JP2009174104A - Bundling band for motor of electric car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bundling band for a motor of an electric car, hardly causing damage of bundled motor components, having high tightening performance in bundling, and excellent in high-temperature oil-resisting performance. <P>SOLUTION: The bundling band for the motor of the electric car is braided with spun yarns comprising a staple fiber of a synthetic fiber having the melting point or the decomposition temperature of ≥280°C, to be like a sleeve of ≥24 strands, and has the high-temperature oil-resisting performance of ≥50%. The high-temperature oil-resisting performance (%)=(T'/T)×100, wherein T means the tensile strength of the bundling band before treatment, T' means the tensile strength of the bundling band after the treatment. The tensile strengths are measured by a method specified in JIS L1013-8.5.1, and the treatment means putting the whole bundling band in a mixture of 0.5 wt.% water and 99.5% automatic transmission fluid in a closed container and heating the container to keep the temperature of the mixture in the container to be 150°C for 1,000 hr. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a binding string for an electric vehicle motor.

  Conventionally, there has been a demand for both efforts to reduce harmful substances contained in automobile exhaust gas and fuel efficiency. In recent years, there has been a further demand for reducing the environmental burden on a global scale. Against this background, the development of electric vehicles has been actively researched and developed. Currently developed electric vehicles include Piure electric vehicles (PEV) equipped with high-capacity secondary batteries, hybrid vehicles (HEV) combining gasoline engines and high-power secondary batteries, and fuel cells. And a fuel cell hybrid vehicle (FCHEV) in which a fuel cell and a high-power secondary battery are combined. In any case, it is necessary to develop a highly efficient motor. Examples of the motor include driving, power generation, and charging. In addition to high efficiency, these motors are also strongly desired to stabilize quality in terms of running stability. In particular, motors for electric vehicles are required to have excellent high-temperature oil resistance as compared with general motors for vehicles. The electric vehicle motor must be present in the ATF (Automatic Transmission Fluid) for efficiency. Since ATF may become high temperature, the motor is required to have high temperature heat resistance in ATF. In addition, development of materials having uniform performance is required for the motor parts.

Conventionally, it has been proposed to use a filament yarn of polyphenylene sulfide (PPS) fiber as an electrically insulating material (see Patent Documents 1 to 3). In addition, a motor binding string for an electric car for a flat electric tube of 8 or more strokes made of a multifilament excellent in high temperature oil resistance has been proposed (Patent Document 4).
JP-A-8-13300 JP-A-10-273825 JP 2001-2448075 A JP 2004-176242 A

  However, since the binding string manufactured from the conventional electrical insulating material has low lubricity at the time of binding, there is a problem that when the binding string is used, a bound motor part, for example, a coil is easily damaged. . Furthermore, when such a binding string is used, there is a problem that heat resistance in ATF is low. In addition, since such a binding string has high bending resistance, the binding string is hard when being bound, and there is a problem in tightening properties. As another proposal, conventionally, an 8-angled string made of polyethylene terephthalate (PET) has been used as a binding string. However, the binding cord made of PET has a problem in high-temperature oil resistance, has a high bending resistance, and the binding cord is hard when binding, and has a problem in tightenability.

  In order to solve such a problem, a tube binding flat electric vehicle motor binding string of 8 or more strokes made of a multifilament excellent in high temperature oil resistance as described above has been proposed. This electric vehicle motor binding string has few scratches on the bound motor parts, has a high tightening property at the time of binding, and has a high temperature oil resistance. Therefore, the above problem is solved. Another object of the present invention is to provide a motor binding string for an electric vehicle that has improved tightening performance during binding.

In order to achieve the above object, a binding string for an electric vehicle motor according to the present invention is:
A spun yarn composed of staple fibers of synthetic fibers having a melting point or decomposition temperature of 280 ° C. or higher, and is formed into a sleeve shape of 24 beats or more,
It is a binding string for an electric vehicle motor having a high temperature oil resistance of 50% or more.
High temperature oil resistance (%) = (T ′ / T) × 100
In the above formula, T means the tensile strength of the binding string before processing, and T ′ means the tensile strength of the binding string after processing.
The said tensile strength means the tensile strength in JISL1013-8.5.1 method.
In the treatment, the entire tying string is put in a mixture of 0.5% by weight of water and 99.5% by weight of automatic transmission fluid in a closed container, and the temperature of the mixture in the container is 1000. It means a process of heating the container so as to be maintained at 150 ° C. for a period of time.

  The high-temperature oil resistance is a comparison of tensile strength before and after high-temperature treatment in oil. The fact that this value is close to 100% means that the tensile strength does not change even when the electric vehicle motor bundling string is subjected to high temperature treatment, and thus the electric vehicle motor bundling string has excellent high-temperature oil resistance. To do.

  Furthermore, since the high-temperature treatment is performed in a mixture of automatic transmission fluid and water, the high oil resistance at high temperature means that the binding string is resistant to hydrolysis.

  The binding string for an electric vehicle motor of the present invention has few scratches on the bound motor parts, has a higher tightening property at the time of binding, and has a high temperature oil resistance.

  The motor part of the binding string for the electric vehicle motor of the present invention means a part constituting the electric vehicle motor, such as a coil, a wire, and a sleeve. The binding string for an electric vehicle motor of the present invention is a braided binding string that can be used for manufacturing the electric vehicle motor by binding such motor parts. Moreover, since the binding string for the electric vehicle motor of the present invention is formed using spun yarn, the surface roughness of the obtained binding string is improved as compared with the case where the string is formed using multifilament yarn. is doing. Therefore, the binding string of the present invention has an excellent effect that the knot is difficult to unravel.

  Furthermore, since the binding string of the present invention has a sleeve shape, when the motor parts are bound, the sleeve is crushed to increase the surface area, and the surface roughness of the binding string is improved. Therefore, the binding string of the present invention is suitable for binding the motor parts by hand. Here, for example, a motor stator of a motor part is tied up by using a binding string in a winding method such as wave winding, lap winding, etc. for the purpose of preventing breakage, miniaturization, and securing an insulation distance. There is. This binding is mainly done with a machine for mass production, but in order to bind with a machine, it is necessary to provide a gap for inserting the machine between the stator end face and the coil end. is there. Therefore, when tied using a machine, it is difficult to reduce the height of the coil end to the limit. On the other hand, if the binding is performed by hand, it is not necessary to make the gap, so that the coil end height can be lowered to the limit. Therefore, when the binding string of the present invention is suitable for binding the motor part by hand, the height of the coil end can be suppressed, and as a result, the volume of the coil end can be suppressed from expanding. Therefore, the weight and winding resistance of the motor on which the motor stator is mounted can be reduced, and as a result, the performance of the motor can be improved.

  Further, since the binding string for an electric vehicle motor according to the present invention has a sleeve shape, the load is not concentrated on only a part of the surface of the motor parts to be bound. As a result, even if the motor parts are insulative, the load Can be reduced. The binding string for an electric vehicle motor of the present invention is particularly suitable for binding a coil end of a permanent magnet motor used in an electric vehicle.

  The binding string for an electric vehicle motor of the present invention can be used, for example, to bind coils in a motor stator as shown in FIG. In FIG. 2, the stator of the motor is, for example, a stator of a three-phase motor, and each phase coil housed in a stator core 1 and a plurality of slots 2 formed on the inner peripheral side of the stator core 1. 3, a wire 4 for connecting the coil 3 of each phase to an external power supply terminal, and a wire insulating tube 5 surrounding each wire 4. In FIG. 2, 6 is a binding string for binding the coil 3, 7 is a thermostat insulating tube, 8 is a slot liner, 9 is a wedge, and 10 is an interphase paper.

  The melting point or decomposition temperature of the synthetic fiber of the spun yarn made of the staple fiber is 280 ° C. or higher, preferably 283 ° C. or higher.

  The synthetic fiber having a melting point or a thermal decomposition temperature of 280 ° C. or higher of the spun yarn made of the staple fiber is preferably a polyphenylene sulfide fiber, an aramid fiber, or a polyetherimide fiber. This is because if the fiber is used, the binding string has high oil resistance at high temperatures. Examples of the synthetic fiber having a melting point or a thermal decomposition temperature of 283 ° C. or higher include polyphenylene sulfide fiber or aramid fiber. Examples of the aramid fibers include para-aramid fibers and meta-aramid fibers, with meta-aramid fibers being preferred.

  The binding string has 24 or more strikes, but preferably has 24 to 48 strikes. This is because, if the binding string is not less than 24 and not more than 48, sufficient strength is obtained and durability is high. More preferably, the binding ties are 24, 32, 36, or 40 strokes. This is because the thickness of the string is not too large and good workability can be obtained. The binding cord of the present invention is flexible, for example, because the central portion is hollow and is assembled into a braid with fibers that can move easily. Therefore, the binding string has high lubricity, and the bound motor parts are not easily damaged when the binding string is used.

  The high temperature oil resistance is 50% or more, more preferably 55% or more. This is because it is possible to obtain a motor that can run stably for a long time in an electric vehicle.

  Further, the thickness of the spun yarn made of the staple fiber is preferably in the range of 100 dtex to 1000. This is because, within the above range, a high degree of string flexibility can be obtained and work efficiency can be improved. The thickness of the spun yarn made of staple fibers is more preferably in the range of 150 dtex to 600 dtex.

  The spun yarn is preferably a single yarn or a twin yarn. The binding string may be made of a single string or a plurality of the spun yarns. The spun yarn has lower strength than the filament yarn. However, the spun yarn has a greater friction between the yarn and the yarn than the filament yarn. Therefore, when binding by hand using the binding string, the yarn is difficult to slip and loosens even after binding. Hateful. That is, the binding string of the present invention is further improved in tightening performance as compared with the binding string using filament yarn. As a result, when, for example, a coil end is bound as a motor component using the binding string of the present invention, expansion can be suppressed and the height of the coil end can be suppressed. As a result, when the coil ends, for example, are bound as motor parts using the binding string of the present invention, the windings are in close contact with each other, so that free movement can be suppressed. As a result, when the coil ends, for example, are bundled by hand as a motor component using the binding string of the present invention, the thread is difficult to slip, so that the hand can be prevented from being damaged.

  Moreover, it is preferable that the thickness (measured according to JIS L1013-8.3.1 (A method)) of the binding string is in a range of 7000 dtex to 30000 dtex. This is because, within the above range, the bending flexibility of the binding string can be maintained within a range where the binding operation can be smoothly performed. The thickness of the binding tie is more preferably in the range of 10000 dtex to 27000 dtex.

  Moreover, it is preferable that the shape of the said binding string is tube shape and flat shape. With such a shape, a tight bundling operation is possible.

  The tensile strength (measured according to JIS L1013-8.5.1) of the binding string is preferably 150N or more and 800N or less, more preferably 200N or more and 700N or less.

  The elongation percentage (measured according to JIS L1013-8.5.1) of the binding string is preferably 20% or more and 60% or less. Therefore, the binding ties of the binding ties are high, and when used in a motor of an automobile, particularly an electric automobile, stable running of the automobile can be realized. The elongation percentage of the binding string is more preferably 30% or more and 50% or less.

  The binding pitch of the binding ties is preferably in the range of 18 stitches / inch or more and 40 stitches / inch or less. This is because, when the braid pitch is 18 stitches / inch or more, the number of crosses of the braid is appropriate, the bundling property of the binding string is improved, and fraying can be suppressed. Further, when the group pitch is 40 stitches / inch or less, the stringing speed is appropriate, and there is no problem in productivity. More preferably, the binding pitch of the binding ties is in the range of 20 stitches / inch to 36 stitches / inch. The set pitch of the braid means a set (number of peaks or valleys) between 1 inch.

  When the binding string is flat, the long diameter of the cross-section of the binding string is preferably 2.0 to 5.0 mm, more preferably 2.5 to 4.5 mm. Further, the minor axis of the cross section of the binding string is preferably 0.5 to 1.5 mm, more preferably 0.7 to 1.3 mm.

  It is preferable that at least a part of the surface of the tying string is subjected to a treatment such as fizzing after the string is formed, and the fluff on the surface is removed. This is because, when the surface fluff is removed, the fluff can be prevented from falling off when the cable tie is used for the motor component, and as a result, the oil can be prevented from becoming dirty. The roasting can be performed, for example, by passing the string through a flame such as a gas burner for a short time (for example, 0.01 seconds to 0.1 seconds).

  The binding string is preferably resin-processed after stringing. This is because the resin processing can suppress the fluffing of the fiber fluff from the binding string when binding using the binding string or after binding. The kind of resin used for the resin processing is not particularly limited as long as it is a resin that can withstand the use conditions of the electric vehicle motor. Examples of the resin include olefin-based, vinyl acetate-based, acrylic-based, and urethane-based resins. The resin processing can be performed by applying a solution obtained by dissolving or suspending the resin in a solvent to the string by applying, spraying, or the like, and drying.

  In the binding string thus processed with the resin, the ratio of the resin to the binding string processed with the resin is, for example, 15 to 40% by weight, preferably 20 to 35% by weight. This is because, if the ratio of the resin to the resin-processed binding string is 15% by weight or more, the resin-processed binding string has an excellent fluff pressing effect. Moreover, it is because it will be easy to bind using the resin-processed binding string if the ratio of the said resin with respect to the said resin-processed binding string is 40 weight% or less. When the resin is a vinyl acetate resin, the ratio of the resin to the resin-processed binding string is, for example, 20% by weight or more and less than 35% by weight. When the resin is a vinyl acetate-based resin, if the ratio of the resin to the resin-processed binding string is 20% by weight or more, the resin-processed binding string has an excellent fluff pressing effect. It is. Further, when the resin is a vinyl acetate resin, if the ratio of the resin to the resin-processed binding string is less than 35% by weight, it is easy to bind using the resin-processed binding string. is there.

  Moreover, the clamping | tightening property at the time of binding using the resin-processed binding string of this invention is high. Therefore, for example, when a coil end is bundled in a motor stator as a motor component, the adhesion between the coils is increased. And it can suppress that a coil loosens and a volume expands. If it does so, when a binding string is varnished after binding components, the amount of varnish adhering to a binding string becomes the minimum necessary. When binding a coil end, for example, as a motor part using a binding string with an excessive amount of varnish adhering to the binding string, the winding may be damaged due to a difference in linear expansion between the windings. The resin-processed binding string of the present invention can suppress the occurrence of such damage, and therefore the reliability of the motor including the coils that are bound using the binding string is improved.

  Next, the manufacturing method of the binding string for motors of this invention is demonstrated. The method for manufacturing a binding string for a motor according to the present invention includes providing the staple fiber of the synthetic fiber, forming the string in a cylindrical shape with a stringing machine of 24 or more strokes, and obtaining the binding string for the motor. .

  The synthetic staple fiber used in this manufacturing method is the same as the synthetic staple fiber in the binding cord for motor of the present invention.

  In the manufacturing method, a binding string for a motor having a desired inner diameter can be obtained by appropriately selecting a stringing machine to be used. The tied ties can be taken up and stored by bobbin winding, casserole winding, shaking off, or the like. The motor binding string can be cut to a desired length to obtain a motor binding string. The motor binding string is preferably heat-treated after stringing and before cutting. This is because, by this heat treatment, the binding string for the motor is stable in dimensions and can prevent fraying of the cut end surface. The heat treatment may be performed continuously after stringing on a cylinder, or may be performed continuously or batchwise as a separate process after stringing.

  The binding string for the motor can be cut using a scissor, a blade such as a rotary blade, a heat cut or the like. The cut braid can prevent fraying by heating and melting the cut end surface or by fusing the fibers in the opening of the braid.

  It is preferable that the manufacturing method further includes a step of resin processing the binding string for the motor. This is because if the motor bundling cord is processed with resin, it is possible to prevent the fluff of fibers from falling off the bundling cord.

(Example)
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely using an Example and a comparative example, this invention is not limited to a following example. In the following Examples and Comparative Examples, the melting point or decomposition temperature and the high temperature oil resistance of the electric vehicle motor bundling string were measured as follows.

  (1) Melting point or decomposition temperature: Using a DSC method (Differential Scanning Calorimetry), the sample was heated together with a standard substance at an elevated temperature of 10 ° C./min, and the temperature at which it was melted or decomposed was measured. .

  (2) High temperature oil resistance: The entire tying cord of 60 cm in length is made up of 0.5 wt% water and 99.5 wt% automatic transmission fluid (ATF WS (trade name), Esso) in a sealed container. The container was heated so that the temperature of the mixture in the container was maintained at 150 ° C. for 1000 hours. The tensile strength (T) of the binding tie before the treatment and the tensile strength (T ′) of the binding tie after the treatment were measured according to the method of JIS L1013-8.5.1.

Each obtained tensile strength was introduced into the following formula to determine high-temperature oil resistance. The average value of the values obtained by measuring 5 times was calculated. In this measurement method, any ATF may be used as the ATF.
High temperature oil resistance (%) = (T ′ / T) × 100
Here, T: Tensile strength of the binding string before treatment T ′: Tensile strength of the binding string after treatment

(3) Thickness of binding string for motor for electric vehicle: It was determined as a fineness fineness according to JIS L 1013-8.3.1 (Method A). That is, the electric vehicle motor bundling string is rewound at a speed of 120 times / minute with a predetermined load of 213 gf (2.0888 N) using a measuring machine having a rod circumference of 1.125 m, and a predetermined yarn length of 90 m A small skein was made and the mass was measured to determine the apparent fineness. The positive fineness (D) was calculated by the following equation using the equilibrium moisture content measured separately. The number of tests was 5, and the average value was expressed (up to 1 decimal place).
F = D × [(100 + RO) / (100 + RS)]
Where F: positive fineness (tex)
D: Apparent fineness (tex)
RO: Official moisture content (%) specified in 3.1 (official moisture content) of JIS L 0105
RS: Equilibrium moisture content (%)

(4) Tensile strength and elongation rate of binding string for electric vehicle motor: determined in accordance with JIS L 1013-8.5.1 method. That is, with the cable tie for an electric vehicle motor loosely stretched, the test was conducted by attaching it to a grip of a tensile tester (type of tester: constant speed extension type, grip interval 25 cm, tensile speed 30 cm / min). . The elongation when the initial load is applied is read as looseness (mm), the sample is further pulled, the load (N) and the elongation (mm) when the sample is cut are measured, and the tensile strength (N / tex) and elongation (%) were calculated. The test was repeated 10 times and expressed as an average value (the tensile strength was 2 digits after the decimal point and the elongation was 1 digit after the decimal point).
T = SD / F
Here, T: Tensile strength (N / tex)
SD: Strength at cutting (N)
F: Positive fineness (tex) of sample
S = “(E2−E1) / (L + E1)] × 100
Where S: Elongation rate (%)
E1: Looseness (mm)
E2: Elongation at cutting (mm) or Elongation at maximum load (mm)
L: Grazing interval (mm)

(5) Bundling strap weight for motors for electric vehicles (weight per meter)
A binding cable for a motor left for 24 hours in a standard state (temperature 20 ± 2 ° C., relative humidity 65 ± 2%) was cut into a length of 50 cm. The weight was measured and multiplied by 2 to obtain the weight per 1 m of the binding cord for motor.

(6) Binding pitch of binding strings for electric vehicle motors Using a linen tester (loupe) with a 1-inch square frame, observe the binding strings. Count the stitches (number of peaks or valleys) between 1 inch of the tying string up to the half.

(7) Tightening performance of binding ties for motors for electric cars 50 copper coils for a coil with a diameter of 0.9 mm are tied by hand using binding ties, and the degree of fixation (return) after tightening is as follows: Shown with a five-point scale.
Evaluation 5: Hand binding property is good, and the binding string does not return after being tied.
Evaluation 4: Hand binding property is almost good, and the return after binding is slight.
Evaluation 3: The hand binding property is a little good and there is a return after binding, but it can be used.
Evaluation 2: The hand-binding property is insufficient, the knot is loose, and the practicality is insufficient.
Evaluation 1: Hand binding property is poor, and after tying, the knot is not fixed and looseness is large.

(8) Ratio of the resin to the resin-processed binding string The weight (W1) of the binding string before resin processing and the weight (W2) of the binding string after resin processing (after drying) were measured. The weight was introduced into the following formula to determine the ratio.
Ratio of resin (% by weight) = [(W2−W1) / (W1 + W2)] × 100

(9) Resin solid content adhesion amount The weight (W1) of the binding string before resin processing and the weight (W2) of the binding string after resin processing (after drying) were measured. The weight was introduced into the following formula to determine the ratio.
Resin solid content adhesion amount (% by weight) = [(W2−W1) / W1] × 100

(10) Dielectric strength test (BDV)
JIS 3003 10.2b) A BDV test was conducted in accordance with the law from two pieces.

(Reference Example 1)
Two multifilament yarns (440 dtex, 100 filaments, 190 type) of polyphenylene sulfide (PPS) fibers (manufactured by Toray Industries, Inc., (trade name) “Torcon”, melting point = 285 ° C.) are arranged and wound on a small bobbin. 16 were prepared. This was set on a 16-placing string making machine and tied into a braid to obtain a binding string for an electric vehicle motor. The binding string has a tube shape, and the appearance is a flat oval shape, with a major axis (width) of 2.0 mm and a minor axis (thickness) of 0.5 mm. This high-strength oil-resistant performance of the binding cord was 91%. The unity weight of this binding string was 0.76 g / m, the group pitch was 18 stitches / inch, and the thickness was 7600 dtex dtex. Further, the binding string had a tensile strength of 320 N and an elongation of 26.3%.

  Twenty-second spun yarn (yarn thickness: 295 dtex) of PPS fiber (trade name “Torcon”, manufactured by Toray Industries, Inc., melting point = 285 ° C.) was aligned and wound on a small bobbin to prepare 32 pieces. . This was mounted on a round structure 32-stitching string making machine and stringed by a push-up braiding method to obtain a binding string for an electric vehicle motor. The binding string has a tube shape, and the appearance is a flat ellipse, and has a major axis (width) of 5 mm and a minor axis (thickness) of 1.2 mm. The high temperature oil resistance of this tying string was 86%. The unity weight of this binding string was 2.45 g / m, the assembly pitch was 32 stitches / inch, and the thickness was 24500 dtex. Further, the binding string had a tensile strength of 503 N and an elongation of 47.1%. The appearance of the obtained cable tie is shown in FIG.

  The cable tie for an electric vehicle motor obtained in Example 1 was passed through the flame of a gas burner at a speed of 1 m / sec and burned. Thereafter, the binding string is immersed in a resin solution containing 1 part by weight of vinyl acetate polymer emulsion (trade name “Cybinol HSA-50L”, manufactured by Syden Chemical Co., Ltd.) and 2 parts by weight of water, and the binding string is While pulling up in the vertical direction, it was lightly squeezed with a sponge and dried at 80 ° C. for 5 minutes for resin processing. In the obtained resin-processed cable tie for an electric vehicle motor, the ratio of the resin to the resin-processed cable tie was 16% by weight. Further, the high temperature oil resistance of the tying string was 87%. The unity weight of this binding string was 2.714 g / m, the assembly pitch was 32 stitches / inch, and the thickness was 27100 dtex. Further, the binding string had a tensile strength of 501 N and an elongation of 47.6%.

  The coil ends of the electric vehicle motor were bound by hand using the binding strings obtained in Example 1 and Example 2, respectively. The tying cord of Example 1 was flexible, had good tightening properties when bound, did not return, and satisfactorily achieved the braided coil braiding. That is, it was confirmed that the binding string of Example 1 has very little fluctuation in tension when binding the binding string, and that the binding string has excellent bundling stability. Moreover, the damage to the coil by binding was not recognized. Furthermore, the binding string overlapped in a flat shape, and both the product made by tightening and the binding state were good. The binding string of Example 2 was slightly harder than the binding string of Example 1, but the binding property was good and there was no looseness. Moreover, the binding string of Example 2 had less fluffing to oil when the motor was used than the binding string of Example 1. In addition, the tying cords obtained in Example 1 and Example 2 are more flexible than the tying cord obtained in Comparative Example 1 and have better tightening properties at the time of tying, no return, and better knitting of the bundled coils. Was achieved.

Two 20-th spun yarns (thickness: 295 dtex) made of meta-aramid fiber (manufactured by Teijin Techno Products Co., Ltd., (trade name) “Comex”, decomposition temperature = 400 ° C.) are aligned on a small bobbin 32 rolls were prepared. This was set on a 32-strike string making machine and stringed by a push-up braid system to obtain a binding string for an electric vehicle motor. The tying string was tube-shaped, but the appearance was a flat oval shape with a major axis (width) of 4.8 mm and a minor axis (thickness) of 1.3 mm. The high-strength oil resistance performance of this tie cord was 92%. The unity weight of this binding string was 2.48 g / m, the assembly pitch was 31 stitches / inch, and the thickness was 24800 dtex. Further, the binding string had a tensile strength of 490 N and an elongation of 47.7%.

  The coil end of the electric vehicle motor was bound by hand with the binding string obtained in Example 3 in the same manner as in Example 1. The tying cord of Example 3 was as flexible as the tying cord of Example 1, had good tightening properties when bound, did not return, and satisfactorily achieved the braided coil. That is, it was confirmed that the binding string of Example 3 had very little fluctuation in tension when binding the binding string, and was excellent in the stability of the binding property of the binding string. Moreover, the damage to the coil by binding was not recognized. Furthermore, the binding string overlapped in a flat shape, and the tightening property and the binding state were good. Further, the binding string obtained in Example 3 was more flexible than the binding string obtained in Comparative Example 1 and had good tightening properties at the time of binding, and did not return, and the braided coil could be satisfactorily achieved. .

  Twenty-second spun yarn (yarn thickness: 295 dtex) of PPS fiber (trade name “Torcon”, manufactured by Toray Industries, Inc., melting point = 285 ° C.) was aligned and wound on a small bobbin to prepare 32 pieces. . This was mounted on a round structure 32-stitching string making machine and stringed by a push-up braiding method to obtain a binding string for an electric vehicle motor. The binding string has a tube shape, and the appearance is a flat ellipse, and has a major axis (width) of 5 mm and a minor axis (thickness) of 1.2 mm. The cable tie for an electric vehicle motor was passed through the flame of a gas burner at a speed of 1 m / sec and burned. The high temperature oil resistance of this tying string was 86%. The unity weight of this binding string was 2.45 g / m, the assembly pitch was 32 stitches / inch, and the thickness was 24500 dtex. Further, the binding string had a tensile strength of 490 N and an elongation of 47.1%.

  The cable tie produced in Example 4 was immersed in a resin solution containing 40 parts by weight of vinyl acetate polymer emulsion (product name “Cybinol HSA-50L”, manufactured by Saiden Chemical Co., Ltd.) and 60 parts by weight of water, The binding string was lightly squeezed with a sponge while being pulled up in the vertical direction, dried at 80 ° C. for 5 minutes, and processed into a resin. In the obtained resin-processed cable tie for electric motors, the ratio of the resin to the resin-processed cable tie was 22% by weight. Moreover, the resin solid content adhesion amount was about 28%. The high temperature oil resistance of the tying string was 88%. The unity weight of this binding string was 3.15 g / m, the assembly pitch was 32 stitches / inch, and the thickness was 31500 dtex. Further, the binding string had a tensile strength of 488 N and an elongation of 45.6%.

  Using the binding strings obtained in Example 4 and Example 5, the coil ends of the electric vehicle motor were respectively bound by hand. The binding string of Example 4 was flexible, had good tightening properties when bound, did not return, and satisfactorily achieved the braided coil. That is, it was confirmed that the binding string of Example 1 has very little fluctuation in tension when binding the binding string, and that the binding string has excellent bundling stability. Moreover, the damage to the coil by binding was not recognized. Furthermore, the binding string overlapped in a flat shape, and both the product made by tightening and the binding state were good. The binding string of Example 5 was slightly harder than the binding string of Example 4, but the binding property was good and there was no looseness. Moreover, the binding string of Example 5 had less fluffing to oil when the motor was used than the binding string of Example 4.

Table 1 summarizes the physical properties of the cable ties for electric vehicle motors obtained in Examples 1 to 5 and Reference Example 1.

  As shown in Table 1, it was confirmed that the bundling cord for motors for electric vehicles according to the present invention was further improved in tightening property during bundling and high in high temperature oil resistance.

[Amount of varnish adhering to the cable tie]
The coil ends of the electric vehicle motor were bound by hand using the binding strings obtained in Example 5 and Reference Example 1, respectively. The tie was vacuum impregnated with varnish, and the varnish was adhered to the tie. The weight of the binding string before and after the varnish treatment was measured, and the amount of varnish adhering to the binding string was obtained from the weight. The average amount of varnish obtained using seven coil ends was 116 g in Example 5 and 131 g in Reference Example 1. From the above results, the binding cord of Example 5 has a lower varnish adhesion amount than the case of Reference Example 1, that is, when the binding cord of Example 5 is used for binding, the wound yarn of the coil end has high adhesion. It was confirmed that the volume bulge was low.

[Insulation resistance effect of cable ties]
The coil ends of the electric vehicle motor were bound by hand using the binding strings obtained in Example 5 and Reference Example 1, respectively. Thereafter, the binding string was unwound and the coil end was collected. FIG. 3A shows the result of measuring the insulation properties of the collected coil ends after binding the coil ends using the binding string obtained in Example 5. FIG. Moreover, after binding a coil end using the binding string obtained by the reference example 1, it decomposes | disassembles and the result of having measured the dielectric strength test (BDV) by two strands is shown in FIG.3 (b). As shown in FIGS. 3A and 3B, in the case of the binding string obtained in Example 5, the insulation voltage is low, but in the case of the binding string obtained in Reference Example 1, the insulation voltage Was confirmed to be high. Since the same coil end is used for bundling, from this result, the bundling string of the present invention has good bundling properties, and as a result, the burden on the coil film can be suppressed. Therefore, damage to the winding film can be suppressed.

  The binding string for an electric vehicle motor of the present invention can be applied to an electric vehicle motor manufacturing application.

It is a top view which shows the external appearance of the binding string for motors for electric vehicles obtained in Example 1 of this invention. It is a schematic perspective view which shows the usage example of an example of the binding string for motors for electric vehicles of this invention. FIG. 3A shows the result of measuring the insulation properties of the collected coil ends after binding the coil ends using the binding string obtained in Example 5, and FIG. It is the result of having measured the insulation of the collect | recovered coil end, after bundling a coil end using the binding string obtained by above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator core 2 Slot 3 Coil 4 Wire 5 Wire insulation tube 6 Cable tie 7 Thermostat insulation tube 8 Slot liner 9 Wedge 10 Interphase paper

Claims (10)

A cable tie for an electric vehicle motor,
A spun yarn composed of staple fibers of synthetic fibers having a melting point or decomposition temperature of 280 ° C. or higher, and is formed into a sleeve shape of 24 beats or more,
Bundling string for electric vehicle motors with high-temperature oil resistance of 50% or more.
High temperature oil resistance (%) = (T ′ / T) × 100
In the above formula, T means the tensile strength of the binding string before processing, and T ′ means the tensile strength of the binding string after processing.
The said tensile strength means the tensile strength in JISL1013-8.5.1 method.
In the treatment, the entire tying string is put in a mixture of 0.5% by weight of water and 99.5% by weight of automatic transmission fluid in a closed container, and the temperature of the mixture in the container is 1000. It means a process of heating the container so as to be maintained at 150 ° C. for a period of time.   The binding string for a motor for an electric vehicle according to claim 1, wherein the synthetic fiber used for the spun yarn is a polyphenylene sulfide fiber, an aramid fiber, or a polyetherimide fiber.   The binding string for an electric vehicle motor according to claim 1 or 2, wherein a thickness of the spun yarn made of the staple fiber is in a range of 100 dtex or more and 1000 dtex or less.   The binding string for an electric vehicle motor according to any one of claims 1 to 3, wherein a thickness of the binding string is in a range of 7000 dtex to 30000 dtex.   The binding string for an electric vehicle motor according to any one of claims 1 to 4, wherein the binding string has a tubular shape and a flat shape.   The binding string for an electric vehicle motor according to any one of claims 1 to 5, wherein the binding string has a tensile strength according to JIS L1013-8.5.1 of 150N or more and 800N or less.   The binding string for an electric vehicle motor according to any one of claims 1 to 6, wherein the binding string has an elongation percentage according to JIS L1013-8.5.1 of 20% or more and 60% or less.   The bundling cord for an electric vehicle motor according to any one of claims 1 to 7, wherein at least a part of the surface of the bundling cord is subjected to a hair baking treatment, and the fluff on the surface is removed.   The binding string for an electric vehicle motor according to claim 1, wherein the binding string is resin-processed.   The binding string for an electric vehicle motor according to claim 9, wherein a ratio of the resin to the resin-processed binding string is 20 to 35% by weight.

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