JP3126931B2 - Method for producing short fiber for reinforcing power transmission belt and power transmission belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a short fiber for reinforcing a power transmission belt and a power transmission belt, and more particularly to a reinforcement added to a rubber friction transmission portion of a power transmission belt such as a V-ribbed belt or a low-edge belt. TECHNICAL FIELD The present invention relates to a method for producing a reinforcing short fiber including a power transmission belt including a power transmission belt having excellent dispersibility in rubber and further improving the running life of the belt, and a power transmission belt.

[0002]

2. Description of the Related Art Among power transmission belts, a V-ribbed belt has a core wire buried in a cushion rubber layer, a cover canvas is laminated on the upper portion of the cushion rubber layer as required, and a lower portion of the cushion rubber layer. And a plurality of ribs serving as frictional transmission parts, and has a power transmission force superior to other V-belts by an increase in the contact area with the pulley due to the presence of the V-shaped ribs. V-ribbed belts have been widely used in place of V-belts to transmit power for driving auxiliary equipment such as air compressors and alternators for automobiles. Recently, pulley diameters have been reduced due to downsizing of engine rooms and weight reduction of engines. , And serpentine drive is being pursued.

[0003] Further, the V-ribbed belt is rich in bending fatigue due to its shape, and can provide high output. Therefore, it is used for small pulley diameters and for high-speed rotation. ing. Recently, 1,1,1,2-tetrafluoroethane is being studied as a substitute for Freon (dichlorofluoromethane), which has been conventionally used in air compressors, because of the problem of environmental destruction. For this reason, compared to conventional Freon,
Same temperature only to cool the must to increase the compressive force and thus torque is increased when operating the air compressor, which had an adverse effect on the V-ribbed belt. For example, the V-ribbed belt used must endure a higher load, and it is necessary to prevent instantaneous slipping of the belt during operation.

[0004] In order to solve these problems, for example, Japanese Patent Publication No. Hei 6-21607 or Japanese Patent Application Laid-Open No. Sho 62-113 has been proposed.
No. 940 discloses that aramid short fibers embedded in a compression rubber layer of a belt are made to protrude from the surface of a rib portion, or are protruded and bent to thereby provide wear resistance, lateral pressure resistance, and sound suppression. A power transmission belt has been proposed. Japanese Patent Application Laid-Open No. 4-36645 also discloses that aramid short fibers and nylon short fibers are used in a compressed rubber layer to stabilize a coefficient of friction to improve noise. Furthermore, Japanese Patent Publication No. 7-117124
The gazette also describes that the use of aramid short fibers and nylon short fibers allows only the aramid short fibers to protrude from the side of the belt, thereby suppressing the amount of sticky sound generated at the initial stage of belt attachment.

[0005]

However, when the aramid short fibers embedded in the compression rubber layer of the belt are protruded from the surface of the rib portion or are bent by protruding, the rigidity of the aramid fibers is too high. , ear at the time of belt running
Disturbing rubbing sound was sometimes generated, but what became more problematic was the poor dispersibility of nylon short fibers,
The location where the short fibers were aggregated was subjected to stress concentration and became small nuclei of cracks.

One of the causes is a method for producing nylon short fibers. In the manufacturing method of the conventional nylon short fibers, in order to use the Sudare for tires using cotton woven as thread connecting warp threads of polyamide fibers which are arranged at predetermined intervals, to cut this in the direction of the yarn joint, resulting A long cotton yarn not cut to a predetermined length was mixed in the obtained nylon short fiber group. When such a nylon short fiber group is kneaded with rubber, the cotton yarn has poor dispersibility compared to nylon, and the cut length is longer than nylon. Was awake. When this short fiber rubber composite is used for the compression rubber layer of a V-ribbed belt, the poor dispersion region becomes a nucleus of a crack, and a crack is generated at an early stage to shorten the belt life.

The present invention has been made to solve the above-mentioned conventional problems, and provides a method for producing a short fiber for reinforcing a power transmission belt, which has excellent dispersibility in rubber and further improves the running life of the belt. It is an object of the present invention to provide a power transmission belt using the reinforcing short fibers.

[0008]

In order to achieve the above object, a method of manufacturing a short fiber for reinforcing a power transmission belt and a V-ribbed belt for a power transmission belt according to the present invention are characterized in that a V-shaped groove of a pulley group is provided. After mating and hanging the belt,
A method of manufacturing a reinforcing short fiber added to a rubber friction transmission portion of a power transmission belt to be used by moving at least one pulley to apply a necessary initial tension to the belt and thereafter fixing the pulley. A power transmission for processing a Sudare weave made of a weft made of a polyamide fiber which is a joining yarn of a warp made of a polyamide fiber arranged at a predetermined interval with a resorcinol-formalin-latex liquid, and cutting this at a predetermined interval in the direction of the weft; In the method of manufacturing short fibers for belt reinforcement, since polyamide fibers are used for both the warp and the weft as the connecting yarn, no foreign material is mixed in the cut nylon short fibers group, Even when this is kneaded with rubber, it can be uniformly dispersed. Therefore, the power transmission belt using the reinforcing short fibers is less likely to cause crack nuclei due to poor dispersion of the short fibers,
The running life of the belt is further improved.

In the invention according to claim 2 of the present application, after engaging with the V-shaped groove of the pulley group and hanging the belt, at least one pulley is moved to apply a necessary initial tension to the belt, Then, in a rubber friction transmission portion of the power transmission belt to be used in a manner of fixing the pulley, a resorcinol-formaln-woven sudale weave made of a weft composed of a polyamide fiber serving as a connecting yarn with a warp composed of a polyamide fiber arranged at a predetermined interval. This is a power transmission belt in which short fibers including polyamide short fibers obtained by treating with a latex liquid and cutting the same at predetermined intervals in the direction of the weft are arranged in the belt width direction, and the reinforcing short fibers are used. The power transmission belt is also less likely to generate crack nuclei due to poor dispersion of short fibers, and the running life of the belt is further improved.

According to the third aspect of the present invention, since aramid short fibers are contained in addition to the polyamide short fibers, in addition to the second aspect of the invention, the amount of generation of adhesive sound at the initial stage of belt attachment is reduced. it can be suppressed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view of a Sudare weave used in the present invention, and FIG. 2 is a view showing a step of cutting a bundle of Sudare weave after adhesion processing. The sudare weave 1 used in the present invention is a joining yarn of a warp yarn 2 obtained by twisting filaments of polyamide fibers such as 6 nylon, 6.6 nylon, 6.10 nylon, 6.4 nylon and 11 nylon arranged at predetermined intervals. 6 nylon,
6 nylon, 6.10 nylon, 6.4 nylon, 11
It is woven with a weft 3 obtained by twisting filaments of polyamide fiber such as nylon. Since the weft yarn 3 is a joining yarn, the weft yarn 3 is thinner and more flexible than the warp yarn 2, and the arrangement interval is large. In addition, the warp yarn 2 and the weft yarn 3 may be the same type or different types of polyamide fibers.

[0012] Specifically, the warp density is 30 to 70 (filaments /
5 cm), and the weft density is 1 to 10 (lines / 5 cm). Further, the warp yarn 2 is a multifilament having a denier of 800 to 1500 and a twist number of 0 (no twist) to 60 (twice / 1).
0 cm) is a cord obtained by collecting 1 to 4 strands twisted together and twisting them with a twist number of 2 to 60 (twice / 10 cm). On the other hand, the weft 3 is obtained by twisting a multifilament of 2 to 1000 deniers with a twist number of 2 to 60 (twice / 10 cm). Needless to say, the weft 3 is 20 to 100 like the warp 2.
Two to ten multifilaments of 0 denier may be twisted or single twisted.

The above-mentioned Sudare weave 1 is subjected to a bonding treatment with a resorcin-formalun-latex liquid (RFL liquid) by a usual method. The RFL solution is obtained by mixing a latex with an initial condensate of resorcinol and formalin, and in this case, the molar ratio of resorcinol to formalin is 1: 0.5 to 3
It is. In addition, the initial condensate of resorcinol and formalin is mixed with latex such that the resin content is 2 to 30 parts by weight with respect to 100 parts by weight of the rubber content of the latex, and the total solid concentration is 5 to 40 parts by weight. Adjusted to% concentration. The latex used here is chloroprene,
Styrene-butadiene-bunylpyridine terpolymer,
Hydrogenated nitrile, chlorosulfonated polyethylene, S
BR, NBR, HNBR and the like.

After the adhesive-treated weave 1 is wound in the direction of the weft 3 (in the direction of the arrow in the drawing) or is bundled by stacking a plurality of the same, the cutter 5 cuts the bundle 6 in the direction of the weft 3. And cut at predetermined intervals to produce nylon short fibers. The cutting length of the nylon short fiber is 2 to 10 mm. If it exceeds 10 mm, the fibers are entangled with each other, or the orientation in the rubber becomes difficult, and the flexibility of the power transmission belt is impaired. On the other hand, if it is less than 2 mm, the reinforcing effect of the rubber friction transmission portion of the power transmission belt is poor, and there is a fear that the fibers themselves may fall off the side surface of the belt when the pulley is fitted with the V-shaped groove.

The above-mentioned nylon short fiber group is used for producing a rubber friction transmission portion of a power transmission belt, such as chloroprene rubber, hydrogenated nitrile rubber, natural rubber, CSM and ACS.
M, SBR, etc. are added to the rubber. This addition method is usually performed by a roll, and the short fibers are arranged in a certain direction. However, since there is no foreign matter in the nylon short fiber group, the dispersion in the rubber becomes uniform.

FIG. 3 is a sectional perspective view of a V-ribbed belt using the above nylon short fibers. In the V-ribbed belt 10, a cord made of polyester, nylon, aramid fiber, or the like is used along the belt length direction in an adhesive rubber layer 11 made of chloroprene rubber, hydrogenated nitrile rubber, natural rubber, CSM, ACSM, SBR, or the like. Become a core wire 1
2 is formed, and the tensile body layer 1 is embedded.
At least one layer of the canvas 15 with rubber woven with cotton yarn or a blend yarn of cotton and synthetic fiber is laminated on the upper surface of 4 to form an extension layer 16.

On the other hand, on the lower surface of the tensile member layer 14, a friction transmission portion 17 made of rubber of the same material as the adhesive rubber layer 11 is formed. More specifically, a plurality of V-shaped extending members extending in the belt length direction are formed. The rib 18 is formed.

Nylon short fibers 19 which are a feature of the present invention are embedded in the rib portions 18 while maintaining the orientation in the belt width direction. That is, short fibers cut to 2 to 10 mm are mixed in 5 to 25 parts by weight, preferably 8 to 15 parts by weight with respect to 100 parts by weight of rubber. In addition, para-aramid fibers (polyparaphenylene terephthalamide) such as Twaron and Kevlar may be embedded in addition to the nylon short fibers 19 and arranged in the width direction of the belt. The mixing ratio of the nylon short fiber and the para-aramid fiber is in the range of 0.2 to 1 times the para-aramid fiber to 1 nylon short fiber.

When the mixing amount of para-aramid fibers is less than 5 parts by weight with respect to 100 parts by weight of rubber, there is no problem in the durability of the belt, but the amount of short fibers protruding is reduced, and particularly the setting of the belt When the belt is run under the condition that the tension is increased, the frictional force of the rib surface 9 does not decrease, the adhesive easily sticks, and a sufficient effect on sound generation cannot be exerted. On the other hand, if the mixing amount of the short fibers exceeds 25 parts by weight, there is an effect on water injection resistance and sound generation during belt running under high tension, but the rigidity of the aramid fibers is too high, and the interface between the fibers and the rubber is high. This causes a problem that peeling occurs and leads to early cracking.

The method for polishing the rib 7 is 80 to 200.
A polishing wheel having a mesh diamond mounted on its surface is rotated, and this is brought into contact with the rotating vulcanization sleeve to form a rib shape. This para-aramid fiber has a length of 2 to 6 mm and a monofilament diameter of 9 to 18 μm. By polishing using the polishing wheel, the filaments of para-aramid fibers protruding from the rib surface 9 are fibrillated and divided into small fibers having smaller diameters. The fibrillated fiber 10 has a thickness of 1/2 to 1/8 of the filament embedded in the rubber, and at least a part of the fibril is curled. The fibrillated fibers 10 protruding from the rib surface 9 reduce the frictional force between the rib surface and the pulley, and prevent the rubber from sticking and abrasion, thereby preventing the sound due to slip. When the meta-aramid fiber is used, no fibrillation phenomenon is observed.

Further, the rubber composition of the friction transmission portion 17 includes:
In addition, carbon black is contained in an amount of 30 to 70 parts by weight with respect to 100 parts by weight of rubber to improve abrasion resistance and prevent adhesion. In addition, it contains a vulcanization accelerator, an antioxidant, a vulcanizing agent and the like. There is no particular limitation on the method for mixing the above components, and for example, kneading can be appropriately performed by a known means and method using a Banbury mixer, a kneader, or the like.

An example of a method for manufacturing a V-ribbed belt is as follows. First, after winding one or a plurality of cover canvases and a cushion rubber layer around the peripheral surface of a cylindrical forming drum, a core wire made of a rope is spirally spun on this, and further corresponds to a friction transmission portion. After a rubber layer is sequentially wound to obtain a laminate, it is vulcanized to obtain a vulcanized sleeve.
Next, the vulcanization sleeve is hung between the drive roll and the driven roll, and is run under a predetermined tension, and the rotated grinding wheel is moved so as to abut the running vulcanization sleeve to compress the vulcanization sleeve. A plurality of 3 to 100 groove portions are polished at once on the surface of the rubber layer.

[0023]

The present invention will be described in more detail with reference to the following examples. Example 1, Comparative Example 1 (Preparation of Nylon Short Fiber) 6.6 Nylon Sudare Weave shown in Table 1 was prepared. Next, after immersing the nylon woven fabric in the RFL solution shown in Table 2, it was heat-treated at 200 ° C. for 2 minutes. After several bundles of the treated nylon weave were stacked to form a bundle, this was cut to a length of 6 mm along the arrangement direction of the wefts with a cutter to produce nylon short fibers. Thereafter, a rubber composite containing short fibers (corresponding to the rubber composition of the rib portion of the V-ribbed belt) having the composition shown in Table 3 was produced. The TB ratio of this rubber composite was evaluated. Table 4 shows the results.

The tensile strength ratio (TB ratio) refers to JIS K63
01, the tensile strength (TB _a ) of the short fibers in the rolled rubber and the tensile strength (TB _b ) in the direction perpendicular thereto.
And the ratio (TB _a / TB _b ) was determined.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

Example 2 and Comparative Example 2 (Method of Manufacturing V-ribbed Belt) One ply of a rubber-made canvas 4 in which chloroprene rubber was frictioned on a plain woven fabric composed of cotton yarns of warp and weft was wound around a cylindrical mold, and then chloroprene rubber was wound. An adhesive rubber sheet made of the composition is wound, and a cord (11,000 d2 × 3) made of polyester fiber is further spun thereon.
Then, the rubber composite containing short fibers shown in Table 3 was wound and completed. The obtained molded body is 160 ° C by a known method,
Vulcanization was performed for 30 minutes to obtain a cylindrical vulcanized rubber sleeve.

The vulcanized rubber sleeve extracted from the cylindrical mold is mounted on a driving roll and a driven roll of a polishing machine.
It was rotated after applying tension. 160 using a grinding wheel with 150 mesh diamond on the surface
The rib was rotated at 0 rpm and brought into contact with a vulcanizing sleeve to polish the 80 ribs. After the sleeve taken out of the grinder was placed in a cutter, the sleeve was cut while rotating to obtain a 3PK900 V-ribbed belt having three ribs.
Table 4 shows the number of short fiber masses of the V-ribbed belt thus obtained and the results of the heat resistance running test. The results are shown in Table 4 below.

The number of short fiber lumps was determined by counting the number of short fiber lumps having a diameter of 1 mm or more in 20 V-ribbed belts produced and calculating the average number of short fiber lumps per belt.

[0031] The heat-resistant running test means that the running machine is a driving pulley (120 mm in diameter) and a driven pulley (85 m in diameter).
m), which is arranged in combination with a tension pulley (diameter: 45 mm). A belt is hung on each pulley of the traveling machine, the ambient temperature is 85 ° C., the number of rotations of the driving pulley is 4900 rpm, and the load of the driven pulley is 12 horsepower.
The tension pulley was caused to travel with an initial tension of 85 kgf, and the time until cracks occurred in the ribs was measured.

[0032]

[Table 4]

As is clear from the results in Table 4, the tensile strength ratio of the example is larger than that of the comparative example.
Since the number of short fiber masses of 1 mm or more is also zero, it is understood that the dispersibility of nylon short fibers in rubber is excellent, and the running life of a belt using the same is also improved.

[0034]

As described above, according to the first aspect of the present invention, there is provided a method for producing a reinforcing short fiber to be added to a rubber friction transmission portion of a power transmission belt. Production of short fibers for power transmission belt reinforcement, in which a sudare weave made by weaving a warp made of fibers with a weft made of a polyamide fiber, which is a joining yarn, is treated with a resorcinol-formalin-latex solution and cut at predetermined intervals in the direction of the weft. In the method, since polyamide fiber is used for both the warp and the weft which is the joining yarn, no foreign material is mixed in the cut nylon short fiber group, and this is kneaded with rubber. Even in this case, the particles can be uniformly dispersed. Therefore, the power transmission belt using the reinforcing short fibers is less likely to cause crack nuclei due to poor dispersion of the short fibers, and has an effect of further improving the running life of the belt.

According to the invention described in claim 2 of the present application, in a rubber friction transmission portion of the power transmission belt, a ward weave made of a polyamide fiber which is a connecting yarn with a warp made of a polyamide fiber arranged at a predetermined interval is used. Is treated with a resorcinol-formalin-latex liquid, and cut at predetermined intervals in the direction of the weft to form a power transmission belt in which short fibers including polyamide short fibers are arranged in the belt width direction. In a power transmission belt using short fibers for use, crack nuclei due to poor dispersion of short fibers are less likely to occur, and the running life of the belt is further improved.

In the invention of claim 3 of the present application, since aramid short fibers are contained in addition to the polyamide short fibers, in addition to the invention of claim 2, the amount of generation of adhesive sound at the initial stage of belt attachment is reduced. There is an effect that can be suppressed.

[Brief description of the drawings]

FIG. 1 is a plan view of a Sudare weave used in the present invention.

FIG. 2 is a view showing a step of cutting a bundle of the Sudare weave after the adhesive treatment.

FIG. 3 is a longitudinal sectional view of a V-ribbed belt according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sumire weave 2 Warp 3 Weft 10 V ribbed belt 11 Adhesive rubber layer 12 Core wire 14 Tensile layer 15 Rubberized canvas 17 Friction transmission part 18 Rib part 19 Nylon short fiber

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-53552 (JP, A) JP-A-7-63242 (JP, A) JP-A-3-287827 (JP, A) JP-A-7-78 118979 (JP, A) JP 44-27460 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16G 1/00-5/20 D01G 1/00-37/00 D06M 13/00-15/72 C08J 5/04-5/24

Claims (3)

(57) [Claims] 1. After fitting a V-shaped groove of a group of pulleys and hanging a belt, at least one pulley is moved to give a necessary initial tension to the belt, and then used in a method of fixing the pulley. This is a method of manufacturing reinforcing short fibers to be added to the rubber friction transmission portion of the power transmission belt, and a sudare weave woven with a weft made of polyamide fibers, which is a connecting yarn of a warp made of polyamide fibers arranged at predetermined intervals. A method for producing short fibers for reinforcing a power transmission belt, comprising treating with a resorcinol-formalin-latex liquid and cutting the liquid at predetermined intervals in the direction of the weft. 2. After engaging with the V-shaped groove of the pulley group and hanging the belt, at least one pulley is moved to give a necessary initial tension to the belt, and then the pulley is used in a fixed manner. In a rubber friction transmission portion of a power transmission belt, a sudare weave made of polyamide fibers which are continuous yarns and woven with a weft composed of polyamide fibers, which are arranged at predetermined intervals, is treated with a resorcinol-formalun-latex liquid, and the weft is subjected to treatment. power transmission belt of the short fibers containing polyamide short fibers obtained by cutting at predetermined intervals in a direction, characterized in that are arranged in the belt width direction. 3. The power transmission belt according to claim 2, further comprising aramid short fibers in addition to the polyamide short fibers.