JP2018048487A - Shovel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shovel capable of further enhancing safety when abnormality related to movement of a revolving superstructure occurs.SOLUTION: A shovel includes a revolving superstructure, a motor for driving the revolving superstructure, a mechanical brake for mechanically stopping the revolving superstructure, and a control device for controlling the driving of the motor. During starting of the shovel, the control device supplies electric power to the motor for a prescribed time in a state in which the mechanical brake is operated, and maintains the state in which the mechanical brake is operated after that.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an excavator.

  Conventionally, an abnormality determination process related to the operation of the turning body and a stop process of the turning body are often performed by detecting an abnormal operation or the like in the turning state of the turning body.

JP 2010-187516 A

  However, there is room for improvement from the viewpoint of safety that the abnormality determination processing and the turning body stop processing are performed after operating the turning body in which an abnormality has already occurred.

  Then, in view of the said subject, it aims at providing the shovel which can further improve the safety | security when the abnormality relevant to operation | movement of a turning body generate | occur | produces.

In order to achieve the above object, in one embodiment of the present invention,
A swivel,
An electric motor for driving the revolving structure;
A mechanical brake for mechanically stopping the swivel body;
A control device that performs drive control of the electric motor,
The control device energizes the electric motor for a predetermined time while the mechanical brake is operating at the time of starting the excavator, and maintains the state in which the mechanical brake is operated thereafter.
An excavator is provided.

In another embodiment of the present invention,
A swivel,
An electric motor for driving the revolving structure;
A detection unit for detecting a driving state of the electric motor;
A mechanical brake for mechanically stopping the swivel body;
A control device that performs drive control of the electric motor based on a detection value of the detection unit,
The control device performs drive control for stopping the electric motor in a state where the mechanical brake is operated, and is generated based on the detection value of the detection unit or the detection value for driving control of the electric motor. When the operation amount to be performed does not satisfy the predetermined condition corresponding to the stop state of the electric motor, it is determined that there is an abnormality related to the operation of the revolving structure, or the drive control of the electric motor is limited.
An excavator is provided.

  According to the present embodiment, it is possible to provide an excavator capable of further improving safety when an abnormality relating to the operation of the revolving structure occurs.

It is a side view which shows an example of an shovel. It is a block diagram which shows an example of a structure of the drive system of an shovel. It is a functional block diagram which shows an example of a structure of the turning control system of an shovel. It is a flowchart which shows roughly the 1st example of the abnormality process by a monitoring part. It is a flowchart which shows schematically the 2nd example of the abnormality process by a monitoring part. It is a flowchart which shows roughly the 3rd example of the abnormality process by a monitoring part. It is a flowchart which shows roughly the 4th example of the abnormality process by a monitoring part.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

  First, the configuration of the excavator according to the present embodiment will be described with reference to FIGS.

  FIG. 1 is a side view showing an example of an excavator according to the present embodiment.

  The shovel according to the present embodiment includes a lower traveling body 1, an upper revolving body 3 that is mounted on the lower traveling body 1 so as to be able to swivel via a turning mechanism 2, a boom 4, an arm 5, and a bucket 6 as working devices. And a cabin 10 on which the operator is boarded.

  The lower traveling body 1 includes, for example, a pair of left and right crawlers, and each crawler is hydraulically driven by traveling hydraulic motors 1A and 1B (see FIG. 2), thereby causing the excavator to travel.

  The upper turning body 3 is turned with respect to the lower traveling body 1 by being electrically driven by a turning electric motor 21 (see FIG. 2) described later.

  The boom 4 is pivotally attached to the center of the front part of the upper swing body 3 so that the boom 4 can be raised and lowered. An arm 5 is pivotally attached to the tip of the boom 4 and a bucket 6 is vertically attached to the tip of the arm 5. It is pivotally attached so that it can rotate. The boom 4, the arm 5, and the bucket 6 are respectively hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9 as hydraulic actuators.

  The cabin 10 is a cockpit where an operator is boarded, and is mounted on the front left side of the upper swing body 3.

  Hereinafter, referring to FIG. 2 and FIG. 3, a hydraulic drive system that drives the hydraulic actuator, an electric drive system (swing drive system) that drives the turning electric motor 21, a power storage system that supplies power to the turning drive system, etc. The system and the turning control system for controlling the turning drive system will be described in detail.

  FIG. 2 is a block diagram illustrating an example of a configuration centering on a drive system of the shovel according to the present embodiment.

  In the figure, the mechanical power line is indicated by a double line, the high-pressure hydraulic line is indicated by a thick solid line, the pilot line is indicated by a broken line, and the electric drive / control line is indicated by a thin solid line.

  First, the excavator hydraulic drive system according to the present embodiment includes an engine 11, a motor generator 12, a speed reducer 13, a main pump 14, and a control valve 17. Further, as described above, the hydraulic drive system according to the present embodiment includes the traveling hydraulic motors 1A and 1B, the boom cylinder 7 and the arm cylinder 8 that hydraulically drive the lower traveling body 1, the boom 4, the arm 5 and the bucket 6, respectively. , And a bucket cylinder 9.

  The engine 11 is a main power source in the hydraulic drive system, and is mounted on the rear part of the upper swing body 3. The engine 11 is, for example, a diesel engine using light oil as fuel, and drives the main pump 14 and the pilot pump 15 via the speed reducer 13. The engine 11 drives the motor generator 12 via the speed reducer 13 and causes the motor generator 12 to generate power.

  The motor generator 12 is an assist power source in the hydraulic drive system, and is mounted on the rear part of the upper swing body 3. The motor generator 12 is connected to a power storage system 120 including a capacitor 19 via an inverter 18A, and is powered by the three-phase AC power supplied from the capacitor 19 and the turning motor 21 via the inverter 18A. To drive the main pump 14 and the pilot pump 15. Further, the motor generator 12 is driven by the engine 11 to perform a power generation operation, and can supply the generated power to the capacitor 19 and the turning motor 21. Switching control between the power running operation and the power generation operation of the motor generator 12 is realized by driving the inverter 18 </ b> A by the controller 30.

  The speed reducer 13 is mounted on the rear part of the upper swing body 3, and includes two input shafts to which the engine 11 and the motor generator 12 are connected, and one output shaft to which the main pump 14 and the pilot pump 15 are coaxially connected in series. Have The reduction gear 13 can transmit the power of the engine 11 and the motor generator 12 to the main pump 14 and the pilot pump 15 at a predetermined reduction ratio. Further, the reduction gear 13 can distribute and transmit the power of the engine 11 to the motor generator 12, the main pump 14, and the pilot pump 15 at a predetermined reduction ratio.

  The main pump 14 is mounted at the rear of the upper swing body 3 and supplies hydraulic oil to the control valve 17 through the high-pressure hydraulic line 16. The main pump 14 is driven by the engine 11 or the engine 11 and the motor generator 12 as described above. The main pump 14 is, for example, a variable displacement hydraulic pump, and can control the discharge flow rate (discharge pressure) by adjusting the stroke length of the piston by controlling the angle (tilt angle) of the swash plate.

  The control valve 17 is a hydraulic control device that is mounted at the center of the upper swing body 3 and controls the hydraulic drive system in accordance with the operation of the operating device 26 by the operator. As described above, the control valve 17 is connected to the main pump 14 via the high-pressure hydraulic line 16, and hydraulic oil supplied from the main pump 14 is supplied to the traveling hydraulic motors 1 </ b> A (for right) and 1 </ b> B (for left). ), The boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9 can be supplied. Specifically, the control valve 17 is a valve unit including a plurality of hydraulic control valves (direction switching valves) that control the flow rate and flow direction of hydraulic oil supplied from the main pump 14 to each of the hydraulic actuators.

  Subsequently, the electric drive system (swing drive system) according to the present embodiment includes a turning electric motor 21, a turning speed reducer 24, a current sensor 21 s, a resolver 22, and a mechanical brake 23.

  The turning electric motor 21 is provided in the turning mechanism 2 that connects the lower traveling body 1 and the upper turning body 3, and performs a power running operation for turning the upper turning body 3 under the control of the controller 30 (the turning control unit 302). Or a regenerative operation in which regenerative electric power is generated to swing and brake the upper swing body 3 is performed. The turning electric motor 21 is connected to the power storage system 120 via the inverter 18B, and is driven by the three-phase AC power supplied from the capacitor 19 and the motor generator 12 via the inverter 18B. The turning electric motor 21 supplies regenerative power to the capacitor 19 and the motor generator 12 via the inverter 18B. Thereby, the capacitor 19 can be charged or the motor generator 12 can be driven by the regenerative power. The switching control between the power running operation and the regenerative operation of the turning electric motor 21 is realized by driving and controlling the inverter 18B by the controller 30 (the turning control unit 302). The turning electric motor 21 includes, for example, an IPM (Interior Permanent Magnet) motor. As a result, a larger induced electromotive force can be generated, so that the power generated by the turning electric motor 21 can be increased during regenerative braking. A resolver 22, a mechanical brake 23, and a turning speed reducer 24 are connected to the rotating shaft 21 </ b> A of the turning electric motor 21.

  The turning speed reducer 24 is connected to the rotating shaft 21A of the turning electric motor 21 and decelerates the output (torque) of the turning electric motor 21 at a predetermined reduction ratio, thereby increasing the torque and turning the upper turning body 3. To drive. That is, during the power running operation, the turning electric motor 21 drives the upper turning body 3 to turn through the turning speed reducer 24. Further, the turning speed reducer 24 increases the inertial rotational force of the upper turning body 3 and transmits it to the turning electric motor 21 to generate regenerative power. That is, during the regenerative operation, the turning electric motor 21 performs regenerative power generation by the inertial rotational force of the upper turning body 3 transmitted through the turning speed reducer 24 and turns the upper turning body 3 by turning.

  The current sensor 21 s is an example of a detection unit that detects the drive state of the turning electric motor 21, and detects the respective currents of the three phases (U phase, V phase, and W phase) of the turning electric motor 21. The current sensor 21s is provided, for example, in a power path between the turning electric motor 21 and the inverter 18B. The current sensor 21 s may be a magnetic sensor using a magnetoresistive effect or a direct measurement type sensor using a shunt resistance or the like as long as the current of the turning electric motor 21 can be detected. The current sensor 21 s transmits detection signals (current detection values Iud, Ivd, Iwd) corresponding to the detected currents of the three phases of the turning electric motor 21 to the controller 30.

  The current sensor 21 s detects a current of two phases of the three phases, and the remaining one-phase current detection value is calculated from the two-phase current detection values detected by the current sensor 21 s. Also good. In addition, the current sensor 21s may be configured to detect the current output from the inverter 18B, built in the inverter 18B.

  The resolver 22 is another example of a detection unit that detects the driving state of the turning electric motor 21, and is a known detection unit that detects the rotational position (rotation angle) of the turning electric motor 21. The resolver 22 transmits a detection signal (rotation angle detection value θd) corresponding to the detected rotation angle to the controller 30.

  An arbitrary sensor (for example, an encoder or the like) may be used instead of the resolver 22 as long as the rotation angle of the turning electric motor 21 can be detected.

  The mechanical brake 23 is a known mechanical braking means that swings and brakes the upper swing body 3. The mechanical brake 23 rotates integrally with the rotating shaft 21A and can move in the axial direction of the rotating shaft 21A (for example, splined to the rotating shaft 21A), and does not rotate, but in the axial direction of the rotating shaft 21A. A braking torque is generated by surface contact with a movable plate (for example, splined to the inner surface of the case as a fixed portion). Specifically, when the supply of pilot pressure from the pilot pump 15 is interrupted, the mechanical brake 23 generates braking torque by bringing the disk and plate into surface contact with the urging force of an elastic body such as a spring. State (operating state). On the other hand, when the pilot pressure from the pilot pump 15 is supplied to the mechanical brake 23, the urging force of the elastic body is canceled by the power of the hydraulic piston driven by the pilot pressure, and the surface contact between the disk and the plate is released. As a result, the brake torque is not generated (non-operating state). Thereby, the mechanical brake 23 can mechanically stop the rotating shaft 21 </ b> A of the turning electric motor 21 and maintain the stopped state of the upper turning body 3. Moreover, the mechanical brake 23 can decelerate and stop the turning mechanism 2 (upper turning body 3) by operating with the turning mechanism 2 (upper turning body 3) turning.

  Subsequently, the power storage system 120 of the excavator according to the present embodiment includes the capacitor 19, the DC bus 110, and the step-up / down converter 100, and is mounted on the right front portion of the upper swing body 3, for example.

  The capacitor 19 is an example of a power storage device that supplies power to the motor generator 12 and the turning motor 21 and charges the generated power of the motor generator 12 and the turning motor 21.

  The DC bus 110 is disposed between the inverters 18 </ b> A and 18 </ b> B and the buck-boost converter 100, and controls power transfer between the capacitor 19, the motor generator 12, and the turning electric motor 21.

  The step-up / step-down converter 100 switches between the step-up operation and the step-down operation so that the voltage value of the DC bus 110 falls within a certain range according to the operation state of the motor generator 12 and the turning electric motor 21. Switching control between the step-up / step-down converter 100 and the step-down operation is realized by the controller 30 based on the detected voltage value of the DC bus 110, the detected voltage value of the capacitor 19, and the detected current value of the capacitor 19.

  Subsequently, the operation system of the shovel according to the present embodiment includes the pilot pump 15, the operation device 26, the pressure sensor 29, the gate lock lever 32, the gate lock switching valve 36, the brake switching valve 38, and the like.

  The pilot pump 15 is mounted on the rear part of the upper swing body 3 and supplies pilot pressure to the mechanical brake 23 and the operating device 26 via the pilot line 25. The pilot pump 15 is, for example, a fixed displacement hydraulic pump, and is driven by the engine 11 or the engine 11 and the motor generator 12 as described above.

  The operating device 26 includes levers 26A and 26B and a pedal 26C. The operation device 26 is provided in the vicinity of the cockpit of the cabin 10, and an operation input means for an operator to operate each operation element (the lower traveling body 1, the upper swing body 3, the boom 4, the arm 5, the bucket 6, etc.). It is. In other words, the operating device 26 is used for hydraulic actuators (travel hydraulic motors 1A and 1B, boom cylinders 7, arm cylinders 8, bucket cylinders 9 and the like) and electric actuators (turning electric motor 21 and the like) that drive the operating elements. It is an operation input means for performing an operation. The operating device 26 (lever 26A, 26B and pedal 26C) is connected to the control valve 17 via a hydraulic line 27. As a result, a pilot signal (pilot pressure) corresponding to the operating state of the lower traveling body 1, the boom 4, the arm 5, the bucket 6 and the like in the operating device 26 is input to the control valve 17. Therefore, the control valve 17 can drive each hydraulic actuator according to the operation state in the operation device 26. The operating device 26 is connected to a pressure sensor 29 via a hydraulic line 28.

  The levers 26A and 26B are disposed on the left and right sides, respectively, as viewed from the operator seated in the cockpit in the cabin 10, and in the front-rear direction and the left-right direction on the basis of the neutral state (the state where no operation is performed). It can be tilted. That is, the upper swing body 3, the boom 4, and the arm 5 with respect to the tilt of the lever 26A in the front-rear direction, the tilt of the lever 26A in the left-right direction, the tilt of the lever 26B in the front-rear direction, and the tilt of the lever 26B in the left-right direction, respectively. , And bucket 6 can be arbitrarily set as an operation target. Hereinafter, it is assumed that the operation pattern of the levers 26A and 26B is a JIS (ISO) pattern, that is, the operation of the upper swing body 3 is performed by tilting the lever 26A from the neutral state in the left-right direction. I do.

  As described above, the pressure sensor 29 is connected to the operating device 26 via the hydraulic line 28, and the pilot pressure on the secondary side of the operating device 26, that is, the pilot pressure corresponding to the operating state of each operating element in the operating device 26. Is detected. The pressure sensor 29 is connected to the controller 30, and a pressure signal (pressure detection value) corresponding to the operation state of the lower traveling body 1, the upper swing body 3, the boom 4, the arm 5, the bucket 6, etc. in the operating device 26 is 30. Thereby, for example, the controller 30 can drive-control the turning electric motor 21 in accordance with the operation state of the upper turning body 3.

  The gate lock lever 32 is an operating means for performing an opening / closing operation of a gate provided at a boarding / alighting portion for a cockpit in the cabin 10.

  The gate lock switching valve 36 is provided on the most upstream side of the pilot line 25 and switches between the communication state and the non-communication state of the pilot line 25 according to the operation state of the gate lock lever 32. For example, the gate lock switching valve 36 turns on / off the electromagnetic solenoid in response to a gate lock signal (ON / OFF) output from a gate lock switch (gate lock SW) 34 that is linked to the operation state of the gate lock lever 32. This is an electromagnetic switching valve that is switched. The gate lock SW 34 is turned off in a state where the gate lock lever 32 is lowered (a state where the passenger seat to / from the cockpit is opened). Then, when a gate lock signal (voltage signal equal to or lower than a predetermined threshold voltage) indicating an OFF state is input from the gate lock SW 34, the gate lock switching valve 36 brings the pilot line 25 into a non-communication state, and the pilot pump 15 The supply of hydraulic oil to the brake 23 and the operating device 26 is shut off. On the other hand, the gate lock SW 34 is turned on when the gate lock lever 32 is raised (when the boarding / alighting portion for the cockpit is closed). Then, when a gate lock signal (voltage signal higher than a predetermined threshold voltage) indicating the ON state is input from the gate lock SW 34, the gate lock switching valve 36 brings the pilot line 25 into a communication state, and the pilot pump 15 performs mechanical braking. The hydraulic oil (pilot pressure) is supplied toward the control unit 23 and the operation device 26. Therefore, when the gate lock lever 32 is lowered, the supply of pilot pressure to the mechanical brake 23 is cut off, so that the mechanical brake 23 is automatically operated when the passenger boarding / alighting part is opened. Further, when the gate lock lever 32 is raised, it can be determined that the operator is seated on the cockpit and is in a steerable state. Therefore, the pilot pressure is supplied to the operating device 26 only when the gate lock lever 32 is pulled up, thereby preventing the operation of each hydraulic actuator due to an unintended operation input to the operating device 26.

  In the figure, the gate lock switching valve 36 represents a case where the gate lock lever 32 is raised (the gate lock SW 34 is turned on), and is directed from the pilot pump 15 to the mechanical brake 23 and the operation device 26. Pilot pressure is supplied.

  The brake switching valve 38 is provided in a pilot line 25 a that is a branching portion connected to the mechanical brake 23 in the pilot line 25 that branches to the mechanical brake 23 and the operating device 26 downstream of the gate lock switching valve 36. The brake switching valve 38 switches between a communication state and a non-communication state of the pilot line 25a in accordance with a control command from the controller 30. That is, the mechanical brake 23 is controlled by the controller 30 (brake control unit 301). For example, the brake switching valve 38 is an electromagnetic switching valve that performs ON / OFF switching of an electromagnetic solenoid in accordance with a control command from the controller 30. When an operation signal indicating the operation state of the mechanical brake 23 (for example, a voltage signal equal to or lower than a predetermined threshold voltage) is input from the controller 30, the brake switching valve 38 brings the pilot line 25 a into a non-communication state and the pilot pump 15 The supply of hydraulic oil to the mechanical brake 23 is shut off. On the other hand, when a non-operation signal indicating a non-operation state of the mechanical brake 23 (for example, a voltage signal higher than a predetermined threshold voltage) is input to the brake switching valve 38, the pilot line 25a is brought into a communication state and the pilot pump 15 Hydraulic oil (pilot pressure) is supplied to the mechanical brake 23.

  In the drawing, the brake switching valve 38 represents a case where a non-operation signal is input from the controller 30, and the pilot pressure is supplied from the pilot pump 15 to the mechanical brake 23.

  Subsequently, the excavator turning control system according to the present embodiment includes a controller 30.

  The controller 30 (an example of a control device) is a main control device that performs drive control in the shovel. The controller 30 is composed of, for example, an arithmetic processing unit (microcomputer) including a CPU, ROM, RAM, I / O, and the like, and performs various driving operations by executing various driving control programs stored in the ROM on the CPU. Control is realized. Hereinafter, the turning control system will be described with reference to FIG.

  FIG. 3 is a functional block diagram showing an example of the configuration of the control system (swing control system) of the upper swing body 3 of the shovel according to the present embodiment.

  As shown in FIG. 3, the controller 30 includes a brake control unit 301, a turning control unit 302, and a monitoring unit 303 as functional units related to the turning control system.

  The brake control unit 301 controls the mechanical brake 23 according to the operating state of the upper swing body 3 by the operating device 26 (lever 26A). When the brake control unit 301 determines that the operation of the upper swing body 3 is being performed based on the detection value of the pressure sensor 29, or when it is determined that the upper swing body 3 has stopped turning (specifically, When a speed detection value ωd described later is equal to or less than a predetermined threshold for determining turning stop), a non-operation signal is transmitted to the brake switching valve 38. As a result, the pilot line 25a enters a communication state, and the mechanical brake 23 enters a non-operating state (OFF state). On the other hand, when the brake control unit 301 determines that the operation of the upper swing body 3 is not performed based on the detection value of the pressure sensor 29, the brake control unit 301 determines that the upper swing body 3 has stopped turning. Then, an operation signal is transmitted to the brake switching valve 38. Thereby, pilot line 25a will be in a non-communication state, and mechanical brake 23 will be in an operation state (ON state).

  The turning control unit 302 is a pressure sensor 29 corresponding to a detected value of the current sensor 21s (current detected values Iud, Ivd, Iwd), a detected value of the resolver 22 (rotation angle detected value θd), and a turning operation of the upper swing body 3. Based on the detected value, the turning electric motor 21 is driven and controlled. In the present embodiment, the turning control unit 302, as will be described later, instead of controlling the three-phase alternating current of the turning electric motor 21 in the stationary coordinate system, rotates coordinates that rotate in synchronization with the rotor of the turning electric motor 21. Vector control is performed to control a direct current in the system (dq coordinate system), that is, a magnetic flux generation current as a d-axis component and a torque generation current as a q-axis component. The turning control unit 302 includes a speed command generation unit 3021, a speed calculation unit 3022, a speed feedback control unit (speed FB control unit) 3023, a torque / current conversion unit 3024, a three-phase / two-phase conversion unit 3025, a torque feedback control unit ( Torque FB control unit) 3026, two-phase / three-phase conversion unit 3027.

  The speed command generation unit 3021 generates a speed command value ωc that is a command value for driving and controlling the upper swing body 3 based on the operation state of the upper swing body 3 in the operating device 26 (lever 26A). Specifically, the speed command generator 3021 receives the detected value of the pressure sensor 29 received through the predetermined interface of the controller 30, specifically, the pressure sensor 29 corresponding to the operation direction and the operation amount of the lever 26A. Based on the detected value, a speed command value ωc is generated. The speed command generation unit 3021 outputs the generated speed command value ωc to the speed FB control unit 3023.

  The speed calculation unit 3022 performs differential processing on the detection value (rotation angle detection value θd) of the resolver 22 received via a predetermined interface of the controller 30, thereby corresponding to the rotation speed of the turning electric motor 21. The speed detection value ωd is calculated. The speed calculation unit 3022 outputs the calculated speed detection value ωd to the speed FB control unit 3023 and the torque / current conversion unit 3024.

  The speed FB control unit 3023 performs speed feedback control of the turning electric motor 21 based on the speed detection value ωd in order to realize the turning speed corresponding to the speed command value ωc. Specifically, the speed FB control unit 3023 uses a known feedback control method, for example, PI control (Proportional-Integral Controller) or the like, based on the difference between the speed command value ωc and the detected speed value ωd. A torque manipulated variable Tr for realizing the value ωc is generated. The speed FB control unit 3023 outputs the generated torque operation amount Tr to the torque / current conversion unit 3024.

  The torque / current conversion unit 3024 converts the torque operation amount Tr into a corresponding current operation amount based on the speed detection value ωd. Specifically, the torque / current conversion unit 3024 is configured to rotate the torque operation amount Tr in synchronization with the rotor of the turning electric motor 21 in each of the d-axis and q-axis current components in the rotating coordinate system (dq coordinate system). Are converted into current manipulated variables Idr and Iqr. The torque / current conversion unit 3024 outputs the generated current operation amounts Idr and Iqr to the torque FB control unit 3026.

  The three-phase / two-phase conversion unit 3025 applies Clark transformation and inverse park transformation to the current detection values Iud, Ivd, and Iwd of the current sensor 21s. Accordingly, the three-phase / two-phase conversion unit 3025 uses the current detection values Iud, Ivd, and Iwd of the current sensor 21s as current detection values corresponding to the d-axis component and the q-axis component of the current detection value in the dq coordinate system, respectively. It can be converted to Idd and Iqd. The three-phase / two-phase conversion unit 3025 outputs the generated current detection values Idd and Iqd to the torque FB control unit 3026 and the monitoring unit 303.

  The torque FB control unit 3026 performs torque feedback control of the turning electric motor 21 based on the detected current values Idd and Iqd in order to realize the current operation amounts Idr and Iqr corresponding to the torque command values. Specifically, the torque FB control unit 3026 uses a known feedback control method, for example, PI control, and the difference between the current manipulated variable Idr and the current detection value Idd, as well as the speed FB control unit 3023, and the current Based on the difference between the manipulated variable Iqr and the detected current value Iqd, voltage manipulated variables Vdr and Vqr in the dq coordinate system for realizing the torque of the turning electric motor 21 corresponding to the current manipulated variables Idr and Iqr are generated. The torque FB control unit 3026 outputs the generated voltage operation amounts Vdr and Vqr to the two-phase / three-phase conversion unit 3027 and the monitoring unit 303.

  The two-phase / three-phase conversion unit 3027 applies forward park transformation to the voltage manipulated variables Vdr and Vqr to generate a two-phase AC voltage manipulated variable in a stationary coordinate system and Three-phase AC voltage operation amounts Vur, Vvr, and Vwr are generated from the AC voltage operation amount. The two-phase / three-phase conversion unit 3027 outputs the generated voltage operation amounts Vur, Vvr, Vwr, that is, the PWM drive signal to the inverter 18B. Thereby, the turning control unit 302 can drive the inverter 18B and perform drive control of the turning electric motor 21 in accordance with the operation state of the upper turning body 3.

  The monitoring unit 303 monitors the occurrence of an abnormality related to the operation of the upper swing body 3. The abnormality related to the operation of the upper swing body 3 means an abnormality of one or a plurality of components related to the process until the actual operation of the upper swing body 3 is realized based on the operation input to the lever 26A. . For example, the abnormality related to the operation of the upper swing body 3 may include an abnormality of the pressure sensor 29 that detects the operation state of the lever 26A. Further, the abnormality related to the operation of the upper swing body 3 includes the abnormality of the inverter 18B (overcurrent, overheating, etc.), the abnormality of the turning electric motor 21 (overcurrent, overheat), etc. Hardware anomalies can be included. Further, the abnormality related to the operation of the upper swing body 3 may include an abnormality of various detection units that detect the swing state of the upper swing body 3 such as the current sensor 21 s and the resolver 22. In addition, the abnormality related to the operation of the upper swing body 3 may include an abnormality in software processing that realizes the function of the swing control unit 302. In particular, when abnormality of various detection units or software that detects the turning state of the upper swing body 3 occurs, the swing electric motor 21 is not properly controlled, and the upper swing body 3 performs an unexpected swing operation. there is a possibility. Specifically, when an offset abnormality or the like occurs in the current sensor 21s, the current detection values Iud, Iwd, and Ivd become values that deviate from the actual values. Therefore, the turning control based on the erroneous current detection values Iud, Iwd, and Ivd. Due to the drive control of the upper swing body 3 by the unit 302, the upper swing body 3 may perform an unexpected swing operation. Further, for example, if an abnormality such as a deviation of the magnetic pole position occurs in the resolver 22, the rotation angle detection value θd and the speed detection value ωd are different from the actual values. Due to the drive control of the turning electric motor 21 by the turning control unit 302 based on the value ωd, the upper turning body 3 may perform an unexpected turning operation. Further, when an abnormality such as a bug in the software processing of the turning control unit 302 occurs, the drive control of the turning electric motor 21 based on the current detection values Iud, Iwd, Ivd and the rotation angle detection value θd is not appropriately performed. There is a possibility that the revolving structure 3 performs an unexpected revolving motion. In contrast, when the monitoring unit 303 determines that there is an abnormality related to the operation of the upper swing body 3, the monitoring unit 303 limits the swing operation of the upper swing body 3. Thereby, the unexpected turning operation | movement of the upper turning body 3 resulting from the abnormality relevant to the operation | movement of the upper turning body 3 can be suppressed. Hereinafter, with reference to FIGS. 4 to 7, an abnormality process by the monitoring unit 303 for an abnormality related to the operation of the upper swing body 3 will be described.

  First, FIG. 4 is a flowchart schematically showing a first example of abnormality processing by the monitoring unit 303. The processing according to this flowchart is, for example, after the excavator startup sequence (starting processing of electric components including the motor generator 12, the turning electric motor 21, the inverters 18A and 18B, the buck-boost converter 100, the capacitor 19, and the like) is completed. May be repeatedly executed at predetermined time intervals until the operation is stopped. Further, the processing according to this flowchart may be performed, for example, when the shovel starts (that is, after the shovel startup sequence).

  In addition, when the operation of the mechanical brake 23 is released during the execution of the processes of steps S104 and S106, the process according to this flowchart ends. Further, the abnormality process at the time of starting the excavator may be executed as one process of the startup sequence.

  In step S102, the monitoring unit 303 determines whether or not the mechanical brake 23 is in an operating state. For example, when the monitoring unit 303 determines that the turning operation of the upper-part turning body 3 is not performed based on the detection value of the pressure sensor 29, the speed detection value ωd is a predetermined threshold value for determining the turning stop. In the following cases, it is determined that the mechanical brake 23 is in an operating state, and in other cases, it is determined that the mechanical brake 23 is not in an operating state. Further, the monitoring unit 303 determines whether or not the mechanical brake 23 is in an operating state by monitoring an output state of an operation signal and a non-operation signal output from the brake control unit 301 to the brake switching valve 38. Also good. The monitoring unit 303 may determine whether or not the mechanical brake 23 is in an operating state by monitoring the output state (ON / OFF) of the gate lock signal output from the gate lock SW 34. The monitoring unit 303 proceeds to step S104 when the mechanical brake 23 is in the operating state, and ends the current process when the mechanical brake 23 is not in the operating state.

  In step S <b> 104, the monitoring unit 303 sets the speed command value ωc to “0” regardless of the detection value from the pressure sensor 29, and requests that the turning electric motor 21 be servo-ON (energized). The signal is output to the turning control unit 302 (speed command generation unit 3021). Thereby, the turning control unit 302 sets the speed command value ωc to “0”, and executes so-called zero speed control of the turning electric motor 21. That is, the turning control unit 302 performs drive control for stopping the turning electric motor 21 in response to a request from the monitoring unit 303.

  In step S104, the turning control unit 302 may execute zero torque control instead of zero speed control as drive control for stopping the turning electric motor 21. In this case, the monitoring unit 303 sets a torque operation amount Tr to “0” regardless of the detection value from the pressure sensor 29, and outputs a request signal requesting that the turning electric motor 21 be servo-on (energized). Output to the turning control unit 302.

  In step S106, the monitoring unit 303 determines whether or not the predetermined time T has elapsed from the output of the request signal, that is, the elapsed time from the start of the zero speed control of the turning electric motor 21 by the turning control unit 302 (the electric motor for turning). It is determined whether or not (21 energization time) has reached a predetermined time T. The turning control unit 302 repeats the process of step S106 when the predetermined time T has not elapsed, and proceeds to step S108 when the predetermined time T has elapsed.

  In step S <b> 108, the monitoring unit 303 transmits a request signal requesting that the turning electric motor 21 be servo-off to the turning control unit 302. Thereby, the turning control unit 302 stops energization of the turning electric motor 21.

  In step S <b> 110, the monitoring unit 303 determines whether there is an abnormality related to the upper swing body 3. Specifically, the monitoring unit 303, during the servo-on period of steps S104 and S106, based on the operation input to the lever 26A, at least one process related to the actual operation of the upper swing body 3 is realized. The presence or absence of an abnormality may be determined by monitoring various states of the constituent elements. For example, when the monitoring unit 303 outputs a signal indicating an abnormal state (overcurrent, overheating, etc.) from the inverter 18B or the turning electric motor 21 during the servo ON period of steps S104 and S106, the operation of the upper turning body 3 is performed. It may be determined that there is an abnormality related to. If the monitoring unit 303 determines that there is an abnormality related to the upper swing body 3, the monitoring unit 303 proceeds to step S <b> 112, and if it determines that there is no abnormality related to the upper swing body 3, ends the current process.

  In step S112, the monitoring unit 303 performs restriction control for restricting the operation of the upper swing body 3. Hereinafter, the restriction includes prohibition. For example, the monitoring unit 303 outputs a request signal for requesting continued operation of the mechanical brake 23 to the brake control unit 301 regardless of the operation state of the upper swing body 3 in the operating device 26 (lever 26A). The operating state of the brake 23 may be continued. For example, the monitoring unit 303 may output a restriction request to the turning control unit 302 and restrict the drive control of the turning electric motor 21 by the turning control unit 302. In this case, the monitoring unit 303 may prohibit the drive control of the turning electric motor 21 by the turning control unit 302 regardless of the operating state of the upper turning body 3 in the operating device 26 (lever 26A). In addition, the monitoring unit 303 invalidates the operation state of the upper swing body 3 in the operating device 26 (lever 26A), that is, the detection value input from the pressure sensor 29 to the swing control unit 302, thereby turning the swing control unit 302. The drive control by may be prohibited. In addition, the monitoring unit 303 sets an upper limit on the speed command value ωc generated by the speed command generation unit 3021 regardless of the operation state of the upper swing body 3 in the operating device 26 (lever 26A), thereby turning the control unit. The drive control by 302 may be limited. Accordingly, the stopped state of the upper swing body 3 is maintained, or the operation of the upper swing body 3 is restricted, so that an unexpected swing operation of the upper swing body 3 can be suppressed. In addition, the monitoring unit 303 warns the operator in the cabin 10 by voice, monitor display, or the like. Thereby, since an operator can recognize the occurrence of an abnormality related to the operation of the upper swing body 3, an appropriate action such as calling a service person to have a repair performed can be urged.

  When there is an abnormality related to the operation of the upper swing body 3 (Y in step S110), the monitoring unit 303 is hydraulically driven hydraulically working elements (lower traveling body 1, boom 4, arm 5, bucket) 6 etc.) may be restricted. Thereby, an operator's uncomfortable feeling by restrict | limiting only operation | movement of the upper turning body 3 can be relieved. In this case, an electromagnetic pressure reducing valve (not shown) is provided in the hydraulic line 27 between the operating device 26 and the control valve 17. As a result, the monitoring unit 303 controls the pressure reducing valve to reduce the pilot pressure acting on the control valve 17 so that the hydraulic work element does not depend on the operating state of the upper swing body 3 in the operating device 26 (lever 26A). Can be restricted.

  Thus, in this example, the controller 30 energizes (servo-ON) the turning electric motor 21 for a predetermined time T while the mechanical brake 23 is operating, for example, when the excavator is activated, and the upper turning body 3. As long as the above operation is not performed, the state where the mechanical brake 23 is still operated is maintained. Therefore, since the mechanical brake 23 is operating, the turning electric motor 21 can be energized for a predetermined time T without operating the upper turning body 3. Therefore, it is possible to determine whether there is an abnormality related to the operation of the upper swing body 3 without operating the upper swing body 3. Further, in order to maintain the state in which the mechanical brake 23 is operating even after the energization period of the predetermined time T is finished, even if there is an abnormality related to the operation of the upper swing body 3, the upper swing body 3 is assumed. Outside turning motion can be suppressed. Therefore, the safety of the excavator can be further enhanced.

  Further, in this example, the controller 30 energizes the servo motor 21 for a predetermined time T (servo ON) while the mechanical brake 23 is operating when the excavator is activated, and relates to the operation of the upper swing body 3. When there is an abnormality to be performed, the operation of the upper swing body 3 is limited. For example, the controller 30 (monitoring unit 303) limits the operation of the upper swing body 3 by limiting the drive control of the turning electric motor 21 by the turning control unit 302. For example, the controller 30 maintains the stopped state of the upper swing body 3 by continuing the operation of the mechanical brake 23 even if the upper swing body 3 is operated by the lever 26A (operation of the upper swing body 3). Is prohibited). For example, even if the operation of the upper swing body 3 is performed by the lever 26 </ b> A, the controller 30 restricts the operation of the upper swing body 3 by prohibiting the drive control of the turning electric motor 21 by the swing control unit 302. . Thereby, even if there is an abnormality related to the operation of the upper swing body 3, the operation of the upper swing body 3 is limited, and therefore an unexpected swing operation of the upper swing body 3 can be suppressed. Therefore, the safety of the excavator can be further enhanced.

  Next, FIG. 5 is a flowchart schematically showing a second example of abnormality processing by the monitoring unit 303. Similar to the first example (FIG. 4), for example, the processing according to this flowchart may be repeatedly executed at predetermined time intervals after the excavator startup sequence is completed until the excavator is stopped. Moreover, the process by this flowchart may be performed at the time of the shovel starting (that is, after the shovel starting sequence), for example, as in the first example (FIG. 4). Further, the abnormality process at the time of starting the excavator may be executed as one process of the startup sequence as in the first example (FIG. 4).

  The abnormality process according to this example (FIG. 5) is the first example (step S103 is added between step S102 and step S104, and in the case of N in step S110, the process of step S111 is added. This is different from the abnormality process according to FIG. Hereinafter, a description will be given focusing on the differences from the first example (FIG. 4).

  When it is determined in step S102 that the mechanical brake 23 is in the operating state, in step S103, the monitoring unit 303 instructs the brake control unit 301 of the mechanical brake 23 regardless of the operation state of the lever 26A. A request to maintain the operation state (operation lock request) is output. Accordingly, the brake control unit 301 transmits an operation signal to the brake switching valve 38 regardless of the operation state of the lever 26A, and maintains the operation state of the mechanical brake 23.

  In step S110, the monitoring unit 303 determines whether there is an abnormality related to the upper swing body 3 as in the case of the first example (FIG. 4). If the monitoring unit 303 determines that there is no abnormality related to the upper swing body 3, the process proceeds to step S111. If the monitoring unit 303 determines that there is an abnormality related to the upper swing body 3, the process proceeds to step S112.

  In step S <b> 111, the monitoring unit 303 outputs a request to release the operation lock of the mechanical brake 23 (operation lock release request) to the brake control unit 301. Accordingly, the brake control unit 301 returns an operation signal or a non-operation signal to the brake switching valve 38 according to the normal operation condition of the mechanical brake 23 and returns to a state in which the operation control of the mechanical brake 23 is performed.

  On the other hand, in step S112, the monitoring unit 303 performs restriction control for limiting the operation of the upper swing body 3 as in the case of the first example (FIG. 4).

  Thus, in this example, the controller 30 energizes (servo-ON) the turning electric motor 21 for a predetermined time T while the mechanical brake 23 is operating, for example, when the excavator is activated, and the upper turning body 3. Regardless of the operation state, by maintaining the mechanical brake 23 in the operating state, the state in which the mechanical brake 23 is operating is maintained thereafter. Thereby, in order to maintain the state in which the mechanical brake 23 is actively operating even after the energization period of the predetermined time T is ended, when there is an abnormality related to the operation of the upper swing body 3, Even if the operation is performed, an unexpected turning motion of the upper swing body 3 can be suppressed. Therefore, the safety of the excavator can be further enhanced.

  Next, FIG. 6 is a flowchart schematically showing a third example of the abnormality process by the monitoring unit 303. The process of this flowchart is the same as in the first example (FIG. 4) and the second example (FIG. 5). For example, after the excavator startup sequence is completed, the excavator is stopped every predetermined time. It may be executed repeatedly. Further, the processing according to this flowchart may be performed at the time of starting the shovel (that is, after the shovel startup sequence), for example, as in the first example (FIG. 4) and the second example (FIG. 5).

  The abnormality process according to this example (FIG. 6) is the second example (FIG. 4) in that step S101 is added before the process of step S102, and the process of step S114 is added after the process of step S112. It is different from the abnormal processing concerning. In the following, description will be made centering on differences from the second example (FIG. 5).

  The abnormality flag F is stored in, for example, a nonvolatile storage device such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) built in the controller 30 and its initial value is set to “0”. Further, the abnormality flag F can be initialized (F = “0”) according to a command from a diagnostic tool that can be connected to the controller 30 through a predetermined connection terminal provided on the excavator, for example. Good.

  In step S101, the monitoring unit 303 determines whether or not the abnormality flag F is “1”. When the abnormality flag F is not “1”, the monitoring unit 303 proceeds to step S102 and executes the processing of steps S102 to S112 as in the case of the second example (FIG. 5), and the abnormality flag F is “1”. If so, the process proceeds to step S112.

  In step S112, the monitoring unit 303 performs restriction control for restricting the operation of the upper swing body 3 as in the first example (FIG. 4) and the second example (FIG. 5).

  In step S114, the monitoring unit 303 sets the abnormality flag F stored in the non-volatile storage device to “1” (maintained if already “1”), and ends the current process.

  As described above, in this example, when there is an abnormality related to the operation of the upper swing body 3, the monitoring unit 303 updates the abnormality flag F to “1” indicating that it is abnormal. That is, when there is an abnormality related to the operation of the upper swing body 3, the monitoring unit 303 stores a flag (F = 1) indicating the abnormality in a nonvolatile storage device. As a result, when a flag indicating abnormality is stored in the nonvolatile storage device (that is, when the abnormality flag F is 1) as in the process of step S101, immediately, the operation is related to the operation of the upper swing body 3. It can be determined that there is an abnormality to be performed. Therefore, if it is determined that there is an abnormality related to the operation of the upper-part turning body 3, even if the excavator is restarted, for example, unless the repair of the abnormal part is completed and the abnormality flag F is initialized, The operation of the upper swing body 3 is always limited. Therefore, the safety of the excavator can be further enhanced.

  The abnormality process according to this example is a mode in which steps S101 and S114 are added to the abnormality process of the second example (FIG. 5), but steps S101 and S114 are added to the abnormality process of the first example (FIG. 4). May be added. In this case, the same operation and effect are obtained.

  Next, FIG. 7 is a flowchart schematically showing a fourth example of abnormality processing by the monitoring unit 303. The process of this flowchart is the same as in the first example (FIG. 4) to the third example (FIG. 6). For example, after the excavator startup sequence is completed, the excavator is stopped every predetermined time. It may be executed repeatedly. Further, the processing according to this flowchart may be performed, for example, when the shovel starts (that is, after the shovel startup sequence), as in the first example (FIG. 4) to the third example (FIG. 6). Moreover, the abnormality process at the time of starting of the shovel may be executed as one process of the start-up sequence as in the first example (FIG. 4) to the third example (FIG. 6).

  The abnormality process according to the present example (FIG. 7) includes various processes for detecting the turning state of the upper swing body 3 as a specific example of the process of step S110, that is, a process for determining whether or not there is an abnormality related to the upper swing body 3. It differs from the first example (FIG. 4) in that it includes processing for determining whether there is an abnormality in the detection unit or software. Hereinafter, a description will be given focusing on the differences from the first example (FIG. 4).

  The process of step S110 according to this example includes the processes of steps S1101 to S1104.

  In step S1101, the monitoring unit 303 satisfies the condition that at least one of the current detection values Idd and Iqd during the servo ON period (steps S104 to S106) corresponds to the stop state of the turning electric motor 21. It is determined whether it is in a state not to be performed. Specifically, the monitoring unit 303 determines whether or not at least one of the current detection value Idd is greater than a predetermined threshold value Iddth and the current detection value Iqd is greater than a predetermined threshold value Iqdth is satisfied. The monitoring unit 303 proceeds to step S1102 when the determination condition is not satisfied, and proceeds to step S1104 when the determination condition is satisfied.

  The predetermined threshold values Iddth and Iqdth may be set as minimum values that can be determined that no current is flowing in the turning electric motor 21 in consideration of detection errors of the current sensor 21s and the resolver 22, for example.

  In step S1102, the monitoring unit 303 determines whether at least one of the voltage operation amounts Vdr and Vqr during the servo ON period (steps S104 to S106) does not satisfy the condition corresponding to the stop state of the turning electric motor 21. Determine whether or not. Specifically, the monitoring unit 303 determines whether or not at least one of the voltage operation amount Vdr being greater than the predetermined threshold value Vdrth and the voltage operation amount Vqr being greater than the predetermined threshold value Vqrth is satisfied. The monitoring unit 303 proceeds to step S1103 when the determination condition is not satisfied, and proceeds to step S1104 when the determination condition is satisfied.

  The predetermined threshold values Vdrth and Vqrth may be set as minimum values that can be determined that the applied voltage of the turning electric motor 21 is 0 in consideration of detection errors of the current sensor 21s and the resolver 22, for example.

  In step S1103, the monitoring unit 303 has no abnormality related to the operation of the upper swing body 3, specifically, no abnormality of various detection units or software for detecting the turning state of the upper swing body 3, that is, It is determined that the operation of the upper swing body 3 is normal. This is because the current detection values Idd and Iqd and the voltage operation amounts Vdr and Vqr satisfy the conditions corresponding to the stop state of the turning electric motor 21 in the situation where the zero speed control is performed by the turning control unit 302.

  On the other hand, in step S1104, the monitoring unit 303 detects that there is an abnormality related to the operation of the upper swing body 3, specifically, an abnormality of various detection units that detect the turning state of the upper swing body 3, or an abnormality of software. judge. In the situation where the zero speed control is performed by the turning control unit 302, at least one of the current detection values Idd and Iqd and the voltage operation amounts Vdr and Vqr does not satisfy the condition corresponding to the stop state of the turning electric motor 21. It is.

  In this example, both the determination of the presence / absence of an abnormality related to the operation of the upper swing body 3 and the limitation of the operation of the upper swing body 3 are performed. However, either one may be performed. That is, in the process of FIG. 7, one of steps S1104 and S112 may be omitted. Further, in this example, the current detection values Idd and Iqd and the voltage operation amounts Vdr and Vqr are related to the operation of the upper swing body 3 based on whether or not the conditions corresponding to the stopped state of the upper swing body 3 are satisfied. It is determined whether or not there is an abnormality, but other detection values (speed detection value ωd) and other operation amounts (torque operation amount Tr, current operation amounts Idr, Iqr, etc.) correspond to conditions in which the upper swing body 3 is stopped. Whether or not there is an abnormality related to the operation of the upper swing body 3 may be determined based on whether or not the above is satisfied. Further, in this example, on the premise of vector control, whether or not the current detection values Idd and Iqd and voltage operation amounts Vdr and Vqr expressed in direct current satisfy the condition corresponding to the stopped state of the upper swing body 3. Based on this, the presence or absence of an abnormality related to the operation of the upper swing body 3 is determined. However, a detected value or an operation amount of a three-phase alternating current may be used regardless of whether or not vector control is employed. In this case, for example, the monitoring unit 303 can determine that at least one of the current detection values Iud, Ivd, and Iwd or at least one of the voltage operation amounts Vur, Vvr, and Vwr has changed with the passage of time. (For example, when it has changed over a predetermined threshold with respect to the passage of time), it may be determined that there is an abnormality related to the operation of the upper swing body 3.

  As described above, in this example, the controller 30 performs drive control (for example, zero speed control) for stopping the turning electric motor 21 while the mechanical brake 23 is operating. Then, during the execution of the drive control (zero speed control), the controller 30 generates an operation amount generated based on the detection value for controlling the drive value of the current sensor 21s, the resolver 22 or the turning electric motor 21. When the condition corresponding to the stop state of the turning electric motor 21 is not satisfied, it is determined that there is an abnormality related to the operation of the upper turning body 3, or the drive control of the turning electric motor 21 is limited. Thereby, since the mechanical brake 23 is operating, it is determined whether or not there is an abnormality related to the operation of the upper swing body 3 without operating the upper swing body 3, or the upper part corresponding to the abnormality The operation of the swing body 3 can be restricted.

  Further, in the present embodiment, on the premise of vector control, the presence / absence of an abnormality related to the operation of the upper swing body 3 is determined using the current detection values Idd and Iqd expressed in direct current and the voltage operation amounts Vdr and Vqr. . Thus, as conditions corresponding to the stopped state of the upper swing body 3, the current detection values Idd and Iqd expressed in direct current and the voltage manipulated variables Vdr and Vqr, the predetermined thresholds Vdrth and Vqrth, and the predetermined thresholds Iddth and Iqdth, It is only necessary to compare the sizes of. Therefore, it is possible to relatively easily determine whether there is an abnormality related to the operation of the upper swing body 3, specifically, the abnormality of various detection units that detect the turning state of the upper swing body 3 or the software.

  In the abnormality process according to this example, step S110 in the abnormality process of the first example (FIG. 4) is replaced with the process of steps S1101 to 1104. However, the second example (FIG. 5) or the third example (FIG. 6). Step S110 in the abnormal process may be replaced with the processes in steps S1101 to S1104. In this case, the same operation and effect are obtained.

  As mentioned above, although the form for implementing this invention was explained in full detail, this invention is not limited to this specific embodiment, In the range of the summary of this invention described in the claim, various Can be modified or changed.

1 Undercarriage (hydraulic operation element)
1A, 1B Traveling hydraulic motor (hydraulic operating element)
3 Upper swing body (revolving body)
4 Boom (hydraulic operating element)
5 Arm (hydraulic operating element)
6 Bucket (hydraulic operating element)
18B Inverter 19 Capacitor 21 Turning motor (motor)
21s current sensor (detection unit, current detection unit)
22 Resolver (detection unit, rotation position detection unit)
23 Mechanical brake 26 Operating device 26A Lever 29 Pressure sensor 30 Controller (control device)
32 Gate lock lever 34 Gate lock switch 36 Gate lock switching valve 38 Brake switching valve 301 Brake control unit 302 Turning control unit 303 Monitoring unit

Claims (13)

A swivel,
An electric motor for driving the revolving structure;
A mechanical brake for mechanically stopping the swivel body;
A control device that performs drive control of the electric motor,
The control device energizes the electric motor for a predetermined time while the mechanical brake is operating at the time of starting the excavator, and maintains the state in which the mechanical brake is operated thereafter.
Excavator. When the excavator is activated, the control device energizes the electric motor for a predetermined period of time while the mechanical brake is in operation, and when there is an abnormality related to the operation of the revolving body, Restrict,
The excavator according to claim 1. When the excavator is activated, the control device energizes the electric motor for a predetermined time in a state where the mechanical brake is operating, and restricts the drive control when there is an abnormality related to the operation of the revolving structure.
The shovel according to claim 2. The control device, when there is an abnormality related to the operation of the swing body, maintains the stopped state of the swing body even if the swing body is operated.
The shovel according to claim 1 or 2. When there is an abnormality related to the operation of the revolving structure, the control device maintains the stopped state of the revolving structure by continuing to operate the mechanical brake even if the operation of the revolving structure is performed.
The excavator according to claim 4. The control device, when there is an abnormality related to the operation of the swing body, maintains the stopped state of the swing body by prohibiting the drive control even if the swing body is operated.
The excavator according to claim 4. With hydraulic working elements that are hydraulically driven,
When there is an abnormality related to the operation of the swivel body, even if the hydraulic work element is operated, the hydraulic work element does not operate.
The excavator according to any one of claims 2 to 6. A non-volatile storage device,
When there is an abnormality related to the operation of the revolving structure, the control device stores a flag indicating the abnormality in a storage device.
The excavator according to any one of claims 2 to 7. A swivel,
An electric motor for driving the revolving structure;
A detection unit for detecting a driving state of the electric motor;
A mechanical brake for mechanically stopping the swivel body;
A control device that performs drive control of the electric motor based on a detection value of the detection unit,
The control device performs drive control for stopping the electric motor in a state where the mechanical brake is operated, and is generated based on the detection value of the detection unit or the detection value for driving control of the electric motor. When the operation amount to be performed does not satisfy the predetermined condition corresponding to the stop state of the electric motor, it is determined that there is an abnormality related to the operation of the revolving structure, or the drive control of the electric motor is limited.
Excavator. The detection unit includes a current detection unit that detects a current of the electric motor,
The control device performs drive control for stopping the electric motor in a state where the mechanical brake is operating, and a current detection value of the current detection unit does not satisfy the predetermined condition of the current detection value Or if the voltage manipulated variable generated based on the detected current value does not satisfy the predetermined condition of the voltage manipulated variable, it is determined that there is an abnormality related to the operation of the swing body, or the drive control of the electric motor Limit,
The excavator according to claim 9. The control device performs drive control for stopping the electric motor in a state where the mechanical brake is operating, and the current detection value or the voltage operation amount indicates that the electric current is flowing through the electric motor. If there is an abnormality related to the operation of the swivel body, or limit the drive control of the electric motor,
The excavator according to claim 10. The control device performs drive control for stopping the electric motor in a state where the mechanical brake is in operation, and at least one of the three-phase current detection value or the voltage operation amount of the electric motor is over time. On the other hand, when it has changed beyond a predetermined threshold, it is determined that there is an abnormality related to the operation of the revolving structure, or the drive control of the electric motor is limited.
The excavator according to claim 11. The detection unit includes a rotation position detection unit that detects a rotation position of the electric motor,
The control device performs vector control of the electric motor as the drive control based on the current detection value of the current detection unit and the position detection value of the rotational position detection unit, and the mechanical brake is in operation. The vector control for stopping the electric motor is performed, and the d-axis component or the q-axis component of the current detection value generated based on the current detection value and the position detection value exceeds a predetermined threshold corresponding to each. Or the d-axis component or q-axis component of the voltage manipulated variable generated based on the d-axis component and q-axis component of the current detection value and the position detection value exceeds a predetermined threshold corresponding to each. Determining that there is an abnormality related to the operation of the revolving structure, or limiting the drive control of the electric motor,
The excavator according to claim 11.

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