JPH10295967A - Joint method of canvas for belt and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve dimensional accuracy after being sewn up, and stabilize tensile force of a sewing thread by sewing up mutual end surfaces of canvas arranged on a work stand by a sewing machine, and controlling so as to move the work stand at a constant speed at that time when the canvas for a belt is joined in an endless shape. SOLUTION: After canvas 3 for a belt is placed on a work stand 2 in a condition where its end surfaces are butted against or superposed on each other, a switch 9 of a sewing machine is turned on, and when a foot switch 10 to move the work stand 2 is stepped, a motor 5 is rotated, and the work stand 2 can move at a constant speed through a belt 7. In this movement, a joining part of the canvas 3 is sewn at a predetermined constant sewing pitch by the sewing machine 4. In this case, the motor 5 is formed of a motor to which an inverter is connected, and when a sewing speed of the sewing machine changes since a thickness or the like of the canvas changes, a frequency of the motor 5 is changed by the inverter, and dispersion of a sewing pitch is corrected by changing a moving speed of the work stand 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for joining a canvas for a belt.
It is applied to urethane or rubber belts for various power transmission such as toothed belts, V-ribbed belts, etc., in order to endless the canvas attached to the belt around the entire circumference for the purpose of reinforcing the belt. The joint method.

[0002]

2. Description of the Related Art Conventionally, for example, a toothed belt is endless by connecting both ends of a strip-shaped canvas, and then placed on a molding die having a tooth-shaped concave shape on an outer peripheral surface, and a core wire is spirally wound thereon. , An unvulcanized rubber sheet is wound, vulcanized, and then sliced to obtain individual belts. In the vulcanization step, the canvas is embossed into a concave shape of a molding die to form a tooth mold, and adheres to the surface of the tooth portion. The toothed belt is protected from breakage of the tooth portion due to meshing with the toothed pulley, and its durability is improved by a canvas (tooth cloth) formed on the tooth mold and adhered to the surface of the tooth portion.

In the step of joining both ends of the canvas, as shown in FIG. 2, both ends A and B of the canvas are vertically overlapped so that the back surfaces a and b face downward. Then, sew it like a normal sewing machine (sew it straight while entanglement the front thread 20 and the back thread 21). Furthermore, the canvas was moved by hand while sewing with a sewing machine. For this reason, variation occurs in the thread sewing pitch,
Furthermore, when the tension of the yarn fluctuates and the tension is small, the joint opens and the softened rubber flows out. Conversely, if the thread tension is too high, the joints will fold,
It enters the teeth and causes chipping.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and has high dimensional accuracy after suturing.
Provided is a method and an apparatus for joining a canvas for a belt, in which a sewing thread tension is stable and an end face can be surely brought into a contact state, and a high-quality belt can be manufactured.

[0005]

That is, a feature of the present invention that conforms to the above invention is that in a method of joining a belt canvas to endless, the end faces of a canvas installed on a work table are stitched together by a sewing machine. In this case, there is a belt canvas joint method for controlling the work table to move at a constant speed. According to the invention as set forth in claim 1, by controlling the work table on which the canvas is placed to be moved at a constant speed when sewing the canvas, the sewing pitch of the thread does not vary. As a result, the bleeding of the rubber from the canvas at a wide pitch is eliminated.

According to a second aspect of the present invention, in addition to the first aspect, as a method of controlling the speed of the worktable, a method of jointing a belt canvas for controlling the speed by connecting an inverter is provided. is there. According to the second aspect of the present invention, as a method of controlling the moving speed of the work table on which the canvas is placed, by using a motor connected with an inverter, the speed control is reliably performed, and the sewing speed of the sewing machine is set to any speed. However, a desired speed for keeping the sewing pitch constant can be obtained.

In a third aspect of the present invention, in addition to the second aspect of the present invention, the method of sewing a canvas is a method of joining a canvas for a belt, which is a method of performing staggered sewing using a sewing machine. According to the third aspect of the present invention, the conventional sewing machine can be used, and the canvas can be sewn against each other, so that when the canvas becomes endless, the joint portion is opened and the rubber is softened. Does not flow out, and the joints do not fold and enter the teeth to cause chipping.

According to a fourth aspect of the present invention, there is provided an apparatus for joining a belt canvas in an endless manner, wherein the moving means for feeding the canvas, the suturing means for sewing the canvas, and the moving speed of the work table are controlled. And a control means for controlling the belt joint device. According to the fourth aspect of the present invention, by providing the moving means for feeding the canvas and the control means for controlling the moving speed of the worktable, the sewing pitch at which the canvas is sewn becomes constant, and the canvas is further sewn. The tension of the thread also becomes constant, so that the joint portion does not open and the softened rubber flows out, and the joint portion does not fold and enter the tooth portion, thereby preventing tooth breakage.

According to a fifth aspect of the present invention, in addition to the fourth aspect, a sewing machine is used as the suturing means.
A motor and a pulley attached to the motor and a toothed belt meshing with the motor are used as the moving means, and the control means is a belt canvas joint device in which an inverter is connected to the motor. According to the fifth aspect of the present invention, by using the pulley attached to the motor and the toothed belt meshing with the pulley as the moving means, the positioning when the canvas is transported can be reliably performed.
Further, by connecting the inverter to the motor as the control means, speed control is reliably performed, and a desired speed for keeping the sewing pitch constant regardless of the sewing speed of the sewing machine is obtained.

According to a sixth aspect of the present invention, in addition to the fifth aspect of the invention, there is provided a belt canvas joint device using a staggered sewing machine as the sewing machine. According to the method described in claim 6, a conventional sewing machine can be used, and the canvas can be sewn by butt, so that when the endless canvas is obtained, the joint portion is opened and the rubber is softened. Does not flow out, or the joint portion breaks and overlaps, enters the tooth portion, and causes chipping.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a belt canvas joint device of the present invention. First, a belt canvas 3 is placed on a work table 2 in a state where end faces of the belt canvas 3 are abutted or overlapped. Then, the user turns on the switch 9 of the sewing machine and depresses the foot switch 10 for moving the work table. Then, the canvas can be sewn at a predetermined constant sewing pitch by moving the worktable at a constant speed. Here, the motor 5 is a motor to which an inverter is connected, and the frequency of the motor is controlled by the inverter, so that the motor can correspond to any number of rotations. By doing so, if the thickness of the canvas changes, and the sewing speed of the sewing machine changes, simply changing the frequency of the motor with the inverter can change the rotation speed of the motor and change the moving speed of the worktable. The moving speed of the workbench can be set in accordance with the sewing speed of the sewing machine, and variations in the sewing pitch can be eliminated.

Here, as a method of joining the canvas, as shown in FIG. 2, both ends A and B of the canvas are vertically overlapped so that the back surfaces a and b are directed downward, so as to form a tubular shape. In this case, it is also possible to use a lock sewing machine, which is a sewing method in which the front thread 20 and the back thread 21 are sewn in a straight line while entangled with each other. FIG. 3 shows a state after the overlap sewing with the lock sewing machine. In addition, as shown in FIG. 4, the stitches can be sewn by moving the needle alternately between the end A and the end B with the end faces a ′ and b ′ of the canvas abutted by the staggered sewing machine as shown in FIG. good.

More preferably, stitching by the above-mentioned staggered sewing method can obtain a tubular canvas having a stable dimension and thread tension at all times. When the canvas is covered on the forming drum by a forming lot, The effect of obtaining a stable and defect-free product without looseness and tightness, and without the risk of entry of the canvas into the teeth and the risk of rubber leaking to the tooth surface due to the joint opening is greater.

[0014]

In the following, examples are given. As a canvas for a belt to be jointed, nylon 6,6 is used as a warp in the width direction, and wooly 6 nylon is used as a weft in the longitudinal direction (circumferential direction of the belt). Was 0.9 mm. Further, the sewing thread used for suturing is made of nylon and has a thickness of 0.1 mm.
2 mm. Then, the canvas was placed on a workbench, and a JEM-1 AC motor manufactured by Shinko Electric was used as a sewing machine motor. This motor is rated at 0.7
It was a 5 kW, 4-pole motor. Then, using this motor, the frequency of the sewing machine motor is adjusted using an inverter, the motor is rotated at a frequency of 55 Hz with the sewing machine motor as a substitute characteristic of the sewing speed of the sewing machine, and the oriental machine is moved to move the work table. A 51K90GU-SF, an AC motor manufactured by Oriental Corporation, and a 5GU25KB manufactured by Oriental Corporation were also used as a speed reducer. And
The inverter was mounted on the motor, the frequency was adjusted, the moving speed was adjusted, and the canvas was sewn while moving the work table at the work table moving speed shown in Table 1. Then, all the sewing pitches of the sewing thread of the canvas in the endless shape were measured in the width direction. Table 1 shows the results. From this result, if the same type of canvas is used, the sewing pitch will be constant unless the moving speed of the worktable changes. Further, as shown in FIG. 5, it can be seen that there is a proportional relationship between the worktable and the sewing pitch.

Next, as a comparative example, the same canvas as in the example was used, and the same sewing thread was used to sew the canvas. Here, the same motor as that used in the embodiment is used for the sewing machine motor.
The frequency of Z was set, and the movement of the canvas was manually performed by a person.
Then, after the sewing was completed, the sewing pitch of the yarn was measured over the entire number in the width direction of the canvas. Table 1 shows the results.

[0016]

[Table 1]

According to this result, the sewing pitch does not vary at all according to the embodiment, whereas the comparative example includes the maximum variation range when the moving speed of the worktable is changed in the embodiment. . From this, it can be seen that when the canvas is transported by hand, the transport speed varies considerably.

[0018]

As described above, according to the first aspect of the present invention, when sewing a canvas, the work table on which the canvas is placed is controlled to move at a constant speed, so that the sewing pitch of the thread can be reduced. No variation occurs, which prevents the rubber from seeping out from the canvas at a wide pitch.

According to a second aspect of the present invention, in addition to the effect of the first aspect, the speed is controlled by using an AC motor connected with an inverter as a method of controlling the moving speed of the work table on which the canvas is placed. Control is assured, and a desired speed for keeping the sewing pitch constant is obtained regardless of the sewing speed of the sewing machine.

According to the third aspect of the present invention, in addition to the effect of the second aspect, a conventional sewing machine can be used, and the canvas can be sewn by butt, so that an endless canvas is obtained. Occasionally, the joint portion does not open and the softened rubber flows out, and the joint portion breaks and overlaps, and does not enter the tooth portion and cause chipping.

According to a fourth aspect of the present invention, by providing a moving means for feeding the canvas and a control means for controlling a moving speed of the work table, a sewing pitch for sewing the canvas is fixed, and the canvas is further sewn. The tension of the sewing thread is also constant, so that the joint portion does not open the mouth and the softened rubber flows out, and the joint portion does not bend and overlap, entering the tooth portion, and causing the lack of teeth.

According to a fifth aspect of the present invention, in addition to the effect of the fourth aspect of the present invention, the positioning when transporting the canvas is achieved by using a pulley attached to the motor and a toothed belt meshing with the pulley as the moving means. Can be performed reliably. Furthermore, by connecting an inverter to the motor as control means, speed control is reliably performed,
Regardless of the sewing speed of the sewing machine, a desired speed for keeping the sewing pitch constant can be obtained.

According to the invention of claim 6, in addition to the effect of the invention of claim 5, a conventional sewing machine can be used, and the canvas can be butt-stitched and sewn. When the joint part is opened, the softened rubber does not flow out, and the joint part does not bend and overlap and enter the tooth part, causing no tooth loss.

[Brief description of the drawings]

FIG. 1 is a schematic view of a joint device for a belt canvas of the present invention.

FIG. 2 is a diagram illustrating a method of overlap sewing by a lock sewing machine.

FIG. 3 is a front and back view of a seam obtained by layer-stitching with a lock sewing machine.

FIG. 4 is a front and back view of a seam sewn with a staggered sewing machine.

FIG. 5 is a graph showing the relationship between the frequency of the worktable moving motor and the thread sewing pitch using the belt canvas joint method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 joint device for canvas for belt 2 work table 3 canvas 4 sewing machine 5 motor 6 pulley 7 toothed belt 8 sewing machine stand 9 switch for sewing machine 10 foot switch 11 limit switch 12 sewing machine thread 13 sewing machine needle and cutter 14 bobbin 15 control panel 20 table Yarn 21 Back yarn 22 Joint 25, 27 Front yarn 25, 28 Back yarn

Continuation of the front page (72) Inventor Teruyuki Yano 4-1-1-21 Hamazoedori, Nagata-ku, Kobe Mitsusei Belt Co., Ltd. (72) Inventor Yoshiki Matsuura 4-1-1, Hamazoedori, Nagata-ku, Kobe Mitsuhoshi Belt Co., Ltd.

Claims (6)

[Claims] In a method of joining a belt canvas to make it endless, control is performed such that when the end faces of a canvas placed on a work table are sewn by a sewing machine, the work table is moved at a constant speed. A joint method for a canvas for a belt, comprising: 2. The method according to claim 1, wherein the speed of the worktable is controlled by a motor connected to an inverter. 3. The method according to claim 2, wherein the sewing of the canvas is a zigzag stitch using a sewing machine. 4. An apparatus for joining a belt canvas to make it endless, comprising: moving means for feeding the canvas; suturing means for sewing the canvas; and control means for controlling a moving speed of the work table. A belt joint device for a belt, comprising: 5. The sewing machine according to claim 4, wherein a sewing machine is used as the suturing means, a motor, a pulley attached to the motor and a toothed belt meshing with the motor are used as the moving means, and an inverter is connected to the motor as the control means. Equipment for jointing canvas for belts. 6. The belt joint apparatus according to claim 5, wherein a staggered sewing machine is used as the sewing machine.