Conveyor belt with teeth

Abstract

The toothed conveyor belt is provided with: a conveyor belt main body having a plurality of teeth provided at a constant pitch on the inner circumference of the conveyor belt; and a core wire which is embedded in the conveyor belt main body so as to have a pitch in the conveyor belt width direction, and in which the peak friction coefficient [mu] A and the average friction coefficient [mu] B measured by the following method satisfy the relationships [mu] A-[mu] B < = 0.3 and [mu] B < = 0.5. A toothed conveyor belt is cut in the width direction, measurement samples corresponding to two conveyor belt teeth are cut from the toothed conveyor belt, a certain load is applied to the measurement samples, the measurement samples are placed in a manner that tooth tops are in contact with a flat plate made of SUS304, friction force generated when the toothed conveyor belt moves in one direction at a speed of 100 mm / min for 30 seconds is measured, and the friction force is measured. The peak friction coefficient [mu] A is the friction coefficient calculated by dividing the maximum value of the friction force of 30 seconds by the vertical resistance, and the average friction coefficient [mu] B is the friction coefficient calculated by dividing the average value of the friction force of 30 seconds by the vertical resistance.

Description

Technical Field

[0001] The invention relates to a toothed conveyor belt.

[0002] This application claims the benefit of priority based on Japanese application No. 2022-120304, filed on July 28, 2022, the entire contents of which are incorporated herein by reference. Background Art

[0003] As toothed belts used for power transmission in machine tools, printing machines, textile machines, injection molding machines, and the like, there are toothed belts made of polyurethane (for example, Patent Documents 1 and 2).

[0004] Patent Document 1 discloses a polyurethane toothed conveyor belt in which a woven or knitted fabric is arranged on the tooth portion side relative to a core wire.

[0005] Patent document 2 discloses a toothed conveyor belt comprising: a conveyor belt body composed of an injection-molded polyurethane conveyor belt material; conveyor belt teeth formed on the above-mentioned conveyor belt body at predetermined intervals; a wear-resistant canvas reinforcement material arranged along the peripheral surface of the above-mentioned conveyor belt teeth; and a tension member having a length and volume embedded in the above-mentioned conveyor belt body and composed of a spirally twisted fiber woven yarn.

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-127442

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 10-148238 Summary of the Invention

[0008] Toothed conveyor belts are required to have excellent durability. Therefore, the conveyor belt teeth must not wear out prematurely, and the conveyor belt body and the wire (core wire) must not be separated prematurely.

[0009] For example, toothed belts with reinforcing fabric on the inner circumference of the teeth tend to be less susceptible to wear. However, these belts tend to heat up during operation, sometimes causing premature separation between the belt body and the wire.

[0010] In view of the above circumstances, an object of the present invention is to provide a toothed conveyor belt having excellent durability.

[0011] (1) The toothed conveyor belt of the present invention has:

[0012] a conveyor belt body having a plurality of teeth arranged at constant intervals on an inner circumference of the conveyor belt; and

[0013] The core wire is embedded in the conveyor belt body at intervals in the width direction of the conveyor belt.

[0014] The peak friction coefficient μA and the average friction coefficient μB measured by the following method satisfy the relationship of μA-μB≤0.3 and μB≤0.5.

[0015] <Measurement method>

[0016] A toothed conveyor belt was cut across its width, and a measurement sample corresponding to two belt teeth was cut from the toothed conveyor belt. The resulting measurement sample was placed on a flat plate so that the belt teeth were in contact with the plate. In this state, the measurement sample was moved in one direction for 30 seconds, and the friction force during this period was measured. The friction coefficient calculated by dividing the maximum friction force over 30 seconds by the vertical resistance was defined as the peak friction coefficient μA. The friction coefficient calculated by dividing the average friction force over 30 seconds by the vertical resistance was defined as the average friction coefficient μB.

[0017] The measurement environment was set at a temperature of 23±5°C and a humidity of 50±5%.

[0018] A constant load is applied to the measurement sample and the sample is placed on a flat plate.

[0019] The flat plate was made of SUS304, and the surface roughness of the surface on which the measurement sample was placed was set to be 1.6 μm or less in terms of Ra (arithmetic mean roughness).

[0020] The moving speed of the measurement sample was set to 100 mm / min.

[0021] According to the toothed belt described above, good durability can be ensured.

[0022] Regarding the toothed conveyor belt, it is important that the peak friction coefficient μA and the average friction coefficient μB measured by the above method satisfy “μA−μB≦0.3” and “μB≦0.5” at the same time.

[0023] Regarding the toothed conveyor belt, by setting the average friction coefficient μB to be less than or equal to 0.5, the friction generated between the belt and the pulley can be reduced, thereby suppressing heat generation during use. In addition, if the friction generated between the belt and the pulley is reduced, wear of the teeth (conveyor belt teeth) is also suppressed.

[0024] Furthermore, regarding the toothed conveyor belt, wear of the teeth (conveyor belt teeth) can be further suppressed not only by reducing the average friction coefficient μB but also by setting the difference between the peak friction coefficient μA and the average friction coefficient μB to 0.3 or less.

[0025] (2) In the toothed conveyor belt of (1) above, preferably, a reinforcing cloth is provided on the inner peripheral surface of the tooth portion.

[0026] In this case, it is suitable to improve the wear resistance of the conveyor belt teeth.

[0027] (3) In the toothed conveyor belt of (1) or (2) above, preferably, the conveyor belt body is made of thermosetting polyurethane.

[0028] In this case, it is suitable to provide a toothed conveyor belt with excellent durability.

[0029] (4) In the toothed conveyor belt according to (3) above, preferably, the belt body contains a lubricant.

[0030] In this case, it is easy to make the peak friction coefficient μA and the average friction coefficient μB fall within the above-mentioned ranges.

[0031] Effects of the Invention

[0032] According to the present invention, a toothed conveyor belt having excellent durability can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a perspective view schematically showing the toothed conveyor belt according to the first embodiment.

[0034] Figure 2 yes Figure 1 The main view in the direction of arrow X.

[0035] Figure 3 yes Figure 1 AA line cross-section.

[0036] Figure 4 This is a diagram for explaining a method for preparing a measurement sample.

[0037] Figure 5 This is a diagram explaining the method for measuring the friction coefficient.

[0038] Figure 6 These are diagrams for explaining the method for manufacturing the toothed conveyor belt according to the first embodiment.

[0039] Figure 7 These are diagrams for explaining the method for manufacturing the toothed conveyor belt according to the first embodiment.

[0040] Figure 8 These are diagrams for explaining the method for manufacturing the toothed conveyor belt according to the first embodiment.

[0041] Figure 9It is a perspective view schematically showing a toothed conveyor belt according to a second embodiment.

[0042] Figure 10 This figure shows the pulley layout of a conveyor belt travel testing machine used for load durability testing. DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments.

[0044] (First embodiment)

[0045] Figure 1 It is a perspective view schematically showing the toothed conveyor belt according to the first embodiment. Figure 2 yes Figure 1 The main view in the direction of arrow X. Figure 3 yes Figure 1 AA line cross-section.

[0046] The toothed belt 10 according to the present embodiment is preferably used for high-load transmission applications such as machine tools, printing machines, textile machines, injection molding machines, and rear wheel drives of two-wheeled vehicles.

[0047] The toothed conveyor belt 10 has a belt length of, for example, greater than or equal to 500 mm and less than or equal to 3000 mm. The toothed conveyor belt 10 has a belt width of, for example, greater than or equal to 10 mm and less than or equal to 200 mm. The toothed conveyor belt 10 has a belt thickness (maximum) of, for example, greater than or equal to 3 mm and less than or equal to 20 mm. The dimensions of the toothed conveyor belts according to the embodiments of the present invention are not limited to these ranges.

[0048] exist Figure 1 Only a portion of the toothed conveyor belt 10 is shown, and the toothed conveyor belt 10 is an endless meshing transmission conveyor belt.

[0049] The toothed conveyor belt 10 has a plurality of conveyor belt teeth 12 on its inner circumference. Figure 1 As shown, the toothed conveyor belt 10 includes a conveyor belt body 11, a core wire 13, and a reinforcing cloth 14. In this embodiment, the conveyor belt teeth 12 are straight teeth.

[0050] The toothed conveyor belt 10 of this embodiment includes a belt body 11 made of an elastomer made of polyurethane. The belt body 11 comprises a flat belt portion 11a having a horizontally long rectangular cross-section and a plurality of teeth 11b integrally formed on the inner circumference of the flat belt portion. The teeth 11b are spaced at regular intervals along the length of the belt.

[0051] The reinforcing cloth 14 is provided so as to cover the inner peripheral surface of the tooth portion 11 b .

[0052] The tooth shape of the conveyor belt teeth 12 is an arc tooth shape such as an S tooth shape.

[0053] The number of the conveyor belt teeth 12 is, for example, greater than or equal to 30 and less than or equal to 400.

[0054] The tooth width of the conveyor belt teeth 12 is, for example, greater than or equal to 2 mm and less than or equal to 10 mm. The tooth width of the conveyor belt teeth 12 is determined by the maximum dimension in the conveyor belt length direction ( Figure 3 Refer to W) provisions.

[0055] The tooth height of the conveyor belt teeth 12 is, for example, greater than or equal to 2 mm and less than or equal to 8 mm. The tooth height of the conveyor belt teeth 12 is the dimension from the tooth bottom 15 between a pair of conveyor belt teeth 12 adjacent to each other in the longitudinal direction of the conveyor belt to the front end of the conveyor belt teeth 12 ( Figure 3 Refer to H) provisions.

[0056] The arrangement pitch of the conveyor belt teeth 12 is, for example, greater than or equal to 8 mm and less than or equal to 14 mm. The arrangement pitch of the conveyor belt teeth 12 is determined by the distance between the tooth tops of a pair of adjacent conveyor belt teeth in the longitudinal direction of the conveyor belt ( Figure 3 Refer to P) provisions.

[0057] The conveyor belt body 11 is preferably made of polyurethane, more preferably made of thermosetting polyurethane.

[0058] The thermosetting polyurethane is a cured product of a thermosetting polyurethane composition in which a curing agent and, as an optional component, a plasticizer are blended into a polyurethane prepolymer.

[0059] When thermosetting polyurethane is used as the material for the belt body 11, the thermosetting polyurethane composition easily impregnates the core yarn and reinforcing cloth, making it suitable for manufacturing toothed conveyor belts in which the components constituting the belt body are impregnated into the core yarn and reinforcing cloth. Toothed conveyor belts in which the components constituting the belt body are impregnated into the core yarn and reinforcing cloth are less susceptible to tooth chipping and wear of the belt teeth, and are less likely to peel off from the core yarn of the belt body, resulting in excellent durability.

[0060] The polyurethane prepolymer is a relatively low molecular weight polyurethane compound having a plurality of NCO groups at its terminals and is obtained by reacting an isocyanate component with a polyol component.

[0061] Examples of the isocyanate component include tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI).

[0062] Examples of the polyol component include polytetramethylene glycol (PTMG) and the like.

[0063] The polyurethane prepolymer may be composed of a single polyurethane compound or a mixture of multiple polyurethane compounds.

[0064] Examples of the curing agent include amine compounds such as 1,4-phenylenediamine, 2,6-diaminotoluene, 1,5-naphthalenediamine, 4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), and isobutyl 4-chloro-3,5-diaminobenzoate. Preferably, the curing agent contains one or more of the above-mentioned substances.

[0065] The curing agent composed of an amine compound is preferably formulated so that the ratio of the molar number of NH2 groups in the curing agent to the molar number of NCO groups in the polyurethane prepolymer, i.e., the α value (NH2 groups / NCO groups) is greater than or equal to 0.70 and less than or equal to 1.10.

[0066] Examples of the plasticizer 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). Preferably, the plasticizer contains one or more of the above-mentioned substances.

[0067] The amount of the plasticizer blended is, for example, 3 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of the polyurethane prepolymer.

[0068] The thermosetting polyurethane preferably further contains a lubricant.

[0069] Examples of the lubricant include fatty acid esters, hydrocarbon resins, paraffin wax, higher fatty acids, fatty acid amides, fatty alcohols, metal soaps, and modified silica gel. Preferably, the lubricant contains one or more of the above substances.

[0070] When the lubricant is contained, the amount thereof blended is, for example, 3 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of the polyurethane prepolymer.

[0071] The thermosetting polyurethane composition may further contain, for example, a colorant, a defoaming agent, a stabilizer, and the like.

[0072] The JIS-A hardness of the polyurethane constituting the conveyor belt body 11 is, for example, greater than or equal to 85 and less than or equal to 100. Preferably, the JIS-A hardness of the polyurethane is greater than or equal to 90 and less than or equal to 100. By setting the JIS-A hardness of the polyurethane to be greater than or equal to 90, good wear resistance can be easily ensured.

[0073] The JIS-A hardness of the polyurethane is measured by a Type A hardness test based on JIS K7312: 1996. A Type A durometer is used for the measurement.

[0074] The toothed conveyor belt 10 includes a core wire 13 made of carbon fiber embedded in the flat belt portion 11 a of the belt body 11 .

[0075] From the perspective of achieving excellent durability and excellent tension maintenance during high-load transmission, the outer diameter of the core wire 13 is preferably greater than or equal to 0.6 mm and less than or equal to 2.2 mm, more preferably greater than or equal to 0.8 mm and less than or equal to 1.2 mm.

[0076] From the viewpoint of achieving excellent durability during high-load transmission and excellent tension retention during high-load transmission, the carbon fibers constituting the core wire 13 are preferably PAN-based carbon fibers.

[0077] In order to achieve excellent durability during high-load transmission, the filament diameter of the carbon fibers is preferably 4 μm or more and 9 μm or less, and more preferably 6 μm or more and 8 μm or less.

[0078] From the perspective of obtaining excellent durability during high-load transmission and excellent tension maintenance during high-load transmission, the total number of carbon fiber filaments constituting the core wire 13 is preferably greater than or equal to 6,000 (6K) and less than or equal to 48,000 (48K), more preferably greater than or equal to 9,000 (9K) and less than or equal to 18,000 (18K), and further preferably 12,000 (12K).

[0079] From the perspective of obtaining excellent durability during high-load transmission and excellent tension maintenance during high-load transmission, the fiber size of the carbon fiber constituting the core wire 13 is preferably greater than or equal to 400tex and less than or equal to 3200tex, more preferably greater than or equal to 600tex and less than or equal to 1200tex, and further preferably 800tex.

[0080] From the viewpoint of obtaining excellent durability and excellent tension maintenance during high-load transmission, it is preferable that the core wire 13 is a twisted yarn. Examples of the twisted yarn constituting the core wire 13 include single twisted yarn, ply twisted yarn, and Lang twisted yarn.

[0081] From the viewpoint of achieving excellent durability and excellent tension retention during high-load transmission, the core yarn 13 of the twisted yarn is preferably a single twisted yarn formed by twisting a carbon fiber filament bundle in one direction.

[0082] From the perspective of achieving excellent durability and excellent tension retention during high-load transmission, the twist number of the core yarn 13 of the single-twisted yarn is preferably greater than or equal to 4 times / 10 cm and less than or equal to 12 times / 10 cm, and more preferably greater than or equal to 6 times / 10 cm and less than or equal to 10 times / 10 cm. The core yarn 13 of the single-twisted yarn can be an S-twisted yarn, a Z-twisted yarn, or both.

[0083] The core wire 13 is provided with a pitch in the width direction of the conveyor belt and is arranged to form a spiral. The core wire 13 can be composed of two yarns, an S-twisted yarn and a Z-twisted yarn, which are arranged to form a double spiral.

[0084] The core wires 13 are arranged to extend parallel to each other at intervals in the width direction of the conveyor belt. In order to achieve excellent durability and excellent tension retention during high-load transmission, the number of core wires 13 per 10 mm of conveyor belt width is preferably greater than or equal to 6 and less than or equal to 10, and more preferably greater than or equal to 7 and less than or equal to 9.

[0085] It is preferable to perform bonding treatment on the core wire 13 by dipping it in a liquid adhesive before molding and then drying it.

[0086] The reinforcing cloth 14 may be a woven fabric or a knitted fabric, and is preferably a woven fabric.

[0087] Examples of the reinforcing cloth 14 include 2 / 2 twill canvas, 3 / 1 twill canvas, plain canvas, and satin canvas formed of warp and weft yarns.

[0088] When the reinforcement cloth 14 is the canvas, the fiber sizes of the warp and the weft are preferably 44 to 933 dtex, more preferably 44 to 235 dtex.

[0089] Furthermore, the yarn density of the warp and weft yarns is preferably 74 to 430 yarns / 5 cm width, and more preferably 132 to 174 yarns / 5 cm width.

[0090] The weight per unit area of ​​the reinforcing cloth 14 is preferably 90 to 600 g / m 2 , more preferably 300 to 450 g / m 2 .

[0091] The reinforcing cloth 14 is preferably provided so that one of the warp and the weft is aligned with the longitudinal direction of the conveyor belt, for example.

[0092] When the weft yarn is made of stretchable yarn such as pre-twisted yarn, the reinforcement fabric 14 has anisotropy in terms of stretch properties. However, in order to improve the stretch properties in the longitudinal direction of the conveyor belt, it is preferable to arrange the weft yarn in the same direction as the longitudinal direction of the conveyor belt.

[0093] Examples of fiber materials constituting the reinforcing cloth 14 include nylon fibers such as nylon 6,6, nylon 4,6, and nylon 6, chemical fibers such as polyketone fibers, aramid fibers, and polyester fibers, and natural fibers such as cotton. The reinforcing cloth 14 may be composed of a single fiber or a plurality of fibers.

[0094] The weft yarns of the reinforcement cloth 14 in the belt circumferential direction may be wool yarns, because wool yarns have excellent elasticity.

[0095] The reinforcing cloth 14 may be subjected to an adhesive treatment such as impregnating it with an epoxy adhesive and then drying it before molding.

[0096] In addition, the reinforcing cloth 14 can be subjected to wear modification treatment using a wear modifier such as a fluororesin such as ultra-high molecular weight polyethylene (UHMWPE), polytetrafluoroethylene (PTFE), perfluoroalkyl alkane (PFA), perfluoroethylene propylene copolymer (FEP), tetrafluoroethylene copolymer (ETFE), or polyvinylidene fluoride (PVDF).

[0097] The wear modification treatment may be performed by, for example, applying an adhesive in which the wear modifier is dispersed to the reinforcing cloth before molding, or by impregnating the reinforcing cloth before molding in the adhesive.

[0098] The toothed conveyor belt 10 is formed such that the cured product of the thermosetting polyurethane composition penetrates into the gaps between the reinforcing cloth 14. Therefore, on the surface (inner circumference) of the conveyor belt teeth 12, not only the reinforcing cloth 14 but also the cured product of the thermosetting polyurethane composition is exposed.

[0099] Regarding the toothed conveyor belt 10 , the peak friction coefficient μA and the average friction coefficient μB measured by the following method satisfy the relationship of “μA−μB≦0.3” and “μB≦0.5”.

[0100] Therefore, good durability can be ensured.

[0101] By setting the average friction coefficient μB of the toothed conveyor belt 10 to 0.5 or less, the friction generated between the belt pulleys and the belt teeth 12 can be reduced, making wear of the belt teeth 12 less likely. Furthermore, reducing this friction can suppress heat generation during use. Suppressing heat also prevents delamination at the interface between the belt body 11 and the core wire 13. As a result, the toothed conveyor belt 10 has excellent durability.

[0102] Furthermore, not only is the average friction coefficient μB reduced, but wear of the conveyor belt teeth 12 can also be suppressed by setting the difference between the peak friction coefficient μA and the average friction coefficient μB to 0.3 or less. A large difference between the peak friction coefficient μA and the average friction coefficient μB causes vibration in the conveyor belt teeth 12 during meshing, which can easily cause wear of the conveyor belt teeth 12. In contrast, setting the difference between the peak friction coefficient μA and the average friction coefficient μB to 0.3 or less suppresses this vibration. As a result, wear of the conveyor belt teeth 12 is reduced, and the durability of the toothed conveyor belt 10 is also improved.

[0103] The preferred lower limit of the average friction coefficient μB is 0.1. It is very difficult to reduce the average friction coefficient μB to less than 0.1.

[0104] The lower limit of the difference between the peak friction coefficient μA and the average friction coefficient μB is not particularly limited, as long as it is greater than 0.

[0105] Next, a method for measuring the peak friction coefficient μA and the average friction coefficient μB will be described.

[0106] Figure 4 This is a diagram for explaining a method for preparing a measurement sample. Figure 4 This is a diagram showing a portion of the toothed belt 10 as viewed from the inner peripheral surface side.

[0107] Figure 5 This is a diagram explaining the method for measuring the friction coefficient.

[0108] (Measurement sample)

[0109] The toothed conveyor belt 10 is cut in the belt width direction, thereby cutting out the measurement sample 50 from the toothed conveyor belt 10 .

[0110] Specifically, the midpoint in the width direction of the conveyor belt and the midpoint between the tooth tops of the adjacent conveyor belt teeth 12 is set as point M (refer to Figure 4 ) through the conveyor belt width direction at two locations (refer to Figure 4 The toothed conveyor belt 10 is cut as shown in the arrow in FIG. 1 . At this time, the toothed conveyor belt 10 is cut so as to include two conveyor belt teeth 12.

[0111] The cut-out measurement sample 50 has a rectangular shape when viewed in the belt thickness direction, and has a length in the belt length direction that is twice the arrangement pitch P of the belt teeth 12 .

[0112] (Measurement method)

[0113] The measurement sample 50 is set so that the conveyor teeth 52 are in contact with the SUS304 flat plate 55. A weight 54 is placed on the back of the measurement sample 50. The weight of the weight 54 is set so that the total weight of the measurement sample 50 and the weight 54 is 1000 g.

[0114] The measurement is performed in this state. Therefore, the friction coefficient is measured while applying a constant load to the measurement sample.

[0115] Next, while a constant load is applied to the measurement sample 50, the measurement sample 50 is moved in one direction at a speed of 100 mm / min for 30 seconds. The friction force at this time is measured, and the friction coefficient (FA / N) calculated by dividing the maximum value FA of the friction force over 30 seconds by the vertical resistance N is defined as the peak friction coefficient μA. The friction coefficient (FB / N) calculated by dividing the average value FB of the friction force over 30 seconds by the vertical resistance N is defined as the average friction coefficient μB.

[0116] The measurement was performed three times, and the average value of the three times was set as the measured value.

[0117] In the measurement of the friction force, the measurement environment was as follows.

[0118] The temperature was set at 23±5°C.

[0119] The humidity was set at 50 ± 5%.

[0120] The surface roughness of the SUS304 flat plate is set to Ra (arithmetic mean roughness) of 1.6 μm or less.

[0121] The friction force was measured using a surface property measuring machine TYPE: 14 manufactured by Shinto Science Co., Ltd.

[0122] The toothed conveyor belt 10 is provided so that the inner peripheral surface of the tooth portion 11b is covered with a reinforcing cloth 14. This improves the wear resistance of the conveyor belt teeth 12.

[0123] The toothed conveyor belt 10 of this embodiment is, for example, wound around a pair of pulleys to transmit power from a driving source to a driven side. The outer diameter of the pulleys is, for example, 20 to 700 mm. The conveyor belt travels at a speed of, for example, 10 to 2000 m / min, and has a transmission capacity of, for example, 0.1 to 600 kW.

[0124] Next, a method for manufacturing the toothed conveyor belt 10 according to the embodiment will be described.

[0125] Figures 6 to 8 1 is a diagram for explaining a method for manufacturing the toothed conveyor belt 10. Figures 6 to 8 The mold and part of the conveyor belt are shown in FIG.

[0126] (1) Figure 6 As shown, a cylindrical inner mold 31 is sequentially covered with a reinforcing cloth 14 processed into a cylindrical shape, and a core wire 13 is spirally wound from above.

[0127] On the outer periphery of the inner mold 31 , axially extending grooves 32 having a cross-section corresponding to the shape of the conveyor belt teeth 12 are arranged at regular intervals in the circumferential direction, and ridges 33 are provided between adjacent grooves 32 .

[0128] The reinforcing cloth 14 processed into a cylindrical shape is molded in advance so as to follow the shape of the groove 32 .

[0129] (2) Next, Figure 7 As shown, the inner mold 31 is housed in the cylindrical outer mold 34. At this time, a cavity C for molding the conveyor main body is formed between the inner mold 31 and the outer mold 34.

[0130] (3) Then, Figure 8 As shown, a thermosetting polyurethane composition 111 including a polyurethane prepolymer and the like is injected and filled into a closed cavity C and heated.

[0131] At this time, the thermosetting polyurethane composition 111 flows and solidifies, thereby forming the belt teeth in the grooves 32 and the tooth bottoms in the ridges 33 .

[0132] At this time, the thermosetting polyurethane composition 111 is not shown in the figure, but is cured by penetrating into the gaps between the reinforcing cloth 14. Therefore, the cured product of the thermosetting polyurethane composition 111 is exposed on the inner peripheral surface of the conveyor belt teeth 12 together with the reinforcing cloth 14.

[0133] As described above, the belt body 11, the core wire 13, and the reinforcing cloth 14 are molded into an integrated cylindrical blank. The molding conditions are, for example, a molding temperature of 170° C., a molding pressure of 12 MPa, and a molding time of 20 minutes.

[0134] Finally, the blank is demolded from the inner mold 31 and the outer mold 34 and then ring-cut to obtain the toothed belt 10 according to this embodiment.

[0135] (Second embodiment)

[0136] The toothed conveyor belt according to the embodiment of the present invention may have Figure 9 The structure of the toothed conveyor belt 20 is shown.

[0137] The toothed belt 20 according to this embodiment differs from the toothed belt 10 according to the first embodiment in that it has a nonwoven fabric 16 embedded along the belt length direction on the inner circumference side of the embedded position of the core wire 13 in the belt thickness direction of the belt body 11.

[0138] The toothed conveyor belt 20 has the same structure as the toothed conveyor belt 10 except that it has the nonwoven fabric 16 .

[0139] Since the toothed belt includes the nonwoven fabric 16 , the rigidity of the tooth portion is high, and improvement in durability under high loads can be expected.

[0140] Regarding the toothed belt 20 , the nonwoven fabric 16 may be composed of a single sheet or a plurality of sheets.

[0141] The nonwoven fabric 16 is made of polyurethane, which forms the belt body 11, and is arranged to form a layer when viewed from the side. The portion of the nonwoven fabric 16 corresponding to the teeth 11b bulges inwardly into the teeth 11b when viewed from the side, extending thickly in the belt thickness direction. The portion of the nonwoven fabric 16 corresponding to the space between the teeth 11b contacts the core 13, compressing it thinly in the belt thickness direction.

[0142] Examples of the fiber material constituting the nonwoven fabric 16 include nylon fibers, polyester fibers, aramid fibers, polyketone fibers, and carbon fibers. The nonwoven fabric 16 may be formed of a single fiber or a plurality of fibers.

[0143] The nonwoven fabric 16 may be subjected to bonding treatment such as being impregnated with a liquid adhesive before molding and then being dried.

[0144] For example, the method for manufacturing the toothed belt 20 having the nonwoven fabric 16 according to this embodiment can be the same as that used in the first embodiment except that part of the manufacturing process of the toothed belt 10 according to the first embodiment is changed.

[0145] Specifically, the cylindrical inner mold 31 is covered with the reinforcing cloth 14 and the non-woven fabric 16 in sequence, and the core wire 13 is wound into a spiral from above. Figure 6 The production can be carried out by following the step (1) described in the description.

[0146] In this case, it is preferable to use the nonwoven fabric 16 having a length such that slight tension is applied in the circumferential direction when the nonwoven fabric 16 is covered on the cylindrical inner mold 31 .

[0147] The thermosetting polyurethane composition is injected and heated to impregnate the nonwoven fabric 16 and solidify the composition. The nonwoven fabric 16 is then arranged and embedded in the conveyor belt body 11 along the longitudinal direction of the conveyor belt, containing the thermosetting polyurethane.

[0148] (Other embodiments)

[0149] The conveyor belt teeth of the toothed conveyor belt according to the embodiment of the present invention are not limited to straight teeth, but may be helical teeth.

[0150] When the conveyor teeth are spiral teeth, the method for preparing the measurement sample is also the same as described above.

[0151] Therefore, when the conveyor belt teeth are helical teeth, depending on the direction of the tooth profile, when the toothed conveyor belt is cut in the conveyor belt width direction, the teeth may not only pass through the bottom of the teeth but also pass through part of the conveyor belt teeth.

[0152] In the toothed conveyor belt according to the embodiment of the present invention, the tooth profile of the conveyor belt teeth may be a trapezoidal tooth profile.

[0153] In the toothed conveyor belt according to the embodiment of the present invention, the belt body may be made of thermoplastic polyurethane or the like.

[0154] The core wire constituting the toothed conveyor belt may be composed of organic fibers such as aromatic polyamide fibers, polyester fibers, PBO fibers, nylon fibers, polyketone fibers, etc., glass fibers, metal fibers, and the like.

[0155] Example

[0156] Hereinafter, the embodiments of the present invention will be described in more detail using examples, but the embodiments of the present invention are not limited to the following examples.

[0157] Toothed conveyor belts were manufactured according to Examples 1 to 3 and Comparative Examples 1 and 2, respectively.

[0158] <Example 1>

[0159] A toothed belt of S8M having the same structure as that of the first embodiment was produced.

[0160] The toothed belt of Example 1 had a belt length of 800 mm, a belt thickness (maximum) of 4.8 mm, and a belt width of 8 mm. The belt teeth were arranged at an 8 mm pitch in accordance with S8M specified in ISO 13050:2014(E).

[0161] Regarding the thermosetting polyurethane composition used to form the conveyor belt body, a thermosetting polyurethane composition is used that is mixed with 16 parts by mass of a curing agent (isobutyl 4-chloro-3,5-diaminobenzoate) and 7.5 parts by mass of a lubricant (fatty acid ester) relative to 100 parts by mass of a polyurethane prepolymer (PTMEG-TDI) in which the diisocyanate component is toluene diisocyanate and the polyol component is polytetramethyl ether glycol.

[0162] The cured product of the thermosetting polyurethane composition had a JIS-A hardness of 95.

[0163] As described above, the JIS-A hardness of the cured product of the thermosetting polyurethane composition was measured using a Type A durometer in accordance with JIS K7312: 1996. The JIS-A hardness was measured in the same manner in Examples 2 and 3 and Comparative Examples 1 and 2.

[0164] The core yarn was a single-ply twisted yarn twisted in one direction at a twist rate of 90 tpm per 1 m of a filament bundle of 12,000 carbon fibers (Tenax-J UTS50 F22, manufactured by Teijin Co., Ltd., 12K, 800 tex, filament diameter: 7.0 μm). Both S-twisted and Z-twisted yarns were prepared for the single-ply twisted yarn core yarn.

[0165] The core wire is subjected to an adhesive treatment in which the core wire is immersed in an adhesive and then dried. Here, a phenol-based adhesive is used as the adhesive.

[0166] The core yarns of the single twisted yarns of the S twisted yarns and the Z twisted yarns are arranged alternately in the width direction of the belt to form a double helix.

[0167] The number of core wires was set to 8 per 10 mm of the belt width.

[0168] The canvas (reinforcement cloth) was a 2 / 2 twill canvas made of three warp yarns of a fiber bundle of nylon 6,6 fibers having a fiber density of 235 dtex for each weft yarn of the fiber bundle.

[0169] The canvas is set up so that the weft is in the same direction as the length of the conveyor belt.

[0170] The canvas is not bonded.

[0171] Regarding canvas, the thickness is 1.2mm, the yarn density of the warp is 113 / 5cm width, the yarn density of the weft is 120 / 5cm width, and the weight per unit area is 385g / m 2 .

[0172] When the peak friction coefficient μA and the average friction coefficient μB of the manufactured toothed conveyor belt were measured by the above-mentioned method, the peak friction coefficient μA was 0.24 and the average friction coefficient μB was 0.21.

[0173] <Example 2>

[0174] A toothed conveyor belt of S8M was produced in the same manner as in Example 1 except that the thermosetting polyurethane composition was changed as described below.

[0175] As a thermosetting polyurethane composition for forming the conveyor belt body, a thermosetting polyurethane composition is used that is blended with 16 parts by mass of a curing agent (3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA)) and 7.5 parts by mass of a lubricant (fatty acid ester) relative to 100 parts by mass of a polyurethane prepolymer (PTMEG-TDI) in which the diisocyanate component is toluene diisocyanate and the polyol component is polytetramethyl ether glycol.

[0176] The JIS-A hardness of the cured product of the thermosetting polyurethane composition measured based on JIS K7312:1996 was 95.

[0177] When the peak friction coefficient μA and the average friction coefficient μB of the manufactured toothed conveyor belt were measured by the above-mentioned method, the peak friction coefficient μA was 0.71 and the average friction coefficient μB was 0.49.

[0178] <Example 3>

[0179] A toothed conveyor belt of S8M was produced in the same manner as in Example 1 except that the thermosetting polyurethane composition and the canvas were changed as follows.

[0180] As a thermosetting polyurethane composition for forming the conveyor belt body, a thermosetting polyurethane composition containing 16 parts by mass of a curing agent (3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA)) was used relative to 100 parts by mass of a polyurethane prepolymer (PTMEG-TDI) having toluene diisocyanate as the diisocyanate component and polytetramethyl ether glycol as the polyol component.

[0181] The JIS-A hardness of the cured product of the thermosetting polyurethane composition measured based on JIS K7312:1996 was 98.

[0182] As the canvas, the same canvas as in Example 1 was used except that it had been subjected to a wear modification treatment using ultra-high molecular weight PE powder.

[0183] As the wear modification treatment, a mixed powder of thermoplastic polyamide powder and ultrahigh molecular weight PE powder was applied to the canvas, and then heat-sealed.

[0184] When the peak friction coefficient μA and the average friction coefficient μB of the manufactured toothed conveyor belt were measured by the above-mentioned method, the peak friction coefficient μA was 0.25 and the average friction coefficient μB was 0.08.

[0185] Comparative Example 1

[0186] A toothed conveyor belt of S8M was produced in the same manner as in Example 1 except that the thermosetting polyurethane composition was changed as described below.

[0187] As a thermosetting polyurethane composition for forming the conveyor belt body, a thermosetting polyurethane composition containing 16 parts by mass of a curing agent (isobutyl 4-chloro-3,5-diaminobenzoate) was used relative to 100 parts by mass of a polyurethane prepolymer (PTMEG-TDI) in which the diisocyanate component was toluene diisocyanate and the polyol component was polytetrahydrofuran.

[0188] The JIS-A hardness of the cured product of the thermosetting polyurethane composition measured based on JIS K7312:1996 was 98.

[0189] When the peak friction coefficient μA and the average friction coefficient μB of the manufactured toothed conveyor belt were measured by the above-mentioned method, the peak friction coefficient μA was 0.89 and the average friction coefficient μB was 0.70.

[0190] Comparative Example 2

[0191] A toothed conveyor belt of S8M was produced in the same manner as in Example 1 except that the thermosetting polyurethane composition was changed as described below.

[0192] As a thermosetting polyurethane composition for forming the conveyor belt body, a thermosetting polyurethane composition containing 16 parts by mass of a curing agent (3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA)) was used relative to 100 parts by mass of a polyurethane prepolymer (PTMEG-TDI) having toluene diisocyanate as the diisocyanate component and polytetramethyl ether glycol as the polyol component.

[0193] The JIS-A hardness of the cured product of the thermosetting polyurethane composition measured based on JIS K7312:1996 was 98.

[0194] When the peak friction coefficient μA and the average friction coefficient μB of the manufactured toothed conveyor belt were measured by the above-mentioned method, the peak friction coefficient μA was 0.80 and the average friction coefficient μB was 0.46.

[0195] (evaluate)

[0196] <Load durability test>

[0197] Figure 10 This figure shows the pulley layout of a conveyor belt travel testing machine used for load durability testing.

[0198] The conveyor belt travel tester 40 is constructed as follows: a driving pulley 41 with 22 teeth and an outer diameter of 54.65 mm and a driven pulley 42 with 33 teeth and an outer diameter of 82.66 mm are arranged at intervals in the transverse direction, and the driven pulley 42 can be loaded with a load shaft load (SW) at the side.

[0199] The toothed belts of each embodiment and comparative example were wound around the drive pulley 41 and driven pulley 42 of the conveyor belt travel tester 40 described above. A torque of 34.24 N·m was applied to the driven pulley 42 along with an axial load (SW) of 608 N. The axial load (SW) was set based on the axial load of the load cell. After setting the target tension, the pulleys were manually rotated to rotate the conveyor belt three times, and the tension was then set again to the target tension. Furthermore, the conveyor belt was operated at an ambient temperature of 60°C, with the drive pulley 41 rotating at 4212 rpm and the driven pulley 42 rotating at 2808 rpm.

[0200] The conveyor belt was stopped periodically for visual inspection and the conveyor belt was continued to run until failures such as tooth chipping, wear of the belt teeth, or separation between the belt body and the core occurred.

[0201] [Table 1]

[0202] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Peak friction coefficient: μA 0.24 0.71 0.25 0.89 0.80 Average friction coefficient: μB 0.21 0.49 0.08 0.70 0.46 μA-μB 0.03 0.22 0.17 0.19 0.34 Durability time (h) 330 133 213 26 42.3 Failure Mode Tooth loss Tooth loss wear and tear peeling wear and tear

[0203] As shown in Table 1, it is clear that the toothed conveyor belt according to the embodiment of the present invention has a longer durability time until a failure occurs and is excellent in durability.

[0204] In the load endurance tests of Examples 1 and 2, the conveyor belt teeth were hardly worn, and the tests were terminated due to tooth chipping of the conveyor belt teeth.

[0205] In the load durability test of Example 3, the conveyor belt teeth were not easily worn, but if the reinforcing cloth was worn, the test was terminated based on the wear of the conveyor belt teeth.

[0206] On the other hand, in the load durability test of Comparative Example 1, the amount of heat generated by the belt body increased, and the test was terminated due to peeling at the interface between the belt body and the core wire.

[0207] In the load endurance test of Comparative Example 2, the test was terminated due to wear of the conveyor belt teeth.

[0208] Description of the label

[0209] 10, 20 toothed conveyor belt

[0210] 11 Conveyor belt body

[0211] 11a Flat belt

[0212] 11b Tooth

[0213] 12, 52 conveyor belt teeth

[0214] 13 core wire

[0215] 14 Reinforcement cloth

[0216] 15 tooth bottom

[0217] 16 non-woven fabrics

[0218] 31 inner mold

[0219] 32 grooves

[0220] 33 ridges

[0221] 34 outer mold

[0222] 40 Conveyor belt travel testing machine

[0223] 41 drive pulley

[0224] 42 driven pulley

[0225] 50 measurement samples

[0226] 54 Heavy Objects

[0227] 55 tablet

[0228] 111 Heat-curing polyurethane composition

[0229] C-cavity

Claims

1. A toothed conveyor belt, comprising: a conveyor belt body having a plurality of teeth arranged at a constant pitch on an inner circumference of the conveyor belt; and The core wires are embedded in the conveyor belt body at intervals in the conveyor belt width direction. The peak friction coefficient μA and the average friction coefficient μB measured by the following method satisfy the relationship of μA-μB≤0.3 and μB≤0.

5. <Measurement method> A toothed conveyor belt is cut in the width direction, and a measurement sample corresponding to two conveyor belt teeth is cut out from the toothed conveyor belt. The obtained measurement sample is placed on a flat plate in such a manner that the conveyor belt teeth are in contact with the flat plate. In this state, the measurement sample is moved in one direction for 30 seconds and the friction force at this time is measured. The friction coefficient calculated by dividing the maximum value of the friction force for 30 seconds by the vertical resistance is set as the peak friction coefficient μA, and the friction coefficient calculated by dividing the average value of the friction force for 30 seconds by the vertical resistance is set as the average friction coefficient μB. The measurement environment was set to a temperature of 23±5°C and a humidity of 50±5%. A certain load is applied to the sample to be measured and it is placed on a flat plate. The flat plate is made of SUS304, and the surface roughness of the surface on which the measurement sample is placed is set to be less than or equal to 1.6 μm in terms of Ra, where Ra is the arithmetic mean roughness. The moving speed of the measurement sample was set to 100 mm / min.

2. The toothed conveyor belt according to claim 1, wherein: A reinforcing cloth is provided on the inner peripheral surface of the tooth portion.

3. The toothed conveyor belt according to claim 1 or 2, wherein: The conveyor belt body is made of thermosetting polyurethane.

4. The toothed conveyor belt according to claim 3, wherein: The conveyor belt body contains lubricant.

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