Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2221—Control of flow rate; Load sensing arrangements
  • E02F9/2225—Control of flow rate; Load sensing arrangements using pressure-compensating valves
  • E02F9/2228—Control of flow rate; Load sensing arrangements using pressure-compensating valves including an electronic controller
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/22—Hydraulic or pneumatic drives
  • E02F9/2203—Arrangements for controlling the attitude of actuators, e.g. speed, floating function
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
  • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
  • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
  • F15B11/162—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for giving priority to particular servomotors or users
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01B—SOIL WORKING IN AGRICULTURE OR FORESTRY; PARTS, DETAILS, OR ACCESSORIES OF AGRICULTURAL MACHINES OR IMPLEMENTS, IN GENERAL
  • A01B31/00—Drags graders for field cultivators
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01B—SOIL WORKING IN AGRICULTURE OR FORESTRY; PARTS, DETAILS, OR ACCESSORIES OF AGRICULTURAL MACHINES OR IMPLEMENTS, IN GENERAL
  • A01B63/00—Lifting or adjusting devices or arrangements for agricultural machines or implements
  • A01B63/02—Lifting or adjusting devices or arrangements for agricultural machines or implements for implements mounted on tractors
  • A01B63/10—Lifting or adjusting devices or arrangements for agricultural machines or implements for implements mounted on tractors operated by hydraulic or pneumatic means
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/76—Graders, bulldozers, or the like with scraper plates or ploughshare-like elements; Levelling scarifying devices
  • E02F3/7622—Scraper equipment with the scraper blade mounted on a frame to be hitched to the tractor by bars, arms, chains or the like, the frame having no ground supporting means of its own, e.g. drag scrapers
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/76—Graders, bulldozers, or the like with scraper plates or ploughshare-like elements; Levelling scarifying devices
  • E02F3/7636—Graders with the scraper blade mounted under the tractor chassis
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/30—Directional control
  • F15B2211/32—Directional control characterised by the type of actuation
  • F15B2211/327—Directional control characterised by the type of actuation electrically or electronically
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/60—Circuit components or control therefor
  • F15B2211/63—Electronic controllers
  • F15B2211/6303—Electronic controllers using input signals
  • F15B2211/6346—Electronic controllers using input signals representing a state of input means, e.g. joystick position
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/60—Circuit components or control therefor
  • F15B2211/665—Methods of control using electronic components
  • F15B2211/6654—Flow rate control
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/60—Circuit components or control therefor
  • F15B2211/665—Methods of control using electronic components
  • F15B2211/6656—Closed loop control, i.e. control using feedback
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/60—Circuit components or control therefor
  • F15B2211/665—Methods of control using electronic components
  • F15B2211/6658—Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
  • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
  • F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
  • F15B2211/78—Control of multiple output members
  • F15B2211/781—Control of multiple output members one or more output members having priority

Definitions

• the present invention relates to hydraulic systems of the work and agricultural machine.
• a mechanical shovel or "wheel loader” is a heavy machine used in construction to move earth or materials such as asphalt, demolition debris, snow, feed, gravel, logs, raw minerals, recycled material, rock, sand, wood chips, etc. inside or on top of another type of machinery (such as a dump truck, a conveyor belt, a feed hopper or a railroad car).
• loaders mechanical shovels
• front loader front loader
• loader shovel
• shovel skip loader
• wheel loader or compact shovel (skid-steer).
• the movement of the arm and bucket is controlled by the user through a joystick located inside the operator's cab of the working vehicle.
• the progress and steering of the vehicle can also be controlled using a joystick.
• Figure 1 shows a motor grader (Grader) which comprises several hydraulically operated members for carrying out 1. Moldboard extender: extension of the share
• a processing unit controls the different hydraulic actuators (not shown) through respective solenoid valves in relation to the commands given by the user through one or more joysticks, levers and buttons.
• Each hydraulic actuator includes a hydraulic cylinder operatively connected respectively to the arm, tool or shovel or steering system, which uses the hydraulic power of a working fluid to allow mechanical operation.
• the flow of hydraulic fluid addressed to the user is proportional to the opening of the cursor and the opening of the cursor where the flow starts to flow to the user is constant and if there are multiple users activated simultaneously, the flow generated by the pump is proportionally distributed only when the cursors of each individual user are opened.
• each valve in the circuit is able to guarantee a predetermined pressure to the relative actuator or user, while the flow generated by the hydraulic pump is shared by the various users. This ensures efficient combined operation of multiple actuators or users.
• the actuation speed of the hydraulic actuator depends on the proportional electric control, integrated with the flow sharing system.
• the hydraulic flow of the working fluid required to operate the arm and the tool is produced by a hydraulic pump which draws from a fluid tank and is driven by an internal combustion engine or an electric motor M, hereinafter simply called “engine “of the vehicle, e.g. from a mechanical link.
• engine an electric motor
• the same engine is also used to drive the wheels as a means of propulsion of the working vehicle. Therefore, the speed of movement of the arm and the tool in a predetermined position depends on the speed of rotation of the motor. For example, when the engine is running at a high rotation speed, a minimum movement of the joystick by the user is required to perform a movement of the arm and / or the tool. Conversely, when the engine is running at low rotational speed or at idle speed, a large movement of the joystick by the user is required.
• the object of the present invention is to improve the response of the hydraulic functions of a work vehicle to the requests of a user.
• the basic idea of the present invention is to group the electro-hydraulic functions in two or more groups, to calculate the available flow of hydraulic fluid in relation to the current operating conditions and to limit the flow of hydraulic fluid towards the set of functions having lower priority, when it appears that the available flow is insufficient to supply all the functions.
• the flow of hydraulic fluid is divided between the sets of hydraulic functions proportionally to the priority attributed to the group itself.
• the distribution is progressively variable until the balance between the available hydraulic flow and the power supply of all the active hydraulic functions is obtained. More specifically, this progression of flow limitation is gradually increasing, involving sets of higher priority functions. Therefore, a flow reduction is applied to the hydraulic functions having higher priority only when it is not possible to do otherwise.
• limit reduction coefficients are defined for each limitation cycle that goes from the lowest priority set to the highest priority set.
• limit reduction coefficients are defined, beyond which it is not possible to limit the flow within the same cycle. Therefore, when the limit reduction coefficient is reached, the flow of a set with higher priority is reduced. When, however, the limit reduction coefficient is applied to all the sets, it starts again from the lower priority set, in other words another Round is performed, setting a more restrictive limit reduction coefficient.
• the limit reduction coefficient is calculated on the basis of the last reduction coefficient multiplied by the value of the basic limit coefficient, i.e. of the first Round.
• the calculation of the limitation coefficient for the set L is carried out keeping the limitation coefficients of the sets M and H unchanged calculated at the last Step of the previous Round, for example Step 3.
• the calculation of the limitation coefficient for the set L is performed by resetting any limitation on the sets M and H, in other words, the flow for them is temporarily reset to 1, that is, without any limitation.
• the second implementation turns out to favour the M and H sets, especially when the number of lower priority organs is greater than the remaining organs that define the M and H sets.
• the algorithm described above is run on a computer comprising means for processing and storing information, interfaced to control the electro-hydraulic valves of the hydraulic circuit.
• the regulation is implemented only after the equilibrium condition between the first available flow and the second required flow has been identified.
• the processing unit can perform calculation cycles in the order of milliseconds, then the implementation of the valves can be performed only after the convergence of the algorithm.
• the number of cycles is deliberately limited to avoid stall conditions.
• the algorithm is performed much more slower in the order of seconds and the implementation of the adjustment is performed parallel to the execution of the algorithm and more preferably at the end of each Round.
• the present invention can be realized thanks to the implementation of electro-hydraulic directional valves with flow sharing, in which the degree of opening is a function of an electrical signal representative of a position of a joystick or a lever.
• Figure 1 shows an example of a work machine of the known art
• FIG. 2 shows a flowchart for checking the hydraulic functions of the machine of Figure 1;
• FIG. 3 shows an iteration table of the control of
• second component does not imply the presence of a “first” component. These terms are in fact used as labels to improve clarity, having no ordinal meaning unless it is clear from the text that there is a precise order to be respected.
• the present invention refers to a system for managing the flows of hydraulic liquid in a work machine or an agricultural machine.
• the different hydraulic functions are grouped for example into three sets indicated as: High Priority, Medium Priority, Low Priority, i.e. sets having high, medium and low operating priority.
• FIG. 2 a flow diagram relating to the control object of the present invention is shown. This flowchart is performed in a closed loop continuously. After the START block, the flow of hydraulic fluid generated A_F and the total flow required R_F necessary for the operation of the various hydraulic functions are acquired simultaneously or in succession, calculated on the basis of the commands given by the user via Joystick, buttons and/or levers.
• Figure 3 shows an example of a table of the reduction coefficients which are applied progressively to bring the overall flow required at least to equal the available flow of hydraulic liquid.
• the labels L, M, H are examples of Low, Medium, High as described above.
• a reduction coefficient is calculated to be applied to the set L.
• the limit reduction coefficient is applied, for example equal to 0.65 and the flow is limited to the adjacent set having higher priority .
• the basic coefficients are equal to 0.75 and 0.85 and are used as a flow reduction limit in steps Step 2 and Step 3.
• the first cycle or Round adopts limit reduction coefficients, called "basic coefficients".
• the basic coefficients are limit coefficients, beyond which, in the first Round it is not possible to reduce the flow for the different sets of users. It is preferred that the basic coefficients are different from each other, with a greater reduction factor for the Low set and so on, progressively to the High set.
• the limit reduction coefficients are calculated considering the respective limit coefficients of the previous round, multiplied by the base coefficient.
• the current limit reduction coefficient is equal to (base coefficient) L i, where i represents the i-th Round.
• base coefficient L i
• Rl the basic coefficients are used without any modification.
• the limitation applies by moving from the leftmost column to the rightmost column of the table and starting from the immediately lower row in the leftmost column when the rightmost column of the table is reached.
• the actuators relating to the steering system and the roadway management are inserted in set H, while the buldozer blade lifter 4 and the rear tracker 7 are inserted in set L, while all the other actuators are associated with the set M.
• the grouping of the hydraulic functions is preordained in response to the activation of a preordained operating mode.
• the vehicle can be equipped with appropriate controls to be able to switch between two or more operating modes.
• the switching between the different operating modes is automatic .
• This automation is based on the acquisition of certain parameters, further to the overall flow of hydraulic fluid generated by the pump, such as, for example, the vehicle's forward speed.
• the reduction coefficient applied LI, Ml, HI at each step of a so-called “Round” are less than or at most equal to the respective limit reduction coefficients 0.65; 0.75; 0.85. Therefore, those values represent a saturation limit, beyond which, it is possible to manipulate the flow of the whole with immediately higher priority.
• the subscripts of LI, M2, H2, etc .. refer to the Round. Only when, as described above, the coefficient LI, M2, HI, etc .. are saturated with the limit reduction coefficient, it proceeds to manipulate the flow of the set having immediately higher priority. Furthermore, as described above, the "manipulation" may or may not provides for a preventive reset, i.e. unitary value, of the limitation coefficient of the set with immediately higher priority before identifying the value of the coefficient that allows to obtain the balance between the flow generated and flow required .
• a preventive reset i.e. unitary value
• the present invention can be advantageously carried out by means of a computer program, which comprises coding means for the realization of one or more steps of the method, when this program is executed on a computer. Therefore, it is understood that the scope of protection extends to said computer program and further to computer readable means which comprise a recorded message, said computer readable means comprising program coding means for carrying out one or more steps of the method, when this program is run on a computer.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Mechanical Engineering (AREA)
• Operation Control Of Excavators (AREA)
• Guiding Agricultural Machines (AREA)
• Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=72644806

Family Applications (1)

Country Status (3)

Family Cites Families (5)

• 2020
  • 2020-07-16 IT IT102020000017347A patent/IT202000017347A1/it unknown
• 2021
  • 2021-07-15 EP EP21740106.6A patent/EP4266856A1/en active Pending
  • 2021-07-15 WO PCT/EP2021/069686 patent/WO2022013329A1/en unknown

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