Construction machine

Abstract

The present invention relates to a construction machine comprising: pumps including a first pump and a second pump that are connected to an engine; pump lines including a first pump line for discharging the flow from the first pump and a second pump line for discharging the flow from the second pump; a main control valve connected to the first pump line and the second pump line; a swing line for allowing communication between the main control valve and a swing actuator; a boom line for allowing communication between the main control valve and a boom actuator; a regeneration line including a first convergence line that communicates with the first pump line and a second convergence line that communicates with the second pump line, and allowing communication between the pump line and the swing line and / or the boom line; and a control unit for controlling that between the first convergence line and the second convergence line, the one with higher regeneration efficiency is to be open, and thus performance and fuel efficiency can be improved.

Description

construction machinery

[0001] The present invention relates to construction machinery, and more particularly, to construction machinery capable of performing civil engineering or construction work.

[0002] In general, construction machinery is a machine used in civil engineering or construction work, such as an excavator or loader, and includes a lower body that can move along the ground, an upper rotating body that is rotatably provided on top of the lower body, a boom that is rotatably connected to the upper rotating body, a hydraulic circuit for operating the upper rotating body and the boom, and a control unit that controls the hydraulic circuit.

[0003] However, conventional construction machines had problems with poor performance and fuel efficiency.

[0004] Accordingly, the present invention aims to provide a construction machine capable of improving performance and fuel efficiency.

[0005] The present invention, in order to achieve the above-described object, provides a construction machine including a pump including a first pump and a second pump connected to an engine, a pump line including a first pump line through which a flow rate is discharged from the first pump and a second pump line through which a flow rate is discharged from the second pump, a main control valve connected on the first pump line and the second pump line, a swing line connecting the main control valve and a swing actuator, a boom line connecting the main control valve and a boom actuator, a first junction line connected to the first pump line and a second junction line connected to the second pump line, and a regeneration line connecting at least one of the swing line and the boom line to the pump line, and a control unit that controls to open one of the first junction line and the second junction line having a greater regeneration efficiency.

[0006] The above recovery line further includes a first merging valve for opening and closing the first merging line and a second merging valve for opening and closing the second merging line, and the control unit can determine opening and closing of the first merging valve or the second merging valve by comparing an output required for the first pump with an output required for the second pump.

[0007] The control unit can calculate the output required for the first pump by multiplying the pressure of the first pump and the flow rate required for the first pump, and can calculate the output required for the second pump by multiplying the pressure of the second pump and the flow rate required for the second pump.

[0008] The flow rate required for the first pump may be compared with a predetermined reference flow rate, and if the flow rate required for the first pump is greater than the reference flow rate, the recovery line may be connected.

[0009] The pressure of the first pump may be compared with a predetermined reference pressure, and if the pressure of the first pump is greater than the reference pressure, the recovery line may be connected.

[0010] If the flow rate required for the first pump is less than or equal to a predetermined reference flow rate or the pressure of the first pump is less than or equal to a predetermined reference pressure, the output required for the first pump is considered to be less than the output required for the second pump, and the first confluence line may be closed and the second confluence line may be opened.

[0011] The above recovery line may further include a swing recovery line branched from the swing line, a swing recovery valve for opening and closing the swing recovery line, a boom recovery line branched from the boom line, a boom recovery valve for opening and closing the boom recovery line, and a terminal line connecting the swing recovery line and the boom recovery line to the first junction line and the second junction line.

[0012] The above recovery line may further include a high pressure accumulator for storing and discharging fluid, a high pressure accumulator line connecting the terminal line and the high pressure accumulator, and a high pressure accumulator valve for opening and closing the high pressure accumulator line.

[0013] The above recovery line may further include a tank for storing fluid, a safety line connecting the terminal line and the tank, and a safety valve for opening and closing the safety line.

[0014] The above recovery line may further include a third junction line branching from the swing recovery line and communicating with the first pump line, and a third junction valve for opening and closing the third junction line.

[0015] The above recovery line may further include a low-pressure accumulator for storing and discharging fluid, a low-pressure accumulator line for connecting the low-pressure accumulator with the swing recovery line, a low-pressure accumulator valve for opening and closing the low-pressure accumulator line, and a make-up line for connecting the low-pressure accumulator line with the swing line.

[0016] The boom actuator may include a cylinder, a piston capable of reciprocating inside the cylinder, and a rod extending from the piston to the outside of the cylinder, the inside of the cylinder being partitioned into a pair of chambers by the piston, the pair of chambers including a rod chamber in which the rod is received and a head chamber which is an opposite chamber of the rod chamber, and the boom line may include a head line connecting the main control valve and the head chamber, a rod line connecting the main control valve and the rod chamber, a cavitation line connecting the head line and the rod line, and a cavitation valve opening and closing the cavitation line.

[0017] The above boom recovery line can be branched from the above cavitation line.

[0018] The above swing line further includes a swing direction control valve for controlling the flow direction of the fluid within the swing line, and the swing recovery line can be connected to and shielded from the swing line by the swing direction control valve.

[0019] And, the present invention provides a construction machine including a first pump for supplying a flow rate to a swing actuator through a first pump line and a second pump for supplying a flow rate to a boom actuator through a second pump line; a high-pressure accumulator for storing and discharging a fluid from the swing actuator or the boom actuator; a first merging line connecting the high-pressure accumulator and the first pump line; a second merging line connecting the high-pressure accumulator and the second pump line; and a control unit for controlling to open one of the first merging line and the second merging line having a greater regenerative efficiency.

[0020] A construction machine according to the present invention comprises a pump including a first pump and a second pump connected to an engine, a pump line including a first pump line through which a flow rate is discharged from the first pump and a second pump line through which a flow rate is discharged from the second pump, a main control valve connected on the first pump line and the second pump line, a swing line connecting the main control valve and a swing actuator, a boom line connecting the main control valve and a boom actuator, a first junction line connected to the first pump line and a second junction line connected to the second pump line, a regeneration line connecting at least one of the swing line and the boom line to the pump line, and a control unit that controls to open one of the first junction line and the second junction line having a greater regeneration efficiency, thereby improving performance and fuel efficiency.

[0021] Figure 1 is a front view showing a construction machine according to one embodiment of the present invention;

[0022] Figure 2 is a schematic diagram showing the hydraulic circuit in the construction machine of Figure 1.

[0023] Fig. 3 is a schematic diagram for explaining the operating principle of the hydraulic circuit of Fig. 2, and is a schematic diagram showing the flow rate in normal mode.

[0024] Fig. 4 is a schematic diagram for explaining the operating principle of the hydraulic circuit of Fig. 2, and is a schematic diagram showing the flow rate in the fuel economy mode during the regenerative mode.

[0025] Fig. 5 is a schematic diagram for explaining the operating principle of the hydraulic circuit of Fig. 2, and is a schematic diagram showing the flow rate in the performance mode during the regenerative mode.

[0026] Fig. 6 is a schematic diagram for explaining the operating principle of the hydraulic circuit of Fig. 2, and is a schematic diagram showing the flow rate in the composite mode during the regenerative mode.

[0027] Fig. 7 is a flowchart illustrating the logic for selecting a pump to be joined in the hydraulic circuit of Fig. 2.

[0028] Fig. 8 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 during boom-down operation in normal mode.

[0029] Figure 9 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Figure 2 when the fluid is stored in the high-pressure accumulator during boom-down operation in the regenerative mode.

[0030] Fig. 10 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 when the fluid cannot be stored in the high-pressure accumulator during boom-down operation in regenerative mode;

[0031] Fig. 11 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 when the fluid joins the pump without passing through the high-pressure accumulator during boom-down operation in regenerative mode.

[0032] Fig. 12 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 during boom-up operation in normal mode.

[0033] Fig. 13 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 during boom-up operation in regenerative mode.

[0034] Fig. 14 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 during swing-acceleration operation in normal mode.

[0035] Fig. 15 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 during swing-acceleration operation in regenerative mode.

[0036] Fig. 16 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 during swing-deceleration operation in normal mode.

[0037] Fig. 17 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 when the fluid is stored in the high-pressure accumulator during the swing-deceleration operation in the regenerative mode.

[0038] Figure 18 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Figure 2 when the fluid cannot be stored in the high-pressure accumulator or is required to join the first pump during the swing-deceleration operation in the regenerative mode.

[0039] Fig. 19 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 during jack-up operation in regenerative mode.

[0040] Fig. 20 is a schematic diagram showing the flow of fluid in the hydraulic circuit of Fig. 2 when idle in normal mode.

[0041] FIG. 21 is a flowchart illustrating a logic for determining the conditions and flow rate for joining fluid to a pump in a hydraulic circuit of a construction machine according to another embodiment of the present invention.

[0042] Fig. 22 is a schematic diagram for explaining the operating principle of a hydraulic circuit controlled according to the logic of Fig. 21, and is a schematic diagram showing the flow rate when the pump output is small and no merging occurs.

[0043] Fig. 23 is a schematic diagram for explaining the operating principle of a hydraulic circuit controlled according to the logic of Fig. 21, and is a schematic diagram showing the flow rate when the pump output is small but the operator wants merging to occur when the bucket actuator is operated.

[0044] Hereinafter, a construction machine according to the present invention will be described in detail with reference to the attached drawings.

[0045] FIG. 1 is a front view illustrating a construction machine according to one embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating a hydraulic circuit in the construction machine of FIG. 1. FIGS. 3 to 6 are schematic diagrams for explaining the operating principles of the hydraulic circuit of FIG. 2. FIG. 7 is a flowchart illustrating the logic for selecting a pump to be joined in the hydraulic circuit of FIG. 2. FIGS. 8 to 20 are schematic diagrams illustrating the flow of fluid in the hydraulic circuit of FIG. 2 according to modes and operations.

[0046] Referring to FIG. 1, a construction machine according to one embodiment of the present invention may include a lower body (Uc) movable along the ground, an upper rotating body (Sw) rotatably provided on an upper portion of the lower body (Uc), a boom (Bm) rotatably coupled to the upper rotating body (Sw), an arm (Am) rotatably coupled to a tip end of the boom (Bm), a bucket (Bk) rotatably coupled to a tip end of the arm (Am), a hydraulic circuit for operating the upper rotating body (Sw), the boom (Bm), the arm (Am), and the bucket (Bk), and a control unit for controlling the hydraulic circuit.

[0047] Referring to FIG. 2, the hydraulic circuit may include a swing actuator (100) for rotating the upper rotor (Sw), a boom actuator (200) for rotating the boom (Bm), a pump (300) driven by receiving power from an engine (Eg), a main control valve (400) for transmitting fluid transported by the pump (300) to the swing actuator (100) and the boom actuator (200), a pump line (500) for connecting the pump (300) and the main control valve (400), a swing line (600) for connecting the main control valve (400) and the swing actuator (100), and a boom line (700) for connecting the main control valve (400) and the boom actuator (200).

[0048] The above swing actuator (100) may include a first opening (110) and a second opening (120) that are connected to each other and a rotor (130) that is connected to the upper rotating body (Sw) and rotates in one direction and the opposite direction depending on the direction of fluid flow between the first opening (110) and the second opening (120).

[0049] The boom actuator (200) may include a cylinder (210) connected to the upper rotating body (Sw), a piston (220) capable of reciprocating inside the cylinder (210), and a rod (230) extending from the piston (220) to the outside of the cylinder (210) and connected to the boom (Bm).

[0050] Here, the interior of the cylinder (210) is partitioned into a pair of chambers (240, 250) by the piston (220), and the pair of chambers (240, 250) may include a load chamber (250) in which the load (230) is received and a head chamber (240) which is an opposite chamber of the load chamber (250).

[0051] The above pump (300) may include a first pump (310) and a second pump (320) connected in parallel to the engine (Eg).

[0052] The above main control valve (400) may include a swing main control valve (410) for transmitting fluid to the swing actuator (100) and a boom main control valve (420) for transmitting fluid to the boom actuator (200).

[0053] The above pump line (500) may include a first pump line (510) that connects the first pump (310) and the swing main control valve (410) and a second pump line (520) that connects the second pump (320) and the boom main control valve (420).

[0054] The above swing line (600) includes a swing direction control valve (690) for controlling the flow direction of the fluid in the swing line (600), a first swing line (610) for connecting one side of the swing direction control valve (690) and the swing main control valve (410), a second swing line (620) for connecting the other side of the swing direction control valve (690) and the swing main control valve (410), a third swing line (630) for connecting the swing direction control valve (690) and the first opening (110) of the swing actuator (100), a fourth swing line (640) for connecting the swing direction control valve (690) and the second opening (120) of the swing actuator (100), and a third swing line (630) for connecting the third swing line (630) and the fourth swing line (640) without allowing the fluid to flow in from the third swing line (630) and the fourth swing line (640). It may include a fifth swing line (650) that allows fluid to be discharged through the swing line (640), a sixth swing line (660) that does not allow fluid to be discharged through the third swing line (630) and the fourth swing line (640) and allows fluid to flow in from the third swing line (630) and the fourth swing line (640), and a seventh swing line (670) that connects the fifth swing line (650) and the sixth swing line (660).

[0055] The above boom line (700) may include a head line (710) that connects the boom main control valve (420) and the head chamber (240), a load line (720) that connects the main control valve (400) and the load chamber (250), a cavitation line (730) that connects the head line (710) and the load line (720), and a cavitation valve (730v) that opens and closes the cavitation line (730).

[0056] Here, the hydraulic circuit according to the present embodiment may further include a recovery line (Reg) that connects at least one of the swing line (600) and the boom line (700) with the pump line (500).

[0057] Specifically, the recovery line (Reg) may include a swing recovery line (810) that is connected and shielded from the swing line (600) by the swing direction control valve (690), a swing recovery valve (810v) that opens and closes the swing recovery line (810), a low-pressure accumulator (820) for storing and discharging low-pressure fluid, a low-pressure accumulator line (830) that connects the low-pressure accumulator (820) to the swing recovery line (810), a low-pressure accumulator valve (830v) that opens and closes the low-pressure accumulator line (830), and a make-up line (840) that connects the low-pressure accumulator line (830) to the fifth swing line (650), the sixth swing line (660), and the seventh swing line (670).

[0058] In addition, the above recovery line (Reg) may further include a boom recovery line (910) branched from the cavitation line (730) and a boom recovery valve (910v) for opening and closing the boom recovery line (910).

[0059] In addition, the recovery line (Reg) may further include a first merging line (930) communicating with the first pump line (510), a first merging valve (930v) for opening and closing the first merging line (930), a second merging line (940) communicating with the second pump line (520), a second merging valve (940v) for opening and closing the second merging line (940), and a terminal line (920) for connecting the swing recovery line (810) and the boom recovery line (910) to the first merging line (930) and the second merging line (940).

[0060] In addition, the recovery line (Reg) may further include a high-pressure accumulator (950) for storing and discharging high-pressure fluid, a high-pressure accumulator line (960) for connecting the terminal line (920) and the high-pressure accumulator (950), and a high-pressure accumulator valve (960v) for opening and closing the high-pressure accumulator line (960).

[0061] In addition, the recovery line (Reg) may further include a tank (T) for storing the discharged fluid, a safety line (970) connecting the terminal line (920) and the tank (T), and a safety valve (970v) for opening and closing the safety line (970).

[0062] Here, the tank (T) can also be communicated with the main control valve (400) through a drain line (Dr).

[0063] In addition, the recovery line (Reg) may further include a third junction line (850) branched from the swing recovery line (810) and connected to the first pump line (510), and a third junction valve (850v) for opening and closing the third junction line (850).

[0064] The above control unit can be configured to improve fuel efficiency and performance by utilizing such a hydraulic circuit.

[0065] Specifically, if the flow rate of the fluid supplied to the main control valve (400) through the pump line (500) is referred to as the supply flow rate (Q_s1, Q_s2), the flow rate of the fluid supplied by the pump (300) to the pump line (500) is referred to as the pump flow rate (Q_p1, Q_p2), and the flow rate of the fluid supplied to the pump line (500) through the recovery line (Reg) is referred to as the recovery flow rate (Q_r1, Q_r2), then the control unit may be configured to determine the pump flow rates (Q_p1, Q_p2) from the difference between the supply flow rates (Q_s1, Q_s2) and the recovery flow rates (Q_r1, Q_r2) determined according to the mode and drive the pump (300).

[0066] Here, the supply flow rates (Q_s1, Q_s2) are the sum of the basic supply flow rates (Q_cmd1, Q_cmd2), which are the minimum flow rates required to operate the swing actuator (100) and the boom actuator (200), and the additional supply flow rates (Q_add1, Q_add2), which are flow rates exceeding the basic supply flow rates (Q_cmd1, Q_cmd2), and the basic supply flow rates (Q_cmd1, Q_cmd2) are determined according to the driver's input value, and the additional supply flow rates (Q_add1, Q_add2) are determined by multiplying the maximum regenerative flow rates (Q_max1, Q_max2), which are the maximum values ​​of the regenerative flow rates (Q_r1, Q_r2), by a predetermined performance constant, and the performance constant can be determined in the range of 0 to 1 depending on the mode.

[0067] In addition, the above-described recovery flow rates (Q_r1, Q_r2) are determined by multiplying the maximum recovery flow rates (Q_max1, Q_max2), which are the maximum values ​​of the above-described recovery flow rates (Q_r1, Q_r2), by a predetermined recovery constant, and the above-described recovery constant can be determined in the range of 0 to 1 depending on the mode.

[0068] More specifically, referring to FIG. 3, the driver can select a normal mode in which the regenerative line (Reg) is deactivated and input the basic supply flow rates (Q_cmd1, Q_cmd2) as 250 lpm (Q_cmd1: 100 lpm, Q_cmd2: 150 lpm) using the joystick. In this case, the performance constant is determined to be 0, so the additional supply flow rates (Q_add1, Q_add2) are determined to be 0 lpm (Q_add1: 0 lpm, Q_add2: 0 lpm), and the supply flow rates (Q_s1, Q_s2) can be determined to be 250 lpm (Q_s1: 100 lpm, Q_s2: 150 lpm). And, since the above recovery constant is determined to be 0, the above recovery flow rates (Q_r1, Q_r2) can be determined to be 0 lpm (Q_r1: 0 lpm, Q_r2: 0 lpm). Accordingly, the pump flow rates (Q_p1, Q_p2) are determined to be 250 lpm (Q_p1: 100 lpm, Q_p2: 150 lpm) obtained by subtracting the recovery flow rates (Q_r1, Q_r2) from the supply flow rates (Q_s1, Q_s2), and the pump (300) can be controlled to discharge the determined flow rates.

[0069] On the other hand, referring to FIG. 4, the driver can select a fuel efficiency mode among the regeneration modes in which the regeneration line (Reg) is activated and input the basic supply flow rates (Q_cmd1, Q_cmd2) as 250 lpm (Q_cmd1: 100 lpm, Q_cmd2: 150 lpm) using the joystick. In this case, the performance constant is determined to be 0, so the additional supply flow rates (Q_add1, Q_add2) are determined to be 0 lpm (Q_add1: 0 lpm, Q_add2: 0 lpm), and the supply flow rates (Q_s1, Q_s2) can be determined to be 250 lpm (Q_s1: 100 lpm, Q_s2: 150 lpm). Meanwhile, the above-described recovery constant is determined as the maximum value currently possible in the range of 0 to 1. Assuming that the maximum value currently possible among the above-described recovery constants is 1, and assuming that the maximum recovery flow rate (Q_max1, Q_max2) is 50 lpm, the recovery flow rate (Q_r1, Q_r2) can be determined as 50 lpm (Q_r1: 0 lpm, Q_r2: 50 lpm) obtained by multiplying the maximum recovery flow rate (Q_max1, Q_max2) by the recovery constant. Accordingly, the pump flow rate (Q_p1, Q_p2) is determined as 200 lpm (Q_p1: 100 lpm, Q_p2: 100 lpm) obtained by subtracting the recovery flow rate (Q_r1, Q_r2) from the supply flow rate (Q_s1, Q_s2), and the pump (300) can be controlled to discharge the determined flow rate. In this case, fuel efficiency can be improved as the energy required for the pump (300) is saved compared to the case of FIG. 3.

[0070] Alternatively, referring to FIG. 5, the driver can select a performance mode among the above regeneration modes and input the basic supply flow rate (Q_cmd1, Q_cmd2) as 250 lpm (Q_cmd1: 100 lpm, Q_cmd2: 150 lpm) using the joystick. In this case, the performance constant is determined as 1, and when the maximum regenerative flow rate (Q_max1, Q_max2) is assumed to be 50 lpm, the additional supply flow rate (Q_add1, Q_add2) is determined as 50 lpm (Q_add1: 0 lpm, Q_add2: 50 lpm), and the supply flow rate (Q_s1, Q_s2) can be determined as 300 pm (Q_s1: 100 lpm, Q_s2: 200 lpm) which is the sum of the additional supply flow rate (Q_add1, Q_add2) and the basic supply flow rate (Q_cmd1, Q_cmd2). Meanwhile, the above-described recovery constant is determined as the maximum value currently possible in the range of 0 to 1. If the maximum value currently possible among the above-described recovery constants is assumed to be 1, the recovery flow rate (Q_r1, Q_r2) can be determined as 50 lpm (Q_r1: 0 lpm, Q_r2: 50 lpm) which is obtained by multiplying the maximum recovery flow rate (Q_max1, Q_max2) by the recovery constant. Accordingly, the pump flow rate (Q_p1, Q_p2) is determined as 250 lpm (Q_p1: 100 lpm, Q_p2: 150 lpm) which is obtained by subtracting the recovery flow rate (Q_r1, Q_r2) from the supply flow rate (Q_s1, Q_s2), and the pump (300) can be controlled to discharge the determined flow rate. In this case, compared to the case of FIG. 3, the energy required for the pump (300) is the same, so there is no improvement in fuel efficiency, but the flow rate of the fluid supplied to the main control valve (400) increases, so that performance can be improved.

[0071] Alternatively, referring to FIG. 6, the driver may select a composite mode among the above regeneration modes and input the basic supply flow rate (Q_cmd1, Q_cmd2) as 250 lpm (Q_cmd1: 100 lpm, Q_cmd2: 150 lpm) using the joystick. In this case, the performance constant is determined as a value desired by the driver in a range greater than 0 and less than 1. Assuming that the driver desires 0.4 as the performance constant, and assuming that the maximum regenerative flow rate (Q_max1, Q_max2) is 50 lpm, the additional supply flow rate (Q_add1, Q_add2) is determined as 20 lpm (Q_add1: 0 lpm, Q_add2: 20 lpm), and the supply flow rate (Q_s1, Q_s2) can be determined as 270 pm (Q_s1: 100 lpm, Q_s2: 170 lpm) which is the sum of the additional supply flow rate (Q_add1, Q_add2) and the basic supply flow rate (Q_cmd1, Q_cmd2). Meanwhile, the above-described recovery constant is determined as the maximum value currently possible in the range of 0 to 1. If the maximum value currently possible among the above-described recovery constants is assumed to be 1, the recovery flow rate (Q_r1, Q_r2) can be determined as 50 lpm (Q_r1: 0 lpm, Q_r2: 50 lpm) which is obtained by multiplying the maximum recovery flow rate (Q_max1, Q_max2) by the recovery constant. Accordingly, the pump flow rate (Q_p1, Q_p2) is determined as 220 lpm (Q_p1: 100 lpm, Q_p2: 120 lpm) which is obtained by subtracting the recovery flow rate (Q_r1, Q_r2) from the supply flow rate (Q_s1, Q_s2), and the pump (300) can be controlled to discharge the determined flow rate. In this case, the fuel efficiency improvement effect is reduced compared to the case of Fig. 4, and the performance improvement effect is reduced compared to the case of Fig. 5, but the fuel efficiency and performance can be improved compared to the case of Fig. 3.

[0072] Meanwhile, in the case of FIGS. 4 to 6, it is assumed that the second joining line (940) is opened, but the control unit may be formed to open the line with the greater regeneration efficiency among the first joining line (930) and the second joining line (940).

[0073] That is, the control unit may be configured to compare the output (P1 Power) required for the first pump (310) with the output (P2 Power) required for the second pump (320) according to the logic illustrated in FIG. 7, and if the output (P1 Power) required for the first pump (310) is greater than the output (P2 Power) required for the second pump (320), open the first merging line (930) with the first merging valve (930v) and close the second merging line (940) with the second merging valve (940v), and if the output (P1 Power) required for the first pump (310) is less than the output (P2 Power) required for the second pump (320), close the first merging line (930) with the first merging valve (930v) and open the second merging line (940) with the second merging valve (940v).

[0074] Specifically, the logic illustrated in FIG. 7 includes a first pump information input step (S1) for receiving the pressure (p_p1) of the first pump (310) and the flow rate (Q_p1 cmd) required for the first pump (310); a first pump output calculation step (S4) for calculating the output (P1 Power) required for the first pump (310) by multiplying the pressure (p_p1) of the first pump (310) and the flow rate (Q_p1 cmd) required for the first pump (310); a second pump information input step (S5) for receiving the pressure (p_p2) of the second pump (320) and the flow rate (Q_p2 cmd) required for the second pump (320); A second pump output calculation step (S6) for calculating the output (P2 Power) required for the second pump (320) by multiplying the pressure (p_p2) of the second pump (320) and the flow rate (Q_p2 cmd) required for the second pump (320); A pump output comparison step (S7) for comparing the output (P1 Power) required for the first pump (310) and the output (P2 Power) required for the second pump (320); And, when the output (P1 Power) required for the first pump (310) is greater than the output (P2 Power) required for the second pump (320), the first merging line (930) is opened by the first merging valve (930v) and the second merging line (940) is closed by the second merging valve (940v), and when the output (P1 Power) required for the first pump (310) is less than the output (P2 Power) required for the second pump (320), the first merging line (930) is closed by the first merging valve (930v) and the second merging line (940) is opened by the second merging valve (940v), and the control unit may be configured to control the regenerative line (Reg) according to the logic.

[0075] Here, the logic may be configured such that a first pump flow rate comparison step (S2) is provided between the first pump information input step (S1) and the first pump output calculation step (S4) to compare the flow rate (Q_p1 cmd) required for the first pump (310) with a predetermined reference flow rate (e.g., 10 lpm), and the first pump output calculation step (S4) is executed when the flow rate (Q_p1 cmd) required for the first pump (310) is determined to be greater than the reference flow rate in the first pump flow rate comparison step (S2).

[0076] And, the logic may be configured to include a first pump pressure comparison step (S3) for comparing the pressure (p_p1) of the first pump (310) with a predetermined reference pressure (e.g., accumulator pressure (p_Accm.)) between the first pump information input step (S1) and the first pump output calculation step (S4), and to execute the first pump output calculation step (S4) when it is determined in the first pump pressure comparison step (S3) that the pressure (p_p1) of the first pump (310) is greater than the reference pressure.

[0077] And, the logic may be formed so that, if the first pump output calculation step (S4) is not executed, the output (P1 Power) required for the first pump (310) is considered to be smaller than the output (P2 Power) required for the second pump (320) in the pump output comparison step (S7), and the first merging line (930) is closed and the second merging line (940) is opened in the merging line selection step (S9).

[0078] In addition, the logic may be configured to include a mode confirmation step (S8) for confirming whether the driver has selected the regeneration mode between the pump output comparison step (S7) and the joining line selection step (S9), and to execute the joining line selection step (S9) when it is confirmed that the regeneration mode has been selected in the mode confirmation step (S8).

[0079] Meanwhile, the control unit may be configured to activate the regenerative line (Reg) when the driver has an intention to activate the regenerative line (Reg), activation of the regenerative line (Reg) is possible, and the operation performed is an operation with a high regenerative efficiency.

[0080] Specifically, there is a boom-down operation in which the piston (220) moves toward the head chamber (240) and the boom actuator (200) contracts, which is a frequently used operation by the user.

[0081] Referring to Fig. 8, when the driver selects the normal mode and performs a boom-down operation, the fluid in the head chamber (240) can flow to the main control valve (400) through the head line (710) by the load of the boom (Bm) applied through the load (230) and then be discharged to the tank (T) through the drain line (Dr). In addition, as the fluid discharged from the second pump (320) flows to the load chamber (250) through the second pump line (520), the main control valve (400) and the load line (720), cavitation of the load chamber (250) can be prevented.

[0082] On the other hand, referring to FIGS. 9 to 11, when the driver selects the regeneration mode and performs a boom-down operation, the cavitation valve (730v) opens the cavitation line (730), so that a portion of the fluid in the head line (710) flows through the cavitation line (730) to the load line (720), thereby preventing cavitation in the load chamber (250). Here, since there is no need to drive the second pump (320) to prevent cavitation in the load chamber (250), fuel efficiency can be improved compared to the case of FIG. 8.

[0083] And, the boom recovery valve (910v) opens the boom recovery line (910), so that the remainder of the fluid in the head line (710) can flow through the boom recovery line (910) to the terminal line (920) and then be stored in the high-pressure accumulator (950) or flow to the pump line (500). That is, as shown in FIGS. 9 and 10, the high-pressure accumulator valve (960v) opens the high-pressure accumulator line (960), so that at least a portion of the fluid in the terminal line (920) is stored in the high-pressure accumulator (950), and the fluid stored in the high-pressure accumulator (950) can be later discharged. Alternatively, as illustrated in FIG. 11, when the fluid cannot be stored in the high-pressure accumulator (950) or the required flow rate in the pump line (500) is large, the high-pressure accumulator valve (960v) closes the high-pressure accumulator line (960) and the merging valve opens the merging line, so that at least a portion of the fluid in the terminal line (920) can flow into the pump line (500) through the merging line. In this way, by regenerating the fluid in the boom line (700), fuel efficiency and / or performance can be improved compared to the case of FIG. 8. Here, in the case of FIG. 10, when the fluid cannot be stored in the high-pressure accumulator (950), the fluid in the head line (710) is discharged to the tank (T) through the main control valve and the drain line (Dr), thereby preventing the speed of the boom actuator (200) from becoming slower than the target speed when recovering the fluid in the boom line (700).

[0084] And, there is a boom-up motion in which the piston (220) moves toward the load chamber (250) and the boom actuator (200) extends, which is a motion frequently used by the user.

[0085] Referring to Fig. 12, when the driver selects the normal mode and performs a boom-up operation, the fluid discharged from the second pump (320) can flow into the head chamber (240) through the second pump line (520), the main control valve (400), and the head line (710). In addition, the fluid in the load chamber (250) can flow into the main control valve (400) through the load line (720) and then be discharged into the tank (T) through the drain line (Dr).

[0086] On the other hand, referring to FIG. 13, when the driver selects the regeneration mode and performs a boom-up operation, the high-pressure accumulator valve (960v) opens the high-pressure accumulator line (960), and the second merging valve (940v) opens the second merging line (940), so that the fluid of the high-pressure accumulator (950) flows to the second pump line (520) through the high-pressure accumulator line (960), the terminal line (920), and the second merging line (940), and the main control valve (400) can transfer the fluid received from the second pump (320) and the second merging line (940) through the second pump line (520) to the head chamber (240) through the head line (710). And, the fluid in the load chamber (250) can flow to the main control valve (400) through the load line (720) and then be discharged to the tank (T) through the drain line (Dr). In this case, by assisting the second pump (320) with the fluid stored in the high-pressure accumulator (950), fuel efficiency and / or performance can be improved compared to the case of FIG. 12.

[0087] And, there is a swing-acceleration motion in which the swing actuator (100) accelerates and a swing-deceleration motion in which the swing actuator (100) decelerates, which are motions frequently used by the user.

[0088] Referring to FIG. 14, when the driver selects the normal mode and performs the swing-acceleration operation, the main control valve (400) connects the first pump line (510) to the first swing line (610) and the second swing line (620) to the drain line (Dr), and the swing direction control valve (690) connects the first swing line (610) to the third swing line (630) and the fourth swing line (640) to the second swing line (620), so that the fluid discharged from the first pump (310) flows through the first pump line (510), the main control valve (400), the first swing line (610), the swing direction control valve (690), the third swing line (630), the first opening (110), the second opening (120), the fourth swing line (640), and the swing direction control valve (690). The fluid is discharged into the tank (T) sequentially passing through the valve (690), the second swing line (620), the main control valve (400) and the drain line (Dr), and the rotor (130) can be accelerated and rotated in one direction.

[0089] Here, although not shown, the main control valve (400) connects the first pump line (510) to the second swing line (620) and connects the first swing line (610) to the drain line (Dr), and the swing direction control valve (690) connects the second swing line (620) to the fourth swing line (640) and connects the third swing line (630) to the first swing line (610), so that the fluid discharged from the first pump (310) flows through the first pump line (510), the main control valve (400), the second swing line (620), the swing direction control valve (690), the fourth swing line (640), the second opening (120), the first opening (110), the third swing line (630), the swing direction control valve (690), the first swing line (610), and the It passes through the main control valve (400) and the drain line (Dr) sequentially and is discharged into the tank (T), and the rotor (130) can be accelerated and rotated in the opposite direction.

[0090] On the other hand, referring to FIG. 15, when the driver selects the regeneration mode and performs the swing-acceleration operation, the main control valve (400) connects the first pump line (510) to the first swing line (610), the swing direction control valve (690) connects the first swing line (610) to the third swing line (630) and connects the fourth swing line (640) to the swing regeneration line (810), and the low-pressure accumulator valve (830v) opens the low-pressure accumulator line (830), so that the fluid discharged from the first pump (310) flows through the first pump line (510), the main control valve (400), the first swing line (610), the swing direction control valve (690), the third swing line (630), the first opening (110), the second opening (120), and the fourth It passes sequentially through the swing line (640), the swing direction control valve (690), the swing recovery line (810) and the low-pressure accumulator line (830) and is stored in the low-pressure accumulator (820), and the rotor (130) can be accelerated and rotated in one direction.

[0091] Here, although not shown, the main control valve (400) connects the first pump line (510) to the second swing line (620), the swing direction control valve (690) connects the second swing line (620) to the fourth swing line (640) and connects the third swing line (630) to the swing recovery line (810), and the low-pressure accumulator valve (830v) opens the low-pressure accumulator line (830), so that the fluid discharged from the first pump (310) flows through the first pump line (510), the main control valve (400), the second swing line (620), the swing direction control valve (690), the fourth swing line (640), the second opening (120), the first opening (110), the third swing line (630), the swing direction control valve (690), and the swing It passes sequentially through the recovery line (810) and the low-pressure accumulator line (830) and is stored in the low-pressure accumulator (820), and the rotor (130) can be accelerated and rotated in the opposite direction.

[0092] And, referring to FIG. 16, when the driver selects the normal mode and performs the swing-deceleration operation, the fluid discharged from the second opening (120) sequentially passes through the fourth swing line (640), the sixth swing line (660), the seventh swing line (670), the fifth swing line (650), and the third swing line (630) and then flows into the first opening (110), and the rotor (130) can rotate at a deceleration rate in one direction.

[0093] Here, although not shown, when the fluid discharged from the first opening (110) sequentially passes through the third swing line (630), the sixth swing line (660), the seventh swing line (670), the fifth swing line (650), and the fourth swing line (640) and then flows into the second opening (120), the rotor (130) can be rotated at a reduced speed in the opposite direction.

[0094] On the other hand, referring to FIG. 17, when the driver selects the regeneration mode and performs a swing-deceleration operation, the swing direction control valve (690) connects the fourth swing line (640) with the swing regeneration line (810), the swing regeneration valve (810v) opens the swing regeneration line (810), and the high-pressure accumulator valve (960v) opens the high-pressure accumulator line (960), so that the fluid discharged from the second opening (120) sequentially passes through the fourth swing line (640), the swing direction control valve (690), the swing regeneration line (810), the terminal line (920), and the high-pressure accumulator line (960) and is stored in the high-pressure accumulator (950), and the rotor (130) can be decelerated and rotated in one direction. At this time, the low-pressure accumulator valve (830v) closes the low-pressure accumulator line (830), and the fluid of the low-pressure accumulator (820) can flow to the suction line of the swing actuator (100) among the swing lines (600) through the make-up line (840).

[0095] Here, although not shown, the swing direction control valve (690) connects the third swing line (630) with the swing regeneration line (810), the swing regeneration valve (810v) opens the swing regeneration line (810), and the high-pressure accumulator valve (960v) opens the high-pressure accumulator line (960), so that the fluid discharged from the first opening (110) sequentially passes through the third swing line (630), the swing direction control valve (690), the swing regeneration line (810), the terminal line (920), and the high-pressure accumulator line (960) and is stored in the high-pressure accumulator, and the rotor (130) can be decelerated and rotated in the opposite direction.

[0096] Meanwhile, when the fluid cannot be stored in the high-pressure accumulator (950) or the flow rate required for the first pump line (510) is large, as shown in FIG. 18, the third merging valve (850v) opens the third merging line (850), so that the fluid in the swing recovery line (810) can flow into the first pump line (510).

[0097] As shown in FIGS. 15, 17 and 18, when accelerating or decelerating a swing in the regenerative mode, the fluid in the swing line (600) is regenerated, thereby improving fuel efficiency and / or performance compared to when accelerating or decelerating a swing in the normal mode, as shown in FIGS. 14 and 16.

[0098] In addition, there is a jack-up operation that the user frequently uses to lift the construction machine by pressing the ground with the bucket (Bk), and during the jack-up operation, the pressure in the load chamber (250) must be rapidly increased and the fluid in the head chamber (240) must be rapidly decreased, which may be a condition that makes it difficult to perform the regeneration mode.

[0099] Accordingly, when the jack-up operation is executed, even if the driver has selected the regeneration mode, the operation is forcibly switched to the normal mode, and as illustrated in FIG. 19, the fluid discharged from the second pump (320) sequentially passes through the second pump line (520), the main control valve (400), and the load line (720) and flows into the load chamber (250), and the fluid in the head chamber (240) sequentially passes through the head line (710), the main control valve (400), and the drain line (Dr) and can be discharged into the tank (T).

[0100] And, when the jack-up operation is stopped, it can switch to the regenerative mode selected by the driver.

[0101] Meanwhile, when the driver selects the normal mode or turns the key off, as shown in FIG. 20, the high-pressure accumulator valve (960v) opens the high-pressure accumulator line (960), and the safety valve (970v) opens the safety line (970), so that the fluid in the high-pressure accumulator (950) is discharged into the tank (T), thereby ensuring system safety.

[0102] The construction machine of this embodiment according to this configuration can improve fuel efficiency and / or performance by regenerating fluid of at least one of the swing line (600) and the boom line (700) by having the hydraulic circuit having the recovery line (Reg) and the control unit controlling the same.

[0103] And, since the hydraulic circuit and the control unit are formed to determine the pump flow rates (Q_p1, Q_p2) from the difference between the supply flow rates (Q_s1, Q_s2) and the regenerative flow rates (Q_r1, Q_r2) determined according to the mode, fuel efficiency can be intensively improved, performance can be intensively improved, or fuel efficiency and performance can be improved at a desired ratio.

[0104] In addition, the hydraulic circuit and the control unit are configured to activate the regenerative line (Reg) when the driver intends to activate the regenerative line (Reg), the regenerative line (Reg) can be activated, and the operation performed is an operation with high regenerative efficiency, thereby effectively and efficiently improving fuel efficiency and / or performance.

[0105] In addition, the hydraulic circuit and the control unit are formed to open the first merging line (930) and the second merging line (940) having a higher regenerative efficiency, thereby maximizing fuel efficiency and / or performance improvement.

[0106] Meanwhile, the fuel efficiency improvement rate may vary depending on the conditions under which the fluid stored in the high-pressure accumulator (950) joins the pump line (500). That is, for example, when the fluid stored in the high-pressure accumulator (950) joins the pump line (500) when a movement primarily used by the operator is performed, fuel efficiency may be improved.

[0107] In consideration of this, it may be desirable for the control unit to be configured to open and close the high pressure accumulator line (960), the terminal line (920), the first merging line (930) and the second merging line (940) (hereinafter, merging flow paths (920, 930, 940, 960)) so that a predetermined flow rate flows from the high pressure accumulator (950) to the pump line (500) under predetermined conditions.

[0108] FIG. 21 is a flowchart illustrating a logic for determining a condition for joining fluid to a pump and a flow rate in a hydraulic circuit of a construction machine according to another embodiment of the present invention, FIG. 22 is a schematic diagram for explaining the operating principle of a hydraulic circuit controlled according to the logic of FIG. 21, and is a schematic diagram showing the flow rate when the output of the pump is small and joining does not occur, and FIG. 23 is a schematic diagram for explaining the operating principle of a hydraulic circuit controlled according to the logic of FIG. 21, and is a schematic diagram showing the flow rate when the output of the pump is small but the operator wants joining to occur when the bucket actuator is operated.

[0109] Referring to FIGS. 21 to 23, a construction machine according to another embodiment of the present invention may include a hydraulic circuit similar to the aforementioned embodiment.

[0110] Here, the hydraulic circuit further includes other actuators such as an arm actuator (1000) for rotating the arm (Am) and a bucket actuator (1100) for rotating the bucket (Bk), in addition to the swing actuator (100) and the boom actuator (200), and the other actuators can also be connected to the pump line (500) through the main control valve (400).

[0111] And, the operator can select a target actuator from a plurality of actuators through a target actuator selection unit, and the control unit can be configured to open the joining flow path (920, 930, 940, 960) when the target actuator operates under a predetermined condition. That is, in the case of the present embodiment, the worker may determine that the operation using the arm actuator (1000) and the bucket actuator (1100) is a mainly used operation, and may select the arm actuator (1000) and the bucket actuator (1100) as the target actuators, and the control unit may be configured to store at least one fluid among the swing line (600) and the boom line (700) in a high-pressure accumulator (950) and then open the junction flow path (920, 930, 940, 960) when at least one among the arm actuator (1000) and the bucket actuator (1100) is used.

[0112] Here, it is not desirable that the merging passage (920, 930, 940, 960) be unconditionally opened when at least one of the arm actuator (1000) and the bucket actuator (1100) is used, as the fuel efficiency is not improved. Accordingly, it may be desirable that the control unit be configured to control the merging passage (920, 930, 940, 960) by comprehensively considering the output of the pump (300), the pressure of the target actuator, the pressure of the high-pressure accumulator (950), and the operator's selection, as illustrated in FIG. 21.

[0113] Specifically, the control unit may be configured to open the confluence flow path (920, 930, 940, 960) when the output of the pump (300) is greater than a predetermined reference output (e.g., 50 kW).

[0114] And, the control unit may be configured to open the confluence passage (920, 930, 940, 960) when the pressure of the target actuator is greater than a predetermined reference pressure (e.g., 10 bar).

[0115] And, the control unit can be configured to open the merging flow path (920, 930, 940, 960) when the pressure of the high pressure accumulator (950) is greater than a predetermined value.

[0116] And, the operator may set a predetermined ratio for each of the target actuator and the pump (300), and the control unit may be configured to control the confluence flow path (920, 930, 940, 960) so that the maximum value among the calculated flow rates obtained by multiplying the ratio by the maximum flow rate that can flow from the high-pressure accumulator (950) to the pump line (500) flows from the high-pressure accumulator (950) to the pump line (500).

[0117] And, when the target actuator includes a first target actuator communicating with the first pump line (510) and a second target actuator communicating with the second pump line (520), a first ratio for the first target actuator, a second ratio for the second target actuator, a third ratio for the first pump (310) and a fourth ratio for the second pump (320) are set by the operator, and the control unit multiplies the first ratio by the maximum flow rate that can flow from the high pressure accumulator (950) to the first pump line (510) for the operation of the first target actuator, a second ratio by the maximum flow rate that can flow from the high pressure accumulator (950) to the second pump line (520) for the operation of the second target actuator, and the operation of the first pump (310). It can be formed to produce a third output flow rate obtained by multiplying the third ratio by the maximum flow rate that can flow from the high pressure accumulator (950) to the first pump line (510) for the operation of the second pump (320), and a fourth output flow rate obtained by multiplying the fourth ratio by the maximum flow rate that can flow from the high pressure accumulator (950) to the second pump line (520) for the operation of the second pump (320).

[0118] And, the control unit may be configured to control the first merging line (930) and the second merging line (940) so that the maximum value among the first output flow rate, the second output flow rate, the third output flow rate, and the fourth output flow rate flows from the high pressure accumulator (950) to the pump line (500).

[0119] That is, the control unit may be configured to control the first output flow rate to flow into the first merging line (930) when the maximum value is the first output flow rate, control the second output flow rate to flow into the second merging line (940) when the maximum value is the second output flow rate, control the third output flow rate to flow into the first merging line (930) when the maximum value is the third output flow rate, and control the fourth output flow rate to flow into the second merging line (940) when the maximum value is the fourth output flow rate.

[0120] According to this configuration, for example, in the situation of FIG. 22, even if a command is input to the bucket actuator (1100) and the arm actuator (1000) through the joystick, if the output of the pump (300) is lower than the reference pressure, the confluence path (920, 930, 940, 960) can be closed.

[0121] Alternatively, in the situation of FIG. 23, that is, if the operator desires forcible recovery to occur when the bucket actuator (1100) is operated even though the output of the pump (300) is lower than the reference pressure, the first merging line (930) may be opened and the second merging line (940) may be closed. Here, the flow rate flowing into the first pump line (510) through the first merging line (930) is determined according to the logic of FIG. 21, and 40 lpm is only an example.

[0122] Here, the fluid in the high-pressure accumulator does not join the pump line when the target actuator operates, but rather, when the flow rate is determined to be necessary from the perspective of the entire equipment when the target actuator operates, the fluid in the high-pressure accumulator joins the pump line. Accordingly, for example, when a user operates a bucket, the effect of the entire equipment moving smoothly can be felt rather than the effect of the bucket moving smoothly.

Claims

1. A pump (300) including a first pump (310) and a second pump (320) connected to an engine (Eg); A pump line (500) including a first pump line (510) through which flow is discharged from the first pump (310) and a second pump line (520) through which flow is discharged from the second pump (320); A main control valve (400) connected to the first pump line (510) and the second pump line (520); A swing line (600) connecting the main control valve (400) and the swing actuator (100); A boom line (700) connecting the main control valve (400) and the boom actuator (200); A recovery line (Reg) including a first junction line (930) communicating with the first pump line (510) and a second junction line (940) communicating with the second pump line (520), and connecting at least one of the swing line (600) and the boom line (700) with the pump line (500); and A construction machine including a control unit that controls opening of the first merging line (930) and the second merging line (940) having a higher regeneration efficiency.

2. In paragraph 1, The above recovery line (Reg) further includes a first merging valve (930v) for opening and closing the first merging line (930) and a second merging valve (940v) for opening and closing the second merging line (940). A construction machine characterized in that the control unit compares the output (P1 Power) required for the first pump (310) with the output (P2 Power) required for the second pump (320) to determine the opening and closing of the first merging valve (930v) or the second merging valve (940v).

3. In paragraph 2, A construction machine characterized in that the control unit calculates the output (P1 Power) required for the first pump (310) by multiplying the pressure (p_p1) of the first pump (310) and the flow rate (Q_p1 cmd) required for the first pump (310), and calculates the output (P2 Power) required for the second pump (320) by multiplying the pressure (p_p2) of the second pump (320) and the flow rate (Q_p2 cmd) required for the second pump (320).

4. In paragraph 3, A construction machine characterized in that the flow rate (Q_p1 cmd) required for the first pump (310) is compared with a predetermined reference flow rate, and the recovery line (Reg) is connected when the flow rate (Q_p1 cmd) required for the first pump (310) is greater than the reference flow rate.

5. In paragraph 3, A construction machine characterized in that the pressure (p_p1) of the first pump (310) is compared with a predetermined reference pressure, and the recovery line (Reg) is connected when the pressure (p_p1) of the first pump (310) is greater than the reference pressure.

6. In paragraph 3, A construction machine in which, when the flow rate (Q_p1 cmd) required for the first pump (310) is lower than or equal to a predetermined reference flow rate or the pressure (p_p1) of the first pump (310) is lower than or equal to a predetermined reference pressure, the output (P1 Power) required for the first pump (310) is considered to be lower than the output (P2 Power) required for the second pump (320), the first merging line (930) is closed, and the second merging line (940) is opened.

7. In paragraph 2, A construction machine, wherein the above recovery line (Reg) further includes a swing recovery line (810) branched from the swing line (600), a swing recovery valve (810v) for opening and closing the swing recovery line (810), a boom recovery line (910) branched from the boom line (700), a boom recovery valve (910v) for opening and closing the boom recovery line (910), and a terminal line (920) for connecting the swing recovery line (810) and the boom recovery line (910) to the first junction line (930) and the second junction line (940).

8. In paragraph 7, A construction machine, wherein the above recovery line (Reg) further includes a high-pressure accumulator (950) for storing and discharging fluid, a high-pressure accumulator line (960) for connecting the terminal line (920) and the high-pressure accumulator (950), and a high-pressure accumulator valve (960v) for opening and closing the high-pressure accumulator line (960).

9. In paragraph 7, A construction machine further comprising: the above recovery line (Reg) comprising a tank (T) for storing fluid, a safety line (970) connecting the terminal line (920) and the tank (T), and a safety valve (970v) for opening and closing the safety line (970).

10. In paragraph 7, A construction machine wherein the above recovery line (Reg) further includes a third junction line (850) branched from the swing recovery line (810) and connected to the first pump line (510), and a third junction valve (850v) for opening and closing the third junction line (850).

11. In paragraph 7, A construction machine, wherein the above recovery line (Reg) further comprises a low-pressure accumulator (820) for storing and discharging fluid, a low-pressure accumulator line (830) for connecting the low-pressure accumulator (820) with the swing recovery line (810), a low-pressure accumulator valve (830v) for opening and closing the low-pressure accumulator line (830), and a make-up line (840) for connecting the low-pressure accumulator line (830) with the swing line (600).

12. In paragraph 7, The above boom actuator (200) includes a cylinder (210), a piston (220) that can reciprocate inside the cylinder (210), and a rod (230) that extends from the piston (220) to the outside of the cylinder (210). The interior of the above cylinder (210) is divided into a pair of chambers (240, 250) by the piston (220), The above pair of chambers (240, 250) include a load chamber (250) in which the load (230) is received and a head chamber (240) which is an opposite chamber of the load chamber (250). The above boom line (700) is a construction machine including a head line (710) that connects the main control valve (400) and the head chamber (240), a load line (720) that connects the main control valve (400) and the load chamber (250), a cavitation line (730) that connects the head line (710) and the load line (720), and a cavitation valve (730v) that opens and closes the cavitation line (730).

13. In paragraph 12, The above boom recovery line (910) is a construction machine branched from the above cavitation line (730).

14. In paragraph 7, A construction machine in which the above swing line (600) further includes a swing direction control valve (690) that controls the flow direction of the fluid within the swing line (600), and the swing recovery line (810) is connected to and shielded from the swing line (600) by the swing direction control valve (690).

15. A first pump (310) for supplying flow to the swing actuator (100) through the first pump line (510) and a second pump (320) for supplying flow to the boom actuator (200) through the second pump line (520); A high pressure accumulator (950) for storing and discharging fluid from the above swing actuator (100) or the above boom actuator (200); A first junction line (930) connecting the high pressure accumulator (950) and the first pump line (510); A second junction line (940) connecting the high pressure accumulator (950) and the second pump line (520); and A construction machine including a control unit that controls opening of the first merging line (930) and the second merging line (940) having a higher regeneration efficiency.

Images