Drive belt

Abstract

A power transmission belt (B) includes an elastomer-made belt body (11) and a carbon fiber-made core wire (12) provided to be embedded in the belt body (11) and formed in a spiral having a pitch in a belt width direction. When the core wire (12) is observed from a side surface orthogonal to a length direction of the core wire (12), an angle θ of an outermost filament (F) in a filament bundle constituting the carbon fiber of the core wire (12) with respect to the length direction of the core wire (12) is 8° or more and 20° or less.

Description

[0001] This application is a divisional application of the patent application with application number 202180033001.4 (international application number PCT / JP2021 / 024895) filed on July 1, 2021, the title of which is “Drive Belt”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to a drive belt. BACKGROUND

[0003] A drive belt using a core wire made of carbon fiber has been known. For example, a toothed belt in which a core wire made of carbon fiber is embedded in a belt main body made of rubber is disclosed in Patent Literature 1.

[0004] Patent Literature 1: Japanese Patent Application Laid-Open No. 2005-24075 SUMMARY

[0005] The present application relates to a drive belt including a belt main body made of an elastomer and a core wire made of carbon fiber, the core wire being provided so as to be embedded in the belt main body and to form a spiral having a pitch in a belt width direction, and an angle formed between an outermost filament in a filament bundle constituting the core wire and a length direction of the core wire when the core wire is viewed from a side surface orthogonal to the length direction of the core wire is 8° or more and 20° or less. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1A is a perspective view of a section of a toothed belt to which the embodiment relates;

[0007] Figure 1B is a longitudinal sectional view of a portion of a toothed belt to which the embodiment relates;

[0008] Figure 2 is a front view when a core wire embedded in a toothed belt main body is viewed from a side surface orthogonal to a length direction;

[0009] Figure 3A is a first explanatory view of a manufacturing method of a toothed belt to which the embodiment relates;

[0010] Figure 3B is a second explanatory view of a manufacturing method of a toothed belt to which the embodiment relates;

[0011] Figure 3C is a third explanatory view of a manufacturing method of a toothed belt to which the embodiment relates;

[0012] Figure 4 is a layout view of a pulley of a belt running tester. DETAILED DESCRIPTION

[0013] Next, the embodiments will be described in detail with reference to the drawings.

[0014] Figure 1A and Figure 1B A toothed belt B according to the embodiments is shown. The toothed belt B according to the embodiments is a meshing transmission belt, for example, for high load transmission applications such as machine tools, printing machines, textile machines, injection molding machines, and the like. The belt length of the toothed belt B according to the embodiments is, for example, 500 mm or more and 3000 mm or less. The belt width is, for example, 10 mm or more and 200 mm or less. The belt thickness (maximum) is, for example, 3 mm or more and 20 mm or less.

[0015] The toothed belt B according to the embodiments includes a toothed belt body 11 that is annular and made of an elastomer formed of a polyurethane resin. The toothed belt body 11 has a flat belt portion 111 having a cross section in the shape of a horizontally long rectangle and a plurality of tooth portions 112 provided on the inner peripheral side of the flat belt portion 111 and integrated with the flat belt portion 111. The plurality of tooth portions 112 are provided at regular intervals in the belt length direction.

[0016] As the tooth profile of the tooth portion 112 in side view, for example, an STS tooth profile in which both sides are outwardly bulged in the shape of a circular arc or a trapezoidal tooth profile can be cited. The number of teeth of the tooth portion 112 is, for example, 30 or more and 400 or less. The tooth width (maximum dimension in the belt length direction) is, for example, 2 mm or more and 10 mm or less. The tooth height is, for example, 2 mm or more and 8 mm or less. The arrangement pitch is, for example, 8 mm or more and 14 mm or less.

[0017] The polyurethane resin that forms the toothed belt body 11 is obtained by curing a polyurethane composition by heating and pressurization, the polyurethane composition being formed by adding a curing agent, a plasticizer, or the like to a polyurethane prepolymer.

[0018] The polyurethane prepolymer is a polyurethane compound having a relatively low molecular weight and having a plurality of isocyanate groups (NCO) at the terminal, obtained by reacting an isocyanate component and a polyol component. As the isocyanate component, for example, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), or the like can be cited. As the polyol component, for example, polytetramethylene ether glycol (PTMG) or the like can be cited. The polyurethane prepolymer can be composed of a single polyurethane compound or can be composed of a mixture of a plurality of polyurethane compounds.

[0019] Examples of curing agents include amine compounds such as 1,4-phenylenediamine, 2,6-diaminotoluene, 1,5-naphthalenediamine, 4,4'-diaminodiphenylmethane, and 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA). The curing agent preferably contains one or more of these compounds. Amine compound curing agents are preferably added such that the ratio of the number of moles of NH2 groups in the curing agent to the number of moles of NCO groups in the polyurethane prepolymer, i.e., the α value (NH2 groups / NCO groups), is 0.70 or greater and 1.10 or less.

[0020] Examples of plasticizers include dialkyl phthalates such as dibutyl phthalate (DBP) and dioctyl phthalate (DOP); dialkyl adipates such as dioctyl adipate (DOA); and dialkyl sebacates such as dioctyl sebacate (DOS). The plasticizer preferably contains one or more of these compounds. The amount of plasticizer added is, for example, 3 parts by mass to 20 parts by mass per 100 parts by mass of the polyurethane prepolymer.

[0021] In addition, as other additives, a colorant, a defoaming agent, a stabilizer, etc. are mentioned, for example.

[0022] The hardness of the polyurethane resin forming the toothed belt main body 11 is, for example, 70° or more and 100° or less. The hardness of the polyurethane resin is measured in accordance with Japanese Industrial Standard JIS K7312:1996.

[0023] like Figure 2 As shown, the toothed belt B according to the embodiment includes a core wire 12 made of carbon fiber and embedded in the flat belt portion 111 of the toothed belt body 11. From the perspective of achieving excellent durability, the outer diameter D of the core wire 12 is preferably 0.4 mm to 2.7 mm, and more preferably 0.5 mm to 2.4 mm.

[0024] From the viewpoint of achieving excellent durability, the carbon fibers constituting the core wire 12 are preferably polyacrylonitrile (PAN)-based carbon fibers. From the same viewpoint, the outer diameter of the carbon fiber filaments F is preferably 4 μm to 9 μm, more preferably 6 μm to 8 μm.

[0025] From the perspective of achieving excellent durability, the total number of carbon fiber filaments F constituting the core wire 12 is preferably 3,000 (3K) or more and 60,000 (60K) or less, more preferably 9,000 (9K) or more and 54,000 (54K) or more, and even more preferably 12,000 (12K) or more and 48,000 (48K) or less. From the same perspective, the fineness of the carbon fiber constituting the core wire 12 is preferably 200 tex or more and 4,000 tex or less, more preferably 600 tex or more and 3,600 tex or less, and even more preferably 800 tex or more and 3,200 tex.

[0026] From the perspective of obtaining excellent durability, the core wire 12 is preferably a twisted wire. As the twisted wire constituting the core wire 12, single twisted wire, ply wire, and lanyard twisted wire (lang's lay) can be cited. From the same perspective, the core wire 12 of the twisted wire is preferably a single twisted wire formed by twisting a filament bundle of carbon fibers in one direction. As the core wire 12 of the single twisted wire, either S twisted wire or Z twisted wire can be used, or both can be used.

[0027] From the perspective of achieving excellent durability, when the total number of carbon fiber filaments F constituting the core yarn 12 of the single-twist yarn is less than 24,000 (24K), the twist per 10 cm length of the core yarn 12 is preferably 2.0 twists / 10 cm or more and 25.0 twists / 10 cm or less, more preferably 3.0 twists / 10 cm or more and 19.0 twists / 10 cm or less, and even more preferably 5.0 twists / 10 cm or more and 11.0 twists / 10 cm or less. From the perspective of achieving excellent durability, when the total number of carbon fiber filaments F constituting the core yarn 12 of the single-twist yarn is 24,000 (24K) or more, the twist per 10 cm length of the core yarn 12 is preferably 1.5 twists / 10 cm or more and 7.5 twists / 10 cm or less, more preferably 2.3 twists / 10 cm or more and 6.6 twists / 10 cm or less, and even more preferably 3.5 twists / 10 cm or more and 5.5 twists / 10 cm or less.

[0028] When the core 12 is viewed from a side direction perpendicular to the longitudinal direction of the core 12, the angle θ formed between the outermost filaments F in the carbon fiber filament bundle constituting the core 12 and the longitudinal direction of the core 12 is 8° or more and 20° or less. From the viewpoint of achieving excellent durability, the angle θ formed between the filaments F and the longitudinal direction of the core 12 is preferably 8° or more and 20° or less, and more preferably 10° or more and 19° or less.

[0029] The core wire 12 is provided so as to form a spiral having a pitch in the width direction. The core wire 12 can also be provided so as to be composed of both an S-twisted wire and a Z-twisted wire, and the two twisted wires form a double spiral. The core wire 12 is arranged so as to extend in parallel with a space left in the width direction, and in this case, the number of core wires 12 per 10 mm of the width is preferably 3 or more and 16 or less per 10 mm, and more preferably 4 or more and 15 or less per 10 mm from the viewpoint of obtaining excellent durability. Note that since the core wire 12 is provided so as to form a spiral having a pitch in the width direction, the length direction of the core wire 12 is inclined with respect to the belt length direction. However, since the inclination angle is very small, the angle θ formed by the outermost filaments F in the filament bundle of the carbon fiber constituting the core wire 12 and the length direction of the core wire 12 and the angle formed by the filaments F and the belt length direction are substantially the same.

[0030] The core wire 12 is preferably subjected to an adhesive treatment such as, for example, being previously soaked in a liquid adhesive before molding and then dried.

[0031] The toothed belt B according to the embodiment includes a nonwoven fabric 13 that is embedded in the toothed belt body 11 at a position that is inward in the circumferential direction from the position at which the core wire 12 is embedded in the thickness direction of the belt. The nonwoven fabric 13 can be composed of one piece or multiple pieces.

[0032] The nonwoven fabric 13 contains the polyurethane resin that forms the toothed belt body 11 and is provided so as to form a layer in a side view. The portion of the nonwoven fabric 13 that corresponds to the tooth portion 112 enters the tooth portion 112 in a manner that bulges toward the inner circumferential side in a side view and expands thicker in the thickness direction of the belt. The portion of the nonwoven fabric 13 that corresponds to the space between the tooth portions 112 is in contact with the core wire 12 and is compressed thinner in the thickness direction of the belt.

[0033] As the fiber material that forms the nonwoven fabric 13, for example, nylon fibers, polyester fibers, aramid fibers, polyketone fibers, carbon fibers, and the like can be listed. The nonwoven fabric 13 can be formed of a single type of fiber or multiple types of fibers.

[0034] The nonwoven fabric 13 is preferably subjected to an adhesive treatment such as, for example, being previously soaked in a liquid adhesive before molding and then dried.

[0035] From the viewpoint of obtaining excellent durability, the toothed belt B according to the embodiment has a belt tension T 0.1 of 30 N / mm or more is preferable, and 45 N / mm or more is more preferable, and from the viewpoint of avoiding an increase in bending rigidity and a deterioration in bending fatigue resistance, the belt tension T 0.1 of 50 N / mm or less is preferable, and 45 N / mm or less is more preferable.

[0036] The belt tension T 0.1 The following procedure was used. First, the toothed belt B according to the embodiment was wound around a pair of flat pulleys each having a pulley diameter of 95.4 mm, with the back surface of the toothed belt B contacting the pair of flat pulleys, in an environment at 25°C. Next, one of the flat pulleys was moved away from the other at a speed of 50 mm / min. At this time, the relationship between the displacement between the pair of flat pulleys and the detected tension was recorded, starting from the time when the tension was detected via either of the pair of flat pulleys. Next, the displacement between the pair of flat pulleys was multiplied by 2 to calculate the belt elongation, and the belt elongation was divided by the belt length of the toothed belt B according to the embodiment in a no-load state, thereby converting the displacement between the pair of flat pulleys into the belt elongation rate. In addition, the detected tension was divided by 2 to calculate the belt tension, and the belt tension was divided by the belt width of the toothed belt B according to the embodiment, thereby converting the detected tension into the belt tension per 1 mm of belt width. Then, the belt tension T was obtained from the relationship between the belt elongation rate and the belt tension 0.1 .

[0037] The toothed belt B according to the embodiment of the above structure, when the core wire 12 is viewed from the side surface orthogonal to the length direction of the core wire 12, has an angle θ of 8° or more and 20° or less between the filaments F of the carbon fiber filament bundle constituting the core wire 12 that are located at the outermost portion and the length direction of the core wire 12, whereby excellent durability can be obtained. It is presumed that this is because the excessive strain of the filaments F of the carbon fiber constituting the core wire 12, which is a brittle material, can be suppressed.

[0038] Next, the manufacturing method of the toothed belt B according to the embodiment will be described.

[0039] First, as shown in Figure 3A , the nonwoven fabric 13 was covered on the inner mold 31 in a cylindrical shape, and the core wire 12 was wound in a spiral shape from above. At this time, since the grooves 32 extending in the axial direction in a shape corresponding to the tooth portion 112 were provided at regular intervals in the circumferential direction on the outer periphery of the inner mold 31, and the protrusions 33 extending in the axial direction were formed between the grooves 32, the nonwoven fabric 13 and the core wire 12 were provided so that the nonwoven fabric 13 and the core wire 12 were supported by the protrusions 33.

[0040] Next, as shown in Figure 3B , the inner mold 31 was housed in the outer mold 34 in a cylindrical shape. At this time, the cavity C for forming the toothed belt body was formed between the inner mold 31 and the outer mold 34.

[0041] Then, as shown in Figure 3CThe liquid polyurethane composition obtained by adding the additive to the polyurethane prepolymer is injected and filled into the closed cavity C, and heated. At this time, the polyurethane composition flows and cures, thereby forming the toothed belt body 11 of the polyurethane resin. In addition, the tooth portion 112 is formed in the groove 32. The core wire 12 is bonded to and embedded in the toothed belt body 11. Further, as the polyurethane composition impregnates and cures, the nonwoven fabric 13 is bonded to and embedded in the toothed belt body 11. As described above, the toothed belt body 11, the core wire 12, and the nonwoven fabric 13 are integrated and molded into a cylindrical belt blank S.

[0042] Finally, the belt blank S is demolded from the inner mold 31 and the outer mold 34, and cut into a ring shape, thereby obtaining the toothed belt B according to the embodiment.

[0043] Note that, in the above embodiment, the toothed belt B is composed of the toothed belt body 11, the core wire 12, and the nonwoven fabric 13, but is not particularly limited thereto, and a reinforcing cloth can be provided on the tooth portion side surface of the inner circumferential side of the toothed belt body and / or the back surface of the outer circumferential side of the toothed belt body.

[0044] In the above embodiment, the toothed belt body 11 of the toothed belt B is formed of a polyurethane resin, but is not particularly limited thereto, and the toothed belt body can be formed of a crosslinked rubber composition.

[0045] In the above embodiment, the toothed belt B is shown as a drive belt, but is not particularly limited thereto, and can be a flat belt, a V-belt, a multi-vee belt, or the like.

[0046] [Example]

[0047] [Experimental Evaluation 1]

[0048] (toothed belt)

[0049] A toothed belt of Example 1 and Comparative Examples 1-1 and 1-2 was produced. The structure of each of these toothed belts is also shown in Table 1.

[0050] [Example 1]

[0051] A toothed belt of the STS tooth shape having the same structure as in the above embodiment was used as Example 1. The belt length of the toothed belt of Example 1 was 1400 mm, the belt width was 14 mm, and the belt thickness (maximum) was 8.6 mm. The tooth portion was S14M prescribed in ISO 13050:2014(E).

[0052] The polyurethane composition used for forming the toothed belt body was prepared by adding 13 parts by mass of 3,3'-dichloro-4,4'-diaminodiphenyl methane as a curing agent and 10 parts by mass of dioctyl phthalate as a plasticizer, relative to 100 parts by mass of a polyurethane prepolymer. The polyurethane resin forming the toothed belt body had a hardness of 92° according to the Japanese Industrial Standard JIS K7312.

[0053] As the core wire, a single twisted wire was used, which was obtained by twisting a filament bundle (total number of filaments: 48,000, total fineness: 3,200 tex) in one direction with a twist per 10 cm length of 4 twists / 10 cm, the filament bundle being obtained by aligning 4 filament bundles of carbon fibers (Torayca T700 SC-12,000, manufactured by Toray Industries, Inc., 12K, 800 tex, outer diameter of filament: 7 μm) with 12,000 filaments each. The angle of the outermost filaments in the filament bundle of the carbon fibers constituting the core wire with respect to the length direction of the core wire was 10°. As the core wire of the single twisted wire, an S twisted wire and a Z twisted wire were prepared, and these twisted wires were subjected to an adhesive treatment in which the twisted wires were dipped in an adhesive and then dried. The core wires of the single twisted wires of the S twisted wire and the Z twisted wire were arranged so as to form a double helix with the S twisted wire and the Z twisted wire alternately arranged in the belt width direction. The number of filaments per 10 mm of the belt width of the core wire was 4. The outer diameter of the core wire was 2.0 mm.

[0054] As the nonwoven fabric, a nylon fiber nonwoven fabric was used, which was prepared by a needle punching method without pressure. The nonwoven fabric was not subjected to an adhesive treatment.

[0055] The belt strength per 1 mm of the belt width of the toothed belt of Example 1 was 1,302 N / mm. The belt tension T 0.1 was 40.0 N / mm.

[0056] <Comparative Example 1-1>

[0057] In the toothed belt of Comparative Example 1-1, a carbon fiber ply (total number of filaments: 48,000, total fineness: 3,200 tex) was used as the core wire, and otherwise, it was the same as in Example 1. The ply was prepared as follows: a filament bundle of carbon fibers with 12,000 filaments, which was the same as that used in Example 1, was twisted in one direction with a twist per 10 cm length of 4 twists to prepare a primary twisted wire, and 4 of the primary twisted wires were aligned and twisted in the opposite direction with a twist per 10 cm length of 4 twists to prepare the ply. The angle of the outermost filaments in the filament bundle of the carbon fibers constituting the core wire of the ply with respect to the length direction of the core wire was 7°.

[0058] The belt strength per 1 mm width of the toothed belt of Comparative Example 1-1 was 1267 N / mm. The belt tension T 0.1 was 38.5 N / mm.

[0059] <Comparative Example 1-2>

[0060] In the toothed belt of Comparative Example 1-2, the twist per 10 cm length of the core wire was 6 twists / 10 cm, and other than this, it was identical to Example 1. The angle of the outermost filaments in the filament bundle of the carbon fiber constituting the core wire to the length direction of the core wire was 21°.

[0061] The belt strength per 1 mm width of the toothed belt of Comparative Example 1-2 was 640 N / mm. The belt tension T 0.1 was 41.0 N / mm.

[0062] [Table 1]

[0063]

[0064]

[0065] (Belt Durability Test)

[0066] Figure 4 The pulley layout of the belt running tester 40 used in the belt durability test is shown. The belt running tester 40 has a driving pulley 41 whose number of teeth is 22 and a driven pulley 42 disposed to the right of the driving pulley 41 whose number of teeth is 33. The driven pulley 42 is configured to be able to move left and right so as to be able to be applied with an axial load, and is also configured to be able to be applied with a load torque.

[0067] With respect to the toothed belts B in Example 1 and each of Comparative Examples 1-1 and 1-2, the toothed belt B in each example was wound between the driving pulley 41 and the driven pulley 42 in an environment of 60°C, and a fixed axial load (SW) of 1960 N was applied to the driven pulley 42, whereby a tension of 1000 N was applied to the toothed belt B, and a load torque of 120 N-m was applied to the driven pulley 42. In this state, the driving pulley 41 was rotated at a rotational speed of 1800 rpm. And, the time until the toothed belt B broke was measured, and this time was taken as the belt durability life.

[0068] (Test Results)

[0069] The test results are shown in Table 1. From this, it is seen that Example 1 is very excellent in durability compared to Comparative Examples 1-1 and 1-2.

[0070] [Assessment 2 of Test]

[0071] (Toothed Belt)

[0072] A toothed belt of Example 2-1 and Example 2-2 and Comparative Example 2-1 and Comparative Example 2-2 was produced. The structure of the toothed belt in each example is also shown in Table 2.

[0073] <Example 2-1>

[0074] A toothed belt of the STS tooth shape having the same structure as the above-described embodiment was produced as Example 2-1. The belt length of the toothed belt of Example 2-1 was 800 mm, the belt width was 8 mm, and the belt thickness (maximum) was 4.8 mm. The tooth portion was S8M prescribed in ISO 13050:2014(E).

[0075] As the core wire, a single-twisted wire obtained by twisting a filament bundle of carbon fibers having the same number of filaments as that used in Example 1, i.e., 12000, at a twist of 6 twists per 10 cm in one direction for each 10 cm length was used. The angle of the filaments located at the outermost part in the filament bundle of carbon fibers constituting the core wire with respect to the length direction of the core wire was 9°. As the core wire of the single-twisted wire, an S-twisted wire and a Z-twisted wire were prepared, and these twisted wires were subjected to an adhesive treatment in which they were dipped in an adhesive and then dried. The core wires of the single-twisted wires of the S-twisted wire and the Z-twisted wire were arranged so as to form a double helix in which they were alternately arranged in the belt width direction. The number of filaments per 10 mm of the belt width of the core wire was 8. The outer diameter of the core wire was 0.9 mm.

[0076] As the polyurethane composition and the nonwoven fabric used for forming the toothed belt main body, the same polyurethane composition and the nonwoven fabric as those of Example 1 were used.

[0077] The belt strength per 1 mm of the belt width of the toothed belt of Example 2-1 was 1150 N / mm. The belt tension T 0.1 was 44.4 N / mm.

[0078] <Example 2-2>

[0079] In Example 2-2, the twist per 10 cm length of the core wire was 10 twists per 10 cm, and other than this, it was the same as Example 2-1. The angle of the filaments located at the outermost part in the filament bundle of carbon fibers constituting the core wire with respect to the length direction of the core wire was 19°.

[0080] The belt strength per 1 mm of the belt width of the toothed belt of Example 2-2 was 738 N / mm. The belt tension T 0.1 was 40.5 N / mm.

[0081] <Comparative Example 2-1>

[0082] Comparative Example 2-1 was the same as Example 2-1 except that the twist number per 10 cm of the core was 4 twists / 10 cm. The angle formed between the outermost filaments of the carbon fiber filament bundle constituting the core and the longitudinal direction of the core was 6°.

[0083] The belt strength of the toothed belt of Comparative Example 2-1 per 1 mm of belt width was 811 N / mm. Belt tension T 0.1 It is 32.7N / mm.

[0084] <Comparative Example 2-2>

[0085] Comparative Example 2-2 was the same as Example 2-1 except that the twist number per 10 cm of the core was 12 twists / 10 cm. The angle formed between the outermost filaments of the carbon fiber filament bundle constituting the core and the longitudinal direction of the core was 21°.

[0086] The belt strength of the toothed belt of Comparative Example 2-2 per 1 mm of belt width was 694 N / mm. Belt tension T 0.1 It is 42.8N / mm.

[0087]

Table 2

[0088]

[0089] (with durability test)

[0090] The belt running test machine 40 used here is the same as the belt running test machine used in the test evaluation 1, and has Figure 4 The pulley layout shown is shown, and the teeth of the toothed belts B of Examples 2-1 and 2-2 and Comparative Examples 2-1 and 2-2 are respectively engaged with the driving pulley 41 and the driven pulley 42 of the belt running test machine 40.

[0091] The toothed belt B in each of Examples 2-1 and 2-2, as well as Comparative Examples 2-1 and 2-2, was wound between the primary pulley 41 and the secondary pulley 42 in a 60°C environment. A fixed axial load (SW) of 608 N was applied to the secondary pulley 42, resulting in a tension of 306 N and a load torque of 34.5 N·m. Under these conditions, the primary pulley 41 was rotated at 4218 rpm. The time until the toothed belt B broke was measured and used as the belt durability life.

[0092] (Test results)

[0093] The test results are shown in Table 2. It can be seen that Example 2-1 and Example 2-2 are much more excellent in durability than Comparative Example 2-1 and Comparative Example 2-2.

[0094] Industrial applicability

[0095] The present application is useful in the technical field of a power transmission belt.

[0096] - Symbol explanation -

[0097] B toothed belt (power transmission belt)

[0098] C cavity

[0099] F filament

[0100] S belt blank

[0101] 11 toothed belt body

[0102] 111 flat belt portion

[0103] 112 tooth portion

[0104] 12 core wire

[0105] 13 nonwoven fabric

[0106] 31 inner mold

[0107] 32 groove

[0108] 33 protrusion

[0109] 34 outer mold

[0110] 40 belt running tester

[0111] 41 driving pulley

[0112] 42 driven pulley

Claims

1. A transmission belt, characterized in that: The belt body comprises a belt main body and a core wire, wherein the belt main body is annular and made of an elastomer, and the core wire is made of carbon fiber, and the core wire is arranged to be buried in the belt main body and form a spiral with a pitch in the belt width direction. When the core wire is viewed from a side perpendicular to the longitudinal direction of the core wire, an angle formed between an outermost filament in a filament bundle of carbon fibers constituting the core wire and the longitudinal direction of the core wire is 8° or more and 20° or less.

2. The transmission belt according to claim 1, characterized in that: The belt main body is formed of polyurethane resin.

3. The transmission belt according to claim 1, wherein: The carbon fibers constituting the core wire are polyacrylonitrile-based carbon fibers.

4. The transmission belt according to claim 1, wherein: The outer diameter of the carbon fiber filament is 4 μm or more and 9 μm or less.

5. The transmission belt according to claim 1, wherein: The total number of the carbon fiber filaments constituting the core wire is 3,000 or more and 60,000 or less.

6. The transmission belt according to claim 1, characterized in that: The core yarn is a single-twisted yarn formed by twisting the carbon fiber filament bundle in one direction.

7. The transmission belt according to claim 6, characterized in that: The total number of the carbon fiber filaments constituting the core yarn as the single-twisted yarn is 3,000 or more and less than 24,000, and the twist per 10 cm length of the core yarn is 2.0 twists / 10 cm or more and 25.0 twists / 10 cm or less.

8. The transmission belt according to claim 6, characterized in that: The total number of the carbon fiber filaments constituting the core yarn as the single-twisted yarn is 24,000 to 60,000, and the twist per 10 cm length of the core yarn is 1.5 to 7.5 twists / 10 cm.

9. The transmission belt according to claim 1, characterized in that: The number of the core wires per 10 mm width is 3 or more / 10 mm and 16 or less / 10 mm.

10. The transmission belt according to claim 1, characterized in that: The belt body is a toothed belt body.

11. The transmission belt according to claim 10, characterized in that: When the tape elongation is 0.1%, the tape tension T per 1mm tape width is 0.1 It is 30 N / mm or more and 50 N / mm or less.

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