Pump Displacement Controlled By Pump Discharge Or Motor Feed Pressure Patents (Class 60/452)
  • Patent number: 10954970
    Abstract: A hydraulic drive device for an industrial vehicle includes a tank, a hydraulic pump, a capacity control valve, a plurality of hydraulic cylinders, a plurality of direction switching valves, a first hydraulic oil passage, a second hydraulic oil passages, a pilot line, a relief valve, a relief pressure setting portion, a plurality of operation detecting portions, and a control unit. The control valve controls the hydraulic pumps so that a differential pressure between a discharge pressure of the hydraulic pump and a pilot pressure of the pilot line is to be a predetermined pressure. The control unit controls the relief pressure setting portion.
    Type: Grant
    Filed: December 20, 2019
    Date of Patent: March 23, 2021
    Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKI
    Inventor: Eisuke Kondo
  • Patent number: 10829909
    Abstract: A controller determines a target rotation speed of an engine from an operation amount of an accelerator operating member. The controller determines whether a vehicle is in coasting deceleration. The controller decreases a differential pressure between a first circuit and a second circuit of a hydraulic circuit according to a deviation between an actual rotation speed of the engine and the target rotation speed, or the operation amount of the accelerator operating member when the vehicle is in the coasting deceleration.
    Type: Grant
    Filed: January 21, 2019
    Date of Patent: November 10, 2020
    Assignee: KOMATSU LTD.
    Inventor: Takahisa Oasa
  • Patent number: 10800390
    Abstract: The hydraulic pressure generating device includes a regulator (spool valve) formed by a cylinder body, a spool which slidably moves within the cylinder body, a pilot chamber in which a pilot pressure which is a hydraulic pressure moving the spool along in an axial direction is inputted and an output chamber out of which an output pressure which is a hydraulic pressure corresponding to the pilot pressure is outputted, wherein the hydraulic pressure generating device further includes a spool position obtaining portion which obtains a relative position of the spool relative to the cylinder body and a pilot pressure controlling portion which controls the pilot pressure based on the relative position obtained by the spool position obtaining portion.
    Type: Grant
    Filed: July 25, 2016
    Date of Patent: October 13, 2020
    Assignees: ADVICS CO., LTD., TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaki Ninoyu, Takahiro Okano, Yoshio Masuda
  • Patent number: 10794044
    Abstract: Provided is a work machine hydraulic control system capable of detecting abnormality in a pump output power switching device independently of the abnormality state of the pump output power switching device. A hydraulic control system of a hydraulic excavator is equipped with an accumulator 21 connected to a hydraulic line 25A between a pilot pump 17 and a pilot valve 20, an unloading valve 27 that is a pump output power switching device, a pressure sensor 29 detecting the pressure of the hydraulic fluid supplied to the pilot valve 20, and a controller 30 having a pump output power control section 31 switching the unloading valve 27 in accordance with the pressure detected by the pressure sensor 29. The controller 30 further has an abnormality determination section 32 that computes a command continuation time in a state in which a command output to the unloading valve 27 is not changed.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: October 6, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yuichi Ogawa, Seiji Hijikata, Masatoshi Hoshino
  • Patent number: 10655650
    Abstract: A valve block arrangement configured as a closed center system includes at least one main spool for controlling a hydraulic consumer. The main spool is configured to open and close at least one pressure medium connection between a hydraulic pump and the consumer in controlled, continuous fashion and, in at least one embodiment, is electrically activated. A bypass flow path with a cut valve branches off between the adjustable, hydraulic pump and the main spool. The cut valve is configured to open and close a pressure medium connection between the hydraulic pump and a tank in controlled, continuous fashion. The cut valve is electrically activatable.
    Type: Grant
    Filed: June 22, 2018
    Date of Patent: May 19, 2020
    Assignee: Robert Bosch GmbH
    Inventors: Wilfried Werner, Botond Szeles, Sebastian Oschmann
  • Patent number: 10473125
    Abstract: To reduce the cost by reducing the number of parts and simplify the control of regeneration in the hydraulic actuator even though the meter-in control and the meter-out control can be performed separately while the supply and the discharge of hydraulic fluid is controlled. A meter-in valve that controls supply flow from a hydraulic pump into a hydraulic cylinder is provided, and meter-out switching valve that switches the direction of supply and discharge of the hydraulic oil into the hydraulic cylinder and controls the discharge flow from the hydraulic cylinder to the oil tank is installed on the down stream side of the meter-in valve, and further, a regeneration control valve is installed on the down stream side of the meter-out switching valve.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: November 12, 2019
    Assignee: Caterpillar SARL
    Inventors: Hideki Nakajima, Shuhei Orimoto, Naoki Kuroda
  • Patent number: 10400426
    Abstract: Provided is a hydraulic control system for a construction machine, including: a control valve (31) for controlling supply and discharge of hydraulic fluid to and from an arm cylinder (4); an operation lever (6) for controlling the position of a spool of the control valve (31); a meter-out flow passage (34) for passing therethrough hydraulic fluid discharged from the arm cylinder; a variable restrictor (23a) provided in the meter-out flow passage; pressure sensors (41, 42) for detecting a magnitude of a negative load applied by an external force to the arm cylinder in a same direction as an actuation direction of the arm cylinder; and a controller (45) for reducing an opening area of the variable restrictor (23a) according to an increase in the magnitude of the negative load calculated with a detection value from the pressure sensors (41, 42).
    Type: Grant
    Filed: September 4, 2015
    Date of Patent: September 3, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Ryohei Yamashita, Shinya Imura, Kouji Ishikawa, Hidekazu Moriki
  • Patent number: 10377414
    Abstract: A dual pressure margin priority circuit and method for controlling flow from a pump to steering valve and low priority inlets. A steering pressure valve controls flow from pump to steering valve inlets, and provides a steering valve load sense pressure. A priority valve controls flow from pump to low priority inlets. A load sense cutoff valve has a first inlet receiving the steering valve load sense pressure. The load sense cutoff valve controls flow through the priority valve based on steering valve load sense pressure at the first cutoff valve inlet. The cutoff valve can include a second inlet coupled to tank, and a load sense input coupled to the steering valve load sense pressure. The cutoff valve can be a pressure limiter valve. The priority and steering pressure valves can be 2-way proportional flow spool valves with bias springs, and contributing and opposing load sense inputs.
    Type: Grant
    Filed: February 9, 2017
    Date of Patent: August 13, 2019
    Assignee: DEERE & COMPANY
    Inventors: Troy E. Schick, Ryan Pence, Aaron M. Quinn
  • Patent number: 9702118
    Abstract: A hydraulic system is disclosed for use with a machine. The hydraulic system may have a pump configured to pressurize fluid, a first actuator configured to receive pressurized fluid from the pump, and an accumulator configured to receive fluid from the first actuator. The hydraulic system may also have a second actuator configured to receive pressurized fluid from the pump and the accumulator, and a pilot circuit configured to receive pressurized fluid from the pump and the accumulator. The hydraulic system may further have at least one valve movable to provide priority of fluid flow from the accumulator to the pilot circuit over the second actuator when a pressure of the accumulator is less than a low-pressure threshold.
    Type: Grant
    Filed: November 19, 2014
    Date of Patent: July 11, 2017
    Assignee: Caterpillar Inc.
    Inventors: Corey Lee Gorman, John J. Krone, Adam Martin Nackers
  • Patent number: 9671763
    Abstract: In a control device for construction machinery, a system operating point calculation unit calculates a plurality of combinations of engine rotational speed and engine torque with which demanded power of an engine can be generated; and calculates system efficiency in each of the combinations according to discharge pressure of a hydraulic. A rotational speed calculation unit calculates target rotational speed of the engine as the engine rotational speed in one of the combinations of the engine rotational speed, the engine torque and the system efficiency calculated by the system operating point calculation unit that includes desired system efficiency. A displacement calculation unit calculates target displacement of the hydraulic pump based on the target rotational speed calculated by the rotational speed calculation unit and demanded flow rate of the hydraulic pump. With this control device, the engine and the hydraulic pump can be controlled at an efficient operating point.
    Type: Grant
    Filed: December 28, 2012
    Date of Patent: June 6, 2017
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Shinji Ishihara, Masatoshi Hoshino, Mitsuo Sonoda
  • Patent number: 9546673
    Abstract: A hydraulic drive system includes a pump, a steering actuator, a loading/unloading apparatus actuator, a drive device, a relief valve, and an input unit. The drive device: flows hydraulic oil from the pump to the loading/unloading apparatus actuator when an operating tool is operated; flows the hydraulic oil from the pump to the steering actuator when a steering has become an operated state from a non-operated state regardless of an operation of the operating tool; and causes the hydraulic oil from the pump to be discharged to a tank via the relief valve to increase the torque of an engine when an increase instruction is inputted to the input unit and the steering is in a non-operated state.
    Type: Grant
    Filed: November 30, 2012
    Date of Patent: January 17, 2017
    Assignee: KABUSHIKI KAISHA KCM
    Inventors: Shinichiro Tanaka, Hiroyasu Kodera, Makoto Ito
  • Patent number: 9534616
    Abstract: A system for determining an estimated output from a variable displacement hydraulic pump includes a prime mover, a torque sensor, a pressure sensor, and a displacement sensor. A controller is configured to determine the output torque from the prime mover, determine an input torque to the variable displacement hydraulic pump based upon the output torque, determine an output from one of the pressure sensor and the displacement sensor based upon the signals. The controller is further configured to determine a failure of another of the pressure sensor and the displacement sensor and determine an estimated output from the another of the pressure sensor and the displacement sensor based upon the input torque to the variable displacement hydraulic pump and the output from the one of the pressure sensor and the displacement sensor.
    Type: Grant
    Filed: January 16, 2015
    Date of Patent: January 3, 2017
    Assignee: Caterpillar Inc.
    Inventors: Santosh Ancha, Aleksandar Egelja, Hongliu Du, Takayuki Sasaki
  • Patent number: 9347200
    Abstract: A fluid control system including a variable displacement pump having a load system control and configured to operate in an open center mode. A pump control is operable between a first arrangement and a second arrangement. The pump control receives pressurized fluid from a first load sensor pressure in fluid communication with the pump and an actuator return pressure in fluid communication with an actuator configured to operate using pressurized fluid from the system, the pump control providing a selective pump control pressure to the pump load system control. When the system is operating in a standby mode, the pump operates in a first minimized displacement condition. When the system is in a stall mode, the pump operates in a second minimized displacement condition.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: May 24, 2016
    Assignee: CNH Industrial America LLC
    Inventors: Matthew J. Hennemann, Richard J. Lech
  • Patent number: 9309969
    Abstract: A method for controlling a hydrostatic drive unit of a work vehicle is disclosed. The method may generally include determining a reference swashplate position for a hydraulic pump of the hydrostatic drive unit, wherein the reference swashplate position is associated with an uncompensated current command, and monitoring an actual swashplate position of the hydraulic pump, wherein the actual swashplate position differs from the reference swashplate position due to a loading condition of the work vehicle. In addition, the method may include determining a current compensation based at least in part on the actual and reference swashplate positions and generating a compensated current command by adjusting the uncompensated current command based on the current compensation, wherein the compensated current command is associated with a compensated swashplate position for the hydraulic that differs from the reference swashplate position.
    Type: Grant
    Filed: January 24, 2014
    Date of Patent: April 12, 2016
    Assignee: CNH Industrial America LLC
    Inventors: Duqiang Wu, Navneet Gulati
  • Patent number: 9206583
    Abstract: A void protection system for a mining shovel having an operator input device includes an independent metering valve assembly including one or more fluid source-cylinder valves for fluidly connecting the fluid source to the hydraulic cylinder. The system also includes a sensor assembly for monitoring the fluid pressure within the rod end and the head end of the hydraulic cylinder, and a control module. The control module is configured to monitor movement of the operator input device, monitor pressure within the hydraulic cylinder, increase the opening of the corresponding fluid source-cylinder valve and increase fluid flow from the fluid source to fill corresponding end of the hydraulic cylinder until pressure in the corresponding end of the hydraulic cylinder is above a first threshold pressure.
    Type: Grant
    Filed: April 10, 2013
    Date of Patent: December 8, 2015
    Assignee: Caterpillar Global Mining LLC
    Inventors: Matthew J. Beschorner, Bryan A. Johnson, Brett J. Janson, Brandon Z. Barnes, Rustu Cesur
  • Patent number: 9139982
    Abstract: A hydraulic control system for a machine is disclosed. The hydraulic control system may have a pump configured to pressurize fluid, and a motor driven by a flow of pressurized fluid from the pump. The hydraulic control system may also have a first accumulator configured to receive pressurized fluid discharged from the motor and to selectively supply pressurized fluid to the motor, and a second accumulator configured to receive pressurized fluid discharged from the motor and selectively supply pressurized fluid to the motor.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: September 22, 2015
    Assignee: Caterpillar Inc.
    Inventors: Pengfei Ma, Jiao Zhang, Dayao Chen, Tonglin Shang
  • Patent number: 9108670
    Abstract: A method is provided for controlling a hydraulic system of a working machine, which hydraulic system includes a first hydraulic machine for providing hydraulic fluid to a first actuator of the working machine, and a second hydraulic machine for providing hydraulic fluid to a second actuator of the working machine and for providing hydraulic fluid to the first actuator. The method includes using a first control mode, and in the first control mode allowing a flow of hydraulic fluid from the second hydraulic machine to the second actuator, wherein the pump pressure of the second hydraulic machine is selected based on the load pressure of the second actuator independently of the load pressure of the first actuator.
    Type: Grant
    Filed: December 2, 2009
    Date of Patent: August 18, 2015
    Assignee: Volvo Construction Equipment AB
    Inventors: Bo Vigholm, Andreas Ekvall, Kim Heybroek
  • Patent number: 9085870
    Abstract: Disclosed is a swing control apparatus of construction machinery, including: a hydraulic pump discharging working oil for driving a swing motor and controlling a discharge flux according to an input pump command value Vpump; a pressure sensor sensing pressure of the working oil discharged from the hydraulic pump; and a control unit calculating the pump command value Vpump based on a swing operation quantity Vsw input from the swing operation unit to output the calculated pump command value to the hydraulic pump, wherein when the input swing operation quantity Vsw is larger than a preset reference swing operation quantity Vswo and the discharge pressure Ppump of the hydraulic pump detected by the pressure sensor is lower than a first reference pressure Pswr1, the control unit calculates a converted swing operation quantity Vsw? gradually increasing from the reference swing operation quantity Vswo to the input swing operation quantity Vsw and calculates the pump command value Vpump of the hydraulic pump corresp
    Type: Grant
    Filed: June 1, 2010
    Date of Patent: July 21, 2015
    Assignee: Doosan Infracore Co., Ltd.
    Inventor: Ki Yong Kim
  • Patent number: 9032726
    Abstract: A controller carries out horsepower control to determine a flow rate of a hydraulic pump based on first characteristics and second characteristics, which each define a maximum input setting of the hydraulic pump by a discharge pressure of the hydraulic pump and a flow rate of the hydraulic pump, and based on the discharge pressure. When the discharge pressure is less than a set pressure and when a state where the discharge pressure is equal to or greater than the set pressure has not continued for a set time period, then the controller determines the flow rate based on the first characteristics, and when the state where the discharge pressure is equal to or greater than the set pressure has continued for the set time period, then the controller determines the flow rate based on the second characteristics.
    Type: Grant
    Filed: February 9, 2012
    Date of Patent: May 19, 2015
    Assignee: KOBELCO CONSTRUCTION MACHINERY CO., LTD.
    Inventor: Toshio Sora
  • Publication number: 20150128580
    Abstract: A hydraulic brake mechanism for use in hydraulic systems to provide braking of a hydraulic motor is disclosed. The brake mechanism provides proper braking under a range of operating conditions, including (1) the start of flow from the pump to the brake and motor and braking is not desired; (2) operating conditions in which constant flow is provided from the pump to the brake and motor and braking is not desired; (3) operating conditions in which abrupt decreases of flow from the pump to the brake and the motor occur, for example where flow is reduced due to being drawn by another work element or hydraulic load, but under which a reduced supply flow is still present and braking is not desired; and (4) operating conditions in which the hydraulic flow from the pump to the brake mechanism and the motor is shut off completely and braking is desired.
    Type: Application
    Filed: November 12, 2014
    Publication date: May 14, 2015
    Inventor: Robert R. Lacher
  • Patent number: 9016053
    Abstract: A device for varying the stroke of first and second hydraulic machines. At least one piston is functionally connected to axes of the hydraulic machines. Depending on power demanded by a driver, the piston can be acted upon, via position and high pressure control valve units of a valve system, with pressures that correspond to a pressure present in the hydraulic machines and that act in a first adjustment direction of the hydraulic machines axes. Pressure in the hydraulic machines is controlled by the position control valve unit and is limited by the high pressure control valve unit. The piston can be acted upon by the valve system with pressures that correspond to the pressure present in the hydraulic machines and that act in a second adjustment direction of the axes of the hydraulic machines, and action of the position control valve unit can be reversed.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: April 28, 2015
    Assignee: ZF Friedrichshafen AG
    Inventor: Jurgen Legner
  • Patent number: 9010102
    Abstract: The present invention relates to a device for controlling a hydraulic pump of construction machinery.
    Type: Grant
    Filed: November 1, 2010
    Date of Patent: April 21, 2015
    Assignee: Doosan Infracore Co., Ltd.
    Inventors: Jae Seok Bang, Woo Yong Jung, Won Sun Sohn
  • Patent number: 8985138
    Abstract: A valve arrangement includes at least two valves and a housing which is configured as an installation cartridge. One of the valves is configured as a pressure regulator and the other of the valves is configured as a delivery flow regulator. The valve arrangement is configured to be inserted or screwed into a variable-displacement pump, thereby minimizing the spatial requirement of the valve arrangement.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: March 24, 2015
    Assignee: Robert Bosch GmbH
    Inventor: Christian Spielvogel
  • Patent number: 8911216
    Abstract: Methods, apparatuses, and computer program products for controlling the torque load of multiple variable displacement hydraulic pumps are described herein. A pump displacement limit for each variable displacement hydraulic pump is determined using a nonlinear control law to limit the total pump torque load of the variable displacement hydraulic pumps on the engine. The value of the actual pump displacement of each variable displacement hydraulic pump is controlled based upon the respective determined pump displacement limit.
    Type: Grant
    Filed: May 6, 2011
    Date of Patent: December 16, 2014
    Assignee: Caterpillar Inc.
    Inventors: Hongliu Du, Patrick W. Sullivan
  • Patent number: 8904777
    Abstract: A pump control device for a construction machine includes a pump regulator, a pump pressure detector, a travelling operation detector, a working operation detector, and a controller instructing the pump flow rate depending on the pump pressure to the pump regulator. The controller stores first and second P-Q characteristics as a horsepower characteristic and instructs the pump flow rate to the pump regulator, based on the first P-Q characteristic when a travelling operation is detected, and based on the second P-Q characteristic when a working operation is detected. The second P-Q characteristic is equal to the first P-Q characteristic in a low-pressure region while is one giving a low characteristic relatively to the first P-Q characteristic so as to increase a horsepower difference as the pump pressure increases, in intermediate-pressure and high-pressure regions.
    Type: Grant
    Filed: February 21, 2012
    Date of Patent: December 9, 2014
    Assignee: Kobelco Construction Machinery Co., Ltd.
    Inventor: Nobuhiro Koga
  • 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
  • Patent number: 8887499
    Abstract: A method for overpressure control in a hydraulic system having multiple hydraulic pumps, with each hydraulic pump being connected by a respective hydraulic circuit for actuating a single respective hydraulic actuator, includes actuating a first variable displacement hydraulic pump, the first hydraulic pump being fluidly linked by a first hydraulic circuit to a first hydraulic actuator for powering the first hydraulic actuator. Upon detecting a pressure that exceeds a predetermined threshold pressure, the flow rate of the first hydraulic pump is electronically modified to a second flow rate lower than the first flow rate whereby the pressure in the first hydraulic circuit is reduced to a pressure that is below the predetermined threshold pressure.
    Type: Grant
    Filed: June 29, 2011
    Date of Patent: November 18, 2014
    Assignees: Caterpillar Inc., Purdue University
    Inventors: Brad Edler, Viral S. Mehta, Lawrence Tognetti, Christopher Williamson
  • Patent number: 8881506
    Abstract: A hydraulic drive system for a hydraulic working machine sets a delivery pressure at a preset value upon raising a temperature of exhaust gas to a temperature needed for combustion of particulate matter by increasing a load to be applied to an engine. In a non-operation state, a variable restrictor is controlled by a controller and a delivery pressure control valve to increase a delivery pressure of a variable displacement hydraulic pump, so that the load is increased to raise the temperature of exhaust gas to the temperature needed for the particulate matter combustion. At this time, the controller controls the delivery pressure control valve such that a delivery pressure to be detected by a delivery pressure sensor will conform with a preset reference delivery pressure. The reference delivery pressure is set to a minimum pressure that can provide the exhaust gas with combustion heat.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: November 11, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tsuyoshi Nakamura, Kouji Ishikawa, Yasushi Arai, Hidenobu Tsukada, Shohei Kamiya
  • Patent number: 8875506
    Abstract: A work vehicle includes a fluid circuit to operate at least one implement for performing work, the fluid circuit having at least a first operating mode and a second operating mode. The first operating mode is configured to operate within a first predetermined flow rate range within a first predetermined fluid pressure level range. The second operating mode is configured to operate within a second predetermined flow rate range and within a second predetermined fluid pressure level range. In response to the fluid circuit operating within the second operating mode, a maximum pressure value of the second predetermined fluid pressure level range is greater than a maximum pressure value of the first predetermined fluid pressure level range, and a maximum value of the second predetermined flow level range is less than a maximum value of the first predetermined flow level range.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: November 4, 2014
    Assignee: CNH Industrial America LLC
    Inventors: Matthew J. Hennemann, Joseph R. Shoemaker
  • Publication number: 20140318116
    Abstract: A hydraulic control device includes: a hydraulic pump connected in parallel to steering and boom cylinders; a steering control valve that controls the direction of operating oil flowing through the steering cylinders; a boom control valve that connects the hydraulic pump to a tank when the valve is at a neutral position and controls the direction of the oil flowing through the boom cylinders when the valve is at an offset position; a meter-in pressure compensator that increases flow rate of the oil flowing through a variable restrictor of the steering control valve in accordance with pressure in front of and behind the restrictor; and a bleed-off pressure compensator that decreases flow rate of the oil flowing through the boom control valve in accordance with the increase in pressure of the oil flowing through the steering cylinders to maintain the predetermined pressure of the oil in the steering control circuit.
    Type: Application
    Filed: November 30, 2012
    Publication date: October 30, 2014
    Applicant: KAWASAK JUKOGYO KABUSHIKI KAISHA
    Inventors: Makoto Ito, Ryo Yamamoto, Kazuto Fujiyama, Hiroyasu Kodera, Shinichiro Tanaka
  • Patent number: 8857169
    Abstract: A main relief valve 13 includes a biasing force altering unit 60, which constitutes, in combination with a gate lock valve 23 and a gate lock lever 24, relief pressure altering means for manually switching the relief pressure of the main relief valve 13 between a first pressure (a standard pressure of 25 MPa, for example) and a second lower pressure for engine start-up (e.g., 3.0 MPa). This allows the main relief valve 13 to return the hydraulic fluid discharged from a hydraulic pump 2 to a tank T in conjunction with an unloading valve 9 when multiple actuators 5a, 5b, . . . are not in operation under the ambient temperature below freezing point. As a result, it is possible to reduce the load on the hydraulic pump during cold engine start-up without compromising the anti-hunting characteristics of the unloading valve, thereby improving the engine start-up performance.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: October 14, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kiwamu Takahashi, Yasutaka Tsuruga, Yoshifumi Takebayashi, Kazushige Mori
  • Publication number: 20140290237
    Abstract: A control pressure switching valve is disposed between a displacement regulator and a pressure control valve. The control pressure switching valve is switched between a control position (j), in which a load sensing control pressure (PLS) is permitted to be outputted from the pressure control valve to the displacement regulator, and a control release position (k), in which the load sensing control pressure (PLS) to be outputted to the displacement regulator is reduced to a prescribed low pressure value. When the regeneration of a filter is determined to be necessary, the controller switches the control pressure switching valve to the control release position (k). When the load sensing control pressure (PLS) is reduced to the low pressure value with the control pressure switching valve switched to the control release position (k), the displacement regulator increases a delivery displacement of a hydraulic pump, thereby increasing rotational load of an engine.
    Type: Application
    Filed: November 19, 2012
    Publication date: October 2, 2014
    Inventors: Hajime Yoshida, Hajime Ishii, Yoshifumi Takebayashi, Shuuhei Noguchi, Hajime Kurikuma
  • Patent number: 8833065
    Abstract: A control device for a hybrid construction machine includes a discharge pressure introduction passage that leads a discharge pressure from a variable volume pump to a regulator, and a load pressure introduction passage that leads one of a maximum load pressure of respective actuators and a load pressure of a hydraulic motor to the regulator. A controller, having determined that the actuators are in an inoperative condition on the basis of a detection result from an operating condition detector, excites a solenoid of a solenoid pilot control valve such that a discharge oil from the variable volume pump is led to the hydraulic motor, and controls the regulator such that a differential pressure between the discharge pressure of the variable volume pump and the load pressure of the hydraulic motor is kept constant.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: September 16, 2014
    Assignee: Kayaba Industry Co., Ltd.
    Inventors: Haruhiko Kawasaki, Masahiro Egawa
  • Patent number: 8818651
    Abstract: A flow control system for a hydraulic pump of a construction machine that can variably control a discharge flow rate of the hydraulic pump in accordance with load pressure generated by a hydraulic actuator. According to the system, the discharge pressure of the hydraulic pump and the operation rate of the operation lever for the hydraulic actuators is detected, and standard load pressures of the respective hydraulic actuators are set. If the discharge pressure of the hydraulic pump is higher than preset load pressures of the hydraulic actuators, the discharge flow rate of the hydraulic pump is reduced in proportion to the operation rate in accordance with degrees of loads generated by the hydraulic actuators. If the discharge pressure of the hydraulic pump is lower than the standard load pressures of the hydraulic actuators, the discharge flow rate of the hydraulic pump is controlled in proportion to the operation rate.
    Type: Grant
    Filed: June 28, 2010
    Date of Patent: August 26, 2014
    Assignee: Volvo Construction Equipment AB
    Inventors: Hea-Gyoon Joung, Sang-Hee Lee, Hung-Ju Shin
  • Patent number: 8807155
    Abstract: A regulator that performs control such that a tilt angle of a variable volume pump increases as a pilot pressure in a pilot flow passage decreases is provided, and when a controller determines that all of a plurality of operation valves for controlling a flow of a discharged oil that is led from the variable volume pump to respective actuators are in a neutral position, the controller supplies the discharged oil from the variable volume pump to a regenerative hydraulic motor by setting a solenoid valve in an open position and sets a pilot flow passage change-over solenoid valve in a blocking position such that the pilot pressure led to the regulator through the pilot flow passage is reduced by a pressure reducing valve.
    Type: Grant
    Filed: April 22, 2010
    Date of Patent: August 19, 2014
    Assignee: Kayaba Industry Co., Ltd.
    Inventors: Haruhiko Kawasaki, Masahiro Egawa
  • Patent number: 8756930
    Abstract: A hydraulic system for a machine is disclosed. The hydraulic system may have a first pump with variable displacement and being load-sense controlled, and a first hydraulic circuit associated with the first pump. The hydraulic system may also have a second pump with variable displacement and being electro-hydraulically controlled, and a second hydraulic circuit associated with the second pump. The hydraulic system may further have a flow-sharing valve arrangement configured to selectively share fluid flow between the first and second hydraulic circuits.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: June 24, 2014
    Assignee: Caterpillar Inc.
    Inventors: Bryan A. Johnson, Jason L. Brinkman, Lawrence J. Tognetti, Chris R. Cesur, Peter Spring, Jiao Zhang
  • Patent number: 8746420
    Abstract: Cut-in-cut-out valves for hydraulic circuits. The hydraulic circuits include a hydraulic pump outputting a variable pressure controlled by a slaving line, an accumulation circuit, a return line to the reservoir, a cut in-cut-out valve. The hydraulic circuits also include a cut-in-cut-out valve having four orifices, a first orifice connected to the supply line, a second orifice connected to the slaving line, a third orifice connected to the return line leading to the reservoir, and a fourth orifice connected to the accumulation circuit. The cut-in-cut-out valve alternates between two positions as a function of the pressure in the accumulation circuit, a cut-in position in which the first, second and fourth orifices are connected to each other, and a cut-out position in which the first and fourth orifices are closed.
    Type: Grant
    Filed: September 12, 2011
    Date of Patent: June 10, 2014
    Assignee: Poclain Hydraulics Industrie
    Inventor: Dominique P Costaz
  • Patent number: 8726648
    Abstract: A hydraulic drive device for a construction machine includes an engine stopping unit and a discharge rate control unit. The engine stopping unit stops the engine when a predetermined state of the construction machine has continued for a predetermined period of time. The discharge rate control unit controls a discharge rate control pressure being input to the regulator, when an exhaust emission control device performs regeneration control, or performs warm-up control, and the gate lock lever is in the open position.
    Type: Grant
    Filed: January 19, 2011
    Date of Patent: May 20, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kensuke Sato, Hiroyuki Azuma, Tsuyoshi Nakamura, Yasuo Okano, Kouji Ishikawa, Mitsuhiko Kanehama
  • Patent number: 8726646
    Abstract: A hydraulic system, and associated method of control, includes an operator input device, a source of hydraulic fluid flow, and a plurality of actuators. At least one valve associated with each actuator for controlling a flow of fluid to and from the actuator. A controller is responsive to a signal from the operator input device to calculate a hydraulic pressure to be supplied to each of the actuators. The controller controls the source of hydraulic fluid flow and the valves for powering the actuators with the calculated hydraulic pressure. The controller also monitors a sensed parameter to determine whether the actuators can be powered with the calculated hydraulic pressure, and in response to a determination that the actuators cannot be powered with the calculated hydraulic pressure, calculates a discrepancy ratio and modifies actuation of the actuators with the discrepancy ratio.
    Type: Grant
    Filed: March 6, 2009
    Date of Patent: May 20, 2014
    Assignee: Parker-Hannifin Corporation
    Inventors: Ray Riedel, Amir Shenouda
  • Patent number: 8720196
    Abstract: Disclosed is a controller of a hybrid, construction machine wherein electric power is generated by utilizing the standby flow rate of first and second main pumps, and the standby flow rate is converted into energy. Pilot channels are connected to the upstream side of on/off valves which are closed when first and second main pumps ensure a standby flow rate, and a controller unit judges that the first and second main pumps are discharging at the standby low rate based on pressure signals from first and second pressure sensors, and brings first and second solenoid valves to an open position.
    Type: Grant
    Filed: May 13, 2009
    Date of Patent: May 13, 2014
    Assignee: Kayaba Industry Co., Ltd.
    Inventors: Haruhiko Kawasaki, Masahiro Egawa
  • Patent number: 8713930
    Abstract: A negative control type hydraulic system in which the use of a pilot pump and a load pressure generator between a hydraulic pump and a control valve is not required to prevent a power loss.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: May 6, 2014
    Assignee: Volvo Construction Equipment Holding Sweden AB
    Inventor: Hae Kyun Cheong
  • 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
  • Patent number: 8701396
    Abstract: A hydraulic system for an operator controlled machine, the system including at least one actuator for moving a machine component, a source of pressurized fluid for delivering pressurized fluid at a system pressure to a control valve which is operable under operator control, to control the flow of fluid from the source to the actuator at a load pressure, along a load pressure path, a flow control apparatus for controlling the flow of fluid from the source to the control valve, the flow control apparatus including an actuating part which is biased by a resilient device to a condition in which the flow control apparatus provides for a maximum flow of fluid to the control valve, actuating part movement by the resilient device being resisted by system pressure fluid and being supported by fluid at a control pressure, the control pressure being derived from the load pressure, and wherein the system includes a pressure control device to which the load pressure is communicated, the pressure control device being opera
    Type: Grant
    Filed: July 16, 2010
    Date of Patent: April 22, 2014
    Assignee: J.C. Bamford Excavators Limited
    Inventors: Harishchandra M. Narotham, Martin R. Smith
  • Patent number: 8689550
    Abstract: A hydraulic control system that includes a controller that controls the accumulator flow rate control valve and a discharge flow rate of the hydraulic pump, wherein the controller: determines a minimum value among an operation demand flow rate to be demanded by an operation amount of hydraulic actuator operating members, a pump flow rate to be determined by a discharge pressure of the hydraulic pump under a constant horsepower control and a maximum flow rate of the hydraulic pump such that the determined minimum value is an actuator supply flow rate to be supplied to the plurality of hydraulic actuators, and controls the discharge flow rate and the accumulator flow rate so as to supply the actuator supply flow rate corresponding to a total flow rate of the discharge flow rate and the accumulator flow rate.
    Type: Grant
    Filed: June 1, 2009
    Date of Patent: April 8, 2014
    Assignee: Caterpillar SARL
    Inventors: Atsushi Wada, Keisuke Shirani, Takashi Iguchi
  • Patent number: 8683793
    Abstract: A method is provided for recuperating potential energy during a lowering operation of a load, wherein a hydraulic system is adapted to lift and lower the load. In the method, at least two energy recuperation modes are provided, one of the modes is selected in response to a current operating state, and the hydraulic system is controlled according to the selected mode.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: April 1, 2014
    Assignee: Volvo Construction Equipment AB
    Inventors: Magnus Bergström, Johan Lillemets, Kim Heybroek, Jan-Ove Palmberg
  • Patent number: 8667786
    Abstract: The present invention relates to a converter comprising a pump which is driven directly or indirectly by a natural force such as a water swell, it being possible for a hydraulic machine to be driven by the pump. The hydraulic machine is force-coupled to an electrical machine which may function as a generator or a motor. According to the present invention, the force acting on the pump is regulated via a control loop as a function of oscillation parameters of the natural force.
    Type: Grant
    Filed: June 20, 2008
    Date of Patent: March 11, 2014
    Assignee: Robert Bosch GmbH
    Inventors: Stefan Zimmermann, Christian Langenstein, Nik Scharmann, Louis Verdegem
  • Patent number: 8661804
    Abstract: A control system for a swashplate pump is disclosed. The control system may have a tiltable swashplate, at least one actuator movable to tilt the swashplate, a supply of pressurized fluid, and a drain. The control system may also have a first circuit connectable to the supply of pressurized fluid and to the drain and configured to control operation of the at least one actuator, and a second circuit connectable to the supply of pressurized fluid and to the drain and configured to control operation of the at least one actuator. The control system may further have a failsafe valve configured to connect the first circuit to at least one of the supply and the drain only during a normal operating condition, and to connect the second circuit to the supply and to the drain only during a failsafe condition.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: March 4, 2014
    Assignee: Caterpillar Inc.
    Inventor: Christoph Wagner
  • Publication number: 20130312397
    Abstract: A method and apparatus for controlling a hydraulic power system is provided that includes a hydraulic motor and a hydraulic pump configured to supply hydraulic fluid to the hydraulic motor. A relief valve is provided that is configured to release hydraulic fluid from a location between the hydraulic pump and the hydraulic motor when a pressure of the hydraulic fluid exceeds a predetermined relief pressure. Above a predetermined threshold pressure for the system, the displacement of the pump is adjusted to at least a minimum displacement that is based on a total demanded flow for the system that includes a desired flow of hydraulic fluid across the relief valve and a first hydraulic fluid flow consumed by the motor.
    Type: Application
    Filed: May 25, 2012
    Publication date: November 28, 2013
    Applicant: CATERPILLAR INC.
    Inventors: Joshua Callaway, Christopher Elliott, Grant Peterson
  • Patent number: 8578709
    Abstract: In an over-loading prevention device including a hydraulic pump, a control valve, and a control lever, a discharge-quantity control unit performs constant-torque control which decreases a discharge quantity in proportion to an increase in a discharge pressure in the pump to control an input torque of the pump uniformly. An operation-state detection unit detects an actuation state of the control lever. A control unit outputs a control signal that sets the pump input torque to a minimum torque according to the constant-torque control, to the discharge-quantity control unit when the control lever is operated over a predetermined speed, and subsequently changes a level of the control signal to a maximum torque according to the constant-torque control in accordance with a predetermined control pattern to raise the pump input torque.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: November 12, 2013
    Assignee: Sumitomo (S.H.I.) Construction Machinery Co., Ltd.
    Inventors: Hiroyuki Tsukamoto, Takashi Nishi
  • Patent number: 8522543
    Abstract: The present disclosure is directed toward a hydraulic control system. The system may have a pump and a tool actuator configured to move a tool with a flow of pressurized fluid provided by the pump. The system may further have a tool control valve configured to control the flow of pressurized fluid to the tool actuator. The system may also have a controller operably connected with the tool control valve and the pump. The controller may be configured to receive a tool movement request. The controller may further be configured to estimate a change in a flow demand across the tool control valve associated with the tool movement request. The controller may also be configured to command adjustment of a discharge flow rate of the pump based on the estimated change in flow demand to satisfy the tool movement request.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: September 3, 2013
    Assignee: Caterpillar Inc.
    Inventors: Andrew J. Krajnik, Patrick W. Sullivan, Jr.