JP6664656B2 - Rubber strip grooving apparatus and grooving method - Google Patents

Description

  The present invention relates to a rubber strip grooving apparatus and a grooving method used for forming an air release groove on a surface of a rubber strip being conveyed.

  In general, in the molding of a pneumatic tire, a so-called strip wind system 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 the tire are laminated and molded. .

  In this strip wind method, a gap may be formed between the wound rubber strips and air residue may be generated after vulcanization molding. Therefore, conventionally, a slit-shaped air is supplied to the rubber strip before being supplied to the molding drum. A relief groove is formed (for example, Patent Documents 1 and 2).

  FIG. 4 is a schematic side view of a general rubber strip grooving device. A rubber strip grooving device 1 (hereinafter, also simply referred to as a “grooving device”) has a conveyor belt for conveying a rubber strip 2. 3 is provided to face the pulley 6.

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

JP 2007-136894 A JP 2008-62639A

  However, even if the grooving roller of the above-described grooving device is pressed against the rubber strip, air release 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 still remains a problem that air remains after vulcanization molding.

  In view of the above, the present invention provides a technology capable of forming a sufficient air escape groove in the entire width direction up to both side edges of the surface of the rubber strip to prevent the occurrence of air residue in the tire after vulcanization molding. The task is to provide.

The invention described in claim 1 is
Pressing a rubber strip formed in a trapezoidal cross section whose both ends are thinner than the center in the width direction and conveyed on the conveyance belt with a grooved roller having a plurality of ridges formed on a pressing surface. A rubber strip grooving device that forms an air escape groove on the surface of the rubber strip by:
The pressing surface of the grooving roller is configured so that the diameter increases at a predetermined angle from the central portion in the axial direction to both side edges along the surface shape of the rubber strip,
The pressing surface of the grooved roller is formed so that the air release groove can be provided in the entire area in the width direction along the surface shape of the rubber strip. is there.

The invention described in claim 2 is
The rubber strip grooving device according to claim 1, 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. .

The invention according to claim 3 is
The rubber strip grooving device according to claim 1 or 2, 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.

The invention described in claim 4 is
The rubber strip grooving device according to any one of claims 1 to 3 , wherein the height of the ridge is 0.2 to 5 mm from the surface of the grooving roller. .

The invention according to claim 5 is
A rubber strip conveying device provided with the rubber strip grooving device according to any one of claims 1 to 4 .

The invention according to claim 6 is
A method for forming a rubber strip, comprising forming an air escape groove on a surface of the rubber strip by using the rubber strip forming apparatus according to any one of claims 1 to 4 .
A rubber strip grooving method, wherein 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 7 is
A pneumatic tire manufacturing method for manufacturing a pneumatic tire using a rubber strip having an air escape groove formed by the rubber strip groove forming method according to claim 6 .

  ADVANTAGE OF THE INVENTION According to this invention, the technique which can form the air release groove | channel sufficiently in the whole area | region of the width direction to both side edges of the surface of a rubber strip, and can prevent that the air residue remains in the tire after vulcanization molding is provided. can do.

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

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

  The grooving device according to the present embodiment is provided so as to face a conveyor belt that conveys a rubber strip, as in the conventional grooving device, and air is applied to the surface of the rubber strip that is conveyed on the conveyor belt. A grooved roller for forming a relief groove is provided, and a plurality of ridges are formed on a pressing surface of the grooved roller.

  However, the grooving device according to the present embodiment differs from the conventional grooving device in the shape of the grooving roller used. Hereinafter, a specific description will be given.

  FIG. 1 is a view for explaining the relationship between a grooved roller and a rubber strip in a 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. FIG. 4 is a side view schematically showing a part of the grooved roller.

  As shown in FIG. 1, in the present embodiment, the pressing surface of the grooving roller 5 is provided so that an air escape groove can be provided in the entire region in the 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 member having a trapezoidal cross section in which both ends are thinner than the center in the width direction, the conventional grooved roller 5 shown in FIG. If it is attempted to form an air escape groove by using this method, the air escape groove is formed only in the central portion of the rubber strip, and the air escape groove cannot be formed sufficiently on 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 conforms to the surface shape of the rubber strip 2 having a trapezoidal cross section. In addition, it is configured such that the diameter increases at a predetermined angle from the central portion in the axial direction toward both side edges.

  Accordingly, when the grooving roller 5 is pressed against the rubber strip 2, the ridge 7 presses the entire area in the width direction of the rubber strip 2, so that not only the center portion of the rubber strip 2 in the width direction but also both side edges are provided. The air escape groove can be formed sufficiently. As a result, it is possible to appropriately prevent air remaining in the tire after vulcanization.

  Although the present invention is not particularly limited, the shape of the ridge 7 formed on the pressing surface of the groove roller 5 is preferably, for example, as follows.

  As shown in FIG. 1, in the present embodiment, the ridge 7 is 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. Is preferably 15 to 90 ° because the distance of the air may become long and a sufficient air releasing effect may not be obtained. The angle a at which the ridge 7 is inclined is, as shown in FIG. 1, an angle formed by an extension of the ridge 7 to the outside of the grooving roller 5 and a side edge of the grooving roller 5. Indicates a sharp angle.

  Further, as shown in FIG. 2, the plurality of ridges 7 are provided at 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 is provided. May not be formed, and if it is too long, air may not be able to escape. Therefore, the thickness is preferably 1 to 50 mm.

  On the other hand, if the height h of the ridge 7 from the surface of the grooved roller 5 is too high, the strip may be cut off. If the height h is too low, a groove having a depth necessary to allow air to escape cannot be obtained. It is preferable that the thickness be 0.2 to 5 mm because of the fear.

  Next, the present invention will be described more specifically based on examples.

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

1. Example 1 and Comparative Examples 1 and 2
In the example, similarly to the above-described embodiment, the diameter increases from the center in the axial direction to both side edges along the surface shape of the rubber strip having a trapezoidal cross section as shown in FIG. An air escape groove was formed in the entire width direction of the surface of the rubber strip by using the grooved roller 5. The width of each ridge 7 formed on the grooving roller 5 was set to 1 mm.

  In Comparative Example 1, an air escape 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. 3C was flat, and the surface of the rubber strip was formed using the grooved roller 5 in which the ridges 7 were formed only on both side edges in the axial direction. An air escape groove was formed in the air hole.

  In Example 1 and Comparative Examples 1 and 2, the angle a of the ridge of each grooved roller, 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 manufactured raw cover and the tire after vulcanization were visually observed to evaluate the degree of residual air (A / T) of each raw cover and the tire. Specifically, the case where no air residue is seen on the raw cover is defined as “good”, and the case where there is air remaining on the raw cover but no air residue is seen on the vulcanized tire is “OK”, and the tire after vulcanization is The case where air remaining was confirmed was evaluated as “impossible”. Table 1 shows the results.

  As shown in Table 1, in the example, the ratio of remaining air in the manufactured tire was smaller than that in comparative examples 1 and 2. Therefore, as shown in FIG. 3A, an air release groove is formed in the entire area of the rubber strip in the width direction using a grooved roller having a pressing surface formed along the surface shape of the rubber strip. Thus, it was confirmed that the generation of air residue can be prevented.

[2] Experiment 2
Examples 2 to 4
In this experiment, as shown in Table 2, in a grooved roller in which the diameter of both ends becomes large according to the surface shape of the rubber strip having a different shape as shown in FIG. And air escape grooves were formed on the surface of the rubber strip. The other conditions and the evaluation criteria for the remaining air were the same as in Experiment 1.

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

[3] Experiment 3
Examples 5 to 8
In this experiment, as shown in Table 3, air release grooves were formed on the surface of the rubber strip by varying the intervals b between the ridges in the grooved roller as shown in FIG. In addition, the angle a of the ridge was set to 45 ° which is an angle within a range confirmed to be preferable in Experiment 2, and the height h of the ridge was set to 1 mm. The other conditions and the evaluation criteria for the remaining air were the same as in Experiment 1.

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

[4] Experiment 4
Examples 9 to 12
In this experiment, as shown in Table 4, in the grooving roller as shown in FIG. 3A, air escape grooves were formed on the surface of the rubber strip with different heights h of the ridges.

  Note that the angle a of the ridge is 45 °, which is an angle within the range confirmed to be preferable in Experiment 2, and the interval b between the ridges is 15 which is within the range confirmed to be preferable in Experiment 3. 0.7 mm. The other conditions and the evaluation criteria for the remaining air were set to the same conditions as in Experiment 1.

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

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above embodiments. Various changes can be made to the above embodiment within the same and equivalent scope as the present invention.

DESCRIPTION OF SYMBOLS 1 Grooving device 2 Rubber strip 3 Conveying belt 5 Grooving roller 6 Pulley 7 Convex a a Convex angle b Convex interval h Convex height

Claims (7)

Pressing a rubber strip formed in a trapezoidal cross section whose both ends are thinner than the center in the width direction and conveyed on the conveyance belt with a grooved roller having a plurality of ridges formed on a pressing surface. A rubber strip grooving device that forms an air escape groove on the surface of the rubber strip by:
The pressing surface of the grooving roller is configured so that the diameter increases at a predetermined angle from the central portion in the axial direction to both side edges along the surface shape of the rubber strip,
A rubber strip grooving device, wherein a pressing surface of the grooving roller is formed so as to be able to provide the air escape groove in an entire region in a width direction along a surface shape of the rubber strip. 2. The rubber strip grooving device according to claim 1, 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. 3. Grooving apparatus of the rubber strip according to claim 1 or claim 2 spacing of the plurality of convex at the side edges parallel to the direction of the grooving roller, characterized in that a 1 to 50 mm. The grooved device for a rubber strip according to any one of claims 1 to 3 , wherein a height of the ridge is 0.2 to 5 mm from a surface of the grooved roller. A rubber strip conveying device provided with the rubber strip groove forming device according to any one of claims 1 to 4 . A method for forming a rubber strip, comprising forming an air escape groove on a surface of the rubber strip by using the rubber strip forming apparatus according to any one of claims 1 to 4 .
A rubber strip grooving method, wherein 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. A pneumatic tire manufacturing method for manufacturing a pneumatic tire using a rubber strip having an air escape groove formed by the rubber strip groove forming method according to claim 6 .

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