JP2001301418A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire, especially a tire for heavy load, with higher tire durability, by effectively suppressing occurrence of separation at an end position in the width direction of a gradient belt layer without degrading abrasion performance or cut durability of a tread part. SOLUTION: The outer peripheral side of a carcass 4 is provided with a main belt 6 comprising at least three gradient belt layers 5-1 to 5-4 arranged tiltingly so as to cross cords with each other between the layers. Width W1 of the largest-width gradient belt layers 5-2 and 5-3 is set 80% or shorter of a tread width TW, and angle of the cord of the innermost gradient belt layer 5-1 to the equator surface E is set relatively smaller. In at least the innermost gradient belt layer 5-1, distance H1 between the center position X of the outermost cord and a treading surface 7 of the tread part measured in the tire diameter direction is short than similarly measured distance between the center position Y of a predetermined cord and the treading surface 7 of the tread part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire having improved tire durability by effectively suppressing the occurrence of separation at the belt end without deteriorating the wear performance and cut durability of the tread portion. In particular, the present invention relates to so-called heavy duty tires used under high air pressure and heavy load conditions such as trucks, buses, and construction vehicles.

[0002]

2. Description of the Related Art Since pneumatic tires, particularly heavy duty tires, are used under high air pressure and heavy load conditions, usually, a belt is formed by a multilayer (corresponding to an inclined arrangement with respect to the tire equatorial plane). In general, tires are reinforced so as to be able to withstand the above-mentioned use conditions by being composed of three or more inclined belt layers.

[0003] In addition, the tire sometimes travels on unpaved rough roads or rough terrain in which projections such as rocks and crushed stones are scattered, but when the running tire steps on the projections, There may be deep cuts that reach the belt from the tread tread, and these cuts will develop along the outer peripheral surface of the belt when the tire is rolling, and ultimately called cut separation There is a risk of failure. In particular, in the case of a tire for heavy load, from the usage mode, since there are relatively many cases in which the bumps are stepped on unpaved rough roads or rough terrain in which protrusions such as rocks and crushed stones are scattered, The above-mentioned failures are easily generated.

[0004] The separation failure is caused by a deformation behavior in which the belt is bent in the tire circumferential direction due to a tire diameter growth or the like that occurs during high air pressure filling or running (rolling). It is derived from the effect of large shear strain generated between the tread rubber and the tread rubber.

[0005] As a means for suppressing the development of cut flaws that cause separation failure, for example, an inclined belt layer in which the cord is arranged at a relatively small angle with respect to the tire equatorial plane is provided, and the belt circumference is provided. It is useful to increase the directional bending stiffness, suppress the radial growth of the tire, and minimize the shear strain as much as possible.

In order to construct the tire such that the tread portion is worn uniformly particularly in the width direction, usually, the inclined belt layer is formed by a profile (crown) of the tread surface of the tread portion when viewed in a cross section in the tire width direction. More specifically, the inclined belt layer is provided with a diameter difference such that the diameter of the inclined belt layer is the largest at the center in the width direction and the smallest at the end position in the width direction. It is common to arrange them.

However, in the case of a tire in which the inclined belt layer in which the cords are arranged at a relatively small angle is arranged with the diameter difference, when the tire is in contact with the tire, the width of the inclined belt layer is adjusted to absorb the diameter difference. The diameter of the end portion in the direction is relatively large, but at this time, the cord at the position is forced to be deformed to be greatly elongated in the tire circumferential direction. As a result of the relatively large deformation of the rubber, rubber breakage occurs and separation is apt to occur at this position, so that sufficient tire durability could not be obtained.

[0008] On the other hand, in the case of a tire in which the inclined belt layer in which the arrangement angle of the cord is set relatively large is arranged with the diameter difference, even if the end portion in the width direction is enlarged in diameter, the position of this position is not changed. Since the cord is not stretched so much, rubber breakage at the end portion in the width direction is unlikely to occur.However, since it is not possible to sufficiently suppress the tire diameter growth, performance such as heat generation and cut durability deteriorates. In this tire, sufficient durability could not be obtained.

Therefore, in a tire having a conventional belt structure, it is difficult to achieve both suppression of separation at the end portion in the width direction of the inclined belt layer and improvement of performance such as cut durability. As a result, sufficient durability is obtained. Could not get.

Therefore, the inventor has proposed that the codes intersect each other,
More preferably, the main belt is composed of at least three inclined belt layers stacked so as to intersect with the tire equatorial plane interposed therebetween, and at least one of these inclined belt layers is formed.
Regarding the inclined belt layer of the layer, a tire in which the arrangement angle of the cord is set relatively small is used, and the other performances such as abrasion performance and cut durability of the tread portion are not deteriorated, and the width direction of the inclined belt layer is not deteriorated. Investigations to effectively prevent separation at the end positions yielded the following findings.

That is, the amount of deformation of the inclined belt layer in the tire circumferential direction at the end position in the width direction of the tire caused by the growth of the tire diameter at the time of high air pressure filling or running is determined by the arrangement of the cords of the inclined belt layer. It has been found that the smaller the angle, the larger the width of the inclined belt layer (regardless of the size of the arrangement angle of the cord), and the larger the circumferential elongation due to the diameter difference absorption, the larger.

The inventor of the present invention can set the width of the widest inclined belt layer and the cross-sectionally extending shape of the widthwise end of the inclined belt layer having the small arrangement angle of the cord by appropriately setting the width of the tread portion. It has been found that the occurrence of separation at the widthwise end portion of the inclined belt layer can be effectively suppressed without significantly deteriorating the wear performance and cut durability.

[0013] Further, in the inclined belt layer in which the cords are arranged at a small angle, a large circumferential tension acts on the cords due to the radial growth. Also, since the cord is easily broken, it has been found that it is preferable to dispose the inclined belt layer at a position where it is less susceptible to cut damage, more specifically, at the innermost position in the tire radial direction.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to effectively suppress the occurrence of separation at the widthwise end of the inclined belt layer without deteriorating the wear performance and cut durability of the tread portion. It is an object of the present invention to provide a so-called heavy duty tire which is used under high air pressure and heavy load conditions, such as a pneumatic tire having improved tire durability, particularly a truck, a bus, a construction vehicle and the like.

[0015]

In order to achieve the above-mentioned object, the present invention relates to a method in which a cord is provided on the outer periphery of a carcass extending in a toroidal shape from a bead portion in which a pair of bead cores are embedded to a sidewall portion and a tread portion. In a pneumatic tire having a main belt composed of at least three inclined belt layers inclined with respect to the surface, adjacent inclined belt layers are arranged such that their cords intersect with each other. Of the widest and widest inclined belt layers, the width shall be 80% or less of the tread width, and the innermost inclined belt layer located on the innermost side in the tire radial direction shall be arranged with respect to the tire equatorial plane. Make the angle relatively small, preferably 13 ° or less,
And, when viewed in the tire width direction cross section, at least the innermost inclined belt layer, when measured in the tire radial direction between the center position of the outermost cord located on the outermost end side in the tire width direction and the tread tread surface. Is shorter than a distance measured similarly between a predetermined cord center position inside the tire width direction and a tread portion tread by a predetermined distance from the outermost cord center position. Tires.

The predetermined distance when the predetermined cord center position is measured from the outermost cord center position in the tire width direction is within a range of 15 to 70% of a half width of the innermost inclined belt layer, and / or Alternatively, it is preferable that the difference between the distances when the center position of the predetermined cord and the center position of the outermost cord are measured from the tread surface of the tread in the tire radial direction is within a range of 80 to 350% of the cord diameter.

Further, when the main belt has the inclined belt layer closest to the innermost inclined belt layer and wider than the inner belt, the center position of the specific cord on the end side is set in the tire radial direction from the tread portion tread surface. It is more preferable that the measured distance is longer than the distance when the center position of the outermost cord of the innermost inclined belt layer is similarly measured.

Further, the entire inclined belt layer is configured to determine a distance between the center position of the outermost cord and the tread portion tread position in the tire radial direction and to determine a distance between the predetermined cord center position and the tread tread position. It is more preferable that the distance be shorter than the distance measured similarly.

In addition, it is preferable that an auxiliary belt composed of at least one protective belt layer covering the entire width of the main belt is disposed on the outer peripheral side of the main belt, and the protective belt layer has a lower treat strength than the inclined belt layer. It is more preferable that the elongation at break is large.

[0020]

FIG. 1 shows a typical half section in the width direction of a pneumatic tire according to the present invention, in which 1 is a pneumatic tire, 2 is a sidewall portion, and 3 is a tread portion. , 4 is a carcass, 5-1 to 5-4 are inclined belt layers,
6 is a main belt.

The tire 1 shown in FIG. 1 has a carcass 4 extending in a toroidal shape from a bead portion (not shown) in which a pair of bead cores (not shown) are embedded to a sidewall portion 2 and a tread portion 3. The main belt 6 includes at least three inclined belt layers in which the cords are arranged inclined with respect to the tire equatorial plane E, and in FIG. 1, four inclined belt layers 5-1 to 5-4. In FIG. 1, the inclined belt layer 5-
Each of 1 to 5-4 is represented only by the cross section of the cord,
The illustration as the cord rubberized layer is omitted for convenience of explanation.

The main features of the configuration of the present invention are as follows.
The width of the widest inclined belt layer is set appropriately, and at least one inclined belt layer having the smaller arrangement angle of the cord is arranged at an appropriate position, and the cross-sectional extending shape of the end 5-1a is appropriately adjusted. To set.

More specifically, the adjacent inclined belt layer 5
-1 and 5-2, 5-2 and 5-3, 5-3 and 5-4 are arranged such that their cords cross each other, and the entire inclined belt layer 5
-1 to 5-4, the widest and widest inclined belt layer (in FIG. 1, two inclined belts 5-2 and 5-3 correspond in FIG. 1).
Makes the width W1 not more than 80% of the tread width TW, and the innermost inclined belt layer 5-1 located on the innermost side in the tire radial direction makes the arrangement angle of the cord relative to the tire equatorial plane E relatively small. When viewed from the cross section in the tire width direction, at least the outermost cord center position X located at the outermost end side of the innermost inclined belt layer 5-1 in the tire width direction and the tread portion tread surface 7 The distance (height) H1 measured in the radial direction is the distance measured in the same way between the predetermined cord center position Y inside the tire width direction and the tread portion tread surface 7 by a predetermined distance d1. (Height) The arrangement is to be shorter than H2.

With this configuration, the occurrence of separation at the widthwise end of the inclined belt layer can be effectively suppressed without deteriorating the abrasion performance and cut durability of the tread portion, and thereby improving tire durability. Performance can be improved.

More specifically, in the present invention,
The main belt 6 is composed of at least three inclined belt layers in which cords are inclined with respect to the tire equatorial plane E, and adjacent inclined belt layers 5-1 and 5-2, 5-2 and 5-3, Five
-3 and 5-4 should be stacked so that their cords cross each other, so that the tires can be sufficiently reinforced to withstand high air pressure and heavy load conditions. it can. The above-described belt configuration greatly contributes particularly to improvement in cut durability.

The main belt 6 has inclined belt layers 5-1 to 5-4 so that the cords cross each other with the tire equatorial plane E interposed therebetween.
It is preferable to use a so-called cross belt formed by arranging the layers.

The widest inclined belt layers 5-2 and 5-3 of all the inclined belt layers 5-1 to 5-4 have the widest inclined belt layers 5-2 when their width W1 is too wide. , 5-3, the separation is likely to occur at the end positions in the width direction. In the present invention, the width W1 is limited to 80% or less of the tread width TW.
It is possible to effectively suppress the separation at the end portions in the width direction of 2, 5-3. The width W1 is the tread width T.
If it is less than 50% of W, the effect of suppressing the growth of diameter at the time of filling the internal pressure is reduced, and there is a possibility that the heat generation of the tread portion and the cut durability may be deteriorated. Therefore, the lower limit value is set to 50%. Is preferred.

According to the present invention, at least the cord arrangement angle with respect to the tire equatorial plane is set relatively small.
By arranging one inclined belt layer, the circumferential bending rigidity of the main belt 6 is increased, and it is possible to suppress the development of cuts and the like which cause separation failure.

Further, when a cut wound reaching the belt from the tread portion is received, a large circumferential tension acts on the cord during running or the like, so that the cord is likely to be broken. Then, such inclined belt layer
Since 5-1 is arranged at the innermost position in the tire radial direction, failures such as cord breakage due to the cut flaws can be effectively prevented.

Further, in the case of a conventional tire in which the inclined belt layer in which the arrangement angle of the cords is set relatively small is arranged with the diameter difference, when the tire is in contact with the tire, the inclined belt layer of the inclined belt layer is absorbed to absorb the diameter difference. Since the width direction end position is relatively large in diameter, the cord at the width direction end position is forced to be deformed to be greatly stretched in the tire circumferential direction, and separation occurs at the width direction end position. It was easy.

For this reason, in the present invention, the widthwise end position of the innermost inclined belt layer 5-1 is disposed outside the normal position in the tire radial direction, more specifically, at least the innermost inclined belt layer The distance (height) H1 when the distance between the outermost cord center position X located on the outermost end side of the belt layer 5-1 in the tire width direction and the tread portion tread surface 7 in the tire radial direction is measured. Also, by arranging so as to be shorter than the distance (height) H2 when the distance between the predetermined cord center position Y located inside the tire width direction and the tread portion tread surface 7 by the predetermined distance d1 is similarly measured. The diameter difference between the width direction end position of the inner inclined belt layer 5-1 and the other position can be minimized, and as a result, the code at the width direction end position is slightly in the tire circumferential direction. Since it is only necessary to stretch it, the separation at the end It is possible to dramatically improve the Shon.

From the viewpoint of the wear performance of the tread portion (particularly, the performance of uniformly abrading in the width direction of the tread portion), it is preferable that the inclined belt layer is disposed in accordance with the contour of the tread surface of the tread portion. As in the present invention, the wear performance is hardly affected as long as only the widthwise end of the inclined belt layer is disposed slightly outside in the tire radial direction than usual.

Therefore, the pneumatic tire of the present invention, by adopting the above configuration, effectively suppresses the occurrence of separation at the belt end position without deteriorating the wear performance and cut durability of the tread portion. Tire durability can be improved.

It is preferable that the angle at which the cords of the innermost inclined belt layer 5-1 are arranged is 13 ° or less. When the arrangement angle is larger than 13 °, the diameter growth of the tire may not be sufficiently suppressed, and in addition, other inclined belt layers
This is because there is no difference between the arrangement angles of the cords 5-2 to 5-4 and the arrangement angle, and it becomes meaningless to arrange. The cords of the inclined belt layers 5-2 to 5-4 other than the innermost inclined belt layer 5-1 are preferably arranged at an angle of 15 to 40 °.

Further, when the predetermined cord center position Y is measured in the tire width direction from the outermost cord center position X, the predetermined distance d1 is 15 to 15 of the half width 0.5W2 of the innermost inclined belt layer 5-1.
Preferably it is in the range of 70%. The predetermined distance d1
If the ratio to the width 0.5W2 is less than 15%, a large effect cannot be obtained. If the ratio exceeds 70%, a sufficient volume of the tread rubber cannot be secured, resulting in wear in the tread portion. This is because the performance may be deteriorated.

Further, when the center position Y of the predetermined cord and the center position of the outermost cord are measured from the tread portion tread surface 7 in the tire radial direction, the difference h of the distance is 80 to 80 of the cord diameter D.
Preferably it is within the range of 350%. If the ratio of the distance difference h to the cord diameter D is less than 80%, the separation at the width direction end of the innermost inclined belt layer 5-1 cannot be sufficiently suppressed, and the ratio is 350%. This is because, if it exceeds, the thickness of the tread rubber becomes excessively thin, and the wear performance in the tread portion 3 may be deteriorated.

FIG. 2 shows an embodiment in which the innermost sloping belt layer 5-1 is also the widest sloping belt layer.
Also for 5-1 to 5-3, applying the relationship of the distance difference h, in addition to widening the appropriate range of the distance difference h, the width direction of the inclined belt layers 5-1 to 5-3 This is preferable because separation at the end can be suppressed. However, with this configuration, the rubber thickness on the tread shoulder side becomes thin, and the wear performance of the tread portion 3 tends to deteriorate.

For this reason, when importance is placed on the wear performance of the tread portion, as shown in FIG.
The inclined belt layer 5-2 that is closest to and wider than this is
The center position Z of the specific cord on the end side is determined by the tread surface 7
And the tread shoulder is arranged such that the distance H3 measured in the tire radial direction is longer than the distance H1 measured similarly at the outermost cord center position X of the innermost inclined belt layer 5-1. What is necessary is just to secure the rubber thickness of the side.

When there are many chances of stepping on a projection such as a rock such as a tire for a construction vehicle, the main belt 6 may be used.
If an auxiliary belt 9 composed of at least one protective belt layer covering the entire width, and two protective belt layers 8-1 and 8-2 in FIG. 3 is arranged on the outer peripheral side of the main belt 6 from the tread portion tread surface, The auxiliary belt 9 can prevent these protrusions from reaching the main belt 6 even if a cut wound that reaches the main belt 6 is received.

In addition, as the protective belt layers 8-1 and 8-2,
It is preferable that the treat strength is small and the elongation at break is large as compared with the inclined belt layers 5-1 to 5-4. Here, the "treat strength" means the breaking strength, and the treat strength of the protective belt layer is 5 to 4 of the treat strength of the inclined belt layer.
It is preferably in the range of 0%, more preferably 10 to 3%.
It is in the range of 0%. In addition, the phrase “large elongation at break” means that the elongation at break is 4% or more, more preferably 5% or more.
８8%.

For this reason, as the cords of the protective belt layers 8-1 and 8-2, for example, a number of so-called high elongation cords (elongation cords) having an elongation at break of 5 to 8% are used. Preferably, the main belt can be effectively protected from rock penetration.

The above is merely an example of the embodiment of the present invention, and various changes can be made within the scope of the claims.

[0043]

Next, a pneumatic tire according to the present invention was prototyped and its performance was evaluated, and will be described below. As test tires, three types of tires, that is, tires for small and medium-sized construction vehicles, tires for trucks and buses, and tires for super-large construction vehicles, were used, and the performance of each tire was evaluated.

(1) Small and Medium Construction Vehicle Tires The tire of the embodiment has a belt structure shown in FIG. 1, a tire size of 14.00R24, a tread width TW of 330 mm,
The width (mm) of each inclined belt layer, the arrangement angle (°) of the cord and the cord diameter D, and the distances H1, H2 and H3 (m
m), and the predetermined distance d1 (mm) are shown in Table 1. The tire structure other than the belt structure was substantially the same as that of a normal tire for a small and medium-sized construction vehicle. For reference, a prototype tire of the conventional example having the belt structure shown in FIG. 4 was also manufactured in the same manner, and the belt structure is also shown in Table 1.

[0045]

[Table 1]

(2) Truck / Bus Tire The tire of the embodiment has the belt structure shown in FIG. 2, the tire size is 275 / 80R22.5, the tread width TW is 210 mm, and the width of each inclined belt layer ( mm), the cord laying angle (°) and the cord diameter D, and the distances H1, H2 and H3 (m
m) and the predetermined distance d1 (mm) are shown in Table 2. The tire structure other than the belt structure was substantially the same as a normal truck / bus tire. For reference, a prototype tire of the conventional example having the belt structure shown in FIG. 5 was similarly manufactured, and the belt structure is also shown in Table 2.

[0047]

[Table 2]

(3) Tires for Super-Large Construction Vehicles The tire of the embodiment has a belt structure shown in FIG. 3, a tire size of 40.00R57 and a tread width TW of 960 mm.
The width (mm) of each inclined belt layer, the arrangement angle (°) of the cord and the cord diameter D, and the distances H1, H2 and H3 (m
m) and the predetermined distance d1 (mm) are shown in Table 3. The tire structure other than the belt structure was substantially the same as that of an ordinary tire for a super-large construction vehicle. For reference, a prototype tire of the conventional example having the belt structure shown in FIG. 6 was also manufactured in the same manner, and the belt structure is also shown in Table 3.

[0049]

[Table 3]

(Performance evaluation) The test was performed to evaluate the wear performance of the tread portion, the cut resistance, and the separation resistance at the widthwise end position of the inclined belt layer.

The wear performance of the tread portion was determined by mounting the tire on a standard rim and rolling the load on the rotating drum at a predetermined speed for a predetermined time under a condition in which a predetermined tire internal pressure (gauge pressure) and a load mass were applied. Thereafter, the amount of wear of the tread rubber was measured and evaluated from the measured values.

The cut resistance is determined in advance at the center in the width direction of the tread portion, up to the inclined belt layer 5-4 for tires for small and medium-sized construction vehicles, and to the inclined belt layer for truck / bus tires. Up to 5-3, in the case of a tire for a super-large construction vehicle, after rolling the load with the cut wound reaching the protective belt layer 8-2 for a predetermined time, measure the separation length from the cut wound Then, evaluation was made from the measured values.

The separation resistance at the end portions in the width direction of the inclined belt layer was evaluated by evaluating the abrasion performance and cut resistance of the tread portion, disassembling the tire, and measuring the separation width at the end positions in the width direction. It measured and evaluated from this measured value.

In the case of tires for small and medium-sized construction vehicles,
Standard rim 10.00, tire pressure 700kPa, load mass
5600kg, rotating drum speed is equivalent to 15km / h, load rolling time is 120 hours. For truck and bus tires, standard rim is 7.50 x 22.5, tire pressure is 875kPa,
The load mass is 3250 kg, the speed of the rotating drum is 60 km / h, the load rolling time is 100 hours, and in the case of a tire for a super-large construction vehicle, the standard rim is 40.00R57, the tire pressure is 700 kPa, and the load mass is 102000 kg. Rotating drum speed 1
0 km / h, and the load rolling time was 200 hours.

Tables 1 to 3 show the evaluation results. Table 1
Table 2 shows the case of tires for trucks and buses, and Table 3 shows the case of tires for super-large construction vehicles. The cut resistance values are 100
The smaller the value, the better.

From the evaluation results shown in Tables 1 to 3, the tires of the examples are smaller than the tires of the conventional example in any of the tires for small and medium-sized construction vehicles, the tires for trucks and buses, and the tires for ultra-large construction vehicles. Thus, the abrasion performance and cut resistance of the tread portion are excellent, and the separation is sufficiently suppressed at the widthwise end position of the inclined belt layer.

[0057]

According to the present invention, the occurrence of separation at the end portion in the width direction of the inclined belt layer is effectively suppressed and the tire durability is improved without significantly deteriorating the wear performance and cut durability of the tread portion. It has become possible to provide so-called heavy duty tires used under high air pressure and heavy load conditions, such as pneumatic tires, particularly trucks, buses, construction vehicles and the like.

[Brief description of the drawings]

FIG. 1 is a half sectional view in the width direction of a pneumatic tire for a small and medium-sized construction vehicle according to the present invention.

FIG. 2 is a half sectional view in the width direction of the pneumatic tire for trucks and buses according to the present invention.

FIG. 3 is a half sectional view in the width direction of a pneumatic tire for a super-large construction vehicle according to the present invention.

FIG. 4 is a half sectional view in the width direction of a conventional pneumatic tire for small and medium-sized construction vehicles.

FIG. 5 is a half sectional view in the width direction of a conventional pneumatic tire for trucks and buses.

FIG. 6 is a half sectional view in the width direction of a conventional pneumatic tire for a super-large construction vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Side wall part 3 Tread part 4 Carcass 5-1 to 5-4 Inclined belt layer 6 Main belt 7 Tread part tread surface 8-1,8-2 Protective belt layer 9 Auxiliary belt

Claims (8)

[Claims] At least three inclined belt layers in which cords are arranged obliquely with respect to the tire equatorial plane are provided on the outer peripheral side of a carcass extending in a toroidal shape from a bead portion in which a pair of bead cores are embedded to a sidewall portion and a tread portion. In the pneumatic tire having the main belt, the adjacent inclined belt layers are arranged so that their cords cross each other, and the widest widest inclined belt layer among all the inclined belt layers has the same width. (W1) is not more than 80% of the tread width (TW), and the innermost sloping belt layer located on the innermost side in the tire radial direction has a relatively small arrangement angle of the cord with respect to the tire equatorial plane, and When viewed in a cross section in the tire width direction, at least the innermost inclined belt layer has a tread and a center position (X) of the outermost cord located on the outermost end side in the tire width direction. The distance measured in the tire radial direction from the outer tread is a predetermined distance (d) from the outermost cord center position (X).
1) A pneumatic tire characterized in that it is shorter than the distance measured similarly between the center position (Y) of the predetermined cord located inside the tire width direction and the tread surface. 2. The pneumatic tire according to claim 1, wherein the arrangement angle of the cord of the innermost inclined belt layer is 13 ° or less. 3. The predetermined distance (d) when the predetermined cord center position is measured from the outermost cord center position in the tire width direction.
1) is 15 to 70% of the half width (0.5W2) of the innermost inclined belt layer
The pneumatic tire according to claim 1 or 2, which is within the range. 4. The difference (h) in distance between the center position of the predetermined cord and the center position of the outermost cord measured from the tread surface of the tread in the tire radial direction is within a range of 80 to 350% of the cord diameter. Item 4. The pneumatic tire according to item 1, 2 or 3. 5. When the main belt has an inclined belt layer closest to and wider than the innermost inclined belt layer,
The distance (H3) when the specific cord center position (Z) on the end side is measured in the tire radial direction from the tread surface of the tread,
The pneumatic tire according to any one of claims 1 to 4, wherein the distance is longer than a distance (H1) when the center position (X) of the outermost cord of the innermost inclined belt layer is similarly measured. 6. The entire inclined belt layer is configured such that a distance measured between the outermost cord center position and the tread portion tread position in the tire radial direction is a distance between the predetermined cord center position and the tread portion tread position. The pneumatic tire according to any one of claims 1 to 5, wherein the distance is shorter than a distance measured similarly. 7. The pneumatic tire according to claim 1, wherein an auxiliary belt including at least one protective belt layer covering the entire width of the main belt is disposed on an outer peripheral side of the main belt. 8. The protective belt layer has a lower treat strength and a larger elongation at break than the inclined belt layer.
The pneumatic tire described in the above.