JP2002103926A - Safety pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety tire capable of being easily manufactured and being simply fitted with a rim and having low fuel consumption, durability in a normal travel, and sufficient load supporting performance in a run-flat travel. SOLUTION: The safety tire incorporating a tube having a plurality of connecting members arranged in the peripheral direction to connect an inner peripheral section and an outer peripheral section inside it in a pneumatic tire is assembled to the rim. Internal pressure is separately filled into the pneumatic tire and the tube to form an assembly of the safety tire and the rim. The tube has an outer peripheral section shape holding a gap between it and a tread section inner face against centrifugal force by the connecting members in a tread section grounding area, with the assembly applied with the prescribed load and traveled at the prescribed speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety pneumatic tire capable of continuing a safe running even in a punctured state for a predetermined distance, in particular, a pneumatic tire having a radial carcass, and an annular tube separately incorporated therein. And a safety pneumatic tire having a combination of:

[0002]

2. Description of the Related Art In order to respond to the demand for safety pneumatic tires or run flat tires that can safely travel a predetermined distance continuously even if the tires are punctured, tires of various special structures, special tubes, Various special tire assemblies have been proposed.

For example, regarding the tire itself, a tire having a crescent-shaped rubber reinforcement in a sidewall portion,
There are tires and the like that apply a sealant to the inner surface of the tread, and as a type that devised a tube inserted into the tire, there are a reinforcing tube, a multi-chamber tube, a foam or sponge filled tube, a folding tube, and the like. As the assembly, a foamed or sponge-filled tire assembly, a core built-in tire assembly and the like are known.

Particularly in a recent example, Japanese Patent Application Laid-Open No. 6-33610
No. 3 proposes a safety tire in which a tube provided with a belt similar to that of a tire is incorporated into the tire, and Japanese Unexamined Patent Publication No. Hei 7-276931 discloses an outer tire and an inner tire having a size slightly smaller than the inner size of the outer tire. A double tire type safety tire is proposed in which a small inner tire is mounted on a rim together.

[0005]

However, all of the above-mentioned conventional safety tires have a problem in that the tire performance is impaired, the manufacturing method is difficult, or the material used is too special to manufacture. In addition to the above, there is a problem in handling when attaching to the rim, and there is also a problem in performance.

For example, a sidewall-reinforced tire is
In addition to the difficulty in the manufacturing method, there is a problem of an increase in weight and a reduction in vibration ride comfort, and in fact, it is extremely difficult to manufacture a multi-chamber tube, and practical use is impossible. In addition, in a tire assembly coated with a sealant or a tire assembly filled with a foaming agent, a method of injecting the sealant or the foaming agent is difficult, and it is difficult to develop and put into practical use an appropriate material. In addition, the core built-in tire assembly involves a great deal of labor and difficulty in mounting on the rim, and in addition,
There is a problem that fuel economy is significantly impaired due to a large increase in weight. Further, a tube or a tire filled with a foam material or a sponge causes a great difficulty in manufacturing, and further, it is difficult to stabilize and control the shape.

[0007] In the latter two safety tires proposed in the publications, a tube provided with a belt and an inner tire cause a significant increase in weight as an assembly of the tire and the rim, and this weight increase significantly increases the rolling resistance. Therefore, it is a non-conforming safety tire in this respect, which does not meet the current demand for low fuel consumption.

In order to solve the above-mentioned problems, a safety tire 101 whose cross section is shown in FIG. 7 has been proposed. The safety tire 101 includes a tubeless tire 102 and a tube 103 built therein, and rims the safety tire 101.
An assembly 105 is constructed by assembling the assembly 104. This assembly 105
Then, the tubeless tire 102 is filled with the internal pressure via the valve 110, and separately from this, the tube 103 is also filled with the internal pressure via the valve 111. At this time, the tube
103 is the inner surface of the tread 112 of the tubeless tire 102
Set dimensions that do not contact 112is.

The safety tire 101 is a tubeless tire 10
When 2 punctures and the internal pressure drops significantly or goes to zero,
The tube 103 expands to a position shown by a two-dot chain line in FIG. 7, and the expanded tube 103 supports a load load in place of the punctured tubeless tire 102 and suppresses an extreme bending deformation of the tubeless tire 102. .

[0010] The safety tire 101 has the advantage that the structure and handling are simple and the weight can be suppressed to a slight increase since only the ordinary tube 103 is added to the ordinary tubeless tire 102. However, on the other hand, there is a problem that it has the following disadvantages.

That is, a tube 103 filled with internal pressure
The cross-sectional shape of the tire becomes closer to a circle, and the portion of the tire equatorial plane E comes closest to the inner surface 112is of the tread portion 112. When the assembly 101 rolls under a load, the tube 103 is moved to the tread portion, particularly in the contact area of the tubeless tire 102.
The outer surface of the tube 103 is worn by the relative movement with the inner surface 112is of the tube 112, and the worn outer surface is damaged as the vehicle travels, or is broken by the expansion of the tubeless tire 102 at the time of puncture. However, after all, it does not function as the safety tire 101 at the time of puncturing. This is where the problem begins.

Therefore, the outer peripheral surface of the tube 103 and the inner surface 112is
In order to avoid contact with the tube 103, the cross-sectional shape of the tube 103 must be reduced. However, in particular, in the case of the low-flat tubeless tire 102 shown in FIG. 7, for example, the tubeless tire 102 having a flatness factor of 70 or less, the inner volume of the tube 103 is reduced by the assembly 105 to prevent the contact. The inner volume of the tubeless tire 102 when it is not used should be approximately １ ／ or less.

However, such a small internal volume tube
Safety tires 101 using 103
When the puncture 102 is punctured, the degree of expansion of the tube 103 is significantly large. As a result, the internal pressure of the expanded tube 103 is significantly lower than the initial internal pressure, the load bearing capacity of the tube 103 and the tubeless tire 102 becomes too small, and the tubeless tire 103 Has a significantly reduced durability. This is the final problem.

Therefore, the inventions according to the first to eleventh aspects of the present invention are easy to manufacture without using any special material or structure, are easy to mount and handle on the rim, and maintain low fuel consumption. It is an object of the present invention to provide a safe pneumatic tire that does not cause trouble in a tube during normal running and has sufficient load supporting performance during puncture running, on the premise that a tube that is effective in various points is used.

[0015]

According to a first aspect of the present invention, there is provided an air conditioner comprising a tread portion, a pair of sidewall portions and a pair of bead portions connected to both sides of the tread portion. In a safety pneumatic tire having a combination of a pneumatic tire and an annular tube separately housed therein, the tube has a plurality of connecting members arranged in a circumferential direction for connecting an inner peripheral portion and an outer peripheral portion inside the tube. At one or more locations in the width direction of the tube, assembling the safety pneumatic tire to the rim, filling the pneumatic tire and the tube with internal pressure individually, and assembling the tube and rim with a tread In the tread ground contact area under a state where a gap is provided between the inner surface of the tread portion and a predetermined load is applied to the assembly, and the assembly runs at a predetermined speed, the tube is: Safe pneumatic tire characterized by having an outer peripheral portion shaped to hold the gap between the tread portion inner surface against the centrifugal force by the coupling member.

According to the first aspect of the present invention, there is provided a second aspect.
As in the invention described in the above, the connecting member of the tube,
The connecting member is composed of one of a plurality of threads and one or more thin gauge rubber strips, and according to the invention described in claims 1 and 2, as in the invention described in claim 3, In the speed range of the assembly, the tube is cut under at least the inflation force of the tube pressure when the internal pressure of the pneumatic tire is zero at the gauge pressure and the strength capable of resisting the expansion action of the belt member due to the centrifugal force generated in the tube. With tensile strength.

According to the first to third aspects of the present invention, as in the fourth aspect of the present invention, the connecting member has a pressure difference of 300 kP obtained by subtracting the tube external pressure from the tube internal pressure.
a It has tensile strength to cut at above.

According to the first to fourth aspects of the present invention, as in the fifth aspect of the present invention, in the above assembly under no load, the volume inside the tube is equal to the volume of the internal pressure portion of the pneumatic tire. It has a value of 0.6 times or more.

Further, according to the invention described in the first to fifth aspects, as in the invention described in the sixth aspect, each of the assembly under a no-load state and the assembly immediately under a load is provided with a tube. Has a gap of 10 mm or more between the inner surface of the bead portion and the pneumatic tire.

According to the invention described in claims 1 to 6, as in the invention described in claim 7, the assembly includes:
The pneumatic tire and the tube are filled with substantially the same internal pressure, and the tube is filled with either one of an internal pressure exceeding the internal pressure of the pneumatic tire within a range of 5 to 50 kPa.

According to the invention described in claims 1 to 7, as in the invention described in claim 8, the inner surface of the pneumatic tire having a tube having a cross-sectional height h in the above-mentioned assembly in a no-load state. The ratio h / H to the sectional height H is 1/3 to 4
/ 5.

Further, according to the invention described in claims 1 to 8, as in the invention described in claim 9, the rim includes a valve for filling the internal pressure of a pneumatic tire, and the tube includes an internal pressure mounted on the rim. According to the invention described in claims 1 to 9, a rim is provided with only one internal pressure filling valve fixed to a tube. The valve is
The invention has a pneumatic pressure regulating valve communicating with the inside of a pneumatic tire, and relates to the invention described in claims 1 to 10.
As in the invention described in 1 above, the tube has an internal pressure filling valve fixed to the tube in an airtight manner.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the examples shown in FIGS. 1 and 2
FIG. 3 is a cross-sectional view of the assembly of the safety pneumatic tire and the rim according to the present invention. FIGS. 3 and 4 show the safety pneumatic tire and the rim assembly shown in FIGS. FIG. 5 and FIG. 6 are cross-sectional views of the assembly shown in FIG. 3 and FIG. 4 when the tire is punctured.

In FIG. 1, a pneumatic tubeless tire (hereinafter referred to as a tire) 2 applied to a safety pneumatic tire (hereinafter referred to as a safety tire) 1 has a tread portion 3.
And a pair of side wall portions 4 and a pair of bead portions 5 connected to both sides thereof. Safety tire 1 is tire 2
In addition, an annular tube (hereinafter, referred to as a tube) 6 incorporated in the tire 2 is provided separately, and a combination of the tire 2 and the tube 6 constitutes the safety tire 1.

In FIGS. 1 and 2, the tire 2 has
Prescribed via valve 8 fixed to rim 7 specified by the standard
Air pressure P_One(kPa) and put it in the tube 6
Also individually via a valve 9 at a predetermined air pressure P_Two(kPa)
And the air pressure P at these gauge pressures_One(kPa), P_Two(kPa)
Under the balance, an assembly of the safety tire 1 and the rim 7 (hereinafter, assembly
Body). Air pressure P_One(kPa)
The maximum air pressure (gauge pressure) and the air pressure P_One And air pressure
P_Two Is P_One = P_Two Or P_One ≒ P_Two (Substantially equivalent)
Or P_Two = P_One + (5 to 50 kPa).
These air pressures P _One , P_Two Under filling, the outer circumference of tube 6
The part has a sufficient clearance with the inner surface 3is of the tread part 3.
You.

Here, the rim 7 and the maximum air pressure P
₁ (kPa) and the maximum load capacity described below indicate the contents described in the following standards. That is, JATMA YEAR BOOK (2000),
ETRTO STANDARD MANUAL 2000, TRA (THETIRE and RIM AS
SOCIATION INC.) 2000 YEAR BOOK standards, if represented by JATMAYEAR BOOK in Japan, the rim is the applicable rim described in the general information.Specifically, the table of applicable rims by tire type (APPROVED RIM CON at ETRTO and TRA
According to the rim size described in TOURS), the maximum air pressure and the maximum load capacity are calculated based on the maximum air pressure (the same table for TRA and the table of tire size for ETRTO) based on the tire type. kPa) and the corresponding force (Newton N) corresponding to the maximum load capacity (mass kg).

Here, the tube 6 includes a plurality of connecting members 10 for connecting the inner peripheral portion and the outer peripheral portion inside the tube 6. A plurality of connecting members 10 are arranged in the circumferential direction of the tube 6 and provided at one or more locations in the width direction of the tube 6. The connecting members 10 shown in FIG. The connecting member 10 (10-1, 1) shown in FIG.
0-2, 10-3) are examples in which three portions are provided in the width direction of the tube 6.

3 and 4, on a flat road surface Sr, the maximum load capacity of the tire 2 according to the above-mentioned standard is 0.8 to 0.8.
A load L (N) corresponding to a range of 1.3 times is applied to the assembly, and the assembly is driven at a speed of 70 to 120 km / h.
Has an outer peripheral shape having a gap δ (mm) between the inner surface 3is of the tread portion 3 and the centrifugal force generated by rotation by the connecting member material 10. In FIG. 2, the gap δ (mm) at the position of the equator plane E of the tire 2 is shown as a representative, and the gap δ is
Along the width of the belt member 10, the dimensions vary somewhat but extend over the entire inner surface 3 is.

In the case of the conventional safety tire 102 shown in FIG. 7, the assembly 105 running at the above-mentioned speed under the load L is applied.
The inner tube 103 protrudes outward in the radial direction of the tire 102 due to the centrifugal force caused by the rotation, and rubs against the inner surface 112is of the tread portion 112 in the contact area of the tread portion 112,
During long-distance running, the rubbing part of the outer periphery of the tube 103 against the inner surface 112is of the tread portion 112 is worn or damaged, and eventually, when the tire 102 is punctured, the tube
103 is also punctured or worried about puncturing,
As described above, the role of the safety tire 101 cannot be fulfilled.

On the other hand, the tube 6 of the present invention has a resistance against the centrifugal force caused by the connecting member 10 provided in the tube 6 in the contact area of the tread portion 3 inside the assembly running at the above speed under the load L. By means, the radial growth of the tube 6 on which the centrifugal force acts is suppressed, and a gap δ (mm) is always formed between the outer peripheral portion of the tube 6 and the inner surface 3is of the tread portion 3, so that the outer peripheral portion of the tube 6 , Tread 3 inner surface 3
The internal volume of the tube 6 can be set sufficiently large in accordance with the internal volume of the tire 2 when the tube 6 is removed without rubbing with the is. In this regard,
At the above speed range of the assembly, the connecting member 10
Has a strength capable of opposing the centrifugal force acting on the

When the tire 6 is punctured, the tube 6 has a load L
FIG. 5 and FIG. 5 and 6, the pressurized air inside the tire 2 flows out due to an external factor such as nail stepping or an internal factor such as a valve failure,
The internal pressure P ₁ at the gauge pressure of the tire 2 becomes 0 (zero),
That is, when the tire 2 is in a punctured state, since the external pressure of the tube 6 becomes zero to slight pressure, the connecting member 10 included in the tube 6 is cut off, and the gap between the inner peripheral portion and the outer peripheral portion of the tube 6 is reduced. The connection is released, whereby the tube 6 expands freely, and the internal pressure P ₂ decreases to the internal pressure P ₂ A.

At this point, the connecting member 10 has a tensile strength at which when the tire 2 is punctured, it is cut at least under the action of the inflation force of the tube 6 due to the internal pressure P ₂ of the tube 6. Here, at least the internal pressure P of the tube 6
Destruction by only ₂ means when the assembly is stopped,
When traveling, the centrifugal force is applied to the other acting force of the internal pressure P _2.

When the punctured assembly runs at a predetermined speed under a load L within the above range, the tread portion 3
In the contact area, at least the outer peripheral portion of the expanded tube 6 is in contact with the inner surface 3is of the tread portion 3, and in the example shown in FIGS. Abut. Originally, since the tube 6 has a sufficient internal volume as described above, the expansion contact of the tube 6 allows the tube 6 to substitute and support the load L of the tire 2. The deflection of the tire 2 is kept to a small increase, and as a result, the increase in the deflection of the tire 2 is small, and the tire 2 can continue running without causing a failure.

On the other hand, the conventional safety tire shown in FIG.
In the case of the tire 102, since the internal volume of the tube 103 cannot be increased, the flexure of the tire 102 becomes remarkably large, and the tire 102 fails during puncture under insufficient durability. In addition, even in a conventional safety tire, a tube having a reinforcing portion on the outer peripheral portion incorporated therein is hardly inflated over the entire outer peripheral portion of the tube because the reinforcing portion extends over the entire width of the tread portion when the tire internal pressure P ₁ = 0. As a result, the amount of deflection of the tire is significantly increased, and the tire itself breaks down in a relatively short traveling distance, and does not function sufficiently as a safety tire.

As described above, since it is only necessary to provide the connecting member 10 inside the tube 6, the safety tire 1 including the tube 6 can be easily manufactured without using any special material or structure, and the rim 7 can be easily manufactured. It is as easy to handle as installing it on a conventional tube, and has a slight connection member 1
Since only 0 is added, an increase in weight is almost negligible, and fuel economy can be maintained.

The connection member 10 has practically the configuration shown in FIGS.
2 or 4 or a plurality of thin gauge rubber strips as shown in FIGS. In the case of a yarn, organic fibers such as nylon fibers, polyester fibers, and rayon fibers can be suitably used.

The connecting member 10 is made of a material having a tensile strength capable of cutting at a pressure difference of 300 kPa or more obtained by subtracting the external pressure of the tube, that is, the internal pressure of the tire 2 from the internal pressure P _{2 of the} tube 6.

1 and 2, the inner volume of the tube 6 in the unloaded assembly is the tire 2
, That is, 0.6 times or more of the volume obtained by subtracting the entire volume including the internal volume of the tube 6 from the internal volume of the tire 2.

In FIGS. 1 and 2, in each of the assembly under no load and the assembly immediately under the load, the tube 6 has a gap between the inner surface of the bead portion 5 of the tire 2. It is preferable to have C and Ca, and to set the gaps C and Ca to 10 mm or more.

1 and 2, the ratio h / H of the cross-sectional height h of the tube 6 to the height H of the inner surface 3is of the tread portion 3 in the cross section of the tire 2 in the unloaded assembly. It is suitable to be in the range of 1/3 to 4/5. If it is within this range, the tube 6 sufficiently fits on the inner surface of the tire 2 when the tire 2 is punctured. Ratio h / H
Is less than 1/3, the amount of deflection of the tire 2 at the time of puncturing becomes too large, and the durability of the tire 2 during puncturing becomes insufficient. When the ratio h / H exceeds 4/5, the tire 2 has a long length. When foreign matter such as nails penetrates, the tube 6
However, it is not possible to secure a space sufficient for the same foreign matter not to penetrate through them, and both are incompatible. Here, the criterion for measuring the heights h and H is a rim diameter line RL, and the height H is a value on the tire equatorial plane.

1 to 6, the rim 7 is provided with an internal pressure filling valve 8 for the tire 2 and the tube 6 is provided with an internal pressure filling valve 9 mounted on the rim 7 in FIGS. There are both a case where the rim 7 is provided separately and a case where the rim 7 is provided with only one internal pressure filling valve 9 which is fixed to the tube 6 (not shown). In the latter case, the valve 9 is provided inside the tire 2. It has an air pressure adjusting valve (not shown) that communicates with it, prevents the pressurized air from flowing out of the tube 6 when the tire 2 is punctured, and maintains a change in the internal pressure P ₂ A from the internal pressure P _{2 of the} tube 6. However, in any case, the internal pressure filling valve 9 fixed to the tube 6 is air-tightly attached to the rim 7.

Here, the tires 2 are suitable for use in relatively high-speed vehicles or high-speed vehicles, such as passenger cars, trucks and buses, which run at relatively high speeds. It is advantageously adapted to flat tires with an aspect ratio nominal of 70 or less. The tire 2 is a tubeless tire because it is necessary to maintain the internal pressure P ₁ between the tire 2 and the tube 6.

1 to 6, a tire 2 has a single ply that reinforces a tread portion 3, a pair of sidewall portions 4, and a pair of bead portions 5 over a bead core 11 embedded in the pair of bead portions 5. The carcass 12 of the rubber-coated ply having the above radial arrangement code, and the carcass 12
A belt 13 for strengthening the tread portion 3 at the outer periphery of the belt, and an inner liner rubber 14 having excellent air impermeability. The radial carcass 12 is suitable to have a folded portion along the outer peripheral surface of the bead core 11 in order to further ensure the durability of the bead portion 5 during puncturing. Note that a normal rubber material for a tube is applied to the tube 6.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The tire 2 applied to the safety tire 1 of the first and second embodiments is a radial ply tire for trucks and buses.
The tire size described in the ETRTO STANDARD MANUAL 2000 is 435 / 50R22.5, and the configuration of the tire 2 is as shown in FIGS. 1 and 2. In particular, the carcass 12 is a one-ply rubber-coated steel cord radial. It has a sequence ply. The height ratio h / H was 10/16.

The safety tire 1 according to the first embodiment includes a tube 6 using nylon fiber for each of the connecting members 10-1, 10-2, and 10-3 in FIG. A tube 6 using a thin gauge rubber strip is provided for each of the three connecting members 10-1, 10-2, and 10-3. In order to evaluate the safety tires 1 of Examples 1 and 2, a conventional safety tire 101 shown in FIG. 7 was prepared. The gap Ca is the same as that of Embodiment 1.
Is 12 mm, and Example 2 is 10 mm.

These safety tires 1 and 101 were used in ETRTO STAN
DARD MANUAL 2000 is mounted on standard rims 7,104, these tires 2,102 and tubes 6,103
Is filled with the maximum air pressure of 900 kPa specified by the above standard,
The internal pressure was set to P ₁ = P ₂ . The tires 2 of the first and second embodiments and the tire 102 of the conventional example are mounted on an actual vehicle, and the tires 2 and 102 are punctured with nails to form tubes 6 and 103.
The internal pressure is measured, and then the maximum load 4
A load L of 4.1 kN was applied, and the running distance until a failure occurred in the tires 2 and 102 was measured.

The measurement results show that after the tires 2 and 102 were punctured, the internal pressure P ₂ A of the tubes 6 of Examples 1 and ₂ was 500 kPa, and the internal pressure of the tube 103 of the conventional example was significantly reduced to 200 kPa. As a result, the running distances of the tires 2 and 102 up to the failure are 500 km in each of the first and second embodiments, and the conventional tire 102 is only 1 km.
It stopped at 5km. Thus, it can be seen that the tires 2 of Examples 1 and 2 incorporating the tube 6 have significantly improved durability during puncturing.

[0048]

According to the first to eleventh aspects of the present invention, a connecting member that cuts by applying a predetermined force to the inside of a tube under a combination of a pneumatic tire and a tube. By providing, it is easy to manufacture without using special materials and structures, and it is easy to mount and handle on the rim, and the weight is equivalent to or slightly heavier than the conventional rubber tube, It is possible to provide a safe pneumatic tire capable of obtaining sufficient durability of a tire and a tube under a running condition in which the tire internal pressure is normal and a puncture running condition of the tire while maintaining low fuel consumption. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view of an assembly of a safety pneumatic tire and a rim according to the present invention.

FIG. 2 is a cross-sectional view of another safety pneumatic tire and rim assembly of the present invention.

3 is a cross-sectional view just below the load when the load of the assembly of the safety pneumatic tire and the rim shown in FIG. 1 is rolling.

4 is a cross-sectional view just below the load when the load of the assembly of the safety pneumatic tire and the rim shown in FIG. 2 is rolling.

FIG. 5 is a cross-sectional view of the assembly shown in FIG. 3 when the tire is punctured.

6 is a cross-sectional view of the assembly shown in FIG. 4 when the tire is punctured.

FIG. 7 is a sectional view of a conventional assembly of a safety tire and a rim.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Safety pneumatic tire 2 Pneumatic tire 3 Tread part 3is Tread inner surface 4 Side wall part 5 Bead part 6 Tube 7 Rim 8, 9 Valve 10 (10-1, 10-2, 10-3) Connecting member 11 Bead core 12 Radial carcass 13 Belt 14 Inner liner E Tire equatorial plane C, Ca clearance h Tube cross section height H Tire inner surface cross section height P ₁ Tire internal pressure P ₂ Tube internal pressure Sr Flat road surface L Load

Claims (11)

[Claims] 1. A safety pneumatic tire having a combination of a tread portion, a pair of sidewall portions and a pair of bead portions connected to both sides thereof, and a ring tube separately incorporated therein. The tube is provided with a plurality of connecting members arranged in the circumferential direction at one or more locations in the tube width direction for connecting the inner peripheral portion and the outer peripheral portion inside the tube, and assembling the safety pneumatic tire to the rim, In an assembly of a tire and a tube and a rim in which a tire and a tube are individually filled with an internal pressure, the tube has a gap between the inner surface of the tread portion and a predetermined load is applied to the assembly. In the tread portion ground area under a condition where the assembly is run at a predetermined speed, the tube has an outer periphery that holds a gap between the tube and the inner surface of the tread portion against the centrifugal force by the connecting member. A safety pneumatic tire having a partial shape. 2. The safety pneumatic tire according to claim 1, wherein the connecting member of the tube comprises one of a plurality of threads and one or more thin gauge rubber strips. 3. The connecting member has a strength capable of resisting an expanding action of the belt member due to a centrifugal force generated in the tube in a speed range of the assembly, and a pressure inside the pneumatic tire being zero as a gauge pressure. The safety pneumatic tire according to claim 1 or 2, wherein the safety pneumatic tire has at least a tensile strength that cuts under an action of an inflation force due to an internal pressure of the tube. 4. The safety pneumatic tire according to claim 1, wherein the connecting member has a tensile strength for cutting at a pressure difference of 300 kPa or more obtained by subtracting the tube external pressure from the tube internal pressure. 5. In the above assembly in a state where no load is applied, the volume inside the tube is set to be 0. 0 of the internal pressure part volume of the pneumatic tire.
The safety pneumatic tire according to any one of claims 1 to 4, which has a value of 6 times or more. 6. In each of the assembly under a no-load condition and the assembly immediately under a load, a tube is provided.
The safety pneumatic tire according to any one of claims 1 to 5, having a gap of 10 mm or more between the inner surface of the bead portion and the pneumatic tire. 7. The above-mentioned assembly is formed by filling the pneumatic tire and the tube with substantially the same internal pressure and filling the tube with an internal pressure exceeding the internal pressure of the pneumatic tire within a range of 5 to 50 kPa. The safety pneumatic tire according to any one of claims 1 to 6. 8. A ratio (h / H) of the cross-sectional height (h) of the tube to the cross-sectional height (H) of the inner surface of the pneumatic tire is 1/3 to 4 in the above-mentioned assembly under no load. The safety pneumatic tire according to any one of claims 1 to 7, which is in the range of / 5. 9. The safety air according to claim 1, wherein the rim includes a valve for filling the internal pressure of a pneumatic tire, and the tube includes a valve for filling the internal pressure separately attached to the rim. Containing tires. 10. The rim includes only one internal pressure filling valve fixed to the tube, and the valve includes a pneumatic pressure regulating valve communicating with the inside of the pneumatic tire.
10. The safety pneumatic tire according to any one of items 9 to 9. 11. The tube has an internal pressure filling valve fixedly attached thereto and hermetically attached to the rim.
10. The safety pneumatic tire according to any one of items 10 to 10.