US20130291530A1 - Boom-swivel compound drive hydraulic control system of construction machine - Google Patents
Boom-swivel compound drive hydraulic control system of construction machine Download PDFInfo
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- US20130291530A1 US20130291530A1 US13/996,818 US201013996818A US2013291530A1 US 20130291530 A1 US20130291530 A1 US 20130291530A1 US 201013996818 A US201013996818 A US 201013996818A US 2013291530 A1 US2013291530 A1 US 2013291530A1
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- boom
- control valve
- hydraulic
- flow rate
- spool
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2292—Systems with two or more pumps
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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
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/2025—Particular purposes of control systems not otherwise provided for
- E02F9/2037—Coordinating the movements of the implement and of the frame
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2221—Control of flow rate; Load sensing arrangements
- E02F9/2239—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance
- E02F9/2242—Control of flow rate; Load sensing arrangements using two or more pumps with cross-assistance including an electronic controller
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2296—Systems with a variable displacement pump
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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
- F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
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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
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
- F15B13/044—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by electrically-controlled means, e.g. solenoids, torque-motors
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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
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/2053—Type of pump
- F15B2211/20546—Type of pump variable capacity
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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
- F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
- F15B2211/205—Systems with pumps
- F15B2211/20576—Systems with pumps with multiple pumps
-
- 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
- F15B2211/3056—Assemblies of multiple valves
- F15B2211/3059—Assemblies of multiple valves having multiple valves for multiple output members
- F15B2211/30595—Assemblies of multiple valves having multiple valves for multiple output members with additional valves between the groups of valves for multiple 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
- F15B2211/40—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
- F15B2211/428—Flow control characterised by the type of actuation actuated by fluid 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
- F15B2211/40—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
- F15B2211/665—Methods of control using electronic components
- F15B2211/6658—Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode
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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
- F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups
Definitions
- the present invention relates to a hydraulic control system for a combined boom and swing operation of a construction machine such as an excavator. More particularly, the present invention relates to a hydraulic system for a construction machine, in which the driving speeds of the boom and the swing device are adjusted according to working conditions during a combined operation in which boom-up and swing manipulations are carried out to perform an excavating and loading work, thereby ensuring a smooth work.
- a conventional hydraulic control system for a combined boom and swing operation of a construction machine in accordance with the prior art as shown in FIG. 1 includes:
- first and second hydraulic pumps 1 and 2 connected to an engine (not shown);
- an actuator (referring to “arm cylinder”) for a swing device and a work apparatus, which is connected to the first hydraulic pump 1 ;
- boom cylinder an actuator for a work apparatus (referring to “boom cylinder”) connected to the second hydraulic pump 2 ;
- a flow rate control valve (MCV) 3 configured to control a flow rate of a hydraulic fluid supplied respectively to the actuators for the swing device and the work apparatus from the first and second hydraulic pumps 1 and 2 .
- a non-explained reference numeral 11 denotes a boom confluence spool that allows the hydraulic fluid discharged from the first hydraulic pump 1 to join the hydraulic fluid discharged from the second hydraulic pump 2 when a boom-up operation is performed.
- an operator manipulates a boom manipulation lever 4 to shift a boom spool 5 and a boom confluence spool 11 so that the hydraulic fluid supplied to the boom cylinder via the boom spool 5 from the second hydraulic pump 2 and the hydraulic fluid supplied to the boom cylinder from the first hydraulic pump 1 via the boom confluence spool 11 join each other to cause the boom cylinder to be driven to perform a boom-up operation.
- an operator manipulates a manipulation lever (not shown) for the swing device to shift a swing spool 6 so that the hydraulic fluid supplied to the arm cylinder from the first hydraulic pump 1 via the swing spool 6 causes the swing device to be driven to swivel the upper swing structure.
- the hydraulic fluid discharged from the first hydraulic pump 1 is supplied to the boom cylinder via the boom spool 5 to drive the boom cylinder and the hydraulic fluid discharged from the first hydraulic pump 1 is distributingly supplied to the boom cylinder and the swing device, respectively, due to a difference in the pressure between the front ends of the boom confluence spool 11 and the swing spool 6 .
- the present invention was made to solve the aforementioned problem occurring in the prior art, and it is an object of the present invention to provide a hydraulic control system for a combined boom and swing operation of a construction machine, in which an operator can easily adjust the driving speeds of the boom and the swing device depending on various kinds of working conditions such as the excavation depth or the height of a dump vehicle during a combined operation in which the boom and the swing device are manipulated to smoothly perform an excavating and loading work.
- Another object of the present invention to provide a hydraulic control system for a combined boom and swing operation of a construction machine, in which in the case where an operator selects a certain work mode needed for the working conditions within an operator cab during the excavating and loading work, the flow rate of the hydraulic fluid distributed to a boom confluence spool and a swing spool is controlled depending on the selected work mode so that the driving speeds of the boom and the swing device can be adjusted under the working conditions needed by the operator.
- a hydraulic control system for a combined boom and swing operation of a construction machine which includes first and second variable displacement hydraulic pumps, an actuator for a swing device and a work apparatus, which is connected to the first hydraulic pump, an actuator for a work apparatus connected to the second hydraulic pump, and a flow rate control valve configured to control a low rate of a hydraulic fluid supplied respectively to the actuators for the swing device and the work apparatus from the first and second hydraulic pumps, the hydraulic control system including:
- a work mode selection switch configured to select a preset work mode according to working conditions
- an electronic proportional pressure control valve mounted in a pilot fluid path that discharges a pilot signal pressure according to a manipulation amount of a boom manipulation lever when the boom manipulation lever is manipulated to perform a boom-up operation, the electronic proportional pressure control valve being configured to output a control signal pressure that is in proportion to the manipulation of the work mode selection switch;
- variable flow rate control valve mounted in a flow path between the first hydraulic pump and a spool for the swing device, the variable flow rate control valve having an opening area variably adjusted in proportion to the control signal pressure of the electronic proportional pressure control valve;
- a controller configured to previously set and store various kinds of work modes according to working conditions to control a flow rate of the hydraulic fluid supplied to the swing device spool and a boom confluence spool according to a work mode selected when the work mode selection switch is manipulated,
- the flow rate of the hydraulic fluid supplied to the swing device spool and the boom confluence spool is variably controlled according to the selected work mode to adjust the driving speeds of the boom and the swing device.
- the electronic proportional pressure control valve is mounted inside the flow rate control valve.
- the electronic proportional pressure control valve is mounted outside the flow rate control valve.
- variable flow rate control valve uses a variable orifice whose opening area is variably adjusted in proportion to the control signal pressure from the electronic proportional pressure control valve.
- the hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention as constructed above has the following advantages.
- An operator can easily adjust the driving speeds of the boom and the swing device depending on various kinds of working conditions such as the excavation depth or the height of a dump vehicle during a combined operation in which the boom and the swing device are manipulated to perform an excavating and loading work, thereby improving workability.
- the driving speeds of the boom and the swing device can be adjusted under the working conditions needed by the operator, thereby improving convenience of the operator.
- FIG. 1 is a block diagram showing the main elements of a hydraulic control system for a combined boom and swing operation of a construction machine in accordance with the prior art
- FIG. 2 is a block diagram showing the main elements of a hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention.
- FIG. 3 is a graph showing the effects of a hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention.
- EPPRV electronic proportional pressure control valve
- a hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention as shown in FIG. 2 includes first and second variable displacement hydraulic pumps, an actuator for a swing device and a work apparatus, which is connected to the first hydraulic pump, an actuator for a work apparatus connected to the second hydraulic pump, and a flow rate control valve configured to control a flow rate of a hydraulic fluid supplied respectively to the actuators for the swing device and the work apparatus from the first and second hydraulic pumps.
- the hydraulic control system includes:
- a work mode selection switch 8 configured to select a preset work mode according to working conditions
- an electronic proportional pressure control valve 9 mounted in a pilot fluid path 7 that discharges a pilot signal pressure according to a manipulation amount of a boom manipulation lever 4 when the boom manipulation lever 4 is manipulated to perform a boom-up operation, the electronic proportional pressure control valve 9 being configured to output a control signal pressure that is in proportion to a the manipulation of the work mode selection switch 8 ;
- variable flow rate control valve 10 mounted in a flow path between the first hydraulic pump 1 and a spool 6 for the swing device, the variable flow rate control valve having an opening area variably adjusted in proportion to the control signal pressure of the electronic proportional pressure control valve 9 ;
- controller configured to previously set and store various kinds of work modes according to working conditions to control a flow rate of the hydraulic fluid supplied to the swing device spool 6 and a boom confluence spool 11 according to a work mode selected when the work mode selection switch 8 is manipulated,
- the flow rate of the hydraulic fluid supplied to the swing device spool 6 and the boom confluence spool 11 is variably controlled according to the selected work mode to adjust the driving speeds of the boom and the swing device.
- the electronic proportional pressure control valve 9 is mounted inside the flow rate control valve (MCV) 3 .
- the electronic proportional pressure control valve 9 may be constructed as an electro proportional pressure reducing valve (EPPRV), and may be mounted inside the flow rate control valve (MCV) 3 .
- EPPRV electro proportional pressure reducing valve
- the electronic proportional pressure control valve 9 is mounted outside the flow rate control valve.
- variable flow rate control valve 10 may use a variable orifice whose opening area is variably adjusted in proportion to the control signal pressure from the electronic proportional pressure control valve 9 .
- a non-explained reference numeral 11 denotes a boom confluence spool that allows the hydraulic fluid of the first hydraulic pump 1 to join the hydraulic fluid of the second hydraulic pump 2 when a boom-up operation is performed.
- the operator manipulates the boom manipulation lever 4 to conduct a boom-up operation and drives the swing device to swivel an upper swing structure in order to perform an excavating and loading work
- the operator manipulates the work mode selection switch 8 to select a certain work mode suitable for various kinds of working conditions such as the height of the ground surface of an excavation work site or the height of a dump vehicle.
- a part of a pilot signal pressure passing by the boom manipulation lever 4 is supplied to a boom spool 5 to shift the boom spool according to the boom-up manipulation of the boom manipulation lever 4 .
- the hydraulic fluid discharged from the second hydraulic pump 2 is supplied to a boom cylinder (not shown) after passing through the boom spool 5 to perform the boom-up operation.
- a part of the pilot signal pressure passing by the boom manipulation lever 4 is supplied to the electronic proportional pressure control valve 9 mounted in the pilot flow path 7 .
- the electronic proportional pressure control valve 9 outputs a pilot signal pressure in proportion to a select signal corresponding to a work mode selected according to the manipulation of the work mode selection switch 8 .
- the signal pressure passing through the electronic proportional pressure control valve 9 is supplied to the variable flow rate control valve 10 so that the opening area of the variable flow rate control valve 10 is controlled. That is, the opening diameter of the variable flow rate control valve 10 is controlled in proportion to the control signal pressure outputted from the electronic proportional pressure control valve 9 depending on the selected work mode.
- the flow rate of the hydraulic fluid discharged from the first hydraulic pump 1 and supplied to the spool 6 for the swing device is reduced to match the selected work mode, and the flow rate of the hydraulic fluid supplied to the boom confluence spool 11 is increased.
- the boom-up operation is performed at a relatively high speed as compared to the swing operation of the upper swing structure so that the loading work can be carried out safely.
- the hydraulic fluid discharged from the first hydraulic pump 1 is supplied to the boom cylinder in proportion to a pilot signal pressure Pi 1 outputted from the electronic proportional pressure control valve 9 to fit the work mode (meaning a line “a” on the graph of FIG. 3 ) selected by the manipulation of the work mode selection switch 8 .
- the hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention, it is possible to adjust the driving speeds of the boom and the swing device depending on various kinds of working conditions such as the excavation depth or the height of a dump vehicle during a combined operation in which boom-up and swing manipulations are carried out to perform an excavating and loading work.
- the driving speeds of the boom and the swing device are adjusted under the working conditions needed by the operator, thereby improving convenience and manipulability.
Abstract
Disclosed is a hydraulic control system for matching the drive speed of a boom up and a swing device according to the operation environment when compound-driving for manipulating boom and swing for excavation compensating error operation. The hydraulic control system of the present invention comprises: an operation mode selection switch for enabling the selection of an operation mode according to the operation environment; an electronic proportional pressure control valve for outputting a control signal pressure that is proportional to the manipulation of the operation mode selection switch when manipulating a boom operation lever for driving the boom up; a variable flow control valve that is placed on a flow channel between a first hydraulic pump and a spool for the swing device, and has an open area thereof that is variably matched proportional to the control signal pressure from the electronic proportional pressure control valve; and a controller having various types of operation modes previously set and stored thereon so as to control the flow being supplied to the spool for the swing device and a spool for the boom merge, according to the operation mode selected when manipulating the operation mode selection switch.
Description
- The present invention relates to a hydraulic control system for a combined boom and swing operation of a construction machine such as an excavator. More particularly, the present invention relates to a hydraulic system for a construction machine, in which the driving speeds of the boom and the swing device are adjusted according to working conditions during a combined operation in which boom-up and swing manipulations are carried out to perform an excavating and loading work, thereby ensuring a smooth work.
- A conventional hydraulic control system for a combined boom and swing operation of a construction machine in accordance with the prior art as shown in
FIG. 1 includes: - first and second variable displacement hydraulic pumps (hereinafter, referred to as “first and second hydraulic pumps”) 1 and 2 connected to an engine (not shown);
- an actuator (referring to “arm cylinder”) for a swing device and a work apparatus, which is connected to the first
hydraulic pump 1; - an actuator for a work apparatus (referring to “boom cylinder”) connected to the second
hydraulic pump 2; and - a flow rate control valve (MCV) 3 configured to control a flow rate of a hydraulic fluid supplied respectively to the actuators for the swing device and the work apparatus from the first and second
hydraulic pumps - In
FIG. 1 , a non-explainedreference numeral 11 denotes a boom confluence spool that allows the hydraulic fluid discharged from the firsthydraulic pump 1 to join the hydraulic fluid discharged from the secondhydraulic pump 2 when a boom-up operation is performed. - Thus, an operator manipulates a
boom manipulation lever 4 to shift aboom spool 5 and aboom confluence spool 11 so that the hydraulic fluid supplied to the boom cylinder via theboom spool 5 from the secondhydraulic pump 2 and the hydraulic fluid supplied to the boom cylinder from the firsthydraulic pump 1 via theboom confluence spool 11 join each other to cause the boom cylinder to be driven to perform a boom-up operation. - On the other hand, an operator manipulates a manipulation lever (not shown) for the swing device to shift a swing spool 6 so that the hydraulic fluid supplied to the arm cylinder from the first
hydraulic pump 1 via the swing spool 6 causes the swing device to be driven to swivel the upper swing structure. - During a combined operation in which the boom and the swing device are operated to perform an excavating and loading work, the hydraulic fluid discharged from the first
hydraulic pump 1 is supplied to the boom cylinder via theboom spool 5 to drive the boom cylinder and the hydraulic fluid discharged from the firsthydraulic pump 1 is distributingly supplied to the boom cylinder and the swing device, respectively, due to a difference in the pressure between the front ends of theboom confluence spool 11 and the swing spool 6. - Meanwhile, in the case where the excavating and loading work is performed, there is required an adjustment of the driving speeds of the boom and the swing device depending on various kinds of working conditions such as the excavation depth or the height of a dump vehicle. That is, the distributed flow rate of the hydraulic fluid supplied to the
boom confluence spool 11 and the swing spool 6 from the firsthydraulic pump 1 needs to be controlled. - In the conventional hydraulic control system, since the flow rate of the hydraulic fluid distributingly supplied to the supplied to the
boom confluence spool 11 and the swing spool 6 from the firsthydraulic pump 1 is fixed to a constant level, the driving speeds of the boom and the swing device are inevitably adjusted to conform to only one kind of working condition. Thus, such a conventional hydraulic control system entails a problem in that an operator must perform a combined operation of the manipulation levers for the boom and the swing device based on the operator's manipulation experience in order to attain the smooth matching of the work apparatus (i.e., attachment of the upper swing structure), thereby resulting in a deterioration of manipulability and workability. - Accordingly, the present invention was made to solve the aforementioned problem occurring in the prior art, and it is an object of the present invention to provide a hydraulic control system for a combined boom and swing operation of a construction machine, in which an operator can easily adjust the driving speeds of the boom and the swing device depending on various kinds of working conditions such as the excavation depth or the height of a dump vehicle during a combined operation in which the boom and the swing device are manipulated to smoothly perform an excavating and loading work.
- Another object of the present invention to provide a hydraulic control system for a combined boom and swing operation of a construction machine, in which in the case where an operator selects a certain work mode needed for the working conditions within an operator cab during the excavating and loading work, the flow rate of the hydraulic fluid distributed to a boom confluence spool and a swing spool is controlled depending on the selected work mode so that the driving speeds of the boom and the swing device can be adjusted under the working conditions needed by the operator.
- To accomplish the above object, in accordance with an embodiment of the present invention, there is provided a hydraulic control system for a combined boom and swing operation of a construction machine, which includes first and second variable displacement hydraulic pumps, an actuator for a swing device and a work apparatus, which is connected to the first hydraulic pump, an actuator for a work apparatus connected to the second hydraulic pump, and a flow rate control valve configured to control a low rate of a hydraulic fluid supplied respectively to the actuators for the swing device and the work apparatus from the first and second hydraulic pumps, the hydraulic control system including:
- a work mode selection switch configured to select a preset work mode according to working conditions;
- an electronic proportional pressure control valve mounted in a pilot fluid path that discharges a pilot signal pressure according to a manipulation amount of a boom manipulation lever when the boom manipulation lever is manipulated to perform a boom-up operation, the electronic proportional pressure control valve being configured to output a control signal pressure that is in proportion to the manipulation of the work mode selection switch;
- a variable flow rate control valve mounted in a flow path between the first hydraulic pump and a spool for the swing device, the variable flow rate control valve having an opening area variably adjusted in proportion to the control signal pressure of the electronic proportional pressure control valve; and
- a controller configured to previously set and store various kinds of work modes according to working conditions to control a flow rate of the hydraulic fluid supplied to the swing device spool and a boom confluence spool according to a work mode selected when the work mode selection switch is manipulated,
- wherein in the case where an operator selects a certain work mode according to the working conditions during a combined operation in which boom-up and swing manipulations are carried out, the flow rate of the hydraulic fluid supplied to the swing device spool and the boom confluence spool is variably controlled according to the selected work mode to adjust the driving speeds of the boom and the swing device.
- According to a more preferable embodiment, the electronic proportional pressure control valve is mounted inside the flow rate control valve.
- The electronic proportional pressure control valve is mounted outside the flow rate control valve.
- The variable flow rate control valve uses a variable orifice whose opening area is variably adjusted in proportion to the control signal pressure from the electronic proportional pressure control valve.
- The hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention as constructed above has the following advantages.
- An operator can easily adjust the driving speeds of the boom and the swing device depending on various kinds of working conditions such as the excavation depth or the height of a dump vehicle during a combined operation in which the boom and the swing device are manipulated to perform an excavating and loading work, thereby improving workability.
- In the case where an operator selects a certain work mode needed for the working conditions within an operator cab during the excavating and loading work, the driving speeds of the boom and the swing device can be adjusted under the working conditions needed by the operator, thereby improving convenience of the operator.
- The above objects, other features and advantages of the present invention will become more apparent by describing the preferred embodiments thereof with reference to the accompanying drawings, in which:
-
FIG. 1 is a block diagram showing the main elements of a hydraulic control system for a combined boom and swing operation of a construction machine in accordance with the prior art; -
FIG. 2 is a block diagram showing the main elements of a hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention; and -
FIG. 3 is a graph showing the effects of a hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention. - Explanation on reference numerals of main elements in the drawings
- 1: first variable displacement hydraulic pump
- 2: second variable displacement hydraulic pump
- 3: flow rate control valve (MCV)
- 4: boom manipulation lever:
- 5: boom spool
- 6: spool for the swing device (i.e., swing spool)
- 7: pilot flow path
- 8: work mode selection switch
- 9: electronic proportional pressure control valve (EPPRV)
- 10: variable flow rate control valve
- 11: boom confluence spool
- Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The matters defined in the description, such as the detailed construction and elements, are nothing but specific details provided to assist those of ordinary skill in the art in a comprehensive understanding of the invention, and the present invention is not limited to the embodiments disclosed hereinafter.
- A hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention as shown in
FIG. 2 includes first and second variable displacement hydraulic pumps, an actuator for a swing device and a work apparatus, which is connected to the first hydraulic pump, an actuator for a work apparatus connected to the second hydraulic pump, and a flow rate control valve configured to control a flow rate of a hydraulic fluid supplied respectively to the actuators for the swing device and the work apparatus from the first and second hydraulic pumps. - The hydraulic control system includes:
- a work
mode selection switch 8 configured to select a preset work mode according to working conditions; - an electronic proportional pressure control valve 9 mounted in a
pilot fluid path 7 that discharges a pilot signal pressure according to a manipulation amount of aboom manipulation lever 4 when theboom manipulation lever 4 is manipulated to perform a boom-up operation, the electronic proportional pressure control valve 9 being configured to output a control signal pressure that is in proportion to a the manipulation of the workmode selection switch 8; - a variable flow
rate control valve 10 mounted in a flow path between the firsthydraulic pump 1 and a spool 6 for the swing device, the variable flow rate control valve having an opening area variably adjusted in proportion to the control signal pressure of the electronic proportional pressure control valve 9; and - a controller (not shown) configured to previously set and store various kinds of work modes according to working conditions to control a flow rate of the hydraulic fluid supplied to the swing device spool 6 and a
boom confluence spool 11 according to a work mode selected when the workmode selection switch 8 is manipulated, - wherein in the case where an operator selects a certain work mode according to the working conditions during a combined operation in which boom-up and swing manipulations are carried out to perform an excavating and loading work, the flow rate of the hydraulic fluid supplied to the swing device spool 6 and the
boom confluence spool 11 is variably controlled according to the selected work mode to adjust the driving speeds of the boom and the swing device. - Herein, the electronic proportional pressure control valve 9 is mounted inside the flow rate control valve (MCV) 3. The electronic proportional pressure control valve 9 may be constructed as an electro proportional pressure reducing valve (EPPRV), and may be mounted inside the flow rate control valve (MCV) 3.
- The electronic proportional pressure control valve 9 is mounted outside the flow rate control valve.
- The variable flow
rate control valve 10 may use a variable orifice whose opening area is variably adjusted in proportion to the control signal pressure from the electronic proportional pressure control valve 9. - In
FIG. 2 , anon-explained reference numeral 11 denotes a boom confluence spool that allows the hydraulic fluid of the firsthydraulic pump 1 to join the hydraulic fluid of the secondhydraulic pump 2 when a boom-up operation is performed. - Hereinafter, a use example of the hydraulic control system for a combined boom and swing operation of a construction machine in accordance with the present invention will be described in detail with reference to the companying drawings.
- As shown in
FIGS. 2 and 3 , in the case where an operator within an operator cab manipulates theboom manipulation lever 4 to conduct a boom-up operation and drives the swing device to swivel an upper swing structure in order to perform an excavating and loading work, the operator manipulates the workmode selection switch 8 to select a certain work mode suitable for various kinds of working conditions such as the height of the ground surface of an excavation work site or the height of a dump vehicle. - A part of a pilot signal pressure passing by the
boom manipulation lever 4 is supplied to aboom spool 5 to shift the boom spool according to the boom-up manipulation of theboom manipulation lever 4. Thus, the hydraulic fluid discharged from the secondhydraulic pump 2 is supplied to a boom cylinder (not shown) after passing through theboom spool 5 to perform the boom-up operation. - On the other hand, a part of the pilot signal pressure passing by the
boom manipulation lever 4 is supplied to the electronic proportional pressure control valve 9 mounted in thepilot flow path 7. At this time, the electronic proportional pressure control valve 9 outputs a pilot signal pressure in proportion to a select signal corresponding to a work mode selected according to the manipulation of the workmode selection switch 8. - By virtue of this operation, the signal pressure passing through the electronic proportional pressure control valve 9 is supplied to the variable flow
rate control valve 10 so that the opening area of the variable flowrate control valve 10 is controlled. That is, the opening diameter of the variable flowrate control valve 10 is controlled in proportion to the control signal pressure outputted from the electronic proportional pressure control valve 9 depending on the selected work mode. - Therefore, the flow rate of the hydraulic fluid discharged from the first
hydraulic pump 1 and supplied to the spool 6 for the swing device is reduced to match the selected work mode, and the flow rate of the hydraulic fluid supplied to theboom confluence spool 11 is increased. In other words, since the flow rate of the hydraulic fluid supplied to theboom confluence spool 11 from the firsthydraulic pump 1 is increased, the boom-up operation is performed at a relatively high speed as compared to the swing operation of the upper swing structure so that the loading work can be carried out safely. - For this reason, in the case where the manipulation lever of the boom-up device and the swing device is manipulated at a full stroke to perform a combined operation, the matching between the boom-up operation and the swing operation is accomplished so that the operator can conveniently perform the excavating and loading work in a desired direction.
- As shown in
FIG. 3 , it can be seen that the hydraulic fluid discharged from the firsthydraulic pump 1 is supplied to the boom cylinder in proportion to a pilot signal pressure Pi1 outputted from the electronic proportional pressure control valve 9 to fit the work mode (meaning a line “a” on the graph ofFIG. 3 ) selected by the manipulation of the workmode selection switch 8. - While the present invention has been described in connection with the specific embodiments illustrated in the drawings, they are merely illustrative, and the invention is not limited to these embodiments. It is to be understood that various equivalent modifications and variations of the embodiments can be made by a person having an ordinary skill in the art without departing from the spirit and scope of the present invention. Therefore, the true technical scope of the present invention should not be defined by the above-mentioned embodiments but should be defined by the appended claims and equivalents thereof.
- As described above, in the hydraulic control system for a combined boom and swing operation of a construction machine in accordance with an embodiment of the present invention, it is possible to adjust the driving speeds of the boom and the swing device depending on various kinds of working conditions such as the excavation depth or the height of a dump vehicle during a combined operation in which boom-up and swing manipulations are carried out to perform an excavating and loading work. In addition, in the case where an operator selects a certain work mode needed for the working conditions within an operator cab during the excavating and loading work, the driving speeds of the boom and the swing device are adjusted under the working conditions needed by the operator, thereby improving convenience and manipulability.
Claims (4)
1. A hydraulic control system for a combined boom and swing operation of a construction machine, which includes first and second variable displacement hydraulic pumps, an actuator for a swing device and a work apparatus, which is connected to the first hydraulic pump, an actuator for a work apparatus connected to the second hydraulic pump, and a flow rate control valve configured to control a flow rate of a hydraulic fluid supplied respectively to the actuators for the swing device and the work apparatus from the first and second hydraulic pumps, the hydraulic control system comprising:
a work mode selection switch configured to select a preset work mode according to working conditions;
an electronic proportional pressure control valve mounted in a pilot fluid path that discharges a pilot signal pressure according to a manipulation amount of a boom manipulation lever when the boom manipulation lever is manipulated to perform a boom-up operation, the electronic proportional pressure control valve being configured to output a control signal pressure that is in proportion to the manipulation of the work mode selection switch;
a variable flow rate control valve mounted in a flow path between the first hydraulic pump and a spool for the swing device, the variable flow rate control valve having an opening area variably adjusted in proportion to the control signal pressure of the electronic proportional pressure control valve; and
a controller configured to previously set and store various kinds of work modes according to working conditions to control a flow rate of the hydraulic fluid supplied to the swing device spool and a boom confluence spool according to a work mode selected when the work mode selection switch is manipulated,
wherein in the case where an operator selects a certain work mode according to the working conditions during a combined operation in which boom-up and swing manipulations are carried out, the flow rate of the hydraulic fluid supplied to the swing device spool and the boom confluence spool is variably controlled according to the selected work mode to adjust the driving speeds of the boom and the swing device.
2. The hydraulic control system according to claim 1 , wherein the electronic proportional pressure control valve is mounted inside the flow rate control valve.
3. The hydraulic control system according to claim 1 , wherein the electronic proportional pressure control valve is mounted outside the flow rate control valve.
4. The hydraulic control system according to claim 1 , wherein the variable flow rate control valve uses a variable orifice whose opening area is variably adjusted in proportion to the control signal pressure from the electronic proportional pressure control valve.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/KR2010/009361 WO2012091187A1 (en) | 2010-12-27 | 2010-12-27 | Boom-swivel compound drive hydraulic control system of construction machine |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130291530A1 true US20130291530A1 (en) | 2013-11-07 |
Family
ID=46383250
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/996,818 Abandoned US20130291530A1 (en) | 2010-12-27 | 2010-12-27 | Boom-swivel compound drive hydraulic control system of construction machine |
Country Status (6)
Country | Link |
---|---|
US (1) | US20130291530A1 (en) |
EP (1) | EP2660478B1 (en) |
JP (1) | JP2014505810A (en) |
KR (1) | KR20130137192A (en) |
CN (1) | CN103299089B (en) |
WO (1) | WO2012091187A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
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WO2016111393A1 (en) * | 2015-01-08 | 2016-07-14 | 볼보 컨스트럭션 이큅먼트 에이비 | Drive control method of hydraulic actuator of construction machine |
US20160251833A1 (en) * | 2013-10-31 | 2016-09-01 | Kawasaki Jukogyo Kabushiki Kaisha | Hydraulic drive system of construction machine |
US9926135B2 (en) * | 2012-10-09 | 2018-03-27 | The Heil Co. | Externally controlled switch mechanism |
US10968604B2 (en) | 2017-05-09 | 2021-04-06 | Hitachi Construction Machinery Co., Ltd. | Work machine |
US11286962B2 (en) * | 2017-09-29 | 2022-03-29 | Volvo Construction Equipment Ab | Flow control valve and hydraulic machine including the same |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
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BR112015002813A2 (en) * | 2012-08-27 | 2017-07-04 | Volvo Constr Equip Ab | hydraulic system for a construction machine |
CN103015473A (en) * | 2012-12-10 | 2013-04-03 | 三一重机有限公司 | Priority control method of excavator and movable arm to rotation and priority valve |
KR102131447B1 (en) | 2013-11-12 | 2020-07-08 | 현대모비스 주식회사 | Airvent of vehicle |
JP6400220B2 (en) * | 2016-03-11 | 2018-10-03 | 日立建機株式会社 | Construction machine control equipment |
EP3704311B1 (en) * | 2017-11-01 | 2024-05-01 | Doosan Bobcat North America, Inc. | Control system for power machine |
DE102019201182A1 (en) * | 2019-01-30 | 2020-07-30 | Putzmeister Engineering Gmbh | vehicle |
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- 2010-12-27 JP JP2013547272A patent/JP2014505810A/en active Pending
- 2010-12-27 CN CN201080071033.5A patent/CN103299089B/en not_active Expired - Fee Related
- 2010-12-27 WO PCT/KR2010/009361 patent/WO2012091187A1/en active Application Filing
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Also Published As
Publication number | Publication date |
---|---|
EP2660478A1 (en) | 2013-11-06 |
CN103299089A (en) | 2013-09-11 |
WO2012091187A1 (en) | 2012-07-05 |
KR20130137192A (en) | 2013-12-16 |
CN103299089B (en) | 2016-08-10 |
JP2014505810A (en) | 2014-03-06 |
EP2660478A4 (en) | 2014-08-20 |
EP2660478B1 (en) | 2017-03-15 |
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Owner name: VOLVO CONSTRUCTION EQUIPMENT AB, SWEDEN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BANG, SANG-HO;ROH, BYUNG-UK;REEL/FRAME:030678/0169 Effective date: 20130620 |
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