EP2615311A1 - Flow rate control device for variable displacement type hydraulic pump for construction equipment - Google Patents
Flow rate control device for variable displacement type hydraulic pump for construction equipment Download PDFInfo
- Publication number
- EP2615311A1 EP2615311A1 EP10857020.1A EP10857020A EP2615311A1 EP 2615311 A1 EP2615311 A1 EP 2615311A1 EP 10857020 A EP10857020 A EP 10857020A EP 2615311 A1 EP2615311 A1 EP 2615311A1
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- EP
- European Patent Office
- Prior art keywords
- flow rate
- hydraulic pump
- manipulation
- control device
- actuators
- Prior art date
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- 238000006073 displacement reaction Methods 0.000 title claims abstract description 23
- 238000010276 construction Methods 0.000 title claims abstract description 22
- 238000001514 detection method Methods 0.000 claims description 19
- 239000000446 fuel Substances 0.000 abstract description 7
- 238000000034 method Methods 0.000 description 11
- 239000012530 fluid Substances 0.000 description 8
- 230000006866 deterioration Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 206010027336 Menstruation delayed Diseases 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
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Classifications
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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
- F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
- F15B13/043—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves
- F15B13/0433—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves the pilot valves being pressure control valves
-
- 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
- E02F9/2232—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps
- E02F9/2235—Control of flow rate; Load sensing arrangements using one or more variable displacement pumps including an electronic controller
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2278—Hydraulic circuits
- E02F9/2282—Systems using center bypass type changeover valves
-
- 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
- E02F9/2285—Pilot-operated systems
-
- 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
-
- 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
- F15B13/021—Valves for interconnecting the fluid chambers of an actuator
-
- 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
- F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
- F15B9/02—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type
- F15B9/04—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by varying the output of a pump with variable capacity
-
- 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
-
- 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
- F15B2211/255—Flow control functions
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
- F15B2211/6346—Electronic controllers using input signals representing a state of input means, e.g. joystick position
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/80—Other types of control related to particular problems or conditions
- F15B2211/88—Control measures for saving energy
Definitions
- the present invention relates to a flow rate control apparatus of a variable displacement hydraulic pump for a construction machine including an excavator. More particularly, the present invention relates to an improved flow rate control apparatus of a variable displacement hydraulic pump for a construction machine, in which an opening area of a hydraulic pump is controlled to be large by a controller that pre-determines a flow rate required by a plurality of actuators during a combined operation of work apparatuses for a construction machine so that a pressure loss of the hydraulic pump can be reduced and fuel efficiency can be improved, and in which during a combined operation, a hydraulic pump discharges a relatively small amount of hydraulic fluid in comparison to a manipulation amount of respective work apparatuses to make wide a manipulation period range of a manipulation device.
- a construction machine including an excavator or a hydraulic shovel is provided with a hydraulic circuit configured so that a work apparatus including a boom, an arm, a bucket and a swing motor is driven by the pressure of a hydraulic fluid discharged from a hydraulic pump.
- a hydraulic excavator 1 includes a crawler-type lower traveling structure 2, an upper swing structure 3 swingably supported on the lower traveling structure 2, and a work apparatus mounted on the upper swing structure 3.
- the work apparatus generally includes a boom 5 configured so that its base is ascendably and descendably supported on the upper swing structure 3, an arm 6 provided at an end of the boom 5, a bucket 7 mounted at a front end of the boom 5, and a swing motor (not shown) configured to provide power during the swing operation of the upper swing structure 3.
- one variable displacement hydraulic pump is frequently used to supply a hydraulic pressure to the work apparatus, and the sum of the required flow rates spent by the actuators for work apparatuses during a combined operation in which a plurality of actuators 14 is controlled by a manipulation device including a manipulation lever or a joystick is controlled to be a discharge flow rate of the hydraulic pump.
- the first actuator is a boom actuator 14a
- the second actuator is a bucket actuator 14c
- the third actuator is swing motor (not shown).
- a work apparatus can be additionally provided to the hydraulic construction machine.
- the control method of the discharge flow rate of the conventional hydraulic pump using the above-mentioned equation entails a problem in that a relatively large amount of hydraulic fluid is discharged from an opening area of a pump flow path, leading to a great increase in a pressure loss, which influences the fuel efficiency and thus increases fuel consumption.
- Korean Patent Laid-Open Publication No. 2001-0033699 discloses a flow rate control apparatus for allowing an output flow rate of the hydraulic pump to be controlled to be a distributed flow rate that is preset in each hydraulic actuator in view of a problem involved in a flow rate control apparatus for a hydraulic shovel in that manipulability is deteriorated during a combined operation.
- the flow rate control apparatus calculates the sum of the absolute values of the required flow rates of the hydraulic actuators to obtain the required flow rates of the hydraulic actuators, and uses the calculated sum of the absolute values in a control method of the pump required flow rate.
- the sum of the required flow rates of the hydraulic actuators from exceeding the maximum discharge flow rate of the hydraulic pump and control the sum of the required flow rates of the hydraulic actuators to be a distributed flow rate according to actuators for work apparatuses during the combined operation.
- Such a flow rate control method using the sum of the absolute values of the required flow rates of the hydraulic actuators can also avoid a shortcoming in that the distributed flow rate is larger than the required flow rate needed by the manipulation of a manipulation device such as a manipulation lever or a joystick.
- this flow rate control method still does not suggest a solution to problems in that a pressure loss occurs during the combined operation and in that during the combined operation, the maximum discharge flow rate of the hydraulic pump is reached rapidly and thus the control range of the discharge flow rate of the hydraulic pump by the manipulation device is narrowed, resulting in a deterioration of manipulability.
- 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 flow rate control apparatus of a variable displacement hydraulic pump for a construction machine, in which the discharge flow rate of a hydraulic pump is controlled to show an effect of making wide an opening area of the hydraulic pump according to the matching condition of the actuators for work apparatuses, thereby reducing a pressure loss and improving fuel efficiency.
- a flow rate control apparatus of a variable displacement hydraulic pump for a construction machine including: an engine; at least one variable displacement hydraulic pump having a swash plate control device for controlling an opening area thereof and configured to be pumped by the engine to provide hydraulic pressure; a plurality of actuators for work apparatuses including a boom actuator or an arm actuator, a bucket actuator, and a swing motor; a work apparatus control valve connected and installed between the hydraulic pump and the actuators for work apparatuses, and configured to control the hydraulic pressure discharged from the hydraulic pump to perform a start, a stop, and a swing operation of the actuators for the work apparatuses and the swing motor during the spool shift; a manipulation amount detection means configured to detect a manipulation amount of a manipulation device to drive the actuators for work apparatuses; and a flow rate controller connected to the manipulation amount detection means and the swash plate control device, and configured to receive a work apparatus manipulation signal of the manipulation device, which is detected by the manipulation amount detection
- the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine has an advantage in that it controls an opening area of the hydraulic pump based on the calculated the square root of the sum of squares of the required flow rates to drive the respective actuators for work apparatuses, so that the plurality of actuators for work apparatuses can be simultaneously manipulated or the opening area of the hydraulic pump, which is relatively large as compared to the prior art, can be secured during a combined operation (this means that the discharge flow rate of hydraulic pump is relatively small), thereby reducing a pressure loss of the hydraulic pump and improving the operation efficiency and fuel efficiency.
- the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine has another advantage in that the hydraulic pump discharges a relatively small amount of hydraulic fluid in the same period range in comparison with the prior art in the manipulation of the manipulation device and the control of the discharge flow rate of the hydraulic pump according to the manipulation of the manipulation device to perform a combined operation, and the manipulation period range of the manipulation device is made relatively wide so that manipulability of the equipment can be improved.
- the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine includes:
- the flow rate controller 18 pre-determines the required flow rates of the respective actuators 15 for work apparatuses through the work apparatus manipulation signal during a combined operation, and then controls the swash plate control device 11 by calculating the square root of the sum of squares of the respective required flow rates to determine the discharge flow rate of the hydraulic pump 12.
- manipulation amount detection means 17 is constructed as a pilot pressure detection sensor, and the swash plate control device 11 is constructed as an electro proportional pressure reducing valve.
- the hydraulic excavator 1 includes a crawler-type lower traveling structure 2, an upper swing structure 3 swingably supported on the lower traveling structure 2, and a work apparatus mounted on the upper swing structure 3.
- the work apparatus generally includes a boom 5 configured so that its base is ascendably and descendably supported on the upper swing structure 3, an arm 6 provided at an end of the boom 5, a bucket 7 mounted at a front end of the boom 5, and a swing motor (not shown) configured to provide power during the swing operation of the upper swing structure 3 as in the prior art.
- the boom 5, the arm 6 and the bucket 7 are operated by respective actuators 14 that are expanded and contacted by hydraulic pressure.
- the manipulation amount of a work apparatus manipulation signal including a pilot pressure or an electric signal is detected by the manipulation amount detection means 17.
- the flow rate controller 18 is connected to the manipulation amount detection means 17 and the swash plate control device 11, and receives a work apparatus manipulation signal of the manipulation device 16, which is detected by the manipulation amount detection means 17 and controls a discharge flow rate of the hydraulic pump 12.
- the flow rate controller 18 pre-determines the required flow rates of the respective actuators 15 for work apparatuses through the work apparatus manipulation signal during a combined operation, and then controls the swash plate control device 11 by calculating the square root of the sum of squares of the respective required flow rates to determine the discharge flow rate of the hydraulic pump 12.
- the manipulation device 16 is installed at a pilot pump 13, and the manipulation amount of the manipulation device 16 is detected by a pilot pressure detection sensor of the manipulation amount detection means 17.
- the discharge flow rate of the hydraulic pump 12 is determined by performing a step S100 of detecting the manipulation amount of the manipulation device 16 to calculate the required flow rates of the respective actuators 14, a step S200 of calculating the square root of the sum of squares of the required flow rates of the respective actuators 14 calculated in the step S100, and a step S300 of outputting a control signal corresponding to a result determined at the step S200 to control the swash plate control device 11.
- the flow rate controller 18 merely does not calculate the sum of the required flow rates of the respective actuators 14 for work apparatuses when a hydraulic pump discharge flow rate is set unlike the conventional flow rate control method. Instead, the flow rate controller 18 calculates the square root of the sum of squares of the respective required flow rates of the actuators 14 for work apparatuses according to a work apparatus manipulation signal of the manipulation device 16 detected by the manipulation amount detection means 17 and determines the calculated square root value to be the discharge flow rate of the hydraulic pump 12.
- the flow rate controller 18 controls the discharge flow rate of the hydraulic pump by calculating the square root of the sum of squares of the required flow rates of the actuators for work apparatuses as defined above and using an output signal of the swash plate control device 11 corresponding to a result of the calculation.
- the discharge flow rate control characteristic line B of the hydraulic pump 12 according to the present invention has a relatively small gradient and shows a relatively long delay period to reach the maximum flow rate in comparison with the discharge flow rate control characteristic line A of the hydraulic pump 12 according to the prior art.
- the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine has the characteristics that when two or more actuators 14 are manipulated simultaneously or a combined operation is performed, the opening area of the hydraulic pump is controlled such that the hydraulic pump discharges a relatively small amount of hydraulic fluid in comparison to the prior art.
- a relatively large opening area can be secured with respect to the same discharge flow rate of the hydraulic pump 12, and thus a pressure loss can be greatly reduced as well as the operation efficiency of the hydraulic pump 12 and the fuel efficiency can be improved.
- the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine has the characteristics that when the manipulation amount of the manipulation device 16 is maintained constantly during a combined operation, the hydraulic pump 12 discharges a relatively small amount of hydraulic fluid in comparison to the prior art and a relatively large manipulation amount as compared to the prior art is required to discharge the same amount of hydraulic fluid as that in the prior art in terms of the control of the manipulation device 16.
- the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine provides an operator with a relatively wide manipulation period range as compared to the prior art in the manipulation of the manipulation device 16 including a manipulation lever or a joystick so that manipulability can be maintained smoothly and stably.
- the present invention is very useful in a the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine, in which the hydraulic pump discharges a relatively small amount of hydraulic fluid in the same period range in comparison with the prior art in the manipulation of the manipulation device and the control of the discharge flow rate of the hydraulic pump according to the manipulation of the manipulation device to perform a combined operation, and the manipulation period range of the manipulation device is made relatively wide so that manipulability can be improved and a pressure loss of the hydraulic pump can be reduced.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Civil Engineering (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Fluid-Pressure Circuits (AREA)
- Operation Control Of Excavators (AREA)
- Control Of Positive-Displacement Pumps (AREA)
Abstract
Description
- The present invention relates to a flow rate control apparatus of a variable displacement hydraulic pump for a construction machine including an excavator. More particularly, the present invention relates to an improved flow rate control apparatus of a variable displacement hydraulic pump for a construction machine, in which an opening area of a hydraulic pump is controlled to be large by a controller that pre-determines a flow rate required by a plurality of actuators during a combined operation of work apparatuses for a construction machine so that a pressure loss of the hydraulic pump can be reduced and fuel efficiency can be improved, and in which during a combined operation, a hydraulic pump discharges a relatively small amount of hydraulic fluid in comparison to a manipulation amount of respective work apparatuses to make wide a manipulation period range of a manipulation device.
- A construction machine including an excavator or a hydraulic shovel is provided with a hydraulic circuit configured so that a work apparatus including a boom, an arm, a bucket and a swing motor is driven by the pressure of a hydraulic fluid discharged from a hydraulic pump.
- Referring to
Fig. 1 , ahydraulic excavator 1 includes a crawler-type lower traveling structure 2, an upper swing structure 3 swingably supported on the lower traveling structure 2, and a work apparatus mounted on the upper swing structure 3. The work apparatus generally includes aboom 5 configured so that its base is ascendably and descendably supported on the upper swing structure 3, anarm 6 provided at an end of theboom 5, a bucket 7 mounted at a front end of theboom 5, and a swing motor (not shown) configured to provide power during the swing operation of the upper swing structure 3. - Depending on a specification of the equipment, one variable displacement hydraulic pump is frequently used to supply a hydraulic pressure to the work apparatus, and the sum of the required flow rates spent by the actuators for work apparatuses during a combined operation in which a plurality of
actuators 14 is controlled by a manipulation device including a manipulation lever or a joystick is controlled to be a discharge flow rate of the hydraulic pump. -
- In the above equation, it can be understood that the first actuator is a
boom actuator 14a, the second actuator is abucket actuator 14c, and the third actuator is swing motor (not shown). It is of course to be noted that a work apparatus can be additionally provided to the hydraulic construction machine. - The control method of the discharge flow rate of the conventional hydraulic pump using the above-mentioned equation entails a problem in that a relatively large amount of hydraulic fluid is discharged from an opening area of a pump flow path, leading to a great increase in a pressure loss, which influences the fuel efficiency and thus increases fuel consumption.
- In addition, during the combined operation, the maximum discharge flow rate of the hydraulic pump is reached rapidly and thus the control range of the discharge flow rate of the hydraulic pump according to a pilot pressure of the manipulation device is narrowed, resulting in a deterioration of manipulability.
- Meanwhile, Korean Patent Laid-Open Publication No.
2001-0033699 - During the combined operation, the flow rate control apparatus calculates the sum of the absolute values of the required flow rates of the hydraulic actuators to obtain the required flow rates of the hydraulic actuators, and uses the calculated sum of the absolute values in a control method of the pump required flow rate. Thus, it is possible to prevent the sum of the required flow rates of the hydraulic actuators from exceeding the maximum discharge flow rate of the hydraulic pump and control the sum of the required flow rates of the hydraulic actuators to be a distributed flow rate according to actuators for work apparatuses during the combined operation.
- Such a flow rate control method using the sum of the absolute values of the required flow rates of the hydraulic actuators can also avoid a shortcoming in that the distributed flow rate is larger than the required flow rate needed by the manipulation of a manipulation device such as a manipulation lever or a joystick. However, this flow rate control method still does not suggest a solution to problems in that a pressure loss occurs during the combined operation and in that during the combined operation, the maximum discharge flow rate of the hydraulic pump is reached rapidly and thus the control range of the discharge flow rate of the hydraulic pump by the manipulation device is narrowed, resulting in a deterioration of manipulability.
- 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 flow rate control apparatus of a variable displacement hydraulic pump for a construction machine, in which the discharge flow rate of a hydraulic pump is controlled to show an effect of making wide an opening area of the hydraulic pump according to the matching condition of the actuators for work apparatuses, thereby reducing a pressure loss and improving fuel efficiency.
- To accomplish the above object, in accordance with the present invention, there is provided a flow rate control apparatus of a variable displacement hydraulic pump for a construction machine including: an engine; at least one variable displacement hydraulic pump having a swash plate control device for controlling an opening area thereof and configured to be pumped by the engine to provide hydraulic pressure; a plurality of actuators for work apparatuses including a boom actuator or an arm actuator, a bucket actuator, and a swing motor; a work apparatus control valve connected and installed between the hydraulic pump and the actuators for work apparatuses, and configured to control the hydraulic pressure discharged from the hydraulic pump to perform a start, a stop, and a swing operation of the actuators for the work apparatuses and the swing motor during the spool shift; a manipulation amount detection means configured to detect a manipulation amount of a manipulation device to drive the actuators for work apparatuses; and a flow rate controller connected to the manipulation amount detection means and the swash plate control device, and configured to receive a work apparatus manipulation signal of the manipulation device, which is detected by the manipulation amount detection means and to control a discharge flow rate of the hydraulic pump, wherein the flow rate controller pre-determines the required flow rates of the respective actuators for work apparatuses through the work apparatus manipulation signal during a combined operation, and then controls the swash plate control device by calculating the square root of the sum of squares of the respective required flow rates to determine the discharge flow rate of the hydraulic pump.
- The flow rate control apparatus of a variable displacement hydraulic pump for a construction machine according to the present invention has an advantage in that it controls an opening area of the hydraulic pump based on the calculated the square root of the sum of squares of the required flow rates to drive the respective actuators for work apparatuses, so that the plurality of actuators for work apparatuses can be simultaneously manipulated or the opening area of the hydraulic pump, which is relatively large as compared to the prior art, can be secured during a combined operation (this means that the discharge flow rate of hydraulic pump is relatively small), thereby reducing a pressure loss of the hydraulic pump and improving the operation efficiency and fuel efficiency.
- In addition, the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine according to the present invention has another advantage in that the hydraulic pump discharges a relatively small amount of hydraulic fluid in the same period range in comparison with the prior art in the manipulation of the manipulation device and the control of the discharge flow rate of the hydraulic pump according to the manipulation of the manipulation device to perform a combined operation, and the manipulation period range of the manipulation device is made relatively wide so that manipulability of the equipment can be improved.
- 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 schematic perspective view showing an excavator for a construction machine according to the prior art; -
Fig. 2 is a flow chart for controlling the discharge flow rate of a hydraulic pump according to the prior art; -
Fig. 3 is a block diagram schematically showing the construction of a flow rate control apparatus according to an embodiment of the present invention; -
Fig. 4 is a flow chart for controlling the discharge flow rate of a hydraulic pump according to the present invention; -
Fig. 5 is a graph showing the flow rate characteristics of the hydraulic pump according to the present invention. - 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.
- Here, the terminology or words used in the specification and the claims of the present invention should not be interpreted as typical meanings or lexical meanings, and they should be interpreted as the meaning and concept conforming to the technological idea of the present invention on the basis of the idea that the inventor can define the concept of the words appropriately in order to illustrate his invention in the best manner.
- Hereinafter, a preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings.
- Referring to
Figs. 3 and 4 , the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine according to the present invention includes: - an
engine 10; - at least one variable displacement
hydraulic pump 12 having a swash plate control device 11 for controlling an opening area thereof and configured to be pumped by theengine 10 to provide hydraulic pressure; - a plurality of
actuators 14 for work apparatuses including a boom actuator or an arm actuator, a bucket actuator, and a swing motor; - a work
apparatus control valve 15 connected and installed between thehydraulic pump 12 and theactuators 14 for work apparatuses, and configured to control the hydraulic pressure discharged from the hydraulic pump to perform a start, a stop, and a swing operation of the actuators for the work apparatuses and the swing motor during the spool shift; - a manipulation amount detection means 17 configured to detect a manipulation amount of a
manipulation device 16 to drive theactuators 14 for work apparatuses; and - a
flow rate controller 18 connected to the manipulation amount detection means 17 and the swash plate control device 11, and configured to receive a work apparatus manipulation signal of themanipulation device 16, which is detected by the manipulation amount detection means 17 and to control a discharge flow rate of thehydraulic pump 12. - The
flow rate controller 18 pre-determines the required flow rates of therespective actuators 15 for work apparatuses through the work apparatus manipulation signal during a combined operation, and then controls the swash plate control device 11 by calculating the square root of the sum of squares of the respective required flow rates to determine the discharge flow rate of thehydraulic pump 12. - In addition, the manipulation amount detection means 17 is constructed as a pilot pressure detection sensor, and the swash plate control device 11 is constructed as an electro proportional pressure reducing valve.
- The operation principle of the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine according to an embodiment of the present invention will be described in further detail with reference to
Figs. 3 to 5 . - In an embodiment of the present invention, the
hydraulic excavator 1 includes a crawler-type lower traveling structure 2, an upper swing structure 3 swingably supported on the lower traveling structure 2, and a work apparatus mounted on the upper swing structure 3. The work apparatus generally includes aboom 5 configured so that its base is ascendably and descendably supported on the upper swing structure 3, anarm 6 provided at an end of theboom 5, a bucket 7 mounted at a front end of theboom 5, and a swing motor (not shown) configured to provide power during the swing operation of the upper swing structure 3 as in the prior art. - In addition, the
boom 5, thearm 6 and the bucket 7 are operated byrespective actuators 14 that are expanded and contacted by hydraulic pressure. - Particularly, in the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine according to an embodiment of the present invention, when an operator manipulates a
manipulation device 16, for example, a manipulation lever or a joystick to drive theactuators 14 for work apparatuses, the manipulation amount of a work apparatus manipulation signal including a pilot pressure or an electric signal is detected by the manipulation amount detection means 17. - The
flow rate controller 18 is connected to the manipulation amount detection means 17 and the swash plate control device 11, and receives a work apparatus manipulation signal of themanipulation device 16, which is detected by the manipulation amount detection means 17 and controls a discharge flow rate of thehydraulic pump 12. - Preferably, the
flow rate controller 18 pre-determines the required flow rates of therespective actuators 15 for work apparatuses through the work apparatus manipulation signal during a combined operation, and then controls the swash plate control device 11 by calculating the square root of the sum of squares of the respective required flow rates to determine the discharge flow rate of thehydraulic pump 12. - The
manipulation device 16 is installed at apilot pump 13, and the manipulation amount of themanipulation device 16 is detected by a pilot pressure detection sensor of the manipulation amount detection means 17. - According to an embodiment of the present invention, the discharge flow rate of the
hydraulic pump 12 is determined by performing a step S100 of detecting the manipulation amount of themanipulation device 16 to calculate the required flow rates of therespective actuators 14, a step S200 of calculating the square root of the sum of squares of the required flow rates of therespective actuators 14 calculated in the step S100, and a step S300 of outputting a control signal corresponding to a result determined at the step S200 to control the swash plate control device 11. - More specifically, the
flow rate controller 18 according to the present invention merely does not calculate the sum of the required flow rates of therespective actuators 14 for work apparatuses when a hydraulic pump discharge flow rate is set unlike the conventional flow rate control method. Instead, theflow rate controller 18 calculates the square root of the sum of squares of the respective required flow rates of theactuators 14 for work apparatuses according to a work apparatus manipulation signal of themanipulation device 16 detected by the manipulation amount detection means 17 and determines the calculated square root value to be the discharge flow rate of thehydraulic pump 12. -
- Here, the
flow rate controller 18 controls the discharge flow rate of the hydraulic pump by calculating the square root of the sum of squares of the required flow rates of the actuators for work apparatuses as defined above and using an output signal of the swash plate control device 11 corresponding to a result of the calculation. The discharge flow rate of the hydraulic pump can be defined by the following equation: - In order to compare the characteristics of the discharge flow rate of the hydraulic pump controlled by the
flow rate controller 18 according to the present invention, during the combined operation of two actuators for work apparatuses, for example, the boom actuator and the bucket actuator, a comparison of the flow rate characteristics is made between the conventional flow rate control method of simply adding the required flow rates of the actuators and the inventive flow rate control method. A result of the comparison shows that the inventive flow rate control method controls the maximum flow rate of the hydraulic pump in a relatively delayed period in comparison with the conventional flow rate control method. - That is, as shown in
Fig. 5 , when the maximum discharge flow rate performance of thehydraulic pump 12 is set to be constant, the discharge flow rate control characteristic line B of thehydraulic pump 12 according to the present invention has a relatively small gradient and shows a relatively long delay period to reach the maximum flow rate in comparison with the discharge flow rate control characteristic line A of thehydraulic pump 12 according to the prior art. - This means that when one
actuator 14 is manipulated alone, there is no difference in control characteristics between the inventive flow rate control method and the conventional flow rate control method. In addition, the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine according to the present invention has the characteristics that when two ormore actuators 14 are manipulated simultaneously or a combined operation is performed, the opening area of the hydraulic pump is controlled such that the hydraulic pump discharges a relatively small amount of hydraulic fluid in comparison to the prior art. - Additionally, a relatively large opening area can be secured with respect to the same discharge flow rate of the
hydraulic pump 12, and thus a pressure loss can be greatly reduced as well as the operation efficiency of thehydraulic pump 12 and the fuel efficiency can be improved. - In the meantime, the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine according to the present invention has the characteristics that when the manipulation amount of the
manipulation device 16 is maintained constantly during a combined operation, thehydraulic pump 12 discharges a relatively small amount of hydraulic fluid in comparison to the prior art and a relatively large manipulation amount as compared to the prior art is required to discharge the same amount of hydraulic fluid as that in the prior art in terms of the control of themanipulation device 16. - By virtue of such characteristics, the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine according to the present invention provides an operator with a relatively wide manipulation period range as compared to the prior art in the manipulation of the
manipulation device 16 including a manipulation lever or a joystick so that manipulability can be maintained smoothly and stably. - As described above, the present invention is very useful in a the flow rate control apparatus of a variable displacement hydraulic pump for a construction machine, in which the hydraulic pump discharges a relatively small amount of hydraulic fluid in the same period range in comparison with the prior art in the manipulation of the manipulation device and the control of the discharge flow rate of the hydraulic pump according to the manipulation of the manipulation device to perform a combined operation, and the manipulation period range of the manipulation device is made relatively wide so that manipulability can be improved and a pressure loss of the hydraulic pump can be reduced.
Claims (3)
- A flow rate control apparatus of a variable displacement hydraulic pump for a construction machine comprising:an engine;at least one variable displacement hydraulic pump having a swash plate control device for controlling an opening area thereof and configured to be pumped by the engine to provide hydraulic pressure;a plurality of actuators for work apparatuses including a boom actuator or an arm actuator, a bucket actuator, and a swing motor;a work apparatus control valve connected and installed between the hydraulic pump and the actuators for work apparatuses, and configured to control the hydraulic pressure discharged from the hydraulic pump to perform a start, a stop, and a swing operation of the actuators for the work apparatuses and the swing motor during the spool shift;a manipulation amount detection means configured to detect a manipulation amount of a manipulation device to drive the actuators for work apparatuses; anda flow rate controller connected to the manipulation amount detection means and the swash plate control device, and configured to receive a work apparatus manipulation signal of the manipulation device, which is detected by the manipulation amount detection means and to control a discharge flow rate of the hydraulic pump,wherein the flow rate controller pre-determines the required flow rates of the respective actuators for work apparatuses through the work apparatus manipulation signal during a combined operation, and then controls the swash plate control device by calculating the square root of the sum of squares of the respective required flow rates to determine the discharge flow rate of the hydraulic pump.
- The flow rate control apparatus of a variable displacement hydraulic pump according to claim 1, wherein the manipulation amount detection means is constructed as a pilot pressure detection sensor.
- The flow rate control apparatus of a variable displacement hydraulic pump according to claim 1, wherein the swash plate control device is constructed as an electro proportional pressure reducing valve.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/KR2010/005742 WO2012033233A1 (en) | 2010-09-09 | 2010-09-09 | Flow rate control device for variable displacement type hydraulic pump for construction equipment |
Publications (1)
Publication Number | Publication Date |
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EP2615311A1 true EP2615311A1 (en) | 2013-07-17 |
Family
ID=45810817
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP10857020.1A Withdrawn EP2615311A1 (en) | 2010-09-09 | 2010-09-09 | Flow rate control device for variable displacement type hydraulic pump for construction equipment |
Country Status (6)
Country | Link |
---|---|
US (1) | US20130160439A1 (en) |
EP (1) | EP2615311A1 (en) |
JP (1) | JP5719440B2 (en) |
KR (1) | KR20130143552A (en) |
CN (1) | CN103097743B (en) |
WO (1) | WO2012033233A1 (en) |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
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KR101774817B1 (en) | 2012-11-23 | 2017-09-05 | 볼보 컨스트럭션 이큅먼트 에이비 | Apparatus and method for controlling preferential function of construction machine |
WO2014112668A1 (en) | 2013-01-18 | 2014-07-24 | 볼보 컨스트럭션 이큅먼트 에이비 | Flow control device and flow control method for construction machine |
US10208458B2 (en) * | 2014-12-10 | 2019-02-19 | Volvo Construction Equipment Ab | Method for compensating for flow rate of hydraulic pump of construction machine |
US9869311B2 (en) * | 2015-05-19 | 2018-01-16 | Caterpillar Inc. | System for estimating a displacement of a pump |
CN105240349B (en) * | 2015-09-21 | 2018-01-26 | 北京中车重工机械有限公司 | A kind of rotary drilling rig and its hydraulic control system |
JP2018021589A (en) | 2016-08-02 | 2018-02-08 | キャタピラー エス エー アール エル | Pump control device and pump control method |
KR102561435B1 (en) * | 2016-08-31 | 2023-07-31 | 에이치디현대인프라코어 주식회사 | Contorl system for construction machinery and control method for construction machinery |
JP6803194B2 (en) * | 2016-10-25 | 2020-12-23 | 川崎重工業株式会社 | Hydraulic drive system for construction machinery |
CN107477039B (en) * | 2017-08-14 | 2020-01-03 | 潍柴动力股份有限公司 | Hydraulic system with flow compensation function and engineering machinery |
EP3575615B1 (en) | 2018-03-15 | 2022-02-16 | Hitachi Construction Machinery Co., Ltd. | Construction machine |
JP7221101B2 (en) * | 2019-03-20 | 2023-02-13 | 日立建機株式会社 | excavator |
JP7253478B2 (en) * | 2019-09-25 | 2023-04-06 | 日立建機株式会社 | working machine |
JP7153627B2 (en) * | 2019-10-31 | 2022-10-14 | 日立建機株式会社 | Work machine and perimeter monitoring system |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06159319A (en) * | 1992-11-25 | 1994-06-07 | Hitachi Constr Mach Co Ltd | Pump discharging flow rate control device for hydraulically operating machine |
JP2567193B2 (en) * | 1993-01-19 | 1996-12-25 | 三星重工業株式會社 | Hydraulic pump discharge flow control device |
JP3471620B2 (en) * | 1998-07-08 | 2003-12-02 | 内田油圧機器工業株式会社 | Bleed-off control method using closed center type electromagnetic proportional directional control valve |
JP3750841B2 (en) | 1998-11-12 | 2006-03-01 | 新キャタピラー三菱株式会社 | Hydraulic control device for work machine |
JP3928793B2 (en) * | 2002-10-30 | 2007-06-13 | 古河機械金属株式会社 | Hydraulic actuator control device |
KR100637675B1 (en) * | 2004-09-15 | 2006-10-25 | 주식회사 파카한일유압 | Regulator for meter-out flow control of hydraulic control valve |
KR100631072B1 (en) * | 2005-06-27 | 2006-10-02 | 볼보 컨스트럭션 이키프먼트 홀딩 스웨덴 에이비 | Hydraulic circuit for heavy equipment option device |
JP2007205464A (en) * | 2006-02-01 | 2007-08-16 | Bosch Rexroth Corp | Control method of variable displacement pump |
JP4434159B2 (en) * | 2006-03-02 | 2010-03-17 | コベルコ建機株式会社 | Hydraulic control device for work machine |
KR101301234B1 (en) * | 2007-12-06 | 2013-08-29 | 볼보 컨스트럭션 이큅먼트 에이비 | pressure compensation hydraulic circuit of control engine revolution of excavator |
-
2010
- 2010-09-09 JP JP2013528094A patent/JP5719440B2/en not_active Expired - Fee Related
- 2010-09-09 KR KR1020137004529A patent/KR20130143552A/en not_active Application Discontinuation
- 2010-09-09 CN CN201080069025.7A patent/CN103097743B/en not_active Expired - Fee Related
- 2010-09-09 EP EP10857020.1A patent/EP2615311A1/en not_active Withdrawn
- 2010-09-09 US US13/821,452 patent/US20130160439A1/en not_active Abandoned
- 2010-09-09 WO PCT/KR2010/005742 patent/WO2012033233A1/en active Application Filing
Non-Patent Citations (1)
Title |
---|
See references of WO2012033233A1 * |
Also Published As
Publication number | Publication date |
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WO2012033233A1 (en) | 2012-03-15 |
KR20130143552A (en) | 2013-12-31 |
CN103097743B (en) | 2016-03-02 |
US20130160439A1 (en) | 2013-06-27 |
JP5719440B2 (en) | 2015-05-20 |
CN103097743A (en) | 2013-05-08 |
JP2013543086A (en) | 2013-11-28 |
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