JP5459713B2 - Electric construction machine - Google Patents

Description

  The present invention relates to an electric construction machine, and more particularly, to an electric construction machine having a function of detecting deterioration of insulation resistance between an electric system including a power storage device, an electric motor, and the like and a vehicle body.

  In recent years, hybrid construction machines have been proposed that use an electric motor and a power storage device (battery, electric double layer capacitor, etc.) to improve energy efficiency and save energy compared to conventional construction machines that use only hydraulic actuators. (For example, refer to Patent Document 1).

  Electric motors (electric actuators) have energy-efficient characteristics such as better energy efficiency than hydraulic actuators, and can regenerate kinetic energy during braking as electric energy (in the case of hydraulic actuators, release it as heat).

  For example, in the prior art disclosed in Patent Document 1, an embodiment of a hydraulic excavator in which an electric motor is mounted as a drive actuator for a revolving structure is shown. Actuators that drive the swing body of a hydraulic excavator to swing with respect to a traveling body (conventionally using a hydraulic motor) are frequently used, and frequently start and stop and accelerate and decelerate repeatedly during work.

  At this time, the kinetic energy of the swinging body during deceleration (during braking) is discarded as heat on the hydraulic circuit in the case of a hydraulic actuator, but in the case of an electric motor, regeneration as electric energy can be expected. Can be planned.

  By the way, since the electric actuator and the electric storage device mounted on such a hybrid hydraulic excavator are used at a high voltage and a large current, when the insulation resistance between the main electric circuit and the vehicle body deteriorates, Current may flow through the vehicle body through the insulation resistance degradation portion, which may lead to a risk of fire or electric shock.

  In order to cope with such a problem, for example, there is an apparatus that detects an insulation resistance deterioration by applying an AC signal of a predetermined frequency to a target circuit and measuring the amplitude level of the AC signal at a predetermined measurement point. . In addition, in a system in which a booster circuit (such as a chopper) is incorporated between an electricity storage device and an inverter, an apparatus that can prevent erroneous detection and continuously detect insulation resistance degradation when the booster circuit is operated is disclosed (for example, Patent Documents). 2).

Furthermore, there is a technique related not only to a means for detecting insulation resistance deterioration but also a method for dealing with a vehicle or machine when insulation resistance deterioration is detected.
By using a means that can identify the insulation resistance degradation part, when insulation resistance deterioration is detected, the motor drive is continued for insulation resistance deterioration in parts where there is little hindrance to driving the motor used for running. A technique is disclosed in which the main relay is turned off to stop driving the motor against insulation resistance deterioration at a site where it is difficult to drive the vehicle by driving the motor (see, for example, Patent Document 3).

JP 2001-16704 A JP 2009-109278 A Japanese Patent Laying-Open No. 2005-304138

  However, in the prior art of Patent Document 3, if the motor is stopped while detecting deterioration of insulation resistance in a portion where it is difficult to drive the vehicle while the vehicle is running, there is a risk of causing a collision with the following vehicle.

  A similar problem arises when the prior art of Patent Document 3 is applied to an electric construction machine. For example, if the insulation resistance deterioration is detected in the above-mentioned part while moving the excavator, the actuator (turning, running, front, etc.) for moving the vehicle body is stopped, and the operation from the place where it stopped can be performed at all. There is a risk of disappearing.

  There are many dangerous places, such as mines, where the construction machine work site has a steep slope like a mine, and many construction machines are operating densely. If it cannot be moved at all, the vehicle body cannot be moved to a safe place and there is a risk of causing a secondary disaster such as collision with other construction machines.

  On the other hand, if the operation / work of the electric construction machine is allowed to continue without limitation in the event of an abnormality as described above, there is a risk that the risk of electric shock from an abnormal location or the occurrence of a fire will continue or increase.

  Furthermore, with respect to insulation resistance deterioration in parts where there is little hindrance to driving the electric motor, even if the electric motor continues to be driven, high voltage is generated in the part where insulation resistance deteriorates. There is a problem that safety is not secured.

  The present invention has been made on the basis of the above-described matters, and its purpose is to reduce the insulation resistance of an electric system such as an electric motor, an inverter, and a power storage device in an electric construction machine using an electric motor for driving a revolving structure. It is an object of the present invention to provide an electric construction machine capable of ensuring the safety of a machine and an operator at a work site even when detected.

  In order to achieve the above object, a first invention provides a hydraulic pump that supplies pressure oil to an actuator, a first electric motor that drives the hydraulic pump, a swivel body, and a second for driving the swivel body. An electric motor, an electricity storage device connected to the first electric motor and the second electric motor, a first inverter for driving the first electric motor, and a second inverter for driving the second electric motor In an electric construction machine, a deterioration of insulation resistance between an electric system composed of the first electric motor, the second electric motor, the first inverter, the second inverter, and the power storage device and a vehicle body is detected. By outputting torque increase / decrease commands to the insulation resistance deterioration detecting means, the first inverter, and the second inverter, respectively, so that the first electric motor and the second electric motor can rotate. A control device for controlling the number, the control device, when the insulation resistance deterioration detection means detects the deterioration of the insulation resistance of the electric system, notifies the operator of the deterioration of the insulation resistance of the electric system, It is assumed that monitoring control means for reducing the rotation speed of the first electric motor is provided.

  In order to achieve the above object, a second invention includes a prime mover, a hydraulic pump that is driven by the prime mover and supplies pressure oil to an actuator, a first electric motor that is driven by the prime mover, and a swing body A second electric motor for driving the revolving structure, an electric storage device connected to the first electric motor and the second electric motor, a first inverter for driving the first electric motor, and the second electric motor In an electric construction machine comprising a second inverter for driving a motor and an operation lever device for turning for commanding driving of the turning body, the first electric motor, the second electric motor, and the first inverter; Insulation resistance deterioration detection means for detecting deterioration of insulation resistance between the vehicle body and an electric system composed of the second inverter and the power storage device, the first inverter and the second input And a control device for controlling the rotational speeds of the first electric motor and the second electric motor by outputting torque increase / decrease commands to the motor, respectively. When the deterioration of the insulation resistance of the electric system is detected, the operator is informed of the deterioration of the insulation resistance of the electric system, and is provided with monitoring control means for reducing the rotational speed or output of the prime mover.

  In order to achieve the above object, the third invention is driven by a prime mover, a hydraulic pump that is driven by the prime mover and supplies pressure oil to the actuator, a revolving body, and a pressure oil supplied from the hydraulic pump. Connected to the hydraulic motor for driving the revolving structure, the first electric motor driven by the drive of the prime mover, the second electric motor for driving the revolving structure, the first electric motor and the second electric motor. A power storage device, a first inverter for driving the first electric motor, a second inverter for driving the second electric motor, and an operation lever device for turning that commands driving of the turning body. In the above-described electric construction machine, the first electric motor, the second electric motor, the first inverter, the second inverter, and the electric storage system between the electric system and the vehicle body. Insulation resistance deterioration detecting means for detecting deterioration of insulation resistance, and when the turning operation lever device is operated, both the second electric motor and the hydraulic motor are driven, and the second electric motor, A hydraulic / electric combined swing mode in which the swing body is driven with the total torque of the hydraulic motor, and only the hydraulic motor is driven when the swing operation lever device is operated, and the torque of only the hydraulic motor is used. A control device for switching to a hydraulic single swing mode for driving the swivel body, and the control device detects the deterioration of the insulation resistance of the electric system when the insulation resistance deterioration detection means detects the deterioration of the insulation resistance of the electric system. In the control switching means for switching to the turning mode, and in the hydraulic only turning mode, the operator is notified of the deterioration of the insulation resistance of the electric system, and the rotational speed of the prime mover Others and that a monitoring control means for reducing the output.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the control device is configured such that when the insulation resistance deterioration detecting unit detects the insulation resistance deterioration of the electric system, the bus in the electric system It is characterized in that it is provided with a bus voltage lowering means for lowering the voltage of the first line than before the detection.

  Furthermore, a fifth invention according to the fourth invention further comprises means for disconnecting an electric circuit from the electric system of the power storage device, and the control device is provided in the electric system by the bus voltage lowering means. It is characterized by comprising a processing sequence for disconnecting the electricity storage device from the electric system by the disconnection means after the bus voltage is lowered.

  According to a sixth aspect of the present invention based on the third aspect, the control device switches the circuit to the circuit opening / closing means or the switching element in the electric system in order to identify an insulation resistance deterioration portion after switching to the hydraulic single swing mode. It is characterized in that it has a processing sequence that involves opening and closing.

  Further, according to a seventh invention, in any one of the first to third inventions, when the insulation resistance deterioration detecting means detects the deterioration of the insulation resistance of the electric system, the control device uses the monitoring control means. In the first processing sequence for memorizing that the machine has been stopped, and at the time of restart after the machine is stopped, the operator is informed that the machine has been stopped last time due to deterioration of the insulation resistance of the electric system, and the rotation speed or output of the prime mover is output. A second processing sequence to be limited is provided.

  According to the present invention, in an electric construction machine using an electric motor for driving a revolving structure, even when insulation resistance deterioration of an electric system such as an electric motor, an inverter, and a power storage device is detected, the machine is brought into a safe posture. At the same time, the minimum power required to move to a safe place is ensured, and the operator is warned of the machine stop, so that the safety of the machine and the operator at the work site can be ensured.

1 is a side view showing a first embodiment of an electric construction machine according to the present invention. 1 is a system configuration diagram of an electric / hydraulic device constituting a first embodiment of an electric construction machine according to the present invention. 1 is a system configuration and control block diagram of a first embodiment of an electric construction machine according to the present invention. 1 is an electric circuit diagram of an electric system constituting a first embodiment of an electric construction machine of the present invention. It is a flowchart figure which shows the process sequence after the insulation resistance degradation detection of 1st Embodiment of the electric construction machine of this invention. It is a flowchart figure which shows the process sequence (restart) after the insulation resistance degradation detection of 1st Embodiment of the electric construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 2nd Embodiment of the electric construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 3rd Embodiment of the electric construction machine of this invention. It is a system configuration | structure and control block diagram of 3rd Embodiment of the electric construction machine of this invention. It is a hydraulic circuit diagram which shows the structure of the turning hydraulic system in 3rd Embodiment of the electric construction machine of this invention. It is a characteristic view which shows the torque control characteristic of the hydraulic pump in 3rd Embodiment of the electric construction machine of this invention. It is a characteristic view which shows the meter-in opening area characteristic and bleed-off opening area characteristic of the spool for rotation in 3rd Embodiment of the electric construction machine of this invention. It is a characteristic view which shows the meter-out opening area characteristic of the spool for rotation in 3rd Embodiment of the electric construction machine of this invention. FIG. 10 is a characteristic diagram showing a composite opening area characteristic of a meter-in throttle of a turning spool 61 and a center bypass cut valve 63 with respect to a hydraulic pilot signal (operation pilot pressure) in a third embodiment of the electric construction machine of the present invention. A hydraulic pilot signal (pilot pressure), meter-in pressure (M / I pressure), assist torque of the swing electric motor at the time of swing drive in the hydraulic / electric combined swing mode in the third embodiment of the electric construction machine of the present invention; It is a characteristic view which shows the time-sequential waveform of the rotational speed (turning speed) of a turning body. It is a characteristic view which shows the meter-out opening area characteristic of the spool 61 for rotation with respect to the hydraulic pilot signal (operating pilot pressure) in 3rd Embodiment of the electric construction machine of this invention. Hydraulic pilot signal (pilot pressure), meter-out pressure (M / O pressure), assist torque of swing electric motor when stopping turning in hydraulic / electric combined swing mode in the third embodiment of the electric construction machine of the present invention FIG. 5 is a characteristic diagram showing a time-series waveform of the rotational speed (swing speed) of the upper swing body. It is a characteristic view which shows the relief pressure characteristic of the variable overload relief valve for rotation in 3rd Embodiment of the electric construction machine of this invention. It is a flowchart figure which shows the abnormality processing sequence (switching from a hydraulic electric combined swing mode to a hydraulic independent swing mode) of the hydraulic excavator of 3rd Embodiment of the electric construction machine of this invention. It is a flowchart figure which shows the process sequence after the insulation resistance degradation detection of 3rd Embodiment of the electric construction machine of this invention. It is a flowchart figure which shows the process sequence (reactivation) after the insulation resistance degradation detection of 3rd Embodiment of the electric construction machine of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking a hydraulic excavator as an example of a construction machine. The present invention can be applied to all construction machines (including work machines) provided with a revolving structure, and the application of the present invention is not limited to a hydraulic excavator. For example, the present invention can be applied to other construction machines such as a crane truck provided with a revolving structure. FIG. 1 is a side view showing an embodiment of an electric construction machine according to the present invention, and FIG. 2 is a system configuration diagram of an electric / hydraulic device constituting the first embodiment of the electric construction machine according to the present invention. FIG. 3 is a system configuration and control block diagram of the first embodiment of the electric construction machine of the present invention.

  In FIG. 1, the electric excavator includes a traveling body 10, a revolving body 20 provided on the traveling body 10 so as to be able to turn, and a shovel mechanism 30 installed on the revolving body 20.

  The traveling body 10 includes a pair of crawlers 11a and 11b and crawler frames 12a and 12b (only one side is shown in FIG. 1), a pair of traveling hydraulic motors 13 and 14 that independently drive and control the crawlers 11a and 11b, and It consists of a speed reduction mechanism.

  The swing body 20 includes a swing frame 21, a drive motor 201 as a prime mover provided on the swing frame 21, a swing electric motor 25, and a battery as a power storage device connected to the drive motor 201 and the swing electric motor 25. 202 and a speed reduction mechanism 26 that decelerates the rotation of the turning electric motor 25, and the driving force of the turning electric motor 25 is transmitted through the speed reduction mechanism 26, and the turning force 20 is transmitted to the traveling body 10 by the driving force. (Swivel frame 21) is swiveled.

  Further, an excavator mechanism (front device) 30 is mounted on the revolving unit 20. The shovel mechanism 30 includes a boom 31, a boom cylinder 32 for driving the boom 31, an arm 33 rotatably supported near the tip of the boom 31, and an arm cylinder 34 for driving the arm 33. The bucket 35 includes a bucket 35 rotatably supported at the tip of the arm 33, a bucket cylinder 36 for driving the bucket 35, and the like.

  Further, a hydraulic system for driving hydraulic actuators such as the traveling hydraulic motors 13 and 14, the swing hydraulic motor 27, the boom cylinder 32, the arc cylinder 34, and the bucket cylinder 36 described above is provided on the swing frame 21 of the swing body 20. 40 is installed. The hydraulic system 40 includes a hydraulic pump 41 (FIG. 2) serving as a hydraulic source for generating hydraulic pressure and a control valve 42 (FIG. 2) for driving and controlling each actuator. The hydraulic pump 41 is driven by a drive motor 201. .

  Next, the system configuration of the electric / hydraulic equipment of the hydraulic excavator will be outlined. As shown in FIG. 2, the driving force of the driving motor 201 as a prime mover is transmitted to the hydraulic pump 41. The control valve 42 is applied to the boom cylinder 32, the arm cylinder 34, the bucket cylinder 36, and the traveling hydraulic motors 13 and 14 in response to an operation command (hydraulic pilot signal) from an operation lever device 73 (see FIG. 3) other than turning. Controls the flow rate and direction of pressure oil supplied.

  The electric system includes the drive motor 201, the battery 202, and the swing electric motor 25 described above, the power control unit 55, the main contactor 56, and the like. The power control unit 55 includes a chopper 51, inverters 52 and 53, a smoothing capacitor 54, and the like, and the main contactor 56 includes a main relay 57, an inrush current prevention circuit 58, and the like. In the present embodiment, a battery 202 having a high energy capacity is required to drive the drive motor 201.

  The DC power from the battery 202 is boosted to a predetermined bus voltage by the chopper 51 and input to the inverter 52 for driving the swing electric motor 25 and the inverter 53 for driving the drive motor 201. The smoothing capacitor 54 is provided to stabilize the bus voltage. The turning electric motor 25 drives the turning body 20 via the speed reduction mechanism 26. The battery 202 is charged / discharged depending on the drive state of the drive motor 201 and the swing electric motor 25 (whether powering or regenerating).

  The controller 80 generates a control command for the control valve 42 and the power control unit 55 by using a turning operation command signal, a pressure signal, a rotation speed signal, and the like (described later), and controls the driving motor 201 as a prime mover and turning control. Control of abnormality of electric system, control of energy management, etc., detection sequence and processing sequence for specifying insulation deterioration part are performed.

  The insulation resistance deterioration detection device 90 is connected to the main circuit of the electric system via paths 90A and 90B. In the present embodiment, the two paths can be detected simultaneously so that the insulation resistance deterioration of the main circuit of the electric system can be detected even when the main relay 57 of the main contactor 56 is opened. Further, the insulation resistance deterioration detection device 90 measures the amplitude level, waveform, etc. of a signal at a predetermined portion by applying the AC or pulse waveform to an AC power supply unit 90C that generates an AC or pulse waveform and the main circuit of the electric system. The measurement unit 90D that compares the applied signal and the measurement signal to calculate an insulation resistance value for the body frame of the target circuit, and compares the preset value with a preset setting value to determine the presence or absence of insulation resistance degradation. And an output unit 90F for notifying the controller 80 of the insulation resistance deterioration determination signal.

  In FIG. 2, 91 to 95 are parts that can be specified by a detection sequence for specifying an insulation resistance deterioration part provided in the controller 80, 91 is a bus between the battery 202 and the main contactor 56, and 92 is a main contactor. 56 denotes a bus between the chopper 51, 93 denotes an inverter 52, a bus between the 53 to chopper 51, 94 denotes a wiring between the drive motor 201 to the inverter 53, and 95 denotes a wiring between the swing electric motor and the inverter 52.

  When the insulation resistance deterioration detecting device 90 detects the insulation resistance deterioration at a certain part, it notifies the controller 80 of a signal indicating deterioration. In response to this signal, the controller 80 performs a predetermined sequence process, which will be described later, on the electric system to cope with the deterioration of the insulation resistance.

Next, devices, control means, control signals and the like necessary for performing turning control and the like according to the present invention will be described in more detail with reference to FIG.
The hydraulic excavator includes a key switch 70 for starting the drive motor 201 and a gate lock lever device 71 that turns on the pilot pressure shut-off valve 76 to disable the hydraulic system when the operation is stopped. The hydraulic excavator includes the above-described controller 80, a hydraulic / electric converter 74a and electric / hydraulic converters 75a and 75b related to input / output of the controller 80, and these constitute a turning control system. The hydraulic / electrical converter 74a is, for example, a pressure sensor, and the electrical / hydraulic converters 75a, 75b are, for example, electromagnetic proportional pressure reducing valves.

  The controller 80 includes an abnormality monitoring / abnormality processing control block 81, an energy management control block 82, an electric turning control block 83A, and the like.

  The hydraulic pilot signal generated by the input of the turning operation lever device 72 is converted into an electric signal by the hydraulic / electric conversion device 74a and input to the electric turning control block 83A. A swing motor speed signal output from the inverter 52 for driving the electric motor in the power control unit 55 is input to the electric swing control block 83A. The electric turning control block 83A calculates a command torque of the turning electric motor 25 by performing a predetermined calculation based on the hydraulic pilot signal from the turning operation lever device 72 and the turning motor speed signal, and sends a torque command to the power control unit 55. EA is output.

  The amount of power stored in the battery 202 increases or decreases depending on the difference between the energy consumed by the swing electric motor 25 and the drive motor 201 during acceleration and the energy regenerated during deceleration. This is controlled by the energy management control block 82, which inputs a voltage / current detection signal of the battery 202 and controls the swing electric motor 25 and the drive motor 201 as appropriate, so that the storage amount of the battery 202 is predetermined. Control to keep within the range.

  When a failure, abnormality or warning state occurs in an electric system such as the power control unit 55, the swing electric motor 25, the battery 202, or the power control unit 55, or when a deterioration detection signal is received from the insulation resistance deterioration detection device 90 The abnormality monitoring / abnormality processing control block 81 and the energy management control block 82 reduce the number of revolutions of the drive motor 201 and control the chopper 51 of the power control unit 55 as a bus voltage lowering means to drive the electric motor 25 and the swing electric motor 25. The bus voltage is lowered to the lowest operable voltage of the motor 201. Thereafter, the electric system is subjected to a sequence process for dealing with the deterioration of the insulation resistance.

Next, an electric circuit of an electric system constituting an embodiment of the electric construction machine of the present invention will be described with reference to FIG. In FIG. 4, the same reference numerals as those shown in FIGS. 1 to 3 are the same parts, and detailed description thereof is omitted.
As shown in FIG. 4, the electric system generally includes a battery 202, a main contactor 56, a chopper 51, a main smoothing capacitor 54, an electric motor 25, an electric motor inverter 52, a driving motor 201, and a driving motor. The inverter 53 is provided.

  The chopper 51 includes a reactor 51a, power transistors (hereinafter referred to as transistors) 51b and 51c such as IGBTs, and a smoothing capacitor 51d as switching elements.

  Reactor 51a has one end connected to the positive electrode of battery 202 via main contactor 56, and the other end connected to the source of transistor 51b and the drain of transistor 51c. The drain of the transistor 51 b is connected to one end of the main smoothing capacitor 54, one end of the drive motor inverter 53, and one end of the electric motor inverter 52. The source of the transistor 51 c is connected to the negative electrode of the battery 202, the other end of the main smoothing capacitor 54, the other end of the drive motor inverter 53 and the other end of the electric motor inverter 52 via the main contactor 56. One end of the reactor 51a is connected to one end of a smoothing capacitor 51d, and the other end of the smoothing capacitor 51d is connected to the source of the transistor 51c.

  A chopper controller (not shown) is connected to the gates of the transistors 51b and 51c to perform switching control. In response to a command from the controller 80, the two transistors 51b and 51c are alternately opened and closed to boost the voltage of the battery 202 to a bus voltage at which the inverter 53 for the drive motor 201 and the inverter 52 for the electric motor 25 can operate. At the same time, an operation of controlling the bus voltage near a predetermined constant value is performed.

  The main smoothing capacitor 54 smoothes the DC voltage. The chopper 51 and the main smoothing capacitor 54 are connected to one side of the inverter 53 for the drive motor 201 and the inverter 52 for the electric motor 25, and the drive motor 201 and the electric motor 25 are connected to the other side, respectively.

  The inverter 53 for the drive motor 201 and the inverter 52 for the electric motor 25 receive a command from an inverter controller (not shown) using a bridge circuit including six transistors 53A and 52A as switching elements such as an IGBT, By repeating ON / OFF of the current and changing the pulse width, a pseudo three-phase alternating current is created, and the drive motor 201 and the electric motor 25 are driven. The inverter controller is controlled by a command from the controller 80.

  In FIG. 4, the path 90A of the insulation resistance deterioration detection device 90 is connected to the bus 91 between the battery 202 and the main contactor 56, and the path 90B is connected to the bus 93 between the inverters 52 and 53 to the chopper 51.

  Here, a detection sequence for specifying the insulation resistance degradation site will be described. As described above, in the electric system, the switching elements 53A and 52A of the inverter 53 for the drive motor 201 and the inverter 52 for the electric motor 25, the transistors 51b and 51c of the chopper 51, and the main relay 57 of the main contactor 56 are connected to the controller 80. Each can be opened and closed by a signal from the energy management control block 82. By monitoring the measurement signal of the insulation resistance deterioration detection device 90 by the abnormality monitoring / abnormality processing control block 81 while controlling the opening / closing of these components, the insulation resistance deterioration portion can be specified.

  For example, when the insulation resistance deterioration portion is the bus 91 between the battery 202 and the main contactor 56, deterioration of the insulation resistance is detected in both the route 90A and the route 90B in the normal state. Here, when the main relay 57 of the main contactor 56 is opened, the deterioration detection of the path 90B is erased, the deterioration of the path 90A remains as it is, and the bus 91 between the battery 202 and the main contactor 56 that is the insulation resistance deterioration portion is specified. can do.

  When the insulation resistance deterioration portion is the wiring 94 between the drive motor 201 and the inverter 53, the deterioration of the insulation resistance is detected in both the path 90A and the path 90B in the normal state, and the main relay 57 of the main contactor 56 is opened. Then, the deterioration detection of the route 90A is erased, and the route 90B remains as the deterioration detection. Next, all the switching elements 53A of the drive motor inverter 53 are turned off, and the deterioration detection of the path 90B is eliminated, whereby the wiring 94 between the drive motor 201 and the inverter 53, which is an insulation resistance deterioration portion, can be specified. .

  The opening / closing control of these components is executed by a detection sequence from the energy management control block 82 of the controller 80.

  Next, in the first embodiment of the electric construction machine of the present invention, a processing sequence when an insulation resistance deterioration detection signal is received from the insulation resistance deterioration detection device 90 will be described with reference to FIGS. 5 and 6. .

  FIG. 5 is a flowchart showing a processing sequence after the insulation resistance deterioration detection of the first embodiment of the electric construction machine of the present invention, and FIG. 6 is the insulation of the first embodiment of the electric construction machine of the present invention. It is a flowchart figure which shows the process sequence (reactivation) after resistance degradation detection.

  First, in step (S101) of FIG. 5, it is determined whether the insulation resistance of the electric system is normal. Specifically, the insulation resistance deterioration detecting device 90 is operated from the energy management control block 82 of the controller 80 during the operation of the electric construction machine, and the applied signal and the measurement signal are compared in the arithmetic unit 90E as described above to compare the target circuit. If the insulation resistance value is equal to or greater than the set value, it is determined that the insulation resistance is normal, and the insulation resistance value is set to the set value. If it is below, it is determined NO because insulation resistance deterioration is detected.

  If YES is determined in the step (S101), the process returns to the original and the determination as to whether the insulation resistance is normal is continued.

  If NO is determined in step (S101), the process proceeds to step (S102) to notify the operator that the insulation resistance has deteriorated, request the machine to stop, and reduce the rotation speed of the drive motor 201. To do. Specifically, a notification signal and a stop request signal are output from an abnormality monitoring / abnormality processing control block 81 of the controller 80 to a monitor or buzzer (not shown), and the energy management control block 82 supplies power to the drive motor 201. Deceleration command is output.

  Next, in step (S <b> 103), the bus voltage is lowered by the chopper 51 to the lowest operating voltage of the drive motor 201 and the swing electric motor 25. Specifically, a step-down command is output from the energy management control block 82 to the chopper 51 of the power control unit 55 as means for lowering the bus voltage, and the transistors 51b and 51c are subjected to switching control so that the bus voltage is kept at a predetermined constant level. Reduce to near value. In this state, the operator moves the construction machine to a place where safety can be ensured, for example.

  Next, in step (S104), it is determined whether or not the state of the key switch 70 is OFF. If it is determined NO, the state of the key switch 70 is continuously determined. If the operator can move the construction machine to a safe place and can determine that the machine can be stopped, the operator can turn off the key switch 70.

  If the key switch 70 is turned OFF and YES is determined in step (S104), the process proceeds to step (S105), and the drive motor 201 is stopped.

  Next, in step (S106), a discharge sequence for completely discharging the bus voltage is performed. Specifically, after the bus voltage is lowered by the chopper 51 as much as possible, the ON / OFF of the switching elements of the inverters 52 and 53 of the power control unit 55 is controlled from the energy management control block 82, whereby the main smoothing capacitor 54 is controlled. The remaining charge is discharged to the coil of the drive motor 201 or the swing electric motor 25. Since the drive motor 201 and the swing electric motor 25 are stopped, the discharge vector control is performed so that the rotation torque is not generated by the discharge current flowing from the inverters 52 and 53 to the motors 201 and 25.

  In step (S107), the main relay 57 of the main contactor 56 is opened. Specifically, the main contactor 56 is controlled from the energy management control block 82 via the power control unit 55.

  In step (S108), the insulation resistance degradation site is determined. Specifically, as described above, the detection sequence is executed in the energy management control block 82 and the abnormality monitoring / abnormality processing control block 81 of the controller 80, thereby specifying the insulation resistance deterioration portion. In addition, the abnormality monitoring / abnormality processing control block 81 stores the portion where the insulation resistance deterioration is detected and the fact that the insulation resistance deterioration is detected. After this, the construction machine stops completely.

  Next, a processing sequence (restart) after detection of insulation resistance deterioration will be described with reference to FIG. This processing sequence is applied to the restart of the construction machine after the previous stop in the processing sequence after the insulation resistance deterioration detection shown in FIG.

  First, in step (S201) in FIG. 6, the key switch 70 is turned from OFF to ON.

  Next, in step (S202), the operator is notified that the insulation resistance deterioration has been detected during the previous construction machine operation and has been stopped in the stop processing sequence. Specifically, a notification signal is output from the abnormality monitoring / abnormality processing control block 81 of the controller 80 to a monitor or buzzer (not shown).

  In step (S203), it is required to select whether or not the detailed measurement of the insulation resistance deterioration is performed again. Specifically, the operator is inquired by a monitor display or the like as in step (S202).

  If YES is determined in the step (S203), the process proceeds to a step (S204), and deterioration of the insulation resistance is detected. Specifically, the insulation resistance deterioration detection device 90 is operated from the abnormality monitoring / abnormality processing control block 81 of the controller 80.

  In step (S205), it is determined whether the insulation resistance of the electric system is normal. Specifically, as described above, the calculation unit 90E of the insulation resistance deterioration detection device 90 compares the applied signal and the measurement signal to calculate the insulation resistance value for the body frame of the target circuit, and the insulation resistance value and the set value In comparison, if the insulation resistance value is equal to or greater than the set value, the insulation resistance is normal and therefore determined as YES, and if the insulation resistance value is equal to or less than the set value, it is determined as NO because the insulation resistance deterioration is detected.

  If NO is determined in this step (S205), the process proceeds to step (S206), and it is determined whether or not the state of the key switch 70 is START. If NO is determined, the key switch 70 is returned to the original state. Continue to determine the status of

  Also, if NO is determined in the previous step (S203), the process proceeds to step (S206). That is, in this case, step (S204) and step (S205) are bypassed.

  If the key switch 70 is set to START and it is determined YES in step (S206), the detailed measurement of the insulation resistance deterioration is not performed or the insulation resistance deterioration is detected. Start in operation mode with a limited number of insulation resistance degradation. Specifically, a notification signal is output from an abnormality monitoring / abnormality processing control block 81 of the controller 80 to a monitor or buzzer (not shown), and a speed limit command for the drive motor 201 is output from the energy management control block 82 to the power control unit 55. Is done.

  If YES is determined in the step (S205), the process proceeds to a step (S207) and it is determined whether or not the state of the key switch 70 is START, and if NO is determined, the return to the original key switch 70 is performed. Continue to determine the status.

  If the key switch 70 is set to START and YES is determined in step (S207), detailed measurement of the insulation resistance deterioration is performed and it is determined that there is no abnormality, so that the operation is started in the standard operation mode. Specifically, the speed increase command of the drive motor 201 is not limited from the energy management control block 82 of the controller 80 to the power control unit 55.

  According to the first embodiment of the present invention described above, in the electric construction machine using the swing electric motor 25 for driving the swing body 20, the swing electric motor 25, the drive motor 201, the inverters 52 and 53, the power storage device. Even if the insulation resistance deterioration of the electric system equipped with the battery 202 or the like is detected, the construction machine is placed in a safe posture and secured to the operator with the minimum power to move it to a safe place. Since the machine stop warning is given, the safety of the construction machine and the operator at the work site can be ensured.

Next, a second embodiment of the electric construction machine of the present invention will be described with reference to FIG.
FIG. 7 is a system configuration diagram of the electric / hydraulic equipment constituting the second embodiment of the electric construction machine of the present invention. In FIG. 7, the same reference numerals as those shown in FIGS. 1 to 6 are the same or corresponding parts, and the description thereof is omitted.

  In the first embodiment shown in FIG. 2, only the drive motor 201 is connected to the drive shaft of the hydraulic pump 41, but in this embodiment, the engine 22 is connected to the drive shaft of the hydraulic pump 41. And the assist generator motor 23 are connected to each other to constitute a so-called hybrid construction machine. In addition, as the power storage device, the electric double layer capacitor 24 is used instead of the battery 202 having a high energy capacity.

  In the first embodiment described above, the rotational speed of the drive motor 201 is reduced by the processing sequence after the insulation resistance deterioration of the power system is detected. However, in this embodiment, the engine is operated by a well-known method. The rotational speed or output of 22 is reduced. For example, the engine speed is set to decrease to the idle speed.

  According to the second embodiment of the present invention, the same effect as that of the first embodiment described above can be obtained.

  Next, a third embodiment of the electric construction machine of the present invention will be described with reference to FIGS. FIG. 8 is a system configuration diagram of electric and hydraulic equipment constituting the third embodiment of the electric construction machine of the present invention, and FIG. 9 is a system configuration of the third embodiment of the electric construction machine of the present invention. It is a control block diagram. 8 and 9, the same reference numerals as those shown in FIGS. 1 to 7 are the same or corresponding parts, and the description thereof is omitted.

  In FIG. 8, the swing body 20 includes a swing frame (not shown), an engine 22 as a prime mover provided on the swing frame, an assist power generation motor 23 driven by the engine 22, a swing electric motor 25, and a swing hydraulic pressure. The motor 27 includes an electric double layer capacitor (hereinafter referred to as a capacitor) 24 connected to the assist power generation motor 23 and the swing electric motor 25, a reduction mechanism 26 that decelerates the rotation of the swing electric motor 25 and the swing hydraulic motor 27, and the like. The driving force of the swing electric motor 25 and the swing hydraulic motor 27 is transmitted through the speed reduction mechanism 26, and the swing body 20 is driven to swing by the drive force.

  As shown in FIG. 8, the driving force of the engine 22 is transmitted to the hydraulic pump 41. The control valve 42 controls the flow rate and direction of the pressure oil supplied to the turning hydraulic motor 27 in accordance with a turning operation command (hydraulic pilot signal) from the turning operation lever device 72 (see FIG. 9). Further, the control valve 42 responds to an operation command (hydraulic pilot signal) from an operation lever device 73 (see FIG. 9) other than turning, and the boom cylinder 32, the arm cylinder 34, the bucket cylinder 36, and the traveling hydraulic motors 13 and 14 are operated. To control the flow rate and direction of pressure oil supplied to.

  The electric system includes the assist power generation motor 23, the capacitor 24, and the swing electric motor 25 described above, a power control unit 55, a main contactor 56, and the like. The power control unit 55 includes a chopper 51, inverters 52 and 53, a smoothing capacitor 54, and the like, and the main contactor 56 includes a main relay 57, an inrush current prevention circuit 58, and the like.

  The DC power from the capacitor 24 is boosted to a predetermined bus voltage by the chopper 51 and input to the inverter 52 for driving the swing electric motor 25 and the inverter 53 for driving the assist power generation motor 23. The smoothing capacitor 54 is provided to stabilize the bus voltage. The rotary electric motor 25 and the rotary hydraulic motor 27 have rotating shafts that are coupled to each other and drive the swing body 20 via the speed reduction mechanism 26. The capacitor 24 is charged and discharged depending on the driving state (whether it is powering or regenerating) of the assist power generation motor 23 and the swing electric motor 25.

  The controller 80 generates a control command for the control valve 42 and the power control unit 55 using a swing operation command signal, a pressure signal, a rotation speed signal, and the like (described later), and a hydraulic single swing mode using the swing hydraulic motor 27; Detection sequence and processing for switching between hydraulic and electric combined swing modes using the swing hydraulic motor 27 and the swing electric motor 25, swing control in each mode, abnormality monitoring of the electric system, control of energy management, etc., and identification of an insulation deterioration part Perform a sequence or the like.

Next, devices, control means, control signals and the like necessary for performing turning control and the like according to the present invention will be described in more detail with reference to FIG.
The hydraulic excavator includes a key switch 70 for starting the engine 22 and a gate lock lever device 71 that disables the operation of the hydraulic system by turning on the pilot pressure cutoff valve 76 when the operation is stopped. The hydraulic excavator includes the above-described controller 80, hydraulic / electrical converters 74a, 74bL, 74bR related to input / output of the controller 80, electric / hydraulic converters 75a, 75b, 75c, 75d, and a hydraulic single swing mode fixing switch 77. These constitute a turning control system. The hydraulic / electrical converters 74a, 74bL, 74bR are, for example, pressure sensors, and the electric / hydraulic converters 75a, 75b, 75c, 75d are, for example, electromagnetic proportional pressure reducing valves.

  The controller 80 includes an abnormality monitoring / abnormality processing control block 81, an energy management control block 82, a hydraulic / electric combined swing control block 83, a hydraulic single swing control block 84, a control switching block 85, and the like.

  When there is no abnormality in the entire system and the swing electric motor 25 can be driven, the controller 80 selects the hydraulic / electric combined swing mode. At this time, the control switching block 85 selects the hydraulic / electric combined swing control block 83, and the swing actuator operation is controlled by the hydraulic / electric combined swing control block 83. The hydraulic pilot signal generated by the input of the turning operation lever device 72 is converted into an electric signal by the hydraulic / electric converter 74 a and input to the hydraulic / electric combined swing control block 83. The operating pressure of the swing hydraulic motor 27 is converted into an electrical signal by the hydraulic / electric converters 74 bL and 74 bR and is input to the hydraulic / electric combined swing control block 83. The swing motor speed signal output from the inverter 52 for driving the electric motor 25 in the power control unit 55 is also input to the hydraulic / electric combined swing control block 83. The hydraulic / electric combined swing control block 83 performs a predetermined calculation based on the hydraulic pilot signal from the swing operation lever device 72, the operating pressure signal of the swing hydraulic motor 27, and the swing motor speed signal, thereby giving a command torque of the swing electric motor 25. And a torque command EA is output to the power control unit 55. At the same time, torque reduction commands EB and EC for decreasing the output torque of the hydraulic pump 41 and the output torque of the swing hydraulic motor 27 by the torque output by the swing electric motor 25 are output to the electric / hydraulic converters 75a and 75b.

  On the other hand, the hydraulic pilot signal generated by the input of the turning operation lever device 72 is also input to the control valve 42, supplies the oil discharged from the hydraulic pump 41 to the turning hydraulic motor 27, and the turning hydraulic motor 27 is also driven simultaneously.

  The amount of electricity stored in the capacitor 24 increases or decreases due to the difference between the energy consumed by the swing electric motor 25 during acceleration and the energy regenerated during deceleration. This is controlled by the energy management control block 82, which performs control to keep the amount of power stored in the capacitor 24 within a predetermined range by generating power or an assist command ED to the assist power generation motor 23.

  When a failure, abnormality or warning state occurs in the electric system such as the power control unit 55, the swing electric motor 25, the capacitor 24, or the power control unit 55, or when a deterioration detection signal is received from the insulation resistance deterioration detection device 90 First, the abnormality monitoring / abnormality processing control block 81 and the energy management control block 82 switch the control switching block 85 to select the hydraulic single swing control block 84, and switch from the hydraulic / electric combined swing mode to the hydraulic single swing mode. Next, the engine speed is reduced, and then the electric system is subjected to a sequence process to cope with the insulation resistance deterioration. Since the swing hydraulic system is basically matched to operate in cooperation with the swing electric motor 25, the hydraulic single swing control block 84 outputs the swing drive characteristic correction command EE and the swing pilot pressure correction command EF, respectively. -Output to the hydraulic pressure conversion devices 75c and 75d, and a correction for increasing the driving torque of the swing hydraulic motor 27 and a correction for increasing the braking torque of the swing hydraulic motor 27, so that the swing can be performed even without the torque of the swing electric motor 25. Control is performed so that operability is not impaired.

  The hydraulic single swing mode fixing switch 77 is used when it is desired to be fixed in the hydraulic single swing mode for some reason, such as when an electric system fails or when a specific attachment is mounted. The fixed switch 77 is operated to the ON position. Then, the switching control block 85 is fixed so as to select the hydraulic single turning control block 84.

Next, details of the swing hydraulic system will be described with reference to FIGS. FIG. 10 is a hydraulic circuit diagram showing a configuration of a turning hydraulic system in the third embodiment of the electric construction machine of the present invention. In FIG. 10, the same reference numerals as those shown in FIGS. 1 to 9 are the same parts, and detailed description thereof is omitted.
The control valve 42 in FIG. 9 includes a valve component called a spool for each corresponding actuator, and the opening area changes as the corresponding spool is displaced in accordance with commands (hydraulic pilot signals) from the operation lever devices 72 and 73. The flow rate of the pressure oil passing through each oil passage changes. The turning hydraulic system shown in FIG. 10 includes only a turning spool.

  The swing hydraulic system can be changed between a first mode in which the maximum output torque of the swing hydraulic motor 27 is the first torque and a second mode in which the maximum output torque of the swing hydraulic motor 27 is a second torque larger than the first torque. It is. Details will be described below.

  In FIG. 10, the swing hydraulic system includes the hydraulic pump 41 and the swing hydraulic motor 27, the swing spool 61, the swing variable overload relief valves 62a and 62b, and the center bypass cut valve 63 as a swing assist valve. And.

  The hydraulic pump 41 is a variable displacement pump, and includes a regulator 64 having a torque control unit 64a. By operating the regulator 64, the tilt angle of the hydraulic pump 41 is changed and the displacement of the hydraulic pump 41 is changed. The discharge flow rate and output torque change. When the torque reduction command EB is output from the hydraulic / electric combined swing control block 83 of FIG. 9 to the electric / hydraulic converter 75a, the electric / hydraulic converter 75a outputs the corresponding control pressure to the torque controller 64a of the regulator 64. The torque control unit 64a changes the pump capacity (tilt angle) so that the maximum output torque of the hydraulic pump 41 is reduced by the amount of torque output from the swing electric motor 25.

  The torque control characteristics of the hydraulic pump 41 are shown in FIG. The horizontal axis indicates the discharge pressure of the hydraulic pump 41, and the vertical axis indicates the capacity of the hydraulic pump 41.

  When the hydraulic / electric combined swing mode is selected and the torque reduction command EB is output to the electric / hydraulic converter 75a, the electric / hydraulic converter 75a generates a control pressure. At this time, the torque controller 64a The setting is in the characteristic of the solid line PT in which the maximum output torque is reduced from the solid line PTS (first mode). When the hydraulic single swing mode is selected and the torque reduction command EB is not output to the electro-hydraulic converter 75a, the torque control unit 64a changes to the characteristic of the solid line PTS (second mode), and the maximum of the hydraulic pump 41 The output torque increases by the area indicated by diagonal lines.

  Returning to FIG. 10, the turning spool 61 has three positions A, B, and C, and continuously receives the turning operation command (hydraulic pilot signal) from the operation lever device 72 from the neutral position B to the A position or the C position. Switch to

  The operation lever device 72 has a built-in pressure reducing valve that reduces the pressure from the pilot hydraulic pressure source 29 according to the lever operation amount, and the pressure (hydraulic pilot signal) according to the lever operation amount is set to either the left or right pressure of the turning spool 61. Give to the room.

  When the turning spool 61 is in the neutral position B, the pressure oil discharged from the hydraulic pump 41 passes through the bleed-off throttle and returns to the tank through the center bypass cut valve 63. When the turning spool 61 receives pressure (hydraulic pilot signal) corresponding to the lever operation amount of the operating lever device 72 and switches to the A position, the pressure oil from the hydraulic pump 41 passes through the meter-in throttle at the A position and turns hydraulic motor. The return oil from the swing hydraulic motor 27 returns to the tank through the meter-out throttle at position A, and the swing hydraulic motor 27 rotates in one direction. On the contrary, when the turning spool 61 receives the pressure (hydraulic pilot signal) corresponding to the lever operation amount and switches to the C position, the pressure oil from the hydraulic pump 41 passes through the meter-in throttle at the C position and turns on the turning hydraulic motor 27. The return oil from the turning hydraulic motor 27 is sent to the left side, returns to the tank through the meter-out throttle at the C position, and the turning hydraulic motor 27 rotates in the opposite direction to that at the A position.

  When the turning spool 61 is located between the B position and the A position, the pressure oil from the hydraulic pump 41 is distributed to the bleed-off throttle and the meter-in throttle. At this time, a pressure corresponding to the opening area of the bleed-off throttle and the opening area of the center bypass cut valve 63 rises on the inlet side of the meter-in throttle, and pressure oil is supplied to the swing hydraulic motor 27 with that pressure, and the pressure (bleed An operating torque corresponding to the opening area of the off diaphragm is applied. Further, the oil discharged from the swing hydraulic motor 27 receives a resistance corresponding to the opening area of the meter-out throttle at that time, and a back pressure is generated, and a braking torque corresponding to the opening area of the meter-out throttle is generated. The same applies to the middle between the B position and the C position.

  When the operating lever of the operating lever device 72 is returned to the neutral position and the turning spool 61 is returned to the neutral position B, the turning hydraulic motor 27 tries to continue rotating with the inertia because the turning body 20 is an inertial body. . At this time, when the pressure (back pressure) of the oil discharged from the swing hydraulic motor 27 tends to exceed the set pressure of the variable overload relief valve 62a or 62b for swing, the overload relief valve 62a or 62b is activated. Thus, a part of the pressure oil is allowed to escape to the tank, so that the increase of the back pressure is limited, and a braking torque corresponding to the set pressure of the overload relief valve 62a or 62b is generated.

  FIG. 12 is a characteristic diagram showing meter-in opening area characteristics and bleed-off opening area characteristics of the turning spool 61 in one embodiment of the hybrid construction machine of the present invention, and FIG. 13 shows the meter-out opening area characteristics. FIG.

  In FIG. 12, the solid line MI is the meter-in opening area characteristic, and the solid line MB is the bleed-off opening area characteristic, both of which are in the present embodiment. The two-dot chain line MBO is a bleed-off opening area characteristic that can ensure good operability in a conventional hydraulic excavator that does not use an electric motor. The bleed-off opening area characteristic MB of the present embodiment has the same control area start point and end point as the conventional one, but the intermediate area is designed to be more open (larger opening area) than the conventional one. Has been.

  In FIG. 13, a solid line MO is a meter-out opening area characteristic of the present embodiment, and a two-dot chain line MOO is a meter-out opening area characteristic that can ensure good operability in a conventional hydraulic excavator that does not use an electric motor. . The meter-out opening area characteristic MO of the present embodiment has the same control region start point and end point as the conventional one, but the intermediate region is designed to open more easily than the conventional one (a larger opening area). Has been.

  FIG. 14 is a diagram showing a combined opening area characteristic of the meter-in throttle of the turning spool 61 and the center bypass cut valve 63 with respect to a hydraulic pilot signal (operating pilot pressure).

  When the hydraulic / electric combined swing mode is selected, the swing drive characteristic correction command EE is not output, so the center bypass cut valve 63 is in the open position shown in the figure, and the meter-in throttle and the center bypass cut of the swing spool 61 The synthetic opening area characteristic with the valve 63 is the characteristic of the dotted line MBC determined only by the bleed-off opening area characteristic MB of FIG. 12 (first mode).

  When the hydraulic single swing mode is selected, the swing drive characteristic correction command EE is output to the electric / hydraulic converter 75c as described above, and the electric / hydraulic converter 75c sends the corresponding control pressure to the center bypass cut valve 63. The center bypass cut valve 63 is switched to the throttle position on the right side of the figure. By switching the center bypass cut valve 63, the composite opening area characteristic of the meter-in throttle of the turning spool 61 and the center bypass cut valve 63 with respect to the hydraulic pilot signal of the turning spool 61 is smaller than the characteristic of the dotted line MBC. The characteristics are changed to those of the solid line MBS (second mode). The combined opening area characteristic of the solid line MBS is equivalent to the bleed-off opening area characteristic that can ensure good operability in the conventional hydraulic excavator.

  FIG. 15 shows a hydraulic pilot signal (pilot pressure), meter-in pressure (M / I pressure), assist torque of the swing electric motor 25, rotation speed of the upper swing body 20 (turn speed) during swing driving in the hydraulic / electric combined swing mode. It is a characteristic view showing a time series waveform of). This is an example in the case where the hydraulic pilot signal is increased in a ramp shape up to the maximum pilot pressure at time T = T1 to T4 after the pilot pressure is 0 and the turning is stopped.

  When the hydraulic / electric combined swing mode is selected, the combined opening area characteristics of the meter-in throttle of the swing spool 61 and the center bypass cut valve 63 as shown by the dotted line MBC in FIG. Since the characteristic is determined only by the characteristic MB, the meter-in pressure (M / I) is lower in the present embodiment because the opening area of the bleed-off diaphragm is larger than in the conventional case. Since the meter-in pressure corresponds to the operating torque (acceleration torque) of the swing hydraulic motor 27, it is necessary to apply the acceleration torque by the swing electric motor 25 as much as the meter-in pressure is lowered. In FIG. 14, the assist torque on the power running side is positive. In the present embodiment, control is performed such that the total value of the assist torque of the swing electric motor 25 and the acceleration torque derived from the meter-in pressure generated by the swing spool 61 is approximately equal to the acceleration torque generated by the conventional hydraulic excavator. To do. Thereby, the turning speed of the turning body 20 can have an acceleration feeling equivalent to that of a conventional hydraulic excavator.

  On the other hand, when the hydraulic single swing mode is selected, the combined opening area characteristic between the meter-in throttle of the swing spool 61 and the center bypass cut valve 63 is smaller than the dotted line MBC in FIG. Since the characteristic is changed, the meter-in pressure generated by the turning spool 61 rises to the solid-line meter-in pressure obtained with the conventional hydraulic shovel shown in FIG. The torque is controlled to be approximately equal to the acceleration torque generated by the conventional hydraulic excavator. Thereby, the turning speed of the turning body 20 can have an acceleration feeling equivalent to that of a conventional hydraulic excavator.

  Further, the fact that the turning hydraulic motor 27 can turn by itself means that the maximum output torque of the turning hydraulic motor 27 is larger than the maximum output torque of the turning electric motor 25. This means that in the hydraulic / electric combined swing mode, even if the swing electric motor 25 moves unintentionally, if the hydraulic circuit is normal, the movement is not so dangerous. Is also advantageous.

  FIG. 16 is a characteristic diagram showing a meter-out opening area characteristic of the turning spool 61 with respect to a hydraulic pilot signal (operating pilot pressure).

  When the hydraulic / electric combined swing mode is selected, the swing pilot pressure correction command EF is not output, so the meter-out opening area characteristic of the swing spool 61 changes in the same way as the meter-out opening area characteristic MO of FIG. 6B. (First mode).

  When the hydraulic single swing mode is selected, as described above, the electric / hydraulic converter 75d in FIG. 9 (electric / hydraulic converters 75dL, 75dR in FIG. 10) outputs the swing pilot pressure correction command EF, and the electric / hydraulic pressure is output. The conversion device 75d corrects and reduces the hydraulic pilot signal (operation pilot pressure) generated by the operation lever device 72. By the correction of the hydraulic pilot signal, the meter-out opening area characteristic for the hydraulic pilot signal of the turning spool 61 is changed to the characteristic of the solid line MOS in which the opening area in the intermediate region is reduced with respect to the characteristic of the dotted line MOC in FIG. Second mode). The opening area characteristic of the solid line MOS is equivalent to the meter-out opening area characteristic that can ensure good operability in a conventional hydraulic excavator.

  FIG. 17 shows a hydraulic pilot signal (pilot pressure), meter-out pressure (M / O pressure), assist torque of the swing electric motor 25, and rotation speed of the swing body 20 (turn) when turning braking is stopped in the hydraulic / electric combined swing mode. It is a characteristic view showing a time-series waveform of (speed). This is an example in which the hydraulic pilot signal is reduced in a ramp shape from the maximum pilot pressure and the maximum turning speed to the pilot pressure of 0 at time T = T5 to T9.

  When the hydraulic single turning mode is selected, the meter-out opening area characteristic with respect to the hydraulic pilot signal of the turning spool 61 changes in the same manner as the meter-out opening area characteristic MO in FIG. 13 as indicated by the dotted line MOC in FIG. Therefore, as shown in FIG. 13, the meter-out pressure (M / O pressure) is lower in the present embodiment because the opening area of the meter-out diaphragm is larger than in the conventional case. Since the meter-out pressure corresponds to the brake torque (braking torque), it is necessary to apply the brake torque by the electric motor 25 as much as the meter-out pressure is lowered. In FIG. 17, the assist torque on the regeneration side is negative. In the present embodiment, control is performed so that the total value of the assist torque of the swing electric motor 25 and the brake torque derived from the meter-out pressure generated by the swing spool 61 is approximately equal to the brake torque generated by the conventional hydraulic excavator. To do. As a result, the turning speed of the turning body 20 can have a deceleration feeling equivalent to that of a conventional hydraulic excavator.

  On the other hand, when the hydraulic single swing mode is selected, the meter-out opening area characteristic with respect to the hydraulic pilot signal of the swing spool 61 is the characteristic of the solid line MOS in which the opening area in the intermediate region is smaller than the characteristic of the dotted line MOC in FIG. Therefore, the meter-out pressure generated by the swing spool 61 rises to the solid-line meter-out pressure obtained with the conventional hydraulic excavator shown in FIG. The brake torque is controlled to be approximately equal to the brake torque generated in the conventional hydraulic excavator, and the turning speed of the swing body 20 can have a deceleration feeling equivalent to that of the conventional hydraulic excavator.

  FIG. 18 is a diagram showing relief pressure characteristics of the variable overload relief valves 62a and 62b for turning.

  When the hydraulic / electric combined swing mode is selected and the torque reduction command EC is output to the electric / hydraulic converter 75b (electric / hydraulic converters 75bL and 75bR in FIG. 10), the electric / hydraulic converter 75b is selected. Generates a control pressure, and the control pressure acts on the set pressure decrease side of the variable overload relief valves 62a and 62b. The relief characteristics of the variable overload relief valves 62a and 62b are the characteristics of the solid line SR where the relief pressure is Pmax1. (First mode). When the hydraulic single swing mode is selected and the torque reduction command EC is not output to the electric / hydraulic converter 75b (the electric / hydraulic converters 75bL and 75bR in FIG. 10), the electric / hydraulic converter 75b supplies the control pressure. Therefore, the relief characteristics of the variable overload relief valves 62a and 62b are the characteristics of the solid line SRS in which the relief pressure has increased from Pmax1 to Pmax2 (second mode), and the braking torque increases as the relief pressure increases. To do.

  Thus, when the hydraulic / electric combined swing mode is selected, the relief pressure of the variable overload relief valves 62a and 62b is set to Pmax1 lower than Pmax2, and therefore the operation lever of the operation lever device 72 is returned to the neutral position. Sometimes, the pressure (back pressure) of the oil discharged from the swing hydraulic motor 27 rises to Pmax1, which is a lower set pressure of the variable overload relief valves 62a and 62b, and the assist torque of the swing electric motor 25 and the variable overload relief. The total value of the brake torque derived from the back pressure generated by the valve 62a or 62b is controlled to be approximately equal to the brake torque generated by the conventional hydraulic excavator, and the swing speed of the swing body 20 is the same as that of the conventional hydraulic excavator. It is possible to have a deceleration feeling of

  When the hydraulic single swing mode is selected, the relief pressure of the variable overload relief valves 62a and 62b is set to Pmax2 higher than Pmax1, so that the operation lever of the operation lever device 72 is returned to the neutral position. The pressure (back pressure) of the oil discharged from the swing hydraulic motor 27 rises to Pmax2, which is a higher set pressure of the variable overload relief valves 62a and 62b, and becomes the back pressure generated by the variable overload relief valve 62a or 62b. The derived brake torque is controlled to be approximately equal to the brake torque generated in the conventional hydraulic excavator, and the turning speed of the swing body 20 can have a deceleration feeling equivalent to that of the conventional hydraulic excavator.

Next, a sequence for switching between the hydraulic / electric combined swing mode and the hydraulic single swing control mode by the abnormality monitoring / abnormality processing control block 81 of the controller 80 will be described with reference to FIG.
FIG. 19 shows a switching sequence from the hydraulic / electric combined swing mode to the hydraulic single swing control mode by the abnormality monitoring / abnormality processing control block 81 of the controller 80.

  The abnormality monitoring / abnormality processing control block 81 is used when an electric system such as the power control unit 55, the electric motor 25, the capacitor 24, the power control unit 55, or the like has a failure, abnormality or warning state, or from the insulation resistance deterioration detecting device 90. When a deterioration detection signal is received, it is determined whether or not a signal (hereinafter referred to as an error signal) notifying that is received (step S300). When the error signal is notified, it is an error signal that requires emergency response. Is further determined (step S310). When switching modes, there is a possibility that a slight shock may occur due to the switching operation of the valves of the hydraulic system, etc. Therefore, if the content of the error signal is not serious and there is no urgency to switch immediately, determine whether it is possible to switch modes (Step S320), the operation of the revolving unit 20 and the timing when the operation lever device 72 for turning is not input, or the travel, front operation and their operation lever devices 73 other than the revolving unit 20 Is switched at the time of idling or the like in which no operation is performed (step S330). For abnormalities such as an inverter overcurrent that may damage the system or cause a serious failure or disaster, the electric system is immediately stopped and switched to the hydraulic single swing mode even during operation (step S310). → S330).

  Next, a processing sequence when an insulation resistance deterioration detection signal is received from the insulation resistance deterioration detection device 90 in the third embodiment of the electric construction machine of the present invention will be described with reference to FIGS. .

  FIG. 20 is a flowchart showing a processing sequence after detection of deterioration of insulation resistance in the third embodiment of the electric construction machine according to the present invention. FIG. 21 shows insulation in the third embodiment of the electric construction machine according to the present invention. It is a flowchart figure which shows the process sequence (reactivation) after resistance degradation detection.

  First, in step (S401) of FIG. 20, it is determined whether or not the insulation resistance of the electric system is normal. Specifically, the insulation resistance deterioration detecting device 90 is operated from the energy management control block 82 of the controller 80 during the operation of the electric construction machine, and the applied signal and the measurement signal are compared in the arithmetic unit 90E as described above to compare the target circuit. If the insulation resistance value is equal to or greater than the set value, it is determined that the insulation resistance is normal, and the insulation resistance value is set to the set value. If it is below, it is determined NO because insulation resistance deterioration is detected.

  If YES is determined in the step (S401), the process returns to the original state and continues to determine whether the insulation resistance is normal.

  If NO is determined in step (S401), the process proceeds to step (S402). First, a switching sequence from the hydraulic / electric combined swing mode to the hydraulic single swing control mode by the abnormality monitoring / abnormality processing control block 81 described above is performed. This is executed to shift to the hydraulic single swing mode. Simultaneously with this switching sequence, the operator is warned that the insulation resistance has deteriorated, requests that the machine be stopped, and reduces the rotational speed or output of the engine 22. Specifically, a notification signal and a stop request signal are output from an abnormality monitoring / abnormality processing control block 81 of the controller 80 to a monitor or buzzer (not shown), for example, a deceleration command is output from an engine control unit (not shown) to the engine 22. Is done. The rotation speed or output of the engine 22 is lowered to such an extent that normal operations are difficult but operation at low speed and traveling are possible. In this state, the assist power generation motor 23 is rotated by the engine 22, but since the work machine such as the revolving body 20 is operated only by the hydraulic actuator, an electric system such as an electric motor is not necessary for the operation of the machine. .

  In step (S403), the insulation resistance degradation site is determined. Specifically, as described above, the detection sequence is executed in the energy management control block 82 and the abnormality monitoring / abnormality processing control block 81 of the controller 80.

  In step (S404), it is determined whether or not the insulation resistance deterioration portion is in the vicinity of the bus line 91 between the capacitor 24 and the main contactor 56. The insulation resistance deterioration portion is any of the main contactor 56 to the chopper 51 bus 92, the inverters 52 and 53 to the chopper 51 bus 93, the assist generator motor 23 to the inverter 53 wiring 94, and the swing electric motor to the inverter 52 wiring 95. In this case, it is determined as NO and the process proceeds to step (S405), and the main relay 57 of the main contactor 56 is opened. Specifically, the main contactor 56 is controlled from the energy management control block 82 via the power control unit 55.

  Next, in step (S406), a discharge sequence for discharging the bus voltage is performed as a bus voltage lowering unit. Specifically, after insulating from the capacitor 24 by the opening operation of the main relay 57, the power management of the inverters 52 and 53 of the power control unit 55 is performed from the energy management control block 82 to assist the charge remaining in the main smoothing capacitor 54. The coil of the generator motor 23 or the swing electric motor 25 is discharged.

  If YES is determined in the step (S404), the process proceeds to a step (S407) to perform a discharge sequence for discharging the capacitor 24 as a bus voltage lowering unit. Specifically, the capacitor 24 is discharged by performing power running control of the inverters 52 and 53 of the power control unit 55 from the energy management control block 82.

  In step (S408), the main relay 57 of the main contactor 56 is opened. Specifically, the main contactor 56 is controlled from the energy management control block 82 via the power control unit 55.

  Next, in step (S409), a discharge sequence for discharging the bus voltage is performed as a bus voltage lowering unit. Specifically, after insulating from the capacitor 24 by the opening operation of the main relay 57, the power management of the inverters 52 and 53 of the power control unit 55 is performed from the energy management control block 82 to assist the charge remaining in the main smoothing capacitor 54. The coil of the generator motor 23 or the swing electric motor 25 is discharged.

  In the previous step (S406) and step (S409), the operator moves the construction machine to a place where safety can be ensured, for example, while discharging the bus voltage. After one of the previous step (S406) and step (S409) is executed, the process proceeds to step (S410).

  In step (S410), it is determined whether or not the state of the key switch 70 is OFF. If the determination is NO, the determination of the state of the key switch 70 is continued by returning to the original state. If the operator can move the construction machine to a safe place and can determine that the machine can be stopped, the operator can turn off the key switch 70.

  If the key switch 70 is turned OFF and YES is determined in step (S410), the process proceeds to step (S411) and the engine 22 is stopped.

  Next, in step (S412), a discharge sequence for completely discharging the bus voltage is performed. When the assist generator motor 23 and the swing electric motor 25 are permanent magnet synchronous motors, the DC voltage corresponding to the self-induced voltage is superimposed on the bus when the engine 22 and the swing hydraulic motor 27 are forcibly rotated. After the electric motor 25 is stopped, it is necessary to perform the discharge sequence again. Specifically, by controlling ON / OFF of the switching elements of the inverters 52 and 53 of the power control unit 55 from the energy management control block 82, the electric charge remaining in the main smoothing capacitor 54 is changed to the assist generator motor 23 or the swing electric motor. 25 coils are discharged. Since the assist power generation motor 23 and the swing electric motor 25 are stopped, the discharge vector control is performed so that the rotation torque is not generated by the discharge current flowing from the inverters 52, 53 to the motors 23, 25. In addition, the abnormality monitoring / abnormality processing control block 81 stores the portion where the insulation resistance deterioration is detected and the fact that the insulation resistance deterioration is detected. After this, the construction machine stops completely.

  Next, a processing sequence (restart) after detection of insulation resistance deterioration will be described with reference to FIG. This processing sequence is applied to the restart of the construction machine after having stopped in the processing sequence after the insulation resistance deterioration detection shown in FIG. 20 last time.

  First, in step (S501) of FIG. 21, the key switch 70 is changed from OFF to ON.

  Next, in step (S502), the insulation resistance deterioration is detected during the previous construction machine operation, and the operator is informed that it has been stopped in the stop processing sequence. Specifically, a notification signal is output from the abnormality monitoring / abnormality processing control block 81 of the controller 80 to a monitor or buzzer (not shown).

  In step (S503), it is required to select whether or not the detailed measurement of the insulation resistance deterioration is performed again. Specifically, the operator is inquired by a monitor display or the like as in step (S502).

  If YES is determined in the step (S503), the process proceeds to a step (S504) to detect insulation resistance deterioration. Specifically, the insulation resistance deterioration detection device 90 is operated from the abnormality monitoring / abnormality processing control block 81 of the controller 80.

  In step (S505), it is determined whether the insulation resistance of the electric system is normal. Specifically, as described above, the calculation unit 90E of the insulation resistance deterioration detection device 90 compares the applied signal and the measurement signal to calculate the insulation resistance value for the body frame of the target circuit, and the insulation resistance value and the set value In comparison, if the insulation resistance value is equal to or greater than the set value, the insulation resistance is normal and therefore determined as YES, and if the insulation resistance value is equal to or less than the set value, it is determined as NO because the insulation resistance deterioration is detected.

  If NO is determined in this step (S505), the process proceeds to step (S506), where it is determined whether or not the state of the key switch 70 is START. If NO is determined, the key switch 70 is returned to the original state. Continue to determine the status of

  Also, if NO is determined in the previous step (S503), the process proceeds to step (S506). That is, in this case, step (S504) and step (S505) are bypassed.

  If the key switch 70 is set to START and it is determined YES in step (S506), the detailed measurement of the insulation resistance deterioration has not been performed or the insulation resistance deterioration has been detected. Or it starts in the operation mode of the insulation resistance degradation state which restricted the output. Specifically, a notification signal is output from the abnormality monitoring / abnormality processing control block 81 of the controller 80 to a monitor or buzzer (not shown) and fixed to the hydraulic single turning control mode, for example, from an engine control unit (not shown) to the engine 22. The speed limit command is output.

  If YES is determined in the step (S505), the process proceeds to a step (S207), and it is determined whether or not the state of the key switch 70 is START. If NO is determined, the process returns to the original state. Continue to determine the status.

  When the key switch 70 is set to START and it is determined YES in step (S507), the detailed measurement of the insulation resistance deterioration is performed and it is determined that there is no abnormality, so that the operation is started in the standard operation mode. Specifically, the output increase signal from the energy management control block 82 of the controller 80 to the power control unit 55 is not limited, and the transition from the hydraulic single swing control mode to the hydraulic / electric combined swing mode is not limited. Further, for example, the speed increase command from the engine control unit (not shown) to the engine 22 is not limited.

  According to the first embodiment of the present invention described above, in the electric construction machine using the swing electric motor 25 for driving the swing body 20, the swing electric motor 25, the assist power generation motor 23, the inverters 52 and 53, the capacitor. Even if insulation resistance deterioration of an electric system equipped with a power storage device such as 24 is detected, the construction machine is placed in a safe posture and secured to the operator with the minimum power required to move it to a safe place. Since the machine stop warning is given, the safety of the construction machine and the operator at the work site can be ensured.

  In the above, the embodiment in the case where the present invention is applied to a hydraulic excavator has been described. However, the present invention can be applied to all construction machines having a revolving body other than the hydraulic excavator.

DESCRIPTION OF SYMBOLS 10 Traveling body 11 Crawler 12 Crawler frame 13 Right traveling hydraulic motor 14 Left traveling hydraulic motor 20 Turning body 21 Turning frame 22 Engine 23 Assist power generation motor 24 Capacitor 25 Turning electric motor 26 Reduction gear 27 Turning hydraulic motor 30 Excavator mechanism 31 Boom 33 Arm 35 Bucket 40 Hydraulic system 41 Hydraulic pump 42 Control valve 51 Chopper 52 Inverter for turning electric motor 53 Inverter for assist power generation motor 54 Smoothing capacitor 55 Power control unit 56 Main contactor 57 Main relay 58 Inrush current prevention circuit 80 Controller 81 Abnormality monitoring・ Abnormality processing control block 82 Energy management control block 83A Electric turning control block 83 Hydraulic electric combined turning control block 84 Hydraulic single control Control block 85 Control switching block 90 Insulation resistance deterioration detection device

Claims (7)

A hydraulic pump that supplies pressure oil to the actuator; a first electric motor that drives the hydraulic pump; a swiveling body; a second electric motor that drives the swiveling body; and the first electric motor and the second electric motor. In an electric construction machine comprising a connected power storage device, a first inverter for driving the first electric motor, and a second inverter for driving the second electric motor,
Insulation resistance deterioration detecting means for detecting deterioration of an insulation resistance between an electric system constituted by the first electric motor, the second electric motor, the first inverter, the second inverter, and the power storage device and a vehicle body. When,
A controller for controlling the rotational speeds of the first electric motor and the second electric motor by outputting torque increase / decrease commands to the first inverter and the second inverter, respectively.
When the insulation resistance deterioration detecting unit detects the deterioration of the insulation resistance of the electric system, the control device notifies the operator of the deterioration of the insulation resistance of the electric system and decreases the rotation speed of the first electric motor. An electric construction machine characterized by comprising monitoring and control means. A prime mover, a hydraulic pump driven by the prime mover to supply pressure oil to the actuator, a first electric motor driven by the drive of the prime mover, a revolving body, a second electric motor for driving the revolving body, An electric storage device connected to the first electric motor and the second electric motor, a first inverter for driving the first electric motor, a second inverter for driving the second electric motor, and driving the swivel body In an electric construction machine provided with an operation lever device for turning to command,
Insulation resistance deterioration detecting means for detecting deterioration of an insulation resistance between an electric system constituted by the first electric motor, the second electric motor, the first inverter, the second inverter, and the power storage device and a vehicle body. When,
A controller for controlling the rotational speeds of the first electric motor and the second electric motor by outputting torque increase / decrease commands to the first inverter and the second inverter, respectively.
When the insulation resistance deterioration detecting means detects the deterioration of the insulation resistance of the electric system, the control device notifies the operator of the deterioration of the insulation resistance of the electric system and reduces the rotational speed or output of the prime mover. An electric construction machine comprising a monitoring control means. A prime mover, a hydraulic pump that is driven by the prime mover and supplies pressure oil to the actuator, a revolving body, a hydraulic motor for driving the revolving body that is driven by the pressure oil supplied from the hydraulic pump, and A first electric motor driven by the drive; a second electric motor for driving the revolving structure; an electric storage device connected to the first electric motor and the second electric motor; and a first electric motor for driving the first electric motor. 1, an electric construction machine including a second inverter for driving the second electric motor, and an operation lever device for turning for commanding driving of the turning body.
Insulation resistance deterioration detecting means for detecting deterioration of an insulation resistance between an electric system constituted by the first electric motor, the second electric motor, the first inverter, the second inverter, and the power storage device and a vehicle body. When,
When the operation lever device for turning is operated, both the second electric motor and the hydraulic motor are driven, and the turning body is driven by the total torque of the second electric motor and the hydraulic motor. Switching between a hydraulic / electric combined swing mode and a hydraulic single swing mode in which only the hydraulic motor is driven when the swing operating lever device is operated, and the swing body is driven with torque of only the hydraulic motor. And a control device for performing
The control device includes control switching means for switching to the hydraulic single swing mode when the insulation resistance deterioration detection means detects deterioration of the insulation resistance of the electric system, and in the hydraulic single swing mode, An electric construction machine characterized by comprising monitoring control means for notifying deterioration of insulation resistance and reducing the rotational speed or output of the prime mover. In the electric construction machine according to any one of claims 1 to 3,
The control device includes bus voltage lowering means for lowering the voltage of the bus in the electric system than before detection when the insulation resistance deterioration detecting means detects the insulation resistance deterioration of the electric system. Electric construction machine. The electric construction machine according to claim 4,
Further comprising means for disconnecting an electrical circuit from the electric system of the electricity storage device,
The control apparatus includes a processing sequence for disconnecting the power storage device from the electric system by the disconnection unit after the bus voltage in the electric system is decreased by the bus voltage lowering unit. Construction machine. The electric construction machine according to claim 3,
The control device includes a processing sequence that involves opening / closing a circuit opening / closing means or a switching element in the electric system in order to identify an insulation resistance deterioration portion after switching to the hydraulic single swing mode. Electric construction machine. In the electric construction machine according to any one of claims 1 to 3,
The control device includes a first processing sequence for storing that the machine has been stopped by the monitoring control means when the insulation resistance deterioration detecting means detects deterioration of the insulation resistance of the electric system, and restarting after the machine is stopped. At the time, an electric construction machine characterized by comprising a second processing sequence for notifying an operator that the machine has been stopped last time due to deterioration of the insulation resistance of the electric system and limiting the rotational speed or output of the prime mover.

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