transmits the rotation drive force of the finishing rotation drive source 182 to the plurality of finishing capstans 182(7), 182(8) and 182(9). The plurality of (in this case, three) finishing capstans 182(7), 182(8) and 182(9) have similar configurations to those of the plurality of first capstans 132(1), 132(2) and 132(3), one finishing rotation drive source 182 has a similar configuration to that of the first rotation drive source 134, and the finishing transmission mechanism part 184 has a similar configuration to that of the first rotation transmission mechanism part 136. Accordingly, the drawing speed ratios between ones of the finishing capstans 182(7), 182(8) and 182(9) in the finishing capstan mechanism part 180 have fixed given values. Needless to say, the number of finishing capstans 182(7), 182(8) and 182(9) does not need to be the same as the number of the first capstans 132(1), 132(2) and 132(3). Further, one drawing capstan may be provided.

Further, the dies 60 are respectively disposed between ones of the plurality of first capstans 132(1), 132(2) and 132(3), the plurality of second capstans 142(4), 142(5) and 142(6) and the plurality of finishing capstans 182(7), 182(8) and 182(9).

This wire drawing machine 120 enables to perform the wire drawing process at a relatively large constant degree of diameter reducing deformation by the first capstan mechanism part 130, perform the wire drawing process at a degree of diameter reducing deformation that is adjusted in accordance with a material of the wire 10 or the like by the second capstan mechanism part 140, and perform the wire drawing process at a degree of diameter reducing deformation that is suitable for finishing by the finishing capstan mechanism part 180. In particular, the finishing process can be performed on given conditions, leading to a merit of more stabilized finished quality.

While the description has been given by an example in which an aluminum wire or an aluminum alloy wire is assumed in the embodiment and modification above, those are also applicable to the wires 10 of various materials. That is, it suffices that the drawing speed ratios in the second capstan mechanism part 40, 140 are experimentally set or adjusted in accordance with the material of the wire 10, a process diameter or the like.

While the description has been given assuming that the respective capstans have the same diameter, the respective diameters may differ from each other. In this case, the drawing speed may be taken as a value obtained by incorporating the diameter into the rotational speed.

Further, the case of a linear wire drawing process line L has been given in the embodiment above, which is not limited thereto. Alternatively, a line may be curved at each capstan portion or other guide roller portion.

While the wire drawing machine and the strand manufacturing method have been described in detail, the forgoing description is in all aspects illustrative, and the present invention is not limited thereto. It is therefore understood that numerous modifications and variations not illustrated can be devised without departing from the scope of the invention.

Claims

1. A wire drawing machine drawing a wire, comprising:

a wire supply part supplying a wire;

a wire pulling part pulling the wire;

a first capstan mechanism part provided between said wire supply part and said wire pulling part on a side closer to said wire supply part, which includes: a plurality of first capstans; a first rotation drive source; and a first rotation transmission mechanism part transmitting a rotation drive force of said first rotation drive source to said plurality of first capstans;

a second capstan mechanism part provided between said wire supply part and said wire pulling part on a side closer to said wire pulling part than said first capstan mechanism part, which includes: a plurality of second capstans; and a plurality of second rotation drive sources rotatively driving said plurality of second capstans in an individual manner; and

a plurality of dies disposed between ones of said plurality of first capstans and said plurality of second capstans.

2. The wire drawing machine according to claim 1, wherein drawing speed ratios between adjacent ones of said plurality of second capstans are set so that a wire that has passed through all of said plurality of second capstans has a smallest finished wire diameter among a plurality of types of finished wire diameters to be manufactured and that a wire that has passed through part of said plurality of second capstans has one finished wire diameter among the plurality of types of finished wire diameters to be manufactured.

3. The wire drawing machine according to claim 1, wherein drawing speed ratios between adjacent ones of said plurality of second capstans are set so as to gradually decrease toward said wire pulling part.

4. The wire drawing machine according to claim 1, wherein:

a wire subjected to a wire drawing process is an aluminum wire or an aluminum alloy wire; and

drawing speed ratios between ones of said plurality of first capstans are set so that the wire whose diameter has been reduced to 0.5 mm or smaller is subjected to wire drawing process while the wire is drawn by said second capstan.

5. The wire drawing machine according to claim 1, further comprising a finishing capstan mechanism part provided between said wire supply part and said wire pulling part on a side closer to said wire pulling part than said second capstan mechanism part, which includes:

at least one finishing capstan;

a finishing rotation drive source; and

a finishing transmission mechanism part transmitting a rotation drive force of said finishing rotation drive source to said finishing capstan.

6. A strand manufacturing method of manufacturing a strand by drawing a wire with a wire drawing machine including:

a wire supply part supplying a wire;

a wire pulling part pulling the wire;

a first capstan mechanism part provided between said wire supply part and said wire pulling part on a side closer to said wire supply part, which includes: a plurality of first capstans; a first rotation drive source; and a first rotation transmission mechanism part transmitting a rotation drive force of said first rotation drive source to said plurality of first capstans;

a second capstan mechanism part provided between said wire supply part and said wire pulling part on a side closer to said wire pulling part, which includes: a plurality of second capstans; and a plurality of second rotation drive sources rotatively driving said plurality of second capstans in an individual manner; and

a plurality of dies disposed between ones of said plurality of first capstans and said plurality of second capstans,

the method comprising:

setting rotational speeds of said plurality of second capstans so that a wire that has passed through all of said plurality of second capstans has a smallest finished wire diameter among a plurality of types of finished wire diameters to be manufactured and that a wire that has passed through part of said plurality of second capstans has one finished wire diameter among the plurality of types of finished wire diameters to be manufactured; and

changing targets of said plurality of second capstans through which said wire passes to all or part thereof, to thereby manufacture strands having the plurality of types of finished wire diameters.