JP2005041389A - Safety tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety tire which can sufficiently cool a tread portion, etc. by always securing a free flow of the air, etc. to be charged into the tire over the whole range from the tread portion to a rim, and in addition, which can bring a sensor to be attached to the rim into smooth and sufficient contact with the air charged into the tire, etc. <P>SOLUTION: The safety tire comprises a tire 1 and an annular hollow air bag 2 which is received inside the tire 1 and has a reinforcing layer 3 at least at the portion opposed to the inside surface of the tire. The tire 1 and the annular hollow air bag 2 are mounted to the rim R. A specified air pressure P (kPa) is loaded into the tire and internal pressure P<SB>0</SB>(kPa) for the air bag is supplied to the air bag 2 so as to satisfy the following condition, P<P<SB>0</SB>≤P+50. In the internal pressure supplied posture, the surface of the air bag 2 opposed to the inside surface of the tire is separated from the inside surface of the tire over the whole range of the cross section in the direction of the width. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a safety tire that can continue to travel safely over a predetermined distance even if the tire internal pressure decreases or disappears due to tire puncture or the like, and in particular, sufficient contact of the sealed gas in the tire with the rim. We propose a technology that guarantees

  Reinforcing tubes, foams, elastic bodies, cores, etc. are housed in the tires as safe tires that enable safe driving over a predetermined distance even in a so-called run-flat state where the tire internal pressure has decreased due to puncture or other factors. In addition to the above, various types of tires that have been reinforced with reinforcing members such as a reinforcing rubber and a reinforcing cord have been proposed. These tires have a tire housing or a reinforcing member to reduce the tire load against a decrease in tire internal pressure. To support the shoulder.

  However, in such a conventional safety tire, the manufacturing process is complicated, and there are many problems in handling at the time of mounting. For example, Japanese Patent Application Laid-Open No. 2001-10314 discloses a solution to such a problem. In WO 02/43975, there is a hollow annular air bladder that expands and deforms as the tire internal pressure decreases and supports the load from the tire while the internal pressure is filled. A safe tire that is easy to manufacture and easy to handle has been proposed.

In addition, in U.S. Patent Application Publication No. 2003/0041941, an inner tire having a pair of bead portions and a reinforcing carcass that is continuous in a toroid shape between both bead portions is disposed inside the outer tire. In a run-flat state in which the internal pressure of the tire is reduced, a safety tire is described in which the load is supported from the outer tire by the inner tire. JP-A-2003-146031 discloses a safety tire on the inner side of the tubeless tire. In the run-flat state, a hollow annular air bladder that expands and deforms as the tire internal pressure falls and replaces the load bearing tire is built in, and air is injected into the tubeless tire on the outer peripheral surface of this air bladder. And a safety tire in which an air flow passage is formed during exhaust. These tires also have an advantage that a safety tire can be relatively easily manufactured and mounted by manufacturing the inner tire or the air bladder separately from the tire.
JP 2001-10314 A International Publication No. 02/43975 Pamphlet US Patent Application Publication No. 2003/0041941 JP 2003-146031 A

  Conventional general pneumatic tires that do not store pneumatic tires or inner tires are particularly common in the tread area due to friction with the road surface and various deformations during normal driving under the specified air pressure. Although heat will be generated, the amount of heat generated is based on the air flow in the tire, etc., and heat will be dissipated through the sidewall, bead, and rim in addition to the tread. Etc. are advantageously cooled as the tire internal temperature decreases.

  On the other hand, in the safety tire described in each of Patent Documents 1 to 3, under normal conditions of the tire, the air filled therein is contained between the tire inner surface and an outer surface such as an air bladder. As a result, it becomes practically impossible to reach the rim surface with particularly high cooling efficiency, so that it becomes difficult to sufficiently cool the heated tread portion. On the other hand, there is a problem that the deterioration of durability cannot be denied, and on the other hand, a pressure sensor, a temperature sensor, etc. for the purpose of detecting a tire failure in advance is mounted on a rim, for example, a rim drop part. There was also a problem that the sensor could not be brought into direct contact with the air in the tire, and therefore proper data could not be collected.

  In addition, in the safety tire described in Patent Document 4, in which a flow passage for injecting and discharging air is formed on the outer peripheral surface of the air bladder, a predetermined internal pressure to each of the tire and the air bladder is obtained. The same was true when the air bladder was strongly pressed against the inner surface of the tire by filling and the flow passage was crushed and deformed.

  An object of the present invention is to solve such problems of the prior art, and the object of the present invention is to remove the rim from the tread portion of air or other gas filled in the tire. The free flow over the entire period until reaching the rim, and by extension, the contact with the rim is ensured at all times, thereby enabling sufficient cooling of the tread portion, etc. It is an object of the present invention to provide a safety tire that can be smoothly and sufficiently brought into contact with a filling gas into the tire.

The safety tire of the present invention comprises a tire and a hollow annular air bladder having a reinforcing layer at least at a portion facing the tire inner surface, housed inside the tire, and mounting them on a rim. While filling the tire with a specified air pressure P (kPa), the air pressure P _o (kPa)
P <P _o ≦ P + 50
With the internal pressure filling posture described above, the surface of the air bladder facing the tire inner surface is separated from the tire inner surface throughout the entire cross section in the width direction.

In addition, other safety tires, in particular, are filled with a prescribed air pressure P (kPa) in the tire, and the air pressure P _o (kPa) in the air
P <P _o ≦ P + 50
In the internal pressure filling posture, the air bladder is positioned away from the inner surface of the tread portion of the tire, and the maximum width W _o of the air bladder is set to the maximum inner surface width W of the tire.
0.5W ≦ W _o ≦ 0.8W
This is the range.

In these safety tires, more preferably, the separation distance from the tire inner surface of the air bladder portion closest to the bead core of the tire is 15 mm or more.
Preferably, the reinforcing layer may be embedded in the cross section of the air bladder in the width direction, and the portion facing the rim thereof may be provided on the facing surface from one side of the air bladder to the other side. A communication passage is provided.
In the safety tire as described above, each of the tire and the air bladder can be filled with an inert gas or other gas pressure other than air pressure.

  By the way, the term “rim” in this specification means a standard rim (or “Approved Rim” or “Recommended Rim”) in the applicable size described in the following standards. In the following standards, the air pressure defined corresponding to the maximum load capacity is assumed, and the maximum load capacity refers to the maximum mass allowed to be loaded on the tire in the following standards.

  Here, the above-mentioned standard refers to an industrial standard that is effective in the region where tires are produced or used. STNDARDS MANUAL of the Japan Auto Tire Association JATMA YEAR BOOK in Japan.

  According to the former safety tire in which the entire surface of the air bladder facing the tire inner surface is separated from the tire inner surface, the air enclosed in the tire and restrained in the partition space between the tire and the air bladder Under the normal condition of the tire, it can freely contact the rim that contributes particularly to the cooling of the tread between both of them, thus providing sufficient cooling of the tread and so on. It is possible to effectively prevent a decrease in durability such as that, and at the same time, it is possible to collect data with high accuracy by a sensor attached to the rim.

Also, the maximum width W _o of the air bladder is set to the maximum inner surface width W of the tire.
0.5W ≦ W _o ≦ 0.8W
According to the latter tire, when the tire is punctured, the air bladder can be sufficiently expanded and deformed without fear of causing breakage or the like, while the inner surface of the tread portion is normal when the tire is normal. The temperature difference between the temperature and the rim temperature can be kept sufficiently low.

  In these tires, when the distance from the inner surface of the air bladder portion closest to the bead core is set to 15 mm or more, due to the load rolling of the tire during normal operation, the action of centrifugal force, etc. There is an advantage that a necessary interval can be secured between the creep and the inner surface of the tire even when the creep due to the above occurs.

  Furthermore, in the cross section in the width direction of the air bladder, when a communication path from one side of the air bladder to the other side is provided on the surface facing the rim, smooth air such as air in the tire is provided. Thus, the cooling efficiency of the air or the like can be further enhanced.

FIG. 1 is a cross-sectional view showing a posture in which a safety tire according to the present invention is assembled to a rim and a predetermined air pressure is filled in each of the tire and the air bladder.
In the figure, reference numeral 1 denotes a tire. The tire 1 is assembled to a rim R and filled with a prescribed air pressure P (kPa) through an air valve (not shown).
Reference numeral 2 denotes a hollow annular air bladder housed in the tire 1, and this air bladder 2 includes at least a portion facing the inner surface of the tire 1, and a portion facing the rim R in the drawing. The reinforcing layer 3 is disposed over the entire cross-section in the width direction, and this also has a predetermined internal pressure P _o (kPa) that satisfies the following expression via an air valve (not shown).
P <P _o ≦ P + 50
Are filled.

  Here, the reinforcing layer 3 can be composed of, for example, at least one composite of a nonwoven fabric and rubber, and this reinforcing layer 3 is in the presence of tire air pressure P (kPa) when the tire 1 is normal. As the expansion restraint member facing the centrifugal force and the force generated by the internal pressure difference acting on the pneumatic crown region 5 facing the inner peripheral surface of the tire tread portion 4 during the load rolling, the crown region 5 is It functions to be positioned at a distance from the inner peripheral surface of the tread portion.

  On the other hand, when the air pressure P (kPa) of the tire 1 is reduced to, for example, atmospheric pressure, and the pressure difference between the inside and outside of the air bladder 2 exceeds a predetermined value, for example, 50 kPa, the air bladder 2 3 is expanded and deformed on the basis of the elongation deformation of 3, and the tire 1 is intimately and evenly adhered to the entire inner surface of the tire 1, and the load is supported from the tire 1 in the presence of the internal pressure of the air bladder. For this reason, even if the tire 1 is punctured, it is possible to continue safe traveling under the action of the air bladder 2.

Further, in this safety tire, in the illustrated internal pressure filling posture, the facing surface of the air bladder 2 facing the tire inner surface is separated from the tire inner surface throughout the entire cross section in the width direction thereof.
According to this, as described above, air or the like enclosed between the tire 1 and the air bladder 2 is removed from the inner surface of the tread portion 4 of the tire 1 from the sidewall portion 6 and It is possible to freely flow between the inner surface of the bead portion 7 and the rim R, and in particular, a large amount of heat can be radiated through the rim R having excellent heat conductivity. Each part can be sufficiently cooled, and the temperature, pressure, and other detection accuracy of the air in the tire by various sensors that may be attached to the tire inner surface of the rim R, the air, etc. Can be advantageously improved under free flow.

  In addition, since the air bladder 2 is located away from the inner surface of the tire in any part thereof, the air bladder 2 is subjected to centrifugal rolling during its load rolling in the normal state of the tire 1. Even if there is a relative displacement with respect to the tire 1 due to a force or the like, it is possible to advantageously eliminate the possibility of frictional wear on both of them. Since the size can be made sufficiently small, the cost of air bladder can be effectively reduced.

By the way, in order to make the non-contact state of the air bladder 2 to the tire inner surface more reliable and appropriate, as described above, with the reinforcing layer 3, the crown region of the air bladder 2 is provided. 5, the assumption that the process apart from the inner surface of the tread portion 4 over a given distance, the maximum width W _o of the air bladder 2 with respect to the maximum inner surface width W of the tire 1,
0.5W ≦ W _o ≦ 0.8W
The range.

  When configured in this manner, in addition to the above, it is possible to cause sufficient expansion deformation of the air bladder 2 due to puncture or the like of the tire 1 without causing the air bladder 2 to break or the like. In addition, the air in the tire or the like can sufficiently flow with respect to the sensor attached to the rim R or the like.

In such a safety tire, more preferably, the separation distance S from the tire inner surface of the air bladder portion closest to the bead core 8 embedded in the tire bead portion 7 is set to 15 mm or more.
When configured in this way, even if creep occurs in the air bladder 2 due to its rolling load when the tire 1 is normal, the air bladder 2 is located closest to the tire inner surface, Contact to the inner surface of the bead portion can be sufficiently prevented, and a flow path to the rim R, such as tire air, can be reliably ensured.

  Preferably, as shown in the enlarged cross-sectional view of the main part in FIG. 2, a predetermined surface is provided in the circumferential direction of the air bladder 2, for example, on the surface facing the rim R in the cross section in the width direction of the air bladder 2. A flow path 9 is provided which is formed of uneven strips extending in the cross-sectional width direction at intervals and communicates from one side of the air bladder 2 to the other side.

The flow path 9 that is not completely crushed by the filling of the internal pressure into the tire 1 and the air bladder 2 and the increase of the tire internal pressure, etc. is the rim R of the filling air or the like into the tire 1. As compared with the case where there is no flow passage 9 extending in the direction crossing the air bladder 2 and it is in close contact with the rim R, the circulation flow of tire in-air is prevented. Moreover, the cooling efficiency of tire air can be further increased.
In addition, although it is supposed that the flow path 9 is formed with an uneven | corrugated strip in the place shown in FIG. 2, the flow path 9 can also be formed by the several uneven | corrugated | grooved part of various arrangement | positioning and shape.

The ratio of the maximum width W _o of the air bladder to the maximum inner surface width W of the tire 1 when the tire 1 having a size of 459/45 and the air bladder 2 are filled with the prescribed air pressure is used as a parameter. Measurement of the expansion time of the air bladder 2 when it was made to form a hole in 1 and the tire internal pressure was rapidly released until it sufficiently adhered to the inner surface of the tire gave the results shown in the graph of FIG. It was.
In addition, this graph shows the average value about 30 safety tires.

According to FIG. 3, the closer the maximum width W _o of the air bladder 2 to the maximum inner surface width W of the tire 1 can reduce the expansion time of the air bladder 2, while its maximum width W _o, 0 When it is less than .5 W, it can be seen that in addition to the expansion time becoming considerably long, there is a high possibility that the air bladder will break before the air bladder fully expands.

In the same manner as in Example 1, the air temperature in the tire 1 was measured at each of the inner surface position of the tire tread portion 4 and the rim drop position in a safety tire using the maximum width of the air bladder _Wo as a parameter. The temperature difference shown by the graph in FIG. 4 was obtained.
The number of safety tires tested is the same as in Example 1, and the tire air temperature is lowered at the rim drop position.

According to FIG. 4, the smaller the maximum width W _o of the air bladder, the smaller the temperature difference, in particular under the excellent cooling efficiency based on the action of the rim, whereas the maximum W _o is 0.8 W. It is understood that the temperature difference rapidly increases as a result of hindering the smooth contact of the air in the tire with the rim.

  That is caused by the creep of the air bladder 2 when the tire 1 is rolled at 100% load with the separation distance S from the tire inner surface of the air bladder portion closest to the bead core 8 of the tire 1 as a parameter. When the change of the separation distance S was measured, the result shown with a graph in FIG. 5 was obtained.

  According to FIG. 5, when the initial separation distance S is set to 15 mm or more, the distance of 5 mm or more is sufficient to provide a smooth flow of air in the tire between the air bag and the tire inner surface after running 2000 km. While the interval can be secured, when the initial separation distance S is 12 mm or less, it is clear that the interval is 2.5 mm or less, and it is difficult to ensure a smooth flow of a sufficient amount of air. It is. In this case, a portion of the air bladder that locally contacts the inner surface of the tire is also generated on the circumference.

Thus, according to the present invention, in a safety tire assembled to a rim and filled with a specified air pressure, sufficient sealing gas contact with the rim is ensured and the cooling efficiency of the sealed gas is increased. As a result, it is possible to effectively prevent a decrease in durability due to heat generation of each component of the tire, and at the same time, sufficiently increase the detection accuracy of temperature, pressure, etc. by a sensor that may be attached to the rim. be able to.
On the other hand, with respect to the decrease or disappearance of tire pressure due to puncture, etc., the air bladder is always properly expanded and deformed, so that safe driving over a predetermined distance can be sufficiently performed with the load supported by the air bladder. Can continue to.

It is sectional drawing of the width direction which shows embodiment of this invention by the filling posture of internal pressure. It is a principal part expanded sectional view which shows other embodiment. It is a graph which shows the expandability of an air bag. It is a graph which shows a temperature difference. It is a graph which shows the space | interval change of an air bag and a tire inner surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tire 2 Air bladder 3 Reinforcement layer 4 Tread part 5 Crown area 6 Side wall part 7 Bead part 8 Bead core 9 Flow path R Rim P Tire air pressure _Po Air internal pressure W _o Air maximum width W Tire maximum inner surface width

Claims (4)

Comprising a tire and a hollow annular air bladder having a reinforcing layer on at least a portion facing the inner surface of the tire, which is housed inside the tire;
Attach them to the rim, fill the tire with the specified air pressure P (kPa), and set the air pressure P _o (kPa)
P <P _o ≦ P + 50
A safety tire in which the facing surface of the air bladder facing the inner surface of the tire is separated from the inner surface of the tire throughout the entire cross section in the width direction. Comprising a tire and a hollow annular air bladder having a reinforcing layer on at least a portion facing the inner surface of the tire, which is housed inside the tire;
Attach them to the rim, fill the tire with the specified air pressure P (kPa), and set the air pressure P _o (kPa)
P <P _o ≦ P + 50
In the internal pressure filling posture, the air bladder is positioned away from the inner surface of the tread portion of the tire, and the maximum width W _o of the air bladder is set to the maximum inner surface width W of the tire.
0.5W ≦ W _o ≦ 0.8W
Safety tires that range from   The safety tire according to claim 1 or 2, wherein a separation distance from an inner surface of the air bladder portion closest to the bead core of the tire is 15 mm or more.   The safety tire according to any one of claims 1 to 3, wherein a communication path from one side of the air bladder to the other side is provided on a surface facing the rim within the cross section in the width direction of the air bladder.

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