PNEUMATIC TIRE

Abstract

A pneumatic tire that can enhance durability and productivity of a carcass edge portion is disclosed. The pneumatic tire can include a tread portion, a side wall portion, and a bead portion and in which a carcass is installed at the bottom of the side wall portion and the tread portion, wherein the carcass is configured with a bottom carcass sheet and an upper carcass sheet, one end of the bottom carcass sheet having a termination point at a position that winds up a bead core of the bead portion in an outward direction, and one end of the upper carcass sheet having a termination point at an inner side surface of the bead portion.

Claims

1. A pneumatic tire comprising: a tread portion; a side wall portion; a bead portion; and a carcass installed at a bottom of the side wall portion and the tread portion, wherein the carcass is configured with a bottom carcass sheet and an upper carcass sheet, one end of the bottom carcass sheet having a termination point at a position that winds up a bead core of the bead portion in an outward direction; and one end of the upper carcass sheet has having a termination point at an inner side surface of the bead portion.

2. The pneumatic tire of claim 1, wherein the termination point of the one end of the bottom carcass sheet is positioned at an end portion of a belt portion or a position exceeding the end portion.

3. The pneumatic tire of claim 1, wherein the termination point of the one end of the bottom carcass sheet is positioned between an end portion of a belt portion and a 60% point of a tire height h.

4. The pneumatic tire of claim 1, wherein the termination point of the one end of the bottom carcass sheet is positioned at a segment from a 40% point to a 60% point of a tire height h.

5. The pneumatic tire of claim 1, wherein the termination point of the one end of the bottom carcass sheet is positioned at a segment between an outer side surface of the bead core and a 40% point of a tire height h.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a diagram illustrating a turn-up state of a conventional tire to which two carcasses are applied.

[0019] FIG. 2 is a table illustrating classification according to a position of a carcass end portion turned up in a bead portion.

[0020] FIG. 3 is a partially cross-sectional view illustrating a turn-up state of a conventional tire to which two carcasses are applied.

[0021] FIG. 4 is a partially cross-sectional view illustrating a pneumatic tire according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, the present invention will be described in detail with reference to the attached drawings. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

[0023] Throughout this specification and the claims that follow, when it is described that an element is connected (accessed, contact, and coupled) to another element, the element may be directly connected to the other element and indirectly connected to the other element through a third element. Further, unless explicitly described to the contrary, the word comprise and variations such as comprises or comprising, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0024] Terms used in the present application are used for describing a specific exemplary embodiment and do not limit the present invention. When using in a description of the present invention and the appended claims, a singular form includes a plurality of forms unless it is explicitly differently represented. Further, in the present specification, a term comprise or have indicates presence of a characteristic, numeral, step, operation, element, component, or combination thereof described in a specification and does not exclude presence or addition of at least one other characteristic, numeral, step, operation, element, component, or combination thereof.

[0025] Hereinafter, an exemplary embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0026] FIG. 1 is a diagram illustrating a turn-up state of a conventional tire to which two carcasses are applied, and FIG. 2 is a table illustrating classification according to a position of a turned up carcass end portion in a bead portion. A carcass structure is classified into a so-called super turn-up height (STUN), high turn-up height (HTUH), a middle turn-up height (MTUH), and a low turn-up height (LTUH). A small diameter shaping method generally has a structure of 1-0 and 2-0 of FIG. 1. A large diameter shaping method has a structure of 1-1 instead of a structure of 2-0.

[0027] In such a conventional configuration, FIG. 3 illustrates a case in which two carcasses are applied to a structure of 2-0 of FIG. 1. In FIG. 3, a bottom carcass sheet 410 is turned up using a bead core 310 as one shaft, and a position of a termination point 411, which is a turn-up edge is positioned at a side wall portion 200. An upper carcass sheet 420 is turned up using the bead core 310 as one shaft, and a position of a termination point 421, which is a turn-up edge is positioned at an external side portion of a bead filler 320. In this case, at an external side portion of the bead filler 320 at which the termination point 421 is positioned, there is a high possibility in which separation is to be started, and this is disadvantageous in durability of a bead portion. Further, in order to secure durability of a tire, there is a restriction that the termination point 421 of the upper carcass sheet 420 and an edge portion of the bead filler 320 should be separated by a predetermined gap or more.

[0028] Accordingly, as shown in FIG. 4, in a pneumatic tire according to the present invention including a tread portion 100, the side wall portion 200, and a bead portion 300 and in which a carcass 400 is installed at the bottom of the side wall portion 200 and the tread portion 100, the carcass 400 is configured with the bottom carcass sheet 410 and the upper carcass sheet 420, one end of the bottom carcass sheet 410 has a termination point 411 at a position that winds up the bead core 310 of the bead portion 300 in an outward direction, and one end of the upper carcass sheet 420 has the termination point 421 at an inner side surface of the bead portion 300.

[0029] According to the above configuration, by enabling a turn-up edge portion not to be formed at the outside of the tire by not turning up the upper carcass sheet 420, a cause of separation of the bead portion is removed.

[0030] In order to more completely remove a separation cause, it is preferable that the termination point 421 of the upper carcass sheet 420 is positioned on a straight line a of the bottom surface of the bead core 310.

[0031] The termination point 411 of one end of the bottom carcass sheet 410 may be positioned at an end portion 510 of a belt portion 500 or a position exceeding the end portion 510, may be positioned between the end portion 510 of the belt portion 500 and a 60% point of a tire height h, may be positioned at a segment from a 40% point to a 60% point of a tire height h, or may be positioned between an outer side surface of the bead core 310 and a point 40% of a tire height h. The position is determined by a tire size or whether a protrusion exists on the tire side wall portion 200.

[0032] The foregoing description of the present invention is an illustration, and it may be understood by a person of ordinary skill in the art that the present invention may be easily changed in different detailed forms without changing the technical spirit or an essential characteristic of the present invention. Therefore, it should be understood that the foregoing exemplary embodiments are not limited but are illustrative. For example, each constituent element described in a single type may be distributedly performed, and constituent elements described in a distributed type may be performed in a combined form.

[0033] The scope of the present invention is represented by claims to be described later, and it should be analyzed that a meaning and the scope of claims and an entire change or a changed form derived from an equivalent concept thereof are included in the scope of the present invention.

REFERENCE NUMERALS FROM THE FIGS

[0034] 100: tread portion [0035] 200: side wall portion [0036] 300: bead portion [0037] 400: carcass [0038] 410: bottom carcass sheet [0039] 411: termination point [0040] 420: upper carcass sheet [0041] 421: termination point [0042] 500: belt portion [0043] 510: end portion