Patents by Inventor Dal Sik Jang

Dal Sik Jang 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: 9829013
    Abstract: The present disclosure relates to a hydraulic system for a construction machine, and more particularly, to a hydraulic system for a construction machine including a plurality of actuators, in which each of the actuators includes a pump/motor, is operated under a control of a corresponding pump/motor, and stores working oil in an accumulator or receives the working oil supplemented from the accumulator in accordance with a difference between a flow rate entering the actuator and a flow rate discharged from the actuator.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: November 28, 2017
    Assignee: DOOSAN INFRACORE CO., LTD.
    Inventors: Yong Lak Cho, Dal Sik Jang, Woo Yong Jung, Min Ha An, A Reum Seo, Sang Woo Lee, Yoon Seok Jang
  • Patent number: 9618018
    Abstract: The present disclosure relates to a hydraulic system for construction equipment, and more particularly, to a hydraulic system, in which an actuator is controlled by a pump/motor. The hydraulic system for construction equipment according to the present disclosure includes logic valves in first and second hydraulic lines provided to an actuator, respectively, and when it is desired to operate the actuator in a state where an operation of the actuator is stopped by closing the logic valves, a pressure difference may be resolved by increasing pressure in sections of a pump/motor and the logic valves in advance even if a load is applied to the actuator, and thus the actuator may implement a desired operation without being affected by the load. That is, it is possible to improve operation controllability of the actuator.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: April 11, 2017
    Assignee: DOOSAN INFRACORE CO., LTD.
    Inventors: Min Ha An, Woo Yong Jung, Yong Lak Cho, A Reum Seo, Dal Sik Jang, Kwang Ho Lim
  • Patent number: 9580888
    Abstract: An exemplary embodiment of the present specification relates to an apparatus for controlling a hydraulic pump for an excavator with respect to a change of an operation mode, the apparatus including: an operating unit configured to generate an operation signal according to an operation of an operator, and including a joystick or a pedal; an oil flow supplying unit configured to supply oil to actuators, in order to drive a plurality of actuators corresponding to the operation signal, and including a plurality of pumps and a plurality of logic valves; and a control unit configured to control the oil flow supplying unit by using a priority algorithm for each operation considering a use frequency and a load of the actuator with respect to a change of a predetermined operation mode according to the operation signal.
    Type: Grant
    Filed: February 6, 2014
    Date of Patent: February 28, 2017
    Assignee: Doosan Infracore Co., Ltd.
    Inventors: Min Ha Ahn, Woo Yong Jung, Dal Sik Jang, Hyeon Sik Ahn, Kwang Ho Lim
  • Publication number: 20160032945
    Abstract: The present disclosure relates to a hydraulic system for a construction machine, and more particularly, to a hydraulic system for a construction machine including a plurality of actuators, in which each of the actuators includes a pump/motor, is operated under a control of a corresponding pump/motor, and stores working oil in an accumulator or receives the working oil supplemented from the accumulator in accordance with a difference between a flow rate entering the actuator and a flow rate discharged from the actuator.
    Type: Application
    Filed: March 13, 2014
    Publication date: February 4, 2016
    Inventors: Yong Lak CHO, Dal Sik JANG, Woo Yong JUNG, Min Ha AN, A Reum SEO, Sang Woo LEE, Yoon Seok JANG
  • Publication number: 20150376871
    Abstract: An exemplary embodiment of the present specification relates to an apparatus for controlling a hydraulic pump for an excavator with respect to a change of an operation mode, the apparatus including: an operating unit configured to generate an operation signal according to an operation of an operator, and including a joystick or a pedal; an oil flow supplying unit configured to supply oil to actuators, in order to drive a plurality of actuators corresponding to the operation signal, and including a plurality of pumps and a plurality of logic valves; and a control unit configured to control the oil flow supplying unit by using a priority algorithm for each operation considering a use frequency and a load of the actuator with respect to a change of a predetermined operation mode according to the operation signal.
    Type: Application
    Filed: February 6, 2014
    Publication date: December 31, 2015
    Inventors: Min Ha Ahn, Woo Yong Jung, Dal Sik Jang, Hyeon Sik Ahn, Kwang Ho Lim
  • Patent number: 9079755
    Abstract: The present disclosure relates to an energy reclaiming system for an electric forklift truck. The energy reclaiming system includes an electronic device operated by a motor when a working machine is raised and operated by a generator when the working machine is lowered, a hydraulic pump/motor connected to the electronic device and configured to perform two functions of a hydraulic pump and a hydraulic motor, a main control valve unit including a lift cylinder operating unit connected to the hydraulic pump/motor and configured to operate a lift cylinder and a secondary consumer operating unit connected to the hydraulic pump/motor and configured to operate a secondary consumer, and a control lever including a control valve configured to control the lift cylinder or the secondary consumer through the lift cylinder operating unit and the secondary consumer operating unit of the main control valve unit, respectively.
    Type: Grant
    Filed: May 19, 2011
    Date of Patent: July 14, 2015
    Assignee: Doosan Corporation
    Inventors: Dong Ho Han, Dal Sik Jang
  • Patent number: 8984875
    Abstract: The present disclosure is a construction machine, such as an excavator, which comprises a plurality of hydraulically driven actuators, in which some of the actuators are provided in a one-to-one pump system where hydraulic pumps are connected to the respective actuators such that a working fluid is supplied from the respective pumps, and the remaining actuators are provided in an auxiliary control valve system where the working fluid is distributed by an auxiliary control valve connected to one or more pumps. When an amount of the working fluid of an actuator associated with the auxiliary control valve is insufficient, the actuator associated with the auxiliary control valve is connected to a pump of the one-to-one pump system to share the pump of the one-to-one pump system.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: March 24, 2015
    Assignee: Doosan Infracore Co., Ltd.
    Inventor: Dal Sik Jang
  • Patent number: 8707690
    Abstract: A hydraulic pump controlling apparatus of a construction machine according to the present disclosure includes: a hydraulic pump in which a swash plate angle is controlled to control a discharge flow; an auxiliary pump; a control valve controlling a flowing direction of a fluid discharged from the hydraulic pump and selectively supplying the fluid to an actuator; an orifice and a relief valve connected between a center bypass line of the control valve and a tank T to be parallel to each other; signal pressure selecting units receiving a fluid passing through the center bypass line of the control valve and a fluid discharged from the auxiliary pump, and selecting the pressure of any one of the fluids as a signal pressure; and a regulator receiving the signal pressure selected from the signal pressure selecting units to control the swash plate angle of the hydraulic pump, and the signal pressure selecting unit selects the pressure of the fluid discharged from the auxiliary pump as the signal pressure and transfe
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: April 29, 2014
    Assignee: Doosan Infracore Co., Ltd.
    Inventors: Young Sik Cho, Dal Sik Jang
  • Publication number: 20130158679
    Abstract: The present disclosure relates to an apparatus and method for controlling construction machinery, and an operation pattern control device according to the present disclosure includes an operation pattern recognition device configured to analyze operation being performed by the construction machinery and a driving control device configured to control individual equipment of the construction machinery to match the operation pattern analyzed by the operation pattern recognition device, and the operation pattern recognition device includes: a data accumulation unit configured to receive and accumulate a manipulation signal of an operator; an operation pattern analysis unit configured to determine a present operation pattern by analyzing data of the accumulated manipulation signal; a probability model analysis unit configured to determine data, which is not determined from the operation pattern analysis unit, by using a probability model; and a pattern result output unit configured to output operation determined f
    Type: Application
    Filed: August 23, 2011
    Publication date: June 20, 2013
    Applicant: DOOSAN INFRACORE CO., LTD.
    Inventors: Joonho Oh, Dal Sik Jang, Daehie Hong, Ki Young Kim
  • Publication number: 20130145751
    Abstract: The present disclosure relates to an energy reclaiming system for an electric forklift truck. The energy reclaiming system includes an electronic device operated by a motor when a working machine is raised and operated by a generator when the working machine is lowered, a hydraulic pump/motor connected to the electronic device and configured to perform two functions of a hydraulic pump and a hydraulic motor, a main control valve unit including a lift cylinder operating unit connected to the hydraulic pump/motor and configured to operate a lift cylinder and a secondary consumer operating unit connected to the hydraulic pump/motor and configured to operate a secondary consumer, and a control lever including a control valve configured to control the lift cylinder or the secondary consumer through the lift cylinder operating unit and the secondary consumer operating unit of the main control valve unit, respectively.
    Type: Application
    Filed: May 19, 2011
    Publication date: June 13, 2013
    Applicant: DOOSAN INDUSTRIAL VEHICLE CO., LTD
    Inventors: Dong Ho Han, Dal Sik Jang
  • Publication number: 20120279211
    Abstract: The present disclosure is a construction machine, such as an excavator, which comprises a plurality of hydraulically driven actuators, in which some of the actuators are provided in a one-to-one pump system where hydraulic pumps are connected to the respective actuators such that a working fluid is supplied from the respective pumps, and the remaining actuators are provided in an auxiliary control valve system where the working fluid is distributed by an auxiliary control valve connected to one or more pumps. When an amount of the working fluid of an actuator associated with the auxiliary control valve is insufficient, the actuator associated with the auxiliary control valve is connected to a pump of the one-to-one pump system to share the pump of the one-to-one pump system.
    Type: Application
    Filed: December 23, 2010
    Publication date: November 8, 2012
    Applicant: DOOSAN INFRACORE CO., LTD.
    Inventor: Dal Sik Jang
  • Publication number: 20110262287
    Abstract: A hydraulic pump controlling apparatus of a construction machine according to the present disclosure includes: a hydraulic pump in which a swash plate angle is controlled to control a discharge flow; an auxiliary pump; a control valve controlling a flowing direction of a fluid discharged from the hydraulic pump and selectively supplying the fluid to an actuator; an orifice and a relief valve connected between a center bypass line of the control valve and a tank T to be parallel to each other; signal pressure selecting units receiving a fluid passing through the center bypass line of the control valve and a fluid discharged from the auxiliary pump, and selecting the pressure of any one of the fluids as a signal pressure; and a regulator receiving the signal pressure selected from the signal pressure selecting units to control the swash plate angle of the hydraulic pump, and the signal pressure selecting unit selects the pressure of the fluid discharged from the auxiliary pump as the signal pressure and transfe
    Type: Application
    Filed: December 23, 2009
    Publication date: October 27, 2011
    Applicant: DOOSAN INFRACORE CO., LTD.
    Inventors: Young Sik Cho, Dal Sik Jang
  • Patent number: 7430859
    Abstract: A fluid pump control system for excavators enables fluid pumps to produce hydraulic flows of a quantity great enough to actuate hydraulic actuators for smooth composite operations. The system includes variable displacement fluid pumps, fluid quantity control mechanisms for controlling the discharge quantity of the respective fluid pumps, fluid quantity control signal lines respectively connected to the fluid quantity control mechanisms, signal pressure control lines for bringing the fluid quantity control signal lines into connection with a fluid tank to drop the fluid quantity control signal pressures within the fluid quantity control signal lines, and a plurality of cutoff valves attached to the signal pressure control lines in tandem and shiftable in concert with the shifting movement of spools of a control valve for increasing the fluid quantity control signal pressures within the signal pressure control lines in proportion to the shifting amounts of the cutoff valves.
    Type: Grant
    Filed: December 29, 2005
    Date of Patent: October 7, 2008
    Assignee: Doosan Infracore Co., ltd.
    Inventors: Dal Sik Jang, Ki Nam Jung
  • Patent number: 6386346
    Abstract: A spool-out type booster brake valve device for industrial vehicles is configured to allow hydraulic working fluid to be supplied not only to a booster chamber but also to a master chamber thereby eliminating the need to use a separate brake fluid reservoir tank for supplementing brake fluid in the master chamber. The brake valve device is used in an industrial vehicle equipped with a fluid pump, a reservoir tank and a brake actuator. The brake valve device includes a valve body having an inlet port, a drain port, a brake port, a booster chamber communicatable with the pump via the inlet port and a master chamber communicatable with the brake actuator via the brake port. The master chamber is connected to the inlet port to receive working fluid from the pump. A valve spool is slidably fitted in the valve body through the booster chamber and the master chamber, the valve spool being shifted between an idle position and an operating position.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: May 14, 2002
    Assignee: Daewoo Heavy Industries Ltd.
    Inventors: Tae Kyung Kim, Dal Sik Jang, Jeong Hee Hong, Sung Ha Park