Method for operating a constant pressure filament driver to an extruder head in a three-dimensional object printer

Patent metadata

Field	Value
Publication number	US-2020207000-A1
Application number	US-202016812846-A
Country	US
Kind code	A1
Filing date	Mar 9, 2020
Priority date	Oct 26, 2016
Publication date	Jul 2, 2020
Grant date	—

Abstract

A method of operating an additive manufacturing system feeds solid extrusion material into a heater using a slip clutch coupled to an actuator of a mechanical driver to supply thermoplastic material into a manifold in an extruder head. The method sets a speed of the actuator so the actuator operates at a rotational speed that is slightly greater than the rotational speed of the mechanical mover. This method helps maintain the pressure of the thermoplastic material in the manifold of the extruder head in a predetermined range no matter how many nozzles are opened in the extruder head.

First claim

What is claimed:

1 . A method comprising:
operating a mechanical mover to exert a force within a predetermined range to move extrusion material into a heater; operating the heater to melt the extrusion material and form thermoplastic material that moves into a manifold in an extruder head; adjusting a torque set point for a slip clutch with reference to print conditions; and limiting with the slip clutch a force exerted by the mechanical mover to the extrusion material.

2 . The method of claim 1 further comprising:
operating an actuator coupled to the mechanical mover at a speed that enables an output shaft of the actuator to rotate at a rate greater than the rate at which the mechanical mover moves the extrusion material.

3 . The method of claim 2 further comprising:
generating with a sensor a signal indicative of the rate at which the mechanical mover rotates; and
adjusting with a controller rotation of the output shaft of the actuator with reference to the signal generated by the sensor.

4 . The method of claim 2 further comprising:
generating with a sensor a signal indicative of a pressure of the thermoplastic material within the extruder head; and
adjusting with a controller rotation of the output shaft of the actuator with reference to the signal generated by the sensor.

5 . The method of claim 2 further comprising:
adjusting a pressure set point for operating the actuator with reference to print conditions.

6 . The method of claim 5 wherein the print conditions are one or more of a type of extrusion material being moved to the heater, a temperature of the thermoplastic material, a speed at which the extruder head is being moved, and a position of a feature being formed on the object.

7 . The method of claim 2 wherein the operation of the actuator rotates a pair of rollers having a nip between the rollers to move solid filament into the heater.

8 . The method of claim 2 wherein the operation of the actuator rotates a screw to move powder or pellet extrusion material into the heater.

9 . The method of claim 1 wherein the operation of the slip clutch is operation of a torque friction disc clutch, a magnetic particle clutch, a magnetic hysteresis clutch, a ferro-fluid clutch, an air pressure clutch, or a permanent magnetic clutch.

10 . The method of claim 3 further comprising:
operating with the controller at least one valve operatively connected between at least one nozzle in the extruder head and the manifold to extrude thermoplastic material from the at least one nozzle selectively to form an object with the thermoplastic material.

11 . The method of claim 10 further comprising:
detecting a clogging of the at least one nozzle with reference to a signal generated by a sensor that is indicative of a pressure in the manifold or a speed of the output shaft of the actuator; and
adjusting a speed of the actuator or the torque set point of the slip clutch in response to detection of the clogging of the at least one nozzle.

12 . The method of 5 further comprising:
operating the actuator to produce a pressure of the thermoplastic material in the manifold in a predetermined range about the adjusted pressure set point before the controller operates the extruder head to form an object with the thermoplastic material.

13 . A method comprising:
operating a mechanical mover to exert a force within a predetermined range to move extrusion material into a heater; operating the heater to melt the extrusion material and form thermoplastic material that moves into a manifold within an extruder head; limiting with a slip clutch a force exerted by the mechanical mover to the extrusion material; and adjusting a torque set point of the slip clutch with reference to print conditions.

14 . The method of claim 13 further comprising:
operating an actuator coupled to the mechanical mover at a speed so an output shaft of the actuator rotates at a rate greater than the rate at which the mechanical mover moves the extrusion material.

15 . The method of claim 14 further comprising:
generating with a sensor a signal indicative of the rate at which the mechanical mover rotates; and
adjusting with a controller rotation of the output shaft of the actuator with reference to the signal generated by the sensor.

16 . The method of claim 14 further comprising:
generating with a sensor a signal indicative of a pressure of the thermoplastic material within the extruder head; and
adjusting with a controller rotation of the output shaft of the actuator with reference to the signal generated by the sensor.

17 . The method of claim 13 wherein the print conditions are one or more of a type of extrusion material being moved to the heater, a temperature of the thermoplastic material, a speed at which the extruder head is being moved, and a position of a feature being formed on an object being formed with the thermoplastic material extruded from the extruder head.

18 . The method of claim 13 further comprising:
operating with a controller at least one valve operatively connected between at least one nozzle in the extruder head and the manifold to extrude thermoplastic material from the at least one nozzle selectively.

19 . The method of 18 further comprising:
operating the actuator to produce a pressure of the thermoplastic material in the manifold in a predetermined range before the controller operates the at least one nozzle in the extruder head to form an object with the thermoplastic material extruded from the at least one nozzle.

20 . The method of claim 19 further comprising:
detecting a clogging of the at least one nozzle with reference to a signal generated by a sensor that is indicative of a pressure in the manifold or a speed of the output shaft of the actuator; and
adjusting the torque set point of the slip clutch in response to detection of the clogging of the at least one nozzle.

Assignees

• Xerox Corp

Inventors

• Mandel Barry P
• Nystrom Peter J
• Lynn Christopher G
• Clark Robert A
• Mantell David A

Classifications

• B29C64/241

  for rotary motion · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title

• B29C64/209

  Heads; Nozzles · CPC title

• B29C64/118 Primary

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title