JPH0495513A - Pneumatic tire - Google Patents

Abstract

PURPOSE:To decrease longitudinal rigidity of a bead filler and increase lateral rigidity, and improve riding comfortableness and handling stability by constituting the tire-bead filler in a bead part by honeycomb-like reinforcing fins in a cross-section crossing the rotary shaft of the tire at right angles. CONSTITUTION:A tire has side wall parts 2 and bead parts 3 on both sides of a tread part 1. A carcass layer 5 is arranged over the whole cross-section of the tire, and its both end parts are bent back so as to wrap bead cores 4 and bead-fillers 6 of the bead parts 3. In this constitution, the bead filler 6 is formed into hollow structures reinforced with sheet-like reinforcing fins 8. That is, the reinforcing fins 8 are formed into a honeycomb-structure in a cross-section crossing the rotary shaft of the tire at right angles to form hollow parts 9. Further, the honeycomb-structure is covered with sheet members 10 so that it is held from both the inside and the outside of the tire. Thus, a decrease in longitudinal rigidity and an increase in lateral rigidity are achieved, and riding comfortableness and handling stability are improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a lightweight pneumatic tire.

More specifically, the present invention relates to a pneumatic tire in which the bead filler of the tire has a hollow structure.

[Conventional technology]

In recent years, the rapid global warming phenomenon has become a major environmental problem, and there is a strong desire to reduce fossil fuel consumption in order to reduce the amount of carbon dioxide released, which is the cause of this global warming phenomenon. There is.

In the case of automobiles, this demand can be satisfied by improving the fuel efficiency of automobiles, but in order to improve the fuel efficiency of automobiles, it is necessary to reduce the weight of the vehicle and reduce its rolling resistance. In particular, since the unsprung weight of a vehicle greatly contributes to reducing the weight of the vehicle, it is important to reduce the weight of tires5 as much as possible and reduce rolling resistance.

However, reducing the volume of each part that makes up a tire generally results in a decrease in tire performance.
It has been extremely difficult to reduce the weight of tires while maintaining or improving conventional tire performance such as steering stability and ride comfort.

[Problem to be solved by the invention]

An object of the present invention is to provide a pneumatic tire that reduces the weight of the tire by devising the structure of the bead filler, reduces the longitudinal stiffness of the bead filler, and increases the lateral stiffness to improve ride comfort and handling stability. It's about doing.

[Means to solve the problem]

The object of the present invention can be achieved in a tire in which a bead filler is embedded in the bead portion, by forming the bead filler into a hollow structure composed of honeycomb-shaped reinforcing fins in a cross section perpendicular to the tire rotation axis.

By making the bead filler hollow, the weight of the tire is reduced, and by forming the hollow structure with honeycomb-shaped reinforcing fins in the cross section perpendicular to the tire rotation axis, longitudinal rigidity is increased. This results in a reduction in lateral stiffness and an increase in lateral rigidity, thereby improving ride comfort and handling stability.

A detailed explanation will be given below based on the drawings.

As shown in FIG. 1, the tire of the present invention has sidewall portions 2 and bead portions 3 on both left and right sides of a tread portion 1. The carcass layer 5 is arranged so as to cover the entire cross section of the tire, and both ends of the carcass layer 5 form a bead core 4 of the bead portion 3.
and the bead filler 6. 7 is a belt layer.

The bead filler 6 is formed into a hollow structure reinforced with thin plate-like reinforcing fins 8.

More specifically, as shown in FIG. 2, the reinforcing fins 8 have a honeycomb shape in a cross section perpendicular to the tire rotation axis, and form a hollow portion 9. That is, the honeycomb-shaped reinforcing fins 8 extend in the axial direction of the tire without changing their shape, forming a so-called honeycomb structure. Thin plate members 10 cover such a honeycomb structure so as to sandwich it from the inside and outside of the tire. This thin plate material 10 may be made of the same material as the reinforcing fins 8, or may be made of a different material.

The material constituting the reinforcing fins of the honeycomb structure is preferably a polymeric material such as resin or rubber, but light metals such as aluminum or special paper may also be used.

Examples of polymeric materials include epoxy resins, polyolefin resins, polyamide resins, polydiene resins, polyurethane resins, and
These resins can also be used as fiber reinforced plastics (FRP) reinforced with organic fibers such as aramid fibers and wholly aromatic polyester fibers, and inorganic fibers such as carbon fibers, silicon carbide fibers, and alumina fibers.

The bead filler with the honeycomb structure described above is different from the conventional solid rubber bead filler by changing the size (cross-sectional area) of the hollow part forming the honeycomb, the thickness of the reinforcing fins, and the length in the tire axial direction. Compared to this, the bending stiffness and lateral stiffness of the bead filler can be changed freely. In particular, the honeycomb structure is characterized by its ability to lower longitudinal rigidity and increase lateral rigidity, thereby improving both ride comfort and handling stability at the same time.

〔Effect of the invention〕

According to the present invention, since the bead filler has a hollow structure using reinforcing fins having a honeycomb structure, it is possible to significantly reduce the weight of the tire. Therefore, since the rolling resistance is reduced, the fuel efficiency of the vehicle is improved. In addition, since the bead filler has a honeycomb shape in the cross section perpendicular to the tire rotation axis, it lowers longitudinal stiffness but increases lateral stiffness, improving both ride comfort and handling stability. . In particular, the tire of the present invention effectively improves the handling stability and riding comfort of radial tires for private automobiles, which require a larger proportion of bead filler in the tire sidewall due to lower profile. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one example of a pneumatic tire of the present invention, and FIG. 2 is an enlarged cross-sectional view of a bead portion of the tire of the present invention in a direction perpendicular to the tire rotation axis. 4... Bead core, 6... Bead filler, 8...
- Reinforced fins.

Claims (1)

[Claims] A pneumatic tire in which a bead filler is embedded in a bead portion, wherein the bead filler has a hollow structure composed of honeycomb-shaped reinforcing fins in a cross section perpendicular to the tire rotation axis.