JP6911425B2 - Pneumatic tires and their manufacturing methods - Google Patents

Description

The present invention relates to a pneumatic tire in which a carcass layer is mounted between a pair of bead portions and a method for manufacturing the same. More specifically, the sidewall portion is visually recognized by embedding a plurality of colored rubber layers in the sidewall portion. The present invention relates to a pneumatic tire that has made it possible to improve the property and a method for manufacturing the same.

It is common practice to decorate the outer surface of the sidewall of a pneumatic tire with a mark consisting of letters, figures, symbols, etc. in order to display a manufacturer name, a brand name, or the like. Such decoration is formed, for example, as a convex portion protruding from the base surface of the outer surface of the sidewall portion or a concave portion recessed with respect to the base surface. In that case, since the decoration (mark, etc.) and the outer surface of the surrounding sidewall are basically the same color (black), there is a problem that it is difficult to obtain sufficient visibility only with such unevenness. rice field.

On the other hand, in order to enhance the visibility of the decoration, it has been proposed to buff the different color rubber embedded in the sidewall portion to expose the different color rubber (for example, Patent Document 1). However, such a method has a problem that the effect of improving visibility is not sufficient because it has only a single color plane in one character or region.

Further, it has been proposed that a color region having a color different from the ground color of the tire is provided on the surface of the sidewall portion by printing, and a mark having a color different from the color region is displayed in the color region (). For example, Patent Document 2). However, in the structure as described above, since the color region is provided by printing, sufficient durability can be obtained as compared with the structure in which the rubber layer itself forms the color region (structure as in Patent Document 1 above). There is concern that there is no such thing.

Japanese Unexamined Patent Publication No. 4-275136 Japanese Patent No. 5719552

An object of the present invention is to provide a pneumatic tire and a method for manufacturing the same, which makes it possible to improve the visibility of the sidewall portion by embedding a plurality of colored rubber layers in the sidewall portion.

The pneumatic tire of the present invention for achieving the above object has a tread portion extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and these sidewall portions. In a pneumatic tire provided with a pair of bead portions arranged inside in the tire radial direction and a carcass layer mounted between the pair of bead portions, the outer surface of the tire is outside the carcass layer in the sidewall portion. A black sidewall rubber layer arranged so as to be exposed to the tire, and a plurality of colored rubber layers inserted between the sidewall rubber layer and the carcass layer and colored in a color other than black and different from each other. possess the door, wherein the color rubber layer is blue, violet, or the colored a cool color rubber layer and the red and blue-green, orange, warm colored in either the yellow color rubber layer , These colored rubber layers are arranged in the order of cold color and warm color from the outer surface side of the tire .

Further, in the method for manufacturing a pneumatic tire of the present invention, a tread portion extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a tire of these sidewall portions. In a method of manufacturing a pneumatic tire having a pair of bead portions arranged radially inside and a carcass layer mounted between the pair of bead portions, the tire is outside the carcass layer in the sidewall portion. A black sidewall rubber layer arranged so as to be exposed on the outer surface, and a plurality of layers inserted between the sidewall rubber layer and the carcass layer and colored in a color other than black and different from each other. An unvulnerable tire having a rubber layer is molded, and the unvulnerable tire is vulnerable in a mold to form a vulnerable tire, and the colored rubber layer is any of blue, bluish purple, and bluish green. It includes a cold-colored rubber layer colored in, and a warm-colored rubber layer colored in any of red, orange, and yellow, and these colored rubber layers are arranged in the order of cold-colored and warm-colored from the outer surface side of the tire. It is a feature.
Further, the method for manufacturing a pneumatic tire of the present invention includes a tread portion extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a tire of these sidewall portions. In a method of manufacturing a pneumatic tire having a pair of bead portions arranged radially inside and a carcass layer mounted between the pair of bead portions, the tire is outside the carcass layer in the sidewall portion. A black sidewall rubber layer arranged so as to be exposed on the outer surface, and a plurality of layers inserted between the sidewall rubber layer and the vulcanization layer and colored in a color other than black and different from each other. An unvulcanized tire having a rubber layer is molded, the unvulcanized tire is vulcanized in a mold to form a vulcanized tire, and the unvulcanized tire is semi-vulcanized in advance in the molding step of the unvulcanized tire. It is characterized in that the colored rubber layer in a state of being inserted is inserted between the sidewall rubber layer and the carcass layer.

In the pneumatic tire of the present invention, a black sidewall rubber layer arranged so as to be exposed on the outer surface of the tire outside the carcass layer in the sidewall portion is inserted between the sidewall rubber layer and the carcass layer. Since it has a plurality of colored rubber layers that are not black and are colored in different colors, the sidewall portion is cut from the tire outer surface side to expose the colored rubber layer to the tire outer surface. , It is possible to form a plurality of color planes colored in different colors in one character or area, and it is possible to improve the visibility of the sidewall portion.

In the present invention, it is preferable that the plurality of colored rubber layers are exposed on the outer surface of the tire. This makes it possible to improve the visibility of the sidewall portion.

In the present invention, it is preferable that the sidewall portion has a protruding portion and the colored rubber layer is arranged on the protruding portion. As a result, by cutting the protruding portion from the tire outer surface side to expose the colored rubber layer to the tire outer surface, it is possible to form a plurality of color planes colored in different colors in one character or region. This leads to improved visibility of the sidewalls.

In the present invention, the colored rubber layer includes a cold colored rubber layer and a warm colored rubber layer, and it is preferable that these colored rubber layers are arranged in the order of cold color and warm color from the outer surface side of the tire. As a result, the color difference from the black sidewall rubber layer becomes clear, and the visibility of the sidewall portion can be effectively improved.

Further, in the method for manufacturing a pneumatic tire of the present invention, a black sidewall rubber layer arranged so as to be exposed on the outer surface of the tire outside the carcass layer in the sidewall portion, and the sidewall rubber layer and the carcass layer are provided. An unvulnerable tire having a plurality of colored rubber layers inserted in between and colored in different colors other than black is molded, and the unvulnerable tire is vulnerable and vulnerable in a mold. Since the tire is molded, the sidewall portion is cut from the tire outer surface side to expose the colored rubber layer to the tire outer surface, thereby forming a plurality of colored surfaces colored in different colors in one character or region. This makes it possible to improve the visibility of the sidewall portion.

In the present invention, it is preferable to cut the sidewall portion of the vulcanized tire from the tire outer surface side to expose a plurality of colored rubber layers on the tire outer surface. This makes it possible to improve the visibility of the sidewall portion.

In the present invention, it is preferable to provide a protruding portion on the sidewall portion and arrange the colored rubber layer on the protruding portion. As a result, by cutting the protruding portion from the tire outer surface side to expose the colored rubber layer to the tire outer surface, it is possible to form a plurality of color planes colored in different colors in one character or region. This leads to improved visibility of the sidewalls.

In the present invention, in the molding process of an unvulcanized tire, it is preferable to insert a pre-vulcanized colored rubber layer between the sidewall rubber layer and the carcass layer. This makes it possible to suppress the rubber flow of the colored rubber layer and improve the dimensional accuracy of the colored rubber layer.

In the present invention, the colored rubber layer includes a cold colored rubber layer and a warm colored rubber layer, and it is preferable to arrange these colored rubber layers in the order of cold color and warm color from the outer surface side of the tire. This makes it possible to effectively improve the visibility of the sidewall portion.

FIG. 5 is a cross-sectional view taken along the meridian showing a pneumatic tire according to an embodiment of the present invention. It is sectional drawing which shows the sidewall part of the pneumatic tire which concerns on this invention. It is sectional drawing which shows the state which the colored rubber layer embedded in the sidewall portion of the pneumatic tire which concerns on this invention is exposed. It is an X arrow view of FIG. It is sectional drawing which shows the modification of the sidewall part of the pneumatic tire which concerns on this invention.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIGS. 1 to 4 show a pneumatic tire according to an embodiment of the present invention. As shown in FIG. 1, the pneumatic tire according to the embodiment of the present invention has a tread portion 1 extending in the tire circumferential direction to form an annular shape and a pair of sidewall portions arranged on both sides of the tread portion 1. It includes 2, 2 and a pair of bead portions 3, 3 arranged inside the sidewall portions 2 in the tire radial direction.

A carcass layer 4 is mounted between the pair of bead portions 3 and 3. The carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction, and is folded back from the inside to the outside of the tire around the bead core 5 arranged in each bead portion 3. As the reinforcing cord of the carcass layer 4, an organic fiber cord such as polyester is preferably used, but a steel cord may be used. A bead filler 6 made of a rubber composition having a triangular cross section is arranged on the outer periphery of the bead core 5.

On the other hand, a plurality of belt layers 7 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1. These belt layers 7 include a plurality of reinforcing cords that are inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged so as to intersect each other between the layers. In the belt layer 7, the inclination angle of the reinforcing cord with respect to the tire circumferential direction is set in the range of, for example, 10 ° to 40 °. As the reinforcing cord of the belt layer 7, a steel cord is preferably used. At least one layer of the belt cover layer 8 is arranged on the outer peripheral side of the belt layer 7 so that the reinforcing cords are arranged at an angle of, for example, 5 ° or less with respect to the tire circumferential direction for the purpose of improving high-speed durability. There is. As the reinforcing cord of the belt cover layer 8, an organic fiber cord such as nylon or aramid is preferably used.

In the pneumatic tire, the tread rubber layer 11 is arranged on the outer peripheral side of the belt layer 7 in the tread portion 1. Further, a sidewall rubber layer 12 exposed on the outer surface of the tire is arranged on the outer side of the carcass layer 4 in the sidewall portion 2 in the tire width direction. Further, a rim cushion rubber layer 13 exposed on the outer surface of the tire is arranged on the bead portion 3. Further, an inner liner layer 14 is arranged along the carcass layer 4 on the inner surface of the tire.

In the pneumatic tire, the sidewall rubber layer 12 exposed on the outer surface of the tire is colored black like a general tire. On the other hand, between the sidewall rubber layer 12 and the carcass layer 4, a colored rubber layer 15 other than black and colored in different colors is inserted. More specifically, as shown in FIG. 2, the colored rubber layer 15 is composed of three colored rubber layers 15A, 15B, and 15C, is arranged in a region including the maximum tire width position, and is a carcass layer 4. It is arranged so as to wrap around the winding end of the tire. Further, the number of layers of the colored rubber layer 15 is preferably 3 or 4 from the viewpoint of distinguishability of each layer. The color of each layer of the colored rubber layer 15 is not particularly limited, but different colors such as red, orange, yellow, blue, green, and purple can be adopted. The thickness t of each layer in the plurality of colored rubber layers 15 is preferably 0.7 mm or more in order to ensure the distinctiveness of each layer.

As shown in FIG. 3, the exposed portion 16 is formed on the sidewall portion 2 by cutting from the outer surface side of the tire. That is, the plurality of colored rubber layers 15 are arranged so as to be exposed on the outer surface of the tire. Further, as shown in FIG. 4, in the exposed portion 16, the colored rubber layers 15A, 15B, and 15C are formed so as to form an ellipse, and the colored rubber layers 15A, 15B, and 15C are arranged at equal intervals from each other. There is.

According to the pneumatic tire configured as described above, the black sidewall rubber layer 12 arranged so as to be exposed on the outer surface of the tire on the outside of the carcass layer 4 in the sidewall portion 2, and the sidewall rubber layer 12 Since it has a plurality of colored rubber layers 15 inserted between the carcass layer 4 and colored in colors other than black and different from each other, the sidewall portion 2 is as shown in FIGS. 3 and 4. By exposing the colored rubber layer 15 to the outer surface of the tire by cutting the tire from the outer surface side of the tire, it is possible to form a plurality of colored surfaces colored in different colors in one character or region, and the sidewall portion 2 It is possible to improve the visibility of the tire.

In the aspect of FIG. 3, an example is shown in which all the three colored rubber layers 15A, 15B and 15C are exposed on the outer surface of the tire, but any of the three colored rubber layers 15A, 15B and 15C Alternatively, only one or two layers may be configured to be exposed on the outer surface of the tire. Further, in the aspect of FIG. 4, an example in which the entire shape of the exposed portion 16 is formed into an elliptical shape is shown, but in addition to FIG. 4, figures such as circles and polygons, characters, symbols, and the like are formed. It can also be formed into.

In the pneumatic tire, it is preferable that the colored rubber layer 15 includes a cold colored rubber layer 15 and a warm colored rubber layer 15, and these colored rubber layers 15 are arranged in the order of cold color and warm color from the outer surface side of the tire. .. That is, it is preferable that the warm-colored rubber layer 15 is arranged on the carcass layer 4 side. Here, examples of warm colors include red, orange, and yellow, and examples of cold colors include blue, bluish purple, and blue-green. At a position deep from the outer surface of the tire (on the side of the carcass layer 4) in the sidewall portion 2, it may be difficult to judge the color surface depending on the amount of light. The color difference from the layer 12 becomes clear, and the visibility of the sidewall portion 2 can be effectively improved.

FIG. 5 shows a modified example of the sidewall portion of the pneumatic tire according to the present invention. As shown in FIG. 5, four colored rubber layers 15A to 15D are arranged on the sidewall portion 2, and a protruding portion 17 protruding from the outer surface of the tire is formed on the outer side thereof. The height h of the protruding portion 17 is preferably 1.0 mm to 2.7 mm. The height h of the protruding portion 17 is the maximum height from the extension line (dotted line shown in FIG. 5) of the contour of the outer surface of the tire of the sidewall portion 2. Further, a colored rubber layer 15 is arranged on the protruding portion 17. Since the colored rubber layer 15 is arranged on the protruding portion 17 in this way, the protruding portion 17 is cut from the outer surface side of the tire to expose the colored rubber layer 15 on the outer surface of the tire, whereby in one character or region. It is possible to form a plurality of color planes colored in different colors, which leads to improvement in visibility of the sidewall portion 2. Further, when cutting the protruding portion 17, decorations such as characters, figures, and symbols can be applied.

Next, a method for manufacturing a pneumatic tire according to the present invention will be described. In the method for manufacturing a pneumatic tire of the present invention, a sidewall rubber layer 12 is arranged outside the carcass layer 4 in the sidewall portion 2 so as to be exposed on the outer surface of the tire, and the sidewall rubber layer 12 and the carcass layer 4 are combined with each other. An unvulcanized tire in which a plurality of colored rubber layers 15 are inserted is formed between the tires. Then, the unvulcanized tire is vulcanized in a mold to form a vulcanized tire. Further, the sidewall portion 2 of the vulcanized tire is cut from the tire outer surface side to expose the plurality of colored rubber layers 15 to the tire outer surface.

According to the pneumatic tire manufactured in this manner, the black sidewall rubber layer 12 arranged so as to be exposed on the outer surface of the tire on the outside of the carcass layer 4 in the sidewall portion 2, and the sidewall rubber layer 12 Since it has a plurality of colored rubber layers 15 inserted between the carcass layer 4 and colored in colors other than black and different from each other, the sidewall portion 2 is as shown in FIGS. 3 and 4. By exposing the colored rubber layer 15 to the outer surface of the tire by cutting the tire from the outer surface side of the tire, it is possible to form a plurality of colored surfaces colored in different colors in one character or region, and the sidewall portion 2 It is possible to improve the visibility of the tire.

In the method for manufacturing a pneumatic tire, in the molding process of an unvulcanized tire, an annular colored rubber layer 15 in a pre-vulcanized state can be inserted between the sidewall rubber layer 12 and the carcass layer 4. preferable. This makes it possible to suppress the rubber flow of the colored rubber layer 15 and improve the dimensional accuracy of the colored rubber layer 15.

In a pneumatic tire having a tire size of 205 / 55R16, provided with a tread portion, a sidewall portion and a bead portion, and a carcass layer mounted between the pair of bead portions, the outside of the carcass layer in the sidewall portion is black. The sidewall rubber layer of the tire is arranged so as to be exposed on the outer surface of the tire, and a colored rubber layer colored in a color other than black and different from each other is arranged between the sidewall rubber layer and the carcass layer. Examples 1 to 1 in which the number of layers, the thickness of the entire colored rubber layer [mm] (thickness of each layer of the colored rubber layer [mm]), and the order of the colored rubber layers from the outer surface of the tire are set as shown in Table 1. I made 6 tires. In Examples 1 to 6, a structure was adopted in which all layers of the colored rubber layer were exposed on the outer surface of the tire.

For comparison, the tires of the conventional example having the same structure as those of Examples 1 to 6 were prepared except that the colored rubber layer was not arranged on the sidewall portion.

For these test tires, visibility and appropriateness of judgment were evaluated by the following evaluation methods, and the results are also shown in Table 1.

Visibility:
The ease of visually observing the sidewall of the tire and recognizing the presence of the colored rubber layer was evaluated. The evaluation results are indicated by "C" when color-based visual recognition is not possible, "B" when color-based visual recognition is difficult, and "A" when color-based visual recognition is easy. ..

Appropriateness of judgment:
By visually observing the sidewall of the tire and judging the color of the colored rubber layer and the number of colored surfaces, it was evaluated whether or not the judgment was appropriate. The evaluation results are indicated by "C" when the visual judgment cannot be made based on the color, "B" when the visual judgment is not always appropriate, and "A" when the visual judgment is appropriate. ..

As is clear from Table 1, the tires of Examples 1 to 6 were excellent in visibility and appropriateness of judgment in comparison with the conventional examples. Since the five colored rubber layers are used in Example 5, the existence of the colored rubber layer in the sidewall portion can be easily confirmed, but the color plane of the colored rubber layer can be accurately confirmed visually. I couldn't judge.

1 tread part 2 sidewall part 3 bead part 4 carcass layer 5 bead core 6 bead filler 7 belt layer 8 belt cover layer 11 tread rubber layer 12 sidewall rubber layer 13 rim cushion rubber layer 14 inner liner layer 15 color rubber layer 16 exposed part 17 protruding part

Claims (9)

A tread portion extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a pair of bead portions arranged inside the tire radial direction of these sidewall portions. In a pneumatic tire in which a carcass layer is mounted between the pair of bead portions, a black sidewall rubber layer arranged so as to be exposed on the outer surface of the tire on the outside of the carcass layer in the sidewall portion. , possess a plurality of layers color rubber layer colored in the inserted and other than black have different colors from each other between said and said sidewall rubber layer carcass layer, the color rubber layer is blue, blue-violet, It includes a cold-colored rubber layer colored in any of blue-green and a warm-colored rubber layer colored in either red, orange, or yellow, and these colored rubber layers are cold-colored or warm-colored from the outer surface side of the tire. Pneumatic tires characterized by being arranged in order. The pneumatic tire according to claim 1, wherein the plurality of colored rubber layers are exposed on the outer surface of the tire. The pneumatic tire according to claim 1 or 2, wherein the sidewall portion has a protruding portion, and the colored rubber layer is arranged on the protruding portion. A tread portion extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a pair of bead portions arranged inside the tire radial direction of these sidewall portions. In the method of manufacturing a pneumatic tire in which a carcass layer is mounted between the pair of bead portions, a black side arranged so as to be exposed on the outer surface of the tire on the outside of the carcass layer in the sidewall portion. An unrefined tire having a wall rubber layer and a plurality of colored rubber layers inserted between the sidewall rubber layer and the carcass layer and colored in colors other than black and different from each other is formed. The unsulfurized tire is sulfurized in a mold to form a sulfurized tire, and the colored rubber layer is a cold colored rubber layer colored in any of blue, bluish purple, and bluish green, and red and orange. A method for manufacturing a pneumatic tire, which comprises a warm colored rubber layer colored in any of yellow and yellow, and arranges these colored rubber layers in the order of cold color and warm color from the outer surface side of the tire. A tread portion extending in the tire circumferential direction to form an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a pair of bead portions arranged inside the tire radial direction of these sidewall portions. In the method of manufacturing a pneumatic tire in which a carcass layer is mounted between the pair of bead portions, a black side arranged so as to be exposed on the outer surface of the tire on the outside of the carcass layer in the sidewall portion. An unvulcanized tire having a wall rubber layer and a plurality of colored rubber layers inserted between the sidewall rubber layer and the carcass layer and colored in colors other than black and different from each other is formed. The unvulcanized tire is vulcanized in a mold to form a vulcanized tire, and in the molding step of the unvulcanized tire, the colored rubber layer in a state of being semi-vulcanized in advance is used as the sidewall rubber layer. A method for manufacturing a pneumatic tire, which comprises inserting the tire between the tire and the carcass layer. The manufacture of a pneumatic tire according to claim 4 or 5, wherein the sidewall portion of the vulcanized tire is cut from the tire outer surface side to expose the plurality of colored rubber layers to the tire outer surface. Method. The method for manufacturing a pneumatic tire according to any one of claims 4 to 6, wherein a protruding portion is provided on the sidewall portion and the colored rubber layer is arranged on the protruding portion. The air according to claim 4, wherein in the molding step of the unvulcanized tire, the colored rubber layer in a pre-vulcanized state is inserted between the sidewall rubber layer and the carcass layer. How to manufacture vulcanized tires. The colored rubber layer includes a cold colored rubber layer colored in any of blue, bluish purple, and bluish green, and a warm colored rubber layer colored in any of red, orange, and yellow , and these colored rubber layers. The method for manufacturing a pneumatic tire according to claim 5 , wherein the colors are arranged in the order of cold color and warm color from the outer surface side of the tire.

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