EP0451274A1 - Hydraulic controller - Google Patents
Hydraulic controller Download PDFInfo
- Publication number
- EP0451274A1 EP0451274A1 EP90901035A EP90901035A EP0451274A1 EP 0451274 A1 EP0451274 A1 EP 0451274A1 EP 90901035 A EP90901035 A EP 90901035A EP 90901035 A EP90901035 A EP 90901035A EP 0451274 A1 EP0451274 A1 EP 0451274A1
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- EP
- European Patent Office
- Prior art keywords
- opening
- extent
- solenoid valve
- hydraulic
- actuating
- 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.)
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- 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
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- 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
- F15B11/042—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the feed line, i.e. "meter in"
- F15B11/0423—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the feed line, i.e. "meter in" by controlling pump output or bypass, other than to maintain constant speed
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- 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
- F15B2211/305—Directional control characterised by the type of valves
- F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
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- 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
- F15B2211/31—Directional control characterised by the positions of the valve element
- F15B2211/3105—Neutral or centre positions
- F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
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- 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
- F15B2211/31—Directional control characterised by the positions of the valve element
- F15B2211/3105—Neutral or centre positions
- F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
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- 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
- F15B2211/321—Directional control characterised by the type of actuation mechanically
- F15B2211/324—Directional control characterised by the type of actuation mechanically manually, e.g. by using a lever or pedal
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- 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
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- 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
- F15B2211/41509—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a directional control valve
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- 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
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- 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
- F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
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- 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
- F15B2211/455—Control of flow in the feed line, i.e. meter-in control
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- 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
- F15B2211/634—Electronic controllers using input signals representing a state of a valve
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- 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
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- 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
- F15B2211/7052—Single-acting output members
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- 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
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- 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
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- 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
- F15B2211/75—Control of speed of the output member
Definitions
- the present invention relates to a hydraulic controlling apparatus for controlling a plurality of hydraulic actuators mounted on a construction machine or the like industrial machine.
- a construction machine such as a power shovel, a bulldozer, a loading shovel or the like machine is usually equipped with a plurality of hydraulic actuators.
- the power shovel is equipped with a plurality of hydraulic actuators such a boom cylinder, an arm cylinder, a bucket cylinder, a hydraulic motor for turning movement and a hydraulic motor for forward/rearward movement of the power shovel.
- a conventional hydraulic controlling apparatus for controlling such plural hydraulic actuators as mentioned above has a plurality of actuating valves interposed between a common hydraulic power supply source and a plurality of hydraulic actuators to control a flow rate of hydraulic oil to be fed to the respective hydraulic actuators, whereby pressurized hydraulic oil is fed to the respective hydraulic actuators with a flow rate which is properly controlled by the corresponding actuating valve.
- a conventional hydraulic controlling apparatus for controlling a hydraulic cylinder 1 employable for light load and a hydraulic cylinder 2 employable for heavy load as shown in Fig. 5 has actuating valves 4 and 5 interposed between the hydraulic cylinders 1 and 2 and a common hydraulic pump 1 to control a flow rate of hydraulic oil.
- actuating valves 4 and 5 interposed between the hydraulic cylinders 1 and 2 and a common hydraulic pump 1 to control a flow rate of hydraulic oil.
- Each of the actuating valves 4 and 5 has a pump port a , a tank port b , a first actuator port c , a second actuator port d and a drain passage e .
- characteristics representative of a relationship between a quantity of actuation of the actuating valve 4 and an extent of opening of the actuating valve 4 are set such that an extent of opening (i.e., an opening area) of a hydraulic passage extending between the port a and the port c as well as an extent of opening of a hydraulic passage extending between the port a and the port d relative to a quantity of actuation of the actuating valve 4 vary in conformity with a characteristic curve A1 in Fig.
- an extent of opening of a hydraulic passage extending between the port b and the port c as well as an extent of opening of a hydraulic passage extending between the port b and the port d vary in conformity with a characteristic curve A2 in the drawing and an extent of opening of the hydraulic passage e varies in conformity with a characteristic curve A3 in the drawing.
- characteristics representative of a relationship between a quantity of actuation of the actuating valve 5 and an extent of opening of the actuating valve 5 are set such that an extent of opening (i.e., an opening area) of a hydraulic passage extending between the port a and the port c as well as an extent of opening of a hydraulic passage between the port a and the port d relative to a quantity of actuation of the actuating valve 5 vary in conformity with a characteristic curve B1 in Fig.
- an extent of opening of a hydraulic passage extending between the port b and the port c as well as an extent of opening of a hydraulic passage extending between the port b and the port d vary in conformity with a characteristic curve B2 in the drawing and an extent of opening of the hydraulic passage e varies in conformity with a characteristic curve B3 in the drawing.
- the actuating valve 5 is designed such that a rate of reduction of the extent of opening of the hydraulic passage e is set larger than that of the actuating valve 4 for the following reason.
- the actuating valve 5 serves to feed pressurized hydraulic oil to the hydraulic cylinder 2 employable for heavy load, there is a need that a flow rate of hydraulic oil to be drained through the hydraulic passage e is quickly reduced, after an actuating operation of the actuating valve 5 starts, so that a torque to be absorbed by the hydraulic pump 3 is increased.
- the actuating valve 5 is constructed such that the extent of opening of the hydraulic passage e varies depending on the characteristic curve B3 having a high rate of reduction of the extent of opening of each hydraulic passage.
- the actuating valve 4 alone is to be actuated.
- the hydraulic passage extending between the port a and the port c or the hydraulic passage extending between the port a and the port d in the actuating valve 4 serves as a variable throttle having the characteristic curve A1
- the drain passage e serves as a variable throttle having the characteristic curve A3.
- the former variable throttle is represented by reference numeral 6 and the latter variable throttle is represented by reference numeral 7 in Fig. 8.
- a quantity of hydraulic oil to be introduced into a hydraulic cylinder 1 in Fig. 8 is determined depending on a ratio of an extent of opening of the throttle 6 to an extent of opening of the throttle 7 as well as a magnitude of load exerted on the hydraulic cylinder 1.
- the hydraulic passage extending between the port a and the port c or the hydraulic passage extending between the port a and the port d serves as a variable throttle having the characteristic curve B1
- the drain passage e in the actuating valve 5 serves as a variable throttle having the characteristic curve B3.
- the former variable throttle is represented by reference numeral 8 and the latter variable throttle is represented by reference numeral 9 in Fig. 9.
- variable throttles 7 and 9 are arranged in series, as shown in Fig. 9.
- the extent of opening of the hydraulic passage e in the actuating valve 4 substantially varies in conformity with a characteristic curve A4 which is represented by a dotted line in Fig. 6.
- the characteristic curve A4 suggests that a quantity of hydraulic oil to be drained through the hydraulic passage e in the actuating valve 4 is remarkably reduced when the both actuating valves 4 and 5 are simultaneously actuated.
- a delivery pressure of hydraulic oil from the hydraulic pump 3 is unavoidably raised up above a necessary level of pressure.
- the conventional hydraulic controlling apparatus has a drawback that when the both actuating valves 4 and 5 are simultaneously actuated, an excessive quantity of hydraulic oil is introduced into the hydraulic cylinder 1 employable for light load and thereby the hydraulic cylinder 1 can not be controlled smoothly.
- the present invention has been made with the foregoing background in mind and its object resides in providing a hydraulic controlling apparatus which assures that when a plurality of actuating valves are simultaneously actuated, a quantity of hydraulic oil corresponding to the simultaneous actuation of the actuating valves is drained through the discharge passage of a hydraulic pump and thereby a plurality of actuators can be controlled smoothly.
- the present invention provides a hydraulic controlling apparatus having a plurality of actuating valves interposed between a hydraulic pump and a plurality of hydraulic actuators, wherein the hydraulic controlling apparatus comprises; a solenoid valve arranged in parallel with the hydraulic pump to control a flow rate of hydraulic oil, presetting means for presetting characteristics representative of an extent of opening of the solenoid valve to be used for one of the actuating valves to be singly actuated and characteristics representative of an extent of opening of the solenoid valve to be used for the plural actuating valves to be simultaneously actuated as typical characteristics representative of an extent of opening of the solenoid valve, detecting means for detecting a quantity of actuation of each of the respective actuating valves, and controlling means for controlling an extent of opening of the solenoid valve based on the characteristics representative of an extent of opening of the solenoid valve to be used for one of the actuating valves to be singly actuated in a case where the one actuating valve is singly actuated based on
- an extent of opening of the solenoid valve is properly controlled in conformity with the characteristics representative of an extent of opening of the solenoid valve to be used for the one actuating valve to be singly actuated.
- an extent of opening of the solenoid valve is properly controlled in conformity with the characteristics representative of an extent of opening of the solenoid valve to be used for the respective actuating valve to be simultaneously actuated.
- the characteristics representative of an extent of opening of the solenoid valve to be used for one of the actuating valves to be singly actuated are set such that they are well adapted to a load exerted on each of the hydraulic actuators, controlling of one of the hydraulic actuators can be controlled smoothly.
- the characteristics representative of an opening of the solenoid valve to be used for the respective actuating valves to be simultaneously actuated are set such that they are well adapted to a load when the respective actuating valve are simultaneously actuated, simultaneous controlling of the respective actuating valves can be controlled smoothly.
- Fig. 1 is a hydraulic circuit diagram which illustrates by way of example hydraulic circuits required for operating a hydraulic controlling apparatus in accordance with an embodiment of the present invention
- Fig. 2 is a block diagram which schematically illustrates controlling means for controlling a solenoid valve adapted to for control a flow rate of hydraulic oil
- Fig. 3 is a graph which illustrates by way of example characteristics indicative of an extent of opening of the solenoid valve for controlling a flow rate of hydraulic oil
- Fig. 4 is a flowchart which illustrates by way of example a procedure of processings to be executed by a controller as shown in Fig. 2
- Fig. 5 is a hydraulic circuit diagram which illustrates by way of examples a conventional hydraulic controlling apparatus
- Fig. 7 are a graph which represents characteristics representative of an extent of opening of respective actuating valves shown in Fig. 5, respectively, and Fig. 8 and Fig. 9 are a hydraulic circuit diagram which illustrates a function of the respective actuating valves shown in Fig. 5.
- Fig. 1 is a hydraulic circuit diagram which illustrates by way of example the hydraulic controlling apparatus of the present invention.
- the hydraulic circuit shown in Fig. 1 includes a hydraulic pump 10 and a solenoid valve 11 for controlling a flow rate of hydraulic oil, and the hydraulic pump 10 and the solenoid valve 11 are arranged in parallel with each other.
- the solenoid valve 11 is constructed such that an extend of opening of a hydraulic passage extending between an input port a and an output port b is set in inverse proportion to an intensity of input electric current.
- the solenoid valve 11 is controlled by controlling means which is exemplified in Fig. 2.
- the hydraulic circuit shown in Fig. 1 includes actuating valves 12 and 13 of which pump ports a are connected to the hydraulic pump 10 and of which tank ports b are connected to a tank 14.
- the actuating valve 12 has a first actuator port c and a second actuator port d , and the first actuator port c is connected to a hydraulic chamber on the head side of a hydraulic cylinder 15 employable for light load, while the second actuator port d is connected to a hydraulic chamber on the bottom side of the actuator 15.
- the actuating valve 13 has a first actuator port c and a second actuator port d , and the first actuator port c is connected to a hydraulic chamber on the head side of a hydraulic cylinder 16 employable for heavy load, while the second actuator port d is connected to a hydraulic chamber on the bottom side of the hydraulic cylinder 16.
- the actuating valve 12 is constructed such that an extent of opening (i.e., an opening area) of a hydraulic passage extending between the port a and the port c as well as an extent of opening of a hydraulic passage extending between the port a and the port d vary in conformity with a characteristic curve A1 in Fig. 6, while an extent of opening of a hydraulic passage extending between the port b and the port c as well as an extent of opening of a hydraulic passage extending the port b and the port d vary in conformity with a characteristic curve A2 in Fig. 6.
- the actuating valve 13 is constructed such that an extent of opening (i.e., an opening area) of a hydraulic passage extending between the port a and the port c as well as an extent of opening of a hydraulic passage extending between the port a and the port d vary in conformity with a characteristic curve B1 in Fig. 7, while an extent of opening of a hydraulic passage between the port b and the port c as well as an extent of opening of a hydraulic passage extending between the port b and the port d vary in conformity with a characteristic curve B2 in Fig. 7.
- the hydraulic cylinder 15 is retracted and expanded correspondingly.
- the hydraulic cylinder 16 is retracted and expanded correspondingly.
- a potentiometer 17 and a potentiometer 18 operate in operative association with actuating levers 12a and 13a of the actuating valves 12 and 13.
- a signal S1 and a signal S2 corresponding to a quantity of actuation of the actuating valves 12 and 13 are outputted from the potentiometers 17 and 18 so that the signal S1 and the signal S2 are inputted into a controller 19, respectively.
- FIG. 3 is a graph which illustrates by way of example characteristics representative of an extent of opening of each of the actuating valves 12 and 13.
- reference character D represents characteristics representative of an extent of opening of the solenoid valve 11 wherein the characteristics are applicable to a case where the actuating valve 12 is single actuated
- reference character E represents characteristics representative of an extent of opening of the solenoid valve 11 wherein the characteristics are applicable to a case where the actuating valve 13 is single actuated
- reference character F represents characteristics indicative of an extent of opening of the solenoid valve 11 wherein the characteristics are applicable to a case where the both actuating valves 12 and 13 are simultaneously actuated.
- an abscissa represents a quantity of actuation of the actuating valve 12 in conjunction with the characteristic curve D as well as a quantity of actuation of the actuating valve 13 in conjunction with the characteristic curve E.
- the abscissa represents a quantity of actuation of either of the actuating valves 12 and 13 in conjunction with the characteristic curve F. Specifically, it represents a quantity of actuation of one of the actuators 12 and 13 which is actuated by a longer distance.
- the actuating valve 12 is actuated when the hydraulic cylinder 15 employable for light load is operated.
- care should be taken such that an excessive quantity of hydraulic oil is not fed to the hydraulic cylinder 15 employable for light load.
- the characteristic curve D is set such that as a quantity of actuation of the actuating valve 12 increases, an extent of opening of the solenoid valve 11 is gradually reduced, in other words, when the actuating valve 12 is singly actuated, an adequate quantity of hydraulic oil is fed to the hydraulic cylinder 15 employable for light load.
- the actuating valve 13 is actuated when the hydraulic cylinder 16 employable for heavy load is actuated.
- care should be taken such that a quantity of hydraulic oil corresponding to a magnitude of heavy load exerted on the hydraulic cylinder 16 is fed to the hydraulic cylinder 16.
- the characteristic curve E is set such that the extent of opening of the solenoid valve 11 starts to be reduced eearliestr than in a case where the characteristic curve D is applicable and moreover a gradient of reduction of the extent of opening of the solenoid valve 11 is larger than that in a case where the characteristic curve D is applicable.
- the characteristic curve E is set such that a gradient of reduction in respect of the extent of opening of the solenoid valve 11 is larger than that in a case where the characteristic curve E is applicable.
- Fig. 4 is a flowchart which illustrates by way of example a procedure of processings to be executed by the controller 19. Now, operation of the hydraulic controlling apparatus of the present invention will be described below with reference to the flowchart in Fig. 4.
- the controller 19 determines based on an output signal S1 from the potentiometer 17 whether the actuating valve 12 is actuated or not (step 100). In addition, the controller 19 determines based on an output signal S2 from the potentiometer 17 whether the actuating valve 13 is actuated or not (step 101).
- controller 19 determines that the both actuating valves 12 and 13 are simultaneously actuated, the controller 19 selects the characteristic curve F shown in Fig. 3 (step 102). Subsequently, the controller 19 compares a magnitude of the output signal S1 with a magnitude of the output signal S2 (step 103).
- the controller 19 determines at the step 103 that a magnitude of the output signal S1 is equal to or larger than a magnitude of the output signal S2, the controller 19 reads from the memory 20 the present extent of opening of the solenoid valve 11 on the characteristic curve F corresponding to a quantity of actuation of the actuating valve 12 and then outputs a valve controlling signal Sf to an amplifier 21 to indicate the present extent of opening of the solenoid valve 11 (step 104).
- the controller 19 determines at the step 103 that a magnitude of the output signal S1 is smaller than a magnitude of the output signal S2, the controller 19 reads from the memory 20 the present extent of opening of the solenoid valve 11 on the characteristic curve F corresponding to a quantity of actuation of the actuating valve 13 and then outputs a valve controlling signal Sf to the amplifier 21 to indicate the present extent of opening of the solenoid valve 11 (step 105).
- the controller 19 controls an extent of opening of the solenoid valve 11 in conformity with the characteristic curve F.
- the controller 19 determines at the step 101 that the actuating valve 13 is not actuated, in other words, in a case where the controller 19 determined that the actuating valve 12 is single actuated, the controller 19 selects the characteristic curve D shown in Fig. 3 (step 106). Subsequently, the controller 19 reads from the memory 20 the present extent of opening of the solenoid valve 11 on the characteristic curve D corresponding to a quantity of actuation of the actuating valve 12 and then outputs a valve controlling signal Sd to the amplifier 21 to indicate the present extent of opening of the solenoid valve 11 (step 107).
- the controller 19 controls an extent of opening of the solenoid valve 11 in conformity of the characteristic curve D.
- the process goes to a step 108 at which the controller 19 determines whether the actuating valve 13 is actuated or not.
- the process returns. In this case, no actuating signal is transmitted to the solenoid valve 11, whereby the solenoid valve 11 is kept in a opened state.
- the controller 19 determines at the step 108 that the actuating valve 13 is actuated, in other words, in a case where the controller 19 determines that the actuating the actuating valve 13 alone is actuated, the controller selects the characteristic curve E shown in Fig. 3 (step 109). Subsequently, the controller 19 reads from the memory 20 the present extent of opening of the solenoid valve 11 corresponding to a quantity of actuation of the actuating valve 13 and then outputs a valve controlling signal Se to the amplifier 21 to indicate the present extent of opening of the solenoid valve 11 (step 110).
- the controller 19 controls an extent of opening of the solenoid valve 11 in conformity with the characteristic curve E.
- the controller 19 determines a quantity of hydraulic oil to be fed to each of the hydraulic cylinders 15 and 16 depending on the present extent of opening of the solenoid valve 11. Therefore, a quantity of hydraulic oil corresponding to a magnitude of load can be fed to the hydraulic cylinders 15 and 16 by properly controlling an extent of opening of the solenoid valve 11 based on the characteristic curve F which is preferably employable in the case where the both actuating valves 12 and 13 are simultaneously actuated, as mentioned above. Consequently, the hydraulic cylinders 15 and 16 have an improved controllability, respectively.
- the characteristics representative of the present extent of opening of the solenoid valve 11 when the both actuating valves 12 and 13 are simultaneously actuated should not be limited only to the aforementioned characteristic curve F.
- the characteristic curve E may be employed without any particular practical inconvenience as typical characteristics representative of an extent of opening of the solenoid valve 11 at the time when the both actuating valves 12 and 13 are simultaneously actuated.
- two manual type actuating valves are employed for the actuating valves 12 and 13.
- solenoid type actuating valves may be employed for the actuating valves 12 and 13. In this case, it is required that the actuating valves 12 and 13 are controlled based on an output from each of the potentiometers 17 and 18.
- one hydraulic cylinder 15 employable for light weight and one hydraulic cylinder 16 employable for heavy load are used as hydraulic actuators for carrying out the present invention.
- the present invention may be applied to a case where three or more hydraulic actuators each having a different magnitude of load to be borne thereby are properly controlled by the hydraulic controlling apparatus of the present invention.
- the respective hydraulic actuators are hydraulically connected to a common hydraulic pump via the respective actuating valves, and a solenoid valve for controlling a flow rate of hydraulic oil (corresponding to the solenoid valve 11 in the aforementioned embodiment) is arranged in parallel with the hydraulic pump in the same manner as in the aforementioned embodiment of the present invention.
- characteristics representative of an extent of opening of a solenoid valve to be used for one actuating valve to be singly actuated are set in the same manner as in the aforementioned embodiment of the present invention.
- characteristics representative of an extent of opening of a solenoid valve to used for a plurality of actuating valves to be simultaneously actuated are likewise set in the same manner as in the aforementioned embodiment of the present invention.
- characteristics representative of an extent of opening of the solenoid valve to be used for a single actuating operation are employed, and the extent of opening of the solenoid valve to be actuated is set based on the characteristics representative of an extent of opening of the solenoid valve and a quantity of actuation of the actuating valve to be singly actuated.
- the characteristics representative of an extent of opening of the solenoid valve to be singly actuated are preset in the same manner as in the aforementioned embodiment of the present invention such that they are well adapted to a magnitude of load exerted on each hydraulic actuator.
- the characteristics representative of an extent of opening of the solenoid valve for the respective actuating valves to be simultaneously actuated are employable.
- the extent of opening of the solenoid valve is set based on a maximum magnitude of actuation of the respective actuating valves to be simultaneously actuated and the characteristics representative of an extent of opening of the solenoid valve to be used for the respective actuating valves to be simultaneously actuated.
- characteristics representative of a smallest extent of opening of the solenoid valve to be used for one actuating valve to be singly actuated may be substituted for the characteristics representative of an extent of opening of the solenoid valve to be used for a plurality of actuating valves to be simultaneously actuated.
- the hydraulic controlling apparatus of the present invention is advantageously employable for a case where a plurality of actuating valves are simultaneously actuated in an adequate way, it can be concluded that the hydraulic controlling apparatus effectively serves as hydraulic controlling means for properly controlling a variety of machines, particularly, a construction machine.
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Abstract
This invention relates to a hydraulic controller having a construction wherein individual operation valves (12, 13) for controlling the oil feed quantity to hydraulic actuators (15, 16) are disposed between a hydraulic pump (10) and the hydraulic actuators (15, 16). In this hydraulic controller, a flow rate regulating solenoid valve (11) is connected to the hydraulic pump (10) in parallel and individual operation opening characteristics which are applied to the single operation of each operation valve (12, 13) and composite operation opening characteristics which are applied to the combinated operation of the operation valves (12, 13) are set in advance as the opening characteristics of the solenoid valve (11). When either one of the operation valves (12, 13) is operated individually, the opening of the solenoid valve (11) is controlled on the basis of a single operation opening characteristics which are to be applied to that operation valve, and when the operation valves (12, 13) are operated in combination, the opening of the solenoid valve (11) is controlled on the basis of a composite operation opening characteristics. Accordingly, single control and combined control of the individual hydraulic actuators (15, 16) can be made smoothly by setting single operation opening characteristics and composite operation opening characteristics matching the load of the individual hydraulic actuators.
Description
- The present invention relates to a hydraulic controlling apparatus for controlling a plurality of hydraulic actuators mounted on a construction machine or the like industrial machine.
- A construction machine such as a power shovel, a bulldozer, a loading shovel or the like machine is usually equipped with a plurality of hydraulic actuators. For example, the power shovel is equipped with a plurality of hydraulic actuators such a boom cylinder, an arm cylinder, a bucket cylinder, a hydraulic motor for turning movement and a hydraulic motor for forward/rearward movement of the power shovel.
- A conventional hydraulic controlling apparatus for controlling such plural hydraulic actuators as mentioned above has a plurality of actuating valves interposed between a common hydraulic power supply source and a plurality of hydraulic actuators to control a flow rate of hydraulic oil to be fed to the respective hydraulic actuators, whereby pressurized hydraulic oil is fed to the respective hydraulic actuators with a flow rate which is properly controlled by the corresponding actuating valve.
- For example, a conventional hydraulic controlling apparatus for controlling a
hydraulic cylinder 1 employable for light load and ahydraulic cylinder 2 employable for heavy load as shown in Fig. 5 has actuatingvalves hydraulic cylinders hydraulic pump 1 to control a flow rate of hydraulic oil. With the conventional hydraulic controlling apparatus as constructed in the above-described manner, a quantity of hydraulic oil to be fed to thehydraulic cylinders actuating valves - Each of the
actuating valves - With respect to the actuating
valve 4, characteristics representative of a relationship between a quantity of actuation of the actuatingvalve 4 and an extent of opening of the actuatingvalve 4 are set such that an extent of opening (i.e., an opening area) of a hydraulic passage extending between the port a and the port c as well as an extent of opening of a hydraulic passage extending between the port a and the port d relative to a quantity of actuation of the actuatingvalve 4 vary in conformity with a characteristic curve A1 in Fig. 6, an extent of opening of a hydraulic passage extending between the port b and the port c as well as an extent of opening of a hydraulic passage extending between the port b and the port d vary in conformity with a characteristic curve A2 in the drawing and an extent of opening of the hydraulic passage e varies in conformity with a characteristic curve A3 in the drawing. - On the other hand, with respect to the actuating
valve 5, characteristics representative of a relationship between a quantity of actuation of the actuatingvalve 5 and an extent of opening of the actuatingvalve 5 are set such that an extent of opening (i.e., an opening area) of a hydraulic passage extending between the port a and the port c as well as an extent of opening of a hydraulic passage between the port a and the port d relative to a quantity of actuation of the actuatingvalve 5 vary in conformity with a characteristic curve B1 in Fig. 7, an extent of opening of a hydraulic passage extending between the port b and the port c as well as an extent of opening of a hydraulic passage extending between the port b and the port d vary in conformity with a characteristic curve B2 in the drawing and an extent of opening of the hydraulic passage e varies in conformity with a characteristic curve B3 in the drawing. - As will be apparent from a comparison of the characteristic curve A3 in Fig. 6 with the characteristic curve B3 in Fig. 7, the actuating
valve 5 is designed such that a rate of reduction of the extent of opening of the hydraulic passage e is set larger than that of the actuatingvalve 4 for the following reason. - Specifically, since the actuating
valve 5 serves to feed pressurized hydraulic oil to thehydraulic cylinder 2 employable for heavy load, there is a need that a flow rate of hydraulic oil to be drained through the hydraulic passage e is quickly reduced, after an actuating operation of the actuatingvalve 5 starts, so that a torque to be absorbed by thehydraulic pump 3 is increased. To this end, the actuatingvalve 5 is constructed such that the extent of opening of the hydraulic passage e varies depending on the characteristic curve B3 having a high rate of reduction of the extent of opening of each hydraulic passage. - Now, it is assumed that e.g., the actuating
valve 4 alone is to be actuated. In this case, the hydraulic passage extending between the port a and the port c or the hydraulic passage extending between the port a and the port d in the actuatingvalve 4 serves as a variable throttle having the characteristic curve A1, while the drain passage e serves as a variable throttle having the characteristic curve A3. The former variable throttle is represented byreference numeral 6 and the latter variable throttle is represented byreference numeral 7 in Fig. 8. - It should be noted that a quantity of hydraulic oil to be introduced into a
hydraulic cylinder 1 in Fig. 8 is determined depending on a ratio of an extent of opening of thethrottle 6 to an extent of opening of thethrottle 7 as well as a magnitude of load exerted on thehydraulic cylinder 1. - On the other hand, in a case where the actuating
valve 5 alone is actuated, the hydraulic passage extending between the port a and the port c or the hydraulic passage extending between the port a and the port d serves as a variable throttle having the characteristic curve B1, while the drain passage e in the actuatingvalve 5 serves as a variable throttle having the characteristic curve B3. The former variable throttle is represented byreference numeral 8 and the latter variable throttle is represented byreference numeral 9 in Fig. 9. - In a case where the both actuating
valves variable throttles - Therefore, e.g., in a case where the actuating
valve 4 is actuated while a quantity of actuation of the actuatingvalve 5 is fixedly determined at L1 in Fig. 7, the extent of opening of the hydraulic passage e in the actuatingvalve 4 substantially varies in conformity with a characteristic curve A4 which is represented by a dotted line in Fig. 6. - The characteristic curve A4 suggests that a quantity of hydraulic oil to be drained through the hydraulic passage e in the actuating
valve 4 is remarkably reduced when the bothactuating valves hydraulic pump 3 is unavoidably raised up above a necessary level of pressure. - Thus, the conventional hydraulic controlling apparatus has a drawback that when the both
actuating valves hydraulic cylinder 1 employable for light load and thereby thehydraulic cylinder 1 can not be controlled smoothly. - The present invention has been made with the foregoing background in mind and its object resides in providing a hydraulic controlling apparatus which assures that when a plurality of actuating valves are simultaneously actuated, a quantity of hydraulic oil corresponding to the simultaneous actuation of the actuating valves is drained through the discharge passage of a hydraulic pump and thereby a plurality of actuators can be controlled smoothly.
- To accomplish the above object, the present invention provides a hydraulic controlling apparatus having a plurality of actuating valves interposed between a hydraulic pump and a plurality of hydraulic actuators, wherein the hydraulic controlling apparatus comprises;
a solenoid valve arranged in parallel with the hydraulic pump to control a flow rate of hydraulic oil,
presetting means for presetting characteristics representative of an extent of opening of the solenoid valve to be used for one of the actuating valves to be singly actuated and characteristics representative of an extent of opening of the solenoid valve to be used for the plural actuating valves to be simultaneously actuated as typical characteristics representative of an extent of opening of the solenoid valve,
detecting means for detecting a quantity of actuation of each of the respective actuating valves, and
controlling means for controlling an extent of opening of the solenoid valve based on the characteristics representative of an extent of opening of the solenoid valve to be used for one of the actuating valves to be singly actuated in a case where the one actuating valve is singly actuated based on a result derived from detection of the detecting means and moreover controlling an extent of opening of the solenoid valve based on the characteristics representative of an extent of opening of the solenoid valve to be used for the respective actuating valves to be simultaneously actuated in a case where the respective actuating valve are simultaneously actuated based on a result derived from detection of the detecting means. - With the hydraulic controlling apparatus of the present invention, in a case where either one of the actuating valves is singly actuated, an extent of opening of the solenoid valve is properly controlled in conformity with the characteristics representative of an extent of opening of the solenoid valve to be used for the one actuating valve to be singly actuated. In a case where two or more actuating valves are simultaneously actuated, an extent of opening of the solenoid valve is properly controlled in conformity with the characteristics representative of an extent of opening of the solenoid valve to be used for the respective actuating valve to be simultaneously actuated.
- Therefore, while the characteristics representative of an extent of opening of the solenoid valve to be used for one of the actuating valves to be singly actuated are set such that they are well adapted to a load exerted on each of the hydraulic actuators, controlling of one of the hydraulic actuators can be controlled smoothly. In addition, while the characteristics representative of an opening of the solenoid valve to be used for the respective actuating valves to be simultaneously actuated are set such that they are well adapted to a load when the respective actuating valve are simultaneously actuated, simultaneous controlling of the respective actuating valves can be controlled smoothly.
- Fig. 1 is a hydraulic circuit diagram which illustrates by way of example hydraulic circuits required for operating a hydraulic controlling apparatus in accordance with an embodiment of the present invention, Fig. 2 is a block diagram which schematically illustrates controlling means for controlling a solenoid valve adapted to for control a flow rate of hydraulic oil, Fig. 3 is a graph which illustrates by way of example characteristics indicative of an extent of opening of the solenoid valve for controlling a flow rate of hydraulic oil, Fig. 4 is a flowchart which illustrates by way of example a procedure of processings to be executed by a controller as shown in Fig. 2, Fig. 5 is a hydraulic circuit diagram which illustrates by way of examples a conventional hydraulic controlling apparatus, Fig. 6 and Fig. 7 are a graph which represents characteristics representative of an extent of opening of respective actuating valves shown in Fig. 5, respectively, and Fig. 8 and Fig. 9 are a hydraulic circuit diagram which illustrates a function of the respective actuating valves shown in Fig. 5.
- Now, the present invention will be described in detail hereinafter with reference to the accompanying drawings which illustrate a hydraulic controlling apparatus in accordance with an embodiment of the present invention.
- Fig. 1 is a hydraulic circuit diagram which illustrates by way of example the hydraulic controlling apparatus of the present invention.
- The hydraulic circuit shown in Fig. 1 includes a
hydraulic pump 10 and asolenoid valve 11 for controlling a flow rate of hydraulic oil, and thehydraulic pump 10 and thesolenoid valve 11 are arranged in parallel with each other. Thesolenoid valve 11 is constructed such that an extend of opening of a hydraulic passage extending between an input port a and an output port b is set in inverse proportion to an intensity of input electric current. In practice, thesolenoid valve 11 is controlled by controlling means which is exemplified in Fig. 2. - In addition, the hydraulic circuit shown in Fig. 1 includes
actuating valves hydraulic pump 10 and of which tank ports b are connected to atank 14. - The actuating
valve 12 has a first actuator port c and a second actuator port d, and the first actuator port c is connected to a hydraulic chamber on the head side of ahydraulic cylinder 15 employable for light load, while the second actuator port d is connected to a hydraulic chamber on the bottom side of theactuator 15. Similarly, the actuatingvalve 13 has a first actuator port c and a second actuator port d, and the first actuator port c is connected to a hydraulic chamber on the head side of ahydraulic cylinder 16 employable for heavy load, while the second actuator port d is connected to a hydraulic chamber on the bottom side of thehydraulic cylinder 16. - The actuating
valve 12 is constructed such that an extent of opening (i.e., an opening area) of a hydraulic passage extending between the port a and the port c as well as an extent of opening of a hydraulic passage extending between the port a and the port d vary in conformity with a characteristic curve A1 in Fig. 6, while an extent of opening of a hydraulic passage extending between the port b and the port c as well as an extent of opening of a hydraulic passage extending the port b and the port d vary in conformity with a characteristic curve A2 in Fig. 6. - On the other hand, the actuating
valve 13 is constructed such that an extent of opening (i.e., an opening area) of a hydraulic passage extending between the port a and the port c as well as an extent of opening of a hydraulic passage extending between the port a and the port d vary in conformity with a characteristic curve B1 in Fig. 7, while an extent of opening of a hydraulic passage between the port b and the port c as well as an extent of opening of a hydraulic passage extending between the port b and the port d vary in conformity with a characteristic curve B2 in Fig. 7. - As the actuating
valve 12 is actuated toward one side as well as toward other side, thehydraulic cylinder 15 is retracted and expanded correspondingly. Further, as the actuatingvalve 13 is actuated toward one side as well as toward other side, thehydraulic cylinder 16 is retracted and expanded correspondingly. - Referring to Fig. 2, a
potentiometer 17 and apotentiometer 18 operate in operative association with actuatinglevers 12a and 13a of the actuatingvalves actuating valves potentiometers controller 19, respectively. - A number of data on characteristics representative of an extent of opening of the
solenoid valve 11 are stored in amemory 20. Fig. 3 is a graph which illustrates by way of example characteristics representative of an extent of opening of each of the actuatingvalves solenoid valve 11 wherein the characteristics are applicable to a case where the actuatingvalve 12 is single actuated, reference character E represents characteristics representative of an extent of opening of thesolenoid valve 11 wherein the characteristics are applicable to a case where the actuatingvalve 13 is single actuated, and reference character F represents characteristics indicative of an extent of opening of thesolenoid valve 11 wherein the characteristics are applicable to a case where the both actuatingvalves - Referring to Fig. 3 again, an abscissa represents a quantity of actuation of the actuating
valve 12 in conjunction with the characteristic curve D as well as a quantity of actuation of the actuatingvalve 13 in conjunction with the characteristic curve E. In addition, the abscissa represents a quantity of actuation of either of theactuating valves actuators - As mentioned above, the actuating
valve 12 is actuated when thehydraulic cylinder 15 employable for light load is operated. Thus, in a case where the actuatingvalve 12 is singly actuated, care should be taken such that an excessive quantity of hydraulic oil is not fed to thehydraulic cylinder 15 employable for light load. - This is because if a quantity of hydraulic oil more than a certain level of necessary quantity is fed to the
hydraulic cylinder 15, control can not smoothly be carried out for thehydraulic cylinder 15 due to a high intensity of hydraulic pressure active in thehydraulic cylinder 15. - In view of the foregoing fact, the characteristic curve D is set such that as a quantity of actuation of the actuating
valve 12 increases, an extent of opening of thesolenoid valve 11 is gradually reduced, in other words, when the actuatingvalve 12 is singly actuated, an adequate quantity of hydraulic oil is fed to thehydraulic cylinder 15 employable for light load. - On the other hand, the actuating
valve 13 is actuated when thehydraulic cylinder 16 employable for heavy load is actuated. Thus, in a case where the actuatingvalve 13 is singly actuated, care should be taken such that a quantity of hydraulic oil corresponding to a magnitude of heavy load exerted on thehydraulic cylinder 16 is fed to thehydraulic cylinder 16. - Therefore, the characteristic curve E is set such that the extent of opening of the
solenoid valve 11 starts to be reduced eariler than in a case where the characteristic curve D is applicable and moreover a gradient of reduction of the extent of opening of thesolenoid valve 11 is larger than that in a case where the characteristic curve D is applicable. - Since the
hydraulic cylinder 15 employable for light load and thehydraulic cylinder 16 employable for heavy load are operated when the bothactuating valves hydraulic cylinder 16 is single actuated is required for operating the hydraulic circuit shown in Fig. 1. While the aforementioned facts are taken into account, the characteristic curve E is set such that a gradient of reduction in respect of the extent of opening of thesolenoid valve 11 is larger than that in a case where the characteristic curve E is applicable. - Fig. 4 is a flowchart which illustrates by way of example a procedure of processings to be executed by the
controller 19. Now, operation of the hydraulic controlling apparatus of the present invention will be described below with reference to the flowchart in Fig. 4. - The
controller 19 determines based on an output signal S1 from thepotentiometer 17 whether the actuatingvalve 12 is actuated or not (step 100). In addition, thecontroller 19 determines based on an output signal S2 from thepotentiometer 17 whether the actuatingvalve 13 is actuated or not (step 101). - If the
controller 19 determines that the both actuatingvalves controller 19 selects the characteristic curve F shown in Fig. 3 (step 102). Subsequently, thecontroller 19 compares a magnitude of the output signal S1 with a magnitude of the output signal S2 (step 103). - In a case where the
controller 19 determines at thestep 103 that a magnitude of the output signal S1 is equal to or larger than a magnitude of the output signal S2, thecontroller 19 reads from thememory 20 the present extent of opening of thesolenoid valve 11 on the characteristic curve F corresponding to a quantity of actuation of the actuatingvalve 12 and then outputs a valve controlling signal Sf to anamplifier 21 to indicate the present extent of opening of the solenoid valve 11 (step 104). - In a case where the
controller 19 determines at thestep 103 that a magnitude of the output signal S1 is smaller than a magnitude of the output signal S2, thecontroller 19 reads from thememory 20 the present extent of opening of thesolenoid valve 11 on the characteristic curve F corresponding to a quantity of actuation of the actuatingvalve 13 and then outputs a valve controlling signal Sf to theamplifier 21 to indicate the present extent of opening of the solenoid valve 11 (step 105). - As a result derived from the determination at the
step 105, when it is found that the both actuatingvalves controller 19 controls an extent of opening of thesolenoid valve 11 in conformity with the characteristic curve F. - On the other hand, in a case where the
controller 19 determines at thestep 101 that the actuatingvalve 13 is not actuated, in other words, in a case where thecontroller 19 determined that the actuatingvalve 12 is single actuated, thecontroller 19 selects the characteristic curve D shown in Fig. 3 (step 106). Subsequently, thecontroller 19 reads from thememory 20 the present extent of opening of thesolenoid valve 11 on the characteristic curve D corresponding to a quantity of actuation of the actuatingvalve 12 and then outputs a valve controlling signal Sd to theamplifier 21 to indicate the present extent of opening of the solenoid valve 11 (step 107). - As a result derived from the determination at the
step 107, when it is found that the actuatingvalve 12 alone is actuated, thecontroller 19 controls an extent of opening of thesolenoid valve 11 in conformity of the characteristic curve D. - Further, in a case where the
controller 19 determines at thestep 100 that the actuatingvalve 12 is not actuated, the process goes to astep 108 at which thecontroller 19 determines whether the actuatingvalve 13 is actuated or not. When thecontroller 19 determines at thestep 108 that the actuatingvalve 13 is not actuated, the process returns. In this case, no actuating signal is transmitted to thesolenoid valve 11, whereby thesolenoid valve 11 is kept in a opened state. - On the other hand, in a case where the
controller 19 determines at thestep 108 that the actuatingvalve 13 is actuated, in other words, in a case where thecontroller 19 determines that the actuating the actuatingvalve 13 alone is actuated, the controller selects the characteristic curve E shown in Fig. 3 (step 109). Subsequently, thecontroller 19 reads from thememory 20 the present extent of opening of thesolenoid valve 11 corresponding to a quantity of actuation of the actuatingvalve 13 and then outputs a valve controlling signal Se to theamplifier 21 to indicate the present extent of opening of the solenoid valve 11 (step 110). - As a result derived from the determination at the
step 110, when it is found that the actuatingvalve 13 alone is actuated, thecontroller 19 controls an extent of opening of thesolenoid valve 11 in conformity with the characteristic curve E. - As will be apparent from the above description, according to the embodiment of the present invention, when it is found that the both actuating
valves controller 19 determines a quantity of hydraulic oil to be fed to each of thehydraulic cylinders solenoid valve 11. Therefore, a quantity of hydraulic oil corresponding to a magnitude of load can be fed to thehydraulic cylinders solenoid valve 11 based on the characteristic curve F which is preferably employable in the case where the both actuatingvalves hydraulic cylinders - It should be noted that the characteristics representative of the present extent of opening of the
solenoid valve 11 when the both actuatingvalves solenoid valve 11 at the time when the both actuatingvalves - According to the aforementioned embodiment of the present invention, two manual type actuating valves are employed for the
actuating valves actuating valves actuating valves potentiometers - Further, according to the aforementioned embodiment of the present invention, one
hydraulic cylinder 15 employable for light weight and onehydraulic cylinder 16 employable for heavy load are used as hydraulic actuators for carrying out the present invention. Alternatively, the present invention may be applied to a case where three or more hydraulic actuators each having a different magnitude of load to be borne thereby are properly controlled by the hydraulic controlling apparatus of the present invention. - Also in the case, the respective hydraulic actuators are hydraulically connected to a common hydraulic pump via the respective actuating valves, and a solenoid valve for controlling a flow rate of hydraulic oil (corresponding to the
solenoid valve 11 in the aforementioned embodiment) is arranged in parallel with the hydraulic pump in the same manner as in the aforementioned embodiment of the present invention. - Since one actuating valve is singly actuated or a plurality of actuating valves are simultaneously actuated depending on a type or kind of work to be conducted, characteristics representative of an extent of opening of a solenoid valve to be used for one actuating valve to be singly actuated are set in the same manner as in the aforementioned embodiment of the present invention. In addition, characteristics representative of an extent of opening of a solenoid valve to used for a plurality of actuating valves to be simultaneously actuated are likewise set in the same manner as in the aforementioned embodiment of the present invention.
- In a case where one actuating valve is single actuated, characteristics representative of an extent of opening of the solenoid valve to be used for a single actuating operation are employed, and the extent of opening of the solenoid valve to be actuated is set based on the characteristics representative of an extent of opening of the solenoid valve and a quantity of actuation of the actuating valve to be singly actuated.
- The characteristics representative of an extent of opening of the solenoid valve to be singly actuated are preset in the same manner as in the aforementioned embodiment of the present invention such that they are well adapted to a magnitude of load exerted on each hydraulic actuator.
- On the other hand, in a case where two or more actuating valves are simultaneously actuated, the characteristics representative of an extent of opening of the solenoid valve for the respective actuating valves to be simultaneously actuated are employable. In this case, the extent of opening of the solenoid valve is set based on a maximum magnitude of actuation of the respective actuating valves to be simultaneously actuated and the characteristics representative of an extent of opening of the solenoid valve to be used for the respective actuating valves to be simultaneously actuated.
- It should be noted that characteristics representative of a smallest extent of opening of the solenoid valve to be used for one actuating valve to be singly actuated may be substituted for the characteristics representative of an extent of opening of the solenoid valve to be used for a plurality of actuating valves to be simultaneously actuated.
- Since the hydraulic controlling apparatus of the present invention is advantageously employable for a case where a plurality of actuating valves are simultaneously actuated in an adequate way, it can be concluded that the hydraulic controlling apparatus effectively serves as hydraulic controlling means for properly controlling a variety of machines, particularly, a construction machine.
Claims (5)
- A hydraulic controlling apparatus having a plurality of actuating valves interposed between a common hydraulic pump and a plurality of hydraulic actuators to control a quantity of hydraulic oil to be fed to each of said hydraulic actuators, wherein said hydraulic controlling apparatus comprises;
a solenoid valve arranged in parallel with said hydraulic pump to control a flow rate of hydraulic oil,
presetting means for presetting characteristics representative of an extent of opening of said solenoid valve to be used for one of the actuating valves to be singly actuated and characteristics representative of an extent of opening of said solenoid valve to be used for the respective actuating valves to be simultaneously actuated as typical characteristic representative of an extent of opening of the solenoid valve,
detecting means for detecting a quantity of actuation of each of the actuating valves, and
controlling means for controlling an extent of opening of the solenoid based on said characteristics representative of an extent of opening of the solenoid valve to be used for one of the actuating valves to be single actuated in a case where said one actuating valve is singly actuated based on a result derived from detection of said detecting means and moreover controlling an extent of opening of the solenoid valve based on said characteristics representative of an extent of opening of the solenoid valve to be used for the respective actuating valves to be simultaneously actuated in a case where the respective actuating valves are simultaneously actuated based on a result derived from detection of said detecting means. - A controlling apparatus as claimed in claim 1, wherein the characteristics representative of an extent of opening of the solenoid valve to be used for the one actuating valve to be singly actuated and the characteristics representative of an extent of opening of the solenoid valve to be used for the respective actuating valves to be simultaneously actuated are set such that the extent of the solenoid valve is reduced as a quantity of actuation of each actuating valve increases.
- A controlling apparatus as claimed in claim 1, wherein the characteristics representative of an extent of opening of the solenoid valve to be used for the one actuating valve to be single actuated are set based on a magnitude of load exerted on each hydraulic actuator.
- A controlling apparatus as claimed in claim 1, wherein an extent of the solenoid valve in conformity with the characteristics representative of an extent of opening of the solenoid valve to be used for the respective actuating valves to be simultaneously actuated are set lower than an extent of opening of the solenoid valve in conformity with the characteristics the representative of an extent of opening of the solenoid valve to be used for one actuating valve to be single actuated.
- A controlling apparatus as claimed in claim 1, wherein the characteristics representative of a smallest extent of opening of the solenoid valve to be used for the one actuating valve to be singly actuated are employed as typical characteristics representative of an extent of opening of the solenoid valve to used for the respective actuating valves to be simultaneously actuated.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP167789/88U | 1988-12-27 | ||
JP1988167789U JPH0288005U (en) | 1988-12-27 | 1988-12-27 |
Publications (2)
Publication Number | Publication Date |
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EP0451274A1 true EP0451274A1 (en) | 1991-10-16 |
EP0451274A4 EP0451274A4 (en) | 1991-11-13 |
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ID=15856144
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP19900901035 Withdrawn EP0451274A4 (en) | 1988-12-27 | 1989-12-27 | Hydraulic controller |
Country Status (4)
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EP (1) | EP0451274A4 (en) |
JP (1) | JPH0288005U (en) |
KR (1) | KR910700415A (en) |
WO (1) | WO1990007651A1 (en) |
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JP6726127B2 (en) * | 2017-03-30 | 2020-07-22 | 川崎重工業株式会社 | Hydraulic system |
US11168464B2 (en) * | 2017-07-14 | 2021-11-09 | Nordhydraulic Ab | Open center hydraulic system and valve |
JP7418278B2 (en) | 2020-04-30 | 2024-01-19 | キャタピラー エス エー アール エル | hydraulic control circuit |
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DE1807173A1 (en) * | 1968-11-06 | 1970-06-18 | Bosch Gmbh Robert | Device for the electro-hydraulic remote control of hydraulic directional control valves |
DE2630468A1 (en) * | 1976-07-07 | 1978-01-12 | Bosch Gmbh Robert | HYDRAULIC CONTROL SYSTEM FOR AT LEAST TWO CONSUMERS |
EP0015296A1 (en) * | 1978-07-13 | 1980-09-17 | Unic Corporation | Device for remote control of hydraulic cranes |
EP0235545A2 (en) * | 1986-01-25 | 1987-09-09 | Hitachi Construction Machinery Co., Ltd. | Hydraulic drive system |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS50117296U (en) * | 1974-03-08 | 1975-09-25 | ||
JPS5985765U (en) * | 1982-12-02 | 1984-06-09 | 内田油圧機器工業株式会社 | Hydraulic circuit device for tailgate lifter |
JPS622805U (en) * | 1985-06-20 | 1987-01-09 |
-
1988
- 1988-12-27 JP JP1988167789U patent/JPH0288005U/ja active Pending
-
1989
- 1989-12-27 KR KR1019900701732A patent/KR910700415A/en not_active Application Discontinuation
- 1989-12-27 EP EP19900901035 patent/EP0451274A4/en not_active Withdrawn
- 1989-12-27 WO PCT/JP1989/001309 patent/WO1990007651A1/en not_active Application Discontinuation
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1807173A1 (en) * | 1968-11-06 | 1970-06-18 | Bosch Gmbh Robert | Device for the electro-hydraulic remote control of hydraulic directional control valves |
DE2630468A1 (en) * | 1976-07-07 | 1978-01-12 | Bosch Gmbh Robert | HYDRAULIC CONTROL SYSTEM FOR AT LEAST TWO CONSUMERS |
EP0015296A1 (en) * | 1978-07-13 | 1980-09-17 | Unic Corporation | Device for remote control of hydraulic cranes |
EP0235545A2 (en) * | 1986-01-25 | 1987-09-09 | Hitachi Construction Machinery Co., Ltd. | Hydraulic drive system |
Non-Patent Citations (1)
Title |
---|
See also references of WO9007651A1 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5468126A (en) * | 1993-12-23 | 1995-11-21 | Caterpillar Inc. | Hydraulic power control system |
US5525043A (en) * | 1993-12-23 | 1996-06-11 | Caterpillar Inc. | Hydraulic power control system |
US5701933A (en) * | 1996-06-27 | 1997-12-30 | Caterpillar Inc. | Hydraulic control system having a bypass valve |
CN103032393A (en) * | 2012-12-14 | 2013-04-10 | 长春新试验机有限责任公司 | Quasi-static loading hydraulic pump servo control device |
WO2024015025A1 (en) * | 2022-07-13 | 2024-01-18 | Tajfun Liv, Proizvodnja In Razvoj D.O.O. | Hydraulic circuit of a mobile hydraulic crane |
Also Published As
Publication number | Publication date |
---|---|
KR910700415A (en) | 1991-03-15 |
WO1990007651A1 (en) | 1990-07-12 |
JPH0288005U (en) | 1990-07-12 |
EP0451274A4 (en) | 1991-11-13 |
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