JP2009281583A - Transmission belt and its method for manufacturing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission belt and a method of manufacturing the transmission belt hardly broken and easily manufactured by having annular metal cords maintaining the wound shape causing no looseness of strand even under continuous repetitive loads. <P>SOLUTION: The transmission belt B1 icnludes the annular metal cords C1 serving as tensile strength bodies, and a covering part 70 covering the annular metal cords C1. The annular metal cord C1 is formed by unstranding a metal cord 20 formed by stranding a plurality of stranded members 1, 2, to divide the metal cord 20 into two wire material groups with different total cross-sectional areas, setting the group of the stranded members 1 with the larger total cross-sectional area as a reused wire material group 3, while setting the group of stranded members 2 with the smaller total cross-sectional area as a non-used wire material group 4, and fitting and winding extra length parts 3b of the reused wire material group 3 into spiral cavity parts 5, from which the non-used wire material group 4 fell off, in the annular part 3a while forming a part in the longitudinal direction of the reused wire material group 3 into annular shape. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transmission belt and a manufacturing method thereof.

Conventionally, as a kind of transmission belt, for example, as described in Patent Document 1, a belt using a metal cord as a core material is known. The metal cord serving as a core material includes at least one filament serving as a central core and a plurality of filaments surrounding the central core.
Further, as described in Patent Document 2, a transmission belt using a twisted cord as a core material is also known. In this transmission belt, the ends of the pair of twisted cords are once untwisted and joined, and then twisted again after the joining as a core material.

  In addition, as a method for producing an annular metal cord, for example, as described in Patent Documents 3 and 4, a half of the wire constituting the wire rope is removed by untwisting or cutting, and 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 3 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 4 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. Both ends of the remaining heart rope are concentrically butted, and the strand on which 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.

JP-A-4-307146 JP 2000-213601 A Japanese Patent No. 3069996 JP-A-5-132881

  In the power transmission belt described in Patent Document 1, it is necessary to work by joining both ends of the metal cord into an annular shape. When joining both ends of the metal cord, the method of joining twisted cords described in Patent Document 2 can be applied to the metal cord. However, when the joining method described in Patent Document 2 is applied, filament untwisting work, joining work, and twisting work occur. For this reason, the process for coupling becomes complicated, and it becomes difficult to manufacture the transmission belt. Further, when the ends of the filament are twisted again, the twisted state differs between the bonded portion and the other portion, which may reduce the mechanical strength of the bonded portion. When the mechanical strength of the joint portion is reduced, the metal cord is broken, and as a result, the transmission belt is easily broken.

  As a method of joining both ends of the metal cord, a method of joining both ends of the metal cord together is also conceivable. However, in this method, since the coupling portion is concentrated at one place in the circumferential direction, the metal cord is easily broken completely.

  Each of the annular metal cords described in Patent Documents 3 and 4 is a sling hanging tool, and is not assumed to be used in a state where a load such as a predetermined bending or tension is repeatedly received. 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 portion where the terminal is twisted in Patent Document 3, stress concentration occurs in these portions 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 3 and 4 do not have a structure that can withstand continuous repeated loads.

  When such an annular metal cord is used for a transmission belt, the rotational load fluctuates under the influence of loosening of the twist or the joint portion of the terminal, and there is a possibility that it is damaged in a relatively short period of time.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a transmission belt that includes an annular metal cord that can maintain a wound shape without being twisted and loosened even with continuous repetitive loads, and that is less likely to break and is easy to manufacture. And a manufacturing method thereof.

The transmission belt according to the present invention capable of solving the above-described problems includes an annular metal cord serving as a strength member, and a covering portion that covers the annular metal cord,
The annular metal cord is
A 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.
While a part of the reuse wire group is formed in a ring shape, an extra length portion of the reuse wire group is fitted and wound in a spiral void portion where the unused wire group is removed in the annular portion. It is characterized by.

  As described above, in the annular metal cord serving as the strength member, the cross-sectional area of the spiral void portion in which the unused wire group in the reused wire group is missing is smaller than the total cross-sectional area of the reused wire group. Since the extra length portion of the reused wire group is fitted in a spiral gap that is narrower than itself, adjacent wires of the wound reused wire group are pressed. 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. Therefore, since the transmission belt in which such an annular metal cord is covered with a covering portion can maintain the shape without twisting and loosening of the annular metal cord even with continuous repeated loads, the breaking strength and fatigue resistance can be maintained. Excellent in production and easy to manufacture.

In the transmission belt according to the present invention, the wire in the reuse wire group preferably has a structure in which a plurality of metal strands are twisted together.
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, it is possible to suppress a decrease in breaking strength, and it is also possible to suppress a decrease in breaking strength for the transmission belt.

In the power transmission belt 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 characteristics of the annular metal cord, and to make it difficult to meander during rotation of the transmission belt.

Further, the transmission belt according to the present invention includes an annular metal cord serving as a tensile body, and a covering portion that covers the annular metal cord,
The annular metal cord is
When one of the S twist direction and the Z twist direction, which are spiral twist directions, is the first twist direction, and the other is the second twist direction,
One cord in which a plurality of first stranded wires formed by twisting a plurality of metal strands in the first twist direction and twisted in the second twist direction,
The other cords that are twisted in the second twist direction by gathering a plurality of second twisted wires made by twisting a plurality of metal strands in the second twist direction, respectively, are untwisted,
Reuse in which a part of the number of the first stranded wires and a part of the number of the second stranded wires are twisted in the second twist direction to form a void in the second twist direction smaller than the total cross-sectional area thereof A group of wires,
A part of the reused wire group is formed in an annular shape, and an extra length part of the reused wire group is fitted and wound around the gap in the annular part.

  In this way, a reusable wire group in which an S-strand wire and a Z-strand wire are mixed is created in the annular metal cord that becomes a tensile body, and the cross-sectional area of the spiral void in the reusable wire group is reused. It is smaller than the total cross-sectional area of the wire group. Since the extra length portion of the reused wire group is fitted in a spiral gap that is narrower than itself, adjacent wires of the wound reused wire group are pressed. 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. In addition, the annular metal cord has excellent fatigue resistance. Therefore, since the transmission belt in which such an annular metal cord is covered with a covering portion can maintain the shape without twisting and loosening of the annular metal cord even with continuous repeated loads, the breaking strength and fatigue resistance can be maintained. Excellent in production and easy to manufacture. In addition, since the S-strand wire and the Z-strand wire are mixed in the annular metal cord, the occurrence of directivity in the mechanical properties of the annular metal cord is suppressed, and it becomes difficult to meander when the transmission belt is driven to rotate.

In the transmission belt according to the present invention, both end portions of the reusable wire group are butted against each other for each wire, and at least the butted portion vicinity including the butted portion is fixed by an adhesive. preferable.
By fixing the ends to each other with an adhesive, the movement of the coupling portion can be suppressed, and the diameter of the portion can be prevented from increasing. Moreover, since the butting position is shifted for each wire, simultaneous breakage of the wire is less likely to occur. Therefore, it is possible to suppress a decrease in the breaking strength of the annular metal cord, and it is also possible to suppress a decrease in the breaking strength of the transmission belt.

In the transmission belt according to the present invention, the wire in the reuse wire group 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, and the transmission belt can also be made more durable.

The transmission belt which concerns on this invention WHEREIN: It is preferable that the winding angle of the said extra length part with respect to the central axis of the said reusable wire group of the said annular part exists in the range of 4.5 degree | times or more and 13.8 degrees or less.
Thereby, since the winding work of a wire becomes easy, a cyclic | annular metal cord can be extended and a power transmission belt 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. Thereby, the breaking strength of the transmission belt can be further improved.

In the power transmission belt according to the present invention, it is preferable that a diameter-type attachment ratio of the wire in the reuse wire group is 80% or more and 105% or less in the state of the annular metal cord.
If the rate of diameter mold is less than 80%, when the reusable wire group is taken out by untwisting a cord in which a plurality of wires are twisted together, the diameter direction of the spiral shape imparted to these wires is reduced. , It extends in the longitudinal direction. As a result, the layer core diameter of the reusable wire group becomes small, so that it becomes difficult to fit the extra length part of the reusable wire group into the spiral gap where the unused wire group is removed. . Further, if the diameter die attachment ratio is larger than 105%, it becomes easy to extend in the annular direction after forming the annular metal cord, and when used as a transmission belt, it becomes difficult to ensure the dimensional accuracy.
It should be noted that the diameter shaping rate is expressed as “Diameter shaping rate (where D is the diameter of the cord when the annular metal cord is created from the reusable wire group” and H is the wave height (including the self-diameter) of the shaped wire. %) = H / D × 100 ”.
In addition, the allowable range of the diameter die attachment ratio is compared with the case where the annular metal cord is handled bare, in the case of the configuration of the present invention in which the annular metal cord is a tensile body and the transmission belt is covered with a covering portion. However, the range of the upper and lower limits is relaxed.

Moreover, the manufacturing method of the transmission belt which can solve the said subject is a manufacturing method of the transmission belt provided with the cyclic | annular metal cord used as a tension body, and the coating | coated part which covers the said cyclic | annular metal cord. ,
Untwisting the cords that twisted together multiple wire rods and dividing them into two wire rod 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.
While making a part of the longitudinal direction of the reusable wire group into an annular shape, the extra length part of the reusable wire group is fitted and wound around the spiral void part from which the unused wire group is removed in the annular part, An annular metal cord is formed.

In this way, the annular metal cord that becomes a tensile body is untwisted and reused the wire group with the larger total cross-sectional area, and a part of it is made into a ring and the remaining surplus portion is unused wire group It can be easily manufactured by fitting and winding it in a spiral gap that has been removed. The spiral void in the reused wire group is smaller than the total cross-sectional area of the reused wire group, and the extra length of the reused wire group is fitted into a spiral void that is narrower than itself, The adjacent wire rods of the wound reuse wire rod group 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.
As described above, according to the present invention, it is possible to maintain the shape without twisting and loosening even with continuous repeated loads, and to easily produce an annular metal cord excellent in breaking strength and fatigue resistance. it can.
Therefore, a transmission belt in which such an annular metal cord is covered with a covering portion is also excellent in breaking strength and fatigue resistance and easy to manufacture.

In the method for manufacturing a transmission belt 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 transmission belt manufacturing method according to the present invention, the wire in the unused wire group may be made of a material having a lower rigidity than the reuse wire group.
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, the wires of the unused wire group can be other than metal, and depending on the material used, the material cost of the unused wire group can be suppressed.

Moreover, the method for manufacturing a transmission belt according to the present invention is a method for manufacturing a transmission belt comprising an annular metal cord that is a tensile body and a covering portion that covers the annular metal cord,
When one of the S twist direction and the Z twist direction, which are spiral twist directions, is the first twist direction, and the other is the second twist direction,
One cord in which a plurality of first stranded wires formed by twisting a plurality of metal strands in the first twist direction and twisted in the second twist direction,
Untwisting each of the other cords twisted in the second twist direction by gathering a plurality of second twisted wires formed by twisting a plurality of metal strands in the second twist direction,
Reuse in which a part of the number of the first stranded wires and a part of the number of the second stranded wires are twisted together in the second twist direction to form a void portion in the second twist direction smaller than the total cross-sectional area thereof. Forming a group of wires,
The annular metal cord is formed by fitting a portion of the reused wire group in the longitudinal direction into an annular portion and winding the extra length part of the reused wire group around the gap in the annular part. To do.

  According to the method of manufacturing a transmission belt having such a configuration, a reusable wire group in which an S-strand wire and a Z-strand wire are mixed is formed in the formation of an annular metal cord serving as a strength member, and a spiral in the reusable wire group is created. The cross-sectional area of the hollow portion is smaller than the total cross-sectional area of the reused wire group. Since the extra length part of the reuse wire group is inserted into a spiral gap narrower than itself, adjacent wires of the wound reuse wire group are pressed. The manufactured annular metal cord has a large contact resistance between the wires, and the wires are strongly constrained 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 addition, the annular metal cord has excellent fatigue resistance. Therefore, since the transmission belt in which such an annular metal cord is covered with a covering portion can maintain the shape without twisting and loosening of the annular metal cord even with continuous repeated loads, the breaking strength and fatigue resistance can be maintained. Excellent in production and easy to manufacture. In addition, since the S-strand wire and the Z-strand wire are mixed in the annular metal cord, the occurrence of directivity in the mechanical properties of the annular metal cord is suppressed, and it becomes difficult to meander when the transmission belt is driven to rotate.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in breaking strength and fatigue resistance, and can provide the transmission belt which is easy to manufacture, and its manufacturing method. Therefore, if the transmission belt of the present invention is used in an industrial machine, the industrial machine can be made excellent in durability.

It is a section perspective view of the power transmission belt concerning this embodiment. It is a perspective view of the cyclic | annular metal cord used for 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 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 cross-sectional perspective view which shows the metal cord used for manufacture of the cyclic | annular metal cord of other embodiment. It is a cross-sectional perspective view which shows the modification of a power transmission belt. It is a perspective view which shows the metal cord which twisted together the single wire and two strand materials.

  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.

  FIG. 1 is a cross-sectional perspective view of a transmission belt according to the present embodiment. The transmission belt B1 according to the present embodiment is a general industrial V-belt. The transmission belt B <b> 1 includes an annular metal cord C <b> 1 that is a strength member and a covering portion 70. The covering portion 70 covers the annular metal cord C1, and a cloth layer 72 is provided on the upper and lower surfaces of the covering portion 70. The covering portion 70 includes a material such as rubber.

The transmission belt B1 has five annular metal cords C1. 2 is a perspective view of the annular metal cord used in the present embodiment, FIG. 3 is a radial sectional perspective view showing the annular metal cord, and FIG. 4A is a diameter showing the annular metal cord C1. It is sectional drawing of a direction, The figure (b) is a side view of the cyclic | annular metal cord C1.
As shown in FIGS. 2 to 4, the annular metal cord C <b> 1 is formed by twisting a plurality of wire rods in a ring shape and using a strand material 1 in which a plurality of metal strands are twisted in advance as a wire rod. ing.

  The annular metal cord C1 used in the present embodiment is prepared by preparing three strand materials 1 that are preliminarily spirally twisted and twisted together, and the other half is formed in a state in which about half the length thereof is annular. It is formed by wrapping around the annular portion. 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 evenly 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 with 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. Moreover, it becomes difficult to meander at the time of rotational drive of the transmission belt B1 incorporating the annular metal cord C1.

  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. 4B, 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. 5, the winding start end portion 1a and the winding end portion 1b are abutted against each other, and the abutting portion 1c and the vicinity including the abutting portion 1c are adhesives. It is fixed by. The adhesive 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.
The butted portions 1c of the three strand materials 1 are configured such that the positions of the annular metal cords C1 in the annular direction are different. In this way, by arranging the coupling positions differently, it is possible to avoid the concentration of points that tend to be weak in strength.

  Further, the abutting portion 1c between the starting end portion 1a and the terminal end portion 1b is disposed on one side of both sides of the circular metal cord C1 except for the inner peripheral side and the outer peripheral side thereof. 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.

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 used for constituting the annular metal cord C1, and the three strand materials 2 are an unused wire group 4 not constituting the annular metal cord C1. In addition, before twisting together these five strand materials 1, it is good to give a spiral type | molding, respectively.

In the present embodiment, when the strand material 1 is twisted so that the diameter mold application rate of the strand material 1 is 80% or more and 105% or less in the state where the annular metal cord C1 is formed, the spiral molding is performed in advance through a molding pin. Is given. Here, when the diameter (wire diameter) of the annular metal cord C1 is D and the wave height (including the self-diameter) of the shaped strand material 1 is H, the diameter shaping ratio is “diameter shaping ratio (% ) = H / D × 100 ”.
When the diameter die-attachment ratio is less than 80%, when the reusable wire group 3 is taken out by untwisting the metal cord 20 in which a plurality of strand materials 1 are twisted together, the spiral imparted to these strand materials 1 The diameter direction of the shape is reduced and the shape is elongated in the longitudinal direction. As a result, since the layer core diameter of the reusable wire group 3 is reduced, when the extra length portion of the reusable wire group 3 is fitted into the spiral void portion in which the unused wire group 4 is removed in an annular shape, It becomes difficult to put. Further, if the diameter die attachment ratio is larger than 105%, it becomes easy to extend in the annular direction after forming the annular metal cord C1, and when used as a transmission belt, it becomes difficult to ensure the dimensional accuracy.

  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, when the total cross-sectional area of the three strand materials 1 constituting the reuse wire group 3 is AS1, and the total cross-section of the three strand materials 2 constituting the non-use wire group 4 is AS2, the expression “AS1” > AS2 ”is satisfied.

  In order to satisfy such a relationship, for example, when forming the strand materials 1 and 2 using the metal strands 10 and 11 having the wire diameter d, the wire diameter d of the metal strand 11 is smaller than the nominal diameter. Can 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. Thereafter, the unused wire group 4 is not used, and the reusable wire group 3 is used to manufacture the annular metal cord C1. FIG. 7 shows a state in which the unused wire group 4 is removed and only the reused wire group 3 is removed.
As shown in FIG. 7, in the reused wire group 3 after removing the unused wire group 4, a spiral gap 5 is formed at a place where the unused wire group 4 was present. The gap 5 has a cross-sectional area equivalent to that of the unused wire group 4 and is smaller than the cross-sectional area of the reused wire group 3.

  Next, as shown in FIG. 8, approximately half the length of the reused wire group 3 is formed into an annular shape, and the extra length portion 3b of the reused wire group is fitted into the spiral gap 5 in the annular portion 3a. Wrap it around. The spiral void portion 5 in the reuse wire group 3 has a spiral void portion whose cross-sectional area is smaller than the total cross-sectional area of the reuse wire group 3 and whose extra length portion 3b of the reuse wire group 3 is narrower than itself. Therefore, the adjacent strand materials 1 of the wound reuse wire group 3 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, the end treatment of the start end portion 1 a and the end end portion 1 b of the strand material 1 can be simplified such as butting. 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 wire which comprises the reuse wire group 3 is not a single wire but the strand material 1 which twisted several metal strands 10, the contact resistance of the strand materials 1 is also large by the unevenness | corrugation of the strand material 1 surface. 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.

  After the winding is performed in an annular shape, the winding start end portion 1a and the winding end portion 1b are butted against each other, and the butted portion 1c and the vicinity including the butting portion 1c are fixed with an adhesive. By fixing the ends with an adhesive, the movement of the butted portion 1c can be suppressed, and the diameter of the portion can be prevented from increasing. Further, by shifting the abutting position for each strand material 1, it becomes difficult for the strand material 1 to be simultaneously broken. Accordingly, it is possible to suppress a decrease in the breaking strength of the annular metal cord C1.

  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. Thereby, further improvement in fatigue resistance of the annular metal cord C1 can be expected.

In addition to the examples shown in the above embodiment, the configurations of the reusable 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. Accordingly, the relationship of “total cross-sectional area AS1 of reused wire rod group> total cross-sectional area AS2 of unused wire rod group” is satisfied. In the same manner as described with reference to FIG. 8, this reusable wire group is fitted with an extra length portion around the annular portion and wound, whereby an annular metal cord in which the strand materials are strongly restrained by contact resistance can be obtained. 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.

  Further, the wire in the unused wire group may not be a metal wire, but may be a wire made of a material such as a resin having a lower rigidity than the metal wire. For example, aramid fibers or vinyl fibers 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. Further, by using a material other than metal for the wire rods of the unused wire group, the material cost can be suppressed depending on the material used.

Also, as another embodiment, two types of cords are prepared, each cord is untwisted, and a necessary number of wires are taken out, twisted as a reusable wire group, and then made into a ring metal cord You can also.
In this embodiment, when one of the S twist direction and the Z twist direction, which are spiral twist directions, is the first twist direction, and the other is the second twist direction, the two types of cords have the following relationship: Prepare.

  First, as one cord, a plurality of first strand materials (first stranded wire materials) formed by twisting a plurality of metal strands in the first twist direction and twisted in the second twist direction are prepared. . As this one cord, as shown in the structure of FIG. 9A, a metal cord 21 that is Z-twisted by assembling three first strand materials 6 in which seven metal strands 12 are S-twisted together is assembled. It can be illustrated.

  In addition, as the other cord, a plurality of second strand materials (second stranded wire materials) formed by twisting a plurality of metal strands in the second twist direction and twisted in the second twist direction is prepared. . As the other cord, as shown in the structure of FIG. 9B, three second strand materials 7 formed by Z-twisting seven metal strands 12 are assembled to form a Z-twisted metal cord 22. It can be illustrated.

  These cords are untwisted, the first strand material 6 and the second strand material 7 are taken out one by one, and the two strand materials are twisted in the second twist direction (Z twist direction) and reused. The wire group. In this reusable wire group, a void portion having a spiral cross-sectional area equivalent to one strand material is formed. Using this reusable wire group, an annular metal cord can be manufactured in the same manner as in the method shown in FIG.

  In the example of FIG. 9, the S twist direction is the first twist direction and the Z twist direction is the second twist direction. Conversely, the Z twist direction is the first twist direction, and the S twist direction is It is good also as a 2nd twist direction.

  As described above, according to the manufactured annular metal cord using the wire obtained by untwisting two types of cords as a reuse wire group, the same effect as the annular metal cord of the form shown in FIGS. In addition, since a reusable wire group in which S-strand strand material and Z-strand strand material are mixed is used, the occurrence of directionality in the mechanical properties of the cyclic metal cord is suppressed, and fatigue resistance is achieved. It is an excellent ring metal cord. Further, the transmission belt incorporating the annular metal cord is difficult to meander during rotation driving.

  As described above, the transmission belt B1 of the present embodiment has the annular metal cord C1 as a strength member. As described above, the annular metal cord C1 can maintain the shape in which the strand material 1 is wound without causing twisting and loosening of the strand material 1 even with continuous repeated load. The transmission belt B1 in which the annular metal cord C1 is covered with the covering portion 70 can maintain the shape without twisting and loosening of the annular metal cord C1 even with continuous repeated loads. It is excellent in fatigue resistance and easy to manufacture.

  Further, the transmission belt B1 of the present embodiment has five annular metal cords C1, but the number of the annular metal cords C1 is not limited to this. The number of the annular metal cords C1 can be adjusted according to the required bending resistance and durability.

  Moreover, the kind of power transmission belt is not restricted to a general industrial V-belt. FIG. 10 is a cross-sectional perspective view showing another modification of the transmission belt. A transmission belt B2 shown in FIG. 10 is a toothed timing belt, and is formed by covering the annular metal cord C1 with a covering member 80 using a tensile strength member. The covering portion 80 includes a material such as rubber. Such a transmission belt B2 is also excellent in breaking strength and fatigue resistance.

Next, examples of the transmission belt according to the present invention will be described.
First, an embodiment of an annular metal cord that serves as a tensile body of a transmission belt will be described.
Metal raw wires having diameters of 0.13 mm, 0.15 mm, and 0.20 mm were prepared by final wet wire drawing using a steel cord material or a saw wire brass plating material, and a predetermined intermediate treatment and processing. Seven or more reels are prepared for the metal strands of the respective wire diameters, and are mounted on the stranded wire supply of the following examples.
In addition, the twister used for the lower twist may use either a buncher type or a tubular type. Moreover, when using a tubular stranded wire machine, it molds a wire (diameter mold rate 93 ± 5%) using a preform before top twisting.

Example 1
(1-1) Preparation of wire (bottom twist) 1 × 7 × d (7 strands of wire diameter d are twisted to form one strand material). Here, d is two types, dout (used for the unused wire group) and use (used for the reusable wire group), and dout = 0.13 mm and use = 0.15 mm. Twist pitch is 7.5mm, twist direction is S twist. Two reels each (500 m per reel) were prepared.
(1-2) Production of metal cord (upper twist) 4 × 7 × (2 dout strand materials + 2 use strand materials). Two reels each of the dout strand material and the douse strand material were supplied, and twisted with a tubular twisting machine with a twist pitch of 10.0 mm and a Z twist to form a 100 m metal cord.
(1-3) Untwisting of the metal cord: The two strand materials of dout are removed from the two strand materials of the duze.
(1-4) Ring metal coding: After forming an annular portion of a predetermined size (diameter 254 mm) with two strand materials of duze, the gap portion formed by removing the two strand materials of dout Wrap along. The terminal is cut so as to be in a butted state, the length is adjusted, and then the abutted portion is fixed with an adhesive that can expand and contract even after curing.

(Example 2)
(2-1) Production of wire (bottom twist) 1 × 7 × d (7 strands of wire diameter d were twisted to form one strand material). Here, d has two types, dout (used for the unused wire group) and use (used for the reused wire group), and dout = 0.20 mm and use = 0.15 mm. The strand material of dout was prepared with a twist pitch of 9.5 mm and one reel (500 m per reel) with S twist. For the strand material of the use, the twist pitch was 7.5 mm, and two reels (500 m for one reel) were prepared by S twist.
(2-2) Production of metal cord (upper twist) 3 × 7 (one dout strand material + two use strand materials). 1 reel of dout strand material and 2 reel of strand material of douse were supplied, and twisted with a twisting pitch of 12.0 mm and Z twist by a tubular twisting machine to form a metal cord of 100 m.
(2-3) Untwisting the metal cord: One strand material of dout is removed from the two strand materials of duze.
(2-4) Ring metal coding: After forming an annular portion of a predetermined size (diameter 254 mm) with two strand materials of duze, a gap portion formed by removing one strand material of dout Wrap along. The terminal is cut so as to be in a butted state, the length is adjusted, and then the abutted portion is fixed with an adhesive that can expand and contract even after curing.

(Example 3)
(3-0) Preparation of wire rod (single wire): As a single wire used for the unused wire rod group, 1 reel (500 m per reel) of 0.6 mm (dout) diameter steel wire was prepared.
(3-1) Production of wire (bottom twist) 1 × 7 × d (7 strands of wire diameter d were twisted to form one strand material). Here, d is a use (used for a reusable wire group), and a use = 0.15 mm. A strand material having a twist pitch of 7.5 mm and a S reel of 2 reel (500 m per reel) was prepared.
(3-2) Production of metal cord (upper twist) 3 × (1 (dout single wire) +7 (two use strand materials)). A single reel of dout and a reel of 2 strands of douse were supplied, and twisted with a twisting pitch of 12.0 mm and Z twist by a tubular twisting machine to form a metal cord of 100 m (see FIG. 11).
(3-3) Untwisting of the metal cord: The single wire of dout is removed from the two strand materials of the use.
(3-4) Ring metal coding: After forming an annular portion of a predetermined size (diameter 254 mm) with two strands of duze, it is attached to the gap formed by removing one single line of dout Wrap around. The terminal is cut so as to be in a butted state, the length is adjusted, and then the abutted portion is fixed with an adhesive that can expand and contract even after curing.

  It can be confirmed that any of the annular metal cords manufactured in Examples 1 to 3 maintains a wound shape without causing twist loosening even when continuously applied with the above-described transmission belt B1. It was.

  DESCRIPTION OF SYMBOLS 1, 2 ... Strand material (wire), 1a ... Start end part, 1b ... Termination part, 3 ... Reuse wire group, 3a ... Annular part, 3b ... Extra length part, 4 ... Unused wire group, 5 ... Gap part, 6 ... 1st strand material, 7 ... 2nd strand material, 10, 11, 12 ... Metal strand, 20, 21, 22 ... Metal cord (code), 70 ... Covering part, B1, B2 ... Transmission belt, C1 ... Ring metal cord.

Claims (12)

An annular metal cord serving as a tensile body, and a covering portion covering the annular metal cord,
The annular metal cord is
A 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.
While a part of the reuse wire group is formed in a ring shape, an extra length portion of the reuse wire group is fitted and wound in a spiral void portion where the unused wire group is removed in the annular portion. A transmission belt characterized by The transmission belt according to claim 1,
The transmission belt according to claim 1, wherein the wire in the reuse wire group has a structure in which a plurality of metal strands are twisted together. The transmission belt according to claim 2,
The power transmission belt according to claim 1, wherein a twist direction of the metal wires and a spiral direction of the winding fitted in the gap are opposite directions. An annular metal cord serving as a tensile body, and a covering portion covering the annular metal cord,
The annular metal cord is
When one of the S twist direction and the Z twist direction, which are spiral twist directions, is the first twist direction, and the other is the second twist direction,
One cord in which a plurality of first stranded wires formed by twisting a plurality of metal strands in the first twist direction and twisted in the second twist direction,
The other cords that are twisted in the second twist direction by gathering a plurality of second twisted wires made by twisting a plurality of metal strands in the second twist direction, respectively, are untwisted,
Reuse in which a part of the number of the first stranded wires and a part of the number of the second stranded wires are twisted in the second twist direction to form a void in the second twist direction smaller than the total cross-sectional area thereof A group of wires,
A transmission belt, wherein a portion of the reused wire group in the longitudinal direction is formed into an annular shape, and an extra length portion of the reused wire group is fitted and wound around the gap in the annular portion. The transmission belt according to any one of claims 1 to 4,
Both ends of the reusable wire group are abutted at different positions for each wire, and at least the vicinity of the butted portion including the butted portion is fixed with an adhesive. The transmission belt according to any one of claims 1 to 5,
The power transmission belt, wherein the wire in the reuse wire group 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 transmission belt according to any one of claims 1 to 6,
The transmission belt, wherein a winding angle of the extra length portion with respect to a central axis of the reusable wire group of the annular portion is within a range of 4.5 degrees or more and 13.8 degrees or less. The transmission belt according to any one of claims 1 to 7,
The transmission belt according to claim 1, wherein a diameter shaping ratio of the wire in the reusable wire group is 80% or more and 105% or less in the state of the annular metal cord. A method of manufacturing a transmission belt comprising an annular metal cord serving as a tensile body and a covering portion covering the annular metal cord,
Untwisting the cords that twisted together multiple wire rods and dividing them into two wire rod 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.
While making a part of the longitudinal direction of the reusable wire group into an annular shape, the extra length part of the reusable wire group is fitted and wound around the spiral void part from which the unused wire group is removed in the annular part, A method of manufacturing a transmission belt, characterized by forming an annular metal cord. It is a manufacturing method of the power transmission belt according to claim 9,
The method of manufacturing a transmission belt, wherein the wire in the unused wire group is a single wire. It is a manufacturing method of the power transmission belt according to claim 9 or 10,
The method of manufacturing a transmission belt, wherein the wire in the unused wire group is made of a material that is less rigid than the reused wire group. A method of manufacturing a transmission belt comprising an annular metal cord serving as a tensile body and a covering portion covering the annular metal cord,
When one of the S twist direction and the Z twist direction, which are spiral twist directions, is the first twist direction, and the other is the second twist direction,
One cord in which a plurality of first stranded wires formed by twisting a plurality of metal strands in the first twist direction and twisted in the second twist direction,
Untwisting each of the other cords twisted in the second twist direction by gathering a plurality of second twisted wires formed by twisting a plurality of metal strands in the second twist direction,
Reuse in which a part of the number of the first stranded wires and a part of the number of the second stranded wires are twisted together in the second twist direction to form a void portion in the second twist direction smaller than the total cross-sectional area thereof. Forming a group of wires,
The annular metal cord is formed by fitting a portion of the reused wire group in the longitudinal direction into an annular portion and winding the extra length part of the reused wire group around the gap in the annular part. A method for manufacturing a transmission belt.

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