Method for operating a vacuum generator and a vacuum generator for carrying out said method

Patent metadata

Field	Value
Publication number	US-9707686-B2
Application number	US-201314378500-A
Country	US
Kind code	B2
Filing date	Feb 11, 2013
Priority date	Feb 13, 2012
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

The present invention is directed toward a method for operating a manipulator system having a vacuum manipulator device for manipulating a workpiece and a vacuum generator for generating a vacuum. The vacuum generator has a suction connection for suctioning in order to provide a vacuum supply for the vacuum manipulator device. Further, a diagnosis cycle is executed, including the steps of: provision of a vacuum for the vacuum manipulator device, and suctioning without a workpiece; and measurement of the equilibrium pressure obtained at the suction connection with a suction pressure sensor.

First claim

The invention claimed is:

1. A method for operating a manipulator system including: a vacuum manipulator device for manipulating a workpiece, and a vacuum generator for generating a vacuum, wherein the vacuum generator has a suction connection for suctioning in order to provide a vacuum supply for the vacuum manipulator device, wherein diagnosis cycles are executed during operation of the manipulator system, said diagnosis cycle comprising the steps of:
providing a vacuum for the vacuum manipulator device, and suctioning without a workpiece over the course of a predefined diagnosis time period for a diagnosis cycle;
measuring equilibrium pressure obtained at the suction connection with a suction pressure sensor;
monitoring variations to the equilibrium pressure determined in different diagnosis cycles;
wherein a first pressure decrease time period is measured in a work cycle via a timing device, over the course of which pressure at the suction connection decreases from ambient pressure to a control threshold value; and/or a second pressure decrease time period is measured with the timing device, over the course of which pressure at the suction connection decreases from the control threshold value to a holding value; and
wherein the pressure at the suction connection during the work cycle, after picking up the workpiece ( 16 ), increases to a blow-off pressure lying above ambient pressure, wherein the blow-off pressure is determined in relation to the equilibrium pressure.

2. The method as set forth in claim 1 , wherein a signal representing the equilibrium pressure is issued via a communications interface.

3. The method as set forth in claim 1 , further including execution of a characterization cycle including the steps of:
connecting the suction connection on the vacuum generator to a calibration suction hole on the vacuum generator;
providing a vacuum at the suction connection and suctioning through the calibration suction hole;
measuring a calibration pressure obtained at the suction connection.

4. The method as set forth in claim 1 , wherein the vacuum supply is deactivated after pressure measured at the suction connection reaches, or has fallen below, a holding value, and after deactivation, a pressure change rate and/or elapsed time for the pressure prevailing at the suction connection are determined.

5. The method as set forth in claim 1 , wherein the equilibrium pressure (pG) is compared with a predefined control threshold value laying between ambient pressure and a holding value, wherein a warning signal is issued if the equilibrium pressure lies beneath the control threshold value.

6. A vacuum generator for executing the method as set forth in claim 1 , said vacuum generator including a suction connection for suctioning, a suction pressure sensor for measuring pressure at the suction connection, and a communications interface for transmitting measurement values from the suction pressure sensor, wherein the equilibrium pressure is measured, obtained during suctioning without a workpiece over the course of a predefined diagnosis time period.

7. The vacuum generator as set forth in claim 6 , further including a controllable calibration valve, whereby the suction connection can be connected selectively to at least one operation output for a vacuum manipulator device, or to a calibration suction hole on the vacuum generator.

Assignees

• Schmalz J Gmbh

Inventors

• Dunkmann Walter
• Holecek Thomas

Classifications

• B25J15/0616

  with vacuum · CPC title

• B25J19/06

  Safety devices · CPC title

• F04F5/52 Primary

  of evacuating pumps · CPC title

• B25J19/02 Primary

  Sensing devices · CPC title

• F04F5/20

  for evacuating · CPC title