Apparatus and method for measuring uniformity and/or dynamic balance of tire

• US 6,658,936 B2
• Filed: 03/06/2002
• Issued: 12/09/2003
• Est. Priority Date: 03/08/2001
• Status: Active Grant

• Current Assignee: Kokusai Keisokuki Kabushiki Kaisha
• Original Assignee: Kokusai Keisokuki Kabushiki Kaisha
• Inventors: Matsumoto, Sigeru
• Primary Examiner(s): MOLLER, RICHARD ALAN
• Application Number:
  US10/091,701
• Publication Number:
  US 20020124650A1
• Time in Patent Office: 643 Days
• Field of Search: 734/60, 734/62
• US Class Current: 73/460
• CPC Class Codes: G01M 1/045 the body being a vehicle wheel
• CPC Class Codes: G01M 1/225 for vehicle wheels in situ G01M1/28
• CPC Class Codes: G01M 17/021 Tyre supporting devices, e.g. chucks for balancing G01M1/04
• CPC Class Codes: G01M 17/022 the tyre co-operating with rotatable rolls

Abstract

There is provided an apparatus for measuring uniformity and dynamic balance of a tire, comprising:

a spindle rotatably supported in a rigidly-supported spindle housing, said tire being fixedly mounted on said spindle, said spindle being rotated when measurement is performed; and

at least one piezoelectric force sensor mounted on a surface of said spindle housing, said at least one piezoelectric force sensor detecting a force generated by rotation of the tire as said spindle is rotated.

Claims

1. An apparatus for measuring uniformity and dynamic balance of a tire, comprising:

a spindle rotatably supported in a rigidly-supported spindle housing, said tire being fixedly mounted on said spindle, said spindle being rotated when measurement is performed; and

at least one piezoelectric force sensor mounted on a surface of said spindle housing, said at least one piezoelectric force sensor detecting a force generated by rotation of the tire as said spindle is rotated.

2. The apparatus according to claim 1, wherein said piezoelectric force sensor includes a triaxial piezoelectric force sensor.

3. The apparatus according to claim 2, wherein the tire is rotated by a rotary drum of said apparatus during the uniformity measurement.

4. The apparatus according to claim 2, wherein said tire and spindle are rotatably driven by said rotary drum to a first rotational speed during the dynamic balance measurement while being pressed by said rotary drum to a first load in a predetermined direction perpendicular to the rotational axis of said spindle,

wherein the tire and said spindle are rotatably driven by said rotary drum to a second rotational speed during the uniformity measurement while being pressed by said rotary drum to a second load in the predetermined direction perpendicular to the rotational axis of said spindle,

wherein said first pressing force is smaller than said first pressing force, and

wherein said second rotational speed is within a range of 60-3300 r.p.m.

5. The apparatus according to claim 4, wherein said first pressing force is within a range of 20-100 kgf.

6. The method according to claim 5, wherein said first pressing force is within a range of 40-60 kgf.

7. The apparatus according to claim 4, wherein said second pressing force is within a range of 100-2000 kgf.

8. The record medium according to claim 4, wherein said first rotational speed is within a range of 750-1400 r.p.m.

9. An apparatus for measuring uniformity and/or dynamic balance of a tire, comprising:

a spindle which is rotatably supported in a rigidly-supported spindle housing, said tire being fixedly mounted on said spindle; and

at least one radial cylindrical bearing that rotatably supports said spindle in said spindle housing, said radial cylindrical bearing including at least a radial double-row cylindrical bearing.

10. The apparatus according to claim 9, wherein a part of a circumferential surface of said spindle on which said radial cylindrical bearing is to be attached is tapered;

wherein an inner surface of said radial cylindrical bearing is tapered such that a cone angle of said inner surface is the same as a cone angle of the tapered part of the circumferential surface of said spindle; and

said radial cylindrical bearing is attached to said spindle so that the inner surface of said radial cylindrical bearing tightly fits on said tapered part of the circumferential surface of said spindle.

11. An apparatus for measuring uniformity and/or dynamic balance of a tire, comprising:

a spindle rotatably mounted in a spindle housing via at least one bearing, the tire being fixedly mounted on said spindle,

wherein said spindle holds the tire between a lower rim attached to said spindle and an upper rim which is arranged oppositely with respect to the lower rim, said upper rim is movable upward and downward with respect to said spindle, said upper rim including a lock shaft downwardly extending from a rotation center of said upper rim, said lock shaft being capable of fitting to a fitting portion formed in said spindle.

12. The apparatus according to claim 11,

wherein said spindle is rotatably supported in said spindle housing via a plurality of bearings; and

wherein the fitting portion of said spindle is located at substantially a midpoint between two of said plurality of bearings.

13. An apparatus for measuring uniformity and/or dynamic balance of a tire, comprising:

a spindle;

a spindle housing rotatably supporting said spindle;

a lower rim attached to said spindle and an upper rim arranged oppositely to said lower rim, said upper rim being movable upward and downward, and rotatable; and

a lock member for holding said upper rim at a predetermined position,

said apparatus being configured to measure uniformity and/or dynamic balance of the tire, by rotating said spindle with holding the tire using said upper and lower rims,

wherein said upper rim includes a lock shaft downwardly extending from the rotation center of said upper rim, the lock shaft being engageable with said spindle, and

wherein said lower rim includes;

a lock shaft insertion cylinder in which said lock shaft can be inserted; and

a lock member attaching hole formed on the circumferential surface of said lock shaft insertion cylinder, one end of said lock shaft insertion cylinder being fixed to one end of said spindle, said lock member being slidable in said lock member attaching hole in the radial direction of said lower rim, said lock member meshing with locking grooves formed on said lock shaft to lock said lock shaft, and

wherein the length of said lock shaft insertion cylinder in the axial direction of said lower rim is 1-2 times as long as the length of said lock member attaching hole in the axial direction of said lower rim.

14. The apparatus according to claim 13, wherein the length of said lock shaft insertion cylinder in the axial direction of said lower rim is 1-1.5 times as long as the length of said lock member attaching hole in the axial direction of said lower rim.

15. An apparatus for measuring dynamic balance of a tire, comprising:

a rotatable spindle, the tire being fixedly mounted on said spindle, said spindle being rotatably supported in a rigidly-supported spindle housing, wherein a force generated by the rotation of the tire can be detected by a piezoelectric force sensor mounted on a surface of said spindle housing, the tire and said spindle being rotatably driven by a rotary drum which is press-contacted with the tire at a first pressing force in the predetermined direction which is perpendicular to the rotational axis of said spindle and rotating the tire.

16. The apparatus according to claim 15, wherein said first pressing force is within a range of 20-100 kgf.

17. The apparatus according to claim 16, wherein said first pressing force is within a range of 40-60 kgf.

18. The apparatus according to claim 17, wherein said piezoelectric force sensor is capable of detecting a force component in a direction perpendicular to both of said predetermined direction and the rotational axis of said spindle.

19. A method for measuring dynamic balance of a tire, comprising:

a tire mounting step for mounting the tire on a spindle of a dynamic balance measuring apparatus, the spindle being rotatably attached to a rigidly-supported spindle housing of the apparatus;

a first tire pressing step for pressing the tire in a predetermined direction perpendicular to the rotational axis of the spindle at a second pressing force with a rotary drum of the apparatus;

a rotary drum rotating step for rotatably driving the rotary drum;

a first rotary drum speed changing step for accelerating the rotation of the tire to a first rotational speed;

a second tire pressing step for changing the amount of the load for pressing the tire by the rotary drum into a first pressing force; and

a first measurement step for detecting a force generated in the tire in the first measurement step by at least one piezoelectric force sensor fittingly mounted on the spindle housing, wherein the first pressing force is 1-10 times as large as the second pressing force.

20. The method according to claim 19, wherein the first pressing force is 2-4 times as large as the second pressing force.

21. The method according to claim 19, wherein the first rotational speed is within a range of 60-3300 r.p.m.

22. The method according to claim 21, wherein the first rotational speed is within a range of 750-1400 r.p.m.

23. A method for measuring dynamic balance and uniformity of a tire, comprising:

a tire mounting step for mounting the tire on a spindle of a dynamic balance measuring apparatus, the spindle being rotatably attached to a rigidly-supported spindle housing of the apparatus;

a first tire pressing step for pressing the tire to a second pressing force by a rotary drum of the apparatus, the rotary drum being capable of pressing the tire in the predetermined direction perpendicular to the rotational axis of the spindle and rotating the tire;

a rotary drum rotating step for rotatably driving the rotary drum;

a first rotary drum speed changing step for accelerating the rotation of the tire to a first rotational speed;

a second tire pressing step for changing the amount of the load for pressing the tire by the rotary drum into a first pressing force;

a first measurement step for detecting a force generated in the tire by at least one piezoelectric force sensor mounted on the spindle housing;

a third tire pressing step for changing the amount of the load for pressing the tire by the rotary drum into a third pressing load;

a second rotary drum speed changing step for changing the rotational speed of the tire into a second rotational speed; and

a second measurement step for detecting a force generated in the tire by said piezoelectric force sensor.

24. The method according to claim 23, wherein said third pressing load is 100-2000 kgf.

25. The method according to claim 23, wherein said second rotational speed is 60 r.p.m.