JP2008195169A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire allowing suppression of a failure occurring along a carcass layer and improvement of durability of a bead part. <P>SOLUTION: This pneumatic tire is provided with at least the bead part 3, a carcass layer 5, a first wire chafer 11, a second wire chafer 13 and a third wire chafer 15. A first width direction inside end part P1 is not overlapped with a second radial direction inside end part P2 in a tread width direction. The second radial direction inside end part P2 is not overlapped with a bead core 3a in the tread width direction. A third radial direction inside end part P3 is located at the tire radial direction inside of the first breadthwise inside end part P1 and the second radial direction inside end part P2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that is mounted on a heavy-duty vehicle having a large load capacity such as a truck or a bus or a vehicle body weight.

  Conventionally, in a pneumatic tire, not only the sidewall portion is greatly bent, but also a falling phenomenon, which is a phenomenon of falling outward in the tread width direction outside the tire radial direction of the bead portion contacting the rim flange of the rim wheel, is often seen. .

  Along with this collapse phenomenon, a failure such as separation occurs due to a shear strain (shear deformation) generated along a carcass layer formed by a carcass main body part that crosses between bead cores and a folded part that is folded around the bead cores. There is a concern that the durability of the bead portion may deteriorate.

  In particular, when used under heavy load, the carcass layer from the bead portion to the sidewall portion is greatly deformed in the tire circumferential direction, and failure tends to occur near the end of the folded portion in the carcass layer. The durability of the part will deteriorate.

  As a method for improving the durability of such a bead portion, the following pneumatic tire is disclosed. For example, a pneumatic tire (hereinafter referred to as a first tire) including a carcass layer in which the position of the end of the folded portion in the carcass layer is folded back to the vicinity of the maximum tire width, and a carcass reinforcing layer that is folded around the bead core along the carcass layer. 1 tire) is disclosed (for example, refer to Patent Document 1).

  Further, a pneumatic tire (hereinafter referred to as a first tire) including a rubber reinforcing layer formed of two layers of rubber having a different hardness from each other is formed between the carcass body portion and the folded portion in the carcass layer so as to taper outward in the tire radial direction. 2 tires) is disclosed (for example, see Patent Document 2).

  Furthermore, a pneumatic tire (hereinafter referred to as a third tire) including at least two layers of chafers formed of a steel cord or an organic fiber cord and rubber on the outer side in the tread width direction of the folded portion in the carcass layer is disclosed. (For example, refer to Patent Document 3).

By the way, in recent pneumatic tires (especially, pneumatic tires mounted on heavy-duty vehicles such as trucks and buses with heavy loads and body weights), the load of the vehicles increases due to an increase in the load of the vehicles. As a result, the load increases and the deformation amount of the bead portion increases (that is, the collapse phenomenon increases).
JP 2002-144826 A JP-A-8-222005 JP 2003-89305 A

  However, although the conventional first tire and the second tire described above are provided with a carcass reinforcing layer and a rubber reinforcing layer, the amount of deformation of the bead portion increases when used under heavy load. As a result, it is insufficient to improve the durability of the bead portion.

  On the other hand, the conventional third tire is provided with a chafer, but when used under heavy load, a failure is likely to occur between the carcass layer and the chafer, and the same as described above. It was insufficient to improve the durability of the bead portion.

  Then, it is made in view of the above-mentioned problem, and it aims at providing the pneumatic tire which can control the failure which occurs along a carcass layer, and can improve the endurance of a bead part. To do.

  In order to solve the above-described problems, the present invention has the following features. First, the invention according to the first aspect of the present invention includes a pair of bead portions including at least a bead core, a carcass layer folded between bead cores and folded around the bead core, and folded around the carcass layer in the bead portion. A first wire chafer formed of metal and rubber; a second wire chafer disposed on the inner side in the tread width direction of the carcass layer in the bead portion; and the first wire chafer formed of metal and rubber And a third wire chafer disposed on the inner side in the tread width direction of the second wire chafer and formed of metal and rubber, and is an end portion located on the inner side in the tread width direction of the first wire chafer. 1 The inner end (P1) in the width direction is on the inner side in the tire radial direction of the second wire chafer. The second radial inner end (P2), which is the end that is positioned, does not overlap in the tread width direction, and the second radial inner end (P2) does not overlap in the tread width direction. The third radial inner end (P3), which is the end located most radially inward in the three-wire chafer, is the first width inner end (P1) and the second radial inner end (P2). The main point is that it is located on the inner side in the tire radial direction.

  According to such a feature, by providing the first wire chafer, the second wire chafer, and the third wire chafer, deformation of the bead portion that contacts the rim flange of the rim wheel is suppressed (affected by tire deformation). Be able to suppress failures that occur along the carcass layer (for example, separation due to shear strain between the carcass layer and the first wire chafer or the second wire chafer) and bead The durability of the part can be improved.

  Specifically, the first wire chafer, the second wire chafer, and the third wire chafer are disposed on the inner side in the tread width direction of the carcass layer. In particular, the third wire chafer is the first wire chafer and By arrange | positioning in the tread width direction inner side of a 2nd wire chafer, the carcass layer used as the frame | skeleton of a pneumatic tire can be reinforced, and the deformation | transformation with respect to a tire peripheral direction can be suppressed.

  Along with the suppression of the deformation in the tire circumferential direction, the temperature rise of the bead portion during vehicle travel can be suppressed, so that the durability of the bead portion can be improved.

  The first width direction inner end (P1) does not overlap the second radial direction inner end (P2) in the tread width direction (that is, the first width direction inner end (P1) is the second radial direction inner side. The second wire chafer is not disposed in the vicinity of the bead core because the second radial inner end (P2) is not overlapped with the bead core in the tread width direction. Shear strain due to the collapse phenomenon between the first wire chafer or the second wire chafer and the carcass layer can be suppressed, and failures such as separation can be suppressed.

  In particular, the third radial inner end (P3) is positioned on the inner side in the tire radial direction than the first width inner end (P1) and the second radial inner end (P2). Can be suppressed, and shear strain due to a collapse phenomenon between the first wire chafer or the second wire chafer and the carcass layer can be suppressed.

  The invention according to another feature of the present invention is summarized in that the first width direction inner end portion (P1) does not overlap with the bead core in the tread width direction.

  According to such a feature, since the first width direction inner end (P1) does not overlap the bead core in the tread width direction, the second wire chafer is not securely fixed to the bead core. Shear distortion due to the collapse phenomenon between the 2-wire chafer and the carcass layer can be suppressed, and failures such as separation can be suppressed.

  In another aspect of the present invention, the second inclination angle (α2), which is the angle at which the metal is inclined with respect to the tire radial direction in the second wire chafer, is in the tire radial direction in the third wire chafer. The gist is that it is different from the third tilt angle (α3), which is the angle at which the metal is tilted.

  According to this feature, the second inclination angle (α2) is different from the third inclination angle (α3), so that deformation in the tire circumferential direction can be suppressed, and durability of the bead portion can be improved. .

  The invention according to another feature of the present invention is the first end that is disposed between the second wire chafer and the third wire chafer and is located at the outermost position in the tire radial direction of the second wire chafer. The gist is to further include a nylon chafer formed of nylon and rubber that covers the two radial outer ends (P4) outward in the tread width direction.

  According to such a feature, the nylon chafer covers the second radially outer end (P4) toward the outer side in the tread width direction, thereby causing a failure that occurs along the carcass layer (for example, adjacent to the carcass layer). Separation due to shear strain between the second wire chafer and the carcass layer) can be suppressed, and the durability of the bead portion can be further improved.

  According to another aspect of the present invention, the second wire chafer is disposed on the outer side in the tire radial direction than the second radial outer end (P4) which is the end most positioned on the outer side in the tire radial direction. The gist is to further include a rubber member formed of rubber having A hardness of 70 degrees or more.

  According to such a feature, a failure that occurs along the carcass layer (for example, the second adjacent to the carcass layer) due to the rubber member being disposed on the outer side in the tire radial direction from the second radially outer end (P4). Separation due to shear strain between the wire chafer and the carcass layer) can be suppressed, and the durability of the bead portion can be further improved.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to suppress the failure which generate | occur | produces along a carcass layer, the pneumatic tire which can improve the durability of a bead part can be provided.

  Next, an example of a pneumatic tire according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, the part from which the relationship and ratio of a mutual dimension differ also in between drawings is contained.

  Note that the pneumatic tire 1 described below is a heavy-duty pneumatic tire that is mounted on a heavy-duty vehicle having a large load capacity such as a truck or a bus or a vehicle body weight.

[First Embodiment]
FIG. 1 is a cross-sectional view in the tread width direction of the pneumatic tire according to the first embodiment, and FIG. 2 is an enlarged cross-sectional view in the tread width direction of a bead portion constituting the pneumatic tire according to the first embodiment. FIG. 3 is a view showing only the chafer constituting the pneumatic tire according to the first embodiment (the arrow A diagram in FIG. 2).

  As shown in FIG. 1, the pneumatic tire 1 has a pair of bead portions 3 including a bead core 3a and a bead filler 3b. Moreover, the pneumatic tire 1 has a carcass layer 5 that is folded back from the inner side in the tread width direction to the outer side in the tread width direction around the bead core 3a across the bead cores 3a.

  A plurality (four layers in FIG. 1) of belt layers 7 are arranged outside the carcass layer 5 in the tire radial direction. A tread portion 9 that is in contact with the road surface is disposed outside the belt layer 7 in the tire radial direction.

  The pneumatic tire 1 has a first wire chafer 11 that is folded around the carcass layer 5 in the bead portion 3 and is formed of metal and rubber. A second wire chafer 13 formed of metal and rubber is disposed on the inner side in the tread width direction of the carcass layer 5 in the bead portion 3. Further, a third wire chafer 15 formed of metal and rubber is disposed inside the first wire chafer 11 and the second wire chafer 13 in the tread width direction.

  Here, the end portion located on the inner side in the tread width direction in the first wire chafer 11 is referred to as a “first width direction inner end portion (P1)” and is located most on the inner side in the tire radial direction on the second wire chafer 13. The end portion is indicated as “second radially inner end portion (P2)”, and the end portion of the second wire chafer 13 that is positioned most radially outward is indicated as “second radially outer end portion (P4)”. The end portion of the third wire chafer 15 that is located at the innermost position in the tire radial direction is referred to as a “third radial direction inner end portion (P3)” (see FIG. 2).

  Further, an angle at which the cord 11a (metal) is inclined with respect to the tire radial direction in the first wire chafer 11 is indicated as “first inclination angle (α1)”, and with respect to the tire radial direction in the second wire chafer 13. The angle at which the cord 13a (metal) is inclined is indicated as “second inclination angle (α2)”, and the angle at which the cord 15a (metal) is inclined with respect to the tire radial direction in the third wire chafer 15 is indicated as “second inclination angle (α2)”. 3 tilt angle (α3) ”(see FIG. 3). That is, the first tilt angle (α1), the second tilt angle (α2), and the third tilt angle (α3) are in the range of 0 to 90 degrees.

  As shown in FIG. 2, the first width direction inner end (P1) does not overlap the second radial direction inner end (P2) in the tread width direction. That is, the first width direction inner end portion (P1) is separated from the second radial direction inner end portion (P2) by a distance D.

  The first width direction inner end portion (P1) does not overlap the bead core 3a in the tread width direction. Moreover, the 2nd radial direction inner side edge part (P2) has not overlapped with the bead core in the tread width direction.

  Further, the third radial direction inner end (P3) is located on the inner side in the tire radial direction than the first width direction inner end (P1) and the second radial direction inner end (P2). In addition, the 3rd wire chafer 15 has covered the 2nd radial direction outer side edge part (P4) toward the tread width direction outer side.

  As shown in FIG. 3, the first tilt angle (α1) and the second tilt angle (α2) are the shear strain between the first wire chafer 11 and the second wire chafer 13 and the carcass layer 5. Are preferably the same in order to suppress separation due to. Further, the third inclination angle (α3) is different from the first inclination angle (α1) and the second inclination angle (α2) in order to suppress deformation in the tire circumferential direction and improve the durability of the bead portion. Preferably it is.

  That is, the cord 11a of the first wire chafer 11 and the cord 15a of the third wire chafer 15 intersect, and the cord 13a of the second wire chafer 13 and the cord 15a of the third wire chafer 15 intersect. It is preferable.

(Operations and effects according to the first embodiment)
According to the pneumatic tire 1 according to the first embodiment described above, the rim flange of the rim wheel R is provided by including the first wire chafer 11, the second wire chafer 13, and the third wire chafer 15. Deformation of the bead portion 3 in contact with F is suppressed (can be made less susceptible to tire deformation), and a failure that occurs along the carcass layer 5 (for example, the carcass layer 5 and the first wire chafer 11 or the first The separation due to shear strain between the two-wire chafer 13 can be suppressed, and the durability of the bead portion 3 can be improved.

  Specifically, the first wire chafer 11, the second wire chafer 13, and the third wire chafer 15 are disposed on the inner side in the tread width direction of the carcass layer 5, and in particular, the third wire chafer 15 is the first wire chafer 15. The carcass layer 5 that is the skeleton of the pneumatic tire 1 can be reinforced by being arranged on the inner side in the tread width direction of the first wire chafer 11 and the second wire chafer 13, and the deformation in the tire circumferential direction is suppressed. can do.

  Along with the suppression of deformation in the tire circumferential direction, an increase in temperature of the bead portion 3 during vehicle travel can be suppressed, so that the durability of the bead portion 3 can be improved.

  The first width direction inner end (P1) does not overlap the second radial direction inner end (P2) in the tread width direction (that is, the first width direction inner end (P1) is the second radial direction inner side. The second wire chafer 13 is disposed in the vicinity of the bead core 3a because the second radial inner end (P2) is not overlapped with the bead core 3a in the tread width direction. Thus, shear strain due to a collapse phenomenon between the first wire chafer 11 or the second wire chafer 13 and the carcass layer 5 can be suppressed, and a failure such as separation can be suppressed.

  In particular, the first width direction inner end (P1) does not overlap the bead core 3a in the tread width direction, and the third radial direction inner end (P3) is the first width direction inner end (P1) and second. By being positioned on the inner side in the tire radial direction from the radially inner end portion (P2), deformation in the tire circumferential direction can be suppressed, and the first wire chafer 11, the second wire chafer 13, and the carcass layer The shear strain due to the falling-down phenomenon between 5 and 5 can be suppressed.

[Second Embodiment]
Next, a pneumatic tire according to a second embodiment will be described with reference to FIG. FIG. 4 is an enlarged sectional view in the tread width direction of a bead portion constituting the pneumatic tire according to the second embodiment. The difference from the pneumatic tire according to the first embodiment described above will be mainly described.

  As shown in FIG. 4, a nylon chafer 17 formed of nylon and rubber is disposed between the second wire chafer 13 and the third wire chafer 15. The nylon chafer 17 covers the second radially outer end portion (P4) facing outward in the tread width direction.

(Operations and effects according to the second embodiment)
According to the pneumatic tire 1 according to the second embodiment, in addition to the operation and effect of the first embodiment, the nylon chafer 17 has the second radially outer end (P4) at the outer side in the tread width direction. By covering the surface, the failure that occurs along the carcass layer 5 (for example, separation due to shear strain between the second wire chafer 13 adjacent to the carcass layer 5 and the carcass layer 5) is suppressed. And the durability of the bead portion 3 can be further improved.

[Third Embodiment]
Next, a pneumatic tire according to a third embodiment will be described with reference to FIG. FIG. 5 is an enlarged cross-sectional view in the tread width direction of a bead portion constituting a pneumatic tire according to a third embodiment. In addition, the part which is different from the pneumatic tire which concerns on 1st Embodiment and 2nd Embodiment mentioned above is mainly demonstrated.

  As shown in FIG. 5, taper toward the outer side in the tire radial direction between the carcass layer 5 and the third wire chafer 15 and on the outer side in the tire radial direction from the second radial outer end (P4). A rubber member 19 formed of rubber having a Shore A hardness of 70 degrees or more is disposed.

  The Shore A hardness was measured by using a Shore hardness meter (hardness tester) to hit a test piece (rubber piece) placed on a table with a hammer and bounce the hammer back. Indicates hardness.

(Operations and effects according to the third embodiment)
According to the pneumatic tire 1 according to the third embodiment, in addition to the operations and effects of the first embodiment, the rubber member 19 is located on the outer side in the tire radial direction from the second radial outer end (P4). To suppress a failure that occurs along the carcass layer 5 (for example, separation due to shear strain between the second wire chafer 13 adjacent to the carcass layer 5 and the carcass layer 5). And the durability of the bead portion 3 can be further improved.

[Other embodiments]
As described above, the contents of the present invention have been disclosed through the embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention.

  Specifically, the pneumatic tire 1 has been described as a heavy-duty pneumatic tire that is mounted on a heavy-duty vehicle having a large load capacity or body weight such as a truck or a bus. However, the pneumatic tire 1 is not limited thereto. Of course, it may be a pneumatic tire mounted on a general passenger car.

  Moreover, although the 3rd wire chafer 15 demonstrated as what covers the 2nd radial direction outer side edge part (P4) toward the tread width direction outer side, it is not limited to this, As shown in FIG. Moreover, the 3rd wire chafer 15 does not need to cover the 2nd radial direction outer side edge part (P4) toward the tread width direction outer side.

  From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  Next, in order to further clarify the effects of the present invention, the results of tests performed using pneumatic tires according to the following Comparative Examples 1 to 3 and Examples 1 to 4 will be described. In addition, the data regarding the pneumatic tire which concerns on Comparative Examples 1-3 and Examples 1-4 were measured on the conditions shown below.

・ Tire size: 46 / 90R87
・ Applicable rim: 29.00 / 6.00
・ Internal pressure condition: 700 kpa
First, the structure of the pneumatic tire according to Comparative Examples 1 to 3 and Examples 1 to 4 will be described with reference to Table 1.

  As shown in Table 1 and FIG. 7, the pneumatic tire according to Comparative Example 1 has a plurality of (four layers in FIG. 7) nylon chafers 17 arranged on the outer side in the tread width direction of the first wire chafer 11. is doing. In the pneumatic tire according to Comparative Example 1, the first inclination angle (α1) is 40 degrees.

  As shown in Table 1 and FIG. 8, the pneumatic tire according to Comparative Example 2 includes a second wire chafer 13 that is disposed on the outer side in the tread width direction of the first wire chafer 11. In the pneumatic tire according to Comparative Example 2, the first inclination angle (α1) is different from the second inclination angle (α2). That is, the cord 11a of the first wire chafer 11 and the cord 13a of the second wire chafer 13 intersect each other. Furthermore, in the pneumatic tire according to Comparative Example 2, the first inclination angle (α1) and the second inclination angle (α2) are 40 degrees.

  As shown in Table 1 and FIG. 9, the pneumatic tire according to Comparative Example 3 includes a second wire chafer 13 disposed on the outer side in the tread width direction of the first wire chafer 11, and the second wire chafer 13. And a third wire chafer 15 that covers the entire surface outward in the tread width direction. In the pneumatic tire according to Comparative Example 3, the first inclination angle (α1) and the second inclination angle (α2) are the same, and the third inclination angle (α3) is the first inclination angle (α1) and the second inclination angle. It is different from the tilt angle (α2). That is, the cord 11a of the first wire chafer 11 and the cord 15a of the third wire chafer 15 intersect, and the cord 13a of the second wire chafer 13 and the cord 15a of the third wire chafer 15 intersect. is doing. Furthermore, in the pneumatic tire according to Comparative Example 3, the first inclination angle (α1), the second inclination angle (α2), and the third inclination angle (α3) are 40 degrees.

  The pneumatic tire according to Example 1 is the one described in the first embodiment (see FIGS. 1 and 2). Moreover, as shown in Table 1, in the pneumatic tire according to Example 1, the first inclination angle (α1) is 40 degrees, the second inclination angle (α2) is 20 degrees, and the third inclination angle ( α3) is 70 degrees.

  The pneumatic tire according to Example 2 has been described in the second embodiment described above (see FIG. 4). In the pneumatic tire according to Example 2, as shown in Table 1, the first inclination angle (α1) is 40 degrees, the second inclination angle (α2) is 20 degrees, and the third inclination angle ( α3) is 70 degrees, and the nylon inclination angle, which is the angle at which nylon is inclined with respect to the tire radial direction in the nylon chafer 17, is 20 degrees.

  The pneumatic tire according to Example 3 has been described in the third embodiment described above (see FIG. 5). In the pneumatic tire according to Example 3, as shown in Table 1, the first inclination angle (α1) is 40 degrees, the second inclination angle (α2) is 20 degrees, and the third inclination angle ( α3) is 70 degrees.

  The pneumatic tire according to Example 4 has been described in the other embodiments described above (see FIG. 6). In the pneumatic tire according to Example 4, as shown in Table 1, the first inclination angle (α1) is 40 degrees, the second inclination angle (α2) is 20 degrees, and the third inclination angle ( α3) is 70 degrees.

The tire circumferential direction deformation amount, the bead portion temperature, and the drum travel distance of the pneumatic tires according to Comparative Examples 1 to 3 and Examples 1 to 4 will be described with reference to Table 2.

<Tire circumferential deformation>
The pneumatic tire according to Comparative Example 1 is mounted on a test drum, and the pneumatic tire is statically loaded with a maximum load capacity of “about 588 kN”, and the tread portion tread position is from the tire rotation center during drum running. Deformation amount of deformation of the outer surface of the bead portion with respect to the tire radial direction until and deformation amount of deformation of the outer surface of the bead portion with respect to the tire radial direction from the tire rotation center to the tread portion treading position of the tread portion; The amount of displacement in the tire circumferential direction measured based on the above was set to “100”, and similarly, the amount of deformation in the tire circumferential direction of each pneumatic tire was displayed as an index. Note that the smaller the numerical value, the smaller the amount of deformation in the tire circumferential direction.

  As a result, since the amount of deformation in the tire circumferential direction is smaller (suppressed) in the pneumatic tires according to Examples 1 to 4 than in the pneumatic tire according to Comparative Example 1, the durability of the bead portion is improved. I found out that

<Bead temperature>
The pneumatic tire according to Comparative Example 1 is attached to a test drum, and the maximum temperature of the outer surface of the bead portion that contacts the rim flange when the drum is running measured by an infrared thermometer (hereinafter, bead portion temperature) is set to “100”. Similarly, the bead temperature of each pneumatic tire was displayed as an index. In addition, bead part temperature is so low that a numerical value is small.

  As a result, since the pneumatic tire according to Examples 1 to 4 has a lower bead portion temperature than the pneumatic tire according to Comparative Example 1, it was found that the durability of the bead portion can be improved.

<Drum mileage>
A pneumatic tire according to Comparative Example 1 is mounted on a test drum, and the pneumatic tire is loaded with a load of “1000 kN”, which is about 1.7 times the maximum load capacity, and is run at a speed of 8 km / h, and the bead portion is The drum travel distance, which is the distance until destruction, was set to “100”, and the drum travel distance of each pneumatic tire was similarly displayed as an index. The larger the numerical value, the longer the drum travel distance.

  As a result, the pneumatic tires according to Examples 1 to 4 have a longer drum travel distance than the pneumatic tires according to Comparative Examples 1 to 3, and thus the durability of the bead portion can be improved.

It is a tread width direction sectional view of the pneumatic tire concerning a 1st embodiment. It is a tread width direction expanded sectional view of a bead part which constitutes a pneumatic tire concerning a 1st embodiment. It is a figure (A arrow figure of FIG. 2) which shows only the chafer which comprises the pneumatic tire which concerns on 1st Embodiment. It is a tread width direction expanded sectional view of a bead part which constitutes a pneumatic tire concerning a 2nd embodiment. It is a tread width direction expanded sectional view of a bead part which constitutes a pneumatic tire concerning a 3rd embodiment. It is a tread width direction expanded sectional view of a bead part which constitutes a pneumatic tire concerning other embodiments. It is a tread width direction expanded sectional view of a bead part which constitutes a pneumatic tire concerning comparative example 1. It is a tread width direction expanded sectional view of the bead part which constitutes the pneumatic tire concerning comparative example 2. It is a tread width direction expanded sectional view of the bead part which constitutes the pneumatic tire concerning comparative example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pneumatic tire, 3 ... Bead part, 3a ... Bead core, 3b ... Bead filler, 5 ... Carcass layer, 5 ... Bead part, 7 ... Belt layer, 9 ... Tread part, 11 ... 1st wire chafer, 11a ... Cord: 13 ... Second wire chafer, 13a ... Cord, 15 ... Second wire chafer, 15 ... Third wire chafer, 15a ... Cord, 17 ... Nylon chafer, 19 ... Rubber member, 21 ... Nylon chafer , R ... rim wheel, F ... rim flange

Claims (5)

A pair of bead portions including at least a bead core;
A carcass layer that is folded between the bead cores and around the bead cores;
A first wire chafer that is folded around the carcass layer in the bead portion and formed of metal and rubber;
A second wire chafer disposed on the inner side in the tread width direction of the carcass layer in the bead portion and formed of metal and rubber;
A third wire chafer disposed on the inner side in the tread width direction of the first wire chafer and the second wire chafer and formed of metal and rubber;
A first width direction inner end portion (P1) which is an end portion located on the inner side in the tread width direction of the first wire chafer is an end portion located most on the inner side in the tire radial direction of the second wire chafer. It does not overlap the inner end (P2) of the two radial directions in the tread width direction,
The second radial inner end (P2) does not overlap the bead core in the tread width direction,
The third radial inner end (P3), which is the end located most radially inward in the third wire chafer, is the first width inner end (P1) and the second radial inner end. A pneumatic tire, which is located on the inner side in the tire radial direction than the portion (P2).   The pneumatic tire according to claim 1, wherein the first width direction inner end portion (P1) does not overlap the bead core in the tread width direction.   The second tilt angle (α2), which is the angle at which the metal is tilted with respect to the tire radial direction in the second wire chafer, is tilted with respect to the tire radial direction in the third wire chafer. The pneumatic tire according to claim 1 or 2, wherein the pneumatic tire is different from a third inclination angle (α3) which is an angle.   A second radially outer end (P4) that is disposed between the second wire chafer and the third wire chafer and that is the end most positioned on the outer side in the tire radial direction of the second wire chafer. The pneumatic tire according to any one of claims 1 to 3, further comprising a nylon chafer formed of nylon and rubber. .   The second wire chafer is formed of rubber having a Shore A hardness of 70 degrees or more, disposed on the outer side in the tire radial direction than the second outer radial end (P4), which is the end most positioned on the outer side in the tire radial direction. The pneumatic tire according to any one of claims 1 to 4, further comprising a rubber member.

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