V-belts for transmission and belt drive mechanisms

Abstract

The present invention relates to a V-belt for transmission comprising a core wire formed by threading a plurality of lower threads containing aromatic polyamide fibers and threading and upper threads, and having a total fiber length of 1000 to 3500 dtex.

Description

V-belts for transmission and belt drive mechanisms The present invention relates to a transmission V-belt used in small belt-driven continuously variable transmissions and the like, and a belt drive mechanism having the transmission V-belt. Drive belts used in power transmission mechanisms of mechanical devices are broadly classified into friction drive belts and meshing drive belts based on the form of power transmission. Examples of friction drive belts include V-belts, V-shaped multi-ribbed belts, and flat belts, while examples of meshing drive belts include toothed belts. Among V-belts, one example is the burr-type belt (burr V-belt) where the rubber layer exposed on the friction drive surface (V-shaped side). Besides burr V-belts without teeth, there are also burr toothed V-belts with teeth only on the inner circumferential surface to improve flexural flexibility, or burr toothed V-belts with teeth on both the inner and outer circumferential surfaces to improve flexural flexibility (burr double-sided toothed V-belt), etc. As an application of such V-belts (especially rough-toothed V-belts), a belt-driven continuously variable transmission (CVT) can be cited. As shown in Figure 1, the belt-driven CVT 30 is a device that continuously changes the gear ratio by winding a V-belt 1A around a drive pulley 31 and a driven pulley 32. Each pulley 31, 32 is composed of fixed pulleys 31a, 32a whose axial movement is controlled or fixed, and movable pulleys 31b, 32b that can move axially. It has a structure that allows for continuous adjustment of the width of the V-grooves formed by the fixed pulleys 31a, 32a and the movable pulleys 31b, 32b. The two end faces of the aforementioned V-belt 1A in the width direction are formed by tapered surfaces that are inclined and coincide with the opposing surfaces of the V-grooves of each pulley 31, 32, and can be inserted into any position in the radial direction of the pulleys according to the adjusted width of the V-grooves. For example, when the width of the V-groove of the drive pulley 31 is narrowed and the width of the V-groove of the driven pulley 32 is widened, and the state changes from the state shown in Figure 1(a) to the state shown in Figure 1(b), the V-belt 1A moves on the outer periphery of the drive pulley 31 in the radial direction and on the inner periphery of the driven pulley 32 in the radial direction, and the winding radius of each pulley 31 and 32 changes continuously, so that the speed ratio can be adjusted steplessly. V-belts (speed change belts) used in such applications require high lateral pressure resistance (high or low rigidity in the width direction) to suppress belt deformation caused by lateral pressure from the pulleys, high or low bending rigidity to reduce the bending radius of the pulleys, and high tensile strength (high or low elongation rigidity) to suppress slippage and achieve the desired speed ratio. This is necessary not only to cope with the rotational movement between the drive pulley and driven pulley, but also to cope with repeated bending actions caused by movement in the radial direction of the pulleys and continuous changes in the winding radius. As a proposal addressing these claims, Japanese Patent Application Publication No. 2010-196888 (Patent Document 1) discloses a transmission belt whose compression rubber layer consists of two layers: an upper layer near the core wire and a lower layer on the inner circumferential side. The hardness of the upper layer is in the range of 93-99, and the hardness of the lower layer is in the range of 80-88. Furthermore, this document states that when the belt width is defined as W and the belt thickness as T, the relationship can be 0.3W≦T≦0.6W. Moreover, this document describes the advantages of the invention as follows: the high hardness of the upper layer improves the belt's resistance to deformation; the low hardness of the lower layer provides excellent resistance to flexural fatigue and reduces the likelihood of cracking; and reducing the belt thickness reduces deformation during flexural stress, thereby suppressing cracking. In Japanese Patent Application Publication No. 2005-265106 (Patent Document 2), a double-toothed V-belt with excellent flexural fatigue resistance is disclosed, which does not accelerate the fatigue of the core wire made of para-aromatic polyamide fiber. The double-toothed V-belt has a core wire made of para-aromatic polyamide fiber and a belt bending stiffness of 600 to 1200 N / mm. 3 The dynamic compression spring constant in the width direction of the belt is above 15000 N / mm. Japanese Patent Application Publication No. 2014-209029 (Patent Document 3) discloses a transmission belt whose core is formed of aromatic polyamide fiber with a width direction of 2.0 N / mm. 2 The strain under stress compression is 0.5-0.8%, and the strain under tension of 2 kN along the length direction is 0.35-0.7%. The document describes the invention's effect as follows: by having slightly lower rigidity in the belt width direction and slightly greater elongation in the belt length direction compared to previous products, even with significant misalignment during speed changes, the protrusion of the core wire from the belt body is suppressed. [Prior Art Documents] [Patent Documents] Patent Document 1: Japanese Patent Application Publication No. 2010-196888 Patent Document 2: Japanese Patent Application Publication No. 2005-265106 Patent Document 3: Japanese Patent Application Publication No. 2014-209029 [Problems to be Solved by the Invention] The belt structures disclosed in Patent Documents 1-3 show certain effects on the required performance of V-belts, but the requirements for miniaturization of belt-driven continuously variable transmissions or improvement of transmission belt durability have become increasingly stringent, necessitating further improvements. In particular, if the winding radius to the pulley becomes smaller, the heat generated when the belt bends and elongates increases, thus accelerating the thermal degradation of the rubber and making it prone to cracking of the rubber or peeling of the core wire, easily reducing the durability of the belt. To this end, it is intended to provide a V-belt for transmission and a belt-transmission mechanism with a V-belt for the transmission that suppresses heat generation even in the case of use in small belt-type continuously variable transmissions and also inhibits the peeling of the core wire and the occurrence of cracking of the compressed rubber layer. [Technical means to solve the problem] The result of repeated studies by the inventors and others in order to achieve the aforementioned topic, they found that the total fiber of the aforementioned core wire was adjusted to 1000~35 dtex, which suppresses heat generation even in the case of use in small belt-type continuously variable transmissions, and also suppresses the peeling of the core wire and the occurrence of cracking of the compressed rubber layer, which completes the present invention. That is, the following states are included in the present invention. State [1]: A V-belt for transmission comprising a core wire formed by threading a plurality of lower threads containing aromatic polyamide fibers and threading and upper threads, and having a total fiber length of 1000 to 3500 dtex. State [2]: A V-belt for transmission such as the aforementioned state [1], where the tensile strength of each core wire is 500 to 1000 N. State [3]: A V-belt is used for transmission such as the aforementioned state [1] or [2], where in the core line, the addition factor of the aforementioned lower thread is 0.5 to 3, and the addition factor of the aforementioned sequential line is 0.5 to 5. State [4]: ​​A V-belt for transmission such as any of the aforementioned states [1] to [3], wherein the pitch of the aforementioned core wire is 0.05–0.25 mm larger than the average diameter of the aforementioned core wire. State [5]: A V-belt for transmission such as any of the aforementioned states [1] to [4], where the average diameter of the aforementioned core wire is 0.4 to 1 mm. State [6]: A V-belt for transmission such as any of the aforementioned states [1] to [5], wherein the elongation stiffness of the V-belt for transmission is 6500–20000 N per 1 mm pitch width. State [7]: V-belt for transmission as in any of the aforementioned states [1] to [6], wherein the bending stiffness of the V-belt for transmission is 40~260 N(mm) per 1 mm pitch width. 2 . State [8]: A V-belt for transmission as in any of the aforementioned states [1] to [7] has a thickness of 5–12 mm and the pitch width of the V-belt for transmission is 10–25 mm. Status [9]: A V-belt for transmission such as any of the preceding states [1] to [8], which is a raw-edged V-belt having inlay teeth at least on the inner peripheral face side. State

[10] : A V-belt for transmission such as any of the preceding states [1] to [9], which is a transmission belt used in a small belt-type continuously variable transmission. Form

[11] : A belt transmission mechanism comprising a V-belt for transmission, and a pulley, as in any of the preceding states [1] to

[10] . Form

[12] : The belt transmission mechanism of the preceding state

[11] , wherein the V-belt for transmission is a raw-edged V-belt with inlay teeth at least on the inner peripheral face side, and it is a transmission belt used in a small belt-type stepless transmission. [Effect of the invention] In the present invention, because the total fiber of the aforementioned core wire is adjusted to 1000~3500 dtex by forming a core line of a V-belt for transmission by forming a plurality of lower threads containing aromatic polyamide fibers, and cracking and detaching the compression core layer. [V-belt for transmission] The V-belt for transmission of the present invention is not specifically limited as long as it comprises a V-belt for transmission consisting of a core wire formed by threading and threading a plurality of lower and upper threads containing aromatic polyamide fibers and having a total fiber of 1000 to 3500 dtex. Furthermore, the V-belt for transmission of the present invention is a friction transmission belt whose friction transmission surface is V-shaped, and a V-belt having such a shape may be a rubber layer exposed by the friction transmission surface (V-shaped side), i.e. a raw edge (Raw-Edge) type belt (wraped) belt (wrapped) with a friction transmission surface covered by an outer covering cloth (covered cloth). Among the others, the raw edge V belt is preferably based on the point of excellence in transmission. Among the gross-edge V-belts, there are gross-edge V-belts without inlays, and hair-edge toothed V-belts with inlays. Further, the burly serrated V-belt includes a burly serrated V-belt with inlays formed only on the inner peripheral side of the burly V-belt, and a burly bilateral serrated V-belt with inlays formed on both the inner and peripheral sides of the burly V-belt. In the present application, the burly V-belt without inlays, the burly serrated V-belt and the burly bilateral serrated V-belt are collectively referred to as the burly V-belt. Among those, a point of large effect based on the present invention is preferably a raw edge toothed V belt used in a variable speed belt (CVT belt), a raw edge bilateral toothed V belt. 2 shows a stereoscopic view of a rough partial section of one example of the raw edge serrated V-belt of the present invention, and FIG. In this example, the rough-edged V-belt 1 has toothed portions on its inner circumferential surface, with toothed peaks 1a and toothed valleys 1b alternately arranged along the length direction of the belt (direction A in the figure). The cross-sectional shape of the toothed peaks 1a in the length direction is approximately semi-circular (curved or wavy), and the cross-sectional shape in the direction orthogonal to the length direction (width direction or direction B in the figure) is trapezoidal. That is, each toothed peak 1a protrudes approximately semi-circularly from the toothed valley 1b in the cross-section in direction A in the belt thickness direction. The rough-edged V-belt 1 has a layered structure, with reinforcing fabric 2, tensile rubber layer 3, core layer (adjoined rubber layer) 4, compression rubber layer 5, and reinforcing fabric 6 sequentially layered from the outer circumference to the inner circumference (the side with the toothed portions). The cross-sectional shape in the belt width direction is a trapezoidal shape in which the belt width decreases from the outer circumference to the inner circumference. Furthermore, a core wire 4a is embedded in the rubber layer 4, and the aforementioned toothed portion is formed on the compressed rubber layer 5 by means of a toothed forming mold. Figure 4 is a schematic partial cross-sectional perspective view showing an example of the burr-edged double-sided toothed V-belt of the present invention, and Figure 5 is a schematic cross-sectional view of the burr-edged double-sided toothed V-belt of Figure 4 cut along the belt length direction. In this example, the burr-edge double-sided toothed V-belt 11 has inner peripheral teeth formed alternately along the length direction of the belt (direction A in the figure) on the inner peripheral surface of the compressed rubber layer 15. The inner peripheral tooth peaks 11a have a generally semi-circular (curved or wavy) cross-sectional shape in the length direction and a trapezoidal shape in the cross-sectional shape in the direction orthogonal to the length direction (width direction or direction B in the figure). That is, each inner peripheral tooth peak 11a protrudes into a generally semi-circular shape from the inner peripheral tooth valley 11b in the cross-section in direction A in the belt thickness direction. Furthermore, the outer peripheral surface also has alternating peripheral tooth peaks 11c and peripheral tooth valleys 11d along the length of the belt. The cross-sectional shape of the peripheral tooth peak 11c in the length direction is approximately trapezoidal, and the cross-sectional shape in the direction orthogonal to the length direction (width direction or direction B in the figure) is approximately rectangular. That is, each peripheral tooth peak 11c protrudes into a approximately trapezoidal shape from the cross-section of the peripheral tooth valley 11d in direction A in the belt thickness direction. The rough-edged double-sided toothed V-belt has a layered structure, in which a tensile rubber layer 13, a core layer (adjoining rubber layer) 14, a compression rubber layer 15, and a reinforcing fabric 16 are sequentially layered from the outer periphery to the inner periphery. The cross-sectional shape of the belt in the width direction is a roughly trapezoidal shape in which the belt width decreases from the outer periphery to the inner periphery. Furthermore, a core wire 14a is embedded in the core layer 14, and the aforementioned inner and outer peripheral toothed portions are formed on the compression rubber layer 15 and the tensile rubber layer 13 respectively by means of a toothed forming mold. (Overall thickness of the V-belt for transmission) In the V-belt for transmission of the present invention (especially the burr-edge V-belt), the overall thickness (average thickness) of the belt is, for example, 5 to 12 mm, preferably 7 to 11.5 mm, and more preferably 8 to 11 mm. In the present invention, if the thickness of the V-belt for transmission is within such a range, the bending stiffness of the belt can be reduced, and even in the case of use in small belt-driven continuously variable transmissions, the occurrence of heat generation, core wire peeling, and rubber cracking can be suppressed. Figure 6, based on Figure 5, shows the definition of the overall thickness of the burr-edge double-sided toothed V-belt of the present invention. Specifically, in Figure 6, in the burr-edge double-sided toothed V-belt 11, the outer peripheral tooth height H5 represents the height of the outer peripheral tooth portion formed on the outer peripheral surface, and the outer peripheral pitch height H4 represents the distance from the center of the core wire to the outer peripheral surface (the top of the tooth portion). Furthermore, the inner peripheral tooth height H2 represents the height of the inner peripheral tooth portion formed on the inner peripheral surface, and the core-valley thickness H3 represents the distance from the center of the core wire to the deepest part of the inner peripheral tooth valley. In contrast, the overall thickness H1 refers to the thickness obtained by adding the inner peripheral tooth height H2, the core-valley thickness H3, and the outer peripheral pitch height H4, and refers to the thickness at the top of the tooth portion (the maximum thickness of the belt). In this application, the overall thickness of a transmission V-belt (especially a burr-tooth V-belt) refers to the thickness from the outer circumferential surface to the inner circumferential surface (the thickness at the thickest part of the belt). In the case of a toothed V-belt, as shown in Figure 6, the top of the tooth is either the inner or outer circumferential surface. Therefore, in a burr-tooth V-belt with teeth only on the inner circumferential surface, the distance from the outer circumferential surface to the top of the tooth on the inner circumferential surface is the overall thickness. That is, in the case of a burr-tooth V-belt, the overall thickness refers to the distance from the top of the tooth on the compression rubber layer (the convex top on the inner circumferential side) to the back of the belt; in the case of a burr-tooth V-belt with teeth on both sides, the overall thickness refers to the distance from the top of the tooth on the compression rubber layer (the convex top on the inner circumferential side) to the top of the tooth on the tension rubber layer (the convex top on the outer circumferential side). (Pitch Width of V-Belts for Transmission) In the V-belts for transmission (especially burr-edge V-belts) of the present invention, the belt pitch width is, for example, 10–25 mm, preferably 12–24.5 mm, and more preferably 15–24 mm. In the present invention, if the belt pitch width of the V-belt for transmission is within such a range, the bending stiffness of the belt can be reduced, and even in the case of use in small belt-driven continuously variable transmissions, the occurrence of heat generation, core wire peeling, and rubber cracking can be suppressed. In particular, when the overall thickness of the belt is within the aforementioned range and the belt pitch width is within such a range, the effect of the present invention is particularly greater and therefore preferred because the thickness is thinner and the pitch width is narrower. Figure 7 shows the definition of the belt pitch width of the burr tooth V-belt of the present invention. That is, Figure 7 is a schematic cross-sectional view of the burr tooth belt 1, which is sequentially layered with reinforcing fabric 2, tensile rubber layer 3, core layer 4, compression rubber layer 5, and reinforcing fabric 6. The belt pitch width W refers to the width of the belt at the pitch line L (the position on the line obtained by connecting the center of the core wires 4a that are buried at equal intervals in the aforementioned core layer 4). (Elongation Stiffness of V-Belts for Transmission) In the V-belts for transmission of the present invention (especially burr-edge V-belts), the elongation stiffness per 1 mm pitch width (elongation stiffness EA of the belt) is, for example, 6200–25000 N, preferably 6500–20000 N, more preferably 7000–18000 N, even more preferably 7500–15000 N, and most preferably 8000–12000 N. In the present invention, because the elongation stiffness EA of the belt is within such a range, heat generation caused by slippage can be suppressed. If the elongation stiffness EA of the belt is too small, there is a risk that the belt will elongate significantly under heavy loads and slip easily. On the other hand, if the elongation stiffness EA of the belt is too large, there is a risk that the belt will not be able to absorb load variations due to elongation and will slip easily. In this application, the elongation stiffness EA of the belt represents the relationship between the tensile force and strain (elongation rate) when the belt is stretched along its length, which means that the belt is not easy to stretch when the elongation stiffness is high, and it is easy to stretch when the elongation stiffness is low. Furthermore, in this application, the elongation stiffness EA of the belt is defined as a proportionality constant of the belt tension relative to the rate of change of belt length within the belt tension range of 200 to 600 N. That is, in this application, the elongation stiffness EA of the belt, plotted on the horizontal axis as the rate of change of belt length (%) and the vertical axis as belt tension (N), can be obtained as the slope of an approximate straight line for every 100 N of belt tension between 200 N and 600 N. More specifically, it can be measured by the method described in the embodiments below. (Bending stiffness of V-belt for transmission) In the V-belt for transmission of the present invention (especially the rough-edged V-belt), the bending stiffness of the belt per 1 mm pitch width (bending stiffness EI of the belt) is, for example, 40 to 260 N (mm). 2 The preferred value is 60–250 N (mm). 2 The optimal value is 80–240 N (mm). 2 The optimal range is 100–235 N (mm). 2 The optimal value is 120–230 N (mm). 2. In the present invention, heating due to buckling can be suppressed because the bending stiffness EI of the belt is in such a range. If the bending stiffness EI of the belt is too small, there is a risk of enlargement of the vibration or sound of the belt, and conversely, if it is too large, there is a risk of enlarged internal heating due to the bending elongation of the belt. In this application, the relationship between the belt's bending stiffness EI indicates the compressive force required to deform into a grass bag shape by compressing the annular belt from the peripheral side, and the pitch diameter when the bend of the belt is treated as a circular arc (the diameter of the circular arc plotted by the pitch line linking the center line of the core wire). Furthermore, in the present application, the flexural stiffness EI of the belt can be determined using an automated stereometer, in detail, by resorting to the method in the embodiments described later. [Core Wire] In the V-belt for transmission of the present invention, the core wire is characterized by the formation of a plurality of lower and upper strands containing aromatic polyamide fibers and a total fiber of 1000 to 3500 dtex. In the present invention, by having such a feature of the core wire, the heat generation during the use of a V-belt for transmission can be suppressed, and the peeling of the core wire and the occurrence of cracking of the compressed rubber layer can be inhibited, which is particularly effective in the case of use as a transmission belt in a small belt-type stepless transmission with a small load ratio. The grounds for being particularly effective in the case of utilization as a variable speed belt may be presumed as follows. As the failure modes of variable speed belts, inset tooth grain cracking and core stripping can be cited, either of which is prone to occur when the temperature of the belt becomes higher. Therefore, it can be said that suppressing the heating of the belt is the key to improving the durability of the variable speed belt. The causes of the heating of the belt can be cited as slipping (frictional heat due to the friction between the belt and the pulley) and flexion (internal heating due to the bending elongation of the belt). Based on the consideration that high elongation rigidity of the transmission belt is basically expected, materials with high tensile elasticity such as aromatic polyamide fiber or carbon fiber are used on the core line, and the core diameter has a tendency to become thicker. Relatively, in the V-belt for transmission of the present invention, it is characterized by a small diameter of the core wire, but the use of aromatic polyamide fibers with high tensile elasticity as the core wire can be presumed to ensure that even small diameter can ensure the elongation rigidity of the belt. Also, because the elongation rigidity of the belt can be maintained at a relatively high level, the elongation of the belt can be inhibited and slipping can be reduced, which can be presumed to inhibit heating. Further, because the bending stiffness of the belt can be reduced by virtue of its small diameter, it can be presumed that heating due to buckling can also be suppressed. That is, in the present invention, because the core wire contains aromatic polyamide fibers and is of small diameter, the elongation stiffness of the belt becomes higher by the higher elasticity of the aromatic polyamide, which suppresses the heating caused by slipping. In the forward wire constituting such a core wire, the lower wire may be a plurality of aromatic polyamide complex yarns containing aromatic polyamide fibers. Aromatic polyamide multifilament yarns may contain other fibers (polyester fibers, etc.) as needed. The proportion of aromatic polyamide fibers can be more than 50% by mass relative to the overall complex yarn (especially 80–100% by mass), preferably all filaments are composed of aromatic polyamide fibers. In the present invention, by means of the core wire containing aromatic polyamide fibers, the elongation stiffness of the belt can be improved, and the heating caused by slipping can be suppressed. Therefore, if the proportion of aromatic polyamide fibers is too small, there is a risk of easy fever. The aromatic polyamide complex yarn may contain multiple strands of aromatic polyamide filaments, such as 100 to 5000, preferably 300 to 2000, preferably 600 to 1500, especially 800 to 1200 filaments. The average fibers of aromatic polyamide filaments are, for example, 0.8 to 10 dtex, preferably 1 to 5 dtex, preferably 1.1 to 2 dtex, and especially 1.5 to 1.7 dtex. Aromatic polyamide fibers based on excellent points in mechanical strength are better for para-system aromatic polyamide fibers. Specifically, it may be a para-system aromatic polyamide fiber of a single repeating unit (e.g., Teito (strain) made "Twaron (registered trademark)" or Du of poly-te-phenylene-p-phenylenediamine fiber Pont-Toray (column) prepared “Kevlar (Kevlar) (registered trademark)”, etc.), can also be copolymer para-system aromatic polyamide fibers containing a plurality of repeating units (e.g., poly-p-phenylenediamine and 3,4'-hydroxydiphenylene terephthalamide) of the copolymer aromatic polyamide fibers "Technora" and others). Among these, the copolymer is particularly ideal for the aromatic polyamide fibers. The tensile elasticity of aromatic polyamide fibers can be selected from a range of around 50–100 GPa, such as 50–90 GPa, preferably 60–90 GPa, preferably 65–85 GPa, and especially 70–80 GPa. In applications that require a high degree of buckling fatigue resistance, aromatic polyamide fibers can be high-stretch aromatic polyamide fibers with tensile elasticities of about 50–70 GPa. If the tensile elasticity is too small, there is a risk of reduced elongation stiffness of the belt, which occurs with the risk of heating due to slipping, and conversely, if it is too large, there is a risk of reduced fatigue resistance to flexion. Further, since the present application, tensile elasticity means the value of the apparent Young’s modulus based on the method of determination of the initial tensile strength recorded in item 8.10 of JIS L 1013 (2021). The fibers of each lower thread are less than 2000 dtex, preferably 500 to 2000 dtex, preferably 1000 to 1900 dtex, especially 1300 to 1800 dtex, and optimally 1500 to 1700 dtex. If the fiber is too small, there is a risk of enlarged elongation and reduced tensile strength or tensile elasticity, and reduced economy, and conversely, if it is too large, there is a risk of reduced flexion fatigue resistance. The number of strips of the lower thread may be plural, preferably 2 to 6, preferably 2 to 4, especially 2 to 3, and optimally 2. If the number of strips is excessive, there is a risk of reduced fatigue resistance to flexion. The addition coefficient (lower coefficient) of each lower thread can be selected from a range of around 0.3 to 5, for example, 0.5 to 3, preferably 0.6 to 2.5, preferably 0.7 to 2, preferably 0.8 to 1.5, and optimally 0.9 to 1.2. If the lower screw coefficient is too small, there is a risk of a higher bending stiffness of the belt, or a reduced flexion fatigue resistance, and conversely, if it is too large, there is a risk of a reduced elongation stiffness of the belt. In the present invention, the lower strand is made by applying a pin to the compound yarn in one direction, the obtained plural of lower strands are aligned and the upper strand of the upper strand is applied in the same direction as the lower strand. The alignment line is excellent in buckling due to the large inclination angle of the filament relative to the length direction of the pinnacle line, which can reduce the bending stiffness of the belt. The addition coefficient of the thread (on the thread) can be selected from a range of about 0.5 to 5, for example, 1 to 4.5, preferably 1.5 to 4, better 2 to 3.8, especially 2.5 to 3.5, optimally 2.8 to 3.2. If the upper screw coefficient is too small, there is a risk of a higher bending stiffness of the belt, or a reduced flexion fatigue resistance, and conversely, if it is too large, there is a risk of a decrease in the elongation stiffness of the belt. The ratio of the coefficient of the upper penis to the coefficient of the lower penis (coefficient of the upper penis / coefficient of the lower penis) is for example 0.5 to 10, preferably 1 to 8, preferably 1.5 to 5, especially 2 to 4, and optimally 2.5 to 3.5. Further, in the present application, the coefficients of the lower and the respective additives of the coefficients of the upper can be calculated based on the following formula. TF=TN×D 0.5 / 960 [expressed as follows: TF: the number of additives, TN: the number of additives per 1 m, D: the fiber (tex)] The total slenderness of the line is 1000~3500 dtex. In the present invention, the bending stiffness of the belt is low because of the relatively small total fibers of the core formed by the alignment wire, which can suppress the heating due to buckling. If the total fiber does not reach 1000 dtex, there is a risk of a lower elongation stiffness of the belt, and if the total fiber exceeds 3500 dtex there is a risk of a higher bending stiffness of the belt. The best total fiber length is 2000~3450 dtex, or 3000~3400 dtex. Surface treatment (or surface treatment) may be performed in order to improve the bonding with the rubber component. As a method of subsequent treatment, customary methods may be utilized, e.g., the method in Japanese Patent Bulletin No. 6349369, etc., comprising resorting to a rubber component consisting of a condensate (a1) containing resorcinol and formaldehyde, containing a carboxyl-modified latex (a2) and a process in which a rubber composition (a) containing a hardener (a3) ​​of a polycarbide imide resin having a plurality of carbodiimide groups (a) is treated with a first treatment agent constituted by a hydrophilic solvent (b), wherein, preferably one comprising the following treatment step METHODS: A 1st treatment process, which is treated with a 1st treatment agent consisting of a rubber composition (a) comprising a hardener (a3) ​​containing a polycarbodiimide resin having a plurality of carbodiimide groups (b) and a 1st treatment agent composed of a hydrophilic solvent (b); The 1st treatment yarns processed from the 1st treatment process are treated with a 2nd treatment agent containing resorcinol, formaldehyde and latex; The clustering of the fibers with each other may be improved if the adjoining component is allowed to saturate between the lower filaments, or between the fibers of the single fibers constituting the lower filament so that the adjoining component is attached to the surface of the fibers. The adhesion rate of the subsequent component (solid component attachment rate) is for example 1–50 mass%, preferably 3–30 mass%, better 5–25 mass%, and especially 10–20 mass% relative to the line before the subsequent treatment. If the proportion of the following components is too small, the fibers are inadequately connected to each other, there is a risk that the fibers rub against each other during flexion and the flexion fatigue resistance is reduced. The average diameter of the core wire (followed by the treated straight wire) is, for example, 0.1–1.2 mm, preferably 0.3–1.1 mm, preferably 0.4–1 mm, especially 0.5–0.9 mm, and optimally 0.6–0.8 mm. Furthermore, in this application, the average diameter of the core wires refers to the average diameter of the core wires in the belt. The average diameter of the core wires is obtained by taking a cross-section of the belt in the width direction using a scanning electron microscope (SEM), measuring the length of all the core wires contained in the belt in the width direction in the photographic image, and using this as the arithmetic mean. However, this measurement is not performed when a portion of the belt lacks a core wire on its side. In this invention, for example, compared to the tensile strength of the core wires in the embodiment of Patent Document 2 (tensile strength of 1300 N for an aromatic polyamide core wire with a total fineness of 9900 dtex), the total fineness of the core wires is smaller, and the tensile strength of each core wire is lower. Therefore, by reducing the core wire pitch and densely arranging them, the elongation stiffness of the belt can be improved. Ideally, the tensile strength of each core wire should be high to improve the elongation stiffness of the belt. However, if the core wires are thickened to increase the tensile strength of each core wire, there is a risk of reduced flexibility, and the core wire pitch needs to be increased, thus preventing a significant increase in the elongation stiffness of the belt. In this invention, by reducing the core wire diameter and densely arranging them while ensuring that the tensile strength of each core wire does not decrease excessively, the elongation stiffness of the belt can be ensured while reducing bending stiffness. The tensile strength of each core wire is, for example, 300–1200 N, preferably 500–1000 N, more preferably 550–800 N, even more preferably 580–700 N, and most preferably 600–650 N. If the tensile strength of each core wire is too low, the elongation stiffness of the belt may decrease; if the tensile strength of each core wire is too high, the bending stiffness of the belt may increase. Furthermore, in this application, the tensile strength of each core wire can be determined in accordance with JIS L 1017 (2002). The core wires are arranged at predetermined intervals along the width of the belt and extend along the length (circumferential direction) of the belt, embedded in the core layer. These core wires function as tensile elements and can be arranged parallel to the belt length direction at a predetermined pitch. However, for production reasons, they are typically arranged in a spiral configuration, extending approximately parallel to the belt length direction at a predetermined pitch. In the spiral configuration, the angle of the core wires relative to the belt length direction can be, for example, less than 5°, and closer to 0° is preferable due to belt mobility considerations. The core wire pitch (the average distance between the centers of adjacent core wires in the cross-section of the belt width direction) is preferably larger than the average diameter of the core wires by a specified range. Specifically, the value obtained by subtracting the core wire diameter from the core wire pitch (the value of "core wire pitch - average core wire diameter," meaning the width of each point in the cross-section of the belt width where no core wire is present) can be selected from approximately 0.03 to 0.3 mm, for example, 0.05 to 0.25 mm, preferably 0.08 to 0.23 mm, more preferably 0.1 to 0.22 mm, and even more preferably 0.15 to 0.21 mm. If the aforementioned value is too small, the core wires may easily climb or rub against each other, reducing the tensile strength of the belt; conversely, if it is too large, the elongation stiffness of the belt may decrease. That is, from the perspective of improving the elongation stiffness of the belt, the above value is ideally small, but if it is too small, the core wires may climb on each other or rub against each other, which may easily reduce the strength. Furthermore, in this application, the number of core wires, as shown in Figure 2, refers to the apparent number of core wires arranged at a specified core wire pitch along the belt width direction when viewed in cross-section. That is, the number of core wires, when a single core wire is spirally embedded, refers to the number of spirals. However, in practice, because the core wires are spirally embedded, even within a single annular V-belt for transmission, the configuration of the core wires varies depending on the location of the cross-section. Therefore, in practical application, when the core wire pitch is a fixed value, the calculated value obtained by dividing the belt width by the core wire pitch, after discarding the decimal point, is considered the approximate "number of core wires" (effective number). [Compression Rubber Layer] In the transmission V-belt of the present invention, the compression rubber layer is formed from a rubber composition (crosslinked rubber composition) containing a first rubber component. (A1) The first rubber component may be a vulcanizable or crosslinkable rubber, such as diene rubbers [natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), hydrogenated nitrile-butadiene rubber (H-NBR), etc.], ethylene-α-olefin elastomers [ethylene-propylene copolymer (EPM), ethylene-propylene-diene terpolymer (EPDM), etc.], chlorosulfonated polyethylene rubber, alkylated chlorosulfonated polyethylene rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber, fluororubber, etc. These rubber components may be used alone or in combination of two or more. Among these, ethylene-α-olefin elastomers and chloroprene rubber are preferred, especially chloroprene rubber, due to its excellent balance of heat resistance, abrasion resistance, and oil resistance, as well as its high productivity. When the first rubber component contains chloroprene rubber, the proportion of chloroprene rubber in the first rubber component can be 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more (especially 90 to 100% by mass), and most preferably 100% by mass (chloroprene rubber only), based on the point that can improve the aforementioned properties and productivity. When the first rubber component contains ethylene-α-olefin elastomer, the proportion of ethylene-α-olefin elastomer in the first rubber component is also the same as the aforementioned proportion of chloroprene rubber. (A2) The rubber composition forming the compression rubber layer with the first short fiber may further contain the first short fiber. Examples of the first short fiber include polyamide short fibers (aliphatic polyamide short fibers such as polyamide 6 short fibers, polyamide 66 short fibers, and polyamide 46 short fibers; aromatic polyamide short fibers, etc.), polyester short fibers [polyalkylene acrylate fibers such as polyethylene terephthalate (PET) short fibers and polyethylene naphthalate (PEN) short fibers; liquid crystal polyester short fibers; polyaryl ester short fibers (amorphous fully aromatic polyester short fibers, etc.), etc.], vinylon short fibers, polyvinyl alcohol-based short fibers, poly(p-phenylenebenzodioxazole) (PBO) short fibers, and other synthetic short fibers; natural short fibers such as cotton, linen, and wool; and inorganic short fibers such as carbon short fibers. These short fibers may be used alone or in combination of two or more. Among these, aromatic polyamide short fibers, aliphatic polyamide short fibers, and other polyamide short fibers are preferred, and a combination of aromatic polyamide short fibers and aliphatic polyamide short fibers is even more preferred. The average fiber diameter of the first short fiber is 2 μm or more, for example, 2 to 100 μm, preferably 3 to 50 μm, more preferably 7 to 40 μm, and even more preferably 10 to 30 μm. The average fiber length of the first short fiber is, for example, 1 to 20 mm, preferably 1.3 to 15 mm, more preferably 1.5 to 10 mm, even more preferably 2 to 5 mm, and most preferably 2.5 to 4 mm. Because the first short fiber inhibits the compression deformation of the belt relative to the pressure from the pulley, it can be embedded in the compression rubber layer in a direction that is approximately parallel to the width of the belt. To improve adhesion to the first rubber component, the first short fiber can undergo conventional bonding treatment. Conventional methods can be used for this bonding treatment, such as treatment with a solution containing: a treatment solution containing an initial condensate of phenols and formalin (a prepolymer of phenolic varnish or methyl phenolic resin, etc.); a treatment solution containing a rubber component (or latex); a treatment solution containing the aforementioned initial condensate and a rubber component (latex); or a treatment solution containing reactive compounds (adhesive compounds) such as silane coupling agents, epoxy compounds (epoxy resins, etc.), isocyanate compounds, and bismaleimide compounds. These methods can be used alone or in combination of two or more. Among these methods, treatment with a solution containing the aforementioned initial condensate and a rubber component (latex) is preferred, and treatment with at least a resorcinol-formaldehyde-latex (RFL) solution is particularly preferred. The proportion of the first short fiber relative to 100 parts by weight of the first rubber component is, for example, 5 to 50 parts by weight, more preferably 5 to 40 parts by weight, even more preferably 10 to 35 parts by weight, and even more preferably 20 to 30 parts by weight. (A3) Other components The rubber composition forming the compression rubber layer may contain conventional additives as other components (first other component). Examples of additives include: crosslinking agents or vulcanizing agents (sulfur-based crosslinking agents, organic peroxides, etc.), co-crosslinking agents (bismaleimide, etc.), crosslinking aids or crosslinking accelerators (thiuram-based accelerators, etc.), delayed crosslinking agents, metal powders (zinc powder, etc.), metal oxides (zinc oxide, magnesium oxide, lead oxide, calcium oxide, barium oxide, iron oxide, copper oxide, titanium oxide, aluminum oxide, etc.), fillers [carbon black, silicon dioxide (hydrated silicon dioxide, etc.) and other reinforcing agents (reinforcing fillers); clay, calcium carbonate, talc, mica] Additives include: elastomers (non-reinforcing fillers or inert fillers, etc.), plasticizers (or softeners) [oils (paraffin oil or naphthenic oil, etc.), aliphatic carboxylic acid plasticizers, aromatic carboxylic acid ester plasticizers, hydroxy carboxylic acid ester plasticizers, phosphate ester plasticizers, ether plasticizers, ether ester plasticizers, etc.], processing agents or processing aids (stearic acid, metal stearate salts, waxes, paraffin, fatty acid amides, etc.), anti-aging agents (antioxidants, heat aging agents, flexural cracking agents, ozone deterioration agents, etc.), adhesion improvers, colorants, tackifiers, coupling agents (silane coupling agents, etc.), stabilizers (UV absorbers, heat stabilizers, etc.), flame retardants, antistatic agents, etc. These additives can be used alone or in combination of two or more. Furthermore, metal oxides can act as crosslinking agents. The proportion of the crosslinking agent (first crosslinking agent) relative to 100 parts by weight of the first rubber component is, for example, 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, even more preferably 3 to 12 parts by weight, and even more preferably 4 to 10 parts by weight. The proportion of fillers such as carbon black (first filler) relative to 100 parts by weight of the first rubber component is, for example, 10 to 200 parts by weight, more preferably 20 to 100 parts by weight, even more preferably 30 to 80 parts by weight, and particularly preferably 40 to 70 parts by weight. The proportion of metal powder relative to 100 parts by weight of the first rubber component is, for example, 1 to 30 parts by weight, more preferably 3 to 20 parts by weight, and even more preferably 5 to 15 parts by weight. The total proportion of other components (first other components) relative to 100 parts by mass of the first rubber component is, for example, 5 to 300 parts by mass, more preferably 10 to 200 parts by mass, even more preferably 30 to 150 parts by mass, and even more preferably 50 to 100 parts by mass. [Stretch rubber layer] The transmission V-belt of the present invention may further include a stretch rubber layer formed of a rubber composition (crosslinked rubber composition) containing a second rubber component. As a second rubber component, it contains a preferred form and can be selected from the rubber components exemplified as the first rubber component. The second rubber component may be a different rubber component from the first rubber component, but is usually the same as the first rubber component. The aforementioned rubber composition may further include short fibers (second short fibers), which, as second short fibers, have a preferred form and can be selected from the short fibers exemplified as first short fibers. The average fiber diameter and average fiber length of the second short fibers have a preferred form and can be selected from the range of the first short fibers. The second short fiber may be a different type of short fiber from the first short fiber, but is generally the same as the first short fiber. The aforementioned rubber composition may further include other components (second other components), which, as second other components, contain preferred forms and may be selected from the other components exemplified as first other components. The second other component may be a component different from the first other component, but is generally the same as the first other component. [Core Layer] The core layer may contain the aforementioned core wire as the core, or it may be a core layer formed solely by the aforementioned core wire. Preferably, it is a core layer (adhesive rubber layer) formed from a cross-linked rubber composition in which the core wire is embedded, based on the advantages of suppressing interlayer peeling and improving belt durability. The adhesive rubber layer is interposed between the tensile rubber layer and the compression rubber layer to bond the tensile rubber layer and the compression rubber layer, and the core wire is embedded in the adhesive rubber layer. (Adhesive rubber layer) The transmission V-belt of the present invention may further include an adhesive rubber layer formed of a hardened material (crosslinked rubber composition) of a rubber composition containing a third rubber component. As a third rubber component, it contains a preferred form and can be selected from the rubber components exemplified as the first rubber component. The third rubber component may be a rubber component different from the first rubber component, but is usually the same as the first rubber component. The aforementioned rubber composition may further include other components (a third other component), which may be selected from the other components exemplified as the first other component. The proportion of the crosslinking agent (third crosslinking agent) relative to 100 parts by weight of the third rubber component is, for example, 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, even more preferably 3 to 12 parts by weight, and even more preferably 4 to 10 parts by weight. The proportion of fillers such as carbon black or silicon dioxide (the third filler) relative to 100 parts by weight of the third rubber component is, for example, 10 to 200 parts by weight, more preferably 20 to 100 parts by weight, even more preferably 30 to 80 parts by weight, and especially preferably 40 to 70 parts by weight. The proportion of the adhesion improver relative to 100 parts by weight of the third rubber component is, for example, 1 to 20 parts by weight, preferably 2 to 15 parts by weight, and more preferably 3 to 10 parts by weight. The total proportion of the third other components relative to 100 parts by weight of the third rubber component is, for example, 5 to 300 parts by weight, more preferably 10 to 200 parts by weight, even more preferably 30 to 150 parts by weight, and particularly preferably 50 to 100 parts by weight. The average thickness of the rubber layer is, for example, 0.8 to 3 mm, preferably 1.2 to 2.8 mm, and even more preferably 1.5 to 2 mm. [Reinforcing Fabric] The V-belt for transmission of the present invention may further include a reinforcing fabric. Examples of forms of the reinforcing fabric include those laminated on the inner peripheral surface of the compression rubber layer, those laminated on the outer peripheral surface of the tension rubber layer, and those embedded in the compression rubber layer and / or the tension rubber layer. The reinforcing fabric can be formed from materials such as woven fabric, wide-angle canvas, braided fabric, and non-woven fabric (especially woven fabric). As needed, it can be bonded, for example treated with RFL liquid (impregnation treatment, etc.), or the bonding rubber can be mixed into the aforementioned fabric through friction treatment, or the aforementioned bonding rubber and the aforementioned fabric can be laminated or embedded in the compression rubber layer and / or tension rubber layer in the aforementioned form. [Manufacturing Method of V-Belt for Transmission] The manufacturing method of the V-belt for transmission (especially the rough-edged V-belt) of the present invention is not particularly limited. For example, the manufacturing method of the rough-edged toothed V-belt of the present invention is also not particularly limited. Regarding the lamination process of each layer (the manufacturing method of the belt sleeve), conventional methods can be used depending on the type of belt. For example, a representative manufacturing method of the rough-edged toothed V-belt will be described below. First, the bulk body of the reinforcing cloth (lower cloth) and the compressed rubber layer body with thin sheets (uncrosslinked rubber thin sheets) is made on the lower side with the aforementioned reinforcing cloth, and alternately configured with teeth corresponding to the inner peripheral inlay portion (peak part 1a and bottom 1b of inlay teeth shown in Fig. 2 ) The part is set up in contact with the flat attached tooth die of the slot part, and the inlay pad (a pad that is not fully cross-linked but in a semi-crosslinked state) is prepared by pressing and pressurizing at a temperature of 60–100°C (especially 70–80°C). The desired length is then obtained by cutting the ends of that inlay pad perpendicularly from a suitable place (particularly the top of the inlay tooth peak portion). Then, an inner female mold cover alternately configured with a tooth and a slot corresponding to the preceding inlay is placed on the outer periphery of the cylindrical mold, snapped into the tooth and slot of the inner master and coiled around the inlay pad and joined at both ends (particularly the top of the inset tooth peak portion), where the outer peripheral build-up layer 1 is followed by a thin sheet of rubber (below) After the adhering rubber: uncrosslinked rubber sheet), the uncrosslinked shaped body is made by spinning and pressing the core line (wire) forming the core body, which is sequentially wound around its periphery. Further, a reinforcing cloth (upper cloth) can be laminated on top of the tensile rubber layer as needed. Subsequently, cross-linked belt envelopes are made by placing the jacket cover in an uncrosslinked molded body in a well-known cross-linking device (vulcanization tank, etc.) and performing cross-link forming at a temperature of 120–200°C (especially 150–180°C). Then, a ring-shaped raw edge toothed V-belt was obtained by cutting and processing into a V using a cutter and other cutting. In the case of bilateral serrated V-belts for gross edges, the hair-edged bilateral toothed V-skin belts were obtained by cutting and processing a cross-linked V-skin belt with a cross-linked belt cover that also formed a nested part on the outer peripheral surface by cutting and processing a cross-linked V-skin cover in a state of the outer periphery of the previously uncrosslinked molded body in a state of alternating serrated and slotted parts corresponding to the peripheral embedded tooth portion. Furthermore, the adjoining rubber layer may be formed by a plurality of adjoining rubber layers with thin sheets, and the core line (wire) forming the core body may be sequentially established in association with the plurality of the adjoining rubber layers with thin sheets according to the embedding position for the adjoining rubber layer. [Examples] Hereafter, the invention is described in more detail based on embodiments, but the invention is not limited by embodiments of those. Further, the following shows details of the materials used in embodiments and comparative examples, embodiments, and evaluation methods for comparative examples. [Materials used] (Rubber composition) Chlorobutadiene Rubber: "PM-40" from Denka (column) Carboxyl-modified NBR latex (COOH modified NBR): "Nipol 1571CL" from ZEON (co.), Japan, active ingredient 38% by mass, high nitrile type (Curing Agent) Polycarbodiimide Dispersion: Nisshinbo Chemical Co., Ltd.'s "CARBODILITE E-02", active ingredient 40% by mass, NCN (carbodiimide) equivalent 445. Polyisocyanate (Polymerized MDI): TOSOH Co., Ltd.'s "MILLIONATE (Registered Trademark) MR-200", NCO content 30% by mass. (Short Fiber) The following short fibers were used. Each short fiber was subjected to a bonding treatment of impregnation in RFL solution [a mixture of 2.6% resorcinol, 1.4% formalin (37% by weight), 17.2% vinylpyridine-styrene-butadiene copolymer latex (manufactured by ZEON Corporation, Japan), and 78.8% water] and drying. The adhesion rate of the bonding component (solid component) was adjusted to 6% by weight relative to the short fiber before treatment. Para-aromatic polyamide staple fiber: Teijin Co., Ltd.'s "Twaron", fiber length 3 mm; Nylon 66 staple fiber: Asahi Kasei Co., Ltd.'s "LEONA", fiber length 3 mm. (Fillers) Carbon Black FEF: SEAST SO manufactured by Tokai CARBON Co., Ltd. Silicon Dioxide: Nipsil VN3 manufactured by TOSOH・SILICA Co., Ltd. (Additives) Naphthenic oil: "Diana Process Oil NS-90S" manufactured by Idemitsu Kosan Co., Ltd. Adhesion improver A (resorcinol formaldehyde co-condensate): "POWERPLAST PP-1860" manufactured by Singh Plasticisers & Resins Co., Ltd. Adhesion improver B (hexamethylol melamine hexamethyl ether): "POWERPLAST PP-1890S" manufactured by Singh Plasticisers & Resins Co., Ltd. Magnesium oxide: "Kyowamag 150" manufactured by Kyowa Chemical Industry Co., Ltd. Crosslinking accelerator MBTS (dibenzothiazole disulfide): "NOCCELER DM" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Crosslinking accelerator TMTD (tetramethylthiuram disulfide): "NOCCELER TT" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Anti-aging agent A (octyldiphenylamine): "NONFLEX OD-3" manufactured by Seiko Chemical Co., Ltd. Anti-aging agent B (4,4'-bis(α,α-dimethylbenzyl)diphenylamine): "NONFLEX DCD" manufactured by Seiko Chemical Co., Ltd. Anti-aging agent C (microcrystalline wax): "SUNTIGHT C" manufactured by Seiko Chemical Co., Ltd. Zinc powder: "M-11" manufactured by Sakai Chemical Industry Co., Ltd. Softener: "ADK CIZER C-8" manufactured by ADEKA Corporation Stearic acid: "BEADS Stearic acid TSUBAKI" manufactured by NOF Corporation Zinc oxide: "Zinc oxide (JIS standard type 2)" manufactured by HAKUSUI TECH Co., Ltd. Co-crosslinking agent (N,N'-m-phenylene dimaleimide): "VULNOC PM" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. (Core wire) The following core wires are used. Adhesion treatment is applied to any core wire using the following treatment method. The adhesion rate (the final adhesion rate after the third treatment process) of the adhesion component (solid component) is adjusted to 15% by mass relative to the core wire before treatment (before the first treatment process). Aromatic polyamide core wires of Examples 1 to 3: A combination of two down-twisted filaments obtained by twisting a 1670 dtex aromatic polyamide fiber bundle ("Technora" manufactured by Teijin Limited) at a twist coefficient of 1.0, and an S-twisted yarn with a total fineness of 3340 dtex twisted in the same direction as the down-twist at a twist coefficient of 3.0 (the diameter of the treatment wire is approximately 0.70 mm, and the tensile strength of each core wire is 620 N) Polyester core wires used in Comparative Examples 1 to 3: Combination of 3 Pieces of PET fiber bundles of 1100 dex (TORAY (strain) made “TETORON”) were combined to obtain the lower filament strands by adding a screw factor of 3.0, and in the reverse direction with the total fiber of 6600 dtex by adding a screw factor of 3.0 mm, tensile strength per 1 core wire is 440 N) Aromatic polyamide core wires used in Comparative Examples 4, 7, and 10: Combined 2 strands of aromatic polyamide fiber bundles of 1670 dtex (“Technora” by Teito (Strain)) were lowered with an addition factor of 1.0 and reversed with an addition factor of 3.0. The total fibers of 3340 dtex diameter were approximately 0 mm, tensile strength per 1 core wire is 620 N) Comparison of the aromatic polyamide core wires used in Examples 5, 8, and 11: Combination of 3 will combine 2 bundles of aromatic polyamide fibers of 1100 dtex ("Technora" made by Teito (strain)) with an addition factor of 1.0 lower threads, in the same direction as the lower fibers to a factor of 3.0 mm, tensile strength per 1 core wire is 1300 N) Aromatic polyamide core wires used in Comparative Examples 6, 9, and 12: Combination of 3 will combine 2 bundles of 1100 dtex aromatic polyamide fibers ("Technora" made by Teito (strain)) with an addition factor of 1.0 lower threads, and inverses with an addition factor of 3.0 The total fibers of 6600 dtex of 95 strands of wires treated with an addition factor of 3.0 mm, tensile strength per 1 core wire is 1300 N) Table 1 aggregates the details of the cores used in Examples 1–3 and Comparative Examples 1–12. [Table 1] (Method for subsequent treatment of the core) (A) Preparation of the 1st treatment agent Prepare the 1st treatment agent with the composition shown in Table 3 by mixing the polycarbide diimide dispersion and water at the ratios shown in Table 3 and stirring for 10 minutes at room temperature. [Table 2] [Table 3] (B) Preparation of the 2nd treatment agent Prepare the 2nd treatment agent with the composition shown in Table 4 by mixing the RFL liquid and water of the composition shown in Table 2 at the ratios shown in Table 4 and stirring for 10 minutes at room temperature. [Table 4] (C) Preparation of the 3rd treatment agent The 3rd treatment agent (rubber paste) was prepared by dissolving the following rubber layer with the rubber composition in toluene in the ratio shown in Table 5 , adding polymeric isocyanate. [Table 5] (D) Subsequent treatment The untreated jig thread was impregnated in the first treatment agent for 10 seconds and the drying treatment was performed at 150°C for 2 minutes (the first treatment process). Then, the threads resorted to the first treatment agent were impregnated in the second treatment agent for 10 seconds and subjected to a drying treatment at 230°C for 2 minutes (the second treatment process). Finally, the core wire was obtained by further heating at 230°C for 2 minutes after the impregnation of the strands treated with the second treatment agent in the third treatment agent was repeated for 3 seconds at 100°C for 1 minute at 100°C, 1 minute. (Reinforcement Fabric) A canvas (gram weight 180 g / m) was obtained where the No. 10 cotton yarn was plain weave with a yarn density of 70 strips / 50 mm 2 ). The canvas will be mixed with a treated canvas (thickness about 0.5 mm, gram weight about 450 g / m) having an adhering rubber layer with a rubber composition 2 ) used as reinforcing cloth. The same reinforcing cloth was used for both the inner and peripheral sides of the belt. [Elongated Rigidity EA of the Belt] Hang the belt of the test body on a scale detector (belt length determination machine) with a pair of equal pitch diameters attached to a V-slot pulley configured above and below, acting a load on the lower side pulley in the direction of separation of the 2 pulleys. In this case, the belt tension (the tension acting on the one-sided span of the belt located between the 2 belt wheels), becomes 1 / 2 of the load acting on the lower side pulley. In detail, the belt length when the belt tension was 200 N was set as the datum length (belt length change rate of 0%) so that the belt tension changed from 200 N to 600 N. The rate of change in belt length relative to the datum length was recorded. The assay temperature was adjusted to 25°C. For the assay results, plots of the rate of change of belt length (%) taken on the horizontal axis and belt tension on the longitudinal axis (N) were prepared. The elongation stiffness EA was expressed as the value per 1 belt, or the value per 1 mm pitch width divided by the pitch width of the belt. [Belt Bending Stiffness EI] An automatic stereographic measuring instrument was used to mount the upper side plate 42 and lower side plate 43 of the belt used for back-compression of the test specimen, as shown in Figure 8. A ring-shaped belt 41 was placed between the upper and lower plates 42 and 43. The distance between the plates was continuously narrowed at a rate of 100 mm / min. The compressive force (bending load) was measured and recorded at six points with pitch diameters D of 110 mm, 100 mm, 90 mm, 80 mm, 70 mm, and 60 mm, at a measurement temperature of 25°C. The bending stiffness EI at the six points was calculated using the following formula, and its average value (arithmetic mean) was obtained. Bending stiffness EI = (compressive force × (pitch diameter D / 2)) 2 ) / 2 (Unit: N(mm) 2 ) Bending stiffness EI is expressed as a value per belt, or as a value per 1 mm of pitch width divided by the belt pitch width. [Durability Test 1 (Peel Resistance Test)] The peel resistance test, as shown in Figure 9, was conducted using a biaxial conveyor testing machine consisting of a 60 mm diameter drive (Dr.) pulley and a 140 mm diameter driven (Dn.) pulley. A burr-edge V-belt was mounted on the two pulleys. The shaft load was set to 700 N, the drive pulley speed to 6000 rpm, and the drive pulley torque to 15 N·m. The belt was conveyed at an ambient temperature of 80°C. The side temperature of the conveyor belt during conveyance was measured using a non-contact thermometer (ICHINEN TASCO Co., Ltd. "THI-500"), and the time taken until peeling occurred on the underside of the core wire (inner circumference of the belt) was compared. [Durability Test 2 (Crack Resistance Test)] The crack resistance test, as shown in Figure 10, was conducted using a biaxial conveyor testing machine consisting of a 120 mm diameter drive (Dr.) pulley and an 80 mm diameter driven (Dn.) pulley. A rough-edged V-belt was mounted on the two pulleys. The shaft load was set to 400 N, the drive pulley speed to 6000 rpm, and the drive pulley torque to 12 N·m. The belt was moved at an ambient temperature of 120°C. The side temperature of the belt during movement was measured using a non-contact thermometer (ICHINEN TASCO Co., Ltd. "THI-500"), and the time until cracking occurred in the tooth groove was compared. Example 1 and Comparative Examples 1 and 4-6 (formation of rubber layers) were rubber compositions as shown in Table 6 (adhesive rubber layer) and Table 7 (compression rubber layer and stretch rubber layer). The rubber was mixed using a well-known method such as a Banbury mixer. The resulting mixed rubber was then passed through calendering rolls to produce calendered rubber sheets (sheets for adhesive rubber layer, sheets for compression rubber layer, and sheets for stretch rubber layer). [Table 6] [Table 7] (Belt Manufacturing) A laminate of reinforcing fabric (bottom fabric) and compression rubber layer sheet (uncrosslinked rubber) is placed on a flat mounting mold with alternating teeth and grooves corresponding to the aforementioned toothed portions. The laminate is pressed at 75°C to create a toothed pad (not fully crosslinked, but in a semi-crosslinked state) for attaching the toothed portions to the mold. Next, both ends of the toothed pad are vertically cut off from the top of the tooth peaks. Next, an inner mold with alternating teeth and grooves corresponding to the aforementioned insert teeth is placed over a cylindrical mold, engaging the teeth and grooves of the inner mold and winding the aforementioned insert pad, joining at the top of the tooth peaks. After layering a first adhesive rubber layer sheet (lower adhesive rubber, uncrosslinked rubber, the same as the aforementioned adhesive rubber layer sheet) around the outer periphery of the wound insert pad, the core wire is spun into a spiral shape, and a second adhesive rubber layer sheet (upper adhesive rubber, the same as the aforementioned adhesive rubber layer sheet), a stretching rubber layer sheet (uncrosslinked rubber), and a reinforcing fabric (upper fabric) are sequentially wound around its outer periphery to create an uncrosslinked molded body. The short fibers are aligned along the width direction of the belt. Furthermore, regarding the core wire pitch, Example 1 and Comparative Example 4 are 0.9 mm, and Comparative Examples 1 and 5-6 are 1.1 mm. Subsequently, the jacket is placed over the uncrosslinked molded body, and the mold is placed in a vulcanizing tank. Crosslinking is performed at 160°C for 20 minutes to obtain the belt sleeve. The belt sleeve is then cut into a V-shaped cross-section along the length of the belt with a cutter at a specified width. The belt sleeve is then processed into a belt with the structure shown in Figure 2, namely a variable speed belt with teeth on the inner circumference, i.e., a rough-edged toothed V-belt (dimensions: top width 24 mm, thickness 11 mm, V angle 30 degrees, outer circumference 900 mm, pitch width 23 mm). Table 8 shows the evaluation results of the belts obtained by Example 1 and Comparative Examples 1 and 4-6. [Table 8] Examples 2 and Comparative Examples 2 and 7–9 do not use the upper fabric, in a state where the mother mold cover of the toothed and slotted portions corresponding in alternate configuration with the peripheral embedded tooth portion is cross-linked at the periphery of the forming body, the cover-cover jacket is cross-linked forming, in addition to fabricating a cross-linked belt cover with the embedded portion of the outer peripheral plane is obtained in the same way as in Example 1. Dimensions of the burrs bilateral toothed V 25 (mm) mm, V angle 30 degrees, outer perimeter length 900 mm, pitch width 23 mm). Further, with respect to core wire pitch, 0.9 mm for Examples 2 and Comparative Examples 7 and 1.1 mm for Comparative Examples 2 and 8–9. Table 9 shows the evaluation results of the belts obtained by means of Example 2 and comparing Examples 2 and 7–9. [Table 9] Examples 3 and Comparative Examples 3 and 10 to 12 do not use the upper fabric, in a state where the mother mold cover is crosslinked at the outer periphery of the serrated and slotted portions corresponding to the peripheral embedded tooth portion in the alternating configuration, the cover-cover jacket is cross-linked forming, in addition to fabricating a cross-linked belt cover with the embedded portion on the outer peripheral plane, obtaining the same hair edge as in Example 1 as in Example 1. Dimensions: 5 mm wide on the upper skin mm, V angle 30 degrees, outer perimeter length 900 mm, pitch width 23 mm). Further, with respect to core wire pitch, 0.9 mm for Examples 3 and Comparative Examples 10 and 1.1 mm for Comparative Examples 3 and 11–12. Table 10 shows the evaluation results of the belts obtained by means of Example 3 and comparing Examples 3 and 10–12. [Table 10] As is made clear based on the results in Tables 8 to 10 , in either type and size of belts, the elongation stiffness of the embodiments using the along the line of aromatic polyamide fibers with a total fiber of less than 3500 dtex have higher elongation stiffness and low bending stiffness than the comparison examples. Also, it can be confirmed that the belt side temperature of the belt of the embodiment remains lower and is excellent in stripping resistance and cracking resistance. In detail, in Comparative Examples 1 to 3, because the core wire is formed of polyester fiber, the total fiber is large, and the addition is multi-stranded, the bending stiffness is high, the belt temperature increases, and the durability is low. In the comparative examples 4, 7, and 10, the bending stiffness is high, the belt temperature is increased, and the durability is low because the core wire is added by a multi-strand screw. In the comparative examples 5, 8, and 11, the bending stiffness is high, the belt temperature is increased, and the durability is low due to the large total fiber of the core wire. In the comparative examples 6, 9, and 12, the bending stiffness is high, the belt temperature increases, and the durability is low because the total fiber of the core wire is large and multi-stranded. [Industrial Applicability] The transmission V-belt of the present invention can be applied to burr V-belts, burr toothed V-belts with toothed sections, etc., and is particularly well applied to V-belts (transmission belts or CVT belts) used in continuously variable transmissions (CVTs) where the gear ratio changes continuously during belt movement, such as burr toothed V-belts and burr double-sided toothed V-belts used in continuously variable transmissions of motorcycles, ATVs (all-terrain vehicles), snowmobiles, etc. In particular, it is particularly well applied to burr toothed V-belts and burr double-sided toothed V-belts used in continuously variable transmissions of small motorcycles with small displacement (e.g., 250 cc or less, preferably 160 cc or less). The present invention has been described in detail or with reference to specific embodiments, but it will be apparent to those skilled in the art that various modifications or alterations can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2023-215734, filed December 21, 2023, and Japanese Patent Application No. 2024-206743, filed November 27, 2024, the contents of which are extracted herein by reference. 1: Rough-edged toothed V-belt / Rough-edged toothed belt 1a: Tooth peak 1b: Tooth valley 1A: V-belt 2, 6, 16: Reinforcing fabric 3, 13: Tensile rubber layer 4, 14: Core layer (attached to rubber layer) 4a, 14a: Core wire; 5, 15: Compression rubber layer; 11: Burr-edged double-sided toothed V-belt; 11a: Inner circumferential tooth peak; 11b: Inner circumferential tooth valley; 11c: Outer circumferential tooth peak; 11d: Outer circumferential tooth valley; 30: Belt-type continuously variable transmission; 31: Drive pulley / pulley; 31a, 32a: Fixed pulley; 31b, 32b: Movable pulley; 32: Driven pulley / pulley; 41: Belt; 42: Upper side plate / upper plate; 43: Lower side plate / lower plate; A, B: Direction; D: Pitch diameter; H1: Overall thickness; H2: Inner circumferential tooth height; H3: Core-valley thickness; H4: Outer circumferential pitch height; H5: Outer circumferential tooth height; L: Pitch line. Figure 1(a) and (b) are schematic cross-sectional views illustrating the transmission mechanism of a belt-driven continuously variable transmission. Figure 2 is a schematic partial cross-sectional perspective view showing an example of the burr-tooth V-belt of the present invention. Figure 3 is a schematic cross-sectional view of the burr-tooth V-belt of Figure 2 cut along the belt length direction. Figure 4 is a schematic partial cross-sectional perspective view showing an example of the burr-tooth double-sided V-belt of the present invention. Figure 5 is a schematic cross-sectional view of the burr-tooth double-sided V-belt of Figure 4 cut along the belt length direction. Figure 6 is a schematic cross-sectional view showing the definition of the overall thickness of the burr-tooth double-sided V-belt of the present invention. Figure 7 is a schematic cross-sectional view showing the definition of the belt pitch width of the burr-tooth V-belt of the present invention. Figure 8 is a schematic diagram illustrating the method for measuring the bending stiffness (EI) of the burr-tooth V-belt obtained by the example. Figure 9 shows the setup for the peel resistance test of the burr-tooth V-belt obtained by the example. Figure 10 shows the setup for the crack resistance test of the burr-tooth V-belt obtained by the example. 1: Burr-edged toothed V-belt / Burr-edged toothed belt 1a: Insertion tooth peak 1b: Inserted tooth valley 2,6: Reinforcing fabric 3: Stretching rubber layer 4: Core layer (attached to rubber layer) 4a: Core wire 5: Compression rubber layer A, B: Direction

Claims

1. A V-belt for transmission with a thickness of 5 to 12 mm and a pitch width of 10 to 25 mm, and having at least inset teeth on the inner circumferential face side, and containing a core line formed by threading and threading 2 to 6 lower threads containing aromatic polyamide fibers and threading and upper threads; The total fiber of the aforementioned core wires is 1000–3500 dtex; 2. If a V belt is used for transmission in claim 1, wherein the pitch of the preceding core wire is 0.05 to 0.25 mm greater than the average diameter of the preceding core wire.

3. If a V-belt for transmission in claim 1 or 2, wherein the average diameter of the preceding core wire is 0.4 to 1 mm.

4. If the V belt for transmission in claim 1 or 2, wherein the elongation stiffness of the V belt for transmission is 6500 to 20000 N per 1 mm pitch width.

5. If the V-belt for transmission in claim 1 or 2, wherein the bending stiffness of the V-belt for transmission per 1 mm pitch width is 40 to 260 N(mm)2.

6. If a V belt for transmission in claim 1 or 2, it is a transmission belt for use in a belt-type continuously variable transmission.

7. A belt transmission mechanism comprising a V belt for transmission as in claim 1 or 2, and a pulley.

8. As in the belt transmission mechanism of claim 7, wherein the V-belt for the preceding transmission is a transmission belt for use in a belt-type continuously variable transmission.

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