JP2010248677A - Annular metallic cord, endless metallic belt, and process for producing annular metallic cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an annular metallic cord in which the twisted state does not get loose and the wound shape can be maintained even when the cord undergoes successive repetitions of a load, to provide an endless metallic belt, and to provide a process for producing an annular metallic cord. <P>SOLUTION: There is provided an annular metallic cord (C1) provided by untwisting a metallic cord (20) comprising a plurality of twisted strands (1, 2), dividing the strands into two groups of wires which differ in total sectional area, the group of strands (1) with a larger total sectional area being a reuse wire group (3) and the group of strands (2) with a smaller total sectional area being a nonuse wire group (4), and while looping one strand out of the reuse wire group (3) so as to make multiple laps, winding the remaining part (1e) by fitting into the spiral hollow part (5) of the annular part (1d), formed by the missing of both the other strands (1) of the reuse wire group (3) and the nonuse wire group (4). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an annular metal cord, an endless metal belt, and a method for producing an annular metal cord.

  Conventionally, as a method of manufacturing an annular metal cord, for example, as described in Patent Documents 1 and 2, after removing half of the wire constituting the wire rope by untwisting or cutting, a part of the remaining wire is removed. It is known that endless processing is performed by winding around the periphery of the ring.

  The wire rope simple endless processing method described in Patent Document 1 is a wire rope formed by twisting six strands having a length slightly more than twice the inner circumference of the design dimension ring. Prepare. This is separated into two strands of three strands to form a base yarn having an inner circumferential length and a margin slightly longer than the inner circumferential length. Next, by using one of the base yarns composed of the three strands of twisted wires, first, a ring portion that is the basis of the design dimension and a strand portion that extends from the combination portion are formed. In addition, the extending strand portion is wound around the ring portion while being twisted, and endless processing is performed in a state where two base yarns (six strands) are twisted together. Thereafter, the twisted end portion of the base yarn is either locked or half-cage-inserted or a combination of half-cage insert and lock-stop is processed.

  The endless sling described in Patent Document 2 is manufactured as follows. First, a half of the total number of strands is cut out over the entire length of the wire rope of a predetermined length, and a heart rope of 1/2 of the total length of the wire rope is cut out. The both ends of the remaining heart rope are concentrically butted, and the strand on the side where the heart rope is cut is wound around the cut portion of the strand on which the heart rope is not cut to make a concentric endless. Thereafter, the sleeve is compressed over both ends of the cord and the strand.

  The endless ring described in Patent Document 3 forms a ring-shaped part by intersecting a part of the wire rope in a ring shape, and after winding the wire rope around the ring-shaped part a predetermined number of times, the wire rope It is formed by inserting a rope core into the twisted portion of the remaining portion.

Japanese Patent No. 3069996 JP-A-5-132881 JP 2007-63677 A

  Each of the annular metal cords described in Patent Documents 1 and 2 is a sling hanging tool, and is not assumed to be used in a manner that repeatedly receives a load such as a predetermined bending or tension. These annular metal cords are obtained by temporarily halving the number of wires on the circumference of a wire rope in a cross section and rewinding the remaining length of the remaining wire in the remaining half of the space. For this reason, the contact resistance between adjacent wires is weak. For this reason, when a load as described above is applied, twisting is likely to occur, and if it is used as it is, it will eventually break.

  Further, since the terminal treatment after the annular winding is a cage insertion or locking by inserting the terminal into the place where the terminal is twisted in Patent Document 1, stress concentration occurs at these places when a repeated load as described above is applied. It breaks early. Moreover, in patent document 2, since both ends are fixed with a sleeve, the code diameter becomes thick only in that portion, and the load becomes uneven in the annular direction. As described above, the annular metal cords described in Patent Documents 1 and 2 do not have a structure that can withstand continuous repeated loads.

  The endless ring, which is an annular metal cord described in Patent Document 3, is wound using the entire wire rope by winding the wire rope a predetermined number of times while twisting around the ring-shaped portion. The pitch varies for each turn, the cord diameter becomes thick, and a uniform strength cannot be obtained in the annular direction. Further, this endless ring is also used for a load lifting operation, and is not assumed to be used in a state where it repeatedly receives loads such as predetermined bending and tension.

  When such an annular metal cord is used for an endless metal belt, the rotational load fluctuates due to the effects of loosening of the twist, the joint portion of the terminal, and the like, and there is a risk of breakage in a relatively short period of time.

  Accordingly, an object of the present invention is to provide an annular metal cord, an endless metal belt, and a method for manufacturing an annular metal cord that can maintain a wound shape without twisting and loosening even with continuous repeated loads. is there.

The annular metal cord according to the present invention that can solve the above-mentioned problems is divided into two wire rod groups having different total cross-sectional areas by untwisting the original cords in which a plurality of wire rods are twisted together,
The wire group with the larger total cross-sectional area is the reused wire group, and the wire group with the smaller total cross-sectional area is the unused wire group.
One reusable wire in the reusable wire group is formed in a loop around a spiral gap where another wire in the reusable wire group and the non-reusable wire group are removed while being formed into a plurality of circular rings. It is characterized in that the long part is fitted and wound into an annular shape.

  According to the annular metal cord having such a configuration, the unused wire group exists in the spiral void portion from which the unused wire group and the unused wire group in the reused wire group are removed. The cross-sectional area of the portion is smaller than the total cross-sectional area of the reused wire group. When the reusable wire is wound around in a plurality of rounds, when the extra length of the reusable wire is fitted into the spiral gap multiple times, the adjacent portions of the reusable wire are pressed against each other Become. Since the contact resistance between the wires is large and the wires are strongly restrained over the entire length of the wires, twist loosening hardly occurs even when a repeated load is applied. Moreover, since the winding state is maintained by the contact resistance between the wires, the terminal processing can be simplified.

The cyclic | annular metal cord which concerns on this invention WHEREIN: It is preferable that the said reuse wire in the said reuse wire group is a structure which twisted together several metal strands.
When the wire has a structure in which metal wires are twisted instead of a single wire, the contact resistance between the wires increases due to the irregularities on the surface of the wire, so that the loosening of the twist is further less likely to occur. Moreover, since the flexibility of the annular metal cord is improved and a uniform load is easily applied to the external force, a decrease in breaking strength can be suppressed.

In the annular metal cord according to the present invention, it is preferable that the twist direction of the metal strands and the spiral direction of the winding fitted in the gap are opposite directions.
By reversing the twisting direction of the metal strands in the wire and the winding direction of the wire, it is possible to suppress the occurrence of directivity in the mechanical properties of the annular metal cord, and to rotate the annular metal cord along the annular direction. Even when used, it becomes difficult to meander.

In the annular metal cord according to the present invention, the reuse rate of the reusable wire in the annular metal cord after the one reused wire is fitted into the gap and wound into an annular shape is 86%. It is preferable that it is 100% or less.
When the reusable wire diameter is less than 86%, when the original cord is untwisted and the reused wire is taken out, the height of the spiral wave is reduced and the gap becomes smaller, making it difficult to wrap around a predetermined number of turns. It becomes.
Moreover, when the diameter shaping | molding rate of a reuse wire exceeds 100%, the height of a spiral wave will become high and a space | gap part will become large, and even if it does not insert, it can wind easily and the contact resistance between wires will reduce. As a result, loosening of the twist is likely to occur and durability is reduced.
In addition, the diameter die-attachment rate is D (the cross-sectional diameter (wire diameter) in which the reusable wire is fitted in a plurality of circular gaps) and D is the wave height (self-diameter) of the reusable wire that has been moulded. When H is included, it is represented by “diameter mold attachment ratio (%) = H / D × 100”.

In the annular metal cord according to the present invention, it is preferable that the start end and the end end of the reuse wire are inserted from between the wound extra length portions and stored inside.
Since the start end and the end end are inserted from between the surplus length portions, the end portions of the wire can be easily fixed, and the contact chance between the surplus length portions of the wire increases, which is advantageous for twist loosening. It is.

The annular metal cord according to the present invention is preferably subjected to an annealing treatment.
Since the annealing process is performed, the processing distortion at the time of twisting is removed, and durability is improved.

In the annular metal cord according to the present invention, the reuse wire preferably has a structure in which a plurality of metal strands having a diameter in a range of 0.06 mm to 0.30 mm are twisted together.
Thereby, moderate rigidity can be given to a wire and it can have a good fatigue resistance. As a result, the annular metal cord can be made more durable.

In the annular metal cord according to the present invention, it is preferable that a winding angle of the reuse wire with respect to a central axis in an annular portion of the reuse wire wound around each other is in a range of 4.5 degrees or more and 13.8 degrees or less. .
Thereby, since the winding work of a wire becomes easy, an annular metal cord can be manufactured more easily. Moreover, the cyclic | annular metal cord which has moderate elongation and there is no winding looseness of a wire can be obtained.

In addition, an endless metal belt according to the present invention includes the annular metal cord according to the present invention.
By using the above-mentioned annular metal cord, the endless metal belt excellent in breaking strength and fatigue resistance can be maintained because the shape of the annular metal cord can be maintained without twisting and loosening even with continuous repeated loads. Obtainable.

Moreover, the manufacturing method of the annular metal cord according to the present invention that can solve the above-mentioned problem is divided into two wire rod groups having different total cross-sectional areas by untwisting the original cord twisted together with a plurality of wire rods,
The wire group with the larger total cross-sectional area is the reused wire group, and the wire group with the smaller total cross-sectional area is the unused wire group.
One reusable wire in the reusable wire group is formed into a plurality of loops, while the other wire rod in the reusable wire group and a spiral void portion from which the unused wire group is removed, an extra length portion It is characterized in that it is fitted and wound into an annular shape.

  According to the manufacturing method of the annular metal cord having such a configuration, the original cord is untwisted so that one wire in the group of wires having a larger total cross-sectional area is formed into a plurality of loops as a reuse wire and reused. An annular metal cord can be easily manufactured by inserting and winding an extra length portion into another spiral wire portion in the wire rod group and the spiral void portion from which the unused wire rod group is removed. The spiral void in the reused wire has a smaller cross-sectional area of the portion where the unused wire group was present than the total cross-sectional area of the reused wire group, and the reused wire is wound in a ring around multiple turns. When the extra length portion of the reuse wire is fitted into the spiral void portion a plurality of times, adjacent portions of the reuse wire are pressed. As a result, the contact resistance between the wires increases, and the wires are strongly restrained over the entire length of the wires, so that twisting and loosening hardly occur even when a repeated load is applied. Moreover, since the winding state is maintained by the contact resistance between the wires, the terminal processing can be simplified.

In the manufacturing method of the annular metal cord according to the present invention, the wire in the unused wire group may be a single wire.
Since the unused wire group is not incorporated into the annular metal cord, the production cost can be reduced by using a single wire that does not require twisting.

In the manufacturing method of the annular metal cord according to the present invention, one of the remaining reused wires in the reused wire group is formed into a plurality of loops while another wire of the reused wire group and the unused wire group It is preferable that the extra-long portion is fitted into the spiral space that has been removed and wound into an annular shape.
An annular metal cord can be manufactured by the remaining wires in the reusable wire group, which is economical.

In the manufacturing method of the annular metal cord according to the present invention, it is preferable that the starting end and the terminal end of the reusable wire are straightened, inserted between the wound extra length portions, and stored inside.
By inserting the starting end and the terminal end between the extra length portions, the end portions of the wire rod can be easily fixed, and the contact opportunities between the extra length portions of the wire rod are increased, which is advantageous for twist loosening. be able to.

In the manufacturing method of the cyclic | annular metal cord which concerns on this invention, it is preferable to give an annealing process.
By performing the annealing treatment, the processing strain at the time of twisting can be removed, and the durability can be enhanced.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the cyclic | annular metal cord, endless metal belt, and cyclic | annular metal cord which can maintain the shape wound without the twist loosening generate | occur | producing with respect to continuous repeated load can be provided. Therefore, if the annular metal cord and the endless metal belt of the present invention are used in an industrial machine, the industrial machine can be made excellent in durability.

It is a perspective view of the annular metal cord concerning this embodiment. It is a cross-sectional perspective view of the radial direction which shows a cyclic | annular metal cord. (A) is sectional drawing of the radial direction which shows a cyclic | annular metal cord, (b) is a side view of a cyclic | annular metal cord. It is an expansion perspective view which shows a part of cyclic | annular metal cord. It is an expansion perspective view which shows a part of cyclic | annular metal cord. It is a cross-sectional perspective view of the radial direction which shows the metal cord used for manufacture of a cyclic | annular metal cord. It is a perspective view which shows the reuse wire group which removed the unused wire group from the metal cord of FIG. It is the schematic which shows one process of forming a cyclic | annular metal cord from the reuse wire group of FIG. It is a perspective view which shows the use condition of the endless metal belt which concerns on this embodiment. It is a schematic block diagram which shows the durability test apparatus of a cyclic | annular metal cord.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

1 is a perspective view of an annular metal cord according to the present embodiment, FIG. 2 is a radial sectional perspective view showing the annular metal cord, and FIG. 3A is a radial direction showing the annular metal cord C1. FIG. 4B is a side view of the annular metal cord C1.
As shown in FIGS. 1 to 3, the annular metal cord C <b> 1 uses one strand material (reusable wire material) 1 in which a plurality of metal strands are twisted in advance as a wire material.

  The annular metal cord C1 of the present embodiment is prepared by preparing a single strand material 1 that is preliminarily spirally wound, and with the remaining length of the remaining length portion in a state where the length is approximately 1/6 of the length. The annular portion is formed by winding a plurality of turns (five turns). The twist direction of winding is, for example, Z twist. When this annular metal cord C1 is viewed in a cross section in the radial direction of the strand material 1, it has a structure in which six strand materials 1 are equally arranged in a circumferential shape.

  Each strand material 1 is one in which five metal strands 10 are twisted together in the S twist direction (under twisted). The metal strand 10 is made of, for example, a high carbon steel wire containing 0.7% by mass or more of carbon (C). By selecting a material containing 0.70% by mass or more of C, the metal wire 10 can be made a steel wire having more excellent breaking strength. Further, the surface of the metal strand 10 may be subjected to a copper alloy (for example, brass) or zinc plating treatment. In addition, the material of the metal strand 10 is not restricted to the said thing, For example, a piano wire may be sufficient.

  Moreover, the diameter of the metal strand 10 exists in the range of 0.06 mm or more and 0.30 mm or less. Thus, since the diameter of the metal strand 10 is 0.06 mm or more, the rigidity of the strand material 1 can be maintained to the minimum, and the annular metal cord C1 can withstand deformation. Moreover, since the diameter of the metal strand 10 is 0.30 mm or less, the rigidity of the strand material 1 does not need to become excessively large. Therefore, the annular metal cord C1 can make it difficult for fatigue fracture due to repeated bending stress.

  That is, when the strand material 1 is formed of the metal strand 10 having such a diameter, the strand material 1 having appropriate rigidity can be obtained. Therefore, winding of the strand material 1 becomes easy, and winding looseness after winding becomes difficult to occur.

  The strand materials 1 are wound in the opposite direction to the Z-twist, that is, the twist direction of the metal strand 10 constituting the strand material 1. On the other hand, since the strand material 1 itself has a configuration in which the metal strand 10 is S-twisted, the annular metal cord C1 is a combination of the S-twisted structure and the Z-winding structure. If the twisting direction of the metal strand 10 and the winding direction of the strand material 1 are reversed, the mechanical properties of the annular metal cord C1 are restrained from generating directionality and are not easily twisted, and the surface appearance has less irregularities. A metal cord C1 can be obtained. Further, even when the annular metal cord C1 is used while being rotated along the annular direction, it becomes difficult to meander.

  The strand material 1 is wound at a predetermined winding angle with respect to the six twisted central axes. For this reason, the strand material 1 is wound without disturbance, and the annular metal cord C1 having a substantially uniform surface state can be obtained. In the present embodiment, as shown in FIG. 3B, the winding angle θ of the strand material 1 with respect to the X direction, that is, the direction in which the central axis of the annular metal cord C1 extends is 4.5 degrees or more and 13.8 degrees or less. It has become. When the winding angle θ is set to 4.5 degrees or more, the strand material 1 is hardly loosened. By setting the winding angle θ to 13.8 degrees or less, it is possible to prevent the elongation of the strand material 1 from becoming excessively large. That is, by setting the winding angle θ of the strand material 1 to 4.5 degrees or more and 13.8 degrees or less, it is possible to obtain a flexible annular metal cord C1 having an appropriate elongation.

  As shown in FIG. 4, the winding start end portion 1a and the winding end portion 1b of the strand material 1 are inserted in between the wound extra length portions 1e and stored in an internal space formed at the center. Has been.

As shown in FIG. 5, the winding start end portion 1a and the winding end portion 1b of the strand material 1 abut each other, and the abutting portion 1c and the vicinity including the abutting portion 1c are bonded with an adhesive. It may be fixed. The adhesive is made of a material that can be expanded and contracted in response to elastic deformation of the annular metal cord C1 even after curing.
In this case, the abutting portion 1c between the starting end portion 1a and the terminal end portion 1b is arranged on one side on both side portions excluding the inner peripheral side and the outer peripheral side of the circular metal cord C1. preferable. Thereby, even if the cyclic | annular metal cord C1 deform | transforms in the radial direction, the load which acts on this butt | matching part 1c can be reduced, and the fracture | rupture in a joint part can be suppressed.

  Further, it is preferable that the annular metal cord C1 is subjected to a low-temperature annealing treatment before the butted portion 1c is bonded. By the low-temperature annealing treatment, the strain generated at the time of twisting (primary twist, upper twist) is removed. Thereby, further improvement in fatigue resistance of the annular metal cord C1 can be expected. Similarly, when the start end portion 1a and the end portion 1b are inserted and fixed between the extra length portions 1e, it is preferable that the low temperature annealing treatment is performed.

  Further, an adhesive resin is applied to the boundary where the strand materials 1 are in contact with each other over the entire annular direction of the annular metal cord C1. Thereby, since strand material 1 can be hold | maintained so that it may not move not only by the contact resistance but also by the adhesive force of resin, it becomes difficult to produce twist loosening, and a shape becomes stable. The adhesive resin is made of a material that can be expanded and contracted in response to the elastic deformation of the annular metal cord C1 even after curing.

Then, the manufacturing method of the cyclic | annular metal cord C1 is demonstrated.
FIG. 6 is a radial sectional perspective view showing a metal cord prepared for manufacturing the annular metal cord C1.
As shown in FIG. 6, the metal cord 20 is formed by twisting three strands 1 of the above-described metal strands 10 (twisted down) and five strands of the metal strands 11 ( It has a twisted wire structure in which three strand materials 2 formed by twisting (twisted) are twisted together (top twisted). The three strand materials 1 are a reusable wire group 3 that is used to form the annular metal cord C1, and the three strand materials 2 are an unused wire group 4 that does not constitute the annular metal cord C1. In addition, before twisting these six strand materials 1 and 2, it is good to give a spiral type | mold respectively.

The reused wire group 3 and the unused wire group 4 are configured such that the reused wire group 3 is larger when the total cross-sectional areas are compared. That is, the total cross-sectional area of the three strand material 1 constituting the reuse wire group 3 and A _S1, three of the total cross-sectional area of the strand material 2 and A _S2 constituting the unused wire group 4, wherein The relationship “A _S1 > A _S2 ” is satisfied.
Here, A _S1 is represented by A _S1 = n · a _S1 where A _S1 is the total cross-sectional area of the reusable wire group 3 and n is the number of strand materials 1 and a _S1 is the cross-sectional area.

  In order to satisfy such a relationship, if the number of the reused wire group 3 and the number of the unused wire group 4 are the same, for example, the strand materials 1 and 2 using the metal strands 10 and 11 having the wire diameter d are used. When the metal wire 11 is formed, the metal wire 11 having a wire diameter d smaller than the nominal diameter may be used. Or you may use that the wire diameter d of the metal strand 10 is thicker than a nominal diameter. Moreover, in order to satisfy | fill the said formula | equation, the wire diameter design value of the metal strands 10 and 11 may be varied beforehand, and the number of the metal strands 10 and 11 used for a strand material may be varied. Further, the number of strand materials used for the reused wire group 3 and the unused wire group 4 may be made different.

  Such a metal cord 20 is untwisted and divided into a reuse wire group 3 which is a group of strand materials 1 and an unused wire group 4 which is a group of strand materials 2. One strand material (reusable wire) 1 is used. Thereafter, the unused wire group 4 is not used, and the annular metal cord C1 is manufactured using one strand material 1 in the reused wire group 3. FIG. 7 shows a state in which one strand material 1 of the reused wire group 3 from which the unused wire group 4 is removed is shown.

  As shown in FIG. 7, one strand material 1 in the reused wire group 3 from which the unused wire group 4 is removed is the other strand material 1 and the unused wire group 4 in the reused wire group 3. Spiral voids 5 are formed at the locations where there was. The portion where the unused wire group 4 exists in the gap 5 has a cross-sectional area equivalent to that of the unused wire group 4 having an area smaller than the cross-sectional area of the reused wire group 3. That is, the gap 5 has a cross-sectional area smaller than the sum of the cross-sectional areas of the five strand materials 1.

  Next, as shown in FIG. 8, the length of the strand material 1 is made approximately 1/6 of an annular length, and the extra length portion 1 e of the strand material 1 is placed in the spiral gap 5 in the annular portion 1 d. It is inserted and wound around a plurality of rounds (5 rounds). The spiral void 5 in the strand material 1 has a cross-sectional area smaller than the sum of the cross-sectional areas of the five strand materials 1, and the extra length portion 1e of the strand material 1 wound around the five-circular annular shape itself. Since it is inserted into the narrower spiral gap 5, the adjacent extra lengths 1e of the wound strand material 1 are pressed in the radial direction. As a result, the contact resistance between the strand materials 1 increases, and the strand materials 1 are strongly restrained over the entire length of the strand material 1, so that twisting and loosening hardly occur even when a repeated load is applied. Moreover, since the winding state is maintained by the contact resistance between the strand materials 1, it is possible to simplify the terminal processing of the start end portion 1 a and the end end portion 1 b of the strand material 1. As described above, according to this embodiment, the strand metal 1 is not loosened even under continuous repeated loads, and the annular metal cord C1 that can maintain the shape around which the strand material 1 is wound is easily manufactured. can do.

  Moreover, since the strand material 1 which comprises the reusable wire group 3 is not a single wire but a wire material obtained by twisting a plurality of metal strands 10, the contact resistance between the strand materials 1 is also large due to the unevenness on the surface of the strand material 1. Therefore, twist loosening is further less likely to occur. Moreover, since the flexibility of the annular metal cord C1 is improved and a uniform load is easily applied to an external force, it is possible to suppress a decrease in breaking strength.

The strand material 1 made into the cyclic | annular metal cord C1 is good in a diameter mold attachment rate being 86% or more and 100% or less. When the strand rate of the strand material 1 is less than 86%, when the metal cord 20 is untwisted and the strand material 1 is taken out, the height of the spiral wave is reduced and the gap portion 5 is reduced, so that a predetermined number of turns are wound. It becomes difficult.
Further, when the diameter ratio of the strand material 1 exceeds 100%, the height of the spiral wave becomes high and the gap portion 5 becomes large, so that it can be easily wound without being fitted, and the contact resistance between the strand materials 1 Decrease. As a result, loosening of the twist is likely to occur and durability is reduced.
The diameter attaching ratio is the cross-sectional diameter of the annular metal cord C1 (the diameter of the cross-section in which one strand material 1 is fitted into a plurality of circumferential gaps and the six strand materials 1 are arranged in a circumferential shape). Is D, and the wave height (including self-diameter) of the shaped strand material 1 is H, it is expressed by “Diameter Die Rate (%) = H / D × 100”.

  After winding in a ring, the strand material 1 is stretched and straightened so as to eliminate the molding at the starting end 1a and the terminal end 1b, and is straightened as much as possible, and inserted between the wound extra lengths 1e. By storing in the formed internal space, the start end 1a and the end end 1b of the strand material 1 are fixed. The starting end 1a and the terminal end 1b of the strand material 1 are straightened and inserted between the extra length portions 1e so that the starting end 1a and the terminal end 1b can be easily fixed. The contact opportunity between the long portions 1e can be increased, which can be advantageous for twist loosening.

Note that the winding start end portion 1a and the winding end portion 1b may be butted against each other, and the butted portion 1c and the vicinity including the butting portion 1c may be fixed with an adhesive.
Moreover, it is good to remove the distortion | strain which generate | occur | produces at the time of twisting (primary twist, upper twist) by performing a low temperature annealing process to the cyclic | annular metal cord C1 whole, before bonding the butt | matching part 1c. In the case where the start end portion 1a and the end end portion 1b are inserted and fixed between the extra length portions 1e, a low temperature annealing process is performed thereafter. Thereby, further improvement in fatigue resistance of the annular metal cord C1 can be expected.

  Further, an adhesive resin may be applied to the boundary where the strand materials 1 are in contact with each other over the entire annular direction of the annular metal cord C1. Thereby, since strand material 1 can be hold | maintained so that it may not move not only by the contact resistance but also by the adhesive force of resin, it becomes difficult to produce twist loosening, and a shape becomes stable.

  Moreover, in the said embodiment, although the cyclic | annular metal cord C1 was manufactured using one strand material 1 of the three reuse wire groups 3, the remaining two strands of the reuse wire group 3 were each. Similarly, as described above, the extra length portion 1e is formed in the spiral void portion 5 from which the unused wire rod group 4 and other wire rods in the reused wire rod group 3 are removed while making the plurality of circular rings as described above. The annular metal cord C1 can be manufactured by fitting and winding, and the economic efficiency can be improved.

In addition to the examples shown in the above embodiment, the configurations of the reused wire group and the unused wire group can be appropriately changed as long as the relationship of the above formula is satisfied.
For example, it is assumed that a metal cord prepared first is a stranded wire made of five strands, and the strand material is formed by twisting seven metal strands. Then, two of the five strand materials are untwisted and removed as an unused wire group to form a reused wire group composed of three strand materials. In the reusable wire group, a spiral void portion having a cross-sectional area equivalent to two strand materials is formed. Therefore, the relationship of “total sectional area A _S1 of reused wire group> total sectional area A _S2 of unused wire group” is satisfied. One of the reusable wire group is the same as described with reference to FIG. 7, and the extra length is added to the annular portion twice as many as the number of strands formed by the reusable wire group (including the first annular portion). By wrapping around and winding only, it is possible to obtain an annular metal cord in which the strand materials are strongly restrained by contact resistance. In the case of this example, since the number of strand materials used for the reused wire group and the unused wire group is different, all the wire diameters of the metal wires used for the reused wire group and the unused wire group may be the same, The unused wire group may be slightly thinner or thicker.

Moreover, since the wire in the unused wire group does not constitute the annular metal cord C1, the structure can be simplified or the material can be changed.
For example, the manufacturing cost can be suppressed by making the wire in the unused wire group a single wire instead of the strand material. When the strand material is used for the unused wire group, the manufacturing cost is increased by twisting the metal strands to form the strand material.

  Moreover, it is good also as a wire rod of materials, such as a fiber weaker than a metal wire, without making the wire rod in an unused wire group into a metal wire. For example, an aramid fiber or carbon fiber twisted in a bundle can be used. If the rigidity of the unused wire group is weaker than that of the reused wire group, it is easy to take out the wire of the unused wire group when untwisting the cord, and work is easy. In addition, by using a material with low rigidity other than metal for the wires of the unused wire group, it can be reused and the material cost can be reduced.

  Next, an example of an endless metal belt provided with the annular metal cord C1 having the above-described configuration will be described. FIG. 9 is a schematic perspective view showing a use state of the endless metal belt according to the present embodiment.

  The endless metal belt B1 is used for a reduction gear 30 used in precision equipment and other industrial machines as shown in FIG. 9, for example. The endless metal belt B1 is composed of three annular metal cords C1 arranged in parallel, and bears power transmission between the small-diameter driving pulley 32 and the large-diameter driven pulley 34. A drive shaft of a drive motor 36 is connected to the rotation center of the drive pulley 32. Circumferential grooves are formed on the outer circumferences of the driving pulley 32 and the driven pulley 34 so that the respective annular metal cords C1 are stably routed. The endless metal belt B1 is connected to the driving pulley 32 and the driven pulley 34. As a result, the rotational force of the driving pulley 32 is transmitted to the driven pulley 34 via the endless metal belt B1. At this time, the rotational speed of the driving pulley 32 is reduced by the driven pulley 34, and the torque of the driving pulley 32 is increased by the driven pulley 34. The driven pulley 34 is axially connected to, for example, another pulley (not shown) and transmits power.

  The annular metal cord C1 has a very high breaking strength as described above. Moreover, since the cross section of the annular metal cord C1 is substantially circular, it is more resistant to twisting than the one having a rectangular cross section. Therefore, compared to the case where a flat belt is used as the endless metal belt, the endless metal belt B1 configured using a plurality of annular metal cords C1 is extremely excellent in bending resistance and durability.

  In the endless metal belt B1 of the present embodiment, three annular metal cords C1 are stretched over the driving pulley 32 and the driven pulley 34. However, the number of annular metal cords C1 to be spanned is as follows. It is not limited to this. The number of the annular metal cords C1 can be adjusted according to the required driving force or belt tension.

  In the present embodiment, the annular metal cord is applied to an endless metal belt that transmits power in a reduction gear. However, the annular metal cord of the present invention is also applicable to an endless metal belt that is used other than the reduction gear. Can be applied. For example, an endless metal belt responsible for power transmission between paper feed rollers in a printer such as a printer, an endless metal belt responsible for direct drive of a single-axis robot, an endless metal belt responsible for driving an XY table mechanism or driving a three-dimensional carriage Applicable to metal belts, endless metal belts responsible for precision driving in optical instruments and inspection machines, measuring instruments, endless metal belts responsible for power transmission between driving pulleys and driven pulleys in continuously variable transmissions for automobiles, etc. Is possible.

Next, examples of the annular metal cord according to the present invention will be described.
Cyclic metal cords were prepared under various conditions and the change in durability was investigated.

(First embodiment)
6 × 5 × d (nominal diameter d = 0.15 mm) annular metal cord (1) Production of strand material (1-1) Production of strand material for reusable wire group 0.82% by mass of carbon (C) Steel wire for steel cords with a diameter of 0.90 mm containing heat treatment and pickling, for example, copper and zinc plating are sequentially applied, alloyed by diffusion, and drawn to a diameter of 0.15 mm through a wire drawing step .
In this way, among the strands drawn to a diameter of 0.15 mm, a tubular strand that can be twisted by using a strand having a diameter of 0.151 to 0.155 mm as measured by a micrometer. Using a machine, 5 strands are twisted with S twist at a twist pitch of 5.0 mm to obtain a strand material for a reusable wire group.
In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance with a preform apparatus. Then, three reels are prepared by winding a predetermined amount of the strand material.
(1-2) Production of Strand Material for Unused Wire Group A steel wire for a steel cord having a diameter of 0.90 mm containing 0.82% by mass of carbon (C) is heat treated and pickled, for example, copper and zinc After plating sequentially, it is alloyed by diffusion and drawn to a diameter of 0.15 mm through a wire drawing step.
In this way, among the strands drawn to a diameter of 0.15 mm, a tubular strand that can be twisted by using a strand having a diameter of 0.146 to 0.150 mm as measured by a micrometer. Using a machine, 5 strands are twisted with S twist at a 5.0 mm twist pitch to obtain a strand material for the unused wire group.
In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance with a preform apparatus. Then, three reels are prepared by winding a predetermined amount of the strand material.
(1-3) Production of metal cords Using a tubular twisted wire machine capable of six strands, the three strand materials for the reusable wire group and the three strand materials for the unused wire group are prepared. A 6 × 5 × d metal cord is formed by twisting a predetermined amount by Z twisting at a twist pitch of 7.5 mm. In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance using a preform apparatus.
(1-4) Untwisting of metal cord The length of the metal cord that has been twisted, including the extra length, about 20 times the annular diameter (layer core diameter: D1) of the annular metal cord ((D1) π × 6) After cutting, the yarn is untwisted over the entire length and separated for each strand material.

(2) Annular metal cord to be produced (2-1) Annular metal cord of Examples (Examples 1 and 2)
Using one of the strands having an average strand diameter du (0.153 mm) of the reused wire group among the six separated strand materials, for example, an annular diameter of 200 mm in diameter is formed, and then 5 The extra length portion is fitted into a spiral gap where the other five strands are removed by circular movement to form a 6 × 5 × du annular metal cord.
In Example 2, annealing treatment is performed at about 260 ° C. for 10 minutes under a reduced pressure environment.
(Comparative Examples 2 and 3)
Using one of the strands having an average strand diameter dn (0.147 mm) of the unused strand group among the six separated strands, for example, an annular diameter of 200 mm is formed, and then 5 The extra length portion is fitted into a spiral void portion from which the other five strand materials are removed by circular movement to form a 6 × 5 × dn annular metal cord.
(Comparative Examples 1 and 4)
For example, an annular diameter of 200 mm is formed by using one strand material having an average strand diameter da (0.150 mm) in the range of 0.150 ± 0.002 mm. Thereafter, the extra length portion is fitted into the spiral void portion from which the other five strand materials have been removed by moving around five times to obtain a 6 × 5 × da annular metal cord.
(2-2) Connection structure of the terminal The starting end and the terminal end of the strand material are cut leaving the necessary length, and the spiral wave shape is flattened as much as possible. In Comparative Example 1, it is inserted and connected to the sleeve, in Comparative Example 2, it is connected by half basket insertion, in Comparative Example 3, it is connected by insertion into the sleeve and half basket insertion, Comparative Example 4, Example 1 , 2 are inserted and connected to the center.

(3) Durability Test (3-1) Durability Test Device FIG. 10 shows a durability test device. As shown in FIG. 10, the durability test apparatus includes a drive pulley 52 that is rotated by a drive motor 51, a driven pulley 53 that is supported so as to be movable toward and away from the drive pulley 52 in the horizontal direction, and a driven pulley 53. And a tension applying portion 54 that applies a load in a direction in which the roller is separated from the drive pulley 52.
The diameters of the driving pulley 52 and the driven pulley 53 were 39.4 mm, and the diameter passing through the center of the cord when the annular metal cord was wound was about 40 mm.
The tension applying portion 54 includes a weight 56 attached to the driven pulley 53 via a rope 55 and a pulley 57 on which the rope 55 is hung. The driven pulley 53 is separated from the driving pulley 52 by the load of the weight 56. The And in this tension | tensile_strength addition part 54, the weight of the weight 56 was adjusted to 15 kg, and the additional tension | tensile_strength was 7.5 kgf (around 5% of the intensity | strength of a cord).
(3-2) Durability Test Method Each annular metal cord is wound around the drive pulley 52 and the driven pulley 53 of the durability test apparatus described above, and the drive pulley 52 is rotated at 3,500 rpm, and is repeatedly applied to the annular metal cord. A tensile bending stress was applied, and the presence / absence of defects such as cutting and loosening of the annular metal cord and breakage of the wire (elementary wire) and the number of times of endurance (conversion number) until the defect occurred were evaluated.
(3-3) Durability test results Table 1 shows the durability test results.

As is clear from Table 1, in Examples 1 and 2, a 6 × 5 × du annular metal cord was formed by using one strand material having an average strand diameter du (0.153 mm) of a reusable wire group. The number of repeated bending bending that can be endured is extremely large. In particular, in Example 2 where the annealing treatment was performed, no cutting was observed.
On the other hand, in the comparative examples 2 and 3 which used the strand material of the average strand diameter dn (0.147mm) of an unused wire group and made it a 6x5xdn cyclic metal cord, it can endure. The number of repeated bending was small.
Further, in the case of Comparative Examples 1 and 4 in which a single strand material having an average strand diameter da (0.150 mm) prepared for comparison is used to form a 6 × 5 × da annular metal cord, it can withstand repetition. The number of tensile bending was small.

(Second embodiment)
6 × 7 × d (nominal diameter d = 0.15 mm) annular metal cord (1) Production of strand material (1-1) Production of strand material for reusable wire group 0.82% by mass of carbon (C) Steel wire for steel cords with a diameter of 0.90 mm containing heat treatment and pickling, for example, copper and zinc plating are sequentially applied, alloyed by diffusion, and drawn to a diameter of 0.15 mm through a wire drawing step .
In this way, among the strands drawn to a diameter of 0.15 mm, a tubular twisted strand that can be twisted 7 using strands having a diameter of 0.146 to 0.150 mm as measured by a micrometer. Using a machine, 7 strands are twisted with S twist at a twist pitch of 5.0 mm to obtain a strand material for a reusable wire group.
In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance with a preform apparatus. Then, three reels are prepared by winding a predetermined amount of the strand material.
(1-2) Production of Strand Material for Unused Wire Group A steel wire for a steel cord having a diameter of 0.90 mm containing 0.82% by mass of carbon (C) is heat treated and pickled, for example, copper and zinc After plating sequentially, it is alloyed by diffusion and drawn to a diameter of 0.15 mm through a wire drawing step.
In this way, among the strands drawn to a diameter of 0.15 mm, a tubular twisted strand that can be twisted with 7 strands using strands with a diameter of 0.151 to 0.155 mm as measured by a micrometer. Using a machine, 7 strands are twisted with S twist at a 5.0 mm twist pitch to obtain a strand material for the unused wire group.
In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance with a preform apparatus. Then, two reels prepared by winding a predetermined amount of the strand material are prepared.
(1-3) Production of metal cord Using a tubular twisted wire machine capable of twisting five wires, three strand materials for the above-mentioned reused wire group and two strand materials for the unused wire group. A 5 × 7 × d metal cord is formed by twisting a predetermined amount by Z twisting at a 6.5 mm twist pitch. In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance using a preform apparatus.
(1-4) Untwisting of metal cord The length of the metal cord that has been twisted, including the extra length, about 20 times the annular diameter (layer core diameter: D1) of the annular metal cord ((D1) π × 6) After cutting, the yarn is untwisted over the entire length and separated for each strand material.

(2) Ring metal cord to be produced (2-1) Ring metal cord of Example (Examples 3 and 4)
One of the strands having an average strand diameter du (0.147 mm) of the reused wire group among the five separated strand materials is used to form, for example, an annular diameter of 200 mm, and then 5 The extra length portion is fitted into the spiral void portion from which the other four strand materials have been removed by circular movement to form a 6 × 7 × du annular metal cord.
In Example 4, annealing is performed at about 260 ° C. for 10 minutes in a reduced pressure environment.
(Comparative Examples 6 and 7)
Using one of the strands having an average strand diameter dn (0.153 mm) of the unused strand group of the five separated strands, for example, an annular diameter of 200 mm is formed, and then 2 The extra length portion is fitted into a spiral void portion in which the other four strand materials are removed by moving around three turns with a small number of rounds to form a 4 × 7 × dn annular metal cord.
(Comparative Example 5)
For example, an annular diameter of 200 mm is formed by using one strand material having an average strand diameter da (0.150 mm) in the range of 0.150 ± 0.002 mm. Thereafter, the extra length portion is fitted into the spiral void portion in which the other four strand materials are removed by moving four times less by one turn to obtain a 5 × 7 × dn annular metal cord.
(Comparative Example 8)
For example, an annular diameter of 200 mm is formed by using one strand material having an average strand diameter da (0.150 mm) in the range of 0.150 ± 0.002 mm. Thereafter, the extra length portion is fitted into the spiral void portion from which the other four strand materials are removed by moving around five times to obtain a 6 × 7 × dn annular metal cord.
(2-2) Connection structure of the terminal The starting end and the terminal end of the strand material are cut leaving the necessary length, and the spiral wave shape is flattened as much as possible. In Comparative Example 5, it is inserted into the sleeve and connected, in Comparative Example 6 it is connected by half basket insertion, in Comparative Example 7 it is connected by insertion into the sleeve and half basket insertion, Comparative Example 8 and Example 3 , 4 are inserted and connected to the center.

(3) Durability test (3-1) Durability test apparatus The above-described durability test apparatus (see FIG. 10) is used.
The diameters of the driving pulley 52 and the driven pulley 53 were 39.4 mm, and the diameter passing through the center of the cord when the annular metal cord was wound was about 40 mm.
Moreover, in the tension | tensile_strength addition part 54, the weight of the weight 56 was adjusted to 15 kg, and the additional tension | tensile_strength was set to 7.5 kgf (around 5% of the intensity | strength of a code | cord | chord).
(3-2) Durability Test Method Each annular metal cord is wound around the drive pulley 52 and the driven pulley 53 of the durability test apparatus described above, and the drive pulley 52 is rotated at 3,500 rpm, and is repeatedly applied to the annular metal cord. A tensile bending stress was applied, and the presence / absence of defects such as cutting and loosening of the annular metal cord and breakage of the wire (elementary wire) and the number of times of endurance (conversion number) until the defect occurred were evaluated.
(3-3) Durability test results Table 2 shows the durability test results.

As can be seen from Table 2, in Examples 3 and 4, a 6 × 7 × du annular metal cord was formed by using one strand material having an average strand diameter du (0.147 mm) of the reusable wire group. The number of repeated bending bending that can be endured is extremely large. In particular, in Example 4 where the annealing treatment was performed, no cutting was observed.
On the other hand, in the comparative examples 6 and 7 which used the strand material of the average strand diameter dn (0.153 mm) of an unused wire group, and made it the 4x7xdn cyclic metal cord, it can endure. The number of repeated bending was small.
Further, in the case of Comparative Example 5 in which a single strand material having an average strand diameter da (0.150 mm) prepared for comparison is used to form an annular metal cord of 5 × 7 × da, it can withstand repeated tensile bending. There were few times.
Furthermore, also in the case of the comparative example 8 which used the strand material of the average strand diameter da (0.150mm) prepared for the comparison as a 6x7xda cyclic | annular metal cord, both ends are made into center part. Since the strand material diameter was larger than the diameter of the inscribed circle at the center of the annular metal cord when inserted into the wire, twisting disturbance occurred only at that portion, so that the number of repeated tensile bending that could be tolerated was small.

(Third embodiment)
6 × (3 + 9) × d (nominal diameter d = 0.082 mm) annular metal cord (1) Production of strand material (1-1) Production of strand material for reusable wire group 0.82% by mass of carbon ( A steel wire for steel cord having a diameter of 4.0 mm containing C) is pickled and drawn to a diameter of 1.5 mm through a wire drawing step. Further, after heat treatment and pickling and drawing to a diameter of 0.55 mm, heat treatment and pickling are performed, for example, copper and zinc plating are sequentially applied, alloyed by diffusion, and then drawn to a diameter of 0.082 mm.
In this way, among the strands drawn to a diameter of 0.082 mm, using strands having an average diameter of 0.085 mm as measured by a micrometer, the diameter is 3.0 mm using a tubular twisting machine. Three strands are twisted by S twist at a twist pitch of 9, and 9 strands are twisted by S twist at a pitch of 4.5 mm using a tubular twisting machine on the outer peripheral side, A strand material for a 3 + 9 reusable wire group.
In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance with a preform apparatus. Then, three reels are prepared by winding a predetermined amount of the strand material.
(1-2) Production of Strand Material for Unused Wire Group A steel wire for a steel cord having a diameter of 4.0 mm containing 0.82% by mass of carbon (C) is pickled and subjected to a wire drawing step to obtain a diameter of 1 .Draw to 5mm. Further, after heat treatment and pickling and drawing to a diameter of 0.55 mm, heat treatment and pickling are performed, for example, copper and zinc plating are sequentially applied, alloyed by diffusion, and then drawn to a diameter of 0.082 mm.
In this way, among the strands drawn to a diameter of 0.082 mm, using strands having an average diameter of 0.079 mm as measured by a micrometer, the diameter is 3.0 mm using a tubular twisting machine. Three strands are twisted by S twist at a twist pitch of 9, and 9 strands are twisted by S twist at a pitch of 4.5 mm using a tubular twisting machine on the outer peripheral side, A strand material for 3 + 9 unused wire group.
In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance with a preform apparatus. Then, three reels are prepared by winding a predetermined amount of the strand material.
(1-3) Production of metal cords Using a tubular twisted wire machine capable of six strands, the three strand materials for the reusable wire group and the three strand materials for the unused wire group are prepared. A 6 × (3 + 9) × d metal cord is formed by twisting a predetermined amount by Z twisting at a twist pitch of 6.0 mm. In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance using a preform apparatus.
(1-4) Untwisting of metal cord The length of the metal cord that has been twisted, including the extra length, about 20 times the annular diameter (layer core diameter: D1) of the annular metal cord ((D1) π × 6) After cutting, the yarn is untwisted over the entire length and separated for each strand material.

(2) Ring metal cord to be produced (2-1) Ring metal cord of Example (Examples 5 and 6)
For example, an annular diameter of 200 mm in diameter is formed by using one of the strand materials having an average strand diameter du (0.085 mm) of the reused wire group among the separated six strand materials. The extra length portion is fitted into a spiral void portion from which the other five strand materials have been removed by circular movement to form a 6 × (3 + 9) × du annular metal cord.
In Example 6, an annealing treatment is performed at about 260 ° C. for 10 minutes under a reduced pressure environment.
(Comparative Examples 10 and 11)
One of the strands having an average strand diameter dn (0.079 mm) of the unused strands among the six separated strands is used to form, for example, an annular diameter of 200 mm, and then 5 The extra length portion is fitted into the spiral void portion from which the other five strand materials have been removed by circular movement to form a 6 × (3 + 9) × dn annular metal cord.
(Comparative Examples 9 and 12)
For example, an annular diameter having a diameter of 200 mm is formed using one strand material having an average strand diameter da (0.082 mm) in the range of 0.082 ± 0.002 mm. Thereafter, the extra length portion is fitted into the spiral void portion from which the other five strand materials have been removed by moving around 5 times to form a 6 × (3 + 9) × da annular metal cord.
(2-2) Connection structure of the terminal The starting end and the terminal end of the strand material are cut leaving the necessary length, and the spiral wave shape is flattened as much as possible. In Comparative Example 9, it is inserted and connected to the sleeve, in Comparative Example 10, it is connected by half basket insertion, in Comparative Example 11, it is connected by insertion into the sleeve and half basket insertion, Comparative Example 12, Example 5 , 6 are inserted and connected to the center.

(3) Durability test (3-1) Durability test apparatus The above-described durability test apparatus (see FIG. 10) is used.
The diameters of the driving pulley 52 and the driven pulley 53 were 24.5 mm, and the diameter passing through the center of the cord when the annular metal cord was wound was about 25 mm.
Moreover, in the tension | tensile_strength addition part 54, the weight of the weight 56 was adjusted to 11 kg, and the additional tension | tensile_strength was 5.5 kgf (around 5% of the intensity | strength of a cord).
(3-2) Durability Test Method Each annular metal cord is wound around the drive pulley 52 and the driven pulley 53 of the durability test apparatus described above, and the drive pulley 52 is rotated at 3,500 rpm, and is repeatedly applied to the annular metal cord. A tensile bending stress was applied, and the presence / absence of defects such as cutting and loosening of the annular metal cord and breakage of the wire (elementary wire) and the number of times of endurance (conversion number) until the defect occurred were evaluated.
(3-3) Durability Test Results Table 3 shows the durability test results.

As is apparent from Table 3, Example 5 was obtained by using one strand material having an average strand diameter du (0.085 mm) of the reusable wire group to form a ring metal cord of 6 × (3 + 9) × du. In Example 6, the number of repeated tensile bending that can be endured was extremely large, and in particular, in Example 6 where the annealing treatment was performed, no cutting was observed.
On the other hand, in Comparative Examples 10 and 11 in which a ring metal cord of 6 × (3 + 9) × dn was used by using one strand material having an average strand diameter dn (0.079 mm) of the unused wire group, The number of repeated pulling and bending that can be tolerated was small.
Further, in the case of Comparative Examples 9 and 12 in which a single strand material having an average strand diameter da (0.082 mm) prepared for comparison is used to form a 6 × (3 + 9) × da annular metal cord, it is durable. The number of repeated tensile bendings obtained was small.

(Fourth embodiment)
6 × 2 × d (nominal diameter d = 0.25 mm) annular metal cord (1) Production of strand material (1-1) Production of strand material for reusable wire group 0.82% by mass of carbon (C) A steel wire for a steel cord having a diameter of 5.5 mm containing the steel is pickled and drawn to a diameter of 1.3 mm through a wire drawing step. Furthermore, after heat treatment and pickling, for example, copper and zinc plating are sequentially performed, alloyed by diffusion, and then drawn to a diameter of 0.25 mm.
In this way, of the strands drawn to a diameter of 0.25 mm, two strands having an average diameter of 0.253 mm as measured with a micrometer are used, and a tubular type twisting machine is used. A strand material for a reusable wire group is obtained by twisting with an S twist at a twist pitch of 7.0 mm.
In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance with a preform apparatus. Then, three reels are prepared by winding a predetermined amount of the strand material.
(1-2) Production of Strand Material for Unused Wire Group A steel wire for steel cord having a diameter of 5.5 mm containing 0.82% by mass of carbon (C) is pickled and subjected to a wire drawing step to obtain a diameter of 1 .Draw to 3 mm. Furthermore, after heat treatment and pickling, for example, copper and zinc plating are sequentially performed, alloyed by diffusion, and then drawn to a diameter of 0.25 mm.
In this way, out of the strands drawn to a diameter of 0.25 mm, using two strands having an average diameter of 0.247 mm as measured by a micrometer, using a tubular twisting machine A strand material for a reusable wire group is obtained by twisting with an S twist at a twist pitch of 7.0 mm.
In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance with a preform apparatus. Then, three reels are prepared by winding a predetermined amount of the strand material.
(1-3) Production of metal cords Using a tubular twisted wire machine capable of six strands, the three strand materials for the reusable wire group and the three strand materials for the unused wire group are prepared. A 6 × 2 × d metal cord is formed by twisting a predetermined amount with a Z twist at a twist pitch of 10.0 mm. In addition, it adjusts to the diameter shaping | molding rate of about 93% in advance using a preform apparatus.
(1-4) Untwisting of metal cord The length of the metal cord that has been twisted, including the extra length, about 20 times the annular diameter (layer core diameter: D1) of the annular metal cord ((D1) π × 6) After cutting, the yarn is untwisted over the entire length and separated for each strand material.

(2) Annular metal cord to be produced (2-1) Annular metal cord of Examples (Examples 7 and 8)
One of the strands having an average strand diameter du (0.253 mm) of the reused wire group among the six separated strands is used to form, for example, an annular diameter of 200 mm, and then 5 The extra length portion is fitted into a spiral gap where the other five strand materials are removed by circular movement to form a 6 × 2 × du annular metal cord.
In Example 8, an annealing treatment is performed at about 260 ° C. for 10 minutes under a reduced pressure environment.
(Comparative Examples 14 and 15)
Using one of the strands having an average strand diameter dn (0.247 mm) of the unused strand group among the six separated strands, for example, an annular diameter of 200 mm is formed, and then 5 The extra length portion is fitted into a spiral gap where the other five strand materials are removed by circular movement to form a 6 × 2 × dn annular metal cord.
(Comparative Examples 13 and 16)
For example, an annular diameter of 200 mm is formed by using one strand material having an average strand diameter da (0.250 mm) in the range of 0.250 ± 0.002 mm. Thereafter, the extra length portion is fitted into a spiral gap where the other five strands are removed by moving around five times to obtain a 6 × 2 × da annular metal cord.
(2-2) Connection structure of the terminal The starting end and the terminal end of the strand material are cut leaving the necessary length, and the spiral wave shape is flattened as much as possible. In Comparative Example 13, the sleeve is inserted and connected, in Comparative Example 14 is connected by half basket insertion, and in Comparative Example 15 is inserted by insertion into the sleeve and connected by half basket, Comparative Example 16 and Example 7 are connected. , 8 are inserted and connected to the center.

(3) Durability test (3-1) Durability test apparatus The above-described durability test apparatus (see FIG. 10) is used.
The diameters of the driving pulley 52 and the driven pulley 53 were 74.2 mm, and the diameter passing through the center of the cord when the annular metal cord was wound was about 75 mm.
Further, in the tension applying part 54, the weight of the weight 56 was adjusted to 16 kg, and the applied tension was set to 8.0 kgf (around 5% of the cord strength).
(3-2) Durability Test Method Each annular metal cord is wound around the drive pulley 52 and the driven pulley 53 of the durability test apparatus described above, and the drive pulley 52 is rotated at 3,500 rpm, and is repeatedly applied to the annular metal cord. A tensile bending stress was applied, and the presence / absence of defects such as cutting and loosening of the annular metal cord and breakage of the wire (elementary wire) and the number of times of endurance (conversion number) until the defect occurred were evaluated.
(3-3) Durability test results Table 4 shows the durability test results.

As can be seen from Table 4, in Examples 7 and 8, a 6 × 2 × du annular metal cord was formed by using one strand material having an average strand diameter du (0.253 mm) of the reusable wire group. The number of repeated bending bending that can be endured becomes extremely large, and in particular, in Example 8 where the annealing treatment was performed, no cutting was observed.
On the other hand, in the comparative examples 14 and 15 which used the strand material of the average strand diameter dn (0.247 mm) of an unused wire group and made it a 6x2xdn cyclic metal cord, it can endure. The number of repeated bending was small.
In addition, in the case of Comparative Examples 13 and 16 in which one of strand materials having an average strand diameter da (0.250 mm) prepared for comparison is used to form a 6 × 2 × da annular metal cord, it can withstand repetition. The number of tensile bending was small.

  From the said 1st-4th Example, the adjacent parts of a strand material are mutually inserted by the extra length part of the strand material of a reuse wire group being inserted in the space | gap part smaller than the total area of a reuse wire group several times. It has been found that a strong annular metal cord capable of maintaining the wound shape without being twisted and loosened is obtained. In particular, it has been found that an annular metal cord with further increased strength can be obtained by annealing treatment.

  DESCRIPTION OF SYMBOLS 1 ... Strand material (reuse wire), 2 ... Strand material (wire), 1a ... Start part, 1b ... Termination part, 1d ... Ring part, 1e ... Extra length part, 3 ... Reuse wire group, 4 ... Unused Wire group, 5 ... gap, 10 ... metal strand, 20 ... metal cord (code), B1 ... endless metal belt, C1 ... annular metal cord.

Claims (14)

The original cord in which a plurality of wires are twisted together is untwisted and divided into two wire groups having different total cross-sectional areas,
The wire group with the larger total cross-sectional area is the reused wire group, and the wire group with the smaller total cross-sectional area is the unused wire group.
One reusable wire in the reusable wire group is formed in a loop around a spiral gap where another wire in the reusable wire group and the non-reusable wire group are removed while being formed into a plurality of circular rings. An annular metal cord characterized in that a long portion is fitted and wound into an annular shape. The annular metal cord according to claim 1,
The cyclic metal cord, wherein the reuse wire in the reuse wire group has a structure in which a plurality of metal strands are twisted together. The annular metal cord according to claim 2, wherein
An annular metal cord, wherein a twist direction of the metal strands and a spiral direction of winding fitted in the gap are opposite directions. The annular metal cord according to any one of claims 1 to 3,
The reusable wire has a diameter ratio of 86% or more and 100% or less in the annular metal cord after the one reused wire is fitted into the gap and wound into an annular shape. An annular metal cord. The annular metal cord according to any one of claims 1 to 4,
An annular metal cord characterized in that the start end and the end of the reusable wire are inserted from between the wound extra length portions and stored therein. The annular metal cord according to any one of claims 1 to 5,
An annular metal cord that is annealed. The annular metal cord according to any one of claims 1 to 6,
The reusable wire has a structure in which a plurality of metal strands having a diameter in a range of 0.06 mm to 0.30 mm are twisted together. The annular metal cord according to any one of claims 1 to 7,
An annular metal cord, wherein a winding angle of the reuse wire with respect to a central axis in an annular portion of the reuse wire wound around each other is in a range of 4.5 degrees or more and 13.8 degrees or less.   An endless metal belt comprising the annular metal cord according to any one of claims 1 to 8. Untwisting the original cords that twisted multiple wires together and divided them into two wire groups with different total cross-sectional areas,
The wire group with the larger total cross-sectional area is the reused wire group, and the wire group with the smaller total cross-sectional area is the unused wire group.
One reusable wire in the reusable wire group is formed into a plurality of loops, while the other wire rod in the reusable wire group and a spiral void portion from which the unused wire group is removed, an extra length portion A method for producing an annular metal cord, characterized in that a ring is inserted and wound into an annular shape. It is a manufacturing method of the annular metal cord according to claim 10,
The method of manufacturing an annular metal cord, wherein the wire in the unused wire group is a single wire. It is a manufacturing method of the annular metal cord according to claim 10 or 11,
One of the remaining reused wire rods in the reused wire rod group is formed into a plurality of circular loops, and the extra length portion is formed in another wire rod of the reuse wire rod group and the spiral void portion from which the unused wire rod group is removed. A method for producing an annular metal cord, characterized in that a ring is inserted and wound into an annular shape. It is a manufacturing method of the annular metal cord according to any one of claims 10 to 12,
A method for producing an annular metal cord, characterized in that a starting end and a terminal end of the reusable wire are straightened, inserted from between the wound extra length portions, and stored inside. It is a manufacturing method of the annular metal cord according to any one of claims 10 to 13,
An annular metal cord manufacturing method characterized by performing an annealing treatment.

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