Patents by Inventor Masaru Kowa

Masaru Kowa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9050677
    Abstract: An arc welding method comprising the steps of accelerating a feeding speed of a welding wire to cause shorting between the welding wire and a base metal when a welding end signal is input during a period of arcing, retracting the welding wire backward thereafter until a wire retracting speed reaches a predetermined rate, controlling the wire retracting speed constant at this speed for a predetermined duration of time, then stopping the backward retraction of the welding wire, and then terminating a welding power output after supplying a predetermined amount of welding current for a predetermined duration of time starting from a time when opening of the shorting occurs during the backward retraction of the welding wire.
    Type: Grant
    Filed: July 23, 2010
    Date of Patent: June 9, 2015
    Assignee: Panasonic Intellectual Property Management Co., Ltd.
    Inventors: Atsuhiro Kawamoto, Yasushi Mukai, Junji Fujiwara, Masaru Kowa
  • Publication number: 20150112480
    Abstract: In sensor-less collision detection of a robot, a conventional method for displaying abnormality of the robot makes an abnormality display of “collision detected” when a collision is erroneously detected, and does not clarify the situations under which the collision has been erroneously detected. In a method for displaying abnormality of a robot, when a collision of the robot is detected and the collision detection is displayed, at least one abnormality display is selected from a plurality of abnormality detection items different from collision detection. This can offer information useful for the user to understand the situations at occurrence of the erroneous collision detection.
    Type: Application
    Filed: December 26, 2014
    Publication date: April 23, 2015
    Inventors: HIROYUKI NAKATA, ATSUMI HASHIMOTO, MASARU KOWA, YASUYOSHI HONUCHI
  • Patent number: 8993925
    Abstract: An arc welding method relates to consumable electrode arc welding in which a welding wire feeding rate suitable for a welding current is determined as an average feeding rate, and the short circuit state and the arc generation state are alternately generated by changing the wire feeding periodically and repeatedly between the forward feeding and the reverse feeding. The method offers arc welding with the average feeding rate according to a welding current, a predetermined frequency, and a predetermined velocity amplitude. In the method, at least any one of the frequency and the velocity amplitude is set to a value suitable for the welding current.
    Type: Grant
    Filed: July 16, 2010
    Date of Patent: March 31, 2015
    Assignee: Panasonic Intellectual Property Management Co., Ltd.
    Inventors: Junji Fujiwara, Yasushi Mukai, Atsuhiro Kawamoto, Masaru Kowa
  • Patent number: 8901454
    Abstract: In a method for controlling pulse arc welding where an arc is created between a wire and a base material, a pulse waveform different from the pulse waveform for steady-state welding is outputted when a predetermined time has passed since short-circuit welding control was started at arc start, and after a sufficiently large melt pool is formed, the pulse waveform for the steady-state welding is outputted. This reduces the generation of spatters after an arc is created and until the arc is stabilized.
    Type: Grant
    Filed: July 11, 2011
    Date of Patent: December 2, 2014
    Assignee: Panasonic Corporation
    Inventors: Akira Nakagawa, Atsuhiro Kawamoto, Junji Fujiwara, Masaru Kowa
  • Patent number: 8859936
    Abstract: A welding control method for a welding device having an output characteristic with a predetermined gradient showing a relation between a welding output voltage and a welding output current. By setting a set target welding voltage that is higher than the set initial welding voltage according to a difference between the set initial welding voltage and the welding output voltage, the welding output voltage is controlled to be the set target welding voltage. Thus, a proper arc length can be achieved early by correcting the change of the arc length due to, for example, motion of the hands of a welding operator.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: October 14, 2014
    Assignee: Panasonic Corporation
    Inventors: Kimiya Sato, Yasushi Mukai, Atsuhiro Kawamoto, Akira Nakagawa, Masaru Kowa
  • Patent number: 8841581
    Abstract: If a short circuit does not occur during deceleration of a wire feed speed in forward feed of a welding wire before the wire feed speed reaches a predetermined wire feed speed, a cyclic change is stopped and the wire feed speed is constantly controlled at the first feed speed. If a short circuit occurs during forward feed at the first feed speed, deceleration from the first feed speed starts, and the cyclic change is resumed for welding. This achieves uniform weld bead without increasing spatters even if any external disturbance such as change of distance between a tip and base material occurs.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: September 23, 2014
    Assignee: Panasonic Corporation
    Inventors: Atsuhiro Kawamoto, Yasushi Mukai, Junji Fujiwara, Toshiyuki Mishima, Masaru Kowa
  • Patent number: 8809736
    Abstract: An arc welding method of the present invention controls a short-circuit current increasing gradient (di/dt), an inflection point at which the short-circuit current increasing gradient (di/dt) changes, the current in a peak period and in a base period, and the time of the peak period in accordance with a difference between a set voltage and an output voltage. This allows the output voltage to be matched with the set voltage, and stabilizes the arc. Thereby, a stable arc welding method can be implemented, even as a method for outputting a welding current based on a welding voltage.
    Type: Grant
    Filed: July 12, 2010
    Date of Patent: August 19, 2014
    Assignee: Panasonic Corporation
    Inventors: Junji Fujiwara, Yasushi Mukai, Atsuhiro Kawamoto, Masaru Kowa
  • Patent number: 8809735
    Abstract: If a short circuit does not occur during deceleration of a wire feed speed in forward feed of a welding wire before the wire feed speed reaches a predetermined wire feed speed, a cyclic change is stopped and the wire feed speed is constantly controlled at the first feed speed. If a short circuit occurs during forward feed at the first feed speed, deceleration from the first feed speed starts, and the cyclic change is resumed for welding. This achieves uniform weld bead without increasing spatters even if any external disturbance such as change of distance between a tip and base material occurs.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: August 19, 2014
    Assignee: Panasonic Corporation
    Inventors: Atsuhiro Kawamoto, Yasushi Mukai, Junji Fujiwara, Toshiyuki Mishima, Masaru Kowa
  • Publication number: 20140203003
    Abstract: Disclosed is a method for controlling arc welding where an arc is generated between a welding wire as a consumable electrode and an object to be welded. The method includes: keeping a wire feed speed at a predetermined constant speed in a steady-state welding period; and at a time point when welding termination is ordered, either switching the wire feed speed from the predetermined constant speed to a wire feed speed at which the welding wire is fed in alternating forward and backward directions, or decreasing the wire feed speed from the predetermined constant speed with time, and then switching the wire feed speed to the wire feed speed at which the welding wire is fed in alternating forward and backward directions at a time point when a predetermined time period has passed since when welding termination was ordered.
    Type: Application
    Filed: March 20, 2014
    Publication date: July 24, 2014
    Applicant: Panasonic Corporation
    Inventors: Junji Fujiwara, Atsuhiro Kawamoto, Masaru Kowa
  • Publication number: 20140203004
    Abstract: In arc welding, determining a current value to be high in an early stage of the arc period is effective in reducing spatters caused by feeble short circuit in the arc period. In that case, to sharply decrease the voltage that has increased with increase in current, an inductance value of a reactor has to be kept small. However, a small inductance value causes a problem—weakness against disturbance. The present invention provides an arc welding control method that performs arc welding while repeating the short-circuit period and the arc period. According to the method, changing an inductance value relating to welding output in the arc period offers stable arc welding with fewer spatters and insusceptibility to disturbance.
    Type: Application
    Filed: March 20, 2014
    Publication date: July 24, 2014
    Applicant: Panasonic Corporation
    Inventors: Noriyuki Matsuoka, Yukinori Hirota, Atsuhiro Kawamoto, Junji Fujiwara, Masaru Kowa, Akira Nakagawa
  • Patent number: 8723080
    Abstract: An arc welding control method for carrying out welding by generating an arc between a wire and a base material. The wire is fed at wire feed speed (Wf) of periodically repeating forward feeding and reverse feeding with predetermined frequency and amplitude from time point (100) at which start of the welding is instructed, or from a certain time point (101) after the start of the welding is instructed, and then the wire feed speed is changed to a constant speed. Since the wire feed speed is controlled by periodically repeating forward feeding and reverse feeding at the arc start, short-circuit can be opened regardless of the electromagnetic pinch force, and spatters, which are generated at the early stage of the arc start because a molten pool is not preset, can be reduced.
    Type: Grant
    Filed: July 6, 2010
    Date of Patent: May 13, 2014
    Assignee: Panasonic Corporation
    Inventors: Atsuhiro Kawamoto, Yasushi Mukai, Junji Fujiwara, Masaru Kowa, Toshiyuki Mishima
  • Patent number: 8604387
    Abstract: A control method for an arc welding apparatus having a function of prohibiting detection of neck based on a change amount of welding voltage and an arc welding apparatus using the method. Thus, since neck determination can be carried out accurately by preventing wrong detection of neck, it is possible to reduce the occurrence of spatter.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: December 10, 2013
    Assignee: Panasonic Corporation
    Inventors: Kei Aimi, Hidetoshi Oyama, Atsuhiro Kawamoto, Masaru Kowa
  • Publication number: 20130299476
    Abstract: Disclosed is a consumable electrode arc welding in which short-circuit welding is performed by alternating short-circuits and arcs while a welding wire is fed automatically. In this method, a short-circuit state and an arc state are alternately generated by feeding the welding wire in periodically alternating forward and backward directions at a predetermined frequency and a predetermined velocity amplitude with reference to a basic wire feed speed based on a set current. The speed of periodic feeding of the welding wire is controlled in such a manner that the waveform to feed the welding wire is different between the forward and backward directions.
    Type: Application
    Filed: June 26, 2012
    Publication date: November 14, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Junji Fujiwara, Atsuhiro Kawamoto, Masaru Kowa
  • Patent number: 8513568
    Abstract: If a short circuit does not occur during deceleration of a wire feed speed in forward feed of a welding wire before the wire feed speed reaches a predetermined wire feed speed, a cyclic change is stopped and the wire feed speed is constantly controlled at the first feed speed. If a short circuit occurs during forward feed at the first feed speed, deceleration from the first feed speed starts, and the cyclic change is resumed for welding. This achieves uniform weld bead without increasing spatters even if any external disturbance such as change of distance between a tip and base material occurs.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: August 20, 2013
    Assignee: Panasonic Corporation
    Inventors: Atsuhiro Kawamoto, Yasushi Mukai, Junji Fujiwara, Toshiyuki Mishima, Masaru Kowa
  • Patent number: 8502114
    Abstract: An AC pulse arc welding method of the present invention sets an appropriate AC frequency based on a wire feed rate and a polarity ratio when the polarity ratio is changed without changing the wire feed rate to control a heat input to a base material, and sets an appropriate straight polarity current value necessary for one drop per pulse from the polarity ratio and the AC frequency in AC pulse welding. The method makes it possible to achieve appropriate AC pulse welding by setting the polarity ratio, and to easily set the welding conditions.
    Type: Grant
    Filed: November 24, 2009
    Date of Patent: August 6, 2013
    Assignee: Panasonic Corporation
    Inventors: Yukinori Hirota, Hiroki Yuzawa, Masaru Kowa, Hideki Ihara
  • Publication number: 20120199567
    Abstract: In a method for controlling pulse arc welding where an arc is created between a wire and a base material, a pulse waveform different from the pulse waveform for steady-state welding is outputted when a predetermined time has passed since short-circuit welding control was started at arc start, and after a sufficiently large melt pool is formed, the pulse waveform for the steady-state welding is outputted. This reduces the generation of spatters after an arc is created and until the arc is stabilized.
    Type: Application
    Filed: July 11, 2011
    Publication date: August 9, 2012
    Applicant: Panasonic Corporation
    Inventors: Akira Nakagawa, Atsuhiro Kawamoto, Junji Fujiwara, Masaru Kowa
  • Publication number: 20120145691
    Abstract: An arc welding method of the present invention controls a short-circuit current increasing gradient (di/dt), an inflection point at which the short-circuit current increasing gradient (di/dt) changes, the current in a peak period and in a base period, and the time of the peak period in accordance with a difference between a set voltage and an output voltage. This allows the output voltage to be matched with the set voltage, and stabilizes the arc. Thereby, a stable arc welding method can be implemented, even as a method for outputting a welding current based on a welding voltage.
    Type: Application
    Filed: July 12, 2010
    Publication date: June 14, 2012
    Applicant: Panasonic Corporation
    Inventors: Junji Fujiwara, Yasushi Mukai, Atsuhiro Kawamoto, Masaru Kowa
  • Publication number: 20120145690
    Abstract: An arc welding method comprising the steps of accelerating a feeding speed of a welding wire to cause shorting between the welding wire and a base metal when a welding end signal is input during a period of arcing, retracting the welding wire backward thereafter until a wire retracting speed reaches a predetermined rate, controlling the wire retracting speed constant at this speed for a predetermined duration of time, then stopping the backward retraction of the welding wire, and then terminating a welding power output after supplying a predetermined amount of welding current for a predetermined duration of time starting from a time when opening of the shorting occurs during the backward retraction of the welding wire.
    Type: Application
    Filed: July 23, 2010
    Publication date: June 14, 2012
    Applicant: Panasonic Corporation
    Inventors: Atsuhiro Kawamoto, Yasushi Mukai, Junji Fujiwara, Masaru Kowa
  • Publication number: 20120111842
    Abstract: An arc welding method relates to consumable electrode arc welding in which a welding wire feeding rate suitable for a welding current is determined as an average feeding rate, and the short circuit state and the arc generation state are alternately generated by changing the wire feeding periodically and repeatedly between the forward feeding and the reverse feeding. The method offers arc welding with the average feeding rate according to a welding current, a predetermined frequency, and a predetermined velocity amplitude. In the method, at least any one of the frequency and the velocity amplitude is set to a value suitable for the welding current.
    Type: Application
    Filed: July 16, 2010
    Publication date: May 10, 2012
    Applicant: Panasonic Corporation
    Inventors: Junji Fujiwara, Yasushi Mukai, Atsuhiro Kawamoto, Masaru Kowa
  • Publication number: 20120097654
    Abstract: An arc welding control method for carrying out welding by generating an arc between a wire and a base material. The wire is fed at wire feed speed (Wf) of periodically repeating forward feeding and reverse feeding with predetermined frequency and amplitude from time point (100) at which start of the welding is instructed, or from a certain time point (101) after the start of the welding is instructed, and then the wire feed speed is changed to a constant speed. Since the wire feed speed is controlled by periodically repeating forward feeding and reverse feeding at the arc start, short-circuit can be opened regardless of the electromagnetic pinch force, and spatters, which are generated at the early stage of the arc start because a molten pool is not preset, can be reduced.
    Type: Application
    Filed: July 6, 2010
    Publication date: April 26, 2012
    Applicant: Panasonic Corporation
    Inventors: Atsuhiro Kawamoto, Yasushi Mukai, Junji Fujiwara, Masaru Kowa, Toshiyuki Mishima