JP6753266B2 - Rubber strip transfer device and tire manufacturing method - Google Patents

Description

The present invention particularly relates to a rubber strip transport device that can be suitably adopted for transporting an unvulcanized rubber strip to a tire forming drum side in a strip wind method, and a method for manufacturing a tire.

In recent years, by spirally winding long unvulcanized rubber strips on a tire forming drum, rubber members for tires such as tread rubber, sidewall rubber, and inner liner rubber can be formed on the tire forming drum. A so-called strip wind type tire manufacturing method for forming has been proposed.

In this strip wind method, for example, as described in Patent Document 1, an unvulcanized rubber strip extruded from a rubber extruder is used by using a transport device in which a non-extensible transport belt is wound around. , It is conveyed in a state of being adhered to the conveying tape. The conveyed rubber strip is transferred to the rubber strip attaching device and then wound around the tire forming drum by the rubber strip attaching device, or is wound directly from the conveying device around the tire forming drum.

On the other hand, the rubber strip adopts, for example, a convex lens-shaped cross-sectional shape in which the gauge thickness on the center side in the width direction is thicker than that on both end sides in order to prevent air accumulation between the rubber strips during winding. Tend.

In this case, the outer end side portion having a thin gauge tends to cool faster than the central side portion during transportation. Therefore, the outer end side portion has stronger adhesion to the transport belt than the central side portion, and is less likely to be peeled off from the transport belt. As a result, when the rubber strip is transferred from the transport device to the rubber strip pasting device or the tire forming drum (hereinafter, may be referred to as "pasting device, etc."), it does not come off from the transport belt, and transfer failure is likely to occur. There's a problem. Moreover, since the gauge thickness of the outer end side portion is thin, the strength is low. Therefore, if it is forcibly peeled off, damage such as edge breakage will occur.

Further, by arranging the transport device in, for example, a temperature control booth or the like to control the temperature, it is possible to suppress the cooling of the outer end side portion during the transport. However, in this case, the pressing pressure when the rubber strip is pressed against the transport belt becomes relatively strong in the central portion where the gauge thickness is thick. As a result, on the contrary, the adhesion of the central portion becomes stronger than that of the outer end side portion, the central portion becomes difficult to peel off from the transport belt, and there arises a problem that transfer failure is likely to occur.

Note that, for example, by making the surface roughness of the transport belt rough over the entire width, the adhesion to the rubber strip can be reduced. However, in this case, if the surface roughness is too rough, the rubber strip will come off from the transport belt during transport and fall, resulting in a problem that transport cannot be performed. Moreover, the adhesiveness of the rubber strip differs depending on the type of rubber. Therefore, when changing the rubber, it is necessary to prepare a plurality of types of transport belts having different surface roughness, select and replace the transport belt according to the type of rubber, which requires a lot of labor and labor. ..

Japanese Unexamined Patent Publication No. 2000-246812

Therefore, the present invention suppresses excessive adhesion of the rubber strip to the transport belt, and even for rubber strips having different adhesiveness, the same transport belt is used, and the rubber strip is suppressed from falling from the transport belt from the transport device. It is an object of the present invention to provide a rubber strip transport device capable of suppressing transfer defects and a method for manufacturing a tire.

The first invention of the present application is a rubber strip transfer device having a belt conveyor that receives a long unvulcanized rubber strip on the rear end side in the transfer direction and sends it out from the front end side.
The belt conveyor includes a transport belt that is wound around by a plurality of guide rollers.
The surface of the transport belt has a holding region that adheres to the rubber strip to hold the rubber strip, and at least the holding region is a first region portion on the width center line side thereof and a second region on both outer sides thereof. It is divided into areas and
It is characterized in that the adhesiveness to the rubber strip is different between the first region portion and the second region portion.

In the rubber strip transport device according to the present invention, the surface roughness is different between the first region portion and the second region portion, or the material of the surface layer is different between the first region portion and the second region portion. , It is preferable to make the adhesiveness to the rubber strip different.

In the rubber strip transport device according to the present invention, the adhesiveness of the first region portion to the rubber strip can be set to be smaller or larger than the adhesiveness of the second region portion to the rubber strip.

The second invention of the present application is a method for manufacturing a tire, in which a tire rubber member is formed by spirally winding a rubber strip conveyed by the rubber strip conveying device of the first invention on the surface of a tire forming drum. It is characterized by including a process.

In the present invention, as described above, in the holding region of the transport belt, the adhesiveness to the rubber strip is different between the first region portion on the width center line side and the second region portion on both outer sides thereof.

Therefore, for example, in a rubber strip transfer device operated in an environment where the outer end side portion having a thin gauge thickness cools faster than the central side portion, the adhesiveness of the second region portion becomes the adhesiveness of the first region portion. Use a transport belt that is small compared to the sex. As a result, the adhesion with the rubber strip can be made uniform in the width direction. As a result, it is possible to suppress transfer defects (peeling defects) caused by the adhesion of the outer end side portion being increased by cooling when transferring from the transfer device. Further, during the transfer, the adhesive is made uniform in the width direction, so that the rubber strip can be prevented from falling off the transfer belt.

Further, for example, in a rubber strip transfer device that is operated in a temperature-controlled environment and the pressing pressure of the rubber strip becomes relatively strong in the central portion where the gauge thickness is thick, the adhesiveness of the first region portion becomes the second region. Use a transport belt that is smaller than the adhesiveness of the part. As a result, the adhesion with the rubber strip can be made uniform in the width direction. As a result, when transferring from the transport device, it is possible to suppress transfer failure (peeling failure) caused by the adhesive pressure on the central side portion being large. Further, during the transfer, the adhesive is made uniform in the width direction, so that the rubber strip can be prevented from falling off the transfer belt.

In addition, by suppressing excessive adhesion and making the adhesion with the rubber strip uniform in the width direction, the peeling ability at the time of transfer and the ability to suppress detachment during transportation are achieved as compared with the case where the adhesion is not uniform in the width direction. Can increase the total potential of. As a result, even for rubber strips having different adhesiveness, it is possible to suppress the transfer failure from the transport device while suppressing the drop of the rubber strip from the transport belt while using the same transport belt.

It is a side view which shows one Example of the rubber strip transfer apparatus of this invention. It is a top view of the transport belt. It is a top view of another example of a conveyor belt. It is sectional drawing in the width direction of a rubber strip. (A) is a cross-sectional view showing an example of a tire rubber member, and (B) is a cross-sectional view showing an example of a tire using the same. It is a conceptual diagram which shows the evaluation method of the rubber adhesiveness to a rubber strip.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIG. 1, the rubber strip transfer device 1 of the present embodiment includes a belt conveyor 2 that receives a long unvulcanized rubber strip G on the rear end side in the transfer direction F and sends it out from the front end side.

In this example, the case where the rubber strip transport device 1 is incorporated in the tire manufacturing line J is shown. In this tire manufacturing line J, the unvulcanized rubber strip G extruded from the rubber extruder 3 is received by the rubber strip transport device 1 at the receiving position P1 and the rubber strip pasting device from the delivery position P2 on the front end side. It is sent to 4. Then, the sent out rubber strip G is spirally wound around the surface of the tire forming drum 5 by the rubber strip attaching device 4. As a result, for example, the tire rubber member K as illustrated in FIG. 5A (the case of the tread rubber K1 is shown in the figure) is formed.

The rubber extruder 3, the rubber strip pasting device 4, and the tire forming drum 5 are not particularly restricted, and those having a conventional well-known structure can be preferably used.

Next, the belt conveyor 2 has a non-extensible transport belt 8 that is wound around by a plurality of guide rollers 7. The rubber strip G is adhesively held on one surface of the transport belt 8 and transported from the receiving position P1 to the delivering position P2.

The belt conveyor 2 of this example may include a storage unit 9 that temporarily stores the rubber strip G from the rubber extruder 3 while being conveyed. The storage portion 9 is formed of an outward accumulator portion 9A in which the transport belt 8 travels from the receiving position P1 side to the delivery position P2 side, and a return accumulator portion 9B traveling from the delivery position P2 side to the receiving position P1 side. To. Of these, the accumulator section 9A for the outward route includes an upper guide roller 7 _f U for the outward route arranged in a horizontal row on the upper side and a lower guide roller 7 _f L for the outward route arranged in a horizontal row on the lower side thereof. Prepare. The transport belt 8 is wound in a zigzag shape while alternately folding back between the upper and lower guide rollers 7 _f U and 7 _f L. Further, the accumulator portion 9B for the return route has the same configuration, and the transport belt 8 is wound in a zigzag shape while alternately folding back between the upper and lower guide rollers 7 _r U and 7 _r L.

The upper guide rollers 7 _f U and 7 _r U for the outward route and the return route are pivotally supported by the fixed frame 10A, respectively. Further, the lower guide rollers 7 _f L and 7 _r L for the outward route and the return route are pivotally supported by the elevating frame 10B that can be raised and lowered.

Further, the rubber strip transfer device 1 may include a first electric motor M1 for driving the transfer belt 8 in synchronization with the rubber extruder 3 and a second electric motor M2 for driving in synchronization with the tire forming drum 5. .. While the tire forming drum 5 is stopped, the transport belt 8 of the return accumulator portion 9B is taken out by the drive of the first electric motor M1, and after the rubber strip G is attached, it is stored in the outward accumulator portion 9A. On the other hand, during the operation of the tire forming drum 5, the transport belt 8 with the rubber strip stored in the outward accumulator portion 9A is taken out by the drive of the second electric motor M2, and the rubber strip G is attached to the rubber strip attaching device 4 And the tire forming drum 5 are sequentially supplied.

Next, as shown in FIG. 2, the transport belt 8 has a holding region Y on its surface that adheres to the rubber strip G and holds the rubber strip G. The width W0 of the holding region Y is substantially the same as the width Wg of the rubber strip G (shown in FIG. 4), and is provided at the center of the transport belt 8 in the width direction in this example.

Further, the holding region Y is divided into a first region portion Y1 on the width center line Co side of the holding region Y and a second region portion Y2 on both outer sides thereof. The width W1 of the first region portion Y1 is preferably in the range of 20 to 80% of the width W0 of the holding region Y. In this example, the case where the surface of the transport belt 8 has the outer region Q outside the holding region Y is shown, but the surface of the transport belt 8 may be formed only by the holding region Y.

The first region portion Y1 and the second region portion Y2 differ in their adhesiveness to the rubber strip G (hereinafter, may be referred to as "anti-raw rubber adhesiveness").

As a method for evaluating the adhesiveness to rubber, as shown in FIG. 6, an unvulcanized rubber strip B as a reference (for example, on the surface As of the test sample A having a surface As for measuring the adhesiveness) (for example, A width of 30 mm, a length of 60 mm, and a thickness of 3 mm) are pressed against each other with a load (for example, 700 g) and a time (for example, 5 seconds) to adhere them. Then, the force when the rubber strip B is peeled off from the test sample A is measured, and the magnitude of the adhesiveness is evaluated. The temperature of the test sample A and the rubber strip B at the time of measurement is, for example, 24 ° C. Further, a cloth material made of organic fibers is embedded in the rubber strip B so that the rubber strip B does not stretch when the rubber strip B is peeled off. The adhesiveness of the reference rubber strip can be measured by, for example, a probe tack test method or the like.

Here, in order to make the adhesiveness to the rubber resistant different, a means for making the surface roughness R1 of the first region portion Y1 different from the surface roughness R2 of the second region portion Y1 can be adopted. Further, as another means, a means for differentiating the material of the surface layer between the first region portion Y1 and the second region portion Y2 can be adopted. When the transport belt 8 has the outer region Q, as shown in FIG. 2, it is preferable that the outer region Q and the second region portion Y2 have the same adhesiveness to the rubber. However, as shown in FIG. 3, the adhesiveness to the rubber can be made different between the outer region Q and the second region Y2.

(2) A case where the surface roughness is different will be described.
In this case, the surface roughness R1 of the first region portion Y1 and the surface roughness R2 of the second region portion Y1 are made different.

Arithmetic mean roughness Ra, maximum height Ry, ten-point average roughness Rz, unevenness average interval Sm, local peak average interval S, and load length ratio tp are known as parameters representing surface roughness. , The first region portion Y1 and the second region portion Y2 are different in any of the parameters. From the viewpoint of correlation with the adhesiveness to unvulcanized rubber, it is preferable to make the arithmetic mean roughness Ra different.

In the first embodiment, the surface roughness R1 (for example, arithmetic average roughness Ra1) of the first region portion Y1 is set to be smaller than the surface roughness R2 (for example, arithmetic average roughness Ra2) of the second region portion Y2. Will be done. That is, the surface of the second region portion Y2 is relatively rough, and the adhesiveness to the rubber is weakened.

Therefore, as shown in FIG. 4, in the rubber strip transport device 1 operated in an environment in which the outer end side portion Ge of the rubber strip G having a thin gauge is cooled faster than the central side portion Gc and the adhesion becomes stronger. , R2> R1, the adhesion with the rubber strip G can be made uniform in the width direction. As a result, it is possible to suppress transfer failure (peeling failure) caused by the adhesion of the outer end side portion Ge being increased by cooling. Further, during the transfer, the adhesive is made uniform in the width direction, so that the rubber strip G can be prevented from coming off the transfer belt 8 and falling.

In addition, by suppressing excessive adhesion and making the adhesion with the rubber strip G uniform in the width direction, the peeling ability at the time of transfer and the prevention of detachment during transportation are suppressed as compared with the case where the adhesion is non-uniform in the width direction. The total potential with the ability can be increased. As a result, even for rubber strips G having different adhesiveness, it is possible to suppress transfer failure from the transport device 1 while suppressing the rubber strip G from falling from the transport belt 8 while using the same transport belt 8. become.

Further, the bottom surface of the rubber strip G has a portion that comes into contact with the second region portion Y2 of the transport belt 8 and has a rough surface, and a portion that comes into contact with the first region portion Y1 and has a surface that does not become rough. As shown in FIG. 5A, such a rubber strip G has a portion where the surface is roughened and a portion where the surface is not roughened between the adjacent rubber strips G when the rubber strips G are wound to form the tire rubber member K. There is a difference in adhesion between and. As a result, when the tire rubber member is formed, it can be expected that the weakly adhesive portion forms an air discharge path and can suppress air accumulation. This effect becomes more remarkable when the temperature during transportation of the rubber strip G is 60 ° C. or higher.

When the arithmetic mean roughness is adopted, the difference | Ra1-Ra2 | between Ra1 and Ra2 is preferably 0.5 μm or more. If the difference is less than 0.5 μm, the uniform adhesion with the rubber strip G becomes insufficient, and the total potential of the peeling ability at the time of transfer and the detachment suppressing ability during transportation cannot be sufficiently increased. If the difference is too large, the rubber strip having an intermediate adhesiveness cannot be stably conveyed. Therefore, the upper limit of the difference is preferably 2.5 μm or less.

Next, for example, an example will be described in which the rubber strip transfer device 1 is arranged in a temperature control booth or the like to suppress uneven cooling of the outer end side portion Ge. In this case, when the rubber strip G is pressed against the transport belt 8 by the guide roller 7 or the like, the pressing pressure at that time becomes relatively strong in the central portion Gc having a thick gauge. As a result, on the contrary, the adhesion of the central side portion Gc becomes stronger than that of the outer end side portion Ge, and the central side portion Gc is less likely to be peeled off from the transport belt 8.

Therefore, in the second embodiment, the surface roughness R1 (for example, arithmetic average roughness Ra1) of the first region portion Y1 is larger than the surface roughness R2 (for example, arithmetic average roughness Ra2) of the second region portion Y2. Is set to. That is, the surface of the first region portion Y1 is relatively rough.

Therefore, in the rubber strip transport device 1 which is operated in a temperature-controlled environment and the pressing pressure of the rubber strip G becomes relatively strong in the central portion Gc with a thick gauge, the rubber strip is formed by R1> R2. Adhesion with G can be made uniform in the width direction. As a result, it is possible to suppress transfer failure (peeling failure) caused by the adhesion of the central portion Gc due to the large pressing pressure. Further, during the transfer, the adhesive is made uniform in the width direction, so that the rubber strip G can be prevented from coming off the transfer belt 8 and falling.

Further, as in the case of the first embodiment, the total potential of the peeling ability at the time of transfer and the disengagement suppressing ability during transportation is increased, and as a result, the same transport belt 8 is applied to the rubber strips G having different adhesiveness. It is also possible to suppress the transfer failure from the transfer device 1 while suppressing the drop of the rubber strip G from the transfer belt 8 while using the above.

Further, as a result of forming a portion where the surface becomes rough and a portion where the surface does not become rough on the bottom surface of the rubber strip G, it is expected that when the tire rubber member is formed, the weakly adhered portion forms an air discharge path and can suppress air accumulation. .. In particular, in the second embodiment, since the surfaces on both ends of the bottom surface of the rubber strip G are not rough, the adhesion to the adjacent rubber strip G is kept high. Therefore, it is possible to suppress the unwinding of the rubber strip G during laminating, and it is possible to obtain the effect of maintaining the forming accuracy and forming efficiency of the tire rubber member K.

(2) A case where the material of the surface layer is different between the first region portion Y1 and the second region portion Y2 will be described. The transport belt 8 is generally formed of a base material made of a synthetic resin and a non-extensible reinforcing core material made of, for example, organic fibers, which is embedded in the base material, and the base material is exposed on the surface. If so, this substrate constitutes the surface layer. When a coating layer is formed on the surface of the base material, this coating layer constitutes the surface layer.

As the surface layer, resin materials such as nylon resin, polyester resin, fluororesin, and silicon resin are appropriately adopted. In general, the adhesiveness to rubber becomes stronger in the order of polyester resin> nylon resin> silicone resin> fluororesin.

By making the material of the surface layer different between the first region portion Y1 and the second region portion Y2 in this way, the adhesiveness to the rubber of the first region portion Y1 and the second region portion Y2 can be made different. .. Specifically, for example, by forming the surface layer of the second region portion Y2 with a fluororesin material and forming the surface layer of the first region portion Y1 with a polyester resin material, the adhesiveness of the second region portion Y2 to the rubber Can be made relatively weak. In this case, the same effect as that of the first embodiment (in the case of R1 <R2) described above can be obtained.

On the contrary, for example, by forming the surface layer of the first region portion Y1 with a fluororesin material and forming the surface layer of the second region portion Y2 with a polyester resin material, the adhesiveness of the first region portion Y1 to the rubber is relatively relative. Can be weakened. In this case, the same effect as that of the second embodiment (in the case of R1> R2) described above can be obtained.

The tire T is shown in FIG. 5 (B). The tire T includes a tire rubber member K including a tread rubber K1, a sidewall rubber K2, an inner liner rubber K3, a bead apex rubber K4, and a chafer rubber K5. Then, in this method of manufacturing the tire T, at least one of the tire rubber members K is spirally wound around the surface of the tire forming drum 5 with the rubber strip G conveyed by the rubber strip conveying device 1. It is configured to include the process of forming a strip wind. Other than this strip wind process, conventional ones can be preferably adopted.

Although the particularly preferable embodiments of the present invention have been described in detail above, the present invention is not limited to the illustrated embodiments, and can be used for transporting rubber strips for various purposes other than tire formation. It can be implemented by transforming it into the above embodiment.

To confirm the effect of the present invention
(Test A):
The belt conveyor shown in FIG. 2 was prototyped with the specifications shown in Table 1. Then, the rubber strip G was conveyed by using the conveyor of FIG. 1 equipped with this belt conveyor to form a pneumatic tire (245 / 40R18) having the tire rubber member K shown in FIG. 5 (A). The width W1 of the first region portion Y1 is 40% of the width W0 of the holding region Y.

The transfer trouble at that time (including the drop of the rubber strip from the transfer belt and the transfer failure from the transfer device) was evaluated.

As shown in FIG. 4, the rubber strip G used had a gauge thickness of the central side portion Gc thicker than that of the outer end side portion Ge. Further, in Test A, the outer end side portion Ge cools faster than the central side portion Gc during transportation, so that the adhesion of the outer end side portion Ge becomes stronger than that of the central side portion Gc.
<Transport trouble>
In Test A, Comparative Example A1 was used to determine the number of troubles (including both the rubber strip G falling from the transport belt and the transfer failure from the transport device) occurring within the operating time (24 hours) of the transport device. It is evaluated with an index of 100. The smaller the number, the smaller the number of troubles and the better.

(Test B)
The belt conveyor shown in FIG. 2 was prototyped with the specifications shown in Table 2. Then, as in Test A, a pneumatic tire (245 / 40R18) was formed, and the transport trouble at that time was evaluated.

In test B, uneven cooling of the outer end side portion Ge of the rubber strip G is suppressed by temperature control. However, since the pressing force when the rubber strip G is pressed against the transport belt becomes relatively stronger in the central portion Gc having a thick gauge, the adhesion of the central portion Gc becomes stronger than that of the outer end side portion Ge. ing.

As shown in Tables 1 and 2, it can be confirmed that in the examples, it is possible to suppress the dropping of the rubber strip from the transport belt and the transfer failure from the transport device, and it is possible to reduce the transport trouble.

(Test C)
The belt conveyor shown in FIG. 2 was prototyped according to the specifications shown in Table 3. Then, the transport trouble when the pneumatic tire (245 / 40R18) was formed was evaluated in the same manner as in Test A. In the test C, the temperature is not controlled, and the outer end side portion Ge of the rubber strip G is unevenly cooled.

(Test D)
The belt conveyor shown in FIG. 2 was prototyped with the specifications shown in Table 4. Then, the transport trouble when the pneumatic tire (245 / 40R18) was formed was evaluated in the same manner as in Test A. In Test D, uneven cooling of the outer end side portion Ge of the rubber strip G is suppressed by temperature control.

As shown in Tables 3 and 4, it can be confirmed that in the examples, it is possible to suppress the drop of the rubber strip from the transfer belt and the transfer failure from the transfer device, and it is possible to reduce the transfer trouble.

1 Rubber strip transport device 2 Belt conveyor 5 Tire forming drum 7 Guide roller 8 Conveyor belt 11 Area range Co Width center line F Transport direction G Rubber strip K Tire rubber member Y Holding area Y1 Central area Y2 Outer area

Claims (6)

A rubber strip transfer device having a belt conveyor that receives a long unvulcanized rubber strip on the rear end side in the transfer direction and sends it out from the front end side.
The belt conveyor includes a transport belt that is wound around by a plurality of guide rollers.
The surface of the transport belt has a holding region that adheres to the rubber strip to hold the rubber strip, and at least the holding region is a first region portion on the width center line side thereof and a second region on both outer sides thereof. It is divided into areas and
A rubber strip transporting device characterized in that the adhesiveness to a rubber strip is different between the first region portion and the second region portion. The rubber strip transport device according to claim 1, wherein the first region portion and the second region portion have different adhesiveness to the rubber strip due to the difference in surface roughness. The rubber strip transporting apparatus according to claim 1, wherein the first region portion and the second region portion have different surface layers made of different materials, so that the adhesiveness to the rubber strip is different. The rubber strip transport device according to any one of claims 1 to 3, wherein the first region portion has less adhesiveness to the rubber strip than the second region portion. The rubber strip transport device according to any one of claims 1 to 3, wherein the first region portion has a higher adhesiveness to the rubber strip than the second region portion. A tire comprising a step of forming a tire rubber member by spirally winding a rubber strip conveyed by the rubber strip conveying device according to any one of claims 1 to 5 on a surface of a tire forming drum. Manufacturing method.

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