JP6701984B2 - Rubber strip conveyor and tire manufacturing method - Google Patents

Description

  In particular, the present invention relates to a rubber strip transporting device that can be suitably used for transporting an unvulcanized rubber strip to a tire forming drum side in a strip wind method, and a tire manufacturing method.

  In recent years, a long unvulcanized rubber strip is spirally wound on a tire forming drum to form a rubber member for a tire such as a tread rubber, a sidewall rubber or an inner liner rubber on a tire forming drum. A so-called strip wind type tire manufacturing method for forming the tire has been proposed.

  In this strip wind method, as described in, for example, Patent Document 1, an unvulcanized rubber strip extruded from a rubber extruder is formed by using a conveying device in which a non-extensible conveying belt is wound so as to be able to circulate. The tape is conveyed while 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 around the tire forming drum directly from the conveying device.

  At this time, if the adhesive strength between the rubber strip and the transport tape is too weak, the rubber strip may fall off the transport belt during transport, and the transport may not be possible. Conversely, if the adhesive strength is too strong, when the rubber strip is transferred from the transfer device to the rubber strip attaching device or the tire forming drum, the transfer strip does not come off and a transfer failure occurs, or the rubber strip is stretched. There is a problem that the thickness changes and the tire molding accuracy is impaired.

  The width of the "stable transport range", which is the range between the lower limit of the adhesive force that allows stable transport without peeling during transport and the upper limit of adhesive force that allows stable transport during peeling, is wide enough. Absent.

  The adhesive force itself is affected by the type of rubber of the rubber strip and the surface roughness of the conveyor belt, but does not significantly affect the width of the stable conveyor range.

  Therefore, conventionally, when changing the rubber strip, a plurality of types of conveyor belts having different surface roughness are prepared, and the conveyor belt is selected and replaced according to the type of rubber of the rubber strip to be changed. Therefore, much labor and labor are required, and the tire production efficiency is impaired.

JP 2000-246812 A

  Therefore, the invention uses a same conveyor belt even for rubber strips having different adhesive properties, and while suppressing the falling of the rubber strip from the conveyor belt, it is possible to suppress a transfer failure from the conveyor device, and It is an object to provide a tire manufacturing method.

A first invention of the present application is a rubber strip transporting device having a belt conveyor for receiving a long unvulcanized rubber strip on a rear end side in a transport direction and sending it out from a front end side,
The belt conveyor has a conveyor belt wound by a plurality of guide rollers so that it can be rotated.
The conveyor belt has a holding area on its surface for holding the rubber strip by adhering to the rubber strip, and the holding area extends in the width direction between the first area portion and the second area portion. Being divided,
The surface roughness of the first area portion and the surface roughness of the second area portion are different from each other.

  In the rubber strip transport device according to the present invention, it is preferable that the width W1 of the first area portion and the width W2 of the second area portion are equal to or more than the width Wg of the rubber strip, respectively.

  In the rubber strip transport device according to the present invention, the difference |Ra1-Ra2| between the arithmetic average roughness Ra1 of the first area portion and the arithmetic average roughness Ra2 of the second area portion is 0.5 μm or more. Preferably.

  A second invention of the present application is a tire manufacturing method, wherein a tire rubber member is formed by spirally winding a rubber strip conveyed by the rubber strip conveying device of the first invention on a surface of a tire forming drum. It is characterized by including steps.

  According to the present invention, as described above, the holding area of the conveyor belt is divided into the first area portion and the second area portion having different surface roughness in the width direction. An area portion having a rough surface has a relatively low adhesion to the rubber strip as compared with a fine area portion.

  Therefore, for example, for a rubber strip containing a rubber having a strong adhesiveness, the rubber strip is adhered to an area portion having a rough surface roughness, for example, the first area portion and conveyed. As a result, the adhesiveness of the rubber strip to the conveyor belt is relatively reduced, and it is possible to suppress the transfer failure from the conveyor device while suppressing the fall from the conveyor belt.

  On the contrary, for a rubber strip containing a rubber having a weak adhesiveness, the rubber strip is adhered to an area portion having a small surface roughness, for example, a second area portion and conveyed. As a result, the adhesiveness of the rubber strip to the conveyor belt is relatively increased, and it is possible to suppress falling from the conveyor belt while suppressing transfer defects from the conveyor device.

  Further, for a rubber strip having a rubber composition having an intermediate adhesiveness, by sticking the rubber strip across the first and second regions, it is possible to prevent the transfer belt from being transferred from the transfer device while suppressing the drop from the transfer belt. Can be suppressed.

It is a side view which shows one Example of the rubber strip conveyance apparatus of this invention. It is a top view of a conveyance belt. It is sectional drawing of the width direction of a rubber strip. (A)-(C) is a top view which illustrates the conveyance method of the rubber strip from which adhesiveness differs. (A) is a sectional view showing an example of a tire rubber member, and (B) is a sectional view showing an example of a tire using the same.

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

  In this example, the case where the rubber strip transporting device 1 is incorporated into the tire manufacturing line J is shown. In the tire manufacturing line J, the unvulcanized rubber strip G extruded and molded from the rubber extruder 3 is received by the rubber strip transport device 1 at the receiving position P1 and the rubber strip attaching device from the front-end-side delivery position P2. Sent to 4. Then, the fed rubber strip G is spirally wound around the surface of the tire forming drum 5 by the rubber strip sticking device 4, whereby the tire rubber member K (see FIG. 5A) is exemplified. Shows the case of tread rubber K1).

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

  Next, the belt conveyor 2 has a non-stretchable conveyor belt 8 which is wound by a plurality of guide rollers 7 so as to be able to rotate. The rubber strip G is adhesively held on one surface of the conveyor belt 8 and conveyed from the receiving position P1 to the delivering position P2.

The belt conveyor 2 of this example includes a storage section 9 for temporarily storing the rubber strip G from the rubber extruder 3 while it is being conveyed. The storage section 9 is formed of a forward path accumulator section 9A in which the transport belt 8 travels from the receiving position P1 side to the delivery position P2 side, and a return path accumulator section 9B in which the transport belt 8 travels from the receiving position P2 side to the receiving position P1 side. It The forward path accumulator portion 9A includes an upper guide roller 7 _f U for the forward path, which is arranged in a horizontal row on the upper side, and a lower guide roller 7 _f L for the forward path, which is arranged in a horizontal row on the lower side. Equipped. The conveyor belt 8 is wound in a zigzag shape while alternately folding back and forth between the upper and lower guide rollers 7 _f U and 7 _f L. Further, the return path accumulator portion 9B has the same structure, and the conveyor belt 8 is wound in a zigzag shape while alternately folding back and forth between the upper and lower guide rollers 7 _r U and 7 _r L.

The guide rollers 7 _f U and 7 _r U for the forward and return paths are pivotally supported by the fixed frame 10A, respectively. The lower guide rollers 7 _f L and 7 _r L for the forward path and the return path are pivotally supported by a vertically movable elevating frame 10B.

  The rubber strip transport device 1 also includes a first electric motor M1 that drives the conveyor belt 8 in synchronization with the rubber extruder 3, and a second electric motor M2 that drives in synchronization with the tire forming drum 5. While the tire forming drum 5 is stopped, the conveyor belt 8 of the return accumulator unit 9B is taken out by the driving of the first electric motor M1 and the rubber strip G is attached, and then stored in the forward accumulator unit 9A. On the other hand, while the tire forming drum 5 is in operation, the conveyor belt 8 with the rubber strip stored in the forward path accumulator portion 9A is taken out by driving 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 FIGS. 2 and 3, the conveyor belt 8 has a holding region Y on its surface for holding the rubber strip G by being adhered to the rubber strip G. The holding area Y is divided in the width direction into a first area Y1 and a second area Y2. The width W1 of the first area portion Y1 and the width W2 of the second area portion Y2 are each equal to or larger than the width Wg (shown in FIG. 3) of the rubber strip G. In this example, the width W1 is equal to the width W2, but the width W1 and the width W2 may be different.

  The surface roughness of the first region Y1 is different from that of the second region Y2.

  In this example, the width of the conveyor belt 8 is larger than the width of the holding area Y, so that the outer area portions Ya and Yb are arranged on both outer sides of the holding area Y in the width direction. In this example, the surface roughness of the first area portion Y1 is equal to that of the outer area portion Ya adjacent to the first area portion Y1, and the second area portion Y2 and the second area portion Y2 have the same surface roughness. The case where the surface roughness of the adjacent outer region portion Yb is equal is shown. However, the surface roughness may be different between the first area portion Y1 and the outer area portion Ya, and the surface roughness may be different between the second area portion Y2 and the outer area portion Yb. Further, the width of the conveyor belt 8 is equal to the width of the holding area Y, that is, the outer area portions Ya and Yb may not be present.

  As parameters expressing the surface roughness, arithmetic average roughness Ra, maximum height Ry, ten-point average roughness Rz, average interval Sm of irregularities, average interval S of local peaks, and load length ratio tp are known. , The first area portion Y1 and the second area portion Y2 are different in any parameter. However, from the viewpoint of the correlation with the adhesiveness to unvulcanized rubber, it is preferable to make the arithmetic average roughness Ra different.

  In this example, the arithmetic average roughness Ra1 of the first area portion Y1 is set to be larger than the arithmetic average roughness Ra2 of the second area portion Y2. That is, the surface roughness of the first area portion Y1 is relatively rough.

  Therefore, as shown in FIG. 4(A), with respect to the rubber strip G containing a rubber having a strong adhesiveness, the rubber strip is adhered to the first region Y1 having a rough surface and conveyed. As a result, the adhesiveness of the rubber strip G to the conveyor belt 8 is relatively reduced, and the transfer failure from the conveyor device 1 can be suppressed while suppressing the fall from the conveyor belt 8.

  Further, as for the rubber strip G containing a rubber having a weak adhesive property, as shown in FIG. 4B, the rubber strip G is adhered to the second region Y2 having a small surface roughness and conveyed. As a result, the adhesiveness of the rubber strip G to the conveyor belt 8 is relatively increased, and it is possible to prevent the rubber strip G from falling from the conveyor belt 8 while suppressing a transfer failure from the conveyor device 1.

  Further, as for the rubber strip G having a rubber compounding intermediate adhesiveness, as shown in FIG. 4C, by adhering the rubber strip G across the first and second region portions Y1 and Y2, It is possible to suppress the transfer failure from the transfer device 1 while suppressing the fall from the transfer belt 8.

  The difference |Ra1-Ra2| between the arithmetic average roughness Ra1 and the arithmetic average roughness Ra2 is preferably 0.5 μm or more. If the difference is less than 0.5 μm, the range of adhesiveness of the rubber strip G that can be stably conveyed becomes narrow, and the above effect cannot be sufficiently exhibited. If the difference is too large, it becomes impossible to stably convey the rubber strip having intermediate tackiness. Therefore, the upper limit of the difference is preferably 2.5 μm or less.

  The tire T is shown in FIG. 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 the method for manufacturing the tire T, at least one of the tire rubber members K is formed by spirally winding the rubber strip G conveyed by the rubber strip conveying device 1 on the surface of the tire forming drum 5. It is configured to include the process of forming strip wind. Other than the strip winding process, conventional ones can be preferably adopted.

  As described above, the particularly preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the illustrated embodiments, and can be used for conveying rubber strips for various purposes other than tire formation, for example, various embodiments. It can be implemented by being modified into the above embodiment.

  In order to confirm the effect of the present invention, a conveyor device (Comparative Examples 1 to 3 and Examples 1 to 3) having a belt conveyor having the specifications shown in Table 1 and having the structure shown in FIG. 1 was prototyped. Then, three types of rubber strips (adhesion index 100, 80, 60) were transported using each device, and the occurrence status of transport trouble was evaluated for each rubber strip.

<Transport trouble>
When the number of occurrences of troubles (falling of the rubber strip from the conveyor belt and improper transfer from the conveyor device) that occurred within the operating time (24 hours) of the conveyor was 100 when the adhesive index of the rubber strip in Comparative Example 1 was 100. Is evaluated as an index. The smaller the number, the less the number of trouble occurrences and the better.

The adhesive index of the rubber strip was measured by measuring the adhesive force of each of the three types of rubber strips based on the probe tack test method, and the highest adhesive force among them was indicated as 100. Specifically, using an adhesive force measuring device manufactured by Toyo Seiki Seisakusho, a cylindrical probe (material: SUS304, surface roughness: root mean square roughness (Rq) of 250 to 500 nm, diameter: 5 mm) At a speed of 10 mm/sec and a contact load of 0.98 N/cm ^{2 for} 1.0 second, and immediately thereafter, the probe is vertically peeled from the rubber sample at a speed of 10 mm/sec. The maximum load required for peeling is measured as the value of the probe tack test (adhesive strength: unit N/cm ² ) at a measurement temperature of 24°C.

  As shown in Table 1, in Examples 1 to 3, it can be confirmed that by selecting the transport position of the rubber strip, three types of rubber strips having different adhesion indexes can be transported while suppressing the transport trouble. On the other hand, in Comparative Examples 2 and 3, it can be confirmed that the two types of rubber strips frequently cause a transport problem, and that it is substantially difficult to transport only one type of rubber strip. In Comparative Example 1, three types of rubber strips can be conveyed, but problems often occur in the two types of rubber strips, and production efficiency tends to be impaired.

1 Rubber Strip Conveying Device 2 Belt Conveyor 5 Tire Forming Drum 7 Guide Roller 8 Conveying Belt G Rubber Strip K Tire Rubber Member Y Holding Region Y1 First Region Y2 Second Region

Claims (4)

A rubber strip transport device having a belt conveyor for receiving a long unvulcanized rubber strip at the rear end side in the transport direction and sending it out from the front end side,
The belt conveyor has a conveyor belt wound by a plurality of guide rollers so that it can be rotated,
The conveyor belt has a holding area on its surface for holding the rubber strip by adhering to the rubber strip, and the holding area extends in the width direction between the first area portion and the second area portion. Being divided,
A rubber strip transport device, wherein the surface roughness of the first area portion and the surface roughness of the second area portion are different.   2. The rubber strip transport device according to claim 1, wherein the width W1 of the first area portion and the width W2 of the second area portion are each equal to or greater than the width Wg of the rubber strip.   The difference |Ra1-Ra2| between the arithmetic average roughness Ra1 of the first area portion and the arithmetic average roughness Ra2 of the second area portion is 0.5 μm or more. 2. The rubber strip transport device according to 2.   A tire including a step of forming a tire rubber member by spirally winding a rubber strip conveyed by the rubber strip conveying device according to claim 1 on a surface of a tire forming drum. Manufacturing method.

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