WO2019054234A1 - Construction machinery - Google Patents

Construction machinery Download PDF

Info

Publication number
WO2019054234A1
WO2019054234A1 PCT/JP2018/032747 JP2018032747W WO2019054234A1 WO 2019054234 A1 WO2019054234 A1 WO 2019054234A1 JP 2018032747 W JP2018032747 W JP 2018032747W WO 2019054234 A1 WO2019054234 A1 WO 2019054234A1
Authority
WO
WIPO (PCT)
Prior art keywords
discharge
pumps
pressure
pump
hydraulic
Prior art date
Application number
PCT/JP2018/032747
Other languages
French (fr)
Japanese (ja)
Inventor
貴雅 甲斐
平工　賢二
宏政 高橋
哲平 齋藤
Original Assignee
日立建機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日立建機株式会社 filed Critical 日立建機株式会社
Publication of WO2019054234A1 publication Critical patent/WO2019054234A1/en

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/24—Safety devices, e.g. for preventing overload
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems

Definitions

  • the present invention relates to a construction machine such as a hydraulic shovel.
  • hydraulic closed circuit system In the hydraulic closed circuit, there is no pressure loss due to the control valve, and since the pump discharges only the necessary flow rate, there is no flow rate loss. In addition, it is possible to regenerate the position energy of the hydraulic actuator and the energy at the time of deceleration. For this reason, energy saving of a construction machine is attained by applying a hydraulic closed circuit system.
  • Patent Document 1 is an example of a hydraulic shovel equipped with a hydraulic closed circuit system. Patent Document 1 enables combined operation and high-speed operation of hydraulic actuators by selectively connecting each of a plurality of hydraulic pumps to any one of a plurality of hydraulic actuators via a switching valve in a closed circuit. The configuration is described.
  • a check valve (check valve) can not be provided in the flow path. Therefore, if, for example, both discharge pumps connected in a closed circuit to the boom cylinder fail, high pressure hydraulic oil in the cap chamber, which is the load holding side of the boom cylinder, flows back to the both discharge pumps, contrary to the operator's intention. As a result, the boom cylinder retracts and the boom may fall.
  • the present invention has been made in view of the above problems, and an object thereof is to provide a construction machine capable of suppressing an unintended operation of a hydraulic actuator even when both discharge type pumps fail in a hydraulic closed circuit system. is there.
  • the present invention provides a plurality of dual discharge pumps, a plurality of hydraulic actuators connected so as to form a closed circuit selectively to the dual discharge pumps, and a plurality of dual actuators.
  • a plurality of switching valves connected between a discharge pump and the plurality of hydraulic actuators, for selectively closing the plurality of dual discharge pumps to the plurality of hydraulic actuators, and operation of the plurality of operation levers
  • Control device for performing the opening / closing control of the plurality of switching valves and the flow control of the plurality of dual discharge pumps according to the plurality of dual discharge pumps, respectively;
  • a construction machine having a drain port for returning, a pressure detector provided in each of the plurality of discharge pumps and detecting a drain pressure of hydraulic oil discharged from the drain port
  • the control device is provided with a device, and when there is a dual discharge pump whose drain pressure detected by the pressure detection device exceeds a predetermined pressure, among the multiple dual discharge pumps, the drain pressure Determines that both discharge pumps whose pressure exceeds a predetermined
  • connection is made to the failed dual discharge pumps. All switching valves being closed are closed. As a result, the backflow of the hydraulic fluid from the hydraulic actuator to the malfunctioning discharge pump is prevented, so that an unintended operation of the hydraulic actuator can be suppressed.
  • FIG. 7 is a diagram showing an example of a table defining the correspondence between each operation of the hydraulic shovel and the open / close command values of the first to fourth switching valves.
  • FIG. 1 is a side view showing a hydraulic shovel according to a first embodiment of the present invention.
  • the hydraulic shovel 100 has a lower traveling body 103 provided with crawler-type traveling devices 8 a and 8 b on both sides in the left-right direction, and an upper revolving structure 102 as a main body pivotally mounted on the lower traveling body 103. And have. On the upper revolving superstructure 102, a cab 101 is provided as an operation room on which an operator rides.
  • the lower traveling body 103 and the upper swing body 102 can be turned via a swing motor 7 as a hydraulic actuator.
  • a base end of a front work implement 104 which is an operating device for performing, for example, excavating work, is rotatably attached.
  • the front side refers to the direction (left direction in FIG. 1) in which the worker who gets on the cab 101 is facing.
  • the front work implement 104 includes a boom 2 on the front side of the upper swing body 102, in which a base end portion is rotatably connected in the vertical direction.
  • the boom 2 operates via a boom cylinder 1 which is a single rod hydraulic cylinder.
  • the tip of the rod 1 b of the boom cylinder 1 is rotatably connected to the upper swing body 102, and the base end of the cylinder tube 1 a of the boom cylinder 1 is rotatably connected to the middle of the boom 2.
  • the proximal end portion of the arm 4 is connected to the distal end portion of the boom 2 so as to be rotatable in the vertical and longitudinal directions.
  • the arm 4 operates via an arm cylinder 3 as a hydraulic actuator which is a single rod hydraulic cylinder.
  • the tip end of the rod 3b of the arm cylinder 3 is rotatably connected to the base end of the arm 4, and the base end of the cylinder tube 3a of the arm cylinder 3 is rotatably connected to the middle of the boom 2 .
  • the base end portion of the bucket 6 is connected to the tip end portion of the arm 4 so as to be rotatable in the vertical direction and the front-rear direction.
  • the bucket 6 operates via a bucket cylinder 5 which is a single rod hydraulic cylinder.
  • the tip of the rod 5b of the bucket cylinder 5 is rotatably connected to the base end of the bucket 6, and the base of the cylinder tube 5a of the bucket cylinder 5 is rotatably connected to the base of the arm 4 There is.
  • a boom control lever 30 (shown in FIG. 2) for operating the boom 2, the arm 4 and the bucket 6 constituting the front work machine 104, an arm control lever 31 (shown in FIG. 2), a bucket lever (Not shown) are arranged.
  • FIG. 2 is a schematic configuration diagram of a hydraulic closed circuit system mounted on the hydraulic shovel 100. As shown in FIG. In addition, in FIG. 2, only the part in connection with the drive of boom cylinder 1 and arm cylinder 3 is shown for simplification of description, and the part in connection with the drive of the other hydraulic actuator is abbreviate
  • the hydraulic closed circuit system 200 selectively connects the first and second pumps of both discharge type (hereinafter appropriately referred to as “both discharge type pumps”) 10 a and 10 b and the first and second pumps. Between the first pumps 10a and 10b and the hydraulic actuators 1 and 3. The hydraulic actuators 1 and 3 connected so as to form the control levers 30 and 31 as operating devices respectively corresponding to the hydraulic actuators 1 and 3 The first to fourth switching valves 11a, 11b, 12a, 12b are connected to selectively connect the first and second pumps 10a, 10b to the hydraulic actuators 1, 3 and 3, respectively, and the operation levers 30, 31.
  • a controller as a control device that performs opening / closing control of the first to fourth switching valves 11a, 11b, 12a, 12b and flow control of the first and second pumps 10a, 10b according to the operation. And a La 40.
  • the first and second pumps 10a and 10b are constituted by dual tilt hydraulic pumps and are driven by an engine (not shown).
  • the first and second pumps 10a and 10b are configured by both motor driven discharge pumps.
  • Both discharge type pumps 10a and 10b respectively adjust the inclination angles of the both tilt swash plate mechanisms 20a and 20b having a pair of supply and discharge ports as flow rate adjustment devices, and the swash plate 52 (shown in FIG. 3).
  • Regulators 21a and 21a for adjusting the displacement volume are provided.
  • the regulators 21 a and 21 b control the discharge direction and the discharge flow rate of both the discharge pumps 10 a and 10 b based on the pump discharge flow rate command value received from the controller 40.
  • both discharge type pumps 10a and 10b also have a function as a regenerative motor driven by hydraulic fluid discharged from the hydraulic actuators 1 and 3.
  • a piston 1c attached to the base end of the rod 1b is provided so as to be capable of reciprocating.
  • a cap chamber 1d is formed on the proximal side of the piston 1c in the cylinder tube 1a
  • a rod chamber 1e is formed on the distal side of the piston 1c in the cylinder tube 1a.
  • a piston 3c attached to the base end of the rod 3b is provided so as to be capable of reciprocating.
  • a cap chamber 3d is formed on the proximal side of the piston 3c in the cylinder tube 3a
  • a rod chamber 3e is formed on the distal side of the piston 3c in the cylinder tube 3a.
  • the switching valves 11a, 11b, 12a, 12b open and close according to the control signal received from the controller 40, and connect both discharge pumps 10a, 10b to the boom cylinder 1 or the arm cylinder 3 in a closed circuit.
  • one supply / discharge port of both discharge pumps 10a is connected to the cap chamber 3d of the arm cylinder 3 through the flow paths L1, L9, L7, and the other supply / discharge port is connected to the flow paths L2, L10, L8.
  • the flow paths L1, L9, L7, L8, L10, and L2 form a closed circuit.
  • one supply / discharge port of both discharge pumps 10b is connected to the cap chamber 1d of the boom cylinder 1 via the flow paths L5, L11, L3, and the other supply / discharge port is connected to the flow paths L6, L12, L4.
  • the flow paths L5, L11, L3, L4, L12, and L6 form a closed circuit, which is connected to the rod chamber 1e of the boom cylinder 1 via the through holes.
  • the oil passage L3 connected to the cap chamber 1d of the boom cylinder 1 and the oil passage L4 connected to the rod chamber 1e are connected to the tank 9 via the flushing valve 13a.
  • the flushing valve 13a absorbs the flow rate difference between the cap side and the rod side of the boom cylinder 1, which is a single rod hydraulic cylinder, by discharging excess hydraulic oil from the low pressure side of the oil passages L3, L4 to the tank 9. .
  • the oil passage L7 connected to the cap chamber 3d of the arm cylinder 3 and the oil passage L8 connected to the rod chamber 3e are connected to the tank 9 via the flushing valve 13b.
  • the flushing valve 13b absorbs the flow difference between the cap side and the rod side of the arm cylinder 3 which is a single rod hydraulic cylinder by discharging excess hydraulic oil to the tank 9 from the low pressure side of the oil passages L7 and L8. .
  • the controller 40 controls the switching valves 11a, 11b, 12a, 12b and the regulators 21a, 21b based on the operation amount of the operation levers 30, 31 and the pressure value of pressure sensors 62a, 62b described later.
  • the switching valve 11a is closed so that one discharge pump 10a is connected to the boom cylinder 1 in a closed circuit.
  • the regulator 21a is controlled so that the hydraulic oil having a flow rate corresponding to the operation amount of the boom operation lever 30 is discharged from the both discharge pumps 10a.
  • the switching valve is such that the two discharge pumps 10a and 10b are connected to the boom cylinder 1 in a closed circuit.
  • the switching valve 12b When the arm 4 is operated at low speed alone (when only the arm control lever 31 is operated small), the switching valve 12b is opened so that one discharge pump 10b is connected to the arm cylinder 3 in a closed circuit. And while closing the switching valve 11a, the regulator 21b is controlled so that the hydraulic oil of the flow volume according to the operation amount of the arm control lever 31 is discharged from the both discharge type pump 10b. On the other hand, when the arm 4 is operated independently at high speed (when only the arm operation lever 31 is operated largely), switching is performed so that the two discharge pumps 10a and 10b are connected to the arm cylinder 3 in a closed circuit.
  • valves 12a and 12b are opened and the switching valves 11a and 11b are closed, and the regulators 21a and 21b are controlled so that hydraulic oil at a flow rate corresponding to the operation amount of the arm operation lever 31 is discharged from both discharge type pumps 10a and 10b. Do.
  • both discharge pumps 10a are connected to the boom cylinder 1 in a closed circuit, and both discharge pumps 10b
  • the switching valves 11a and 12b are opened and the switching valves 12a and 11b are closed so that the closed circuit is connected to the arm cylinder 3, and the hydraulic fluid of the flow rate according to the operation amount of the boom control lever 30 is
  • the regulator 21a is controlled so as to be discharged, and the regulator 21b is controlled so that the hydraulic oil at a flow rate corresponding to the operation amount of the arm control lever 31 is discharged from the both discharge type pumps 10b.
  • Both discharge pumps 10a (10b) have a relief valve 22a (22b) for relieving hydraulic fluid to the other supply / discharge port when the pressure at one supply / discharge port exceeds a predetermined value, and a closed circuit pressure Hydraulic fluid when the discharge pressure of make-up check valves 23a and 24b (23a and 24b) and charge pump 25a (25b) and charge pump 25a (25b) for raising cavitation and becoming higher than a predetermined value
  • These units may be provided separately from the discharge pumps 10a and 10b, although they are integrally provided with a charge relief valve 26a (26b) for relieving the pressure.
  • FIG. 3 is a schematic cross-sectional view of both discharge pumps 10a and 10b.
  • both discharge type pumps 10a (10b) are provided with a casing 50a (50b) and a tilting and swash plate mechanism 20a (20b) disposed in the casing 50a (50b).
  • the both tilt swash plate mechanism 20a (20b) is composed of a shaft 51, a swash plate 52, a cylinder block 53, a plurality of pistons 54, a valve plate 55 and the like.
  • the charge relief valve 26a (26b) and the like are also arranged.
  • the shaft 51 is rotatably supported by the casing 50 a (50 b) via a bearing 56.
  • the swash plate 52 is provided around the shaft 51 so that the inclination angle with respect to the rotation axis of the shaft 51 can be changed.
  • the cylinder block 53 is non-rotatably coupled to the shaft 51 by, for example, spline fitting.
  • the cylinder block 53 has a plurality of cylinder chambers 57 formed around the shaft 51.
  • a piston 54 is provided in each cylinder chamber 57 so as to be capable of reciprocating.
  • Each cylinder chamber 57 intermittently communicates with the supply and discharge ports 58 and 59 through the valve plate 55 when the cylinder block 53 rotates.
  • Each piston 54 rotates around the shaft 51 together with the cylinder block 53, and reciprocates in each cylinder chamber 57 in accordance with the inclination angle of the swash plate 52.
  • the hydraulic oil is sucked from one of the supply and discharge ports 58 (59) and discharged as pressure oil from the other supply and discharge port 59 (58).
  • the inclination angle of the swash plate 52 is changed through the regulators 21a and 21b (shown in FIG. 2), the discharge direction and the discharge flow rate of both discharge pumps 10a (10b) change.
  • the casing 50a (50b) is provided with a drain port 60a (60b) for discharging the hydraulic oil.
  • the drain port 60a (60b) is connected to the tank 9 via a drain pipe 61a (61b).
  • a pressure sensor 62a (62b) as a pressure detection device for detecting the pressure (hereinafter referred to as "drain pressure") of the hydraulic oil discharged from the inside of the casing 50a (50b) to the tank 9 It is provided.
  • drain pressure the pressure of the hydraulic oil discharged from the inside of the casing 50a (50b) to the tank 9 It is provided.
  • the pressure sensor 62a (62b) be disposed closer to the drain port 60a (60b) of the drain pipe 61a (61b). As a result, the difference between the drain pressure detected at the time of failure and the drain pressure detected at the normal time becomes large, so that it is possible to improve the detection accuracy of the failure.
  • the pressure sensor 62a (62b) may be disposed in the casing 50a (50b).
  • FIG. 4 is a control block diagram of the controller 40.
  • the controller 40 includes an operation amount detection unit 41, a vehicle body control calculation unit 42, a pump signal output unit 43, a switching valve signal output unit 44, a pressure detection unit 45, and a failure determination unit 46. ing.
  • the operation amount detection unit 41 detects an operation amount (for example, a pilot pressure) of the boom control lever 30 and the arm control lever 31. Information on the detected amount of operation is sent to the vehicle body control calculation unit 42.
  • an operation amount for example, a pilot pressure
  • the vehicle body control calculation unit 42 sets the first to fourth switching valves 11a, 11b, 12a, 12b based on the operation amount of the boom operation lever 30 and the arm operation lever 31 and the determination result from the failure determination unit 46 described later.
  • the open / close command value and the discharge flow rate command value of the first and second pumps 10a and 10b are set.
  • Information on the set open / close command values of the first to fourth switching valves 11a, 11b, 12a, 12b is sent to the switching valve signal output unit 44.
  • Information on discharge flow rate command values of the set first and second pumps 10 a and 10 b is sent to the pump signal output unit 43.
  • the pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value from the vehicle body control calculation unit 42 to the first and second regulators 21a and 21b, and the discharge flow rates of the first and second pumps 10a and 10b. Control.
  • the switching valve signal output unit 44 outputs a control signal corresponding to the open / close command value from the vehicle body control calculating unit 42 to the first to fourth switching valves 11a, 11b, 12a, 12b, and the first to fourth switching valve 11a. , 11b, 12a, 12b are opened and closed.
  • the pressure detection unit 45 detects the pressure values of the first and second pressure sensors 62a and 62b. Information on the detected pressure value is sent to the failure determination unit 46.
  • the failure determination unit 46 determines that the first and second pumps 10a and 10b are normal based on the pressure values of the first and second pressure sensors 62a and 62b (the drain pressures of the first and second pumps 10a and 10b). It is determined whether or not. Information on the determination result is sent to the vehicle control control unit 42.
  • FIG. 5 is a control flow diagram of the controller 40.
  • the control flow shown in FIG. 5 is started after the engine of the hydraulic shovel 100 starts and the controller 40 is powered on.
  • each step constituting the control flow will be described in order.
  • step S1 the failure determination unit 46 acquires the pressure values P1 and P2 of the first and second pressure sensors 62a and 62b from the pressure detection unit 45.
  • step S2 the failure determination unit 46 determines whether the pressure value P1 of the first pressure sensor 62a is larger than the pressure threshold P0.
  • the pressure threshold P0 is a threshold for determining the failure of the first and second pumps 10a and 10b, and is equal to or greater than the maximum drain pressure when the first and second pumps 10a and 10b are normal. Is also set to a slightly lower value.
  • step S3 the vehicle body control calculation unit 42 performs the first and third switching connected to the first pump 10a.
  • the open / close command values of the valves 11a and 12a are set to be closed.
  • the switching valve signal output unit 44 outputs a control signal (closing signal) corresponding to the opening / closing command value (closing) from the vehicle body control calculating unit 42 to the switching valves 11 and 12 to make the first and third switching valves 11a and 12a. Close
  • step S4 the vehicle body control calculating unit 42 sets the discharge flow rate command values of the first and second pumps 10a and 10b to zero (0).
  • the pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value (0) from the vehicle body control calculation unit 42 to the regulators 21a and 21b, and the discharge flow rate of the first and second pumps 10a and 10b is zero ( Control to 0).
  • step S4 the controller 40 ends the control and stops the operation of the hydraulic shovel 100.
  • step S2 If it is determined in step S2 that the pressure value P1 is less than or equal to the pressure threshold P0 (NO), the failure determination unit 46 determines that the pressure value P2 of the second pressure sensor 62b is larger than the pressure threshold P0 in step S5. It is determined whether or not.
  • step S6 the vehicle body control calculation unit 42 performs the second and fourth switchings connected to the second pump 10b.
  • the open / close command values of the valves 11 b and 12 b are set to be closed.
  • the switching valve signal output unit 44 outputs a control signal (closing signal) corresponding to the opening / closing command value (closing) to the second and fourth switching valves 11b and 12b, and closes the second and fourth switching valves 11b and 12b. .
  • step S7 the vehicle body control calculation unit 42 sets the discharge flow rate command values of the first and second pumps 10a and 10b to zero (0).
  • the pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value (0) to the regulators 21a and 21b to control the discharge flow rate of the first and second pumps 10a and 10b to zero (0).
  • the controller 40 ends the control and stops the operation of the hydraulic shovel 100.
  • step S5 If it is determined in step S5 that the pressure value P2 is less than or equal to the pressure threshold P0 (NO), the operation amount detection unit 41 detects the operation amount of the boom operation lever 30 and the arm operation lever 31 in step S8. .
  • step S9 based on the operation amount of boom operation lever 30 and arm operation lever 31, vehicle body control operation unit 42 opens / closes the first to fourth switching valves 11a, 11b, 12a, 12b and discharge flow rate command.
  • the switching valve signal output unit 44 outputs a control signal corresponding to the opening / closing command value to the first to fourth switching valves 11a, 11b, 12a, 12b, and opens / closes the first to fourth switching valves 11a, 11b, 12a, 12b. .
  • step S10 the vehicle body control calculating unit 42 sets the discharge flow rate command value based on the operation amount of the boom operation lever 30 and the arm operation lever 31.
  • the pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value to the first and second regulators 21a and 21b to control the discharge flow rate of the first and second pumps 10a and 10b.
  • the boom 2 and the arm 4 of the hydraulic shovel 100 operate according to the operation of the boom control lever 30 and the arm control lever 31.
  • step S10 the controller 40 repeatedly executes the processes after step S1.
  • FIG. 6 is a diagram showing an operation of the hydraulic closed circuit system 200 when the first pump 10a breaks down while driving the boom cylinder 1 using the first pump 10a.
  • movement of the 1st pump 10a is shown for simplification of description, and the part in connection with operation
  • the first switching valve 11a is opened and the third switching valve 12a is closed (step S9 in FIG. 5).
  • the hydraulic fluid of the flow rate according to the operation amount of the boom operation lever 30 is discharged from the first pump 10a (step S10 in FIG. 5).
  • the boom cylinder 1 supports the weight of the front work implement 104, and the cap chamber 1d of the boom cylinder 1 has a high pressure.
  • FIG. 7 is a schematic configuration diagram of a hydraulic closed circuit system according to the present embodiment.
  • the hydraulic closed circuit system 200A further includes a monitor 33 as a display device and an operation button 32 as an instruction input device, and the controller 40A further includes a monitor output unit 47.
  • the monitor 33 and the instruction input device 32 are disposed in the cab 101.
  • FIG. 8 is a control block diagram of the controller 40A.
  • the operation amount detection unit 41 ⁇ / b> A detects an input signal from the operation button 32 in addition to the operation amounts of the boom operation lever 30 and the arm operation lever 31. Information of the detected operation amount and input signal is sent to the vehicle control control unit 42.
  • the vehicle body control calculation unit 42A is based on the operation amount of the boom operation lever 30 and the arm operation lever 31, the input signal from the operation button 32, and the determination result from the failure determination unit 46, the first to fourth switching valve 11a, The open / close command values of 11b, 12a, 12b and the discharge flow rate command values of the first and second pumps 10a, 10b are set.
  • 9A to 9C are control flow diagrams of the controller 40A.
  • step S5 In the control flow (shown in FIG. 5) in the first embodiment, after the failure of the first pump 10a is detected in step S2 and steps S3 and S4 are executed, or the failure of the second pump 10b is detected in step S5. Then, after executing steps S6 and S7, the controller 40 ends the control and decides to stop the operation of the hydraulic shovel 100, but in the control flow shown in FIGS. 9A to 9C, the second pump is performed after step S4.
  • a process steps SY1 to SY7) for adding the process (steps SX1 to SX6) for operating the hydraulic shovel 100 using only 10b and for operating the hydraulic shovel 100 using only the first pump 10a after step S7 ) Has been added.
  • each added step will be described in order.
  • the monitor output unit 47 outputs the failure information of the first pump 10a to the monitor 33.
  • FIG. 10 is a view showing an example of a display screen of the monitor 33. As shown in FIG.
  • FIG. 10 on the left side of the display screen 33a, a simplified diagram of the hydraulic circuit of the hydraulic closed circuit system 200A is displayed, and the failure location is shaded. Thus, the operator can confirm the failure point. Further, on the right side of the display screen 33a, a message indicating that a failure of the first pump 10a has been detected, and a message inquiring whether to shift from the normal mode to the degeneration mode are displayed.
  • the normal mode is a control mode in which the hydraulic shovel 100 is operated using all the dual discharge pumps 10a and 10b
  • the degenerate mode is a normal dual discharge without using a failed dual discharge pump. It is a control mode in which the hydraulic shovel 100 is operated using only the die pump. The operator can instruct the controller 40 to shift from the normal mode to the degeneration mode by operating the operation button 32.
  • step SX2 based on the information of the input signal from the instruction input device 32, the vehicle body control calculation unit 42 determines whether or not the transition from the normal mode to the degeneration mode is instructed.
  • step SX2 If it is determined in step SX2 that the transition from the normal mode to the degeneration mode is instructed (YES), the vehicle body control calculation unit 42 performs the first to fourth switching of each operation of the hydraulic shovel 100 in step SX3. From the table (a normal table described later) used when the first and second pumps 10a and 10b are both normal, a table defining the correspondence with the open / close command values of the valves 11a, 11b, 12a, 12b Switching to a table (a first degeneration table to be described later) used when one pump 10a breaks down.
  • a table a normal table described later
  • FIG. 11 is a diagram showing an example of a table defining the correspondence between each operation of the hydraulic shovel 100 and the open / close command values of the first to fourth switching valves.
  • the table 70 is a table used when both the first and second pumps 10a and 10b are normal (hereinafter referred to as a "normal table"), and the table 71 has a failure in the first pump 10a.
  • the table 72 is a table (hereinafter referred to as a “first degeneration table”) used in the case where the second pump 10 b fails, and the table 72 is a table (hereinafter referred to as a “second degeneration table”).
  • the first degeneration table 71 since the first pump 10a is not used, the open / close command values of the first and third switching valves 11a and 12a connected to the first pump 10a are closed regardless of the operation of the hydraulic shovel 100. It has become.
  • Each of the tables 70 to 72 is stored in advance in the controller 40, and is referred to by the vehicle control control unit 42.
  • step SX4 the vehicle body control calculation unit 42 acquires the operation amount of the boom operation lever 30 and the arm operation lever 31 from the operation amount detection unit 41.
  • step SX5 the vehicle body control calculation unit 42 refers to the first reduction table 71, and based on the operation amount of the boom operation lever 30 and the arm operation lever 31, the first to fourth switching valves 11a, 11b, 12a, Set the open / close command value of 12b.
  • the switching valve signal output unit 44 outputs a control signal corresponding to the opening / closing command value to the first to fourth switching valves 11a, 11b, 12a, 12b, and opens / closes the first to fourth switching valves 11a, 11b, 12a, 12b. .
  • step SX6 the vehicle body control calculating unit 42 sets the discharge flow rate command value of the second pump 10b based on the operation amount of the boom operation lever 30 or the arm operation lever 31.
  • the pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value to the second regulator 21b to control the discharge flow rate of the second pump 10b.
  • the boom 2 and the arm 4 of the hydraulic shovel 100 operate according to the operation of the boom control lever 30 and the arm control lever 31.
  • the controller 40 repeatedly executes the processing of step SX4 and subsequent steps.
  • step SX2 If it is determined in step SX2 that transition from the normal mode to the degeneration mode is not instructed (NO), the controller 40 ends the control and stops the operation of the hydraulic shovel 100.
  • step SY1 to SY6 The process for operating the hydraulic shovel 100 with only the first pump 10a added after step S7 (steps SY1 to SY6) displays the failure of the second pump 10b at step SY1, and the second degeneration at step SY3.
  • the process is the same as steps SX1 to SX6 except that the table 72 is switched to and the second degeneration table 72 is referred to in steps SY5 and SY6, so the description will be omitted.
  • Example of this invention was explained in full detail, this invention is not limited to an above-described Example, A various modified example is included.
  • this invention is not restricted to this, It is applicable to the general construction machinery which drives a several hydraulic actuator by a hydraulic closed circuit.
  • the above-described embodiments are described in detail to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described.
  • operation button instruction input device
  • 33 ... monitor display device
  • 33a ... display screen 40, 40A ... controller, 41, 41A ... operation amount detection unit, 42, 42A ... vehicle body
  • Control arithmetic unit 43 Pump signal output unit 44: Switching valve signal output unit 45: Pressure detection unit 46: Failure determination unit 47: Monitor output unit 50a, 50b: Casing 51: shaft 52: Oblique Plate, 53: cylinder block, 54: piston, 55: valve plate, 56: bearing, 57: cylinder chamber, 58 59 ... supply / discharge port, 60a, 60b ... drain port, 61a, 61b ... drain piping, 62a ... first pressure sensor (pressure detection device), 62b ...
  • second pressure sensor pressure detection device
  • 70 normal table
  • 71 ... 1st degeneration table
  • 72 ... 2nd degeneration table
  • 100 ... hydraulic excavator, 101 ... cab, 102 ... upper revolving unit, 103 ... lower traveling unit, 104 ... front work machine, 200, 200 A ... hydraulic closed circuit system, L ⁇ L12 ... Flow path.

Abstract

Provided is construction machinery with which it is possible to suppress the unintended operation of a hydraulic actuator even when a double discharge pump breaks down in a hydraulic closed circuit system. A hydraulic closed circuit system (200) is provided with pressure sensors (62a, 62b) for detecting the drain pressure of working oil discharged from drain ports (60a, 60b) of a plurality of double discharge pumps (10a, 10b). When, among the plurality of double discharge pumps, there exists a double discharge pump the drain pressure of which that was detected by the pressure sensors exceeds a prescribed pressure, a controller (40) determines that the double discharge pump the drain pressure of which exceeds a prescribed pressure is a broken double discharge pump and closes all of the selector valves, among a plurality of selector valves (11a, 11b, 12a, 12b), that are connected to the broken double discharge pump.

Description

建設機械Construction machinery
　本発明は、油圧ショベル等の建設機械に関する。 The present invention relates to a construction machine such as a hydraulic shovel.
　近年、油圧ショベルやホイールローダなどの建設機械において、省エネ化が重要な開発項目になっている。建設機械の省エネ化には油圧システム自体の省エネ化が重要であり、両吐出型の油圧ポンプと油圧アクチュエータとを直接接続し両者間で直接圧油を給排する油圧閉回路を用いた油圧システム（以下「油圧閉回路システム」という。）の適用が検討されている。油圧閉回路では、制御弁による圧損がなく、必要な流量のみをポンプが吐出するため流量損失もない。また、油圧アクチュエータの位置エネルギや減速時のエネルギを回生することもできる。このため、油圧閉回路システム適用することにより、建設機械の省エネ化が可能となる。 BACKGROUND ART In recent years, energy saving has become an important development item in construction machines such as hydraulic shovels and wheel loaders. The energy saving of the hydraulic system itself is important for energy saving of the construction machine, and the hydraulic system using the hydraulic closed circuit which directly connects the both discharge hydraulic pump and the hydraulic actuator and supplies and discharges the pressure oil directly between them. Application of (hereinafter referred to as "hydraulic closed circuit system") is under consideration. In the hydraulic closed circuit, there is no pressure loss due to the control valve, and since the pump discharges only the necessary flow rate, there is no flow rate loss. In addition, it is possible to regenerate the position energy of the hydraulic actuator and the energy at the time of deceleration. For this reason, energy saving of a construction machine is attained by applying a hydraulic closed circuit system.
　油圧閉回路システムを搭載した油圧ショベルを開示するものとして、例えば特許文献1がある。特許文献１には、複数の油圧ポンプのそれぞれを複数の油圧アクチュエータのいずれか１つに切換弁を介して選択的に閉回路接続することにより、油圧アクチュエータの複合動作と高速動作を可能にした構成が記載されている。 Patent Document 1 is an example of a hydraulic shovel equipped with a hydraulic closed circuit system. Patent Document 1 enables combined operation and high-speed operation of hydraulic actuators by selectively connecting each of a plurality of hydraulic pumps to any one of a plurality of hydraulic actuators via a switching valve in a closed circuit. The configuration is described.
特開２０１５－４８８９９号公報JP 2015-48899 A
　特許文献１に記載の油圧閉回路システムでは、作業者によるレバー操作に応じて、１つの両吐出型ポンプに対していずれか１つの油圧アクチュエータが流路を介して接続されるよう、複数の切換弁がコントローラにより開閉制御されると共に、レバー操作量に応じて各両吐出型ポンプの吐出流量が制御される。例えば、ブーム上げ操作を行った場合、少なくとも１つの両吐出型ポンプとブームシリンダとが閉回路接続され、当該両吐出型ポンプの一方の給排ポートからレバー操作量に応じた流量の作動油がブームシリンダのキャップ室に供給され、ブームシリンダのロッド室から排出された作動油が他方の給排ポートから吸入される。これにより、ブームシリンダが伸展し、ブームが上昇する。ここで、油圧閉回路では、流路内を作動油が双方向に流れるようにするため、流路内にチェック弁（逆止弁）を設けることができない。そのため、例えばブームシリンダに閉回路接続された両吐出型ポンプが故障すると、ブームシリンダの負荷保持側であるキャップ室の高圧の作動油が当該両吐出型ポンプに逆流し、作業者の意図に反してブームシリンダが縮退動作し、ブームが落下するおそれがある。 In the hydraulic closed circuit system described in Patent Document 1, in response to the lever operation by the operator, a plurality of switchings are performed so that any one hydraulic actuator is connected to one dual discharge pump via a flow path. The valve is controlled to open and close by the controller, and the discharge flow rate of each discharge pump is controlled according to the lever operation amount. For example, when the boom raising operation is performed, at least one of both discharge pumps and the boom cylinder are connected in a closed circuit, and the hydraulic oil of the flow rate corresponding to the lever operation amount is supplied from one supply / discharge port of both discharge pumps. The hydraulic fluid supplied to the cap chamber of the boom cylinder and discharged from the rod chamber of the boom cylinder is sucked from the other supply / discharge port. This extends the boom cylinder and raises the boom. Here, in the hydraulic closed circuit, in order to allow the hydraulic oil to flow in both directions in the flow path, a check valve (check valve) can not be provided in the flow path. Therefore, if, for example, both discharge pumps connected in a closed circuit to the boom cylinder fail, high pressure hydraulic oil in the cap chamber, which is the load holding side of the boom cylinder, flows back to the both discharge pumps, contrary to the operator's intention. As a result, the boom cylinder retracts and the boom may fall.
　本発明は、上記課題に鑑みてなされたものであり、その目的は、油圧閉回路システムにおいて両吐出型ポンプが故障した場合でも、意図しない油圧アクチュエータの動作を抑制できる建設機械を提供することにある。 The present invention has been made in view of the above problems, and an object thereof is to provide a construction machine capable of suppressing an unintended operation of a hydraulic actuator even when both discharge type pumps fail in a hydraulic closed circuit system. is there.
　上記目的を達成するために、本発明は、複数の両吐出型ポンプと、前記複数の両吐出型ポンプに選択的に閉回路を構成するよう接続された複数の油圧アクチュエータと、前記複数の両吐出型ポンプと前記複数の油圧アクチュエータとの間に接続され、前記複数の両吐出型ポンプのそれぞれを複数の油圧アクチュエータに選択的に閉回路接続する複数の切換弁と、複数の操作レバーの操作に応じて前記複数の切換弁の開閉制御および前記複数の両吐出型ポンプの流量制御を行う制御装置とを備え、前記複数の両吐出型ポンプは、それぞれ、内部に漏れ出す作動油をタンクに戻すドレンポートを有する建設機械において、前記複数の両吐出型ポンプのそれぞれに設けられ、前記ドレンポートから排出される作動油のドレン圧力を検出する圧力検出装置を備え、前記制御装置は、前記複数の両吐出型ポンプの中に、前記圧力検出装置で検出されたドレン圧が所定の圧力を超えた両吐出型ポンプが存在するときに、前記ドレン圧が所定の圧力を超えた両吐出型ポンプは故障した両吐出型ポンプであると判定し、前記複数の切換弁のうち、前記故障した両吐出型ポンプに接続されている全ての切換弁を閉じるものとする。 In order to achieve the above object, the present invention provides a plurality of dual discharge pumps, a plurality of hydraulic actuators connected so as to form a closed circuit selectively to the dual discharge pumps, and a plurality of dual actuators. A plurality of switching valves connected between a discharge pump and the plurality of hydraulic actuators, for selectively closing the plurality of dual discharge pumps to the plurality of hydraulic actuators, and operation of the plurality of operation levers Control device for performing the opening / closing control of the plurality of switching valves and the flow control of the plurality of dual discharge pumps according to the plurality of dual discharge pumps, respectively; In a construction machine having a drain port for returning, a pressure detector provided in each of the plurality of discharge pumps and detecting a drain pressure of hydraulic oil discharged from the drain port The control device is provided with a device, and when there is a dual discharge pump whose drain pressure detected by the pressure detection device exceeds a predetermined pressure, among the multiple dual discharge pumps, the drain pressure Determines that both discharge pumps whose pressure exceeds a predetermined pressure is a broken discharge pump, and closes all the switching valves connected to the broken discharge pumps among the plurality of switching valves It shall be.
　以上のように構成した本発明によれば、複数の両吐出型ポンプのいずれかが故障し、故障した両吐出型ポンプのドレン圧力が所定の圧力を超えると、故障した両吐出型ポンプに接続されている全ての切換弁が閉じられる。これにより、油圧アクチュエータから故障した両吐出型ポンプへの作動油の逆流が防止されるため、意図しない油圧アクチュエータの動作を抑制することができる。 According to the present invention configured as described above, when any one of the plurality of dual discharge pumps fails and the drain pressure of the double discharge pumps that has failed exceeds the predetermined pressure, connection is made to the failed dual discharge pumps. All switching valves being closed are closed. As a result, the backflow of the hydraulic fluid from the hydraulic actuator to the malfunctioning discharge pump is prevented, so that an unintended operation of the hydraulic actuator can be suppressed.
　本発明によれば、油圧閉回路システムを搭載した建設機械において、両吐出型ポンプが故障した場合でも、意図しない油圧アクチュエータの動作を抑制することができる。 According to the present invention, in a construction machine equipped with a hydraulic closed circuit system, even when both discharge type pumps fail, an unintended operation of the hydraulic actuator can be suppressed.
本発明の第１の実施例に係る油圧ショベルを示す側面図である。It is a side view showing a hydraulic shovel concerning a 1st example of the present invention. 図１に示す油圧ショベルに搭載された油圧閉回路システムの概略構成図である。It is a schematic block diagram of the hydraulic closed circuit system mounted in the hydraulic shovel shown in FIG. 図１に示す両吐出型ポンプの概略断面図である。It is a schematic sectional drawing of the both discharge type pump shown in FIG. 図２に示すコントローラの制御ブロック図である。It is a control block diagram of a controller shown in FIG. 図２に示すコントローラの制御フロー図である。It is a control flowchart of the controller shown in FIG. 第１ポンプがブームシリンダに接続された状態で第１ポンプが故障した場合の油圧閉回路システムの動作を示す図である。It is a figure which shows operation | movement of a hydraulic closed circuit system when a 1st pump fails in the state which the 1st pump was connected to the boom cylinder. 本発明の第２の実施例に係る油圧閉回路システムの概略構成図である。It is a schematic block diagram of a hydraulic closed circuit system concerning a 2nd example of the present invention. 図７に示すコントローラの制御ブロック図である。It is a control block diagram of a controller shown in FIG. 図７に示すコントローラの制御フロー図である。It is a control flowchart of the controller shown in FIG. 図７に示すコントローラの制御フロー図である。It is a control flowchart of the controller shown in FIG. 図７に示すコントローラの制御フロー図である。It is a control flowchart of the controller shown in FIG. 図６に示すモニタの表示画面の一例を示す図である。It is a figure which shows an example of the display screen of the monitor shown in FIG. 油圧ショベルの各動作と第１～第４切換弁の開閉指令値との対応関係を規定したテーブルの一例を示す図である。FIG. 7 is a diagram showing an example of a table defining the correspondence between each operation of the hydraulic shovel and the open / close command values of the first to fourth switching valves.
　以下、本発明の実施の形態に係る建設機械として油圧ショベルを例に挙げ、図面を参照して説明する。なお、各図中、同等の部材には同一の符号を付し、重複した説明は適宜省略する。 Hereinafter, a hydraulic shovel is mentioned as an example as a construction machine concerning an embodiment of the invention, and it explains with reference to drawings. In addition, in each figure, the same code | symbol is attached | subjected to an equivalent member, and the overlapping description is abbreviate | omitted suitably.
　図１は、本発明の第１の実施例に係る油圧ショベルを示す側面図である。 FIG. 1 is a side view showing a hydraulic shovel according to a first embodiment of the present invention.
　図１において、油圧ショベル１００は、左右方向の両側にクローラ式の走行装置８ａ，８ｂを備えた下部走行体１０３と、下部走行体１０３上に旋回可能に取り付けられた本体としての上部旋回体１０２とを備えている。上部旋回体１０２上には、オペレータが搭乗する操作室としてのキャブ１０１が設けられている。下部走行体１０３と上部旋回体１０２とは、油圧アクチュエータとしての旋回モータ７を介して旋回可能とされている。 In FIG. 1, the hydraulic shovel 100 has a lower traveling body 103 provided with crawler- type traveling devices 8 a and 8 b on both sides in the left-right direction, and an upper revolving structure 102 as a main body pivotally mounted on the lower traveling body 103. And have. On the upper revolving superstructure 102, a cab 101 is provided as an operation room on which an operator rides. The lower traveling body 103 and the upper swing body 102 can be turned via a swing motor 7 as a hydraulic actuator.
　上部旋回体１０２の前側には、例えば掘削作業等を行うための作動装置であるフロント作業機１０４の基端部が回動可能に取り付けられている。ここで、前側とは、キャブ１０１に搭乗する作業者が向く方向（図１中の左方向）をいう。 On the front side of the upper revolving superstructure 102, a base end of a front work implement 104, which is an operating device for performing, for example, excavating work, is rotatably attached. Here, the front side refers to the direction (left direction in FIG. 1) in which the worker who gets on the cab 101 is facing.
　フロント作業機１０４は、上部旋回体１０２の前側に基端部が上下方向に回動可能に連結されたブーム２を備えている。ブーム２は、片ロッド式油圧シリンダであるブームシリンダ１を介して動作する。ブームシリンダ１のロッド１ｂの先端部は上部旋回体１０２に回動可能に連結され、ブームシリンダ１のシリンダチューブ１ａの基端部はブーム２の中間部に回動可能に連結されている。ブーム２の先端部には、アーム４の基端部が上下、前後方向に回動可能に連結されている。アーム４は、片ロッド式油圧シリンダである油圧アクチュエータとしてのアームシリンダ３を介して動作する。アームシリンダ３のロッド３ｂの先端部はアーム４の基端部に回動可能に連結され、アームシリンダ３のシリンダチューブ３ａの基端部はブーム２の中間部に回動可能に連結されている。アーム４の先端部には、バケット６の基端部が上下、前後方向に回動可能に連結されている。バケット６は、片ロッド式油圧シリンダであるバケットシリンダ５を介して動作する。バケットシリンダ５のロッド５ｂの先端部はバケット６の基端部に回動可能に連結され、バケットシリンダ５のシリンダチューブ５ａの基端部はアーム４の基端部に回動可能に連結されている。 The front work implement 104 includes a boom 2 on the front side of the upper swing body 102, in which a base end portion is rotatably connected in the vertical direction. The boom 2 operates via a boom cylinder 1 which is a single rod hydraulic cylinder. The tip of the rod 1 b of the boom cylinder 1 is rotatably connected to the upper swing body 102, and the base end of the cylinder tube 1 a of the boom cylinder 1 is rotatably connected to the middle of the boom 2. The proximal end portion of the arm 4 is connected to the distal end portion of the boom 2 so as to be rotatable in the vertical and longitudinal directions. The arm 4 operates via an arm cylinder 3 as a hydraulic actuator which is a single rod hydraulic cylinder. The tip end of the rod 3b of the arm cylinder 3 is rotatably connected to the base end of the arm 4, and the base end of the cylinder tube 3a of the arm cylinder 3 is rotatably connected to the middle of the boom 2 . The base end portion of the bucket 6 is connected to the tip end portion of the arm 4 so as to be rotatable in the vertical direction and the front-rear direction. The bucket 6 operates via a bucket cylinder 5 which is a single rod hydraulic cylinder. The tip of the rod 5b of the bucket cylinder 5 is rotatably connected to the base end of the bucket 6, and the base of the cylinder tube 5a of the bucket cylinder 5 is rotatably connected to the base of the arm 4 There is.
　キャブ１０１内には、フロント作業機１０４を構成するブーム２、アーム４およびバケット６を操作するためのブーム操作レバー３０（図２に示す）、アーム操作レバー３１（図２に示す）、バケットレバー（図示せず）が配置されている。 In the cab 101, a boom control lever 30 (shown in FIG. 2) for operating the boom 2, the arm 4 and the bucket 6 constituting the front work machine 104, an arm control lever 31 (shown in FIG. 2), a bucket lever (Not shown) are arranged.
　図２は、油圧ショベル１００に搭載された油圧閉回路システムの概略構成図である。なお、図２では、説明の簡略化のため、ブームシリンダ１およびアームシリンダ３の駆動に関わる部分のみを示し、その他の油圧アクチュエータの駆動に関わる部分は省略している。 FIG. 2 is a schematic configuration diagram of a hydraulic closed circuit system mounted on the hydraulic shovel 100. As shown in FIG. In addition, in FIG. 2, only the part in connection with the drive of boom cylinder 1 and arm cylinder 3 is shown for simplification of description, and the part in connection with the drive of the other hydraulic actuator is abbreviate | omitted.
　図２において、油圧閉回路システム２００は、両吐出型の第１、第２ポンプ（以下適宜「両吐出型ポンプ」という。）１０ａ，１０ｂと、第１、第２ポンプに選択的に閉回路を構成するよう接続された油圧アクチュエータ１，３と、油圧アクチュエータ１，３にそれぞれ対応した操作装置としての操作レバー３０，３１と、第１ポンプ１０ａ，１０ｂと油圧アクチュエータ１，３との間に接続され、第１、第２ポンプ１０ａ，１０ｂのそれぞれを油圧アクチュエータ１，３に選択的に閉回路接続する第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂと、操作レバー３０，３１の操作に応じて第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂの開閉制御および第１、第２ポンプ１０ａ，１０ｂの流量制御を行う制御装置としてのコントローラ４０とを備えている。 In FIG. 2, the hydraulic closed circuit system 200 selectively connects the first and second pumps of both discharge type (hereinafter appropriately referred to as “both discharge type pumps”) 10 a and 10 b and the first and second pumps. Between the first pumps 10a and 10b and the hydraulic actuators 1 and 3. The hydraulic actuators 1 and 3 connected so as to form the control levers 30 and 31 as operating devices respectively corresponding to the hydraulic actuators 1 and 3 The first to fourth switching valves 11a, 11b, 12a, 12b are connected to selectively connect the first and second pumps 10a, 10b to the hydraulic actuators 1, 3 and 3, respectively, and the operation levers 30, 31. A controller as a control device that performs opening / closing control of the first to fourth switching valves 11a, 11b, 12a, 12b and flow control of the first and second pumps 10a, 10b according to the operation. And a La 40.
　第１、第２ポンプ１０ａ，１０ｂは両傾転型の油圧ポンプによって構成されており、エンジン（図示せず）によって駆動される。なお、原動機として電動モータを備える油圧ショベルの場合は、第１、第２ポンプ１０ａ，１０ｂはモータ駆動の両吐出型ポンプで構成される。両吐出型ポンプ１０ａ，１０ｂは、それぞれ、流量調整装置として一対の給排ポートを有する両傾転斜板機構２０ａ，２０ｂと、斜板５２（図３に示す）の傾斜角を調整してポンプ押しのけ容積を調整するレギュレータ２１ａ，２１ａとを備えている。レギュレータ２１ａ，２１ｂは、コントローラ４０から受信したポンプ吐出流量指令値に基づき、両吐出型ポンプ１０ａ，１０ｂの吐出方向および吐出流量を制御する。また、両吐出型ポンプ１０ａ，１０ｂは、油圧アクチュエータ１，３から排出される作動油によって駆動される回生モータとしての機能も有する。 The first and second pumps 10a and 10b are constituted by dual tilt hydraulic pumps and are driven by an engine (not shown). In the case of a hydraulic shovel provided with an electric motor as a prime mover, the first and second pumps 10a and 10b are configured by both motor driven discharge pumps. Both discharge type pumps 10a and 10b respectively adjust the inclination angles of the both tilt swash plate mechanisms 20a and 20b having a pair of supply and discharge ports as flow rate adjustment devices, and the swash plate 52 (shown in FIG. 3). Regulators 21a and 21a for adjusting the displacement volume are provided. The regulators 21 a and 21 b control the discharge direction and the discharge flow rate of both the discharge pumps 10 a and 10 b based on the pump discharge flow rate command value received from the controller 40. Moreover, both discharge type pumps 10a and 10b also have a function as a regenerative motor driven by hydraulic fluid discharged from the hydraulic actuators 1 and 3.
　ブームシリンダ１のシリンダチューブ１ａ内には、ロッド１ｂの基端部に取り付けられたピストン１ｃが往復動可能に設けられている。シリンダチューブ１ａ内のピストン１ｃより基端側にはキャップ室１ｄが形成され、シリンダチューブ１ａ内のピストン１ｃより先端側にはロッド室１ｅが形成されている。キャップ室１ｄに作動油が供給されると、ピストン１ｃがシリンダチューブ１ａの先端側に押圧され、ロッド１ｂが伸長移動する。一方、ロッド室１ｅに作動油が供給されると、ピストン１ｃがシリンダチューブ１ａの基端側に押圧され、ロッド１ｂが縮退移動する。 In the cylinder tube 1a of the boom cylinder 1, a piston 1c attached to the base end of the rod 1b is provided so as to be capable of reciprocating. A cap chamber 1d is formed on the proximal side of the piston 1c in the cylinder tube 1a, and a rod chamber 1e is formed on the distal side of the piston 1c in the cylinder tube 1a. When hydraulic fluid is supplied to the cap chamber 1d, the piston 1c is pressed to the tip end side of the cylinder tube 1a, and the rod 1b is extended and moved. On the other hand, when the hydraulic fluid is supplied to the rod chamber 1e, the piston 1c is pressed to the base end side of the cylinder tube 1a, and the rod 1b is retracted.
　同様に、アームシリンダ３のシリンダチューブ３ａ内には、ロッド３ｂの基端部に取り付けられたピストン３ｃが往復動可能に設けられている。シリンダチューブ３ａ内のピストン３ｃより基端側にはキャップ室３ｄが形成され、シリンダチューブ３ａ内のピストン３ｃより先端側にはロッド室３ｅが形成されている。キャップ室３ｄに作動油が供給されると、ピストン３ｃがシリンダチューブ３ａの先端側に押圧され、ロッド１ｂが伸長移動する。一方、ロッド室３ｅに作動油が供給されると、ピストン３ｃがシリンダチューブ３ａの基端側に押圧され、ロッド１ｂが縮退移動する。 Similarly, in the cylinder tube 3a of the arm cylinder 3, a piston 3c attached to the base end of the rod 3b is provided so as to be capable of reciprocating. A cap chamber 3d is formed on the proximal side of the piston 3c in the cylinder tube 3a, and a rod chamber 3e is formed on the distal side of the piston 3c in the cylinder tube 3a. When the hydraulic fluid is supplied to the cap chamber 3d, the piston 3c is pressed to the tip end side of the cylinder tube 3a, and the rod 1b is extended and moved. On the other hand, when the hydraulic fluid is supplied to the rod chamber 3e, the piston 3c is pressed to the base end side of the cylinder tube 3a, and the rod 1b retracts.
　切換弁１１ａ，１１ｂ，１２ａ，１２ｂは、コントローラ４０から受信した制御信号に応じて開閉し、両吐出型ポンプ１０ａ，１０ｂをそれぞれブームシリンダ１またはアームシリンダ３に閉回路接続する。 The switching valves 11a, 11b, 12a, 12b open and close according to the control signal received from the controller 40, and connect both discharge pumps 10a, 10b to the boom cylinder 1 or the arm cylinder 3 in a closed circuit.
　両吐出型ポンプ１０ａに接続されている切換弁１１ａが開いているときは、両吐出型ポンプ１０ａに接続されている他の切換弁１２ａは閉じられる。これにより、両吐出型ポンプ１０ａの一方の給排ポートが流路Ｌ１，Ｌ３を介してブームシリンダ１のキャップ室１ｄに接続され、他方の給排ポートが流路Ｌ２，Ｌ４を介してブームシリンダ１のロッド室１ｅに接続され、流路Ｌ１～Ｌ４は閉回路を形成する。一方、切換弁１２ａが開いているときは、切換弁１１ａは閉じられる。これにより、両吐出型ポンプ１０ａの一方の給排ポートが流路Ｌ１，Ｌ９，Ｌ７を介してアームシリンダ３のキャップ室３ｄに接続され、他方の給排ポートが流路Ｌ２，Ｌ１０，Ｌ８を介してアームシリンダ３のロッド室３ｅに接続され、流路Ｌ１，Ｌ９，Ｌ７，Ｌ８，Ｌ１０，Ｌ２は閉回路を形成する。 When the switching valve 11a connected to both discharge pumps 10a is open, the other switching valve 12a connected to both discharge pumps 10a is closed. Thus, one supply / discharge port of both discharge pumps 10a is connected to the cap chamber 1d of the boom cylinder 1 via the flow paths L1 and L3, and the other supply / discharge port is connected to the boom cylinder via the flow paths L2 and L4. The flow paths L1 to L4 are connected to the rod chamber 1e of 1 and form a closed circuit. On the other hand, when the switching valve 12a is open, the switching valve 11a is closed. Thus, one supply / discharge port of both discharge pumps 10a is connected to the cap chamber 3d of the arm cylinder 3 through the flow paths L1, L9, L7, and the other supply / discharge port is connected to the flow paths L2, L10, L8. The flow paths L1, L9, L7, L8, L10, and L2 form a closed circuit.
　同様に、両吐出型ポンプ１０ｂに接続されている切換弁１２ｂが開いているときは、両吐出型ポンプ１０ｂに接続されている他の切換弁１１ｂは閉じられる。これにより、両吐出型ポンプ１０ｂの一方の給排ポートは流路Ｌ５，Ｌ７を介してアームシリンダ３のキャップ室３ｄに接続され、他方の給排ポートは流路Ｌ６，Ｌ８を介してアームシリンダ３のロッド室３ｅに接続され、流路Ｌ５，Ｌ７，Ｌ８，Ｌ６は閉回路を形成する。一方、切換弁１１ｂが開いているときは、切換弁１２ｂは閉じられる。これにより、両吐出型ポンプ１０ｂの一方の給排ポートが流路Ｌ５，Ｌ１１，Ｌ３を介してブームシリンダ１のキャップ室１ｄに接続され、他方の給排ポートが流路Ｌ６，Ｌ１２，Ｌ４を介してブームシリンダ１のロッド室１ｅに接続され、流路Ｌ５，Ｌ１１，Ｌ３，Ｌ４，Ｌ１２，Ｌ６は閉回路を形成する。 Similarly, when the switching valve 12b connected to both discharge pumps 10b is open, the other switching valve 11b connected to both discharge pumps 10b is closed. Thereby, one supply / discharge port of both discharge pumps 10b is connected to the cap chamber 3d of the arm cylinder 3 through the flow paths L5, L7, and the other supply / discharge port is the arm cylinder through the flow paths L6, L8. The flow paths L5, L7, L8 and L6 are connected to the third rod chamber 3e to form a closed circuit. On the other hand, when the switching valve 11b is open, the switching valve 12b is closed. Thus, one supply / discharge port of both discharge pumps 10b is connected to the cap chamber 1d of the boom cylinder 1 via the flow paths L5, L11, L3, and the other supply / discharge port is connected to the flow paths L6, L12, L4. The flow paths L5, L11, L3, L4, L12, and L6 form a closed circuit, which is connected to the rod chamber 1e of the boom cylinder 1 via the through holes.
　ブームシリンダ１のキャップ室１ｄに接続された油路Ｌ３とロッド室１ｅに接続された油路Ｌ４とは、フラッシング弁１３ａを介してタンク９に接続されている。フラッシング弁１３ａは、油路Ｌ３，Ｌ４の低圧側から余剰な作動油をタンク９に排出することにより、片ロッド式油圧シリンダであるブームシリンダ１のキャップ側とロッド側との流量差を吸収する。同様に、アームシリンダ３のキャップ室３ｄに接続された油路Ｌ７とロッド室３ｅに接続された油路Ｌ８とは、フラッシング弁１３ｂを介してタンク９に接続されている。フラッシング弁１３ｂは、油路Ｌ７，Ｌ８の低圧側から余剰な作動油をタンク９に排出することにより、片ロッド式油圧シリンダであるアームシリンダ３のキャップ側とロッド側との流量差を吸収する。 The oil passage L3 connected to the cap chamber 1d of the boom cylinder 1 and the oil passage L4 connected to the rod chamber 1e are connected to the tank 9 via the flushing valve 13a. The flushing valve 13a absorbs the flow rate difference between the cap side and the rod side of the boom cylinder 1, which is a single rod hydraulic cylinder, by discharging excess hydraulic oil from the low pressure side of the oil passages L3, L4 to the tank 9. . Similarly, the oil passage L7 connected to the cap chamber 3d of the arm cylinder 3 and the oil passage L8 connected to the rod chamber 3e are connected to the tank 9 via the flushing valve 13b. The flushing valve 13b absorbs the flow difference between the cap side and the rod side of the arm cylinder 3 which is a single rod hydraulic cylinder by discharging excess hydraulic oil to the tank 9 from the low pressure side of the oil passages L7 and L8. .
　コントローラ４０は、操作レバー３０，３１の操作量と後述する圧力センサ６２ａ，６２ｂの圧力値とに基づいて、切換弁１１ａ，１１ｂ，１２ａ，１２ｂとレギュレータ２１ａ，２１ｂとを制御する。 The controller 40 controls the switching valves 11a, 11b, 12a, 12b and the regulators 21a, 21b based on the operation amount of the operation levers 30, 31 and the pressure value of pressure sensors 62a, 62b described later.
　例えば、ブーム２を単独で低速動作させる場合（ブーム操作レバー３０のみが小さく操作された場合）は、１台の両吐出型ポンプ１０ａがブームシリンダ１に閉回路接続されるように切換弁１１ａを開きかつ切換弁１２ａを閉じると共に、ブーム操作レバー３０の操作量に応じた流量の作動油が両吐出型ポンプ１０ａから吐出されるようにレギュレータ２１ａを制御する。一方、ブーム２を単独で高速動作させる場合（ブーム操作レバー３０のみが大きく操作された場合）は、２台の両吐出型ポンプ１０ａ，１０ｂがブームシリンダ１に閉回路接続されるように切換弁１１ａ，１１ｂを開きかつ切換弁１２ａ，１２ｂを閉じると共に、ブーム操作レバー３０の操作量に応じた流量の作動油が両吐出型ポンプ１０ａ，１０ｂから吐出されるようにレギュレータ２１ａ，２１ｂを制御する。 For example, when the boom 2 alone is operated at a low speed (when only the boom control lever 30 is operated small), the switching valve 11a is closed so that one discharge pump 10a is connected to the boom cylinder 1 in a closed circuit. While opening and closing the switching valve 12a, the regulator 21a is controlled so that the hydraulic oil having a flow rate corresponding to the operation amount of the boom operation lever 30 is discharged from the both discharge pumps 10a. On the other hand, when the boom 2 is independently operated at high speed (when only the boom control lever 30 is largely operated), the switching valve is such that the two discharge pumps 10a and 10b are connected to the boom cylinder 1 in a closed circuit. 11a and 11b are opened and the switching valves 12a and 12b are closed, and the regulators 21a and 21b are controlled so that hydraulic oil at a flow rate corresponding to the operation amount of the boom operation lever 30 is discharged from both discharge pumps 10a and 10b. .
　アーム４を単独で低速動作させる場合（アーム操作レバー３１のみが小さく操作された場合）は、１台の両吐出型ポンプ１０ｂがアームシリンダ３に閉回路接続されるように、切換弁１２ｂを開きかつ切換弁１１ａを閉じると共に、アーム操作レバー３１の操作量に応じた流量の作動油が両吐出型ポンプ１０ｂから吐出されるように、レギュレータ２１ｂを制御する。一方、アーム４を単独で高速動作させる場合（アーム操作レバー３１のみが大きく操作された場合）は、２台の両吐出型ポンプ１０ａ，１０ｂがアームシリンダ３に閉回路接続されるように、切換弁１２ａ，１２ｂを開きかつ切換弁１１ａ，１１ｂを閉じると共に、アーム操作レバー３１の操作量に応じた流量の作動油が両吐出型ポンプ１０ａ，１０ｂから吐出されるようにレギュレータ２１ａ，２１ｂを制御する。 When the arm 4 is operated at low speed alone (when only the arm control lever 31 is operated small), the switching valve 12b is opened so that one discharge pump 10b is connected to the arm cylinder 3 in a closed circuit. And while closing the switching valve 11a, the regulator 21b is controlled so that the hydraulic oil of the flow volume according to the operation amount of the arm control lever 31 is discharged from the both discharge type pump 10b. On the other hand, when the arm 4 is operated independently at high speed (when only the arm operation lever 31 is operated largely), switching is performed so that the two discharge pumps 10a and 10b are connected to the arm cylinder 3 in a closed circuit. The valves 12a and 12b are opened and the switching valves 11a and 11b are closed, and the regulators 21a and 21b are controlled so that hydraulic oil at a flow rate corresponding to the operation amount of the arm operation lever 31 is discharged from both discharge type pumps 10a and 10b. Do.
　ブーム２およびアーム４を複合動作させる場合（ブーム操作レバー３０およびアーム操作レバー３１が同時に操作された場合）は、両吐出型ポンプ１０ａがブームシリンダ１に閉回路接続され、かつ両吐出型ポンプ１０ｂがアームシリンダ３に閉回路接続されるように切換弁１１ａ，１２ｂを開きかつ切換弁１２ａ，１１ｂを閉じると共に、ブーム操作レバー３０の操作量に応じた流量の作動油が両吐出型ポンプ１０ａから吐出されるようにレギュレータ２１ａを制御し、アーム操作レバー３１の操作量に応じた流量の作動油が両吐出型ポンプ１０ｂから吐出されるようにレギュレータ２１ｂを制御する。 When the boom 2 and the arm 4 are combined (when the boom control lever 30 and the arm control lever 31 are simultaneously operated), both discharge pumps 10a are connected to the boom cylinder 1 in a closed circuit, and both discharge pumps 10b The switching valves 11a and 12b are opened and the switching valves 12a and 11b are closed so that the closed circuit is connected to the arm cylinder 3, and the hydraulic fluid of the flow rate according to the operation amount of the boom control lever 30 is The regulator 21a is controlled so as to be discharged, and the regulator 21b is controlled so that the hydraulic oil at a flow rate corresponding to the operation amount of the arm control lever 31 is discharged from the both discharge type pumps 10b.
　なお、両吐出型ポンプ１０ａ（１０ｂ）は、一方の給排ポートの圧力が所定値以上になった場合に他方の給排ポートに作動油をリリーフさせるリリーフ弁２２ａ（２２ｂ）と、閉回路圧力を高めてキャビテーションを防止するためのメイクアップチェック弁２３ａ，２４ｂ（２３ａ，２４ｂ）およびチャージポンプ２５ａ（２５ｂ）と、チャージポンプ２５ａ（２５ｂ）の吐出圧が所定値以上になった場合に作動油をリリーフさせるチャージリリーフ弁２６ａ（２６ｂ）とを一体に備えているが、これらの装置は両吐出型ポンプ１０ａ，１０ｂとは別に設けても良い。 Both discharge pumps 10a (10b) have a relief valve 22a (22b) for relieving hydraulic fluid to the other supply / discharge port when the pressure at one supply / discharge port exceeds a predetermined value, and a closed circuit pressure Hydraulic fluid when the discharge pressure of make-up check valves 23a and 24b (23a and 24b) and charge pump 25a (25b) and charge pump 25a (25b) for raising cavitation and becoming higher than a predetermined value These units may be provided separately from the discharge pumps 10a and 10b, although they are integrally provided with a charge relief valve 26a (26b) for relieving the pressure.
　図３は、両吐出型ポンプ１０ａ，１０ｂの概略断面図である。 FIG. 3 is a schematic cross-sectional view of both discharge pumps 10a and 10b.
　図３において、両吐出型ポンプ１０ａ（１０ｂ）は、ケーシング５０ａ（５０ｂ）と、ケーシング５０ａ（５０ｂ）内に配置された両傾転斜板機構２０ａ（２０ｂ）とを備えている。両傾転斜板機構２０ａ（２０ｂ）は、シャフト５１、斜板５２、シリンダブロック５３、複数のピストン５４、バルブプレート５５等により構成されている。なお、図示は省略するが、ケーシング５０ａ（５０ｂ）内には、レギュレータ２１ａ（２１ｂ）、リリーフ弁２２ａ（２２ｂ）、メイクアップチェック弁２３ａ，２４ｂ（２３ａ，２４ｂ）、チャージポンプ２５ａ（２５ｂ）、チャージリリーフ弁２６ａ（２６ｂ）等も配置されている。 In FIG. 3, both discharge type pumps 10a (10b) are provided with a casing 50a (50b) and a tilting and swash plate mechanism 20a (20b) disposed in the casing 50a (50b). The both tilt swash plate mechanism 20a (20b) is composed of a shaft 51, a swash plate 52, a cylinder block 53, a plurality of pistons 54, a valve plate 55 and the like. Although not shown, in the casing 50a (50b), the regulator 21a (21b), the relief valve 22a (22b), the make-up check valves 23a, 24b (23a, 24b), the charge pump 25a (25b), The charge relief valve 26a (26b) and the like are also arranged.
　シャフト５１は、ケーシング５０ａ（５０ｂ）にベアリング５６を介して回転可能に支持されている。斜板５２は、シャフト５１の回転軸に対する傾斜角が可変となるようにシャフト５１周りに設けられている。シリンダブロック５３は、例えばスプライン嵌合により、シャフト５１に対して回転不能に結合されている。シリンダブロック５３は、シャフト５１周りに形成された複数のシリンダ室５７を有する。各シリンダ室５７には、ピストン５４が往復動可能に設けられている。 The shaft 51 is rotatably supported by the casing 50 a (50 b) via a bearing 56. The swash plate 52 is provided around the shaft 51 so that the inclination angle with respect to the rotation axis of the shaft 51 can be changed. The cylinder block 53 is non-rotatably coupled to the shaft 51 by, for example, spline fitting. The cylinder block 53 has a plurality of cylinder chambers 57 formed around the shaft 51. A piston 54 is provided in each cylinder chamber 57 so as to be capable of reciprocating.
　各シリンダ室５７は、シリンダブロック５３が回転することにより、バルブプレート５５を介して給排ポート５８，５９と間欠的に連通する。各ピストン５４は、シリンダブロック５３と共にシャフト５１の周りを回転すると共に、斜板５２の傾斜角に応じて各シリンダ室５７内を往復動する。これにより、一方の給排ポート５８（５９）から作動油を吸い込み、他方の給排ポート５９（５８）から圧油として吐出する。レギュレータ２１ａ，２１ｂ（図２に示す）を介して斜板５２の傾斜角を変化させると、両吐出型ポンプ１０ａ（１０ｂ）の吐出方向および吐出流量が変化する。 Each cylinder chamber 57 intermittently communicates with the supply and discharge ports 58 and 59 through the valve plate 55 when the cylinder block 53 rotates. Each piston 54 rotates around the shaft 51 together with the cylinder block 53, and reciprocates in each cylinder chamber 57 in accordance with the inclination angle of the swash plate 52. As a result, the hydraulic oil is sucked from one of the supply and discharge ports 58 (59) and discharged as pressure oil from the other supply and discharge port 59 (58). When the inclination angle of the swash plate 52 is changed through the regulators 21a and 21b (shown in FIG. 2), the discharge direction and the discharge flow rate of both discharge pumps 10a (10b) change.
　ケーシング５０ａ（５０ｂ）には、作動油を排出するためのドレンポート６０ａ（６０ｂ）が設けられている。ドレンポート６０ａ（６０ｂ）は、ドレン配管６１ａ（６１ｂ）を介してタンク９に接続されている。これにより、両傾転斜板機構２０ａ（２０ｂ）等からケーシング５０ａ（５０ｂ）内に漏れ出た作動油をタンク９に戻すことができる。 The casing 50a (50b) is provided with a drain port 60a (60b) for discharging the hydraulic oil. The drain port 60a (60b) is connected to the tank 9 via a drain pipe 61a (61b). As a result, the hydraulic oil leaking from the both tilt swash plate mechanisms 20a (20b) and the like into the casing 50a (50b) can be returned to the tank 9.
　ドレン配管６１ａ（６１ｂ）には、ケーシング５０ａ（５０ｂ）内からタンク９へ排出される作動油の圧力（以下「ドレン圧力」という。）を検出する圧力検出装置としての圧力センサ６２ａ（６２ｂ）が設けられている。両吐出型ポンプ１０ａ（１０ｂ）が正常に機能しているときは、ケーシング５０ａ（５０ｂ）内に漏れ出る作動油の流量は小さいため、ケーシング５０ａ（５０ｂ）内は低圧（０～０．３ＭＰａ程度）であり、ドレン圧力も低い。一方、ケーシング５０ａ（５０ｂ）内に配置されている部品が故障すると、ケーシング５０ａ（５０ｂ）内に多量の作動油が漏れ出すことにより、ケーシング５０ａ（５０ｂ）内は高圧となり、ドレン圧力も高くなる。従って、ドレン圧力を監視することにより、両吐出型ポンプ１０ａ，１０ｂの故障を検出することができる。ここで、圧力センサ６２ａ（６２ｂ）をドレン配管６１ａ（６１ｂ）のタンク９寄りに配置した場合は、両吐出型ポンプ１０ａ（１０ｂ）の故障の有無を問わず、圧力センサ６２ａ（６２ｂ）で検出される圧力は大気圧程度となり、故障の検出精度が低下する。そのため、圧力センサ６２ａ（６２ｂ）は、ドレン配管６１ａ（６１ｂ）のドレンポート６０ａ（６０ｂ）寄りに配置することが望ましい。これにより、故障時に検出されるドレン圧力と正常時に検出されるドレン圧力との差が大きくなるため、故障の検出精度を向上させることが可能となる。なお、圧力センサ６２ａ（６２ｂ）は、ケーシング５０ａ（５０ｂ）内に配置しても良い。 In the drain pipe 61a (61b), a pressure sensor 62a (62b) as a pressure detection device for detecting the pressure (hereinafter referred to as "drain pressure") of the hydraulic oil discharged from the inside of the casing 50a (50b) to the tank 9 It is provided. When both discharge pumps 10a (10b) are functioning normally, the flow rate of the hydraulic oil leaking into the casing 50a (50b) is small, so the low pressure (about 0 to 0.3 MPa) in the casing 50a (50b) And the drain pressure is also low. On the other hand, when the parts arranged in the casing 50a (50b) fail, a large amount of hydraulic oil leaks out into the casing 50a (50b), so the inside of the casing 50a (50b) becomes high pressure and the drain pressure also becomes high. . Therefore, by monitoring the drain pressure, it is possible to detect a failure of both discharge pumps 10a and 10b. Here, when the pressure sensor 62a (62b) is disposed closer to the tank 9 of the drain pipe 61a (61b), the pressure sensor 62a (62b) detects whether the both discharge pumps 10a (10b) are defective or not. The pressure applied is approximately atmospheric pressure, which lowers the accuracy of failure detection. Therefore, it is desirable that the pressure sensor 62a (62b) be disposed closer to the drain port 60a (60b) of the drain pipe 61a (61b). As a result, the difference between the drain pressure detected at the time of failure and the drain pressure detected at the normal time becomes large, so that it is possible to improve the detection accuracy of the failure. The pressure sensor 62a (62b) may be disposed in the casing 50a (50b).
　図４は、コントローラ４０の制御ブロック図である。 FIG. 4 is a control block diagram of the controller 40.
　図４において、コントローラ４０は、操作量検出部４１と、車体制御演算部４２と、ポンプ信号出力部４３と、切換弁信号出力部４４と、圧力検出部４５と、故障判定部４６とを備えている。 In FIG. 4, the controller 40 includes an operation amount detection unit 41, a vehicle body control calculation unit 42, a pump signal output unit 43, a switching valve signal output unit 44, a pressure detection unit 45, and a failure determination unit 46. ing.
　操作量検出部４１は、ブーム操作レバー３０およびアーム操作レバー３１の操作量（例えばパイロット圧）を検出する。検出された操作量の情報は、車体制御演算部４２へと送られる。 The operation amount detection unit 41 detects an operation amount (for example, a pilot pressure) of the boom control lever 30 and the arm control lever 31. Information on the detected amount of operation is sent to the vehicle body control calculation unit 42.
　車体制御演算部４２は、ブーム操作レバー３０およびアーム操作レバー３１の操作量と後述する故障判定部４６からの判定結果とに基づいて、第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂの開閉指令値および第１、第２ポンプ１０ａ，１０ｂの吐出流量指令値を設定する。設定された第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂの開閉指令値の情報は、切換弁信号出力部４４へと送られる。設定された第１、第２ポンプ１０ａ，１０ｂの吐出流量指令値の情報は、ポンプ信号出力部４３へと送られる。 The vehicle body control calculation unit 42 sets the first to fourth switching valves 11a, 11b, 12a, 12b based on the operation amount of the boom operation lever 30 and the arm operation lever 31 and the determination result from the failure determination unit 46 described later. The open / close command value and the discharge flow rate command value of the first and second pumps 10a and 10b are set. Information on the set open / close command values of the first to fourth switching valves 11a, 11b, 12a, 12b is sent to the switching valve signal output unit 44. Information on discharge flow rate command values of the set first and second pumps 10 a and 10 b is sent to the pump signal output unit 43.
　ポンプ信号出力部４３は、車体制御演算部４２からの吐出流量指令値に応じた制御信号を第１、第２レギュレータ２１ａ，２１ｂに出力し、第１、第２ポンプ１０ａ，１０ｂの吐出流量を制御する。 The pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value from the vehicle body control calculation unit 42 to the first and second regulators 21a and 21b, and the discharge flow rates of the first and second pumps 10a and 10b. Control.
　切換弁信号出力部４４は、車体制御演算部４２からの開閉指令値に応じた制御信号を第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂに出力し、第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂを開閉する。 The switching valve signal output unit 44 outputs a control signal corresponding to the open / close command value from the vehicle body control calculating unit 42 to the first to fourth switching valves 11a, 11b, 12a, 12b, and the first to fourth switching valve 11a. , 11b, 12a, 12b are opened and closed.
　圧力検出部４５は、第１、第２圧力センサ６２ａ，６２ｂの圧力値を検出する。検出された圧力値の情報は、故障判定部４６へと送られる。 The pressure detection unit 45 detects the pressure values of the first and second pressure sensors 62a and 62b. Information on the detected pressure value is sent to the failure determination unit 46.
　故障判定部４６は、第１、第２圧力センサ６２ａ，６２ｂの圧力値（第１、第２ポンプ１０ａ，１０ｂのドレン圧力）に基づいて、第１、第２ポンプ１０ａ，１０ｂが正常であるか否かを判定する。判定結果の情報は、車体制御演算部４２へと送られる。 The failure determination unit 46 determines that the first and second pumps 10a and 10b are normal based on the pressure values of the first and second pressure sensors 62a and 62b (the drain pressures of the first and second pumps 10a and 10b). It is determined whether or not. Information on the determination result is sent to the vehicle control control unit 42.
　図５は、コントローラ４０の制御フロー図である。図５に示す制御フローは、油圧ショベル１００のエンジンが始動し、コントローラ４０の電源が入った後に開始される。以下、当該制御フローを構成する各ステップについて順に説明する。 FIG. 5 is a control flow diagram of the controller 40. The control flow shown in FIG. 5 is started after the engine of the hydraulic shovel 100 starts and the controller 40 is powered on. Hereinafter, each step constituting the control flow will be described in order.
　ステップＳ１にて、故障判定部４６は、第１、第２圧力センサ６２ａ，６２ｂの圧力値Ｐ１，Ｐ２を圧力検出部４５から取得する。 In step S1, the failure determination unit 46 acquires the pressure values P1 and P2 of the first and second pressure sensors 62a and 62b from the pressure detection unit 45.
　ステップＳ２にて、故障判定部４６は、第１圧力センサ６２ａの圧力値Ｐ１が圧力閾値Ｐ０よりも大きいか否かを判定する。ここで、圧力閾値Ｐ０は、第１、第２ポンプ１０ａ，１０ｂの故障判定を行うための閾値であり、第１、第２ポンプ１０ａ，１０ｂが正常なときの最大ドレン圧力と同等かそれよりも僅かに低い値に設定されている。 In step S2, the failure determination unit 46 determines whether the pressure value P1 of the first pressure sensor 62a is larger than the pressure threshold P0. Here, the pressure threshold P0 is a threshold for determining the failure of the first and second pumps 10a and 10b, and is equal to or greater than the maximum drain pressure when the first and second pumps 10a and 10b are normal. Is also set to a slightly lower value.
　ステップＳ２で圧力値Ｐ１が圧力閾値Ｐ０よりも大きい（ＹＥＳ）と判定された場合は、ステップＳ３にて、車体制御演算部４２は、第１ポンプ１０ａに接続されている第１、第３切換弁１１ａ，１２ａの開閉指令値を閉に設定する。切換弁信号出力部４４は、車体制御演算部４２からの開閉指令値（閉）に応じた制御信号（閉信号）を切換弁１１，１２に出力し、第１、第３切換弁１１ａ，１２ａを閉じる。 When it is determined in step S2 that the pressure value P1 is larger than the pressure threshold P0 (YES), in step S3, the vehicle body control calculation unit 42 performs the first and third switching connected to the first pump 10a. The open / close command values of the valves 11a and 12a are set to be closed. The switching valve signal output unit 44 outputs a control signal (closing signal) corresponding to the opening / closing command value (closing) from the vehicle body control calculating unit 42 to the switching valves 11 and 12 to make the first and third switching valves 11a and 12a. Close
　ステップＳ４にて、車体制御演算部４２は、第１、第２ポンプ１０ａ，１０ｂの吐出流量指令値をゼロ（０）に設定する。ポンプ信号出力部４３は、車体制御演算部４２からの吐出流量指令値（０）に応じた制御信号をレギュレータ２１ａ，２１ｂに出力し、第１、第２ポンプ１０ａ，１０ｂの吐出流量をゼロ（０）に制御する。ステップＳ４が終了すると、コントローラ４０は制御を終了し、油圧ショベル１００の稼働を停止する。 In step S4, the vehicle body control calculating unit 42 sets the discharge flow rate command values of the first and second pumps 10a and 10b to zero (0). The pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value (0) from the vehicle body control calculation unit 42 to the regulators 21a and 21b, and the discharge flow rate of the first and second pumps 10a and 10b is zero ( Control to 0). When step S4 is completed, the controller 40 ends the control and stops the operation of the hydraulic shovel 100.
　ステップＳ２で圧力値Ｐ１が圧力閾値Ｐ０以下である（ＮＯ）と判定された場合は、ステップＳ５にて、故障判定部４６は、第２圧力センサ６２ｂの圧力値Ｐ２が圧力閾値Ｐ０よりも大きいか否かを判定する。 If it is determined in step S2 that the pressure value P1 is less than or equal to the pressure threshold P0 (NO), the failure determination unit 46 determines that the pressure value P2 of the second pressure sensor 62b is larger than the pressure threshold P0 in step S5. It is determined whether or not.
　ステップＳ５で圧力値Ｐ２が圧力閾値Ｐ０よりも大きい（ＹＥＳ）と判定された場合は、ステップＳ６にて、車体制御演算部４２は、第２ポンプ１０ｂに接続されている第２、第４切換弁１１ｂ，１２ｂの開閉指令値を閉に設定する。切換弁信号出力部４４は、開閉指令値（閉）に応じた制御信号（閉信号）を第２、第４切換弁１１ｂ，１２ｂに出力し、第２、第４切換弁１１ｂ，１２ｂを閉じる。 If it is determined in step S5 that the pressure value P2 is larger than the pressure threshold P0 (YES), then in step S6, the vehicle body control calculation unit 42 performs the second and fourth switchings connected to the second pump 10b. The open / close command values of the valves 11 b and 12 b are set to be closed. The switching valve signal output unit 44 outputs a control signal (closing signal) corresponding to the opening / closing command value (closing) to the second and fourth switching valves 11b and 12b, and closes the second and fourth switching valves 11b and 12b. .
　ステップＳ７にて、車体制御演算部４２は、第１、第２ポンプ１０ａ，１０ｂの吐出流量指令値をゼロ（０）に設定する。ポンプ信号出力部４３は、吐出流量指令値（０）に応じた制御信号をレギュレータ２１ａ，２１ｂに出力し、第１、第２ポンプ１０ａ，１０ｂの吐出流量をゼロ（０）に制御する。ステップＳ７の処理が終了すると、コントローラ４０は制御を終了し、油圧ショベル１００の稼働を停止する。 In step S7, the vehicle body control calculation unit 42 sets the discharge flow rate command values of the first and second pumps 10a and 10b to zero (0). The pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value (0) to the regulators 21a and 21b to control the discharge flow rate of the first and second pumps 10a and 10b to zero (0). When the process of step S7 ends, the controller 40 ends the control and stops the operation of the hydraulic shovel 100.
　ステップＳ５で圧力値Ｐ２が圧力閾値Ｐ０以下である（ＮＯ）と判定された場合は、ステップＳ８にて、操作量検出部４１は、ブーム操作レバー３０およびアーム操作レバー３１の操作量を検出する。 If it is determined in step S5 that the pressure value P2 is less than or equal to the pressure threshold P0 (NO), the operation amount detection unit 41 detects the operation amount of the boom operation lever 30 and the arm operation lever 31 in step S8. .
　ステップＳ９にて、車体制御演算部４２は、ブーム操作レバー３０およびアーム操作レバー３１の操作量に基づいて、第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂの開閉指令値および吐出流量指令値を設定する。切換弁信号出力部４４は、開閉指令値に応じた制御信号を第１～４切換弁１１ａ，１１ｂ，１２ａ，１２ｂに出力し、第１～４切換弁１１ａ，１１ｂ，１２ａ，１２ｂを開閉する。 In step S9, based on the operation amount of boom operation lever 30 and arm operation lever 31, vehicle body control operation unit 42 opens / closes the first to fourth switching valves 11a, 11b, 12a, 12b and discharge flow rate command. Set the value The switching valve signal output unit 44 outputs a control signal corresponding to the opening / closing command value to the first to fourth switching valves 11a, 11b, 12a, 12b, and opens / closes the first to fourth switching valves 11a, 11b, 12a, 12b. .
　ステップＳ１０にて、車体制御演算部４２は、ブーム操作レバー３０およびアーム操作レバー３１の操作量に基づいて、吐出流量指令値を設定する。ポンプ信号出力部４３は、吐出流量指令値に応じた制御信号を第１、第２レギュレータ２１ａ，２１ｂに出力し、第１、第２ポンプ１０ａ，１０ｂの吐出流量を制御する。これにより、ブーム操作レバー３０およびアーム操作レバー３１の操作に応じて、油圧ショベル１００のブーム２およびアーム４が動作する。ステップＳ１０が終了すると、コントローラ４０は、ステップＳ１以降の処理を繰り返し実行する。 In step S10, the vehicle body control calculating unit 42 sets the discharge flow rate command value based on the operation amount of the boom operation lever 30 and the arm operation lever 31. The pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value to the first and second regulators 21a and 21b to control the discharge flow rate of the first and second pumps 10a and 10b. Thereby, the boom 2 and the arm 4 of the hydraulic shovel 100 operate according to the operation of the boom control lever 30 and the arm control lever 31. When step S10 is completed, the controller 40 repeatedly executes the processes after step S1.
　図６は、第１ポンプ１０ａを用いてブームシリンダ１を駆動している最中に第１ポンプ１０ａが故障した場合の油圧閉回路システム２００の動作を示す図である。なお、図６では、説明の簡略化のため、第１ポンプ１０ａの動作に関わる部分のみを示し、第２ポンプ１０ｂの動作に関わる部分は省略している。 FIG. 6 is a diagram showing an operation of the hydraulic closed circuit system 200 when the first pump 10a breaks down while driving the boom cylinder 1 using the first pump 10a. In addition, in FIG. 6, only the part in connection with operation | movement of the 1st pump 10a is shown for simplification of description, and the part in connection with operation | movement of the 2nd pump 10b is abbreviate | omitted.
　図６において、ブーム操作レバー３０を操作していない間（時刻０～Ｔ１）は、ブーム操作レバー３０の操作量はゼロ（０）となる。このとき、第１ポンプ１０ａは正常に機能しているため、ケーシング５０ａ内は低圧（０ＭＰａ～０．３ＭＰａ程度）であり、ドレン圧力は圧力閾値Ｐ０よりも小さい。 In FIG. 6, while the boom control lever 30 is not operated (time 0 to T1), the operation amount of the boom control lever 30 is zero (0). At this time, since the first pump 10a functions normally, the inside of the casing 50a has a low pressure (approximately 0 MPa to 0.3 MPa), and the drain pressure is smaller than the pressure threshold P0.
　その後、時刻Ｔ１でブーム操作レバー３０の操作が開始されると、第１切換弁１１ａが開きかつ第３切換弁１２ａが閉じることにより（図５のステップＳ９）、第１ポンプ１０ａがブームシリンダ１に閉回路接続され、ブーム操作レバー３０の操作量に応じた流量の作動油が第１ポンプ１０ａから吐出される（図５のステップＳ１０）。このとき、ブームシリンダ１はフロント作業機１０４の自重を支持しており、ブームシリンダ１のキャップ室１ｄは高圧となっている。 Thereafter, when the operation of the boom operation lever 30 is started at time T1, the first switching valve 11a is opened and the third switching valve 12a is closed (step S9 in FIG. 5). The hydraulic fluid of the flow rate according to the operation amount of the boom operation lever 30 is discharged from the first pump 10a (step S10 in FIG. 5). At this time, the boom cylinder 1 supports the weight of the front work implement 104, and the cap chamber 1d of the boom cylinder 1 has a high pressure.
　その後、時刻Ｔ２で第１ポンプ１０ａが故障すると、ブームシリンダ１のキャップ室１ｄから第１ポンプ１０ａのケーシング５０ａ内に多量の作動油が漏れ出すことにより、ケーシング５０ａ内は高圧となり、ドレン圧力は圧力閾値Ｐ０よりも大きくなる（図５のステップＳ２でＹＥＳと判定される）。その結果、第１ポンプ１０ａに接続されている第１、第２切換弁１１ａ，１２ａが全て閉じられる（図５のステップＳ３）。これにより、ブームシリンダ１のキャップ室１ｄから第１ポンプ１０ａへの作動油の逆流が防止されるため、意図しないブームシリンダ１の縮退動作することを抑制することができる。 Thereafter, when the first pump 10a breaks down at time T2, a large amount of hydraulic oil leaks from the cap chamber 1d of the boom cylinder 1 into the casing 50a of the first pump 10a, so the inside of the casing 50a becomes high pressure, and the drain pressure It becomes larger than the pressure threshold P0 (it is determined as YES in step S2 of FIG. 5). As a result, all of the first and second switching valves 11a and 12a connected to the first pump 10a are closed (step S3 in FIG. 5). Thereby, since back flow of hydraulic fluid from cap chamber 1d of boom cylinder 1 to first pump 10a is prevented, it is possible to suppress unintended retraction operation of boom cylinder 1.
　以上のように構成した本実施例によれば、両吐出型ポンプ１０ａ，１０ｂのいずれかが故障し、故障した両吐出型ポンプのドレン圧力が所定の圧力Ｐ０を超えると、故障した両吐出型ポンプに接続されている全ての切換弁が閉じられる。これにより、両吐出型ポンプが故障した場合でも、油圧アクチュエータ１，３から故障した両吐出型ポンプへの作動油の逆流が防止されるため、意図しない油圧アクチュエータ１，３の動作を抑制することができる。 According to the present embodiment configured as described above, when either of the two discharge pumps 10a and 10b is broken and the drain pressure of the broken two discharge pumps exceeds the predetermined pressure P0, the broken double discharge type All switching valves connected to the pump are closed. As a result, even if both discharge pumps fail, backflow of hydraulic fluid from the hydraulic actuators 1 and 3 to the broken discharge pumps is prevented, so unintended operation of the hydraulic actuators 1 and 3 is suppressed. Can.
　本発明の第２の実施例は、いずれかの両吐出型ポンプが故障した場合に、意図しない油圧アクチュエータ１，３の動作を抑制しつつ、他の正常な両吐出型ポンプのみを用いて油圧ショベル１００を稼働できるようにしたものである。以下、第１の実施例との相違点を中心に説明する。 According to the second embodiment of the present invention, in the event of failure of either of the two discharge pumps, hydraulic control is performed using only other normal double discharge pumps while suppressing unintended operation of the hydraulic actuators 1, 3 The shovel 100 can be operated. Hereinafter, differences from the first embodiment will be mainly described.
　図７は、本実施例に係る油圧閉回路システムの概略構成図である。 FIG. 7 is a schematic configuration diagram of a hydraulic closed circuit system according to the present embodiment.
　図７において、油圧閉回路システム２００Ａは、表示装置としてのモニタ３３と、指示入力装置としての操作ボタン３２とを更に備えており、コントローラ４０Ａは、モニタ出力部４７を更に備えている。モニタ３３および指示入力装置３２は、キャブ１０１内に配置されている。 In FIG. 7, the hydraulic closed circuit system 200A further includes a monitor 33 as a display device and an operation button 32 as an instruction input device, and the controller 40A further includes a monitor output unit 47. The monitor 33 and the instruction input device 32 are disposed in the cab 101.
　図８は、コントローラ４０Ａの制御ブロック図である。 FIG. 8 is a control block diagram of the controller 40A.
　図８において、操作量検出部４１Ａは、ブーム操作レバー３０およびアーム操作レバー３１の操作量に加えて、操作ボタン３２からの入力信号を検出する。検出された操作量および入力信号の情報は、車体制御演算部４２へと送られる。 In FIG. 8, the operation amount detection unit 41 </ b> A detects an input signal from the operation button 32 in addition to the operation amounts of the boom operation lever 30 and the arm operation lever 31. Information of the detected operation amount and input signal is sent to the vehicle control control unit 42.
　車体制御演算部４２Ａは、ブーム操作レバー３０およびアーム操作レバー３１の操作量と操作ボタン３２からの入力信号と故障判定部４６からの判定結果とに基づいて、第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂの開閉指令値および第１、第２ポンプ１０ａ，１０ｂの吐出流量指令値を設定する。 The vehicle body control calculation unit 42A is based on the operation amount of the boom operation lever 30 and the arm operation lever 31, the input signal from the operation button 32, and the determination result from the failure determination unit 46, the first to fourth switching valve 11a, The open / close command values of 11b, 12a, 12b and the discharge flow rate command values of the first and second pumps 10a, 10b are set.
　図９Ａ～図９Ｃは、コントローラ４０Ａの制御フロー図である。 9A to 9C are control flow diagrams of the controller 40A.
　第１の実施例における制御フロー（図５に示す）では、ステップＳ２で第１ポンプ１０ａの故障を検出してステップＳ３，Ｓ４を実行した後、またはステップＳ５で第２ポンプ１０ｂの故障を検出してステップＳ６，Ｓ７を実行した後に、コントローラ４０は制御を終了し、油圧ショベル１００の稼働を停止することとしたが、図９Ａ～図９Ｃに示す制御フローでは、ステップＳ４の後に第２ポンプ１０ｂのみを用いて油圧ショベル１００を稼働するための処理（ステップＳＸ１～ＳＸ６）を追加し、ステップＳ７の後に第１ポンプ１０ａのみを用いて油圧ショベル１００を稼働するための処理（ステップＳＹ１～ＳＹ７）を追加している。以下、追加した各ステップについて順に説明する。 In the control flow (shown in FIG. 5) in the first embodiment, after the failure of the first pump 10a is detected in step S2 and steps S3 and S4 are executed, or the failure of the second pump 10b is detected in step S5. Then, after executing steps S6 and S7, the controller 40 ends the control and decides to stop the operation of the hydraulic shovel 100, but in the control flow shown in FIGS. 9A to 9C, the second pump is performed after step S4. A process (steps SY1 to SY7) for adding the process (steps SX1 to SX6) for operating the hydraulic shovel 100 using only 10b and for operating the hydraulic shovel 100 using only the first pump 10a after step S7 ) Has been added. Hereinafter, each added step will be described in order.
　ステップＳＸ１にて、モニタ出力部４７は、第１ポンプ１０ａの故障情報をモニタ３３に出力する。 At step SX1, the monitor output unit 47 outputs the failure information of the first pump 10a to the monitor 33.
　図１０は、モニタ３３の表示画面の一例を示す図である。 FIG. 10 is a view showing an example of a display screen of the monitor 33. As shown in FIG.
　図１０において、表示画面３３ａの左側には、油圧閉回路システム２００Ａの油圧回路の簡略図が表示されており、故障箇所が網掛け表示されている。これにより、作業者は故障個所を確認することができる。また、表示画面３３ａの右側には、第１ポンプ１０ａの故障を検出した旨のメッセージと、通常モードから縮退モードに移行するか否かを問い合せるメッセージとが表示されている。ここで、通常モードとは、全ての両吐出型ポンプ１０ａ，１０ｂを用いて油圧ショベル１００を稼働する制御モードであり、縮退モードとは、故障した両吐出型ポンプを使用せず正常な両吐出型ポンプのみを用いて油圧ショベル１００を稼働する制御モードである。作業者は、操作ボタン３２を操作することにより、コントローラ４０に通常モードから縮退モードへの移行を指示することができる。 In FIG. 10, on the left side of the display screen 33a, a simplified diagram of the hydraulic circuit of the hydraulic closed circuit system 200A is displayed, and the failure location is shaded. Thus, the operator can confirm the failure point. Further, on the right side of the display screen 33a, a message indicating that a failure of the first pump 10a has been detected, and a message inquiring whether to shift from the normal mode to the degeneration mode are displayed. Here, the normal mode is a control mode in which the hydraulic shovel 100 is operated using all the dual discharge pumps 10a and 10b, and the degenerate mode is a normal dual discharge without using a failed dual discharge pump. It is a control mode in which the hydraulic shovel 100 is operated using only the die pump. The operator can instruct the controller 40 to shift from the normal mode to the degeneration mode by operating the operation button 32.
　ステップＳＸ２にて、車体制御演算部４２は、指示入力装置３２からの入力信号の情報に基づいて、通常モードから縮退モードへの移行が指示されたか否かを判定する。 In step SX2, based on the information of the input signal from the instruction input device 32, the vehicle body control calculation unit 42 determines whether or not the transition from the normal mode to the degeneration mode is instructed.
　ステップＳＸ２で通常モードから縮退モードへの移行が指示された（ＹＥＳ）と判定された場合は、ステップＳＸ３にて、車体制御演算部４２は、油圧ショベル１００の各動作と第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂの開閉指令値との対応関係を規定したテーブルを、第１、第２ポンプ１０ａ，１０ｂが共に正常である場合に使用するテーブル（後述の通常テーブル）から、第１ポンプ１０ａが故障した場合に使用するテーブル（後述の第１縮退テーブル）に切り換える。 If it is determined in step SX2 that the transition from the normal mode to the degeneration mode is instructed (YES), the vehicle body control calculation unit 42 performs the first to fourth switching of each operation of the hydraulic shovel 100 in step SX3. From the table (a normal table described later) used when the first and second pumps 10a and 10b are both normal, a table defining the correspondence with the open / close command values of the valves 11a, 11b, 12a, 12b Switching to a table (a first degeneration table to be described later) used when one pump 10a breaks down.
　図１１は、油圧ショベル１００の各動作と第１～第４切換弁の開閉指令値との対応関係を規定したテーブルの一例を示す図である。 FIG. 11 is a diagram showing an example of a table defining the correspondence between each operation of the hydraulic shovel 100 and the open / close command values of the first to fourth switching valves.
　図１１において、テーブル７０は、第１、第２ポンプ１０ａ，１０ｂが共に正常である場合に使用するテーブル（以下「通常テーブル」という。）であり、テーブル７１は、第１ポンプ１０ａが故障した場合に使用するテーブル（以下「第１縮退テーブル」という。）であり、テーブル７２は、第２ポンプ１０ｂが故障した場合に使用するテーブル（以下「第２縮退テーブル」という。）である。第１縮退テーブル７１では、第１ポンプ１０ａを使用しないため、油圧ショベル１００の動作に関わらず、第１ポンプ１０ａに接続されている第１、第３切換弁１１ａ，１２ａの開閉指令値が閉となっている。一方、第２縮退テーブル７２では、第２ポンプ１０ｂを使用しないため、油圧ショベル１００の動作に関わらず、第２ポンプ１０ｂに接続されている第２、第４切換弁１１ａ，１２ａの開閉指令値が閉となっている。各テーブル７０～７２は、コントローラ４０に予め記憶されており、車体制御演算部４２によって参照される。 In FIG. 11, the table 70 is a table used when both the first and second pumps 10a and 10b are normal (hereinafter referred to as a "normal table"), and the table 71 has a failure in the first pump 10a. The table 72 is a table (hereinafter referred to as a “first degeneration table”) used in the case where the second pump 10 b fails, and the table 72 is a table (hereinafter referred to as a “second degeneration table”). In the first degeneration table 71, since the first pump 10a is not used, the open / close command values of the first and third switching valves 11a and 12a connected to the first pump 10a are closed regardless of the operation of the hydraulic shovel 100. It has become. On the other hand, in the second degeneration table 72, since the second pump 10b is not used, the open / close command values of the second and fourth switching valves 11a and 12a connected to the second pump 10b regardless of the operation of the hydraulic shovel 100 Is closed. Each of the tables 70 to 72 is stored in advance in the controller 40, and is referred to by the vehicle control control unit 42.
　ステップＳＸ４にて、車体制御演算部４２は、ブーム操作レバー３０およびアーム操作レバー３１の操作量を操作量検出部４１から取得する。 In step SX4, the vehicle body control calculation unit 42 acquires the operation amount of the boom operation lever 30 and the arm operation lever 31 from the operation amount detection unit 41.
　ステップＳＸ５にて、車体制御演算部４２は、第１縮退テーブル７１を参照し、ブーム操作レバー３０およびアーム操作レバー３１の操作量に基づいて、第１～第４切換弁１１ａ，１１ｂ，１２ａ，１２ｂの開閉指令値を設定する。切換弁信号出力部４４は、開閉指令値に応じた制御信号を第１～４切換弁１１ａ，１１ｂ，１２ａ，１２ｂに出力し、第１～４切換弁１１ａ，１１ｂ，１２ａ，１２ｂを開閉する。 In step SX5, the vehicle body control calculation unit 42 refers to the first reduction table 71, and based on the operation amount of the boom operation lever 30 and the arm operation lever 31, the first to fourth switching valves 11a, 11b, 12a, Set the open / close command value of 12b. The switching valve signal output unit 44 outputs a control signal corresponding to the opening / closing command value to the first to fourth switching valves 11a, 11b, 12a, 12b, and opens / closes the first to fourth switching valves 11a, 11b, 12a, 12b. .
　ステップＳＸ６にて、車体制御演算部４２は、ブーム操作レバー３０またはアーム操作レバー３１の操作量に基づいて、第２ポンプ１０ｂの吐出流量指令値を設定する。ポンプ信号出力部４３は、吐出流量指令値に応じた制御信号を第２レギュレータ２１ｂに出力し、第２ポンプ１０ｂの吐出流量を制御する。これにより、ブーム操作レバー３０およびアーム操作レバー３１の操作に応じて、油圧ショベル１００のブーム２およびアーム４が動作する。このとき、故障した第１ポンプ１０ａの吐出流量はゼロ（０）に制御されているため、エネルギ損失を抑えることができる。ステップＳＸ６が終了すると、コントローラ４０は、ステップＳＸ４以降の処理を繰り返し実行する。 In step SX6, the vehicle body control calculating unit 42 sets the discharge flow rate command value of the second pump 10b based on the operation amount of the boom operation lever 30 or the arm operation lever 31. The pump signal output unit 43 outputs a control signal corresponding to the discharge flow rate command value to the second regulator 21b to control the discharge flow rate of the second pump 10b. Thereby, the boom 2 and the arm 4 of the hydraulic shovel 100 operate according to the operation of the boom control lever 30 and the arm control lever 31. At this time, since the discharge flow rate of the failed first pump 10a is controlled to zero (0), energy loss can be suppressed. When step SX6 is completed, the controller 40 repeatedly executes the processing of step SX4 and subsequent steps.
　ステップＳＸ２で通常モードから縮退モードへの移行が指示されなかった（ＮＯ）と判定された場合は、コントローラ４０は制御を終了し、油圧ショベル１００の稼働を停止する。 If it is determined in step SX2 that transition from the normal mode to the degeneration mode is not instructed (NO), the controller 40 ends the control and stops the operation of the hydraulic shovel 100.
　なお、ステップＳ７の後に追加した第１ポンプ１０ａのみで油圧ショベル１００を稼働させるための処理（ステップＳＹ１～ＳＹ６）は、ステップＳＹ１で第２ポンプ１０ｂの故障を表示し、ステップＳＹ３で第２縮退テーブル７２に切り換え、ステップＳＹ５，ＳＹ６で第２縮退テーブル７２を参照する点を除き、ステップＳＸ１～ＳＸ６と同様であるため、説明は省略する。 The process for operating the hydraulic shovel 100 with only the first pump 10a added after step S7 (steps SY1 to SY6) displays the failure of the second pump 10b at step SY1, and the second degeneration at step SY3. The process is the same as steps SX1 to SX6 except that the table 72 is switched to and the second degeneration table 72 is referred to in steps SY5 and SY6, so the description will be omitted.
　以上のように構成した本実施例によれば、油圧閉回路システム２００Ａにおいて両吐出型ポンプが故障した場合でも、意図しない油圧アクチュエータ１，３の動作を抑制しつつ、他の正常な両吐出型ポンプのみを用いて油圧ショベル１００を稼働することができる。 According to the present embodiment configured as described above, even if both discharge pumps fail in the hydraulic closed circuit system 200A, other normal double discharge types can be performed while suppressing unintended operation of the hydraulic actuators 1, 3 The hydraulic shovel 100 can be operated using only the pump.
　以上、本発明の実施例について詳述したが、本発明は、上記した実施例に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施例は、本発明を油圧ショベルに適用したものであるが、本発明はこれに限られず、複数の油圧アクチュエータを油圧閉回路で駆動する建設機械全般に適用可能である。また、上記した実施例は、本発明を分かり易く説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施例の構成に他の実施例の構成の一部を加えることも可能であり、ある実施例の構成の一部を削除し、あるいは、他の実施例の一部と置き換えることも可能である。 As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to an above-described Example, A various modified example is included. For example, although the above-mentioned Example applied this invention to a hydraulic shovel, this invention is not restricted to this, It is applicable to the general construction machinery which drives a several hydraulic actuator by a hydraulic closed circuit. Further, the above-described embodiments are described in detail to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. In addition, it is also possible to add part of the configuration of another embodiment to the configuration of one embodiment, or to delete part of the configuration of one embodiment or replace part of the configuration of another embodiment. It is possible.
　１…ブームシリンダ（油圧アクチュエータ）、１ａ…シリンダチューブ、１ｂ…ロッド、１ｃ…ピストン、１ｄ…キャップ室、１ｅ…ロッド室、２…ブーム、３…アームシリンダ（油圧アクチュエータ）、３ａ…シリンダチューブ、３ｂ…ロッド、３ｃ…ピストン、３ｄ…キャップ室、３ｅ…ロッド室、４…アーム、５…バケットシリンダ、５ａ…シリンダチューブ、５ｂ…ロッド、６…バケット、７…旋回モータ（油圧アクチュエータ）、８ａ，８ｂ…走行装置、９…タンク、１０ａ…第１ポンプ（両吐出型ポンプ）、１０ｂ…第２ポンプ（両吐出型ポンプ）、１１ａ…第１切換弁、１１ｂ…第２切換弁、１２ａ…第３切換弁、１２ｂ…第４切換弁、１３ａ，１３ｂ…フラッシング弁、２０ａ，２０ｂ…両傾転斜板機構、２１ａ，２１ｂ…レギュレータ、２２ａ，２２ｂ…リリーフ弁、２３ａ，２３ｂ，２４ａ，２４ｂ…メイクアップチェック弁、２５ａ，２５ｂ…チャージポンプ、２６ａ，２６ｂ…チャージリリーフ弁、３０…ブーム操作レバー（操作装置）、３１…アーム操作レバー（操作装置）、３２…操作ボタン（指示入力装置）、３３…モニタ（表示装置）、３３ａ…表示画面、４０，４０Ａ…コントローラ、４１，４１Ａ…操作量検出部、４２，４２Ａ…車体制御演算部、４３…ポンプ信号出力部、４４…切換弁信号出力部、４５…圧力検出部、４６…故障判定部、４７…モニタ出力部、５０ａ，５０ｂ…ケーシング、５１…シャフト、５２…斜板、５３…シリンダブロック、５４…ピストン、５５…バルブプレート、５６…ベアリング、５７…シリンダ室、５８，５９…給排ポート、６０ａ，６０ｂ…ドレンポート、６１ａ，６１ｂ…ドレン配管、６２ａ…第１圧力センサ（圧力検出装置）、６２ｂ…第２圧力センサ（圧力検出装置）、７０…通常テーブル、７１…第１縮退テーブル、７２…第２縮退テーブル、１００…油圧ショベル、１０１…キャブ、１０２…上部旋回体、１０３…下部走行体、１０４…フロント作業機、２００，２００Ａ…油圧閉回路システム、Ｌ１～Ｌ１２…流路。 DESCRIPTION OF SYMBOLS 1 boom cylinder (hydraulic actuator) 1a cylinder tube 1b rod 1c piston 1d cap chamber 1e rod chamber 2 boom 3 arm cylinder 3 hydraulic cylinder actuator 3a cylinder tube 3b: rod, 3c: piston, 3d: cap chamber, 3e: rod chamber, 4: arm, 5: bucket cylinder, 5a: cylinder tube, 5b: rod, 6: bucket, 7: turning motor (hydraulic actuator), 8a , 8b: traveling device, 9: tank, 10a: first pump (both-discharge pump), 10b: second pump (both-discharge pump) 11a: first switching valve, 11b: second switching valve, 12a Third switching valve, 12b: Fourth switching valve, 13a, 13b: Flushing valve, 20a, 20b: Double-inclined swash plate mechanism, 21a, 21b Regulators 22a, 22b: relief valves, 23a, 23b, 24a, 24b: make-up check valves, 25a, 25b: charge pumps, 26a, 26b: charge relief valves, 30: boom control lever (operating device), 31: arms Operation lever (operation device), 32 ... operation button (instruction input device), 33 ... monitor (display device), 33a ... display screen, 40, 40A ... controller, 41, 41A ... operation amount detection unit, 42, 42A ... vehicle body Control arithmetic unit 43: Pump signal output unit 44: Switching valve signal output unit 45: Pressure detection unit 46: Failure determination unit 47: Monitor output unit 50a, 50b: Casing 51: shaft 52: Oblique Plate, 53: cylinder block, 54: piston, 55: valve plate, 56: bearing, 57: cylinder chamber, 58 59 ... supply / discharge port, 60a, 60b ... drain port, 61a, 61b ... drain piping, 62a ... first pressure sensor (pressure detection device), 62b ... second pressure sensor (pressure detection device), 70 ... normal table, 71 ... 1st degeneration table, 72 ... 2nd degeneration table, 100 ... hydraulic excavator, 101 ... cab, 102 ... upper revolving unit, 103 ... lower traveling unit, 104 ... front work machine, 200, 200 A ... hydraulic closed circuit system, L ~ L12 ... Flow path.

Claims (3)

  1. 　複数の両吐出型ポンプと、
    　前記複数の両吐出型ポンプに選択的に閉回路を構成するよう接続された複数の油圧アクチュエータと、
    　前記複数の両吐出型ポンプと前記複数の油圧アクチュエータとの間に接続され、前記複数の両吐出型ポンプのそれぞれを複数の油圧アクチュエータに選択的に閉回路接続する複数の切換弁と、
    　複数の操作レバーの操作に応じて前記複数の切換弁の開閉制御および前記複数の両吐出型ポンプの流量制御を行う制御装置とを備え、前記複数の両吐出型ポンプは、それぞれ、内部に漏れ出た作動油をタンクに戻すドレンポートを有する建設機械において、
    　前記複数の両吐出型ポンプのそれぞれに設けられ、前記ドレンポートから排出される作動油のドレン圧力を検出する圧力検出装置を備え、
    　前記制御装置は、前記複数の両吐出型ポンプの中に、前記圧力検出装置で検出されたドレン圧が所定の圧力を超えた両吐出型ポンプが存在するときに、前記ドレン圧が所定の圧力を超えた両吐出型ポンプは故障した両吐出型ポンプであると判定し、前記複数の切換弁のうち、前記故障した両吐出型ポンプに接続されている全ての切換弁を閉じる
    　ことを特徴とする建設機械。     Multiple dual discharge pumps,
    A plurality of hydraulic actuators connected to form a closed circuit selectively to the plurality of dual discharge pumps;
    A plurality of switching valves connected between the plurality of dual discharge pumps and the plurality of hydraulic actuators for selectively closing the plurality of dual discharge pumps to the plurality of hydraulic actuators;
    The control device performs opening / closing control of the plurality of switching valves and flow control of the plurality of dual discharge pumps according to the operation of the plurality of control levers, and the plurality of dual discharge pumps respectively leak inside In a construction machine having a drain port for returning discharged hydraulic oil to a tank,
    A pressure detection device provided in each of the plurality of discharge pumps and detecting a drain pressure of hydraulic oil discharged from the drain port;
    The control device is configured such that, in the plurality of dual discharge pumps, when there is a dual discharge pump in which the drain pressure detected by the pressure detection device exceeds a predetermined pressure, the drain pressure is a predetermined pressure It is determined that the both discharge type pump exceeding the limit is a broken both discharge type pump, and all the switching valves connected to the broken both discharge type pump among the plurality of switching valves are closed. Construction machinery.
  2. 　請求項１に記載の建設機械において、
    　前記制御装置は、前記ドレン圧が所定の圧力を超えた両吐出型ポンプが故障した両吐出型ポンプであると判定したときに、前記故障した両吐出型ポンプの吐出流量をゼロに制御する
    　ことを特徴とする建設機械。     In the construction machine according to claim 1,
    The control device controls the discharge flow rate of the failed dual discharge pump to zero when it is determined that the dual discharge pump fails when the drain pressure exceeds a predetermined pressure. Construction machines characterized by
  3. 　請求項１に記載の建設機械において、
    　表示装置と指示入力装置とを更に備え、
    　前記制御装置は、
    　前記複数の両吐出型ポンプの全てを使用して前記複数の油圧アクチュエータを駆動する通常モードと、前記複数の両吐出型ポンプのうち１つの両吐出型ポンプ以外の両吐出型ポンプのみを使用して前記複数の油圧アクチュエータを駆動する縮退モードとを有し、
    　前記１つの両吐出型ポンプが故障したと判定したときに、前記１つの両吐出型ポンプの故障情報を前記表示装置に表示させ、前記指示入力装置の操作に応じて前記通常モードから前記縮退モードに切り換わる
    　ことを特徴とする建設機械。     In the construction machine according to claim 1,
    It further comprises a display device and an instruction input device,
    The controller is
    Only a normal mode in which the plurality of hydraulic actuators are driven using all of the plurality of dual discharge pumps, and only dual discharge pumps other than one dual discharge pump among the multiple dual discharge pumps And a retraction mode for driving the plurality of hydraulic actuators,
    When it is determined that the single discharge pump has failed, failure information of the single discharge pump is displayed on the display device, and the normal mode is selected from the normal mode according to the operation of the instruction input device. A construction machine characterized by switching to
PCT/JP2018/032747 2017-09-12 2018-09-04 Construction machinery WO2019054234A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2017-174669 2017-09-12
JP2017174669A JP2019049335A (en) 2017-09-12 2017-09-12 Construction machine

Publications (1)

Publication Number Publication Date
WO2019054234A1 true WO2019054234A1 (en) 2019-03-21

Family

ID=65722767

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/032747 WO2019054234A1 (en) 2017-09-12 2018-09-04 Construction machinery

Country Status (2)

Country Link
JP (1) JP2019049335A (en)
WO (1) WO2019054234A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113216314A (en) * 2020-01-21 2021-08-06 卡特彼勒路面机械公司 Hydraulic tank protection system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7096178B2 (en) * 2019-02-08 2022-07-05 日立建機株式会社 Construction machinery

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6317421U (en) * 1986-07-16 1988-02-05
JP2008196403A (en) * 2007-02-14 2008-08-28 Hitachi Sumitomo Heavy Industries Construction Crane Co Ltd Abnormality discrimination device for hydraulic pump
JP2017115994A (en) * 2015-12-24 2017-06-29 日立建機株式会社 Work machine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6317421U (en) * 1986-07-16 1988-02-05
JP2008196403A (en) * 2007-02-14 2008-08-28 Hitachi Sumitomo Heavy Industries Construction Crane Co Ltd Abnormality discrimination device for hydraulic pump
JP2017115994A (en) * 2015-12-24 2017-06-29 日立建機株式会社 Work machine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113216314A (en) * 2020-01-21 2021-08-06 卡特彼勒路面机械公司 Hydraulic tank protection system
CN113216314B (en) * 2020-01-21 2023-11-03 卡特彼勒路面机械公司 Hydraulic tank protection system

Also Published As

Publication number Publication date
JP2019049335A (en) 2019-03-28

Similar Documents

Publication Publication Date Title
EP3604824B1 (en) Construction machine
JP6244459B2 (en) Work machine
KR101876895B1 (en) Hydraulic drive device of construction machine
US20020108486A1 (en) Hydraulic recovery system for construction machine and construction machine using the same
JP6785203B2 (en) Construction machinery
US9328480B2 (en) Hydraulic excavator
WO2018012264A1 (en) Construction machinery
WO2019054234A1 (en) Construction machinery
US10829908B2 (en) Construction machine
JP2022024770A (en) Construction machine
JP2018145984A (en) Hydraulic transmission for construction machine
JP6663539B2 (en) Hydraulic drive
JP7444032B2 (en) construction machinery
JP6591370B2 (en) Hydraulic control equipment for construction machinery
JP7227176B2 (en) construction machinery
JP3643300B2 (en) Hydraulic work machine
JP6782272B2 (en) Construction machinery
JP5978176B2 (en) Work machine
JP2014201885A (en) Hydraulic shovel
JP7146669B2 (en) construction machinery
JP7210397B2 (en) construction machinery
WO2024009966A1 (en) Construction machine
JP2020020421A (en) Hydraulic driving device
JP2020056226A (en) Driving system of hydraulic shovel

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18855553

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18855553

Country of ref document: EP

Kind code of ref document: A1