Balancing machine for vehicle wheels with analog to digital conversion and adjustable sampling frequency

• US 7,775,108 B2
• Filed: 09/04/2007
• Issued: 08/17/2010
• Est. Priority Date: 09/05/2006
• Status: Active Grant

• Current Assignee: Sicam S.r.l. (Robert Bosch GmbH)
• Original Assignee: Sicam S.r.l. (Robert Bosch GmbH)
• Inventors: Montanari, Marco
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): Shah; Samir M
• Application Number:
  US11/896,517
• Publication Number:
  US 20080053223A1
• Time in Patent Office: 1,078 Days
• Field of Search: 734/57, 734/62, 734/73, 734/60, 301/5.21
• US Class Current: 73/460
• CPC Class Codes: G01M 1/02 Details of balancing machines or devices
• CPC Class Codes: G01M 1/225 for vehicle wheels in situ G01M1/28

Abstract

The upgraded balancing machine for vehicle wheels comprise a supporting frame for gripping and rotation means for gripping and rotating a wheel to be balanced around a rotation axis, a first sensor for detecting the unbalance of the wheel with respect to the rotation axis suitable for generating a first analog signal, a second sensor for detecting at least one portion of the profile of the wheel suitable for generating a second analog signal, at least one analog to digital converter associated with at least one of the first and the second detection sensors and suitable for converting at least one of the first and the second analog signals into a corresponding digital signal, a processing and control unit associated with the conversion device and suitable for processing the digital signal, and an adjustment unit for adjusting the sampling frequency of at least one of the first and the second analog signals associated with the conversion device. The adjustment unit responds to a first signal generated by a shaft encoder, and responds to a programmable timer, so that the frequency of the sampling operation can be altered.

Claims

1. A balancing machine for vehicle wheels comprising:

a supporting frame for gripping and rotation means for gripping and rotating a wheel to be balanced around a rotation axis, the wheel including a profile,

first detection means for detecting an unbalance of said wheel with respect to said rotation axis and generating a first analog signal,

second detection means for detecting at least one portion of the profile of said wheel and generating a second analog signal,

at least one conversion device connected to at least one of said first and said second detection means for converting at least one of said first and said second analog signal into a corresponding digital signal,

a processing and control unit associated with said at least one conversion device and suitable for processing said digital signal, and

adjustment means for adjusting a sampling frequency of at least one of said first and said second analog signals,

said adjustment means comprising at least one determination device for determining said sampling frequency starting with a frequency generated by a programmable timer,

said determination device synchronizes said sampling frequency with respect to a frequency of at least one reference signal, and

a shaft encoder generates said reference signal for the determination device during the rotation of said wheel and at just one angular position of said wheel with respect to said rotation axis.

2. The machine according to claim 1, wherein said determination device adjusts said sampling frequency with respect to a speed of change of at least one of said first and said second analog signals.

3. The machine according to claim 1, wherein said determination device is associated with said processing and control unit.

4. The machine according to claim 1, wherein said first detection means is an optical sensor.

5. The machine according to claim 1, wherein said first detection means is an encoder.

6. The machine according to claim 1, wherein said reference signal is an electrical signal pulse.

7. The machine according to claim 1, wherein said first detection means comprises at least one force transducer operatively associated with said gripping and rotation means.

8. The machine according to claim 1, wherein said second detection means comprises at least one first detection sensor for scanning a portion of a tread profile of said wheel.

9. The machine according to claim 8, wherein said second detection means comprise guiding means permitting movement of said first sensor in a direction substantially parallel to said rotation axis.

10. The machine according to claim 9, wherein said guiding means comprise at least two supporting bars for said first sensor, associated with said frame and arranged parallel to said rotation axis.

11. The machine according to claim 1, wherein

said adjustment means comprise at least one determination device for determining said sampling frequency starting with a frequency generated by a programmable timer, the determination device being suitable for the synchronization of said sampling frequency with respect to a frequency of at least one reference signal;

said second detection means comprise at least one sensor for scanning at least a portion of a tread profile of said wheel, and guiding means for allowing movement of said sensor in a direction substantially parallel to said rotation axis; and

first generation means for providing a reference signal during the movement of said sensor along said guiding means and at predefined axial positions of said sensor.

12. The machine according to claim 1, wherein said second detection means is an encoder.

13. The machine according to claim 1, wherein said second detection means further includes a second detection sensor for detecting a portion of a side surface of said wheel.

14. The machine according to claim 1, wherein said second detection means comprise at least one first detection sensor for detecting at least a portion of a tread profile of said wheel and at least a second detection sensor for detecting a portion of the side surface of said wheel, at least one of said first sensor and said second sensor being an optical sensor.

15. The machine according to claim 1, wherein said second detection means comprise at least one first detection sensor for detecting at least a portion of a tread profile of said wheel and at least a second detection sensor for detecting a portion of the side surface of said wheel, at least one of said first sensor and said second sensors being a distance sensor.

16. The machine according to claim 1, wherein said second detection means comprise at least one first detection sensor for detecting at least a portion of a tread profile of said wheel and at least a second detection sensor for detecting a portion of the side surface of said wheel, at least one of said first sensor and said second sensor being a laser sensor.

17. The machine according to claim 1, wherein said processing and control unit is a microprocessor unit.