KR20200059915A - Heavy duty pneumatic tire - Google Patents

Abstract

Disclosed is a pneumatic tire for a heavy load, including: a bead unit comprising a bead core and an apex; a body ply which turns up and covers the bead unit; and a steel chafer which covers the body ply. The pneumatic tire for a heavy load can include: a first cord which continuously covers an end of the bead unit and an end of the body ply; and a second cord which covers the steel chafer.

Description

Heavy-duty pneumatic tires {HEAVY DUTY PNEUMATIC TIRE}

The present invention relates to a pneumatic tire for heavy loads, and more particularly, to a pneumatic tire for heavy loads that can prevent separation due to overheating and reduce intensive heat generation of the bead.

In general, heavy-duty pneumatic tires are mainly used in buses and trucks. This heavy-duty pneumatic tire forms an interior space through which air can be injected, and includes a shoulder portion, a side wall portion, and a bead portion on both sides along the width direction of the tire, centering on the tread portion.

The bead portion of the heavy-duty pneumatic tire wraps around the end of the body cord that supports the interior of the tire, maintains a shape to maintain performance when driving, and plays an important role in mounting on the rim.

On the other hand, it is difficult to dissipate heat from the part where the rim is mounted to the end of the apex, and the bead is thickly designed and manufactured to prevent it from being separated from the rim due to the characteristics of the heavy-duty tire. For this reason, it is structurally vulnerable to heat generation, and according to the use environment, a separation accident due to overheating of the bead frequently occurs in a high temperature area.

In order to solve this, conventionally, it has been proposed in a method to be solved by inserting a reinforcing material into the bead. However, as for the concrete solution, a bead part may be broken due to the occurrence of shear stress due to weight increase using a steel cord, and the conventional structure using a nylon cord has the effect of improving the heat-resistant durability of concrete structures and materials. There may not be.

In this regard, "the heavy-duty pneumatic tire for reinforced bead (domestic patent registration no. 10-1723745)" and "the heavy-duty pneumatic tire for improved bead durability (domestic publication 10-2004-0029607)" Can be referenced.

In the case of the conventional " pneumatic tire for heavy load with reinforced bead portion ", it is characterized by a configuration of a reinforcement cord surrounding a part of the carcass fly turn-up end portion and the exposed surface outside the apex. At this time, the EPI of the reinforcing cord is up to 21, and the attachment position is set at the end of the body ply and the steel chaper, respectively, from the bottom of the bead. This material and the attachment position can prevent the stress concentration occurring at the end of the steel cord due to the overload, but the resistance to heat transmitted to the bead portion is insignificant.

In addition, in the case of the conventional "pneumatic tire for heavy load with improved bead durability", it is characterized by suppressing deformation of the bead using two nylon reinforcements. Both nylon reinforcements are simple shapes that wrap the outside of the steel chaper, and it is difficult to improve the heat-resistant durability except the effect of suppressing deformation due to stress concentration.

Patent Literature 1: Domestic Patent Registration No. 10-1723745 (Registration on March 30, 2017) Patent Literature 2: Domestic Patent Publication No. 10-2004-0029607 (published on April 8, 2004)

The present invention is to provide a heavy-duty pneumatic tire that minimizes heat generated at the ends of the bead and the body ply, improves the durability of the bead and increases the structural stability of the bead.

According to an aspect of the present invention, a bead portion made of a bead core and an apex, a body ply encasing the bead portion by turning it up, and a pneumatic tire for a heavy load comprising a steel chaper surrounding the body ply, with an end of the bead portion It may include a first cord that wraps the end of the body ply continuously, and a second cord that wraps the steel chaper.

In this case, the first cord and the second cord may be nylon cords made of nylon.

In addition, the first code and the second code may satisfy EPI in the range of 20 to 30.

In addition, the distance from the inner end of the first cord to the inner end of the steel chaper satisfies the range of 5 mm to 15 mm, and the distance from the outer end of the body ply to the outer end of the steel chaper satisfies the range of 5 mm to 25 mm. The inner end of the first cord may be located between the inner end of the steel chaper and the inner end of the second cord.

In addition, the distance from the inner end of the first cord to the inner end of the second cord satisfies a range of 5 mm to 20 mm, and the distance from the outer end of the steel chaper to the outer end of the second cord is 15 mm to 35 mm. Satisfies the range, and the outer end of the second cord may be positioned higher than the outer end of the body ply.

Embodiments of the present invention by reducing the bead portion and the steel chaper structure, by reducing the high-temperature heat generated by the rim (RIM) while being transferred to the tire, to minimize the deformation of the bead portion and the body ply end by the high temperature heat There is an advantage that, in the end, bead durability can be improved.

1 is a view showing the shape of a bead of a tire according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation according to an embodiment of the present invention. The following description is one of several aspects of the present invention that can be patented, and the following description may form part of the detailed description of the present invention. However, specific descriptions of well-known configurations or functions in describing the present invention may be omitted to clarify the present invention.

The present invention can be applied to various changes and may include various embodiments, and specific embodiments will be illustrated in the drawings and described in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

And terms including ordinal numbers such as first and second may be used to describe various components, but the corresponding components are not limited by these terms. These terms are only used to distinguish one component from another. When a component is said to be 'connected' or 'connected' to another component, it is understood that other components may be directly connected to or connected to the other component, but other components may exist in the middle. It should be. The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

1 is a view showing the shape of a bead of a tire according to the present invention.

As shown in Figure 1, the heavy-duty pneumatic tire according to the present invention, the bead portion consisting of a bead core (1) and an apex (2), a body ply (3) to wrap up the bead portion, and a body fly ( 3) includes a steel chaper (4) surrounding the end, the end of the bead portion and the end of the body ply (3) can be wrapped by a first cord (61), the steel chaper (4) is a second cord (62) Can be wrapped by

Specifically, the first cord 61 is positioned between the bead portion and the body ply 3, and may be disposed to surround the outer surface of the end portion of the bead portion and the end of the body ply 3. The first cord 61 may be a nylon cord made of nylon.

For example, the first cord 61 may be composed of a first bead inner cord portion 61a surrounding an outer surface of a bead portion and a first bead outer cord portion 61b surrounding an end of the body ply 3. . The first bead inner code portion 61a and the first bead outer code portion 61b may be provided in an extended form and bent in an “S” shape (see FIG. 1).

The second cord 62 may be disposed to surround the outer end surface of the steel chaper 4. Like the first cord 61, the second cord 62 may be a nylon cord made of nylon.

For example, the second cord 62 may be composed of a second chaper outer cord portion 62a surrounding the end outer surface of the steel chaper 4 and a second extension cord portion 62b extending from the second chaper outer end. You can. The second chaper outer cord portion 62a and the second extension cord portion 62b may be provided in an extended form and bent in a “J” shape (see FIG. 1).

In particular, these first codes 61 and second codes 62 can satisfy EPI in the range of 20 to 30.

If the EPI of the first cord 61 and the second cord 62 is lower than 20, there is a disadvantage in that the effect of the heat-resistant durability performance is insufficient because the density of the nylon cord constituting the nylon chaper and supporting the bead is insufficient. When the EPI of the 1 cord 61 and the 2nd cord 62 is higher than 30, the topping rubber gauge of the nylon chaper is insufficient, thereby exposing the cord to damage due to external impact. Accordingly, the first cord 61 and the second cord 62 have an EPI in the range of 20 to 30, thereby improving durability against heat generated at the ends of the bead portion and the body ply 3.

In addition, the distance H1 from the inner end of the first cord 61 to the inner end of the steel chaper 4 satisfies a range of 5 mm to 15 mm, and the steel chaper 4 at the outer end of the body ply 3 The distance to the outer end (H3) of the, satisfies the range of 5mm to 25mm, the inner end of the first cord 61 is located between the inner end of the steel chaper 4 and the inner end of the second cord 62 Can be.

If the distance between the ends of the steel cord is less than 5 mm, deformation may occur at the cord ends due to stress concentration. In addition, the distance H1 from the inner end of the first cord 61 to the inner end of the steel chaper 4 is up to 15 mm, and the distance from the outer end of the body ply 3 to the outer end of the steel chaper 4 (H3) is sufficient to satisfy the durability performance at the maximum level of 25mm, and if it exceeds this, the expected effect is insufficient in terms of performance, which can be an unnecessary design figure when considering manufacturing cost.

In addition, the distance H2 from the inner end of the first cord 61 to the inner end of the second cord 62 satisfies the range of 5 mm to 20 mm, and the second cord (at the outer end of the steel chaper 4) ( The distance H4 to the outer end of 62) satisfies the range of 15 mm to 35 mm, and the outer end of the second cord 62 may be positioned higher than the outer end of the body ply.

If the distance between the nylon and steel cord ends is less than 5 mm, strain may occur at the cord ends due to stress concentration. In addition, the distance H2 from the inner end of the first cord 61 to the inner end of the second cord 62 is up to 20 mm, from the outer end of the steel chaper 4 to the outer end of the second cord 62 The distance (H4) is sufficient to satisfy the durability performance at the maximum level of 35mm, and if it exceeds this, the expected effect is insufficient in terms of performance, which can be an unnecessary design figure when considering manufacturing cost.

Here, the inner and outer sides of the first cord 61, the inner and outer sides of the second cord 62, the inner and outer sides of the steel chaper 4, and the inner and outer sides of the body ply 3, the center line C of the bead portion With reference to, the left direction of FIG. 1 may be defined as the inside, and the right direction of FIG. 1 may be defined as the outside.

As described above, the first cord 61 is inserted in an S-shape between the bead portion and the body ply 3 to cover the end of the body ply 3, thereby minimizing heat transfer from the rim. , Through this, it is possible to prevent deformation of the bead by dispersing the stress applied to the body ply 3. In addition, the second cord 62 is disposed to surround the steel chaper 4, thereby reinforcing the body ply 3 from turning up and loosening, and minimizing heat transfer.

As described above, the present invention can minimize the deformation of the bead portion and the body ply end by the high temperature heat by reducing the high temperature heat generated from the driving rim and transmitted to the tire by reinforcing the bead portion and the steel chaper structure. In the end, it has excellent advantages such as improving the bead durability.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may be implemented in other specific forms without changing the technical spirit or essential features of the present invention. You will understand. For example, a person skilled in the art can change the material, size, etc. of each component depending on the application field, or combine or replace the embodiments to implement the present invention in a form not explicitly disclosed, but this also applies to the present invention. It is not beyond the scope of. Therefore, the embodiments described above are illustrative in all respects and should not be understood as limiting, and it should be said that these modified embodiments are included in the technical idea described in the claims of the present invention.

1: Bead core 2: Apex
3: Body fly 4: Steel chaper
61: 1st code 61a: 1st bead inner code part
61b: first bead outer code section 62: second code
62a: 2nd chaper outer cord part 62b: 2nd extension cord part
H1: Distance from the inner end of the first cord to the inner end of the steel chaper
H2: Distance from the inner end of the first cord to the inner end of the second cord
H3: Distance from the outer end of the body ply to the outer end of the steel chaper
H4: Distance from the outer end of the steel chaper to the outer end of the second cord

Claims (5)

A heavy-duty pneumatic tire comprising a bead portion made of a bead core and an apex, a body ply wrapped by turning up the bead portion, and a steel chaper surrounding the body ply,
A heavy-duty pneumatic tire comprising a first cord continuously wrapping the end of the bead and the end of the body ply, and a second cord surrounding the steel chaper. According to claim 1,
The first cord and the second cord are heavy-duty pneumatic tires that are nylon cords made of nylon. According to claim 1,
The first cord and the second cord are heavy-duty pneumatic tires satisfying EPI in the range of 20 to 30. According to claim 1,
The distance H1 from the inner end of the first cord to the inner end of the steel chaper satisfies a range of 5mm to 15mm,
The distance H3 from the outer end of the body ply to the outer end of the steel chaper satisfies a range of 5 mm to 25 mm,
The inner end of the first cord
A heavy-duty pneumatic tire positioned between the inner end of the steel chaper and the inner end of the second cord. According to claim 1,
The distance H2 from the inner end of the first cord to the inner end of the second cord satisfies a range of 5 mm to 20 mm,
The distance H4 from the outer end of the steel chaper to the outer end of the second cord satisfies a range of 15 mm to 35 mm,
The outer end of the second cord is a pneumatic tire for heavy loads positioned higher than the outer end of the body fly.

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