JP2004244212A - Manufacturing method for rolls for feeding electric wires - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for rolls for feeding electric wires capable of feeding each electric wire certainly without damaging it. <P>SOLUTION: The invention includes an electric wire feeding device 1 furnished with a pair of wire feeding rolls 4a and 4b, which are formed in a ring shape and whose peripheral surfaces 8a and 8b are faced with a gap in between. The rolls 4a and 4b pinch an electric wire 5 between their peripheral surfaces 8a and 8b and are rotated interlockingly in the opposite directions so as to send out the wire 5. Their peripheral surfaces 8a and 8b are provided with surface unevenness by means of electric discharge machining. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００２８】
そして、表面あらさＡは、以下の式２で示される。こうして、本明細書に記した表面あらさＡとは、粗さ曲線ｆ（ｘ）からその平均線ｈｍの方向に基準長さＬだけ抜き取り、この抜き取り部分の山頂部と谷底部との間隔Ａを粗さ曲線ｆ（ｘ）の縦倍率の方向に測定し、この値をマイクロメートル（μｍ）で表したものをいう（図５参照）。表面あらさＡを求める場合には、きずとみなされるような並はずれて高い山及び谷がない部分から、基準長さＬだけ抜き取る。
【数２】

【００２９】
本実施形態によれば、ロール４ａ，４ｂの外周面８ａ，８ｂに凹凸１２を形成する。このため、外周面８ａ，８ｂと電線５との間の摩擦係数を大きくすることができ、外周面８ａ，８ｂと電線５とが滑ることを防止できる。したがって、電線５を確実に送り出すことができる。
【００３０】
また、放電加工により外周面８ａ，８ｂに凹凸１２を形成する。このため、凹凸１２を形成する際の電圧値及び電流値などを容易に制御でき、所望の表面あらさに凹凸１２を形成できるとともに、凹凸１２の表面あらさのばらつきを抑制できる。したがって、所望の表面あらさにばらつきを少なく凹凸１２を形成できるので、電線５を傷つけることを防止できる。したがって、電線５を傷つけることなく確実に送り出すことができるロール４ａ，４ｂを得ることができる。
【００３１】
さらに、本出願の発明者らは、前述した外周面８ａに多種多様な方法で凹凸１２を形成したロール４ａを製造し、製造したロール４ａを用いて電線５を送り出してみた。このときの、電線５の外表面の傷の有無を以下の表１に示す。
【表１】

【００３２】
表１において、比較例１は、周知のローレット加工により、図６に示すように、外周面８ａに平目模様に凹凸１２を形成した。ローレット加工とは、周知のローレット駒を回転したロール４ａの外表面８ａに強く押し付けて行う塑性加工である。比較例２は、周知のローレット加工により、図７に示すように、外周面８ａにあやめ模様に凹凸を形成した。
【００３３】
また、表１において、比較例３は、周知の溶射により、外周面８ａに凹凸１２を形成した。溶射とは、溶融状態にした金属を、ロール４ａの外周面８ａに高速度で吹き付けて薄い皮膜をつくる表面処理法の一種である。比較例４は、周知のショットブラストにより、外周面８ａに凹凸１２を形成した。ショットブラストとは、ロール４ａの外周面８ａに、インペラを高速回転させその遠心力又は圧縮空気などによってショット（鉄粒）をたたきつける方法である。
【００３４】
さらに、表１において、本発明品とは、放電加工によりロール４ａの外周面８ａに凹凸１２を形成している。
【００３５】
表１において、本発明品及び比較例１〜４ともに、前述した式２で定義される表面あらさをＡμｍとしている。さらに、表１に示すばらつきとは、図５に示す中心線ｈｍと、前記中心線ｈｍから最も離れた凹凸１２の表面１２ａとの距離Ｄを示している。このばらつきが、本発明品の±２０μｍとなっているのに対し、比較例１及び比較例２では±１２０μｍ、比較例３では±６０μｍ、比較例４では±９０μｍとなっている。
【００３６】
このため、本発明品は、比較例１ないし比較例４より表面あらさのばらつきが小さいことにより、送り出した電線５の外表面に傷が発生しないことが明らかとなった。
【００３７】
さらに、本発明品は、放電加工により凹凸１２を形成することにより、比較例１ないし比較例４より表面あらさのばらつきを抑制できることが明らかとなった。このため、ローレット加工、溶射及びショットブラストに比べ、放電加工は、凹凸１２を形成する際の電圧値及び電流値などを容易に制御でき、所望の表面あらさに凹凸１２を形成できるとともに、凹凸１２の表面あらさのばらつきを抑制できることが明らかとなった。
【００３８】
前述した表１に結果を示す実験によっても、放電加工によりロール４ａの外周面８ａに凹凸１２を形成することで、電線５を傷つけることなく確実に送り出すことができることが明らかとなった。
【００３９】
【発明の効果】
以上説明したように本発明は、電線送り用ロールの外周面に凹凸を形成する。このため、外周面と電線との間の摩擦係数を大きくすることができ、外周面と電線とが滑ることを防止できる。したがって、電線を確実に送り出すことができる。
【００４０】
また、放電加工により外周面に凹凸を形成する。このため、凹凸を形成する際の電圧値及び電流値などを容易に制御でき、所望の表面あらさに凹凸を形成できるとともに、凹凸の表面あらさのばらつきを抑制できる。したがって、所望の表面あらさにばらつきを少なく凹凸を形成できるので、電線を傷つけることを防止できる。したがって、電線を傷つけることなく確実に送り出すことができる電線送り用ロールを得ることができる。
【図面の簡単な説明】
【図１】本発明の一実施形態にかかる電線送り用ローラを備えた電線送り装置を示す斜視図である。
【図２】図１中のＩＩ−ＩＩ線に沿う断面図である。
【図３】図１に示された電線送り用ローラの外周面に凹凸を形成する放電加工装置の構成を示す説明図である。
【図４】図３に示された放電加工装置の電極を互いに近づけた状態を示す説明図である。
【図５】図１に示された電線送り用ローラの外周面を含む断面を一部拡大して示す説明図である。
【図６】外周面にローレット加工を施して平目模様に凹凸を形成した電線送り用ローラの側面図である。
【図７】外周面にローレット加工を施してあやめ模様に凹凸を形成した電線送り用ローラの側面図である。
【符号の説明】
４，４ａ，４ｂ 電線送り用ロール
５ 電線
８ａ，８ｂ 外周面
１２ 凹凸[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing an electric wire feeding roll used when moving an electric wire for processing an end of the electric wire.
[0002]
[Prior art]
2. Description of the Related Art As an electric wire feeder used for processing an end of an electric wire, for example, an electric wire feeder having a base portion and a pair of rolls is known (for example, see Patent Document 1). The base portion has a flat surface that is flat along a feed direction of the electric wire (hereinafter, referred to as a pass line).
[0003]
The rolls are each formed in a disk shape and are rotatably provided on the base portion. The pair of rollers are arranged such that their outer peripheral surfaces are spaced apart from each other and their centers of rotation are parallel to each other. Each of the rolls is driven to rotate by a drive source such as a motor. The pair of rolls move (send) the electric wire along the longitudinal direction of the electric wire by interposing the electric wire between the outer peripheral surfaces and being rotationally driven by a drive source or the like in conjunction with each other in the opposite direction.
[0004]
[Patent Document 1]
JP-A-7-14444 (FIG. 12)
[0005]
[Problems to be solved by the invention]
On the other hand, electric wires disposed in an engine room of an automobile or the like sometimes have a covering portion formed of a relatively hard resin or the like in order to improve heat resistance. Such a coating portion made of a relatively hard resin has a surface that is easily slipped and is relatively easily damaged.
[0006]
In the above-described conventional wire feeder, the outer surface of the roll and the outer surface of the wire cover sometimes slip when the wire is fed out, because the surface of the cover is slippery. For this reason, it was difficult for the conventional wire feeder to reliably feed the wire.
[0007]
In order to prevent the outer peripheral surface of the roll and the outer surface of the covering portion of the electric wire from slipping, if the interval between the outer peripheral surfaces of the roll is reduced, the covering portion may be plastically deformed so that the cross-sectional shape becomes flat. And the surface of the covering portion is damaged. As described above, the conventional electric wire feeding device has a disadvantage when an electric wire having a coating portion made of relatively hard resin is sent out.
[0008]
Therefore, an object of the present invention is to provide a method of manufacturing a wire feeding roll capable of sending out a wire without damaging the wire.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems and achieve the object, a method for manufacturing a wire feeding roll according to the present invention, in which an electric wire is sandwiched between outer peripheral surfaces thereof, is rotated in opposite directions in conjunction with each other to move the electric wire. In the method for manufacturing a pair of electric wire feeding rolls, the outer peripheral surface is subjected to electric discharge machining to form irregularities on the outer peripheral surface.
[0010]
According to the present invention, irregularities are formed on the outer peripheral surface of the wire feeding roll. For this reason, the friction coefficient between the outer peripheral surface and the electric wire can be increased, and the outer peripheral surface and the electric wire can be prevented from slipping. Further, irregularities are formed on the outer peripheral surface by electric discharge machining. Therefore, it is possible to easily control the voltage value and the current value when forming the unevenness, to form the unevenness with a desired surface roughness, and to suppress the unevenness of the surface roughness of the unevenness.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An electric wire feeder 1 including an electric wire feed roll according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7. The electric wire feeder 1 is used when performing various processing such as peeling on the electric wire 5 (shown in FIG. 1 and the like), and is an apparatus that feeds the electric wire 5 toward a peeling blade or the like.
[0012]
As shown in FIG. 2, the electric wire 5 includes a conductive core wire 10 and an insulating covering portion 11. The core wire 10 is composed of a plurality of conductive strands. The core wire 10 is configured by twisting a plurality of elements. The covering portion 11 is made of an insulating synthetic resin and covers the core wire 10. The electric wire 5 is provided with a core wire 10 and a covering portion 11 and has a round cross section.
[0013]
As shown in FIG. 1, the electric wire feeding device 1 includes a base 2, a driving mechanism 3 (shown in FIG. 2), and a pair of electric wire feeding rolls (hereinafter, referred to as rolls) 4.
[0014]
The base 2 is fixed to an apparatus for processing the electric wire 5 such as a peeling machine by a bolt (not shown). The base 2 is formed in a box shape. The surface 2a of the base 2 is flat. The surface 2a of the base 2 is flat along a pass line as a direction in which the electric wire 5 is sent out.
[0015]
The drive mechanism 3 is housed in the base 2 as shown in FIG. The drive mechanism 3 includes a motor (not shown) and a pair of output shafts 6. The output shafts 6 are each formed in a columnar shape. The output shafts 6 are arranged in parallel at a distance from each other. One end 6 a of the output shaft 6 is exposed outside the base 2, and the other end is accommodated in the base 2. The output shaft 6 is rotationally driven at the same rotational speed in opposite directions by a motor or the like.
[0016]
The pair of rolls 4 are made of metal. As shown in FIGS. 1 and 2, the pair of rolls 4 are formed in an annular shape. One of the rolls 4 on the near side in FIG. 1 (hereinafter denoted by reference numeral 4a) is fixed to one end 6a of one output shaft 6 by a nut 7 or the like. The other one of the rolls 4 (hereinafter denoted by reference numeral 4b) is fixed to one end 6a of the other output shaft 6 by a nut 7 or the like. The rolls 4a and 4b and the output shaft 6 are coaxially arranged.
[0017]
A gap corresponding to the outer diameter of the electric wire 2 is provided between the outer peripheral surface 8a of one roll 4a and the outer peripheral surface 8b of the other roll 4b, as shown in FIG. For this reason, the pair of rolls 4a, 4b are arranged with their outer peripheral surfaces 8a, 8b facing each other and spaced apart.
[0018]
The other roll 4b is provided with a pair of flanges 9. The flange 9 projects from the outer peripheral surface 8b of the other roll 4b in the outer peripheral direction over the entire circumference of the other roll 4b. The flange 9 is formed in an annular shape. The pair of flanges 9 are arranged at an interval from each other along the axis of the output shaft 6.
[0019]
Further, the other roll 4b is formed thicker than the one roll 4a. Further, the outer diameters of the rolls 4a and 4b are equal. These rolls 4a and 4b are arranged in a state where one roll 4a has entered between a pair of flanges 9 provided on the other roll 4b. The pair of rolls 4a and 4b are rotated by the driving mechanism 3 and the like in opposite directions at the same rotational speed. The pair of rolls 4a, 4b are rotated in opposite directions with the electric wire 5 interposed between the outer peripheral surfaces 8a, 8b, and move the electric wire 5 in contact with the outer peripheral surfaces 8a, 8b along the longitudinal direction of the electric wire 5. Move (send).
[0020]
As shown in FIG. 5, fine irregularities 12 are formed on the outer peripheral surfaces 8a and 8b of the pair of rolls 4a and 4b. The irregularities 12 are formed by the electric discharge machine 20 shown in FIGS.
[0021]
As shown in FIGS. 3 and 4, the electric discharge machining device 20 includes a DC power supply 21, a capacitor 22, a switch 23, a pair of electrodes 24 and 25, a variable resistor 26, a storage tank 27, and the like. I have. The DC power supply 21 charges the capacitor 22 and the like. The capacitor 22 stores electric power from the DC power supply 21. The switch 23 supplies power from the DC power supply 21 to the capacitor 22 or stops supply of power from the DC power supply 21 to the capacitor 22 when turned on and off.
[0022]
The electric power stored in the capacitor 22 is supplied to the pair of electrodes 24 and 25. One electrode 24 is housed in a housing tank 27. One electrode 24 is formed in an annular shape. The inner diameter of one electrode 24 is larger than the outer diameter of rolls 4a and 4b. The other electrode 25 is provided so as to be able to freely contact and separate from the one electrode 24. Note that “contact and separation” means approaching and separating from each other.
[0023]
The other electrode 25 holds these rolls 4a and 4b while being inserted into the inner periphery of the rolls 4a and 4b. The other electrode 25 is electrically connected to the rolls 4a and 4b. 3 and 4 show one of the rolls 4a as a representative. The variable resistor 26 increases and decreases the current value and the voltage value of the electric power stored in the capacitor 22 from the DC power supply 21. The storage tank 27 is formed in a box shape with an open top. The storage tank 27 stores a known insulating oil 28.
[0024]
In the electric discharge machine 20 having the above-described configuration, the roll 4a is attached to the other electrode 25 in a state in which the storage tank 27 is filled with the insulating oil 28, as shown in FIG. At this time, one electrode 24 is positioned below the liquid level 28a of the insulating oil 28, and the other electrode 25 is kept away from the one electrode 24. In this state, as shown in FIG. 3, the switch 23 is turned on to charge the capacitor 22 with the power from the DC power supply 21.
[0025]
After the charging of the capacitor 22 is completed, the switch 23 is turned off and the other electrode 25 is brought closer to the one electrode 24 as shown in FIG. Then, discharge occurs between one electrode 24 and the outer peripheral surface 8a of the roll 4a. Due to this discharge, the metal constituting the roll 4a is slightly scattered from the outer peripheral surface 8a. By repeating the above-described discharge, fine irregularities 12 are formed on the outer peripheral surface 8a.
[0026]
At this time, the fineness, that is, the surface roughness of the formed unevenness 12 is A μm (micrometer). This surface roughness is defined as follows.
[0027]
First, the surface 12a of the unevenness 12 is measured by a well-known surface roughness measuring device. Then, as shown in FIG. 5, the direction along the surface 12a of the unevenness 12 is defined as the X axis, and the direction orthogonal to the surface 12a of the unevenness 12 is defined as the Y axis. A part of the measured surface 12 is taken out, and hm expressed by the following equation 1 is obtained from the part. In the following equation 1, L indicates the above-described partial length (hereinafter referred to as a reference length), and f (x) is a function indicating the surface 12a of the unevenness 12; This is called a roughness curve. Further, hm is the center line of the unevenness 12 indicated by a dashed line in FIG. 5, and is hereinafter referred to as an average line.
(Equation 1)

[0028]
The surface roughness A is represented by the following equation (2). In this way, the surface roughness A described in the present specification means that a reference length L is extracted from the roughness curve f (x) in the direction of the average line hm, and the interval A between the peak and the valley bottom of the extracted portion is determined. The roughness curve f (x) is measured in the direction of the vertical magnification, and this value is expressed in micrometers (μm) (see FIG. 5). When obtaining the surface roughness A, a portion having no extraordinarily high peaks and valleys, which is regarded as a flaw, is extracted by a reference length L.
(Equation 2)

[0029]
According to the present embodiment, the irregularities 12 are formed on the outer peripheral surfaces 8a, 8b of the rolls 4a, 4b. Therefore, the friction coefficient between the outer peripheral surfaces 8a, 8b and the electric wire 5 can be increased, and the outer peripheral surfaces 8a, 8b and the electric wire 5 can be prevented from slipping. Therefore, the electric wire 5 can be reliably sent out.
[0030]
Also, irregularities 12 are formed on the outer peripheral surfaces 8a and 8b by electric discharge machining. For this reason, the voltage value and the current value when forming the unevenness 12 can be easily controlled, and the unevenness 12 can be formed to a desired surface roughness, and the variation in the surface roughness of the unevenness 12 can be suppressed. Therefore, the unevenness 12 can be formed with a small variation in the desired surface roughness, so that the electric wire 5 can be prevented from being damaged. Therefore, it is possible to obtain the rolls 4a and 4b that can reliably send out the electric wire 5 without damaging the electric wire 5.
[0031]
Further, the inventors of the present application manufactured the roll 4a in which the irregularities 12 were formed on the outer peripheral surface 8a by various methods described above, and sent out the electric wire 5 using the manufactured roll 4a. At this time, the presence or absence of a flaw on the outer surface of the electric wire 5 is shown in Table 1 below.
[Table 1]

[0032]
In Table 1, in Comparative Example 1, unevenness 12 was formed in a plain pattern on the outer peripheral surface 8a by a known knurling process, as shown in FIG. The knurl processing is a plastic processing performed by strongly pressing a well-known knurl piece against the outer surface 8a of the rotated roll 4a. In Comparative Example 2, as shown in FIG. 7, irregularities were formed in the iris pattern on the outer peripheral surface 8a by well-known knurling.
[0033]
In Table 1, in Comparative Example 3, the irregularities 12 were formed on the outer peripheral surface 8a by well-known thermal spraying. The thermal spraying is a type of surface treatment in which a molten metal is sprayed at a high speed on the outer peripheral surface 8a of the roll 4a to form a thin film. In Comparative Example 4, the irregularities 12 were formed on the outer peripheral surface 8a by well-known shot blasting. The shot blast is a method in which an impeller is rotated at a high speed on the outer peripheral surface 8a of the roll 4a to strike a shot (iron particle) by centrifugal force or compressed air.
[0034]
Further, in Table 1, with the product of the present invention, irregularities 12 are formed on the outer peripheral surface 8a of the roll 4a by electric discharge machining.
[0035]
In Table 1, the surface roughness defined by the above-described Expression 2 is A μm for both the product of the present invention and Comparative Examples 1 to 4. Further, the variation shown in Table 1 indicates the distance D between the center line hm shown in FIG. 5 and the surface 12a of the unevenness 12 farthest from the center line hm. This variation is ± 20 μm for the product of the present invention, ± 120 μm for Comparative Examples 1 and 2, ± 60 μm for Comparative Example 3, and ± 90 μm for Comparative Example 4.
[0036]
For this reason, it became clear that the product of the present invention did not have any flaws on the outer surface of the fed electric wire 5 because the variation in surface roughness was smaller than that of Comparative Examples 1 to 4.
[0037]
Further, it has been clarified that the unevenness of the surface roughness of the product of the present invention can be suppressed as compared with Comparative Examples 1 to 4 by forming the irregularities 12 by electric discharge machining. For this reason, compared with knurling, thermal spraying and shot blasting, electric discharge machining can easily control the voltage value and current value at the time of forming the irregularities 12, and can form the irregularities 12 on a desired surface roughness, and can form the irregularities 12. It became clear that the variation of the surface roughness can be suppressed.
[0038]
The experiment showing the results in Table 1 described above has also revealed that the electric wire 5 can be reliably sent out without damage by forming the irregularities 12 on the outer peripheral surface 8a of the roll 4a by electric discharge machining.
[0039]
【The invention's effect】
As described above, the present invention forms irregularities on the outer peripheral surface of the wire feeding roll. For this reason, the friction coefficient between the outer peripheral surface and the electric wire can be increased, and the outer peripheral surface and the electric wire can be prevented from slipping. Therefore, the electric wire can be reliably sent out.
[0040]
Further, irregularities are formed on the outer peripheral surface by electric discharge machining. Therefore, it is possible to easily control the voltage value and the current value when forming the unevenness, to form the unevenness with a desired surface roughness, and to suppress the unevenness of the surface roughness of the unevenness. Therefore, unevenness can be formed with little variation in the desired surface roughness, so that it is possible to prevent the electric wire from being damaged. Therefore, it is possible to obtain an electric wire feeding roll that can reliably send out the electric wire without damaging the electric wire.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an electric wire feeder provided with an electric wire feed roller according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along the line II-II in FIG.
FIG. 3 is an explanatory view showing a configuration of an electric discharge machine for forming irregularities on the outer peripheral surface of the electric wire feeding roller shown in FIG. 1;
FIG. 4 is an explanatory view showing a state in which electrodes of the electric discharge machine shown in FIG. 3 are brought close to each other.
FIG. 5 is an explanatory diagram showing a partially enlarged cross section including the outer peripheral surface of the wire feeding roller shown in FIG. 1;
FIG. 6 is a side view of an electric wire feeding roller in which knurling is performed on the outer peripheral surface to form irregularities in a flat pattern.
FIG. 7 is a side view of an electric wire feeding roller in which knurling is performed on an outer peripheral surface to form irregularities in an iris pattern.
[Explanation of symbols]
4, 4a, 4b Electric wire feeding roll 5 Electric wires 8a, 8b Outer peripheral surface 12

Claims (1)

In a method of manufacturing a pair of wire feeding rolls for moving the wire, the wires being rotated in opposite directions in conjunction with each other, with the wire sandwiched between outer peripheral surfaces of the wires,
A method for producing a wire feeding roll, wherein electric discharge machining is performed on the outer peripheral surface to form irregularities on the outer peripheral surface.

Images