JP2012193770A - Composite v belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a composite V belt to efficiently transmit power.SOLUTION: The composite V belt B includes a plurality of blocks 10 each having a slit-like fitting part 11 which opens sideward at each of both sides in a belt breadthwise direction and a pair of endless tension belts 20 each fitted with the fitting part 11 of the plurality of blocks 10 so as to couple the plurality of blocks 10. Each of the blocks 10 has a fitting protrusion 12a on an upper surface of each fitting part 11. Each of the pair of tension belts 20 has, on an upper surface side thereof, a fitting recess 21 formed to fit with the fitting protrusion 12a on the upper surface of the fitting part 11 of the block 10 and a lower surface side formed as a flat surface with a coefficient of friction of 0.7 or higher.

Description

  The present invention relates to a composite V-belt.

  2. Description of the Related Art Belt-type continuously variable transmissions that can improve operability during shifting, improve fuel consumption, and the like are known as transmissions in agricultural machines and automobiles (for example, Patent Documents 1 and 2). . The composite V-belt used in such a belt-type continuously variable transmission has a configuration in which a large number of blocks are locked and fixed at intervals in the belt length direction in an endless tension band, and thereby wound around a pulley. Sometimes both sides are able to withstand the high lateral pressure from the pulley.

JP 2000-120794 A International Publication 2010/023824 Pamphlet

  An object of the present invention is to enable power transmission with high efficiency of a composite V-belt.

Each of the present invention includes a plurality of blocks each having slit-like fitting portions that are open laterally on both sides in the belt width direction,
Each of a pair of endless tension bands fitted to connect the plurality of blocks to the fitting portions of the plurality of blocks,
With
Each of the plurality of blocks has a fitting convex portion formed on the upper surface of each fitting portion,
Each of the pair of tension bands has a flat surface with a fitting recess formed on the upper surface of the fitting convex portion on the upper surface of the fitting portion of the block and a lower surface of a friction coefficient of 0.7 or more. It is the composite V belt comprised in this.

  According to the present invention, it has a structure that fits to the block on the upper surface side of the tension band, and the lower surface side is configured to be a flat surface having a friction coefficient of 0.7 or more, so that power can be transmitted with high efficiency. .

It is a perspective view of the V belt for high load transmission. It is II-II sectional drawing in FIG. It is a side view of a block. It is a side view of a tension belt. It is explanatory drawing which shows the measuring method of the friction coefficient of a tension belt. (A) And (b) is a figure which shows the pulley layout of a belt transmission. (A) And (b) is explanatory drawing which shows the difference in an effect | action by the presence or absence of the fitting structure of the lower surface side of a tension belt. (A)-(d) is a pulley layout figure of the belt running test implemented by the test evaluation 1. FIG. (A)-(c) is a side view of the test evaluation belts 1-3 evaluated by test evaluation 2. FIG. It is explanatory drawing which shows the test method in the test evaluation 2. FIG. It is a graph which shows the relationship between the temperature in a thermostat, and belt bending rigidity.

  Hereinafter, embodiments will be described in detail based on the drawings.

  1 and 2 show a composite V-belt B according to this embodiment. The composite V-belt B is suitably used as a transmission belt, for example, in a motorcycle continuously variable transmission with an engine displacement of 250 cc or less.

  The composite V-belt B according to the present embodiment has a configuration in which a plurality of blocks 10 are connected to each other on both sides by a pair of endless tension bands 20. For example, the composite V-belt B has a belt length of 450 to 750 mm and a belt pitch width of 20 to 30 mm. In the composite V belt B, for example, the number of blocks 10 is 90 to 375 and the block pitch is 2 to 5 mm.

  FIG. 3 shows block 10.

  Each block 10 is formed with a slit-like fitting portion 11 that opens laterally on both sides in the belt width direction of a trapezoidal plate-like body whose upper base is longer than the lower base in plan view. "Is arranged in a shape that the letter" "is horizontal. Each block 10 is formed so that the upper part from the fitting part 11 has a uniform thickness in a side view, while the lower part from the fitting part 11 becomes thinner as it goes downward. . Each block 10 has a height of 10 to 16.5 mm, a width of 20 to 30 mm, and a thickness of 2 to 5 mm, for example. The angle formed by both sides, that is, the belt angle is, for example, 15 to 26 °.

Each fitting part 11 of each block 10 is formed so as to extend horizontally at a uniform interval from the back part on the center side toward the opening on the side part. Each fitting portion 11 is formed with an upper fitting convex portion 12a made of a protrusion having a substantially rectangular cross section extending in the belt width direction so that both sides in the thickness direction are sandwiched by flat surfaces on the upper side surface. At the same time, a lower support convex portion 12b made of a protrusion having an arcuate cross section extending in the belt width direction is formed on the entire lower surface. In addition, it is preferable that the maximum curvature of the curved surface of the lower support convex portion 12b is equal to or smaller than the pulley diameter of the minimum pulley to be used. Each fitting part 11 is comprised by the surface which the back part continued from the upper surface inclines in the back | inner side, and the surface which inclines to the outer side continuously from the surface, and continues to a lower surface. Each fitting portion 11 is, for example, a belt thickness direction of the clearance _{t 1} is 0.7～3.0Mm, and depth in the belt width direction is 2 to 5 mm. For example, the upper fitting convex portion 12a has a height of 0.5 to 1.0 mm and a width of 1.0 to 2.0 mm. The width of the flat surfaces on both sides of the upper fitting convex portion 12a is, for example, 5.0 to 15.0 mm. The lower support convex portion 12b has a radius of curvature of, for example, 1.0 to 1.5 mm. In addition, the shape and dimension structure of the upper fitting convex part 12a and the lower support convex part 12b are not limited to these.

  Each block 10 has a configuration in which a metal reinforcing material 13 disposed in the center so as to form a skeleton is covered with a hard resin coating material. The entire metal reinforcing material 13 does not need to be covered with the hard resin coating material. It is sufficient that at least the contact portion with the tension band 20 and the pulley is covered, and the metal reinforcing material 13 is exposed in the other portions. It may be.

  The metal reinforcing member 13 is formed in a shape that has the letter “H” beside it, like the block 10, and the center pillars 13c vertically move between the center portions of the upper and lower beams 13a and 13b extending in the belt width direction. It has the structure connected to. The metal reinforcing material 13 is made of, for example, a lightweight aluminum alloy having high strength and high elastic modulus. In the metal reinforcing member 13, for example, the height of the upper beam 13a is 5.0 to 9.5 mm, and the height of the lower beam 13b is 5.0 to 9.5 mm.

  The hard resin coating material is made of, for example, a hard thermosetting phenol resin material, and aramid short fibers or milled carbon fibers may be mixed. The hard resin coating material has a layer thickness of, for example, 0.8 to 1.5 mm.

  FIG. 4 shows the tension band 20.

Each tension band 20 is formed in an endless flat band shape. Each tension band 20 is chamfered on the upper side and the lower side so that one side corresponds to the shape of the back part of the block 10, and the other side corresponds to the inclination of the side part of the block 10. Formed on the inclined surface. Each tension band 20 is formed with fitting recesses 21 having a shape corresponding to the upper fitting protrusions 12a of the block 10 extending in the belt width direction on the upper surface side at a constant pitch in the belt length direction, and friction on the lower surface side. It is configured on a flat surface with a coefficient μ ′ 0.7 or more. Each tension band 20 has a length of 450 to 750 mm, a width of 20 to 30 mm, and a thickness of 2 to 5 mm, for example. Particularly the thinnest portion (fitted into partial) _{t 2} is for example 0.7~3.0mm thickness at the bottom of the fitting recess 21. ratio total thickness of t ₂ is, for example, 16%. The fitting recess 21 is larger than the upper fitting protrusion 12a of the block 10, and has a depth of 0.5 to 1.0 mm and a width of 1.0 to 2.0 mm, for example. The friction coefficient μ ′ on the lower surface side of the tension band 20 is 0.7 or more, but is preferably 0.7 to 1.5. The friction coefficient μ ′ on the lower surface side of the tension band 20 is the elastic modulus of the material such as rubber, fiber (including reinforcing short fibers), resin, etc. constituting the lower surface side of the tension band 20, and its blending (for example, the blending amount of the reinforcing short fibers). Etc.). Further, as shown in FIG. 5, the friction coefficient μ ′ is obtained by winding a test piece B created by cutting the tension band 20 into a strip shape around the pulley P at a winding angle θ so that the lower surface side contacts. One end when one end extending horizontally from P is connected to a load cell L fixed to the wall, and a weight W is attached to the other end hanging vertically from the pulley P, and the pulley P is rotated. From the tension Tt (load of the load cell L) and the tension Ts (weight of the weight W) of the other part, μ ′ = ln (Tt) based on the Euler expression exp (μ′θ) = Tt / Ts / Ts) / θ.

  Each tension band 20 has a core wire 23 embedded in a spiral having a pitch in the belt width direction at the center of the shape-retaining rubber layer 22 constituting the main body in the belt thickness direction. The upper reinforcing fabric 24 and the lower reinforcing fabric 25 are pasted on the upper surface side and the lower surface side, respectively. Therefore, the flat surface on the lower surface side of the tension band 20 is composed of the lower reinforcing cloth 25. The tension band 20 may be configured such that the upper reinforcing cloth 24 and / or the lower reinforcing cloth 25 is not provided. In the case where the lower reinforcing cloth 25 is not provided, the lower surface of the tension band 20 is used. The flat surface on the side is constituted by the shape-retaining rubber layer 22.

  The shape-retaining rubber layer 22 is formed of a rubber composition using H-NBR, EPDM, or the like as raw rubber. The rubber composition constituting the shape-retaining rubber layer 22 is preferably reinforced by adding an unsaturated carboxylic acid metal salt such as zinc dimethacrylate or zinc diacrylate to the raw rubber, and is a reinforcing material. In addition to carbon black or silica, organic short fibers such as aramid short fibers and nylon short fibers are preferably blended and reinforced, and further, crosslinked with an organic peroxide such as dicumyl peroxide. preferable. The rubber composition constituting the shape retaining rubber layer 22 preferably has a rubber hardness of 70 ° or more when measured with a JIS-C hardness meter, and has a rubber hardness of 70 to 80 °. It is more preferable.

  The core wire 23 is subjected to a treatment of heating after being immersed in an RFL aqueous solution in a high-strength fiber twisted yarn or braid such as aramid fiber, PBO fiber, carbon fiber, and / or a treatment of drying after being immersed in rubber paste. It is configured. The core wire 23 is composed of, for example, a filament bundle of 2640 to 4400 dtex and has an outer diameter of 0.55 to 0.70 mm.

  Each of the upper and lower reinforcing fabrics 24 and 25 is a process of heating after immersing in an RFL aqueous solution in a woven fabric, knitted fabric, or non-woven fabric such as aramid fiber or nylon fiber, and / or dipping or coating rubber paste on rubber paste. It is comprised of what has been subjected to a drying process. Each of the upper and lower reinforcing cloths 24 and 25 has a thickness of 0.6 to 1.2 mm, for example.

  These dimensions and configurations are not limited to these.

  In the composite V belt B of the present embodiment, a tension band 20 is fitted so as to connect the fitting portions 11 of the plurality of blocks 10 to each other. Specifically, the tension band 20 is inserted into each fitting portion 11 of each block 10 from one side portion chamfered, and the upper fitting convex portion 12a on the upper side surface of the fitting portion 11 is formed. While fitting into the fitting recess 21 on the upper surface side of the tension band 20, the top part of the lower support convex part 12 b of the lower surface is in contact with the flat surface on the lower surface side of the tension band 20, and the back part of the fitting part 11 The tension band 20 is fitted into the fitting portion 11 so that one side of the tension band 20 abuts. Thus, a structure in which the plurality of blocks 10 are locked and fixed to the pair of tension bands 20 at intervals in the belt length direction is formed, and the tension bands exposed on both sides and outside of the plurality of blocks 10 The other side part of 20 is comprised by the power transmission part which contacts a pulley.

In the composite V belt B of the present embodiment, the gap t ₁ of the gap of the fitting portion 11 of the block 10 is slightly smaller than the thickness t ₂ of the fitting recess 21 of the tension band 20. Accordingly, the tension band 20 is fitted into the fitting portion 11 of the block 10 in a compressed state. Here, the tightening allowance t ₂ -t ₁ is, for example, 0.03 to 0.15 mm, and the tightening allowance is a ratio of the tightening allowance t ₂ -t ₁ to the gap t ₁ of the gap of the fitting portion 11 of the block 10. When the rate is expressed by α = {(t ₂ −t ₁ ) / t1} × 100, α = 1 to 5% is preferable, and 2 to 3% is more preferable.

  Further, in the composite V belt B of the present embodiment, the tension band 20 is provided so as to protrude from the side of the block 10, thereby projecting an impact when the composite V belt B enters the pulley. It can be relaxed by the tension band 20. Here, the allowance Δd is, for example, 0.03 to 0.15 mm, and the insertion pitch width w of the tension band 20 in the belt pitch line is, for example, 7.5 to 12.0 mm. The output allowance rate, which is the ratio of the output allowance Δd to the insertion pitch width of the tension band 20 at the tenth tension band engagement position (or half the block pitch width at the tension band engagement position of the block 10) w, is expressed by When expressed by w) × 100, β is preferably 0.3 to 1.5%, and more preferably 0.4 to 7%. The allowance Δd can be easily measured by scanning the side surface of the composite V-belt B with a tracer (contour shape measuring device).

  The product α × β of the interference allowance rate α and the allowance rate β is preferably 0.6 to 5.0, and more preferably 0.8 to 2.1.

  6A and 6B show a belt transmission device 30 using the composite V-belt B. FIG.

  The belt transmission device 30 includes a drive shaft 31 and a driven shaft 33 arranged in parallel thereto, a drive pulley 32 on the drive shaft 31, and a substantially the same diameter as the drive pulley 32 on the driven shaft 33. The following driven pulleys 34 are provided. The drive pulley 32 includes a fixed sheave that is rotatably and non-slidably fixed on the drive shaft 31, and a movable sheave that is rotatably and slidably supported so as to face the fixed sheave. ing. Similarly, the driven pulley 34 includes a fixed sheave that is rotatably and non-slidably fixed on the driven shaft 33, and a movable sheave that is rotatably and slidably supported so as to face the fixed sheave. It has. Each of the driving pulley 32 and the driven pulley 34 has a V groove formed between the fixed sheave and the movable sheave, and the composite V belt B is stretched between the V grooves of the driving pulley 32 and the driven pulley 34. . Each of the driving pulley 32 and the driven pulley 34 is configured so that the pulley pitch diameter (pulley diameter at a position corresponding to the belt pitch line) is in a range of 55 to 155 mm.

  In this belt transmission device 30, the power required for belt transmission is supplied on the drive shaft 31 side and consumed on the driven shaft 33 side, and the belt winding diameter of the drive pulley 32 and the winding diameter of the driven pulley 34 are the same. By changing, the running speed of the composite V-belt B is changed. Specifically, when the movable sheave of the drive pulley 32 is brought close to the fixed sheave and the movable sheave of the driven pulley 34 is moved away from the fixed sheave, as shown in FIG. This is larger than the belt winding diameter of the driven pulley 34. As a result, the composite V-belt B travels at a high speed. Conversely, when the movable sheave of the drive pulley 32 is moved away from the fixed sheave and the movable sheave of the driven pulley 34 is moved closer to the fixed sheave, as shown in FIG. Becomes smaller than the belt winding diameter of the driven pulley 34, and as a result, the composite V-belt B travels at a low speed. That is, in the belt transmission device 30, the continuously variable transmission mechanism is configured with the above configuration.

  In the composite V belt B of the present embodiment as described above, the upper surface side of the tension band 20 has a structure that fits the block 10, while the lower surface side is configured as a flat surface having a friction coefficient μ′0.7 or more. The block 10 does not have a fitting structure on the lower surface side of the tension band 20, and the degree of freedom is increased while the block 10 is moderately restrained with respect to the tension band 20, and as shown in FIG. Even when bending deformation is applied, the belt bending rigidity can be prevented from increasing and heat generation can be suppressed. On the other hand, when the tension band 20 has a fitting structure on the lower surface side, as shown in FIG. 7B, when the belt is wound around the pulley and bending deformation is applied, the lower surface side of the tension band 20 is fitted. The joint recess 21 ′ is closed, and the fitting force to the block 10 is increased, thereby causing a compressive strain and increasing heat generation. Further, if the tension band 20 has a fitting structure on both the upper surface side and the lower surface side, the expansion of the tension band 20 is more significant than the expansion of the block 10 when the belt temperature rises. However, in the case of the composite V-belt B of this embodiment, the increase in the belt bending rigidity can be suppressed. As a result, according to the composite V-belt B of this embodiment, it is possible to transmit power with high efficiency. In the case of transmission of extremely high load power in a belt type continuously variable transmission or the like in an automobile or the like, a fitting structure with the block 10 on the lower surface side of the tension band 20 is important, but a motorcycle with a displacement of 250 cc or less. If the load is about the same as the continuously variable transmission, the upper side of the tension band 20 has a fitting structure with the block 10 and the lower side has a fitting structure like the composite V belt B of this embodiment. By using a structure that does not, power transmission with extremely high efficiency becomes possible. In the composite V-belt B of the present embodiment, the center of gravity of the block 10 is on the belt pitch line, that is, the center position of the core wire 23 in the belt thickness direction from the viewpoint of enabling power transmission with high efficiency. Is preferred.

  Next, a method for manufacturing the composite V belt B will be described.

-Sheet-like uncrosslinked rubber composition preparation step-
A raw material rubber is kneaded into a rubber kneading machine such as a Banbury mixer, and then a rubber compounding agent is added thereto and kneaded. Then, the kneaded uncrosslinked rubber composition is processed into a sheet by a calender roll.

−Core preparation process−
A cord 23 is obtained by subjecting a twisted yarn or braid to a treatment of heating after being immersed in an RFL aqueous solution and / or a treatment of drying after being immersed in rubber paste. In addition, you may perform the process dried after immersing in twisted yarn etc. in an epoxy solution or an isocyanate solution before these processes.

-Upper and lower reinforcing fabric preparation process-
Upper and lower reinforcing cloths 24, 25, which are woven fabric, knitted fabric or non-woven fabric subjected to heating treatment after being immersed in an RFL aqueous solution and / or drying treatment after being immersed in rubber paste or coated with rubber paste, To do. In addition, you may perform the process dried after immersing in an epoxy solution or an isocyanate solution to a woven fabric etc. before these processes.

-Tension band forming process-
A cylindrical die having no irregularities on its outer peripheral surface is covered with a lower reinforcing cloth 25 formed into a cylindrical shape, and a predetermined layer of an uncrosslinked rubber composition processed into a sheet shape is provided thereon.

  Next, a cylindrical mold is placed in the heating and pressurizing apparatus, and the inside of the apparatus is set to a predetermined temperature and pressure so that the crosslinking of the uncrosslinked rubber composition proceeds about half, and the state is maintained for a predetermined time. At this time, the crosslinking of the uncrosslinked rubber composition proceeds about half, and the shape of the lower half of the shape-retaining rubber layer 22 is formed.

  Subsequently, the cylindrical mold is taken out from the heating and pressurizing apparatus, the core wire 23 is spirally wound at an equal pitch from above the semi-crosslinked rubber composition, and the uncrosslinked rubber composition is processed into a sheet shape again thereon. A predetermined layer is provided, and an upper reinforcing cloth 24 formed in a cylindrical shape is placed thereon.

  Next, a cylindrical sleeve having protrusions extending in the mold axial direction in the shape of the fitting recess 21 of the tension band 20 provided on the inner peripheral surface at equal pitches is placed on the outermost layer.

  Then, a cylindrical mold in which a material is set is placed in the heating and pressing apparatus, the interior of the apparatus is set to a predetermined temperature and pressure, and the state is maintained for a predetermined time. At this time, crosslinking of the semi-crosslinked and uncrosslinked rubber composition proceeds to form the shape retaining rubber layer 22. Further, the adhesive on the surface of the core wire 23 and the shape-retaining rubber layer 22 are mutually diffused so that the core wire 23 is integrally bonded to the shape-retaining rubber layer 22 and is attached to the upper and lower reinforcing cloths 24 and 25. The upper and lower reinforcing cloths 24 and 25 are integrally bonded to the shape-retaining rubber layer 22 by the mutual diffusion of the adhesive and the shape-retaining rubber layer 22. As described above, a cylindrical slab is formed on the surface of the cylindrical mold.

  Finally, the cylindrical mold is taken out from the heating and pressurizing device, the cylindrical slab formed on the peripheral surface is removed from the mold, this is cut into a band with a predetermined width, and chamfering is performed. The tension band 20 is formed.

-Block molding process-
After the metal reinforcing material 13 is set in the cavity formed in the block mold and the mold is clamped, the hard resin coating material is injected into the cavity and then the mold is opened after cooling. The metal reinforcing material 13 is placed in the hard resin coating material. The block 10 which is the inserted molded product is taken out. And the various processing required in order to raise intensity | strength is given to the shape | molded block 10. FIG.

-Assembly process-
The upper fitting convex portion 12a of the block 10 is made to correspond to the fitting concave portion 21 of one tension band 20, the upper fitting convex portion 12a is fitted into the fitting concave portion 21, and the lower side of the tension band 20 is flat. The tension band 20 is inserted into one fitting part 11 of the block 10 so that the surface abuts on the top of the lower support convex part 12 b of the block 10, and the block 10 is locked to the tension band 20. This operation is performed for the entire circumference of the tension band 20. Similarly, the other tension band 20 is inserted into the other fitting portion 11 of the block 10, thereby obtaining the composite V-belt B.

[Test Evaluation 1]
(Composite V belt)
A composite V-belt for the following test evaluation was produced. Each configuration is also shown in Table 1.

<Example 1>
A composite V-belt having the same configuration as that of the above embodiment, the belt length is 612 mm, the belt angle is 26 °, the belt pitch width is 25 mm, the block pitch is 3 mm, the block thickness is 2.95 mm, and the block height is 12.5 mm, 3 mm upper beam height of metal reinforcement, rubber composition constituting the tension band shape rubber layer measured by JIS-C hardness meter is 81 °, friction on the lower surface side of the tension band The coefficient μ ′ is 0.9, the tightening allowance (t ₂ −t ₁ ) is 0.05 mm and the tightening allowance rate α is 1.67%, the allowance Δd is 0.05 mm and the allowance allowance β is 0.50%, In addition, Example 1 in which α × β was 0.83 was designated as Example 1.

<Example 2>
Tightening allowance (t ₂ -t ₁ ) is 0.03 mm, Tightening allowance rate α is 1.00%, Output allowance Δd is 0.06 mm, Output allowance rate β is 0.60%, and α × β is 0.60 A composite V-belt having the same configuration as that of Example 1 except for the above was taken as Example 2.

<Example 3>
Tightening allowance (t ₂ -t ₁ ) is 0.06 mm, Tightening allowance rate α is 2.00%, Output allowance Δd is 0.03 mm, Output allowance rate β is 0.30%, and α × β is 0.60 Except for this, a composite V belt having the same configuration as in Example 1 was designated as Example 3.

<Example 4>
The tightening allowance (t ₂ -t ₁ ) is 0.09 mm, the tightening allowance rate α is 3.00%, the allowance Δd is 0.09 mm, the allowance allowance β is 0.90%, and α × β is 2.70. Except for this, a composite V belt having the same configuration as in Example 1 was designated as Example 4.

<Example 5>
Tightening allowance (t ₂ -t ₁ ) is 0.12 mm and fastening allowance rate α is 4.00%, outgoing allowance Δd is 0.12 mm, outgoing allowance rate β is 1.20%, and α × β is 4.80. A composite V belt having the same configuration as that of Example 1 except that the above is used as Example 5.

<Example 6>
The tightening allowance (t ₂ -t ₁ ) is 0.10 mm, the tightening allowance rate α is 3.33%, the allowance Δd is 0.15 mm, the allowance allowance β is 1.50%, and α × β is 5.00. Except for this, a composite V belt having the same configuration as in Example 1 was designated as Example 6.

<Example 7>
The tightening allowance (t ₂ -t ₁ ) is 0.15 mm and the tightening allowance rate α is 5.00%, the allowance Δd is 0.10 mm, the allowance allowance β is 1.00%, and α × β is 5.00. Except for this, a composite V belt having the same configuration as in Example 1 was designated as Example 7.

<Example 8>
Tightening allowance (t ₂ -t ₁ ) is 0.03 mm, Tightening allowance rate α is 1.00%, Output allowance Δd is 0.14 mm, Output allowance rate β is 1.40%, and α × β is 1.40. A composite V-belt having the same configuration as that of Example 1 was designated as Example 8 except that.

<Example 9>
Tightening allowance (t ₂ -t ₁ ) is 0.14 mm, Tightening allowance rate α is 4.67%, Output allowance Δd is 0.03 mm, Output allowance rate β is 0.30%, and α × β is 1.40. A composite V-belt having the same configuration as that of Example 1 was designated as Example 9 except that.

<Example 10>
A composite V belt having the same configuration as that of Example 1 except that the friction coefficient μ ′ on the lower surface side of the tension band is 0.7 is designated as Example 10.

<Example 11>
A composite V belt having the same configuration as that of Example 1 except that the friction coefficient μ ′ on the lower surface side of the tension band is 1.2 was designated as Example 11.

<Comparative Example 1>
Tightening allowance (t ₂ -t ₁ ) is 0.04 mm, Tightening allowance rate α is 1.33%, Output allowance Δd is 0.04 mm, Output allowance rate β is 0.40%, and α × β is 0.53 A fitting recess is formed on the lower surface side of the tension band to be fitted to the lower support convex part on the lower surface side of the block fitting part. Therefore, both the upper surface side and the lower surface side of the tension band are formed. A composite V belt having the same configuration as that of Example 1 except that it has a fitting structure was used as Comparative Example 1.

<Comparative example 2>
The tightening allowance (t ₂ -t ₁ ) is 0.13 mm, the tightening allowance rate α is 4.33%, the allowance Δd is 0.14 mm, the allowance allowance β is 1.40%, and α × β is 6.07. A composite V-belt having the same configuration as that of Comparative Example 1 was used as Comparative Example 2 except for the above.

<Comparative Example 3>
The tightening allowance (t ₂ -t ₁ ) is 0.03 mm, the tightening allowance rate α is 1.00%, the allowance Δd is 0.17 mm, the allowance allowance β is 1.70%, and α × β is 1.70. A composite V-belt having the same configuration as that of Comparative Example 1 was used as Comparative Example 3 except for the above.

<Comparative example 4>
Tightening allowance (t ₂ -t ₁ ) is 0.17 mm, Tightening allowance rate α is 5.67%, Output allowance Δd is 0.03 mm, Output allowance rate β is 0.30%, and α × β is 1.70. A composite V belt having the same configuration as that of Comparative Example 1 was used as Comparative Example 4 except for the above.

<Comparative Example 5>
The friction coefficient μ ′ on the lower surface side of the tension band is 1.2, the tightening allowance (t ₂ -t ₁ ) is 0.05 mm, the tightening allowance rate α is 1.67%, the allowance allowance Δd is 0.05 mm, and the allowance allowance rate A composite V belt having the same configuration as Comparative Example 1 except that β is 0.50% and α × β is 0.83 is referred to as Comparative Example 5.

<Comparative Example 5>
The friction coefficient μ ′ on the lower surface side of the tension band is 1.2, the tightening allowance (t ₂ -t ₁ ) is 0.05 mm, the tightening allowance rate α is 1.67%, the allowance allowance Δd is 0.05 mm, and the allowance allowance rate A composite V belt having the same configuration as Comparative Example 1 except that β is 0.50% and α × β is 0.83 is referred to as Comparative Example 5.

<Comparative Example 6>
The friction coefficient μ ′ on the lower surface side of the tension band is 1.2, the upper side surface and the lower side surface of the fitting part of the block are both flat surfaces, and the upper surface side and the lower surface side of the tension band are both flat. A composite V-belt having the same configuration as that of Example 1 except that the upper surface side and the lower surface side of the tension band have no fitting structure was used as Comparative Example 6.

<Comparative Example 7>
A composite V belt having the same configuration as that of Example 1 except that the friction coefficient μ ′ on the lower surface side of the tension band is 0.6 is referred to as Comparative Example 7.

(Test evaluation method)
The following belt running test was conducted.

<Transmission characteristics test>
For each of the composite V-belts B of Examples 1 to 11 and Comparative Examples 1 to 7, as shown in FIG. 8A, a driving pulley 71 having a pulley pitch diameter of 65.2 mm and a driven pulley having a pulley pitch diameter of 130.4 mm 72, a dead weight of 3000 N is loaded on the driven pulley 72, the inside of the thermostatic chamber 73 is set to room temperature, the drive pulley 71 is rotated at a rotation speed of 2600 rpm, and the slip ratio is 2%. N · m) was determined as a transmission characteristic.

<Transmission efficiency test>
For each composite V-belt B of Examples 1-11 and Comparative Examples 1-7, as shown in FIG. 8B, a driving pulley 71 having a pulley pitch diameter of 130.4 mm and a driven pulley having a pulley pitch diameter of 65.2 mm 72, a dead weight of 2000 N is loaded on the driven pulley 72, the inside of the thermostatic chamber 73 is set to room temperature, the driving pulley 71 is rotated at a rotational speed of 6000 rpm with a driving shaft torque of 30 N · m, and N _{1 at} that time : Input rotation speed, N ₂ : output rotation speed, Tr ₁ : input torque, and Tr ₂ : output torque, (N ₂ × Tr ₂ ) / (N ₁ × Tr ₁ )) × 100 was determined as the transmission efficiency. . Further, the transmission efficiency was similarly determined while blowing 90 ° C. warm air into the thermostat 73.

<Exothermic characteristic test>
For each composite V-belt B of Examples 1-11 and Comparative Examples 1-7, as shown in FIG. 8C, a driving pulley 71 having a pulley pitch diameter of 130.4 mm and a driven pulley having a pulley pitch diameter of 65.2 mm 72, and a dead weight of 3000 N is loaded on the driven pulley 72, and the driving pulley 71 is rotated at a rotational speed of 3000 rpm with no driving shaft torque while blowing hot air of 120 ° C. into the thermostatic chamber 73. Then, the temperature of the belt surface was measured with a non-contact type thermometer, and the steady belt temperature was obtained as a heat generation characteristic.

<High-speed durability test>
For each of the composite V belts of Examples 1 to 11 and Comparative Examples 1 to 7, as shown in FIG. 8D, a driving pulley 71 having a pulley pitch diameter of 133.6 mm and a driven pulley 72 having a pulley pitch diameter of 61.4 mm. In addition, a dead weight of 2500 N is loaded on the driven pulley 72 and the driving pulley 71 is rotated at a rotational speed of 5016 rpm with a driving shaft torque of 63.7 N · m while blowing warm air of 120 ° C. into the thermostat 73. The belt was run for a maximum running time of 500 hours until the belt broke. The running time until the belt breaks was defined as the high-speed durability life.

(Test evaluation results)
The test results are shown in Table 2.

  The transmission characteristics are 83.0 N · m in Examples 1 to 9, 78.0 N · m in Example 10, and 90.0 N · m in Example 11, and 83.0 N · m in Comparative Examples 1 to 5. m, Comparative Example 6 was 40.0 N · m, and Comparative Example 6 was 60.0 N · m.

  The transmission efficiency at room temperature is 98% in Examples 1 to 11, and 97% in Comparative Example 1, 96% in Comparative Example 2, 97% in Comparative Example 3, 97% in Comparative Example 4, and Comparative Example 5 Was 97%, Comparative Example 6 was 98%, and Comparative Example 7 was 98%. At 90 ° C., Examples 1-6 were 98%, Example 7 were 97%, and Examples 8-11 were 98%, and Comparative Example 1 was 92%, Comparative Example 2 was 90%, Comparative Example 3 Was 91%, Comparative Example 4 was 91%, Comparative Example 5 was 91%, Comparative Example 6 was 98%, and Comparative Example 7 was 98%.

  The heat generation characteristics are 106 ° C for Example 1, 106 ° C for Example 2, 105 ° C for Example 3, 108 ° C for Example 4, 114 ° C for Example 5, 112 ° C for Example 6, and Example 7 for Example 7. 115 ° C., Example 8 is 108 ° C., Example 9 is 110 ° C., Example 10 is 100 ° C., and Example 11 is 110 ° C., and Comparative Example 1 is 110 ° C., Comparative Example 2 is 145 ° C. Example 3 was 125 ° C, Comparative Example 4 was 145 ° C, Comparative Example 5 was 112 ° C, Comparative Example 6 was 135 ° C, and Comparative Example 7 was 130 ° C.

  The high-speed durability life is 500 hours or more in Examples 1 to 11, 500 hours or more in Comparative Example 1, 350 hours in Comparative Example 2, 500 hours or more in Comparative Example 3, 500 hours or more in Comparative Example 4, and Comparative Example 5 was 500 hours or longer, Comparative Example 6 was 300 hours, and Comparative Example 7 was 450 hours. In all of Comparative Examples 2, 6, and 7, the failure mode was block failure.

  The total evaluation was ○ in Examples 1 to 11 and × in Comparative Examples 1 to 7.

[Test evaluation 2]
As shown in FIG. 9A, a composite V belt (Comparative Example 5 of Test Evaluation 1) in which fitting structures are formed on both the upper surface side and the lower surface side of the tension band 20 is referred to as Test Evaluation Belt 1, FIG. As shown in FIG. 9 (c), the composite V belt having the same configuration as the test evaluation belt 1 except that the upper surface side of the tension band 20 is formed as a flat surface is used. A composite V belt (Example 1 of Test Evaluation 1) having the same configuration as that of the test evaluation belt 1 except that the lower surface side of 20 was formed as a flat surface was used as the test evaluation belt 3.

For each of the test evaluation belts 1 to 3, as shown in FIG. 10, the curvature radius in the belt pitch line is between the lower support member 92 and the upper pressing member 94 coupled to the load cell 93 in the thermostatic chamber 91. The reaction force F was detected by the load cell 93 while the temperature in the thermostatic chamber 91 was raised from room temperature to around 170 ° C. The belt bending stiffness EI was calculated and calculated based on the formula EI = 1.74 × F × 6 ² × 10 ⁻¹ .

  FIG. 11 shows the relationship between the temperature in the thermostatic chamber 91 and the belt bending rigidity.

  According to FIG. 11, in the test evaluation belt 1, the belt bending rigidity significantly increases as the temperature in the thermostatic chamber 91 rises, whereas in the test evaluation belt 2, the increase rate of the belt bending rigidity increases in the test evaluation belt 1. It can be seen that the test evaluation belt 3 has almost no increase in belt bending rigidity.

  The present invention is useful for composite V-belts.

B Composite V-belt 10 Block 11 Fitting portion 12a Upper fitting convex portion 12b Lower supporting convex portion 13 Metal reinforcing material 13a Upper beam 13b Lower beam 13c Center pillar 20 Tension band 21, 21 'Fitting concave portion 22 Shape retaining rubber Layer 23 Core 24 Upper reinforcing cloth 25 Lower reinforcing cloth 30 Belt transmission device 31 Drive shaft 32 Drive pulley 33 Drive shaft 34 Drive pulley 71 Drive pulley 72 Drive pulley 73 Constant temperature tank 91 Constant temperature tank 92 Lower support member 93 Load cell 94 Upper side Press member

Claims (5)

A plurality of blocks each having slit-shaped fitting portions that are open laterally on both sides in the belt width direction,
Each of a pair of endless tension bands fitted to connect the plurality of blocks to the fitting portions of the plurality of blocks,
With
Each of the plurality of blocks has a fitting convex portion formed on the upper surface of each fitting portion,
Each of the pair of tension bands has a flat surface with a fitting recess formed on the upper surface of the fitting convex portion on the upper surface of the fitting portion of the block and a lower surface of a friction coefficient of 0.7 or more. Composite V-belt constructed in The composite V-belt according to claim 1, wherein
Each of the plurality of blocks is a composite V-belt whose center of gravity is on the belt pitch line. In the composite V belt according to claim 1 or 2,
Each of the pair of tension bands is a composite V belt having a shape-retaining rubber layer having a rubber hardness of 75 ° or more as measured by a JIS-C hardness meter. In the composite V belt according to any one of claims 1 to 3,
Α = {(t ₂ −t ₁ ) / t ₁ } where t _{1 is} the gap between the fitting portions of the block and t ₂ is the thickness of the fitting portion of the tension band into the fitting portion of the block. The fastening margin rate α represented by × 100 is 1 to 5%,
In addition, when the amount of protrusion of the tension band protruding from the fitting portion of the block is Δd and the insertion pitch width of the tension band at the tension band engagement position of the block is w, β = (Δd / w) The birth rate β represented by × 100 is 0.3 to 1.5%,
Further, a composite V belt in which α × β is 0.6 to 5.0. In the composite V belt according to any one of claims 1 to 4,
A composite V-belt that is used for continuously variable transmissions.

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