JP5628702B2 - Stitching apparatus and raw tire manufacturing method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a stitching device and a raw tire manufacturing method, and more particularly, to a stitching device that can add air bleeding irregularities to a raw tire and a raw tire manufacturing method that adds air bleeding irregularities.

Conventionally, in the process of loading a molded green tire into a vulcanization mold and vulcanizing, there has been a problem of adversely affecting the quality of the product tire due to residual air.
That is, if air remains between the constituent members of the tire, defects such as air accumulation may occur inside the tire after vulcanization, and there is air between the green tire and the vulcanization mold. If it remains, a defect called a bear may occur on the surface of the tire, which may reduce the commercial value of the tire.

Here, in order to cope with the above problem, many methods for removing residual air have been proposed.
First, as a method for bleeding air between tire constituent members, a method of extruding air between members by pressing with a stitching roll when attaching the tire constituent members is known (for example, Patent Document 1).
Furthermore, as a method for discharging air between the raw tire and the vulcanization mold, for example, Patent Document 2 discloses that the surface of a component member on the tire surface side extends in the tire radial direction with a predetermined pitch at a predetermined pitch. A method of providing irregularities (grooves) for air discharge is described.

JP 2005-280258 A Japanese Patent Laid-Open No. 10-67056

However, in the method described in Patent Document 2, the roughness of the irregularities added to the surface of the raw tire is not sufficient, and the air discharge effect due to the irregularities is not sufficient, and thus it is possible to completely suppress the occurrence of tire bears. could not.
In addition, the methods described in Patent Documents 1 and 2 are both steps for countermeasures against air residuals, but are performed in separate steps. Therefore, there is a problem that labor and cost are increased due to an increase in the number of steps.
Therefore, it is desired to perform the surface treatment of the constituent members of the raw tire that can sufficiently suppress the generation of bears, and to perform the surface treatment in the same process as the above stitching.

  An object of the present invention is to provide a stitching device capable of adding irregularities that can be sufficiently vented to suppress the occurrence of tire bears to a raw tire and a sufficiently rough irregularity for air bleeding on the surface. An object of the present invention is to provide a method for producing a green tire.

The inventor has intensively studied to solve the above problems.
As a result, at least one roller for stitching is provided, and the relative position of the stitching roller and the roller during rotation is constant, and the surface has irregularities on the surface that has a difference in peripheral speed during roller rotation. By using a stitching device equipped with a single unevenness addition roller, it is possible to add unevenness with sufficient roughness to discharge residual air to the raw tire surface in the same process as stitching. Obtained knowledge.

The gist configuration of the present invention for solving the above-described problems is as follows.
(1) A stitching device comprising at least one pressing roller and at least one unevenness adding roller having unevenness on the surface,
The relative position of the pressing roller and the unevenness adding roller is constant when the roller rotates,
The stitching apparatus according to claim 1, wherein a circumferential speed of the unevenness adding roller is faster than a circumferential speed of the pressing roller when the roller rotates.

(2) The shaft of the irregularity addition roller and the shaft of the pressing roller are connected by a timing belt,
The stitching device according to (1), wherein the shaft diameter of the unevenness adding roller is smaller than the shaft diameter of the pressing roller shaft.

(3) The shaft of the irregularity addition roller and the shaft of the pressing roller are connected by a timing belt,
The stitching device according to (1) or (2), wherein a roller diameter of the unevenness adding roller is smaller than a roller diameter of the pressing roller.

  (4) The pressing roller has irregularities on the surface, and the density of the irregularities on the surface of the irregularity-adding roller is larger than the density of irregularities on the surface of the pressing roller, the above (1) to (3) The stitching apparatus as described in any one.

(5) Using at least one pressing roller to produce a raw tire by laminating tire constituent members,
Using the at least one irregularity-adding roller that has a constant surface relative to the pressing roller during rotation, rotates at a peripheral speed faster than the pressing roller, and has irregularities on the surface, the tire component A method for producing a green tire, comprising a step of adding irregularities to a surface.

(6) The shaft of the irregularity adding roller and the shaft of the pressing roller are connected by a timing belt,
The raw tire manufacturing method according to (5), wherein the shaft diameter of the unevenness adding roller is smaller than the shaft diameter of the pressing roller shaft.

(7) The shaft of the unevenness adding roller and the shaft of the pressing roller are connected by a timing belt,
The raw tire manufacturing method according to (5) or (6), wherein a roller diameter of the unevenness adding roller is smaller than a roller diameter of the pressing roller.

  (8) The pressing roller has irregularities on the surface, and the density of the irregularities on the surface of the irregularity-adding roller is greater than the density of irregularities on the surface of the pressing roller, the above (5) to (7) The manufacturing method of the raw tire as described in any one.

According to the present invention, there is provided a stitching device capable of adding sufficient unevenness for air bleeding to the surface of a raw tire simultaneously with stitching, and a method for producing a raw tire having sufficient unevenness for air bleeding on the surface. Can be provided.
Thereby, a high-quality tire can be manufactured without increasing the number of manufacturing steps of the raw tire.

It is (a) schematic front view and (b) side view which show the stitching apparatus concerning one Embodiment of this invention. It is a figure which shows the usage condition of the stitching apparatus of this invention. It is (a) schematic front view and (b) side view which show the stitching apparatus of a comparative example.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 (a) is a schematic front view showing a stitching device of the present invention, and FIG. 1 (b) is a side view showing the stitching device of the present invention.

As shown in FIGS. 1 (a) and 1 (b), the stitching device 1 of the present invention includes at least one pressing roller 2 and at least one unevenness-adding roller 3 having unevenness on the surface. In the illustrated example, a pressing roller 2 and an unevenness-adding roller 3 having a roller diameter smaller than that of the pressing roller and having unevenness (not shown) on the surface are provided.
Further, in the illustrated example, the pressing roller 2 has a shaft 2a, the unevenness adding roller 3 has a shaft 3a, and the shaft 2a of these pressing rollers and the shaft 3a of the unevenness adding roller are: They are connected by a timing belt 4.
Further, in the illustrated example, the shaft diameter of the shaft 3a of the unevenness adding roller is smaller than the shaft diameter of the shaft 2a of the pressing roller.
In the illustrated example, the stitching device 1 includes a support member 5 that is a means for moving the entire device 1, and the shaft 2a and the shaft 3a are fixed to the support member 5 and can only rotate.

It is important that the stitching device of the present invention first includes at least one pressing roller.
Hereinafter, a usage example of the pressing roller will be described with reference to FIG.

The green tire molding step includes a first molding step of molding a first tire laminated member by pasting a tire constituent member such as an inner liner, a carcass ply, and a sidewall on a cylindrical molding drum, Transfer the first tire lamination member of the tire to another molding drum, expand it in a toroidal shape with pressure fluid, and attach the remaining tire constituent members such as a belt and tread to the first tire lamination member Some of them consist of a molding process.
Affixing in the second molding step is usually performed by placing and affixing structural members such as tread rubber and sidewalls on the first tire lamination member and pressing them from the outside with a pressing roller.
Specifically, as shown in FIG. 2, a first tire laminated member 6 made of an inner liner, a carcass, a bead core, etc. is fixed to a molding drum 8 by a bead portion 7, and compressed air is given to a sealed interior 9. Apply pressure from the outside of the tread rubber 11 and the side wall portion 12 to be applied with the pressing roller 2 while applying sufficient tension to the applied belt 10 to ensure rigidity and rotating the molding drum 8. Add
The stitching device 1 is moved laterally (in the direction of arrow B in FIG. 2) to press from the center portion CL of the tread rubber 11 to the sidewall portion 12.

  As described above, the first tire laminated member 6 and the remaining tires are moved by relatively rotating and relatively moving the pressing roller 2 with respect to the first tire laminated member 6 while being pressed by the pressing roller 2. The structural member can be strongly adhered and air between the members can be pushed out and removed.

  Further, the stitching device of the present invention has at least an irregularity-adding roller having irregularities on the surface, whose peripheral speed when the roller rotates is higher than that of the pressing roller, and whose relative position is constant with the pressing roller when the roller rotates. It is important to have one.

As shown in FIGS. 1 (a) and 1 (b), the stitching device 1 according to the present invention is configured so that the shaft 2a of the pressing roller and the shaft 3a of the unevenness adding roller are connected to each other by a timing belt 4. The unevenness adding roller 3 is also rotated by the torque generated by the rotation of the pressing roller 2 at this time.
Here, since the shaft diameter of the shaft 3a of the unevenness adding roller is smaller than the shaft diameter of the shaft 2a of the pressing roller, the shaft of the unevenness adding roller 3 is determined by the number of rotations of the shaft 2a of the pressing roller 2 per unit time. The rotational speed of 3a is larger. Thereby, the circumferential speed of the unevenness adding roller can be made faster than the pressing roller.

Further, in the stitching device 1 of the present invention, the pressing roller 2 and the concave / convex addition roller 3 have their respective axes fixed to the support member 5, so that the relative position during roller rotation is constant.
“The relative position is constant” means that, even when the circumferential speed of the unevenness adding roller and the circumferential speed of the pressing roller are different, the unevenness adding roller and the pressing roller move in the same direction, and The movement distance per unit time with respect to the tire structural member which performs surface treatment is said to be equal.

As described above, the surface of the unevenness adding roller is made unit time by increasing the peripheral speed of the unevenness adding roller faster than that of the pressing roller while keeping the relative position of the unevenness adding roller relative to the pressing roller during rotation. The area of the raw tire that comes into contact with the surface of the component increases, and the surface of the component that becomes the surface of the raw tire can be rubbed by the unevenness of the surface of the unevenness adding roller. Roughness irregularities can be added.
The unevenness on the surface of the green tire becomes a discharge path for residual air between the green tire and the vulcanization mold during vulcanization.

Here, the method of providing a difference in the peripheral speed between the pressing roller and the unevenness adding roller is not limited to the above method, and for example, a predetermined peripheral speed is generated in each roller by a motor. There are methods.
According to the method of connecting the roller shafts with the timing belt as described above, there is an advantage that no components such as a motor are required.

In addition, as shown in FIG. 2, when the stitching device 1 is moved laterally from the center portion CL of the tread rubber 11 to the sidewall portion 12, stitching is first performed by a pressing roller, and then the unevenness adding roller is used. It should be processed in the order of adding irregularities to the surface.
This is because even if the surface treatment is first performed by the unevenness adding roller, the unevenness added by the unevenness roller may disappear if the surface treatment portion is subsequently stitched by the pressing roller.

Furthermore, it is preferable that the pressing force of the unevenness adding roller can be adjusted when adding unevenness to the surface of the green tire.
For example, as shown in FIG. 1 (b), the pressing force can be adjusted by making the position of the unevenness adding roller 3 movable in the direction of arrow A.

When the pressing roller has irregularities, the irregularity density on the surface of the irregularity adding roller is preferably larger than the irregularity density on the surface of the pressing roller.
This is because it is possible to add more unevenness to the surface of the raw tire.

Here, the stitching device of the present invention may have a plurality of pressing rollers. This is because the pressure-bonding effect and processing efficiency by stitching can be improved.
Moreover, the stitching apparatus of this invention may have two or more rollers for uneven | corrugated addition. This is because the irregularity can be added and the processing efficiency can be improved.
As described above, since the processing with the unevenness adding roller needs to be performed after the processing with the pressing roller, for example, in the case of the stitching apparatus of the type shown in FIGS. 1 (a) and 1 (b), the support member 5 It is preferable that all the pressing rollers are arranged on one side and all the unevenness-adding rollers are arranged on the other side with reference to.

  As described above, according to the present invention, at the same time as stitching between tire constituent members using at least one pressing roller, the relative position with respect to the pressing roller is constant and rotates at a higher peripheral speed than the pressing roller. In addition, by using the at least one irregularity-adding roller having irregularities on the surface and adding irregularities to the surface of the tire constituent member, a raw tire having irregularities with sufficient density on the surface can be produced. .

  In order to confirm the effect of adding irregularities to the surface of the raw tire by the stitching device of the present invention, the surface roughness of the raw tire when stitching was performed using the stitching device of the inventive example and the comparative example (JIS A test was conducted to evaluate the arithmetic average roughness Ra) defined in B 0031 (1994) and the bare occurrence rate of the surface of the tire after vulcanization.

As a stitching apparatus of the invention example, a stitching apparatus having one pressing roller and one unevenness-imparting roller as shown in FIGS. 1 (a) and 1 (b) was prototyped.
In addition, as a stitching apparatus of a comparative example, a stitching apparatus having a pressing roller having irregularities on the surface as shown in FIGS. 3 (a) and 3 (b) was prototyped.

In the above test, the stitching apparatus shown in FIG. 2 described above was performed using the stitching apparatuses of the invention example and the comparative example, and the arithmetic average roughness Ra of the surface of the green tire after bonding was measured.
Next, each green tire was fitted in a vulcanization mold and vulcanized, and the occurrence rate of bare on the surface of the finished tire after vulcanization was evaluated.
The test results are shown in Table 1 below.

As shown in Table 1, when the stitching device of the comparative example was used, the arithmetic average roughness Ra of the surface of the raw tire was 20 μm, and the bear occurrence rate of the finished tire after vulcanization was 2%. On the other hand, when the stitching apparatus of the inventive example was used, the arithmetic average roughness Ra of the surface of the raw tire was 70 μm, and the bear occurrence rate of the finished tire after vulcanization was 0%.
From this, when using the stitching device of the present invention, it is possible to add sufficient unevenness to the air release on the surface of the raw tire simultaneously with the stitching process, and to suppress the occurrence of bears in the finished tire. I understand that I can do it.

  According to the present invention, a raw tire is manufactured using a stitching device capable of adding irregularities that can be sufficiently vented to the raw tire, and the raw tire is vulcanized to produce a high-quality tire. Can be manufactured.

1 Stitching device
2 Pressing roller
2a Press roller shaft
3 Convex / concave roller
3a Shaft for adding irregularities
4 Timing belt
5 Support member
6 First tire laminate
7 Bead section
8 Molding drum
9 Sealed inside
10 belt
11 Tread rubber
12 sidewall
13 Stitching roller
A Adjustable direction of the roller
B Horizontal movement direction of stitching device
CL tire equator

Claims (8)

A stitching device comprising at least one pressing roller and at least one unevenness adding roller having unevenness on the surface,
The relative position of the pressing roller and the unevenness adding roller is constant when the roller rotates,
The stitching apparatus according to claim 1, wherein a circumferential speed of the unevenness adding roller is faster than a circumferential speed of the pressing roller when the roller rotates. The shaft of the unevenness adding roller and the shaft of the pressing roller are connected by a timing belt,
2. The stitching device according to claim 1, wherein the shaft diameter of the unevenness adding roller is smaller than the shaft diameter of the pressing roller shaft. The shaft of the unevenness adding roller and the shaft of the pressing roller are connected by a timing belt,
3. The stitching device according to claim 1, wherein a roller diameter of the unevenness adding roller is smaller than a roller diameter of the pressing roller.   4. The pressing roller has irregularities on its surface, and the density of irregularities on the surface of the irregularity adding roller is higher than the density of irregularities on the surface of the pressing roller. Stitching device. Using at least one pressing roller, the tire components are bonded together to produce a raw tire.
Using the at least one irregularity-adding roller that has a constant surface relative to the pressing roller during rotation, rotates at a peripheral speed faster than the pressing roller, and has irregularities on the surface, the tire component A method for producing a green tire, comprising a step of adding irregularities to a surface. The shaft of the unevenness adding roller and the shaft of the pressing roller are connected by a timing belt,
6. The raw tire manufacturing method according to claim 5, wherein the shaft diameter of the unevenness adding roller is smaller than the shaft diameter of the pressing roller shaft. The shaft of the unevenness adding roller and the shaft of the pressing roller are connected by a timing belt,
7. The raw tire manufacturing method according to claim 5, wherein a roller diameter of the unevenness adding roller is smaller than a roller diameter of the pressing roller.   8. The pressing roller has irregularities on the surface, and the density of irregularities on the surface of the irregularity-adding roller is higher than the density of irregularities on the surface of the pressing roller. Manufacturing method of raw tires.

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