JPH10296872A - Manufacture of belt having teeth, sewing strength by sewing machine measuring jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an early cutting of a belt having teeth, from a joint part, and noises from generating by using a canvas cloth wherein a mechanical resistance value which is measured by inserting an insertion bar between a sewing thread of the stitches by a sewing machine and the canvas cloth, is specified. SOLUTION: A joint part 4 is sewn together by butting the ends of a canvas cloth 1 and using a sewing machine thread 6 comprising a filament twist yarn, or a monofilament thread of polyamide, polyester, polypropylene, or aramide, etc. The canvas cloth 1 is treated in advance with an RFL solution, an isocyanate solution or an epoxy solution. In this case, an insertion bar 10 such as a stainless steel, of which the sharp end becomes a needle state of an acute angle, is inserted by using a sewing strength by sewing machine measuring jig 9 fitted in a tension gauge 11 by welding, and a mechanical resistance value at the time of insertion is measured. For this belt with teeth, a cylindrical canvas cloth 1 having a sewing strength by sewing machine wherein the mechanical resistance value is in a range of 1-5 kg needs to be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a toothed belt and a jig for measuring the sewing strength of a sewing machine, and measures the sewing strength of a joint portion of a cylindrical canvas sewn with a sewing machine.
The present invention relates to a method for manufacturing a toothed belt which uses a cylindrical canvas having a predetermined range of strength to prevent early cracking and sound generation from the joint portion and a jig for measuring the sewing strength of a sewing machine.

[0002]

2. Description of the Related Art A conventional toothed belt is composed of a rubber compound using chloroprene as a raw material rubber on teeth and a back, and an RFL using SBR vinylpyridine latex as a latex component.
(Resorcinol / Formalin / Latex) A cover fabric used in the longitudinal direction of the belt using glass fiber cords or aramid fiber cords that have been adhesively treated with liquid as core wires, and crimped nylon as wefts.
Used as a belt for OHC driving (overhead cam driving) for automobiles.

[0003] The above-mentioned cover canvas generally has a joint portion, and a hot melt joint in which the ends of the canvas are heated and melted and joined together, or a method of joining with a sewing machine in order to increase the strength of the joint portion is adopted. ing. However, in the case of the toothed belt for driving the OHC, since the environmental temperature to be used becomes high due to the compact engine room and the use of FF, and the hot melt joint cannot withstand the strength sufficiently, the sewing machine joint is mainly used. Has become.

Further, when the sewing machine joint portion is located at a tooth valley portion or a corner portion of a tooth bottom, the sewing thread of the joint portion is greatly stretched and finally cut to open the canvas.
Cracks may occur. For this reason, the present applicant has improved this in Japanese Patent Publication No. Hei 3-18821.

[0005]

However, in the case of a sewing machine joint, the strength of the sewing machine changes in the feed amount depending on the rigidity of the canvas and the state of the canvas surface when sewing. When these conditions change, the strength of the sewing machine may fluctuate even under the same sewing conditions. Then, there is a problem that the toothed belt becomes defective irrespective of whether the sewing is strong or weak. For example, a cylindrical canvas with a strong seam will have a form in which the joints protrude,
When this is used for manufacturing a toothed belt, the protruding portion of the joint portion is embedded in the tooth portion, and an early crack is generated from this portion, causing early cracking failure during belt running. On the other hand, when the sewing is weak, the sewing thread is locally stretched, and unvulcanized rubber during the production of the toothed belt overflows from this portion, so-called puncture failure occurs.
It was the cause of pronunciation.

The present invention is intended to solve such a problem. The sewing strength of a joint portion of a cylindrical canvas sewn with a sewing machine is set in advance to a predetermined range so that the joint strength of the joint portion can be reduced. An object of the present invention is to provide a method for manufacturing a toothed belt which prevents early cutting and sound generation, and a jig for measuring the sewing strength of a sewing machine.

[0007]

That is, according to the first aspect of the present invention, after a cylindrical canvas sewn into a sewing machine is inserted into the peripheral surface of the toothed mold, a cord made of cord is spun, and By laminating a rubber layer and vulcanizing,
In the method of manufacturing a toothed belt in which the surface of a tooth portion is covered with the cylindrical canvas, the edges of the canvas are butt-stitched and sewn to produce a cylindrical canvas. And a method of manufacturing a toothed belt using a canvas having a mechanical resistance value of 1 to 5 kg measured by inserting an insertion rod therebetween. That is, in this manufacturing method, by measuring the sewing strength of the joint portion quantitatively with a mechanical resistance value, by using a cylindrical canvas falling within an appropriate resistance value range,
A method for manufacturing a toothed belt in which early cutting from a joint portion is prevented can be provided.

According to the invention of claim 2 of the present application, in a sewing stitch strength measuring jig for measuring a mechanical resistance value by inserting an insertion rod between a thread of a sewing seam and a canvas, the tip is in a needle state. In the sewing stitch strength measuring jig with the inserted insertion rod attached to the tension gauge, the insertion rod can be smoothly inserted between the sewing seam thread and the canvas,
The mechanical resistance can be measured accurately.

[0009]

FIG. 1 is a perspective view of a cylindrical canvas used in a method for manufacturing a toothed belt according to the present invention. The cylindrical canvas 1 is made of plain woven fabric, twill woven fabric, satin woven fabric, etc., and the weft 2 in the belt longitudinal direction is polyamide fiber such as aramid fiber, 6 nylon, 6.6 nylon, 12 nylon, polyester fiber, polyvinyl alcohol fiber. Although it is not particularly limited, a yarn containing a multifilament yarn of para-aramid fiber is preferable. The multi-filament yarn of para-aramid fiber may include a yarn made of meta-aramid fiber. The specific configuration of the weft 2 is a twist of three types of yarns: a multi-filament yarn of para-aramid fiber, a spun yarn of meta-aramid fiber, and a urethane elastic yarn. The other two weft yarns are formed by twisting three kinds of yarns: multifilament yarn of para-aramid fiber, aliphatic fiber yarn (6 nylon, 66 nylon, polyester, polyvinyl alcohol, etc.), and urethane elastic yarn. It may be.

The warp 3 of the canvas 1 includes filament yarn of aramid fiber composed of para-aramid fiber and meta-aramid fiber, nylon 6, nylon 6.6, nylon 12
It is made of filament yarn such as polyamide such as nylon, polyvinyl alcohol and polyester. Preferably, if a multifilament yarn in which the filament yarn of the aramid fiber is formed by converging the filament yarn of the para-aramid fiber to the weft 2 is used, the rigidity can be balanced and the cover canvas having a uniform thickness can be obtained.

The multifilament yarn of the para-aramid fiber is a multifilament yarn obtained by gathering a plurality of condensed filament yarns of 0.3 to 1.2 denier, or 0.3 to 1.2 denier. Is a multifilament yarn obtained by converging a plurality of filament raw yarns, for example, Kevlar, Technora, and Twaron. If the thickness of the filament yarn is less than 0.3 denier, the tensile strength of the cover canvas in the longitudinal direction of the belt decreases, and the abrasion resistance due to contact with the pulley decreases. On the other hand, if the thickness of the filament raw yarn exceeds 1.2 denier, the rigidity of the yarn in the direction in which the multi-filament yarn of para-aramid fiber is driven in the process of bonding the cover as a canvas after weaving. Since the warp and the weft as the canvas cannot be balanced, wrinkles are generated due to the uneven thickness of the cloth, and it cannot be used for a toothed belt which requires a uniform PLD value.

The total amount of weft in the longitudinal direction of the belt is 20 to
A multifilament yarn containing 80% by weight of para-aramid fiber is preferred. The reason for this is that if it is less than 20% by weight, the tensile strength of the cover canvas in the longitudinal direction of the belt will be reduced, and it will be easy for teeth to break when the belt runs under a high load. This is because the rigidity of the fiber in the driving direction of the multifilament yarn becomes excessively large, as in the above-described reason, so that a canvas having a uniform thickness cannot be obtained.

The joint portion 4 is sewn with the ends of the canvas 1 butt through a sewing thread 6 made of a twisted filament such as polyamide such as 6 nylon, 6.6 nylon, 12 nylon, polyester, polypropylene, aramid or the like, or a monofilament thread. .

The canvas 1 is previously treated with an RFL solution, an isocyanate solution or an epoxy solution. R
The FL solution is obtained by mixing a latex with an initial condensate of resorcinol and formalin. The latex used here is styrene. butadiene. Latex such as vinylpyridine terpolymer, hydrogenated nitrile rubber, chlorosulfonated polyethylene, epichlorohydrin.

FIG. 2 is a view showing a state in which the sewing strength of the obtained cylindrical canvas 1 is measured, and FIG. 3 is a plan view of a sewing strength measuring jig used for this measurement. It is. According to this, the length is 200 to 500 mm and the diameter is 1 to 3 m like a stainless steel having a sharp needle at the tip.
The mechanical resistance value at the time of insertion can be measured using a sewing machine sewing strength measuring jig 9 in which the m insertion bar 10 is attached to the tension gauge 11 by welding. In this method, first, the insertion rod 9 is inserted between the sewing thread 6 on the inside of the canvas and the main body of the cylindrical canvas 1 by about 100 to 400 mm, so that the maximum value of the mechanical resistance value, which is the pushing pressure, is measured by the tension gauge 11. Can be measured quantitatively. When the strength of the sewing machine is small, the mechanical resistance value is small, and when the strength of the sewing machine is large, the mechanical resistance value is large.

In the case of the present invention, the mechanical resistance value is 1 to 5 k.
It is necessary to use a cylindrical canvas 1 having a sewing strength in the range of g. When the resistance value is less than 1 kg, the sewing thread 6 is locally stretched as shown in FIG.
During the manufacture of the toothed belt, unvulcanized rubber overflows from the joint 4, causing so-called puncture failure. On the other hand, if the resistance value exceeds 5 kg, the joint 4 protrudes and forms a toothed belt. When used in the manufacture of a belt, as shown in FIG. 7, the protruding portion of the joint portion 4 is buried in the tooth portion 14, and an early crack is generated from this portion, resulting in cracking during running of the belt.

FIG. 4 is a cross-sectional view of the toothed mold showing the formation of the toothed belt. The toothed mold 12 has grooves 13 arranged at regular intervals along the circumferential direction.
The above-mentioned cylindrical canvas 1 is inserted into the surface of
After the glass fiber cord or the aramid fiber cord forming 7 is spirally wound, and the raw rubber sheet 16 forming the tooth portion 14 and the back portion 15 is laminated, the jacket is put on this and vulcanized in a vulcanizing can. During vulcanization, the flow of the raw rubber causes the groove-like portion 13 to be formed together with the cylindrical canvas 1.
Pour into As the raw material rubber sheet, a rubber having improved heat aging resistance, such as hydrogenated nitrile rubber, chlorosulfonated polyethylene (CSM), alkylated chlorosulfonated polyethylene (ACSM), and chloroprene rubber is preferable. The hydrogenated nitrile rubber has a hydrogenation rate of 80% or more, and preferably 90% or more in order to exhibit heat resistance and ozone resistance. A hydrogenated nitrile rubber having a hydrogenation rate of less than 80% has extremely low heat resistance and ozone resistance.

FIG. 5 is a side view of the toothed belt according to the present invention. The toothed belt 20 has a plurality of teeth 14 and a core wire 17 made of glass fiber cord or aramid fiber cord along the belt longitudinal direction. Consisting of a buried back 15
The cylindrical canvas 1 is stuck on the surface of the tooth section 14, the joint section 4 of the canvas 1 does not largely enter the tooth section 14, and the sewing thread 6 is not stretched.

[0019]

The present invention will be described below in detail with reference to examples. Examples 1-3, Comparative Examples 1-2 A 200-denier filament yarn obtained by converging a 1.5-denier para-aramid fiber filament yarn into a warp of a canvas, and a weft (Technola 200 ^D / 2 yarns and Conex Using 30 count and spandex 140 ^D / 1) and weft (Technola 200 ^D / 1)
Weaving texture (110 warp / 5cm, weft 120 / 5cm)
Was woven. After weaving, the canvas is vibrated in water to shrink it to about 1/2 the width at the time of weaving, and then the hydrogenated nitrile rubber compound is dissolved in methyl ethyl ketone and immersed in a processing solution to which isocyanate has been added. It was dried to give a 0.9 mm treated canvas. The canvas used the weft direction in the longitudinal direction of the belt.

After cutting the above treated canvas to a predetermined length,
The ends of the canvas were butted, a 6-nylon monofilament thread was used as a sewing thread, and the feed rate of the canvas was adjusted to produce several types of cylindrical canvas. Then, a 30 mm insertion rod of a sewing strength measuring jig was inserted between the sewing thread and the canvas of each cylindrical canvas, and a mechanical resistance value was measured with a tension gauge. Table 1 shows the results.

As a core wire, about 200 glass fiber filaments having a strand diameter of about 9 μm, which are melt-spun and surface-treated with a silane coupling agent, are bundled into strands, and the three strands are aligned to prepare an RFL solution. Dipped, 130
After drying at 250C for 2 minutes and baking at 250 to 300C for 2 minutes, a ply-twisted yarn twisted in the S-direction at about 12 times / 10 cm and a ply-twisted yarn twisted in the Z-direction the same number of times were prepared.

Next, thirteen primary twisted yarns in the S direction are aligned.
Glass fiber cord twisted in the Z direction at a rate of about 8 turns / 10 cm, and 13 twisted lower twisted yarns are similarly arranged in the same direction, and glass fibers having a twist number of 8 turns / 10 cm in the S direction. For each RFL liquid, a pair of RFL-treated glass fiber cords each having a twisting direction of S and Z were used. Then, in order to bond each RFL-treated glass fiber cord to the back, the teeth, and the tooth cloth, the rubber composition is further dissolved in a solvent, immersed in an overcoat solution containing isocyanate, and dried to form a core wire. A fiber cord was produced.

In the production of the toothed belt, the cylindrical canvas was wound around a toothed mold, the glass fiber cord was spun thereon, and then a rubber sheet made of a hydrogenated nitrile rubber compound was wound. Subsequently, this was vulcanized, and the obtained vulcanized sleeve was cut into a predetermined width to obtain individual belts. The size of the belt is 105S8M19
(Belt tooth type: STPD type, number of teeth: 105, belt width: 19.1 mm, tooth pitch: 8 mm). Table 1 also shows the results of observing the appearance of the joint portion of the canvas of the obtained toothed belt.

In addition, the running time of each toothed belt leading to chipping during high-load running was measured. The running tester used here is a drive pulley (21 teeth), a driven pulley (2 teeth)
1) and three axes of idler pulleys (21 teeth), a toothed belt was wound around these pulleys, and the number of meshing teeth with the driven pulley was set to 6 teeth. In this manner, the running time until the toothed belt was chipped at an ambient temperature of 120 ° C., a rotation speed of the driving pulley of 6,000 rpm, and a load of the driven pulley of 7 hp was measured. The results are also shown in Table 1.

[0025]

[Table 1]

As a result, in the embodiment in which the cylindrical canvas having the sewing strength of the joint portion of the cylindrical canvas falling within the range of 1 to 5 kg is used for the production of the toothed belt, the joint portion of the canvas is also observed in the appearance inspection. It did not penetrate greatly into the teeth, and the sewing thread was stretched and no bleeding of rubber was observed. Further, even when the toothed belt of the embodiment is run under a high load,
No cracks were seen from the joints, indicating that the running time leading to tooth chipping was also improved.

[0027]

As described above, according to the first aspect of the present invention, in a method for manufacturing a toothed belt, a cylindrical canvas is produced by butt-stitching the ends of a canvas and sewing the same. A method of manufacturing a toothed belt using a cylindrical canvas having a mechanical resistance value of 1 to 5 kg measured by inserting an insertion rod between the seam thread and the canvas, The use of a cylindrical canvas within the appropriate range of resistance by quantitatively measuring the sewing strength of the seam with a mechanical resistance value prevents teeth from being prematurely cut from the joint. The method of manufacturing the attached belt can be effective.

According to the invention of claim 2 of the present application, there is provided a sewing strength measuring jig in which an insertion rod having a needle-like tip is attached to a tension gauge, and the insertion rod is provided between a thread of a sewing seam and a canvas. This has the effect that the mechanical resistance can be accurately measured.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cylindrical canvas used in a method for manufacturing a toothed belt according to the present invention.

FIG. 2 is a diagram showing a state in which the strength of sewing on a cylindrical canvas is measured.

FIG. 3 is a plan view of a jig for measuring sewing strength according to the present invention;

FIG. 4 is a cross-sectional view of the toothed mold showing the formation of the toothed belt.

FIG. 5 is a side view of the toothed belt according to the present invention.

FIG. 6 is a side view of a conventional toothed belt showing a state where a puncture failure has occurred.

FIG. 7 is a side view of the conventional toothed belt, showing a state in which a protruding portion of a joint portion is embedded in the tooth portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Canvas 4 Joint part 6 Sewing thread 9 Sewing machine sewing strength measuring jig 10 Insert rod 11 Tension gauge 14 Tooth part 15 Back part 17 Core wire

Claims (2)

[Claims] 1. After inserting a sewing-stitched cylindrical canvas into the peripheral surface of a toothed mold, spinning a cord made of cord, laminating a rubber layer on the cord, and vulcanizing the cord.
In the method of manufacturing a toothed belt in which the surface of a tooth portion is covered with the cylindrical canvas, the edges of the canvas are butt-stitched and sewn to produce a cylindrical canvas. A mechanical resistance value is measured by inserting an insertion rod between the belt and a canvas having a value of 1 to 5 kg. 2. A sewing machine for measuring a mechanical resistance value by inserting an insertion rod between a sewing thread and a canvas of a sewing seam. A sewing jig measuring jig characterized by being attached to a sewing machine.