JP5735371B2 - Transmission V-belt and method for producing and using the same - Google Patents

Description

  The present invention relates to a transmission V-belt that can be used in a transmission, and more particularly to a transmission V-belt that has excellent transmission efficiency and can maintain acceleration performance over a long period of time, and a method for manufacturing and using the same.

  In recent years, due to exhaust gas regulations and solid fuel depletion problems, transmission V-belts are required to have improved fuel efficiency (fuel efficiency) in addition to side pressure resistance and durability. Specifically, in order to improve fuel consumption, it is required to reduce the transmission loss of the belt. Therefore, in order to reduce the energy loss (transmission loss) due to the bending of the belt, cogs are provided on the inner peripheral side of the belt or on both the inner peripheral side and the outer peripheral side (back side) to reduce the belt's bending rigidity. Cogged V-belts with reduced loss have been developed.

  For example, in JP-A-10-238596 (Patent Document 1), the rubber hardness of at least one of the stretched and compressed rubber layers is set to 90 to 96 °, and the rubber hardness of the adhesive rubber layer is set to a range of 83 to 89 °. In addition, a transmission V-belt in which aramid short fibers are oriented in the belt width direction is disclosed in the stretch and compression rubber layers. In this document, the occurrence of cracks and separation (separation) of each rubber layer and cord is prevented at an early stage, the lateral pressure resistance is improved, and the high load transmission capability is improved.

  However, even this transmission V-belt has a large energy loss and cannot sufficiently improve fuel consumption. That is, the fuel efficiency is influenced not only by the energy loss due to the bending of the belt but also by the frictional force generated by the friction between the friction transmission surface and the pulley. However, in this transmission V-belt, since this frictional force is large, the friction transmission surface and the pulley cannot slide smoothly, and this becomes an energy loss (transmission loss), resulting in a reduction in fuel consumption.

  On the other hand, a transmission V-belt such as a low edge belt is generally ground on both sides (friction transmission surfaces) in order to set the belt angle and the width of the back surface of the belt to predetermined values. For example, Japanese Patent Application Laid-Open No. 2008-44017 (Patent Document 2) describes a side surface of a transmission belt formed by embedding a core wire made of an aramid fiber between a compression rubber layer and an elongated rubber layer in the belt longitudinal direction. In polishing, while rotating the transmission belt in the longitudinal direction of the belt, the polishing tool is brought into contact with the side surface of the transmission belt, and the lubricating action of moisture is applied to the contact surface of the polishing tool to the side surface of the transmission belt, A side polishing method for a power transmission belt for polishing is disclosed. In such a polishing method, the short fiber protrudes from the side surface by polishing, and the side surface has a low coefficient of friction due to the protruding short fiber. Further, the reduction of the friction coefficient, that is, the reduction of the frictional force makes the sliding between the friction transmission surface and the pulley smooth, thereby improving the fuel consumption.

  A transmission belt used for a continuously variable transmission is known as this type of transmission V-belt. This speed change belt has a structure in which the speed change ratio (the rotation ratio between the driving pulley and the driven pulley) can be changed steplessly by moving the belt up and down in the pulley radial direction.

  One of the performances required for this transmission belt is acceleration performance. The acceleration performance means the performance from when the speed change belt starts to change until the vehicle speed rapidly increases. The speed change speed is the speed of the drive (Dr.) pulley at which the belt starts to change speed, and the higher the speed change speed, the higher the acceleration performance. In general, the acceleration performance of the belt is good if the region during shifting is flat or right-up. FIG. It is a graph showing the relationship between a rotation speed and a vehicle speed. As is clear from FIG. 1, the vehicle speed is small until the belt starts shifting (during LOW), but when the belt begins to move outward in the radial direction of the pulley (shifting starts), the vehicle speed increases rapidly (during shifting). Finally, the maximum speed (at the time of TOP) is reached.

  FIG. 2 shows the dr. It is the figure which represented the position with respect to a pulley typically. At the time of LOW before shifting, the belt is located on the inner side in the pulley radial direction and the vehicle speed is small. Dr. When the number of rotations of the pulley increases and exceeds a predetermined number of rotations (shifting rotation number), Dr. One of the pulleys (movable pulley piece) moves (in the direction in which the groove width of the pulley decreases), and accordingly, the belt moves outward (in gear shifting) in the pulley radial direction, and the vehicle speed rapidly increases. At the time of TOP after shifting, the belt is positioned on the outer peripheral side of the pulley, and the vehicle speed becomes the maximum speed.

  If the acceleration performance is insufficient, the vehicle speed after acceleration does not increase sufficiently, or the time until the vehicle reaches the maximum speed (TOP) becomes longer. The acceleration performance is greatly affected by the surface condition of the friction transmission surface. That is, when the belt is run for a long time, the friction transmission surface is worn by rubbing against the pulley, so that the surface state changes, but if this change is large, the acceleration performance also changes greatly. In the polishing method of Patent Document 2, since the entire belt side surface is polished, the short fibers protrude in both the stretch rubber layer and the compression rubber layer on the belt side surface. Therefore, when the belt is run for a long time, the short fibers (particularly, the short fibers of the compressed rubber layer) are rubbed with the pulley and cut or worn and lost, and the surface state changes greatly. For this reason, the acceleration performance of the belt changes greatly between the initial running time (when new) and after running for a long time.

JP-A-10-238596 (claims, paragraph [0005]) JP 2008-44017 A (Claim 1, FIG. 1)

  Accordingly, an object of the present invention is to provide a transmission V-belt that can stably maintain acceleration performance for a long period of time even when used in a transmission without reducing transmission efficiency, and a method for manufacturing and using the same. .

  Another object of the present invention is to provide a transmission V-belt that can maintain side pressure resistance and durability, and that can improve fuel efficiency, and a method for manufacturing and using the same.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventor has formed an adhesive rubber layer, a compressed rubber layer formed on one surface of the adhesive rubber layer, and the other surface of the adhesive rubber layer. In the transmission V-belt provided with the stretched rubber layer, short fibers are embedded in the compressed rubber layer and the stretched rubber layer so as to be oriented in the width direction of the belt, and the short fibers protrude at least on the side surfaces of the stretched rubber layer, In addition, by forming a smooth region on the side of the compressed rubber layer where the protruding length of the short fibers is lower than that of the stretched rubber layer, the acceleration performance is prolonged even when used in a transmission without reducing the transmission efficiency. The present invention was completed by finding that it can be stably maintained for a period of time.

  That is, the transmission V-belt of the present invention includes an adhesive rubber layer having a core wire embedded in the longitudinal direction of the belt, a compression rubber layer formed on one surface of the adhesive rubber layer, and the other of the adhesive rubber layer. A transmission V-belt provided with a stretched rubber layer formed on the surface, wherein short fibers are embedded in the compressed rubber layer and the stretched rubber layer so as to be oriented in the belt width direction, and at least the stretched rubber layer Short fibers protrude from the side surfaces, and the side surface of the compressed rubber layer has a smooth region in which the average protrusion height of the short fibers is lower than the average protrusion height of the short fibers in the entire side surface of the stretched rubber layer. The entire side surface of the compressed rubber layer (particularly the entire side surfaces of the compressed rubber layer and the adhesive rubber layer) may be a smooth region. In the smooth region, the short fibers may not protrude. In the transmission V-belt of the present invention, the belt angle in the smooth region is substantially the same as the pulley angle, and the belt angle in the stretched rubber layer is substantially the same as the pulley angle or smaller than the pulley angle. May be. The transmission V-belt of the present invention may be a transmission belt constituted by a low edge cogged V-belt.

  The present invention also includes a method for producing the transmission V-belt, which includes a polishing step of polishing at least a side surface of the stretch rubber layer among the side surfaces of the stretch rubber layer, the adhesive rubber layer, and the compression rubber layer. In the production method of the present invention, at least the side surface (especially the entire side surface) on the belt inner peripheral side among the side surfaces of the compressed rubber layer may not be polished. Further, only the side surface of the stretched rubber layer may be polished.

  The present invention also includes a method of using the transmission V-belt in a transmission.

  In the present invention, in a transmission V-belt comprising an adhesive rubber layer, a compressed rubber layer formed on one surface of the adhesive rubber layer, and an extended rubber layer formed on the other surface of the adhesive rubber layer Short fibers are embedded in the compressed rubber layer and the stretched rubber layer so as to be oriented in the belt width direction, the short fibers protrude at least on the side surfaces of the stretched rubber layer, and the side surfaces of the compressed rubber layer are formed on the stretched rubber layer. Therefore, the acceleration performance can be stably maintained for a long time even when used in a transmission without lowering the transmission efficiency. Furthermore, the lateral pressure resistance and durability can be maintained, and fuel consumption can be improved.

FIG. 1 is a graph showing the relationship between the rotational speed of the drive pulley and the vehicle speed. FIG. 2 is a diagram schematically showing the position of the belt with respect to the drive pulley. FIG. 3 is a schematic perspective view showing an example of the transmission V-belt of the present invention. FIG. 4 is a schematic sectional view of the transmission V-belt of FIG. 3 cut in the belt longitudinal direction. FIG. 5 is an enlarged view of the belt side surface of FIG. FIG. 6 is a schematic cross-sectional view showing an example of the relationship between the belt angle and the pulley angle. FIG. 7 is a schematic cross-sectional view showing another example of the relationship between the belt angle and the pulley angle. FIG. 8 is a schematic diagram for explaining a method for measuring transmission efficiency. FIG. 9 is a schematic view for illustrating a method of polishing a part of the side surface of the belt sleeve. FIG. 10 is a schematic cross-sectional view for illustrating another example of the polishing portion on the side surface of the belt sleeve. FIG. 11 is a schematic diagram for explaining a method of measuring a friction coefficient in the embodiment. FIG. 12 is a schematic diagram for explaining a high-speed running test in the example. FIG. 13 is a schematic diagram for explaining a durability running test in the example.

[V-belt for transmission]
The transmission V-belt of the present invention comprises an adhesive rubber layer having a core wire embedded in the longitudinal direction of the belt, a compressed rubber layer formed on one surface of the adhesive rubber layer, and the other surface of the adhesive rubber layer. In the transmission V-belt provided with the formed stretch rubber layer, the short fiber protrudes on the side surface of the stretch rubber layer, and the short fiber protrudes lower on the side surface of the compression rubber layer than the stretch rubber layer. Since it has a smooth region, acceleration performance can be stably maintained for a long time even when used in a transmission without reducing transmission efficiency, and fuel efficiency can be improved.

  FIG. 3 is a schematic perspective view showing an example of a transmission V-belt (low-edge cogged V-belt) according to the present invention, and FIG. 4 is a schematic cross-sectional view of the transmission V-belt of FIG. 3 cut in the longitudinal direction of the belt. FIG. 5 is an enlarged view of the side surface of the belt in FIG. 4.

  In this example, the transmission V-belt 1 has a plurality of cog portions 1a formed at predetermined intervals along the longitudinal direction of the belt on the inner peripheral surface of the belt main body. The cross-sectional shape in the direction perpendicular to the longitudinal direction and the longitudinal direction is trapezoidal. That is, each cog part 1a protrudes in a trapezoidal cross section from the cog bottom part 1b in the belt thickness direction. The transmission V-belt 1 has a laminated structure, and the reinforcing cloth 2, the stretch rubber layer 3, the adhesive rubber layer 4, from the belt outer peripheral side toward the inner peripheral side (side on which the cog 1 a is formed), A compressed rubber layer 5 and a reinforcing cloth 6 are sequentially laminated. The cross-sectional shape in the belt width direction is a trapezoidal shape in which the belt width decreases from the belt outer peripheral side toward the inner peripheral side. Further, a core wire 4a2 is embedded in the adhesive rubber layer 4, and the cog 1a is formed on the compressed rubber layer 5 by a molding die with cogs. As shown in FIG. 3, in the stretch rubber layer 3 and the compression rubber layer 5, short fibers 3a and short fibers 5a are respectively oriented in the belt width direction in order to suppress the compressive deformation of the belt against the pressure from the pulley. Buried. Further, short fibers 3 a protrude from the side surface of the stretched rubber layer 3.

(Stretch rubber layer)
The stretch rubber layer is formed of a rubber composition containing a rubber component and short fibers. In the present invention, in the stretched rubber layer, the short fibers embedded so as to be oriented parallel or substantially parallel to the belt width direction protrude at the side surface which is a contact surface with the pulley. Therefore, the slidability with respect to the pulley can be improved, the surface friction coefficient can be lowered to suppress sound generation, and wear due to friction with the pulley can be reduced.

(1) Short fiber The average protrusion height of the short fiber in the entire side surface of the elongated rubber layer may be 50 μm or more, for example, 50 to 200 μm, preferably 60 to 180 μm, more preferably 70 to 160 μm (particularly 80 to 150 μm). If the average protrusion height is too small, the friction coefficient of the surface cannot be sufficiently reduced, and if it is too large, breakage or dropout is likely to occur. The average protrusion height is obtained by, for example, observing a cross section cut in the belt width direction with an electron microscope or the like, and measuring a plurality of short fibers protruding from the belt side surface (protrusion height) (for example, 10 to 1000). , Preferably 30 to 500, more preferably 50 to 200, especially about 100), and these can be calculated by averaging.

  The shape of the short fiber in the protruding portion is not particularly limited, the shape protruding substantially perpendicularly from the side surface, the shape curled in one direction (for example, the polishing direction), the shape fibrillated at the tip, and melted by the heat during polishing It may be a shape such as a flowering shape. Furthermore, the shape described in JP-A-7-98044 and JP-A-7-151191 may be used.

On the side surface of the stretch rubber layer, a region (non-smooth region) in which short fibers protrude is formed on the entire side surface (or substantially the entire side surface), and the density of short fibers protruding on the side surface is, for example, 20,000 to 200,000 / Cm ² , preferably 40,000 to 150,000 pieces / cm ² , more preferably about 60,000 to 130,000 pieces / cm ² .

  The average length of the short fibers is, for example, 1 to 20 mm, preferably 2 to 15 mm, more preferably 3 to 10 mm, and may be about 1 to 8 mm (for example, 3 to 6 mm). If the average length of the short fibers is too small, the mechanical properties (for example, the modulus) in the line direction cannot be sufficiently increased. On the other hand, if the average length is too large, poor dispersion of the short fibers in the rubber composition occurs. There is a risk of cracking the rubber and premature damage to the belt.

  The average fiber diameter of the short fibers is, for example, about 5 to 50 μm, preferably 7 to 40 μm, and more preferably about 9 to 35 μm (particularly 10 to 30 μm). If the fiber diameter is too small, the effect of improving the slidability is small, and if too large, the mechanical properties of the stretched rubber layer are lowered.

Examples of the short fibers include polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), polyamide fibers (polyamide 6 fibers, polyamide 66 fibers, polyamide 46 fibers, aramid fibers, etc.), polyalkylene arylate fibers [polyethylene terephthalate ( PET) fiber, C _2-4 alkylene C _6-14 arylate fiber such as polyethylene naphthalate (PEN) fiber, etc.], vinylon fiber, polyvinyl alcohol fiber, synthetic fiber such as polyparaphenylene benzobisoxazole (PBO) fiber Natural fibers such as cotton, hemp and wool; inorganic fibers such as carbon fibers are widely used. These short fibers can be used alone or in combination of two or more. Among these short fibers, synthetic fibers (polyamide fiber, polyalkylene arylate fiber, etc.) and natural fibers (cotton, etc.), especially rigid, high strength, modulus, aramid fibers, PBO fibers are preferred. Aramid short fibers also have high wear resistance, and are commercially available under the trade names “Conex”, “Nomex”, “Kevlar”, “Technola”, “Twaron” and the like. PBO short fibers have a wear resistance higher than that of aramid short fibers, and are commercially available under the trade name “Zylon”.

  The short fibers may be treated with a conventional adhesion treatment (or surface treatment), for example, resorcin-formalin-latex (RFL) solution, in order to improve dispersibility and adhesion in the rubber composition.

  The proportion of the short fibers is, for example, about 5 to 50 parts by mass, preferably 10 to 40 parts by mass, and more preferably about 15 to 35 parts by mass (particularly 20 to 30 parts by mass) with respect to 100 parts by mass of the rubber component. . If the proportion of the short fibers is too small, the mechanical properties and the sliding property with the pulley cannot be improved. If the proportion is too large, the mechanical properties and poor dispersion of the short fibers are generated and the durability is lowered.

(2) Rubber component The rubber component may be vulcanized or cross-linkable rubber such as diene rubber (natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (nitrile rubber). And hydrogenated nitrile rubber), ethylene-α-olefin elastomer, chlorosulfonated polyethylene rubber, alkylated chlorosulfonated polyethylene rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber, fluororubber, and the like. These rubber components can be used alone or in combination of two or more.

  Preferred rubber components are ethylene-α-olefin elastomers (ethylene-α-olefin rubbers such as ethylene-propylene rubber (EPR) and ethylene-propylene-diene monomers (EPDM, etc.)) and chloroprene rubber. A particularly preferred rubber component is chloroprene rubber. The chloroprene rubber may be a sulfur-modified type or a non-sulfur-modified type.

(3) Other additives In the rubber composition, if necessary, conventional additives such as a vulcanizing agent or a crosslinking agent (or a crosslinking agent system) (for example, a sulfur-based vulcanizing agent), a co-crosslinking agent ( For example, bismaleimides), vulcanization aids or vulcanization accelerators (eg thiuram accelerators), vulcanization retarders, metal oxides (eg zinc oxide, magnesium oxide, calcium oxide, barium oxide, Iron oxide, copper oxide, titanium oxide, aluminum oxide, etc.), reinforcing agents (carbon black, silicon oxide such as hydrous silica), fillers (clay, calcium carbonate, talc, mica, etc.), softeners (paraffin oil, naphthene) Oils such as oils), processing agents or processing aids (stearic acid, metal stearate, wax, paraffin, fatty acid amide, etc.), anti-aging agents (antioxidants) Heat aging inhibitors, anti-bending materials, anti-ozone agents, etc.), colorants, tackifiers, plasticizers, coupling agents (such as silane coupling agents), stabilizers (UV absorbers, heat stabilizers) Etc.), flame retardants, antistatic agents and the like. The metal oxide may act as a crosslinking agent. These additives can be used alone or in combination of two or more.

  The thickness of the stretched rubber layer is, for example, about 0.8 to 10.0 mm, preferably 1.2 to 6.5 mm, and more preferably about 1.6 to 5.2 mm.

(Compressed rubber layer)
The compressed rubber layer is also formed of a rubber composition containing a rubber component and short fibers. In the present invention, a non-smooth region in which short fibers protrude on the entire side surface of the stretch rubber layer is formed, whereas on the side surface of the compression rubber layer, the average protrusion height of the short fibers on the entire side surface of the stretch rubber layer. It has the smooth area | region where the average protrusion height of a short fiber is lower than this. By forming such a smooth region on the side surface of the compressed rubber layer, the change in the surface state of the side surface of the compressed rubber layer due to wear with the pulley can be reduced, and the acceleration performance of the transmission belt can be maintained constant for a long time. .

  In the smooth region, the average protruding height of the short fibers may be lower than the average protruding height of the short fibers in the entire side surface of the stretched rubber layer, for example, less than 50 μm, preferably 30 μm or less (for example, 0 to 30 μm, further Preferably, it is 10 μm or less (for example, 0 to 10 μm), and may be substantially 0 μm.If the average protrusion height is too large, the protruding portion of the short fiber is frictionally worn by rubbing with the pulley, and the side surface Because the surface condition changes greatly, the acceleration performance of the belt cannot be maintained continuously.The lower limit of the protruding height is not particularly set, but if it is not polished only by cutting processing, the short fiber does not protrude (cut short fibers) Only the surface is exposed and the rest is embedded in rubber), and the average protrusion height is substantially 0 μm. From the viewpoint of productivity and simplicity, a compressed rubber layer in which short fibers do not protrude is preferable. .

  The smooth region is preferably formed on the side surface of the inner peripheral side of the belt on the side surface of the compressed rubber layer. Further, when the transmission V-belt has a cog portion, at least the entire cog portion (from the belt inner peripheral side (cog top portion) to the cog bottom portion on the side surface of the compression rubber layer can stably maintain the acceleration performance of the transmission belt. It is preferable that a smooth region is formed in a region including In particular, in the present invention, on the side surface of the compressed rubber layer, a region including from the belt inner peripheral side (cog top) to the center of the interface between the adhesive rubber layer and the compressed rubber layer and the cog bottom (for example, the compressed rubber layer) A smooth region is preferably formed on the entire side surface. If a smooth region is formed in such a region, the acceleration performance can be maintained constant without reducing the transmission efficiency. If the smooth area is not formed in the specified area on the inner circumference side and the short fibers are protruding, the influence of the short fibers on the pulley due to cutting and wear increases, and the acceleration performance of the belt is stabilized for a long time. Cannot be maintained.

  The area ratio occupied by the smooth region with respect to the entire side surface of the compressed rubber layer is, for example, about 50% or more, preferably about 60 to 100%, and more preferably about 80 to 100% (particularly about 100%).

  A region in which short fibers protrude from a part of the side surface of the compressed rubber layer (particularly, a region from the interface between the adhesive rubber layer and the compressed rubber layer to the center of the interface and the bottom of the cog) (non-smooth region) The average protruding height of the short fibers may be the same as or lower than the average protruding height of the short fibers in the stretched rubber layer. Examples of the shape of the protruding short fiber include the shape exemplified in the section of the stretched rubber layer and are usually polished together with the stretched rubber layer, and thus have the same shape. The density of the protruding short fibers can also be selected from the range described in the section of the extensible rubber layer.

  The rubber composition may be the rubber composition exemplified in the section of the stretched rubber layer. That is, the type of the short fiber can be selected from the types described in the section of the stretched rubber layer, and the average length, the average fiber diameter, and the ratio to the rubber component can also be selected from the range described in the section of the stretched rubber layer. The rubber component and additive can also be selected from the types described in the section of the stretched rubber layer. As the rubber composition of the compressed rubber layer, the same rubber composition as that of the stretched rubber layer is usually used from the viewpoint of simplicity and productivity.

  The thickness of the compressed rubber layer is, for example, about 2.0 to 25.0 mm, preferably about 3.0 to 16.0 mm, and more preferably about 4.0 to 12.0 mm.

(Adhesive rubber layer)
The adhesive rubber layer is formed of a rubber composition containing a core wire and a rubber component. The core wires are embedded in the adhesive rubber layer so as to extend in the longitudinal direction of the belt. Usually, a plurality of core wires are embedded in parallel at a predetermined pitch parallel to the longitudinal direction of the belt. The line spacing (spinning pitch) is, for example, about 0.5 to 3 mm, preferably about 0.8 to 1.5 mm, and more preferably about 1 to 1.3 mm.

  As the core wire, a twisted cord using multifilament yarn (for example, various twists, single twists, rung twists, etc.) can be used. The average wire diameter (fiber diameter of the twisted cord) of the core wire is, for example, about 0.5 to 3 mm, preferably about 0.6 to 1.5 mm, and more preferably about 0.7 to 1.2 mm.

  As the fibers constituting the core wire, fibers exemplified as short fibers can be used. Among the fibers, synthetic fibers such as polyester fibers and aramid fibers, inorganic fibers such as glass fibers and carbon fibers are widely used, and polyester fibers such as polyethylene terephthalate fibers and polyethylene naphthalate fibers because the belt slip rate can be reduced. Is particularly preferred. The polyester fiber may be a multifilament yarn. The fineness of the core wire composed of the multifilament yarn may be, for example, about 2000 to 10000 denier (particularly 4000 to 8000 denier). The surface of the core wire may be subjected to conventional adhesion treatment (or surface treatment) in the same manner as the short fibers.

  The rubber component can be selected from the types described in the section of the stretched rubber layer. The rubber component often uses the same type or type of rubber as the rubber component of the stretch rubber layer and the compression rubber layer. The rubber composition may further contain the additive exemplified in the section of the stretched rubber layer, and may further contain an adhesion improver (resorcin-formaldehyde cocondensate, amino resin, etc.).

  Even in the adhesive rubber layer, the core may be exposed on the side of the belt from the viewpoint of improving the initial slidability, but the side of the adhesive rubber layer can be highly improved in the stability of acceleration performance by use. Is preferably a smooth region. In particular, if the core wire protrudes from the side surface of the belt (scratching or fraying), a phenomenon that the core wire protrudes from the side surface of the belt when the belt travels (pop-out) may occur, which may reduce the durability of the belt. .

  The thickness of the adhesive rubber layer is, for example, about 0.4 to 3.0 mm, preferably about 0.6 to 2.2 mm, and more preferably about 0.8 to 1.4 mm.

(Reinforcing cloth)
In the transmission V-belt, a reinforcing cloth may be laminated on the surface of the compressed rubber layer and / or the stretched rubber layer. The reinforcing cloth can be formed, for example, by laminating a cloth material (preferably a woven cloth) such as a woven cloth, a wide angle sail cloth, a knitted cloth, and a non-woven cloth on the surface of the compression rubber layer and / or the stretch rubber layer. For example, after the adhesive treatment, for example, treatment with RFL liquid (immersion treatment, etc.), friction for rubbing adhesive rubber into the cloth material, or lamination (coating) of the adhesive rubber and the cloth material, a compressed rubber layer And / or may be laminated on the surface of the stretch rubber layer.

(Belt angle)
The belt angle of the transmission V-belt of the present invention is selected according to the angle of the pulley. For example, it may be formed at the same angle as the pulley angle or at an angle smaller than the pulley angle. . In the present specification, the belt angle means an angle formed by both side surfaces of the belt, that is, an angle when both side surfaces are extended and intersected as shown by broken lines in FIGS. In particular, in the present invention, an angle formed by both side surfaces of a non-smooth region (a polishing portion described later) is defined as a belt angle, and when the polishing portion is not formed, both sides of a smooth region (an unpolished portion described later) are formed. The angle formed by the surface may be defined as the belt angle. Similarly, the pulley angle means an angle formed by the slopes of the pulleys.

  FIG. 6 shows a case where the belt angle α of the belt 11 and the pulley angle β of the pulley 12 are the same, and the belt angles of the polishing portion 13 and the unpolished portion 14 are formed to be the same angle.

  FIG. 7 is an example of another embodiment, in which the belt angle γ of the polishing portion 23 is formed smaller than the pulley angle β. Further, in this belt, the belt angle of the polishing portion 23 and the unpolished portion 24 is formed at different angles, and the belt angle α of the unpolished portion 24 is formed at the same angle as the pulley angle β. That is, the relationship of the angle is “belt angle γ of the polished portion <belt angle α of the unpolished portion = pulley angle β”. In this embodiment, the polishing portion and the pulley are not in direct contact with each other, and only the unpolished portion is in contact, so that a sliding loss with the pulley is reduced and transmission efficiency is improved. Even if the unpolished part wears due to friction with the pulley and the polished part comes into contact with the pulley, the short fiber protrudes in the polished part and the friction coefficient is low, so it is possible to suppress an increase in sliding loss. It is.

  That is, in the transmission V-belt of the present invention, the belt angle in the smooth region may be approximately the same as the pulley angle, and the belt angle in the stretched rubber layer (or non-smooth region) may be substantially the same as the pulley angle. The angle may be smaller than the pulley angle. If the belt angle in the smooth region is formed at substantially the same angle as the pulley angle, the belt and the pulley can contact in the smooth region. Therefore, in the non-smooth region, the belt angle is formed at an angle smaller than the pulley angle. Even if it is a case, it is excellent in durability, generation | occurrence | production of abnormal noise etc. can be suppressed by long-term use, and it can drive | operate stably.

(Transmission efficiency)
When the transmission V-belt of the present invention is used, a non-smooth region in which short fibers protrude from the side surface of the stretched rubber layer is formed, so that transmission efficiency can be improved. The transmission efficiency is an index for the belt to transmit the rotational torque from the drive pulley to the driven pulley. The higher the transmission efficiency, the smaller the belt transmission loss and the better the fuel efficiency. In the two-axis layout in which the belt 31 is hung on the two pulleys of the drive (Dr.) pulley 32 and the driven (Dn.) Pulley 33 shown in FIG. 8, the transmission efficiency can be obtained as follows.

When the rotational speed of the driving pulley is ρ ₁ and the pulley radius is r ₁ , the rotational torque T ₁ of the driving pulley can be expressed by ρ ₁ × Te × r ₁ . Te is an effective tension obtained by subtracting the loose side tension (tension on the side where the belt faces the driven pulley) from the tension side tension (tension on the side where the belt faces the driving pulley). Similarly, when the rotational speed of the driven pulley is ρ ₂ and the pulley radius is r ₂ , the rotational torque T ₂ of the driven pulley is represented by ρ ₂ × Te × r ₂ . The transmission efficiency T ₂ / T ₁ is calculated by dividing the rotational torque T ₂ of the driven pulley by the rotational torque T ₁ of the drive pulley, and can be expressed by the following equation.

T ₂ / T ₁ = (ρ ₂ × Te × r ₂ ) / (ρ ₁ × Te × r ₁ ) = (ρ ₂ × r ₂ ) / (ρ ₁ × r ₁ )
Actually, the transmission efficiency does not become a value of 1 or more, but the closer to 1, the smaller the belt transmission loss and the better the fuel economy. T ₂ / T ₁ may be 0.7 or more, for example, 0.7 to 0.9, preferably about 0.75 to 0.85.

[Manufacturing method of transmission V-belt]
The production method of the transmission V-belt of the present invention is not particularly limited, and a conventional method can be used for the lamination process of each layer (a production method of the belt sleeve).

  For example, in the case of a cogged V belt, a laminated body composed of a reinforcing cloth (under cloth) and a sheet for a compressed rubber layer (unvulcanized rubber) is arranged with teeth and grooves alternately with the reinforcing cloth down. Installed on a flat cogged mold, cog pad with the cog part formed by press-pressing at a temperature of about 60-100 ° C (especially 70-80 ° C) (not completely vulcanized, in a semi-cured state) After producing a certain pad), both ends of the cog pad may be cut vertically from the top of the cog crest. Furthermore, an inner mother die in which teeth and grooves are alternately arranged is covered on a cylindrical mold, and a cog pad is wound around the teeth and the grooves, and a joint is formed at the top of the cog crest, and this is wound. After laminating the first adhesive rubber layer sheet (lower adhesive rubber: unvulcanized rubber) on the cog pad, the core wire was spun into a spiral shape, and the second adhesive rubber layer sheet (upper adhesive) Rubber: Same as the adhesive rubber layer sheet), a stretch rubber layer sheet (unvulcanized rubber), and a reinforcing cloth (upper cloth) may be wound in order to produce a molded body. After that, a jacket is put on and the mold is placed in a vulcanizing can, and vulcanized at a temperature of about 120 to 200 ° C. (especially 150 to 180 ° C.) to prepare a belt sleeve. Cutting may be performed.

  In the stretched rubber layer sheet and the compressed rubber layer sheet, as a method of aligning the orientation direction of the short fibers in the belt width direction, a conventional method, for example, rubber between a pair of calendar rolls provided with a predetermined gap is used. Rolled into a sheet shape, cut both sides of the rolled sheet with short fibers oriented in the rolling direction in a direction parallel to the rolling direction, and rolled the rolled sheet to have a belt forming width (length in the belt width direction) Examples include a method in which side surfaces cut in a direction perpendicular to the direction and in a direction parallel to the rolling direction are joined together. For example, the method described in JP2003-14054A can be used.

  The present invention is characterized by undergoing a step of partially polishing the side surface of the obtained V-shaped belt sleeve. As a method for polishing the side surface of the belt sleeve, a conventional method can be used. For example, the belt sleeve is suspended between a driving pulley and a driven pulley, and the belt sleeve is rotated while rotating in the longitudinal direction of the belt under a predetermined tension. For example, a method in which the polished polishing tool is brought into contact with the side surface of the sleeve for polishing can be used. In the present invention, among the belt side surfaces (extension rubber layer, adhesive rubber layer, and compression rubber layer), at least the side surfaces of the extension rubber layer are polished, and at least a part of the side surfaces of the compression rubber layer (particularly the inner peripheral region) is polished. By not polishing, a smooth region can be formed on the side surface of the compressed rubber layer, so that acceleration performance can be stably maintained for a long time even when used in a transmission. As a polishing tool, for example, sanding paper or the like can be used. The polishing method may be, for example, a polishing method described in JP 2008-44017 A (Patent Document 2).

  Among these polishing methods, a method using a rotatable disk-shaped polishing tool can be used because the side surface is easily polished partially. FIG. 9 is a schematic view for illustrating a method of polishing a part of the side surface (back side) of the belt sleeve. In this example, the polishing tool 41 has a disk shape whose surface that contacts the belt sleeve is formed of sanding paper and is rotationally driven by the rotating shaft 42. Sanding paper is disposed on the polishing tool 41 so as to come into contact with both side surfaces of the belt sleeve, and the polishing tool 41 can move in the direction of approaching and detaching from the side surface of the transmission belt. By bringing the polishing tool 41 close to and in contact with the side surface of the belt sleeve, the side surface of the belt sleeve can be polished by the polishing tool 41. In this example, the width of the outer peripheral surface of the polishing tool 41 is adjusted to a width capable of polishing the entire side surfaces of the adhesive rubber layer and the stretched rubber layer, and the outer peripheral surface of the disc-shaped polishing tool is adjusted to the side surface of the belt sleeve. The entire side surfaces of the adhesive rubber layer and the stretched rubber layer can be polished by locally pressing against a part (the back side) and polishing. By polishing in this way, it is possible to polish only the back side (adhesive rubber layer and stretched rubber layer) of the side surface of the belt and cause the short fibers to protrude from the side surface of the stretched rubber layer, thereby reducing the friction coefficient. Furthermore, when the core wire is exposed from the side surface by polishing the side surface of the adhesive rubber layer, the friction coefficient can be further reduced. In FIG. 9, polishing is performed with the rotation shaft 42 oriented parallel to the side surface of the belt sleeve, but by changing the angle of the rotation shaft, the belt angle of the polishing part and the belt angle of the unpolished part are different. May be. When changing the angle between the polishing part and the unpolished part, it is preferable to form the belt angle of the polishing part smaller than the belt angle of the unpolished part.

  FIG. 10 is a schematic cross-sectional view for illustrating another example of the polishing portion on the side surface of the belt sleeve. In this example, the belt side surface is not only the side surface of the stretched rubber layer and the adhesive rubber layer, but also in the compressed rubber layer, from the interface 53 between the adhesive rubber layer and the compressed rubber layer, the central portion of the interface 53 and the cog bottom 52. The side surface of the region up to this point is also polished to form a polishing portion 51.

  In the present invention, the polishing portion to be polished in the polishing step may polish at least the side surface of the stretched rubber layer, and the side surface of the adhesive rubber layer and the side surface of the compressed rubber layer may be polished even if polished. Or either. In the case of polishing the side surface of the compressed rubber layer, it is preferable that at least the inner peripheral side surface (for example, the region including the entire cog portion) be an unpolished portion. In particular, as shown in FIG. It is preferable that the region from (the top of the cog portion) to the central portion of the interface between the adhesive rubber layer and the compressed rubber layer and the cog bottom portion (for example, the entire side surface of the compressed rubber layer) is an unpolished portion. Depending on the purpose, the side surface of the adhesive rubber layer may be polished in order to improve the initial slidability, but from the point that the stability of acceleration performance can be highly improved, the side surface of the adhesive rubber layer is It is preferable to polish only the side surface of the stretched rubber layer (only the entire side surface of the stretched rubber layer) without polishing.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the following examples, measurement methods or evaluation methods for each physical property, and raw materials used in the examples are shown below. Unless otherwise specified, “part” and “%” are based on mass.

(1) Average protruding height of short fibers A belt is cut in a direction parallel to the belt width direction, and this cut surface is enlarged and observed using a scanning electron microscope ("JSM5900LV" manufactured by JEOL Ltd.). The protruding heights of the more protruding short fibers (100 fibers) were measured, and the average protruding height was obtained by averaging 100 measured values.

(2) Density of short fibers The belt is cut in a direction parallel to the belt thickness direction (perpendicular to the direction of short fiber orientation), and this cut surface is scanned using a scanning electron microscope ("JSM5900LV" manufactured by JEOL Ltd.). The number of short fibers existing in a predetermined area (for example, 1 mm ² ) was counted, and this was calculated by converting per 1 cm ² .

(3) Belt angle The belt angle is obtained by tracing the V shape of the belt using a contact-type shape measuring instrument ("CBH-1" manufactured by Mitutoyo Corporation) and using analysis software based on the shape data. The angle formed by both sides was measured.

(4) Friction coefficient As shown in FIG. 11, the friction coefficient of the belt is such that one end of the cut low-edge cogged V-belt 61 is fixed to the load cell 62, and a load 63 of 3 kgf is placed on the other end. The belt 61 was wound around the pulley 64 by setting the winding angle of the belt around the pulley 64 to 45 °. The belt 61 on the load cell 62 side was pulled at a speed of 30 mm / min for about 15 seconds, and the average friction coefficient of the friction transmission surface was measured. In the measurement, the pulley 64 was fixed so as not to rotate. This measurement was performed on a new belt and a belt after running-in under the following conditions.

  In the running-in, as shown in FIG. 12, a belt is hung on a driving (Dr.) pulley having a diameter of 95 mm and a driven (Dn.) Pulley having a diameter of 85 mm, the rotational speed of the driving pulley is 5000 rpm, and the driven pulley is 3 N · m. The belt was run for 24 hours in a room temperature atmosphere.

(5) Speed change speed A low-edge cogged V-belt is set on a 125cc two-wheeled scooter, and the drive pulley speed is rapidly increased from 1500 rpm (idle state) to 8000 rpm (full slot) in 1 second. The number of revolutions (the number of revolutions of the drive pulley when the belt of FIG. The speed change speed was measured for a new belt and a belt after running-in, and the change in the speed change speed after the new and running-in was determined. The smaller the change, the more stable the acceleration performance of the belt can be maintained for a long time.

(6) High-speed running test In this running test, the transmission efficiency of the belt when the belt was run while sliding on the pulley radially outward was evaluated. In particular, when the rotational speed of the drive pulley increases, centrifugal force acts strongly on the belt. Further, the belt tension acts low at a position on the loose side of the drive pulley (see FIG. 12), and the belt tends to jump outward in the pulley radial direction at this position due to the combined action with the centrifugal force. If this pop-out does not occur smoothly, that is, if a frictional force acts strongly between the belt's frictional transmission surface and the pulley, the frictional force causes a belt transmission loss, resulting in a decrease in transmission efficiency.

  As shown in FIG. 12, the high-speed running test was performed using a two-axis running test machine including a driving (Dr.) pulley 72 having a diameter of 95 mm and a driven (Dn.) Pulley 73 having a diameter of 85 mm. Next, a low-edge cogged V-belt (new) 71 is hung on each pulley 72, 73, the rotational speed of the driving pulley 72 is 5000 rpm, a load of 3 N · m is applied to the driven pulley 73, and the belt is run at room temperature. 71 was run. Then, after running, the rotational speed of the driven pulley 72 was read from the detector, and the transmission efficiency was obtained from the above formula. In addition, the presence or absence of abnormal noise during running of the belt was audibly confirmed.

(7) Endurance Running Test The endurance running test uses a two-axis running test machine comprising a driving (Dr.) pulley 82 having a diameter of 50 mm and a driven (Dn.) Pulley 83 having a diameter of 125 mm, as shown in FIG. It was done. Next, a low-edge cogged V-belt (new article) 81 is hung on each pulley 82, 83, the rotational speed of the driving pulley 82 is 5000 rpm, a load of 10 N · m is applied to the driven pulley 83, and the ambient temperature is 80 ° C. The belt 81 was run for 400 hours. The running time was evaluated without the belt 81 being stopped by cutting or the like.

(8) Raw material Aramid short fiber: “Conex short fiber” manufactured by Teijin Techno Products Limited, average fiber length 3 mm, average fiber diameter 14 μm
Cotton short fiber: Denim cut yarn, average fiber length 6mm, average fiber diameter 13μm
Naphthenic oil: “RS700” manufactured by DIC Corporation
Carbon black: “Seast 3” manufactured by Tokai Carbon Co., Ltd.
Anti-aging agent: “Nonflex OD3” manufactured by Seiko Chemical Co., Ltd.
Vulcanization accelerator: Tetramethylthiuram disulfide (TMTD)
Silica: “Nipsil VN3” manufactured by Tosoh Silica Corporation
Core wire: A fiber obtained by bonding a cord of total denier 6,000 in which a PET fiber of 1,000 denier is twisted with a 2 × 3 twist structure and an upper twist coefficient of 3.0 and a lower twist coefficient of 3.0.

Examples 1-3 and Comparative Examples 1-3
(Formation of rubber layer)
The rubber compositions in Table 1 (compressed rubber layer, stretched rubber layer) and Table 2 (adhesive rubber layer) were each kneaded using a known method such as a Banbury mixer, and the kneaded rubber was passed through a calender roll. Rolled rubber sheets (compressed rubber layer sheet, stretch rubber layer sheet, adhesive rubber layer sheet) were prepared. Formulation A and Formulation B in Table 1 were the same except that the types of short fibers and the blending amounts thereof were different.

(Manufacture of belts)
75. Laminate of reinforcing cloth (lower cloth) and compressed rubber layer sheet (unvulcanized rubber) is placed on a flat cogged mold with teeth and grooves alternately arranged with the reinforcing cloth facing down. A cog pad (not completely vulcanized but in a semi-vulcanized state) with a cog part formed by press-pressing at 0 ° C. was produced. Next, both ends of the cog pad were cut vertically from the top of the cog crest.

  Cover the inner die with teeth and grooves alternately on a cylindrical mold, engage the teeth and grooves, wrap a cog pad, and joint at the top of the cog crest. After laminating an adhesive rubber layer sheet (lower adhesive rubber: unvulcanized rubber), the core wire is spun into a spiral shape, and an adhesive rubber layer sheet (upper adhesive rubber: the adhesive rubber layer sheet) is formed thereon. And a stretched rubber layer sheet (unvulcanized rubber) and a reinforcing cloth (upper cloth) were sequentially wound to prepare a molded body. Thereafter, the jacket was put on and the mold was placed in a vulcanizing can and vulcanized at a temperature of 160 ° C. for 20 minutes to obtain a belt sleeve. This sleeve is cut into a V shape with a cutter, and a belt having a structure shown in FIG. 3, ie, a cog on the inner peripheral side of the belt, without polishing or polishing a part (back side) or the whole of both sides of the belt. A low edge cogged V-belt (size: upper width 22.0 mm, thickness 11.0 mm, outer peripheral length 800 mm) as a transmission belt was produced.

  In Example 1, the adhesive rubber layer (including the core wire), the stretched rubber layer, and the upper cloth were polished, and the compressed rubber layer was not polished. Example 2 is the same as Example 1 except that the adhesive rubber layer is not polished. Example 3 is the same as Example 2 except that the blending of the stretched rubber layer and the compressed rubber layer is different. On the other hand, Comparative Example 1 is the same as Example 1 except that the entire belt side surfaces (lower cloth to upper cloth) are polished. Comparative Example 2 is the same as Example 1 except that both sides of the belt are not polished. Comparative Example 3 is the same as Comparative Example 2 except that the belt angle is reduced.

In the obtained belt, the average protruding height of short fibers in the stretched rubber layers (formulation A) of Examples 1 and 2 and Comparative Example 3 was 150 μm, the density was 97,000 pieces / cm ² , and Example 3 In the stretched rubber layer (Blend B), the average protruding height of short fibers was 55 μm, and the density was 120,000 fibers / cm ² .

  Table 3 shows the evaluation results of the belts obtained in the examples and comparative examples.

  As is apparent from Table 3, since Examples 1 to 3 had a lower coefficient of friction when compared with Comparative Example 2, the sliding loss with the pulley was reduced and the transmission efficiency was high. In Examples 1 to 3, since the compressed rubber layer was not polished, the change in the friction coefficient of the belt was small and the change in the transmission rotation speed was small between when new and after running-in. On the other hand, in Comparative Example 1, since the entire belt side surface is polished, the friction coefficient at the time of a new article is lower than that in Examples 1 to 3, and the transmission efficiency is increased, but after running-in, the short fibers protrude. As a result, the friction coefficient increased, the difference between the new product and after running-in increased, and the change in the speed of the transmission increased.

  Further, comparing Examples 1 to 3, Example 1 polished to adhesive rubber has a small coefficient of friction when new and transmission efficiency is better than that of Examples 2 and 3, but after acclimation and when new. The change in the friction coefficient was large, and the change in the shift rotational speed was larger than in Examples 2 and 3. In Example 3, the cotton short fibers were less prone to protrude than the aramid short fibers, and thus the friction coefficient was high. However, the changes in transmission efficiency and shift speed were the same as in Example 2.

  Comparative Example 2 was non-polished and had the lowest transmission efficiency due to the high coefficient of friction when new. In Comparative Example 3, the belt angle was smaller than the pulley angle, and the belt rear surface did not contact the pulley, so the friction coefficient and sliding loss were reduced, and the transmission efficiency was the same as in Examples 1-3. However, since the inner peripheral side of the belt was in strong contact with the pulley and the belt was deformed, the belt fell inwardly in the pulley radial direction and the cog tip of the belt contacted the pulley, generating abnormal noise (cog pitch noise).

  The transmission V-belt according to the present invention is used for a belt (transmission belt) used in a transmission in which the transmission ratio changes steplessly while the belt is running, has a V-shaped cross section, and requires various transmission losses. Friction power transmission V-belt, for example, low-edge belt with V-shaped cross-section, low-edge cogged V-belt provided with cogs on the inner peripheral side or both inner and outer peripheral sides of the low-edge belt, V-ribbed belt, etc. Can be used for Cogd V-belts.

DESCRIPTION OF SYMBOLS 1 ... Transmission V belt 2,6 ... Reinforcement cloth 3 ... Stretch rubber layer 3a ... Protruding short fiber 4 ... Adhesive rubber layer 4a ... Core wire 5 ... Compression rubber layer 5a ... Short fiber

Claims (11)

An adhesive rubber layer having a core wire embedded in the longitudinal direction of the belt; a compression rubber layer formed on one surface of the adhesive rubber layer; and an elastic rubber layer formed on the other surface of the adhesive rubber layer. A transmission V-belt,
Short fibers are embedded in the compressed rubber layer and the stretched rubber layer so as to be oriented in the belt width direction,
At least a side surface of the stretched rubber layer protrudes short fibers, and the side surface of the compressed rubber layer has a smooth region in which the average projecting height of short fibers is lower than the average projecting height of short fibers in the entire side surface of the stretched rubber layer. A transmission V-belt.   The transmission V-belt according to claim 1, wherein the entire side surface of the compressed rubber layer is a smooth region.   The transmission V-belt according to claim 1 or 2, wherein the entire side surfaces of the compressed rubber layer and the adhesive rubber layer are smooth regions.   The transmission V-belt according to any one of claims 1 to 3, wherein the short fibers do not protrude in a smooth region.   The belt angle in the smooth region is substantially the same as the pulley angle, and the belt angle in the stretched rubber layer is substantially the same as the pulley angle or smaller than the pulley angle. The transmission V-belt described.   The transmission V-belt according to any one of claims 1 to 5, wherein the transmission V-belt is a transmission belt constituted by a low-edge cogged V-belt.   The method for producing a transmission V-belt according to any one of claims 1 to 6, further comprising a polishing step of polishing at least a side surface of the stretched rubber layer among the side surfaces of the stretched rubber layer, the adhesive rubber layer, and the compressed rubber layer.   The manufacturing method according to claim 7, wherein at least a side surface of the inner peripheral side of the belt among the side surfaces of the compressed rubber layer is not polished.   The manufacturing method according to claim 7 or 8, wherein the entire side surface of the compressed rubber layer is not polished.   The manufacturing method according to claim 7, wherein only the side surface of the stretched rubber layer is polished.   A method of using the transmission V-belt according to claim 1 for a transmission.

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