TIRE ACTION FORCE DETECTING DEVICE

• US 20100071453A1
• Filed: 04/25/2008
• Published: 03/25/2010
• Est. Priority Date: 04/25/2007
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Isono, Hiroshi
• Granted Patent: US 8,096,173 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: G01L 5/164 using variations in inductance
• CPC Class Codes: G01L 5/169 using magnetic means
• CPC Class Codes: G01M 17/021 Tyre supporting devices, e.g. chucks for balancing G01M1/04

Abstract

An apparatus to accurately detect a force acting on a tire, based on a stress acting on a connection mechanism that connects a wheel and a wheel support member. A tire-acting-force detection apparatus is applied to a vehicle including a wheel unit composed of a wheel and a tire held at an outer circumferential portion of the wheel; a wheel support member which supports the wheel by a wheel support portion perpendicular to a rotation axis such that the wheel can rotate about the rotation axis; and a connection mechanism which connects a circular plate portion of the wheel and a wheel support portion of the wheel support member at a plurality of positions separated from one another about the rotation axis. The tire-acting-force detection apparatus includes a plurality of detection elements detecting stresses acting on each bolt, and an electronic circuit apparatus calculating a tire acting force, which acts at the ground contact point of the tire, based on the detected stresses.

Claims

1. A tire-acting-force detection apparatus for a vehicle which includes a wheel unit composed of a wheel having a circular plate portion perpendicular to a rotation axis and a tire held at an outer circumferential portion of the wheel;

a wheel support member which is supported by a vehicle body for rotation about the rotation axis and which supports the wheel for rotation about the rotation axis by a wheel support portion thereof extending perpendicularly to the rotation axis; and

at least one connection means for connecting the circular plate portion of the wheel and the wheel support portion of the wheel support member, the tire-acting-force detection apparatus being adapted to estimate a tire acting force, which is a force acting at a ground contact point of the tire, and comprising;

at least one stress detection means for detecting a stress acting on the corresponding connection means; and

calculation means for calculating the tire acting force on the basis of the detected stress.

2. A tire-acting-force detection apparatus according to claim 1, wherein the connection means has a center axis parallel to the rotation axis;

and the stress detection means detects a stress acting on the corresponding connection means at a plurality of positions about the center axis.

3. A tire-acting-force detection apparatus according to claim 2, wherein the stress detection means detects, at a plurality of positions about the center axis of the corresponding connection means, a stress in a direction parallel to the center axis.

4. A tire-acting-force detection apparatus according to claim 2, wherein the stress detection means detects, at a plurality of positions about the center axis of the corresponding connection means, a stress in a direction passing through the center axis and perpendicular to the center axis.

5. A tire-acting-force detection apparatus according to claim 1, wherein a plurality of connection means are disposed around the rotation axis to be separated from one another;

and the stress detection means detects a stress acting on each of the plurality of connection means.

6. A tire-acting-force detection apparatus according to claim 5, wherein the calculation means calculates at least one of a stress acting in the front-rear direction of the tire at the ground contact point of the tire, a stress acting in the lateral direction of the tire at the ground contact point of the tire, and a stress acting in the vertical direction of the tire at the ground contact point of the tire, on the basis of at least one of a stress acting in the rotational direction of the wheel unit at the position of the center axis of each connection means, a stress acting in the lateral direction of the wheel unit at the position of the center axis of each connection means, and a stress acting in the vertical direction of the wheel unit at the position of the center axis of each connection means, the stresses being presumed to act at the position of the center axis of each connection means on the basis of stresses at a plurality of positions about the center axis.

7. A tire-acting-force detection apparatus according to claim 1, wherein a plurality of connection means are disposed around the rotation axis to be separated from one another;

and the stress detection means detects stresses acting on two connection means whose angular interval therebetween about the rotation axis is closest to 180°

.

8. A tire-acting-force detection apparatus according to claim 7, wherein the calculation means calculate a stress acting in the front-rear direction of the tire at the ground contact point of the tire on the basis of stresses which are presumed, on the basis of stresses at a plurality of positions about the center axis of each connection means, to act in the rotational direction of the wheel unit at the positions of the center axes of the two connection means.

9. A tire-acting-force detection apparatus according to claim 1, wherein a plurality of connection means are disposed around the rotation axis to be separated from one another;

and the stress detection means detects stresses acting on two connection means whose angular interval therebetween about the rotation axis is closest to 90°

.

10. A tire-acting-force detection apparatus according to claim 9, wherein the calculation means calculates a stress acting in the vertical direction of the tire at the ground contact point of the tire on the basis of stresses which are presumed, on the basis of stresses at a plurality of positions about the center axis of each of two connection means, to act in the vertical direction of the wheel unit at the positions of the center axes of the two connection means.

11. A tire-acting-force detection apparatus according to claim 1, wherein a plurality of connection means are disposed around the rotation axis to be separated from one another;

and the stress detection means detects a stresses acting on one connection means.

12. A tire-acting-force detection apparatus according to claim 11, wherein the calculation means calculates a stress acting in the front-rear direction of the tire at the ground contact point of the tire or a stress acting in the vertical direction of the tire at the ground contact point of the tire, on the basis of a stress acting in the rotational direction of the wheel unit at the position of the center axis of the one connection means and a stress acting in the vertical direction of the wheel unit at the position of the center axis of the one connection means, the stresses being presumed to act at the position of the center axis of the one connection means on the basis of stresses at a plurality of positions about the center axis.

13. A tire-acting-force detection apparatus according to claim 1, further comprising a disk member which is interposed between the circular plate portion of the wheel and the wheel support member and functions as the wheel support portion, wherein the disk member is fixed to the wheel support member and is connected to the circular plate portion of the wheel by a plurality of connection means.

14. A tire-acting-force detection apparatus according to claim 1, wherein the connection means includes a holding portion provided on the wheel support portion, and a connection element which is cantilevered at one end portion by the holding portion, is fixedly connected at the other end portion to the circular plate portion, and extends parallel to the rotation axis;

and the stress detection means includes strain detection means for detecting a strain of the connection element caused by an elastic deformation thereof.

15. A tire-acting-force detection apparatus according to claim 1, wherein the connection means includes a holding portion provided on the wheel support portion, and a connection element which is cantilevered at one end portion by the holding portion, is fixedly connected at the other end portion to the circular plate portion, and extends parallel to the rotation axis;

and the stress detection means includes strain detection means for detecting a strain of the holding portion caused by an elastic deformation thereof.

16. A tire-acting-force detection apparatus according to claim 1, wherein the connection means includes a holding portion provided on the wheel support portion, and a connection element which is cantilevered at one end portion by the holding portion, is fixedly connected at the other end portion to the circular plate portion, and extends parallel to the rotation axis;

and the stress detection means includes displacement amount detection means for detecting an amount of relative displacement of the connection element in relation to the holding portion caused by an elastic deformation of the connection element.

17. A tire-acting-force detection apparatus according to claim 1, wherein the connection means includes a holding portion provided on the wheel support portion, and a connection element which is cantilevered at one end portion by the holding portion, is fixedly connected at the other end portion to the circular plate portion, and extends parallel to the rotation axis;

and the stress detection means includes surface pressure detection means for detecting a surface pressure between the connection element and the wheel support portion.

18. A tire-acting-force detection apparatus according to claim 17, wherein the surface pressure detection means detects a surface pressure in a direction perpendicular to the center axis between the connection element and the wheel support portion.

19. A tire-acting-force detection apparatus according to claim 17, wherein the surface pressure detection means includes a detection element disposed between the connection element and the wheel support portion, and adjustment means for adjusting a surface pressure which acts on the detection element in a state where no extra stress acts on the tire by adjusting a clearance between the connection element and the wheel support portion in a direction perpendicular to the center axis.

20. A tire-acting-force detection apparatus according to claim 17, wherein the surface pressure detection means detects a surface pressure in a direction along the center axis between the connection element and the circular plate portion of the wheel.

21. A tire-acting-force detection apparatus according to claim 20, further comprising a detection element disposed between the connection element and the circular plate portion of the wheel;

and a stress transfer means which is disposed between the connection element and the circular plate portion, is fitted onto the connection element, and transfers stress from the circular plate portion to the detection element along the center axis.

22. A tire-acting-force detection apparatus according to claim 14, wherein the one end portion of the connection element has a larger cross sectional area than that of the other end portion of the connection element.

23. A tire-acting-force detection apparatus according to claim 14, wherein the wheel support portion includes load limiting means which is fitted onto the connection element at a position separated from one end portion thereof toward the wheel unit side along the center axis, and limits elastic deformation of the connection element to thereby limit load acting on the connection element.

24. A tire-acting-force detection apparatus according to claim 23, wherein the load limiting means is a portion of the wheel support portion.

25. A tire-acting-force detection apparatus according to claim 24, wherein an elastic seal ring annularly extending around the center axis is disposed between the connection element and a portion of the wheel support portion, wherein the elastic seal ring prevents a foreign substance from reaching the stress detection means.

26. A tire-acting-force detection apparatus according to claim 23, wherein the load limiting means extends annularly around the connection element between the connection element and the wheel support portion;

and first and second seal rings each annularly extending around the center axis are disposed between the connection element and the load limiting means and between the load limiting means and the wheel support portion, respectively, wherein the first and second elastic seal rings prevent a foreign substance from reaching the stress detection means.

27. A tire-acting-force detection apparatus according to claim 14, wherein at least a portion of the connection element assumes a tubular shape;

and the stress detection means detects a strain of the tubular-shaped portion of the connection element.

28. A tire-acting-force detection apparatus according to claim 15, wherein at least a portion of the holding portion assumes a tubular shape;

and the stress detection means detects a strain of the tubular-shaped portion of the holding portion.