Vacuum gripping device and method for operating a vacuum gripping device

Patent metadata

Field	Value
Publication number	US-10549405-B2
Application number	US-201515741442-A
Country	US
Kind code	B2
Filing date	Jul 13, 2015
Priority date	Jul 13, 2015
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

A method for operating a vacuum gripping device including a suction gripper unit, which is provided with at least one suction gripper. The suction gripper unit can be connected, via a control valve device connected to it, selectively to a vacuum source or to a positive pressure source generating an ejector pulse in the suction gripper. The ejector pulse is generated as a function of the actual pressure established in the suction gripper unit after its connection to the positive pressure source. A vacuum gripping device suitable for executing this method and including a pressure measurement device for detecting the actual pressure and an electronic control unit used for controlling the control valve device and communicating with the pressure measurement device.

First claim

The invention claimed is:

1. A method for operating a vacuum gripping device comprising a suction gripper unit, which is provided with at least one suction gripper and which can be connected, via a control valve device connected to the suction gripper unit, selectively to a vacuum source causing a negative pressure in the suction gripper or to a positive pressure source generating an ejector pulse in the suction gripper,
wherein the ejector pulse is generated as a function of the actual pressure established in the suction gripper unit after its connection to the positive pressure source, and
wherein, during the generation of the ejector pulse, an actual pressure prevailing in the suction gripper unit is measured and the positive pressure source is disconnected from the suction gripper unit by means of the control valve device when a pressure drop is detected during the measurement of the actual pressure.

2. The method according to claim 1 , wherein an actual pressure prevailing in the suction gripper unit is measured during the generation of the ejector pulse and the positive pressure source is disconnected from the suction gripper unit by means of the control valve device when the measured actual pressure has reached a preset positive pressure limit value.

3. The method according to claim 2 , wherein a pressure of 0.05 bar to 0.15 bar is chosen as a positive pressure limit value.

4. The method according to claim 1 , wherein, during the generation of the ejector pulse, an actual pressure prevailing in the suction gripper unit is measured, and this actual pressure is regulated to provide a target pressure by suitable control of the control valve device accompanied by an at least short-time overshooting of atmospheric pressure.

5. The method according to claim 4 , wherein atmospheric pressure is preset as target pressure and the pressure control is parameterised in such a way that an overshooting into a positive pressure occurs in the pressure course of the actual pressure during the control process.

6. The method according to claim 1 , wherein the pressure drop is detected by determining a negative gradient of the actual pressure course within a differentiation of the measured actual pressure course.

7. The method according to claim 1 , wherein an ejection confirmation signal is generated on the basis of the detection of the pressure drop.

8. The method according to claim 1 , wherein the suction gripper unit comprises a working line connected to the at least one suction gripper and to the control valve device, which working line is formed by a flexible hose line.

9. The method according to claim 8 , wherein the actual pressure is measured in the region of the suction gripper in the transitional region between the working line and the suction gripper.

10. The method according to claim 8 , wherein the actual pressure is measured in the region of the control valve device in the transitional region between the control valve device and the working line.

11. The method according to claim 1 , wherein a piezoelectric valve device, is used as a control valve device.

12. The method according to claim 1 , wherein a digitally switchable switching valve device, which expediently comprises individual control valves for the control of the connection to the positive pressure source and for the control of the connection to the vacuum source, is used as a control valve device.

13. A vacuum gripping device comprising a suction gripper unit, which is provided with at least one suction gripper and which can be connected, via a control valve device connected to the suction gripper unit, selectively to a vacuum source causing a negative pressure in the suction gripper or to a positive pressure source generating an ejector pulse in the suction gripper, wherein an electronic control unit is provided for controlling the control valve device, and wherein at least one pressure measurement device suitable for measuring the actual pressure prevailing in the suction gripper unit and communicating with the electronic control unit is assigned to the suction gripper unit,
wherein the electronic control unit is provided with control means, by means of which the control valve device can be controlled for generating the ejector pulse as a function of the actual pressure established in the suction gripper unit after its connection to the positive pressure source, and
wherein, during the generation of the ejector pulse, an actual pressure prevailing in the suction gripper unit is measured and the positive pressure source is disconnected from the suction gripper unit by means of the control valve device when a pressure drop is detected during the measurement of the actual pressure.

14. The vacuum gripping device according to claim 13 , wherein the device it is designed to execute the method according to claim 1 .

15. A method for operating a vacuum gripping device comprising a suction gripper unit, which is provided with at least one suction gripper and which can be connected, via a control valve device connected to the suction gripper unit, selectively to a vacuum source causing a negative pressure in the suction gripper or to a positive pressure source generating an ejector pulse in the suction gripper,
wherein the ejector pulse is generated as a function of the actual pressure established in the suction gripper unit after its connection to the positive pressure source, and
wherein, during the generation of the ejector pulse, an actual pressure prevailing in the suction gripper unit is measured, and this actual pressure is regulated to provide a target pressure by suitable control of the control valve device accompanied by an at least short-time overshooting of atmospheric pressure.

16. A vacuum gripping device comprising a suction gripper unit, which is provided with at least one suction gripper and which can be connected, via a control valve device connected to the suction gripper unit, selectively to a vacuum source causing a negative pressure in the suction gripper or to a positive pressure source generating an ejector pulse in the suction gripper, wherein an electronic control unit is provided for controlling the control valve device, and wherein at least one pressure measurement device suitable for measuring the actual pressure prevailing in the suction gripper unit and communicating with the electronic control unit is assigned to the suction gripper unit, and
wherein the electronic control unit is provided with control means, by means of which the control valve device can be controlled for generating the ejector pulse as a function of the actual pressure established in the suction gripper unit after its connection to the positive pressure source, and
wherein, during the generation of the ejector pulse, an actual pressure prevailing in the suction gripper unit is measured, and this actual pressure is regulated to provide a target pressure by suitable control of the control valve device accompanied by an at least short-time overshooting of atmospheric pressure.

Assignees

• Festo Ag & Co Kg

Inventors

• Meyer Manuel
• Anderle Jens
• Wirtl Hannes

Classifications

• H10P72/78

  using vacuum or suction, e.g. Bernoulli chucks · CPC title

• B25B11/005 Primary

  Vacuum work holders · CPC title

• B65G2249/04

  Arrangements of vacuum systems or suction cups · CPC title

• B65G47/91 Primary

  incorporating pneumatic, e.g. suction, grippers · CPC title