JPH10138712A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire having the function to prevent or suppress splays of water without reducing a control stabilizing performance. SOLUTION: The tire is structured to be provided with a carcass constituting a skeleton of the tire, and a tread arranged radially outside a crown part of the carcass. In this case, when a line circumferentially extending along the tread-end edge of the tread surface is considered a tread-ground contact end line, and the distance between both ends of the ground contact part of the tread surface in the tireaxis direction is considered a tread-ground contact width, in state where the tire is loaded in a normal rim, a normal inner pressure is filled, and a normal load is applied, splay preventing zones are provided in the tread surface area equivalent to 20% of the tread-ground contact width inside the tread- ground contact line in the tire-axial direction, and/or in the tread surface area equivalent to 20% of the tread-ground contact width outside the tread-ground contact line in the tire-axial direction. Then, grooves in which widths W are about from 1 to 4 mm, and depths (d) are about from 2 to 6mm, are provided at intervals S of about 3 to 7mm, are provided in the splay preventing zones.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire having a function of preventing or suppressing splashes.

[0002]

2. Description of the Related Art Conventionally, for example, JP-A-48-40102,
As disclosed in JP-A-49-905, JP-A-49-11006, JP-A-50-132603, and JP-A-52-129103, tires are used to prevent scattering of mud and water by the tires during running of the vehicle. A number of proposals have been made for a long time to provide a splash prevention projection at the end of the tread.

[0003]

However, if the projections for preventing water splashing are provided at the end of the tread as described above, the steering stability is deteriorated. Therefore, for an agricultural machine for which the steering stability is not so strongly required. The above-mentioned water splash prevention projections have been put to practical use in tires and aircraft tires, but as described above for tires for which steering stability is strongly required, such as tires for passenger cars, tires for trucks and buses. No water splash prevention projection has been put to practical use. In addition, the above-mentioned water splash prevention projection has problems such as an increase in tire weight, an increase in cost, and a decrease in productivity.

[0004] An object of the present invention is to provide a pneumatic tire having a function of preventing or suppressing water splash without reducing the steering stability performance of the tire by solving the above-mentioned disadvantages of the prior art. is there.

[0005]

In order to achieve the above object, a tire according to the present invention is a pneumatic tire having a carcass forming a skeleton of a tire and a tread arranged radially outward of a crown portion of the carcass. In the tire, in a state where the tire is mounted on a regular rim, filled with a regular internal pressure, and a regular load is statically applied, a line connecting an edge of a tread surface on a tread surface in a tire circumferential direction is defined as a tread tread end line, When the axial distance between the two ends of the tread surface in the tire axial direction is defined as the tread contact width, (1) the tread surface area and / or the tread contact end line which is 20% of the tread contact width inward in the tire axial direction from the tread contact end line. A splash prevention band is provided on the tread surface area of 20% of the tread contact width outward in the tire axial direction, and (2) the splash prevention band has a width of 1 to 4 About m, a pneumatic tire, wherein a groove of 2 to about 6mm deep are disposed at 3 or 7mm intervals of about.

[0006] The inventors of the present invention have investigated the situation in which water splashes occur due to tires during running of the vehicle. It was found that a thin water film was formed along the tread surface area of about 1/4 of the tread contact width outward in the tire axial direction from the end line, and that water spattered around eventually contributed greatly.

The pneumatic tire according to the present invention is configured as described above. In particular, the tire is mounted on a regular rim, filled with a regular internal pressure, and statically loaded with a regular load. When the line connecting the edges in the tire circumferential direction is a tread ground contact end line, and when the tire axial distance between both ends of the tread surface on the tread surface is the tread ground contact width,
(1) Splash prevention zones on the tread surface area of 20% of the tread contact width inward in the tire axial direction from the tread contact end line and / or on the tread surface area of 20% of the tread contact width outward in the tire axial direction from the tread contact end line. (2) Since a groove having a width of about 1 to 4 mm and a depth of about 2 to 6 mm is arranged at intervals of about 3 to 7 mm in the splash prevention zone, a thin water film generated along the tread surface Can be reduced, and as a result, it is possible to prevent or suppress the splash by the tires when the vehicle is running.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The tires of Examples 1 and 2 and the tires of Conventional Examples 1 and 2 according to the present invention will be described in detail below.
All tire sizes are 195 / 65R14.

The tire of Example 1 comprises four circumferential grooves extending in a direction parallel to the circumferential direction and a number of lateral grooves formed in the outer portion of the tread and extending in a direction of about 70 degrees in the circumferential direction. Has a tread pattern. The tread of the tire of Example 1 has a tread surface area of 20% of the tread contact width inward in the tire axial direction from the tread contact end line and a tread surface of 20% of the tread contact width outward in the tire axial direction from the tread contact end line. The area has an anti-splash zone. As shown in the cross-sectional view of FIG. 1, the splash prevention zone has a width w = 3 mm and a depth d = 2.
mm, inclined grooves extending in a direction of about 45 degrees in the circumferential direction are arranged at intervals of s = 5 mm.

The tire of Example 2 comprises four circumferential grooves extending in a direction parallel to the circumferential direction and a number of lateral grooves formed in the outer portion of the tread and extending in a direction substantially 90 degrees in the circumferential direction. Has a tread pattern. The tread of the tire of Example 2 has a tread surface area of 20% of the tread contact width in the tire axial direction inside from the tread contact end line and a tread surface of 20% of the tread contact width outward in the tire axial direction from the tread contact end line. The area has an anti-splash zone. As shown in the cross-sectional view of FIG. 2, circumferential grooves having a width w = 1 to 2 mm and a depth d = 2 mm are arranged at intervals of s = 3 mm in the splash prevention band.
Further, as shown in the sectional view of FIG. 3, the width w = 1 to 2 m
The horizontal grooves with m and depth d = 4 mm are arranged at intervals of s = 6 mm.

The tire of Conventional Example 1 is substantially the same as the tire of Example 1 except that the above-mentioned splash preventing band is not provided.

The tire of Conventional Example 2 is substantially the same as the tire of Example 2 except that the above-mentioned splash preventing band is not provided.

The tires of Examples 1 and 2 according to the present invention and the tires of Conventional Examples 1 and 2 were subjected to a comparative test of the occurrence of splashing. The comparative test of the generation of the splash is usually performed at a water depth of 10 to measure the hydroplaning performance of the tire.
1.5cm high and 30cm wide at a position 2m beside the vehicle passing at 40km / h on a linear test course of mm
A container having a depth of 50 cm was installed, and the amount of water entering the container was measured.

When the evaluation result is indicated by an index with the result of the pneumatic tire of Conventional Example 1 set to 100, it was 88 for the pneumatic tire of Example 1 according to the present invention. When the result of the pneumatic tire of Conventional Example 2 was indicated by an index with the result being 100, the value of the pneumatic tire of Example 2 according to the present invention was 81. The smaller the number, the smaller the amount of splash generated by the tires during running of the vehicle.

[0015]

From the above results, it can be understood that the tire of the embodiment according to the present invention is a tire in which the generation of splash is suppressed as compared with the conventional tire.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an inclined groove provided in a splash prevention band.

FIG. 2 is a cross-sectional view of a circumferential groove provided in a splash prevention band.

FIG. 3 is a cross-sectional view of a lateral groove provided in a splash prevention band.

Claims (1)

[Claims] 1. A pneumatic tire having a carcass forming a skeleton of a tire and a tread disposed radially outward of a crown portion of the carcass, the tire is mounted on a regular rim, filled with a regular internal pressure, and loaded with a regular load. When statically loaded, a line connecting the edges of the tread surface on the tread surface in the circumferential direction of the tire is defined as a tread tread end line, and the axial distance between both ends of the tread surface on the tread surface is defined as a tread tread width. (1) Spread the tread surface area of 20% of the tread contact width in the tire axial direction inward from the tread contact end line and / or the tread surface area of 20% of the tread contact width outward in the tire axial direction from the tread contact end line. (2) A groove having a width of about 1 to 4 mm and a depth of about 2 to 6 mm is formed in the splash prevention band, for 3 to 7 m.
A pneumatic tire, wherein the pneumatic tires are arranged at intervals of about m.