Device and method for detecting force acting on tire

• US 20050188756A1
• Filed: 02/25/2005
• Published: 09/01/2005
• Est. Priority Date: 02/26/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Morikawa, Kenji
• Granted Patent: US 7,028,540 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: G01L 5/162 of piezoresistors

Abstract

Two axle-side linking portions and two wheel-side linking portions are included in a rotation body. They are alternately arranged in four positions that are disposed, with equal intervals, along a circumference of a coaxial circle within the rotation body. Four regions located between the axle-side linking portions and the wheel-side linking portions are formed by an elastically deformable member. Further, four ceramic load sensors are arranged respectively in middle positions of the four regions along the coaxial circle. Force acting on a tire is thereby detected only from detection values by a load sensor group of the four load sensors.

Claims

1. A device for detecting force acting on a tire that is attached into a wheel disk that rotates around an axle, the device comprising:

a rotation body that is provided between the axel and the disk wheel and is integrally rotatable with the wheel disk around the axel,

axel-side linking portions that are included in the rotation body and link with the axel;

wheel-side linking portions that are included in the rotation body and link with the disk wheel;

at least one pair of a first load sensor and a second load sensor, wherein the first load sensor is arranged, in a rotational direction around the axel, in an order of the axel-side linking portion, the first load sensor, and the wheel-side linking portion, wherein the second load sensor is arranged, in the rotational direction around the axel, in an order of the wheel-side linking portion, the second load sensor, and the wheel-side linking portion; and

sandwiched portions, each of the sandwiched portions is provided between the axel-side linking portion and the wheel-side linking portion, wherein the each of the sandwiched portions includes one of the first load sensor and the second load sensor and is formed of a member that is elastically deformable in the rotational direction,

wherein, when a torque around the axel is transmitted to the rotation body from one of the axel-side linking portion and the wheel-side linking portion, the axel-side linking portion and the wheel-side linking portion cause the sandwiched portions to be elastically deformed,

wherein, when the sandwiched portions are deformed, one of the first load sensor and the second load sensor receives compression force while the other receives extension force, and

wherein the force acting on the tire is detected based on the received compression force and the received extension force.

2. The device for detecting force acting on a tire of claim 1,

wherein the first load sensor and the second load sensor include zirconia and La_1-xSr_xMnO₃ (0≦

x≦

1) that includes effect of pressure resistance.

3. The device for detecting force acting on a tire of claim 1,

wherein at least two pairs of the first load sensor and the second load sensor are provided,

wherein the first load sensor of one pair of the two pairs is designated as a third load sensor, while the second load sensor of the one pair is designated as a fourth load sensor,

wherein at least one sensor group is constituted by the first load sensor, the second load sensor, the third load sensor, and the fourth load sensor,

wherein the four load sensors are arranged in an order of the first load sensor, the second load sensor, the third load sensor, and the fourth load sensor, on a circumference of a circle having a center that is on a rotational axis of the axel, in respective four regions that are formed by dividing the circumference of the circle with 90-degree intervals, and

wherein the force acting on the tire is detected only based on values detected by the at least one sensor group.

4. The device for detecting force acting on a tire of claim 3,

wherein the first load sensor, the second load sensor, the third load sensor, and the fourth load sensor are arranged on the circumference of the circle with 90-degree intervals,

wherein a detection load in the rotational direction detected by the first load sensor is defined as F1,

a detection load in a direction reverse to the rotational direction detected by the second load sensor is defined as F2,

a detection load in the rotational direction detected by the third load sensor is defined as F3,

a detection load in the direction reverse to the rotational direction detected by the fourth load sensor is defined as F4,

a distance from a center of the rotation body to each of the load sensors is defined as Rs,

a radius of the tire is defined as Rt,

a rotation torque is defined as T, and

the force acting on the tire that is vertically applied is defined as Fcs, and

wherein T is expressed by a first formula:

T={(F1+F3)−

(F2+F4)}×

Rs, and

Fcs is expressed by a second formula;

Fcs={(F1−

F3)²+(F2−

F4)²−

(T/Rt)²}^1/2.

5. A method for detecting force acting on a tire, the method using the second formula of claim 4.

6. A method for detecting force acting on a tire that is attached into a wheel disk that rotates around an axle, by using a detecting device that includes:

a rotation body that is provided between the axel and the disk-wheel and is integrally rotatable with the wheel disk around the axel,

axel-side linking portions that are included in the rotation body and link with the axel;

wheel-side linking portions that are included in the rotation body and link with the disk wheel;

at least two pairs of a first load sensor and a second load sensor, wherein the first load sensor is arranged, in a rotational direction around the axel, in an order of the axel-side linking portion, the first load sensor, and the wheel-side linking portion, wherein the second load sensor is arranged, in the rotational direction around the axel, in an order of the wheel-side linking portion, the second load sensor, and the axel-side linking portion; and

sandwiched portions, each of which is provided between the axel-side linking portion and the wheel-side linking portion, includes one of the first load sensor and the second load sensor, and is formed of a member that is elastically deformable around the axel,

wherein, when a torque around the axel is transmitted to the rotation body from one of the axel-side linking portion and the wheel-side linking portion, the axel-side linking portion and the wheel-side linking portion cause the sandwiched portions to be elastically deformed,

wherein, when the sandwiched portions are deformed, one of the first load sensor and the second load sensor detects a value by receiving compression force while the other detects a value by receiving extension force,

wherein the first load sensor of one pair of the two pairs is designated as a third load sensor, while the second load sensor of the one pair is designated as a fourth load sensor,

wherein at least one sensor group is constituted by the first load sensor, the second load sensor, the third load sensor, and the fourth load sensor,

wherein the four load sensors are arranged in an order of the first load sensor, the second load sensor, the third load sensor, and the fourth load sensor, on a circumference of a circle having a center that is on a rotational axis of the axel, with 90-degree intervals,

wherein the force acting on the tire is detected only based on values detected by the at least one sensor group,

wherein a detection load in the rotational direction detected by the first load sensor is defined as F1,

a detection load in a direction reverse to the rotational direction detected by the second load sensor is defined as F2,

a detection load in the rotational direction detected by the third load sensor is defined as F3,

a detection load in the direction reverse to the rotational direction detected by the fourth load sensor is defined as F4,

a distance from a center of the rotation body to each of the load sensors is defined as Rs,

a radius of the tire is defined as Rt,

a rotation torque is defined as T, and

wherein T is expressed by a first formula;

T={(F1+F3)−

(F2+F4)}×

Rs,

the force acting on the tire that is vertically applied is defined as Fcs, the method comprising;

a step of detecting the force acting on the tire, defined as Fcs, using a second formula;

Fcs={(F1−

F3)²+(F2−

F4)²−

(T/Rt)²}^1/2.