JP6836391B2 - How to make a pneumatic tire - Google Patents

Description

The present invention relates to a pneumatic tire.

Conventionally, as a pneumatic tire, a composite rubber ribbon composed of two layers of conductive rubber and non-conductive rubber is spirally wound, and the conductive rubbers are partially overlapped to form a conductive path. Has been proposed (see, for example, Patent Document 1).

Further, as another pneumatic tire, a base tread provided inside the cap tread in the radial direction of the tire is proposed in which a surface layer portion and an inner layer portion are formed (see, for example, Patent Document 2).

However, the former pneumatic tire is characterized by ensuring conductivity when the composite rubber ribbon is spirally wound, and does not take into consideration the rolling resistance (RR) of the tire.

Further, the latter pneumatic tire is configured to wind a wide base tread, and if the tire size and shape are different, it is necessary to prepare a tire corresponding to the tire size and shape.

Japanese Unexamined Patent Publication No. 2014-43138 Japanese Unexamined Patent Publication No. 2013-233899

An object of the present invention is to provide a method for manufacturing a pneumatic tire which can flexibly cope with a difference in size and the like by a ribbon method and has low rolling resistance.

The present invention provides means for solving the above problems.
A method for manufacturing a pneumatic tire having a rubber member in which strip rubber is spirally wound.
The strip rubber is spirally wound to form a rubber member,
The strip rubber is composed of an outer surface layer made of rubber specialized in wear performance and an inner surface layer made of rubber specialized in fuel efficiency performance .
The strip rubber is formed in a triangular cross section having a bottom surface and a slope so as to gradually narrow from both sides from the inner surface layer toward the outer surface layer.
The strip rubber has the same cross section and is wound in multiple layers.
The strip rubber provides a method for manufacturing a pneumatic tire, characterized in that the inner surface layer is exposed only to the bottom surface.

With this configuration, the outer surface side can be composed of an outer surface layer made of rubber specialized for wear performance simply by winding the strip rubber, and excellent wear resistance can be exhibited. Further, since the inner surface side is made of rubber specializing in fuel efficiency, it is possible to suppress rolling resistance and improve fuel efficiency.

The strip rubber is preferably wound so that halves in the width direction overlap.

With this configuration, it is possible to easily form a layer made of rubber specialized in wear performance and a layer made of rubber specialized in fuel efficiency performance in the tire radial direction simply by winding the strip rubber.

According to the present invention, since the strip rubber composed of the outer surface layer made of the wear performance specialized rubber and the inner surface layer made of the fuel consumption performance specialized rubber is spirally wound, the wear resistance during running is maintained. At the same time, rolling resistance can be suppressed and fuel efficiency can be improved.

It is a meridian semi-cross-sectional view which shows the outline of the pneumatic tire which concerns on this embodiment. It is sectional drawing of the strip rubber for forming the tread part and the shoulder part of FIG. It is the schematic of the extruder for forming the strip rubber of FIG. It is sectional drawing which shows the state which wound the strip rubber of FIG. 2 in a spiral shape. It is sectional drawing of the strip rubber which concerns on another embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings. It should be noted that the following description is essentially merely an example and is not intended to limit the present invention, its application, or its use. In addition, the drawings are schematic, and the ratio of each dimension is different from the actual one.

FIG. 1 is a meridian semi-cross-sectional view showing an outline of a pneumatic tire according to the present embodiment. This pneumatic tire is provided with a carcass ply 2, a belt layer 3, and a reinforcing layer 4 from the inner liner 1 located on the inner diameter side in the tire radial direction toward the tire outer diameter side, and the surface side is the tread portion 5 and the shoulder portion. It is composed of 6. Both ends of the carcass ply 2 extend to the bead core 7, are folded back from the inside to the outside of the tire, and sandwich the bead filler 8. The illustration and description of other components will be omitted.

The belt layer 3 is composed of a first belt portion 9 arranged inside in the tire radial direction and a second belt portion 10 arranged outside. The first belt portion 9 extends halfway through the shoulder portion 6 in the tire width direction. The second belt portion 10 has a narrower forming range outward in the tire width direction than the first belt portion 9.

The reinforcing layer 4 is made of reinforcing rubber by arranging fiber cords of a resin material (for example, nylon 66) in a plurality of rows at predetermined intervals and covering them with a rubber material, and spirally wound so as to cover the belt layer 3. It was done.

The tread portion 5 and the shoulder portion 6 are formed by winding the strip rubber 11.

As shown in FIG. 2, the strip rubber 11 has a triangular cross section and extends in a strip shape. Further, the strip rubber 11 is composed of two layers, a rubber specialized in wear performance and a rubber specialized in fuel efficiency performance. The fuel efficiency performance specialized rubber constitutes the bottom portion of the strip rubber 11, that is, the inner surface layer 12, and the other portion, that is, the outer surface layer 13 is composed of the wear performance specialized rubber. Hereinafter, in the strip rubber 11, the surface on which the inner surface layer 12 is exposed is referred to as a bottom surface 14, one slope on which the outer surface layer 13 and a part of the inner surface layer 12 are exposed is referred to as a first slope 15, and the other is referred to as a second slope 16. Further, the portion of the bottom surface 14 corresponding to the first slope 15 is referred to as the first half surface 17, and the portion corresponding to the second slope 16 is referred to as the second half surface 18.

Rubber specialized in wear performance is made of a material that is hard to wear but has excellent grip, which is suitable for use in parts that come into direct contact with the road surface. The fuel-efficient rubber is made of a high-resilience material and acts to reduce the rolling resistance of the tire.

The strip rubber 11 can be formed by using the two extruders 19 shown in FIG.

Each extruder 19 includes a screw (not shown) in the main body 20. The screw is rotated by a drive device 21 such as a motor. The main body 20 is provided with a hopper 22 for inserting rubber. A die 24 having a base 23 is attached to the tip portion of both extruders 19. A pair of feed rollers 25, a crimping roller 26, and a drum 27 are arranged in front of the die 24.

The pneumatic tire having the above configuration can be obtained by vulcanizing and molding a green tire formed as follows.

In forming the green tire, the inner liner 1, the belt layer 3 and the reinforcing layer 4 are wound around the outer circumference of the drum 27. Then, the strip rubber 11 is wound around these outer circumferences.

The strip rubber 11 to be wound is formed as follows.

First, the wear performance specialized rubber and the fuel consumption performance specialized rubber are input from the hopper 22 of each extruder 19. The rubber specialized in wear performance and the rubber specialized in fuel efficiency performance are sent forward while being kneaded by the rotation of the screw, merged by the die 24, and the strip rubber 11 having a triangular cross section overlapped in two layers from the base 23 at the tip. Extruded as.

After passing between the pair of feed rollers 25, the strip rubber 11 is wound around the outer circumference of the previously wound reinforcing layer 4 while being pressed by the crimping roller 26.

As shown in FIG. 4, the strip rubber 11 starts winding from the central portion of the reinforcing layer 4 so that the bottom surface 14 is in close contact with the outer peripheral surface of the reinforcing layer 4, and is spirally wound toward one side edge portion. To do. Here, with reference to the cross-sectional position shown in FIG. 4, the winding portion of the first lap is the first winding portion, the winding portion of the second lap is the second winding portion, and so on. The turning part is referred to as the nth winding part.

When the second winding portion is wound around the first winding portion of the strip rubber 11, the first half surface 17 of the bottom surface 14 of the second winding portion comes into contact with the second slope 16 of the first winding portion. .. The remaining half of the second winding portion is elastically deformed, and the second half surface 18 comes into contact with the reinforcing layer 4. In this state, the inner surface layer 12 of the first winding portion and the inner surface layer 12 of the second winding portion are continuous. Hereinafter, in the same manner, the inner surface layer 12 of the nth winding portion and the inner surface layer 12 of the (n + 1) winding portion are made continuous.

Subsequently, if the winding position of the strip rubber 11 exceeds the side edge portion of the reinforcing layer 4, the strip rubber 11 is folded back, and this time, the strip rubber 11 is wound to a position exceeding the side edge portion on the opposite side. The second layer is wound in the same manner as the first layer wound earlier. When it is wound to the center position, it is wound directly to the reinforcing layer, and when it exceeds the opposite side edge portion, it is folded back and wound as the second layer, and is terminated at the winding end position of the central portion.

In the rubber member obtained by winding in this way, the inner surface layer 12 composed of the fuel consumption performance specialized rubber is located on the inner diameter side in both the first layer and the second layer, and the wear performance specialized rubber is located. The outer surface layer 13 composed of is located on the outer diameter side. That is, each has a two-layer structure composed of the fuel efficiency performance specialized rubber of the inner surface layer 12 and the wear performance specialized rubber of the outer surface layer 13, and has a four-layer structure as a whole.

According to this, the outer diameter surface of the tire can be composed of the outer surface layer 13 made of the rubber specialized for wear performance. Further, the inner surface layer 12 made of rubber specializing in fuel efficiency can be arranged on the inner diameter side of the tire. Therefore, the rolling resistance can be reduced by the inner surface layer 12 while providing the outer surface layer 13 having excellent wear resistance and grip.

Further, the tread portion 5 and the shoulder portion 6 which are rubber members can be formed only by winding the strip rubber 11 having a two-layer structure in which the inner surface layer 12 and the outer surface layer 13 are integrated. Therefore, the manufacturing process can be simplified and the product can be manufactured at low cost. In addition, it is possible to flexibly cope with the manufacture of various pneumatic tires having different sizes.

The present invention is not limited to the configuration described in the above embodiment, and various modifications can be made.

In the above embodiment, the number of windings when the strip rubber 11 is spirally wound is shown only in the example shown in FIG. 4, but it can be freely changed according to the difference in the tire width dimension of the pneumatic tire. Can be done.

In the above embodiment, the strip rubber 11 is wound in two layers, but it may be wound in one layer or three or more layers. It is also possible to partially increase the number of turns to make the number of layers in the tire width direction different.

In the above embodiment, the thickness of the inner surface layer 12 and the outer surface layer 13 of the strip rubber 11 and the width dimension of the strip rubber itself are not particularly mentioned, but they can be freely set according to the specifications of the pneumatic tire.

In the above embodiment, a part of the inner surface layer 12 is exposed not only on the bottom surface 14 of the strip rubber 11 but also on the first slope 15 and the second slope 16, but as shown in FIG. 5, the bottom surface 14 is exposed. It can also be configured to be exposed only. According to this, the inner surface layer 12, that is, the fuel-efficient rubber specialized rubber can be configured so as not to be exposed on the tread portion 5 and the shoulder portion 6 obtained by winding the strip rubber 11.

1 ... Inner liner 2 ... Carcass ply 3 ... Belt layer 4 ... Reinforcing layer 5 ... Tread part 6 ... Shoulder part 7 ... Bead core 8 ... Bead filler 9 ... 1st belt part 10 ... 2nd belt part 11 ... Strip rubber 12 ... Inner surface Layer 13 ... Outer surface layer 14 ... Bottom surface 15 ... First slope 16 ... Second slope 17 ... First half surface 18 ... Second half surface 19 ... Extruder 20 ... Main body 21 ... Drive device 22 ... Hopper 23 ... Base 24 ... Die 25 ... Feed roller 26 ... Crimping roller 27 ... Drum

Claims (2)

A method for manufacturing a pneumatic tire having a rubber member in which strip rubber is spirally wound.
The strip rubber is spirally wound to form a rubber member,
The strip rubber is composed of an outer surface layer made of rubber specialized in wear performance and an inner surface layer made of rubber specialized in fuel efficiency performance .
The strip rubber is formed in a triangular cross section having a bottom surface and a slope so as to gradually narrow from both sides from the inner surface layer toward the outer surface layer.
The strip rubber has the same cross section and is wound in multiple layers.
The strip rubber is a method for manufacturing a pneumatic tire , wherein the inner surface layer is exposed only to the bottom surface . The method for manufacturing a pneumatic tire according to claim 1, wherein the strip rubber is wound so that halves in the width direction overlap each other.

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