Pneumatic tire with specifically arranged strain sensors

• US 7,513,144 B2
• Filed: 10/31/2007
• Issued: 04/07/2009
• Est. Priority Date: 11/07/2006
• Status: Expired due to Fees

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: Miyoshi, Akihiro
• Primary Examiner(s): Allen; Andre J
• Assistant Examiner(s): Jenkins; Jermaine
• Application Number:
  US11/980,490
• Publication Number:
  US 20080127753A1
• Time in Patent Office: 524 Days
• Field of Search: 73146-1468, 340442-447
• US Class Current: 73/146
• CPC Class Codes: G01L 5/169 using magnetic means

Abstract

A pneumatic tire comprises a tread portion, a pair of bead portions and a pair of sidewall portions, and at least one of the sidewall portions is provided with at least three strain sensors disposed at least three circumferentially different mounting positions, respectively. The at least three strain sensors are oriented at angles θ with respect to tire radial directions at the respective mounting positions. The orientation angles θ of at least two of the at least three strain sensors are different from one another and their difference(s) is(are) not less than 20 degrees in absolute value.

Claims

1. A pneumatic tire comprising

a tread portion,

a pair of bead portions, and

a pair of sidewall portions,

at least one of the sidewall portions provided with at least three strain sensors disposed at least three mounting positions, respectively,

said at least three mounting positions arranged around the tire rotational axis at intervals in the tire circumferential direction,

said at least three strain sensors oriented at angles θ

with respect to tire radial directions at the respective mounting positions, wherein the orientation angle θ

is defined as being a plus value when oriented towards one tire circumferential direction, and a minus value when oriented towards the other tire circumferential direction, wherein

the orientation angles θ

of at least two of said at least three strain sensors are different from one another and their difference(s) is(are) not less than 20 degrees in absolute value.

2. The pneumatic tire according to claim 1, wherein

the orientation angle θ

of each of the strain sensors is in a range of −

80 to +80 degrees.

3. The pneumatic tire according to claim 1, wherein

with respect to each of said at least three strain sensors, the remainder thereof includes zero or only one sensor whose difference in the orientation angle θ

therefrom is less than 20 degrees in absolute value.

4. The pneumatic tire according to claim 1, wherein

differences in the orientation angle θ

between the circumferentially adjacent strain sensors are not less than 30 degrees in absolute value.

5. The pneumatic tire according to claim 1, wherein

said at least three mounting positions are in the maximum tire section width position of the sidewall portion or alternatively on the radially inner side thereof.

6. The pneumatic tire according to claim 1, wherein

one of the sidewall portions is provided with said at least three strain sensors, and

the other sidewall portion is also provided with at least three strain sensors,

the strain sensors of the other sidewall portion are disposed at mounting positions circumferentially different from those of the strain sensors of one sidewall portion.

7. The pneumatic tire according to claim 6, wherein

the number of the strain sensors of one sidewall portion is the same as the number of the strain sensors of the other sidewall portion.

8. The pneumatic tire according to claim 1, wherein

in the strain sensors oriented at the angles θ

, their most sensitive directions to linear strain are at said angles θ

.

9. A method for determining a tire force exerted on the pneumatic tire according to claim 1, comprising

obtaining:

strain data on strain at predetermined fixed measuring positions around the tire rotational axis, from the strain sensors;

identification data identifying the strain sensors; and

position data on the positions of the strain sensors,

repapering a determinant for calculating the tire force according to said identification data, and

computing the determinant using the strain data to determine the tire force.