JP2002188691A - Low-edge cog belt and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent exfoliation at an upper part of a cog valley of a compressed rubber layer in short period of time. SOLUTION: A manufacturing method for a log-edge cog belt 1 is composed of a process which forms a reinforcing cloth 10 glued to the surface of a compressed rubber layer to a cog shape in advance, a process which forms the cog shape by laminating a rubber sheet constituting a compressed rubber layer 5 on the shaped reinforcing cloth 10, a process which fits the rubber sheet consisting of the cog-shaped reinforcing cloth 10 and the compressed rubber 5 to a cylindrical mold possessing projecting parts and recessed parts corresponding to the cog shape consisting of cog valleys and cog mountains and winds on the cylindrical mold by butting the both end, and a vulcanization forming process which winds a rubber sheet constituting a lower cushion rubber layer 3, core wires 4, a rubber sheet constituting an upper cushion rubber layer 2, a rubber sheet constituting a elongated rubber layer 6 and a reinforcing cloth 10 in order on the rubber sheet constituting the compressed rubber layer and presses with heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-edge cog belt and a method for manufacturing the same, and more particularly, to a low-edge cog belt for preventing early separation of an upper part of a cog valley and a method for manufacturing the same.

[0002]

2. Description of the Related Art A low-edge cog belt 1 shown in FIG.
By providing a cog shape in which cog peaks 7 and cog valleys 8 are alternately arranged at least on the side of the compressed rubber layer 5 of the low edge belt, a transmission having good flexibility is provided by periodically reducing the thickness of the belt. It is a belt. In the manufacturing process of the low-edge cog belt 1, an unvulcanized rubber sheet for forming the compressed rubber layer 5 and an unvulcanized rubber for forming the lower cushion rubber layer 3 on a flat cog-shaped mold longer than the belt circumference. A primary forming step of laying the sheet on top of one another and press-curing to mold a cog shape composed of the cog peak portion 7 and the cog valley portion 8 is included. The cog-shaped sheet obtained in this primary forming step is fitted and wound on a cylindrical mold equipped with a cylindrical matrix having convex and concave strips corresponding to the cog shape, and the cut surfaces at both ends are abutted. Further, the core wire 4, the upper cushion rubber layer 2, the extension rubber layer 6, and the reinforcing cloth 10 are wound,
Vulcanization and molding were performed by applying heat and pressure.

[0003]

Here, the lower cushion rubber layer 3 is subjected to pressure from the mold at the time of molding the cog ridges 7 and the cog valleys 8 in the primary molding step.
As shown in FIG. 7, there is a problem that the thickness of the upper part of the cog valley 8 becomes extremely thin along the shape of the cog valley 7 and the cog valley 8. If the lower cushion rubber layer 3 becomes very thin in the upper part of the cog valley portion 8 as described above, there is a problem that the stress of the belt bending cannot be relieved, and the lower cushion rubber layer 3 is separated from that portion at an early stage. An object of the present invention is to provide a low-edge cog belt in which the lower cushion rubber layer 3 has a uniform and sufficient thickness over the entire circumference of the belt in order to prevent the lower cushion rubber layer 3 from peeling off at the upper part of the cog valley 8 and its production. It is to provide a method.

[0004]

According to a first aspect of the present invention, there is provided a low-edge cog belt according to the first aspect of the present invention, wherein the thickness of the lower cushion rubber layer is uniform over the entire circumference of the belt. It is.

According to a second aspect of the present invention, there is provided a method of manufacturing a low-edge cog belt, wherein a reinforcing cloth to be adhered to the surface of the compressed rubber layer is previously molded into a cog shape, and a compressed rubber layer is formed on the molded reinforcing cloth. Laminating rubber sheets to form a cog shape, and forming the reinforcing cloth molded into the cog shape and a rubber sheet forming a compression rubber layer into a cylindrical mold having convex and concave ridges corresponding to the cog shape. A process of fitting and winding so that both ends thereof abut each other,
On the rubber sheet forming the compressed rubber layer, a rubber sheet forming the lower cushion rubber layer, a cord, a rubber sheet forming the upper cushion rubber layer, a rubber sheet forming the extension rubber layer, and a reinforcing cloth are sequentially wound. And vulcanizing by heating and pressurizing, and then vulcanizing and molding the raw edge cog belt.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The low-edge cog belt of the present invention and a method for manufacturing the same will be described in detail below. In addition,
The low-edge cog belt according to the present invention is not limited to a low-edge belt having a cog portion only in the compression rubber layer, but also includes a low-edge belt having a cog portion in both the compression rubber layer and the extension rubber layer. Also, a low-edge cog belt in which a reinforcing cloth is directly adhered to the upper cushion rubber layer without including the extension rubber layer is included.

A low edge cog belt is manufactured according to the following steps. First, as shown in FIG. 2, as shown in FIG. 2, the reinforcing cloth 10 is placed on a mold 26 having concave parts 24 and convex parts 25 alternately, and the reinforcing cloth 10 is rotated while the pinion roll 29 is rotated. The mold is formed by pressing to conform to the surface shape.

As a second step, as shown in FIG. 3, a rubber sheet 20 for forming the compressed rubber layer 7 is placed on the molded reinforcing cloth 10 and pressed by a press plate 27, as shown in FIG. A cog pad 21 having a cog crest 22 and a cog trough 23 is manufactured. The mold 26 and the press plate 27 are preferably heated to a temperature of 40 to 100 ° C. in order to facilitate deformation of the rubber member 20.

As a third step, as shown in FIG. 5, the cog pad 21 is fixed to the top 31 of the cog peak 22 at an angle α of 0.
By cutting so that the angle is 〜40 °, one end face 30 is cut.
Is formed, and then the other end surface 30 is formed at a predetermined number of cogs and the other end surface inclined in the same direction as the one end surface.

As a fourth step, as shown in FIG. 6, the mold 35 is mounted on a molding machine (not shown), and the cog ridge 22 of the cog pad is fitted into the groove 36 of the mold.
After the cog pad 21 having a predetermined length is wound around the mold 35 to bring the both ends into surface contact, the rubber sheet 3 forming the lower cushion rubber layer is wound, and the core wire 4 (not shown) is spirally wound. A laminate of a rubber sheet for forming the upper cushion rubber layer 2 and a rubber sheet for forming the stretched rubber layer 6 and one or several reinforcing cloths is wound thereon to produce a molded body. The mold 35 taken out of the molding machine is placed on a support table, and a matrix (not shown) made of vulcanized rubber having concave portions provided at predetermined intervals along the circumferential direction, and a jacket (not shown) ) Is inserted.

As a fifth step, the molded body is transferred to a vulcanizer and vulcanized by a usual method. After vulcanization, the jacket, the matrix, and then the cylindrical sleeve are extracted from the mold 35, and the sleeve is cut to a predetermined angle and width to obtain a low-edge cog belt.

The obtained low edge cog belt will be described in detail with reference to FIG. The cord 4 is preferably a low-stretch and high-strength rope. For example, a rope obtained by twisting an organic fiber such as an aramid fiber, a polyamide fiber, or a polyester fiber, an inorganic fiber such as a glass fiber, or a metal fiber is used. Generally resorcin-formalin-latex (RFL)
By processing, it is firmly bonded to the cushion rubber layer. Further, rubber glue may be further applied to the RFL-treated surface.

The rubber used for the cushion rubber layers (upper cushion rubber layer 2, lower cushion rubber layer 3) is chloroprene rubber (CR), hydrogenated nitrile rubber (HN
BR), HNBR in which unsaturated carboxylic acid metal salts are dispersed,
A single material such as chlorosulfonated polyethylene (CSM), natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR) or a blend thereof may be used, and CR having excellent heat resistance and abrasion resistance may be used. HNBR,
HNBR in which unsaturated metal carboxylate is dispersed is preferred, and HNBR in which unsaturated metal carboxylate is dispersed is preferred.
Is particularly preferred.

The cushion rubber layer is usually made of a compressed rubber layer 5.
As a result of being separately laminated as the lower cushion rubber layer 3 and the upper cushion rubber layer 2 adjacent to the extension rubber layer 6, the core wire 4 and other rubber portions are bonded together, and at the same time, each member is bent by a belt. There is a function to reduce the stress between them.

The same rubber as that used for the cushion rubber layer is used for the rubber composition forming the rubber used for the compression rubber layer 5 and the extension rubber layer 6.

The rubber constituting each part of the belt includes reinforcing agents such as carbon black and silica, fillers such as calcium carbonate and talc, a crosslinking assistant, a vulcanization accelerator, a plasticizer, a stabilizer, and the like. Various additives such as a processing aid, an antioxidant, and a coloring agent are blended. Further, the compression rubber layer 5 and the extension rubber layer 6 may use a rubber composition containing aramid short fibers.

The reinforcing cloth 10 adhered to the compression rubber layer 5 and the extension rubber layer 6 is made of cotton, polyester fiber, nylon, or the like, and is woven in plain weave, twill weave, satin weave, or the like. A wide-angle canvas having an intersection angle of about 90 to 120 degrees may be used. After the RFL treatment, the reinforcing cloth 10 is friction-coated with a rubber composition and used as a canvas with rubber.

In the method of manufacturing the low-edge cog belt 1 according to the present invention, in the primary molding step where the rubber sheet forming the compressed rubber layer 5 and the rubber sheet forming the lower cushion rubber layer 3 are conventionally molded simultaneously, Layer 5
Is characterized in that only the rubber sheet that forms The rubber sheet that forms the lower cushion rubber layer 3 is attached to the surface of the molded rubber sheet 5 after the rubber sheet that forms the compressed rubber layer 5 is wound around the mold.
As shown in the figure, the obtained lower cushion rubber layer 3 has a substantially uniform and sufficient thickness over the entire circumference of the low-edge cog belt 1, and the lower cushion rubber layer 3 becomes thinner at the upper part of the cog valley 8. Can be avoided. Therefore, early peeling at the upper part of the cog valley 8 is also prevented.

The thickness of the lower cushion rubber layer 3 is usually 0.4 mm or more and less than 0.8 mm before molding.
If the thickness is less than 0.4 mm, a sufficient thickness of the lower cushion rubber layer after molding is not ensured, which is not preferable.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The speed change belt of the present invention will be described below in more detail based on embodiments. Example 1 A 1,100-denier para-aramid fiber was prepared by priming 21.0 times / 10 cm and ply twisting 11.4 times / 10c.
Untreated cords having a total denier of 6,600 were prepared by twisting yarns in the reverse direction in a 2 × 3 twist configuration. After immersing the untreated cord in the isocyanate-based adhesive,
After drying at 70 to 180 ° C. and further immersion in an RFL solution, a stretching heat fixing treatment was performed at 200 to 240 ° C. to prepare a cord for cord treatment.

As a reinforcing cloth, para-aramid fiber and P
A plain woven canvas made of ET was used. After immersion in the RFL solution, heat treatment was performed at 150 ° C. for 2 minutes to obtain a treated canvas, and then a rubber composition containing CR as a main component was subjected to friction coating to obtain a canvas with rubber.

A rubber composition containing CR as a main component and containing aramid short fibers was prepared as a rubber sheet for forming a compressed rubber layer and a rubber sheet for forming an extended rubber layer. Further, a rubber composition containing CR as a main component and not containing aramid short fibers was prepared as a rubber sheet for forming a lower cushion rubber layer and a rubber sheet for forming an upper cushion rubber layer.

A one-ply reinforcing cloth and a rubber sheet forming a compressed rubber layer are laminated, placed in a mold in which concave portions and convex portions are alternately arranged in a plane, and heated at 80 ° C. to form a cog. To obtain a cog pad.

Subsequently, the above-mentioned cog pad, a rubber sheet for forming a lower cushion rubber layer, a core wire, a rubber sheet for forming an upper cushion rubber layer, and an extension rubber layer in a cylindrical mold having a concave strip corresponding to the cog shape. Forming a rubber sheet,
And a reinforcing cloth were sequentially wound, and then an outer mold having a smooth inner peripheral surface was externally fitted. Then put a jacket on,
The rubber sleeve was obtained by placing the mold in a vulcanizer and vulcanizing. This rubber sleeve is mounted on a cutting machine, and the V-angle is set with a cutter blade so that the V-angle becomes 30 degrees.
The shape was cut at regular intervals to obtain individual low edge cog belts.

Further, the surface of the side surface of the compressed rubber layer was surface-treated by rotating the belt and the sandpaper while bringing the 80th sandpaper into contact with the side surface of the belt. The obtained low-edge cog belt has an upper width of 25 m.
m, thickness 15 mm, length 950 mm, cog-shaped pitch 11 mm, and cog-shaped height 7.5 mm. The thickness of the lower cushion rubber layer was 0.4 mm, and the thickness did not decrease periodically at the upper part of the cog valley, and was obtained with a substantially uniform thickness over the entire circumference of the belt.

The obtained belt was mounted on a scooter drive system and a running test was conducted. As a result, no peeling of the upper part of the cog valley was observed at an early stage of a traveling distance of 500 km. Peeling resistance was observed.

COMPARATIVE EXAMPLE 1 As in the prior art, a cog-shaped mold was formed in a state where the rubber sheet forming the compressed rubber layer and the rubber sheet forming the lower cushion rubber layer were overlapped in the primary molding step. The low edge cog belt was produced by the procedure of above. As shown in FIG. 7, the lower cushion rubber layer of the obtained low-edge cog belt has a wavy shape depending on the wavy shape composed of the cog valley portion 7 and the cog valley portion 8. The thickness was such that the layer 5 and the core wire 4 were closer to each other. When a running test was performed on the actual machine in the same manner as in the example, peeling of the upper part of the cog valley was observed at an early stage of a running distance of 500 km.

[0028]

As described above, the low edge cog belt according to the first aspect of the present invention is a low edge cog belt characterized in that the lower cushion rubber layer has a uniform thickness over the entire circumference of the belt. It shows excellent durability against peeling at the upper part of the cog valley of the compressed rubber layer.

According to a second aspect of the present invention, there is provided a method of molding a reinforcing cloth to be pasted on a surface of a compressed rubber layer into a cog shape in advance, and forming a rubber sheet on which a compressed rubber layer is formed on the molded reinforcing cloth. The step of laminating and forming a cog shape, and the reinforcing cloth molded into the cog shape and a rubber sheet forming a compressed rubber layer are fitted into a cylindrical mold having convex and concave ridges corresponding to the cog shape. A step of winding the two ends so as to abut each other, and a rubber sheet forming a lower cushion rubber layer, a cord, and a rubber sheet forming an upper cushion rubber layer on a rubber sheet forming the compressed rubber layer;
And vulcanizing the rubber sheet by sequentially winding a rubber sheet forming a stretched rubber layer and a reinforcing cloth, and then applying heat and pressure to vulcanize and mold the low-edge cog belt. By limiting the shaping of the shape to only the compressed rubber layer, the rubber sheet forming the lower cushion rubber layer is wound in the molding step of the subsequent process, so that the thickness of the lower cushion rubber layer at the upper part of the cog valley is sufficiently ensured. Thus, a low-edge cog belt having excellent durability against peeling at the upper part of the cog valley of the compressed rubber layer can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an embodiment of a low-edge cog belt of the present invention.

FIG. 2 is a view showing a step of molding a reinforcing cloth into a cog shape.

FIG. 3 is a view showing a step of forming a cog shape on a rubber sheet and a reinforcing cloth forming a compressed rubber layer.

FIG. 4 is a view showing a cog pad with a reinforcing cloth obtained in the step shown in FIG. 3;

FIG. 5 is a perspective view showing a cog pad with a reinforcing cloth in which a cog crest is cut at two places and an end is formed at two places.

FIG. 6 is a view showing a step of winding a rubber sheet forming a lower cushion rubber layer on a rubber sheet forming a compressed rubber layer wound around a mold.

FIG. 7 is a view showing an example of a conventional low edge cog belt.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low edge cog belt 2 Upper cushion rubber layer 3 Lower cushion rubber layer 4 Core wire 5 Compressed rubber layer 6 Extension rubber layer 7 Cog crest 8 Cog trough 10 Reinforcement cloth

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B29K 105: 24 B29K 105: 24

Claims (2)

[Claims] 1. A core wire is buried between a lower cushion rubber layer and an upper cushion rubber layer, and a compression rubber layer is arranged below the lower cushion rubber layer, and an extension rubber layer is arranged above the upper cushion rubber layer. In a low-edge cog belt having a cog shape in which cog peaks and cog valleys are alternately arranged on at least the compression rubber layer, and a reinforcing cloth is attached to the surfaces of the compression rubber layer and the extension rubber layer, at least A low edge cog belt characterized in that the thickness of the cushion rubber layer is uniform over the entire circumference of the belt. 2. A core wire is buried between a lower cushion rubber layer and an upper cushion rubber layer, and a compression rubber layer is disposed below the lower cushion rubber layer, and an extension rubber layer is disposed above the upper cushion rubber layer. A method of manufacturing a low-edge cog belt having a cog shape in which cog peaks and cog valleys are alternately arranged in at least a compression rubber layer, and a reinforcing cloth is attached to surfaces of the compression rubber layer and the extension rubber layer. A step of molding a reinforcing cloth to be pasted on the surface of the compressed rubber layer in a cog shape in advance, and a step of laminating a rubber sheet forming a compressed rubber layer on the molded reinforcing cloth to form a cog shape, A step of fitting a reinforcing cloth molded into a cog shape and a rubber sheet forming a compressed rubber layer into a cylindrical mold having convex and concave ridges corresponding to the cog shape and winding the ends so that both ends thereof abut each other, Previous A rubber sheet forming the lower cushion rubber layer, a cord, a rubber sheet forming the upper cushion rubber layer, a rubber sheet forming the extension rubber layer, and a reinforcing cloth are sequentially wound on the rubber sheet forming the compressed rubber layer. And vulcanizing by heating and pressurizing, followed by vulcanization molding.