JP2005119543A - Tire internal pressure warning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core type tire assembly in which the occurrence of a flat tire can be immediately warned to a driver, and a remaining travelable distance is displayed correctly. <P>SOLUTION: A tire internal pressure warning device comprises a tire assembly 3 having a support ring 2, a transmission means 4 which transmits radio a wave signal in a normal condition, and is held by a tread 12 and the support ring 2 and broken to stop transmission when internal pressure is dropped, a reception/warning means 6 which receives the radio wave signal from the transmission means 4 and transmits the warning signal as an internal pressure dropped state when the reception is stopped, a controller 7 to calculate the remaining travelable distance L2 in the internal pressure dropped state based on the warning signal, and a distance display meter 8 to display the remaining travelable distance L2. The transmission means 4 receives the electromagnetic wave from a power supply means 9 as power supply energy. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tire internal pressure warning device that displays a remaining distance that a tire can travel when puncture or the like occurs in a tire having run-flat performance.

  Even when a decrease in internal pressure occurs due to puncture or the like, the internal pressure decreases in the tire lumen surrounded by the tire and the rim as a tire assembly that can safely travel a distance of several hundred kilometers at a speed of about 80 km / h, for example. There has been proposed a core type that is equipped with an annular support ring that abuts against the inner surface of the tread to support a load (see, for example, Patent Document 1).

  However, even in this core type tire assembly, the travel speed and travel distance are limited during run-flat travel. Therefore, it is highly desirable to detect the decrease in internal pressure and notify the driver of the decrease in internal pressure so that the driver can run safely and safely until reaching a tire repair shop, etc., and to display the remaining distance that can be traveled. It is rare.

  In recent years, various types of internal pressure alarm devices for detecting and alarming a decrease in the internal pressure of a tire have been proposed. As the internal pressure decrease detection means, for example, an indirect formula that is calculated from the rotational speed of the tire or the like (Patent Document 2) In addition, a direct type that directly measures tire internal pressure using a pressure sensor is known.

  However, in the case of the core type tire assembly, since the change in the dynamic load radius of the tire is small between non-puncture and puncture, it is difficult to accurately detect the decrease in internal pressure with the indirect detection means. It is difficult.

On the other hand, the direct type requires a power source for the pressure sensor to measure the internal pressure and transmit the measurement data. In order to reduce the amount of electricity used, the internal pressure is maintained at regular intervals (for example, about 5 minutes). Monitoring (measurement and transmission of internal pressure) is performed. Therefore, when the internal pressure is rapidly reduced, such as puncture, it cannot be detected immediately, and there is a problem that the driver drives without recognizing puncture during the time lag. In addition, the conventional internal pressure warning device can warn of the occurrence of punctures, but it does not know the remaining distance that can be traveled. There is also a problem that cannot continue. Even if it is attempted to display the remaining distance that can be traveled, the remaining distance cannot be obtained accurately because the puncture occurrence time itself is inaccurate.
Japanese Patent Laid-Open No. 10-6721 JP-A-8-145654

  Therefore, the present invention, in the core type tire assembly, can immediately alert the driver of the occurrence of puncture, can accurately display the remaining distance that can be traveled, until reaching the tire repair factory, etc. An object of the present invention is to provide a tire internal pressure warning device capable of continuing run-flat traveling more safely and safely.

In order to achieve the above object, the invention of claim 1 of the present application provides a tire, a wheel rim for assembling the tire, a tire rim enclosed by the tire and the wheel rim, and mounted on the wheel rim. A tire assembly including an annular support ring made of an elastic body having a support surface that abuts against the inner surface of the tread portion when the internal pressure of the tread portion decreases and supports a load;
It is attached to one of the inner surface of the tread part or the support surface of the support ring, and can always transmit a radio wave signal. Possible transmission means,
Receiving / warning means for attaching to a vehicle and receiving a radio signal from the transmitting means, and for transmitting a warning signal by judging that the internal pressure of the tire is reduced when reception is stopped,
A controller that calculates the remaining distance that the vehicle can travel in a state in which the internal pressure is reduced, based on an alarm signal from the reception / alarm means;
And a distance indicator provided in the driver's seat of the vehicle and displaying the remaining distance,
The transmitting means is characterized in that the electromagnetic wave transmitted from the power transmitting means attached to the vehicle is supplied with power.

  According to a second aspect of the present invention, the controller calculates a travel distance from the generation of the alarm signal, and calculates the remaining travelable distance by subtracting the travel distance from a predetermined travelable distance. It is characterized by that.

  According to a third aspect of the present invention, the tire assembly includes temperature detection means for detecting the temperature of the support ring and transmitting the temperature data to the support ring, and the controller is configured to have a predetermined travel distance. The remaining distance that can be traveled is obtained by comparing the distance / temperature curve between the temperature of the support ring and the temperature of the support ring and the transmitted temperature data.

  Since the present invention is configured as described above, in the core type tire assembly, it is possible to immediately alert the driver of the occurrence of puncture and to accurately display the remaining distance that can be traveled. It is possible to perform the run-flat traveling more safely and safely until the vehicle reaches the point.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram conceptually showing a tire internal pressure alarm device 1 according to the present invention, FIGS. 2 and 3 are sectional views showing the tire assembly, and FIG. 4 is a partial perspective view showing a part of a support ring used therefor. It is.
In FIG. 1, the tire internal pressure warning device 1 is
(1) a tire assembly 3 having a run-flat performance with the support ring 2 attached thereto;
(2) A transmission means 4 that is attached to the tire assembly 3 and transmits a radio signal at all times and breaks when the internal pressure drops due to puncture and stops transmission.
(3) Receiving / alarming means 6 for receiving the radio signal from the transmitting means 4 attached to the vehicle 5 and for transmitting a warning signal by judging that the internal pressure of the tire is reduced when the reception is stopped;
(4) Based on an alarm signal from the reception / alarm means, a controller 7 for calculating a remaining distance that can be traveled in a state where the internal pressure is reduced;
(5) At least a distance indicator 8 provided on the vehicle 5 and displaying the remaining distance is provided.

  As shown in FIGS. 2 and 3, the tire assembly 3 includes a tire 10, a wheel rim 11 for assembling the tire 10, and an inner surface 12S of the tread portion 12 disposed in the tire lumen when the internal pressure is reduced. The support ring 2 that provides run-flat performance by abutting and supporting a load is provided.

  Here, the tire 10 is a so-called tubeless tire in which the inner surface of the tire is formed of a low-air-permeable inner liner rubber layer, and the tread portion 12 that contacts the road surface, and both ends of the tire 10 inward in the tire radial direction. It is formed in a toroidal shape having a pair of side wall portions 13 extending and a bead portion 14 formed at the inner end in the radial direction of each side wall portion 13. In addition, the tire 10 includes a carcass 16 that is engaged with the bead core 15 of the bead portion 14 from the tread portion 12 through the sidewall portion 13, and a belt layer that is disposed radially outside the carcass 16 and inside the tread portion 12. Reinforced by a known cord layer including 17, the necessary tire stiffness and strength are ensured.

  In the present example, the carcass 16 is wound on both sides of the main body portion 16a straddling the bead cores 15 and 15 through the inside of the bead core 15 in the radial direction of the tire and then wound outward in the radial direction of the tire. Then, an example in which a folded portion 16b that passes through the inside of the bead core 15 and terminates along the main body portion 16a is provided is illustrated. In such a folded structure, when tension is applied to the main body portion 16a, the rubber surrounded by the loop-shaped portion of the folded portion 16b is drawn between the bead core 15 and the rim seat 11a or 11b of the wheel rim 11 and acts like a wedge. Then, the bead portion 14 is locked to the rim. As a result, it is possible to effectively prevent the bead portion 14 from coming off the rim. Details of such a configuration are described in, for example, Japanese Patent Publication No. 9-509122.

  The wheel rim 11 includes first and second rim seats 11a and 11b on which the bead portions 14 of the tire 10 are seated, and a support ring mounting surface 11s for mounting the support ring 2 therebetween. A well portion 11c having a circumferential groove shape into which one bead portion 14 is dropped when the rim is assembled is formed.

  The first and second rim seats 11a and 11b are shown to be inclined in the direction opposite to the direction of the conventional rim seat in the meridian cross section including the tire axis. That is, the outer diameter gradually decreases toward the outer side in the tire axial direction. The minimum outer diameter of the first rim sheet 11a is formed smaller than the minimum outer diameter of the second rim sheet 11b. The bead portions 14 and 14 of the tire 10 are also designed with different bead inner diameters so as to match the first and second rim sheets 11a and 11b.

  The maximum outer diameter Ds of the support ring mounting surface 11s is formed larger than the flange outer end diameter Da on the first rim seat 11a side. As a result, the support ring 2 can be easily assembled from the first rim sheet 11a side. Further, a protrusion 11f extending in the circumferential direction for preventing movement of the support ring 2 in the tire axial direction is provided at one end of the support ring mounting surface 11s, and a concave groove 11h is provided at the other end. .

  The support ring 2 includes an inner ring body 20 attached to the support ring mounting surface 11s, an outer ring body 21 having a support surface 2S that comes into contact with the inner surface 12S of the tread portion 12 when an internal pressure is reduced, A load support portion 22 that connects the inner and outer ring bodies 20, 21 in the radial direction is integrally provided, and in this example, is attached to the center of the tire centering on the tire equator C. The support ring 2 can be formed of, for example, rubber, polyurethane, EPDM, or other various elastic materials. In order to ensure durability, the JIS D hardness is 30 to 70 degrees, the 10% modulus is 30 to 150 MPa, the loss tangent tan. Those having δ of 0.01 to 0.10 are particularly preferred. The JISD hardness and 10% modulus are values at 23 ° C., and the loss tangent was measured using a viscoelastic spectrometer at a temperature of 100 ° C., an initial strain of 10%, a displacement amplitude of ± 0.25%, and a frequency of 10 Hz. Value.

  The inner and outer ring bodies 20 and 21 are concentric cylinders, preferably 2 to 10 mm, and more preferably 4 to 4 in order to ensure necessary rigidity and strength and to maintain good steering stability during run-flat. It is desirable to form with a thickness of 6 mm.

  The inner ring body 20 is set to have an inner diameter slightly smaller than the outer diameter Ds of the support ring mounting surface 11s, whereby the support ring 2 is fitted into the support ring mounting surface 11s. . The ring body 20 is embedded with a cord ply (not shown) in which reinforcing cords such as aromatic polyamide, glass fiber, and steel are arranged, thereby increasing circumferential rigidity, and from the support ring mounting surface 11s. It is preferable to prevent easy falling off. In this example, the inner ring body 20 is formed with an annular protrusion 20c that is fitted into the concave groove 11h to prevent positional displacement in the tire axial direction.

  Further, as shown in FIG. 4, the load support portion 22 extends between the inner and outer ring bodies 20 and 21 and continuously extends in a substantially zigzag shape in the circumferential direction. Specifically, a first side piece 22a extending in the circumferential direction along one side edge of the inner and outer ring bodies 20, 21; a second side piece 22b extending in the circumferential direction along the other side edge; It is formed in a zigzag shape including oblique side portions 22c that are inclined with respect to the direction and alternately connect between the first and second side piece portions 22a and 22b. Thereby, a necessary load supporting capability can be imparted to the support ring 2 while suppressing an increase in weight to a minimum. Moreover, the heat dissipation effect can be enhanced and the durability of the support ring 2 can be improved. Therefore, it is preferable that the thickness of the load support portion 22 is, for example, about 5 to 15 mm, and the repetition pitch in the circumferential direction is 15 to 55 mm.

  Next, the transmission means 4 is attached to one of the inner surface 12S of the tread portion 12 or the support surface 2S of the support ring 2, in this example, the support surface 2S. As conceptually shown in FIG. 5, the transmission means 4 operates using electromagnetic waves transmitted from the power transmission means 9 attached to the vehicle 5 as power supply energy, and can always transmit a radio wave signal, while the other ( In this example, the contact with the inner surface 12S) is broken and the transmission of the radio signal is stopped.

  Here, in this example, the transmitting means 4 includes a transmitter 24 that transmits an unmodulated continuous wave or intermittent wave that does not include tire internal pressure data from the antenna portion 24a, and the transmitter 24. For example, a charging unit 25 such as a storage battery for supplying DC power and a power receiver 26 for converting the electromagnetic wave from the power transmission means 9 into DC power and charging the charging unit 25 are formed. The power receiver 26 includes a power receiving antenna unit 26a that receives electromagnetic waves from the power transmission means 9 and sends out the high frequency power P1, and a detection unit 26b that converts the high frequency power P1 into DC power and supplies the DC power to the charging unit 25. And a power reception control unit 26c.

  The power transmission means 9 includes a power transmission antenna unit 27a that converts the high frequency power P2 into electromagnetic waves and transmits the electromagnetic wave to the power receiving antenna unit 26a, a high frequency power generation unit 27b that generates the high frequency power P2 from the DC power supply 28 of the vehicle 5, The power transmitter 27 includes a power transmission control unit 27c.

  Therefore, the high-frequency power P2 generated by the high-frequency power generation unit 27b from the DC power supply 28 on the vehicle side is transmitted from the power transmission antenna unit 27a to the power reception antenna unit 26a as an electromagnetic wave. The electromagnetic waves are sequentially converted into high frequency power P1 and DC power through the power receiving antenna unit 26a and the detection unit 26b, and are charged in the charging unit 25. The transmitting means 4 converts the direct current from the charging unit 25 into an unmodulated radio wave signal and transmits it from the antenna unit 24a. The power reception control unit 26c and the power transmission control unit 27c control the charging state of the charging unit 25. For example, when the charging is insufficient, the power transmission unit 9 is operated to supply power energy.

  As described above, since the power source energy is sequentially supplied by the electromagnetic waves, the transmission means 4 can continuously transmit the radio wave signal when the non-internal pressure is reduced. Further, when the internal pressure is lowered (during puncture), the transmission means 4 is sandwiched between the tread portion 12 and the support ring 2 and is broken, and the transmission of the radio signal is stopped. For that purpose, the transmission means 4 must be sandwiched between the tread portion 12 and the support ring 2 at the time of puncture and can be damaged at least to the extent that transmission is stopped. It is preferable to form it with such strength that it can be damaged. Note that when the tire assembly 3 rides on a curbstone or the like in a non-punctured state, the tread portion 12 and the support ring 2 may contact or approach each other, which may accidentally damage the transmission means 4. For this purpose, it is preferable that at least one, preferably two, for example, two transmitting means 4 are arranged in each tire assembly 3.

  In addition, when attaching the said transmission means 4 to the support ring 2, it is preferable to affix on the support surface 2S at the time of manufacture of this support ring 2. FIG. In addition, when attached to the tire 10, it can be attached to the inner surface 12S of the tread portion 12 before or after vulcanization molding of the tire, but preferably vulcanized together with the affixed tire 10 before vulcanization molding. Desirable from the viewpoint of adhesive strength.

  Next, as shown conceptually in FIG. 6, the reception / alarm means 6 includes a receiver 29 having an antenna portion 29a for receiving a radio signal from the transmission means 4, and a tire when the reception is stopped. And a transmitter 30 for transmitting an alarm signal by determining that the internal pressure has been reduced. The transmitter 30 includes, for example, various indicators (including lamps) and / or speakers (including buzzers) arranged in the driver's seat, and is actuated by the alarm signal to lower the internal pressure to the driver. An alarm device 31 is connected for visually and audibly informing the occurrence of.

  In this way, by configuring the transmission means 4 and the reception / alarm means 6, it is possible to accurately and immediately detect the occurrence of a decrease in internal pressure and provide an alarm. Further, since an expensive pressure sensor is not required and an inexpensive transmitter for non-modulated wave can be adopted as the transmitter 24, the internal pressure alarm device 1 can be provided at a low cost.

  Next, the controller 7 includes a storage unit 7a and a calculation unit 7b. Based on an alarm signal from the reception / alarm unit 6, the controller 7 determines a travel distance L1 in a state in which the internal pressure is reduced in this example. The remaining travel distance L2 is calculated by subtracting the travel distance L1 from the travelable distance L0.

  The travel distance L1 can be calculated based on, for example, the product of the number of tire rotations obtained from an existing tire rotation sensor in the vehicle 5 and the circumference of the tire. However, when the internal pressure is reduced, the dynamic load radius of the tire is smaller than that in the normal internal pressure state, and the circumference of the tire is also reduced. For this reason, in the controller 7 of this example, the calculation result of the travel distance L1a in the normal internal pressure state is multiplied by the correction coefficient α smaller than 1, and the travel distance L1 in the state where the internal pressure is reduced since the alarm signal is generated is more accurate. Calculate with correction.

  In the present example, the remaining travelable distance L2 is obtained by subtracting the travel distance L1 from a preset travelable distance L0 of the tire 10. The remaining distance L2 that can be traveled is sequentially displayed in real time on a distance indicator 8 arranged in the driver's seat. As a result, excessive travel exceeding the travelable distance L0 can be reliably prevented, safety can be ensured, and the driver can continue to travel with confidence until reaching the repair shop, etc. Depending on the distance L2, it is possible to prompt a change in the travel route or the like.

  The correction coefficient α and the travelable distance L0 can be determined for each tire type based on various travel experiments. The correction coefficient α and the travelable distance L0 are stored in advance in the storage unit of the controller 7. 7a.

  Next, another embodiment of the internal pressure alarm device 1 will be illustrated. In this embodiment, as shown in FIG. 7, the support ring 2 is provided with temperature detecting means 19 for detecting the temperature T of the support ring 2 and transmitting the temperature data. By comparing the set distance / temperature curve Y with the temperature data from the temperature detecting means 19, the remaining distance L2 that can be traveled is calculated.

  The temperature detection means 19 includes a temperature sensor such as a thermistor and a transmitter that transmits temperature data from the temperature sensor as a radio signal. In this example, the temperature detection means 19 has a dedicated power supply separately, operates when the internal pressure is reduced, and transmits the temperature data of the support ring 2.

  The distance / temperature curve Y is a curve showing the relationship between the travel distance L when the internal pressure is reduced and the temperature T of the support ring 2 as shown in FIG. 8, and the measurement results based on various travel experiments. From, it can set for every kind of tire. The distance / temperature curve Y data is stored in advance in the storage unit 7a of the controller 7. Further, the calculation unit 7b of the controller 7 compares the distance / temperature curve Y with the transmitted temperature data to calculate the remaining distance L2 that can be traveled. That is, in the present embodiment, based on the distance / temperature curve Y, the travelable distance L0 and the travel distance L1 are regarded as the temperatures T0 and T1, and the difference between the temperatures T2 (= T0−T1) is converted into the distance. The remaining distance L2 that can be traveled is displayed.

  In such a case, the accuracy of the remaining travelable distance L2 obtained can be further increased.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  Based on the specifications in Table 1, a direct internal pressure alarm device using pressure sensors (Comparative Examples 1 and 2) and an internal pressure alarm device according to the present invention using non-modulated wave transmitting means (Examples 1 to 4) are prototyped. Then, the vehicle was run, and the detection time from the occurrence of zero internal pressure (puncture) to the detection, the possibility of erroneous detection, and the display accuracy of the remaining distance L2 that can be run were evaluated.

(1) Detection time:
The detection time from when the internal pressure was reached to when it was detected was measured. ,
(2) Possibility of false detection of 0 internal pressure:
Δ = High possibility of false detection, ○ = Low possibility of false detection, ◎ = Low possibility of false detection.
(3) Display accuracy of remaining travelable distance L2:
Δ = Display accuracy is low due to inaccurate detection timing, ○ = Display accuracy is high, ◎ = Display system is very high.

1 is a diagram conceptually showing an internal pressure alarm device for a tire according to the present invention. It is sectional drawing which shows a tire assembly. It is sectional drawing which expands and shows a part of tire assembly. It is a perspective view which shows a part of support ring. It is a diagram which shows notionally the transmission means and the power transmission means 9. FIG. 3 is a diagram conceptually showing a reception / alarm unit and a controller. It is sectional drawing of the tire assembly which illustrates other embodiment of this invention. It is a diagram which illustrates a distance and temperature curve.

Explanation of symbols

2 Support ring 2S Support surface 3 Tire assembly 4 Transmission means 5 Vehicle 6 Reception / alarm means 7 Controller 8 Distance indicator 9 Power transmission means 10 Tire 11 Wheel rim 12 Tread portion 12S Inner surface 19 Temperature detection means Y Distance / temperature curve

Claims (3)

A tire, a wheel rim for assembling the tire, and a tire rim that is attached to the wheel rim within the tire lumen and is in contact with the inner surface of the tread portion when the internal pressure of the tire is reduced to support a load. A tire assembly including an annular support ring made of an elastic body having a support surface;
It is attached to one of the inner surface of the tread part or the support surface of the support ring, and can always transmit a radio wave signal. Possible transmission means,
Receiving / warning means for attaching to a vehicle and receiving a radio signal from the transmitting means, and for transmitting a warning signal by judging that the internal pressure of the tire is reduced when reception is stopped,
A controller that calculates the remaining distance that the vehicle can travel in a state in which the internal pressure is reduced, based on an alarm signal from the reception / alarm means;
And a distance indicator provided on the vehicle and displaying the remaining distance,
The internal pressure alarm device for a tire, wherein the transmission means uses power as an electromagnetic wave transmitted from a power transmission means attached to the vehicle.   2. The controller calculates a travel distance from the generation of the warning signal and obtains the remaining travel distance by subtracting the travel distance from a predetermined travel distance. The tire internal pressure alarm device described.   The tire assembly includes temperature detection means for detecting the temperature of the support ring and transmitting the temperature data to the support ring, and the controller is configured to provide a distance between a predetermined travel distance and the temperature of the support ring. 2. The tire internal pressure warning device according to claim 1, wherein the remaining travelable distance is obtained by comparing a temperature curve with the transmitted temperature data.

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