Patents by Inventor Sei Shimahara

Sei Shimahara 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: 9309649
    Abstract: A work machine equipped with an automatic hammering function is capable of preventing breakage of the hammer caused by blank firing. Hydraulic oil fed to a hydraulic breaker at the distal end of a work machine is controlled by first and second spools. Operating an operation lever so as to contract single rod type boom cylinders to press the hydraulic breaker against an object to be crushed. Head-side pressure and rod-side pressure of the boom cylinders are respectively detected by pressure sensors. Any one of switches is used to switch the mode of automatic hammering operation between an automatic hammering inhibiting mode and an automatic hammering authorizing mode. In the automatic hammering authorizing mode, a controller controls the first and second spools of the hydraulic breaker so as to open them only when head-side pressure and rod-side pressure of the boom cylinders are in a given range of pressing force.
    Type: Grant
    Filed: February 2, 2010
    Date of Patent: April 12, 2016
    Assignee: Caterpillar SARL
    Inventors: Hiroyasu Nishikawa, Sei Shimahara, Manabu Nakanishi, Masashi Shibata
  • Patent number: 9103095
    Abstract: A controller controls the solenoid-operated variable pressure relief valves that are provided to control, at set pressures that can be electrically commanded, pressure of hydraulic oil fed to an attachment cylinder. The controller is provided with a control logic that is capable of controlling the aforementioned solenoid-operated variable pressure relief valves. The control logic performs the aforementioned calculation by compensating for pressure override characteristics of each solenoid-operated variable pressure relief valve based on input signals related to the set relief pressure for and a relief valve passing flow rate of the solenoid-operated variable pressure relief valve, and outputting to the solenoid-operated variable pressure relief valve command signals related to the adjusted set relief pressure resulting from the compensation of the pressure override characteristics.
    Type: Grant
    Filed: December 27, 2011
    Date of Patent: August 11, 2015
    Assignee: Caterpillar SARL
    Inventors: Hiroyasu Nishikawa, Sei Shimahara, Manabu Nakanishi, Masashi Shibata
  • Patent number: 8899035
    Abstract: A hydraulic pump driven by an engine, a hydraulic actuator, and a negative control circuit are provided on an open center hydraulic circuit, for guiding the hydraulic pressure in the center bypass to the hydraulic pump, as a negative control pressure. A negative control pressure control device controls the negative control pressure to an arbitrary value is also provided. The pump characteristic of the hydraulic pump is set such that the discharge flow rate is minimized when the negative control pressure in the negative control circuit is equal to or greater than a first predetermined pressure. Furthermore, an idling detection device that detects whether the hydraulic actuator is in a non-operated state or not is provided. The negative control pressure is forcefully controlled to the first predetermined pressure or higher when the non-operating state is detected.
    Type: Grant
    Filed: August 17, 2010
    Date of Patent: December 2, 2014
    Assignee: Caterpillar SARL
    Inventors: Hiroyasu Nishikawa, Seiichi Akiyama, Yusuke Shimizu, Atsunobu Doi, Sei Shimahara, Manabu Nakanishi, Masashi Shibata
  • Publication number: 20120260646
    Abstract: A controller controls the solenoid-operated variable pressure relief valves that are provided to control, at set pressures that can be electrically commanded, pressure of hydraulic oil fed to an attachment cylinder. The controller is provided with a control logic that is capable of controlling the aforementioned solenoid-operated variable pressure relief valves. The control logic performs the aforementioned calculation by compensating for pressure override characteristics of each solenoid-operated variable pressure relief valve based on input signals related to the set relief pressure for and a relief valve passing flow rate of the solenoid-operated variable pressure relief valve, and outputting to the solenoid-operated variable pressure relief valve command signals related to the adjusted set relief pressure resulting from the compensation of the pressure override characteristics.
    Type: Application
    Filed: December 27, 2011
    Publication date: October 18, 2012
    Applicant: Caterpillar Sarl
    Inventors: Hiroyasu Nishikawa, Sei Shimahara, Manabu Nakanishi, Masashi Shibata
  • Publication number: 20120036845
    Abstract: A hydraulic pump driven by an engine, a hydraulic actuator, and a negative control circuit are provided on an open center hydraulic circuit, for guiding the hydraulic pressure in the center bypass to the hydraulic pump, as a negative control pressure. A negative control pressure control device controls the negative control pressure to an arbitrary value is also provided. The pump characteristic of the hydraulic pump is set such that the discharge flow rate is minimized when the negative control pressure in the negative control circuit is equal to or greater than a first predetermined pressure. Furthermore, an idling detection device that detects whether the hydraulic actuator is in a non-operated state or not is provided. The negative control pressure is forcefully controlled to the first predetermined pressure or higher when the non-operating state is detected.
    Type: Application
    Filed: August 17, 2010
    Publication date: February 16, 2012
    Inventors: Hiroyasu Nishikawa, Seiichi Akiyama, Yusuke Shimizu, Atsunobu Doi, Sei Shimahara, Manabu Nakanishi, Masashi Shibata
  • Publication number: 20110315415
    Abstract: A work machine equipped with an automatic hammering function is capable of preventing breakage of the hammer caused by blank firing. Hydraulic oil fed to a hydraulic breaker at the distal end of a work machine is controlled by first and second spools. Operating an operation lever so as to contract single rod type boom cylinders to press the hydraulic breaker against an object to be crushed. Head-side pressure and rod-side pressure of the boom cylinders are respectively detected by pressure sensors. Any one of switches is used to switch the mode of automatic hammering operation between an automatic hammering inhibiting mode and an automatic hammering authorizing mode. In the automatic hammering authorizing mode, a controller controls the first and second spools of the hydraulic breaker so as to open them only when head-side pressure and rod-side pressure of the boom cylinders are in a given range of pressing force.
    Type: Application
    Filed: February 2, 2010
    Publication date: December 29, 2011
    Applicant: CATERPILLAR JAPAN LTD.
    Inventors: Hiroyasu Nishikawa, Sei Shimahara, Manabu Nakanishi, Masashi Shibata
  • Patent number: 7958907
    Abstract: A fluid pressure circuit that can, in either case where a first actuator that is fed from a first pump or a second actuator that is fed from a second pump is operated, by allowing feeding of the hydraulic fluid to a specific actuator from either the first or second pump, improve interlockability with the specific actuator. A control valve is incorporated with a plurality of first-group spools fed from a drive pump and a plurality of second-group spools fed from an idle pump. A solenoid selector valve unit switches a pilot line of a second-group tool controlling spool to a communicating state at the time of detection of a spool operation by a first pressure switch and switches a pilot line of a first-group tool controlling spool to a communicating state at the time of detection of a spool operation by a second pressure switch.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: June 14, 2011
    Assignee: Caterpillar S.A.R.L.
    Inventors: Hiroyasu Nishikawa, Sei Shimahara
  • Patent number: 7930970
    Abstract: A control unit for a work machine that allows automatically obtaining optimal operability even when the weight of a work arm in the work machine is changed. In a work machine where at least a part of a work arm to be operated by a fluid pressure actuator is provided so as to be replaceable, a control unit for a work machine includes: a pilot-operated control valve that controls the fluid pressure actuator; a proportional solenoid valve that pilot-controls the pilot-operated control valve by a pilot control pressure according to an electrical signal corresponding to a manual operation amount; a measuring means that measures a weight of at least the part of the work arm; and a controller that converts characteristics between the manual operation amount and the pilot control pressure of the proportional solenoid valve to characteristics according to the weight of the work arm measured by the measuring means.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: April 26, 2011
    Assignee: Caterpillar S.A.R.L.
    Inventors: Hiroyasu Nishikawa, Sei Shimahara, Manabu Nakanishi
  • Patent number: 7926411
    Abstract: A valve control unit that prevents a decline in interlocking operation performance when pilot pressure control of a plurality of pilot-operated control valves is carried out by proportional solenoid valves. First and second proportional solenoid valves include a Common Operation Table of lever operation amount/boom-up pilot pressure characteristics and are inputted with a common boom-up lever operation amount. A third proportional solenoid valve also includes the Operation Table and is inputted with a stick-in lever operation amount common to the fourth proportional solenoid valve. The fourth proportional solenoid valve includes an Operation Table of lever operation amount/stick-in pilot pressure characteristics different from that of the first, second, and third proportional solenoid valves and is inputted with the stick-in lever operation amount common to the third proportional solenoid valve.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: April 19, 2011
    Assignee: Caterpillar S.A.R.L.
    Inventors: Hiroyasu Nishikawa, Sei Shimahara, Manabu Nakanishi
  • Publication number: 20090159143
    Abstract: A fluid pressure circuit that can, in either case where a first actuator that is fed from a first pump or a second actuator that is fed from a second pump is operated, by allowing feeding of the hydraulic fluid to a specific actuator from either the first or second pump, improve interlockability with the specific actuator. A control valve is incorporated with a plurality of first-group spools fed from a drive pump and a plurality of second-group spools fed from an idle pump. A solenoid selector valve unit switches a pilot line of a second-group tool controlling spool to a communicating state at the time of detection of a spool operation by a first pressure switch and switches a pilot line of a first-group tool controlling spool to a communicating state at the time of detection of a spool operation by a second pressure switch.
    Type: Application
    Filed: February 20, 2007
    Publication date: June 25, 2009
    Applicant: Shin Caterpillar Mitsubishi Ltd.
    Inventors: Hiroyasu Nishikawa, Sei Shimahara
  • Publication number: 20090114298
    Abstract: A valve control unit that prevents a decline in interlocking operation performance when pilot pressure control of a plurality of pilot-operated control valves is carried out by proportional solenoid valves. First and second proportional solenoid valves include a Common Operation Table of lever operation amount/boom-up pilot pressure characteristics and are inputted with a common boom-up lever operation amount. A third proportional solenoid valve also includes the Operation Table and is inputted with a stick-in lever operation amount common to the fourth proportional solenoid valve. The fourth proportional solenoid valve includes an Operation Table of lever operation amount/stick-in pilot pressure characteristics different from that of the first, second, and third proportional solenoid valves and is inputted with the stick-in lever operation amount common to the third proportional solenoid valve.
    Type: Application
    Filed: February 20, 2007
    Publication date: May 7, 2009
    Applicant: SHIN CATERPILLAR MITSUBISHI LTD.
    Inventors: Hiroyasu Nishikawa, Sei Shimahara, Manabu Nakanishi
  • Publication number: 20090090237
    Abstract: A control unit for a work machine that allows automatically obtaining optimal operability even when the weight of a work arm in the work machine is changed. In a work machine where at least a part of a work arm to be operated by a fluid pressure actuator is provided so as to be replaceable, a control unit for a work machine includes: a pilot-operated control valve that controls the fluid pressure actuator; a proportional solenoid valve that pilot-controls the pilot-operated control valve by a pilot control pressure according to an electrical signal corresponding to a manual operation amount; a measuring means that measures a weight of at least the part of the work arm; and a controller that converts characteristics between the manual operation amount and the pilot control pressure of the proportional solenoid valve to characteristics according to the weight of the work arm measured by the measuring means.
    Type: Application
    Filed: February 20, 2007
    Publication date: April 9, 2009
    Applicant: Shin Caterpillar Mitsubishi Co., Ltd.
    Inventors: Hiroyasu Nishikawa, Sei Shimahara, Manabu Nakanishi