Method of and device for optical scanning of vehicle wheel

TECHNICAL FIELD

The invention relates to a method for optically scanning a vehicle wheel according to the preamble of claim 1 and an apparatus for its implementation in accordance with the preamble of claim 10.

BACKGROUND

In the method and apparatus according to WO 98/10261, the light beam emitted from the light source designed as a laser beam source is directed into an area near the inner side mounted on the rim of the counterweight. The beam reflected from the scanned area is taken to change the position sensitive receiver and a method of triangulation, the position of the scanned area and a counterweight mounted on the rim to control. The light source and responsive to a change in position of the receiving device placed on a common support, which can be rotated manually so that the emitted light beam can be directed to the desired area on which a counterweight mounted on the rim.

Furthermore, the known device comprises a stepping motor, whereby after measurement of the balanced wheel unbalance can be rotated light source so that the light beam emitted by it is directed at the balancing location on the wheel rim to be balanced, for example, via securing counterweights.

Furthermore, from WO 96/07880 discloses a method and apparatus for balancing vehicle wheels in which a scanning device is determined contour, in particular an inner contour of the wheel rim and from this circuit in combination with the measured values ​​of the imbalance measuring device determines the optimal position and size balances.

Disclosure of invention

Object of the invention is to provide a method and apparatus of the above type, enabling a simple way to register the comprehensive characteristics of the circuit, in particular an edge rounding, and the like of the vehicle wheel rim.

In accordance with the invention in a method of the above type, this object is achieved by the characterizing features of claim 1 and a device of the above type by the characterizing features of claim 10 of the claims.

To this end, the beam emitted, in particular, a light source formed as a laser, and sensitive to a change in position of a receiving device which receives the beam reflected from the portion wheel scanned emitted beam synchronously rotate about a common axis for successive incremental measurement intervals by substantially perpendicular to the measurement plane formed by the surface of the vehicle wheel rim. When successive incremental measurements measured the distance from the corresponding scanned one after the other parts of the wheel to the starting point, as measured in a fixed position on the balancer on which measurements are made imbalance. Preferably, the distance to the reference point measured in the direction of the emitted light beam and the reflected light beam using a one-dimensional active triangulation method. It follows inevitably determine the position of the scanned area of ​​each wheel relative to a fixed reference point on the machine. Of the plurality of interconnected scanned and measured wheel portions can very accurately determine the contour, in particular an inner contour of the vehicle wheels. The scanning movement is performed stepper motor which rotates synchronously light source and responsive to a change in position of a receiving device about a common pivot axis. For this light source, and responsive to a change in the position receiver can be mounted on a common rack, rotatable about an axis of rotation. With the encoder, which can be incorporated in a stepper motor or mounted separately determined rotational angle position of the light source and sensitive to changes in the position of the receiving device and transmitted to the data processing device together with the measuring signals responsive to changes in the position of the receiving device. The pivot axis, around which rotate the light source and responsive to a change in position of the receiving device, has a predetermined position opposite to the reference point, which may be provided fixed on the balancer.

Measuring plane, wherein the moving light source and sensitive to changes in position and a receiving device respectively emitted and reflected light beams, preferably extends parallel to the wheel axis. At the wheel of the horizontal axis of the measuring plane may extend below the wheel axle. However, the measurement plane wheels may also extend obliquely to a horizontal line, in particular radially with respect to the measuring roller and thus the wheel axis.

Furthermore, the light beam can scan the disc portion located radially vehicle wheels. Preferably, you can scan and detect the angular position of the base points of the spokes or webs extending radially from the middle of the drive wheels. These measured values ​​can then be used for placing counterweights back spokes, as shown in US 5,591,909.

Rotation angle to the general movement of rotation of the light source and responsive to changes in the position of the receiving device about the common axis of rotation is preferably measured in such a way that, starting approximately from the center of the wheel through the radially extending portion of drive wheel, the inner surface of the rim and the bead, the scanning light beam and the received receiver component of the reflected beam can be rotated. In addition, when the rotating wheel by the invention can determine the lateral displacement in the axial direction of the wheel portions, a scanned light beam.

After measuring imbalance light beam can be directed at the portion on the wheel balancer, which should make balancing imbalance, as is known from WO 98/10261.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in the following description of embodiments with reference to the drawing figures, in which:

1 shows a top view of an embodiment of an optical scanning device for scanning the balanced vehicle;

2 is shown in Figure 1 shows a scanning device mounted on the lower side of the balancer dynamometer a bottom;

3 shows a front view in the axial direction of the measuring roller, shown in Figures 1 and 2 an exemplary embodiment;

4 shows the individual elements of the scanning device in perspective.

Of Figures device for optical scanning of the balanced vehicle wheel 1 with a radial part 23 and the rim of the wheel disc 22 comprises a light source 6 and is sensitive to changes in the position receiving device 7, which are mounted on a common stand 18. The overall strut 18 may have a crank shape, at both ends of a light source 6, and sensitive to changes in position of the receiving device. Rack 18 and fixed thereon a light source 6 and the sensitivity to changes in position of the receiving device 7 are rotatably mounted about a pivot axis 4.

In known manner, the balanced vehicle wheel 1 is fixed on the measuring roll 2 the balancing machine having a load cell 16, shown in Figures 2 and 3. Mounting the balanced vehicle wheel 1 is carried out in the middle so that the wheel axle 3 and the measuring roller shaft 11 are coaxial, when the vehicle wheel is fixed for measuring the unbalance measuring roll 2.

The dynamometer 16 can be formed in known manner, for example as shown in WO 00/14503 (DE 19,844,975 A1). The dynamometer has support plates 12-15, which are pivotally connected to each other and arranged in a substantially vertical direction. Due to such a structure of the measuring system of virtual plots measuring roller bearing 2 on the frame 17 of the balancing machine. With transmitters which are not detailed in the figures depicted are measured centrifugal force corresponding to unbalance wheel and processed in known manner for balancing the electronic data processing device 8.

In order to optimize the balancing apparatus using images can determine the contour of the rim inner side 22 facing the axis 3 of the wheel and the radial portion 23 of the disc wheel. On the radial wheel disc portion 23 can determine the position drives and radial spokes, in particular the angular positions of the points on the base portion of the wheel axis.

For this purpose the measurement plane, as shown in Figure 1, a light source 6, a light beam scanned by the corresponding points on the wheel of a vehicle, in particular on its inner side. The reflected beam from the scan area is taken to change the position sensitive receiver 7. It may be for this optical receiver 24, focusing the reflected beam on the sensor 25 CCD (charge coupled device). This CCD sensor can handle independently several local maximum illumination. The direction of the reflected beam depends on the distance of the scanned area of ​​the light source 6. Therefore, according to the distance the reflected beam is directed to an optical receiver 24 on a certain area CCD sensor 25, which then sends a signal responsive to the position and, respectively, depending on the position in an electronic data processing device 8.

When processing data on the contour of the wheel via the rotary drive 5, which has the general rack 18 and the stepping motor 10, and also not shown in more detail the intermediate gear is made necessary pivotal movement of the light source 6 and the receiver 7. By means of the stepper motor 10 Front 18 rotated by a small angle to the plane of the measurement value. Thus scanned successive points or portions of the vehicle and the corresponding distance from the light source 6 are determined using measurement signals transmitted by the sensor CCD 25.

Since the pivot axis 4 around which rotate the light source 6 and sensor CCD 25 mounted on the frame 17 of the machine still receive current position determination portion scanned in each case on the wheel of the vehicle relative to the dynamometer 16, in particular the sensors of the dynamometer. Therefore, the measurement data obtained can be processed with the measurement data of the dynamometer 16 which is determined by measuring the imbalance at the wheel of the vehicle to the optical balancing, as shown in DE 4122844 A1.

The corresponding values ​​of the angular positions of the light source 6 and is sensitive to changes in the position of the receiver 7 and CCD sensor 25 are processed in the encoder 9 which is integrated into the stepper motor 10 or can be installed separately. The corresponding rotation angle signals are supplied from the encoder 9 to the electronic data processing device 8.

How, in particular, can be seen from Figure 3, the plane of the measurement, which are installed and turn the light source 6 and the sensitivity to changes in position of the receiving device 7 is below 16 dynamometer balancer. For this rack 18, designed as a bell crank, pivotally mounted about an axis of rotation 4 with overcoming the preload plate 20 to the rack 19 (Figure 4). Plate 19 is secured through a curved strut mounting plate 21 to the frame 17 of the balancing machine, for example via a threaded connection (3 and 4). For a compact placement of the stepper motor 10 can be installed in the support plates 12-15 dynamometer 16.

Figure 3 shows the placement of the stepper motor 10 through the support plates.

Springs 20, supported at its folds 26, 27 on the support plate 19 and the rack 18, the light source 6 and sensitive to changes in position of the receiver unit 7 are subjected to pre-tension in the rest position. In this rest position the light source 6 and coming out of it a beam of light is directed to the central portion of the wheel 1 of the vehicle in the vicinity of the axis 3 of the wheel. Therefore, when scanning the inner surface of the vehicle wheel scanning beam emitted by light source 6 is turned inside stepper motor drive, that is near the wheel axis 3, to the outside, i.e. towards the periphery of the wheel, against the force of pretensioning spring 20.

With the shown device can also determine the lateral deviation in the axial direction of scan wheel, in particular located on the radius of the scanned portions of the wheel.

List of products

1 a vehicle wheel

2 measuring roller

3 wheel axle

4 axis of rotation

5 rotary drive

6 light source

Receiver 7

8, the electronic data processing device

9 Resolver Sensor

10 stepper motor

11, the axis of the measuring roller

12 base plate

13 base plate

14 support plate

15 support plate

16 Dynamometer

17 frame

18 swiveling

19 plate rack

20 spring

21 mounting plate

22 rim

23 item radial wheel disc

24 of the optical receiver

25 CCD sensor

26 bending spring

27 bending spring