EP4325068A1 - Système de commande pour un vérin - Google Patents

Système de commande pour un vérin Download PDF

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Publication number
EP4325068A1
EP4325068A1 EP23190030.9A EP23190030A EP4325068A1 EP 4325068 A1 EP4325068 A1 EP 4325068A1 EP 23190030 A EP23190030 A EP 23190030A EP 4325068 A1 EP4325068 A1 EP 4325068A1
Authority
EP
European Patent Office
Prior art keywords
chamber
load
descent
conduit
pressure
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.)
Pending
Application number
EP23190030.9A
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German (de)
English (en)
Inventor
Francesco Dotti
Pierre Luigi Zaccarelli
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Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP4325068A1 publication Critical patent/EP4325068A1/fr
Pending legal-status Critical Current

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Classifications

    • 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
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/044—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out"
    • F15B11/0445—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out" with counterbalance valves, e.g. to prevent overrunning or for braking
    • 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
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/044—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out"
    • 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
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • 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
    • F15B2211/40—Flow control
    • F15B2211/41—Flow control characterised by the positions of the valve element
    • F15B2211/413—Flow control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional valves
    • 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
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41527—Flow control characterised by the connections of the flow control means in the circuit being connected to an output member and a directional control valve
    • 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
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/426—Flow 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
    • F15B2211/40—Flow control
    • F15B2211/46—Control of flow in the return line, i.e. meter-out 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
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50563—Pressure control characterised by the type of pressure control means the pressure control means controlling a differential pressure
    • F15B2211/50581—Pressure control characterised by the type of pressure control means the pressure control means controlling a differential pressure using counterbalance valves
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/52—Pressure control characterised by the type of actuation
    • F15B2211/526—Pressure 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
    • F15B2211/50—Pressure control
    • F15B2211/575—Pilot pressure control
    • F15B2211/5753—Pilot pressure control for closing a valve
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/575—Pilot pressure control
    • F15B2211/5756—Pilot pressure control for opening a valve
    • 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
    • F15B2211/6306—Electronic controllers using input signals representing a pressure
    • F15B2211/6313—Electronic controllers using input signals representing a pressure the pressure being a load pressure
    • 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
    • F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051—Linear output members
    • F15B2211/7053—Double-acting output members
    • 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
    • F15B2211/76—Control of force or torque of the output member
    • F15B2211/761—Control of a negative load, i.e. of a load generating hydraulic energy
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/85—Control during special operating conditions
    • F15B2211/851—Control during special operating conditions during starting

Definitions

  • the present invention relates to the field of a control system for controlling an actuator cylinder in an hydraulic application.
  • Control systems for hydraulic cylinders for moving the arms of machines such as telehandlers and cranes have evolved more and more over the years and require to fulfill an increasing number of functions.
  • They require high safety so that in the event of a pipeline rupture, the system is able to control the actuator cylinder and stop it, preventing a possible load fall.
  • high stability of the system is required so that the user can ensure that he or she can control the system without generating sudden jerks, which could cause the user a sense of discomfort.
  • such systems involve the use of hydraulic balancing valves or valves driven by an external line.
  • FIG. 1 A first example of a control system for an actuator cylinder known from the state of the art is shown in Figure 1 .
  • Such a system shows a simple hydraulic balancing valve.
  • a device includes a first conduit 2, arranged to connect a first chamber C1 of a cylinder C with a distributor D, a second conduit 3, arranged to connect a second chamber C2 of the cylinder C with the distributor D, a balancing valve 44, arranged along the first conduit 2, which is arranged to allow fluid flow from the distributor D to the first chamber C1 and to allow fluid flow from the first chamber C1 to the distributor D only when driven with a pilot pressure above a minimum value.
  • balancing valve 44 in order to allow cylinder movement, balancing valve 44 must be opened by a pressure signal from chamber C2 opposite to that which is to be controlled by the valve. In this way there is a balance of forces between the two chambers, and the valve opens in relation to this balance.
  • This system causes the downward velocities of the arm to be very similar as the applied load changes. The higher the load C3, the less pressure it will take to open the valve; the thrust generated in the chamber opposite the controlled one will therefore be low.
  • the load is very low, the pressure to open the valve will increase, and consequently so will the thrust generated in the opposite chamber. In this way, the pressure in the cylinder chamber will always be averagely constant, so the rate of descent will also be constant.
  • valves have limitations in terms of stability and response delay. Since the opening control is not adjustable, the valve undergoes abrupt opening, which tends to generate instability of movement. To remedy this problem, a damping device is inserted on the drive signal, but this generates pressure spikes in fast movements and an activation delay that, although tolerated, is a weakness of the system.
  • FIG. 2 A second example of a control system for an actuator cylinder known from the state of the art, which describes an externally line-driven valve, is described in patent application EP 2 786 959 A1 and is depicted in Figure 2 .
  • a control valve 4 arranged along the first conduit 2, which is arranged to allow fluid flow from the distributor D to the first chamber C1 and to allow ii fluid flow from the first chamber C1 to the distributor D only when supplied with a pilot pressure above a minimum value.
  • Such a device further comprises a third conduit 5, which connects the second conduit 3 with a section of the first conduit 2 between the control valve 4 and the control valve D, a shutoff valve 6, arranged along the third conduit 5, which is movable, on command, between an opening configuration, wherein it allows ii flow along the third conduit 5, and a closing configuration, wherein it prevents ii flow along the third conduit 5.
  • Actuating valve 6 is configured to receive an open command only if control valve 4 is supplied with pilot pressure. In order to allow cylinder movement, control valve 4 must therefore be opened by a pressure signal from an external line P, usually connected to the line that controls the opening of the distributor.
  • This system allows for movement control independent of the state of the cylinder, without having to push into the other chamber, since the movement will be by gravity.
  • the advantages of such a system lie in the saving of power to obtain the same movement and in the possibility of obtaining very precise movements without any kind of intervention delay and pressure peaks on the line.
  • the present invention addresses the problem of realizing a control system for an actuator cylinder that can solve the above problems.
  • the present invention relates to a control system according to the features listed in claim 1.
  • Such a configuration i.e., the realization of a system capable of fully automatically limiting the rate of load descent based on a:
  • said weight of said load (C3) is calculated by means of a pressure sensed at said first chamber (11).
  • said information corresponding to a descent request of said load is provided to said control system via an input device, preferably a joystick (M), and wherein in said step a. said descent request signal is received via said input device.
  • an input device preferably a joystick (M)
  • said information corresponding to a request for descent of said load is detected by sensing a pressure or pressure change at said second chamber (12).
  • FIG 3 shows a schematic of a control system for an actuator cylinder 10.
  • Said cylinder 10 includes a first and a second chamber 11, 12 and a piston 13 separating said first chamber 11 from said second chamber 10.
  • Said actuator cylinder is configured to allow direct or indirect displacement of a load C3.
  • said actuator cylinder can be configured, as shown in figure 8 , to move a mechanical arm such as the lifting arm 500 of a telescopic hoist 1000, which is configured so as to be able to move loads (it is clear, however, that the load can be represented by the weight of the mechanical arm itself, which is moved unloaded and does not require the presence of an external body).
  • the 1000 telehandler includes a main body 530 comprising wheels for moving the telehandler along the ground.
  • a lifting arm 500 which is mechanically connected to said main body and which, by means of the actuator cylinder 10 is movable relative to the main body 530.
  • Said actuator cylinder 10 is configured to provide relative movement of said lifting arm 500 relative to said main body 530 along the arc of circumference 520.
  • the lifting arm 500 which in this particular case is a telescopic arm, can be telescopically extended, as shown by arrow 510 in the figure.
  • a bucket or any element capable of moving a C3 load (such as, for example, simple mechanical forks) may be positioned at an end portion of said lifting arm.
  • the present invention is not limited to the application of a telescopic lift but of any operating machine comprising a main body and an arm mechanically connected to said main body, wherein the arm can be moved relative to the main body by means of said actuator cylinder 10.
  • the system includes a first feed conduit 20 of said first chamber 11 of said cylinder 10, a second feed conduit 21 of said second chamber 12 of said cylinder 10, wherein an increase in the volume of said second chamber 12 causes said load C3 supported by said cylinder 10 to descend downwardly.
  • Said first feed conduit 20 and said second feed conduit 21 are connectable to a distribution valve 100 configured to control a feed operation and a discharge operation of said first feed conduit 20 and said second feed conduit 21.
  • Said control system includes a retaining system 30 positioned along said first supply conduit 20 and configured to open a passage for a fluid coming from said distribution valve 100 and directed to said first chamber 11 if the pressure difference between the pressure of said fluid coming from said distribution valve 100 and the pressure in said first chamber 11 exceeds a first predetermined value. This is due to the presence of the one-way valve shown in the right position of balancing valve 31.
  • the retaining system 30 is configured to regulate the flow of fluid leaving said first chamber 11 and directed to said distribution valve 100. This is due to the presence of the left position of balancing valve 31.
  • the adjustment of the positioning of the proportional balancing valve 31 is provided by the proportional solenoid valve 32, which allows the piloting pressure of the balancing valve 31 and thus its opening to be adjusted.
  • the first chamber 11 will be under pressure.
  • the same pressure will be present in the pilot line 33 of balancing valve 31, which receives the pressure from the first chamber 11 via restriction 36.
  • Proportional solenoid valve 32 allows the pilot pressure to be adjusted and thus to go to open and close balancing valve 31.
  • proportional solenoid valve 32 is in the normally closed position. It will, when energized with a given current, begin to open and go to empty pilot port 33. This emptying of pilot port 33 will then go on to reduce the pressure in the first chamber 11 as the reconduition in pilot pressure will cause the balancing valve 31 to open and consequently empty the first chamber 11.
  • the electro-proportional valve could be of the normally open type and close if supplied with a given current (such a system, however, would be entirely dangerous since in the event of a power failure it would cause the load to drop).
  • the proportional solenoid valve 32 makes it possible to regulate the load drop. Such regulation is accomplished by means of an electronic control unit (shown symbolically with element 99 in Figure 8 ).
  • This descent phase can alternatively begin as a result of the reception of a pressure signal in the second chamber 12 or as a result of a signal received from an input device, such as a common joystick M.
  • pilot conduit 33 There is then a pressure-limiting valve 34 in the pilot conduit 33 that will empty the pilot conduit 33 if the pressure within it exceeds a predetermined value. Such emptying of pilot conduit 33 will then go on to reduce the pressure in the first chamber 11 as the reconduition in pilot pressure will cause balancing valve 31 to open and consequently empty the first chamber 11.
  • valve 35 in the piloting port 33 to ensure fast emptying of the first chamber 11.
  • a valve 35 represents an entirely optional element.
  • such a system comprises a pressure sensor PC2 configured to sense the pressure at said first chamber 11.
  • Said pressure sensor indirectly enables measurement of the weight C3 supported by said actuator cylinder 10.
  • said pressure sensor PC2 may be replaced by other means capable of deriving the weight of said load C3 or a quantity dependent thereon.
  • systems comprising force sensors positioned directly on the arm of the operating machine capable of detecting such a load or sensors positioned at the wheels of the operating machine are known from the state of the art.
  • FIG 4a and Figure 4b show two different diagrams of a control system for an actuator cylinder 10 at which the control method according to the present invention (which will be described later) can be used.
  • the system in Figure 4a includes a balancing valve 37 positioned directly along the first conduit 20 whose pilot conduit is directly controlled by a proportional solenoid valve 38, which is configured to regulate the pilot pressure arriving at balancing valve 37.
  • valve 38 receives pressurized fluid from the second conduit 21 and as a result of a current signal received from an electronic control unit 99 will regulate the pressure in the piloting conduit thereby adjusting the opening of the first conduit 20, so as to regulate the downward phase of load C3.
  • valve 38 is positioned between the piloting conduit and an exhaust, thus allowing the piloting pressure to be adjusted by going to discharge the unwanted pressure to the exhaust.
  • valve 38 will then go to zero pressure in the piloting conduit, thus going to discharge all pressure to a tank T.
  • the valve will tend to increase the pressure in the piloting conduit going to decrease the amount of pressure discharged to tank T.
  • a pump P (as the pressure source) is connected to the valve 100, which is commanded to feed the port V1 of the valve and thus begin the descent phase.
  • the control unit 99 will go to detect an opening command and the magnitude of this command will also preferably be detected.
  • a user will be able to request a more or less rapid descent of the load C3.
  • the purpose of the present invention is precisely to regulate the opening of the electro-proportional valve in such a way as to prevent sudden surges or accelerations during the downward phase.
  • this purpose has been achieved by allowing extremely limited electro-proportional valve openings so as to go to limit the rate of descent of the load (i.e., by going to throttle the descent).
  • this function was particularly disadvantageous in the case of extremely limited loads or even in the absence of loads in that it went too far in limiting the descent of the load.
  • the present invention developed a method of controlling the electro-proportional valve capable of providing the maximum possible rate of descent but at the same method of meeting predetermined criteria.
  • a second step 91 of the method preferably takes place the calculation of an initial value of said current signal before said balancing valve 31, 37 opens a flow of fluid along said first conduit 20 and thus to begin the descent of said load C3.
  • step 91 one will have gone to correct a reference function, for example, a simple reference curve, which has as its input a demand for the descent of the load and as its output a current signal to be supplied to the electro-proportional valve 32, 38, wherein such correction has been made on the basis of the weight of said load C3.
  • a reference function for example, a simple reference curve, which has as its input a demand for the descent of the load and as its output a current signal to be supplied to the electro-proportional valve 32, 38, wherein such correction has been made on the basis of the weight of said load C3.
  • this correction was made, in the case shown in the figure, only for an initial value of the current signal needed to start the descent because the greater the weight of the load, the greater will be the current signal needed to start the descent (in essence to open the balancing valve 31, 37.
  • a third step the actual correction of the reference function takes place as it is corrected to adjust the opening according to the load.
  • the load C3 is located very far from the main body 530 of the operating machine 1000 there will be a particularly large moment generated by this load and it will therefore be necessary to limit the descent speed of the load so as to prevent undesirable effects.
  • the first reference function correction that will be described here is based on the weight of the load or a quantity dependent on it.
  • a first received parameter is, for example, a function 925 describing a first correction factor.
  • a first correction factor 925 is a function that describes a correction value depending on the load (in the particular case shown depending on the pressure in bar detected by sensor PC2).
  • this value of the first correction factor to be applied to the first reference function will be calculated.
  • This value will preferably be inversely proportional to the magnitude of the load C3 since, as mentioned, as the load increases it will be preferable to have a decrease in the rate of load descent. Therefore, the value will be equal to 1 for extremely small load values and will decrease as load C3 increases.
  • such first correction factor is applied, preferably by multiplication, to said first reference curve exclusively for values of said current signal corresponding to a fluid flow leaving said first chamber 11 and directed to said distribution valve 100 other than zero. Therefore, such correction will be made only for current values greater than the initial value calculated in step 91.
  • a first correct reference function (shown with a dashed line) will have been obtained in this way to be used in the step for calculating the current signal that can then be sent to the electro proportional valve 32, 38.
  • a current value I_P between 400 and 500 mA
  • the single value of the signal I_P calculated in step 926 and corresponding to the request of Joystick M is reprocessed.
  • the output current signal is not made to vary instantaneously from the initial value calculated in step 91 to the final I_P value calculated in step 926 but there is a ramp starting from that minimum value (in the case shown in the figure 400 mA) and is increased gradually until it reaches that value calculated 926 so as to avoid sudden acceleration.
  • a delay parameter in the case shown in the figure of 0.5 s
  • Such a parameter will preferably also be dependent on the magnitude of the load C3.
  • step 92 the correction of the second reference function based on the position of said load C3 also takes place, which will be described in detail below.
  • the second reference function correction that will be described here is based on the position of the load C3 or a quantity dependent on it.
  • position is preferably meant the distance between said load C3 and main body 530.
  • a first parameter received is a function 935 describing a second correction factor.
  • a second correction factor 935 is a function that describes a correction value depending on the position of the load (in the particular case shown depending on the extension 510 in meters of the lifting arm 500).
  • step 935 such a value of the second correction factor will be calculated to be applied to the second reference function.
  • This value will preferably be inversely proportional to the distance of the load C3 from the main body 530 of the operating machine 1000 since, as mentioned above, as the distance increases it will be preferable to have a decrease in the speed of descent of the load so as to prevent tipping or simply oscillation of the machine itself. Therefore, the value will be 1 for extremely small values of that distance and will decrease as that distance increases.
  • said second correction factor is applied, preferably by multiplication, to said second reference curve exclusively for values of said current signal corresponding to a flow of fluid leaving said first chamber 11 and directed toward said distribution valve 100 other than zero. Therefore, such correction will be made only for current values greater than the initial value calculated in step 91.
  • a second correct reference function (shown with a dashed line) will have been obtained in this way to be used in the step for calculating the current signal that can then be sent to the electro proportional valve 32, 38.
  • a current value I_T between 500 and 600 mA
  • the single value I_T of the signal calculated in step 936 and corresponding to the request of Joystick M is reprocessed.
  • the output current signal is not made to vary instantaneously from the initial value calculated in step 91 to the final value calculated in step 936 but there is again a ramp starting from this minimum value (in the case shown in the figure 400 mA) and is gradually increased until it reaches this value calculated 936 so as to avoid sudden acceleration.
  • a delay parameter in the case shown in the figure of 0.5 s
  • This parameter will preferably be dependent on the magnitude (weight) of the load C3 or alternatively on the position of the load itself.
  • the two current signals calculated in steps 92 and 93, respectively, will preferably be compared in step 94, and the minimum of the two values will be taken so that both quantities (weight and position) can be taken into account and both risks dependent on them can be effectively prevented.
  • the minimum of the two values of the current signals calculated in 92 and 93 respectively will be sent to the restraint system 30 which will then adjust the descent of the load C3 based on the current signal received. Specifically, this current signal will be sent to the electro-proportional valve 32, 38, which will then go on to regulate the pilot pressure and the consequent descent of load C3.
EP23190030.9A 2022-08-11 2023-08-07 Système de commande pour un vérin Pending EP4325068A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT202200017223 2022-08-11

Publications (1)

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EP4325068A1 true EP4325068A1 (fr) 2024-02-21

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11287206A (ja) * 1998-04-03 1999-10-19 Kobe Steel Ltd 流体圧式駆動装置及び建設機械の速度制御装置
JP2000255988A (ja) * 1999-03-02 2000-09-19 Kobelco Contstruction Machinery Ltd 液圧作業機械のアクチュエータ制御回路
US20130298541A1 (en) * 2012-05-10 2013-11-14 Eaton Corporation Load energy assist and horsepower management system
EP2786959A1 (fr) 2013-04-05 2014-10-08 Bosch Rexroth Oil Control S.p.A. Dispositif d'anti-cavitation pour vérin hydraulique
US10794510B1 (en) * 2017-12-20 2020-10-06 Sun Hydraulics, Llc Electrohydraulic counterbalance and pressure relief valve
US11225981B2 (en) * 2017-05-03 2022-01-18 Cnh Industrial America Llc Vehicle with a boom comprising a hydraulic control circuit with a load control valve

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11287206A (ja) * 1998-04-03 1999-10-19 Kobe Steel Ltd 流体圧式駆動装置及び建設機械の速度制御装置
JP2000255988A (ja) * 1999-03-02 2000-09-19 Kobelco Contstruction Machinery Ltd 液圧作業機械のアクチュエータ制御回路
US20130298541A1 (en) * 2012-05-10 2013-11-14 Eaton Corporation Load energy assist and horsepower management system
EP2786959A1 (fr) 2013-04-05 2014-10-08 Bosch Rexroth Oil Control S.p.A. Dispositif d'anti-cavitation pour vérin hydraulique
US11225981B2 (en) * 2017-05-03 2022-01-18 Cnh Industrial America Llc Vehicle with a boom comprising a hydraulic control circuit with a load control valve
US10794510B1 (en) * 2017-12-20 2020-10-06 Sun Hydraulics, Llc Electrohydraulic counterbalance and pressure relief valve

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