JP2020110933A - Method for manufacturing composite rubber sheet - Google Patents

Abstract

To provide a method for manufacturing a composite rubber sheet suppressing center misalignment between a first rubber sheet and a second rubber sheet that include a cord that extends obliquely with respect to a longitudinal direction.SOLUTION: A composite rubber sheet 6 comprises: a belt-shaped belt member 2 comprising of a cord extending obliquely with respect to the longitudinal direction and a topping rubber covering the cord; and a belt-shaped rubber sheet 4. A method for manufacturing the composite rubber sheet 6 comprises the steps of: (A) determining a position of a center line of the belt member 2 in a portion hanging down due to own weight of the belt member 2; and (B) aligning a position of the center line of the belt member 2 and a position of a center line of the rubber sheet 4 in a width direction and superposing the belt member 2 and the rubber sheet 4 each other. Preferably, in the step (B), the belt member 2 and the rubber sheet 4 having the width different from that of the belt member 2 are superposed.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for manufacturing a composite rubber sheet.

Patent Document 1 (JP-A-2017-148995) discloses a method of manufacturing a breaker used for a tire. This breaker is laminated to the carcass inside the tread of the tire. This carcass forms the framework of the tire. This breaker reinforces the carcass. This breaker includes a cord extending obliquely with respect to the longitudinal direction and a topping rubber that covers the cord.

JP, 2017-148995, A

A composite rubber sheet obtained by pressure-bonding this breaker and another rubber sheet may be used for tire production. In this composite rubber sheet, the breaker and the rubber sheet are pressed together. Compared with the pressure bonding of rubber sheets without cords, the pressure bonding between a breaker having a cord and a rubber sheet is likely to cause a positional deviation in the width direction. This misalignment impairs the molding accuracy of the tire obtained using the composite rubber sheet.

An object of the present invention is to provide a method for manufacturing a composite rubber sheet that suppresses center misalignment between a first rubber sheet including a cord extending obliquely with respect to the longitudinal direction and a second rubber sheet.

The composite rubber sheet produced by the production method according to the present invention includes a strip-shaped first rubber sheet including a cord extending obliquely with respect to the longitudinal direction and a topping rubber covering the cord, and a strip-shaped second rubber sheet. Is provided. The manufacturing method of this composite rubber sheet is
(A) A step of determining a center position of the first rubber sheet in a portion where the first rubber sheet hangs down by its own weight, and (B) a center position of the first rubber sheet and a center position of the second rubber sheet. Is aligned in the width direction, and the first rubber sheet and the second rubber sheet are overlapped.

Preferably, in the step (B), the first rubber sheet and the second rubber sheet having a width different from that of the first rubber sheet are overlapped.

Preferably, in the step (A), a first mark indicating the center position is attached to the first rubber sheet. In the step (B), the center position of the first rubber sheet and the center position of the second rubber sheet are aligned with each other based on the first mark.

In the method for manufacturing a composite rubber sheet according to the present invention, center misalignment between the first rubber sheet and the second rubber sheet that are superposed is suppressed. By using this composite rubber sheet, the molding accuracy of the tire can be improved. This method for producing a composite rubber sheet can contribute to the improvement of tire molding accuracy.

FIG. 1 is a plan view of a belt member used in the method for manufacturing a composite rubber sheet according to the present invention. FIG. 2 is a plan view of a second rubber sheet used in the method for manufacturing the composite rubber sheet according to the present invention. FIG. 3 is a plan view of a composite rubber sheet obtained by the method for manufacturing a composite rubber sheet according to the present invention. FIG. 4 is a conceptual diagram showing a part of a manufacturing apparatus for the method for manufacturing a composite rubber sheet according to the present invention. FIG. 5 is an explanatory diagram showing a usage state of the manufacturing apparatus of FIG. FIG. 6 is another explanatory diagram showing a usage state of the manufacturing apparatus of FIG.

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

FIG. 1 shows a plan view of a belt member 2 as a first rubber sheet used in this manufacturing method. The belt member 2 has a strip shape. The belt member 2 includes a large number of cords 2a and a topping rubber 2b that covers the cords 2a. These cords 2 a are arranged in the longitudinal direction of the belt member 2. The cord 2a extends obliquely with respect to the longitudinal direction. The material of the cord 2a is not particularly limited, but is steel, for example. The material of the cord 2a may be organic fiber. The topping rubber 2b is made of an unvulcanized rubber composition.

A double-headed arrow W1 in FIG. 1 represents the width of the belt member 2. The alternate long and short dash line CL1 represents the center line of the belt member 2. The center line CL1 represents the widthwise center position of the belt member 2. The alternate long and short dash line Lc represents the axis of the code 2a. The double-headed arrow θ represents the inclination angle of the cord 2a. The inclination angle θ is measured as an angle formed by the center line CL1 and the axis line Lc in a plan view.

FIG. 2 shows a plan view of the rubber sheet 4 as the second rubber sheet used in this manufacturing method. The rubber sheet 4 has a strip shape. The rubber sheet 4 is made of an unvulcanized rubber composition. A double-headed arrow W2 in FIG. 2 indicates the width of the rubber sheet 4. The dashed-dotted line CL2 represents the center line of the rubber sheet 4. The center line CL2 represents the widthwise center position of the rubber sheet 4.

FIG. 3 shows a plan view of the composite rubber sheet 6 obtained by this manufacturing method. The composite rubber sheet 6 is formed by pressing the belt member 2 and the rubber sheet 4 together. In this composite rubber sheet 6, the width W1 of the belt member 2 is larger than the width W2 of the rubber sheet 4. In FIG. 3, the center line CL1 of the belt member 2 and the center line CL2 of the rubber sheet 4 are aligned in the width direction in the width direction. A double-headed arrow WR represents the width of protrusion of the right end portion of the belt member 2. The double-headed arrow WL represents the protruding width of the left end portion of the belt member 2. The protruding widths WR and WL are measured as the distance from the end of the rubber sheet 4 to the end of the belt member 2 in the width direction.

FIG. 4 shows a part of the manufacturing apparatus 8 for the composite rubber sheet 6. In FIG. 4, the belt member 2, the rubber sheet 4, the composite rubber sheet 6, and the liner 10 are shown by a chain double-dashed line together with the manufacturing apparatus 8. The liner 10 is made of a thin resin sheet. In this manufacturing apparatus 8, the rubber sheet 4 is prepared in a state where the liner 10 is overlapped. The liner 10 protects the surface of the rubber sheet 4. The liner 10 prevents the rubber sheet 4 from sticking. In the obtained composite rubber sheet 6, the liner 10 is peeled off from the rubber sheet 4. In FIG. 4, a rubber sheet winding body 12 in which the rubber sheet 4 and the liner 10 are overlapped and wound, a composite rubber sheet winding body 14 in which the composite rubber sheet 6 is wound, and a liner 10 are further shown. And the liner winding body 16 wound with are shown.

The arrow X in FIG. 4 represents the front-rear direction frontward of the manufacturing apparatus 8, the arrow Y represents the left-right direction rightward, and the arrow Z represents the up-down direction upward.

The manufacturing apparatus 8 includes a guide roller 18, a first pressure-bonding guide roller 20, a second pressure-bonding guide roller 22, a pressure-bonding roller 24, a winding roller 26, a feeding roller 28, a belt conveyor 30, a belt conveyor 32, a peeling guide bar 34, and The liner take-up roller 36, the first sensor 38, the first centering guide 40, the second sensor 42, and the second centering guide 44 are provided. Although not shown, the manufacturing apparatus 8 further includes a control device.

The guide roller 18 guides the belt member 2 toward the first pressure-bonding guide roller 20. The belt member 2 is fed toward the guide roller 18 from a conveyor device (not shown) such as a belt conveyor.

The first pressure-bonding guide roller 20 includes a pair of roller bodies 20a. The first pressure-bonding guide roller 20 guides the belt member 2, the rubber sheet 4, and the liner 10 toward the second pressure-bonding guide roller 22. The first pressure guide roller 20 and the guide roller 18 convey the belt member 2 while forming the hanging portion 46 on the belt member 2 between them.

The second pressure-bonding guide roller 22 includes a pair of roller bodies 22a. The second pressure-bonding guide roller 22 guides the belt member 2, the rubber sheet 4, and the liner 10 toward the peeling guide bar 34.

The pressure roller 24 includes a pair of roller bodies 24a. The pressure-bonding roller 24 is a pair of roller bodies 24 a that pressure-bond the belt member 2 and the rubber sheet 4. The pressure bonding roller 24 forms the composite rubber sheet 6 from the belt member 2 and the rubber sheet 4. The pressure roller 24 guides the composite rubber sheet 6 to the winding roller 26.

The winding roller 26 winds the composite rubber sheet 6. The winding roller 26 winds the composite rubber sheet 6 to form the composite rubber sheet winding body 14.

The feeding roller 28 is mounted with the rubber sheet winding body 12. The feeding roller 28 feeds the rubber sheet 4 on which the liner 10 is superposed from the rubber sheet winding body 12. The belt conveyor 30 and the belt conveyor 32 convey the rubber sheet 4 and the liner 10 from the feeding roller 28 toward the first pressure guide roller 20.

The peeling guide bar 34 is located between the second pressure-bonding guide roller 22 and the pressure-bonding roller 24. In this manufacturing apparatus 8, the liner winding roller 36 winds the liner 10. The peeling guide bar 34 guides the liner 10 peeled off from the rubber sheet 4 to the liner winding roller 36. The liner winding roller 36 winds the liner 10 to form the liner winding body 16.

The first sensor 38 includes a sensor 38a and a sensor 38b. The sensor 38a detects the left end of the belt member 2 in the width direction. The sensor 38b detects the right end of the belt member 2 in the width direction. The first sensor 38 detects the left and right ends of the belt member 2 at the hanging portion 46 of the belt member 2. The hanging portion 46 hangs downward due to its own weight. In the manufacturing apparatus 8, the first sensor 38 detects the left and right ends at the portion that hangs downward from the first pressure-bonding guide roller 20. The first sensor 38 transmits the positional information of the left and right ends of the belt member 2 to the control device.

The first centering guide 40 includes a centering roller 40a and a centering roller 40b. The centering roller 40a contacts the left end of the belt member 2 in the width direction. The centering roller 40b contacts the right end of the belt member 2 in the width direction. Each of the centering roller 40a and the centering roller 40b is movable in the left-right direction.

The second sensor 42 includes a sensor 42a and a sensor 42b. The sensor 42a detects the left end in the width direction of the rubber sheet 4. The sensor 42b detects the right end of the rubber sheet 4 in the width direction. The second sensor 42 detects the left and right ends of the rubber sheet 4 on which the liner 10 is overlapped. The second sensor 42 detects the left and right ends of the rubber sheet 4 being conveyed by the belt conveyor 30. The second sensor 42 transmits the position information of the left and right ends of the rubber sheet 4 to the control device.

The second centering guide 44 includes a centering roller 44a and a centering roller 44b. The centering roller 44a contacts the left end of the rubber sheet 4 in the width direction. The centering roller 44b contacts the right end of the rubber sheet 4 in the width direction. Each of the centering roller 44a and the centering roller 44b is movable in the left-right direction.

The control device includes an interface board as an input/output unit, a memory as a storage unit, and a processor as an arithmetic unit. The interface board has a function of receiving the positional information from the first sensor 38 and the positional information from the second sensor 42. The processor has a function of calculating the position (first center position) of the center line CL1 of the belt member 2 from the position information of the left and right ends of the belt member 2. The processor has a function of controlling the first centering guide 40 to adjust the position of the center line CL1 of the belt member 2 to a predetermined position in the width direction. The processor has a function of calculating the position (second center position) of the center line CL2 of the rubber sheet 4 from the position information of the left and right ends of the rubber sheet 4. The processor has a function of controlling the second centering guide 44 to align the position of the center line CL2 of the rubber sheet 4 with a predetermined position in the width direction.

FIG. 5 shows a usage state of the manufacturing apparatus 8. In FIG. 5, the belt member 2 is guided from the lower side to the upper side by the first pressure-bonding guide roller 20, the second pressure-bonding guide roller 22, and the pressure-bonding roller 24. The rubber sheet 4 is guided from the lower side to the upper side by the first pressure-bonding guide roller 20, the second pressure-bonding guide roller 22, and the pressure-bonding roller 24. The liner 10 is guided from the lower side to the upper side by the first pressure-bonding guide roller 20, the second pressure-bonding guide roller 22, and the peeling guide bar 34.

In FIG. 5, the belt member 2, the rubber sheet 4, and the liner 10 are close to each other from the first pressure guide roller 20 toward the second pressure guide roller 22. The second pressure guide roller 22 overlaps the belt member 2 and the rubber sheet 4. The liner 10 is peeled from the rubber sheet 4 by being guided by the peeling guide bar 34. The pressure roller 24 presses the belt member 2 and the rubber sheet 4 together. By this pressure bonding, the composite rubber sheet 6 is obtained.

In FIG. 6, the first centering guide 40 and the second centering guide 44 are shown together with the belt member 2 and the rubber sheet 4. In FIG. 6, for convenience of description, the center line CL1 of the belt member 2 and the center line CL2 of the rubber sheet 4 are shown shifted in the width direction. In the manufacturing apparatus 8, the control device controls the first centering guide 40 to adjust the position of the center line CL1 of the belt member 2 to a predetermined position in the width direction. This control device controls the second centering guide 44 to adjust the position of the center line CL2 of the rubber sheet 4 to a predetermined position in the width direction. As a result, the center line CL1 as the first center position and the center line CL2 as the second center position are aligned in the width direction. The belt member 2 and the rubber sheet 4 which have been aligned are superposed and pressure-bonded.

Here, a method of manufacturing the composite rubber sheet 6 according to the present invention will be described using the manufacturing apparatus 8.

In this manufacturing method, as shown in FIG. 4, the hanging portion 46 is formed on the conveyed belt member 2 (STEP 1). The hanging portion 46 hangs downward between the guide roller 18 and the first pressure-bonding guide roller 20. The first sensor 38 detects the left and right ends of the belt member 2 at the portion that hangs downward from the first pressure-bonding guide roller 20 (STEP 2). The control device calculates the center line CL1 at the hanging portion 46. As a result, the position of the center line CL1 of the belt member 2 is determined (STEP 3).

The rubber sheet 4 on which the liner 10 is superposed is fed from the rubber sheet winding body 12 (STEP 4). The second sensor 42 detects the left and right ends of the rubber sheet 4 conveyed by the belt 30 (STEP 5). The control device calculates the center line CL2 of the rubber sheet 4. As a result, the position of the center line CL2 of the rubber sheet 4 is determined (STEP 6).

The control device controls the first centering guide 40 to adjust the widthwise position of the belt member 2 sent to the first pressure-bonding guide roller 20. As a result, the position of the center line CL1 is adjusted to the predetermined position. The control device controls the second centering guide 44 to adjust the width direction position of the rubber sheet 4 sent to the first pressure-bonding guide roller 20. As a result, the position of the center line CL2 is aligned with the predetermined position. The belt member 2 and the rubber sheet 4 are superposed by the first pressure-bonding guide roller 20 and the second pressure-bonding guide roller 22. In this way, the position of the center line CL1 and the position of the center line CL2 are aligned in the width direction, and the belt member 2 and the rubber sheet 4 are overlapped (STEP 7).

The liner 10 is peeled off from the rubber sheet 4 (STEP 8). The stripped liner 10 is guided by the peeling guide bar 34 and sent toward the liner winding roller 36. The rubber sheet 4 from which the liner 10 has been peeled off and the belt member 2 are pressure bonded by the pressure roller 24 (STEP 10). By this pressure bonding, the composite rubber sheet 6 is obtained. The composite rubber sheet 6 is wound up by the winding roller 26, and the composite rubber sheet winding body 14 is obtained (STEP 11).

In the tire manufacturing method using the composite rubber sheet 6, the composite rubber sheet 6 unwound from the composite rubber sheet winding body 14 is cut into a predetermined length. The composite rubber sheet member obtained by the cutting is combined with other members forming each part of the tire to form a raw cover. The raw cover is vulcanized with a mold to obtain a tire from the raw cover.

Generally, the belt member 2 is conveyed by rollers or a belt conveyor. The belt member 2 including the cord 2a that extends obliquely with respect to the longitudinal direction is likely to meander by contacting a roller or a belt conveyor. In the method for manufacturing the composite rubber sheet 6 according to the present invention, the position of the center line CL1 is determined in the hanging portion 46 of the belt member 2. In this manufacturing method, the position of the center line CL1 is stable. As a result, the position of the center line CL1 of the belt member 2 and the position of the center line CL2 of the rubber sheet 4 are easily aligned. The occurrence of misalignment in this alignment is suppressed.

In this manufacturing method, the width W1 of the belt member 2 and the width W2 of the rubber sheet 4 are different. In this manufacturing method, the positions of the center line CL1 and the center line CL2 are aligned. This manufacturing method is suitable for bonding the belt member 2 and the rubber sheet 4 having different widths W1 and W2.

In this manufacturing method, the belt member 2 may be provided with a mark (first mark) indicating the position of the center line CL1. For example, in STEP3 of determining the center line CL1, a line as a mark may be clearly indicated at the position of the center line CL1 on the surface of the belt member 2. The method of applying the mark is not particularly limited, but examples thereof include application of paint and spraying. This method may be marking by physically applying a jig to the belt member 2 to form a streak. In STEP 7 where the belt member 2 and the rubber sheet 4 are overlapped with each other, the specified line may be detected by a sensor (not shown). The widthwise position of the belt member 2 sent to the first pressure-bonding guide roller 20 may be adjusted based on the detected position of the line.

By attaching a mark indicating the position of the center line CL1 to the belt member 2, it is possible to easily form the hanging portion 46 away from the first pressure guide roller 20. For example, the sagging portion 46 can be formed in a step higher than the guide roller 18, and the first sensor 38 can detect the left and right ends of the belt member 2.

Further, the rubber sheet 4 may also be provided with a mark (second mark) indicating the position of the center line CL2. Thereby, the positions where the second sensor 42 detects the left and right ends of the rubber sheet 4 can be easily separated from the first pressure-bonding guide roller 20. The degree of freedom of the installation position of the second sensor 42 increases.

Furthermore, by detecting this mark in the obtained composite rubber sheet 6, it is possible to easily detect the positional deviation between the belt member 2 and the rubber sheet 4 in the width direction.

Further, although the rubber sheet 4 does not include a cord here, the second rubber sheet may include a cord in the present invention. Like the belt member 2, a hanging portion may be formed on the second rubber sheet. In the second rubber sheet, the left and right ends of the second rubber sheet may be detected at the portion that hangs downward due to its own weight.

Hereinafter, the effects of the present invention will be clarified by examples, but the present invention should not be limitedly interpreted based on the description of the examples.

[Example]
The manufacturing apparatus shown in FIG. 4 was prepared. Using this manufacturing apparatus, a composite rubber sheet was obtained by pressing the belt member and the rubber sheet together.

[Comparative example]
The left and right ends of the belt member were detected on the belt conveyor without forming a hanging portion on the conveyed belt member. The position of the center line of the belt member was determined based on the detected left and right ends. Other than that was carried out similarly to Example 1, and obtained the composite rubber sheet.

[Evaluation]
With respect to each composite rubber sheet, the protruding widths WR and WL (see FIG. 3) of the belt member were measured by changing the measurement position in the longitudinal direction. An average value and a standard deviation σ were calculated for each of the protrusion width WR and the protrusion width WL in the example and the protrusion width WR and the protrusion width WL in the comparative example. The results are shown in Table 1.

As shown in Table 1, the difference between the average value of the protrusion width WR of the example and the average value of the protrusion width WL is smaller than that of the comparative example. The standard deviation σ of the example is smaller than that of the comparative example. From this evaluation result, the superiority of the present invention is clear.

The method described above can be widely applied to the production of a composite rubber sheet obtained by crimping a strip-shaped rubber sheet having a cord extending obliquely with respect to the longitudinal direction and another rubber sheet.

2... Belt member 2a... Cord 4... Rubber sheet 6... Composite rubber sheet 8... Manufacturing device 20... First pressure-bonding guide roller 22... Second pressure-bonding guide roller 24. ..Crimping rollers 38, 42... Sensors 40, 44... Centering guides 46... Hanging parts

Claims (3)

A method for producing a composite rubber sheet, comprising a strip-shaped first rubber sheet including a cord extending obliquely with respect to a longitudinal direction and a topping rubber covering the cord, and a strip-shaped second rubber sheet,
(A) A step of determining a center position of the first rubber sheet in a portion where the first rubber sheet hangs down by its own weight, and (B) a center position of the first rubber sheet and a center position of the second rubber sheet. Is aligned in the width direction and the first rubber sheet and the second rubber sheet are overlapped with each other. The method for producing a composite rubber sheet according to claim 1, wherein, in the step (B), the first rubber sheet and the second rubber sheet having a width different from that of the first rubber sheet are overlapped with each other. In the step (A), a first mark indicating the center position is attached to the first rubber sheet,
The composite rubber sheet according to claim 1 or 2, wherein in the step (B), the center position of the first rubber sheet and the center position of the second rubber sheet are aligned based on the first mark. Production method.

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