JP2013023776A - Binding string for coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binding string for coil with sufficient tensile strength free from fray at an edge face which improves workability.SOLUTION: There is provided a binding string for coil obtained by braiding a fiber thread in which a braid part is formed by braiding a synthetic fiber having a melting point or decomposition temperature of 280°C or more around a center thread including a synthetic fiber having a melting point or decomposition temperature of 280°C or more, and a crystal melting heat of the synthetic fiber constituting the braid part is larger than that of the synthetic fiber constituting the center thread. There is also provided the binding string for coil in which the synthetic fiber having a melting point or decomposition temperature of 280°C or more is a PPS fiber. There is also provided the binding string for coil in which a braid pitch in the braid part is 6.5 mm or less. There is also provided a method of manufacturing a binding string for coil comprising subjecting the binding string to heat setting after a braid part is formed by braiding a synthetic fiber having a melting point or decomposition temperature of 280°C or more around a center thread including a synthetic fiber having a melting point or decomposition temperature of 280°C or more.

Description

  The present invention relates to a bundling cord for bundling a coil of a motor for an automobile or a compressor motor of a refrigerator or an air conditioner, and in particular, has a sufficient tensile strength and prevents workability by preventing fraying of an end face. For improved

  Conventionally, a binding string for binding a coil wire is used for a coil of an automobile motor, a refrigerator, a compressor motor of an air conditioner, or the like. In recent years, the coil operating environment has become increasingly severe in order to meet the demand for higher performance and multi-functionality of devices, and the binding string is also required to have characteristics that can follow it. For example, currently developed motors for electric vehicles require heat resistance of 280 ° C or higher and durability to ATF (automatic transmission fluid), and compressor motors have durability against alternative CFC refrigerants. Is required. Of course, a sufficient tensile strength is also required as a basic characteristic of the tying string. As a binding string that can withstand such a demand, for example, a braided fiber yarn such as polyphenylene sulfide fiber (PPS fiber) or aramid fiber is preferably used (see, for example, Patent Documents 1 to 3). ).

Japanese Patent No. 3899647: Toray Japanese Patent No. 3848649: Gosen JP 2009-174104 A: Gosen

  On the other hand, since the polyphenylene sulfide fiber and the aramid fiber as described above are fibers having high rigidity, the braid is unwound on the cut end face due to the rigidity of the fiber, resulting in fraying. When such a fray occurs, not only the bundling operation becomes very difficult, but also the fibers are likely to jump out, and there is a problem that the tensile strength and the wear resistance are lowered accordingly.

  The present invention was made to solve such problems of the prior art, and the object of the present invention is to provide a coil having sufficient tensile strength and improved workability by preventing fraying of the end face. It is to provide a cable tie.

In order to achieve the above object, the coil binding string according to the present invention is formed by braiding a synthetic fiber having a melting point or decomposition temperature of 280 ° C. or more on the outer periphery of a center yarn made of synthetic fibers having a melting point or decomposition temperature of 280 ° C. or more. A braided portion is formed, and the amount of crystal melting heat of the synthetic fiber constituting the braided portion is larger than the amount of crystal melting heat of the synthetic fiber constituting the center yarn.
The synthetic fiber having the melting point or decomposition temperature of 280 ° C. or higher is considered to be polyphenylene sulfide fiber.
Further, it is conceivable that the braiding pitch in the braided portion is 6.5 mm or less.
Also, the method for producing a coil tie string according to the present invention comprises braiding a synthetic fiber having a melting point or decomposition temperature of 280 ° C. or more on the outer periphery of a center yarn made of synthetic fibers having a melting point or decomposition temperature of 280 ° C. or more. After the formation, heat setting is performed.

According to the coil binding string of the present invention, since heat setting is performed in a braided state, the fiber yarn is held in a braided shape, and thus a highly rigid fiber is used. However, fraying hardly occurs on the cut end face.
Further, the heat-set synthetic fiber tends to have a slight decrease in tensile strength as the amount of heat of crystal fusion increases. Here, in the coil binding string of the present invention, the heat of crystal melting of the fibers constituting the center yarn is kept small, and the heat of crystal melting of the fibers constituting the braided portion is larger than the heat of crystal melting of the center yarn. Therefore, the center yarn can provide a sufficient tensile strength, and the overall tensile strength can be improved.
Further, when the pitch of the braid is 6.5 mm or less, it is possible to prevent further fraying from being combined with the effect of the heat setting.

It is a figure which shows embodiment by this invention, and is a partially notched perspective view which shows the structure of a binding string.

  Embodiments of the present invention will be described below with reference to the drawings. As the fibers of the braided portion 3, 16 polyphenylene sulfide fiber multifilaments (440 dtex, 100 filaments) are prepared on a small bobbin, set on a stringing machine, and the polyfilament sulfide fiber multifilament (fibers of the center yarn 2) 10 pieces (440 dtex, 100 filaments) are prepared, set in a stringing machine so as to be the center of the braided part 3, and the braided part 3 is configured under the condition that the braid pitch is 6.0 mm. Next, the binding string 1 is continuously introduced into a heating furnace maintained at a temperature of 260 ° C. and heat set. In this way, a binding string 1 having an outer diameter of 1.15 mm as shown in FIG. 1 is created.

  The binding string thus obtained was tested for the properties of fraying properties and tensile strength. As for the test, the example according to the above embodiment is Example 1, the center yarn 2 is not present in the above embodiment, the heat set is subjected to Comparative Example 1, and the heat set is not performed according to the above embodiment. This was designated as Comparative Example 2, and the one without the center yarn 2 in the above embodiment and not heat-set as Comparative Example 3. In the test for hotness, the edges were observed after cutting with a blade. The tensile strength test was performed in accordance with “8.5.5.1 Standard time test” of “8.5 Tensile strength and elongation” of JIS-L1013: 2010. The test results are shown in Table 1.

  Moreover, about the fiber which comprises the braided part and center yarn in Example 1 and Comparative Example 2, using a DSC method (Differential Scanning Calorimetry), a sample was measured at 10 ° C./min together with a standard substance. The amount of heat which was heated at an elevated temperature and dissolved or decomposed was measured. These test results are shown in Table 2.

  As shown in Table 1, Example 1 and Comparative Example 1 subjected to heat setting had very good workability when performing a bundling operation because there was no fray on the end face. On the other hand, in Comparative Examples 2 and 3 in which heat setting was not performed, the braiding of the end portion was unraveled at the time of cutting, resulting in large fraying. Therefore, the bundling work has become very difficult. Moreover, although all the binding cords of Example 1, Example 2, Comparative Example 1, and Comparative Example 2 had sufficient tensile strength in actual use, Comparative Examples 1 and 3 without the center yarn 2 were As compared with the fact that the tensile strength is reduced by applying heat set, Example 1 and Comparative Example 2 were able to obtain high tensile strength even when subjected to heat set. .

  In addition, as shown in Table 2, the heat of crystal melting of the fibers constituting the center yarn of Example 1 subjected to heat setting is the braided yarn of Comparative Example 2 and the fibers constituting the center yarn not subjected to heat setting. While the value was close to the heat of crystal fusion, the heat of crystal fusion of the fibers constituting the braided portion of Example 1 was larger than the heat of crystal fusion of the fibers constituting the center yarn of Example 1. Was confirmed.

  The present invention is not limited to the above embodiment.

  Synthetic fibers having a melting point or decomposition temperature of 280 ° C. or higher used in the present invention include, for example, polyphenylene sulfide fibers, aramid fibers, polyether sulfone fibers, polyether ketone fibers, polyether ether ketone fibers, and tetrafluoroethylene fibers. Among these, polyphenylene sulfide fiber is preferable. The thickness of the fiber may be appropriately selected in consideration of usage conditions and the like. Moreover, as a shape of a fiber, conventionally well-known various things are used. Examples thereof include a monofilament shape, a multifilament shape, and a spun yarn shape. These may be appropriately selected in consideration of usage conditions and the like. Of course, you may use independently and may use it in combination of multiple types. Among these, it is preferable to use a multifilament shape from the viewpoint of easy bundling and difficulty in bundling.

  In the above-described embodiment, the center yarn 2 is configured by arranging ten fiber yarns. However, for example, the center yarn 2 may be twisted or configured by a braided braid. Further, the number of fiber yarns can be appropriately designed according to the finished dimensions, the required tensile strength, and the like.

  The braided portion 3 can be appropriately designed according to necessary characteristics such as the number of striking and the braid pitch. In particular, the braiding pitch is preferably 6.5 mm or less. When the braid pitch exceeds 6.5 mm, the braid can be easily unwound at the cut end face, and there is a possibility that a fray will occur due to an external force.

  Moreover, in the said embodiment, although the multifilament of the polyphenylene sulfide fiber was used about all the fiber yarns of the center yarn 2 and the braid part 3, the thickness of the fiber which comprises the center yarn 2, the braid part 3, for example is used. It is also conceivable to change appropriately or to combine a multifilament and a monofilament.

  What is necessary is just to design suitably about the temperature and time of a heat set so that it may become the grade hold | maintained at the shape of a braid according to the material, thickness, etc. of a fiber yarn. If the temperature exceeds the melting point of the fiber yarn material, the fiber yarn melts and is cut. The heat setting may be performed simultaneously with the braiding, or may be performed in a separate process after the braiding. It is also conceivable to form a coating with a sizing agent on the outer periphery of the braided portion 3. Examples of the sizing agent include silicone varnishes, urethane varnishes, epoxy varnishes, acrylic varnishes, unsaturated polyester varnishes, amidoimide ester varnishes, polybutadiene varnishes, and polyimide varnishes that are varnishes diluted with a solvent. , Generally called water-based paint, acrylic emulsion, urethane emulsion, polyolefin emulsion, vinyl acetate emulsion, polyethylene emulsion, polyester emulsion, styrene emulsion, silicone emulsion A photo-curing paint, thermosetting paint, catalytic polymerization paint and the like which are also called solventless paints and are used without being diluted are not particularly limited. When forming a film with a sizing agent, it is also possible to perform baking and heat setting of the film at the same time.

  As described above in detail, according to the present invention, it is possible to obtain a binding string with improved workability by preventing the end face from being frayed. This binding string can be suitably used as a string for binding, for example, a coil of a motor for an automobile or a coil of a compressor motor of a refrigerator or an air conditioner.

1 Bundling string 2 Center yarn 3 Braid

Embodiments of the present invention will be described below with reference to the drawings. As the braided part 3, 16 polyphenylene sulfide fiber multifilaments (440 dtex, 100 filaments) are prepared on a small bobbin and set on a stringing machine. 440 dtex, 100 filaments) were five prepared was set in a braiding machine so that the center portion of the braid 3, braid pitch constitutes a braid portion 3 under the condition of 6.0 mm, a binding string 1. Next, the binding string 1 is continuously introduced into a heating furnace maintained at a temperature of 260 ° C. and heat set. In this way, a binding string 1 having an outer diameter of 1.15 mm as shown in FIG. 1 is created.

As shown in Table 1, Example 1 and Comparative Example 1 subjected to heat setting had very good workability when performing a bundling operation because there was no fray on the end face. On the other hand, in Comparative Examples 2 and 3 in which heat setting was not performed, the braiding of the end portion was unraveled at the time of cutting, resulting in large fraying. Therefore, the bundling work has become very difficult. Moreover, although all the binding cords of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 had sufficient tensile strength in actual use, Comparative Examples 1 and 3 without the center yarn 2 were As compared with the fact that the tensile strength is reduced by applying heat set, Example 1 and Comparative Example 2 were able to obtain high tensile strength even when subjected to heat set. .

Claims (4)

A binding string for a coil formed by braiding fiber yarn,
A braided portion formed by braiding a synthetic fiber having a melting point or a decomposition temperature of 280 ° C. or higher is formed on the outer periphery of a center yarn made of a synthetic fiber having a melting point or a decomposition temperature of 280 ° C. or higher. A binding string for a coil, wherein the heat of crystal fusion is larger than the heat of crystal fusion of the synthetic fiber constituting the center yarn. The binding cord for a coil according to claim 1, wherein the synthetic fiber having a melting point or a decomposition temperature of 280 ° C or higher is a polyphenylene sulfide fiber. The coil binding string according to claim 2, wherein a braiding pitch in the braided portion is 6.5 mm or less. A method for producing a binding string for a coil formed by braiding fiber yarns,
It is characterized by heat setting after forming a braided portion by braiding synthetic fibers having a melting point or decomposition temperature of 280 ° C. or more on the outer periphery of a center yarn made of synthetic fibers having a melting point or decomposition temperature of 280 ° C. or more. A method for manufacturing a binding cord for a coil.

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