METHOD OF AND APPARATUS FOR DETERMINING GEOMETRICAL DIMENSIONS OF A VEHICLE WHEEL

• US 20080297777A1
• Filed: 05/23/2008
• Published: 12/04/2008
• Est. Priority Date: 05/23/2007
• Status: Active Grant

• Current Assignee: Snap-On Equipment S.r.l. (Snap-On Incorporated)
• Original Assignee: Snap-On Equipment S.r.l. (Snap-On Incorporated)
• Inventors: Sotgiu, Paolo
• Granted Patent: US 7,768,632 B2
• Time in Patent Office: Days
• US Class Current: 356/139.09
• CPC Class Codes: B60C 25/0527 Adapting to different wheel diameters, i.e. distance between support and tool
• CPC Class Codes: B60C 25/0554 optical, e.g. cameras
• CPC Class Codes: B60C 25/138 with rotary motion of tool or tyre support
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence
• CPC Class Codes: G01B 11/2513 with several lines being projected in more than one direction, e.g. grids, patterns
• CPC Class Codes: G01M 17/013 Wheels
• CPC Class Codes: G05B 2219/37048 Split beam, stripe projection on object, lines detected with cameras

Abstract

A method and an apparatus of determining geometrical dimensions of a motor vehicle wheel (rim/tyre assembly) 1 by contact-less sensing, wherein the wheel is fixed on wheel receiving means 2 of a tyre changer, that at least one light beam 21 is emitted on to the wheel or at least a part of the wheel, wherein the light beam reflected at the impingement area is detected, and wherein the directions of the emitted and reflected light beams are evaluated for determining the shape and/or position of the respective impingement area on the wheel.

Claims

1. A method of determining geometrical dimensions of a motor vehicle wheel (rim/tyre assembly) by contact-less sensing, characterised in that the wheel is fixed on wheel receiving means of a tyre changer, that at least one light beam is emitted on to the wheel or at least a part of the wheel, wherein the light beam reflected at the impingement area is detected, and that the directions of the emitted and reflected light beams are evaluated for determining the shape and/or position of the respective impingement area on the wheel.

2. A method according to claim 1, characterised in that the emitted light beam is a planar light beam reflected on the wheel surface in a stripe-shaped impinging area.

4. A method according to one of the claims 1 to 3, characterised in that at least one light beam is directed on to the wheel or to the rim which rotated about a stationary axis.

5. A method according to one of the claims 1 to 4, characterised in that at least one light beam is emitted on to wheel or on to the rim from one or more given positions.

6. A method according to one of the claims 1 to 5, characterised in that at least one annular surface around the wheel axis is sensed on the wheel or on the rim with the at least one light beam.

7. A method according to one of the claims 1 to 6, characterised in that at least one of the two rim beads is sensed with the light beam.

8. A method according to one of the claims 1 to 7, characterised in that the outer peripheral surface of the wheel or of the rim is sensed with the light beam.

9. A method according to one of the claims 1 to 8, characterised in that the spacings of the respective wheel parts or rim parts which are sensed by the light beam relative to a stationary reference are ascertained.

10. A method according to one of the claims 1 to 9, characterised in that the operation of determining the spacing is effected in accordance with a triangulation method.

11. A method according to one of the claims 1 to 10, characterised in that respective emitted and reflected light beams associated to the at least plurality of impingement points of the impingement area are detected and the positions of the respective impingement points are determined.

12. A method of fitting or removing a motor vehicle tyre in which, using a method according to one of claims 1 to 10, the rim contour along which at least one fitting or removal tool is guided during the fitting or removal operation is contact-lessly sensed and the movement of the fitting or removal tool is guided in dependence on the sensed contour without contact with the rim surface.

13. A method according to claim 12, characterised in that the movement of the at least one fitting or removal tool is controlled in dependence on the sensed position of at least one of the two rim beads and in dependence on the stored or sensed contour of the rim bed.

14. A method according to claim 12 or 13, characterised in that the movement on the at least one fitting or removal tool is controlled in dependence on the detected position of the outer peripheral edge of at least one of the two rim beads (12).

15. A method according to one of the claims 1 to 14, characterized in that the emitted light beam is a single linear beam which is moved, especially swivelled in a planar plane.

37. Use of a method according to one of the claims 1 to 14 or of an apparatus according to one of the claims 16 to 36 for determining at least one of the parameters:

tyre runout, tread wear of the tyre, tyre conicity, tyre defects on the tread and/or on the side walls, rim defects on the outside and/or on the inside of the rim and bead seat geometry on the rim.

3. A method of determining geometrical dimensions of a rim of a motor vehicle wheel by contact-less sensing, characterised in that at least one light beam is emitted on to the rim or at least a part of the rim, wherein the light beam reflected at a planar impingement area on the rim surface is detected, and that the directions of the emitted and reflected light beams are evaluated for determining the shape and/or position of the respective stripe-shaped impingement area on the rim.

16. Apparatus for determining the geometrical dimensions of a motor vehicle wheel comprising a sensing device (6, 7, 8) for sensing the wheel surface or a part of the wheel surface and a computer-aided evaluation arrangement (18) for evaluation of the electrical sensing signals supplied by the sensing device (6, 7, 8) characterised in that the sensing device (6, 7, 8) has at least one light source (15) which emits a light beam from at least one given position in at least one given direction on to the wheel surface or a part of the wheel surface and a detector (16) which detects the direction of the light beam reflected by the wheel surface, and that the evaluation arrangement (18) is suitable for determining the position of the location sensed by the light beam on the wheel surface, from the directions of the emitted light beam and the reflected light beam.

17. Apparatus according to claim 16, characterised in that two sensing devices (6, 7) having the light sources (15) and the detectors (16) are provided for sensing the two rim beads (12).

18. Apparatus according to claim 16 or claim 17, characterised in that at least one light source (15) and an associated detector (16) are provided as the sensing device (8) for sensing the outside surface of the rim or of the wheel.

19. Apparatus according to one of the claims 16 to 18, characterised in that the emitted light beam is a planar light beam or a light beam emitted in a planar plane.

20. Apparatus according to one of claims 16 to 19, characterised in that the light source (15) and the detector (16) are pivotable synchronously about a common axis (17) and an electrical signal proportional to the respective pivot angle is fed to the evaluation arrangement (18) for emit a single light beam in a planar plane.

21. Apparatus according to one of the claims 16 to 18, characterised in that the at least one light source (15) and the detector (16) are positioned stationary, wherein the emitted light beam is a planar or sheet-shaped light beam.

22. Apparatus according to one of claim 16 to 21, characterised in that the evaluation arrangement (18) is suitable for determining the positions of the respective locations which are sensed on the wheel surface or on the rim surface from the directions of the light beam emitted by the light source (15) and the light beam reflected at the wheel surface or the rim surface by means of triangulation.

23. Apparatus according to one of claims 16 to 22, characterised in that the wheel or the rim (3) is mounted on a wheel receiving device (2) rotatably about the wheel axis (11).

24. Apparatus according to one of claims 16 to 23, characterised in that a rotary angle sensor (13) detects the respective rotary angle position of the wheel or the rim (3) and supplies a corresponding electrical signal to the evaluation arrangement (18).

26. Apparatus according to claim 25, characterised in that the sensing device (6, 7, 8) is an optical sensing device according to one of claims 16 to 22.

27. Apparatus according to one of claims 23 to 26, characterised in that the sensing device (6, 7, 8) is arranged in front of the at least one fitting or removal tool (5) in the direction of rotation of the wheel receiving device (2).

28. Apparatus according to one of the claims 23 to 27, characterized in that the sensing direction of the sensing devices (6, 7) is approximately parallel to the rotation axis (11) of the wheel or the rim.

29. Apparatus according to one of claims 16 to 28, characterised in that the spatial positions of the respectively sensed points on the wheel or the rim is determined with respect to the machine frame of the apparatus and in particular with respect to the respective fitting or removal tool (5).

30. Apparatus according to one of claims 24 to 29, characterised in that the respective spatial position of the rim beads (12) and in particular the outer peripheral edges of the rim beads (12) is determined.

31. Apparatus according to one of claims 24 to 30, characterised in that the evaluation arrangement (18) is suitable for determining the spatial position of the rim bed (14) which is between the rim beads (12).

32. Apparatus according to one of claims 24 to 31, characterised in that for different wheel types, contours of the rim beads (14) are stored in a store (19) of the control device (9) or in a store connected to the control device (9).

33. Apparatus according to one of claims 24 to 32, characterised in that the contours of the rim beads (14) are additionally stored in the store (19).

34. Apparatus according to one of the claims 16 to 33, characterised in that for different wheel types features of the wheels are stored in a store of the control device.

35. Apparatus according to one of the claims 16 to 34, characterised in that the light source (15) is a laser.

36. Apparatus according to one of the claims 16 to 35, characterised in that the detector (16) comprises a complementary metal oxide semiconductor (CMOS) device or a charge coupled device (CCD).

25. Apparatus for fitting or removing a motor vehicle tyre (4) comprising a rotatably supported wheel receiving device (2) to which the wheel or the rim (3) is to be fixed, at least one fitting or removal tool (5), a rotary drive device (10) for the wheel receiving device and a sensing device (6, 7, 8) for sensing the radially outer rim contour (12, 14) along which the at least one fitting or removal tool is to be guided during the fitting or removal operation, characterised in that the sensing device (6, 7, 8) is a sensing device which contract-lessly senses the rim contour and the sensing signals of which are converted into electrical sensing signals, and that a control device (9) is connected to an evaluation arrangement (18) for evaluating the sensing signals, which control device controls the at least one fitting or removal tool (5) in the fitting or removal operation in dependence on the sensing signals without contact with the rim surface.