JP2006266378A - Power transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission belt such as a V-ribbed belt and a low edge V belt capable of reducing deviated motion on one side caused when a rear surface of the belt is abutted on and engaged with an idler pulley and preventing occurrence of abnormal sound. <P>SOLUTION: This power transmission belt 1 is constituted by burying a core wire 2 into a bonded rubber layer 3 along the longitudinal direction of the belt, arranging a compressed rubber layer 4 adjacent to the bonded rubber layer 3, and laminating at least the rear surface 6 of the belt by a sail cloth 5. A connection line 13 for connecting each crossing point 12 of a weft 10 and a warp 11 of the sail cloth 5 is inclined for an axial line 15 in the longitudinal direction of the belt, and the direction of the inclination of the connection line 13 is the same direction as the direction of final twisting of the core wire 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission belt. More specifically, in a power transmission belt such as a V-ribbed belt or a low-edge V-belt, when the belt back is in contact with and engaged with an idler pulley, the belt is moved straight without causing a deviation. The present invention relates to a power transmission belt that fits into the next pool and reduces abnormal noise.

  In Patent Document 1, a compressed rubber layer extending in parallel to the belt longitudinal direction and having a plurality of ribs in a parallel state, an adhesive rubber layer in which a cord made of a cord is embedded in the upper part, and a sewing machine joint on the back surface A V-ribbed belt having a configuration in which the canvas is adhered is disclosed. This canvas is originally provided in order to maintain the longitudinal crack resistance of the belt, and is a plain woven fabric in which warp and weft are woven and rubberized.

  Conventionally, a woven fabric widely used as a back canvas of a V-ribbed belt is a mechanically wide-angle treatment of a plain woven canvas with a warp and weft crossing angle of 90 degrees, that is, a tenter treatment, and both yarns in the longitudinal direction of the belt. On the other hand, there is a wide angle processed crossing at 120 degrees. The basic structure of this canvas is a canvas in which the number of warps and wefts is 10 or more / 10 mm for both the warp and the weft, and the single yarn tensile force is 9 N or more / the plain fabric is forced with a spun yarn of 100% cotton fiber yarn. In addition, the wide angle process, that is, the tenter process, makes the number of driving with the belt 14 or more / 10 mm for both the warp and the weft.

  These canvases are immersed in resorcin-formaldehyde-latex liquid (RFL liquid) and then subjected to friction by rubbing unvulcanized rubber into the canvas, or immersed in RFL liquid and then immersed in a soaking solution in which the rubber is dissolved in a solvent. As a result, the adhesion to the rubber layer was improved.

Further, in Patent Document 2, the joint line of the back canvas of the V-ribbed belt extends in a direction perpendicular to the belt length direction, and the ends of the canvas abut each other and are sewn together. It is described that the uneven height is made 14 μm or less to make it smooth.
Japanese Patent Laid-Open No. 4-151048 Japanese Patent Publication No. WO96 / 22479

  However, when the V-ribbed belt is suspended between the driving pulley and the driven pulley and the back surface of the belt is brought into contact with the idler pulley, it has been clarified that periodic noise is generated periodically. In general, the sewing machine joint area of the canvas was a part where periodic abnormal noise was generated, but since the joint part was made flat, the abnormal noise generation was eliminated, but abnormal noise also occurred in other areas. Confirmed to do. One reason for this is that the belt is offset on the idler pulley with which the back of the belt is in contact, and does not move straight with respect to the rib pulley that enters next.

  That is, when a twisted cord is used as the core wire, when the belt is rotated, a twisting rotational force is normally generated in the cord due to the tension applied to the belt. For this reason, due to the rotational force applied to each cord embedded in the belt, the belt does not fit into the V-groove, and the belt rear surface moves in the width direction on the idler pulley, and then the belt enters the pulley. There was a sound.

  Therefore, in order to improve such a shortcoming defect, conventionally, two cords having different twist directions are arranged alternately to form a core wire, and the rotational force generated in the cord is canceled to prevent the deviation. . However, in this case as well, it is necessary to simultaneously wind two cords having different twisting directions around the cylindrical mold in a spiral shape, which not only complicates the manufacturing process but also requires process control man-hours. Inevitable.

  In addition, when a treated canvas, which has been subjected to friction by rubbing unvulcanized rubber against the canvas after being immersed in the RFL solution, rubber wrinkles may occur. The rubber bag was deposited as a rubber adhesive on the back of the belt, and this also caused abnormal noise.

  The present invention addresses such problems, and in power transmission belts such as V-ribbed belts and low-edge V-belts, reduces the deviation that occurs when the back of the belt contacts and engages with idler pulleys, It is an object of the present invention to provide a power transmission belt with improved noise generation.

  That is, in the invention described in claim 1, the core wire is embedded in the adhesive rubber layer along the belt longitudinal direction, the compression rubber layer is disposed adjacent to the adhesive rubber layer, and at least the belt back surface is laminated with the canvas. In the power transmission belt, the connecting line connecting the intersections of the warp and weft of the canvas is inclined with respect to the longitudinal axis of the belt, and the inclination direction of the connecting line is the same as the twist direction of the core wire. This is a belt for power transmission that is the direction, and since the inclination direction of the connecting wire is the same direction as the twisted direction of the core wire, it cancels the rotational force of the cord generated when the twisted cord is used as the core wire, and goes straight It becomes a belt with excellent properties and can reduce the occurrence of abnormal noise.

  In the invention according to claim 2 of the present application, the crossing angle between the connecting line connecting the warp and weft of the canvas and the axis in the longitudinal direction of the belt is set to 5 to 10 degrees so that the straightness is further improved and the noise is increased. Can be reduced.

  In the invention according to claim 3 of the present application, since the core wire is twisted by various twists and the upper twist has a twist coefficient of 2.5 to 4.0, it becomes a belt having excellent straightness and prevents the generation of abnormal noise. Can do.

  In the invention according to claim 4 of the present application, since the canvas is bonded with a treatment liquid in which a water-dispersible cross-linking agent is mixed in a mixed solution of a carbon black dispersion and a resorcin-formaldehyde-latex liquid, the canvas is vulcanized. Since the latex component impregnated in the rubber is cross-linked and the rubber is prevented from seeping out from the gap between the canvases, it is possible to suppress the generation of an adhesive even when the rear running is performed for a long time.

  In the invention according to claim 5 of the present application, the power transmission belt is a V-ribbed belt comprising an adhesive rubber having a core wire embedded along the longitudinal direction of the belt and a compressed rubber layer having at least one rib portion along the longitudinal direction of the belt. It is.

  As described above, according to the invention described in the claims of the present application, since the inclination direction of the connecting wire is the same as the twisted direction of the core wire, the rotational force of the cord generated when the twisted cord is used as the core wire is reduced. It is possible to cancel out, reduce the deviation in the width direction of the belt, improve the straightness of the belt, and reduce the occurrence of abnormal noise.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows a V-ribbed belt 1 according to the present invention. The V-ribbed belt 1 has a cord 2 made of a high strength and low elongation cord embedded in an adhesive rubber layer 3 and has a compression rubber layer 4 as an elastic layer below it. The compressed rubber layer 4 is provided with a plurality of rib portions 7 having a substantially triangular cross section extending in the belt longitudinal direction, and a canvas 5 is laminated on the belt back surface portion.

  In the canvas 5, as shown in FIG. 2, the warp 10 and the weft 11 of the canvas 5 have a wide angle of 100 to 135 degrees, and the connecting line 13 that connects the intersections 12 of the warp 10 and the weft 11 and the belt length. The crossing angle α with the direction axis 15 must be 5 to 10 degrees, preferably 6 to 8 degrees. The inclination direction of the connecting wire 13 (in the present embodiment, the upper right direction from the bottom upward) coincides with the upper twist direction (Z twist direction) of the core wire 2 shown in FIG. On the contrary, if the inclination direction of the connecting wire 13 is from the bottom to the top and the upper left direction), the upper twist direction of the core wire 2 coincides with the S twist direction. As a result, the untwisting rotational force generated in the cord due to the tension applied to the belt is canceled by the crossing angle of the canvas, and the deviation of the belt is reduced, so that the abnormal noise of the belt caused by this is suppressed.

  When the crossing angle α is less than 5 degrees, the rotational force of untwisting that occurs in the cord cannot be suppressed, and the belt is deviated and abnormal noise is generated. If the angle exceeds 10 degrees, the canvas 5 is installed in a considerably deviated state, and the rotational force generated in the canvas is excessively larger than the rotational force of the cord.

  The wide-angle canvas 5 is, for example, a mechanically wide-angle treatment, that is, a tenter treatment of a plain weave canvas having a warp and weft crossing angle of 90 degrees, so that both threads become 100 to 135 degrees with respect to the belt longitudinal direction. Crossed wide angle processing.

  The canvas 5 includes natural fibers such as cotton and hemp, inorganic fibers such as metal fibers and glass fibers, and polyamide, polyester, polyethylene, polyurethane, polyfluoroethylene, polyacryl, polyvinyl alcohol, wholly aromatic polyester, wholly aromatic. Woven into plain weave, twill weave, satin weave, etc. using yarns composed of organic fibers such as group polyamide.

  The canvas 5 is abutted at the width end, and is formed into a cylindrical body having one joint portion by sewing with a sewing machine such as an overlock using cotton yarn. In the case of producing a cylindrical body, it may be an elongated wide-angle canvas composed of warps 10 and wefts 11 arranged so that the crossing angle is about 100 to 120 °. This wide-angle canvas is obtained by performing a tenter process for forcibly increasing the crossing angle of the warp 10 and the weft 11. Even when this canvas 1 is used, it is possible to produce a belt canvas by joining the wide ends of the wide-angle canvas and butting joints.

  The canvas 5 is immersed in a mixture of carbon black dispersion and RFL for 0.1 to 20 seconds, and then heat treated at 100 to 200 ° C. for 30 to 600 seconds.

  In addition, it is preferable that the solid content weight ratio of carbon black and RFL in the said liquid mixture is 1: 9-7: 3. When the added amount of carbon black is less than the above range, the color of the treated fiber material becomes non-uniform and the appearance is poor. On the other hand, when the added amount of carbon black is increased, the adhesive force between the canvas and the belt body decreases. Moreover, it is desirable to adjust a solid content compounding quantity so that the total solid content concentration in a liquid mixture may be 5-40% concentration.

  The carbon black dispersion is, for example, a suspension in which N330 grade carbon black is dispersed in water together with a surfactant.

  The RFL liquid is a mixture of resorcin and formaldehyde initial condensate and rubber latex, and the molar ratio of resorcin and formaldehyde is preferably 1: 0.5 to 1: 3 in order to increase the adhesive force. It is. The initial condensate of resorcin and formaldehyde is mixed with latex so that the resin content is 10 to 100 parts by weight with respect to 100 parts by weight of the rubber content of the latex, and the total solid content concentration is 5 to 40. % Concentration is adjusted. In addition, you may add 0.1 to 5.0weight% of well-known surfactant to RFL liquid.

  The latex is a latex of styrene-butadiene-vinylpyridine terpolymer, chlorosulfonated polyethylene, nitrile rubber, hydrogenated nitrile rubber, epichlorohydrin, natural rubber, SBR, chloroprene rubber, olefin-vinyl ester copolymer, EPDM, etc. It is.

  A water-dispersible cross-linking agent is blended in the mixed solution. By blending the cross-linking agent into the mixed solution, the latex component impregnated in the canvas at the time of belt vulcanization is cross-linked, and the rubber constituting the belt main body is prevented from oozing out from the gap in the opening of the canvas. Further, when the obtained belt is run, a long-term adhesive wear suppression effect is seen, and thereby, abnormal noise can be reduced.

  Colloidal sulfur is mentioned as a water dispersible crosslinking agent. Colloidal sulfur is generally obtained by drying a sol prepared by subjecting precipitated sulfur or powdered sulfur to a ball mill or colloid mill together with a dispersant. Moreover, an organic peroxide can be used.

  Examples of organic peroxides include di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, 1.1-t-butylperoxy-3.3.5-trimethylcyclohexane, 2.5-di- Methyl-2.5-di (t-butylperoxy) hexane, 2.5-di-methyl-2.5-di (t-butylperoxy) hexane-3, bis (t-butylperoxydi-isopropyl) benzene, 2.5- Examples include di-methyl-2.5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, and t-butylperoxy-2-ethyl-hexyl carbonate. In addition, the said organic peroxide can be used individually by 1 type, or can use 2 or more types together.

  The compressed rubber layer 4 is made of hydrogenated nitrile rubber, ethylene-α-olefin elastomer, chloroprene rubber, natural rubber, CSM, ACSM, SBR, and the hydrogenated nitrile rubber has a hydrogenation rate of 80% or more. In order to exhibit the characteristics of heat resistance and ozone resistance, 90% or more is preferable. Hydrogenated nitrile rubber having a hydrogenation rate of less than 80% has extremely low heat resistance and ozone resistance. Considering oil resistance and cold resistance, the amount of bound acrylonitrile is preferably in the range of 20 to 45%.

  The ethylene-α-olefin elastomer is a copolymer of ethylene and α-olefin (propylene, butene, hexene, or octene), or a copolymer of ethylene, the α-olefin, and a non-conjugated diene. Refers to rubber made of ethylene-propylene rubber (EPM) or ethylene-propylene-diene terpolymer (EPDM). Examples of the diene component include non-conjugated dienes having 5 to 15 carbon atoms such as ethylidene norbornene, dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, and methylene norbornene.

  For the compressed rubber 4, polyamide short fibers such as 6 nylon, 66 nylon, and 610 nylon can be used. The polyamide short fibers are preferably in the range of about 1 to 8 mm, and the thickness is preferably 5 to 10 denier. In addition to the polyamide short fibers, cotton, rayon, and aramid fibers can be used for the compressed rubber layer 4, but stick slip noise can be more effectively reduced by using the polyamide short fibers alone.

  And the compounding quantity of all the short fibers with respect to the raw material rubber of the compression rubber layer 4 is set to 10-40 weight part with respect to 100 mass parts of rubber | gum. By setting the blending amount of all short fibers to 10 parts by weight or more, the difference in transmission force between DRY and WET of the transmission belt can be reduced, and the generation of abnormal noise by reducing the occurrence of stick-slip noise. It can be reduced. If the blending amount of all short fibers exceeds 40 parts by weight, the dispersion of the short fibers in the raw rubber is deteriorated and the rubber physical properties are deteriorated. preferable.

  As the core wire 2, polyester fiber, aramid fiber, glass fiber, etc. are used, and among them, the total denier number of 4,000 to 8,000 is obtained by twisting together polyester fiber filament groups mainly composed of polyethylene terephthalate. Treated cords are preferred to reduce belt slip and extend belt life. The upper twist number of this cord is 8 to 20/10 cm (twist coefficient 2.5 to 4), and the lower twist number is 10 to 41/10 cm (twist coefficient 2 to 4.5). When the total denier is less than 4,000, the modulus and strength of the cord are too low. When the total denier is more than 8,000, the belt becomes thick and the bending fatigue property is deteriorated.

The twist coefficient is calculated by the following formula. Here, T is the number of twists / 10 cm, and D is the total denier number.
That is, twist coefficient = 0.00348 × T × √D

  The core 2 is subjected to an adhesion treatment for the purpose of improving the adhesion to rubber. As such an adhesion treatment, it is common to immerse the cord in the RFL solution and then heat and dry to form a uniform adhesion layer on the surface. However, the present invention is not limited to this, and there is also a method of performing a pretreatment with an epoxy or isocyanate compound and then treating with an RFL solution.

  The cord subjected to the bonding treatment can be finished into a belt having a high modulus by setting the spinning pitch, that is, the winding pitch of the core wire to 1.0 to 1.3 mm. If the length is less than 1.0 mm, the cord cannot ride on the adjacent cord and cannot be wound. On the other hand, if the length exceeds 1.3 mm, the modulus of the belt gradually decreases.

  In spinning, the core wire 2 is not provided with S twist and Z twist alternately, and it is necessary to use either S twist or Z twist.

  On the other hand, the adhesive rubber layer 3 has heat resistance, and the same kind of rubber as the compressed rubber layer 4 is used. However, short fibers are not mixed, but if necessary, normal agents such as carbon black, reinforcing agents such as silica, fillers such as calcium carbonate and talc, plasticizers, stabilizers, processing aids, and coloring agents. What is used for rubber compounding is used.

  A typical manufacturing method of the V-ribbed belt is as follows. First, a canvas and an adhesive rubber layer are wound around the circumferential surface of a cylindrical molding drum, and then a cord made of a cord is spun into a spiral shape, and then an adhesive rubber layer and a compressed rubber layer are wound in order. After obtaining a laminated body, this is bridge | crosslinked and a sleeve is obtained.

  Next, the bridging sleeve is hung on the driving roll and the driven roll and travels under a predetermined tension, and the rotated grinding wheel is moved so as to abut against the traveling bridging sleeve and the compressed rubber layer of the bridging sleeve The surface is polished with 3 to 100 grooves at a time.

  The thus obtained bridging sleeve is removed from the driving roll and the driven roll, the bridging sleeve is hung on the other driving roll and the driven roll, traveled, cut into a predetermined width by a cutter, and each V-ribbed belt. Finish.

  In the present invention, in addition to the above-mentioned V-ribbed belt, a low-edge V-belt 8 having canvas attached only to the upper and lower surfaces of the belt as shown in FIG. 4 also belongs to the technical category of the present invention. The belt 8 has the core 2 embedded in the adhesive rubber layer 3 and has a compression rubber layer 4 as an elastic layer below it. The compressed rubber layer 4 may be provided with cogs at predetermined intervals along the longitudinal direction.

Hereinafter, the present invention will be described in more detail with reference to examples.
Examples 1-3, Comparative Examples 1-2
In this example, an untreated cotton canvas (a plain weave of 20 s / 2 cotton, 82 warps / 5 cm, and 82 wefts / 5 cm) with a warp and weft crossing angle of 90 degrees is shown in Table 1. It was immersed in a treatment solution of the mixture of RFL solution for 10 seconds, subjected to a wide angle treatment with a warp and weft crossing angle of 120 degrees with a tenter, and heat treatment was performed at 150 ° C. for 4 minutes.

  Subsequently, a V-ribbed belt was produced. The core wire used was a total denier of 1,100 denier polyethylene terephthalate fiber (PET fiber) in a 1 × 5 twist configuration with an upper twist factor of 3.0 and a lower twist factor of 3.0. The one obtained by bonding the cord was used.

  A compressed rubber and an adhesive rubber layer were prepared from the rubber compositions shown in Table 2, respectively, kneaded with a Banbury mixer, and then rolled with a calendar roll. The compressed rubber layer contains short fibers (10 parts by weight of aramid cut yarn and 10 parts by weight of nylon cut yarn) and is oriented in the belt width direction.

  The manufacturing method of the V-ribbed belt is a normal method. First, the above-mentioned canvas of 1 ply is inserted into a drum as a cylindrical canvas, and then an adhesive rubber layer is wound around it, the core wire is spun, and a compressed rubber layer is further formed. After placement, a bridging jacket is inserted over the compressed rubber layer. Next, the mold was placed in a vulcanizing can and crosslinked, and then the cylindrical crosslinked sleeve was taken out of the mold. The compressed rubber layer of the sleeve taken out was molded into a rib by a grinding wheel, and cut from the molded body into individual belts. The obtained V-ribbed belt was K-type 6PK1,100 having a length of 1,100 mm according to the RMA standard.

  In the V-ribbed belt thus obtained, the crossing angle α between the connecting line connecting the intersections of the warp and weft of the canvas and the axis in the longitudinal direction of the belt, the amount of belt deviation, and the occurrence of abnormal noise Table 3 shows the measurement results.

  The amount of belt deviation is set between two parallel pulleys with a diameter of 65 mm on both the drive side and the driven side so that the rear canvas surface of the belt is in contact with the pulley, and 5 kgf / rib tension is applied between the shafts. This is the amount of movement in the width direction per second when the drive pulley is run at a rotational speed of 200 rpm. When moving to the left with respect to the belt traveling direction (+), when moving to the right Is represented by (−).

  Further, the V-ribbed belt is suspended from a driving pulley having an outer peripheral length of 155 mm and a driven pulley having an outer peripheral length of 60 mm, and is engaged with an idler pulley having an outer peripheral length of 75 mm on the back surface of the belt at an angle of 40 °. I checked the presence or absence of abnormal noise by running with a book.

  In Examples 1 to 3, the belt offset amount was small and no abnormal noise of the belt was generated. However, in Comparative Example 1, the belt offset was large because the crossing angle of the canvas was small, and the belt abnormal noise was Occurred. In Comparative Example 2, the crossing angle of the canvas was too large, so that the belt deviation was large, and an abnormal noise of the belt was generated.

Examples 4-7, Comparative Examples 3-4
The core used was a 1,100-denier polyethylene terephthalate fiber (PET fiber) with a 1 x 5 twist configuration, and a total denier 5,500 cord that was twisted by varying the upper and lower twist coefficients. The treated one was used. Other than that, a V-ribbed belt of K-type 6PK1100 having a length of 1,100 mm according to the RMA standard was produced in the same manner as in Example 1.

  Table 4 shows the results of measurement of the crossing angle of the canvas, the amount of deviation of the belt, and the presence or absence of abnormal noise in the belt thus produced. Note that the rotational force of the cord is 500 mm between chucks, when one cord is applied, 1 kg of load is applied with the lower end fixed so as not to rotate, the upper end rotates, and the upper end rotates clockwise. Is represented by (+), and when rotating counterclockwise is represented by (−).

  In Examples 4 to 7, the rotational angle of the cord generated when a load is applied is determined by the intersection angle between the connecting line connecting the intersections of the warp and weft of the canvas and the axis in the longitudinal direction of the belt. Therefore, it can be seen that the belt offset is small and no abnormal noise of the belt is generated.

  In the comparative example 3, since the rotational force of the cord is small, it is affected by the rotational force of the canvas caused by the crossing angle of the canvas, and the belt deviation becomes large and the noise of the belt is generated. In Comparative Example 4, since the cord rotating force was large, the cord rotating force could not be completely suppressed due to the crossing angle of the canvas.

The perspective view of the V ribbed belt concerning the present invention is shown. FIG. 2 is a diagram showing an intersection angle α between a connecting line connecting the intersections of warp and weft of a canvas attached to the belt back surface portion of the V-ribbed belt shown in FIG. 1 and an axis in the belt longitudinal direction. It is a top view of the Z strand core wire used for the V ribbed belt of FIG. It is sectional drawing of the low edge V belt which is another example of the power transmission belt which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 V ribbed belt 2 Core wire 3 Adhesive rubber layer 4 Compression rubber layer 5 Canvas 6 Belt back surface 7 Rib part 8 Low edge V belt 10 Warp 11 Weft 12 Intersection 13 Connection line 14 Axis line

Claims (5)

  A power transmission belt in which a core wire is embedded in an adhesive rubber layer along a longitudinal direction of the belt, a compression rubber layer is disposed adjacent to the adhesive rubber layer, and at least the back surface of the belt is laminated with a canvas, The connecting line connecting each intersection with the weft is inclined with respect to the longitudinal axis of the belt, and the inclination direction of the connecting line is the same direction as the twisted direction of the core wire. belt.   The power transmission belt according to claim 1, wherein an intersection angle between a connecting line connecting each intersection of the warp and weft of the canvas and an axis in the longitudinal direction of the belt is 5 to 10 degrees.   The power transmission belt according to claim 1, wherein the core wire is twisted by various twists, and the upper twist is a twist coefficient of 2.5 to 4.0.   The power transmission belt according to claim 1, wherein the canvas is bonded with a processing liquid in which a water-dispersible cross-linking agent is mixed in a mixed solution of a carbon black dispersion and a resorcin-formaldehyde-latex liquid. 5. The V-ribbed belt according to claim 1, wherein the power transmission belt is a V-ribbed belt comprising an adhesive rubber having a core wire embedded in the longitudinal direction of the belt and a compressed rubber layer having at least one rib portion along the longitudinal direction of the belt. The power transmission belt described in Crab.

Images