Hydraulic device for construction machinery and control method thereof

Abstract

A hydraulic device for construction machinery and a control method thereof are disclosed. In this embodiment, flow rate loss that may occur during a multi-operation process of an excavator can be reduced, and fuel efficiency can be improved.

Description

Hydraulic device for construction machinery and control method thereof

[0001] The present invention relates to a hydraulic device for a construction machine and a hydraulic control method thereof, which allows an operator to selectively use different operating modes when using the construction machine.

[0002] Construction machinery broadly refers to all machinery used in civil engineering, construction, or industrial sites. Generally, construction machinery is equipped with an engine and a hydraulic pump that operates using the engine's power, and it drives or operates various work devices using the power generated through the engine and hydraulic pump.

[0003] For example, excavators, a type of construction machine, perform tasks such as excavation work to dig the ground, loading work to transport soil, crushing work to demolish buildings, and leveling work to prepare the ground at civil engineering, construction, and construction sites.

[0004] An excavator is a construction machine that performs tasks such as excavation work to dig the ground, loading work to transport soil, crushing work to demolish buildings, and leveling work to prepare the ground at civil engineering, construction, and construction sites. It consists of a driving body that serves as the moving part of the equipment, an upper slewing body mounted on the driving body that rotates 360 degrees, and a working device.

[0005] In addition, the excavator includes a travel motor used for travel, a swing motor used for the upper swinging body swing, and drive devices such as a boom cylinder, arm cylinder, bucket cylinder, and optional cylinder used for the working device. These drive devices are driven by hydraulic fluid discharged from a variable displacement hydraulic pump driven by an engine or an electric motor.

[0006] A hydraulic system equipped in a conventional excavator comprises an actuator driven by operating fluid discharged from a hydraulic pump, a main control valve provided between the hydraulic pump and the actuator, a spool for a workpiece managed by the hydraulic pump, a flow path through which the oil discharged from the hydraulic pump travels, and a flow control unit that controls the swash plate angle of the hydraulic pump to regulate the flow rate of the hydraulic pump.

[0007] For example, when an excavator is in standby mode, pressure loss occurs depending on the spool design, causing problems such as reduced efficiency and reduced fuel economy. Also, when swing acceleration occurs, flow loss increases, causing problems such as reduced fuel economy, so countermeasures for this need to be taken.

[0008] Embodiments of the present invention aim to provide a hydraulic device for construction machinery and a hydraulic control method thereof that can reduce flow loss and improve efficiency when construction machinery, such as excavators, performs various operations simultaneously.

[0009] A hydraulic device for a construction machine according to one embodiment of the present invention comprises: an operating mode selection unit (10) composed of a first operating mode and a second operating mode among operating modes for operating the construction machine; an operating unit (20) operated by a driver riding in the construction machine; a pump unit (100) for discharging hydraulic fluid required for operating the construction machine according to the operation of the operating unit (20); a plurality of driving units (200) equipped with an actuator unit (210) to which hydraulic fluid discharged from the pump unit (100) is supplied and a motor unit (220); and a merging valve unit (300) provided to selectively merge the hydraulic fluid discharged from the pump unit (100) according to one of the operating modes selected from the first operating mode or the second operating mode. and includes a control unit (400) provided to perform pressure control for the pump unit (100) according to either the first operating mode or the second operating mode selected, or to simultaneously perform flow rate control so that the supply flow rate and the target flow rate of the operating fluid supplied to the drive unit (200) become the same as the pressure control for the pump unit (100).

[0010] The control unit (400) calculates the required flow rate of the pump unit (100) through the preset flow rate value of the pump unit (100) required for the operation of the drive unit (200) in the first operating mode, and then performs pressure control for the pump unit (100) differently.

[0011] The pump unit (100) comprises a first pump unit (110) provided to supply hydraulic fluid to the drive unit (200); and a second pump unit (120) provided to supply hydraulic fluid to the drive unit (200) together with the first pump unit (110).

[0012] The first pump unit (110) is equipped with a first pressure gauge (112) to detect the pressure of the discharged working fluid and includes a first swash plate angle sensor unit (114) for detecting the swash plate angle provided in the first pump unit (110), and the second pump unit (120) is equipped with a second pressure gauge (122) to detect the pressure of the discharged working fluid and includes a second swash plate angle sensor unit (124) for detecting the swash plate angle provided in the second pump unit (112).

[0013] When the drive unit (200) is operated in combination in the first operating mode, the control unit (400) calculates the required flow rate for the drive unit (200) based on the amount of operation of the operating unit (20) and the preset value of the pump unit (100), and then compares this with the actual discharge flow rate of the pump unit (100) to perform pressure control of the pump unit (100) for the operating fluid supplied to the drive unit (200).

[0014] The control unit (400) performs pressure control to increase the discharge flow rate of the first pump unit (110) when the required flow rate of the drive unit (200) is less than the actual discharge flow rate of the first pump unit (110).

[0015] The control unit (400) controls the discharge flow rate of the increased first pump unit (110) to match the required flow rate of the drive unit (200).

[0016] The control unit (400) performs pressure control so that the discharge flow rate of the second pump unit (120) is reduced when the required flow rate of the driving unit (200) is greater than the actual discharge flow rate of the second pump unit (120).

[0017] The control unit (400) controls the displacement of the spool to remain the same when the required flow rate of the drive unit (200) and the actual discharge flow rate of the second pump unit (120) are the same.

[0018] When the driver selects the second operating mode, the control unit (400) controls the flow of the operating fluid to be combined with the confluence valve unit (300) according to the amount of operation of the operating unit (20) and the preset setting value, and at the same time, when the highest operating pressure among the operating pressures of the driving unit (200) is assumed to be PA, the discharge pressure of the pump unit (100) is increased by △P compared to PA to perform pressure control for the pump unit (100).

[0019] The control unit (400) receives the pressure of the actuator unit (210), the pressure of the pump unit (100), and the area information of the spool, and calculates the actual flow rate of the hydraulic fluid supplied to the actuator unit (210).

[0020] The control unit (400) calculates the target flow rate and the actual flow rate of the actuator unit (210), respectively, and controls the displacement of the spool to decrease if the target flow rate is greater than the actual flow rate.

[0021] The control unit (400) calculates the target flow rate and the actual flow rate of the actuator unit (210), respectively, and controls the displacement of the spool to increase when the target flow rate is smaller than the actual flow rate.

[0022]

[0023] The control unit (400) calculates the target flow rate and the actual flow rate of the actuator unit (210), respectively, and if the target flow rate is the same as the actual flow rate, it performs control to maintain the displacement of the spool as is.

[0024]

[0025] A hydraulic device for a construction machine according to another embodiment of the present invention comprises an operating unit (20) for operating the construction machine, a pump unit (100) for discharging hydraulic fluid necessary for the operation of the construction machine according to the operation of the operating unit (20), a main control valve (60) including a plurality of spools for selectively supplying hydraulic fluid discharged from the pump unit (100) to a plurality of driving units (200), and controlling the spools so that the supply flow rate and the target flow rate of the hydraulic fluid supplied to the driving units (200) become equal, and controlling the pressure of the pump unit (100) to be higher than the highest operating pressure among the operating pressures of the driving units (200).

[0026]

[0027] A control method for a hydraulic device for construction machinery according to the present embodiment includes: an operation mode selection step (ST100) in which an operator on board the construction machinery selects either a first operation mode or a second operation mode; and an operation mode control step (ST200) in which pressure control for a pump unit is performed according to either the first operation mode or the second operation mode selected, or flow rate control is performed simultaneously with pressure control for the pump unit so that the supply flow rate and the target flow rate of the hydraulic fluid supplied to the drive unit become the same.

[0028] The above operating mode control step (ST200) includes a first calculation step (ST210) for calculating the required flow rate of the pump unit and the actual discharge flow rate of the pump unit according to the amount of operation of the control unit when the operator selects the first operating mode; and a second calculation step (ST220) for comparing and determining the required flow rate of the pump unit and the actual discharge flow rate of the pump unit.

[0029] In the second operation step (ST220) above, if the required flow rate of the pump unit is greater than the actual discharge flow rate of the pump unit, a first pump unit control step (ST222) is performed to control the pressure of the pump unit to increase.

[0030] In the second operation step (ST220) above, if the required flow rate of the pump unit is smaller than the actual discharge flow rate of the pump unit, a second pump unit control step (ST224) is performed to control the pressure of the pump unit to decrease.

[0031] The above operating mode control step (ST200) includes: a third calculation step (ST230) for calculating the target flow rate of the actuator unit according to the amount of operation of the control unit when the operator selects the second operating mode; a fourth calculation step (ST240) for calculating the actual flow rate of the operating fluid supplied to the actuator unit by receiving input information on the pressure of the actuator unit (210), the pressure of the pump unit (100), and the area of ​​the spool; and a fifth calculation step (ST250) for comparing and determining the target flow rate and the actual flow rate of the actuator unit.

[0032] The above operating mode control step (ST200) further includes a pump unit pressure control step (ST260) that performs pressure control for the pump unit by increasing the discharge pressure of the pump unit by △P above the highest operating pressure (PA) of the actuator unit operating pressure caused by the operation of the operating part.

[0033] The above fifth operation step (ST250) further includes a spool displacement control step (ST252) that controls the displacement of the spool according to the target flow rate and the actual flow rate of the actuator unit.

[0034] These embodiments can ensure stable operation by minimizing flow loss when performing various complex tasks using a construction machine equipped with multiple actuator units.

[0035] These embodiments improve convenience and work efficiency by allowing the operator to freely switch between a first operating mode and a second operating mode as needed while performing various tasks using the excavator, and to immediately perform excavation work.

[0036] FIG. 1 is a drawing illustrating the configuration of a hydraulic device for construction machinery according to the present embodiment.

[0037] FIG. 2 is a schematic diagram of a hydraulic device for construction machinery according to the present embodiment.

[0038] FIG. 3 is an operating state diagram illustrating when a hydraulic device for construction machinery according to the present embodiment is operated in a first operating mode.

[0039] FIG. 4 is a diagram briefly illustrating the operating state of FIG. 3.

[0040] FIG. 5 is a drawing showing the activated components according to the operating state of FIG. 3.

[0041] FIG. 6 is an operating state diagram illustrating when a hydraulic device for construction machinery according to the present embodiment is operated in a second operating mode.

[0042] FIG. 7 is a drawing showing the activated components according to the operating state of FIG. 6.

[0043] FIG. 8 is a diagram briefly illustrating the operating state of FIG. 6.

[0044] FIG. 9 is a flowchart illustrating a control method for a hydraulic device for construction machinery according to the present embodiment.

[0045] FIG. 10 is a flowchart illustrating the operating state of a control method for a hydraulic device for construction machinery according to the present embodiment.

[0046] The advantages and features of the present disclosure and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, like reference numerals refer to like components.

[0047] When one component is referred to as being "connected to" or "coupled to" another component, it includes cases where it is directly connected or coupled to the other component, or cases where another component is interposed. Conversely, when one component is referred to as being "directly connected to" or "directly coupled to" another component, it indicates that no other component is interposed. "And / or" includes each of the mentioned items and all combinations of one or more of them.

[0048] The terms used herein are for describing embodiments and are not intended to limit the disclosure. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0049] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another.

[0050]

[0051] A hydraulic device for construction machinery according to the present embodiment will be described with reference to the drawings. For reference, the flow rate of the hydraulic fluid supplied to the actuator unit in the present embodiment can be easily changed through the operation mode conversion. For reference, FIG. 1 is a diagram showing the configuration of a hydraulic device for construction machinery according to the present embodiment, FIG. 2 is a schematic diagram of a hydraulic device for construction machinery according to the present embodiment, FIG. 3 is an operation state diagram showing the hydraulic device for construction machinery according to the present embodiment when it is operated in a first operation mode, and FIG. 4 is a diagram briefly showing the operation state of FIG. 3.

[0052]

[0053] Referring to the attached FIGS. 1 to 4, the infant device for a construction machine according to the present embodiment comprises an operating mode selection unit (10) configured with a first operating mode and a second operating mode among operating modes for operating the construction machine, an operating unit (20) operated by a driver riding on the construction machine, a pump unit (100) that discharges operating fluid necessary for operating the construction machine according to the operation of the operating unit (20), an actuator unit (210) to which the operating fluid discharged from the pump unit (100) is supplied, a plurality of driving units (200) equipped with a motor unit (220), and a merging valve unit (300) provided to selectively merge the operating fluid discharged from the pump unit (100) according to any one of the operating modes selected from the first operating mode or the second operating mode.

[0054] And it includes a control unit (400) provided to perform pressure control for the pump unit (100) according to one of the first operating modes or the second operating modes selected above, or to simultaneously perform flow rate control so that the supply flow rate and the target flow rate of the operating fluid supplied to the drive unit (200) become the same as the pressure control for the pump unit (100).

[0055] The present embodiment may be configured so that the operator selects and uses a first operating mode or a second operating mode through the control unit (20), or operates automatically by the control unit (400). In addition, the subject of operation is not necessarily limited to the operator or the control unit (400) and may change depending on the situation. Therefore, more convenient and stable use and operation of the construction machine may be possible.

[0056]

[0057] The above construction machine is described as an excavator as an example, but it may be changed to other specifications. The operation mode selection unit (10) according to the present embodiment may be placed, for example, around the driver's seat or on the instrument panel, and is configured as a button or touch type so that it can be conveniently operated by being placed within a distance where the driver's hand can move.

[0058] In particular, in the first operating mode, the flow rate of the pump unit (100) is controlled according to the amount of operation of the joystick operated by the driver, and the displacement of the spool is determined by the amount of operation of the joystick.

[0059] The above actuator unit (210) has a supply flow rate determined according to the operating pressure and joystick operation amount of each actuator unit (210), and when multiple actuator units (210) operate simultaneously, more flow rate is supplied to the actuator unit (210) with the lower operating pressure.

[0060] In addition, in the second operating mode, the pump unit is pressure controlled, and the spool displacement can be controlled so that the supply flow rate to each actuator unit according to the spool operation amount becomes the same as the actual flow rate.

[0061]

[0062] The above-mentioned control unit (20) may use a joystick, but may be changed to a lever or other form. The above-mentioned pump unit (100) includes, for example, a first pump unit (110) provided to supply hydraulic fluid to the drive unit (200), and a second pump unit (120) provided to supply hydraulic fluid to the drive unit (200) together with the first pump unit (110).

[0063] The first pump unit (110) is equipped with a first pressure gauge (112) to detect the pressure of the discharged working fluid and includes a first swash plate angle sensor unit (114) for detecting the swash plate angle provided in the first pump unit (110).

[0064] The second pump unit (120) is equipped with a second pressure gauge (122) to detect the pressure of the discharged working fluid and includes a second swash plate angle sensor unit (124) for detecting the swash plate angle provided in the second pump unit (112).

[0065] The first pressure gauge (112), the second pressure gauge (122), the first swashplate angle sensor unit (114), and the second swashplate angle sensor unit (124) are configured to transmit detected information to the control unit (400).

[0066]

[0067] The drive unit (200) according to the present embodiment includes an actuator unit (210) and a motor unit (220). For example, the actuator unit (210) includes a first arm actuator (211), a first boom actuator (213), and a bucket actuator (215), and the motor unit (220) includes a swing motor (221), a first travel motor (222), an option motor (223), a driving motor, and a second travel motor (225). The actuator unit (210) and the motor unit (220) are shown as drawing numbers only in part of the overall configuration to aid understanding of the description, and additionally, other configurations may be included.

[0068] The first arm actuator (211) is provided to drive the arm, the first boom actuator (213) is provided to drive the boom, the bucket actuator (215) is provided to drive the bucket, the swing motor (221) is provided to rotate the swivel body, and the driving motor is provided to drive the lower driving body.

[0069] In addition, the first and second travel motors (222, 225) and the optional motor (223) are provided for the driving or specific operation of the excavator. A pressure gauge is installed in each of the actuator unit (210) and the motor unit (220), and data transmission is performed with the control unit (400) to be described later.

[0070] In this embodiment, a first hydraulic line (30) is provided, with one end connected to a first pump unit (110) and the other end connected to an actuator unit (210) or a motor unit (220). Additionally, a second hydraulic line (40) is provided, with the other end connected to a second pump unit (120) and the other end connected to an actuator unit (210) or a motor unit (220).

[0071] Additionally, the third hydraulic line (50) is configured such that one end is connected to the first hydraulic line (30) extended from the first pump unit (110), the other end is connected to the second hydraulic line (40) extended from the second pump unit (120), and each end is connected to both sides of the junction valve unit (300).

[0072]

[0073] The control unit (400) according to the present embodiment calculates the required flow rate for the drive unit (200) through the preset flow rate value of the pump unit (100) required for the operation of the drive unit (200) in the first operating mode, and then performs pressure control of the pump unit (100) for the working fluid supplied to the drive unit (200) by comparing it with the actual discharge flow rate of the pump unit (100).

[0074] In this case, the working fluid is kept blocked from being supplied to the joining valve unit (300), and the working fluid is controlled to be discharged through the first pump unit (110) and the second pump unit (120), respectively.

[0075] For example, the control unit (400) calculates the required flow rate that the first pump unit (110) and the second pump unit (120) need to pump through the set flow rate value when the first boom actuator (213), the first arm actuator (211), and the optional motor (223) are operated together.

[0076] That is, the flow rate of the first pump unit (110) is 100 LPM, which is the target flow rate at which the first boom actuator (213) can operate, and the flow rate of the second pump unit (120) corresponds to 70 LPM and 100 LPM, which are the target flow rates at which the first arm actuator (211) and the optional motor (223) can operate, respectively, so that when these are added, it corresponds to 170 LPM.

[0077] The control unit (400) calculates the required flow rate of the pump unit (100) by calculating the information input through the first swash plate angle sensor unit (114) and the second swash plate angle sensor unit (124).

[0078]

[0079] The control unit (400) controls the flow rate of the pump unit (100) for the working fluid supplied to the drive unit (200) by comparing it with the actual discharge flow rate of the pump unit (100).

[0080] For example, if the required flow rate of the above-mentioned drive unit (200) is less than the actual discharge flow rate of the first pump unit (110), pressure control is performed on the first pump unit (110) so that the discharge flow rate of the first pump unit (110) is increased.

[0081]

[0082] The control unit (400) controls the discharge flow rate of the first pump unit (110) to be 100 LPM when the required flow rate (Q1) of the first pump unit (110) is 100 LPM and the actual discharge flow rate (Q2) of the first pump unit (110) is 90 LPM. It also provides hydraulic pressure that enables the first boom actuator (213) to operate stably.

[0083] And the control unit (400) performs pressure control so that the discharge flow rate of the second pump unit (120) is reduced when the required flow rate of the second pump unit (120) is 170 LPM or the actual discharge amount of the working fluid discharged from the second pump unit (120) is 180 LPM.

[0084]

[0085] The control unit (400) controls the displacement of the spool to remain the same when the required flow rate of the drive unit (200) and the actual discharge flow rate of the second pump unit (120) are the same.

[0086] For reference, the above control unit (400) is controlled by a plurality of spools provided in the main control valve (60) according to a preset value based on the amount of operation of the joystick provided in the operating unit (20) and other operating environments.

[0087]

[0088] A case in which a hydraulic device for construction machinery according to the present embodiment is controlled in a second operating mode is described with reference to the drawings.

[0089] Referring to the attached FIGS. 5 to 8, the control unit (400) according to the present embodiment simultaneously performs pressure control for the pump unit (100) in the second operating mode and flow rate control so that the supply flow rate and the target flow rate of the hydraulic fluid supplied to the drive unit (200) become the same. In this case, the present embodiment can prevent malfunctions caused by pressure fluctuations or insufficient pressure of the hydraulic fluid and ensure stable operation under conditions where various operations of the excavator are performed simultaneously.

[0090] To this end, the control unit (400) controls the flow rate of the operating fluid to be combined with the confluence valve unit (300) according to the amount of operation of the operating unit (20) and a preset value, and at the same time, when assuming the highest operating pressure among the operating pressures of the driving unit (200) is PA, it increases the discharge pressure of the pump unit (100) by △P compared to PA to perform pressure control for the pump unit (100).

[0091] The control unit (400) calculates the target flow rate of the actuator unit (210) based on a preset setting value according to the amount of operation of the joystick provided in the control unit (20). Then, it connects to the joining valve unit (300) so that the flow rates of the working fluid discharged from the first pump unit (110) and the second pump unit (120) are joined.

[0092] Then, the pressure of the actuator unit (210), the pressure of the pump unit (100), and the area information of the spool are received as input, and the actual flow rate of the operating fluid supplied to the actuator unit (210) is calculated.

[0093]

[0094] For example, the control unit (400) detects the pressure of the actuator unit (210) and the motor unit (220) using a separately provided pressure sensor, and calculates the supply flow rate of the hydraulic fluid supplied to the actuator unit (210) and the motor unit (220) using the pressure of the pump unit (100) and the spool area information calculated from the displacement of the spool.

[0095]

[0096] The control unit (400) calculates the target flow rate (Q3) and the actual flow rate (Q4) of the actuator unit (210), respectively, and controls the displacement of the spool to decrease if the target flow rate (Q3) is greater than the actual flow rate (Q4).

[0097] In addition, the control unit (400) calculates the target flow rate and the actual flow rate of the actuator unit (210), and if the target flow rate is smaller than the actual flow rate, controls the displacement of the spool to increase.

[0098] In one example, in this embodiment, when the operating pressure (PA) of the first boom actuator (213) is 150 bar, the operating pressure of the first arm actuator (211) is 170 bar, and the operating pressure of the option motor (223) is 200 bar, pressure control is performed so that the pump unit (100) operates at the highest operating pressure, which is the operating pressure of the option motor (223), at least 20 bar (△P) higher than 200 bar.

[0099] In this case, the control unit (400) controls the pump unit (100) to discharge the working fluid at 220 bar, thereby reducing the loss of flow rate due to insufficient pressure of the working fluid during excavator operation and improving fuel efficiency.

[0100] In addition, the control unit (400) calculates the target flow rate and the actual flow rate of the actuator unit (210), and if the target flow rate is the same as the actual flow rate, it performs control to maintain the displacement of the spool as is.

[0101] The reason the control unit (400) controls the target flow rate and the actual flow rate of the actuator unit (210) in this manner is to reduce flow rate loss that may occur when the excavator performs a specific task while rotating and accelerating, and to improve fuel efficiency, thereby enabling efficient work under various working conditions.

[0102]

[0103] A hydraulic device for construction machinery according to the present embodiment comprises an operating unit (20) for operating the construction machinery, a pump unit (100) for discharging hydraulic fluid necessary for the operation of the construction machinery according to the operation of the operating unit (20), a main control valve (60) including a plurality of spools for selectively supplying hydraulic fluid discharged from the pump unit (100) to a plurality of driving units (200), and controlling the spools so that the supply flow rate and the target flow rate of the hydraulic fluid supplied to the driving units (200) become equal, and controlling the pressure of the pump unit (100) to be higher than the highest operating pressure among the operating pressures of the driving units (200).

[0104]

[0105] A hydraulic control method for a construction machine according to the present embodiment will be explained with reference to the drawings.

[0106] Referring to the attached FIGS. 9 and 10, the hydraulic control method of a construction machine according to the present embodiment includes an operation mode selection step (ST100) in which an operator on board the construction machine selects either a first operation mode or a second operation mode, and an operation mode control step (ST200) in which pressure control for a pump unit is performed according to either the first operation mode or the second operation mode selected, or flow rate control is performed simultaneously so that the supply flow rate and the target flow rate of the hydraulic fluid supplied to the drive unit become the same as the pressure control for the pump unit. For reference, the pump unit is composed of a first pump unit and a second pump unit.

[0107] The above operating mode selection step (ST100) allows the operator seated in the excavator to select a first operating mode or a second operating mode before starting actual work.

[0108] For example, after selecting the first operating mode, excavation work can be performed for a predetermined period of time, and then a second operating mode can be selected to perform other excavation work.

[0109] This embodiment aims to improve fuel efficiency through stable excavation operations by minimizing flow loss according to the first operating mode or the second operating mode.

[0110] The above operating mode control step (ST200) includes a first calculation step (ST210) that calculates the required flow rate of the pump unit and the actual discharge flow rate of the pump unit according to the amount of operation of the control unit when the operator selects the first operating mode, and a second calculation step (ST220) that compares and determines the required flow rate of the pump unit and the actual discharge flow rate of the pump unit.

[0111] The first calculation step (ST210) calculates the required flow rate that the first pump unit and the second pump unit must pump using the set flow rate value of the pre-set pump unit (100) when the first boom actuator, the first arm actuator, and the optional motor operate together.

[0112] In addition, the actual discharge flow rate is calculated using the sensor value input through the pressure gauge or swash plate angle sensor unit equipped in the first and second pump units.

[0113] For example, if the required flow rate of the pump unit is greater than the actual discharge flow rate of the pump unit, control (ST222) for the first pump unit is performed so that the pressure of the pump unit increases.

[0114] For example, if the required flow rate of the first pump unit is 100 LPM and the actual discharge flow rate of the first pump unit is 90 LPM, the discharge flow rate of the first pump unit is controlled to be 100 LPM.

[0115]

[0116] The second operation step (ST220) includes a second pump unit control step (ST224) such that the pressure of the pump unit is reduced when the required flow rate of the pump unit is less than the actual discharge flow rate of the pump unit.

[0117] For example, if the required flow rate of the second pump unit is 170 LPM but the actual discharge flow rate of the working fluid discharged from the second pump unit is 180 LPM, pressure control is performed so that the discharge flow rate of the second pump unit (120) is reduced.

[0118] If the required flow rate of the drive unit and the actual discharge flow rate of the second pump unit are the same, the displacement of the spool is controlled to remain unchanged.

[0119]

[0120] The operation mode control step (ST200) according to the present embodiment includes a third calculation step (ST230) that calculates the target flow rate of the actuator unit according to the amount of operation of the control unit when the operator selects the second operation mode, a fourth calculation step (ST240) that calculates the actual flow rate of the operating fluid supplied to the actuator unit by receiving the pressure of the actuator unit (210), the pressure of the pump unit (100), and the area information of the spool, and a fifth calculation step (ST250) that compares and determines the target flow rate and the actual flow rate of the actuator unit, respectively.

[0121] The above third calculation step (ST230) calculates the target flow rate of the actuator unit based on a preset setting value according to the amount of operation of the joystick. Then, it controls the connection to the merging valve unit so that the flow rates of the operating fluid discharged from the first pump unit and the second pump unit are combined.

[0122] Then, the pressure of the actuator unit, the pressure of the pump unit, and the area information of the spool are input, and the actual flow rate of the hydraulic fluid supplied to the actuator unit is calculated (ST240).

[0123] Then, the target flow rate and the actual flow rate of the above actuator unit are calculated and a comparison judgment is performed (ST250).

[0124] This embodiment further includes a spool displacement control step (ST252) that controls the displacement of the spool according to the target flow rate and the actual flow rate of the actuator unit. The spool displacement control step (ST252) controls the displacement of the spool to decrease when the target flow rate is greater than the actual flow rate.

[0125] In addition, after calculating the target flow rate and the actual flow rate of the actuator unit, if the target flow rate is smaller than the actual flow rate, the displacement of the spool is controlled to increase.

[0126]

[0127] Unlike the first operating mode, the above second operating mode performs pressure control for the pump unit based on the highest pressure state among the pressures of the individual actuator units constituting the actuator unit.

[0128] For example, the above operating mode control step (ST200) further includes a pump unit pressure control step (ST260) that performs pressure control for the pump unit by increasing the discharge pressure of the pump unit by △P above the highest operating pressure (PA) of the actuator unit operating pressure caused by the operation of the operating part.

[0129] In this embodiment, when the operating pressure (PA) of the first boom actuator is 150 bar, the operating pressure of the first arm actuator is 170 bar, and the operating pressure of the optional motor is 200 bar, pressure control is performed so that the pump unit operates at a pressure of at least 20 bar (△P) higher than the highest operating pressure of the optional motor, which is 200 bar.

[0130]

[0131] In this case, the working fluid is discharged from the pump unit at 220 bar, and fuel efficiency can be improved by reducing the loss of flow due to insufficient pressure of the working fluid during excavator operation.

[0132] In addition, this embodiment calculates the target flow rate and the actual flow rate of the actuator unit, and if the target flow rate is the same as the actual flow rate, controls the displacement of the spool to be maintained as is.

[0133] The reason for controlling the target flow rate and the actual flow rate of the actuator unit (210) in this way is to reduce flow loss that may occur when the excavator performs a specific task while rotating and accelerating, and to improve fuel efficiency, thereby enabling efficient work under various working conditions.

[0134]

[0135] Although an embodiment of the present invention has been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes are also to be included within the scope of the rights of the present invention.

[0136] These embodiments can be applied to various construction machines using hydraulics to implement flow control with improved convenience.

Claims

1. An operation mode selection unit (10) composed of a first operation mode and a second operation mode among the operation modes for operating a construction machine; A control unit (20) operated by a driver riding on the above construction machine; A pump unit (100) that discharges hydraulic fluid required for the operation of the construction machine according to the operation of the above control unit (20); A plurality of drive units (200) equipped with an actuator unit (210) to which the working fluid discharged from the pump unit (100) is supplied, and a motor unit (220); A joining valve unit (300) provided to selectively join the working fluid discharged from the pump unit (100) according to one of the first operating modes or the second operating modes selected above; and A hydraulic device for construction machinery comprising a control unit (400) provided to perform pressure control for the pump unit (100) according to one of the first operating modes or the second operating modes selected above, or to simultaneously perform flow rate control so that the supply flow rate and the target flow rate of the operating fluid supplied to the drive unit (200) become the same as the pressure control for the pump unit (100).

2. In Paragraph 1, The above control unit (400) calculates the required flow rate of the pump unit (100) through a preset flow rate value of the pump unit (100) required for the operation of the drive unit (200) in a first operating mode, and then performs pressure control for the pump unit (100) differently.

3. In Paragraph 2, The above pump unit (100) is a first pump unit (110) provided to supply working fluid to the drive unit (200); It includes a second pump unit (120) provided to supply hydraulic fluid to the drive unit (200) together with the first pump unit (110), and The first pump unit (110) is equipped with a first pressure gauge (112) to detect the pressure of the discharged hydraulic fluid, and includes a first swash plate angle sensor unit (114) for detecting the swash plate angle equipped in the first pump unit (110). A hydraulic device for construction machinery, wherein the second pump unit (120) is equipped with a second pressure gauge (122) to detect the pressure of the discharged hydraulic fluid, and a second swash plate angle sensor unit (124) for detecting the swash plate angle equipped in the second pump unit (112).

4. In Paragraph 3, A hydraulic device for construction machinery, wherein the above control unit (400) calculates the required flow rate for the drive unit (200) based on the amount of operation of the operating unit (20) and the preset value of the pump unit (100) when the drive unit (200) is operated in a first operating mode, and then compares this with the actual discharge flow rate of the pump unit (100) to control the pressure of the pump unit (100) for the operating fluid supplied to the drive unit (200).

5. In Paragraph 4, The above control unit (400) is a hydraulic device for construction machinery that performs pressure control to increase the discharge flow rate of the first pump unit (110) when the required flow rate of the drive unit (200) is less than the actual discharge flow rate of the first pump unit (110).

6. In Paragraph 5, The above control unit (400) is a hydraulic device for construction machinery that controls the discharge flow rate of the increased first pump unit (110) to match the required flow rate of the drive unit (200).

7. A control unit (20) for operating the construction machine; A pump unit (100) that discharges hydraulic fluid required for the operation of the construction machine according to the operation of the above control unit (20); A main control valve (60) comprising a plurality of spools, wherein the hydraulic fluid discharged from the pump unit (100) is selectively supplied to a plurality of driving units (200); and A hydraulic device for construction machinery that controls the spool so that the supply flow rate and the target flow rate of the operating fluid supplied to the drive unit (200) become equal, and performs pressure control of the pump unit (100) to be higher than the highest operating pressure among the operating pressures of the drive unit (200).

8. In Paragraph 1, A hydraulic device for construction machinery, wherein the above control unit (400) controls the flow of hydraulic fluid to be combined with the junction valve unit (300) according to the amount of operation of the above operating unit (20) and a preset value when the driver selects a second operating mode, and simultaneously performs pressure control for the pump unit (100) by increasing the discharge pressure of the pump unit (100) by △P above PA, assuming that the highest operating pressure among the operating pressures of the above driving unit (200) is PA.

9. In Paragraph 8, The above control unit (400) is a hydraulic device for construction machinery that receives the pressure of the actuator unit (210), the pressure of the pump unit (100), and the area information of the spool, and calculates the actual flow rate of the hydraulic fluid supplied to the actuator unit (210).

10. In Paragraph 9, The above control unit (400) calculates the target flow rate and the actual flow rate of the actuator unit (210) respectively, and controls the displacement of the spool to decrease when the target flow rate is greater than the actual flow rate.

11. In Paragraph 9, The above control unit (400) is a hydraulic device for construction machinery that calculates the target flow rate and the actual flow rate of the actuator unit (210) respectively, and controls the displacement of the spool to increase when the target flow rate is smaller than the actual flow rate.

12. In Paragraph 9, The above control unit (400) calculates the target flow rate and the actual flow rate of the actuator unit (210) respectively, and if the target flow rate is the same as the actual flow rate, performs control to maintain the displacement of the spool as is. A hydraulic device for construction machinery.

13. An operation mode selection step (ST100) in which an operator on board a construction machine selects either a first operation mode or a second operation mode; and A control method for a hydraulic device for a construction machine, comprising an operating mode control step (ST200) for performing pressure control for a pump unit according to one of the first operating mode or the second operating mode selected above, or simultaneously performing flow rate control so that the supply flow rate and the target flow rate of the hydraulic fluid supplied to the drive unit become the same as the pressure control for the pump unit.

14. In Paragraph 13, The above operating mode control step (ST200) includes a first calculation step (ST210) that calculates the required flow rate of the pump unit and the actual discharge flow rate of the pump unit according to the amount of operation of the control unit when the operator selects the first operating mode; A control method for a hydraulic device for construction machinery comprising a second calculation step (ST220) for comparing and determining the required flow rate of the pump unit and the actual discharge flow rate of the pump unit.

15. In Paragraph 14, A control method for a hydraulic device for construction machinery, wherein a first pump unit control step (ST222) is performed to control the pressure of the pump unit to increase when the required flow rate of the pump unit in the second operation step (ST220) is greater than the actual discharge flow rate of the pump unit.

16. In Paragraph 14, A control method for a hydraulic device for construction machinery, wherein a second pump unit control step (ST224) is performed to control the pressure of the pump unit to decrease when the required flow rate of the pump unit in the second calculation step (ST220) is smaller than the actual discharge flow rate of the pump unit.

17. In Paragraph 13, The above operating mode control step (ST200) includes a third calculation step (ST230) that calculates the target flow rate of the actuator unit according to the amount of operation of the control unit when the operator selects the second operating mode; A fourth calculation step (ST240) that receives input information regarding the pressure of the actuator unit (210), the pressure of the pump unit (100), and the area of ​​the spool, and calculates the actual flow rate of the operating fluid supplied to the actuator unit; A control method for a hydraulic device for construction machinery comprising a fifth calculation step (ST250) for comparing and determining the target flow rate and the actual flow rate of the actuator unit.

18. In Paragraph 17, A control method for a hydraulic device for construction machinery, wherein the above-mentioned operating mode control step (ST200) further includes a pump unit pressure control step (ST260) that performs pressure control for a pump unit by increasing the discharge pressure of the pump unit by △P above the highest operating pressure (PA) of the actuator unit caused by the operation of the operating part.

19. In Paragraph 17, The above fifth operation step (ST250) further includes a spool displacement control step (ST252) that controls the displacement of the spool according to the target flow rate and actual flow rate of the actuator unit, in a control method for a hydraulic device for construction machinery.

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