JPH0616003A - Solid tire - Google Patents

Abstract

PURPOSE:To realize high speed and improve riding comfort, by piling first and the second medium rubber layers and a tread rubber layer on the radial outer side of the tire of a base rubber layer, which is to be mounted to a rim, for forming four layers having required thickness and hardness to maintain wear resistance and fitting ability to the rim. CONSTITUTION:A base rubber layer 2 is mounted to a rim J, and the first and the second medium layers 3 and 4, and a tread rubber layer 5 to form a tread face 5A are sequentially laid in the radial direction of a tire to form four layers. The thicknesses of each of the layers 2 to 5 are respectively 0.15-0.30, 0.2-0.35, 0.2-0.35 and 0.25-0.40 times in height for the cross section height TH of the tire. The first medium rubber layer 3 has JISA hardness of 45-55 degrees and the second medium rubber layer 4 has JISA hardness of 65-75 degrees, whose tangent losses are 0.04 or less. This results in improving riding comfortableness and heat build-up resistance, and realizing high speed and power up, while maintaining wear resistance, cut resistance and fitting ability to a rim.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid tire which has a high degree of utilization by improving the riding comfort and suppressing heat generation, thereby increasing the speed of the tire and improving the running performance.

[0002]

2. Description of the Related Art A so-called pneumatic type solid tire mounted on a rim for a pneumatic tire and having substantially the same cross-sectional shape as a pneumatic tire is becoming increasingly popular as a tire that can be easily used. In recent years, in particular, the use of pneumatic tires has been expanded to a range where they are used, and higher performance such as speeding up and powering up has been required. On the other hand, in terms of driver's health management, there is a demand for a flexible and comfortable tire that is rich in cushioning properties.

[0003]

However, in order to increase the speed and power up, it is necessary to suppress low heat generation due to running of the tire, and for that purpose, the elasticity of the rubber forming the solid tire must be increased. . On the other hand, in order to improve the riding comfort, it is necessary that the hardness of rubber is low.
In addition, there is a problem in that the original performance of the solid tire, such as wear resistance of the tread surface and retention of fitting force with the rim, must be maintained.

The inventor has solved the above-mentioned problems by laminating a plurality of rubber layers made of a rubber composition suitable for each required performance and by controlling the distribution of the rubber thickness of each rubber layer. The inventors have discovered what is possible and completed the present invention.

An object of the present invention is to provide a solid tire capable of achieving high speed, power up and improvement of riding comfort while maintaining wear resistance and fitting force with a rim.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a pneumatic type solid tire mounted on a rim for a pneumatic tire, a base rubber layer mounted on the rim, and a radial direction of the base rubber layer of the tire. An outer first intermediate rubber layer, a second intermediate rubber layer radially outside of the first intermediate rubber layer, and a tread whose outer and outer peripheral surfaces in the radial direction of the second intermediate rubber layer form a tread surface. 4 with rubber layer
The base rubber layer has a rubber thickness T.
B is 0.15 to 0.30 times the tire cross-section height TH, the first
In the intermediate rubber layer, the rubber thickness T1 is 0.2 to 0.35 times the tire cross-section height TH and the JISA hardness is 45 to 55 degrees.
The rubber thickness T2 of the second intermediate rubber layer is the tire cross-section height T.
0.2 ~ 0.35 times H and JISA hardness 68 ~ 75
In addition, the tangent loss of the rubber is 0.04 or less, and the rubber thickness TA of the tread rubber layer is 0.25 of the tire cross-section height TH.
It is a solid tire characterized by being 0.40 times.

[0007]

By laminating and forming four rubber layers having different compositions as described above, the ride comfort is improved while maintaining the wear resistance, the cut resistance, and the fitting force with the rim, and at the time of traveling. The heat generation can be suppressed, and the speed and power can be increased.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the figure, a solid tire 1 is a so-called pneumatic tire mounted on a rim J and having a cross-sectional shape substantially the same as that of a pneumatic tire. Further, the solid tire I includes a base rubber layer 2 mounted on the rim J, a first intermediate rubber layer 3 which is externally fitted in contact with the base rubber layer 2 on the outer side in the tire radial direction, and the first intermediate rubber. A second intermediate rubber layer 4 which is externally fitted in contact with the radial outside of the layer 3;
The second intermediate rubber layer 4 is formed by a four-layer body including the tread rubber layer 5 which is externally fitted in contact with the outer side in the radial direction and whose outer peripheral surface forms the tread surface 5A.

The bottom surface 2A of the base rubber layer 2 is a rim J.
The rubber thickness TB from the bead base line BL is tightly fitted to the rim sheet 9 of 0.15 times or more of the tire cross-section height TH which is the maximum tire height from the bead base line and is less than 0. It is set to 30 times or less. The base rubber layer 2 has a JIS A hardness of 75 to 9 in this embodiment.
It is 0 degree, and if necessary, carbon or a fabric made of organic fiber is mixed into the rubber composition for reinforcement.

If the rubber thickness TB is less than 0.15 times the tire cross-section height TH, the fitting force with the rim J is reduced and the rim shift occurs. On the other hand, if it exceeds 0.30 times, it is restricted in other rubber layers. This is because it becomes difficult to secure the required rubber thickness. A reinforcing layer 7 may be embedded in the base rubber layer 2 as shown by a chain line in FIG. The reinforcing layer 7 is formed by winding an organic fiber cord at a small angle in the tire circumferential direction and winding the same. By providing the reinforcing layer 7, loosening of the fitting with the rim J caused by the temperature rise of the tire is suppressed. You can.

The first intermediate rubber layer 3 has a rubber thickness T1.
Is 0.2 to 0.35 times the tire cross-section height TH, and the rubber is formed of a soft rubber having a JISA hardness of 45 to 55 degrees. As the rubber composition, a soft rubber composition of natural or butadiene type rubber mixed with 30 to 50 PHR of carbon black is preferably used.

The rubber thickness T1 is less than the tire sectional height TH of 0.
If it is less than 2 times, there is a risk of damage due to the load acting on the tire. Even if the thickness exceeds 0.35 times, the ride comfort cannot be improved and the necessary rubber thickness of other rubber layers cannot be secured. This is because the running performance is reduced. The rubber hardness is JIS
When the A hardness is less than 45 degrees, the elasticity of the rubber is abnormally low and the running stability is lowered, while when it exceeds 55 degrees, the cushioning property is deteriorated.

The second intermediate rubber layer 4 has a rubber thickness T2.
Is 0.2 to 0.5 times the tire cross-sectional height TH, the JISA hardness of the rubber is 68 to 75 degrees, and the tangent loss (tan is the ratio of the loss elastic modulus to the dynamic elastic modulus).
δ) is set to 0.04 or less to suppress heat generation due to energy loss.

The rubber thickness T2 is less than the tire sectional height TH of 0.
If it is less than twice, the rubber thickness becomes thin and the second intermediate rubber layer 4
Has insufficient rigidity and is poor in the effect of suppressing heat generation.
If it exceeds 35 times, it becomes difficult to secure the required rubber thickness of the other rubber layers. Further, when the JIS A hardness is less than 68 degrees and the tangent loss is less than 0.04, elasticity becomes low and heat is easily generated.
If it exceeds 5 degrees, there is a risk of cracking due to the load acting on the tire.

The tread rubber layer 5 has a rubber thickness TA of 0.25 to 0.40 times the tire cross section height TH. If it is less than 0.25 times, the rubber thickness is thin, so that there is a risk of breakage during stone trapping, and if it exceeds 0.40 times, it becomes difficult to secure the necessary rubber thickness of other rubber layers. The tread rubber layer 5 has a hardness of 60 to 70 degrees in terms of JIS A hardness, and a rubber composition having excellent wear resistance and cut resistance is used. JISA hardness is 6
If it is less than 0 degree, the cut resistance and wear resistance are poor, and 70 °
This is because if it exceeds the range, the grip performance deteriorates.

[0016]

As described above, the solid tire of the present invention is
Since the rubber layer is made up of four rubber layers with different properties and the distribution of the thickness is regulated, the ride comfort and heat resistance are improved while maintaining wear resistance, cut resistance, and fitting force with the rim. As a result, speeding up and power up can be achieved, and the use of solid tires can be expanded.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 2 Base rubber layer 3 First intermediate rubber layer 4 Second intermediate rubber layer 5 Tread rubber layer J Rim T1, T2, TA, TB Rubber thickness TH Section height

Claims (1)

[Claims] 1. In a pneumatic type solid tire mounted on a rim for a pneumatic tire, a base rubber layer mounted on the rim, and a first intermediate rubber layer on the tire radial outside of the base rubber layer. And a second intermediate rubber layer on the outer side in the radial direction of the first intermediate rubber layer, and a tread rubber layer on the outer side in the radial direction of the second intermediate rubber layer whose outer peripheral surface forms a tread surface. In addition, the rubber thickness TB of the base rubber layer is 0.
15 to 0.30 times, and the first intermediate rubber layer has a rubber thickness T1 of 0.2 to 0.35 times the tire cross-section height TH and JISA.
The hardness is 45 to 55 degrees, and the second intermediate rubber layer has a rubber thickness T.
2 is 0.2 to 0.35 times the tire section height TH and JI
SA hardness is 68 to 75 degrees and the tangent loss of rubber is 0.0
4 or less, a solid tire characterized in that the tread rubber layer has a rubber thickness TA of 0.25 to 0.40 times the tire section height TH.