Method and an engagement sensor device for engagement measurement for a machine tool

• US 7,891,104 B2
• Filed: 09/26/2008
• Issued: 02/22/2011
• Est. Priority Date: 10/19/2007
• Status: Expired due to Fees

• Current Assignee: Alfing Kessler Sondermaschinen GmbH (Alfing Sondermaschinen-Beteiligungsverwaltungsgesellschaft mbH)
• Original Assignee: Alfing Kessler Sondermaschinen GmbH (Alfing Sondermaschinen-Beteiligungsverwaltungsgesellschaft mbH)
• Inventors: Muellner, Ralf
• Primary Examiner(s): Bennett; G. Bradley
• Assistant Examiner(s): Courson; Tania C
• Application Number:
  US12/286,052
• Publication Number:
  US 20090100695A1
• Time in Patent Office: 879 Days
• Field of Search: 334/12, 336/45, 33D/IG.1, 333/661.1
• US Class Current: 33/412
• CPC Class Codes: B23Q 17/002 for indicating or measuring the holding action of work or tool holders B23Q3/16 takes precedence
• CPC Class Codes: Y10T 408/21 with signal, indicator, illuminator or optical means

Abstract

In a method and an engagement sensor device for engagement measurement for a machine tool for processing workpieces using tools or a laser the machine tool possesses a clamping device with a clamping face for clamping an object, in particular a tool or a workpiece and the engagement sensor device is provided for the measurement or engagement of a face of clamped object at the clamping face or any gap between the face of the clamped object and the clamping face. The sensor device comprises at least one engagement sensor, arranged to the side of the clamping face, with a measurement range aligned in the direction of the gap or of the clamping face for the detection of an electrical or magnetic stimulation field, such field extending between the face of clamped object and the clamping face and being able to be influenced by any gap, the measurement range extending essentially along the clamping face in accordance with a depth direction of any gap or parallel to the clamping face.

Claims

1. An engagement sensor device for engagement measurement for a machine tool for processing workpieces using tools or a laser, in the case of which the machine tool possesses a clamping device with a clamping face for clamping an object, in particular a tool or a workpiece, and the engagement sensor device is provided for the measurement or engagement of a face of the clamped object at the clamping face or any gap between the face of the clamped object and the clamping face, comprising at least one engagement sensor, arranged to the side of the clamping face, with a measurement range aligned in the direction of the gap or of the clamping face for the detection of an electrical or magnetic stimulation field, such field extending between the face of clamped object and the clamping face and being able to be influenced by any gap, the measurement range extending essentially along the clamping face in accordance with a depth direction of any gap or parallel to the clamping face.

2. The engagement sensor device in accordance with claim 1, wherein the stimulation field extends athwart the clamping face and more particularly perpendicularly to it.

3. The engagement sensor device in accordance with claim 1, wherein the at least one engagement sensor is a contact-free capacitive or inductive distance sensor.

4. The engagement sensor device in accordance with claim 1, wherein the clamping device is able to be moved and more particularly turned in relation to a machine frame of the engagement sensor device.

5. The engagement sensor device in accordance with claim 1, wherein the clamping device is movable and wherein the sensor device is arranged in a stationary manner in relation to the movable clamping device.

6. The engagement sensor device in accordance with claim 1, wherein the sensor device is disposed on a sensor holder movable in a manner independent from the clamping device.

7. The engagement sensor device in accordance with claim 1, designed for producing an engagement signal on the basis of engagement measurement of the engagement of the clamped object face on the clamping face and on the basis of a reference distance measurement of a reference distance between the sensor device and an outline, extending adjacent to the clamping face, of the clamped object.

8. The engagement sensor device in accordance with claim 7, wherein the at least one engagement sensor possesses a measurement range able to be switched over between an engagement setting for the engagement measurement and a reference setting for reference distance measurement.

9. The engagement sensor device in accordance with claim 7, comprising a reference sensor for reference distance measurement.

10. The engagement sensor device in accordance with claim 7, wherein the movable sensor holder is provided for resetting the at least one engagement sensor between a reference measurement position for reference distance measurement and an engagement measurement position for reference distance measurement and an engagement measurement position for engagement measurement.

11. The engagement sensor device in accordance with claim 1, wherein the sensor device comprises an evaluating means for deriving a dependent engagement signal produced by the at least one engagement sensor.

12. The engagement sensor device in accordance with claim 11, wherein the evaluating means is adapted for detection of a movement and more particularly a rotation, of the clamping device.

13. The engagement sensor device in accordance with claim 11, wherein the evaluating means is designed for detecting engagement of the face of the clamped object on the clamping face at least two measurement positions.

14. The engagement sensor device in accordance with claim 1, comprising a stimulation field generator for producing the stimulation field, such generator being disposed in the clamped object and/or the clamping device and/or the sensor device.

15. The engagement sensor device in accordance with claim 14, wherein the stimulation field generator constitutes a component of the at least one engagement sensor.

16. The engagement sensor device in accordance with claim 15, comprising several engagement sensors arranged along a common outline defined by the clamped object and the clamping device.

17. A machine tool comprising an engagement sensor device in accordance with claim 1.

18. The machine tool in accordance with claim 17, wherein the clamping device comprises a spindle.

19. The machine tool in accordance with claim 18, wherein the clamping face is provided on a terminal side of a rotor of the spindle and wherein the measurement range of the at least one engagement sensor extends athwart the axis of rotation of the spindle and more especially radially thereto.

20. The machine tool in accordance with claim 18, wherein the sensor device is disposed on a spindle holder holding the spindle and more particularly rotatably supporting the spindle rotor.

21. A method for engagement measurement in a machine tool for processing workpieces by means of tools or a laser, in the case of which the following steps are performed:

clamping a object to be clamped, more particularly a tool or a workpiece, on a clamping face of a clamping device,

measurement of engagement of a face of the clamped object on the clamping face or of any gap between the face of the clamped object and the clamping face using a sensor device,

comprising

detection of an electrical and/or magnetic stimulation field extending between the face of the clamped object and the clamping face using at least one engagement sensor placed laterally of the clamping face with a measurement range aligned in the direction of the gap or of the clamping face, the measurement range extending essentially along the clamped object in accordance with a depth direction of any gap or parallel to the clamping face.

22. The method in accordance with claim 21 comprising moving the sensor device and/or clamping device during detection of the stimulation field.