JP2001336581A - Transmission belt cloth, abutting joint method thereof and abutting joint device and transmission belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably retain an abutting state of a sewing part of joint parts 8, 9 in the case where end portions of a rubber coated cloth 12 with an non- vulcanized rubber are abutted and sewed by an overredging industrial sewing machine to joint them and a cylindrical sewing cloth 7 becoming a back surface cloth 5 of a V ribbed belt 13 is formed. SOLUTION: After end portions of a rubber drawing cloth 12 are abutted and sewed, the sewing part is opened to the abutted state and is pressurized while it is heated to a temperature less than vulcanization temperature of the rubber. The abutted parts are joined in the state that the rubber is fused to a sewing thread 10 and the abutted state of the sewing parts is retained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a cloth used for a power transmission belt, a butt joint method and a butt joint device for the cloth for the belt, and a power transmission belt.

[0002]

2. Description of the Related Art Conventionally, for example, V
When joining the ends of the rubberized cloth used for the back cloth of the ribbed belt, the ends of the cloth should be overlapped with each other in order to eliminate the steps at the joints of the cloth and improve the quality and quality of the belt. It is known that after butt-stitching with a lock sewing machine, the stitched portion is opened in a butt-stitch state to eliminate a step at a joint portion (for example, see Japanese Patent Application Laid-Open No. 10-295967).

[0003]

However, in the above-described conventional joint method, there is not much problem when the kind of the raw material polymer used for the belt body is, for example, chloroprene rubber.
If it is changed to a polymer with relatively low tackiness such as DM, it is difficult to maintain the butt state only by butt stitching with the overlock sewing machine, and the sewn portion of the cloth often overlaps during the subsequent belt forming. Inevitable.

That is, when chloroprene rubber is used as a raw material of the belt and as a polymer applied to the cloth, the chloroprene rubber has an adhesive property. Occurs, and even if the cut surfaces are abutted,
The cut surfaces have an action of maintaining the butted state together with the sewing thread due to their adhesiveness.

However, the rubber of the cloth is made of hydrogenated NBR or E.
In the case of PDM or the like, since the adhesiveness is low, the adhesiveness of the cut surface obtained by cutting the cloth with a scalpel of an overlock sewing machine is reduced as described above. They cannot be kept in abutting condition.

[0006] Specifically, in the case of producing a cylindrical cylindrical suture cloth serving as a back cloth for a V-ribbed belt, first, an ordinary plain woven cloth is subjected to an adhesive treatment or a rubber coating treatment, and then the plain woven cloth is subjected to a 45-pitch cloth. ° to make a bias cloth (Fig. 2
(A)). Then, the non-cut ends of the plurality of bias cloths are sequentially butt-stitched with an overlock sewing machine, and then the stitched portions are opened to produce a long bias cloth (see FIGS. 2B and 2C). .

At this time, as shown in FIGS. 6 and 7, a plurality of bias cloths 13, 1 in a long bias cloth 14 are used.
If the tension of the sewing thread 10 at the joint portion of 3,.
When the sewing thread 10 at the joint portion is loosened, the seam of the joint portion is opened or the non-cut end portion 13b of the joint portion as shown in FIG. , 13b are displaced in the direction of 45 ° along them (this displacement has a form that is simply displaced or overlapped). Conversely, if the tension of the sewing thread 10 is too tight and too strong, a phenomenon occurs in which the non-cut ends 13b overlap each other, as shown in FIG.

Then, as shown in FIG. 10A, the long bias cloth 14 sewn at 45 ° as described above.
Is cut into a fixed length at a right angle cut line C2 perpendicular to the length direction to form a fixed size cloth 15, and then the cut ends 15a, 15a of the fixed size cloth 15 are stitched together. Then, a cylindrical suture cloth 7 having a cylindrical shape is formed (see FIG. 3).

At this time, even if the sewing is normally performed with the thread at the 45 ° stitch portion, which is the joint portion between the bias cloths 13, 13, as shown in FIG. Non-cut end 1 of the seam
3b, 13b are shifted in the direction of 45 ° and cut at right angle C
The phenomenon that 2 shifts on the way appears. Therefore, when the cut ends 15a, 15a of the fixed-size cloth 15 are sewn at right angles to form the cylindrical sewn cloth 7 with the right-angle cut line C2 being displaced, a 45 ° line sewn portion (biased cloth) is formed. 13
In the intersection of the non-cut ends 13b, 13b between the non-cut ends 13b, 13b) and the cut ends 15a, 15a at right angles, the sewn portions partially overlap as shown in FIG. As shown in FIG.

In view of the above, there are no steps or holes due to the wrapping of the back cloth in the production of the belt, so that the restriction that must originally be in a butt state cannot be observed, and there is a problem that the intended purpose cannot be achieved. I do.

Therefore, the abutting state is maintained even after the 45 ° stitching between the non-cut ends 13b, 13b of the bias cloth 13 is completed, and even when the long bias cloth 14 is cut at a right angle, the deviation of the 45 ° stitched portion is maintained. It is essential to prevent the occurrence and maintain the butted state of the sewn portions even after the end of the cylindrical sewing of the fixed-size cloth 15.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the invention is to butt and sew the ends of unvulcanized rubber cloth serving as a belt cloth with an overlock sewing machine as described above. An object of the present invention is to make it possible to stably maintain the butted state of the sewn portions between the ends of the cloth by improving the joint method when joining.

[0013]

In order to achieve the above object, according to the present invention, the sewn portion of the cloth with chloroprene rubber is kept in a butt state by the adhesiveness of rubber, and hydrogenated NBR or EPDM rubber is used. Even in this case, attention was paid to the point that similar adhesiveness easily appeared by heating to a predetermined temperature, and the sewn portion of the cloth was pressed in a heated state and held in a butt state.

More specifically, according to the first aspect of the present invention, as the power transmission belt cloth, the ends of the unvulcanized rubber cloth are sewn together by an overlock sewing machine, and the butt portion is made of rubber. Is characterized in that the rubber is fused to the sewing thread by heating and pressing to a temperature lower than the vulcanization temperature. In the invention of claim 2,
The rubber is hydrogenated NBR or EPDM. Furthermore, the invention of claim 3 is an invention of a power transmission belt, and a power transmission belt of the invention is provided with the power transmission belt cloth of the above-mentioned claim 1 or 2.

According to the constitutions of the present invention, in the unvulcanized rubber cloth, the butt portion butt-stitched by the overlock sewing machine is heated and pressurized to a temperature lower than the vulcanization temperature of the rubber, and the butt portion is sewn. Since the rubber is joined to the sewing thread in a fused state, the fusion of the rubber to the sewing thread causes adhesiveness at the butt portion, and the adhesive state stably holds the butt portion at the butt portion. You.

According to a fourth aspect of the present invention, there is provided a method of butt-joining a cloth for a power transmission belt. In this invention, the ends of the cloth with unvulcanized rubber are butt-stitched together with an overlock sewing machine, and then the stitching is performed. The parts are opened in a butt state and pressurized while being heated to a temperature lower than the vulcanization temperature of the rubber, so that the butt parts are joined in a state where the rubber is fused to the sewing thread and the butt state of the sewn parts is maintained. It is characterized by the following. In the invention of claim 5, the rubber is hydrogenated NBR or EPDM. According to these inventions, the same functions and effects as those of the first to third inventions can be obtained.

According to a sixth aspect of the present invention, a sewn portion of an unvulcanized rubber cloth sewn in a butt state by an overlock sewing machine is opened in a butt state and heated while being heated to a temperature lower than the vulcanization temperature of the rubber. The invention relates to a butt joint device for a transmission belt cloth in which the butt portion is joined to the sewing thread in a state where the butt portion is fused to the sewing thread so as to maintain the butt state of the sewn portion. A receiving portion for receiving a sewn portion of a cloth with rubber in a butted state, a support member movably disposed along the sewn portion of the cloth on the receiving portion with respect to the receiving portion; A pressure roll that is provided so as to be capable of coming in contact with and separated from the receiving portion, and that presses the stitched portion of the cloth between the receiving portion and the pressing portion by an operation of approaching the receiving portion, and heats at least one of the receiving portion or the pressing roll. Heating means and the support A driving means for moving the pressure-sensitive roll relatively to the receiving part, pressurizing the sewn portion of the cloth between the two, and heating the sewn part of the cloth by the heating means. The pressure roll is relatively moved with respect to the receiving portion, so that the butted state of the sewn portion of the cloth is maintained. In the invention of claim 7, the rubber is hydrogenated NBR or EPDM.

According to these inventions, the stitched portion of the cloth with unvulcanized rubber is arranged on the receiving portion in abutting state, and in this state, the pressure roll approaches the receiving portion, and the pressure roll and The sewn portion of the cloth is sandwiched between the receiving portion and the receiving portion, and pressure is applied. In this state, the sewn portion of the cloth is heated by the heating means, and the pressing roll is relatively moved with respect to the receiving portion by the driving of the driving means. Pressed. Therefore, the present invention can provide the same functions and effects as those of the first to third aspects.

In the invention according to claim 8, the heating means is a heater built in a pressure roll. This makes it easier to obtain the desired heating means.

According to the ninth aspect of the present invention, a cylinder having an axial center in a direction of coming into contact with and separating from the receiving portion is mounted and fixed to the support, and a pressure roll is rotatably supported on a piston rod of the cylinder. Structure. With this configuration, the pressure roll can be brought into and out of contact with the receiving portion with a simple structure.

[0021]

FIG. 4 shows a V-ribbed belt B as a power transmission belt according to an embodiment of the present invention. The belt B includes a belt body 1 in which a core wire 3 is embedded, and a back cloth 5 integrally vulcanized and bonded to the back of the belt body 1. The belt body 1 has a belt length at its bottom. , And a plurality of (three in the illustrated example) rib portions 2, 2,... Protruding so as to extend in the belt width direction. The belt body 1 is made of hydrogenated NBR or EPDM as a polymer having relatively low tackiness.

The V-ribbed belt B is formed by a known method, that is, as shown in FIG. 1, a cylindrical sewing cloth 7 (a cloth for a transmission belt) serving as the back cloth 5, a belt body 1 and a core wire 3. , And vulcanized with a molding die (not shown) to form a cylindrical belt molded body, and portions of ribs 2, 2,... For each belt B were continuously ground. It is manufactured after cutting.

As shown in FIG. 1, a right angle joint 8 extending parallel to the axial direction is provided on the outer peripheral portion of the cylindrical suture cloth 7.
And an oblique joint 9 whose one end intersects the right-angle joint 8 at an angle of 45 ° and the other end intersects one end of the cylindrical suture 7. The cylindrical suture cloth 7 has the ends of the rubberized cloth 12 with the unvulcanized rubber sewn together in an overlock sewing machine at each of the joints 8 and 9, and the butt joint portion is formed of rubber. Are heated and pressurized to a temperature lower than the vulcanization temperature to bond the rubber to the sewing threads 10, 10,...

FIG. 2 shows a method of making the above-mentioned cylindrical suture cloth 7.
3 and FIG. 3, basically, first, FIG.
As shown in (a), the warp yarns 12a, 12a,... And the weft yarns 12b, 12b,.
The rubberized cloth 12 to which the unvulcanized rubber made of M is adhered or applied is cut obliquely using a bias cutter (not shown) so that an angle between the cloth 12 and the width direction is a predetermined angle θ = 45 °. The bias cloths 13, 13,... Are cut obliquely along the line CI.

Then, as shown in FIG. 2 (b), the plurality of bias cloths 13, 13,... Are overlapped so that their cut-side ends 13a, 13a are at right angles, and The portions 13b, 13b (ends in the width direction of the rubberized cloth 12) are sequentially butted together with an overlock sewing machine (not shown) and sewn with overlock seams to open the long bias cloth 14.

Then, as shown in FIG. 2 (c), the long bias cloth 14 produced in this manner is cut by a bias cutter along a right angle cut line C2 in a direction perpendicular to the length direction (width direction). By cutting, a fixed size cloth 15 having a length corresponding to the belt length is formed. At this time, for example, the bias cloth 1
The long bias cloth 1 is crossed in the range of L1 in FIG.
Cut 4 As a result, as shown in FIG. 1, the joint portion of the entire cylindrical sewn cloth 7 is formed by the diagonal joint 9 formed from the sewn portions in the sizing cloth 15 and the cut parts 15 a, 15 a of the sizing cloth 15. And the right-angled joint portion 8 consisting of the sewn portions of the two crosses. In addition, the bias cloth 13, 1
L2 in FIG. 2 (c) so as not to cross
When the long bias cloth 14 is cut in the range, the joint part of the entire cylindrical suture cloth 7 becomes the diagonal joint part 9 composed of the sewn part in the fixed cloth 15 and the cut part 15 of the fixed cloth 15.
a, right-angled joint part 8 consisting of a sewn part between 15a
Appear without crossing.

Thereafter, as shown in FIG. 3, the cut portions 15a, 15a of the fixed-size cloth 15 are sewn with a sewing machine to form a cylindrical suture cloth 7. That is, when the cut portions 15a, 15a of the sizing cloth 15 are to be stitched together,
Is folded, and the cut portions 15a, 15a are overlapped. In this state, the cut portions 15a, 15a are sewn together with an overlock stitch by an overlock sewing machine (not shown), and then opened.

In the embodiment of the present invention, (1) the non-cut side ends 13b, 13b of the bias cloths 13, 13,... When making the bias cloth 14,
And (2) when the cut portions 15a, 15a of the fixed-size cloth 15 are stitched together with an overlock sewing machine in a butt state to form the cylindrical suture cloth 7, the stitched portions of the butt stitches are all protruded. Open to the mating state and use rubberized cloth 12
By applying pressure while heating to a temperature lower than the vulcanization temperature of the rubber in the above, the butted portion is joined in a state where the rubber is fused to the sewing thread 10 and the butted state of the stitched portion is maintained.

The 45 ° suturing portion of the above (1) is butt-fused, but the method is the same as the method of butt-welding the cylindrical suturing portion of (2), and the joint device used is also the same. Therefore, the 45 ° suturing portion is not shown.

When forming the right-angled joint 8 of the cylindrical sewing cloth 7 in the above (2), the cut sections 15a, 15a of the fixed-size cloth 15 are butt-stitched together with an overlock sewing machine as described above, and then the stitching is performed. The portions are opened in a butt state and pressurized while being heated to a temperature lower than the vulcanization temperature of the rubber, so that the butt portions of the right-angle joint portions 8 are joined in a state where the rubber is fused to the sewing thread 10 and the sewn portions are joined. In order to maintain the butt state, a butt joint device 20 shown in FIG. 5 is used.

The butt joint device 20 has a substantially L-shaped base 2 having a rectangular frame-shaped base 21a and a rectangular frame-shaped side 21b erected on the right end of the base 21a.
1 is provided at the upper end of the side 21b of the base 21.
A cylindrical receiving portion 22 extending horizontally in parallel with a is mounted and fixed at one end in a cantilevered state. The receiving portion 22 has the cylindrical sewn cloth 7 attached thereto from the other end thereof in an outer fitting state. A linear receiving ridge 22a that receives the inner peripheral surface of the sewn portion in the right-angle joint 8 of the suture cloth 7 on the upper surface is protruded, and the width of the upper surface of the receiving ridge 22a is determined by the width of the sewn portion in the right-angle joint 8. The size (for example, 10 mm) is set to be larger than the width (for example, 5 mm) so as to be able to receive uniformly.

On the left side of the rear end of the base 21a of the base 21, a column 23 that is higher than the side 21b of the base 21 is erected. On the other hand, the rear portion of the side portion 21b is extended upward to the same height as the upper end of the column portion 23, and a support portion 24 extending in the left-right direction is provided between the column portion 23 and the upper end portion of the extension of the side portion 21b. Has been passed over. A substantially plate-like guide rail 25 extending horizontally in the left-right direction in parallel with the receiving part 22 is attached and fixed to the front surface of the support part 24, and a slider 26 as a support slides on the guide rail 25 in the vertical direction. It is movably supported in a locked state. These guide rails 25 and sliders 26 are known ones called, for example, LM guides (trade names). The sliders 26 slide while rolling balls (not shown) contained therein on the guide rails 25. . Therefore, the slider 26 is moved from the receiving portion 22 to the cylindrical suture cloth 7 on the receiving portion 22.
Are disposed so as to be relatively movable in the left-right direction along the stitched portion of the right-angled joint portion 8.

A driving device 27 for moving the slider 26 relative to the receiving portion 22 in the left-right direction is provided.
The driving device 27 is provided with a driven pulley 29 having a longitudinal axis center rotatably supported via a bracket 28 at the left end of the upper surface of the support portion 24. On the other hand, an electric motor 30 whose output speed is variable by an inverter (not shown) is fixedly mounted on the right end of the upper surface of the support portion 24. The drive pulley 31 provided on the output shaft of the motor 30 and the driven pulley 29 A belt 32 is stretched between them.
A connecting portion 33 attached to and fixed to the slider 26 is integrally connected and fixed to the lower side of the belt 32 so as to move and integrally rotate. Is slid in the left-right direction along the guide rail 25.

An air cylinder 35 having a vertical axis which is in contact with and separated from the receiving portion 22 is attached and fixed to the lower part of the front surface of the slider 26 (support). The piston rod 35a of the air cylinder 35 is a cylinder body. The cylinder body 35b protrudes downward from the cylinder body 35b so as not to rotate. A plate 36 is fixed to the lower end of the piston rod 35a, and a pair of front and rear bearings 37, 37 project from the lower surface of the plate 36. A pressure roll 38 having a directional axis is rotatably supported. Therefore, the pressure roll 38 is supported by the slider 26, and can be moved up and down by the expansion and contraction operation of the air cylinder 35 to be able to contact and separate from the receiving portion 22, and is lowered by the extension operation of the air cylinder 35. When approaching the receiving portion 22, the stitched portion of the right-angle joint portion 8 of the cylindrical suture 7 on the receiving portion 22 is sandwiched between the receiving portion 22 and the upper surface of the receiving ridge 22 a of the receiving portion 22 and pressed. Although not shown, a pressure adjusting valve is connected in the middle of the air pipe connected to the air cylinder 35, and adjusting the air pressure to the air cylinder 35 by the pressure adjusting valve allows the right-angle joint section to be formed. The pressure applied to the stitched portion 8 is variable.

The pressure roll 38 has a sufficient heat capacity. Although not shown, an electric heater serving as a heating means for heating the pressure roll 38 and a heating means for heating the pressure roll 38 are provided inside the pressure roll 38. A temperature sensor for detecting the temperature is built in, and the electric heater and the temperature sensor are connected to a control circuit. In this control circuit, the heating temperature of the pressure roll 38 by the electric heater is adjusted to control the temperature of the cylindrical suture cloth 7. Control is performed so that the temperature is maintained at a predetermined temperature (for example, 120 ° C. to 140 ° C.) lower than the vulcanization temperature of the rubber in the right-angle joint 8.

Accordingly, the pressure roll 38 is lowered by the extension operation of the air cylinder 35 to approach the receiving portion 22 to press the sewn portion of the right-angle joint 8 of the cylindrical sewn cloth 7 therebetween, and to be raised by the electric heater. The belt 32 is run by the electric motor 30 of the driving device 27 while the sewn portion of the right-angle joint 8 is heated by the heated pressure roll 38, and the slider 26 fixed to the belt 32 is moved along the guide rail 25. By sliding the pressure roll 38 relative to the receiving portion 22 by sliding the left and right sides, the stitching portion of the right-angle joint 8 in the cylindrical suture 7 is brought into a butt state and pressed while heating. I have.

The upper end of a cantilever holding arm 40 is pivotally supported on the front surface of the left end of the support portion 24 with an axis in the left-right direction. Is formed with an engaging portion 40a which engages with and holds the left end of the receiving portion 22. When the right-angle joint 8 of the cylindrical suture 7 is pressed by the pressing roll 38, the cantilever holding arm 40 Thus, the left end of the receiving portion 22 is held and the receiving portion 22 is supported at both left and right ends.

The operation of joining the right-angle joint 8 of the cylindrical suture 7 using the butt joint device 20 will be described. The engagement between the engaging portion 40a at the lower end of the cantilever holding arm 40 and the left end of the receiving portion 22 is described. After the engagement is released and the lower end of the cantilever holding arm 40 is rotated upward, the cylindrical suture 7 is externally fitted to the receiving portion 22 from the left end and attached. The suture portion of the right-angle joint 8 is disposed on the upper side, and the receiving ridge 22 at the upper end of the receiving portion 22 is provided.
aPlace on top.

Next, the cantilever holding arm 40 is rotated downward, and the engaging portion 40a at the lower end thereof is engaged with the left end of the receiving portion 22 to support the receiving portion 22 at both left and right ends. Thereafter, the pressure roll 38 is heated to a predetermined temperature lower than the vulcanization temperature of the rubber by the built-in electric heater, and the pressure roll 38 is extended by the extension operation of the air cylinder 35.
Descends from the ascending position, receives the sewn portion of the right-angled joint portion 8 of the cylindrical sewn cloth 7 on the receiving portion 22, and presses the sewn portion with the ridge 22a to apply a predetermined pressure. In this state, the slider 26 moves the guide rail 25 by the operation of the electric motor 30.
The pressure roller 38 rolls by applying pressure while heating the sewn portion of the right-angle joint 8 of the cylindrical sewn cloth 7 by the slide of the slider 26. When the slider 26 reaches the end in the movement direction, the electric motor 3
0 is reversed, the slider 26 slides in the opposite direction, and the pressure roll 38 is pressed and rolled while heating the sewn portion of the same right angle joint 8 again.

When the slider 26 returns to the original position, the operation of the electric motor 30 stops, the slider 26 stops moving, the air cylinder 35 contracts, and the pressure roll 38 rises to the original position. Then, the pressurization of the sewn portion of the right-angle joint 8 of the cylindrical sewn cloth 7 is stopped. Thereafter, the cantilever holding arm 40 is rotated upward, and the cylindrical suture 7 is removed from the left end of the receiving portion 22. With the above, the joining of the stitching portion of the right-angle joint 8 of one cylindrical suture 7 is completed, and thereafter, the same operation is repeated for each cylindrical suture 7.

Incidentally, the bias cloths 13, 13,
When the non-cut side ends 13b, 13b are butt-stitched together with an overlock sewing machine, the stitched portion (the stitched portion that becomes the diagonal joint 9 of the cylindrical stitching cloth 7)
The joints of the right-angle joint 8 are joined in a state where the rubber is fused to the sewing thread 10 by pressing the joints while heating to a temperature lower than the vulcanization temperature of the rubber by opening the joints to a joint state. In order to maintain the mating state, another butt joint device (not shown) is used. The structure of this other butt joint device is basically the same as the joint device 20 shown in FIG. 5, and when comparing the two, for example, the receiving portion 22 is not a columnar shape but a plate shape. The other structure is the same except that it is not a cantilever structure, and the description is omitted.

Therefore, in this embodiment, in the cylindrical suture cloth 7, the rubberized cloth 12 with unvulcanized rubber is used.
Right angle joint part 8 and oblique joint part 9 formed by butt-stitching the ends of
The butted portions are pressurized while being heated to a temperature lower than the vulcanization temperature of the rubber, so that the rubber at the butted portions is joined to the sewing thread 10 in a fused state. That is, the rubber adhered or applied to the rubberized cloth 12 is the V-ribbed belt B
Even if hydrogenated NBR or EPDM, which are the same polymers as the belt body 1 of the comparative example, are relatively low in tackiness, tackiness occurs in the butted portions of the joint portions 8 and 9 due to heating and pressing. The adhesiveness allows the stitched state of the stitched portion to be stably held. As a result, as shown in FIG.
9 is a cylindrical suture cloth 7 with no overlapping or displacement of the butted ends.
As a result, the quality of the V-ribbed belt B can be improved.

In the above-described embodiment, the joints 8, 9 of the cylindrical suture 7 are heated by incorporating a heater in the pressure roll 38 and operating the heater. A heater is provided in the receiving ridge 22 a of the portion 22, and the joint portions 8 and 9 of the cylindrical suture 7 are received by the receiving portion 22.
Heating may be performed from the side, and a heater may be provided on both the pressure roll 38 and the receiving portion 22.

In the above embodiment, the receiving portion 22 is fixed, and the pressing roll 38 is rolled by the movement of the slider 26. However, the pressing roll 38 is fixed so as not to be movable, and the receiving portion is fixed. 22 may be moved, and the same operation and effect as in the above embodiment can be obtained.

Further, in the above embodiment, the power transmission belt is the V-ribbed belt B, and the belt cloth used for the back cloth 5 is targeted. However, the present invention is applied to a power transmission belt other than the V-ribbed belt B and the belt used therefor. The present invention can also be applied to a case where a belt cloth is jointed.

[0046]

Next, a specific embodiment will be described. An experiment was conducted in which the butted state of the stitched portions of the right-angle joint portions 8 in the cylindrical suture cloth 7 was maintained using the butted joint device 20 shown in FIG. At this time, the heating temperature of the pressure roll 38 is set to 110 ° C, 120 ° C, 130 ° C.
And the pressing force of the cylindrical suture cloth 7 on the right-angle joint 8 is 0.196 MPa, 0.245 MPa,
In addition to the four types of 0.294 MPa and 0.343 MPa, the moving speed of the pressure roll 38 is set to 1000 mm / min.
The four types were changed to 00 mm / min, 2000 mm / min, and 2500 mm / min, and the butt-holding state of the stitched portion of the joint portion 8 was observed. Table 1 shows the results. The room temperature was 18 ° C.

[0047]

[Table 1]

Considering the results shown in Table 1, when the joint portion 8 is joined by the present apparatus, the rubber at the abutting portion does not fuse with each other, and the sewing thread 10 is buried about half in the rubber. A phenomenon in which the butted portion can be held satisfactorily appears.

When both the pressure and the temperature of the joint portion 8 are too high, the rubber of the rubberized cloth 12 is fused to the sewing thread 10, but the rubber portion is greatly deformed and the rubber is hardened. Flows.

Further, if time passes in a state of heating and pressurizing, the rubber is vulcanized. Therefore, it is preferable that the heat history is as small as possible during this joining. In consideration of this point, the temperature of the rubber portion of the cylindrical suture cloth 7 immediately after the passage of the pressure roll 38 is important. However, in each of the above examples, almost no heat is accumulated, and even if touched by hand. I didn't feel like there was heat storage.

The desirable condition is that the pressure roll 38
At a heating temperature of 120 ° C. and a moving speed of the pressure roll 38 of 2
Under the conditions of 000 mm / min and a pressure of 0.294 MPa, a V-ribbed belt B was prototyped based on the cylindrical suture cloth 7 to which the joint portion 8 was joined, and the quality (adhesive strength) of the suture portion of the back cloth 5 was determined. ) And the like, no problems occurred. From these facts, it has been proved that the effect of the present invention, particularly the use of the butt joint device 20 having the configuration of the above embodiment, is effective.

[0052]

As described above, according to the first to ninth aspects of the present invention, the end of the unvulcanized rubber cloth to be the power transmission belt cloth is butt-stitched and joined by an overlock sewing machine. At the same time, the sewn portions of the ends of the fabric are opened in a butt state and pressurized while heating to a temperature lower than the vulcanization temperature of the rubber, and the butt portions are joined in a state where the rubber is fused to the sewing thread, and then sewn. By maintaining the butt state of the parts, the butt parts sewn by the overlock sewing machine in the cloth with unvulcanized rubber are made to adhere by heating and pressure welding, and the butt state of the sewn parts is changed. It is possible to stably hold and eliminate a step or a hole in the cloth for the power transmission belt, and it is possible to reliably maintain the constraint that the joint portion is brought into a butted state.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of a cylindrical suture cloth as a V-ribbed belt cloth according to an embodiment of the present invention.

FIG. 2 is a view showing a step of forming a long bias cloth at the time of manufacturing a cylindrical suture cloth.

FIG. 3 is a view showing a step of butt-stitching a fixed-size cloth at the time of manufacturing a cylindrical suture cloth.

FIG. 4 is a partial perspective view of a V-ribbed belt.

FIG. 5 is a perspective view of a butt joint device for a cylindrical suture.

FIG. 6 is a plan view showing a normal diagonal joint formed by butt-stitching non-cut ends of a bias cloth.

FIG. 7 is an enlarged perspective view of a normal oblique joint portion.

FIG. 8 is a diagram corresponding to FIG. 6, showing an abnormal state in which the cut end of the oblique joint has shifted.

FIG. 9 is a diagram corresponding to FIG. 7, showing an abnormal state in which cut ends of the oblique joints overlap.

FIG. 10 is a view showing a state in which a right angle cut line is shifted after cutting a fixed size cloth from a long bias cloth.

FIG. 11 is a view corresponding to FIG. 1 showing a state in which a 45 ° line sewn portion and a right angle sewn portion are overlapped at a crossing portion of the sewn into a cylindrical shape with the right-angle cut line of the fixed-size cloth being shifted; It is.

FIG. 12 is a diagram corresponding to FIG. 1 showing a state in which a 45 ° line sewn portion is opened when the sewn into a cylindrical shape with the right-angle cut line of the fixed-size cloth shifted;

[Explanation of symbols]

 B V-ribbed belt (transmission belt) 1 Belt main body 5 Back cloth 7 Cylindrical suture cloth (cloth for transmission belt) 8 Right angle joint section 9 Diagonal joint section 10 Sewing thread 12 Rubberized cloth (cloth with unvulcanized rubber) 20 Butt joint device 22 Receiving part 26 Slider (support) 27 Driving device 35 Air cylinder 35a Piston rod 38 Pressure roll

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29K 105: 08 B29K 105: 08 B29L 29:00 B29L 29:00

Claims (9)

[Claims] 1. An end of an unvulcanized cloth with rubber is stitched by an overlock sewing machine in a butt state, and the butt section is heated and pressed to a temperature lower than the vulcanization temperature of the rubber to press the rubber. A cloth for a power transmission belt, which is joined to a sewing thread in a fused state. 2. The cloth for a power transmission belt according to claim 1, wherein the rubber is hydrogenated NBR or EPDM. 3. A power transmission belt comprising the power transmission belt cloth of claim 1 or 2. 4. After butt-stitching the ends of the cloth with unvulcanized rubber with an overlock sewing machine, the stitched portions are opened in a butt state and pressurized while heating to a temperature lower than the vulcanization temperature of the rubber. A butt joint method for a transmission belt cloth, wherein the butt portion is joined in a state in which rubber is fused to a sewing thread to maintain the butt state of the sewn portion. 5. The butt joint method for a transmission belt cloth according to claim 4, wherein the rubber is hydrogenated NBR or EPDM. 6. A sewn portion of an unvulcanized rubber cloth sewn in a butt state by an overlock sewing machine is opened in a butt state, and pressurized while being heated to a temperature lower than a vulcanization temperature of the rubber. What is claimed is: 1. A butt joint device for a cloth for a power transmission belt in which a joining portion is joined in a state where rubber is fused to a sewing thread so as to maintain a butt state of a sewn portion, wherein the suturing portion of the cloth with unvulcanized rubber is provided. Receiving portion in a butted state, a support disposed relative to the receiving portion along a sewn portion of the cloth on the receiving portion, A pressurizing roll that is provided and sandwiches and presses a sewn portion of the cloth between the receiving portion and the receiving portion by an operation of approaching the receiving portion; heating means for heating at least one of the receiving portion or the pressing roll; Relative to the receiving part A driving means for causing the pressure roll to approach the receiving portion, press the sewing portion of the cloth therebetween and heating the sewing portion of the cloth by the heating means, and receive the pressing roll by the driving means. Characterized in that the butt joint of the sewn portion of the cloth is maintained by moving the cloth relative to the butt joint. 7. The butt joint apparatus for a transmission belt cloth according to claim 6, wherein the rubber is hydrogenated NBR or EPDM. 8. The butt joint apparatus for a transmission belt cloth according to claim 6, wherein the heating means is a heater built in a pressure roll. . 9. The butt joint device for a transmission belt cloth according to claim 6, wherein a cylinder having an axial center in a direction of coming into contact with and separating from the receiving portion is attached and fixed to the support. A pressure roll is rotatably supported on the piston rod of the transmission belt.