US20070166168A1 - Control system for a work machine and method for controlling a hydraulic cylinder in a work machine - Google Patents

Control system for a work machine and method for controlling a hydraulic cylinder in a work machine Download PDF

Info

Publication number
US20070166168A1
US20070166168A1 US11/623,622 US62362207A US2007166168A1 US 20070166168 A1 US20070166168 A1 US 20070166168A1 US 62362207 A US62362207 A US 62362207A US 2007166168 A1 US2007166168 A1 US 2007166168A1
Authority
US
United States
Prior art keywords
hydraulic
machine
recited
hydraulic cylinder
control system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/623,622
Other languages
English (en)
Inventor
Bo Vigholm
Markku PALO
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Volvo Construction Equipment AB
Original Assignee
Volvo Construction Equipment AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Volvo Construction Equipment AB filed Critical Volvo Construction Equipment AB
Priority to US11/623,622 priority Critical patent/US20070166168A1/en
Assigned to VOLVO CONSTRUCTION EQUIPMENT AB reassignment VOLVO CONSTRUCTION EQUIPMENT AB ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: VIGHOLM, BO, MR., PALO, MARKKU, MR.
Publication of US20070166168A1 publication Critical patent/US20070166168A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/14Energy-recuperation means
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/2058Electric or electro-mechanical or mechanical control devices of vehicle sub-units
    • E02F9/2095Control of electric, electro-mechanical or mechanical equipment not otherwise provided for, e.g. ventilators, electro-driven fans
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2203Arrangements for controlling the attitude of actuators, e.g. speed, floating function
    • E02F9/2207Arrangements for controlling the attitude of actuators, e.g. speed, floating function for reducing or compensating oscillations
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2217Hydraulic or pneumatic drives with energy recovery arrangements, e.g. using accumulators, flywheels
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2221Control of flow rate; Load sensing arrangements
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2278Hydraulic circuits
    • E02F9/2289Closed circuit
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2278Hydraulic circuits
    • E02F9/2292Systems with two or more pumps
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20Drives; Control devices
    • E02F9/22Hydraulic or pneumatic drives
    • E02F9/2278Hydraulic circuits
    • E02F9/2296Systems with a variable displacement pump
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02FDREDGING; SOIL-SHIFTING
    • E02F9/00Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/26Indicating devices
    • E02F9/264Sensors and their calibration for indicating the position of the work tool
    • E02F9/265Sensors and their calibration for indicating the position of the work tool with follow-up actions (e.g. control signals sent to actuate the work tool)
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03CPOSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
    • F03C1/00Reciprocating-piston liquid engines
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04BPOSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B17/00Pumps characterised by combination with, or adaptation to, specific driving engines or motors
    • F04B17/03Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/0406Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed during starting or stopping
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/20Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205Systems with pumps
    • F15B2211/20507Type of prime mover
    • F15B2211/20515Electric motor
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/20Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205Systems with pumps
    • F15B2211/2053Type of pump
    • F15B2211/20561Type of pump reversible
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/20Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205Systems with pumps
    • F15B2211/2053Type of pump
    • F15B2211/20569Type of pump capable of working as pump and motor
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/20Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/27Directional control by means of the pressure source
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/305Directional control characterised by the type of valves
    • F15B2211/30505Non-return valves, i.e. check valves
    • F15B2211/30515Load holding valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/305Directional control characterised by the type of valves
    • F15B2211/3056Assemblies of multiple valves
    • F15B2211/30565Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve
    • F15B2211/3057Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve having two valves, one for each port of a double-acting output member
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/50Pressure control
    • F15B2211/505Pressure control characterised by the type of pressure control means
    • F15B2211/50509Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/60Circuit components or control therefor
    • F15B2211/63Electronic controllers
    • F15B2211/6303Electronic controllers using input signals
    • F15B2211/6306Electronic controllers using input signals representing a pressure
    • F15B2211/6313Electronic controllers using input signals representing a pressure the pressure being a load pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/60Circuit components or control therefor
    • F15B2211/63Electronic controllers
    • F15B2211/6303Electronic controllers using input signals
    • F15B2211/6336Electronic controllers using input signals representing a state of the output member, e.g. position, speed or acceleration
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/70Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/705Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051Linear output members
    • F15B2211/7053Double-acting output members
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/80Other types of control related to particular problems or conditions
    • F15B2211/85Control during special operating conditions
    • F15B2211/851Control during special operating conditions during starting
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/80Other types of control related to particular problems or conditions
    • F15B2211/88Control measures for saving energy
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/8593Systems

Definitions

  • the present invention relates to a control system for a work machine and a method for controlling at least one hydraulic cylinder in a work machine.
  • the work machine is described in terms of a wheel loader. This is a preferred but is in no way limiting to the invention as the he invention can also be used for other types of work machines (or work vehicles), such as an excavator loader (backhoe) and excavating machine.
  • backhoe excavating machine.
  • the invention relates, for example, to controlling lifting and/or tilting cylinders for operating an implement.
  • the invention relates to a control system which comprises a hydraulic machine that functions as both pump and motor.
  • the hydraulic machine is connected in a driving manner to an electric machine which functions as both motor and generator.
  • the hydraulic machine therefore functions as a pump in a first operating state and supplies pressurized hydraulic fluid to the hydraulic cylinder.
  • the hydraulic machine also functions as a hydraulic motor in a second operating state and is driven by a hydraulic fluid flow from the hydraulic cylinder.
  • the electric machine therefore functions as an electric motor in the first operating state and as a generator in the second operating state.
  • the first operating state corresponds to a work operation, such as lifting or tilting, being carried out with the hydraulic cylinder. Hydraulic fluid is therefore directed to the hydraulic cylinder for movement of the piston of the cylinder.
  • the second operating state is an energy recovery state.
  • a first object of the invention is to provide a control system, preferably for a lifting and/or tilting function, which affords an opportunity for energy-efficient operation.
  • a control system for a work machine which system comprises an electric machine, a hydraulic machine and at least one hydraulic cylinder, the electric machine being connected in a driving manner to the hydraulic machine, the hydraulic machine being connected to a piston side of the hydraulic cylinder via a first line and a piston-rod side of the hydraulic cylinder via a second line, the hydraulic machine being adapted to be driven by the electric machine and supply the hydraulic cylinder with pressurized hydraulic fluid from a tank in a first operating state and to be driven by a hydraulic fluid flow from the hydraulic cylinder and drive the electric machine in a second operating state.
  • the hydraulic cylinder is preferably adapted to move an implement in order to perform a work function.
  • the hydraulic cylinder comprises a lifting cylinder for moving a loading arm which is pivotably connected to a vehicle frame, the implement being arranged on the loading arm.
  • the hydraulic cylinder comprises a tilting cylinder for moving the implement which is pivotably connected to the loading arm.
  • the speed of the cylinder is preferably controlled directly by the electric machine, that is to say no control valves are required between the hydraulic machine and the cylinder for regulating direction and speed of the movement. In some cases, on/off valves which open and respectively close a communication for the hydraulic fluid flow are required.
  • a second object of the invention is to provide a method for controlling a hydraulic cylinder, preferably for a lifting and/or tilting function, which provides smooth operation and reduces jerking/jolting of the driver.
  • a third object of the invention is to provide a method which takes account of the size of the load and provides energy-efficient operation.
  • a method according to claim 36 comprising the steps of detecting a load acting on the implement, of comparing the size of the detected load with a predetermined load level, and of, if the detected load lies below the predetermined load level, bringing the piston-rod side of the hydraulic cylinder into flow communication with the piston side so that hydraulic fluid coming from the piston-rod side is brought to the piston side without passing through the hydraulic machine.
  • a fourth object of the invention is to provide a method which provides energy-efficient operation during movement of the implement.
  • a fifth object of the invention is to provide a method which provides energy-efficient springing of the movement of the implement during transport.
  • a method according to claim 44 comprising the steps of delivering such a pressure to the hydraulic cylinder that the implement is brought into a basic position, of bringing a first port of the hydraulic machine into flow communication with a piston side of the hydraulic cylinder via a first line and a second port of the hydraulic machine into flow communication with a piston-rod side of the hydraulic cylinder via a second line, and of, in the event of a disturbance which results in an upward movement of the implement, supplying a corresponding quantity of hydraulic fluid to the hydraulic cylinder and, in the event of a downward movement of the implement, draining a corresponding quantity of hydraulic fluid from the hydraulic cylinder.
  • FIG. 1 shows a side view of a wheel loader
  • FIGS. 2-6 show different embodiments of a control system for controlling a work function of the wheel loader
  • FIG. 7 shows an embodiment of a control system for controlling a number of functions of the wheel loader
  • FIG. 8 shows a control system for controlling one or more of the functions of the wheel loader
  • FIG. 9 shows a further embodiment of the control system for controlling a work function of the wheel loader.
  • FIG. 1 shows a side view of a wheel loader 101 .
  • the wheel loader 101 comprises a front vehicle part 102 and a rear vehicle part 103 , which parts each comprise a frame and a pair of drive axles 112 , 113 .
  • the rear vehicle part 103 comprises a cab 114 .
  • the vehicle parts 102 , 103 are coupled together with one another in such a way that they can be pivoted in relation to one another about a vertical axis by means of two hydraulic cylinders 104 , 105 which are connected to the two parts.
  • the hydraulic cylinders 104 , 105 are thus arranged on different sides of a center line in the longitudinal direction of the vehicle for steering, or turning the wheel loader 101 .
  • the wheel loader 101 comprises an apparatus 111 for handling objects or material.
  • the apparatus 111 comprises a lifting arm unit 106 and an implement 107 in the form of a bucket which is mounted on the lifting arm unit.
  • the bucket 107 is filled with material 116 .
  • a first end of the lifting arm unit 106 is coupled rotatably to the front vehicle part 102 for bringing about a lifting movement of the bucket.
  • the bucket 107 is coupled rotatably to a second end of the lifting arm unit 106 for bringing about a tilting movement of the bucket.
  • the lifting arm unit 106 can be raised and lowered in relation to the front part 102 of the vehicle by means of two hydraulic cylinders 108 , 109 , which are each coupled at one end to the front vehicle part 102 and at the other end to the lifting arm unit 106 .
  • the bucket 107 can be tilted in relation to the lifting arm unit 106 by means of a third hydraulic cylinder 110 , which is coupled at one end to the front vehicle part 102 and at the other end to the bucket 107 via a link arm system.
  • a number of embodiments of a control system for the hydraulic functions of the wheel loader 101 will be described in greater detail below. These embodiments relate to lifting and lowering of the lifting arm 106 via the lifting cylinders 108 , 109 , see FIG. 1 . However, the various embodiments of the control system could also be used for tilting the bucket 107 via the tilting cylinder 110 .
  • FIG. 2 shows a first embodiment of a control system 201 for performing lifting and lowering of the lifting arm 106 , see FIG. 1 .
  • the hydraulic cylinder 108 in FIG. 2 therefore corresponds to the lifting cylinders 108 , 109 (although only one cylinder is shown in FIG. 2 ).
  • the control system 201 comprises an electric machine 202 , a hydraulic machine 204 and the lifting cylinder 108 .
  • the electric machine 202 is connected in a mechanically driving manner to the hydraulic machine 204 via an intermediate drive shaft 206 .
  • the hydraulic machine 204 is connected to a piston side 208 of the hydraulic cylinder 108 via a first line 210 and a piston-rod side 212 of the hydraulic cylinder 108 via a second line 214 .
  • the hydraulic machine 204 is adapted to function as a pump, be driven by the electric machine 202 and supply the hydraulic cylinder 108 with pressurized hydraulic fluid from a tank 216 in a first operating state and to function as a motor, be driven by a hydraulic fluid flow from the hydraulic cylinder 108 and drive the electric machine 202 in a second operating state.
  • the hydraulic machine 204 is adapted to control the speed of the piston 218 of the hydraulic cylinder 108 in the first operating state. No control valves are therefore required between the hydraulic machine and the hydraulic cylinder for said control. More precisely, the control system 201 comprises a control unit 802 , see FIG. 8 , which is electrically connected to the electric machine 202 in order to control the speed of the piston of the hydraulic cylinder 108 in the first operating state by controlling the electric machine.
  • the hydraulic machine 204 has a first port 220 which is connected to the piston side 208 of the hydraulic cylinder via the first line 210 and a second port 222 which is connected to the piston-rod side 212 of the hydraulic cylinder via the second line 214 .
  • the second port 222 of the hydraulic machine 204 is moreover connected to the tank 216 in order to allow the hydraulic machine, in the first operating state, to draw oil from the tank 216 via the second port 222 and supply the oil to the hydraulic cylinder 108 via the first port 220 .
  • the control system 201 comprises a means 224 for controlling pressure, which pressure means 224 is arranged on a line 226 between the second port 222 of the hydraulic machine 204 and the tank 216 in order to allow pressure build-up on the piston-rod side 212 . More precisely, the pressure control means 224 comprises an electrically controlled pressure-limiting valve.
  • the control system 201 also comprises a sensor 228 for sensing pressure on the piston side 208 of the hydraulic cylinder 108 .
  • a sensor 228 for sensing pressure on the piston side 208 of the hydraulic cylinder 108 .
  • the line 226 to the tank is blocked via the pressure-limiting valve 224 , which results in the pressure in the line 214 to the piston-rod side being increased and said intensified downward movement (power down) being obtained.
  • the pressure sensor registers that the pressure is below a certain level (for example 20 bar) on the piston side.
  • the pressure level on the electrically controlled pressure limiter is then increased to a suitable level so that pressure build-up takes place in the piston-rod side.
  • the first port 220 of the hydraulic machine 204 is connected to the tank 216 via a first suction line 230 .
  • a means 232 in the form of a non-return valve, is adapted to allow suction of hydraulic fluid from the tank and obstruction of a hydraulic fluid flow to the tank through the suction line 230 .
  • the second port 222 of the hydraulic machine 204 is connected to the tank 216 via a second suction line 234 .
  • a means 236 in the form of a non-return valve, is adapted to allow suction of hydraulic fluid from the tank and obstruction of a hydraulic fluid flow to the tank through the suction line 234 .
  • a means 237 for opening/closing is arranged on the second line 214 between the second port 222 of the hydraulic machine 204 and the piston-rod end 212 of the hydraulic cylinder 108 .
  • This means 237 comprises an electrically controlled valve with two positions. In a first position, the line 214 is open for flow in both directions. In a second position, the valve has a non-return valve function and allows flow in only the direction toward the hydraulic cylinder 108 .
  • the electric valve 237 is opened and the rotational speed of the electric machine 202 determines the speed of the piston 218 of the hydraulic cylinder 108 . Hydraulic fluid is drawn from the tank 216 via the second suction line 234 and is pumped to the piston side 208 of the hydraulic cylinder 108 via the first line 210 .
  • An additional line 242 connects the second port 222 of the hydraulic machine 204 and the tank 216 .
  • a means 243 for opening/closing is arranged on the first line 210 between the first port 220 of the hydraulic machine 204 and the piston end 208 of the hydraulic cylinder 108 .
  • This means 243 comprises an electrically controlled valve with two positions. In a first position, the line 210 is open for flow in both directions. In a second position, the valve has a non-return valve function and allows flow in only the direction toward the hydraulic cylinder 108 .
  • a lowering movement is initiated.
  • the electric valve 243 is closed.
  • a first side 208 of the piston 218 of the hydraulic cylinder is pressurized, which side is opposite a second side on which said load acts.
  • the piston side 208 is pressurized.
  • the hydraulic machine 204 is driven in a first rotation direction so that said first side 208 of the piston of the hydraulic cylinder is pressurized.
  • the hydraulic machine 204 is therefore rotated by a certain angle in the “wrong direction”.
  • a sensor 248 is adapted to sense the position of the piston rod.
  • a detected upward movement of the piston rod indicates that the pressurization is complete.
  • the pump 204 is rotated by a predetermined angle in the “wrong direction”.
  • the valve 243 is then opened to the piston side 208 , the rotation direction is changed for the hydraulic machine 204 and the lowering movement starts.
  • the electrically controlled pressure limiter may need to be adjusted slightly in order to improve refilling to the piston-rod side.
  • the hydraulic machine is therefore allowed to rotate in a second rotation direction, opposite the first rotation direction, whereupon the lowering movement can start.
  • the pressure applied is therefore reduced so that the lowering movement can start.
  • a hydraulic flow from the hydraulic cylinder 108 drives the hydraulic machine 204 in the second rotation direction. More precisely, the pressurization of the first side 208 of the hydraulic cylinder is reduced gradually so that a smooth lowering movement is achieved.
  • Pressurization can also be effected by the electric machine 202 first being driven with a certain torque in the “wrong direction”, where the torque level is based on the value of the pressure sensor 228 immediately before.
  • hydraulic fluid can be drawn from the tank 216 via the suction line 230 and on through the additional line 242 .
  • the electrically controlled valves 237 , 243 function as load-holding valves. They are closed in order that electricity is not consumed when there is a hanging load and also in order to prevent dropping when the drive source is switched off According to an alternative, the valve 237 on the piston-rod side 212 is omitted. However, it is advantageous to retain the valve 237 because external forces can lift the lifting arm 106 .
  • a filtering unit 238 and a heat exchanger 240 are arranged on the additional line 242 between the second port 222 of the hydraulic machine 204 and the tank 216 .
  • An additional filtering and heating flow can be obtained by virtue of the hydraulic machine 204 driving a circulation flow from the tank 216 first via the first suction line 230 and then via the additional line 242 when the lifting function is in a neutral position. Before the tank, the hydraulic fluid thus passes through the heat exchanger 240 and the filter unit 238 .
  • the electrically controlled pressure limiter 224 can also be used as a back-up valve for refilling to the piston-rod side 212 when lowering takes place.
  • the counter-pressure can be varied as required and kept as low as possible, which saves energy.
  • the counter-pressure can be lower the hotter the oil is and lower the lower the lowering speed is. When the filtering flow is run, the counter-pressure can be zero.
  • a first pressure-limiting valve 245 is arranged on a line which connects the first port 220 of the hydraulic machine 204 to the tank 216 .
  • a second pressure-limiting valve 247 is arranged on a line which connects the piston side 208 of the hydraulic cylinder 108 to the tank 216 .
  • the two pressure-limiting valves 245 , 247 are connected to the first line 210 between the hydraulic machine 204 and the piston side 208 of the hydraulic cylinder 108 on different sides of the valve 243 .
  • the two pressure-limiting valves 245 , 247 which are also referred to as shock valves, are spring-loaded and adjusted to be opened at different pressures. According to an example, the first pressure-limiting valve 245 is adjusted to be opened at 270 bar, and the second pressure-limiting valve 247 is adjusted to be opened at 380 bar.
  • the movement of the bucket may be counteracted by an obstacle.
  • the pressure-limiting valves 245 , 247 then ensure that the pressure is not built up to levels which are harmful for the system.
  • the bucket 107 is in a neutral position, that is to say stationary in relation to the frame of the front vehicle part 102 .
  • the second pressure limiter 247 is opened at a pressure of 380 bar.
  • the valve 243 on the first line 210 between the hydraulic machine 204 and the piston side 208 of the hydraulic cylinder 108 is open.
  • the first pressure limiter 245 is opened at a pressure of 270 bar. If an external force should force the loading arm 106 upward during a lowering operation with power down, the pressure limiter 224 on the line 226 between the second port 222 of the hydraulic machine 204 and the tank 216 is opened.
  • the pressure-limiting valves 245 , 247 can be designed with variable opening pressure.
  • the pressure-limiting valves 245 , 247 are electrically controlled. If electric control is used, only one valve 247 is sufficient for the shock function. This valve 247 is controlled depending on whether the valve 243 is open or closed. The opening pressure can be adjusted depending on activated or non-activated lifting/lowering function and also depending on the cylinder position.
  • a method for regenerating energy when the implement 107 is moved during movement of the work machine 101 is described below with reference to FIG. 2 .
  • the method can be said to constitute an active springing system for the lifting function.
  • the method can either be selected by an operator via a control element or a control, such as a knob or lever, in the cab or be initiated automatically.
  • a sensor 248 is adapted for sensing the position of the lifting arm 106 in relation to the frame of the front vehicle part 102 .
  • the sensor 248 is adapted to detect the position of the piston rod.
  • the sensor 248 could alternatively detect the angular position of the loading arm 106 relative to the frame.
  • the sensor 248 detects the position of the implement repeatedly, essentially continuously, and produces corresponding signals.
  • a control unit 802 receives the position signals from the sensor 248 .
  • the control unit 802 is usually referred to as a CPU (central processing unit) and comprises a microprocessor and a memory.
  • the position of the loading arm 106 is stored in the memory before the energy regeneration function is activated.
  • the two valves 237 and 243 on both sides of the lifting cylinder 108 are opened.
  • the hydraulic machine 204 is controlled so that such a pressure is delivered to the hydraulic cylinder 108 that the implement 107 is brought into a basic position.
  • the loading arm 106 is therefore held in position with a certain torque.
  • the loading arm 106 During movement of the wheel loader 101 , that is to say transport, the loading arm 106 will be acted on by vertical forces owing to the weight of the load and irregularities of the ground and move up and down.
  • the sensor 248 registers such disturbances which result in the loading arm 106 being moved from the basic position.
  • the control unit 802 produces a signal for the electric machine 202 which allows the hydraulic machine 204 to be driven by a hydraulic fluid flow from the hydraulic cylinder 108 and the energy from the hydraulic machine 204 is regenerated in the electric machine 202 . More precisely, the first port 220 of the hydraulic machine 204 is brought into flow communication with the piston side 208 of the hydraulic cylinder 108 . The control unit 802 therefore sends a signal to the valve 243 on the first line 210 , which is thus opened.
  • the lifting arm 106 moves downward, the basic position is passed through, the counter-torque of the electric machine 204 increasing so that the movement of the lifting arm is braked and in the end stops. Oil is then pumped into the cylinder 108 so the lifting arm 106 moves upward again.
  • control unit 802 registers this.
  • the control unit controls the hydraulic machine 204 (via the electric machine 202 ) so that the hydraulic machine follows with a certain torque and fills hydraulic fluid to the piston side 208 .
  • the torque applied decreases depending on how far from the basic position the lifting arm 106 is. A springing function is thus obtained.
  • a second port 222 of the hydraulic machine 204 is brought into flow communication with the piston-rod side 212 of the hydraulic cylinder 108 .
  • the hydraulic cylinder 108 is controlled continuously so that the implement 107 is kept within a predetermined range around the basic position. Adjustment is also carried out continuously between the disturbances so that the loading arm 106 does not move too far from the basic position.
  • valve 243 on the piston side 208 can be closed temporarily in order to save the energy which is consumed for holding the load.
  • the function also damps shocks which occur as a result of external forces such as, for example, collision with the bucket 107 .
  • pressure sensors are used for registering the course of the pressure variations which occur in the event of a disturbance. If pressure sensors are used, the valve 243 on the piston side 208 can if appropriate be closed as long as no lowering movement takes place (depending on how quickly it is possible to open in the event of a disturbance).
  • the hydraulic machine 204 is controlled so that a springing function is achieved. In other words, if a disturbance presses the lifting arm 106 down, the hydraulic machine 204 regenerates electricity and at the same time the torque is increased so that braking of the movement takes place (like a spring).
  • This spring characteristic can be dependent on a number of different parameters and have a different appearance.
  • the spring characteristic is dependent on the following parameters:
  • the same spring travel is obtained for the same disturbance force (irrespective of the weight of the load).
  • the spring travel is longer the greater the disturbance force is.
  • the disturbance force can be registered via pressure sensors or the derivative on the position sensor.
  • the springing is controlled so that the heavier the detected load is the shorter the spring travel.
  • the springing is controlled so that the lighter the detected load is the shorter the spring travel.
  • the computer registers the type of handling (bucket, pallet fork, timber fork etc.) in a manner known per se.
  • the damping in the system is determined by the size of the torque which the pump applies when the unit is to be raised again after being pressed down.
  • This torque application (spring characteristic) can also be a function of the parameters above.
  • FIG. 3 shows a second embodiment of the control system 301 .
  • the first port 220 of the hydraulic machine 204 is connected to the piston-rod side 212 of the hydraulic cylinder 108 via a line 302 which connects the piston-rod side 212 and the piston side 208 of the hydraulic cylinder 108 in parallel to the hydraulic machine 204 .
  • a means 304 for flow control in the form of an electrically controlled on/off valve, is arranged on said parallel line 302 in order to control the flow communication between the piston-rod side 212 and the piston side 208 .
  • the valve 304 the maximum flow via the hydraulic machine 204 can be lowered, that is to say the pump displacement can be reduced or a lower maximum speed can be used.
  • the pressure sensor 228 indicates whether the weight of the load is below or above a predetermined value, which indicates whether the load is considered to be light or heavy.
  • the additional valve 304 is opened, which results in more rapid lifting being possible by virtue of hydraulic fluid for the piston side 208 being obtained both from the hydraulic machine 204 and from the piston-rod side 212 .
  • the electric valve 237 on the second line 214 on the piston-rod side 212 is therefore closed.
  • the additional valve 304 on the parallel line 302 is opened.
  • pressurization takes place, for example by the electric machine 202 first being driven with a certain torque in the “wrong direction”, where the torque level is based on the value of the pressure sensor 228 immediately before.
  • the hydraulic machine 204 rotates by a certain angle in the “wrong direction”.
  • the valve 243 on the first line 210 is then opened to the piston side 208 , the rotation direction of the hydraulic machine 204 is changed, and the lowering movement starts.
  • the lowering movement of a heavy load can be performed as follows: the pressure sensor 228 indicates heavy load.
  • the additional valve 304 on the parallel line 302 is closed. In this state, all the flow from the piston side 208 passes via the hydraulic machine 204 .
  • the electrically controlled pressure limiter may need to be adjusted slightly in order to improve refilling to the piston-rod side 212 .
  • the pressure sensor 228 therefore detects a load acting on the implement and generates a corresponding signal.
  • the control unit 802 see FIG. 8 , compares the size of the detected load with a predetermined load level. If the detected load is below the predetermined load level, a corresponding signal is sent to the valve 304 , which is opened, the piston-rod side 212 of the hydraulic cylinder 108 being brought into flow communication with the piston side 208 so that hydraulic fluid coming from the piston-rod side is brought to the piston side without passing through the hydraulic machine 204 .
  • a corresponding signal is sent to the valve 237 , which is opened, the piston-rod side of the hydraulic cylinder being brought into flow communication with the second port 222 of the hydraulic machine 204 so that hydraulic fluid coming from the piston-rod side 212 is brought to the second port of the hydraulic machine.
  • FIG. 4 shows a third embodiment of the control system 401 .
  • a flow control means 402 in the form of an electrically controlled proportional valve, is connected on a line 404 which extends between the first line 210 and the tank 216 in order to allow a certain leakage flow from the hydraulic machine 204 to the tank at the start of a lifting movement.
  • the hydraulic machine 204 thus has a certain basic revolution before lifting takes place. This reduces starting friction.
  • the valve 402 can then be closed gradually the greater the lifting speed becomes.
  • the valve 402 is a small valve which only produces an adequate drainage flow so that the hydraulic machine 204 starts working before the cylinder movement starts.
  • a flow control means 406 in the form of an electrically controlled proportional valve, is connected on the first line 210 between the hydraulic machine 204 and the piston side 208 of the hydraulic cylinder in order to control the size of the hydraulic fluid flow from the hydraulic cylinder 108 to the hydraulic machine 204 at the start of the lowering movement.
  • the electric machine 202 has a low counter-torque in order to prevent starting friction and a jerky start.
  • the valve 406 is opened proportionally and the piston speed is controlled. In parallel with the valve 406 being opened, the counter-torque in the electric machine 202 is increased and the hydraulic machine 204 gradually takes over the speed control of the lowering movement. In the end, the valve 406 is fully open and the lowering speed is controlled completely by the electric machine 202 .
  • FIG. 5 shows a fourth embodiment of the control system 501 .
  • the hydraulic machine 204 can be connected via a connection means 502 to an additional hydraulic actuator 504 which is adapted to perform a work function which is separate from a work function performed by said hydraulic cylinder 108 .
  • the connection means 502 consists of an electrically controlled directional valve.
  • the additional work function can be, for example, implement locking or an emergency pump for the steering function.
  • FIG. 6 shows a fifth embodiment of the control system 601 , which is a development of the first embodiment, see FIG. 2 .
  • said means for allowing suction of hydraulic fluid from the tank 216 through the suction lines 230 , 234 consist of electrically controlled on/off valves 632 , 636 instead of non-return valves. This reduces problems of cavitation on the suction side.
  • the valve 636 which connects the second port 222 of the hydraulic machine 204 to the tank 216 can be open when the hydraulic machine rotates in the direction so that hydraulic fluid passes to the cylinder 108 .
  • the valve 636 is closed when the rotation is changed.
  • the valve 632 which connects the first port 220 of the hydraulic machine 204 to the tank 216 is opened when the filtering and heating flow is run.
  • the valve 636 may also need to be opened if the unit stops dead during ongoing lowering, which results in cavitation occurring on account of the fact that the hydraulic machine 202 does not have time to stop.
  • Such a course of events can be registered by, for example, registering the state of the hydraulic machine 202 and the state of the cylinder 108 .
  • FIG. 7 shows a control system 701 comprising a subsystem 707 for the lifting function, a subsystem 709 for the tilting function, a subsystem 711 for the steering function and a subsystem 731 for an additional function.
  • a control system 701 comprising a subsystem 707 for the lifting function, a subsystem 709 for the tilting function, a subsystem 711 for the steering function and a subsystem 731 for an additional function.
  • the subsystem 709 shown in FIG. 7 for the tilting function has a construction corresponding to the system for the lifting function.
  • FIG. 7 illustrates the electric machine with reference sign 703 and the hydraulic machine with reference sign 705 .
  • a pressure-limiting valve 702 or shock valve, is added, which connects the piston-rod side of the tilting cylinder 110 to the tank.
  • the subsystem 711 shown in FIG. 7 for the steering function comprises said first and second steering cylinders 104 , 105 , which are adapted for frame-steering the wheel loader 101 .
  • the system also comprises a first drive unit 704 and a second drive unit 706 , which each comprise an electric machine 708 , 710 and a hydraulic machine 712 , 714 .
  • Each electric machine 708 , 710 is connected in a driving manner to its associated hydraulic machine 712 , 714 .
  • a first 712 of the two hydraulic machines is connected to a piston side 716 of the first hydraulic cylinder 104 and a piston-rod side 718 of the second hydraulic cylinder 105 .
  • a second 714 of the two hydraulic machines is connected to a piston side 720 of the second hydraulic cylinder 105 and a piston-rod side 722 of the first hydraulic cylinder 104 .
  • a first of the hydraulic machines 712 is adapted to be driven by its associated electric machine 708 and to supply the hydraulic cylinders 104 , 105 with pressurized hydraulic fluid from the tank 216
  • the second hydraulic machine 714 is adapted to be driven by a hydraulic fluid flow from the hydraulic cylinders 104 , 105 and to drive its associated electric machine 710 , and vice versa.
  • the hydraulic machines are therefore driven in opposite directions during operation.
  • a first electrically controlled control means (control valve) 724 is arranged between the hydraulic machine 712 of the first drive unit 704 and the steering cylinders 104 , 105
  • a second electrically controlled control means (control valve) 726 is arranged between the hydraulic machine 714 of the second drive unit 706 and the steering cylinders 104 , 105 .
  • the subsystem 731 shown in FIG. 7 for the additional function preferably comprises only one drive unit 734 for providing all the additional functions. This means that it is easier to add an additional function, see arrow 766 , as only a valve unit has to be added.
  • the drive unit 734 comprises a pump 736 which is driven mechanically by an electric motor 738 .
  • This additional function can consist of, for example, the implement 107 comprising parts which are movable relative to one another, the movement of which is controlled. Such functions can consist of a sweeping roller, clamping arms etc.
  • a hydraulic actuator in the form of a hydraulic cylinder 732 is adapted for carrying out the movement in the control system 731 shown.
  • the pump 736 is connected to a piston side 740 and a piston-rod side 742 via a first and a second line 744 , 746 .
  • An inlet valve in the form of an electrically controlled proportional valve 748 , 750 is arranged on each of the first and second lines 744 , 746 .
  • the piston side 740 and the piston-rod side 742 are connected to the tank 216 via a third and fourth line 752 , 754 .
  • An outlet valve in the form of an electrically controlled proportional valve 756 , 758 is arranged on each of the third and fourth lines 752 , 754 .
  • a pressure sensor 760 , 762 is arranged on each of the third and fourth lines 752 , 754 .
  • An additional pressure sensor 764 is arranged on the line downstream of the pump 736 and upstream of the inlet valves 748 ,
  • more pumps and if appropriate electric motors can be added for the purpose of increasing the maximum flow.
  • the pump for the lifting or the tilting function can moreover be connected in parallel for any topping of the flow.
  • Functions with another type of valve can also be added.
  • the additional function can be controlled via inlet control: on activation of a function, the load pressure in the cylinder 732 is registered.
  • the pump 736 is set with a torque which gives a certain level of higher pressure before the inlet valve 748 , 750 , which is registered via the pressure sensor 764 before the valve. This means that the inlet valve 748 , 750 has a known pressure drop. By virtue of the fact that the pressure drop can be read off, the flow can now be adjusted via control of the inlet valve (regulating the opening area). If a number of functions are running at the same time, the pump 736 builds up a torque which is a certain level higher than the highest registered load pressure.
  • the outlet valve 756 , 758 opens to a level which gives a specific counter-pressure, which can be read off via the pressure sensor 760 , 762 on the outlet side of the cylinder 732 . If the counter-pressure is higher on account of a hanging load, the outlet valve 756 , 758 is regulated so that the pressure on the inlet side does not fall below a certain level. Functions which have a motor instead of a cylinder can be regulated in the same way.
  • the additional function can alternatively be controlled via outlet control: the pump 736 is set with a torque which gives a certain pressure level before the outlet valve 756 , 758 , which is registered via the pressure sensor 760 , 762 before the outlet valve.
  • the outlet valve 756 , 758 has a pressure drop which is known (the tank side is in principle pressureless).
  • a pressure sensor is arranged on the tank side. It is then possible to have control of the pressure drop across the valve (in some cases the system is not pressureless).
  • the flow can now be adjusted via control of the outlet valve 756 , 758 (regulating the opening area). If a number of functions are running at the same time, the pump builds up a torque which gives a certain level of pressure at the pressure sensor (on the outlet side) which has the lowest pressure.
  • the inlet valve 748 , 750 can be opened fully so that no pressure drop occurs (lower losses). If it is hanging load, the cylinder 732 drives, or if a pump flow deficiency occurs, the outlet valve 756 , 758 is also regulated so that the pressure on the inlet side of the cylinder 732 does not fall below a certain level. Prioritizing/weighting can take place between the functions is the pump flow is not sufficient.
  • both the inlet valve 748 , 750 and the outlet valve 756 , 758 can be opened fully so that no pressure drop is generated.
  • the speed of the sweeping roller is then controlled directly via the speed of the pump 736 . If another function is temporarily controlled simultaneously, it is possible to change over temporarily to inlet control or outlet control.
  • the control system 731 affords opportunities for a maximum feed pressure limitation.
  • the pressure can be read off via the pressure sensor, and the inlet valve can be throttled when the pressure becomes too high.
  • the control system 731 also affords opportunities for dealing with a shock pressure.
  • the pressure can be read off via pressure sensor, and the outlet valve can drain to the tank when the pressure level becomes too high.
  • a back-up valve can be added after the valve 756 , 758 on the outlet side (toward the tank 216 ), together with refilling valves for the cylinder 732 . This provides more available pump flow when a number of functions are running simultaneously and then if a function has a load which drives the flow.
  • FIG. 8 shows a control system for controlling the control system 701 shown in FIG. 7 for the lifting function, the tilting function, the steering function and the additional function.
  • a number of elements, or controls, 804 , 806 , 808 , 810 , 812 , 814 are arranged in the cab 114 for manual operation by the driver and are electrically connected to the control unit 802 for controlling the various functions.
  • a wheel 804 and a control lever 806 are adapted for controlling the steering function.
  • a lifting lever 808 is adapted for the lifting function and a tilting lever 810 is adapted for the tilting function.
  • a lever 812 is adapted for controlling the third function, and an additional control 814 is adapted for pump control (adjustable flow) for the third function.
  • a number of additional functions with associated controls can be added.
  • the electric machines 202 , 703 , 708 , 710 , 738 are electrically connected to the control unit 802 in such a way that they are controlled by the control unit and that they can provide operating state signals to the control unit.
  • the control system comprises one or more energy storage means 820 connected to one or more of said electric machines 202 , 703 , 708 , 710 , 738 .
  • the energy storage means 820 can consist of a battery or a supercapacitor, for example.
  • the energy storage means 820 is adapted to provide the electric machine with energy when the electric machine 202 is to function as a motor and drive its associated pump 204 .
  • the electric machine 202 is adapted to charge the energy storage means 820 with energy when the electric machine 202 is driven by its associated pump 204 and functions as a generator.
  • the wheel loader 101 also comprises a power source 822 in the form of an internal combustion engine, which usually consists of a diesel engine, for propulsion of the vehicle.
  • the diesel engine 822 is connected in a driving manner to the wheels of the vehicle via a drive line (not shown).
  • the diesel engine 822 is moreover connected to the energy storage means 820 via a generator (not shown) for energy transmission.
  • FIG. 8 also shows the other components which are connected to the control unit 802 according to the first embodiment of the control system for the lifting function, see FIG. 2 , such as the electrically controlled valves 224 , 237 , 243 , the position sensor 248 and the pressure sensor 228 . It will be understood that corresponding components for the tilting function and the steering function and the additional function are connected to the control unit 802 .
  • FIG. 9 shows a further embodiment of the control system 901 .
  • the control system 901 comprises a hydraulic cylinder 902 which is reversed, which means that a load 904 draws the cylinder out via its weight.
  • This control system 901 can be said to be a variant of the control system 201 according to the first embodiment, see FIG. 2 .
  • the system comprises an additional, smaller pump 908 .
  • the smaller pump has a driving connection to the hydraulic machine 204 .
  • the small pump 908 contributes to pumping hydraulic fluid from the tank 216 to the piston side 906 via a suction line 912 .
  • the small pump 908 performs no useful work.
  • the small pump 908 only pumps hydraulic fluid round through itself via a small non-return valve 914 .
  • the non-return valve 914 is therefore connected between an inlet side 916 and an outlet side 918 of the additional pump 908 , so that, during a lifting movement, the pump 908 only pumps hydraulic fluid in a circuit 920 comprising the non-return valve 914 .
  • the non-return valve 914 is therefore arranged in parallel with the small pump 908 .
  • this system 901 functions similarly to the basic system (see FIG. 2 ), apart from the filtering and heating flow being a little greater.
  • the pump According to a previously known pump, there is a regulator in the pump, which provides a pressure-limiting function so that the displacement of the pump is adjusted down in the event of pressure being too high.
  • the built-in pressure-limiting function of the pump can be omitted, and a simpler/cheaper pump can therefore be used as a hydraulic machine.
  • a first embodiment of the regulating method comprises the steps of detecting an operating parameter and of generating a corresponding parameter signal, of determining a level of said pressure based on the level of the detected operating parameter, of comparing the determined pressure level with a predetermined maximum level and of controlling the hydraulic machine so that a delivered pressure lies below the predetermined maximum level. More precisely, the parameter signal generated is received by the control unit (computer) and is processed, after which a control signal is sent to the electric machine which has a driving connection to the hydraulic machine to reduce the delivered torque if the determined pressure level exceeds the predetermined maximum level.
  • the preferred embodiment comprises the step of detecting a torque delivered by the electric machine and of determining the level of said pressure based on the detected torque. Furthermore, a level of said pressure based on at least the detected torque and the displacement of the hydraulic machine is calculated.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • Operation Control Of Excavators (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Lifting Devices For Agricultural Implements (AREA)
US11/623,622 2006-01-16 2007-01-16 Control system for a work machine and method for controlling a hydraulic cylinder in a work machine Abandoned US20070166168A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US11/623,622 US20070166168A1 (en) 2006-01-16 2007-01-16 Control system for a work machine and method for controlling a hydraulic cylinder in a work machine

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
SE0600087A SE531309C2 (sv) 2006-01-16 2006-01-16 Styrsystem för en arbetsmaskin och förfarande för styrning av en hydraulcylinder hos en arbetsmaskin
SE0600087-1 2006-01-16
US75999606P 2006-01-18 2006-01-18
US11/623,622 US20070166168A1 (en) 2006-01-16 2007-01-16 Control system for a work machine and method for controlling a hydraulic cylinder in a work machine

Publications (1)

Publication Number Publication Date
US20070166168A1 true US20070166168A1 (en) 2007-07-19

Family

ID=38331484

Family Applications (7)

Application Number Title Priority Date Filing Date
US11/623,622 Abandoned US20070166168A1 (en) 2006-01-16 2007-01-16 Control system for a work machine and method for controlling a hydraulic cylinder in a work machine
US12/097,920 Active 2029-06-18 US8225706B2 (en) 2006-01-16 2007-01-16 Method for controlling a hydraulic cylinder and control system for a work machine
US12/158,054 Active 2028-09-18 US8065875B2 (en) 2006-01-16 2007-01-16 Method for springing a movement of an implement of a work machine
US12/097,917 Active 2029-06-03 US8407993B2 (en) 2006-01-16 2007-01-16 Method for controlling a hydraulic cylinder in a work machine
US12/097,922 Active 2029-07-15 US8240144B2 (en) 2006-01-16 2007-01-16 Method for controlling a hydraulic machine in a control system
US12/097,923 Active 2028-05-28 US7908048B2 (en) 2006-01-16 2007-01-16 Control system for a work machine and method for controlling a hydraulic cylinder
US12/097,916 Expired - Fee Related US9670944B2 (en) 2006-01-16 2007-01-16 Method for controlling a hydraulic cylinder in a work machine and control system for a work machine

Family Applications After (6)

Application Number Title Priority Date Filing Date
US12/097,920 Active 2029-06-18 US8225706B2 (en) 2006-01-16 2007-01-16 Method for controlling a hydraulic cylinder and control system for a work machine
US12/158,054 Active 2028-09-18 US8065875B2 (en) 2006-01-16 2007-01-16 Method for springing a movement of an implement of a work machine
US12/097,917 Active 2029-06-03 US8407993B2 (en) 2006-01-16 2007-01-16 Method for controlling a hydraulic cylinder in a work machine
US12/097,922 Active 2029-07-15 US8240144B2 (en) 2006-01-16 2007-01-16 Method for controlling a hydraulic machine in a control system
US12/097,923 Active 2028-05-28 US7908048B2 (en) 2006-01-16 2007-01-16 Control system for a work machine and method for controlling a hydraulic cylinder
US12/097,916 Expired - Fee Related US9670944B2 (en) 2006-01-16 2007-01-16 Method for controlling a hydraulic cylinder in a work machine and control system for a work machine

Country Status (5)

Country Link
US (7) US20070166168A1 (zh)
EP (6) EP1979550B1 (zh)
CN (6) CN101370989B (zh)
SE (1) SE531309C2 (zh)
WO (6) WO2007081279A1 (zh)

Cited By (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080294316A1 (en) * 2006-01-16 2008-11-27 Volvo Construction Equipment Ab Method for Controlling a Hydraulic Cylinder in a Work Machine and Control System for a Work Machine
WO2009071264A1 (de) * 2007-12-04 2009-06-11 Robert Bosch Gmbh Hydraulisches system mit einem verstellbaren schnellsenkventil
US20090326768A1 (en) * 2008-06-30 2009-12-31 Caterpillar Inc. Digging control system
WO2010028100A1 (en) 2008-09-03 2010-03-11 Parker Hannifin Corporation Velocity control of unbalanced hydraulic actuator subjected to over-center load conditions
EP2247459A2 (en) * 2008-01-23 2010-11-10 Parker-Hannifin Corporation Electro-hydraulic machine for hybri drive system
US20110056192A1 (en) * 2009-09-10 2011-03-10 Robert Weber Technique for controlling pumps in a hydraulic system
US20110056194A1 (en) * 2009-09-10 2011-03-10 Bucyrus International, Inc. Hydraulic system for heavy equipment
US20110064706A1 (en) * 2008-01-11 2011-03-17 U.S. Nutraceuticals, Llc D/B/A Valensa International Method of preventing, controlling and ameliorating urinary tract infections and supporting digestive health by using a synergistic cranberry derivative, a d-mannose composition and a proprietary probiotic blend
US20110233931A1 (en) * 2010-03-23 2011-09-29 Bucyrus International, Inc. Energy management system for heavy equipment
WO2012034781A1 (de) * 2010-09-14 2012-03-22 Zf Friedrichshafen Ag Hydraulische antriebsanordnung
US20120089279A1 (en) * 2010-10-06 2012-04-12 Bucyrus International, Inc. Energy management and storage system
US20130140822A1 (en) * 2011-12-05 2013-06-06 Fabio Saposnik Fluid power driven charger
US8606451B2 (en) 2010-10-06 2013-12-10 Caterpillar Global Mining Llc Energy system for heavy equipment
US8718845B2 (en) 2010-10-06 2014-05-06 Caterpillar Global Mining Llc Energy management system for heavy equipment
WO2014074713A1 (en) * 2012-11-07 2014-05-15 Parker-Hannifin Corporation Smooth control of hydraulic actuator
AU2013201057A1 (en) * 2012-11-06 2014-05-22 SINGH, Kalvin Jit MR Improvements in and Relating to Load Transfer
US20140182279A1 (en) * 2011-09-09 2014-07-03 Sumitomo Heavy Industries, Ltd. Shovel and method of controlling shovel
EP2778113A1 (en) * 2013-03-14 2014-09-17 The Raymond Corporation Hydraulic regeneration system and method for a material handling vehicle
WO2014176252A1 (en) * 2013-04-22 2014-10-30 Parker-Hannifin Corporation Method of increasing electro-hydrostatic actuator piston velocity
US9096115B2 (en) 2011-11-17 2015-08-04 Caterpillar Inc. System and method for energy recovery
US20150275927A1 (en) * 2012-11-07 2015-10-01 Parker-Hannifin Corporation Electro-hydrostatic actuator deceleration rate control system
US9190852B2 (en) 2012-09-21 2015-11-17 Caterpillar Global Mining Llc Systems and methods for stabilizing power rate of change within generator based applications
EP2955389A1 (en) * 2014-06-13 2015-12-16 Parker Hannifin Manufacturing Finland OY Hydraulic system with energy recovery
US20170114807A1 (en) * 2014-06-02 2017-04-27 Project Phoenix, LLC Linear actuator assembly and system
US9920755B2 (en) 2014-02-28 2018-03-20 Project Phoenix, LLC Pump integrated with two independently driven prime movers
US10072676B2 (en) * 2014-09-23 2018-09-11 Project Phoenix, LLC System to pump fluid and control thereof
US10294936B2 (en) 2014-04-22 2019-05-21 Project Phoenix, Llc. Fluid delivery system with a shaft having a through-passage
US10465721B2 (en) 2014-03-25 2019-11-05 Project Phoenix, LLC System to pump fluid and control thereof
EP3594413A1 (en) * 2018-07-12 2020-01-15 Eaton Intelligent Power Limited Power architecture for a vehicle such as an off-highway vehicle
US10539134B2 (en) 2014-10-06 2020-01-21 Project Phoenix, LLC Linear actuator assembly and system
US10544861B2 (en) 2014-06-02 2020-01-28 Project Phoenix, LLC Hydrostatic transmission assembly and system
US10598176B2 (en) 2014-07-22 2020-03-24 Project Phoenix, LLC External gear pump integrated with two independently driven prime movers
US10677352B2 (en) 2014-10-20 2020-06-09 Project Phoenix, LLC Hydrostatic transmission assembly and system
CN111350627A (zh) * 2020-04-01 2020-06-30 东方电气自动控制工程有限公司 一种带手自动切换的液压调速控制系统
EP3722516A1 (en) * 2019-04-11 2020-10-14 Gebroeders Geens N.V. Drive system for a work vehicle
US10822772B1 (en) * 2017-02-03 2020-11-03 Wrightspeed, Inc. Hydraulic systems with variable speed drives
US10865788B2 (en) 2015-09-02 2020-12-15 Project Phoenix, LLC System to pump fluid and control thereof
US11085440B2 (en) 2015-09-02 2021-08-10 Project Phoenix, LLC System to pump fluid and control thereof
WO2021225645A1 (en) * 2020-05-05 2021-11-11 Parker-Hannifin Corporation Hydraulic dissipation of electric power
CN114251214A (zh) * 2021-12-09 2022-03-29 中国船舶重工集团公司第七一九研究所 分数阶动力系统混沌状态的判断方法及装置
US11408445B2 (en) 2018-07-12 2022-08-09 Danfoss Power Solutions Ii Technology A/S Dual power electro-hydraulic motion control system
WO2023041476A1 (de) * 2021-09-15 2023-03-23 Hms – Hybrid Motion Solutions Gmbh Hydraulisches antriebssystem mit einer 4q pumpeneinheit
US20230312242A1 (en) * 2022-03-31 2023-10-05 Oshkosh Corporation Regeneration control for a refuse vehicle packer system
WO2024046697A1 (de) * 2022-08-31 2024-03-07 Bucher Hydraulics Ag Elektrisch-hydraulischer aktor

Families Citing this family (60)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2588290A1 (en) 2004-12-01 2006-06-08 Haldex Hydraulics Corporation Hydraulic drive system
DE102006042372A1 (de) * 2006-09-08 2008-03-27 Deere & Company, Moline Ladegerät
JP5600274B2 (ja) * 2010-08-18 2014-10-01 川崎重工業株式会社 作業機械の電液駆動システム
US20120055149A1 (en) * 2010-09-02 2012-03-08 Bucyrus International, Inc. Semi-closed hydraulic systems
EP2466017A1 (en) * 2010-12-14 2012-06-20 Caterpillar, Inc. Closed loop drive circuit with open circuit pump assist for high speed travel
JP5509433B2 (ja) * 2011-03-22 2014-06-04 日立建機株式会社 ハイブリッド式建設機械及びこれに用いる補助制御装置
US8833067B2 (en) * 2011-04-18 2014-09-16 Caterpillar Inc. Load holding for meterless control of actuators
EP2700827A4 (en) * 2011-04-19 2015-03-11 Volvo Constr Equip Ab HYDRAULIC CIRCUIT FOR CONTROLLING THE EXTRACTS OF A CONSTRUCTION MACHINE
US8666574B2 (en) * 2011-04-21 2014-03-04 Deere & Company In-vehicle estimation of electric traction motor performance
EP2940319B1 (en) * 2011-05-31 2019-03-13 Volvo Construction Equipment AB A hydraulic system and a method for controlling a hydraulic system
US8886415B2 (en) * 2011-06-16 2014-11-11 Caterpillar Inc. System implementing parallel lift for range of angles
WO2013000155A1 (zh) * 2011-06-30 2013-01-03 Lio Pang-Chian 液压远端传动控制装置
JP5752526B2 (ja) * 2011-08-24 2015-07-22 株式会社小松製作所 油圧駆動システム
US8944103B2 (en) 2011-08-31 2015-02-03 Caterpillar Inc. Meterless hydraulic system having displacement control valve
US8863509B2 (en) * 2011-08-31 2014-10-21 Caterpillar Inc. Meterless hydraulic system having load-holding bypass
CN103857927B (zh) * 2011-10-11 2016-08-17 沃尔沃建造设备有限公司 建造设备的电动液压系统中的执行器位移测量系统
US9080310B2 (en) * 2011-10-21 2015-07-14 Caterpillar Inc. Closed-loop hydraulic system having regeneration configuration
CN104053843B (zh) * 2011-10-27 2016-06-22 沃尔沃建造设备有限公司 设置有致动器冲击降低系统的混合动力挖掘机
CN102493976B (zh) * 2011-12-01 2014-12-10 三一重工股份有限公司 一种工程机械的动力控制系统及控制方法
WO2013095208A1 (en) * 2011-12-22 2013-06-27 Volvo Construction Equipment Ab A method for controlling lowering of an implement of a working machine
EP2795002B1 (en) * 2011-12-23 2022-03-30 J.C. Bamford Excavators Limited A hydraulic system including a kinetic energy storage device
JP5730794B2 (ja) * 2012-01-18 2015-06-10 住友重機械工業株式会社 建設機械のエネルギ回生装置
US20130189062A1 (en) * 2012-01-23 2013-07-25 Paul Bark Hydraulic pump control system for lift gate applications
DE102012101231A1 (de) * 2012-02-16 2013-08-22 Linde Material Handling Gmbh Hydrostatisches Antriebssystem
JP5928065B2 (ja) * 2012-03-27 2016-06-01 コベルコ建機株式会社 制御装置及びこれを備えた建設機械
EP2836654B1 (en) 2012-04-11 2017-06-07 Clark Equipment Company Lift arm suspension system for a power machine
US8825314B2 (en) * 2012-07-31 2014-09-02 Caterpillar Inc. Work machine drive train torque vectoring
US9279736B2 (en) 2012-12-18 2016-03-08 Caterpillar Inc. System and method for calibrating hydraulic valves
US9890799B2 (en) 2013-04-19 2018-02-13 Parker-Hannifin Corporation Method to detect hydraulic valve failure in hydraulic system
CN105358844B (zh) 2013-04-22 2017-05-24 派克汉尼芬公司 用于控制液压致动器中压力的方法
CN105164347B (zh) * 2013-08-05 2017-11-03 川崎重工业株式会社 建筑机械用能量再生装置
JP2015137753A (ja) * 2014-01-24 2015-07-30 カヤバ工業株式会社 ハイブリッド建設機械の制御システム
US20170016460A1 (en) * 2014-01-27 2017-01-19 Volvo Construction Equipment Ab Device for controlling regenerated flow rate for construction machine and method for controlling same
WO2015152775A1 (en) 2014-04-04 2015-10-08 Volvo Construction Equipment Ab Hydraulic system and method for controlling an implement of a working machine
US9546672B2 (en) 2014-07-24 2017-01-17 Google Inc. Actuator limit controller
US9841101B2 (en) * 2014-09-04 2017-12-12 Cummins Power Generation Ip, Inc. Control system for hydraulically powered AC generator
US9759212B2 (en) * 2015-01-05 2017-09-12 Danfoss Power Solutions Inc. Electronic load sense control with electronic variable load sense relief, variable working margin, and electronic torque limiting
US10851811B2 (en) * 2015-09-10 2020-12-01 Festo Se & Co. Kg Fluid system and process valve
WO2017070539A1 (en) * 2015-10-23 2017-04-27 Aoi (Advanced Oilfield Innovations, Dba A.O. International Ii, Inc.) Prime mover system and methods utilizing balanced flow within bi-directional power units
DE102015119108A1 (de) * 2015-11-06 2017-05-11 Pleiger Maschinenbau Gmbh & Co. Kg Verfahren und Vorrichtung zum Ansteuern einer hydraulisch betätigten Antriebseinheit einer Armatur
US9657675B1 (en) 2016-03-31 2017-05-23 Etagen Inc. Control of piston trajectory in a free-piston combustion engine
US10550863B1 (en) 2016-05-19 2020-02-04 Steven H. Marquardt Direct link circuit
US10914322B1 (en) 2016-05-19 2021-02-09 Steven H. Marquardt Energy saving accumulator circuit
US11015624B2 (en) 2016-05-19 2021-05-25 Steven H. Marquardt Methods and devices for conserving energy in fluid power production
MX2019002569A (es) * 2016-09-06 2019-10-07 Aperia Tech Inc Sistema para inflado de neumáticos.
DE102016217541A1 (de) * 2016-09-14 2018-03-15 Robert Bosch Gmbh Hydraulisches Antriebssystem mit mehreren Zulaufleitungen
CN106337849A (zh) * 2016-11-23 2017-01-18 中冶赛迪工程技术股份有限公司 一种trt机组静叶直驱式电液伺服控制系统
EP3629725B1 (de) * 2017-05-23 2021-03-31 FSP Fluid Systems Partners Holding AG Steuereinrichtung für eine ausbringvorrichtung und ausbringvorrichtung mit einer steuereinrichtung
US10392774B2 (en) 2017-10-30 2019-08-27 Deere & Company Position control system and method for an implement of a work vehicle
DE102017131004A1 (de) * 2017-12-21 2019-06-27 Moog Gmbh Stellantrieb mit hydraulischem Abflussverstärker
KR102586623B1 (ko) * 2018-09-27 2023-10-10 볼보 컨스트럭션 이큅먼트 에이비 작업유닛 방출에너지 회생 시스템 및 방법
CN112912631B (zh) * 2018-10-24 2023-05-05 沃尔沃建筑设备公司 用于作业机械的液压系统
DE102018128318A1 (de) * 2018-11-13 2020-05-14 Moog Luxembourg S.à.r.l. Elektrohydrostatisches Aktuatorsystem
EP3959383B1 (en) * 2019-04-26 2023-06-07 Volvo Construction Equipment AB A hydraulic system and a method for controlling a hydraulic system of a working machine
NO20200709A1 (no) * 2019-06-17 2020-12-18 Conrobotix As Sylinder, hydraulisk system, anleggsmaskin og fremgangsmåte
DE102019131980A1 (de) * 2019-11-26 2021-05-27 Moog Gmbh Elektrohydrostatisches System mit Drucksensor
CN115398065B (zh) * 2019-12-12 2024-03-08 沃尔沃建筑设备公司 液压系统以及用于控制作业机械的液压系统的方法
CN114482184B (zh) * 2022-02-28 2023-08-22 西安方元明鑫精密机电制造有限公司 一种基于伺服系统力矩控制的挖掘机用电动缸缓冲控制系统
CN114951580A (zh) * 2022-06-27 2022-08-30 沈阳广泰真空科技股份有限公司 一种驱动冷却辊旋转的方法、装置、存储介质及电子设备
DE102022211393A1 (de) * 2022-10-27 2024-05-02 Robert Bosch Gesellschaft mit beschränkter Haftung Hydraulische Anordnung mit Lasthaltefunktion und Steuerungsverfahren der hydraulischen Anordnung

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4961316A (en) * 1987-10-28 1990-10-09 Bt Industries Aktiebolag Controlled electric pump drive for hydraulic lifting arrangement with gas spring in motor
US5179836A (en) * 1990-03-19 1993-01-19 Mannesmann Rexroth Gmbh Hydraulic system for a differential piston type cylinder
US20050196288A1 (en) * 2004-03-05 2005-09-08 Deere & Company, A Delaware Corporation. Closed circuit energy recovery system for a work implement

Family Cites Families (51)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2590454A (en) * 1949-09-13 1952-03-25 John S Pilch Hydraulic by-pass system and valve therefor
US3473325A (en) * 1967-11-13 1969-10-21 Eltra Corp Unitary hydraulic shock absorber and actuator
US3604313A (en) * 1970-05-14 1971-09-14 Gen Signal Corp Hydraulic power circuit with rapid lowering provisions
US4046270A (en) * 1974-06-06 1977-09-06 Marion Power Shovel Company, Inc. Power shovel and crowd system therefor
SE396239B (sv) * 1976-02-05 1977-09-12 Hytec Ab Metod och anordning for reglering av den effekt som tillfors ett hydrauliskt, ett pneumatiskt eller ett hydraulpneumatiskt system
US4509405A (en) * 1979-08-20 1985-04-09 Nl Industries, Inc. Control valve system for blowout preventers
JPS56115428A (en) 1980-02-15 1981-09-10 Hitachi Constr Mach Co Ltd Hydraulic controller
JPS5822299A (ja) * 1981-07-29 1983-02-09 日産自動車株式会社 フオ−クリフト
DE3506335A1 (de) * 1985-02-22 1986-08-28 Mannesmann Rexroth GmbH, 8770 Lohr Sicherheitsschaltung fuer ein hydrauliksystem
US4712376A (en) 1986-10-22 1987-12-15 Caterpillar Inc. Proportional valve control apparatus for fluid systems
DE3710028A1 (de) * 1987-03-27 1988-10-06 Delmag Maschinenfabrik Druckmittelbetriebene antriebseinrichtung
US5116187A (en) * 1988-05-24 1992-05-26 Kabushiki Kaisha Komatsu Seisakusho Automatic speed changing apparatus for wheel loader
JPH0790400B2 (ja) * 1989-10-18 1995-10-04 アイダエンジニアリング株式会社 プレスのダイクッション装置
US5046309A (en) 1990-01-22 1991-09-10 Shin Caterpillar Mitsubishi Ltd. Energy regenerative circuit in a hydraulic apparatus
WO1991016506A1 (en) * 1990-04-24 1991-10-31 Kabushiki Kaisha Komatsu Seisakusho Device for controlling height of blade of tracked vehicle
GB2250108B (en) * 1990-10-31 1995-02-08 Samsung Heavy Ind Control system for automatically controlling actuators of an excavator
DE4402653C2 (de) * 1994-01-29 1997-01-30 Jungheinrich Ag Hydraulische Hubvorrichtung für batteriebetriebene Flurförderzeuge
US5537818A (en) * 1994-10-31 1996-07-23 Caterpillar Inc. Method for controlling an implement of a work machine
IT1283752B1 (it) * 1996-04-19 1998-04-30 Fiat Om Carrelli Elevatori Sistema di sollevamemto ed abbassamento del supporto del carico di un carrello elevatore elettrico.
JP3478931B2 (ja) * 1996-09-20 2003-12-15 新キャタピラー三菱株式会社 油圧回路
US5890870A (en) * 1996-09-25 1999-04-06 Case Corporation Electronic ride control system for off-road vehicles
DE19645699A1 (de) * 1996-11-06 1998-05-07 Schloemann Siemag Ag Hydrostatisches Getriebe
US6481202B1 (en) * 1997-04-16 2002-11-19 Manitowoc Crane Companies, Inc. Hydraulic system for boom hoist cylinder crane
DE19754828C2 (de) * 1997-12-10 1999-10-07 Mannesmann Rexroth Ag Hydraulische Steueranordnung für eine mobile Arbeitsmaschine, insbesondere für einen Radlader, zur Dämpfung von Nickschwingungen
JPH11171492A (ja) * 1997-12-15 1999-06-29 Toyota Autom Loom Works Ltd 産業車両におけるデータ設定装置及び産業車両
DE60043729D1 (de) * 1999-06-28 2010-03-11 Kobelco Constr Machinery Ltd Bagger mit hybrid-antriebsvorrichtung
US6173572B1 (en) * 1999-09-23 2001-01-16 Caterpillar Inc. Method and apparatus for controlling a bypass valve of a fluid circuit
US6260356B1 (en) * 2000-01-06 2001-07-17 Ford Global Technologies, Inc. Control method and apparatus for an electro-hydraulic power assisted steering system
US6502393B1 (en) * 2000-09-08 2003-01-07 Husco International, Inc. Hydraulic system with cross function regeneration
JP4512283B2 (ja) * 2001-03-12 2010-07-28 株式会社小松製作所 ハイブリッド式建設機械
JP3939956B2 (ja) 2001-10-17 2007-07-04 東芝機械株式会社 建設機械の油圧制御装置
JP3782710B2 (ja) * 2001-11-02 2006-06-07 日邦興産株式会社 油圧プレス装置
US6691603B2 (en) * 2001-12-28 2004-02-17 Caterpillar Inc Implement pressure control for hydraulic circuit
CN1215962C (zh) * 2002-02-08 2005-08-24 上海三菱电梯有限公司 变频驱动液压电梯控制系统及控制方法
JP4099006B2 (ja) * 2002-05-13 2008-06-11 コベルコ建機株式会社 建設機械の回転駆動装置
CA2492715C (en) 2002-06-12 2016-12-06 Cardinalcommerce Corporation Universal merchant platform for payment authentication
SE523110C2 (sv) * 2002-07-15 2004-03-30 Stock Of Sweden Ab Hydraulsystem
KR100638392B1 (ko) * 2002-09-05 2006-10-26 히다치 겡키 가부시키 가이샤 건설기계의 유압구동장치
US6779340B2 (en) * 2002-09-25 2004-08-24 Husco International, Inc. Method of sharing flow of fluid among multiple hydraulic functions in a velocity based control system
US6854268B2 (en) * 2002-12-06 2005-02-15 Caterpillar Inc Hydraulic control system with energy recovery
JP2004190845A (ja) * 2002-12-13 2004-07-08 Shin Caterpillar Mitsubishi Ltd 作業機械の駆動装置
DE502004004847D1 (de) * 2003-07-05 2007-10-18 Deere & Co Hydraulische Federung
US20050066655A1 (en) 2003-09-26 2005-03-31 Aarestad Robert A. Cylinder with internal pushrod
US7197871B2 (en) * 2003-11-14 2007-04-03 Caterpillar Inc Power system and work machine using same
CN1325756C (zh) * 2004-05-09 2007-07-11 浙江大学 采用变频技术的闭式回路液压抽油机
US7369930B2 (en) * 2004-05-14 2008-05-06 General Motors Corporation Method and apparatus to control hydraulic pressure in an electrically variable transmission
US7089733B1 (en) 2005-02-28 2006-08-15 Husco International, Inc. Hydraulic control valve system with electronic load sense control
US8657083B2 (en) 2005-04-04 2014-02-25 Volvo Construction Equipment Ab Method for damping relative movements occurring in a work vehicle during advance
US7565801B2 (en) * 2005-06-06 2009-07-28 Caterpillar Japan Ltd. Swing drive device and work machine
SE531309C2 (sv) * 2006-01-16 2009-02-17 Volvo Constr Equip Ab Styrsystem för en arbetsmaskin och förfarande för styrning av en hydraulcylinder hos en arbetsmaskin
JP5064843B2 (ja) * 2007-03-08 2012-10-31 株式会社小松製作所 作業機ポンプの回転制御システム

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4961316A (en) * 1987-10-28 1990-10-09 Bt Industries Aktiebolag Controlled electric pump drive for hydraulic lifting arrangement with gas spring in motor
US5179836A (en) * 1990-03-19 1993-01-19 Mannesmann Rexroth Gmbh Hydraulic system for a differential piston type cylinder
US20050196288A1 (en) * 2004-03-05 2005-09-08 Deere & Company, A Delaware Corporation. Closed circuit energy recovery system for a work implement

Cited By (77)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9670944B2 (en) * 2006-01-16 2017-06-06 Volvo Construction Equipment Ab Method for controlling a hydraulic cylinder in a work machine and control system for a work machine
US20080294316A1 (en) * 2006-01-16 2008-11-27 Volvo Construction Equipment Ab Method for Controlling a Hydraulic Cylinder in a Work Machine and Control System for a Work Machine
WO2009071264A1 (de) * 2007-12-04 2009-06-11 Robert Bosch Gmbh Hydraulisches system mit einem verstellbaren schnellsenkventil
DE102008034301B4 (de) 2007-12-04 2019-02-14 Robert Bosch Gmbh Hydraulisches System mit einem verstellbaren Schnellsenkventil
US20110064706A1 (en) * 2008-01-11 2011-03-17 U.S. Nutraceuticals, Llc D/B/A Valensa International Method of preventing, controlling and ameliorating urinary tract infections and supporting digestive health by using a synergistic cranberry derivative, a d-mannose composition and a proprietary probiotic blend
EP2247459A2 (en) * 2008-01-23 2010-11-10 Parker-Hannifin Corporation Electro-hydraulic machine for hybri drive system
EP2247459A4 (en) * 2008-01-23 2013-12-11 Parker Hannifin Corp ELECTROHYDRAULIC MACHINE FOR HYBRID DRIVE SYSTEM
US8160783B2 (en) 2008-06-30 2012-04-17 Caterpillar Inc. Digging control system
US20090326768A1 (en) * 2008-06-30 2009-12-31 Caterpillar Inc. Digging control system
WO2010028100A1 (en) 2008-09-03 2010-03-11 Parker Hannifin Corporation Velocity control of unbalanced hydraulic actuator subjected to over-center load conditions
US9234532B2 (en) 2008-09-03 2016-01-12 Parker-Hannifin Corporation Velocity control of unbalanced hydraulic actuator subjected to over-center load conditions
US20110056194A1 (en) * 2009-09-10 2011-03-10 Bucyrus International, Inc. Hydraulic system for heavy equipment
US20110056192A1 (en) * 2009-09-10 2011-03-10 Robert Weber Technique for controlling pumps in a hydraulic system
US20110233931A1 (en) * 2010-03-23 2011-09-29 Bucyrus International, Inc. Energy management system for heavy equipment
US8362629B2 (en) 2010-03-23 2013-01-29 Bucyrus International Inc. Energy management system for heavy equipment
WO2012034781A1 (de) * 2010-09-14 2012-03-22 Zf Friedrichshafen Ag Hydraulische antriebsanordnung
US20120089279A1 (en) * 2010-10-06 2012-04-12 Bucyrus International, Inc. Energy management and storage system
US8718845B2 (en) 2010-10-06 2014-05-06 Caterpillar Global Mining Llc Energy management system for heavy equipment
US8626403B2 (en) * 2010-10-06 2014-01-07 Caterpillar Global Mining Llc Energy management and storage system
US8606451B2 (en) 2010-10-06 2013-12-10 Caterpillar Global Mining Llc Energy system for heavy equipment
US9120387B2 (en) 2010-10-06 2015-09-01 Caterpillar Global Mining Llc Energy management system for heavy equipment
US20140182279A1 (en) * 2011-09-09 2014-07-03 Sumitomo Heavy Industries, Ltd. Shovel and method of controlling shovel
US9574329B2 (en) * 2011-09-09 2017-02-21 Sumitomo Heavy Industries, Ltd. Shovel and method of controlling shovel
US9096115B2 (en) 2011-11-17 2015-08-04 Caterpillar Inc. System and method for energy recovery
US20130140822A1 (en) * 2011-12-05 2013-06-06 Fabio Saposnik Fluid power driven charger
US9190852B2 (en) 2012-09-21 2015-11-17 Caterpillar Global Mining Llc Systems and methods for stabilizing power rate of change within generator based applications
AU2013201057B2 (en) * 2012-11-06 2014-11-20 SINGH, Kalvin Jit MR Improvements in and Relating to Load Transfer
AU2013201057A1 (en) * 2012-11-06 2014-05-22 SINGH, Kalvin Jit MR Improvements in and Relating to Load Transfer
US20150275927A1 (en) * 2012-11-07 2015-10-01 Parker-Hannifin Corporation Electro-hydrostatic actuator deceleration rate control system
US9897112B2 (en) 2012-11-07 2018-02-20 Parker-Hannifin Corporation Smooth control of hydraulic actuator
US9790963B2 (en) * 2012-11-07 2017-10-17 Parker-Hannifin Corporation Electro-hydrostatic actuator deceleration rate control system
WO2014074713A1 (en) * 2012-11-07 2014-05-15 Parker-Hannifin Corporation Smooth control of hydraulic actuator
US9360023B2 (en) 2013-03-14 2016-06-07 The Raymond Corporation Hydraulic regeneration system and method for a material handling vehicle
EP2778113A1 (en) * 2013-03-14 2014-09-17 The Raymond Corporation Hydraulic regeneration system and method for a material handling vehicle
US10309429B2 (en) 2013-04-22 2019-06-04 Parker Hannifin Corporation Method of increasing electro-hydrostatic actuator piston velocity
WO2014176252A1 (en) * 2013-04-22 2014-10-30 Parker-Hannifin Corporation Method of increasing electro-hydrostatic actuator piston velocity
US9920755B2 (en) 2014-02-28 2018-03-20 Project Phoenix, LLC Pump integrated with two independently driven prime movers
US11118581B2 (en) 2014-02-28 2021-09-14 Project Phoenix, LLC Pump integrated with two independently driven prime movers
US11713757B2 (en) 2014-02-28 2023-08-01 Project Phoenix, LLC Pump integrated with two independently driven prime movers
US10465721B2 (en) 2014-03-25 2019-11-05 Project Phoenix, LLC System to pump fluid and control thereof
US11280334B2 (en) 2014-04-22 2022-03-22 Project Phoenix, LLC Fluid delivery system with a shaft having a through-passage
US10294936B2 (en) 2014-04-22 2019-05-21 Project Phoenix, Llc. Fluid delivery system with a shaft having a through-passage
US10544861B2 (en) 2014-06-02 2020-01-28 Project Phoenix, LLC Hydrostatic transmission assembly and system
US10544810B2 (en) 2014-06-02 2020-01-28 Project Phoenix, LLC Linear actuator assembly and system
US20170114807A1 (en) * 2014-06-02 2017-04-27 Project Phoenix, LLC Linear actuator assembly and system
US10738799B2 (en) * 2014-06-02 2020-08-11 Project Phoenix, LLC Linear actuator assembly and system
US11867203B2 (en) 2014-06-02 2024-01-09 Project Phoenix, LLC Linear actuator assembly and system
US11067170B2 (en) 2014-06-02 2021-07-20 Project Phoenix, LLC Hydrostatic transmission assembly and system
US11060534B2 (en) 2014-06-02 2021-07-13 Project Phoenix, LLC Linear actuator assembly and system
EP2955389A1 (en) * 2014-06-13 2015-12-16 Parker Hannifin Manufacturing Finland OY Hydraulic system with energy recovery
US9797419B2 (en) 2014-06-13 2017-10-24 Parker Hannifin Manufacturing Finalnd Oy Hydraulic system with energy recovery
US11512695B2 (en) 2014-07-22 2022-11-29 Project Phoenix, LLC External gear pump integrated with two independently driven prime movers
US10995750B2 (en) 2014-07-22 2021-05-04 Project Phoenix, LLC External gear pump integrated with two independently driven prime movers
US10598176B2 (en) 2014-07-22 2020-03-24 Project Phoenix, LLC External gear pump integrated with two independently driven prime movers
US11408442B2 (en) 2014-09-23 2022-08-09 Project Phoenix, LLC System to pump fluid and control thereof
US10072676B2 (en) * 2014-09-23 2018-09-11 Project Phoenix, LLC System to pump fluid and control thereof
US10808732B2 (en) 2014-09-23 2020-10-20 Project Phoenix, LLC System to pump fluid and control thereof
US11242851B2 (en) 2014-10-06 2022-02-08 Project Phoenix, LLC Linear actuator assembly and system
US10539134B2 (en) 2014-10-06 2020-01-21 Project Phoenix, LLC Linear actuator assembly and system
US10677352B2 (en) 2014-10-20 2020-06-09 Project Phoenix, LLC Hydrostatic transmission assembly and system
US11054026B2 (en) 2014-10-20 2021-07-06 Project Phoenix, LLC Hydrostatic transmission assembly and system
US11846283B2 (en) 2015-09-02 2023-12-19 Project Phoenix, LLC System to pump fluid and control thereof
US10865788B2 (en) 2015-09-02 2020-12-15 Project Phoenix, LLC System to pump fluid and control thereof
US11085440B2 (en) 2015-09-02 2021-08-10 Project Phoenix, LLC System to pump fluid and control thereof
US10822772B1 (en) * 2017-02-03 2020-11-03 Wrightspeed, Inc. Hydraulic systems with variable speed drives
US11697349B2 (en) 2018-07-12 2023-07-11 Danfoss A/S Power architecture for a vehicle such as an off-highway vehicle
US11104234B2 (en) 2018-07-12 2021-08-31 Eaton Intelligent Power Limited Power architecture for a vehicle such as an off-highway vehicle
US11408445B2 (en) 2018-07-12 2022-08-09 Danfoss Power Solutions Ii Technology A/S Dual power electro-hydraulic motion control system
EP3594413A1 (en) * 2018-07-12 2020-01-15 Eaton Intelligent Power Limited Power architecture for a vehicle such as an off-highway vehicle
EP3722516A1 (en) * 2019-04-11 2020-10-14 Gebroeders Geens N.V. Drive system for a work vehicle
BE1027189B1 (nl) * 2019-04-11 2020-11-10 Gebroeders Geens N V Aandrijfsysteem voor een werkvoertuig
CN111350627A (zh) * 2020-04-01 2020-06-30 东方电气自动控制工程有限公司 一种带手自动切换的液压调速控制系统
WO2021225645A1 (en) * 2020-05-05 2021-11-11 Parker-Hannifin Corporation Hydraulic dissipation of electric power
WO2023041476A1 (de) * 2021-09-15 2023-03-23 Hms – Hybrid Motion Solutions Gmbh Hydraulisches antriebssystem mit einer 4q pumpeneinheit
CN114251214A (zh) * 2021-12-09 2022-03-29 中国船舶重工集团公司第七一九研究所 分数阶动力系统混沌状态的判断方法及装置
US20230312242A1 (en) * 2022-03-31 2023-10-05 Oshkosh Corporation Regeneration control for a refuse vehicle packer system
WO2024046697A1 (de) * 2022-08-31 2024-03-07 Bucher Hydraulics Ag Elektrisch-hydraulischer aktor

Also Published As

Publication number Publication date
CN101370985A (zh) 2009-02-18
WO2007081278A1 (en) 2007-07-19
US20080295505A1 (en) 2008-12-04
WO2007081280A1 (en) 2007-07-19
EP1979549A1 (en) 2008-10-15
EP1979551A1 (en) 2008-10-15
SE0600087L (sv) 2007-07-17
US8407993B2 (en) 2013-04-02
CN101370989A (zh) 2009-02-18
WO2007081276A1 (en) 2007-07-19
EP1979546A1 (en) 2008-10-15
US20080295504A1 (en) 2008-12-04
CN101370988B (zh) 2011-05-25
WO2007081279A1 (en) 2007-07-19
CN101370987B (zh) 2013-03-13
US20080292474A1 (en) 2008-11-27
CN101370988A (zh) 2009-02-18
US20090287373A1 (en) 2009-11-19
US8240144B2 (en) 2012-08-14
EP1979551B1 (en) 2015-03-25
US20080302099A1 (en) 2008-12-11
US8225706B2 (en) 2012-07-24
EP1979547A4 (en) 2012-03-21
EP1979550B1 (en) 2017-10-18
EP1979550A4 (en) 2016-08-17
EP1979549B1 (en) 2014-01-08
SE531309C2 (sv) 2009-02-17
CN101370990B (zh) 2013-05-29
EP1979550A1 (en) 2008-10-15
WO2007081281A1 (en) 2007-07-19
CN101370987A (zh) 2009-02-18
WO2007081277A1 (en) 2007-07-19
EP1979548A1 (en) 2008-10-15
CN101370985B (zh) 2011-12-21
US8065875B2 (en) 2011-11-29
EP1979551A4 (en) 2012-02-29
CN101370986B (zh) 2013-03-13
US9670944B2 (en) 2017-06-06
EP1979548A4 (en) 2012-03-14
EP1979549A4 (en) 2012-03-21
EP1979546A4 (en) 2012-03-14
EP1979547A1 (en) 2008-10-15
US20080294316A1 (en) 2008-11-27
EP1979547B1 (en) 2013-10-16
EP1979548B1 (en) 2013-03-20
CN101370989B (zh) 2013-03-06
US7908048B2 (en) 2011-03-15
CN101370990A (zh) 2009-02-18
CN101370986A (zh) 2009-02-18
EP1979546B1 (en) 2015-04-22

Similar Documents

Publication Publication Date Title
US20070166168A1 (en) Control system for a work machine and method for controlling a hydraulic cylinder in a work machine
US8657083B2 (en) Method for damping relative movements occurring in a work vehicle during advance
US7712309B2 (en) Arrangement and a method for controlling a work vehicle
US20160290367A1 (en) Hydraulic load sensing system
US7845458B2 (en) Control system for frame-steering of a vehicle and method for controlling two steering cylinders in a frame-steered vehicle

Legal Events

Date Code Title Description
AS Assignment

Owner name: VOLVO CONSTRUCTION EQUIPMENT AB, SWEDEN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:VIGHOLM, BO, MR.;PALO, MARKKU, MR.;REEL/FRAME:018968/0023;SIGNING DATES FROM 20070129 TO 20070130

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION