JP2017080978A - Grooving apparatus and grooving method for rubber strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of appropriately forming an air vent groove on a surface of a rubber strip, so as to prevent residual air in a tire after curing and molding.SOLUTION: A grooving apparatus for a rubber strip presses a rubber strip conveyed on a conveyor belt, with a grooving roller having a plurality of ridges on a pressing surface so as to form an air vent groove on a surface of the rubber strip. The pressing surface of the grooving roller is formed to allow the air vent grooves to be formed on an entire surface in width direction along a surface shape of the rubber strip.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a rubber strip grooving device and a grooving method used for forming an air escape groove on the surface of a rubber strip being conveyed.

  In general, in forming a pneumatic tire, a so-called strip wind method is used in which various belt-shaped rubber strips are spirally wound around a body to be wound such as a molding drum, and rubber members for tires are stacked and molded. .

  In this strip wind method, a gap is formed between the wound rubber strips, and there is a risk of air remaining after vulcanization molding. Therefore, conventionally, a slit-like air is provided in the rubber strip before being supplied to the molding drum. An escape groove is formed (for example, Patent Documents 1 and 2).

  FIG. 4 is a schematic side view of a general rubber strip grooving device. The rubber strip grooving device 1 (hereinafter also simply referred to as “grooving device”) is a conveyor belt that conveys the rubber strip 2. 3 pulleys 6 are provided to face each other.

  FIG. 5 is a view for explaining the relationship between the conventional grooving roller and the rubber strip. A plurality of ridges 7 are formed on the pressing surface of the grooving roller 5, and the grooving roller 5 is connected to the rubber strip 2. The air escape groove is formed on the surface of the rubber strip 2.

JP 2007-136894 A JP 2008-62639 A

  However, even if the grooving roller of the grooving device described above is pressed against the rubber strip, air escape grooves may not be sufficiently formed on both side edges of the rubber strip, and a gap is formed between the wound rubber strips. As a result, there is still a problem that air remains after vulcanization molding.

  Therefore, the present invention provides a technology that can sufficiently prevent air from being generated in a vulcanized tire by sufficiently forming an air escape groove in the entire width direction up to both side edges of the surface of the rubber strip. The issue is to provide.

The invention described in claim 1
A rubber strip grooving device that forms an air escape groove on the surface of the rubber strip by pressing the rubber strip conveyed on the conveyor belt with a grooving roller having a plurality of ridges formed on the pressing surface. And
In the rubber strip grooving device, the pressing surface of the grooving roller is formed so that the air escape groove can be provided in the entire width direction along the surface shape of the rubber strip. is there.

The invention described in claim 2
The pressing surface of the grooving roller is configured to increase in diameter at a predetermined angle from a central portion in the axial direction toward both side edge portions along the surface shape of the rubber strip. Item 2. The rubber strip grooving device according to Item 1.

The invention according to claim 3
The groove of the rubber strip according to claim 1 or 2, wherein the plurality of ridges extend in a direction inclined at an angle of 15 to 90 ° with respect to a side edge of the grooving roller. Attachment device.

The invention according to claim 4
4. The grooving of a rubber strip according to claim 1, wherein an interval between the plurality of ridges in a direction parallel to a side edge of the grooving roller is 1 to 50 mm. 5. Device.

The invention described in claim 5
5. The rubber strip grooving device according to claim 1, wherein a height of the ridge is 0.2 to 5 mm from a surface of the grooving roller. .

The invention described in claim 6
A rubber strip conveying device provided with the rubber strip grooving device according to any one of claims 1 to 5.

The invention described in claim 7
A rubber strip grooving method for forming an air escape groove on a surface of the rubber strip using the rubber strip grooving device according to any one of claims 1 to 5.
The rubber strip grooving method is characterized in that an air escape groove is formed in the entire width direction of the surface of the rubber strip by pressing the rubber strip with the grooving roller.

The invention according to claim 8 provides:
It is a manufacturing method of a pneumatic tire which manufactures a pneumatic tire using the rubber strip in which the air escape groove was formed by the grooving method of the rubber strip according to claim 7.

  According to the present invention, there is provided a technique capable of preventing air from remaining in a vulcanized tire by sufficiently forming an air escape groove in the entire width direction up to both side edges of the surface of the rubber strip. can do.

It is a figure explaining the relationship between the grooving roller and rubber strip in the grooving apparatus of the rubber strip which concerns on one embodiment of this invention. It is a side view which shows typically a part of grooving roller provided in the grooving apparatus of the rubber strip which concerns on one embodiment of this invention. It is a front view which shows typically the grooving roller in the Example and comparative example of this invention. It is a typical side view of a general rubber strip grooving device. It is a figure explaining the relationship between the conventional grooving roller and a rubber strip.

  Hereinafter, the present invention will be described with reference to the drawings based on embodiments.

  Similar to the conventional grooving apparatus, the grooving apparatus according to the present embodiment is provided so as to face the transport belt that transports the rubber strip, and air is applied to the surface of the rubber strip transported on the transport belt. A grooving roller for forming a relief groove is provided, and a plurality of ridges are formed on the pressing surface of the grooving roller.

  However, the grooving apparatus according to the present embodiment is different from the conventional grooving apparatus in the shape of the grooving roller used. This will be specifically described below.

  FIG. 1 is a view for explaining the relationship between a grooving roller and a rubber strip in the rubber strip grooving device according to the present embodiment, and FIG. 2 is provided in the rubber strip grooving device according to the present embodiment. It is a side view which shows typically a part of grooving roller.

  As shown in FIG. 1, in the present embodiment, the pressing surface of the grooving roller 5 can be provided with air escaping grooves in the entire width direction along the surface shape (profile) of the rubber strip 2. It differs from the prior art in that it is formed.

  That is, since the rubber strip 2 is a trapezoidal section member whose both end portions are thinner than the center portion in the width direction, the conventional grooved roller 5 shown in FIG. If it is used to form an air escape groove, the air escape groove is formed only at the center portion of the rubber strip, and the air escape groove cannot be formed sufficiently at both side edges.

  On the other hand, in the rubber strip grooving device according to the present embodiment, as shown in FIG. 1, the pressing surface of the grooving roller 5 follows the surface shape of the rubber strip 2 having a trapezoidal cross section. In addition, the diameter is configured to increase at a predetermined angle from the central portion in the axial direction toward both side edge portions.

  As a result, when the grooved roller 5 is pressed against the rubber strip 2, the ridges 7 press the entire region in the width direction of the rubber strip 2, so that not only the central portion in the width direction of the rubber strip 2 but also the side edges A sufficient air escape groove can be formed. As a result, it is possible to appropriately prevent air residue from occurring in the vulcanized tire.

  In addition, although this invention is not specifically limited, It is preferable that the shape of the protruding item | line 7 formed in the pressing surface of the grooving roller 5 is set as the following structures, for example.

  As shown in FIG. 1, in this embodiment, the ridges 7 are formed so as to extend in a direction inclined at a predetermined angle a with respect to the side edge of the grooving roller 5. It is preferable that the angle is 15 to 90 ° because there is a possibility that a sufficient air escape effect may not be obtained. In addition, as shown in FIG. 1, the angle “a” at which the ridges 7 are inclined is within the angle formed by the extension line of the ridges 7 to the outside of the grooving roller 5 and the side edges of the grooving rollers 5. Indicates an acute angle.

  Further, as shown in FIG. 2, the plurality of ridges 7 are provided so as to have a predetermined interval b in a direction parallel to the side edge of the grooving roller 5, but if the interval b is too short, the air escape groove It is preferable that the thickness is 1 to 50 mm because air may not be allowed to escape if the length is too long.

  Moreover, if the height h from the surface of the grooved roller 5 of the ridge 7 is too high, the strip may be cut, and if it is too low, a groove having a depth necessary to escape air cannot be obtained. Since there exists a possibility, it is preferable that it is 0.2-5 mm.

  Next, based on an Example, this invention is demonstrated more concretely.

[1] Experiment 1
The three types of grooved rollers shown in FIG. 3 were pressed against the CAP rubber strip having a trapezoidal cross section to form an air escape groove on the surface of each rubber strip. Then, a pneumatic tire having a size of 265 / 65R17 was manufactured using a rubber strip in which an air escape groove was formed.

1. Example 1 and Comparative Examples 1 and 2
In the example, as in the above-described embodiment, the diameter increases from the central part in the axial direction toward both side edges so as to follow the surface shape of the rubber strip having a trapezoidal cross section as shown in FIG. An air relief groove was formed in the entire width direction of the surface of the rubber strip using the grooved roller 5. In addition, the width | variety of each protrusion 7 formed in the grooving roller 5 was set to 1 mm.

  In Comparative Example 1, an air relief groove was formed on the surface of the rubber strip using a conventional grooved roller 5 having a flat pressing surface as shown in FIG. Further, in Comparative Example 2, the pressing surface as shown in FIG. 3 (c) is flat and the surface of the rubber strip using the grooving rollers 5 in which the ridges 7 are formed only on both side edges in the axial direction. An air relief groove was formed on the surface.

  In Example 1 and Comparative Examples 1 and 2, the ridge angle a, the interval b between the ridges, and the height h of the ridges were all the same as shown in Table 1.

2. Evaluation Each raw cover and tire after vulcanization were visually observed, and the degree of air residue (A / T) of each raw cover and tire was evaluated. Specifically, “good” is defined when there is no air remaining in the raw cover, and “good” when there is residual air in the raw cover but no residual air is present in the vulcanized tire. The case where remaining air was confirmed was evaluated as “impossible”. The results are shown in Table 1.

  From Table 1, in the example, the ratio of air remaining in the tire after production was reduced as compared with Comparative Examples 1 and 2. For this reason, an air relief groove is formed in the entire width direction of the rubber strip using a grooving roller having a pressing surface formed so as to follow the surface shape of the rubber strip as shown in FIG. As a result, it was confirmed that the generation of remaining air could be prevented.

[2] Experiment 2
Examples 2-4
In this experiment, as shown in Table 2, in the grooving roller in which the diameters at both ends increase according to the surface shape of the rubber strip having different shapes as shown in FIG. The air escape groove was formed on the surface of the rubber strip by making each different. The other conditions and the remaining air evaluation criteria were the same as in Experiment 1.

  From Table 2, when Examples 2 to 4 were compared, the ratio of remaining air in Example 3 and Example 4 was lower than that in Example 2. From this, it was confirmed that the angle of the ridge is preferably 15 to 90 °.

[3] Experiment 3
Examples 5-8
In this experiment, in the grooving roller as shown in FIG. 3A, as shown in Table 3, the air gap groove was formed on the surface of the rubber strip by changing the interval b between the ridges. In addition, as the angle a of the ridge, the angle within a range confirmed to be preferable in Experiment 2 was 45 °, and the height h of the ridge was 1 mm. The other conditions and the remaining air evaluation criteria were the same as in Experiment 1.

  From Table 3, when Examples 5 to 8 are compared, the ratio of the remaining air in Example 6 and Example 7 was reduced as compared with Example 5 and Example 8. From this, it was confirmed that the interval between the ridges is preferably 1 to 50 mm.

[4] Experiment 4
Examples 9-12
In this experiment, in the grooved roller as shown in FIG. 3 (a), as shown in Table 4, the height h of the ridges was varied to form air escape grooves on the surface of the rubber strip.

  The angle a of the ridges is 45 °, which is an angle within the range confirmed to be preferable in Experiment 2, and the interval b of the ridges is an interval within the range confirmed to be preferable in Experiment 3. 15 7 mm. The other conditions and the remaining air evaluation criteria were set to the same conditions as in Experiment 1.

  From Table 4, when Examples 9 to 12 were compared, the proportion of air remaining in Example 10 and Example 11 was lower than in Examples 9 and 12. From this, it was confirmed that the height of the ridge is preferably 0.2 to 5 mm. Further, in Example 12 in which the height of the ridges was 6 mm, the air escape groove became too deep, and the occurrence of strip breakage was a concern.

  While the present invention has been described based on the embodiments, the present invention is not limited to the above embodiments. Various modifications can be made to the above-described embodiments within the same and equivalent scope as the present invention.

DESCRIPTION OF SYMBOLS 1 Grooving apparatus 2 Rubber strip 3 Conveying belt 5 Grooving roller 6 Pulley 7 Convex line a Angle of convex line b Spacing of convex line

Claims (8)

A rubber strip grooving device that forms an air escape groove on the surface of the rubber strip by pressing the rubber strip conveyed on the conveyor belt with a grooving roller having a plurality of ridges formed on the pressing surface. And
The rubber strip grooving apparatus, wherein the pressing surface of the grooving roller is formed so that the air escape groove can be provided in the entire width direction along the surface shape of the rubber strip.   The pressing surface of the grooving roller is configured to increase in diameter at a predetermined angle from a central portion in the axial direction toward both side edge portions along the surface shape of the rubber strip. Item 2. A rubber strip grooving device according to Item 1.   The groove of the rubber strip according to claim 1 or 2, wherein the plurality of ridges extend in a direction inclined at an angle of 15 to 90 ° with respect to a side edge of the grooving roller. Attachment device.   4. The grooving of a rubber strip according to claim 1, wherein an interval between the plurality of ridges in a direction parallel to a side edge of the grooving roller is 1 to 50 mm. 5. apparatus.   The rubber strip grooving apparatus according to any one of claims 1 to 4, wherein a height of the ridge is 0.2 to 5 mm from a surface of the grooving roller.   6. A rubber strip conveyance device provided with the rubber strip grooving device according to claim 1. A rubber strip grooving method for forming an air escape groove on a surface of the rubber strip using the rubber strip grooving device according to any one of claims 1 to 5.
A method for grooving a rubber strip, wherein an air escaping groove is formed in the entire width direction of the surface of the rubber strip by pressing the rubber strip with the grooving roller.   The manufacturing method of a pneumatic tire which manufactures a pneumatic tire using the rubber strip by which the air escape groove | channel was formed with the grooving method of the rubber strip of Claim 7.

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