Pneumatic tire

Patent metadata

Field	Value
Publication number	US-11590802-B2
Application number	US-202016926999-A
Country	US
Kind code	B2
Filing date	Jul 13, 2020
Priority date	Aug 29, 2019
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

A pneumatic tire comprises: a bead portion provided with an inside bead apex rubber disposed between a turned up portion and a main portion of a carcass ply, and an outside bead apex rubber disposed axially outside the turned up portion and having a radially outer edge; and a the sidewall portion provided with a sidewall reinforcing cord layer disposed axially outside the carcass and having a radially inner edge which is spaced apart from the radially outer edge of the outside bead apex rubber by a radial distance of not less than 5% of a tire section height.

First claim

The invention claimed is:

1. A pneumatic tire comprising:
a tread portion,
a pair of axially spaced bead portions,
a pair of sidewall portions extending between the bead portions and the tread portion,
a toroidal carcass composed of a carcass ply which extends between the bead portions through the tread portion and the sidewall portions and is turned up in each of the bead portions so as to form a pair of turned up portions and a main portion therebetween, and
a belt disposed radially outside the toroidal carcass in the tread portion,

wherein
each of the turned up portions extends radially outwardly so that the distance in the tire radial direction between a radially outer edge of the turned up portion and a maximum tire cross-section width position is in a range of not more than 5% of a tire cross-sectional height,

wherein
in each of the bead portions, an inside bead apex rubber is disposed between the main portion and the turned up portion of the carcass ply,
an outside bead apex rubber is disposed axially outside the turned up portion,
a clinch rubber is disposed on the axially outside of the outside bead apex rubber so as to form an outer surface of the bead portion,
a complex elastic modulus of the inside bead apex rubber is larger than a complex elastic modulus of the clinch rubber which is larger than a complex elastic modulus of the outside bead apex rubber,
the outside bead apex rubber extends in the tire radial direction to have a radially outer edge and a radial dimension of not less than 20% but not more than 40% of the tire cross-section height, and
the radially outer edge of the outside bead apex rubber is positioned radially outside a radially outer edge of the clinch rubber,
in each of the sidewall portions, a sidewall reinforcing cord layer is disposed axially outside the carcass and extends in the tire radial direction to have a radially inner edge and a radially outer edge, and the sidewall reinforcing cord layer is composed of reinforcing cords laid at an angle of from 70 to 90 degrees with respect to the tire circumferential direction,
said radially outer edge of the sidewall reinforcing cord layer is positioned radially outside a midpoint in the tire radial direction between the maximum tire cross-section width position and an axially outer edge of the belt, and
the distance in the tire radial direction between said radially outer edge of the sidewall reinforcing cord layer and said axially outer edge of the belt is not less than 5% but not more than 35% of the tire cross-sectional height,
said radially inner edge of the sidewall reinforcing cord layer is spaced radially outwardly apart from said radially outer edge of the outside bead apex rubber,
said radially inner edge of the sidewall reinforcing cord layer is positioned radially inside the radially outer edge of the turned up portion of the carcass ply, and a radially inner edge portion of the sidewall reinforcing cord layer overlaps with a radially outer edge portion of the turned up portion and is disposed axially outside of the turned up portion,
a distance in the tire radial direction between said radially inner edge of the sidewall reinforcing cord layer and the maximum tire cross-section width position is not less than 10% but not more than 20% of the tire cross-sectional height, and
a distance in the tire radial direction between said radially inner edge of the sidewall reinforcing cord layer and said radially outer edge of the outside bead apex rubber is not less than 5% but not more than 10% of the tire cross-sectional height.

2. The pneumatic tire according to claim 1 , wherein said radially inner edge of the sidewall reinforcing cord layer is positioned radially inside the maximum tire cross-section width position.

3. The pneumatic tire according to claim 1 , wherein the dimension in the tire radial direction of the sidewall reinforcing cord layer is not less than 20% but not more than 60% of the tire cross-sectional height.

4. The pneumatic tire according to claim 3 , wherein said radially inner edge of the sidewall reinforcing cord layer is positioned radially inside the maximum tire cross-section width position.

5. The pneumatic tire according to claim 1 , wherein the thickness of the sidewall reinforcing cord layer is in a range from 1% to 5% of the tire cross-sectional height.

6. The pneumatic tire according to claim 5 , wherein said radially inner edge of the sidewall reinforcing cord layer is positioned radially inside the maximum tire cross-section width position.

7. A pneumatic tire comprising:
a tread portion,
a pair of axially spaced bead portions,
a pair of sidewall portions extending between the bead portions and the tread portion,
a toroidal carcass composed of a carcass ply which extends between the bead portions through the tread portion and the sidewall portions and is turned up in each of the bead portions so as to form a pair of turned up portions and a main portion therebetween, and
a belt disposed radially outside the toroidal carcass in the tread portion,

wherein
each of the turned up portions extends radially outwardly so that the distance in the tire radial direction between a radially outer edge of the turned up portion and a maximum tire cross-section width position is in a range of not more than 5% of a tire cross-sectional height,

wherein
in each of the bead portions, an inside bead apex rubber is disposed between the main portion and the turned up portion of the carcass ply,
an outside bead apex rubber is disposed axially outside the turned up portion,
a clinch rubber is disposed on the axially outside of the outside bead apex rubber so as to form an outer surface of the bead portion,
a complex elastic modulus of the inside bead apex rubber is larger than a complex elastic modulus of the clinch rubber which is larger than a complex elastic modulus of the outside bead apex rubber,
the outside bead apex rubber extends in the tire radial direction to have a radially outer edge and a radial dimension of not less than 20% but not more than 40% of the tire cross-section height, and
the radially outer edge of the outside bead apex rubber is positioned radially outside a radially outer edge of the clinch rubber,
in each of the sidewall portions, a sidewall reinforcing cord layer is disposed axially outside the carcass and extends in the tire radial direction to have a radially inner edge and a radially outer edge, and the sidewall reinforcing cord layer is composed of reinforcing cords laid at an angle of from 70 to 90 degrees with respect to the tire circumferential direction,
said radially outer edge of the sidewall reinforcing cord layer is positioned radially outside a midpoint in the tire radial direction between the maximum tire cross-section width position and an axially outer edge of the belt, and
the distance in the tire radial direction between said radially outer edge of the sidewall reinforcing cord layer and said axially outer edge of the belt is not less than 5% but not more than 35% of the tire cross-sectional height,
said radially inner edge of the sidewall reinforcing cord layer is spaced radially outwardly apart from said radially outer edge of the outside bead apex rubber, and
said radially inner edge of the sidewall reinforcing cord layer is positioned radially inside the radially outer edge of the turned up portion of the carcass ply, and a radially inner edge portion of the sidewall reinforcing cord layer overlaps with a radially outer edge portion of the turned up portion and is disposed axially outside of the turned up portion,
the radial dimension of the inside bead apex rubber is in a range from 5% to 15% of the tire cross-sectional height,
the carcass consists of said

Assignees

• Sumitomo Rubber Ind

Inventors

• Watanabe Yuma
• Kuniyasu Yasuaki

Classifications

• B60C2009/0215

  Partial carcass reinforcing plies, i.e. the plies neither crossing the equatorial plane nor folded around the bead core · CPC title

• B60C15/0653

  with particular configuration of the cords in the respective bead reinforcing layer · CPC title

• B60C15/0018

  not folded around the bead core, e.g. floating or down ply · CPC title

• B60C9/18

  Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers · CPC title

• B60C9/12

  built-up with rubberised layers of discrete fibres or filaments · CPC title