Patents by Inventor Yong Lak Cho
Yong Lak Cho 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).
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Patent number: 12152611Abstract: A hydraulic system comprises: a hydraulic pump that includes an swash plate; an swash plate angle sensor for measuring the angle of the swash plate; an swash plate driving piston for moving the swash plate of the hydraulic pump in response to changes in pressure applied to a large diameter section; an swash plate control hydraulic line for supplying the large diameter section with a portion of the hydraulic oil discharged by the hydraulic pump; a control valve that controls the flow rate of the hydraulic oil that is following into and out of the large diameter section; an electro-proportional pressure reducing valve for producing pilot pressure that is to be transmitted to one side of the control valve; and a control device for controlling the electro-proportional pressure reducing valve according to an operation signal of an operation device and the angle information from the swash plate angle sensor.Type: GrantFiled: November 29, 2021Date of Patent: November 26, 2024Assignee: HD HYUNDAI INFRACORE CO., LTD.Inventor: Yong Lak Cho
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Publication number: 20240110581Abstract: A hydraulic system comprises: a hydraulic pump that includes an swash plate; an swash plate angle sensor for measuring the angle of the swash plate; an swash plate driving piston for moving the swash plate of the hydraulic pump in response to changes in pressure applied to a large diameter section; an swash plate control hydraulic line for supplying the large diameter section with a portion of the hydraulic oil discharged by the hydraulic pump; a control valve that controls the flow rate of the hydraulic oil that is following into and out of the large diameter section; an electro-proportional pressure reducing valve for producing pilot pressure that is to be transmitted to one side of the control valve; and a control device for controlling the electro-proportional pressure reducing valve according to an operation signal of an operation device and the angle information from the swash plate angle sensor.Type: ApplicationFiled: November 29, 2021Publication date: April 4, 2024Inventor: Yong Lak CHO
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Patent number: 11047405Abstract: A control system for construction machinery, includes a hydraulic pump, at least one control valve installed in a center bypass line connected to the hydraulic pump and configured to control a flow direction of a working oil discharged from the hydraulic pump to selectively supply the working oil to an actuator, a bypass control valve installed downstream from the control valve in the center bypass line to variably control an amount of the working oil draining to a drain tank through the center bypass line, and a controller configured to control operations of the hydraulic pump and the bypass control valve according to a manipulation signal of an operator and to open the bypass control valve according to pump peak occurrence to reduce a pump peak.Type: GrantFiled: March 6, 2018Date of Patent: June 29, 2021Assignee: DOOSAN INFRACORE CO., LTD.Inventors: Woo-Yong Jung, Yong-Lak Cho, Chang-Mook Kim
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Patent number: 10883253Abstract: The present disclosure relates to a method for controlling a swing motor in a hydraulic system and a hydraulic system. The method for controlling the swing motor in the hydraulic system and the hydraulic system according to the exemplary embodiment of the present disclosure may ensure the sufficient amount of hydraulic oil in a make-up line in a situation in which the hydraulic oil needs to be supplementarily supplied to the swing motor in the hydraulic system. Therefore, it is possible to prevent the occurrence of cavitation in the swing motor by stably supplying the amount of hydraulic oil at the point in time where the hydraulic oil needs to be supplementarily supplied to the swing motor. In addition, it is possible to prevent the occurrence of abnormal noise which is harsh to the ear when the cavitation occurs.Type: GrantFiled: March 12, 2015Date of Patent: January 5, 2021Assignee: DOOSAN INFRACORE CO., LTD.Inventor: Yong Lak Cho
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Patent number: 10757239Abstract: An electronic device includes an earphone jack assembly disposed to align with an opening in the housing of the electronic device. The earphone jack assembly includes at least one structure including a first passage having a first cross-sectional area, a second passage having a second cross-sectional area smaller than the first cross-sectional area, a third passage, and a microphone disposed outside of the at least one structure and including a substrate having a hole connected to the third passage. The first passage extends from the opening in a first direction, and includes a first end connected to the opening and a second end opposite to the first end, the second passage extends from the second end of the first passage in the first direction, and the third passage extends from the second passage in a second direction different from the first direction.Type: GrantFiled: August 22, 2018Date of Patent: August 25, 2020Assignee: Samsung Electronics Co., Ltd.Inventors: Jae Il Seo, Ki Jae Kim, Dae Young Noh, Soon Woong Yang, Yong Lak Cho
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Patent number: 10577777Abstract: A control system for construction machinery includes a main control valve installed in a hydraulic line between a hydraulic pump and actuators, and including a first group of electro proportional pressure reducing valves outputting a secondary pressure in proportion to an external pressure command signal to a first spool for controlling a first group of actuators of the actuators, and a second group of electro proportional pressure reducing valves outputting a secondary pressure in proportion to an external pressure command signal to a second spool for controlling a second group of actuators of the actuators, a first pressure sensor configured to detect the secondary pressure outputted from the first group of electro proportional pressure reducing valves and a second pressure sensor configured to detect the secondary pressure outputted from the second group of electro proportional pressure reducing valves, and a controller configured to output pressure command signals to the electro proportional pressure reduType: GrantFiled: January 12, 2016Date of Patent: March 3, 2020Assignee: DOOSAN INFRACORE CO., LTD.Inventors: Yong-Lak Cho, Hyun-Sik Lim, Soo-Kwang Lee, Young-Shik Cho
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Publication number: 20200040917Abstract: A control system for construction machinery, includes a hydraulic pump, at least one control valve installed in a center bypass line connected to the hydraulic pump and configured to control a flow direction of a working oil discharged from the hydraulic pump to selectively supply the working oil to an actuator, a bypass control valve installed downstream from the control valve in the center bypass line to variably control an amount of the working oil draining to a drain tank through the center bypass line, and a controller configured to control operations of the hydraulic pump and the bypass control valve according to a manipulation signal of an operator and to open the bypass control valve according to pump peak occurrence to reduce a pump peak.Type: ApplicationFiled: March 6, 2018Publication date: February 6, 2020Inventors: Woo-Yong JUNG, Yong-Lak CHO, Chang-Mook KIM
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Publication number: 20190068770Abstract: An electronic device includes an earphone jack assembly disposed to align with an opening in the housing of the electronic device. The earphone jack assembly includes at least one structure including a first passage having a first cross-sectional area, a second passage having a second cross-sectional area smaller than the first cross-sectional area, a third passage, and a microphone disposed outside of the at least one structure and including a substrate having a hole connected to the third passage. The first passage extends from the opening in a first direction, and includes a first end connected to the opening and a second end opposite to the first end, the second passage extends from the second end of the first passage in the first direction, and the third passage extends from the second passage in a second direction different from the first direction.Type: ApplicationFiled: August 22, 2018Publication date: February 28, 2019Inventors: Jae Il SEO, Ki Jae KIM, Dae Young NOH, Soon Woong YANG, Yong Lak CHO
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Patent number: 10196797Abstract: The present disclosure provides a pressure peak reduction valve for an excavator. The pressure peak reduction valve includes at least: a poppet seat which has an inlet port, and at least one communication hole which communicates with a hydraulic tank and is formed in an outer circumferential surface of the poppet seat; a main poppet which slides in the poppet seat; a poppet spring which is provided in the main poppet; a valve seat which has one end portion inserted into the main poppet so as to be in contact with one end portion of the poppet spring; a cone which is provided to be inserted into an openable hole formed at an end portion of the valve seat; an adjustment screw which is provided in the valve seat; and a piston which slides in the adjustment screw.Type: GrantFiled: December 12, 2014Date of Patent: February 5, 2019Assignee: DOOSAN INFRACORE CO., LTD.Inventors: Hyun Sik Lim, Yong Lak Cho
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Patent number: 10167615Abstract: A control system for construction machinery includes first and second hydraulic pumps connected to an engine, a swing control valve and a first boom control valve installed in a first center bypass line connected to the first hydraulic pump, a second boom control valve installed in a second center bypass line connected to the second hydraulic pump, a shutoff valve installed in a control line through which a boom raising pilot signal pressure is supplied to the first boom control valve and configured to selectively open and close the control line, and a control unit configured to electronically control the shutoff valve according to a manipulation signal, wherein the control unit closes the shutoff valve such that the first boom control valve is shifted to a neutral position when a swing operation priority mode is selected.Type: GrantFiled: June 1, 2016Date of Patent: January 1, 2019Assignee: DOOSAN INFRACORE CO., LTD.Inventor: Yong-Lak Cho
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Publication number: 20180044891Abstract: A control system for construction machinery includes a main control valve installed in a hydraulic line between a hydraulic pump and actuators, and including a first group of electro proportional pressure reducing valves outputting a secondary pressure in proportion to an external pressure command signal to a first spool for controlling a first group of actuators of the actuators, and a second group of electro proportional pressure reducing valves outputting a secondary pressure in proportion to an external pressure command signal to a second spool for controlling a second group of actuators of the actuators, a first pressure sensor configured to detect the secondary pressure outputted from the first group of electro proportional pressure reducing valves and a second pressure sensor configured to detect the secondary pressure outputted from the second group of electro proportional pressure reducing valves, and a controller configured to output pressure command signals to the electro proportional pressure reduType: ApplicationFiled: January 12, 2016Publication date: February 15, 2018Inventors: Yong-Lak CHO, Hyun-Sik LIM, Soo-Kwang LEE, Young-Shik CHO
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Patent number: 9841037Abstract: Disclosed are a hydraulic system for construction equipment and a method of controlling the same, and the hydraulic system for construction equipment includes: a plurality of pressure control-type hydraulic pumps driven by an engine provided in construction equipment; an actuator driven by working oil discharged from the hydraulic pump; a closed center-type main control valve provided between the hydraulic pump and the actuator, and bypassing a virtual flow rate; and a controller configured to control the hydraulic pump by receiving the bypassed virtual flow rate from the main control valve.Type: GrantFiled: March 19, 2014Date of Patent: December 12, 2017Assignee: Doosan Infracore Co., Ltd.Inventors: Yong Ho Tho, Woo Yong Jung, Yong Lak Cho
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Patent number: 9829013Abstract: 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: GrantFiled: March 13, 2014Date of Patent: November 28, 2017Assignee: 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
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Publication number: 20170107691Abstract: The present disclosure relates to a method for controlling a swing motor in a hydraulic system and a hydraulic system. The method for controlling the swing motor in the hydraulic system and the hydraulic system according to the exemplary embodiment of the present disclosure may ensure the sufficient amount of hydraulic oil in a make-up line in a situation in which the hydraulic oil needs to be supplementarily supplied to the swing motor in the hydraulic system. Therefore, it is possible to prevent the occurrence of cavitation in the swing motor by stably supplying the amount of hydraulic oil at the point in time where the hydraulic oil needs to be supplementarily supplied to the swing motor. In addition, it is possible to prevent the occurrence of abnormal noise which is harsh to the ear when the cavitation occurs.Type: ApplicationFiled: March 12, 2015Publication date: April 20, 2017Applicant: Doosan Infracore Co., Ltd.Inventor: Yong Lak CHO
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Patent number: 9618018Abstract: 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: GrantFiled: March 26, 2014Date of Patent: April 11, 2017Assignee: DOOSAN INFRACORE CO., LTD.Inventors: Min Ha An, Woo Yong Jung, Yong Lak Cho, A Reum Seo, Dal Sik Jang, Kwang Ho Lim
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Publication number: 20160356020Abstract: A control system for construction machinery includes first and second hydraulic pumps connected to an engine, a swing control valve and a first boom control valve installed in a first center bypass line connected to the first hydraulic pump, a second boom control valve installed in a second center bypass line connected to the second hydraulic pump, a shutoff valve installed in a control line through which a boom raising pilot signal pressure is supplied to the first boom control valve and configured to selectively open and close the control line, and a control unit configured to electronically control the shutoff valve according to a manipulation signal, wherein the control unit closes the shutoff valve such that the first boom control valve is shifted to a neutral position when a swing operation priority mode is selected.Type: ApplicationFiled: June 1, 2016Publication date: December 8, 2016Inventor: Yong-Lak Cho
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Publication number: 20160326721Abstract: The present disclosure provides a pressure peak reduction valve for an excavator. The pressure peak reduction valve includes at least: a poppet seat which has an inlet port, and at least one communication hole which communicates with a hydraulic tank and is formed in an outer circumferential surface of the poppet seat; a main poppet which slides in the poppet seat; a poppet spring which is provided in the main poppet; a valve seat which has one end portion inserted into the main poppet so as to be in contact with one end portion of the poppet spring; a cone which is provided to be inserted into an openable hole formed at an end portion of the valve seat; an adjustment screw which is provided in the valve seat; and a piston which slides in the adjustment screw.Type: ApplicationFiled: December 12, 2014Publication date: November 10, 2016Inventors: Hyun Sik LIM, Yong Lak CHO
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Publication number: 20160290370Abstract: Disclosed are a hydraulic system for construction equipment and a method of controlling the same, and the hydraulic system for construction equipment includes: a plurality of pressure control-type hydraulic pumps driven by an engine provided in construction equipment; an actuator driven by working oil discharged from the hydraulic pump; a closed center-type main control valve provided between the hydraulic pump and the actuator, and bypassing a virtual flow rate; and a controller configured to control the hydraulic pump by receiving the bypassed virtual flow rate from the main control valve.Type: ApplicationFiled: March 19, 2014Publication date: October 6, 2016Inventors: Yong Ho Tho, Woo Yong Jung, Yong Lak Cho
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Publication number: 20160032945Abstract: 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: ApplicationFiled: March 13, 2014Publication date: February 4, 2016Inventors: Yong Lak CHO, Dal Sik JANG, Woo Yong JUNG, Min Ha AN, A Reum SEO, Sang Woo LEE, Yoon Seok JANG
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Patent number: 9191474Abstract: An electronic device is provided including a mainboard having a ground; a conductive bracket coupled to the mainboard; and an elastic member coupled to the mainboard, and electrically connected with the ground of the mainboard; wherein the elastic member is in elastic contact with the conductive bracket; and wherein the elastic member is electrically connected to the conductive bracket.Type: GrantFiled: December 23, 2013Date of Patent: November 17, 2015Assignee: Samsung Electronics Co., Ltd.Inventors: Young-Kwang Song, Sung-Won Park, Yong-Lak Cho