By Means Sensing Rotational Speed Of Prime Mover Or Pump Patents (Class 60/449)
  • Patent number: 10337173
    Abstract: A work machine includes an engine, a pilot pump to be driven by the engine to supply a pilot fluid, an operation pump to receive a first pilot fluid to change an output power in accordance with the first pilot fluid, a pilot fluid tube provided between the pilot pump and the operation pump, an operation valve connected to the pilot fluid tube to output the first pilot fluid, the first pilot fluid being a part of the pilot fluid supplied from the pilot fluid, a temperature sensor to measure a temperature of at least one of an operation fluid including the pilot fluid, a cooling water, an engine oil, and an outside air, and a pressure controller to control a first pilot pressure of the pilot fluid outputted from the operation valve when a temperature measured by the temperature sensor is equal to or higher than a first temperature.
    Type: Grant
    Filed: December 27, 2016
    Date of Patent: July 2, 2019
    Assignee: KUBOTA CORPORATION
    Inventors: Yuji Fukuda, Ryosuke Kinugawa, Hiroaki Nakagawa
  • Patent number: 9357709
    Abstract: A combination of a towing vehicle and an agricultural harvesting machine drawn by the towing machine is provided. The harvesting machine includes at least one working assembly for conveying crop (G), for processing crop (G) or both. The harvesting machine also includes a working connection to the towing vehicle in order to be supplied with drive power by the towing vehicle in order to operate the at least one working assembly and a control device can be operated in a harvesting mode in order to specify a ground speed (v) for the combination depending on ascertained operating parameters of the harvesting machine and the towing vehicle.
    Type: Grant
    Filed: January 22, 2014
    Date of Patent: June 7, 2016
    Assignee: USINES CLAAS FRANCE S.A.S.
    Inventors: Julien Waechter, Frédéric Chesnier, Thorsten Scharf
  • Patent number: 9109346
    Abstract: In a work machine including a hydraulic pump (1), a swing motor (2), and swing relief valves (3a and 3b), the amount of the swing operation (P1) related to the swing motion of the swing motor (2) is detected, and the hydraulic pressure (P2) supplied from the hydraulic pump (1) to the swing motor is also detected. Additionally, the required flow rate (FR) of hydraulic oil required for the swing motor (1) is set based on the amount of the swing operation (P1). In addition, the volume of relief (FE) is estimated from the hydraulic pressure (P2) based on the override characteristics of the swing relief valves (3a and 3b). The discharge flow rate of the hydraulic pump (1) is controlled based on the value obtained by subtracting the volume of relief (FE) from the required flow rate (FR).
    Type: Grant
    Filed: August 18, 2010
    Date of Patent: August 18, 2015
    Assignee: Caterpillar SARL
    Inventors: Tetsuya Yoshino, Seiichi Akiyama, Yuya Kanenawa
  • Patent number: 9050880
    Abstract: A vehicle includes a transmission housing disposed on a frame to independently drive a pair of wheels. The transmission includes first and second motor having collinear motor shafts and first and second pump hydraulically connected to the respective motors and having collinear pump shafts. An input shaft extends into the housing and drives both pump shafts and has an axis of rotation that is perpendicular to the pump shaft axes of rotation.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: June 9, 2015
    Assignee: Hydro-Gear Limited Partnership
    Inventors: Raymond Hauser, Lonnie E. Holder
  • Patent number: 9032725
    Abstract: A method for operating a working machine provided with a power source providing power and a plurality of power consuming systems connected to the power source includes the steps of providing a model predicting a power demanded by at least one of the power consuming systems, detecting at least one operational parameter indicative of a power demand, using the detected operational parameter in the prediction model, and balancing a provided power to the demanded power according to the prediction model.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: May 19, 2015
    Assignee: Volvo Construction Equipment AB
    Inventor: Reno Filla
  • Publication number: 20150040554
    Abstract: A hydraulic linear actuator system known as the “Dynaco Stepper Pump Hydraulics System” is which is an electrically driven hydraulic pump system made of durable materials for use in an electronically controllable hydraulic system comprised of: (a) an electrically driven stepper motor; (b) a hydraulic pump to pressurize a hydraulic fluid; (c) a means to connect the stepper motor to the hydraulic pump; (d) a pressurized reservoir for a quantity of hydraulic fluid; (e) a means to supply pressurized fluid to a hydraulic actuator; (f) the hydraulic actuator with a means to provide linear motion to an object; (g) the means to provide linear motion to an object; (h) a means to return lowered pressurized fluid to the reservoir. An alternative embodiment is further comprised of a controller with a series of feedback signals.
    Type: Application
    Filed: August 6, 2014
    Publication date: February 12, 2015
    Inventors: Gary L. Smith, Laurens MOLENAAR
  • Patent number: 8943820
    Abstract: A method of controlling a pump and motor system having at least one of a variable displacement pump and a variable displacement motor. The method may comprise providing an engine drivingly coupled to a primary load and a secondary load, the secondary load being driven by the pump and motor system. The method may also comprise sensing a change in engine speed in response to a change in the primary load. The method may further comprise changing the engine speed to compensate for the primary load change. The method may further comprise changing a displacement of the at least one variable displacement pump and the variable displacement motor to maintain a constant secondary load.
    Type: Grant
    Filed: December 9, 2009
    Date of Patent: February 3, 2015
    Assignee: Caterpillar Inc.
    Inventors: Douglas J. Carlton, Corwin E. Storer
  • Patent number: 8855871
    Abstract: In an engine-overrun-preventing control device, if an engine speed exceeds a maximum speed, a minimum value of an inching rate is set such that higher the actual engine speed results in a higher minimum value of an inching rate. The hydraulic pump displacement is adjusted to obtain a higher inching rate between the minimum value of the inching rate and an inching rate set based on a brake stroke. If the engine speed exceeds a commanded speed and a pressure time-rate-of-change at the pump intake exceeds a prescribed value, the minimum value of the inching rate is set such that the higher the pressure time-rate-of-change, the higher the minimum value of the inching rate. The pump displacement is adjusted to obtain a higher inching rate between the minimum value of the inching rate set based on the pressure time-rate-of-change and the inching rate set based on the brake stroke.
    Type: Grant
    Filed: September 9, 2011
    Date of Patent: October 7, 2014
    Assignee: Komatsu Ltd.
    Inventors: Yoshitaka Onodera, Jun Hashimoto, Hideyuki Hiraiwa, Shinji Kaneko
  • Patent number: 8738241
    Abstract: A machine having a pump overspeed protection system operating thereon includes an internal combustion engine, a plurality of ground engaging elements, and a drivetrain coupling the internal combustion engine and the ground engaging elements. The drivetrain includes a torque converter having a locked configuration and an unlocked configuration. The machine also includes a plurality of pumps driven by the internal combustion engine. An electronic control is in communication with the internal combustion engine, the torque converter, and the plurality of pumps.
    Type: Grant
    Filed: May 31, 2011
    Date of Patent: May 27, 2014
    Assignee: Caterpillar Inc.
    Inventors: Michael Evan Hague, Sameer Marathe, Zhiyong Wei, Matthew Stephen Marquette
  • Patent number: 8554425
    Abstract: A control system is provided to control the rate of pressure rise in a hydraulic lift and flotation system. When a hydraulic cylinder of the hydraulic lift and flotation system is to be adjusted, the pressure in the hydraulic lift and flotation system has to be increased to a predetermined pressure controlled by a relief valve before the hydraulic cylinder can be operated. The unload valve of the hydraulic lift and flotation system can be closed in a controlled or regulated manner in order to control the rate at which pressure rises in the hydraulic lift and flotation system.
    Type: Grant
    Filed: February 13, 2013
    Date of Patent: October 8, 2013
    Assignee: CNH America LLC
    Inventors: Douglas R. Otto, Robert L. Fackler
  • Patent number: 8495871
    Abstract: A hydraulic system includes an engine driven adjustable hydraulic pump which supplies fluid to a hydraulic consumer, and an electronic control unit. The adjustable pump includes flow controller for controlling a pressure difference between the consumer and the adjustable pump to a pre-determined control pressure difference. The flow controller includes an actuator controlled by the control unit, through which the pressure difference can be controlled. The electronic control unit receives an engine speed signal and controls the actuator to control the pressure difference, in order to make power delivery of the adjustable pump conform to the operating conditions of a vehicle.
    Type: Grant
    Filed: December 4, 2009
    Date of Patent: July 30, 2013
    Assignee: Deere & Company
    Inventor: Marcus Bitter
  • Patent number: 8464526
    Abstract: A hydraulic load ramping system, in certain aspects, may utilize load sensing feedback from an engine, thereby reducing the possibility of overloading the engine as well as smoothing the transition between hydraulic load levels. In particular, by ramping between hydraulic load levels, unwanted movement of hydraulically-driven equipment may be minimized. In addition, by efficiently monitoring the load sensing feedback and ramping between hydraulic load levels, the hydraulic output may be maximized.
    Type: Grant
    Filed: February 6, 2009
    Date of Patent: June 18, 2013
    Assignee: Illinois Tool Works Inc.
    Inventor: Ross Renner
  • Patent number: 8429908
    Abstract: A hydraulic system includes an engine driven variable displacement hydraulic pump which supplies fluid to a hydraulic consumer and an electronic control unit. A flow rate adjusting unit includes a stop that can be brought into engagement with an adjusting piston. In order conform the power output of the pump to the operating conditions of the vehicle, the stop of the flow rate adjusting unit includes adjusting devices that can be controlled by the control unit, so that the maximum flow rate of the pump can be varied by the electronic control unit. The electronic control unit generates a control signal for the adjusting device as a function of a sensed engine speed.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: April 30, 2013
    Assignee: Deere & Company
    Inventor: Wolfgang Bauer
  • Patent number: 8387755
    Abstract: A lubrication system is provided that includes a pump operatively connected to one or more supply lines for delivery of a lubricant, the system including a first pressure sensor associated with the supply line at a first position, and a second pressure sensor associated with the supply line at a second position downstream of the first position and pump, a controller configured to receive pressure signals and control operation of the pump based upon the pressure differential between the pressures at the first position and second position. The pressure differential may be employed to determine when a pressure at a third position downstream of the second position has been achieved. At least one of the pressure sensors may be positioned adjacent to the pump, the controller further being operable to deactivate the pump in the event that a maximum pump pressure has been met.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: March 5, 2013
    Assignee: Caterpillar Inc.
    Inventor: John P. Marek
  • Patent number: 8371117
    Abstract: Torque control for a construction machine three-pump system that can accurately control the total absorption torque of first, second, and third hydraulic pumps and effectively use the output torque of an engine. A pump base torque computation section 42 calculates a pump base torque Tr from a target rotation speed. A subtraction section 44 calculates a reference value Tf for the maximum absorption torque available to the first and second hydraulic pumps 2, 3 by subtracting a third pump reference absorption torque T3r from the pump base torque Tr. A correction torque computation section 45 calculates a correction torque value from the delivery pressure of the third hydraulic pump 4. An addition section 46 calculates a target absorption torque Tn by adding the correction torque value Tm to the reference value Tf. A first regulator 31 is controlled so as to obtain the target absorption torque Tn.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: February 12, 2013
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kazunori Nakamura, Kouji Ishikawa, Nobuei Ariga, Akihiro Narazaki
  • Patent number: 8302396
    Abstract: A control method for a hydraulic type continuously variable transmission for suppressing a harmful effect due to the reacceleration just after deceleration of a vehicle. In a hydraulic type continuously variable transmission, the operation of a shifting actuator is stopped to suspend the shift control (S7) when a throttle valve is rapidly opened just after fully closed (S4: Yes) and an engine speed NE [rpm] is being rapidly increased (S6: Yes). Accordingly, even when the actual engine speed NE becomes much greater than a target engine speed T_NE during reacceleration just after deceleration of a vehicle, unexpected shift control (upshifting) can be prevented, so that more desirable torque can be produced.
    Type: Grant
    Filed: January 28, 2009
    Date of Patent: November 6, 2012
    Assignee: Honda Motor Co., Ltd.
    Inventors: Yasutaka Usukura, Kazuhiko Nakamura
  • Patent number: 8296024
    Abstract: The described system and method allow a controller to calibrate a transmission variator of a continuously variable transmission for torque control by obtaining static and dynamic qualities and parameters of the variator through an automated calibration procedure. The system and method employ a pair of transmission mode configurations and operational configurations in combination to obtain system-specific information. In this way, the system is able to calibrate out the system variations to provide effective feed forward torque control of the continuously variable transmission. In an embodiment, a first calibration operation is performed while the transmission is neutralized and a second calibration operation is performed while the transmission is engaged in a mode providing a fixed variator output speed.
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: October 23, 2012
    Assignee: Caterpillar Inc.
    Inventors: Jason Stoller, Chad Brickner, Brian Lister
  • Patent number: 8266903
    Abstract: An engine lag down control system for construction machinery has a machinery body controller having first, second and third torque control units and a solenoid valve. The first torque control unit controls a torque control valve to a minimum pump torque corresponding to a target number of engine revolutions when a non-operated state of a control device has continued beyond a monitoring time. The second torque control unit controls the torque control valve such that the above-described minimum pump torque is held for a predetermined holding time subsequent to the operation of the control device from the non-operated state. The third torque control unit controls the torque control valve such that from a time point of a lapse of the predetermined holding time, the pump torque is gradually increased on a basis of a predetermined torque increment rate.
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: September 18, 2012
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yoichi Kowatari, Yasushi Arai, Kouji Ishikawa, Kazunori Nakamura, Nobuei Ariga, Hideo Karasawa, Yuuki Gotou, Motoyuki Yabuuchi
  • Patent number: 8206264
    Abstract: A load control structure for a work vehicle comprises: set rotation speed detection device for detecting a set rotation of an engine of the work vehicle; actual rotation speed detection device that senses an actual rotational speed of the engine; continuously variable speed change device that receives power from an engine of the work vehicle; speed change position detecting device for detecting a speed change operation position of the continuously variable speed change device; operating device for speed-shifting the continuously variable speed change device; control device for controlling the operation of the operating device; wherein the control device calculates a drop amount of the actual engine rotation speed from the set rotation speed based on the detected information from the set rotation speed detection device and the actual rotation speed detection device, and sets a limit operation position for the continuously variable speed change device based on the calculated drop amount and a correlation data t
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: June 26, 2012
    Assignee: Kubota Corporation
    Inventors: Eiji Nishi, Keishiro Nishi, Atsushi Shinkai, Yasunobu Nakatani
  • Patent number: 8196400
    Abstract: A method of controlling a work vehicle includes detecting an operational condition of a powertrain which is adapted to propel the vehicle, wherein a power source in the powertrain is adapted to operatively drive at least one variable displacement pump, wherein the pump is adapted to operatively drive at least one hydraulic actuator via hydraulic fluid for moving a work implement and/or steering the vehicle. The method further includes comparing the detected operational condition with a predetermined critical condition, limiting a maximum available displacement of the pump and thereby establishing an available pump displacement range if the magnitude of the detected operational condition is within the predetermined critical condition, detecting a hydraulic load associated to the actuator, and adjusting the pump displacement of the pump in response to the detected hydraulic load within the available pump displacement range.
    Type: Grant
    Filed: March 13, 2006
    Date of Patent: June 12, 2012
    Assignee: Volvo Construction Equipment AB
    Inventor: Markku Palo
  • Patent number: 8136355
    Abstract: A pump control apparatus for a hydraulic work machine includes: a rotation speed setting device that sets a target rotation speed for an engine; a rotation speed control device that controls an engine rotation speed so as to adjust the engine rotation speed to the target rotation speed; a first variable hydraulic pump used to drive a work hydraulic actuator, driven by the engine; a second variable hydraulic pump used to drive a cooling fan, driven by the engine; and a pump control device that controls an output flow rate of the first variable hydraulic pump and an output flow rate of the second variable hydraulic pump so as to ensure that a sum of an intake torque of the first variable hydraulic pump and an intake torque of the second variable hydraulic pump does not exceed an engine output torque determined in advance based upon the target rotation speed.
    Type: Grant
    Filed: December 18, 2006
    Date of Patent: March 20, 2012
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Gen Yasuda, Akihide Yamazaki
  • Patent number: 8042331
    Abstract: A fixed displacement binary pump is provided for a powertrain on a vehicle. A hydraulic system is operatively connected with first and second discharge ports of the pump and is operable to alternately permit fluid flow through both discharge ports (i.e., full displacement or volumetric output of the pump) or permit flow through only the first discharge port (i.e., partial displacement or volumetric output of the pump). The pump may be packaged in a front support of the transmission. An auxiliary pump may be provided that is operable to supplement the output of the binary pump or to be used when the binary pump is off. A method of operating the binary pump and auxiliary pump is provided.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: October 25, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: John C. Schultz, Daryl A. Wilton, Edward W. Mellet
  • Patent number: 7980994
    Abstract: A load control structure for a work vehicle comprises: set rotation speed detection device for detecting a set rotation of an engine of the work vehicle; actual rotation speed detection device that senses an actual rotational speed of the engine; continuously variable speed change device that receives power from an engine of the work vehicle; speed change position detecting device for detecting a speed change operation position of the continuously variable speed change device; operating device for speed-shifting the continuously variable speed change device; control device for controlling the operation of the operating device; wherein the control device calculates a drop amount of the actual engine rotation speed from the set rotation speed based on the detected information from the set rotation speed detection device and the actual rotation speed detection device, and sets a limit operation position for the continuously variable speed change device based on the calculated drop amount and a correlation data t
    Type: Grant
    Filed: February 25, 2010
    Date of Patent: July 19, 2011
    Assignee: Kubota Corporation
    Inventors: Eiji Nishi, Keishiro Nishi, Atsushi Shinkai, Yasunobu Nakatani
  • Publication number: 20110146259
    Abstract: A hydraulic system includes an engine driven variable displacement hydraulic pump which supplies fluid to a hydraulic consumer and an electronic control unit. A flow rate adjusting unit includes a stop that can be brought into engagement with an adjusting piston. In order conform the power output of the pump to the operating conditions of the vehicle, the stop of the flow rate adjusting unit includes adjusting devices that can be controlled by the control unit, so that the maximum flow rate of the pump can be varied by the electronic control unit. The electronic control unit generates a control signal for the adjusting device as a function of a sensed engine speed.
    Type: Application
    Filed: December 17, 2009
    Publication date: June 23, 2011
    Inventor: Wolfgang Bauer
  • Patent number: 7810323
    Abstract: A device for use in a work vehicle such as a wheel loader, capable of reliably preventing engine stall due to rapid application of high hydraulic load, without causing problems such as deterioration in fuel efficiency or vehicle performance and waste of energy. When determining that an engine speed detected by the engine speed detecting sensor has been decreased to the threshold value or lower, the controller implements a control to reduce the absorption torque of the variable displacement hydraulic pump. The hydraulic load is thus shifted to a low hydraulic load line. The change of the hydraulic load from the high hydraulic load to the low hydraulic load gives a margin to the current torque of the engine with respect to the low hydraulic load. Consequently, the actual speed of the engine is increased to return onto the regulation line, exceeding the threshold value.
    Type: Grant
    Filed: September 5, 2005
    Date of Patent: October 12, 2010
    Assignee: Komatsu Ltd.
    Inventor: Yuuichi Iwamoto
  • Patent number: 7797934
    Abstract: A hydraulic control system for a machine is disclosed. The hydraulic control system may have a source driven by an engine to pressurize fluid, and a tool actuator movable by pressurized fluid. The hydraulic control system may further have a first valve element movable to control an amount of pressurized fluid directed to the tool actuator, and an interface device movable by an operator to control an amount of pressurized fluid directed to move the first valve element. The hydraulic control system may also have a second valve element movable to limit an amount of pressurized fluid available to move the first valve element, and a controller in communication with the second valve element. The controller may be configured to move the second valve element to reduce pressurized fluid directed to the first valve element in an amount related to a load on the engine.
    Type: Grant
    Filed: April 30, 2007
    Date of Patent: September 21, 2010
    Assignee: Caterpillar Inc
    Inventors: Kevin A. Bacon, Andrew J. Smith
  • Publication number: 20090282824
    Abstract: A concrete agitating drum (1) is driven by a hydraulic motor (81). A connection switch-over valve (20) is arranged to have a function to regulate a flow cross-sectional area of pressurized working oil supplied to the hydraulic motor (81) from a variable capacity hydraulic pump (10). The variable capacity hydraulic pump (10) is driven by a combustion engine (60) together with a charge pump (11). When a discharge pressure of the charge pump (11) is low, the connection switch-over valve (20) maintains a small flow cross-sectional area to rotate the agitating drum (1) at a low rotation speed so that fuel consumption of the combustion engine (60) is suppressed to be small. When the discharge pressure of the charge pump (11) becomes high, the connection switch-over valve (20) enlarges the flow cross-sectional area, thereby realizing a rated rotation speed of the agitating drum (1).
    Type: Application
    Filed: July 13, 2007
    Publication date: November 19, 2009
    Applicant: KAYABA INDUSTRY CO., LTD.
    Inventors: Kunihiro Ando, Masaya Abe, Yoshihito Iwasaki
  • Publication number: 20090217654
    Abstract: A load control device for an engine of a work vehicle that purposes to render the work vehicle, such as a wheel loader or the like, capable of raising a vehicle speed in a short period of time by providing a sufficient traction force when a high traveling load is imposed, without causing degradation of a vehicle body performance, waste of energy, and other problems. The load control device is provided with variable displacement hydraulic pumps (7, 8, 9) being provided with absorption torque changing means (19, 22) for changing absorption torque. A controller (18) determines whether a traveling load is in a high state, and when it has been determined that the traveling load is in the high state, control for lowering the absorption torque for the hydraulic pumps (7, 8, 9) is carried out. This control is carried out, provided, for example, that a “power mode” is selected with the power mode switch (31).
    Type: Application
    Filed: May 14, 2009
    Publication date: September 3, 2009
    Applicant: KOMATSU LTD.
    Inventor: Yuuichi Iwamoto
  • Patent number: 7549287
    Abstract: A hydrostatic system and method of operation thereof, wherein at least one of a fluid motor and a pump of the system has a displacement which is variable for controlling a speed of operation of the motor, the pump being driven by an engine, and a controller configured for monitoring the speed of operation of the motor and an operating characteristic of the engine and automatically controlling the displacement responsive thereto, wherein if the operating characteristic is indicative of engine performance above a predetermined threshold, the controller will control the displacement for maintaining the speed of operation of the motor at about a predetermined value, and, if the operating characteristic is indicative of engine performance below the threshold, the controller will hold the displacement at a constant value. As a result, the controller can prevent the system from further decreasing the engine performance.
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: June 23, 2009
    Assignee: CNH America LLC
    Inventors: Christopher A. Foster, Richard P. Strosser, Justin Ringwald, Robert L. Fackler
  • Patent number: 7546729
    Abstract: A method for reducing a torque load associated with an implement includes determining a speed associated with a power source, wherein the power source is configured to provide power to a hydraulic pump, determining a position associated with an implement system, and limiting a flow associated with the hydraulic pump based on the speed associated with the power source and the position associated with the implement system.
    Type: Grant
    Filed: December 18, 2006
    Date of Patent: June 16, 2009
    Assignee: Caterpillar Inc.
    Inventors: Marvin Kent Palmer, Steven Conrad Budde, SriVidya Lavanya Kamisetty
  • Patent number: 7543447
    Abstract: A traveling working vehicle maintains fuel economy while ensuring a sufficient work rate in heavy-load work. A torque control regulator 26 controls the absorption torque of a hydraulic pump 22 to ensure that it does not exceed a preset maximum absorption torque, and an accelerator pedal 12 commands a target revolution speed of an engine 1. Revolution speed deviation computing sections 52 and 62, a modification torque computing section 53, a modification revolution speed computing section 63, speed ratio computing sections 54 and 64, traveling state determining sections 55 and 65, and working state determining sections 56 and 66 determine an operating state of the traveling working vehicle. Both the pump base torque of the hydraulic pump 22 and the target revolution speed of the engine 1 are modified depending on the determination result of the state determining sections.
    Type: Grant
    Filed: November 11, 2005
    Date of Patent: June 9, 2009
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kentaro Itoga, Kazunori Nakamura, Tsuyoshi Nakamura, Motoyuki Yabuuchi
  • Publication number: 20090120083
    Abstract: A method of controlling an electro-hydraulic system having an engine driving a variable displacement pump, a hydraulic valve and a hydraulic actuator in order to achieve more efficient engine operation is disclosed. The pressures in the electro-hydraulic system are monitored and commands are received indicating the desired movement of the hydraulic actuator. Based on the pressure and the commands, the operation being performed by the machine is determined and the engine is set to an efficient setting for the particular segment of machine operation.
    Type: Application
    Filed: November 13, 2007
    Publication date: May 14, 2009
    Applicants: CATERPILLAR INC., SHIN CAT MITSUBISHI LTD.
    Inventors: Randy N. Peterson, Todd Lawrence Baker, Michael Todd Verkuilen, Aleksandar M. Egelja, Tetsuya Yoshino
  • Patent number: 7513110
    Abstract: A control apparatus of a construction machine includes a hydraulic pump driven by a prime mover, a hydraulic actuator, and a rotation speed detection device for detecting an actual rotation speed of the prime mover. The control apparatus includes a prime mover control device for controlling a rotation speed of the prime mover, and an input torque control device for adjusting an input torque for the hydraulic pump based on a deviation between the actual rotation speed detected by the rotation speed detection device and a control rotation speed set through an operation of the operating device, and the input torque control device executes control to decrease the input torque if the control rotation speed is greater than the actual rotation speed and the deviation calculated by subtracting the control rotation speed from the actual rotation speed is smaller than a predetermined negative value.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: April 7, 2009
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yukihiro Tatsuno, Hidetoshi Satake
  • Publication number: 20090031721
    Abstract: A method of controlling a work vehicle includes detecting an operational condition of a powertrain which is adapted to propel the vehicle, wherein a power source in the powertrain is adapted to operatively drive at least one variable displacement pump, wherein the pump is adapted to operatively drive at least one hydraulic actuator via hydraulic fluid for moving a work implement and/or steering the vehicle. The method further includes comparing the detected operational condition with a predetermined critical condition, limiting a maximum available displacement of the pump and thereby establishing an available pump displacement range if the magnitude of the detected operational condition is within the predetermined critical condition, detecting a hydraulic load associated to the actuator, and adjusting the pump displacement of the pump in response to the detected hydraulic load within the available pump displacement range.
    Type: Application
    Filed: March 13, 2006
    Publication date: February 5, 2009
    Inventor: Markku Palo
  • Publication number: 20090007559
    Abstract: The servo-control system for hydraulic unit according to the invention comprises a pump driven by a motor feeding hydraulic fluid to a vibrator or vibrating system comprising eccentric weights driven in rotation by at least one hydraulic motor receiving said fluid. It also comprises adaptation means for continuous adaptation of the rotation speed of the motor of the hydraulic unit in relation to the energy actually consumed by the vibrator.
    Type: Application
    Filed: July 3, 2008
    Publication date: January 8, 2009
    Applicant: PTC
    Inventor: Guillaume DAZIN
  • Publication number: 20080236157
    Abstract: An engine lag down suppressing device of construction machinery, comprising a vehicle body controller (13) having a first torque control means and a second torque control means, and a third torque control means. The first torque control means controls a torque control valve (7) to the minimum pump torque (value: Min) according to a target engine rotational speed (Nr) when the operating device (5) in the non-operated state of an continues for a monitoring time (TX1) to suppress an engine lag down after a specified holing time to hold a torque to a low pump torque is passed when the operating device in the non-operated state is operated. The second torque control means controls the torque control valve (7) to hold the minimum pump torque for a specified holding time (Tx2) after the operating device (5) in the non-operated state is operated.
    Type: Application
    Filed: August 27, 2004
    Publication date: October 2, 2008
    Applicant: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yoichi Kowatari, Yasushi Arai, Kouji Ishikawa, Kazunori Nakamura, Nobuei Ariga, Hideo Karasawa, Yuuki Gotou, Motoyuki Yabuuchi
  • Patent number: 7416045
    Abstract: The modular transmission uses only a pair of small and light hydraulic machines of remarkably improved volumetric efficiency with pistons having body portions substantially as long as the axial length of the respective cylinders in which they reciprocate. The two hydraulic machines operate in a closed loop, one being used as a pump driven by the vehicle's engine, and the other used as a motor. Each machine has a fully articulatable swash plate. By computer control, the angles of the swash plates of the two machines are infinitely varied to provide an appropriate optimum ratio of engine/wheel speed for all conditions from start-up, city driving, hill climbing varied according to load and steepness, and over-drive for highway. This complete vehicle operation is attained while the vehicle's engine continues to operate at relatively constant speeds and relatively low RPM.
    Type: Grant
    Filed: June 15, 2005
    Date of Patent: August 26, 2008
    Assignee: Torvec, Inc.
    Inventors: Keith E. Gleasman, Matthew R. Wrona
  • Patent number: 7398648
    Abstract: The present invention includes a hydraulic pump 10 driven by a prime mover 1, a traveling motor 12 driven with pressure oil delivered from the hydraulic pump 10, a control valve 11 for traveling that controls a flow rate of the pressure oil delivered from the hydraulic pump 10 to the traveling motor 12, a counterbalance valve 13 switched in response to a motor load pressure supplied via the control valve 11, that generates a braking pressure at a conduit L1A or L1B disposed on a return side of the traveling motor 12 as the load pressure becomes lower, an overspeed detection means 42 for detecting an overspeed state in the traveling motor 12, and a motor overspeed inhibiting means 50 for inhibiting rotation of the traveling motor 12 if the overspeed detection means 42 detects an overspeed state in the traveling motor 12 until a braking pressure is generated through a switchover at the counterbalance valve 13 and the traveling motor 12 is no longer in the overspeed state.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: July 15, 2008
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yukihiro Tatsuno, Kazuhiro Ichimura
  • Patent number: 7386978
    Abstract: A method is described for controlling a hydraulic system, particularly of mobile working machine, with at least one internal combustion engine driving at least one hydraulic pump with adjustable volumetric displacement and possibly additional fixed-displacement pumps.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: June 17, 2008
    Assignee: CNH America LLC
    Inventors: Monika Ivantysynova, Robert Rahmfeld, Jürgen Weber
  • Patent number: 7370475
    Abstract: A modification torque ?T and a torque converter speed ratio e is computed from input and output revolution speeds of a torque converter 31. A first determination coefficient ? corresponding to the speed ratio e, and a second determination coefficient ? corresponding to a pump pressure are computed. A selector 87 selects the smaller one of these coefficients as a determination coefficient ?, and the modification torque ?T is multiplied by ? to provide a modification torque ?TA. An adder 89 adds the modification torque ?TA (negative value) to a pump base torque TR to provide a modified pump base torque TRA, whereby a maximum pump absorption torque TRA is controlled so as to become TRA. The maximum pump torque reducing control can then be performed while accurately confirming a work situation during the combined operation of travel and a working actuator.
    Type: Grant
    Filed: November 15, 2004
    Date of Patent: May 13, 2008
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tsuyoshi Nakamura, Kazunori Nakamura, Toichi Hirata, Genroku Sugiyama, Kentaro Itoga
  • Patent number: 7353651
    Abstract: A zero turning radius mower has a dual hydrostatic pump with right and left pump arms. A linkage between the pump arms and a pair of control levers destrokes both sides of the pump simultaneously if engine speed drops below a specified value. The linkage allows each pump arm to have a first stroke range if the engine powering the pump is above the specified value, and a second smaller stroke range if the engine powering the pump is below the specified value.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: April 8, 2008
    Assignee: Deere & Company
    Inventors: Brian Matthew Adkins, Kevin Patrick Lund
  • Patent number: 7316113
    Abstract: A control device for a work machine hydraulic pump used on a work vehicle according to the present invention has an object to rapidly accelerate the engine to start the vehicle quickly and to rapidly produce a large tractive force when an operator starts depressing the accelerator pedal while operating the work machine operating lever from the neutral position. The control device controls the capacity of the work machine hydraulic pump so as not to exceed the capacity upper limit corresponding to the currently detected engine speed, when the engine speed detected by the engine speed detecting device is equal to or lower than a predetermined speed (maximum torque speed).
    Type: Grant
    Filed: July 12, 2005
    Date of Patent: January 8, 2008
    Assignee: Komatsu Ltd.
    Inventor: Seiichirou Takebe
  • Patent number: 7281373
    Abstract: A fluid pump control device for wheel loaders includes an engine for driving an axle through a transmission, a main pump, a variable-displacement steering pump with a pump regulator, an auxiliary pump, an electronic proportional control valve provided on a discharge quantity control signal line leading to the pump regulator for variably controlling a pilot pressure conveyed the pump regulator, a hydraulic load detector for detecting a real hydraulic load (Px), an engine revolution detector for detecting the number of revolution (N1) of the engine, a transmission revolution detector for detecting the number of output shaft revolution (N2) of the transmission. A controller is adapted to control the electronic proportional control valve and hence the fluid discharge quantity of the steering pump, based on the real hydraulic load (Px), the number of revolution (N1) of the engine and the number of output shaft revolution (N2) of the transmission.
    Type: Grant
    Filed: December 27, 2005
    Date of Patent: October 16, 2007
    Assignee: Doosan Infracore Co., Ltd.
    Inventor: Hyeong Ho Kim
  • Patent number: 7269945
    Abstract: A method for compensating a flow rate at a neutral position of an operation lever of construction equipment is adapted so that when RPM of an engine becomes different, an actuator can be identically driven according to an operating amount of the operation lever.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: September 18, 2007
    Assignee: Volvo Construction Equipment Holding Sweden AB
    Inventor: Sang Ki Bae
  • Patent number: 7032379
    Abstract: There is provided an oil supply unit for a running power transmission of a vehicle. The oil supply unit includes a housing, a hydraulic pump of a variable displacement type, a detecting mechanism and a control mechanism. The detecting mechanism is constructed to monitor a driven state of an engine. The control mechanism is constructed to operate an output adjusting member of the hydraulic pump to thereby regulate the discharge quantity against the suction quantity of the hydraulic pump based on the driven state of the engine.
    Type: Grant
    Filed: April 7, 2004
    Date of Patent: April 25, 2006
    Inventor: Kazuhiko Ohtsuki
  • Patent number: 6986368
    Abstract: A hydraulic circuit for a tree-cutting machine having a feed mechanism powered by hydraulic fluid at the output of a hydraulic motor. The hydraulic motor may comprise a variable-displacement motor. The hydraulic circuit may comprise elements which provide an anti-stall mode, wherein the feed mechanism is operated to withdraw the cutting element upon pressure at an input port of the hydraulic motor exceeding a threshold.
    Type: Grant
    Filed: August 1, 2002
    Date of Patent: January 17, 2006
    Assignee: Risley Enterprises Ltd.
    Inventor: Larry Brown
  • Patent number: 6852064
    Abstract: An electronic transmission control system that can achieve a transmission ratio based on the operator inputs and the current vehicle operating conditions. The transmission constantly connects the engine to the load, and the transmission ratio is only varied by a change in command from the present invention. The transmission's mechanical function is solely to vary the ratio between its input and output. In using the present invention, an operator must select an operating mode, either automatic or manual, using a two-position switch. While in the automatic mode, the present invention determines the vehicle speed by considering the position of the throttle and the operator's use of brakes. In the manual mode, the present invention further considers the operator's selection of a gear condition.
    Type: Grant
    Filed: May 12, 2003
    Date of Patent: February 8, 2005
    Assignee: Sauer-Danfoss, Inc.
    Inventors: Ryan R. Carlson, Manfred Maiers, Steven H. Gluck
  • Patent number: 6823672
    Abstract: To provide a control system, which can realize a saving in energy and an improvement in the efficiency of work, for a construction machine having an engine, hydraulic pumps, pump regulators, a fuel injection system, hydraulic actuators, control valves including plural flow control valves, and control devices, a controller is constructed including an engine speed control for correcting an inputted reference target engine speed NRO to obtain a corrected target engine speed NROO, a pump absorption torque control for determining a target maximum pump absorption torque value TRO, and a first correcting system for correcting the corrected target engine speed NROO and the target maximum pump absorption torque value TRO into a new target engine speed NRO1 and a new target maximum pump absorption torque TR1, respectively, in accordance with a coolant temperature signal TH1 detected by a coolant temperature detector.
    Type: Grant
    Filed: August 15, 2002
    Date of Patent: November 30, 2004
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Kazunori Nakamura
  • Patent number: 6688102
    Abstract: The present invention discloses a traveling control device, including a crawler type right and left traveling body; a right and a left hydraulic motor for operating the right and left traveling body said right and left hydraulic motors each having a pump as a hydraulic source; an operator means for outputting an operation command to the right and the left hydraulic motor; and a pump pressure controller means for controlling pump pressure to be supplied to the right and the left hydraulic motor according to a control input of the operator means, wherein the pump pressure controller means controls the pump pressure based on different pump pressure properties for single traveling in which only one of hydraulic motors is operated, and for double traveling in which both of hydraulic motors are simultaneously operated.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: February 10, 2004
    Assignee: Kobelco Construction Machinery Co., Ltd.
    Inventor: Hidekazu Oka
  • Patent number: 6684636
    Abstract: A method is provided for controlling displacement of a variable displacement pump coupled to a load. The method includes determining an electrical signal to be applied to a proportional solenoid for a desired pump displacement based on known pump characteristics. The electrical signal is provided to the proportional solenoid. The displacement of the variable displacement pump is controlled based on the electrical signal to the proportional solenoid.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: February 3, 2004
    Assignee: Caterpillar Inc
    Inventor: David P. Smith