JP2009228768A - Flat belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a warpage in a belt width direction in a flat belt even when the flat belt undergoes abrasion or deterioration. <P>SOLUTION: A flat belt A includes: an adhesion rubber layer 10 extended endlessly in a ring and having a core member 13 embedded therein; a first rubber layer 11 laminated on one side of the adhesion rubber layer 10 and a second rubber layer 12 laminated on the other side of the adhesion rubber layer 10. The elastic modulus of the adhesion rubber layer 10 in the belt width direction is greater than those of the first rubber layer 11 and the second rubber layer 12 in their belt width directions. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a flat belt.

  2. Description of the Related Art Conventionally, flat belts are widely known as belts used for transporting paper sheets such as ATM banknotes and ticket gates of automatic ticket gates, and driving spindles of machine tools. Since the flat belt is formed thinner than a thick belt such as a V-belt, energy loss due to bending of the belt is relatively small, and therefore the transmission efficiency is higher than that of a V-belt or the like.

  This flat belt usually has a structure in which two or more layers of members are laminated, and these two or more layers are often made of different materials. The members constituting the belt have different linear expansion coefficients depending on the material. That is, when the constituent members of the belt have different materials, the rate at which each constituent member expands and contracts varies depending on the temperature change of heating and cooling.

  Therefore, for example, in a belt having a two-layer structure in which a canvas is laminated on one surface of a rubber layer, the rubber layer and the canvas have different linear expansion coefficients. There is a difference in the elongation. As a result, warpage occurs in the width direction of the belt.

  Further, even if the belt has a three-layer structure in which a rubber layer made of the same material as the adhesive rubber layer is laminated on the sliding surface side and the back surface side of the adhesive rubber layer in which a plurality of core wires are embedded as a core, the adhesive rubber layer When the thickness of the sliding rubber layer, which is a rubber layer laminated on the sliding surface side, differs from the thickness of the back rubber layer, which is a rubber layer laminated on the back side of the adhesive rubber layer, these sliding rubber layers Since the stretch of the back rubber layer is different, the belt is warped in the width direction.

  When the belt is warped, the sliding surface of the belt is difficult to come into sliding contact with the entire pulley, and the surface pressure received by the sliding surface from the pulley is biased to a part in the belt width direction. As a result, wear on the sliding surface is partially biased and promoted, and the running of the belt becomes unstable and slip easily occurs, making it difficult to perform reliable transmission.

On the other hand, for example, in the flat belt of Patent Document 1, constituent members having the same material and thickness are arranged symmetrically in the belt thickness direction with the center in the belt thickness direction as a boundary. As a result, even if each constituent member of the belt expands or contracts, the belt is balanced on both sides in the belt thickness direction to prevent the belt from warping.
JP-A-8-99704

  However, even the flat belt disclosed in Patent Document 1 wears the sliding surface as the belt travels, and the thickness of the sliding rubber layer decreases, so that the constituent members of the belt move in the belt thickness direction. Since the symmetrical arrangement is lost, the belt is warped.

  In addition, when either the sliding rubber layer or the back rubber layer of the belt is altered due to adhesion of oil, chemicals, water, etc., or the sliding rubber layer or the back rubber layer is cured by heating due to the occurrence of slip, etc. Even in this case, the above-described state in which the constituent members of the belt are arranged symmetrically in the belt thickness direction collapses, so that the belt is warped.

  The present invention has been made in view of such various points, and an object thereof is to suppress warpage in the belt width direction of the flat belt even if the flat belt is worn or deteriorated.

  In order to achieve the above object, in the present invention, the elastic modulus in the belt width direction of the adhesive rubber layer is made larger than the elastic modulus in the belt width direction of each of the first rubber layer and the second rubber layer.

  Specifically, a flat belt according to the present invention is formed in an annular shape extending endlessly, an adhesive rubber layer in which a core body is embedded, a first rubber layer laminated on one side of the adhesive rubber layer, and the above A flat belt provided with a second rubber layer laminated on the other side of the adhesive rubber layer, wherein the elastic modulus in the belt width direction of the adhesive rubber layer is determined by each of the first rubber layer and the second rubber layer. Is larger than the elastic modulus in the belt width direction.

  The adhesive rubber layer includes a first adhesive rubber layer formed closer to the first rubber layer than the center of the core and a second adhesive formed closer to the second rubber layer than the center of the core. The thickness of one of the first adhesive rubber layer and the second adhesive rubber layer is preferably 0.8 times or more and 1.2 times or less of the other thickness.

  The adhesive rubber layer includes a first adhesive rubber layer formed closer to the first rubber layer than the center of the core and a second adhesive formed closer to the second rubber layer than the center of the core. The elastic modulus in the belt width direction in one of the first adhesive rubber layer and the second adhesive rubber layer is 0.8 times or more and 1.2 times the elastic modulus in the belt width direction in the other. The following is preferable.

  The first adhesive rubber layer preferably has the same thickness as the second adhesive rubber layer.

  It is preferable that the first adhesive rubber layer has the same elastic modulus in the belt width direction as the elastic modulus in the belt width direction of the second adhesive rubber layer.

  The adhesive rubber layer preferably contains short fibers oriented in the belt width direction.

  The difference in elastic modulus in the belt width direction between the adhesive rubber layer and the first rubber layer is equal to or greater than the value of the elastic modulus in the belt width direction in the first rubber layer, and the adhesive rubber layer and the second rubber layer. It is preferable that the difference in elastic modulus in the belt width direction is greater than or equal to the elastic modulus value in the belt width direction of the second rubber layer.

  The thickness of the adhesive rubber layer is preferably 30% or more of the thickness of the entire belt.

  The first rubber layer has the same thickness as the second rubber layer and is formed of the same material as the second rubber layer, and the elastic modulus in the belt width direction of the first rubber layer is the second rubber layer. The elastic modulus in the belt width direction is preferably the same.

  The core body may be constituted by a plurality of core wires that extend in the belt length direction and are arranged at predetermined intervals in the belt width direction.

-Action-
In the flat belt of the present invention, since the elastic modulus in the belt width direction of the adhesive rubber layer is larger than the elastic modulus in the belt width direction of each of the first rubber layer and the second rubber layer, the adhesive rubber layer includes the first rubber layer and It is harder to expand and contract in the belt width direction than the second rubber layer. As a result, when elongation occurs in the first rubber layer and the second rubber layer, the belt width from the end in the belt width direction of the adhesive rubber layer between the adhesive rubber layer and the first rubber layer and the second rubber layer, respectively. Stress in the direction toward the center of the direction is generated, and the adhesive rubber layer suppresses the elongation in the belt width direction of the first rubber layer and the second rubber layer. On the other hand, when the first rubber layer and the second rubber layer are shrunk, an end portion in the belt width direction from the center in the belt width direction of the adhesive rubber layer between the adhesive rubber layer and the first rubber layer and the second rubber layer, respectively. The adhesive rubber layer suppresses shrinkage of the first rubber layer and the second rubber layer in the belt width direction. Therefore, even if the flat belt is worn or deteriorated, it is possible to suppress warpage in the belt width direction of the flat belt.

  By the way, if the thickness of one of the first adhesive rubber layer and the second adhesive rubber layer is smaller than 0.8 times the thickness of the other, the elongation of the first adhesive rubber layer and the second adhesive rubber layer is increased. Since the difference in shrinkage becomes relatively large, the adhesive rubber layer itself tends to warp in the belt width direction.

  On the other hand, even if the thickness of one of the first adhesive rubber layer and the second adhesive rubber layer is larger than 1.2 times the thickness of the other, the elongation of the first adhesive rubber layer and the second adhesive rubber layer is increased. The difference in shrinkage becomes relatively large, and the warp in the belt width direction is likely to occur in the adhesive rubber layer itself.

  Therefore, when the thickness of one of the first adhesive rubber layer and the second adhesive rubber layer is 0.8 times or more and 1.2 times or less of the other thickness, the first adhesive rubber layer and the second adhesive rubber Since a difference in expansion / contraction with the layer is suppressed, warpage in the belt width direction in the adhesive rubber layer itself is suppressed.

  Further, if the elastic modulus in the belt width direction in one of the first adhesive rubber layer and the second rubber layer is smaller than 0.8 times the elastic modulus in the belt width direction in the other, the first adhesive rubber layer Since the difference in expansion / contraction between the second adhesive rubber layer and the second adhesive rubber layer is relatively large, the adhesive rubber layer itself tends to bend in the belt width direction.

  On the other hand, if the elastic modulus in the belt width direction in one of the first adhesive rubber layer and the second rubber layer is greater than 1.2 times the elastic modulus in the belt width direction in the other, the first adhesive rubber layer The difference in expansion and contraction between the second adhesive rubber layer and the second adhesive rubber layer becomes relatively large, and the adhesive rubber layer itself tends to warp in the belt width direction.

  Therefore, when the elastic modulus in the belt width direction on one of the first adhesive rubber layer and the second adhesive rubber layer is 0.8 times or more and 1.2 times or less than the elastic modulus in the belt width direction on the other side, A difference in expansion and contraction between the first adhesive rubber layer and the second adhesive rubber layer is suppressed, and warpage in the belt width direction in the adhesive rubber layer itself is suppressed.

  When the first adhesive rubber layer has the same thickness as the second adhesive rubber layer, the first adhesive rubber layer and the first adhesive rubber layer are different from the case where the thicknesses of the first adhesive rubber layer and the second adhesive rubber layer are different from each other. Since the difference in expansion and contraction with the second adhesive rubber layer is suppressed, warpage in the belt width direction in the adhesive rubber layer itself is further suppressed.

  When the first adhesive rubber layer has the same elastic modulus in the belt width direction as the elastic modulus in the belt width direction in the second adhesive rubber layer, the belt width in the first adhesive rubber layer and the second adhesive rubber layer Since the difference in expansion and contraction between the first adhesive rubber layer and the second adhesive rubber layer is suppressed as compared with the case where the elastic modulus in the direction is different from each other, the warp in the belt width direction in the adhesive rubber layer itself is further suppressed. .

  When the adhesive rubber layer includes short fibers oriented in the belt width direction, the belt width direction of the adhesive rubber layer is suppressed while suppressing a decrease in the adhesion of the adhesive rubber layer to the first rubber layer and the second rubber layer. It becomes possible to increase the elastic modulus. Furthermore, in the production of a flat belt, when a plurality of core wires are arranged at predetermined intervals in the belt width direction as cores on an uncured adhesive rubber layer, the rubber material is locally between adjacent core wires. Since entering is suppressed, movement of each core wire in the belt width direction is suppressed, and a plurality of core wires can be arranged at desired positions.

  The difference in elastic modulus in the belt width direction between the adhesive rubber layer and the first rubber layer is equal to or greater than the value of the elastic modulus in the belt width direction in the first rubber layer, and the belt width direction in the adhesive rubber layer and the second rubber layer. Is equal to or greater than the value of the elastic modulus in the belt width direction of the second rubber layer, it is possible to further suppress warpage of the flat belt in the belt width direction.

  When the thickness of the adhesive rubber layer is 30% or more of the entire belt thickness, the adhesive rubber layer is relatively thick with respect to the entire belt, so that the adhesive rubber layer is more difficult to expand and contract. It is possible to further suppress the warp in the belt width direction of the flat belt.

  The first rubber layer has the same thickness as the second rubber layer and is formed of the same material as the second rubber layer, and the elastic modulus in the belt width direction of the first rubber layer is the elasticity in the belt width direction of the second rubber layer. In the case of the same rate, the flat belt has a symmetrical structure in the belt thickness direction with the center in the belt thickness direction as the boundary, so the belt width direction in the adhesive rubber layer, the first rubber layer, and the second rubber layer Even if there is a difference in the expansion and contraction of the belt, it is possible to balance the both sides in the belt thickness direction, and to further suppress the warp in the belt width direction of the flat belt until the flat belt is worn or deteriorated.

  According to the present invention, since the elastic modulus in the belt width direction of the adhesive rubber layer is larger than the elastic modulus in the belt width direction of each of the first rubber layer and the second rubber layer, the adhesive rubber layer includes the first rubber layer and the first rubber layer. It is harder to expand and contract in the belt width direction than two rubber layers. As a result, the adhesive rubber layer can suppress the expansion and contraction of the first rubber layer and the second rubber layer in the belt width direction, so that even if the flat belt is worn or deteriorated, the warp in the belt width direction of the flat belt is suppressed. be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

Embodiment 1 of the Invention
1 and 2 show Embodiment 1 of the present invention. FIG. 1 is a perspective view schematically showing a flat belt A according to the first embodiment. FIG. 2 is a cross-sectional view schematically showing the structure of the flat belt A. As shown in FIG.

  As shown in FIGS. 1 and 2, the flat belt A includes an adhesive rubber layer 10 that extends endlessly and is formed in an annular shape, and a sliding rubber that is a first rubber layer laminated on one side of the adhesive rubber layer 10. A layer 11 and a back rubber layer 12 as a second rubber layer laminated on the other side of the adhesive rubber layer 10 are provided. The flat belt A has a belt width of, for example, 20 mm, and a total belt thickness of 2.50 mm.

  The sliding rubber layer 11 is laminated on the belt inner side of the adhesive rubber layer 10, while the back rubber layer 12 is laminated on the belt outer side of the adhesive rubber layer 10. That is, the sliding rubber layer 11 has a sliding surface on the surface opposite to the adhesive rubber layer 10 that comes into sliding contact with the pulley when the flat belt A is run around the pulley.

  The sliding rubber layer 11 and the back rubber layer 12 are formed of the same material such as ethylene propylene rubber (hereinafter also referred to as EPDM). The sliding rubber layer 11 has the same thickness as the back rubber layer 12, and the elastic modulus in the belt width direction of the sliding rubber layer 11 is the same as the elastic modulus in the belt width direction of the back rubber layer 12. That is, the sliding rubber layer 11 and the back rubber layer 12 are formed to a thickness of, for example, 0.6 mm, and the elastic modulus in the belt width direction is, for example, 70 MPa. The sliding rubber layer 11 and the back rubber layer 12 also have an elastic modulus in the belt length direction of, for example, 70 MPa.

  The adhesive rubber layer 10 has a core body embedded therein, and the core body below the core wire rubber layer 10a which is a first adhesive rubber layer formed on the sliding rubber layer 11 side from the center of the core body. The center rubber layer 10b is a second adhesive rubber layer formed on the back rubber layer 12 side of the center.

  The adhesive rubber layer 10 (under-core wire rubber layer 10a and over-core wire rubber layer 10b) is formed of, for example, the same EPDM as the sliding rubber layer 11 and the back rubber layer 12. The adhesive rubber layer 10 is formed to a thickness of 1.3 mm, for example. That is, the thickness of the adhesive rubber layer 10 is 52% of the thickness of the entire belt and 30% or more of the thickness of the entire belt.

  The under-core wire rubber layer 10a has the same thickness as the over-core wire rubber layer 10b, and the under-core wire rubber layer 10a and the over-core wire rubber layer 10b are each formed to a thickness of 0.65 mm or the like. That is, the core body is embedded in the center position in the thickness direction of the adhesive rubber layer 10.

  The adhesive rubber layer 10 includes short fibers in both the under-core rubber layer 10a and the over-core rubber layer 10b. The short fibers are oriented in the belt width direction, and are, for example, polyamide, polyester, glass fiber, carbon fiber, or aramid fiber.

  The under-core wire rubber layer 10a has the same elastic modulus in the belt width direction as the elastic modulus in the belt width direction of the over-core rubber layer 10b. The elastic modulus in the belt width direction of the adhesive rubber layer 10 (under-core wire rubber layer 10a and over-core wire rubber layer 10b) is larger than the elastic modulus in the belt width direction of each of the sliding rubber layer 11 and the back rubber layer 12.

  The difference in the elastic modulus in the belt width direction between the adhesive rubber layer 10 and the sliding rubber layer 11 is equal to or greater than the value of the elastic modulus in the belt width direction in the sliding rubber layer 11. The difference in the elastic modulus in the belt width direction is equal to or greater than the value of the elastic modulus in the belt width direction of the back rubber layer 12.

  That is, the elastic modulus in the belt width direction of the adhesive rubber layer 10 is at least twice the elastic modulus in the belt width direction of each of the sliding rubber layer 11 and the back rubber layer 12, and is, for example, 400 MPa. The elastic modulus in the belt length direction of the adhesive rubber layer 10 is, for example, 80 MPa. That is, both the under-core rubber layer 10a and the over-core rubber layer 10b have an elastic modulus in the belt width direction of, for example, 400 MPa, and an elastic modulus in the belt length direction of, for example, 80 MPa.

  The core body includes a plurality of core wires 13 that extend in the belt length direction and are arranged at predetermined intervals in the belt width direction. Each core wire 13 has a diameter of 0.5 mm or the like, and is formed by, for example, binding organic fibers such as aramid fiber, polyester fiber, polyamide fiber, and rayon fiber, or inorganic fibers such as glass fiber and steel in a cord shape. ing. The space | interval of the adjacent core wire 13 is 0.85 mm etc., for example. Thus, the flat belt A including the sliding rubber layer 11 and the back rubber layer 12 is formed in the belt thickness direction of the adhesive rubber layer 10 in which the core body is embedded in the center in the belt thickness direction.

  As a manufacturing method of the flat belt A, first, the rubber material of the sliding rubber layer 11 and the under-core-wire rubber layer 10a containing short fibers is poured into a predetermined mold in order, and the rubber material of the sliding rubber layer 11 is The rubber material of the core wire lower rubber layer 10a is laminated. Next, after arranging a plurality of core wires 13 at a predetermined interval on the rubber material of the under-core wire rubber layer 10a, the on-core rubber layer 10b and the back rubber layer containing short fibers similar to the under-core wire rubber layer 10a. The rubber material 12 and the rubber material of the back rubber layer 12 are sequentially laminated on the sliding rubber layer 11 and the core wire 13.

  Thereafter, the rubber materials of the sliding rubber layer 11, the lower core rubber layer 10a, the upper core rubber layer 10b, and the back rubber layer 12 are vulcanized. At this time, the rubber materials of the lower core wire rubber layer 10 a and the upper core wire rubber layer 10 b enter between the adjacent core wires 13, and a plurality of core wires 13 are embedded in the adhesive rubber layer 10. Thus, the flat belt A in which the sliding rubber layer 11, the adhesive rubber layer 10, and the back rubber layer 12 are laminated in order is formed. A known flat belt manufacturing method can be applied to the flat belt A manufacturing method.

-Effect of Embodiment 1-
Therefore, according to the first embodiment, since the elastic modulus in the belt width direction of the adhesive rubber layer 10 is larger than the elastic modulus in the belt width direction of each of the sliding rubber layer 11 and the back rubber layer 12, the adhesive rubber layer 10 is It is less likely to expand and contract in the belt width direction than the sliding rubber layer 11 and the back rubber layer 12. As a result, when the sliding rubber layer 11 and the back rubber layer 12 are stretched in the belt width direction, the adhesive rubber layer 10 is interposed between the adhesive rubber layer 10 and the sliding rubber layer 11 and the back rubber layer 12, respectively. Stress in the direction from the end in the belt width direction toward the center in the belt width direction is generated, and the adhesive rubber layer 10 can suppress the extension of the sliding rubber layer 11 and the back rubber layer 12 in the belt width direction. When the sliding rubber layer 11 and the back rubber layer 12 are contracted in the belt width direction, the belt in the adhesive rubber layer 10 is interposed between the adhesive rubber layer 10 and the sliding rubber layer 11 and the back rubber layer 12, respectively. Stress in the direction from the center in the width direction toward the end in the belt width direction is generated, and the adhesive rubber layer 10 can suppress the contraction of the sliding rubber layer 11 and the back rubber layer 12 in the belt width direction. As a result, even if the flat belt A is worn or deteriorated, warpage of the flat belt A in the belt width direction can be suppressed.

  Furthermore, since the under-core rubber layer 10a has the same thickness as the over-core rubber layer 10b, the under-core rubber layer 10a is more than when the under-core rubber layer 10a and the over-core rubber layer 10b have different thicknesses. And a difference in expansion / contraction between the cord and the rubber layer 10b on the cord can be suppressed. As a result, the warp in the belt width direction of the adhesive rubber layer 10 itself can be suppressed, and as a result, the warp of the flat belt A in the belt width direction can be further suppressed.

  Further, since the under-core rubber layer 10a has the same elastic modulus in the belt width direction as that of the over-core rubber layer 10b, the under-core rubber layer 10a and the over-core rubber layer 10b It can suppress that a difference arises in the expansion / contraction of the rubber layer 10a below a core wire, and the rubber layer 10b on a core wire rather than the case where the elasticity modulus of a belt width direction differs. As a result, warpage in the belt width direction in the adhesive rubber layer 10 itself can be further suppressed.

  Since the adhesive rubber layer 10 includes short fibers oriented in the belt width direction, the belt width of the adhesive rubber layer 10 is suppressed while suppressing a decrease in the adhesive property of the adhesive rubber layer to the sliding rubber layer 11 and the back rubber layer 12. The elastic modulus in the direction can be increased. Furthermore, in the production of the flat belt A, when a plurality of core wires 13 are arranged at predetermined intervals in the belt width direction as cores on the uncured adhesive rubber layer 10, a rubber material is provided between the adjacent core wires 13. Therefore, it is possible to suppress the movement of each core wire 13 in the belt width direction and to arrange the plurality of core wires 13 at desired positions.

  The difference in the elastic modulus in the belt width direction between the adhesive rubber layer 10 and the sliding rubber layer 11 is equal to or greater than the value of the elastic modulus in the belt width direction in the sliding rubber layer 11, and the adhesive rubber layer 10 and the back rubber layer 12 Since the difference in the elastic modulus in the belt width direction is equal to or greater than the value of the elastic modulus in the belt width direction of the back rubber layer 12, warping in the belt width direction of the flat belt A can be further suppressed.

  Since the thickness of the adhesive rubber layer 10 is 30% or more of the thickness of the entire belt, the adhesive rubber layer 10 is relatively thick with respect to the entire belt. This makes it difficult for the adhesive rubber layer 10 to further expand and contract, so that warpage of the flat belt A in the belt width direction can be further suppressed.

  The sliding rubber layer 11 has the same thickness as the back rubber layer 12 and is formed of the same material as the back rubber layer 12, and the elastic modulus in the belt width direction of the sliding rubber layer 11 is the belt width direction of the back rubber layer 12. Accordingly, the flat belt A has a symmetrical structure in the belt thickness direction with the center in the belt thickness direction as a boundary. As a result, even if a difference occurs in the expansion and contraction of the adhesive rubber layer 10, the sliding rubber layer 11, and the back rubber layer 12, the flat belt A is balanced until the flat belt A is worn or deteriorated. The warp in the belt width direction can be further suppressed.

<< Other Embodiments >>
In the first embodiment, the under-core rubber layer 10a has the same thickness as the over-core rubber layer 10b. However, the present invention is not limited to this, and the under-core rubber layer 10a and the over-core rubber layer 10b. May be different in thickness.

  If the thickness of one of the under-core wire rubber layer 10a and the over-core wire rubber layer 10b is less than 0.8 times the thickness of the other, the elongation between the under-core wire rubber layer 10a and the over-core wire rubber layer 10b will be described. Since the difference in shrinkage is relatively large, the adhesive rubber layer 10 itself is likely to warp in the belt width direction.

  On the other hand, if the thickness of one of the under-core wire rubber layer 10a and the over-core wire rubber layer 10b is larger than 1.2 times the thickness of the other, the under-core wire rubber layer 10a and the over-core wire rubber layer 10b The difference between the expansion and contraction of the adhesive rubber layer 10 becomes relatively large, and the adhesive rubber layer 10 itself is easily warped.

  Therefore, from the viewpoint of suppressing the warp of the adhesive rubber layer 10 itself by suppressing the difference in expansion and contraction between the under-core rubber layer 10a and the over-core rubber layer 10b, the under-core rubber layer 10a and the over-core rubber layer 10b One thickness is preferably 0.8 times or more and 1.2 times or less of the other thickness.

  In Embodiment 1 described above, the lower core wire rubber layer 10a has the same elastic modulus in the belt width direction as that of the upper core wire rubber layer 10b. However, the present invention is not limited to this. The elastic core layer 10a and the elastic core layer may have different elastic moduli in the belt width direction.

  If the elastic modulus in the belt width direction in one of the under-core wire rubber layer 10a and the over-core rubber layer 10b is smaller than 0.8 times the elastic modulus in the belt width direction in the other, the under-core rubber layer Since the difference in expansion and contraction between the rubber layer 10b and the rubber layer 10b on the cord is relatively large, the adhesive rubber layer 10 itself is likely to be warped.

  On the other hand, even if the elastic modulus in the belt width direction in one of the under-core rubber layer 10a and the over-core rubber layer 10b is greater than 1.2 times the elastic modulus in the belt width direction in the other, The difference in expansion and contraction between the rubber layer 10a and the corded rubber layer 10b becomes relatively large, and the adhesive rubber layer 10 itself tends to be warped.

  Therefore, from the viewpoint of suppressing the warp of the adhesive rubber layer 10 itself by suppressing the difference in expansion and contraction between the under-core rubber layer 10a and the over-core rubber layer 10b, the under-core rubber layer 10a and the over-core rubber layer 10b The elastic modulus in the belt width direction on one side is preferably 0.8 to 1.2 times the elastic modulus in the belt width direction on the other side.

  In Embodiment 1 described above, the core body is composed of a plurality of core wires 13, but the present invention is not limited to this, and the core body is composed of, for example, a woven fabric core body made of aramid fibers or the like. Also good.

  In the first embodiment, the adhesive rubber layer 10, the sliding rubber layer 11, and the back rubber layer 12 are formed of EPDM. However, the present invention is not limited to this, and the adhesive rubber layer 10, the sliding rubber layer, and the like. 11 and the back rubber layer 12 may be formed of different materials such as acrylonitrile butadiene rubber (NBR), butadiene rubber (BR), or chloroprene rubber (CR), and may be formed of a known rubber material. Is possible. The adhesive rubber layer 10, the sliding rubber layer 11, and the back rubber layer 12 are preferably formed of the same rubber material from the viewpoint of suppressing the difference in expansion and contraction in these layers.

  In the first embodiment, the adhesive rubber layer 10 includes short fibers. However, the present invention is not limited to this, and the adhesive rubber layer 10 may not include short fibers.

  In the first embodiment, the difference in the elastic modulus in the belt width direction between the adhesive rubber layer 10 and the sliding rubber layer 11 is equal to or greater than the value of the elastic modulus in the belt width direction in the sliding rubber layer 11. The difference in elastic modulus in the belt width direction between the back rubber layer 12 and the back rubber layer 12 is equal to or greater than the elastic modulus value in the belt width direction in the back rubber layer 12. Further, the elastic modulus in the belt width direction of the sliding rubber layer 11 and the back rubber layer 12 is 70 MPa, and the elastic modulus in the belt width direction of the adhesive rubber layer 10 is 400 MPa. However, the present invention is not limited to this. The elastic modulus in the belt width direction of each of the adhesive rubber layer 10, the sliding rubber layer 11, and the back rubber layer 12 may be another elastic modulus, and the elastic modulus in the belt width direction of the adhesive rubber layer 10 may be It only needs to be larger than the elastic modulus in the belt width direction in each of the sliding rubber layer 11 and the back rubber layer 12.

  In the first embodiment, the sliding rubber layer 11 has the same thickness as the back rubber layer 12, but the present invention is not limited to this, and the sliding rubber layer 11 has a thickness different from that of the back rubber layer 12. The sliding rubber layer 11 may be formed to be slightly thicker than the back rubber layer 12 in consideration of wear associated with traveling. Then, when the sliding rubber layer 11 is worn, it is possible to balance both sides in the belt thickness direction, and it is possible to suppress the warp of the flat belt A in the belt width direction over a long period of time.

  The flat belt A of the first embodiment may have a structure in which a canvas is laminated on at least one of the sliding rubber layer 11 and the back rubber layer 12.

"Example"
Next, examples in which the present invention is specifically implemented will be described. In this example, a running test was performed on the flat belt A of Example 1 which is a flat belt of the present invention, and the amount of warpage of the sliding rubber layer 11 relative to the amount of wear of the sliding rubber layer 11 was measured. Here, the amount of warpage is the amount of deformation of the sliding rubber layer 11 in the flat belt A from the initial state.

  The flat belt A of Example 1 is a flat belt A having the same structure as the flat belt A shown in the first embodiment. Each core wire 13 has a structure in which three aramid core wires each having a diameter of 2400 denier are bundled, and the overall diameter is about 0.5 mm. Further, the adhesive rubber layer 10 includes aramid fibers as short fibers.

  As a comparative example, a running test is performed on the flat belt A of Comparative Example 1 having the same elastic modulus of each rubber layer as in Example 1, and sliding with respect to the wear amount of the sliding rubber layer 100 is performed. The amount of warpage of the rubber layer 100 was measured.

  As shown in FIG. 3, the flat belt of Comparative Example 1 includes a sliding rubber layer 100, a back rubber layer 101 laminated on one side of the sliding rubber layer 100, and the sliding rubber layer 100 and the back rubber layer. 101 is constituted by a plurality of core wires 102 which are core bodies embedded between them. Similar to the flat belt A of Example 1, the flat belt of Comparative Example 1 has a belt width of 20 mm and a total belt thickness of 2.5 mm.

  The sliding rubber layer 100 and the back rubber layer 101 are each formed of EPDM, and the elastic modulus in the belt length direction and the belt width direction is 70 MPa. These sliding rubber layer 100 and back rubber layer 101 do not contain short fibers. The sliding rubber layer 100 and the back rubber layer 101 each have a thickness of 1.25 mm and are formed to have the same thickness. That is, the plurality of core wires 102 are embedded in the center in the belt thickness direction. The plurality of core wires 102 have the same structure as that of the first embodiment, and extend in the belt length direction and are arranged at predetermined intervals in the belt width direction.

  A running test was performed on each of the flat belts of Example 1 and Comparative Example 1, and the results of measuring the amount of warpage of the sliding rubber layers 11 and 100 with respect to the amount of wear of the sliding rubber layers 11 and 100 are shown in FIGS. Shown in FIG. 4 is a diagram showing the amount of warpage of the sliding rubber layers 11, 100 with respect to the wear of the sliding rubber layers 11, 100. FIG. 5 is a graph of the amount of warpage of the sliding rubber layers 11 and 100 with respect to the wear of the sliding rubber layers 11 and 100 shown in FIG.

  For the flat belt of Comparative Example 1, a relatively large amount of warpage of the sliding rubber layer 100 was measured with wear due to running. On the other hand, for the flat belt A of Example 1, a warpage amount equal to or less than ¼ of the warpage amount of the flat belt of Comparative Example 1 was measured.

  Therefore, even if the flat belt A is worn by providing the adhesive rubber layer 10 whose elastic modulus in the belt width direction is larger than the elastic modulus in the belt width direction in each of the sliding rubber layer 11 and the back rubber layer 12. It was found that the warp in the belt width direction in the flat belt A can be suppressed.

  As described above, the present invention is useful for a flat belt, and is particularly suitable for the case where the flat belt A is to be prevented from warping in the belt width direction even if the flat belt is worn or altered.

1 is a perspective view schematically showing a flat belt according to Embodiment 1. FIG. 1 is a cross-sectional view schematically showing the structure of a flat belt according to Embodiment 1. FIG. 3 is a cross-sectional view schematically showing the structure of a flat belt of Comparative Example 1. FIG. It is a figure which shows the curvature amount with respect to the abrasion loss of an Example and a comparative example. It is the figure which graphed the curvature amount with respect to the abrasion loss of an Example and a comparative example.

Explanation of symbols

A Flat belt 10 Adhesive rubber layer 10a Under-core rubber layer (first adhesive rubber layer)
10b Rubber layer on the cord (second adhesive rubber layer)
11 Sliding rubber layer (first rubber layer)
12 Back rubber layer (second rubber layer)
13 heart (heart)

Claims (10)

An adhesive rubber layer extending in an endless manner and formed in an annular shape, with a core body embedded therein;
A first rubber layer laminated on one side of the adhesive rubber layer;
A flat belt comprising a second rubber layer laminated on the other side of the adhesive rubber layer,
A flat belt, wherein an elastic modulus in a belt width direction of the adhesive rubber layer is larger than an elastic modulus in a belt width direction of each of the first rubber layer and the second rubber layer. In claim 1,
The adhesive rubber layer includes a first adhesive rubber layer formed closer to the first rubber layer than the center of the core and a second adhesive formed closer to the second rubber layer than the center of the core. Composed of a rubber layer,
The flat belt, wherein one thickness of the first adhesive rubber layer and the second adhesive rubber layer is 0.8 times or more and 1.2 times or less of the other thickness. In claim 1,
The adhesive rubber layer includes a first adhesive rubber layer formed closer to the first rubber layer than the center of the core and a second adhesive formed closer to the second rubber layer than the center of the core. Composed of a rubber layer,
The elastic modulus in the belt width direction of one of the first adhesive rubber layer and the second adhesive rubber layer is 0.8 times or more and 1.2 times or less than the elastic modulus in the belt width direction of the other. Flat belt. In claim 2,
The flat belt, wherein the first adhesive rubber layer has the same thickness as the second adhesive rubber layer. In claim 3,
The flat belt, wherein the first adhesive rubber layer has the same elastic modulus in the belt width direction as the elastic modulus in the belt width direction of the second adhesive rubber layer. In claim 1,
A flat belt characterized in that the adhesive rubber layer contains short fibers oriented in the belt width direction. In claim 1,
The difference in elastic modulus in the belt width direction between the adhesive rubber layer and the first rubber layer is equal to or greater than the value of the elastic modulus in the belt width direction in the first rubber layer,
A flat belt, wherein a difference in elastic modulus in the belt width direction between the adhesive rubber layer and the second rubber layer is equal to or greater than a value of an elastic modulus in the belt width direction in the second rubber layer. In claim 1,
A flat belt characterized in that the thickness of the adhesive rubber layer is 30% or more of the thickness of the entire belt. In claim 1,
The first rubber layer has the same thickness as the second rubber layer, and is formed of the same material as the second rubber layer,
The flat belt according to claim 1, wherein an elastic modulus in the belt width direction of the first rubber layer is the same as an elastic modulus in the belt width direction of the second rubber layer. In claim 1,
The flat belt is characterized by comprising a plurality of core wires extending in the belt length direction and arranged at predetermined intervals in the belt width direction.

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