Evaluation method for pneumatic tires and system thereof

• US 7,895,886 B2
• Filed: 01/29/2007
• Issued: 03/01/2011
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Tozawa, Yukio, Shimura, Kazuhiro, Iizuka, Hiroshi
• Primary Examiner(s): Caputo; Lisa M
• Assistant Examiner(s): JENKINS, JERMAINE L
• Application Number:
  US12/158,977
• Publication Number:
  US 20100132445A1
• Time in Patent Office: 1,492 Days
• Field of Search: None
• US Class Current: 73/146
• CPC Class Codes: B60C 2019/004 Tyre sensors other than for detecting tyre pressure
• 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 23/20 Devices for measuring or signalling tyre temperature only
• CPC Class Codes: G01M 17/02 Tyres
• CPC Class Codes: G07C 5/08 Registering or indicating performance data other than driving, working, idle, or waiting time, with or without registering driving, working, idle or waiting time

Abstract

An evaluation method for pneumatic tires and a system thereof, is provided, capable of appropriately evaluating an adverse effect, such as deterioration, of tire temperature by expressing severity of a temperature imposed on a member of tire made of rubber or the like in quantitative and convenient manners. Detection counts are calculated for each detected temperature according to a detection counts calculating unit 102 based on information of temperatures of pneumatic tires detected by a temperature sensor of a temperature detector 101. Temperature severity numbers of the pneumatic tires are calculated from a computing equation by a severity calculating unit 104 based on the detection counts and contribution coefficients of deterioration of tire rubber with temperatures stored in a contribution coefficient storage 103 as parameters. Using the calculated temperature severity number, a determination unit 105 determines thermal deterioration of the tire.

Claims

1. An evaluation method for pneumatic tires which comprises the steps:

a step of inputting information of pneumatic tire temperatures sequentially detected for each predetermined time by a temperature sensor into a system and a step of making the system evaluate an adverse effect of the pneumatic tire temperatures based on the information, characterized in that the system performs the following operations;

determining a total detection counts N of detected temperatures and a count ni of temperatures detected for each detected temperature Ti;

substituting a contribution coefficient ki which is constituted of power function of temperatures and is associated with a state change in a tire member previously given using temperatures as parameters and a rate β

into a computing equation TSN=Σ

(Ti×

ni×

ki/N)×

β

to calculate a temperature severity number TSN of the pneumatic tire; and

evaluating an adverse effect of a tire temperature using the calculated temperature severity number TSN.

2. The evaluation method for pneumatic tires according to claim 1, characterized in that the contribution coefficient ki constituted of power function of temperatures is a rate set based on the Arrhenius'"'"' equation of reaction rate.

3. The evaluation method for pneumatic tires according to claim 2, characterized in that the adverse effect of a temperature is deterioration and the state change in a tire member is deterioration of the tire member.

4. The evaluation method for pneumatic tires according to claim 3, characterized in that a value between 1/100 and 100 inclusive except 0 is used as the rate β

.

5. The evaluation method for pneumatic tires according to claim 3, characterized in that a detectable temperature range is divided into a plurality of temperature zones, the contribution coefficient ki is previously set for each temperature zone, and the contribution coefficient ki corresponding to a temperature zone relative to a detected temperature Ti in a predetermined temperature zone is used for the calculation.

6. The evaluation method for pneumatic tires according to claim 1, characterized in that the adverse effect of a temperature is deterioration and the state change in a tire member is deterioration of the tire member.

7. The evaluation method for pneumatic tires according to claim 6, characterized in that a value between 1/100 and 100 inclusive except 0 is used as the rate β

.

8. The evaluation method for pneumatic tires according to claim 6, characterized in that a detectable temperature range is divided into a plurality of temperature zones, the contribution coefficient ki is previously set for each temperature zone, and the contribution coefficient ki corresponding to a temperature zone relative to a detected temperature Ti in a predetermined temperature zone is used for the calculation.

9. An evaluation system for pneumatic tires, evaluating an adverse effect of a temperature of a pneumatic tire based on information of temperatures of the pneumatic tire detected by a temperature sensor, characterized by comprising:

temperature detection means which include the temperature sensor, detect temperatures Ti of the pneumatic tire and output information of the temperatures;

contribution coefficient storage means previously storing, for each temperature Ti, contribution coefficients ki which are constituted of a power function and are associated with a state change in a tire member with temperatures as parameters;

detection counts calculating means for calculating a count ni of temperatures detected for each detected temperature Ti and a total detection counts N of detected temperatures based on the detected temperature information;

temperature severity number calculating means of substituting the total detection counts N, the count ni of temperatures detected, the contribution coefficient ki and the rate β

into a computing equation TSN=Σ

(Ti×

ni×

ki/N)×

β

to calculate a temperature severity number TSN of the pneumatic tire; and

determination means of determining an adverse effect of a tire temperature using the calculated temperature severity number TSN.

10. The evaluation system for pneumatic tires according to claim 9, characterized in that the contribution coefficient ki constituted of power function of temperatures is a rate set based on the Arrhenius'"'"' equation of reaction rate.

11. The evaluation system for pneumatic tires according to claim 10, characterized in that the adverse effect of a temperature is deterioration and the state change in a tire member is deterioration of the tire member.

12. The evaluation system for pneumatic tires according to claim 11, characterized in that a value between 1/100 and 100 inclusive except 0 is used as the rate β

.

13. The evaluation system for pneumatic tires according to claim 11, characterized in that the contribution coefficient storage means have the contribution coefficient ki previously set for each of a plurality of temperature zones obtained by dividing a detectable temperature range, and that temperature severity number calculating means performs the calculation using a contribution coefficient ki corresponding to a temperature zone relative to a detected temperature Ti in a predetermined temperature zone.

14. The evaluation system for pneumatic tires according to claim 11, characterized in that the temperature detection means measure any of a tire internal temperature, a tire internal air temperature and a tire surface temperature with the temperature sensor.

15. The evaluation system for pneumatic tires according to claim 11, characterized by including alarm means of, if the temperature severity number TSN is above a predetermined value, determining tire deterioration to be above a specified value, and issuing an alarm.