Toothed belt

Abstract

To provide a toothed belt capable of suppressing an increase in width while ensuring the number of core cords required for wiring of electrical signals and a power source.SOLUTION: A toothed belt of the present invention comprises a belt body, a plurality of teeth arranged at equal intervals in the longitudinal direction on one side of the belt body, and n (n is an integer of 3 or more) core cords embedded in the belt body along the longitudinal direction. Some adjacent core cords among the n core cords are electric conductive and are arranged such that the average interval between the some adjacent conductive core cords is smaller than the value that is obtained by dividing the average interval between the two core cords located at the outermost sides in the width direction of the belt body by (n-1). The main component of the belt body is rubber or resin, and an electrical signal or power source is assigned to the some adjacent conductive core cords.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a toothed belt. [Background technology]

[0002] Toothed belts are used for lifting and transporting objects in factories, warehouses, etc. These toothed belts include a belt body, teeth arranged at equal intervals along the length on one side of the belt body, and a plurality of core cords arranged at equal intervals across the width of the belt and embedded in the belt body along the length.

[0003] The toothed belt can be configured as an endless belt or an open belt with both ends. Of these, the open toothed belt is fixed to a cart so that its teeth can fit into a toothed pulley, and is used to move the cart up and down or left and right by rotating the toothed pulley.

[0004] Some of the above-mentioned carts are equipped with stoppers to prevent the loaded cargo from slipping off the cart. These stoppers may be electrically controlled so that they can be retracted so as not to cause an obstruction when loading or unloading cargo onto the cart. In this way, carts often have additional functions that are electrically controlled.

[0005] A toothed belt has been proposed in which the wiring for electrical signals and power sources (hereinafter simply referred to as "wiring") that control these additional functions also serves as a core cord (see JP 2019-60403 A). In this toothed belt, the core cord is made of an electrically conductive material, so it also serves as a power supply cable, allowing the wiring to be embedded within the toothed belt while preventing an increase in the thickness of the toothed belt. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-60403 Summary of the Invention [Problem to be solved by the invention]

[0007] When the core cords of a toothed belt are also used as wiring, the number of core cords is determined by the greater of the number determined by the strength required for the toothed belt and the number of required wires. Therefore, as the number of wires increases, the number of core cords is determined by the number of wires, and the width of the toothed belt tends to become unnecessarily large. If the width of the toothed belt becomes unnecessarily large, it may become difficult to reduce the size of a device incorporating the toothed belt, such as a cart.

[0008] The present invention has been made in view of the above-mentioned inconveniences, and has as its object to provide a toothed belt that can prevent an increase in width while ensuring the number of core cords required for wiring electrical signals and power sources. [Means for solving the problem]

[0009] The inventors of the present invention conducted extensive research into toothed belts in which core cords double as wiring, and focused on the following points: In conventional toothed belts in which core cords double as wiring, the spacing between adjacent core cords is determined to ensure insulation. However, because core cords generally have a small diameter, the electrical resistance of a single core cord is high, and the same electrical signal or power source is assigned to several core cords. Based on these facts, the inventors of the present invention focused on the fact that core cords to which the same electrical signal or power source are assigned do not need to be insulated from each other, and the spacing between them can be narrowed, thereby completing the present invention.

[0010] That is, the toothed belt of the present invention comprises a belt body, a plurality of teeth arranged at equal intervals in the longitudinal direction on one surface of the belt body, and n (n is an integer of 3 or more) core cords embedded in the belt body along the longitudinal direction, wherein some adjacent core cords of the n core cords are conductive and are arranged so that the average spacing between them is smaller than the value obtained by dividing the average spacing between the two core cords located outermost in the width direction of the belt body by (n-1).

[0011] In this toothed belt, by making the average spacing between some adjacent core cords small, it is possible to keep the increase in width of the toothed belt small relative to the number of core cords.Furthermore, in this toothed belt, by assigning the same electrical signal or power source to some adjacent core cords with small average spacing, it is possible to avoid insulation problems between these some adjacent core cords, thereby suppressing an increase in width while ensuring the number of core cords required for wiring.

[0012] It is preferable to form a bundle cord in which some of the adjacent core cords are substantially in contact with each other. By forming the bundle cord in which some of the adjacent core cords are substantially in contact with each other in this way, the increase in the width of the toothed belt relative to the number of core cords can be further reduced. Here, "substantially in contact" is a concept that includes not only cases in which the core cords are actually in contact with each other partially or entirely, but also cases in which there is an unavoidable small gap, for example, a gap of 0.1 mm or less.

[0013] The toothed belt may preferably include a plurality of the bundle cords, so that the bundle cords can be assigned to a plurality of electrical signals or power sources, respectively, and therefore the increase in width of the toothed belt relative to the number of core cords can be further minimized.

[0014] The bundle cord preferably has three or more core cords. The number of the bundle cords is not limited to two, but can be three or more. By having three or more core cords in the bundle cord, the electrical resistance can be further reduced, making it suitable for use as wiring for electrical signals or power sources.

[0015] The two core cords positioned at the outermost sides in the width direction may be single-wire cords that are not included in the bundle cord. The electrical resistance of the two core cords positioned at the outermost sides in the width direction may increase over time due to wear caused by friction with the sides of the toothed belt. Therefore, by not including the two core cords positioned at the outermost sides in the width direction in the bundle cord and not using them for wiring electrical signals or power, the reliability of the wiring can be improved.

[0016] Preferably, the n core cords include a single-wire cord that is not included in the bundle cord, and the electrical resistivity of the core cords forming the bundle cord is lower than the electrical resistivity of the single-wire cord. By lowering the electrical resistivity of the core cords used in the bundle cord in this way, the number of core cords included in the bundle cord can be reduced. Therefore, the increase in the width of the toothed belt can be further minimized.

[0017] It is preferable that the average diameters of the n core cords are substantially equal. By making the average diameters of the n core cords substantially equal in this way, it becomes easier to ensure the strength of the toothed belt. Here, "substantially equal" means that differences that may arise due to manufacturing variations, for example, variations of 5% or less, are allowed.

[0018] In this specification, "average" refers to the average of measurements taken at 10 random locations. Furthermore, "average core cord spacing" refers to the average distance between the central axes of the core cords. [Effects of the Invention]

[0019] As described above, the toothed belt of the present invention can prevent an increase in width while ensuring the number of core cords required for wiring electrical signals and power sources. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic perspective view showing a toothed belt according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view of the toothed belt taken along line AA in FIG. 1. [Figure 3] FIG. 2 is a schematic cross-sectional view of the toothed belt taken along line BB in FIG. 1. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a toothed belt different from that shown in FIG. 3. [Figure 5] FIG. 5 is a schematic cross-sectional view showing a toothed belt different from those shown in FIGS. 3 and 4. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a toothed belt different from those shown in FIGS. 3 to 5. [Figure 7] FIG. 7 is a schematic cross-sectional view showing a toothed belt different from those shown in FIGS. 3 to 6. [Figure 8] FIG. 8 is a schematic cross-sectional view showing a toothed belt different from those shown in FIGS. 3 to 7. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0022] The toothed belt 1 shown in Figures 1, 2 and 3 comprises a belt body 10, a plurality of teeth 20 arranged at equal intervals in the longitudinal direction on one side of the belt body 10, and 12 core cords 30 embedded in the belt body 10 along the longitudinal direction.

[0023] <Belt body> The main component of the belt body 10 is rubber or resin. Examples of the rubber include ethylene-α-olefin elastomers such as ethylene-propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), and hydrogenated nitrile rubber (H-NBR). The rubber may be one of these, or a blend of two or more. Examples of the resin include thermoplastic polyester, polyamide, and polyurethane. Resin is preferred as the main component of the belt body 10 from the viewpoint of low dust generation, and thermoplastic urethane is particularly preferred due to its excellent abrasion resistance. Here, the term "main component" refers to the component with the highest content, preferably a component with a content of 50% by mass or more, and more preferably 90% by mass or more.

[0024] The average thickness of the belt body 10 is determined appropriately depending on the strength required of the toothed belt 1, and can be, for example, 1 mm or more and 10 mm or less.

[0025] The length of the belt body 10 is determined appropriately depending on the application of the toothed belt 1. The toothed belt 1 is mainly used as an open belt having both ends.

[0026] The belt body 10 may contain various additives, such as antioxidants, heat stabilizers, light stabilizers, anti-fogging agents, flame retardants, surface conditioners, pigments, fillers, waxes, and the like.

[0027] <Tooth part> The tooth portion 20 is a convex ridge portion having a cross section of a trapezoid, triangle, semicircle, mountain shape, wave shape, normal distribution curve shape, etc. The tooth portion 20 is arranged so that its ridge line (axial direction) coincides with the width direction of the belt body 10.

[0028] The average height of the toothed portions 20 and the pitch between the toothed portions 20 are determined appropriately depending on the application of the toothed belt 1. The average height of the toothed portions 20 can be, for example, 1.0 mm or more and 10 mm or less. The pitch between the toothed portions 20 can be, for example, 2 mm or more and 25 mm or less.

[0029] The main component of the tooth portion 20 can be the same as that of the belt body 10. The tooth portion 20 may also contain the same additives as those of the belt body 10.

[0030] <Core cord> The twelve core cords 30 are linear bodies having a circular cross section, and are arranged in the width direction of the belt body 10, as shown in FIG.

[0031] The twelve core cords 30 have substantially the same average diameter. By making the twelve core cords 30 have substantially the same average diameter in this way, it is easy to ensure the strength of the toothed belt 1. The average diameter of the core cords 30 is determined appropriately depending on the electrical resistance required for the bundle cords 31, which will be described later, and can be, for example, 0.2 mm or more and 2.5 mm or less.

[0032] 2, the twelve core cords 30 are arranged parallel to the longitudinal direction of the belt body 10 and at a constant distance from the other surface (the surface on which the toothed portions 20 are not arranged) of the belt body 10. In other words, the twelve core cords 30 are arranged in a plane, and the plane formed by the core cords 30 is parallel to the surface of the belt body 10.

[0033] As shown in Figures 1 and 3, the 12 core cords 30 include bundle cords 31 in which some adjacent core cords 30 are substantially in contact with each other, and single-wire cords 32 that are not included in the bundle cords 31.

[0034] The bundled cord 31 is mainly used to reinforce the toothed belt 1 and also as wiring for electrical signals or power, and is pulled out from the end of the belt body 10 as shown in Fig. 1. On the other hand, the single-wire cord 32 is mainly used to reinforce the toothed belt 1, and its end coincides with the end of the belt body 10 as shown in Fig. 1.

[0035] (Bundle Code) The bundle cords 31 are made up of conductive core cords 30. Examples of such core cords 30 include steel cords and copper cords. Among these, steel cords are preferred from the viewpoint of the strength of the toothed belt 1, and copper cords are preferred from the viewpoint of conductivity.

[0036] As described above, the bundle cords 31 are formed such that some adjacent core cords 30 are substantially in contact with each other. By forming some adjacent core cords 30 as bundle cords 31 in this manner such that some adjacent core cords 30 are substantially in contact with each other, it is possible to further reduce the increase in width of the toothed belt 1 relative to the number of core cords 30.

[0037] The toothed belt 1 may also include a plurality of bundled cords 31. The number of bundled cords 31 is preferably the same as the number of types of electric signals or power sources. By including a plurality of bundled cords 31 in the toothed belt 1 in this way, a bundled cord 31 can be assigned to each of the plurality of electric signals or power sources, and the increase in width of the toothed belt 1 relative to the number of core cords 30 can be further minimized.

[0038] The toothed belt 1 shown in FIG. 3 includes four bundle cords 31 (first bundle cord 31a, second bundle cord 31b, third bundle cord 31c, and fourth bundle cord 31d), but the number of bundle cords 31 is not limited to this and may be three or less, or five or more.

[0039] Spaces are provided between the multiple bundle cords 31 and between the bundle cords 31 and the solid-wire cords 32. The lower limit of the average spacing between the multiple bundle cords 31 and between the bundle cords 31 and the solid-wire cords 32 is preferably 0.3 mm, more preferably 0.5 mm. On the other hand, the upper limit of the average spacing is preferably 4 mm, more preferably 1 mm. If the average spacing is below the lower limit, there is a risk that sufficient insulation between the multiple bundle cords 31 cannot be ensured, or that the flexibility of the toothed belt 1 may be insufficient. Conversely, if the average spacing exceeds the upper limit, there is a risk that the toothed belt 1 may become unnecessarily large in the width direction, or that the core cords 30 may not be effective in improving the strength, durability, driving accuracy, etc. of the toothed belt 1.

[0040] As described above, there are gaps between the multiple bundle cords 31 and between the bundle cords 31 and the single-wire cords 32. Meanwhile, the core cords 30 constituting the bundle cords 31 are in contact with each other. Therefore, of the 12 core cords 30, some adjacent core cords 30 constituting the bundle cord 31 are arranged so that the average gap between the two core cords 30 located outermost in the width direction of the belt body 10 (corresponding to the two single-wire cords 32 in FIG. 3) is smaller than the value obtained by dividing the average gap between the two core cords 30 located outermost in the width direction of the belt body 10 by 11 (= 12 - 1) (the average value of the average gap between adjacent core cords 30).

[0041] The bundle cord 31 can be configured to have two core cords 30, such as the first bundle cord 31a and the second bundle cord 31b, or can be configured to have three or more core cords 30 (three in FIG. 3), such as the third bundle cord 31c and the fourth bundle cord 31d. By having three or more core cords 30 in this way, the electrical resistance can be further reduced, making the bundle cord 31 suitable for use as wiring for electrical signals or power sources.

[0042] The number of core cords 30 included in one bundle cord 31 can be determined appropriately depending on the resistance value required for the electrical signal or power source assigned to the bundle cord 31.

[0043] (single-wire cord) The single-wire cords 32 can be the same type of cord as the core cords 30 that make up the bundled cords 31, but they may also be different types of cords. In this case, it is preferable that the electrical resistivity of the core cords 30 that make up the bundled cords 31 is lower than the electrical resistivity of the single-wire cords 32. By lowering the electrical resistivity of the core cords 30 used in the bundled cords 31 in this way, it is possible to reduce the number of core cords 30 included in the bundled cords 31 to achieve the required resistance value. Therefore, the increase in the width of the toothed belt 1 can be further minimized.

[0044] In particular, it is preferable to use an insulating cord as the single-wire cord 32. By using an insulating cord for the single-wire cord 32, even if it comes into contact with the bundled cords 31, it is unlikely to affect the electrical signal or power supply function of the bundled cords 31. Examples of such insulating cords include aramid cords, glass cords, and polyester cords.

[0045] In the toothed belt 1, the two core cords 30 located on the outermost sides in the width direction of the belt body 10 are single-wire cords 32 that are not included in the bundled cords 31. The two core cords 30 (single-wire cords 32) located on the outermost sides in the width direction may experience an increase in electrical resistance over time due to wear caused by friction from the sides of the toothed belt 1. For this reason, the two core cords 30 located on the outermost sides in the width direction are not included in the bundled cords 31 and are not used for wiring electrical signals or power, thereby improving the reliability of the wiring.

[0046] The lower limit of the average distance between the central axis of the outermost single-wire cord 32 and the adjacent side surface of the belt body 10 (also referred to as the "average distance between the single-wire cord 32 and the side surface of the belt body 10") is preferably 0.3 mm, more preferably 0.5 mm. On the other hand, the upper limit of the average distance between the single-wire cord 32 and the side surface of the belt body 10 is preferably 1 mm, more preferably 0.7 mm. If the average distance between the single-wire cord 32 and the side surface of the belt body 10 is less than the lower limit, the outermost single-wire cord 32 may be exposed from the side surface of the belt body 10 during manufacturing of the toothed belt 1. Conversely, if the average distance between the single-wire cord 32 and the side surface of the belt body 10 exceeds the upper limit, the side edges of the belt body 10 may easily flap during driving, which may result in insufficient improvement in driving accuracy by the core cord 30.

[0047] <Toothed Belt Manufacturing Method> The toothed belt 1 can be manufactured by a manufacturing method including, for example, an extrusion molding step and a tooth portion forming step.

[0048] (Extrusion molding process) In the extrusion molding step, an extrusion molded body containing a rubber or resin composition as a main component and having the core cord 30 embedded therein is formed by extrusion molding.

[0049] Specifically, the core cords 30 are inserted through a crosshead attached to the tip of the cylinder of an extruder and extruded so that both sides of the core cords 30 are covered with molten rubber or resin composition. Alternatively, the melt-extruded rubber or resin composition and the core cords 30 may be sandwiched between a pair of rolls and pressurized to embed the core cords 30 in the rubber or resin composition.

[0050] At this time, the core cords 30 constituting the bundle cords 31 are arranged so as to be in contact with each other, while adjacent bundle cords 31 and the bundle cords 31 and the single-wire cords 32 are arranged with a gap therebetween.

[0051] The heating temperature for melting the rubber or resin composition in extrusion molding depends on the type of rubber or resin, whether a curing agent is used, and other factors, but the lower limit of the heating temperature is preferably 150°C. On the other hand, the upper limit of the heating temperature is preferably 250°C. If the heating temperature is below the lower limit, the rubber or resin composition may not be sufficiently melted, making extrusion molding difficult. Conversely, if the heating temperature exceeds the upper limit, the extrusion-molded body may become unnecessarily hot, resulting in an unnecessarily long cooling time and a decrease in the production efficiency of the toothed belt 1.

[0052] (Tooth formation process) In the toothed portion forming step, toothed portions 20 are formed on the extrusion molded body after the extrusion molding step, whereby the toothed belt 1 can be obtained.

[0053] Specifically, the tooth portion 20 can be formed by preparing a cylindrical mold roll having recesses on its outer surface corresponding to the tooth portion 20, and wrapping the extrusion molded body around the mold roll while heating one side of the extrusion molded body.

[0054] The heating temperature in the toothed portion forming step is determined appropriately depending on the temperature at which the extrusion-molded body can melt and form the toothed portion 20 on one surface, with a lower limit of 150°C being preferred. On the other hand, an upper limit of 250°C being preferred. If the heating temperature is below the lower limit, the extrusion-molded body may not be softened sufficiently, making it difficult to form the toothed portion 20. Conversely, if the heating temperature exceeds the upper limit, the entire toothed belt 1 may be susceptible to deformation due to heat.

[0055] <Advantages> In the toothed belt 1, by making the average spacing between some adjacent core cords 30 small, it is possible to keep the increase in width of the toothed belt 1 small relative to the number of core cords 30. In addition, in the toothed belt 1, by assigning the same electrical signal or power source to some adjacent core cords 30 with small average spacing, it is possible to avoid insulation problems between these some adjacent core cords 30, and therefore it is possible to keep the increase in width while ensuring the number of core cords 30 required for wiring.

[0056] [Other embodiments] The present invention is not limited to the above-described embodiment, and can be implemented in various other forms, including those described above, with various modifications and improvements.

[0057] In the above embodiment, the core cords having substantially the same average diameter include a bundle cord in which some adjacent core cords are substantially in contact with each other, and a single-filament cord that is not included in the bundle cord. However, the configuration of the core cords is not limited to this. Several variations will be described below. Note that in each variation, components that are similar to those of the toothed belt 1 shown in Figure 3 will be assigned the same reference numerals and detailed description will be omitted.

[0058] <Variation 1> The toothed belt 2 shown in Figure 4 comprises a belt body 10, a plurality of teeth 20 arranged at equal intervals in the longitudinal direction on one side of the belt body 10, and 12 core cords 30 embedded in the belt body 10 along the longitudinal direction.

[0059] In the toothed belt 2, the multiple core cords 30 include bundled cords 31 in which some adjacent core cords 30 are substantially in contact with each other, and single-wire cords 33 that are not included in the bundled cords 31. In addition, in the toothed belt 2, the two core cords 30 located on the outermost sides in the width direction of the belt body 10 are single-wire cords 33 that are not included in the bundled cords 31.

[0060] In the toothed belt 2, the average diameters of the 12 core cords 30 are not the same. In the toothed belt 2 shown in Fig. 4, the average diameters of the core cords 30 constituting the bundled cords 31 are different from those of the single-wire cords 33, and the average diameters of the core cords 30 constituting the bundled cords 31 are larger than those of the single-wire cords 33. By increasing the average diameter of the core cords 30 constituting the bundled cords 31 in this way, the electrical resistance of the bundled cords 31 can be further reduced, making it suitable for use as wiring for electrical signals or power sources.

[0061] Conversely, the average diameter of the core cords 30 constituting the bundled cords 31 may be smaller than the average diameter of the single-wire cords 33. In this case, it becomes possible to finely adjust the electrical resistance of the bundled cords 31 by adjusting the number of core cords 30.

[0062] The present invention also contemplates a configuration in which the average diameter of any of the core cords 30 is changed, such as by changing the average diameter of the core cords 30 for each bundle cord 31.

[0063] When the core cords 30 do not have the same average diameter, the core cords 30 are preferably arranged so that the toothed portions 20 are aligned on the same plane. By arranging the core cords 30 in this manner, the manufacture of the toothed belt 2 is facilitated.

[0064] <Variation 2> The toothed belt 3 shown in Figure 5 comprises a belt body 10, a plurality of teeth 20 arranged at equal intervals in the longitudinal direction on one side of the belt body 10, and 13 core cords 30 embedded in the belt body 10 along the longitudinal direction.

[0065] In the toothed belt 3, the multiple core cords 30 include bundled cords 31 in which some adjacent core cords 30 are substantially in contact with each other, and single-wire cords 33 that are not included in the bundled cords 31.

[0066] In the toothed belt 3, the two core cords 30 located at the outermost positions in the width direction of the belt body 10 are single-wire cords 33 that are not included in the bundle cords 31, and single-wire cords 33 are arranged between adjacent bundle cords 31. By arranging the single-wire cords 33 between adjacent bundle cords 31 in this way, the strength, durability, driving accuracy, etc. of the toothed belt 3 due to the core cords 30 can be improved.

[0067] When a single-wire cord 33 is disposed between adjacent bundle cords 31, it is preferable that the single-wire cord 33 be an insulating cord. By using an insulating cord for the single-wire cord 33 in this way, defects such as short circuits are less likely to occur in the conductive bundle cords 31 even when the spacing between the bundle cords 31 and the single-wire cords 33 is narrowed, and this makes it possible to further minimize the increase in the width of the toothed belt 3 relative to the number of core cords 30. As the insulating cord, a cord similar to the insulating cord described for the toothed belt 1 shown in Figure 3 can be used.

[0068] 5 shows a case where one single-wire cord 33 is arranged between each adjacent bundle of cords 31, but a plurality of single-wire cords 33 may be arranged. Also, the number of cords may be changed depending on the arrangement position.

[0069] Also, although Figure 5 shows a case where all bundle cords 31 have two core cords 30, the number of core cords 30 included in the bundle cord 31 may be three or more, and may differ for each bundle cord 31.

[0070] <Variation 3> The toothed belt 4 shown in Figure 6 comprises a belt body 10, a plurality of teeth 20 arranged at equal intervals in the longitudinal direction on one side of the belt body 10, and 15 core cords 30 embedded in the belt body 10 along the longitudinal direction.

[0071] In the toothed belt 4, the multiple core cords 30 include bundled cords 31 in which some adjacent core cords 30 are substantially in contact with each other, and do not include any single-wire cords that are not included in the bundled cords 31. Such a configuration that does not include any single-wire cords is also within the scope of the present invention.

[0072] In the toothed belt 4, the bundled cords 31 function not only as wiring but also as reinforcement for the toothed belt 4, making it possible to omit a single-wire cord. In the toothed belt 4 in which the single-wire cord is omitted in this manner, it is preferable to use a high-strength steel cord as the conductive core cord 30 constituting the bundled cords 31.

[0073] <Variation 4> The toothed belt 5 shown in Figure 7 comprises a belt body 10, a plurality of teeth 20 arranged at equal intervals in the longitudinal direction on one side of the belt body 10, and 21 core cords 30 embedded in the belt body 10 along the longitudinal direction.

[0074] In the toothed belt 5, the plurality of core cords 30 include a bundle cord 34 in which some adjacent core cords 30 are substantially in contact with each other.

[0075] The bundle cord 34 is made up of three core cords 30. As shown in Fig. 7, the bundle cord 34 is arranged so that two core cords 30 are in contact with the belt body 10 in the width direction, and the other core cord 30 is in contact with the two core cords 30 from the surface side of the belt body 10.

[0076] By providing the core cords 30 arranged so as to contact the surface side of the belt body 10 in this way, it is possible to include multiple core cords 30 in the bundle cord 34 without expanding in the width direction of the belt body 10. Therefore, the increase in the width of the toothed belt 5 relative to the number of core cords 30 can be further suppressed.

[0077] 7 illustrates a case where one bundle cord 34 includes three core cords 30, but the number of core cords 30 included in one bundle cord 34 is not limited to three and may be, for example, four or more. Also, the number of core cords included in each bundle cord 34 may differ.

[0078] In addition, although the case where the plurality of core cords 30 does not include a single-wire cord has been described in FIG. 7, they may include a single-wire cord.

[0079] <Variation 5> The toothed belt 6 shown in Figure 8 comprises a belt body 10, a plurality of teeth 20 arranged at equal intervals in the longitudinal direction on one side of the belt body 10, and eight conductive core cords 30 embedded in the belt body 10 along the longitudinal direction.

[0080] 8, in the toothed belt 6, the eight core cords 30 alternately have narrower and wider average spacing between adjacent core cords 30, starting from the core cord 30 located on the outermost side in the width direction of the belt body 10. In other words, of the eight core cords 30, some adjacent core cords 30 are conductive and are arranged so that the average spacing is smaller than the value obtained by dividing the average spacing between the two core cords 30 located on the outermost side in the width direction of the belt body 10 by 7 (= 8 - 1).

[0081] Such a configuration is also within the scope of the present invention, and the same electrical signal or power source is assigned to two adjacent core cords 30 that are spaced closely apart on average.

[0082] The lower limit of the ratio of the narrowest average spacing (D1 in FIG. 8) to the widest average spacing (D2 in FIG. 8) between two adjacent core cords 30 is preferably 2:3, more preferably 1:4, and even more preferably 1:10. If the ratio is below the lower limit, the effect of reducing the width of the toothed belt 6 may be insufficient. On the other hand, there is no particular upper limit to the ratio. In other words, the narrowest average spacing between two adjacent core cords 30 may be 0.

[0083] In the toothed belt 6 shown in Figure 8, the average spacing between adjacent core cords 30 alternates between narrow and wide, but for example, the spacing may alternate between narrow and wide every third cord, and the number of repetitions may vary depending on the position of the core cords 30.

[0084] <Other> In the above embodiments, the case where a specific number of core cords is provided has been described, but the number of core cords is not limited to the number in each embodiment as long as it is three or more.

[0085] In the above embodiment, a case has been described in which bundled cords are used as wiring for electrical signals or power sources, and single-wire cords are used for reinforcement, but bundled cords may be used that are not used as wiring, and conversely, single-wire cords may be used as wiring. [Industrial Applicability]

[0086] The toothed belt of the present invention can prevent an increase in width while ensuring the number of core cords required for wiring electrical signals and power sources. [Explanation of symbols]

[0087] 1, 2, 3, 4, 5, 6 toothed belt 10 Belt body 20 Tooth 30 core cord 31, 34 bundle cord 31a 1st Bundle Code 31b Second Bundle Code 31c 3rd Bundle Code 31d 4th Bundle Code 32, 33 single-wire cord

Claims

1. The belt body, a plurality of teeth arranged at equal intervals in the longitudinal direction on one surface of the belt body; three or more core cords embedded in the belt body along the length direction; Equipped with When the number of the core cords is n, Among the n core cords, some adjacent core cords are conductive and are arranged such that the average spacing between the some adjacent conductive core cords is smaller than the average spacing between two core cords positioned outermost in the width direction of the belt body divided by (n-1), The main component of the belt body is rubber or resin, The toothed belt may be such that the same electrical signal or power source is assigned to some of the adjacent conductive core cords.

2. 2. The toothed belt according to claim 1, wherein some of the adjacent core cords form a bundle cord in which the core cords are substantially in contact with each other.

3. 3. A toothed belt according to claim 2, comprising a plurality of said bundle cords.

4. 4. The toothed belt according to claim 2, wherein the bundle of cords has three or more core cords.

5. The core cord is four or more, 5. The toothed belt according to claim 2, wherein the two core cords positioned outermost in the width direction are single cords that are not included in the bundle cords.

6. The n core cords include a single cord that is not included in the bundle cord, 6. The toothed belt according to claim 2, wherein the core cord forming the bundle of cords has an electric resistivity lower than that of the single-wire cord.

7. 7. The toothed belt according to claim 1, wherein the n core cords have substantially the same average diameter.

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