Device for determining a status of an ultrasonic welding process

Patent metadata

Field	Value
Publication number	US-11969817-B2
Application number	US-202117497513-A
Country	US
Kind code	B2
Filing date	Oct 8, 2021
Priority date	Apr 9, 2019
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

Abstract

A device to determine a state of an ultrasound welding process, which can be carried out using an ultrasound tool, includes a sensor element and an evaluation unit. The sensor element is configured to detect an electrical control signal from an ultrasound tool. The evaluation unit is configured to determine a signal property of the control signal and to determine the status of the ultrasound welding process based on a reference signal profile and on the determined signal property. An assembly with an ultrasound welding system and a method are also included.

First claim

What is claimed is:

1. A device to determine a state of an ultrasound welding process using an ultrasound tool, the device comprising:
a sensor device configured to detect an electric control signal of the ultrasound tool;
an evaluation unit configured to:
determine a signal property of the electric control signal; and
determine the state of the ultrasound welding process based on a reference signal profile and on the determined signal property;

a first connection configured to be connected to an output of an ultrasound generator;
a second connection configured to be connected to a signal input of the ultrasound tool;
a signal path electrically connecting the first connection and the second connection, wherein the sensor device is configured to measure the electric control signal along the signal path;
a switching element disposed in the signal path and configured to interrupt the signal path to electrically separate the first connection from the second connection; and
a signal generator configured to generate a control signal for the ultrasound tool and to control the ultrasound tool when the switching element interrupts the signal path.

2. The device according to claim 1 , wherein the switching element is configured to interrupt the signal path when the sensor device detects that the ultrasound generator is not sending any control signal to the ultrasound tool.

3. The device according to claim 1 , wherein the signal generator is further configured to generate the control signal for the ultrasound tool, wherein the control signal is generated based on an equivalent circuit.

4. The device according to claim 1 , wherein the sensor device is further configured to measure an electrical signal on the signal path, while the signal generator of the device controls the ultrasound tool via the signal path.

5. The device according to claim 4 , wherein the evaluation unit is further configured to determine replacement parameters based on the measured electrical signal, while the signal generator of the device drives the ultrasound tool via the signal path.

6. The device according to claim 1 , wherein the signal generator is further configured to generate the control signal based on an operating signal of the ultrasound generator.

7. The device according to claim 6 , wherein the operating signal is at a frequency between ±2 kHz of an operating frequency of the ultrasound generator.

8. The device according to claim 1 , further comprising a discharging circuit element electrically connected to the signal path and configured in a conducting state to short-circuit the ultrasound tool so that a residual charge in the ultrasound tool can flow off.

9. The device according to claim 1 , wherein the sensor device comprises at least one of a voltage meter to measure a voltage signal and a current transformer to measure a current signal.

10. An assembly with an ultrasound welding system and the device according to of claim 1 , wherein the device is connected between the ultrasound generator of the ultrasound welding system and the ultrasound tool of the ultrasound welding system.

11. A method to determine a state of an ultrasound welding process, the method comprising:
measuring an electrical control signal of an ultrasound tool using a sensor device;
determining of a signal property of the control signal using an evaluation unit;
determining a status of the ultrasound welding process based on a reference signal profile and on the signal property determined by the evaluation unit;
disconnecting an ultrasound generator from the ultrasound tool by a switching element;
generating a control signal by a signal generator; and
controlling the ultrasound tool when the ultrasound generator is disconnected from the ultrasound tool.

12. The method according to claim 11 , further comprising determining a replacement parameter for a welding system based on a particular status of the ultrasound welding process based on the generated control signal.

Assignees

• Draexlmaier Lisa Gmbh

Inventors

• Klimas Felix
• Herzing Thomas
• Lehmann Lutz
• Zemann Daniel
• Ertz Gabriel
• Twiefel Jens
• Wallaschek Joerg
• Weinstein Michael

Classifications

• B23K20/10 Primary

  making use of vibrations, e.g. ultrasonic welding · CPC title

• B23K31/125

  Weld quality monitoring · CPC title

• B23K20/106 Primary

  Features related to sonotrodes · CPC title

• B06B1/0253

  taken directly from the generator circuit · CPC title

• B06B2201/72

  Welding, joining, soldering · CPC title