Ultrasonic press using servo motor with delayed motion

Patent metadata

Field	Value
Publication number	US-9586361-B2
Application number	US-201514827455-A
Country	US
Kind code	B2
Filing date	Aug 17, 2015
Priority date	May 8, 2006
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

An ultrasonic welding system includes a motion control system that is coupled to and that causes controlled movement of an ultrasonic welding stack, in accordance with control inputs that are based on one or more control signals that are received from one or more sensors. The motion control system initiates a welding operation, subsequent to which an initial motion delay occurs until a predetermined condition is satisfied. Subsequently, in response to the predetermined condition being satisfied, the ultrasonic welding stack is caused to move in accordance with a weld profile. Subsequently, in response to an occurrence of a predetermined delay initiating condition, the ultrasonic welding stack is caused to stop motion and to maintain a stationary position. Subsequently, in response to an occurrence of a predetermined delay terminating condition, motion of the ultrasonic welding stack is resumed in accordance with the weld profile.

First claim

What is claimed is:

1. An ultrasonic welding system comprising:
an ultrasonic welding stack movable, in response to control inputs, to initiate a welding operation by applying vibrational energy to a workpiece;
one or more sensors to measure at least one control variable and to output a control signal corresponding to the at least one control variable; and
a motion control system coupled to and causing controlled advancing movement of the ultrasonic welding stack, the motion control system being responsive to the control inputs based on one or more control signals received from the one or more sensors, the motion control system including
initiating the welding operation by applying vibrational energy to a workpiece,
subsequent to the initiating of the welding operation, optionally initially delaying any advancing movement of the ultrasonic welding stack until one or more of the control signals indicate that respective control variables satisfy a predetermined condition,
subsequent to the optional initial delay and in response to the predetermined condition being satisfied, causing the ultrasonic welding stack to advance in accordance with a weld profile,
subsequent to the ultrasonic welding stack moving in accordance with the weld profile, causing the ultrasonic welding stack to stop advancing movement and maintain a stationary position in response to an occurrence of a predetermined delay initiating condition, and
in response to an occurrence of a predetermined delay terminating condition, resume advancing movement of the ultrasonic welding stack in accordance with the weld profile,
wherein vibrational energy continues to be applied to said workpiece while said ultrasonic welding stack is stopped and while the advancing movement of the welding stack continues.

2. The ultrasonic welding system of claim 1 , the motion control system further including, subsequent to resuming the advancing movement of the ultrasonic welding stack:
causing the ultrasonic welding stack to stop advancing movement at least once more and maintain another stationary position in response to an occurrence of another one or more predetermined delay initiating conditions; and
in response to an occurrence of another one or more predetermined delay terminating conditions, resuming again the advancing movement of the ultrasonic welding stack in accordance with the weld profile.

3. The ultrasonic welding system of claim 1 , wherein at least one of the one or more sensors senses a force output by the linear actuator movable element, the predetermined delay initiating condition being a specified force, the predetermined delay terminating condition being a specified change in force relative to the specified force.

4. The ultrasonic welding system of claim 1 , wherein the one or more sensors sense a distance traversed from the start of the weld and a force output by a linear actuator movable element, the predetermined delay initiating condition being a specified distance, the predetermined delay terminating condition being a specified change in force relative to a force sensed at the time of occurrence of the predetermined delay initiating condition.

5. The ultrasonic welding system of claim 1 , wherein the one or more sensors sense a power input to a transducer of the ultrasonic welding stack and a force output by a linear actuator movable element, the predetermined delay initiating condition being a specified power, the predetermined delay terminating condition being a specified change in force relative to a force sensed at the time of occurrence of the predetermined delay initiating condition.

6. The ultrasonic welding system of claim 1 , wherein at least one of the one or more sensors senses a power input to a transducer of the ultrasonic welding stack, the predetermined delay initiating condition being a specified power, the predetermined delay terminating condition being a specified change in power relative to the specified power.

7. The ultrasonic welding system of claim 1 , wherein the one or more sensors sense a power input to a transducer of the ultrasonic welding stack and a force output by a linear actuator movable element, the predetermined delay initiating condition being a specified cumulative power, the predetermined delay terminating condition being a specified change in force relative to a force sensed at the time of occurrence of the predetermined delay initiating condition.

8. The ultrasonic welding system of claim 1 , wherein one of the one or more sensors senses a force output by a linear movable element and another one of the one or more sensors tracks elapsed time from the occurrence of the predetermined delay initiating condition, the predetermined delay initiating condition being a specified force, the predetermined delay terminating condition being a specified elapsed time.

9. The ultrasonic welding system of claim 1 , wherein one of the one or more sensors senses a distance traversed from a weld start and another one of the one or more sensors tracks elapsed time from the occurrence of the predetermined delay initiating condition, the predetermined delay initiating condition being a specified distance, the predetermined delay terminating condition being a specified elapsed time.

10. The ultrasonic welding system of claim 1 , wherein one of the one or more sensors senses a power input to a transducer of the ultrasonic welding stack and another one of the one or more sensors tracks elapsed time from the occurrence of the predetermined delay initiating condition, the predetermined delay initiating condition being a specified power, the predetermined delay terminating condition being a specified elapsed time.

11. The ultrasonic welding system of claim 1 , wherein one of the one or more sensors senses a power input to a transducer of the ultrasonic welding stack and another one of the one or more sensors tracks elapsed time from the occurrence of the predetermined delay initiating condition, the predetermined delay initiating condition being a specified cumulative power, the predetermined delay terminating condition being a specified elapsed time.

12. The ultrasonic welding system of claim 1 , wherein the one or more sensors sense one or more parameters selected from a group consisting of
(a) a force output by a linear actuator movable element,
(b) an output torque of a servo-motor,
(c) a position of the ultrasonic welding stack,
(d) a distance traversed from a start of a weld,
(e) a power input to a transducer of the ultrasonic welding stack,
(f) a cumulative power input to the transducer of the ultrasonic welding stack,
(g) a frequency of the ultrasonic welding stack
(h) a phase of the transducer of the ultrasonic welding stack, and
(i) an elapsed time subsequent to the initiating of the welding operation;
wherein the predetermined delay initiating condition includes one or more of a specified
(1) force,
(2) output torque,
(3) position,
(4) distance,
(5) power,
(6) cumulative power,
(7) frequency,
(8) phase, and
(9) elapsed time;
wherein the predetermined delay terminating condition includes one or more of a specified absolute or relative value of
(i) force,
(ii) output torque,
(iii) power,
(iv) cumulative power,
(v) frequency,
(vi) phase, and
(vii) elapsed time; and
wherein reference for the relative value is a level of a respective parameter sensed at the occurrence of the predetermined delay initiating condition.

13. The ultrasonic welding system of claim 1 , wherein the one or more sensors sense values and rates of change for one or more parameters selected from a group consisting of
(a) a force output by a linear

Assignees

• Dukane Corp
• Dukane Ias Llc

Inventors

• Klinstein Leo
• Golko Paul
• Jurkowski William E

Classifications

• B29C66/30223

  said melt initiators being rib-like · CPC title

• B29C66/9513

  characterised by specific vibration frequency values or ranges · CPC title

• B29C66/93431

  the speed being kept constant over time · CPC title

• B29C66/9231

  by measuring the displacement of the joining tools · CPC title

• B29C65/08 Primary

  using ultrasonic vibrations {(non-plastics element to plastics elements B29C65/645)} · CPC title