JPH07290914A - Assembly of pneumatic tire with rim - Google Patents

Abstract

PURPOSE:To vary tire interior pressure in accordance with the temperature variation and make running performance on ice and snow road and on-road compatible by charging the interior cavity of the tire assembled with a rim with a solid absorbent which absorbs gas inside the interior cavity as the temperature lowers and releases the gas as the temperature rises. CONSTITUTION:An airtight interior cavity 4 enclosed by a tread part 12, a side wall part 13, a bead part 14 and a rim 3 is formed in an assembly 1 of a pneumatic tire 2 with the rim 3. An absorbent 5 of a granular solid activated charcoal 5A is stored in a container body 6 made of a tough cloth or a metal of permeability formed in a hollow ring shape and provided in the interior cavity 4 along the outer circumference of ring pieces 22. Thus traveling performance on ice and snow road is improved by the absorbent 5 absorbing gas inside the interior cavity 4 as the temperature lowers and lowering the internal pressure, traveling performance on the road is improved by the absorbent 5 releasing the absorbed gas as the temperature rises and rising the internal pressure, and the tire can be made to an all weather type.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly of a pneumatic tire and a rim capable of achieving both traveling performance on ice and snow roads and traveling performance on road.

[0002]

2. Description of the Related Art When traveling on ice or snowy roads, it is known to reduce the internal pressure of tires to increase the ground contact area and enhance the grip force. Tires intended for running are premised to be used at low internal pressure.

When such a tire having a low internal pressure is run at a high speed on a dry road surface in a period other than the winter season, the steering stability is inferior when the internal pressure remains low, and moreover, the distortion of each part of the tire is large during the running. This often causes structural defects in the tire such as cuts in the wall.

In order to solve one of the above problems, an internal pressure control system has been developed which is directly connected to the inner cavity of a tire and controls the internal pressure of the inner cavity. However, this system is widely used because of its complicated structure and high cost. There isn't.

The present invention is based on the fact that the tire inner cavity is loaded with an adsorbent capable of inhaling and discharging the gas loaded in the inner cavity, and the inner pressure can be changed according to the fluctuation of the temperature, It is an object of the present invention to provide an assembly of a pneumatic tire and a rim that can solve the above problems.

[0006]

According to the present invention, a solid adsorbent that absorbs gas in the inner cavity as the temperature decreases and releases it as the temperature rises is provided in the inner cavity of a pneumatic tire having a rim. It is an assembly of a pneumatic tire and a rim to be loaded.

Further, the gas is preferably an inorganic or organic gas which can be absorbed and released by the adsorbent.

[0008]

The solid adsorbent is, for example, activated carbon as an organic adsorbent, or silica gel (Si) as an inorganic adsorbent.
O ₂ · nH ₂ O) is preferably adopted.

Each of these solid adsorbents is porous and absorbs gas in the tire cavity at low temperatures, and this absorption reduces the tire internal pressure. Further, as the temperature rises, the gas sucked into the solid adsorbent is released and the tire internal pressure rises.

In a pneumatic tire, when snow falls or when it runs on a snowy road, the temperature drops, and the gas in the inner cavity is absorbed by the adsorbent to lower its pressure (internal pressure). As a result, the ground contact area during traveling is increased, and especially when traveling on an ice / snow road surface in winter, grip power and braking force are increased, and ice / snow performance can be enhanced. On the other hand, on a dry road surface, the tire heats up due to frictional heat by traveling at a relatively high speed, and as the temperature rises, the gas stored in the adsorbent is released and the internal pressure increases, improving the running stability and stabilizing. Can drive at high speed. Furthermore, when the temperature of the atmosphere becomes higher than room temperature, such as in summer, a large amount of gas is released from the adsorbent and the internal pressure increases, which increases the vertical spring constant of the tire, resulting in higher running stability. It can be held, and higher speed running becomes possible.

By thus loading the adsorbent having the above-mentioned structure in the inner cavity, the tire can maintain a running condition suitable for the temperature, and both the snow and snow road performance and the on-road performance can be achieved.

The gas to be filled in the lumen is a gas that can be effectively absorbed and released by the adsorbent, such as methane.
If the organic gas such as ethane and the inorganic gas such as nitrogen are used, the difference in fluctuation of the internal pressure becomes larger.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The pneumatic tire and rim assembly 1 includes a pneumatic tire 2, a rim 3 into which the pneumatic tire 2 is fitted, and an adsorbent loaded in the pneumatic tire 2 and a lumen 4 formed by the rim 3. 4 and.

The pneumatic tire 2 includes a tread portion 12, a pair of sidewall portions 13 and 13 extending radially inward from both ends thereof, and a bead of a rim 3 extending radially inward of the sidewall portion 13. And a bead portion having a bead bottom surface 14a fitted to the base 19.

Therefore, a pneumatic tire and rim assembly 1
The inner cavity 4 surrounded by the tread portion 12, the sidewall portion 13, the bead portion 14 and the rim 3 and having airtightness is formed therein.

The pneumatic tire 2 has a tread portion 12
From the side wall portion 13 to the bead core 15 of the bead portion 14 is wound up from the inner side in the tire axial direction to the outer side, and the carcass 16 is composed of one carcass ply of a radial arrangement and locked, and the inside of the tread portion 12. And the belt layer 17 disposed on the outer side in the radial direction of the carcass 16. Also, the carcass 1 extending between the bead cores 15 and 15.
A bead apex 18 extending from the bead core 15 to the outer side in the tire radial direction is arranged between the body portion of 6 and the winding portions at both ends thereof, and retains the shape and rigidity of the bead portion 12.

The belt layer 17 comprises a plurality of plies using cords having high tensile rigidity, such as steel and aromatic polyamide, in the tire circumferential direction in the present embodiment so that the cords cross each other. It is formed by arranging at a relatively small angle of 15 to 30 °. When the carcass 16 is a tire for passenger cars, organic fiber cords such as nylon, rayon, polyester, etc. can be used.

The rim 3 connects a pair of bead bases 19, 19 which are arranged in the tire axial direction to each other with a cylindrical ring piece 21. The rim flange 22 is provided at the outer end of the bead base 19 in the axial direction of the tire. Start up.

In this embodiment, the adsorbent 5 is granular solid activated carbon 5A, which is formed of a hollow annular member having air permeability and a strong cloth or metal to prevent scattering. It is accommodated in the container body 6. In this embodiment, the container body 6 has an elastic member 7 such as rubber that is stretchable and wound around the inner surface in the radial direction. Therefore, the container body 6 accommodating the adsorbent 5 is arranged along the outer peripheral surface of the ring piece 22 of the rim 3 and attached to the rim 3.

The activated carbon 5A is a porous carbon material having a large specific surface area and adsorption capacity, and is produced by subjecting charcoal or the like to a high temperature treatment with steam and high temperature calcination, even though it has been sufficiently carbonized. . The form is preferably within the range shown in Table 1. An inorganic adsorbent such as silica gel (SiO ₂ · nH ₂ O) can be used instead of the activated carbon 5A.

[0021] The adsorbing material 5, in the case of using activated carbon 5A, a tire having a tire size is 265 / 70R15, in the inner space volume in the range of activated carbon and not more than 3kg less 100g against 0.05 m ³ Is loaded. 100
This is because if it is less than g, the change in internal pressure is small and it is not effective, and if it exceeds 3 kg, the tire weight becomes large and various running performance is affected.

As the gas filled in the lumen 4, in addition to air, methane (CH ₄ ), ethane (C ₂ H ₆ ), nitrogen (N
It is possible to use gases such as ₂ ) or a mixture of these gases and air. This is because each of the methane, ethane, and nitrogen gases has a property of being easily adsorbed by the adsorbent and changes the internal pressure more effectively. In addition to the above gases, an organic or inorganic gas that is easily adsorbed by the adsorbent can be used.

[0023]

【Concrete example】

1) Test A For tires with a tire size of 265 / 70R15,
The relationship between changes in temperature and internal pressure was investigated by varying the adsorbent loading and the type of gas enclosed in the lumen.

FIG. 2 shows the results when 1 kg of activated carbon was loaded as an adsorbent and the kind of gas enclosed in the lumen was changed. As a result of the test, it was confirmed that by enclosing methane and ethane gas, the change in the internal pressure was larger due to the change in temperature difference than in the case of 100% air.

FIG. 3 shows the relationship between the amount of activated carbon and the change in internal pressure when 100% of methane gas is enclosed in the lumen. It shows that the greater the amount of activated carbon, the greater the change in internal pressure.

FIG. 4 shows the relationship of the fluctuation of the internal pressure due to the temperature difference when 1 kg of activated carbon was loaded and the mixing ratio of the methane gas sealed in the lumen was changed. It was confirmed that the higher the mixing ratio of methane gas, the greater the change in internal pressure.

As a result of the above-mentioned test, the larger the adsorbent loading amount, the higher the adsorbability of the gas filled in the inner cavity, and the higher the mixing ratio of the gases, the greater the fluctuation of the tire internal pressure. It has been found. Furthermore, it has been confirmed that by filling the inner cavity with an adsorbent and encapsulating a highly adsorbent gas, it is possible to obtain a tire internal pressure fluctuation that is approximately two times or more that of a conventional tire not loaded with an adsorbent. It was

2) Test B With respect to the tire having the same size as that of the test A, the running performance was tested with an actual vehicle using activated carbon as an adsorbent and different kinds and mixing ratios of gas filling the lumen.
The conventional tires were also tested and their performances were compared. The test method is as follows.

1) Braking property on ice While running on a test road formed by an ice disk at a speed of 30 km / H, a four-wheel lock is applied to brake suddenly.
The braking distance until the car stopped was measured, and the reciprocal value thereof was displayed as an index with Comparative Examples 1, 11, and 21 being 100, respectively. The larger the value, the better.

2) Snow Running Performance, Road Running Stability, and Road Ride Comfort Judgment was made based on the driver's feeling, and Comparative Examples 1, 11, and 21 were displayed as indices with 100 as each. The larger the value, the better. Table 2 shows the test results
Shown in.

[0031]

[Table 2]

As a result of the test, it was possible to improve the running performance on the snowy and snowy roads while substantially maintaining the road performance in the example as compared with the comparative example.

[0033]

As described above, the pneumatic tire and rim assembly of the present invention is characterized by loading a solid adsorbent into the inner cavity of the tire, which reduces the internal pressure as the temperature decreases. By improving the running performance on ice and snow roads, and increasing the internal pressure when the temperature rises to improve the running performance on the road, both ice and snow running performance and on-road running performance are achieved, and it is suitable for all climates and all sky models. The tire can be provided economically.

[Brief description of drawings]

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

FIG. 2 is a graph showing the relationship between the air temperature and the internal pressure by the difference in the filling gas.

FIG. 3 is a graph showing the relationship between air temperature and internal pressure by the difference in the loading of activated carbon.

FIG. 4 is a graph showing the relationship between air temperature and internal pressure by the mixing ratio of the charging gas.

[Explanation of symbols]

 2 Pneumatic tire 3 Rim 4 Lumen 5 Adsorbent

[Table 1]

Claims (2)

[Claims] 1. An inner cavity of a pneumatic tire having a rim assembled,
An assembly of a pneumatic tire and a rim, which is loaded with a solid adsorbent that absorbs gas in the inner cavity as the temperature drops and releases as the temperature rises. 2. The pneumatic tire / rim assembly according to claim 1, wherein the gas comprises an organic or inorganic gas that can be absorbed and released by the adsorbent.