Method for measuring forces acted upon tire and apparatus for measuring forces acted upon tire
First Claim
1. A method for measuring at least one of forces in a peripheral direction and a radial direction of a running tire mounted onto a rim acted upon a ground contact face, in which when a point on an outer peripheral face of the rim is Q and an intersect between a straight line passing through the point Q under no action of external force and extending in the radial direction and an inner peripheral face of a tread portion of the tire is P, said forces are determined from a variant pattern that a relative displacement of the point P to the point Q in the peripheral direction or the radial direction is changed in accordance with a rotating position of the point Q when the point P passes through the ground contact portion of the tire,wherein a magnetic field formed by a magnet arranged on one of the point P and the point Q is continuously measured by a magnetic sensor arranged on the other of the point P and the point Q, and the variant pattern of the relative displacement between the point P and the point Q is determined by reverse calculation from a variant pattern of a magnetic flux density changed in accordance with the relative displacement;
- andwherein the measurement of the magnetic flux density is conducted by using the magnet arranged so that a magnetic force line distribution of the magnetic field forms a plane symmetry with respect to a meridional plane of the tire including the point P or the point Q under no action of external force to the tire,and the force acting in the peripheral direction of the tire is determined from an average between maximum value and minimum value of a variant pattern of a tire peripheral component in the measured magnetic flux density and the force acting in the radial direction of the tire is determined from a difference between the maximum value and the minimum value of the variant pattern.
1 Assignment
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Accused Products
Abstract
There is provided an apparatus for measuring forces acted upon a tire in which a radial force and a peripheral force acting to the tire, which are required for the high precision measurement of a friction coefficient on a road surface, are simply measured in a high precision by detecting a magnetic field formed by a magnet fixed to a tread portion of the tire by a magnetic sensor fixed to a rim and measuring the forces acting to the tire from a variant pattern of a magnetic flux density detected un the rotation of the tire and without influencing upon the balance of the tire, which contributes to the high precision measurement of the friction coefficient on the road surface.
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Citations
20 Claims
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1. A method for measuring at least one of forces in a peripheral direction and a radial direction of a running tire mounted onto a rim acted upon a ground contact face, in which when a point on an outer peripheral face of the rim is Q and an intersect between a straight line passing through the point Q under no action of external force and extending in the radial direction and an inner peripheral face of a tread portion of the tire is P, said forces are determined from a variant pattern that a relative displacement of the point P to the point Q in the peripheral direction or the radial direction is changed in accordance with a rotating position of the point Q when the point P passes through the ground contact portion of the tire,
wherein a magnetic field formed by a magnet arranged on one of the point P and the point Q is continuously measured by a magnetic sensor arranged on the other of the point P and the point Q, and the variant pattern of the relative displacement between the point P and the point Q is determined by reverse calculation from a variant pattern of a magnetic flux density changed in accordance with the relative displacement; - and
wherein the measurement of the magnetic flux density is conducted by using the magnet arranged so that a magnetic force line distribution of the magnetic field forms a plane symmetry with respect to a meridional plane of the tire including the point P or the point Q under no action of external force to the tire, and the force acting in the peripheral direction of the tire is determined from an average between maximum value and minimum value of a variant pattern of a tire peripheral component in the measured magnetic flux density and the force acting in the radial direction of the tire is determined from a difference between the maximum value and the minimum value of the variant pattern. - View Dependent Claims (5, 6)
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2. A method for measuring at least one of forces in a peripheral direction and a radial direction of a running tire mounted onto a rim acted upon a ground contact face, in which when a point on an outer peripheral face of the rim is Q and an intersect between a straight line passing through the point Q under no action of external force and extending in the radial direction and an inner peripheral face of a tread portion of the tire is P, said forces are determined from a variant pattern that a relative displacement of the point P to the point Q in the peripheral direction or the radial direction is changed in accordance with a rotating position of the point Q when the point P passes through the ground contact portion of the tire,
wherein a magnetic field formed by a magnet arranged on one of the point P and the point Q is continuously measured by a magnetic sensor arranged on the other of the point P and the point Q, and the variant pattern of the relative displacement between the point P and the point Q is determined by reverse calculation from a variant pattern of a magnetic flux density changed in accordance with the relative displacement; -
wherein the measurement of the magnetic flux density is conducted by using the magnet arranged so that a magnetic force line distribution of the magnetic field forms a plane symmetry with respect to a meridional plane of the tire including the point P or the point Q under no action of external force to the tire, and the force acting in the radial direction of the tire is determined from a maximum value or a minimum value of a variant pattern of a tire radial component of the measured magnetic flux density.
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3. A method for measuring at least one of forces in a peripheral direction and a radial direction of a running tire mounted onto a rim acted upon a ground contact face, in which when a point on an outer peripheral face of the rim is Q and an intersect between a straight line passing through the point Q under no action of external force and extending in the radial direction and an inner peripheral face of a tread portion of the tire is P, said forces are determined from a variant pattern that a relative displacement of the point P to the point Q in the peripheral direction or the radial direction is changed in accordance with a rotating position of the point Q when the point P passes through the ground contact portion of the tire,
wherein a magnetic field formed by a magnet arranged on one of the point P and the point Q is continuously measured by a magnetic sensor arranged on the other of the point P and the point Q, and the variant pattern of the relative displacement between the point P and the point Q is determined by reverse calculation from a variant pattern of a magnetic flux density changed in accordance with the relative displacement; -
wherein the measurement of the magnetic flux density is conducted by using the magnet arranged so that a widthwise component of a magnetic flux density of the magnetic field changes along the peripheral direction of the tire under no action of external force to the tire, and the force acting in the peripheral direction of the tire is determined from an average between maximum value and minimum value of a variant pattern of a tire widthwise component in the measured magnetic flux density and the force acting in the radial direction of the tire is determined from a difference between the maximum value and the minimum value of the variant pattern.
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4. A method for measuring at least one of forces in a peripheral direction and a radial direction of a running tire mounted onto a rim acted upon a around contact face, in which when a point on an outer peripheral face of the rim is Q and an intersect between a straight line passing through the point Q under no action of external force and extending in the radial direction and an inner peripheral face of a tread portion of the tire is P, said forces are determined from a variant pattern that a relative displacement of the point P to the point Q in the peripheral direction or the radial direction is changed in accordance with a rotating position of the point Q when the point P passes through the ground contact portion of the tire,
wherein a magnetic field formed by a magnet arranged on one of the point P and the point Q is continuously measured by a magnetic sensor arranged on the other of the point P and the point Q, and the variant pattern of the relative displacement between the point P and the point Q is determined by reverse calculation from a variant pattern of a magnetic flux density changed in accordance with the relative displacement; -
wherein the measurement of the magnetic flux density is carried out in parallel with respect to a pair of magnets arranged near to each other so that changes of widthwise components of magnetic flux densities formed along the peripheral direction of the tire form a reversal relation under no action of external force to the tire, and when an average value of maximum values in a reversal pattern reversed from a variant pattern of the magnetic flux density of the tire widthwise component measured on one of the magnets and in a variant pattern of the magnetic flux density of the tire widthwise component measured on the other magnet is an average maximum value and an average value of minimum values in these patterns is an average minimum value, the force acting in the peripheral direction of the tire is determined from an average between the average maximum value and the average minimum value, and the force acting in the radial direction of the tire is determined from a difference between the average maximum value and the average minimum value.
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7. An apparatus for measuring forces acted upon a tire, the apparatus comprising:
- a magnet arranged on an inner peripheral face of a tread portion; and
a magnetic sensor attached directly or indirectly through a fitting jig to an outer peripheral face of a rim, wherein the magnet is arranged so that a magnetic force line distribution of a magnetic field forms a plane symmetry with respect to a meridional plane of the tire including a point P or a point Q under no action of external force to the tire, the magnet having magnetic poles of the same polarity at both ends in a longitudinal direction. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
- a magnet arranged on an inner peripheral face of a tread portion; and
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8. An apparatus for measuring forces acted upon a tire, the apparatus comprising:
- a magnet arranged on an inner peripheral face of a tread portion; and
a magnetic sensor attached directly or indirectly through a fitting jig to an outer peripheral face of a rim, wherein a pair of magnets are arranged near to each other so that changes of widthwise components of magnetic flux densities formed along a peripheral direction of the tire form a reversal relation under no action of external force to the tire.
- a magnet arranged on an inner peripheral face of a tread portion; and
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17. An apparatus for measuring forces acted upon a tire, the apparatus comprising:
- a magnet arranged on an inner peripheral face of a tread portion; and
a magnetic sensor attached directly or indirectly through a fitting jig to an outer peripheral face of a rim, wherein the magnet is arranged so that a magnetic force line distribution of a magnetic field forms a plane symmetry with respect to a meridional plane of the tire including a point P or a point Q under no external force to the tire, the magnet having magnetic poles of the same polarity at both ends in a longitudinal direction. - View Dependent Claims (19, 20)
- a magnet arranged on an inner peripheral face of a tread portion; and
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18. An apparatus for measuring forces acted upon a tire, the apparatus comprising:
- a magnet attached directly or indirectly through a fitting jig to an outer peripheral face of a rim; and
a magnetic sensor arranged on an inner peripheral face of a tread portion, wherein a pair of magnets are arranged near to each other so that changes of widthwise components of magnetic flux densities formed along a peripheral direction of the tire form a reversal relation under no action of external force to the tire.
- a magnet attached directly or indirectly through a fitting jig to an outer peripheral face of a rim; and
Specification