belt

Abstract

A belt according to an embodiment of the present invention comprises: a belt body; one or more current-flowing core body cords that include electrically conductive core wires; and one or more reinforcement core body cords having a higher electrical resistance per unit length than the current-flowing core body cords. The current-flowing core body cords and the reinforcement core body cords are embedded, along the longitudinal direction, in the belt body by being spaced apart from each other in the width direction of the belt body. The current-flowing core body cords have covering films that constitute a peripheral surface so as to cover the core wires. The covering films are fused to the belt body.

Description

[Technical field]

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

[0002] In some cases, belts are used to lift and transport objects in factories, warehouses, etc. In this case, for example, a dolly is fixed to the belt by a screw through a through hole opened in the belt, and the dolly is moved up and down or left and right by rotating a pulley that drives the belt. The object is lifted and transported in the dolly.

[0003] 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 stored so as not to be an obstacle when loading or unloading cargo onto or from the cart. In this way, carts are often equipped with additional functions that are electrically controlled.

[0004] A belt has been proposed in which the wiring for electrical signals and power sources (hereinafter simply referred to as "wiring") that control such additional functions is also used as a core cord (see JP 2019-60403 A). In this belt, the core cord is made of a material that can conduct electricity, so it also serves as a power supply cable, making it possible to embed the wiring within the belt while preventing an increase in the thickness of the belt. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-60403 A Summary of the Invention [Problem to be solved by the invention]

[0006] In such belts with the core cord having the electric current function, the core cord that carries the electric current function is connected to a wire, so tension may be applied to the core cord in a direction different from the movement of the belt, which may cause the core cord to easily separate from the belt body, resulting in the risk of malfunction of the belt.

[0007] The present invention has been made in consideration of such inconveniences, and aims to provide a belt that can prevent the core cord from peeling off from the belt body even when the core cord is used as wiring for electrical signals or power. [Means for solving the problem]

[0008] A belt according to one embodiment of the present invention comprises a belt main body, one or more electric core cords including a conductive core wire, and one or more reinforcing core cords having a higher electrical resistance per unit length than the electric core cords, the electric core cords and the reinforcing core cords being embedded in the belt main body along the length direction with gaps in the width direction of the belt main body, the electric core cord having a coating film that forms a circumferential surface so as to cover the core wire, and the coating film being fused to the belt main body. Effect of the Invention

[0009] The belt of the present invention can prevent the core cord from peeling off from the belt body even when the core cord is used as wiring for electrical signals or power. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view showing a belt according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the belt of FIG. 1 taken along line AA. [Diagram 3] FIG. 3 is a schematic cross-sectional view of the belt of FIG. 1 taken along line BB. [Figure 4] FIG. 4 is a schematic perspective view showing a reinforcing core cord in the vicinity of a belt hole of the belt of FIG. [Diagram 5] FIG. 5 is a schematic perspective view showing a reinforcing core cord in the vicinity of a belt hole having a different configuration from that in FIG. [Figure 6] FIG. 6 is a schematic perspective view showing a belt according to an embodiment different from that shown in FIG. [Figure 7] FIG. 7 is a schematic cross-sectional view of a belt according to an embodiment different from that shown in FIGS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Description of the embodiment of the present invention] First, the embodiments of the present invention will be listed and described.

[0012] A belt according to one embodiment of the present invention comprises a belt main body, one or more electric core cords including a conductive core wire, and one or more reinforcing core cords having a higher electrical resistance per unit length than the electric core cords, the electric core cords and the reinforcing core cords being embedded in the belt main body along the length direction with gaps in the width direction of the belt main body, the electric core cord having a coating film that forms a circumferential surface so as to cover the core wire, and the coating film being fused to the belt main body.

[0013] In this belt, the electric core cord has a core wire and a coating film, so when wiring is connected to the electric core cord, tension applied to the core cord is transmitted to both the core wire and the coating film. Of these, the coating film is fused to the belt body, so tension acts in the same direction on both the belt body and the electric core cord. Therefore, this belt can prevent the electric core cord from peeling off from the belt body.

[0014] The belt body may be mainly composed of an elastomer, and the coating film may be mainly composed of polyethylene or polyester. By making the belt body mainly composed of an elastomer and the coating film mainly composed of polyethylene or polyester, the coating film can be easily fused to the belt body.

[0015] The elastomer is preferably a flame-retardant material, which can reliably prevent the belt body from catching fire due to electrical leakage or the like.

[0016] The belt may be provided with a cover layer having a lower friction coefficient than the belt body and covering one or both sides of the belt body. By providing a cover layer having such a low friction coefficient, the belt can have excellent abrasion resistance during use.

[0017] The cover layer on at least one side may preferably be mainly made of a nylon resin or a fluorine resin, so that the coefficient of friction of the cover layer can be reduced.

[0018] It is preferable to provide a cover layer having a hardness higher than that of the belt body, covering one or both sides of the belt body. By providing such a cover layer having a high hardness, the strength and abrasion resistance of the belt can be increased.

[0019] The main component of the cover layer on at least one side is preferably a thermoplastic elastomer resin. By using a thermoplastic elastomer resin as the main component of the cover layer in this manner, the belt body and the cover layer can be made difficult to peel off from each other.

[0020] The JIS-A hardness of the belt body is preferably equal to or greater than 70 and less than 100. By setting the JIS-A hardness of the belt body within the above range, it is possible to increase the transmission efficiency while preventing a decrease in strength.

[0021] The belt body may have a core support portion, which is a recess for supporting the electric core cord and the reinforcing core cord, on at least one side, and the core support portion may be covered. By having the core support portion in this manner, it is easy to control the embedding positions of the electric core cord and the reinforcing core cord when manufacturing the belt. In addition, by covering the core support portion, it is possible to prevent the electric core cord from shorting out with other conductors when using the belt.

[0022] The core cords positioned at the outermost sides in the width direction may be reinforcing core cords. The electrical resistance of the core cords positioned at the outermost sides in the width direction may increase over time due to wear caused by friction from the side of the belt. For this reason, the core cords positioned at the outermost sides in the width direction are reinforcing core cords and are not used for wiring for electrical signals or power, thereby improving the reliability of the wiring.

[0023] It is preferable that the belt has a plurality of the electric core cords, and the reinforcing core cord is disposed between adjacent electric core cords. By disposing the reinforcing core cord between adjacent electric core cords in this manner, it is possible to prevent the strength of the belt from being locally reduced.

[0024] It is preferable that the core cord group has a plurality of the above-mentioned electric core cords, and 2 to 5 of the above-mentioned electric core cords are adjacent to each other in a row. By configuring the core cord group in this way, it is easy to connect in parallel to wiring that requires low resistance, such as power wiring. Furthermore, when the electric core cords are used in parallel for the same signal, the average interval between the electric core cords that make up the core cord group can be narrowed, which further suppresses an increase in the width of the belt.

[0025] The core wire of the electric core cord may be a soft copper wire or a copper alloy wire. Copper has low electrical resistance per unit length and is suitable for electric current applications. In addition, soft copper wire and copper alloy wire are easily bent, so that problems such as breakage can be prevented.

[0026] The core wire of the electric core cord may be a single wire, a bunched wire, or a rope-stranded wire. By using a single wire as the core wire of the electric core cord, the cross section of the core becomes closely packed, which makes it easy to reduce the resistance of the core wire. Furthermore, by using a bunched wire or a rope-stranded wire as the core wire of the electric core cord, the strength of the core can be increased, preventing defects such as wire breakage, and improving the flex fatigue resistance of the belt.

[0027] The current-carrying core cord may be a shielded wire, a cable, or a shielded cable. By using the current-carrying core cord as a shielded wire, a cable, or a shielded cable in this manner, the noise resistance of the current-carrying core cord can be improved.

[0028] The belt body may have one or more belt holes penetrating in the thickness direction. By providing the belt body with one or more belt holes in this way, the belt can be easily fixed to a dolly or the like.

[0029] The electric core cord may have a connector on at least one end thereof, so that wiring between the belt and other devices can be easily performed.

[0030] The belt may be a flat belt. The belt may be suitably used as a flat belt that requires an electric current carrying function.

[0031] The belt may be a toothed belt having a plurality of teeth disposed at equal intervals in the length direction on one surface of the belt body. The belt may be suitably used as a toothed belt requiring an electric current carrying function.

[0032] Here, "main component" means the component with the highest content, preferably a content of 50% by mass or more, more preferably 90% by mass or more. "JIS-A hardness" means the hardness measured by placing the indenter of an A-type hardness tester against the surface of a fixed belt in accordance with JIS-K-7312:1996 (A method).

[0033] The "coefficient of friction" refers to a value measured by the following procedure. A test piece measuring 5 cm x 15 cm square is cut from the belt. The test piece is fixed to a static friction coefficient measuring device (for example, the static friction measuring device Type:10 manufactured by Shinto Chemical Co., Ltd.). A polished steel is fixed on top of the test piece, the platform of the measuring device is raised, and the scale is read when the polished steel moves, which is the friction coefficient value.

[0034] [Details of the embodiment of the present invention] A belt according to an embodiment of the present invention will be described with reference to the drawings.

[0035] [First embodiment] The belt 1 shown in Fig. 1, Fig. 2 and Fig. 3 includes a belt body 10, four conductive core cords 20, six reinforcing core cords 30, and a cover layer 40. The belt 1 is a flat belt. The belt 1 can be suitably used as a flat belt that requires a conductive function.

[0036] In addition, the belt body 10 has one or more (three in FIG. 1) belt holes 11 penetrating in the thickness direction, and the current-carrying core cord 20 and the reinforcing core cord 30 are embedded in the belt body 10 along the length direction at intervals in the width direction of the belt body 10.

[0037] <Belt body> The main component of the belt body 10 is rubber or resin. Examples of the rubber include ethylene-α-olefin rubber such as ethylene-propylene rubber (EPR) and ethylene propylene diene monomer rubber (EPDM), chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), hydrogenated nitrile rubber (H-NBR), etc. The rubber may be one of these, or a blend of two or more of them. Examples of the resin include thermoplastic polyester, polyamide, polyurethane, etc.

[0038] Among them, the main component of the belt body 10 is preferably an elastomer such as ethylene-α-olefin rubber, thermoplastic polyurethane, polyamide, polyester, etc., and more preferably thermoplastic urethane, polyamide, and polyester. Thermoplastic urethane has low dust generation and excellent abrasion resistance. Polyamide has excellent oil resistance, chemical resistance, and abrasion resistance. Polyester has excellent water resistance, low-temperature flexibility, strength, and fatigue resistance. In addition, the elastomer is preferably a flame-retardant material. By using the elastomer as a flame-retardant material in this way, it is possible to reliably prevent the belt body 10 from catching fire due to electrical leakage or the like.

[0039] The average thickness of the belt body 10 is appropriately determined depending on the strength required for the belt 1, and can be, for example, 1 mm or more and 10 mm or less.

[0040] The width and length of the belt body 10 are appropriately determined depending on the application of the belt 1. The belt 1 is mainly used as an open belt having both ends.

[0041] The lower limit of the JIS-A hardness of the belt body 10 is preferably 70, and more preferably 75. On the other hand, the JIS-A hardness of the belt body 10 is preferably less than 100, more preferably less than 95, and even more preferably less than 80. If the JIS-A hardness of the belt body 10 is less than the above lower limit, the strength of the belt body 10 and therefore the strength of the belt 1 may be insufficient. Conversely, if the JIS-A hardness of the belt body 10 is equal to or greater than the above upper limit, the transmission efficiency of the belt 1 may be reduced.

[0042] 1 and 2, in the belt 1, a belt body 10 has, on one side (drive side), a plurality of core support parts 20a which are recesses for supporting the electric core cords 20 and the reinforcing core cords 30. When the belt 1 is manufactured, the belt body 10 can be manufactured, for example, by extrusion molding, while the electric core cords 20 and the reinforcing core cords 30 are supported by the plurality of core support parts 20a. In other words, by having the core support parts 20a in this way, it is easy to control the embedding positions of the electric core cords 20 and the reinforcing core cords 30 when manufacturing the belt 1.

[0043] The core support portion 20a is preferably covered. In the belt 1, it is covered with a second cover layer 42 described later. By covering the core support portion 20a, it is possible to prevent the current-carrying core cord 20 from shorting out with other conductors when the belt 1 is used.

[0044] 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.

[0045] The belt holes 11 are used to fix an object to be connected, such as a cart, to the belt 1, and specifically, for example, screws are inserted to fasten the belt 1. The cross-sectional shape of the belt holes 11 is not particularly limited, but is generally circular. The following description is based on the assumption that the cross-section of the belt holes 11 is circular, but other shapes are not excluded.

[0046] The belt hole 11 may be a single one, but it is preferable to provide a plurality of belt holes 11 in order to prevent the connection object from rotating. The number of belt holes 11 may be three or more depending on the weight of the connection object. Alternatively, it is possible to provide more belt holes 11 than the number of fastenings to the connection object so that the attachment position can be adjusted.

[0047] The belt hole 11 is preferably provided in the center in the width direction of the belt body 10. By providing the belt hole 11 in the center in the width direction of the belt body 10, the above-mentioned connection objects can be stably connected.

[0048] Moreover, the belt holes 11 are generally provided at one end or both ends in the longitudinal direction of the belt body 10. This is because the above-mentioned connection object is often connected to the end of the belt body 10 in the longitudinal direction.

[0049] When multiple belt holes 11 are provided, the multiple belt holes 11 are arranged so that their centers are aligned along the length direction. The distance between adjacent belt holes 11 is appropriately determined so that the above-mentioned objects to be connected can be fastened. The multiple belt holes 11 are preferably aligned at equal intervals. By arranging the multiple belt holes 11 at equal intervals in this manner, pressure applied to the belt main body 10 when fastening the above-mentioned objects to be connected is more likely to be uniformly distributed, and damage to the belt main body 10 due to localized concentration of pressure can be suppressed.

[0050] The lower limit of the diameter of the belt hole 11 is preferably 2 mm, and more preferably 3 mm. Meanwhile, the upper limit of the diameter of the belt hole 11 is preferably 7 mm, and more preferably 6 mm. If the diameter of the belt hole 11 is less than the above-mentioned lower limit, there is a risk that the fastening strength with the above-mentioned connection object may not be sufficiently ensured. Conversely, if the diameter of the belt hole 11 exceeds the above-mentioned upper limit, there is a risk that the strength of the belt main body 10 in the vicinity of the belt hole 11 may be insufficient, or that the number of cords of the electric core cord 20 may not be sufficiently ensured.

[0051] <Electrical core cord> The electric core cord 20 is a linear body having, for example, a circular cross section. As shown in Fig. 3, the electric core cord 20 includes a conductive core wire 21 and has a coating film 22 that forms a circumferential surface so as to cover the core wire 21.

[0052] 1, the electric core cord 20 may have a connector 23 on at least one end. The connector 23 is a member for connecting the electric core cord 20 to a signal line outside the belt 1. By providing the connector 23 on at least one end of the electric core cord 20 in this manner, wiring between the belt 1 and other devices can be easily performed. The connectors 23 may be provided on both ends of the electric core cord 20.

[0053] The current-carrying core cord 20 may be a shielded wire, a cable, or a shielded cable. By forming the current-carrying core cord 20 as a shielded wire, a cable, or a shielded cable in this manner, the noise resistance of the current-carrying core cord 20 can be improved.

[0054] The lower limit of the average diameter of the electric core cord 20 is preferably 0.2 mm, more preferably 0.5 mm, and even more preferably 1 mm. On the other hand, the upper limit of the average diameter of the electric core cord 20 is preferably 2.5 mm, and more preferably 1.5 mm. If the average diameter of the electric core cord 20 is less than the lower limit, the electric resistance of the electric core cord 20 may not be sufficiently reduced, and the electric core cord 20 may not function sufficiently as an electric signal or power source. Conversely, if the average diameter of the electric core cord 20 exceeds the upper limit, the width of the belt 1 may become too large. Here, the "average diameter" refers to the average value of the diameters measured at any 10 points. The same applies to all "averages" below. In other words, the "average" refers to the average calculated from the values ​​measured at any 10 points on the measurement subject.

[0055] (Core wire) Examples of the core wire 21 include steel wire and copper wire. Among them, copper wire is preferable, and soft copper wire or copper alloy wire is more preferable. Copper wire has low electrical resistance per unit length and is suitable for current carrying applications. In addition, soft copper wire and copper alloy wire are easily bent, so that problems such as breakage can be prevented.

[0056] The core wire 21 of the electric current core cord 20 may be a single wire, a bunched wire, or a rope twisted wire. By making the core wire 21 of the electric current core cord 20 a single wire, the cross section of the core wire 21 becomes closely packed, and it is easy to reduce the resistance of the core wire 21. Furthermore, by making the core wire 21 of the electric current core cord 20 a bunched wire or a rope twisted wire, the strength of the core wire 21 is increased, and the occurrence of defects such as wire breakage can be suppressed, and the flex fatigue resistance of the belt 1 can be improved.

[0057] (Coating film) The covering film 22 is preferably made of an insulator. By making the covering film 22 of an insulator in this way, it is possible to prevent a change in electrical characteristics when the current-carrying core cord 20 comes into contact with another current-carrying core cord 20 or the like. In addition, since the belt 1 is manufactured while supporting the current-carrying core cord 20 from below, at the support point, as shown in FIG. 2, the belt 1 after manufacture may have a core support portion 20a where a part of the current-carrying core cord 20 is exposed from the belt body 10. Even if the core support portion 20a is present in this way, the covering film 22 made of an insulator can prevent a short circuit or electric shock when a current flows through the current-carrying core cord 20.

[0058] The coating film 22 is fused to the belt body 10. That is, the coating film 22 maintains its original shape, and the belt body 10 and the coating film 22 are heated and melted at the interface with the belt body 10 to be fused thereto.

[0059] The melting point of the main component of the coating film 22 is preferably lower than that of the main component of the belt body 10. By making the melting point of the main component of the coating film 22 lower than that of the main component of the belt body 10 in this manner, the molding temperature of the belt 1 during production can be made to be equal to or higher than the melting point of the coating film 22, and the coating film 22 can be reliably fused.

[0060] When the main component of the belt body 10 is an elastomer, the main component of the coating film 22 is preferably polyethylene or polyester. By making the main component of the belt body 10 an elastomer and the main component of the coating film 22 polyethylene or polyester in this way, the coating film 22 can be easily fused to the belt body 10.

[0061] (Relationship with belt holes) As shown in FIG. 3, the belt hole 11 may be provided on the reinforcing core cord 30 described later. That is, the reinforcing core cord 30 may be cut off by the belt hole 11. In this case, as shown in FIG. 4, the part of the reinforcing core cord 30 exposed to the belt hole 11 (cut part 30a in FIG. 4) may be scraped off, or as shown in FIG. 5, the part of the reinforcing core cord 30 corresponding to the belt hole 11 (cut part 30b in FIG. 4) may be cut off. In either case, the reinforcing core cord 30 reinforces the area where the belt hole 11 is not provided. On the other hand, the belt hole 11 cannot be provided on the electric core cord 20 because the belt hole 11 would lose electrical connection. In other words, the electric core cord 20 is arranged to avoid the belt hole 11.

[0062] Here, the distance at which the electric core cord 20 is separated from the belt hole 11 will be considered. A screw is inserted into the belt hole 11 to fasten the belt 1 to the object to be connected. Since the upper surface of the screw has a larger diameter than the belt hole 11 due to its structure, when the screw is tightened to fix the belt 1 to the object to be connected, the upper surface of the screw is pressed against the belt 1. If the electric core cord 20 is disposed in an area close to the upper surface of the screw, the resistance value of the electric core cord 20 may change due to this pressing pressure, and the desired electrical characteristics may not be obtained. For this reason, the electric core cord 20 needs to be separated from the belt hole 11 by a certain distance so that the electrical characteristics are not changed by the pressing force of the screw. Specifically, the lower limit of the distance between the electric core cord 20 and the periphery of the belt hole 11 (distance D shown in FIG. 3) is preferably 0.5 mm, more preferably 0.7 mm. On the other hand, the upper limit of the distance D is not particularly limited, but it can be set to, for example, 5 mm, since if it is made too large, it may not be possible to arrange the required number of conductive core cords 20.

[0063] <Reinforcing core cord> The reinforcing core cord 30 is a linear body having, for example, a circular cross section. The reinforcing core cord 30 includes a core wire 31 and has a higher electrical resistance per unit length than the conductive core cord 20.

[0064] The core wire 31 of the reinforcing core cord 30 can be made of the same material as the core wire 21 of the electric core cord 20, but it is preferable that the core wire 31 of the reinforcing core cord 30 is made of a different material from the core wire 21 of the electric core cord 20. By making the core wire 31 of the reinforcing core cord 30 different from the core wire 21 of the electric core cord 20 in this manner, it becomes possible to adopt a material with low electrical resistivity as the core wire 21 of the electric core cord 20, and therefore it is easy to reduce the number of parallel electric core cords 20 for ensuring the required electrical resistance. In particular, it is preferable that the core wire 21 of the electric core cord 20 is made of a copper wire with low electrical resistivity, and the core wire 31 of the reinforcing core cord 30 is made of an aramid wire having insulating properties.

[0065] In addition, when the core wire 31 of the reinforcing core cord 30 is conductive, it is preferable that the core wire 21 of the current-carrying core cord 20 is a copper wire covered with an insulating covering film 22, and the core wire 31 of the reinforcing core cord 30 is a steel wire. Steel wires have high rigidity and can maintain their strength even when their diameter is small. The reinforcing core cord 30 can also be configured without an insulating layer (covering film). Since the current-carrying core cord 20 has the covering film 22, even if a steel wire without an insulating layer comes into contact with the current-carrying core cord 20, the electric signal or the function of the current-carrying core cord 20 as a power source is unlikely to be affected. In this way, the reinforcing core cord 30 does not need to be provided with an insulating layer and can have a small diameter, so it does not particularly require a space in the width direction. Therefore, by using a steel wire for the core wire 31 of the reinforcing core cord 30, the strength of the belt 1 can be maintained while ensuring a wide area for the current-carrying core cord 20. From the above, by making the core wire 21 of the conductive core cord 20 a copper wire covered with an insulating coating film 22 and making the core wire 31 of the reinforcing core cord 30 a steel wire, it is possible to further prevent an increase in the width of the belt 1 while ensuring the number of core cords required for wiring electrical signals and power sources.

[0066] The lower limit of the average diameter of the reinforcing core cord 30 is preferably 0.1 mm, more preferably 0.2 mm, and even more preferably 0.5 mm. On the other hand, the upper limit of the average diameter of the reinforcing core cord 30 is preferably 2 mm, and more preferably 1 mm. If the average diameter of the reinforcing core cord 30 is less than the lower limit, the strength of the reinforcing core cord 30 may be insufficient. On the other hand, if the average diameter of the reinforcing core cord 30 exceeds the upper limit, the weight of the belt 1 may be too heavy, the bending rigidity of the belt 1 may be too high, and the belt 1 may be difficult to wind around a pulley with a small diameter, or the thickness of the belt body 10 for covering the reinforcing core cord 30 may be too thick.

[0067] <Relationship between the current-carrying core cord and the reinforcing core cord> The average diameter of the electric core cord 20 is preferably larger than the average diameter of the reinforcing core cord 30. By making the average diameter of the electric core cord 20 larger than the average diameter of the reinforcing core cord 30 in this manner, it is possible to easily reduce the electrical resistance per unit length of the electric core cord 20. In particular, when the material of the electric core cord 20 and the material of the reinforcing core cord 30 are the same, by making the average diameter of the electric core cord 20 larger than the average diameter of the reinforcing core cord 30, it is possible to reduce the electrical resistance per unit length.

[0068] The four conductive core cords 20 and six reinforcing core cords 30 (collectively referred to as "core cords") are arranged so that the shortest distance from one side of the belt body 10 to the outer periphery of the core cords is constant, as shown in Fig. 3. By arranging them in this way, the belt body 10 can be easily manufactured by extrusion molding while supporting the ten core cords from below.

[0069] It is preferable that the core cords positioned at the outermost sides in the width direction of the belt body 10 are reinforcing core cords 30. There is a risk that the electrical resistance of the core cords positioned at the outermost sides in the width direction increases over time due to wear caused by rubbing against the side of the belt 1. For this reason, the core cords positioned at the outermost sides in the width direction are reinforcing core cords 30, and are not used for wiring for electrical signals or power, thereby improving the reliability as wiring.

[0070] The lower limit of the average distance between the central axis of the reinforcing core cord 30 arranged on the outermost side and the side surface of the belt body 10 adjacent thereto (also referred to as the "average distance between the reinforcing core cord 30 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 reinforcing core cord 30 and the side surface of the belt body 10 is preferably 1 mm, more preferably 0.7 mm. If the average distance between the reinforcing core cord 30 and the side surface of the belt body 10 is less than the lower limit, there is a risk that the reinforcing core cord 30 arranged on the outermost side will be exposed from the side surface of the belt body 10 during the manufacture of the belt 1. Conversely, if the average distance between the reinforcing core cord 30 and the side surface of the belt body 10 exceeds the upper limit, the side edge of the belt body 10 will be easily fluttered during driving, and the effect of improving the driving accuracy by the reinforcing core cord 30 may be insufficient.

[0071] 3, in the belt 1, a reinforcing core cord 30 is disposed between adjacent electric core cords 20. By disposing the reinforcing core cord 30 between adjacent electric core cords 20 in this manner, it is possible to prevent the strength of the belt 1 from being locally reduced.

[0072] The arrangement of the current-carrying core cords 20 and the reinforcing core cords 30 may be symmetrical with respect to the center of the belt body 10 in the longitudinal direction. The belt 1 is used under tension when driven, and by arranging the current-carrying core cords 20 and the reinforcing core cords 30 symmetrically in this manner, tension is applied uniformly in the width direction of the belt body 10, and deviation of the belt 1 while it is running can be prevented.

[0073] The lower limit of the average pitch P of adjacent core cords (see FIG. 3; the average distance in the width direction of the belt 1 between the central axes of adjacent core cords) is preferably 0.3 mm, more preferably 0.5 mm. On the other hand, the upper limit of the average pitch P is preferably 4 mm, more preferably 1 mm. If the average pitch P is less than the lower limit, the insulation between the multiple current-carrying core cords 20 may not be sufficiently ensured, or the flexibility of the belt 1 may be insufficient. Conversely, if the average pitch P exceeds the upper limit, the belt 1 may become unnecessarily large in the width direction, or the reinforcing core cord 30 may not sufficiently improve the strength, durability, driving accuracy, etc. of the belt 1. Note that, in the case where a core cord is not arranged at a position overlapping with a belt hole 11, the average pitch P between two core cords arranged on either side of the belt hole 11 is not limited to the above.

[0074] The average pitch P is preferably constant regardless of the combination of the types of adjacent core cords (the electric core cord 20 and the reinforcing core cord 30). In other words, the average pitch P is preferably equal between adjacent electric core cords 20, between adjacent reinforcing core cords 30, and between adjacent electric core cords 20 and reinforcing core cords 30, regardless of the combination of the adjacent core cords. By arranging the core cords at an equal pitch in this way regardless of the type of core cord, it is possible to prevent fluttering during driving of the belt body 10. Furthermore, by making the average pitch P equal, a load is applied uniformly to each core cord, so that early breakage due to localized load on a specific core cord and an increase in the electrical resistance of the electric core cord 20 can be prevented. Note that "the average pitches P are equal" includes the case where the average pitches P are completely equal, as well as the case where each average pitch P is within a practical error range (for example, an error range of 5% or less from the median).

[0075] <Cover layer> In the belt 1, the cover layer 40 is composed of a first cover layer 41 that covers the conveying surface of the belt body 10 and a second cover layer 42 that covers the driving surface. That is, in the belt 1, the cover layer 40 covers both sides of the belt body 10.

[0076] The cover layer 40 preferably has a friction coefficient lower than that of the belt body 10. By providing the cover layer 40 with such a low friction coefficient, the belt 1 can be made to have excellent abrasion resistance during use. Specifically, the friction coefficient of the cover layer 40 is preferably 0.15 or more and 0.25 or less.

[0077] In this case, the main component of the cover layer 40 is preferably a nylon resin or a fluororesin. By making the main component of the cover layer 40 a nylon resin or a fluororesin in this manner, the friction coefficient of the cover layer 40 can be reduced. Examples of the nylon resin include nylon 6,6 and nylon 6. Examples of the fluororesin include polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA).

[0078] It is also preferable that the hardness of the cover layer 40 is higher than that of the belt body 10. By providing a cover layer 40 having such a high hardness, it is possible to increase the strength and abrasion resistance of the belt 1. From the viewpoint of effectiveness, the JIS-A hardness of the cover layer 40 is preferably 85 or more and 95 or less.

[0079] In this case, the main component of the cover layer 40 is preferably a thermoplastic elastomer resin. By using a thermoplastic elastomer resin as the main component of the cover layer 40 in this manner, it is possible to make it difficult for the belt body 10 and the cover layer 40 to peel off from each other. Examples of the thermoplastic elastomer resin include thermoplastic polyurethane (TPU).

[0080] The first cover layer 41 and the second cover layer 42 may be made of different materials. For example, the first cover layer 41 may be made of a nylon resin or a fluorine resin having a lower friction coefficient than that of the belt body 10, and the second cover layer 42 may be made of a thermoplastic elastomer resin having a higher hardness than that of the belt body 10.

[0081] The lower limit of the average thickness of the cover layer 40 is preferably 15 μm, more preferably 25 μm. On the other hand, the upper limit of the average thickness of the cover layer 40 is preferably 3000 μm, more preferably 2000 μm. If the average thickness of the cover layer 40 is less than the lower limit, the cover layer 40 may be easily torn. On the other hand, if the average thickness of the cover layer 40 exceeds the upper limit, the rigidity of the belt 1 may be too high. The average thickness of the first cover layer 41 and the average thickness of the second cover layer 42 may be different, but are preferably equal from the viewpoint of warping of the belt 1.

[0082] <Method of manufacturing the belt> The belt 1 can be manufactured by a manufacturing method including, for example, an extrusion molding step and a cover layer lamination step.

[0083] (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 conductive core cord 20 and the reinforcing core cord 30 embedded therein is formed by extrusion molding.

[0084] Specifically, multiple core cords (electrical core cords 20 and reinforcing core cords 30) are inserted into a crosshead attached to the tip of the cylinder of an extruder, and are supported by a core support part 20a, and extrusion molded so that both sides of the core cords are covered with molten rubber or resin composition. Alternatively, the molten extruded rubber or resin composition and the multiple core cords may be sandwiched between a pair of rolls and pressurized to embed the multiple core cords in the rubber or resin composition. This rubber or resin composition constitutes the belt body 10.

[0085] The heating temperature for melting the rubber or resin composition in the extrusion molding depends on the type of rubber or resin, whether a curing agent is used, etc., 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 melt sufficiently, which may make extrusion molding difficult. Conversely, if the heating temperature exceeds the upper limit, the extrusion molded body becomes unnecessarily hot, which may result in an unnecessarily long cooling time and a decrease in the manufacturing efficiency of the belt 1. In addition, the maximum value of the heating temperature is set to a temperature higher than the melting point of the coating film 22 so that the coating film 22 is fused to the belt body 10 by this heating.

[0086] The belt body 10 can be obtained by cooling the extrusion molded body.

[0087] <Cover layer lamination process> In the cover layer lamination step, the cover layers 40 are laminated on both sides of the belt body 10 obtained in the extrusion molding step.

[0088] The cover layer 40 can be laminated by unrolling the thin-film cover layer 40 from the upper or lower side or both sides of the belt body 10 when the belt body 10 is molded in the above-mentioned extrusion molding process, and inserting and sandwiching it between the belt body 10 and the above-mentioned roll, for example.

[0089] Next, the laminate in which the cover layer 40 is laminated on the belt body 10 is cooled. Examples of the cooling method include air cooling, water cooling, etc. The cooling temperature and time conditions are not particularly limited, but examples of the set conditions include conditions that allow the internal temperature of the laminate to be cooled to 10°C or higher and 40°C or lower.

[0090] The belt 1 can be manufactured in the manner described above.

[0091] <Advantages> In the belt 1, the electric core cord 20 has a core wire 21 and a covering film 22, so that when wiring is connected to the electric core cord 20, tension applied to the core cord is transmitted to both the core wire 21 and the covering film 22. Of these, the covering film 22 is fused to the belt body 10, so tension acts in the same direction on both the belt body 10 and the electric core cord 20. Therefore, the belt 1 can prevent the electric core cord 20 and the belt body 10 from peeling off from each other.

[0092] Second Embodiment The belt 2 shown in Fig. 4 comprises a belt body 10, a plurality of teeth 50 arranged at equal intervals in the longitudinal direction on one surface of the belt body 10, four current-carrying core cords 20 including a conductive core wire 21, and six reinforcing core cords 30 having a higher electrical resistance per unit length than the current-carrying core cords 20, the current-carrying core cords 20 and the reinforcing core cords 30 being embedded in the belt body 10 along the longitudinal direction at intervals in the width direction of the belt body 10, the current-carrying core cords 20 having a coating film 22 constituting a circumferential surface so as to cover the core wire 21, and the coating film 22 being fused to the belt body 10. The belt 2 is a toothed belt.

[0093] The belt 2 can be configured in the same manner as the belt 1 shown in Fig. 1, except that it has the toothed portion 50 and does not have the cover layer 40, and therefore the same reference numerals are used and detailed description is omitted. In the belt 2, the belt holes 11 may be provided between the toothed portions 50 as shown in Fig. 4, but they may also be provided so as to penetrate the toothed portions 50. Furthermore, when the belt 2 has a plurality of belt holes 11, the intervals between the belt holes 11 may match the intervals between the toothed portions 50 as shown in Fig. 4, but they do not have to match.

[0094] <Tooth> The tooth portion 50 is a convex portion having a cross section of a trapezoid, a triangle, a semicircle, a mountain shape, a wave shape, a normal distribution curve shape, etc. The tooth portion 50 is arranged so that its ridge line (axial direction) coincides with the width direction of the belt body 10.

[0095] The average height of the tooth portion 50 and the pitch between the tooth portions 50 are appropriately determined depending on the application of the belt 2. The average height of the tooth portion 50 can be, for example, 1.0 mm or more and 10 mm or less. The pitch between the tooth portions 50 can be, for example, 2 mm or more and 25 mm or less.

[0096] The main component of the tooth portion 50 may be the same as that of the belt body 10. The tooth portion 50 may also contain the same additives as those of the belt body 10.

[0097] <Advantages> The belt 2 can be suitably used as a toothed belt that requires an electrical conduction function.

[0098] [Other embodiments] The present invention is not limited to the above-described embodiment, and can be embodied in various other forms in addition to the above-described forms with various modifications and improvements.

[0099] In the above embodiment, the belt of the present invention is described as having four electric core cords and six reinforcing core cords, but the number of electric core cords and reinforcing core cords is not limited to the above, and each may be configured with any number of cords, such as 1 or more. The number of electric core cords is appropriately determined according to the number of wirings for required electric signals and power sources, and the number of reinforcing core cords is appropriately determined according to the strength required for the belt.

[0100] In the above embodiment, the belt body has one or more belt holes penetrating in the thickness direction. However, belt holes are not an essential component, and belts without belt holes are also intended by the present invention.

[0101] In the above embodiment, a case has been described in which the belt body has a core support portion on one side, but the belt body may be configured to have a core support portion on both sides of the belt body, or conversely, may be configured not to have a core support portion.

[0102] In the above first embodiment, the cover layer covers both sides of the belt body, but the cover layer may cover only one of the conveying surface or the driving surface. Also, the present invention contemplates a belt without a cover layer.

[0103] In the above second embodiment, a toothed belt without a cover layer has been described, but the belt may have a cover layer covering one or both sides of the belt body. In this case, the cover layer can be configured in the same manner as the cover layer in the first embodiment.

[0104] In the above embodiment, the electric core cord has a connector on at least one end side. However, the present invention also contemplates a belt in which the electric core cord does not have a connector.

[0105] In the above embodiment, a configuration in which the reinforcing core cords are arranged between adjacent electric core cords has been described, but the arrangement of the electric core cords and the reinforcing core cords is not limited to this. As shown in FIG. 5, the belt 3 may be configured such that adjacent electric core cords 20 are continuously arranged to form a core cord group 24. By configuring the core cord group 24 in this manner, it is easy to connect the belt 3 in parallel to wiring that requires low resistance, such as power wiring. The belt 3 may be configured in the same manner as the belt 1 shown in FIG. 3, except that the core cord group 24 is formed, and corresponding components are therefore denoted by the same reference numerals and detailed description thereof will be omitted.

[0106] The number of conductive core cords 20 constituting the core cord group 24 is preferably 2 to 5. If the number is less than the lower limit, it is not possible to form the core cord group 24. Conversely, if the number exceeds the upper limit, the spacing between the reinforcing core cords 30 in the core cord group 24 becomes too large, and there is a risk of the strength in the vicinity of the core cord group 24 decreasing.

[0107] The average spacing between the electrical core cords 20 constituting the core cord group 24 is preferably smaller than the average spacing between the electrical core cords 20 and the reinforcing core cords 30. When electrical core cords 20 are used in parallel for the same signal, the average spacing between the electrical core cords 20 constituting the core cord group 24 can be narrowed, further preventing an increase in the width of the belt 3.

[0108] In the belt 3 shown in Fig. 5, the core cord group 24 is provided in one location, but the core cord group 24 may be provided in multiple locations. Also, as shown in Fig. 5, a single electric core cord 20 that does not belong to any of the core cord groups 24 may be provided, or all of the electric core cords 20 may belong to any of the core cord groups 24. [Industrial Applicability]

[0109] The belt of the present invention can suppress an increase in width while ensuring the number of core cords required for wiring electrical signals and power sources. [Explanation of symbols]

[0110] 1, 2, 3 Belt 10 Belt body 11 Belt holes 20 Electrical core cord 20a Core support part 21 Core Wire 22 Coating membrane 23 Connector 24 Core cord group 30 Reinforcing core cord 30a, 30b resection part 31 Core Wire 40 Cover Layer 41 First cover layer 42 Second Cover Layer 50 Tooth D Distance P Average pitch

Claims

1. The belt body, One or more conductive core cords including a conductive core wire; one or more reinforcing core cords having a higher electrical resistance per unit length than the conductive core cord; Equipped with the conductive core cord and the reinforcing core cord are embedded in the belt body along the length direction at intervals in the width direction of the belt body, the conductive core cord has a coating film that forms a circumferential surface so as to cover the core wire, The coating film is fused to the belt body.

2. The main component of the belt body is an elastomer, 2. The belt according to claim 1, wherein the main component of the coating film is polyethylene or polyester.

3. 3. The belt of claim 2, wherein said elastomer is a flame retardant material.

4. 4. The belt according to claim 1, 2 or 3, further comprising a cover layer having a lower friction coefficient than the belt body and covering one or both sides of the belt body.

5. 5. The belt according to claim 4, wherein the main component of the cover layer on at least one side is a nylon resin or a fluorine resin.

6. 4. The belt according to claim 1, further comprising a cover layer having a hardness higher than that of the belt body and covering one or both sides of the belt body.

7. 7. The belt according to claim 6, wherein the main component of the cover layer on at least one side is a thermoplastic elastomer resin.

8. 4. The belt according to claim 1, 2 or 3, wherein the belt body has a JIS-A hardness of 70 or more and less than 100.

9. the belt body has a core support portion, which is a recessed portion for supporting the conductive core cord and the reinforcing core cord, on at least one surface thereof; 4. The belt according to claim 1, 2 or 3, wherein the core support portion is coated.

10. 4. The belt according to claim 1, 2 or 3, wherein the core cords positioned on the outermost sides in the width direction are reinforcing core cords.

11. A plurality of the conductive core cords are provided, 4. The belt according to claim 1, 2 or 3, wherein the reinforcing core cord is disposed between adjacent conductive core cords.

12. A plurality of the conductive core cords are provided, 4. The belt according to claim 1, 2 or 3, wherein a core cord group is formed in which 2 to 5 of the conductive core cords are adjacent to each other in series.

13. 4. The belt according to claim 1, 2 or 3, wherein the core wire of the electric current-carrying core cord is a soft copper wire or a copper alloy wire.

14. 4. The belt according to claim 1, 2 or 3, wherein the core wire of the electric current-carrying core cord is a single wire, a bunched wire or a rope stranded wire.

15. 4. The belt according to claim 1, 2 or 3, wherein the current-carrying core cord is a shielded wire, a cable or a shielded cable.

16. 4. The belt according to claim 1, 2 or 3, wherein the belt body has one or a plurality of belt holes penetrating therethrough in the thickness direction.

17. 4. The belt according to claim 1, 2 or 3, wherein the electric current-carrying core cord has a connector on at least one end side.

18. 4. The belt according to claim 1, 2 or 3, which is a flat belt.

19. 4. The belt according to claim 1, 2 or 3, which is a toothed belt having a plurality of teeth disposed at equal intervals in the longitudinal direction on one surface of the belt body.

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