JP4460676B2 - V-ribbed belt and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a V-ribbed belt and a manufacturing how.
[0002]
[Prior art]
Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open Nos. 3-219147 and 7-4470, etc., the side pressure resistance and wear resistance of the frictional transmission portion of the belt are improved, and the difference during belt running is improved. For the purpose of preventing sound, the short fiber group is mixed in the bottom rubber part while maintaining the orientation in the belt width direction, and a part of the short fiber group is protruded from the surface of the bottom rubber part. The transmission belt is known.
[0003]
However, even in the transmission belt in which a part of the short fiber group protrudes in this way, if the area of the protruding part of the short fiber group occupying the surface of the bottom rubber part is small, the area where the rubber and the pulley are in direct contact with each other is small. Since it becomes large, the wear resistance is not so improved.
[0004]
Therefore, Japanese Patent Laid-Open No. 1-164839 discloses an aramid short fiber mixed in the bottom rubber portion 100 as shown in FIG. 12 for the purpose of increasing the exposed area of the short fiber group on the surface of the bottom rubber portion. A transmission belt has been proposed in which the protruding length of 101 is 0.065 mm to 0.13 mm longer than the conventional one, and the protruding portion 102 is bent in a certain direction 103 along the driving surface of the belt.
[0005]
[Problems to be solved by the invention]
However, in the transmission belt disclosed in Japanese Patent Laid-Open No. 1-164839, although the exposed area of the short fiber 101 is increased, the protruding portion 102 of the short fiber is bent at the bottom because the protruding portion 102 is bent from the base. The surface of the part 100 is substantially flush. Therefore, the surface unevenness | corrugation considered that it is effective in suppression of abnormal noise is hard to be formed, and the subject that the effect of noise prevention was not fully acquired occurred.
[0006]
Further, since the protruding portion 102 of the short fiber is bent in one direction 103 along the surface of the bottom rubber portion 100, the characteristics of the belt greatly change when the traveling direction is reversed. Therefore, in order to obtain the belt characteristics as designed, it was necessary to carefully check the running direction when attaching the belt. Further, the belt cannot be used for a device in which the traveling direction is switched appropriately.
[0007]
The present invention has been made in view of the foregoing, it is an object excellent in abrasion resistance, to provide a-independent V-ribbed belt and the running direction noises hardly occurs It is in.
[0008]
[Means for Solving the Problems]
The present invention that to achieve the above object, the short fiber group of para-aramid fibers or meta-aramid fibers in a plurality of V-ribs are mixed so as to be oriented in a predetermined direction, the short from the surface of said plurality of V-ribs a V-ribbed belt in which a part of the fiber group is protruded,
The protruding portion of the short fiber stands up from the surface of the plurality of V ribs and is curled .
The protruding portions of the short fiber groups are different in the bending direction of the protruding portions of the respective short fibers so that the protruding directions are dispersed, and the protruding portions of the short fibers are once in one direction from the root toward the tip. After curving, it is curved in a direction different from that direction .
[0009]
Due to the above, the protruding portion of the short fiber is curved, and thus has a sufficiently large exposed area with respect to the surface of the V-rib . As a result, the wear resistance of the V rib is improved. Further, since the short fibers are erected from the surface of the V-rib , the root portion is lifted from the surface of the V-rib . As a result, since the micro unevenness | corrugation which makes the base part of a short fiber a convex part is formed in V rib , generation | occurrence | production of abnormal noise is suppressed.
[0010]
In addition, since the bending directions of the protruding portions of the short fiber group are different from each other and the protruding directions of the protruding portions are dispersed, the wear resistance of the belt is uniform in any direction. Therefore, even if the running direction of the belt is reversed, the characteristic does not change and the direction dependency of the belt is eliminated.
[0011]
Furthermore, since the protruding portion of the short fiber is once bent in one direction from the root toward the tip, and then is bent in a direction different from the direction, when the belt is wound around the pulley, the short fiber is brought into contact with the pulley. On the other hand, a restoring force such as a leaf spring is exerted, and tension fluctuations accompanying the running of the belt are absorbed by the restoring force. Therefore, transmission performance is stabilized. In addition, when the surface pressure is large, the pressure applied to the short fiber also increases, but the force applied to the root portion is relieved by the restoring force of the curved portion of the short fiber. Therefore, the short fibers are prevented from coming off from the V-rib, and the wear resistance is improved and the life of the belt is extended.
[0012]
It is preferable that at least the tip of the short fiber protrusion is flat.
[0013]
By the said matter, the surface area of a short fiber increases and the abrasion resistance of a belt improves.
[0014]
The short fiber protrusion may have a tear at the tip.
[0015]
By the said matter, the surface area of a short fiber increases and the abrasion resistance of a belt improves.
[0016]
Method for manufacturing a V-ribbed belt according to the present invention is a method of manufacturing the V-ribbed belt above the V-ribs which short fiber group are mixed so as to be oriented in a predetermined direction, 50% of the abrasive grain size The step of grinding with a grindstone having superabrasive grains protruding by about 95% is included.
[0017]
The above matters, the amount of projection of the superabrasive is large, direct contact between the V-ribs bond portion and the V-ribbed belt of the super abrasive grains is prevented, occurrence of frictional heat is suppressed. Therefore, the grinding process can be performed under a wide range of conditions, such as increasing the grinding speed. Moreover, it becomes easy to increase the protruding amount of the short fiber protruding from the surface of the V-rib , and it is also easy to curve the protruding portion.
[0018]
Another method for manufacturing the V-ribbed belt according to the present invention is a method of manufacturing the V-ribbed belt above the V-shaped ribs that are mixed as short fiber groups are oriented in a predetermined direction, the abrasive density A step of grinding with a grindstone having 3.5% to 55% superabrasive grains is included.
[0019]
Due to the above-mentioned matters, since the abrasive grain density is small, the chip pocket becomes large and the grinding chips are easily discharged. For this reason, clogging due to chips is less likely to occur, so that an increase in grinding load and heat generation on the grinding surface due to clogging are suppressed. Therefore, the grinding process can be performed under a wide range of conditions. Further, since the short fibers protruding from the surface of the V-rib are difficult to cut, it becomes easy to form a protruding portion having a long protruding length and to curve the protruding portion.
[0020]
Another method for manufacturing the V-ribbed belt according to the present invention is a method of manufacturing the V-ribbed belt above the V-shaped ribs that are mixed as short fiber groups are oriented in a predetermined direction, the abrasive particle size It includes a step of grinding with a grindstone having 50% to 95% protruding and superabrasive grains having an abrasive density of 3.5% to 55%.
[0021]
Due to the above-described matters, the amount of superabrasive grains protruding is large and the grain density is small, so an increase in grinding load and heat generation on the grinding surface are suppressed, and the grinding process can be performed under a wide range of conditions. Moreover, it becomes easy to form the protrusion part of the short fiber which protrudes from the surface of V rib long, or to curve a protrusion part.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
FIG. 1 shows a cross-sectional shape of a V-ribbed belt 10 that is a transmission belt according to an embodiment of the present invention. This V-ribbed belt 10 is used for auxiliary machines of the drive unit and other general industrial applications of the automobile.
[0024]
In the adhesive rubber layer 4, tensile bodies 2 extending in the belt length direction are embedded in a state where they are arranged at equal intervals in the belt width direction (left and right direction in FIG. 1). A canvas layer 5 is provided on the upper surface side of the adhesive rubber layer 4, that is, on the belt outer surface side. A plurality of V ribs 7 extending in the belt length direction are provided in the belt width direction on the lower surface side of the adhesive rubber layer 4, that is, on the belt inner surface side . Contact Chakugomu layer 4 and V-shaped ribs 7, for example chloroprene rubber, H-NBR rubber, CSM rubber, natural rubber, SBR rubber, butadiene rubber, EPM, it can be formed from such EPDM.
[0025]
A plurality of aramid short fibers 8, 8,... Are embedded in the V rib 7 while maintaining the orientation in a predetermined direction. Specifically, in the present embodiment, the aramid short fibers 8 are embedded while maintaining the orientation in the belt width direction. The aramid short fibers 8 may be para aramid fibers or meta aramid fibers. That is, polyparaphenylene isophthalamide or polymetaphenine isophthalamide may be used. Specifically, Kevlar (trade name of DuPont), Technora (trade name of Teijin Ltd.), Toaron (trade name of Enka Company), etc. can be used as para-aramid fibers, Nex (trade name of Teijin Limited), Nomex (trade name of DuPont), etc. can be used.
[0026]
As shown in FIG. 2, some of the aramid short fibers 8, 8,... Embedded in the V rib 7 protrude from the side surface 11 of the V rib 7. The protrusions 15, 15,... Of the aramid short fibers 8 are curved so as to increase the apparent volume and cover the side surfaces 11 of the V ribs 7, respectively. The protrusions 15, 15,... Of the aramid short fibers 8, 8,... Are not curved in the same direction, but are irregularly curved in multiple directions so that the respective bending directions are different. That is, the plurality of projecting portions 15, 15,... Are dispersed and curved in various directions, so that the wear resistance of the V-ribbed belt 10 is equally improved in any direction. As a result, the direction dependency of the belt is eliminated, and the V-ribbed belt 10 exhibits the same performance in any travel direction.
[0027]
Next, the shape of the protrusion 15 of each aramid short fiber 8 will be described in detail with reference to FIG. The root portion 12 of the protruding portion 15 of the aramid short fiber 8 stands from the side surface 11 of the V rib 7. In other words, the root portion 12 of the aramid short fiber 8 is substantially upright with respect to the side surface 11 of the V rib 7. The intermediate portion 13 of the protruding portion 15 is curved from the root portion 12. The distal end portion 14 of the protruding portion 15 is bent in a direction different from the bending direction of the intermediate portion 13. For example, in the aramid short fiber 8 shown in FIG. 3, the distal end portion 14 is bent in a direction opposite to the bending direction of the intermediate portion 13. That is, the aramid short fibers 8 are curved in two stages. Specifically, the aramid short fibers 8 are curved in a predetermined direction from the root toward the tip and then curved in the direction opposite to the direction. Is formed. As a result, the aramid short fiber 8 is entirely lifted from the side surface 11 of the V-rib 7 and is formed in a curl shape, and thus exhibits a restoring force like a leaf spring. In addition, micro irregularities having the root portion 12 as a convex portion are formed on the surface of the V rib 7.
[0028]
The length of the protrusion 15 of the aramid short fiber 8 is preferably 50 μm or less.
[0029]
In addition, the aramid short fibers 8, 8,... Include those having a flat shape due to friction with a grindstone during grinding, which will be described later, or having a tear at the tip as shown in FIG. It is.
[0030]
-Manufacturing method of V-ribbed belt-
Next, a method for manufacturing the V-ribbed belt 10 will be described.
[0031]
First, an unvulcanized rubber sheet to be the adhesive rubber layer 4, a cord to be the tensile body 2, an unvulcanized rubber sheet in which aramid short fibers are mixed, and the like are laminated in order, and these are heated and vulcanized to form a cylindrical shape. A belt molded body is obtained.
[0032]
Thereafter, as shown in FIG. 5, the belt molded body 19 is wound between the main roll 22 and the tension roll 23 of the drive mechanism 20 and is caused to travel by the drive mechanism 20. Then, while the grindstone 21 is rotationally driven, the belt molded body 19 is ground by being pressed against the running belt molded body 19. At this time, the mixed aramid short fiber 8 is difficult to be cut because of the large Greig tensile modulus, and a part of the aramid short fiber 8 protrudes from the side surface 11 of the V rib 7. Specifically, the stress generated on the fiber surface due to the interference between the aramid short fibers 8 and the abrasive grains is released, and the aramid short fibers 8 are plastically deformed and the tips thereof are curved.
[0033]
At this time, by adjusting the type of the grindstone 21, the pressing force of the grindstone 21, etc., it is possible to adjust the length, shape, flatness of the protruding portion of the aramid short fiber 8, the torn state of the tip, etc. Is possible.
[0034]
As the grindstone 21, it is preferable to use one having a structure in which diamond abrasive grains 24 are fixed to the peripheral surface of a disc-shaped grinding wheel 25 by electroplating, brazing, baking or the like. However, the abrasive grains are not limited to diamond abrasive grains, and other superabrasive grains such as CBN can also be used. 6A is a diagram in which a part of the peripheral surface of the grinding wheel 25 is projected from the vertical direction, and FIG. 6B is a cross-sectional view taken along the line AA of FIG. 6A. As shown in FIGS. 6 (a) and 6 (b), an adhesive (metal bond, nickel bond, etc.) is thinly stretched and applied on the peripheral surface of the grinding wheel 25 (see FIG. 5). A portion 26 is formed.
[0035]
The diamond abrasive grains 24 are evenly arranged and bonded on the bond portion 26. The grain size of the abrasive grains 24 is preferably # 30 to # 200, and is set to # 140 in this embodiment. The protruding amount of the abrasive grains 24 from the bond portion 26 is preferably 50% to 95% of the total height of the abrasive grains 24. In the present embodiment, the protruding amount of the abrasive grains 24 is set to 80%. The abrasive grain density of the abrasive grains 24 (ratio of the surface area of the abrasive grains to the ground surface) is preferably 3.5% to 55%, and is set to 45% in the present embodiment.
[0036]
In the grinding process, it is preferable to rotate the grinding wheel 25 at a peripheral speed of 500 to 2000 m / min. In this embodiment, the peripheral speed is set to 1000 m / min. The grinding speed ratio Vs / Vw, which is the ratio of the peripheral speed Vw of the belt to the peripheral speed Vs of the grindstone 21, is preferably 0.002 to 0.04, and is 0.004 in this embodiment.
[0037]
-Effects of this embodiment-
As described above, in the present V-ribbed belt 10, since the protruding portion 15 of the aramid short fiber 8 is plastically deformed and curved, the apparent area of the aramid short fiber 8 with respect to the side surface 11 of the V rib 7 is large. . Therefore, the V-ribbed belt 10 has high wear resistance.
[0038]
In addition, the surface area of the aramid short fibers 8 is further increased due to the flat shape of the aramid short fibers 8 and the formation of a tear at the tip. Therefore, the wear resistance of the V-ribbed belt 10 is further improved. Although the original strength of the short fiber may be impaired when the short fiber tip is fibrillated, the aramid short fiber 8 of the belt 10 is in a state where a tear has occurred without being fibrillated. That is, the tear of the aramid short fibers 8 in the belt 10 is a macro tear rather than fibrillation. Therefore, the original strength of the aramid short fibers 8 is not impaired.
[0039]
Since the aramid short fibers 8, 8,... Are curved in multiple directions, their performance can be exhibited without depending on the running direction of the belt 10. Therefore, when the belt 10 bites the pulley or leaves the pulley, a stable sliding resistance can be obtained on the sliding surface between the belt 10 and the pulley. As a result, there is little fluctuation in the sliding resistance, and the running of the belt is stabilized. Therefore, the present V-ribbed belt 10 exhibits equivalent side pressure resistance and wear resistance in any direction.
[0040]
Since the intermediate portion 13 and the tip portion 14 of the protrusion 15 of the aramid short fiber 8 are curved, and the bending direction of the intermediate portion 13 and the bending direction of the tip portion 14 are different, the aramid short fiber 8 is a leaf spring. As a result, the fluctuation of the pressure applied to the V-ribbed belt 10 is absorbed by the restoring force. Therefore, the running of the belt is further stabilized, and the power can be transmitted stably. Further, the force applied to the root portion 12 of the aramid short fiber 8 is relieved by the restoring force. Therefore, the aramid short fibers 8 are prevented from coming off and the deterioration of the V-ribbed belt 10 is suppressed.
[0041]
Since the root portion 12 of the aramid short fiber 8 stands up with respect to the side surface 11 of the V rib 7, the root portion 12 becomes a convex portion, and micro unevenness is formed on the side surface 11 of the V rib 7. Therefore, it is possible to effectively prevent the generation of abnormal noise.
[0042]
Moreover, in the manufacturing method of the V-ribbed belt according to the present embodiment, grinding is performed using superabrasive grains in which 50% to 95% of the abrasive grain size protrudes from the bond part 26. Contact with 7 is unlikely to occur. Therefore, there is little heat generation by friction. Therefore, grinding can be performed satisfactorily. Moreover, since diamond having a relatively high thermal conductivity is used as the superabrasive grains, heat generation can be effectively suppressed.
[0043]
Since the abrasive density of the superabrasive grains is relatively coarse, 3.5% to 55%, the gap between the abrasive grains, that is, the chip pocket becomes large. Therefore, clogging due to chips is less likely to occur during grinding. Less heat is generated due to clogging of chips. Therefore, grinding can be performed satisfactorily.
[0044]
Then, by using the grinding wheel 25 having superabrasive grains having a large amount of protrusion and a small abrasive density in this way, it is easy to protrude the aramid short fibers 8 from the side surface 11 of the V rib 7 for a comparatively long time. became. Further, it becomes easy to form the protruding portion 15 in a curl shape in which the root portion 12 stands.
[0045]
-Performance comparison example-
Next, a performance comparison test comparing the present V-ribbed belt 10 with a conventional V-ribbed belt will be described. As a conventional V-ribbed belt, an aramid short fiber that is linearly extended was used. In the test, as shown in FIG. 7, a tension W1 on the tension side of the belt and a tension on the loose side are detected by suspending a weight W on the sample belt 32 via the guide roller 33 and detecting the load cell value of the load cell 31. This was carried out by detecting T2 and calculating the change with time of these ratios (tension ratios) T1 / T2. The tension ratio T1 / T2 indicates the friction coefficient μ = (1 / π) ln (T1 / T2).
[0046]
As a result, as shown in FIG. 8, in the V-ribbed belt 10 according to the present embodiment, it has been clarified that the fluctuation of the tension ratio T1 / T2 is reduced compared to the conventional case. Also, as shown in FIG. 9, when comparing the tension ratio T1 / T2 after running continuously for 24 hours, it is clear that the fluctuation of the tension ratio T1 / T2 is smaller in the V-ribbed belt 10 than in the prior art. Became. In other words, it has been found that the V-ribbed belt 10 has not only excellent initial performance but also excellent performance during running deterioration as compared with the conventional V-ribbed belt.
[0047]
The reason is considered as follows. That is, in the conventional V-ribbed belt, since the tilting direction of the aramid short fibers is one direction, the sliding resistance in a predetermined direction is stable, but the sliding resistance in the reverse direction is high. There was a tendency to become. Therefore, when the tension direction fluctuates from the one direction to the opposite direction, the sliding resistance greatly changes with respect to the minute tension fluctuation, and as a result, the tension fluctuation tends to increase. However, in the present V-ribbed belt 10, since the aramid short fibers 8, 8,... Are irregularly curved in multiple directions, there is little change in sliding resistance against minute tension fluctuations. Therefore, it is considered that the tension fluctuation is not increased and the tension ratio is stable.
[0048]
By the way, when the variation of the sliding resistance is large, a so-called belt noise is likely to occur. Therefore, a performance comparison test was also performed for the belt squeal at the time of starting using a belt in which aramid short fibers were bent in a certain direction as a conventional V-ribbed belt. Depending on the usage environment, it may be used with water or oil entering between the V-ribs and pulleys. Therefore, squeal is measured not only in the initial state of the belt but also during water injection. It was. As a result, as shown in FIG. 10, it was found that the squealing noise of the present V-ribbed belt 10 was much smaller than that of the conventional V-ribbed belt. The main reason for this is considered to be that there is little fluctuation in the tension ratio in the present V-ribbed belt 10 as described above.
[0049]
Further, in the conventional belt, the squealing noise is remarkably increased at the time of water injection, whereas in this V-ribbed belt 10, the squealing sound is very small even at the time of water injection. The reason is considered as follows. That is, in the present V-ribbed belt 10, the protruding portion 15 of the aramid short fiber 8 is formed in a curl shape and the root portion 12 stands up, so that the moisture on the side surface 11 of the V rib 7 is aramid short fiber 8. It becomes easy to flow through the gap between the root portions 12 of the. Therefore, moisture is unlikely to stay on the side surface 11 of the V rib 7 and is easily drained well. For this reason, it is considered that the generation of squealing is suppressed in the V-ribbed belt 10 even when moisture is mixed.
[0050]
-Modification-
The application target of the present invention is not limited to the V-ribbed belt 10 described above, and may be another type of V-ribbed belt. For example, a combined V-ribbed belt 10A as shown in FIG. 11 may be used .
[0051]
【The invention's effect】
As described above, according to the present invention, since the protruding portion of the short fiber is curved, it is possible to secure a large exposed area of the short fiber with respect to the surface of the V-rib , and to improve the wear resistance of the belt. Can do. Further, since the protrusion of the short fiber stands up from the surface of the V-ribs, it is possible to form a micro unevenness on the surface of the V-ribs, it is possible to effectively suppress the generation of abnormal noise. Further, by making the curved directions of the protruding portions of the respective short fibers different from each other, the V-rib of the belt exhibits equivalent side pressure resistance and wear resistance in any direction, and the belt Direction dependency can be eliminated. In addition, the short fiber has a restoring force like a leaf spring by forming the protruding portion of the short fiber so as to bend in one direction from the root toward the tip and then in a direction different from the direction. As a result, it is possible to effectively absorb the fluctuation in tension accompanying the running of the belt. Therefore, power can be transmitted stably. Further, the restoring force reduces the force applied to the root portion of the protruding portion of the short fiber, and prevents the short fiber from coming off from the V rib. Accordingly, the deterioration of the short fibers hardly occurs and the life of the belt is extended.
[0052]
By forming the protruding portion of the short fiber so that at least the tip thereof is flat, the surface area of the short fiber can be increased, and the wear resistance of the belt can be further improved.
[0053]
In addition, the surface area of the short fiber can be increased and the wear resistance of the belt can be improved by generating a tear at the tip of the protruding portion of the short fiber.
[0054]
The V-ribs mixed so that the short fibers are oriented in a predetermined direction are ground with a grindstone having superabrasive grains protruding from 50% to 95% of the abrasive grain diameter, so that the bond portion of the superabrasive grains and V it is possible to prevent contact between V rib ribbed belt, it is possible to suppress the generation of frictional heat. Also, the V-ribbed belt in which the short fibers is curved with rising from the surface of the V-ribs, can be easily manufactured.
[0055]
The V-ribs mixed so that the short fibers are oriented in a predetermined direction are ground with a grindstone having superabrasive grains with an abrasive density of 3.5% to 55%, thereby ensuring a large chip pocket for the abrasive grains. And clogging of grinding chips can be suppressed. Also, the V-ribbed belt in which the short fibers is curved with rising from the surface of the V-ribs, can be easily manufactured.
[0056]
V-ribs mixed so that the short fibers are oriented in a predetermined direction are ground by a grindstone having 50% to 95% of the abrasive grain diameter protruding and superabrasive grains having an abrasive grain density of 3.5% to 55%. By doing so, generation | occurrence | production of frictional heat can be suppressed and clogging of grinding chips can be suppressed. Also, the V-ribbed belt in which the short fibers is curved with rising from the surface of the V-ribs, can be easily manufactured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a V-ribbed belt according to the present invention.
FIG. 2 is a cross-sectional view of the vicinity of the surface of a V-rib.
FIG. 3 is a schematic view showing a protrusion of an aramid short fiber.
FIG. 4 is a schematic diagram showing a tip of a protrusion of an aramid short fiber.
FIG. 5 is a schematic diagram of a V-ribbed belt grinding apparatus.
6A is an enlarged plan view showing a part of the peripheral surface of the grinding wheel, and FIG. 6B is a cross-sectional view taken along line AA in FIG.
FIG. 7 is a schematic configuration diagram of a test apparatus for a performance comparison test.
FIG. 8 is a performance comparison diagram showing fluctuations in the tension ratio in the initial state.
FIG. 9 is a performance comparison diagram showing fluctuations in tension ratio after continuous running for 24 hours.
FIG. 10 is a performance comparison diagram related to squeal.
FIG. 11 is a cross-sectional view of a combined V-ribbed belt.
FIG. 12 is a view showing a protruding aspect of aramid short fibers of a conventional transmission belt.
[Explanation of symbols]
2 Tensile body
4 Adhesive rubber layer
7 V rib
8 Aramid short fibers
10 V-ribbed belt
11 Side (surface)
12 Root
13 Middle section
14 Tip
15 Protrusion
21 Whetstone
24 Super abrasive
25 grinding wheel
26 Bond Department

Claims (6)

V the short fiber group para-aramid fibers or meta-aramid fibers in a plurality of V-ribs are mixed so as to be oriented in a predetermined direction, a part of the short fiber group from the surface of said plurality of V-ribs protrude a ribbed belt,
The protruding portion of the short fiber stands up from the surface of the plurality of V ribs and is curled .
The protruding portions of the short fiber groups are different in the bending direction of the protruding portions of the respective short fibers so that the protruding directions are dispersed, and the protruding portions of the short fibers are once in one direction from the root toward the tip. V-ribbed belts from curved curved in different directions with the direction. Protrusion of the short fibers, V-ribbed belt according to claim 1, wherein at least the tip is flatly formed. Protrusion of the short fibers, V-ribbed belt according to claim 1 or 2 tear occurs in the tip. A method of manufacturing a V-ribbed belt according to any of claims 1 to 3,
The V-shaped ribs that are mixed as short fiber groups are oriented in a predetermined direction, the production of V-ribbed belt which contains a step of grinding by the grinding wheel having superabrasive grains 50% to 95% of the abrasive grain size is projected Method. A method of manufacturing a V-ribbed belt according to any of claims 1 to 3,
The V-shaped ribs that are mixed as short fiber groups are oriented in a predetermined direction, the production of V-ribbed belt which contains a step of grinding by the grinding wheel abrasive grains density has a superabrasive 3.5% to 55% Method. A method of manufacturing a V-ribbed belt according to any of claims 1 to 3,
V-ribs mixed so that the short fiber group is oriented in a predetermined direction are formed by a grindstone having 50% to 95% of the abrasive grain diameter protruding and superabrasive grains having an abrasive grain density of 3.5% to 55%. method for manufacturing a V-ribbed belt which contains grinding to process.

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