JP2000120801A - V-ribbed belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a V-ribbed belt capable of reducing vibration and noise and extending the belt life as restraining the belt from stretching and slipping and restraining slip noise during the operation of an automobile in the rain. SOLUTION: A V-ribbed belt 1 includes a twine core 4 of 4,000 to 8,000 total deniers of a polyester fiber filament group, whose main group unit is ethylene-2,6-naphthalate, twined together, a belt tensile elastic modulus of 22,000 to 30,000 N/ribs, and 5 to 20 pts.wt. of a cotton short fiber in a compressed part 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-ribbed belt, and more particularly to a V-ribbed belt which suppresses belt elongation and slip, reduces vibration and abnormal noise on the slack side, and further extends the life of the belt.

[0002]

2. Description of the Related Art 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 plurality of rib portions are provided below the cushion rubber layer. Is provided. The V-ribbed belt has been widely used in place of the V-belt for power transmission of a multi-shaft drive such as a water pump or a generator of an automobile. Conventionally, in order to efficiently transmit the power of the belt, it is necessary to reduce the slip ratio between the belt and the pulley, and the belt tension is increased to reduce the slip ratio. In addition, when the vehicle is running in the rain, water enters the engine room, water adheres between the belt and the pulley, and the belt slips, so that a slip noise is generated.

[0003] Furthermore, the current automobile is becoming quieter,
In particular, sounds other than engine sounds are regarded as abnormal sounds. Therefore, the belt tension is increased to reduce the slip ratio so that the belt noise caused by water does not occur even if water enters the engine room during traveling in rain.

[0004]

However, when the belt tension is increased, when the belt shrinkage stress during dry heating is increased, the belt dry heat shrinkage rate increases and the belt length shrinks with time. did. Further, in the conventional multi-axis drive device, a V-ribbed belt having a cord of polyethylene terephthalate fiber as a cord is suspended, and a belt separated from a pulley of a generator having a large rotational inertia generates a large inertia torque and power generation. It was instantaneously stretched to carry the torque, and caused abnormal noise due to the resonance phenomenon occurring between the pulleys on the slack side.

The present invention has been made to solve the above problems, and in order to cope with such problems, belt elongation and slip are suppressed to reduce vibration and abnormal noise on the slack side, and further extend the life of the belt. It is an object of the present invention to provide a V-ribbed belt capable of suppressing a slip noise even when a vehicle travels in the rain.

[0006]

That is, the invention according to claim 1 of the present application is directed to a cushion rubber layer in which a cord is buried along an extension portion and a belt longitudinal direction, and a peripheral portion of the belt adjacent to the cushion rubber layer. In a multi-shaft drive device in which a V-ribbed belt composed of a compression section having a plurality of ribs extending in a direction is suspended on a driving pulley and at least one driven pulley, the core of the V-ribbed belt is mainly ethylene-2,6-naphthalate. Total denier number of 4,000 to 8.0 obtained by twisting polyester fiber filaments as constituent units
And the belt has a tensile modulus of 17,000.
N / rib or more, and 5 to 5 cotton short fibers in the compressed part
V-ribbed belt containing 20 parts by weight.

According to the first aspect of the present invention, the V-ribbed belt has a cord having a total denier of 4,000 to 8,000 in which a polyester fiber filament group having ethylene-2,6-naphthalate as a main constituent unit is twisted. And the tensile elasticity of the belt is more than 17,000 N / rib, so it is possible to suppress the belt elongation and slip, reduce the vibration and abnormal noise on the slack side, and further extend the life of the belt. it can. Further, since the compression section contains 5 to 20 parts by weight of the cotton fiber, the cotton fiber absorbs moisture on the belt and prevents slippage due to the water.

According to the second aspect of the present invention, the belt has an initial load of 147 N and is left under an atmosphere of 100 ° C. for 30 minutes to have a shrinkage stress upon dry heating of the belt of 100 to 100.
V-ribbed belt which is 200N.

According to the second aspect of the present invention, the belt has 14
After the initial load of 7N was applied and the belt was left to stand in an atmosphere of 100 ° C. for 30 minutes, the shrinkage stress upon dry heating of the belt was 100 to 20.
Since the V-ribbed belt is 0N, the belt slip ratio can be reduced and the life of the belt can be extended.

[0010]

FIG. 1 is a sectional perspective view showing a V-ribbed belt according to the present invention. In FIG. 1, a V-ribbed belt 1 is composed of an extension portion 2 made of a cover canvas 3, a cushion rubber layer 5 in which a cord 4 made of a cord is embedded, and a compression portion 6 which is an elastic layer below the cushion rubber layer 5. . The compression section 6 has a plurality of trapezoidal ribs 7 extending in the belt longitudinal direction and having a substantially triangular cross section.

The ribs 7 include hydrogenated nitrile rubber, chloroprene rubber, natural rubber, CSM, ACSM, SBR
The hydrogenated nitrile rubber has a hydrogenation rate of 80% or more, and preferably 90% or more in order to exhibit heat resistance and ozone resistance characteristics. A hydrogenated nitrile rubber having a hydrogenation rate of less than 80% has extremely low heat resistance and ozone resistance. In consideration of oil resistance and cold resistance, the amount of bound acrylonitrile is preferably in the range of 20 to 45%.

The ribs 7 are mixed with short fibers made of cotton to improve the lateral pressure resistance of the ribs 7, and the short fibers protrude from the surface of the ribs 7 which come into contact with the pulleys. Reduce the coefficient of friction to reduce noise during belt running. Further, short cotton fibers are projected from the surface of the rib 7 to absorb water adhering to the surface of the rib 7. Short fibers include nylon 6, nylon 66, polyester, and aramid fibers in addition to cotton. Cotton, which absorbs moisture most easily, is most suitable. The short cotton fiber is added in an amount of 5 to 20 parts by weight based on 100 parts by weight of the rubber. If the added amount of the short cotton fiber is less than 5 parts by weight, there is no water absorbing effect, and the water adhering to the surface of the rib 7 cannot be sufficiently absorbed. On the other hand, if the added amount of the cotton short fiber exceeds 20 parts by weight, the short fiber will not be uniformly dispersed in the rubber.

In order to improve the adhesion of the ribs 7 to the rubber, the cotton short fibers are subjected to an adhesion treatment with a treatment liquid selected from an epoxy compound and an isocyanate compound.

The above-mentioned core wire 4 is made of ethylene-
Adhesive-treated cords having a total denier of 4,000 to 8,000 obtained by twisting polyester fiber filaments having 2,6-naphthalate as a main constituent unit are used. The number of twists of this cord is 10 to 23/10 cm, and the number of twists is 17 to 38/10 cm. When the total denier is less than 4,000, the modulus and strength of the cord become too low, and when it exceeds 8,000,
The thickness of the belt is increased, and the bending fatigue is deteriorated.

The ethylene-2,6-naphthalate used in the present invention is usually prepared by condensation polymerization of naphthalene-2,6-dicarboxylic acid or an ester-forming derivative thereof with ethylene glycol in the presence of a catalyst under appropriate conditions. To be synthesized. At this time, if one or more appropriate third components are added before the completion of the polymerization of ethylene-2,6-naphthalate, a copolymer polyester is synthesized.

The bonding process of the cord 4 is carried out by (1) impregnating the untreated cord into a tank containing a treatment liquid selected from an epoxy compound and an isocyanate compound and pre-dipping it; Drying by passing through a drying oven set to a temperature of 30 ° C. for 30 to 600 seconds.
Immerse in the tank containing the adhesive liquid consisting of L liquid, (4) 2
3 to the stretching heat setting processor set at 10-260 ° C
It is stretched for -1 to 3% through 0 to 600 seconds to obtain a stretched cord.

Examples of the epoxy compound include polyhydric alcohols such as ethylene glycol, glycerin, and pentaerythritol; reaction products of polyalkylene glycols such as polyethylene glycol with halogen-containing epoxy compounds such as epichlorohydrin; (4-hydroxyphenyl) dimethylmethane,
It is a reaction product with polyhydric phenols such as phenol-formaldehyde resin and resorcin-formaldehyde resin and halogen-containing epoxy compounds. This epoxy compound is used by being mixed with an organic solvent such as toluene and methyl ethyl ketone.

The RFL solution is obtained by mixing a latex with an initial condensate of resorcinol and formalin, and the latex used here includes chloroprene, styrene / butadiene / vinylpyridine terpolymer, hydrogenated nitrile, NBR, etc. It is.

The cord subjected to the stretching heat setting treatment has a spinning pitch, that is, a core winding pitch of 1.0 to 1.0 mm.
By setting the thickness to 1.3 mm, a belt having a high modulus can be finished. If it is less than 1.0 mm, the cord cannot ride on the adjacent cord and cannot be wound,
On the other hand, if it exceeds 1.3 mm, the modulus of the belt gradually decreases.

The cover canvas 3 is a cloth woven in a plain weave, a twill weave, a satin weave, or the like using a yarn made of cotton, polyamide, polyethylene terephthalate, and aramid fiber.

The V-ribbed belt using the core 4 has a tensile modulus of at least 17,000 N / rib, preferably 2
2,000 to 33,000 N / rib, and with such a tensile modulus, even if there is a torque fluctuation in the drive shaft, the belt expands due to the belt tension fluctuation, and in this state, it has a large rotational inertia. Even if the V-ribbed belt follows the generator 13, the V-ribbed belt does not expand rapidly, and vibration and abnormal noise on the slack side are reduced.

Furthermore, an initial load of 147N is applied to the belt,
To give a characteristic that the belt has a shrinkage stress on dry heat generated after being left for 30 minutes in an atmosphere of 100 ° C for 100 to 200 N, the V-ribbed belt 1 has a small belt slip ratio and a long belt life. Was completed. If the shrinkage stress during dry heating of the belt is less than 100 N, the belt tends to stretch easily, the belt tension is greatly reduced, and the slip ratio tends to increase. When the belt shrinkage stress during dry heating exceeds 200 N, the belt length tends to shrink with time, and the effect of reducing the slip ratio is small.

When the aramid fiber is used, the modulus of the belt can be increased. However, since there is no heat shrinkage, a separate auto tensioner is required, and there is a disadvantage that the transmission mechanism becomes complicated. However, ethylene-2,6
-A core wire using a polyester fiber whose main constituent unit is naphthalate causes heat shrinkage, so that an auto tensioner may not be used.

[0024]

The present invention will be described below in more detail with reference to specific examples. Examples 1 to 3 and Comparative Examples 1 and 2 1000 denier ethylene-2,6-naphthalate fiber (PEN fiber), 1000 denier and 1
100 denier polyethylene naphthalate fiber (PE
T fiber) in a 2 × 3 twist configuration, with a top twist coefficient of 3.0 and a lower twist coefficient of 3.0 and twisted in a multi-twist to form a total denier of 60.
00 or 6600 raw code was prepared. The properties are shown in Table 1.

[0025]

[Table 1]

Next, each treatment code was pre-dipped into 90 g of toluene with an adhesive consisting of 10 g of PAPI (a polyisocyanate compound manufactured by Kasei Upjohn Co., Ltd.), and then placed in a drying oven set at a temperature of about 170 to 190 ° C. 3
It was dried by passing through for 00 seconds, then impregnated with an adhesive composed of an RFL solution shown in Table 2, and subjected to a hot stretch fixing treatment under the treatment conditions shown in Table 3 to obtain a treated code.

[0027]

[Table 2]

[0028]

[Table 3]

The method of manufacturing the V-ribbed belt in this embodiment is as follows. First, a single ply of rubberized canvas in which chloroprene rubber was frictionally wound on a plain woven fabric in which the warp and the weft are cotton yarns was wound around a cylindrical mold.
An adhesive rubber sheet composed of a chloroprene rubber composition shown in Table 4 was wound, the above cord was spun thereon, and a rubber layer composed of a chloroprene rubber composition shown in Table 4 was wound to complete molding. 160 ° by a known method
C, vulcanized for 30 minutes to obtain a cylindrical vulcanized rubber sleeve.

The above-described vulcanized rubber sleeve was mounted on a driving roll and a driven roll of a polishing machine, and was rotated after applying tension. A polishing wheel having a 150-mesh diamond mounted on its surface was rotated at 1600 rpm, and this was brought into contact with a vulcanization sleeve to polish a rib portion. After the sleeve taken out of the polishing machine was set on the cutting machine, it was cut while rotating.

In the produced V-ribbed belt, the cords made of the above-mentioned stretch-fixed cords are embedded in the cushion rubber layer, and a cotton sail cloth with rubber is laminated one ply on the upper side, and on the other side under the cushion rubber layer. There was a compression section and three ribs were in the longitudinal direction of the belt. This V-ribbed belt is a K-type 3-ribbed belt having a length of 1100 mm according to the RMA standard, a rib pitch of 3.56 mm, and a rib height of 2.9 m.
m, rib angle 40 °, and various belt lengths.

Here, the compression part and the cushion rubber layer are
Each was prepared from the rubber compositions shown in Table 4, kneaded with a Banbury mixer, and then rolled with a calender. The compression section contains short fibers and is oriented in the belt width direction. In addition, the short fibers were previously prepared by adding PAPI to 90 g of toluene.
(Polyiacyanate compound manufactured by Kasei Upjohn)
It was immersed in a processing solution consisting of 10 g.

[0033]

[Table 4]

Next, the static performance of the cord and the V-ribbed belt was evaluated. Table 5 shows the results.
In addition, the test method of a cord and a belt is as follows.

Cord strength The cord strength was determined based on JIS L-1071 (1983).

The dry heat shrinkage of the cord is 150 based on JIS L-1071 (1983).
The temperature was determined by standing at an ambient temperature of 30 ° C. for 30 minutes.

The cord was subjected to an initial load of 25 g / d of shrinkage stress upon dry heating, and left standing in an atmosphere of 150 ° C. for 8 minutes.

(4) Tensile Modulus of Belt The belt was wound around two grooved pulleys, and one of the pulleys was pulled at a speed of 50 mm / min to measure the moving distance and load of the pulley. ).

Subsequently, the V-ribbed belt is formed into a three-shaft comprising a driving pulley (140 mm in diameter) shown in FIG. 2, a driven pulley (55 mm in diameter) provided on a generator, and a driven pulley (150 mm in diameter) provided on an air compressor. A belt is hung on the pulley, a tension pulley (diameter: 85 mm) is brought into contact between a driven pulley provided on the generator and a driven pulley provided on the air compressor, and the tension pulley is adjusted to apply a tension of 390N to the belt. Gave. The running conditions are as follows: ambient temperature is room temperature, drive pulley rotation speed is 10
00 rpm, angular velocity fluctuation 1.0 deg. The load on the driven pulley (55 mm in diameter) is 1.9 kw.

First, a sound test was performed using this driving device. Table 5 shows the tension at which sound was generated by gradually lowering the tension as the sound generation limit tension.

[0041]

[Table 5]

It can be seen from Table 5 that the V-ribbed belt of the present invention has a lower sounding limit tension than the conventional belt.

Next, the embodiment and the comparative example 1 were carried out using an actual engine.
The speed fluctuation was examined with the belt of No. 1. The engine speed at this time was 650 rpm. As a measurement, the speed fluctuation of only the pulley and the behavior of the belt in comparison with the speed fluctuation of the pulley were investigated. The results at this time are shown in FIGS.

From FIGS. 3 and 4, the belt of the embodiment draws the same curve as the speed fluctuation of the pulley, whereas the belt of the comparative example of FIG. This is what is called, and causes a slight difference between the pulley speed fluctuation and the slight slip. This minute slip causes sound generation. Therefore, in the embodiment, it is considered that the minute slip which is a factor of sound generation does not occur.

[0045]

As described above, according to the first aspect of the present invention, the core of the V-ribbed belt has a total denier of twisted polyester fiber filaments mainly composed of ethylene-2,6-naphthalate. 4,000 ~
It has 8,000 twisted yarns, and the tensile modulus of the belt is 17,
Since it is 000 N / rib or more, there is an effect that the elongation and slip of the belt are suppressed, vibration and abnormal noise on the slack side are reduced, and the belt life can be further extended. In addition, since the compression section contains 5 to 20 parts by weight of cotton fiber, the cotton fiber has an effect of absorbing water on the belt and preventing slippage due to water.

According to the second aspect of the present invention, the belt has an initial load of 147 N and is left under an atmosphere of 100 ° C. for 30 minutes to have a shrinkage stress upon dry heating of the belt of 100 to 100.
Since the V-ribbed belt is 200 N, there is an effect that the belt slip ratio can be reduced and the life of the belt can be extended.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a V-ribbed belt of the present invention.

FIG. 2 is a schematic diagram showing a driving device using the V-ribbed belt of the present invention.

FIG. 3 is a diagram illustrating a speed variation of a pulley and a speed variation of a belt according to the embodiment.

FIG. 4 is a diagram showing a variation in pulley speed and a variation in belt speed according to Comparative Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 V-ribbed belt 2 Extension part 3 Cover canvas 4 Core wire 5 Cushion rubber layer 6 Compression part 7 Rib 10 Multi-axis drive device 11 Drive shaft 12 Follower shaft 14 Follower shaft 16 Drive pulley 17 Follower pulley 18 Follower pulley

Claims (2)

[Claims] 1. A V-ribbed belt comprising a stretching portion, a cushion rubber layer having a cord embedded in a longitudinal direction of the belt, and a compression portion having a plurality of ribs extending in the circumferential direction of the belt adjacent to the cushion rubber layer. In a drive pulley and a multi-axis drive suspended on at least one driven pulley,
The core of the V-ribbed belt is formed by twisting polyester fiber filaments having ethylene-2,6-naphthalate as a main constituent unit in a total denier of 4,000 to 8,
2,000 twisted yarns, and the belt has a tensile modulus of 17,00.
0N / rib or more, and 5 cotton short fibers
A V-ribbed belt containing up to 20 parts by weight. 2. An initial load of 147 N is applied to the belt,
2. The V-ribbed belt according to claim 1, wherein the belt has a dry heat shrinkage stress of 100 to 200 N after being left for 30 minutes in an atmosphere of 0 ° C. 3.