JP6110679B2 - Belt connection structure, conveyor belt and belt connection method - Google Patents

Description

  The present invention relates to a belt connection structure, a conveyor belt, and a belt connection method.

  Belt conveyors that are used for transporting mineral resources and earth and sand from the mining site to the shipping port, etc., use belts in which reinforcing linear cores (cords) are embedded. In recent years, this belt is also frequently used for a pipe conveyor that is used by rounding the conveyance surface into a cylindrical shape in order to prevent spillage during conveyance.

  As shown in FIG. 5, the belt has a cord 102 arranged in multiple rows in the width direction, an intermediate rubber layer 103 filled around the cord 102, and a front surface and a back surface of the intermediate rubber layer 103. It is formed by connecting the laminated body 101 provided with the abrasion-resistant cover rubber layer 104 laminated | stacked endlessly.

  As a method of connecting the end portions of the laminate 101, generally, (A) the cover rubber layer 104 and the intermediate rubber layer 103 are removed at a pair of end portions of the laminate 101, and a fixed-length cord 102 is exposed. (B) a pair of end portions of the laminate 101 from which the cord 102 is exposed are attached together, and as shown in FIG. 6, a cord 102 extending from one end portion and a cord extending from the other end portion And (C) a step of disposing an unvulcanized rubber composition that forms the intermediate rubber layer 103 around the belt in the thickness direction and the width direction of the cord 102 that are alternately juxtaposed. (D) laminating an unvulcanized rubber composition for forming the cover rubber layer 104 on the front and back surfaces of the intermediate rubber layer 103; and (E) vulcanizing the unvulcanized rubber composition to obtain an intermediate rubber. Layer 103 and cover rubber layer 104 How and forming is adopted.

  In the juxtaposition of the cords in the step (B), if the cord diameter is larger than the spacing in the width direction between the cords, the cord spacing is reduced, and the width of the rubber filled between the cords is reduced. The connection strength of the part decreases. Therefore, for example, a step is provided in the length of the cord extending from the end of the belt to prepare a long cord and a short cord, and the distance between the cords is increased by abutting the short cords extending from different ends. A connection method has been devised (see JP-A-11-173384).

  According to the method of abutting the short cords described above, the width of the filled rubber can be increased by increasing the interval between the juxtaposed cords. However, since the total length in the belt longitudinal direction of the area sandwiched between the cord extending from one end and the cord extending from the other end is reduced, the cord is secured to ensure the strength of the connecting portion. It is necessary to increase the extension length, that is, the length of the connecting portion. Therefore, it is necessary to increase the construction time and increase the size of the equipment, and there is a problem that the manufacturing cost of the conveyor increases. In the above publication, the strength is improved by increasing the distance between the short cord extending from one end and the long cord extending from the other end, but it is difficult to say that the strength improvement is sufficient. In addition, since the installation work of the cord becomes complicated, an increase in cost is inevitable.

JP-A-11-173384

  The object of the present invention has been made based on the above circumstances, and a belt connection structure capable of easily and reliably improving the connection strength between cords extending from a pair of belt ends, and the connection of this belt It is an object of the present invention to provide a belt conveyor using a structure and a belt connecting method.

The invention made to solve the above problems is
Arranged between a pair of opposite ends of a flat belt in which a plurality of cords are embedded in the longitudinal direction,
One cord group in which a single long cord extending from one end and a single cord or a plurality of short cords having a shorter extension distance than the long cord are arranged in parallel in a predetermined order in the width direction;
Similarly, the long cord and the short cord extending from the other end portion are arranged in parallel in the same width direction as the one cord group, and the short cord extending from the other end portion is the short cord of the one cord group. The other cord group that is abutted with the cord and that the long cord extending from the other end is juxtaposed with the long cord of the one cord group,
A belt connection structure comprising: a combined rubber cord around the one cord group and the other cord group;
A plurality of long cords in the one cord group and the other cord group are juxtaposed in succession, and the long cords are juxtaposed juxtaposed at least on one side in the width direction.

  The connection structure of the belt is because the long cords are continuously juxtaposed in one cord group and the other cord group, and the long cords are juxtaposed adjacent to at least one side in the width direction, that is, Since a plurality of extended codes are arranged in parallel in a sequence where three or more short codes are not consecutive, the distance between the combined codes is larger than that of a conventional code arrangement in which a long code and a short code are repeated in a certain order. Although reduced, the total length of the region sandwiched between the long code or short code of one code group and the long code or short code of the other code group can be effectively increased. As a result, the distance between the combined cords (the width of the filled rubber layer between the cords) and the total length of the region can be secured in a well-balanced manner, and the connection strength of the belt can be easily and reliably improved.

  A first connection region in which the length of the short cord is one type and is sandwiched between one short cord extending from the one end and the long cord extending from the other end and adjacent to the short cord The longitudinal length s1 of the second connection region sandwiched between the one long cord extending from one end and the long cord adjacent to the long cord extending from the other end It is good that it is 40% or more and 50% or less of the length s2. Thus, by making the length of the short cord one type, the process and equipment at the time of connecting the belt can be simplified, so the manufacturing cost of the belt conveyor can be reduced. Further, by setting the ratio of the longitudinal length s1 of the first connection area to the longitudinal length s2 of the second connection area within the above range, that is, the opposing short cords are substantially in the longitudinal center of the connection structure. The total length of the connection area can be extended to the maximum by making the two face each other.

  When the length of the short code is one type, it is preferable that a plurality of short codes in the one code group and the other code group are not juxtaposed. In this way, by preventing short codes from being juxtaposed continuously in one code group and the other code group, codes belonging to different code groups are necessarily adjacent in the width direction (between codes belonging to different code groups). Since the long cord and the short cord are arranged in the order in which the regions to be formed are necessarily formed between the cords, the connection strength in the belt connection structure can be further improved.

A diameter d of the cord, an interval W between a long cord or short cord extending from one end and a long cord or short cord extending from the other end, a longitudinal length s2 of the second connection region, The total length L between a pair of ends of the longitudinal length s1 of the first connection region and the longitudinal length s2 of the second connection region, and the total number n of long cords and short cords extending from one end portion It is preferable that the relationship satisfies the following formulas (1) and (2).
1.2 + 0.1d ≦ W (1)
s2 <L / n (2)

  In this way, by arranging the long cord and the short cord extending from the pair of end portions in a predetermined order so as to satisfy the above formulas (1) and (2), it is possible to extend from different end portions having a trade-off relationship. It is possible to improve the connection strength of the connection structure of the belt effectively by improving the distance W between the outgoing cords and the total length L of the connection regions in a well-balanced manner.

  The cord is preferably a steel cord. By using a steel cord as the cord, the tear strength, impact resistance, etc. of the connection structure of the belt can be improved in combination with the improvement of the connection strength due to the above-described cord combination structure.

  The belt conveyor manufactured using the connection structure of the belt has high strength at the connection portion and is excellent in manufacturing cost.

Moreover, another invention made in order to solve the said subject is:
Extending a plurality of cords at a pair of opposite ends of a flat belt having a plurality of cords embedded in the longitudinal direction;
The plurality of extended cords are formed into a long cord and a single or a plurality of short cords each having a shorter extension distance than the long cord, and a plurality of the long cords are juxtaposed, and at least the width of the short cord. Forming a cord group in which the long cords are juxtaposed side by side on one side in the direction at the pair of end portions;
Matching the short code of one code group with the short code of the other code group, juxtaposing the long code of one code group with the long code of the other code group;
And a step of disposing a rubber layer around the one cord group and the other cord group in combination.

  According to the belt connection method, the total length of the region sandwiched between the long cord or short cord of one cord group and the long cord or short cord of the other cord group is maintained while maintaining the interval of the combined cords. Can be effectively enlarged.

  The “longitudinal length of the first connection region (second connection region)” means an average value of the longitudinal lengths of all the first connection regions (second connection regions) in the belt connection structure. .

  As described above, the belt connection structure, belt conveyor, and belt connection method of the present invention can easily and reliably improve the connection strength between the cords extending from the pair of belt ends.

It is a typical sectional view showing the connection structure of the belt concerning one embodiment of the present invention. It is a typical top view showing arrangement of a cord in a belt connection structure concerning one embodiment of the present invention. It is a typical top view which shows arrangement | positioning of the cord in the connection structure of the belt which concerns on embodiment different from embodiment of FIG. FIG. 3 is a schematic plan view showing the arrangement of cords in a belt connection structure according to an embodiment different from the embodiment of FIGS. 1 and 2. It is typical sectional drawing which shows the connection structure of the conventional belt. It is a typical top view which shows arrangement | positioning of the cord in the connection structure of the conventional belt.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

  A belt connection structure 1 shown in FIG. 1 is disposed between a pair of opposite ends of a flat belt in which a plurality of cords A are embedded in the longitudinal direction. The belt connection structure 1 includes a cord group extending from one end (first cord group), a cord group extending from the other end (second cord group, and belts of these cord groups. An intermediate rubber layer 4 filled around the thickness direction and the width direction and a cover rubber layer 5 laminated on both surfaces of the intermediate rubber layer 4 are provided.

<Code group>
FIG. 2 is a schematic plan view showing the arrangement of the first cord group and the second cord group excluding the intermediate rubber layer 4 and the cover rubber layer 5 in the belt connection structure 1. In the first cord group, a single long cord 2a extending from one belt end 10a and a single short cord 3a having a shorter extension distance than the long cord 2a are belts in a predetermined order. Parallel in the width direction. In the second cord group, the long cord 2b and the short cord 3b extending from the other belt end portion 10b in the same manner as the first cord group are in the same order in the width direction as the first cord group (mirror target order). In parallel. The short code 3a of the first code group is abutted with the short code 3b of the second code group, and the long code 2a of the first code group is juxtaposed with the long code 2b of the second code group. One long code 2b of the second code group is arranged between the long codes 2a of the code group. Between these cords, rubber forming the intermediate rubber layer 4 is filled.

  As described above, the long cords 2a and 2b and the short cords 3a and 3b in the first cord group and the second cord group are arranged in the belt width direction in a predetermined order. This predetermined order means that in the first code group (and the second code group), two long cords 2a (2b) are juxtaposed, and the long cords are arranged on both sides of the short cord 3a (3b) in the belt width direction. 2a (2b) is the order in which the two adjacent to each other are juxtaposed (except for the short cord closest to the end in the belt width direction). That is, in the first code group and the second code group, the codes are arranged in the order of “long code, long code, short code” in the belt width direction.

  The diameter d of the cords (the long cords 2a and 2b and the short cords 3a and 3b) included in the belt connection structure 1 may be 2 mm or more and 15 mm or less, for example. Moreover, the distance (pitch) between the axial centers of the cords in the first cord group and the second cord group can be, for example, 8 mm or more and 25 mm or less.

  The length in the longitudinal direction of the first connection region P sandwiched between one short cord 3a of the first code group and the long code 2b of the second code group adjacent to the short code 3a is defined as a first connection length s1. If the length in the longitudinal direction of the second connection region Q sandwiched between one long cord 2a of the two cord groups and the long cord 2b of the second cord group adjacent to the long cord 2a is the second connection length s2, The lower limit of the ratio of the one connection length s1 to the second connection length s2 is preferably 40%, and more preferably 45%. On the other hand, the upper limit of the ratio of the first connection length s1 to the second connection length s2 is preferably 50%, and more preferably 49%. When the ratio of the first connection length s1 to the second connection length s2 is less than the lower limit, the area of the first connection region P is small, and the connection strength of the belt connection structure 1 may be reduced. On the contrary, when the ratio of the first connection length s1 to the second connection length s2 exceeds the upper limit, the distance between the short cords 3a and 3b that are abutted with each other is lost, and the arrangement of the cords may be difficult.

  The connection structure length s3 that is the length of the belt connection structure 1 in the longitudinal direction of the belt can be, for example, 300 mm or more and 4,000 mm or less. The ratio of the second connection length s2 to the connection structure length s3 is preferably 50% or more and 95% or less. When the ratio of the second connection length s2 to the connection structure length s3 exceeds the upper limit, when the cords are combined as described above, the length of the portion that bends the cords may be reduced, and the arrangement of the cords may be difficult. is there. On the other hand, when the ratio of the second connection length s2 to the connection structure length s3 is less than the lower limit, the connection strength of the belt connection structure 1 may not be sufficiently obtained, or the manufacturing cost may increase. Moreover, as the space | interval of the front-end | tips of the short code 3a of the 1st code group and the short code 3b of the 2nd code group which were faced | matched, it can be 10 mm or more and 50 mm or less, for example.

The distance W between the long code 2a or the short code 3a of the first code group and the long code 2b or the short code 3b of the second code group preferably satisfies the relationship of the cord diameter d and the following formula (1). When the interval W is less than (1.2 + 0.1d), the width of the rubber filled between the cords becomes small, and the connection strength of the belt connection structure 1 may be reduced. Further, the upper limit of the interval W is preferably 7 mm. If the interval W exceeds the upper limit, the distance between the codes becomes too large, and there is a possibility that the labor for arranging the codes increases.
1.2 + 0.1d ≦ W (1)

The total number L of the long cord 2a and the short cord 3a included in the first cord group is the sum L between the pair of belt ends of the first connection length s1 of the first connection region P and the second connection length s2 of the second connection region Q. The connection length (L / n) per cord divided by n preferably satisfies the relationship of the second connection length s2 and the following formula (2). When the connection length (L / n) per cord is s2 or less, the ratio of the connection length per cord to the longitudinal length of the belt connection structure 1 is small, so the connection strength between cords In order to increase this, it is necessary to increase the length in the longitudinal direction of the belt connection structure 1, which may increase the manufacturing cost. Even if the ratio of the short cord to the long cord is reduced to the maximum in the belt connection structure 1, the connection length (L / n) per cord exceeds twice the second connection length s2. There is no.
s2 <L / n (2)

  The material of the cord used for the belt connection structure 1 is not particularly limited, and synthetic fibers such as nylon, polyester, and aramid, steel, and the like can be used, but steel is preferable from the viewpoint of strength, elongation, life, and the like.

<Intermediate rubber layer>
The intermediate rubber layer 4 is formed from a rubber composition filled around the combined first cord group and second cord group. Examples of the base rubber of the rubber composition forming the intermediate rubber layer 4 include natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPM, EPDM), isoprene rubber ( IR), acrylonitrile-butadiene rubber (NBR, NIR, etc.) and the like.

  The rubber composition forming the intermediate rubber layer 4 is added with a vulcanizing agent such as sulfur, organic peroxide, metal oxide, phenol resin, quinone dioxime and the like. Examples of sulfur-based vulcanizing agents include powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface-treated sulfur, insoluble sulfur, dimorpholine disulfide, alkylphenol disulfide, and the like. Examples of organic peroxide vulcanizing agents include benzoyl peroxide, t-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide, 2,5-dimethyl-2,5-di (t-butyl peroxide). Oxy) hexane, 2,5-dimethylhexane-2,5-di (peroxylbenzoate), and the like. Examples of the metal oxide vulcanizing agent include zinc white and magnesium oxide.

  In addition to the vulcanizing agent, the rubber composition forming the intermediate rubber layer 4 can contain, for example, a vulcanization accelerator, a vulcanization aid, a vulcanization retarder, and the like.

  Examples of the vulcanization accelerator include aldehyde / ammonia, guanidine, thiourea, thiazole, sulfenamide, thiuram, and dithiocarbamate vulcanization accelerators.

  Examples of the vulcanization aid include zinc oxide, stearic acid, oleic acid, and zinc salts thereof.

  Examples of the adhesion improver include organic acid cobalt.

  The rubber composition forming the intermediate rubber layer 4 includes other reinforcing agents such as carbon black and silica, fillers such as calcium carbonate and talc, waxes such as microcrystalline wax, and oils such as aroma oil. , Polymers, anti-aging agents, antioxidants, pigments (dyes), plasticizers, thixotropic agents, UV absorbers, flame retardants, solvents, surfactants (including leveling agents), dispersants, dehydrating agents, One or more kinds of compounding agents such as a rust inhibitor, an adhesion-imparting agent, an antistatic agent and a processing aid can be blended.

  Examples of the carbon black include carbon black for rubber such as FEF, ISAF, and HAF.

  The average thickness t1 (including the steel cord) t1 of the intermediate rubber layer 4 is not particularly limited, and may be, for example, 2.5 mm or more and 20 mm or less. Further, the average distance t2 from the surface of the steel cord to the surface of the intermediate rubber layer 4 is not particularly limited, and can be, for example, 0.3 mm or more and 2.5 mm or less.

<Cover rubber layer>
The cover rubber layer 5 is laminated on the front and back surfaces of the intermediate rubber layer 4. As the base rubber of the rubber composition forming the cover rubber layer 5 and the compounding agent blended in the base rubber, the same rubber as the intermediate rubber layer 4 (but not including the adhesion improver) can be used. .

  It does not specifically limit as average thickness of the cover rubber layer 5, For example, it is 3 mm or more and 30 mm or less.

<Belt connection method>
The belt connection structure 1 can be obtained by a belt connection method having the following steps.
(1) A step of extending a plurality of cords at a pair of belt end portions 10a, 10b facing each other of a flat belt (2) Forming the plurality of extended cords into long cords 2a, 2b and short cords 3a, 3b The first code group and the second code group in which a plurality of the long codes 2a and 2b are juxtaposed in succession and the long codes 2a and 2b are juxtaposed adjacent to each other in the width direction of the short codes 3a and 3b are described above. (3) The short cord 3a of the first cord group is matched with the short cord 3b of the second cord group, and the long cord 2a of the first cord group is matched with the second cord group. A step of combining the cord groups in juxtaposition with the long cord 2b (4) A step of disposing a rubber layer around the combined first cord group and second cord group (5) The intermediate rubber layer 4 and the cover rubber layer 5 Forming process

<(1) Cord extension process>
In the cord extending step, the rubber layers at both belt end portions of the flat belt are removed, and a plurality of cords are exposed to extend from the belt end portions 10a and 10b. Specifically, the rubber layer at both ends of the flat belt is cut and peeled using a cutter knife or the like, and the residue of the rubber layer adhering to the peripheral surface of the cord is polished with sandpaper, a wire brush, etc. Remove with solvent. Note that the end of each steel cord, which is likely to be the starting point of breakage of the joint, is not inclined at right angles to the longitudinal direction of the belt so that it does not simultaneously pass the position bent in the longitudinal direction on the pulley or roller. Is preferably formed.

<(2) Code group formation process>
In the cord group forming step, two long cords 2a (2b) are juxtaposed in parallel, and the short cords 3a (3b) (excluding the short cords closest to the end in the belt width direction) on both sides in the belt width direction By repeating the order in which the long cords 2a (2b) are arranged adjacent to each other, that is, in the belt width direction from the side end of one belt to the other side end, “long code, long code, short code” A first code group and a second code group in which codes are arranged are formed. Specifically, among the cords exposed in the cord extending process, the short cord 3a (3b) is formed by cutting the tip of the cord every two cords, and the first cord group and the second cord group are Form. When the rubber layer at the end of the belt is cut at an incline with respect to the longitudinal direction of the belt, the tip position of each steel cord is the width of the belt so that the protruding lengths of the long cord and the short cord are substantially equal to each other. Each cord is processed so as to be shifted in the longitudinal direction of the belt along the direction.

<(3) Code group combination process>
In the code group combining step, the short code 3a of the first code group is matched with the short code 3b of the second code group, and the long code 2a of the first code group is juxtaposed with the long code 2b of the second code group. A plurality of codes are combined and arranged so that one long code 2b of the second code group is positioned between the long codes 2a of the first code group.

<(4) Rubber layer disposing step>
In the rubber layer disposing step, a rubber composition for forming the intermediate rubber layer 4 is disposed around the belt of the combined first cord group and second cord group in the thickness direction and the width direction. Specifically, a rubber composition sheet is formed which is filled with a rubber composition that forms an intermediate rubber layer 4 between cords, and then forms an intermediate rubber layer 4 on the front and back surfaces of a cord group filled with the rubber composition. Are further laminated. At this time, the adhesiveness between the cord and the intermediate rubber layer 4 can be enhanced by applying in advance a solution obtained by dissolving the rubber composition in a solvent on the peripheral surface of each cord.

<(5) Intermediate rubber layer and cover rubber layer forming step>
In the intermediate rubber layer and cover rubber layer forming step, a rubber composition for forming the cover rubber layer 5 is laminated on the front and back surfaces of the rubber composition disposed around the cord group, and these rubber compositions are vulcanized. Thus, the intermediate rubber layer 4 and the cover rubber layer 5 are formed. Thereby, the edge parts of a belt are connected and the connection structure 1 of the said belt is obtained.

<Advantages>
The belt connection structure 1 has a longer length of the first cord group, although the distance between the combined cords is smaller than that of the conventional long cords 2a and 2b and the short cords 3a and 3b repeated in a certain order. The total length of the region sandwiched between the cord 2a or the short cord 3a and the long cord 2b or the short cord 3b of the second cord group (the first connection length s1 and the second of the first connection region P between the belt end portions 10a and 10b) The sum L) of the second connection length s2 of the connection region Q can be effectively increased. As a result, the distance between the cords and the total length of the region can be secured in a well-balanced manner, and the connection strength of the belt can be easily and reliably improved.

  Further, the belt connection structure 1 is excellent in workability because the length of the short cord is one type. Further, in the first code group and the second code group, the long codes 2a and 2b are arranged adjacent to each other on both sides in the width direction of the short codes 3a and 3b, so that codes belonging to different code groups must be in the width direction. Since the long cords 2a and 2b and the short cords 3a and 3b are arranged in an adjacent order (a region sandwiched between cords belonging to different cord groups is always formed between the cords), the belt connection structure 1 is more Demonstrates high connection strength.

<Conveyor belt>
Since the belt connection structure 1 has a high connection strength as described above and is excellent in manufacturing cost, a conveyor belt excellent in strength and cost can be obtained by using the belt connection structure 1. .

[Other Embodiments]
The belt connection structure of the present invention is not limited to the above-described embodiment, and may be the following embodiment.

  In the above embodiment, in each code group (first code group and second code group), two long codes are juxtaposed between the short code and the short code, but three or more long codes are continuous. May be juxtaposed. As an example of this, FIG. 3 shows an embodiment in which three long codes are juxtaposed in each code group. Thus, when the cord interval in the cord group is large or the cord diameter is small with respect to the width of the belt, by reducing the proportion of short cords and increasing the number of consecutive long cords, the interval of the combined cords The total length of the connection region sandwiched between the long code or the short code of one cord group and the long code or the short cord of the other cord group can be effectively increased. In other words, when there is a margin in the cord interval, the total length of the connection region is increased by increasing the ratio of the long cords in each cord group, thereby reducing the longitudinal length of the connection structure of the belt and the manufacturing cost. Can be reduced.

  In the above embodiment, the total number of long codes and short codes in each code group is 6. However, the number of codes included in each code group is not limited. In addition, for example, when a predetermined order of “long code, long code, short code” is repeated as in the above embodiment, it is within the intended scope of the present invention to include one or more of the predetermined orders. That is, even if a code that does not form a predetermined order, such as “long code, long code, short code, long code, long code, short code, long code” is included, the predetermined order is included. As long as it is included in the configuration of the present invention, the effects of the present invention can be achieved. As long as a predetermined order is included in this way, the cord closest to the end in the belt width direction of each cord group may be either a long cord or a short cord.

  Further, in the belt connection structure of the present invention, each cord group may include a plurality of short cords. For example, the belt connection structure 21 shown in FIG. 4 includes first short cords 13a and 13b each cord group having a shorter extension distance than the long cords 2a and 2b, and an extension distance longer than the first short cords 13a and 13b. Includes the second short cords 23a and 23b, the first short code 13a of the first code group and the second short code 23b of the second code group are matched, and the second short code 23a of the first code group and the second short code 23a The cords are arranged so as to match the first short cords 13b of the two cord groups. The first short cords 13a and 13b and the second short cords 23a and 23b are the lengths in the longitudinal direction of the connection region R sandwiched between the first short cord 13a of the first cord group and the first short cord 13b of the second cord group. And the length in the longitudinal direction of the connection region S sandwiched between the second short cord 23a of the first code group and the long code 2b of the second code group is formed to be about 1/3 of the second connection length s2. Has been. Such a belt connection structure 21 can also provide the effects of the present invention. This belt connection structure 21 has the same “long cord” and “short cord” in the first cord group and the second cord group when the first short cord and the second short cord are bundled as “short cord”. They are arranged in parallel in the order of the width direction (the order of “long code, long code, short code, short code, long code, long code, short code, short code”).

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Example 1]
A flat belt (width: 90 mm) in which six steel cords having a diameter d of 5.8 mm were embedded at a pitch of 14.2 mm (distance between cord axes), and the steel cords were extended at both ends thereof. Next, as shown in FIG. 1, a code is formed in the order of “long code, long code, short code, long code, long code, short code” in the width direction at both ends, and a short extending from one end. The cord and the short cord extending from the other end were abutted, and the long cord extending from one end and the long cord extending from the other end were juxtaposed. Thereafter, a rubber composition comprising sulfur, a vulcanization accelerator, a vulcanization acceleration aid, stearic acid, organic acid cobalt, carbon black, aroma oil, and an anti-aging agent to a rubber component composed of natural rubber and styrene butadiene rubber. The product was filled between the cords, and the rubber composition was laminated on the front and back surfaces of the cord group. Next, on the front and back surfaces of the laminated rubber composition, for the rubber component composed of natural rubber and styrene butadiene rubber, sulfur, vulcanization accelerator, vulcanization acceleration aid, stearic acid, carbon black, aroma oil, and A rubber composition added with an anti-aging agent is further laminated and vulcanized to form an intermediate rubber layer (distance from the steel cord surface to the intermediate rubber layer surface: 0.3 mm) and a cover rubber layer (thickness: 6 mm). Then, both end portions of the flat belt were connected to obtain an endless conveyor belt of Example 1.

  In Example 1, the length s1 in the longitudinal direction of the first connection region sandwiched between one short cord extending from one end and the long cord extending from the other end and adjacent to the short cord is 150 mm. The longitudinal length s2 of the second connection region sandwiched between the one long cord extending from one end and the long cord extending from the other end and adjacent to the long cord is 330 mm, and the belt The length s3 in the belt longitudinal direction of the connection structure was set to 530 mm. The sum L of the longitudinal length s1 of the first connection region and the longitudinal length s2 of the second connection region is 2,430 mm. A value obtained by dividing the total sum L by the number of cords 6 is 405 mm / line, which is larger than 330 mm of s2, and therefore satisfies the above formula (2). The distance W between the long cord or short cord extending from one end and the long cord or short cord extending from the other end is 2.72 mm, (1.2 + 0.1 × 5.8) ) Since it is larger than mm, the above formula (1) is satisfied.

[Comparative Example 1]
The same flat belt as in Example 1 is used, and steel cords are extended at both ends thereof, and the long cords are arranged in the order of “long cord, short cord, long cord, short cord, long cord, short cord” in the width direction. And short cords were alternately arranged in parallel, and both ends of the flat belt were connected in the same manner as in Example 1 to obtain an endless conveyor belt of Comparative Example 1. In Comparative Example 1, the lengths of the first connection region, the second connection region, and the connection structure of the belt are the same as in Example 1, but the longitudinal length s1 of the first connection region and the length of the second connection region are the same. The total length L of the lengths s2 in the longitudinal direction is 1,740 mm, and the value divided by the number of cords 6 is 290 mm / piece, which does not satisfy the above formula (2). The cord interval W was 3.67 mm.

[Evaluation of connection strength]
The conveyor belt of Example 1 and Comparative Example 1 is set to a biaxial pulley having a diameter of 500 mm (distance between shaft centers: 3,000 mm), and the connecting portion of the belt is outside one pulley (opposite the other pulley). The tension of 56,000 N was repeatedly applied to this one pulley in the pulley parallel direction at a frequency of once every 25 seconds, and the number of times until the connecting portion was broken was measured.

  The measurement results of the connection strength are shown in Table 1.

  As shown in Table 1, it can be seen that Example 1 can endure a tension load five times or more that of Comparative Example 1, and is excellent in connection strength and durability. In other words, since Example 1 can ensure sufficient connection strength with a connection length shorter than that of Comparative Example 1, it is excellent in manufacturability.

  Since the belt connection structure and the conveyor belt of the present invention are excellent in connection strength, they can be suitably used for transporting deposits and the like.

1, 11, 21 Belt connection structure 2a, 2b Long cord 3a, 3b Short cord 4 Intermediate rubber layer 5 Cover rubber layer 13a, 13b First short cord 23a, 23b Second short cord

Claims (6)

Arranged between a pair of opposite ends of a flat belt in which a plurality of cords are embedded in the longitudinal direction,
One cord group in which a single long cord extending from one end and a single cord or a plurality of short cords having a shorter extension distance than the long cord are arranged in parallel in a predetermined order in the width direction;
Similarly, the long cord and the short cord extending from the other end portion are arranged in parallel in the same width direction as the one cord group, and the short cord extending from the other end portion is the short cord of the one cord group. The other cord group that is abutted with the cord and that the long cord extending from the other end is juxtaposed with the long cord of the one cord group,
A belt connection structure comprising: a combined rubber cord around the one cord group and the other cord group;
A plurality of long cords in the one cord group and the other cord group are juxtaposed continuously, and the long cords are juxtaposed adjacent to at least one side in the width direction of the short cords ,
A first connection region in which the length of the short cord is one type and is sandwiched between one short cord extending from the one end and the long cord extending from the other end and adjacent to the short cord The longitudinal length s1 of the second connection region sandwiched between the one long cord extending from one end and the long cord adjacent to the long cord extending from the other end A belt connection structure characterized by being 40% to 50% of the length s2 . The belt connecting structure according to claim 1 , wherein a plurality of short cords are not juxtaposed in the one cord group and the other cord group. A diameter d of the cord, an interval W between a long cord or short cord extending from one end and a long cord or short cord extending from the other end, a longitudinal length s2 of the second connection region, The total length L between a pair of ends of the longitudinal length s1 of the first connection region and the longitudinal length s2 of the second connection region, and the total number n of long cords and short cords extending from one end portion The belt connection structure according to claim 2, wherein the relationship satisfies the following expressions (1) and (2).
1.2 + 0.1d ≦ W (1)
s2 <L / n (2) The belt connecting structure according to any one of claims 1 to 3 , wherein the cord is a steel cord. A conveyor belt provided with the connection structure of the belt of any one of Claims 1-4 . Extending a plurality of cords at a pair of opposite ends of a flat belt having a plurality of cords embedded in the longitudinal direction;
The plurality of extended cords are formed into a long cord and a single or a plurality of short cords each having a shorter extension distance than the long cord, and a plurality of the long cords are juxtaposed, and at least the width of the short cord. Forming a cord group in which the long cords are juxtaposed side by side on one side in the direction at the pair of end portions;
Matching the short code of one code group with the short code of the other code group, juxtaposing the long code of one code group with the long code of the other code group;
Around the combined said one code group and the other code group possess a step of disposing a rubber layer,
A first connection region in which the length of the short cord is one type and is sandwiched between one short cord extending from the one end and the long cord extending from the other end and adjacent to the short cord The longitudinal length s1 of the second connection region sandwiched between the one long cord extending from one end and the long cord adjacent to the long cord extending from the other end The belt connecting method is 40% or more and 50% or less of the length s2 .

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