TIRE INFORMATION TRANSMITTER AND TIRE INFORMATION ACQUISITION SYSTEM USING THE TRANSMITTER

• US 20080211650A1
• Filed: 02/19/2008
• Published: 09/04/2008
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Ebinuma, Toshimitsu, Nihei, Hideki, Nakatani, Koji
• Granted Patent: US 7,701,326 B2
• Time in Patent Office: Days
• US Class Current: 340/447
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0484 Detecting an ongoing tyre inflation

Abstract

A tire information transmitter measures ambient information in a tire cavity region including at least pressure to wirelessly transmit to outside the tire cavity region. The tire transmitter comprises: a sensor unit having a pressure sensor for measuring a pressure in the tire cavity region; a control unit for comparing a level of a pressure signal representing pressure measured by the sensor unit with a threshold value and for generating an operation signal indicating that the tire information transmitter is operating; and a transmitting unit for wirelessly transmitting the pressure signal or the operation signal. The control unit controls the transmitting of the transmitting unit and compares the level of the pressure signal with the threshold value continually after a supply of driving power is started, and has a comparing mode in which the transmitting unit transmits the operation signal at a first time interval, and a transmitting mode in which the transmitting unit transmits the pressure signal at a second time interval which is shorter than the first time interval. Further, the control unit irreversibly shifts from the comparing mode to the transmitting mode, once the level of the pressure signal exceeds the threshold value, as a result of the comparing.

Claims

1. A tire information transmitter comprising:

a sensor unit having a pressure sensor for measuring a pressure in a tire cavity region;

a control unit for comparing the measured pressure to a threshold value; and

a transmitting unit for wirelessly transmitting the pressure signal or the operation signal;

wherein the control unit controls the frequency at which the transmitting unit transmits the pressure signal based upon whether the measured pressure exceeds the threshold value.

2. The tire information transmitter of claim 1, wherein the control unit generates an operation signal indicating that the tire information transmitter is operating when the measured pressure exceeds a threshold.

3. The tire information transmitter of claim 1, wherein the transmitting unit transmits the pressure signal at a first frequency when the measured pressure is less than the threshold value and at a second frequency when the measured pressure is greater than the threshold value, and wherein the first frequency is less than the second frequency.

4. The tire information transmitter of claim 1, wherein the tire information transmitter is mounted to a cavity region surrounded by an inner peripheral surface of a tire and a wall surface of a wheel.

5. The tire information transmitter of claim 1, wherein the sensor unit, the control unit and the transmitting unit are housed in a housing box and an outer surface of the housing box has a curbed surface fitting on a bottom surface of the wheel so as to be attached to the bottom surface of the wheel.

6. The tire information transmitter of claim 1, wherein the tire information transmitter further comprises a battery for driving the sensor unit, the control unit and the transmitting unit.

7. The tire information transmitter of claim 1, wherein the transmitting frequency depends on the measured pressure when the measured pressure exceeds the threshold value.

8. A tire information acquisition system comprising the tire information transmitter of claim 1, further comprising a receiver configured to receive the transmitted pressure signal from the tire information transmitter.

9. The tire information acquisition system of claim 8, wherein the receiver is mounted outside of the tire cavity region surrounded by a inner peripheral surface of a tire and the wall surface of the wheel.

10. A method of monitoring a tire, comprising:

measuring a pressure in a tire cavity region;

comparing the measured pressure to a threshold value;

wirelessly transmitting the pressure signal or the operation signal; and

controlling the frequency of the transmitting based upon whether the measured pressure exceeds the threshold value.

11. The method of claim 10, further comprising indicating that the tire information transmitter is operating when the measured pressure exceeds a threshold.

12. The method of claim 10, further comprising controlling the frequency of the transmitting to be a first frequency when the measured pressure is less than the threshold value and a second frequency when the measured pressure is greater than the threshold value, wherein the first frequency is less than the second frequency.

13. The method of claim 10, further comprising controlling the frequency of the transmitting to be dependent on the measured pressure when the measured pressure exceeds the threshold value.

14. The method of claim 10, further comprising receiving the transmitted pressure signal from the tire information transmitter.

15. A tire information transmitter, comprising:

means for measuring a pressure in a tire cavity region;

means for comparing the measured pressure to a threshold value;

means for wirelessly transmitting the pressure signal or the operation signal; and

means for controlling the frequency of the transmitting based upon whether the measured pressure exceeds the threshold value.