JP2006205916A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire enhancing ride comfort and noise vibration performance while suppressing reduction of high speed durability and high load durability. <P>SOLUTION: The pneumatic tire is provided with a belt reinforcement layer in which an organic fiber cord 16 is wound on an outer side in a tire radial direction of a belt layer. Further, a broken part 18 is arranged on the organic fiber cord 16. Thereby, tension of the belt reinforcement layer generated in a tire circumferential direction is reduced and enhancement of the ride comfort and noise vibration performance can be realized. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pneumatic tire provided with a belt reinforcing layer that reinforces a belt layer.

  In recent years, flattened tires have been required to have higher performance in terms of high-speed durability and high load durability (extra-loading) (see, for example, Patent Document 1).

  In order to improve high-speed durability and high-load durability (especially plunger energy), conventionally, increasing the number of belt reinforcement layers to increase the strength (force of the belt reinforcement layer against the cord pulling direction) I have done it.

However, conventionally, by improving the strength of the belt reinforcing layer, the circumferential rigidity of the belt is increased, and there is a problem that riding comfort and NV performance (noise vibration performance) are deteriorated.
Japanese Utility Model Publication No. 61-161104

  In view of the above facts, an object of the present invention is to provide a pneumatic tire with improved riding comfort and noise vibration performance while suppressing a decrease in high speed durability and high load durability.

  The invention according to claim 1 is a pneumatic tire provided with a belt reinforcing layer formed by winding an organic fiber cord on the outer side in the tire radial direction of the belt layer, wherein the discontinuous portion of the organic fiber cord is the belt reinforcement. It is characterized by being arranged in a layer.

  Thereby, the tension of the belt reinforcing layer generated in the tire circumferential direction can be reduced, and the riding comfort and NV performance (noise vibration performance) can be improved. Therefore, it is possible to provide a pneumatic tire with improved riding comfort and noise vibration performance while suppressing a decrease in high speed durability and high load durability.

  The invention according to claim 2 is characterized in that the organic fiber cords are arranged so as not to continuously overlap in the tire radial direction.

  Thereby, the effect of reducing the tension of the belt reinforcing layer can be increased, and the riding comfort and the NV performance can be easily improved.

  The invention according to claim 3 is characterized in that the discontinuous portions are not adjacent to each other in the adjacent organic fiber cords.

  Thereby, since a part with low rigidity cannot be made to adjoin, it is easy to maintain high-speed durability and high load durability.

  The organic fiber cord may be constituted by a single cord or a ribbon-like spiral member.

  By the way, the engine of a vehicle equipped with a pneumatic tire tends to generate vibration when the angle formed is 90 ° or 120 °.

  Accordingly, in the invention according to claim 4, the discontinuous portions are formed in the adjacent organic fiber cords respectively, and an angle formed by the discontinuous portions around the tire central axis is n times 90 ° (n is a natural number) ).

  Thereby, it is easy to prevent the engine and the tire from resonating, and it is easy to suppress deterioration of uniformity.

  According to a fifth aspect of the present invention, the discontinuous portions are respectively formed in the adjacent organic fiber cords, and an angle formed by the discontinuous portions around the tire central axis is n times 120 ° (n is a natural number). It is deviated.

  Thereby, like the invention of Claim 4, it is easy to prevent an engine and a tire from resonating, and it is easy to suppress deterioration of uniformity.

  The invention according to claim 6 is characterized in that the total sum of the angles formed deviates from n times 360 ° (n is a natural number).

  Thereby, it is easy to suppress the deterioration of uniformity.

  Since the present invention has the above configuration, the following effects can be obtained.

  According to the first aspect of the present invention, it is possible to provide a pneumatic tire with improved riding comfort and noise vibration performance while suppressing a decrease in high speed durability and high load durability.

  According to the second aspect of the present invention, the effect of reducing the tension of the belt reinforcing layer can be increased, and the riding comfort and the NV performance can be easily improved.

  According to invention of Claim 3, since a part with low rigidity cannot be made to adjoin, it is easy to maintain high-speed durability and high load durability.

  According to the invention described in claim 4, it is easy to prevent the engine and the tire from resonating, and it is easy to suppress deterioration of uniformity.

  According to the invention described in claim 5, as in the invention described in claim 4, it is easy to prevent the engine and the tire from resonating, and it is easy to suppress deterioration of uniformity.

  According to the invention described in claim 6, it is easy to further suppress deterioration of uniformity.

  Hereinafter, a pneumatic radial tire is mentioned as an embodiment, and an embodiment of the invention is described. In the second and subsequent embodiments, the same components as those already described are denoted by the same reference numerals and description thereof is omitted.

[First Embodiment]
First, the first embodiment will be described. As shown in FIG. 1, in the pneumatic radial tire 10 according to the present embodiment, as shown in FIG. 1, a belt layer 11 and a belt that protects the belt layer 11 are provided outside a crown portion of a carcass extending in a toroidal shape. The reinforcing layer 12 and the tread 14 provided with the grooves are sequentially arranged.

  As shown in FIG. 2, the belt reinforcing layer 12 is a layer formed by winding an organic fiber cord 16 around the outer side of the belt layer in the tire radial direction.

  In this embodiment, the organic fiber cord 16 is configured as a ribbon-like spiral member. The organic fiber cord 16 is provided with a tearing portion (missing portion) 18 as a discontinuous portion, thereby reducing the tension of the belt reinforcing layer 12 generated in the tire circumferential direction, thereby improving the riding comfort and NV performance. (Noise vibration performance) is improved.

  In this embodiment, the continuous organic fiber cord 16 does not overlap in the tire radial direction. Further, the tearing portions 18 of the adjacent organic fiber cords 16 are arranged so as not to be adjacent to each other, so that a portion having low rigidity can be prevented from being adjacent to each other, so that high-speed durability and high load durability can be easily maintained. ing.

  In order to manufacture the pneumatic radial tire 10, a large number of organic fiber cords that have been cut into a predetermined length in advance are prepared. Then, after winding the belt ply to form the belt layer 11, the organic fiber cord 16 is wound around the outer side of the belt layer 11 in the tire radial direction and held in a wound state. As a result, a tearing portion 18 is formed between the start end 16S and the end end 16E of the organic fiber cord 16. The length of the organic fiber cord 16 is such that the end 16E of the next organic fiber cord 16 is located at a position away from the start end 16S of the organic fiber cord 16 in the tire circumferential direction by a predetermined distance d. It is set in consideration of the outer diameter.

  Further, the second organic fiber cord 16 adjacent to the wound first organic fiber cord 16 is wound. At this time, the positions of the start end 16S and the end end 16E are adjusted so that the broken portion 18B of the second organic fiber cord 16 is not adjacent to the broken portion 18A of the first organic fiber cord 16.

  In this way, the organic fiber cord 16 is sequentially wound.

  In addition, since the rubber material enters the fractured portion 18 in the subsequent vulcanization process, a large step does not occur in the fractured portion 18.

  Moreover, as shown in FIG. 3, you may form one tearing part 18 for every 3 times winding. Thereby, even if it does not consider the arrangement position of the torn part 18, the torn part 18 does not adjoin.

  As described above, in the present embodiment, the tear portion 18 of the organic fiber cord 16 is disposed in the belt reinforcing layer 12, so that the tire circumferential tension generated in the belt reinforcing layer 12 can be reduced, and riding comfort and The NV performance can be improved. Therefore, it is possible to provide a pneumatic tire with improved riding comfort and noise vibration performance while suppressing a decrease in high speed durability and high load durability. In addition, since the adjacent broken portions 18 of the organic fiber cords 16 are not adjacent to each other, the low rigidity portions are not adjacent to each other, and it is easy to maintain high speed durability and high load durability.

[Second Embodiment]
Next, a second embodiment will be described. In this embodiment, compared with 1st Embodiment, the arrangement position of the torn part of each organic fiber cord which comprises a belt reinforcement layer differs.

  As shown in FIG. 4, the center position A of the broken portion of the first organic fiber cord 16 </ b> A (first organic fiber cord) is a position below the tire center axis O.

  The center position B of the tearing portion of the second organic fiber cord 16B (second organic fiber cord) adjacent to the first organic fiber cord 16A is 90 ° counterclockwise of the tire center axis O with respect to the center position A. Is also at a position forming a large angle β (angle AOB = β).

  The center position C of the torn portion of the third organic fiber cord 16C (third organic fiber cord) adjacent to the second organic fiber cord 16B is 90 ° counterclockwise of the tire center axis O with respect to the center position B. Is also at a position forming a large angle γ (angle BOC = γ).

  The center position D of the torn portion of the fourth organic fiber cord 16D (fourth organic fiber cord) adjacent to the third organic fiber cord 16C is 90 ° counterclockwise of the tire center axis O with respect to the center position C. Is also at a position that forms a large angle δ (angle COD = δ).

  The same applies to the fifth and subsequent organic fiber cords.

  As described above, in the adjacent organic fiber cords, the center position of the fractured portion is located at a position larger than 90 ° around the tire central axis O and at an angle deviating from n times 90 ° (n is a natural number). Thus, the organic fiber cord is sequentially arranged. In the present embodiment, β, γ, and δ are angles other than n times 120 ° (n is a natural number).

  In this embodiment, the total value (β + γ + δ +...) Of the angles formed by the center positions of the tear portions of adjacent organic fiber cords around the tire center axis is an angle not equal to n times 360 ° (n is a natural number). Has been.

  Thereby, it is easy to prevent the engine and the tire from resonating, and it is easy to suppress deterioration of uniformity.

[Third Embodiment]
Next, a third embodiment will be described. As shown in FIG. 5, in the present embodiment, the arrangement positions of the tearing portions 18 of the respective organic fiber cords 16 constituting the belt reinforcing layer are different from those in the first embodiment.

  In this embodiment, all the torn parts 18 of the organic fiber cord are adjacent along the tire axial direction.

  Thereby, although the rigidity level | step difference of the tire site | part in which the tearing part 18 is formed becomes weak compared with 1st Embodiment, since it becomes easy to arrange | position the organic fiber cord 16, manufacture of a pneumatic radial tire becomes easy. .

[Fourth Embodiment]
Next, a fourth embodiment will be described. As shown in FIG. 6, in this embodiment, the angles β, γ, δ... Are all set to 110 ° in the second embodiment.

  In FIG. 6, 16E indicates the fifth organic fiber cord, and E indicates the center position of the broken portion of the organic fiber cord 16E. Moreover, it may not be 110 degrees in particular, for example, 100 degrees may be sufficient.

  By this embodiment, a tearing part does not overlap and it can suppress deterioration of high-speed durability and high load durability.

<Test example>
In order to confirm the effect of the present invention, the inventor has an example of a pneumatic radial tire according to the third embodiment (hereinafter referred to as a tire of Example 1), and two examples of the pneumatic radial tire according to the fourth embodiment. (Hereinafter, the tire of Example 2 and the tire of Example 3) and the pneumatic radial tire of the conventional example (hereinafter referred to as the tire of the conventional example) were prepared.

  The conventional tire is an ordinary conventional tire in which a broken portion of the organic fiber cord is not formed. In the tire of Example 1, the tire circumferential direction length d (distance d between the start end and the end of the organic fiber cord) of the torn portion is 30 mm. In the tire of Example 2, the tire circumferential direction length d of the torn portion is 30 mm, and in the tire of Example 3, the tire circumferential direction length d of the torn portion is 100 mm (see FIG. 7).

  And, using these tires, performance was evaluated by performing tests of interior sound, high speed durability, and high load durability.

  For high load durability, the plunger energy was measured and FMVSS-compliant.

  The high speed durability was FMVSS compliant, and performance evaluation was performed by performing steps 1 to 19 as shown in Table 1.

  Here, the number of steps shown in Table 1 is an index of a high-speed durability test defined by FMVSS. That is, in a state where 88% of the maximum load rating is applied, the vehicle runs for 120 minutes at 50 MPH (mill / hour) in Step 1, cools for 180 minutes in Step 2, and further runs for 30 minutes at 75 MPH in Step 3. To do. Thereafter, as in steps 4 to 19, the traveling speed is increased by 5 MPH and traveling for 30 minutes is sequentially performed. This is a test for evaluating high-speed durability at a step where the tire is broken. The larger the number of steps, the better the high-speed durability.

  In this test example, all tire sizes were 245 / 45R19. Celsior manufactured by Toyota Motor Corporation was used as the test vehicle, and the load was the weight of the vehicle plus one passenger. The tire internal pressure was 230 kPa, and the vehicle speed was 60 km / h.

  The in-vehicle sound was evaluated by the OA value using the conventional tire as a reference (0 db).

  The evaluation results are shown in Table 2. The evaluation results in Table 2 indicate that the lower the in-vehicle sound, the better the riding comfort and noise vibration performance.

  As can be seen from Table 2, in the tires of Examples 1 to 3, it was found that the interior noise was lower than that of the conventional tire, and the riding comfort and noise vibration performance were good.

  The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. Needless to say, the scope of rights of the present invention is not limited to the above embodiment.

1 is a tire radial direction cross-sectional view of a pneumatic radial tire according to a first embodiment. 1 is a perspective view showing an example in which a belt reinforcing layer is provided on a pneumatic radial tire according to a first embodiment. It is a perspective view which shows the modification of the structure of the organic fiber cord which comprises the belt reinforcement layer of the pneumatic radial tire which concerns on 1st Embodiment. 4A and 4B are a perspective view showing a structure of an organic fiber cord constituting a belt reinforcing layer of a pneumatic radial tire according to the second embodiment, and a tire shaft showing a position of a broken portion, respectively. It is the schematic diagram seen from the direction. It is a perspective view which shows the structure of the organic fiber cord which comprises the belt reinforcement layer of the pneumatic radial tire which concerns on 3rd Embodiment. 6 (A) and 6 (B) are examples of a pneumatic radial tire according to the fourth embodiment, respectively, and a perspective view showing a structure of an organic fiber cord constituting a belt reinforcing layer and a position of a broken portion. It is the schematic diagram seen from the tire axial direction shown. 7A and 7B are another example of the pneumatic radial tire according to the fourth embodiment, respectively, and are a perspective view showing a structure of an organic fiber cord constituting the belt reinforcing layer, and a broken portion. It is the schematic diagram seen from the tire axial direction which shows a position.

Explanation of symbols

10 Pneumatic radial tire (pneumatic tire)
11 Belt layer 12 Belt reinforcing layer 16 Organic fiber cord 16A Organic fiber cord 16B Organic fiber cord 16C Organic fiber cord 16D Organic fiber cord 16E Organic fiber cord 18 Broken portion (non-continuous portion)

Claims (6)

A pneumatic tire provided with a belt reinforcing layer formed by winding an organic fiber cord on the outer side in the tire radial direction of the belt layer,
A pneumatic tire characterized in that a discontinuous portion of the organic fiber cord is disposed on the belt reinforcing layer.   The pneumatic tire according to claim 1, wherein the organic fiber cords are arranged so as not to continuously overlap in the tire radial direction.   The pneumatic tire according to claim 1, wherein the discontinuous portions are not adjacent to each other in the adjacent organic fiber cords. The discontinuous portions are respectively formed in the adjacent organic fiber cords,
4. The pneumatic tire according to claim 3, wherein an angle formed between the non-continuous portions around the tire central axis is deviated from n times 90 ° (n is a natural number). The discontinuous portions are respectively formed in the adjacent organic fiber cords,
The pneumatic tire according to claim 3, wherein an angle formed by the non-continuous portions around the tire central axis is deviated from n times 120 ° (n is a natural number).   6. The pneumatic tire according to claim 4, wherein the sum of the angles formed deviates from n times 360 ° (n is a natural number).

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