JP4492384B2 - Run flat tire - Google Patents

Description

The present invention relates to a core-type run-flat tire in which a core that supports a vehicle load during run-flat travel is disposed inside a pneumatic tire.

2. Description of the Related Art A run flat tire is known in which even when the tire air pressure decreases, the vehicle can safely travel a certain distance in that state. A so-called core-type run flat tire in which a support is attached to the inside of the tire is known as a kind of run flat tire (Patent Document 1).
JP 2004-175271 A

  By the way, in the conventional core type run-flat tire, when the tire is punctured and reaches a state where the air pressure is zero, the temperature of the tire may increase due to friction between the core and the tire. When the temperature of the tire rises in this way, for example, the core leg is deformed by the generated heat, so that the core cannot support the tire and run flat running becomes impossible. As a solution to this, in Patent Document 1 described above, the core leg is prevented from being deformed by increasing the rigidity of the core. However, tire temperatures remain elevated and are not a fundamental solution.

  Further, when the temperature of the tire rises due to friction, the inner surface of the tire that rubs against the core deteriorates. For this reason, when the tire is punctured, there is a possibility that the traveling distance that can be safely traveled is reduced, the life of the run-flat tire body is shortened, and the performance of the run-flat tire that should be secured cannot be satisfied.

  Therefore, an object of the present invention is to provide a core type run flat tire capable of preventing an increase in tire temperature during run flat running.

  That is, the run-flat tire according to the present invention is a core-type run-flat tire in which a core that supports a vehicle load during run-flat running is arranged inside the pneumatic tire. A temperature adjusting means for cooling the pneumatic tire is sometimes provided.

  According to this invention, the temperature adjusting means is attached to the core, and the temperature adjusting means cools the tire during puncture. At the time of puncture, the air pressure of the pneumatic tire becomes zero, the inner surface of the tire contacts the surface of the core, and the tire generates heat due to friction between the tire and the core. At this time, the temperature adjusting means directly cools the inner surface of the tire. By suppressing the increase in the tire temperature in this way, it is possible to secure a travel distance that can safely travel during puncture and to maintain the performance of the run flat tire that should be originally performed. Further, by suppressing the deterioration of the tire body due to the temperature rise, the original tire life can be maintained.

  Further, in the run flat tire according to the present invention, there is provided a collision preventing means that is provided in the core so as to cover the temperature adjusting means and prevents the inner surface of the pneumatic tire from directly colliding with the temperature adjusting means during the run flat running. You may make it provide further. Alternatively, the temperature adjusting means may be accommodated in a recess formed in the core.

  According to these inventions, it is possible to prevent the inner surface of the tire and the temperature adjusting means from directly colliding with each other during run flat traveling. For this reason, the impact given to the temperature adjusting means by the collision is alleviated, and the temperature adjusting means can be prevented from being damaged.

  In the run-flat tire according to the present invention, the temperature adjusting means has a cooling function and a heating function, and a temperature detecting means for detecting the temperature of the pneumatic tire, and an air pressure detection for detecting the air pressure of the pneumatic tire. And a temperature adjusting means is disposed inside the pneumatic tire when the temperature detected by the temperature detecting means is equal to or higher than a temperature threshold value and the air pressure detected by the air pressure detecting means is equal to or higher than the air pressure threshold value. When the air pressure is properly adjusted by cooling the air, the temperature detected by the temperature detection means is not higher than the temperature threshold, and the air pressure detected by the air pressure detection means is not higher than the air pressure threshold Preferably, the air inside the pneumatic tire is heated to appropriately adjust the air pressure of the pneumatic tire.

  According to this invention, when the temperature detected by the temperature detecting means is equal to or higher than the temperature threshold value and the air pressure detected by the air pressure detecting means is equal to or higher than the air pressure threshold value, the air inside the pneumatic tire is removed. Cool and adjust the air pressure of the pneumatic tire properly, and if the temperature detected by the temperature detection means is not higher than the temperature threshold and the air pressure detected by the air pressure detection means is not higher than the air pressure threshold, air The air inside the tire is heated to properly adjust the air pressure of the tire. Thus, the tire air pressure can be adjusted using the cooling function and heating function of the temperature adjusting means.

  According to the present invention, it is possible to prevent an increase in tire temperature during run-flat traveling.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a schematic view showing a cross-sectional structure of a first embodiment of a run flat tire according to the present invention. A pneumatic tire 2 is attached to a rim wheel 1 in the run flat tire according to the present embodiment. As the pneumatic tire 2, a rubber tire is used. An air chamber 3 is formed inside the pneumatic tire 2, and a predetermined groove-shaped tread pattern 22 is formed on the outer surface 21 of the pneumatic tire 2. The structure of the pneumatic tire 2 itself is basically the same as that of a normal vehicle tire.

  A core 4 is disposed in the air chamber 3. The core 4 is attached to the rim wheel 1 and provided so as to protrude toward the tread side. Moreover, the outer peripheral surface 41 of the core 4 is formed in parallel with the tread part inner surface 23 of the pneumatic tire 2 at the time of normal air pressure. By arranging the core 4 in the air chamber 3 in this way, the air chamber 3 includes a core inner air chamber 31 between the inner peripheral surface 42 of the core 4 and the rim wheel 1, and the core 4. The outer peripheral surface 41 of the pneumatic tire 2 and a core outer side air chamber 32 between the tread portion inner surface 23 of the pneumatic tire 2 are divided.

  The run-flat tire according to this embodiment includes a core inner temperature sensor (temperature detection means) 5, a core outer temperature sensor (temperature detection means) 6, an air pressure sensor (air pressure detection means) 7, a control unit 8, and a temperature adjustment unit. (Temperature adjusting means) 9 and protector (collision preventing means) 10 are provided.

  The core inner temperature sensor 5 detects the temperature of the core inner air chamber 31 and is disposed on the inner peripheral surface 42 of the core 4. The core outer temperature sensor 6 detects the temperature of the core outer air chamber 32 and is disposed on the outer peripheral surface 41 of the core 4. As the core inner temperature sensor 5 and the core outer temperature sensor 6, for example, a platinum sensor is used. The core inner temperature sensor 5 and the core outer temperature sensor 6 are electrically connected to the control unit 8 and output information about the detected temperature to the control unit 8.

  The air pressure sensor 7 detects air pressure in the air chamber 3 and is attached to the rim wheel 1, for example. The air pressure sensor 7 is electrically connected to the control unit 8 and outputs information on the detected air pressure of the air chamber 3 to the control unit 8.

  When the core inner temperature sensor 5, the core outer temperature sensor 6, the air pressure sensor 7 and the control unit 8 are electrically connected, the connection is made, for example, via a slip ring 11 so that the wiring does not get tangled with the rotation of the tire. It is preferable to do so. Or you may make it provide a contact etc. as what shows the function similar to the slip ring 11, for example.

  The control unit 8 controls the temperature adjusting unit 9 based on the temperature and air pressure information input from the core inner temperature sensor 5, the core outer temperature sensor 6, and the air pressure sensor 7, so that the pneumatic tire 2 and the air The temperature of the chamber 3 and the air pressure are adjusted. Further, the temperature adjustment unit 9 cools or heats the pneumatic tire 2 according to the control of the control unit 8. For example, when the pneumatic tire 2 is punctured, the temperature adjusting unit 9 directly cools the inner surface 23 of the tread portion, and otherwise adjusts the temperature and air pressure of the air chamber 3. For example, a semiconductor element (Peltier element) that exhibits the Peltier effect is used as the temperature adjustment unit 9. Moreover, the temperature adjustment part 9 has a cooling function and a heating function by changing the direction of the current flowing through the temperature adjustment part 9.

  More specifically, for example, when the pneumatic tire 2 is punctured, the air pressure in the air chamber 3 is lowered. As a result, the outer peripheral surface 41 of the core 4 comes into contact with the inner surface 23 of the tread portion of the pneumatic tire 2, and the pneumatic tire 2 generates heat due to this friction. In such a case, the control unit 8 operates so that the temperature adjusting unit 9 has a cooling function. The temperature adjustment unit 9 cools the pneumatic tire 2 by directly cooling the inner surface 23 of the tread portion of the pneumatic tire 2.

  An increase in temperature of the outer surface 21 of the pneumatic tire 2 is suppressed by, for example, traveling wind. However, since the pneumatic tire 2 made of rubber or the like has a low thermal conductivity, it is difficult to dissipate the frictional heat on the inner surface 23 of the tread portion where heat is actually generated with the traveling wind. For this reason, effective cooling is performed by cooling the tread part inner surface 23 of the pneumatic tire 2 directly.

  The protector 10 is for preventing the inner surface 23 of the tread portion of the pneumatic tire 2 from directly colliding with the temperature adjusting unit 9 during run flat traveling. The protector 10 is provided on the outer peripheral surface 41 of the core 4 so as to cover the temperature adjusting unit 9. This protector 10 is made of a member having good thermal conductivity and capable of withstanding impact, and for example, a metal one is used.

  Next, operations during normal running and run-flat running of the run-flat tire of this embodiment will be described with reference to the flowchart of FIG. Each control process in the flowchart of FIG. 2 is executed by the control unit 8.

Air pressure P of the air chamber 3 is whether the air pressure threshold P ₀ or more values are determined. The air pressure P is obtained by reading the detection signal of the air pressure sensor 7, and P ₀ is an air pressure threshold value preset in the control unit 8. (Step S101).

In step S101, if the air pressure P is equal to or greater than the air pressure threshold P ₀ is the possibility that the pneumatic tire 2 is punctured is determined not, the temperature T ₂ of the core outer air chamber 32 is temperature whether the threshold T ₀ temperature above is determined. Temperature T ₂ is is used which reads the detection signal of the core outer temperature sensor 6. The threshold value T ₀ is a temperature threshold value preset in the control unit 8. (Step S102).

In step S102, if temperature T ₂ is equal to or higher than the temperature threshold T _0, the air chamber 3 inside the air is determined to be inflated, for example, by the temperature rise of the pneumatic tire 2 and the air chamber 3 . At this time, a current is supplied to the temperature adjusting unit 9 so as to perform a cooling function, and the air chamber 3 is cooled. (Step S103). Air chamber 3 is cooled to the air pressure P is similar to the air pressure threshold P _0, the process flow returns to step S101.

On the other hand, in step S102, if temperature T ₂ is not temperature threshold T ₀ or more, the air pressure P of the air chamber 3 is determined to have risen by, for example, putting too much air, for putting too much air Perform alarm processing. For example, a character display, a lamp, or a buzzer is used for the alarm process (step S104). Then, the process flow returns to step S101.

Returning to step S101, if the air pressure P is not the air pressure threshold _{P 0} or more, the difference between the temperature _{T 1} of the temperature _{T 2} and the core inner air chamber 31 of the core outer air chamber 32 _(T 2 -T ₁ ) Is determined, and it is determined whether or not it is equal to or greater than the temperature difference threshold value X. (Step S105). Here, the temperature T ₂ is read from the detection signal of the core outer temperature sensor 6, and the temperature T ₁ is read from the detection signal of the core inner temperature sensor 5. X is a temperature difference threshold value preset in the control unit 8.

In step S105, when the difference (T ₂ −T ₁ ) between the temperature T ₂ and the temperature T ₁ is equal to or greater than the temperature difference threshold value X, it is determined that the pneumatic tire 2 is in a puncture state. This is because, when the pneumatic tire 2 is punctured by contact between the outer peripheral surface 41 and the pneumatic tread portion inner surface 23 of the tire 2 of the core 4, the internal temperature T ₂ of the core outer air chamber 32 is increased, the core inner This is because the difference from the temperature T ₁ of the air chamber 31 increases. At this time, an electric current is supplied to the temperature adjusting unit 9 so as to perform a cooling function, and the temperature adjusting unit 9 directly cools the inner surface 23 of the tread portion of the pneumatic tire 2. (Step S106). The pneumatic tire 2 is cooled until the temperature difference (T ₂ −T ₁ ) becomes the same as the temperature difference threshold value X, and the process flow returns to step S101.

On the other hand, in step S105, temperature _{T 2} and when the difference between the temperature _{T 1 (T} 2 -T ₁₎ is less than the temperature difference threshold X is, the temperature _{T 2} of the core outer air chamber 32 is a temperature threshold whether the value T ₀ or more temperature is determined. (Step S107).

In step S107, the fact that temperature T ₂ is a temperature threshold value T ₀ or more, the temperature is in normal or slightly elevated, is that the air pressure is low. That is, for example, although the pneumatic tire 2 has already been punctured, the outer peripheral surface 41 of the core 4 is still on the inner surface 23 of the tread portion of the pneumatic tire 2 because the air in the air chamber 3 is in the process of gradually taking out. It is judged that it is not in contact with. At this time, an alarm process is performed for the pneumatic tire 2 being punctured and the air pressure being lowered. In this alarm processing, for example, a character display, a lamp, a buzzer, or the like is used (step S108) as in step S104. Then, the process flow returns to step S101.

On the other hand, it judged that at step S107, if temperature T ₂ is not temperature threshold T ₀ or more, the air chamber 3 inside the air is reduced, for example, by a temperature lowering of the pneumatic tire 2 and the air chamber 3 Is done. At this time, a current in the direction opposite to that in steps S103 and S106 is passed through the temperature adjusting unit 9, and the air chamber 3 is heated. (Step S109). Air chamber 3 is heated to the air pressure P is similar to the air pressure threshold P _0, the process flow returns to step S101.

  As described above, according to the run flat tire according to the present embodiment, the temperature adjustment unit 9 is attached to the core 4, and the temperature adjustment unit 9 cools the pneumatic tire 2 at the time of puncture. At the time of puncture, the air pressure of the pneumatic tire 2 becomes zero, the inner surface 23 of the tread portion of the pneumatic tire 2 and the outer peripheral surface 41 of the core 4 come into contact, and the pneumatic tire 2 generates heat due to the friction. At this time, the temperature adjusting unit 9 directly cools the inner surface 23 of the tread portion of the pneumatic tire 2. By suppressing the temperature rise of the pneumatic tire 2 in this manner, it is possible to secure a travel distance that can be safely traveled during puncture and to maintain the performance of the run-flat tire that should be originally intended. Moreover, the original life of the pneumatic tire 2 can be maintained by suppressing the deterioration of the main body of the pneumatic tire 2 due to the temperature rise.

  In addition, according to the present embodiment, the protector 10 is provided on the core 4 so as to cover the temperature adjustment unit 9, so that the inner surface 23 of the tread portion of the pneumatic tire 2 and the temperature adjustment unit 9 can be used during the run-flat running. A direct collision can be prevented. For this reason, the impact given to the temperature adjustment part 9 by a collision is relieved, and it can prevent that the temperature adjustment part 9 is damaged.

Further, according to the present embodiment, the internal temperature T ₂ is a temperature threshold value T ₀ or more and, if the air pressure P is the air pressure threshold P ₀ or more, cooling the air inside the pneumatic tire properly adjusting the air pressure of the pneumatic tire, not the internal temperature T ₂ is a temperature threshold value T ₀ or more and the internal pneumatic tire when the air pressure P is not the air pressure threshold P ₀ or more air To adjust the air pressure of the pneumatic tire properly. Thus, the tire air pressure can be adjusted using the cooling function and the heating function of the temperature adjusting unit 9.

In the present embodiment, the temperature threshold value T ₀ , the air pressure threshold value P _0, and the temperature difference threshold value X are set to constant values in the control processing of FIG. You may employ | adopt the range which has. That is, when it is determined whether or not it is greater than or equal to the threshold value, it is determined whether or not it is greater than or equal to the upper limit value of the range, and when it is determined whether or not it is less than or equal to the threshold value, the lower limit value of the range It may be determined whether or not:

(Second Embodiment)
Next, a run flat tire according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic view showing a cross-sectional structure of the run flat tire of the second embodiment. This run-flat tire has substantially the same configuration as the run-flat tire of the first embodiment shown in FIG. 1, and is different in the shape of the core 4 and the position where the temperature adjusting unit 9 is disposed. That is, a recess 43 is formed on the outer peripheral surface 41 of the core 4, and the temperature adjustment unit 9 is accommodated inside the recess 43. At that time, it is preferable that the temperature adjusting unit 9 is provided so as not to protrude from the outer peripheral surface 41 of the core 4.

  With such a configuration, the tread portion inner surface 23 of the pneumatic tire 2 and the temperature adjusting unit 9 are prevented from directly colliding at the time of puncture. For this reason, the impact given to the temperature adjustment part 9 by a collision is relieved, and it can prevent that the temperature adjustment part 9 is damaged.

It is the schematic which shows the cross-section of 1st Embodiment of the run flat tire which concerns on this invention. It is a flowchart for demonstrating operation | movement of 1st Embodiment of the run flat tire which concerns on this invention. It is the schematic which shows the cross-section of 2nd Embodiment of the run flat tire which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rim wheel, 2 ... Pneumatic tire, 23 ... Tread part inner surface, 3 ... Air chamber, 31 ... Core inner side air chamber, 32 ... Core outer side air chamber, 4 ... Core, 41 ... Outer peripheral surface, 42 ... Inner peripheral surface, 43 ... concave portion, 5 ... core inner temperature sensor, 6 ... core outer temperature sensor, 7 ... air pressure sensor, 8 ... control unit, 9 ... temperature adjusting unit, 10 ... protector.

Claims (4)

In a core type run flat tire in which a core that supports the vehicle load at the time of run flat traveling is arranged inside the pneumatic tire,
A temperature adjusting means that is attached to the core and cools the pneumatic tire during the run-flat running;
Run-flat tire characterized by. A collision preventing means provided on the core so as to cover the temperature adjusting means, and preventing an inner surface of the pneumatic tire from directly colliding with the temperature adjusting means during the run-flat running;
The run flat tire according to claim 1.   The run-flat tire according to claim 1, wherein the temperature adjusting means is accommodated in a recess formed in the core. The temperature adjusting means has a cooling function and a heating function,
Temperature detecting means for detecting the temperature of the pneumatic tire;
Air pressure detecting means for detecting the air pressure of the pneumatic tire;
Further comprising
The temperature adjusting means is disposed inside the pneumatic tire when the temperature detected by the temperature detecting means is equal to or higher than a temperature threshold value and the air pressure detected by the air pressure detecting means is equal to or higher than an air pressure threshold value. And the air pressure of the pneumatic tire is appropriately adjusted, the temperature detected by the temperature detecting means is not equal to or higher than the temperature threshold value, and the air pressure detected by the air pressure detecting means is Heating the air inside the pneumatic tire when it is not equal to or greater than the air pressure threshold value, and appropriately adjusting the air pressure of the pneumatic tire;
The run flat tire according to any one of claims 1 to 3.

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