JP5487427B2 - Hybrid construction machine - Google Patents

Description

  The present invention relates to a hybrid construction machine, and more particularly to a hybrid construction machine having a rotating body such as a hydraulic excavator.

  In recent years, 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. (See 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. An actuator that swings and drives an upper swing body of a hydraulic excavator with respect to a lower traveling body (usually using a hydraulic motor) is frequently used, and frequently starts and stops and accelerates and decelerates 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.

  In addition, there has been proposed a construction machine in which both a hydraulic motor and an electric motor are mounted and a revolving body is driven by a total torque (Patent Document 2 and Patent Document 3).

  Patent Document 2 discloses an energy regeneration device for a hydraulic construction machine in which an electric motor is directly connected to a rotating body driving hydraulic motor, and a controller commands an output torque to the electric motor according to an operation amount of an operation lever. At the time of deceleration (braking), the electric motor regenerates the kinetic energy of the revolving structure and stores it in the battery as electric energy.

  In Patent Document 3, a temperature sensor is installed in an electric motor, an inverter, and a power storage device, and when an individual temperature is detected and a preset temperature is exceeded, the value of a torque command for the electric motor is reduced to perform electric operation. There is disclosed a hybrid construction machine that suppresses heat generation of devices and maintains a required output of the machine by increasing a torque command to the hydraulic motor for a decrease in the output of the electric motor.

  Both of the prior arts in Patent Documents 2 and 3 can be operated without an uncomfortable feeling even for an operator accustomed to a conventional hydraulic actuator-driven construction machine by using both an electric motor and a hydraulic motor as a turning drive actuator. Energy saving is achieved with a simple and practical configuration.

JP 2001-16704 A JP 2004-124381 A JP 2009-52339 A

  In the hybrid hydraulic excavator described in Patent Document 1, the kinetic energy of the revolving body during deceleration (during braking) is regenerated as electric energy by the electric motor, which is effective from the viewpoint of energy saving.

However, since the electric motor has characteristics different from those of the hydraulic motor, the following problems occur when the electric motor is used to drive the revolving structure of the construction machine.
(1) Hunting (especially in the low speed range, in a stopped state) due to speed feedback control failure of the electric motor.
(2) Operational discomfort due to differences in characteristics with the hydraulic motor.
(3) If an electric motor that guarantees an output equivalent to a hydraulic motor is used, the outer shape becomes too large, or the cost becomes extremely high.

  The hybrid hydraulic excavators described in Patent Documents 2 and 3 are equipped with both a hydraulic motor and an electric motor, and solve the above problems by driving the swivel body with a total torque, and are accustomed to conventional hydraulic actuator-driven construction machines. In addition, the operator can operate the system without a sense of incongruity, and energy saving is achieved with a simple and practical configuration.

  Further, in the hybrid hydraulic excavator described in Patent Document 3, when the temperature of the electric motor, inverter, and power storage device is detected and the set temperature is exceeded, the driving torque of the electric motor is suppressed in order to suppress the heat generation of the electric devices. And the drive torque of the hydraulic motor is increased. As a result, the overall torque for driving the revolving structure can be maintained, so that the operator can perform the driving operation with peace of mind.

  By the way, in the hybrid hydraulic excavator described above, when it is necessary to drive the swivel body only with the hydraulic motor, the electric motor is forcibly rotated without outputting torque. In such a state, in the case of a permanent magnet type electric motor using a permanent magnet for the rotor portion, when the rotor portion is rotated, an induced voltage is generated in the electric motor terminal portion due to the power generation action.

  In the case of a hybrid hydraulic excavator provided with an assist power generation motor that charges and discharges an electric storage device, an induced voltage is generated at the terminal portion of the assist power generation motor that is rotated by the prime mover.

  When a construction machine is operated in such a state and an electric system such as an electric motor, an inverter, or a power storage device has failed, the above-described induced voltage is short-circuited by the failure location, and an unexpected short-circuit current is generated. May occur. As a result, for example, an element such as an IGBT constituting the inverter may be broken, or a part of the electric system may be overheated to deteriorate the performance.

  The present invention has been made on the basis of the above-described matters, and the object of the present invention is in a hybrid construction machine that uses an electric motor to drive a revolving structure, and an electric system such as an electric motor, an inverter, and a power storage device breaks down. It is an object of the present invention to provide a hybrid construction machine capable of preventing an unexpected accident that occurs from an electric system even when a situation occurs in which a rotating body is driven by a motor alone.

  In order to achieve the above object, a first invention provides a prime mover, a hydraulic pump driven by the prime mover, a turning body, an electric motor for driving the turning body, and the hydraulic pump driven by the hydraulic pump. A hydraulic motor for driving the swinging body, an electricity storage device connected to the electric motor, a first inverter that transfers power between the electricity storage device and the electric motor, and a swing that commands driving of the swinging body In a hybrid construction machine including an operation lever device for a temperature, a temperature sensor that detects an internal temperature of the electric motor, a temperature sensor that detects an internal temperature of the first inverter, and the operation lever device for turning The oil that drives both the electric motor and the hydraulic motor when the engine is operated, and drives the swivel body with the total torque of the electric motor and the hydraulic motor. Switching between an electric combined turning mode and a hydraulic single turning mode in which only the hydraulic motor is driven when the turning operation lever device is operated, and the turning body is driven with the torque of only the hydraulic motor. A control device that performs the control to switch to the hydraulic single swing mode when a failure or abnormality occurs in a first electric system that includes the electric motor, the power storage device, and the first inverter. In the switching means and in the hydraulic single swing mode, the rotational speed of the prime mover is set to limit the rotational speed of the hydraulic motor so that the detection value from each temperature sensor is within a preset limit value. It is assumed that a supervisory control unit for limiting control is provided.

  In order to achieve the above object, the second invention provides a prime mover, a hydraulic pump driven by the prime mover, a turning body, an electric motor for driving the turning body, and the hydraulic pump driven by the hydraulic pump. A hydraulic motor for driving the swinging body, an electricity storage device connected to the electric motor, a first inverter that transfers power between the electricity storage device and the electric motor, and a swing that commands driving of the swinging body In a hybrid construction machine provided with an operation lever device for an electric current, both a current sensor for detecting an output current of the electric motor and both the electric motor and the hydraulic motor when the operation lever device for turning is operated And a hydraulic / electric combined swing mode in which the swing body is driven by the sum of torques of the electric motor and the hydraulic motor, and the operation lever device for the swing operates. A control device that drives only the hydraulic motor and switches to a hydraulic single swing mode that drives the swivel body with the torque of only the hydraulic motor when the motor is operated, and the control device includes the electric motor And a control switching means for switching to the hydraulic single swing mode when a failure or abnormality occurs in a first electric system comprising the power storage device and the first inverter, and in the hydraulic single swing mode, from the current sensor And a monitoring control means for stopping the prime mover in order to stop the hydraulic motor when the detected value exceeds a preset limit value.

  In order to achieve the above object, a third invention provides a prime mover, a hydraulic pump driven by the prime mover, a turning body, an electric motor for driving the turning body, and the hydraulic pump driven by the hydraulic pump. A hydraulic motor for driving the revolving structure, an assist power generation motor driven by the prime mover, a power storage device connected to the electric motor and the assist power generation motor, and power transfer between the power storage device and the electric motor A hybrid type comprising: a first inverter that performs power supply; a second inverter that performs power transfer between the power storage device and the assist power generation motor; and a turning operation lever device that commands driving of the swivel body In a construction machine, a temperature sensor that detects an internal temperature of the assist power generation motor, and a temperature sensor that detects an internal temperature of the second inverter; When the operation lever device for turning is operated, both the electric motor and the hydraulic motor are driven, and the swivel body is driven by the total torque of the electric motor and the hydraulic motor. A control device for switching between a mode and a hydraulic single swing mode in which only the hydraulic motor is driven when the swing operation lever device is operated, and the swing body is driven with torque of only the hydraulic motor And the control device switches to the hydraulic single swing mode when a failure or abnormality occurs in a second electric system including the assist power generation motor, the power storage device, and the second inverter. And in the hydraulic single swing mode, the prime mover of the prime mover is set so that the detected value from each temperature sensor is within a preset limit value. And that a monitoring control means for limiting controls rotation number.

  In order to achieve the above object, a fourth invention provides a prime mover, a hydraulic pump driven by the prime mover, a turning body, an electric motor for driving the turning body, and the hydraulic pump driven by the hydraulic pump. A hydraulic motor for driving the revolving structure, an assist power generation motor driven by the prime mover, a power storage device connected to the electric motor and the assist power generation motor, and power transfer between the power storage device and the electric motor A hybrid type comprising: a first inverter that performs power supply; a second inverter that performs power transfer between the power storage device and the assist power generation motor; and a turning operation lever device that commands driving of the swivel body In a construction machine, the current sensor that detects the output current of the assist generator motor and the electric motor when the turning operation lever device is operated. A hydraulic / electric combined swing mode in which both the motor and the hydraulic motor are driven to drive the swing body with the sum of torques of the electric motor and the hydraulic motor, and the operation lever device for the swing is operated. And a control device that switches only to the hydraulic single swing mode in which only the hydraulic motor is driven and the swing body is driven with torque of only the hydraulic motor, and the control device includes the assist generator motor and Control switching means for switching to the hydraulic single swing mode when a failure or abnormality occurs in a second electric system including the power storage device and the second inverter, and in the hydraulic single swing mode, from the current sensor It is assumed that the apparatus includes a monitoring control unit that stops the prime mover when the detected value exceeds a preset limit value.

According to a fifth invention, in the first or second invention, a first cable having one end connected to the electric motor and a connector provided on the other end to which the first inverter is connected; which is connected with the first inverter first connector of the cable and a first connector detachable when said failure or abnormality occurs in the first electric system, said from said first connector first cable The connector is removed.

Furthermore, a sixth invention is the third or fourth invention, wherein the first cable has one end connected to the electric motor and a connector at the other end to which the first inverter is connected, and the assist. A second cable having one end connected to the generator motor and a connector at the other end to which the second inverter is connected, and a second cable connected to the first inverter and detachable from the connector of the first cable. A first connector including a first connector and a second connector connected to the second inverter and detachable from the connector of the second cable, the first electric motor including the electric motor, the power storage device, and the first inverter; If the failure or abnormality occurs in the system, the disconnect the connector of the first cable from the first connector, or failure or abnormality occurs in the second electric system Case is characterized by removing the connector of the second cable from the second connector.

According to a seventh aspect, in the fifth aspect, the first inverter includes a first dummy connector provided in the first inverter, the first dummy connector having no internal connection line and detachable from the connector of the first cable. If the failure or abnormality occurs in the first electric system is characterized by mounting the connector of the first cable to the first dummy connector.

Further, according to an eighth invention, in the sixth invention, a first dummy connector provided in the first inverter and having no internal connection line, wherein the connector of the first cable can be attached and detached, and the second And a second dummy connector to which the connector of the second cable can be attached and detached without having an internal connection line. When a failure or abnormality occurs in the first electric system, the first the first cable connector is attached to the first dummy connector or, if the failure or the abnormality in the second electric system occurs, mounting the connector of the second cable to the second dummy connector It is characterized by.

In a ninth aspect based on any one of the sixth aspect or the eighth aspect, the monitoring control means is configured so that both the connector of the first cable and the connector of the second cable are both the other connectors. Even if it is not mounted, the internal temperature and the rotational speed of the electric motor are monitored.
Furthermore, the tenth invention, in any one of the fifth or seventh invention, the monitoring control means, the connector of the first cable, even if with other any connector not mounted, The internal temperature and rotation speed of the electric motor are monitored.

  According to the present invention, in a hybrid construction machine that uses an electric motor to drive a revolving structure, an electric system such as an electric motor, an inverter, and a power storage device fails, and the revolving structure is driven by a hydraulic motor alone. However, since the temperature and current of the electric system can be monitored, it is possible to prevent unexpected accidents that occur from the electric system. In addition, even if the electric system fails, as long as the temperature and current of the electric system to be monitored are within a certain range, the swivel body can continue to be driven by the hydraulic motor alone, so the operator can work for a long time with peace of mind. it can. As a result, the operating efficiency of the hybrid construction machine can be improved.

1 is a side view showing a first embodiment of a hybrid construction machine of the present invention. 1 is a system configuration diagram of an electric / hydraulic device that constitutes a first embodiment of a hybrid construction machine of the present invention. FIG. 1 is a system configuration and control block diagram of a first embodiment of a hybrid construction machine of the present invention. 1 is a hydraulic circuit diagram showing a configuration of a turning hydraulic system in a first embodiment of a hybrid construction machine of the present invention. It is a characteristic view which shows the torque control characteristic of the hydraulic pump in 1st Embodiment of the hybrid type 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 1st Embodiment of the hybrid type construction machine of this invention. It is a characteristic view which shows the meter-out opening area characteristic of the spool for rotation in 1st Embodiment of the hybrid type construction machine of this invention. FIG. 5 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 the first embodiment of the hybrid construction machine of the present invention. A hydraulic pilot signal (pilot pressure), meter-in pressure (M / I pressure), assist torque of a swing electric motor at the time of swing drive in the hydraulic / electric combined swing mode in the first embodiment of the hybrid 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 (operation pilot pressure) in 1st Embodiment of the hybrid type 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 first embodiment of the hybrid 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 1st Embodiment of the hybrid type construction machine of this invention. FIG. 3 is a flowchart showing an abnormality processing sequence (switching from a hydraulic / electric combined swing mode to a hydraulic single swing mode) of the hydraulic excavator according to the first embodiment of the hybrid construction machine of the present invention. It is a flowchart figure which shows the abnormality processing sequence (returning to the hydraulic / electric combined swing mode) of the hydraulic excavator of the first embodiment of the hybrid construction machine of the present invention. It is a flowchart figure which shows the monitoring sequence (the 1) from the malfunction of the hydraulic shovel of 1st Embodiment of the hybrid type construction machine of this invention, and an abnormal condition. It is a characteristic view which shows an example of the relationship between the rotation speed of the hydraulic motor applied to the monitoring sequence shown in FIG. 15, and a limit temperature. It is a flowchart figure which shows the monitoring sequence (the 2) from failure of the hydraulic shovel of 1st Embodiment of the hybrid type construction machine of this invention, and an abnormal condition. It is a flowchart figure which shows the monitoring sequence (the 3) from the failure of the hydraulic shovel of 1st Embodiment of the hybrid type construction machine of this invention, and an abnormal condition. It is a flowchart figure which shows the monitoring sequence (the 4) from failure of the hydraulic shovel of 1st Embodiment of the hybrid type construction machine of this invention, and an abnormal condition. It is a system block diagram of the electric / hydraulic apparatus which comprises 2nd Embodiment of the hybrid type construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 3rd Embodiment of the hybrid type construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 4th Embodiment of the hybrid type construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 5th Embodiment of the hybrid type construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 6th Embodiment of the hybrid type construction machine of this invention. It is a system block diagram of the electric / hydraulic apparatus which comprises 7th Embodiment of the hybrid type 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 a hybrid 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 hybrid construction machine according to the present invention. FIG. 3 is a system configuration and control block diagram of the first embodiment of the hybrid construction machine of the present invention.

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

  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, an engine 22 as a prime mover provided on the swing frame 21, an assist power generation motor 23 driven by the engine 22, a swing electric motor 25, a swing hydraulic motor 27, and an assist. The electric double layer capacitor 24 connected to the generator motor 23 and the swing electric motor 25, and a speed 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 is transmitted through the speed reduction mechanism 26, and the turning body 20 (the turning frame 21) is driven to turn with respect to the traveling body 10 by the driving force.

  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 the engine 22.

  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 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. 3). Further, the control valve 42 responds to an operation command (hydraulic pilot signal) from an operation lever device 73 (see FIG. 3) 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 rotation shafts of the swing electric motor 25 and the swing hydraulic motor 27 are coupled to 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.

  A current sensor 65 for detecting a current I1 flowing through the cable and an inverter 53 for driving the assist power generation motor 23 are connected to the cable for transferring power between the inverter 52 that drives the swing electric motor 25 and the swing electric motor 25. And the assist power generation motor 23 are each provided with a current sensor 66 for detecting a current I2 flowing through the cable. Each of these sensors 65 and 66 is electrically connected to the controller 80.

  In addition, a temperature sensor Se1 that detects the temperature t1 inside the swing electric motor 25, and a temperature sensor Se2 that detects the temperature t2 inside the inverter 52 that drives the swing electric motor 25. Are provided respectively. Inside the assist generator motor 23 is a temperature sensor Se3 that detects the temperature t3 inside, and inside the inverter 53 that drives the assist generator motor 23 is a temperature sensor Se4 that detects the temperature t4 inside. Each is provided. Each of these sensors Se1, Se2, Se3, Se4 is electrically connected to the controller 80.

  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; Control of hydraulic / electric combined swing mode using the swing hydraulic motor 27 and the swing electric motor 25, swing control of each mode, abnormality monitoring of the electric system, energy management, and the like is performed.

Next, devices, control means, control signals and the like necessary for performing turning control according to the present invention will be described in more detail with reference to FIG.
The hydraulic excavator includes an ignition key 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 has a 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 for driving the electric motor 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. As a result, the turning electric motor 25 is driven. 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. As a result, the turning spool 61 (see FIG. 4) is switched from the neutral position to the A position or the C position, the oil discharged from the hydraulic pump 41 is supplied 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 receives the voltage / current / temperature detection signals of the capacitor 24 described above, and generates power or outputs an assist command ED to the assist power generation motor 23. Control is performed to keep the amount within a predetermined range.

  If a failure, abnormality or warning state occurs in the electric system such as the power control unit 55, the swing electric motor 25, or the capacitor 24, or if the charged amount of the capacitor 24 is out of a predetermined range, abnormality monitoring / abnormal processing The 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. 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.

  Further, in the monitoring sequence from the hydraulic single swing control mode due to a failure or abnormal state described later, the rotational speed control is performed so that the rotational speed of the swing hydraulic motor 27 does not exceed a preset limit value. The rotation speed of the swing hydraulic motor 27 is detected from, for example, a resolver of the swing electric motor 25 that is rotated by the rotation of the swing body.

  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. 4 is a hydraulic circuit diagram showing the configuration of the turning hydraulic system in the first embodiment of the hybrid construction machine of the present invention. 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.
The control valve 42 in FIG. 3 includes a valve component called a spool for each actuator, and the corresponding spool is displaced according to a command (hydraulic pilot signal) from the operation lever devices 72 and 73 to change the opening area. The flow rate of the pressure oil passing through the oil passage changes. The turning hydraulic system shown in FIG. 4 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.

  4, 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. 3 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 setting of the torque control unit 64a so that the maximum output torque of the hydraulic pump 41 is reduced by the amount of torque output by 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 setting of the controller 64a is performed. Is a 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. 4, the turning spool 61 has three positions of 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 the pressure (hydraulic pilot signal) corresponding to the lever operation amount and switches to the A position, the pressure oil from the hydraulic pump 41 passes to the right side of the turning hydraulic motor 27 through the meter-in throttle at the A position. 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. 6 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. 7 shows the meter-out opening area characteristics. FIG.

  In FIG. 6, a solid line MI is a meter-in opening area characteristic, and a solid line MB is a bleed-off opening area characteristic, both of which are in the present embodiment. The two-dot chain line MB0 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. 7, a solid line MO is a meter-out opening area characteristic of the present embodiment, and a two-dot chain line MO0 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. 8 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 a dotted line MBC characteristic determined only by the bleed-off opening area characteristic MB of FIG. 6 (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 combined 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. 9 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, as shown by the dotted line MBC in FIG. 8, the combined opening area characteristic of the meter-in throttle of the swing spool 61 and the center bypass cut valve 63 is the bleed-off opening area 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. 8, 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 of 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 excavator 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. 10 is a characteristic diagram showing the meter-out opening area characteristic of the turning spool 61 with respect to the hydraulic pilot signal (operating pilot pressure).

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

  When the hydraulic single swing mode is selected, as described above, the electric / hydraulic converter 75d of FIG. 3 (electric / hydraulic converters 75dL, 75dR of FIG. 4) 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 correcting the hydraulic pilot signal, the meter-out opening area characteristic with respect to 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 the conventional hydraulic excavator.

  FIG. 11 shows a hydraulic pilot signal (pilot pressure), meter-out pressure (M / O pressure), assist torque of the swing electric motor 25, 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. 7 as indicated by the dotted line MOC in FIG. Accordingly, as shown in FIG. 7, the meter-out pressure (M / O pressure) is lower in this 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. 11, 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 turning mode is selected, the meter-out opening area characteristic for the hydraulic pilot signal of the turning spool 61 is 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. Therefore, the meter-out pressure generated by the turning spool 61 rises to the solid-line meter-out pressure obtained with the conventional hydraulic excavator shown in FIG. 11, and is derived from the meter-out pressure generated by the turning spool 61. 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. 12 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. 4), 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. 4), the electric / hydraulic converter 75b controls 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, so that the operation lever of the operation lever device 72 is returned to the neutral position. Furthermore, 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 valve. The total value of the brake torque derived from the back pressure generated by 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 equivalent to that of the conventional hydraulic excavator. It becomes possible to have a deceleration feeling.

  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 FIGS. 13 and 14.
FIG. 13 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 a signal (hereinafter referred to as an error signal) notifying that when an electric system such as the electric motor 25, the capacitor 24, the power control unit 55 or the like has a failure, abnormality or warning state. It is determined whether it has been notified (step S100), and if an error signal is notified, it is further determined whether it is an error signal that requires an emergency response (step S110). 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 S120), the operation of the revolving structure 20 and the timing when the operation lever device 72 for revolving is not input, or the travel, front operation and their operation lever devices 73 other than the revolving structure 20. Is switched at the time of idling or the like when no operation is performed (step S130). For abnormalities that may damage the system, such as an inverter overcurrent abnormality, or that may lead to a serious failure or disaster, the electric system is immediately stopped and switched to the hydraulic single swing mode even during operation (step S110). → S130).

  FIG. 14 shows a return sequence from the hydraulic single turning control mode to the hydraulic / electric combined turning mode by the abnormality monitoring / abnormality processing control block 81 of the controller 80.

  When the abnormality monitoring / abnormality processing control block 81 is switched to the hydraulic single turn control mode by the process shown in the flowchart of FIG. 13, first, a predetermined error signal elimination process is performed during the hydraulic single turn control (step S150). Next, it is determined whether or not the error signal has been eliminated (step S160), and if the error signal has been eliminated by the error signal elimination processing or naturally, it is further judged whether or not the mode can be switched (step S170). Then, switching to the hydraulic / electric combined swing mode (return operation) is performed at the timing when the turning operation and operation are not performed, or at the time of idling when the operation including the front is not performed at all (step S180).

  Next, a monitoring sequence from the hydraulic single swing control mode according to the failure and abnormal state of the hydraulic excavator according to the first embodiment of the hybrid construction machine of the present invention will be described with reference to FIGS. FIG. 15 is a flowchart showing a monitoring sequence (part 1) from the failure and abnormal state of the hydraulic excavator of the first embodiment of the hybrid construction machine of the present invention, and FIG. 16 is applied to the monitoring sequence shown in FIG. It is a characteristic view which shows an example of the relationship between the rotation speed of a hydraulic motor, and limit temperature.

  FIG. 15 shows a monitoring sequence after switching 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 of FIG.

  First, in step (S201) of FIG. 15, the temperature signals t1 and t2 and the rotation speed signal r of the swing hydraulic motor 27 are read. Specifically, the internal temperature signal t1 of the swing electric motor 25 detected from the temperature sensors Se1 and Se2, the internal temperature signal t2 of the inverter 52 that drives the swing electric motor 25, and the swing rotated by the rotation of the swing body 20. The rotation speed r detected from, for example, a resolver of the electric motor 27 is read.

  In the next step (S202), it is checked whether the temperature signal captured in step (S201) is high. Specifically, the limit value characteristics of the temperature signals t1 and t2 with respect to the rotation speed r of the swing hydraulic motor 27 set and stored in advance are compared with the detection signals read in step (S201). FIG. 16 shows an example of limit value characteristics of the rotational speed r of the swing hydraulic motor 27 and the temperature signals t1 and t2. In FIG. 16, ta is the limit value temperature at the maximum rotation speed rm of the swing hydraulic motor 27, tb is the required stop temperature of the swing hydraulic motor 27, and ra is the maximum allowable speed at the stop required temperature tb of the swing hydraulic motor 27. Each is shown. A line segment AB indicates the limit value characteristic of the rotational speed control.

For example, in FIG. 16, when the rotational speed of the swing hydraulic motor 27 is r ₀ , in this step (S202), if the temperature signals t1 and t2 are lower than t ₀ on the limit value characteristic, it is determined as NO, and if it is higher. It is determined YES.

  If it is determined NO in this step (S202), the process returns to the previous step (S201) and is repeated.

  If YES is determined in the step (S202), the process proceeds to a step (S203), and the rotational speed limit control of the engine 22 is performed in order to decrease the rotational speed of the turning hydraulic motor 27. Specifically, control is performed to lower the rotational speed of the engine 22 in order to lower the rotational speed r of the swing hydraulic motor 27 until the temperature signals t1 and t2 become lower than the temperature on the limit value characteristic described above. At this time, the operator is notified by a display on the monitor or by voice that the temperature signals t1 and t2 have exceeded the limit characteristic values.

  Next, in step (S204), as in step (S201), the temperature signals t1 and t2 and the rotation speed signal r of the swing hydraulic motor 27 are read.

  In the next step (S205), it is checked whether the temperature signal acquired in step (S204) is abnormally high. Specifically, the temperature signals t1 and t2 read in step (S204) are compared with the required stop temperature tb of the swing hydraulic motor 27.

  If it is determined NO in this step (S205), the process returns to the previous step (S201) and is repeated.

  If YES is determined in the step (S205), the process proceeds to a step (S206) to notify the operator that the temperature signals t1 and t2 have exceeded the required stop temperature by display or sound on a monitor or the like.

  Next, in step (S207), it is checked whether it is time to stop the swing hydraulic motor 27 and the engine 22. Specifically, it is determined whether or not the turning body 20 can stop turning, and that the turning hydraulic motor does not rotate at high speed. In addition, it is determined whether or not there is a problem with the vehicle body when the engine 22 is stopped.

  If it is determined NO in this step (S207), the process returns to the previous step (S204) and is repeated.

  If YES is determined in the step (S207), the engine 22 is controlled to be stopped in order to stop the swing hydraulic motor 27. At this time, when the temperature signals t1 and t2 exceed the required stop temperature value, the operator is notified that the engine 22 is stopped by display or sound on a monitor or the like.

  FIG. 17 shows a monitoring sequence (part 2) from the failure and abnormal state of the hydraulic excavator of the first embodiment of the hybrid construction machine of the present invention. The monitoring sequence (part 1) described with reference to FIG. 15 monitors the internal temperature signal t1 of the swing electric motor 25 and the internal temperature signal t2 of the inverter 52 that drives the swing electric motor 25, so that the hydraulic single swing control mode is performed. The monitoring sequence (part 2) is a current provided in a cable or the like for power transfer between the inverter 52 that drives the swing electric motor 25 and the swing electric motor 25. The current I1 detected by the sensor 65 is monitored.

  First, in step (S301) of FIG. 17, the current signal I1 and the rotation speed signal r of the swing hydraulic motor 27 are read. Specifically, the current I1 between the inverter 52 that drives the swing electric motor 25 detected by the current sensor 65 and the swing electric motor 25 is read.

  In the next step (S302), it is checked whether the current signal acquired in step (S301) is not abnormally high. Specifically, the current signal I1 read in step (S301) is compared with the preset required current value It for stopping the swing hydraulic motor 27.

  If it is determined NO in this step (S302), the process returns to the previous step (S301) and the calculation is repeated.

  If YES is determined in the step (S302), the process proceeds to a step (S303) to notify the operator that the current signal I1 has exceeded the required stop current value by display or sound on a monitor or the like.

  Next, in step (S304), it is checked whether it is time to stop the engine 22 in order to stop the swing hydraulic motor 27. Specifically, it is determined whether or not the turning body 20 can stop turning, and that the turning hydraulic motor does not rotate at high speed.

  If it is determined NO in this step (S304), the process returns to the previous step (S301) and is repeated.

  If YES is determined in the step (S304), the engine 22 is controlled to be stopped in order to stop the swing hydraulic motor 27. At this time, when the current signal I1 exceeds the required stop current value, the operator is informed that the engine 22 is stopped by display or sound such as a monitor.

  FIG. 18 shows a monitoring sequence (part 3) from the failure and abnormal state of the hydraulic excavator of the first embodiment of the hybrid construction machine of the present invention. The monitoring sequence (part 1) described with reference to FIG. 15 monitors the internal temperature signal t1 of the swing electric motor 25 and the internal temperature signal t2 of the inverter 52 that drives the swing electric motor 25, so that the hydraulic single swing control mode is performed. In the monitoring sequence (part 3), the internal temperature signal t3 of the assist power generation motor 23 and the internal temperature signal t4 of the inverter 53 that drives the assist power generation motor 23 are monitored. Thus, an unexpected accident of the electric system driven by the prime mover 22 is prevented. The monitoring sequence (No. 3) starts from a state where the prime mover can be normally operated, and stops the prime mover 22 as necessary.

  First, in step (S401) of FIG. 18, the temperature signals t3 and t4 and the rotation speed signal r1 of the assist power generation motor 23 are read. Specifically, the internal temperature signal t3 of the assist power generation motor 23 detected from the temperature sensors Se3 and Se4, the internal temperature signal t4 of the inverter 53 that drives the assist power generation motor 23, and the assist power generation motor 23 that is rotated by the engine 22. For example, the rotational speed r1 detected from a resolver or the like is read.

  In the next step (S402), it is checked whether the temperature signal captured in step (S401) is high. Specifically, the temperature signal t3 and t4 limit value characteristics with respect to the rotational speed r1 of the assist generator motor 23 set and stored in advance are compared with the detection signals read in step (S401). Limit value characteristics similar to those in FIG. 16 are stored.

  If NO is determined in this step (S402), the process returns to the previous step (S401) and the calculation is repeated.

  If YES is determined in the step (S402), the process proceeds to a step (S403), and the rotational speed limitation control of the assist generator motor 23 is performed. Specifically, in order to reduce the rotational speed r1 of the assist power generation motor 23 until the temperature signals t3 and t4 become lower than the temperature on the limit value characteristic described above, control for decreasing the rotational speed of the engine 22 is performed. At this time, the operator is notified by a display or sound on the monitor or the like that the temperature signals t3 and t4 have exceeded the limit characteristic value.

  Next, in step (S404), as in step (S401), the temperature signals t3 and t4 and the rotation speed signal r1 of the assist generator motor 23 are read.

  In the next step (S405), it is checked whether the temperature signal captured in step (S404) is not abnormally high. Specifically, the temperature signals t3 and t4 read in step (S404) are compared with the stop necessary temperature tb1 of the assist power generation motor 23.

  If it is determined NO in this step (S405), the process returns to the previous step (S401) and the calculation is repeated.

  If YES is determined in the step (S405), the process proceeds to a step (S406) to notify the operator that the temperature signals t3 and t4 have exceeded the required stop temperature by display or sound on a monitor or the like.

  Next, in step (S407), it is checked whether it is time to stop the engine 22 or not. Specifically, it is determined whether or not the engine 22 can be stopped and that the working environment of the construction machine is safe.

  If NO is determined in this step (S407), the process returns to the previous step (S404) and the calculation is repeated.

  If YES is determined in the step (S407), the engine 22 is controlled to be stopped in order to stop the assist power generation motor 23. At this time, when the temperature signals t3 and t4 exceed the required stop temperature value, the operator is informed that the engine 22 is stopped by display or sound on a monitor or the like.

  FIG. 19 shows a monitoring sequence (part 4) from the failure and abnormal state of the hydraulic excavator of the first embodiment of the hybrid construction machine of the present invention. The monitoring sequence (part 3) described in FIG. 18 is driven by the prime mover 22 by monitoring the internal temperature signal t3 of the assist generator motor 23 and the internal temperature signal t4 of the inverter 53 that drives the assist generator motor 23. However, the monitoring sequence (part 4) is a current provided in a cable or the like for power transfer between the inverter 53 that drives the assist power generation motor 23 and the assist power generation motor 23. The current I2 detected by the sensor 66 is monitored.

  First, in step (S501) of FIG. 19, the current signal I2 and the rotation speed signal r1 of the assist generator motor 23 are read. Specifically, the current I2 between the inverter 53 that drives the assist power generation motor 23 detected from the current sensor 66 and the assist power generation motor 23 is read.

  In the next step (S502), it is checked whether the current signal captured in step (S501) is not abnormally high. Specifically, the current signal I2 read in step (S501) is compared with a preset required current value It2 for stopping the assist generator motor 23.

  If it is determined NO in this step (S502), the process returns to the previous step (S501) and the calculation is repeated.

  If YES is determined in the step (S502), the process proceeds to a step (S503) to notify the operator that the current signal I2 has exceeded the required stop current value by display or sound on a monitor or the like.

  Next, in step (S504), it is checked whether it is time to stop the engine 22 or not. Specifically, it is determined whether or not the engine 22 can be stopped and that the working environment of the construction machine is safe.

  If NO is determined in this step (S504), the process returns to the previous step (S501) and the calculation is repeated.

  If YES is determined in the step (S504), the engine 22 is controlled to be stopped in order to stop the assist power generation motor 23. At this time, when the current signal I2 exceeds the required stop current value, the operator is notified that the engine 22 is stopped by display or sound on a monitor or the like.

  According to the first embodiment of the present invention described above, in the hybrid construction machine that uses the electric motor to drive the swing body 20, the electric system such as the swing electric motor 25, the inverter 52, and the power storage device 24 fails. Even when the swing body 20 is driven by the swing hydraulic motor 27 alone, the temperature and current of the electric system can be monitored, so that an unexpected accident that occurs from the electric system can be prevented. Further, even after the electric system has failed, if the temperature and current of the electric system to be monitored are within a certain range, the swinging body 20 can be continuously driven by the swing hydraulic motor 27 alone, so that the operator can feel safe for a long time. Can perform work. As a result, the operating efficiency of the hybrid construction machine can be improved.

Next, a hydraulic excavator according to a second embodiment of the hybrid construction machine of the present invention will be described with reference to FIG. FIG. 20 is a system configuration diagram of the electric / hydraulic equipment constituting the second embodiment of the hybrid construction machine of the present invention. In FIG. 20, the same reference numerals as those shown in FIGS. 1 to 19 are the same or corresponding parts, and the description thereof is omitted.
The purpose of the present embodiment is to isolate the failure location when any abnormality or failure occurs in the electric system. Specifically, in the power control unit 55 of the first embodiment, a socket-type connector 93 to which the output cable of the swing electric motor driving inverter 52 is connected and a socket-type dummy connector 95 that is not internally connected The plug-type connector 92 provided at the other end of the power cable 59 having one end connected to the swing electric motor 25 is normally connected to the socket-type connector 93.

  Similarly, in the power control unit 55 of the first embodiment, the socket type connector 91 to which the output cable of the assist power generation motor driving inverter 53 is connected and the socket type dummy connector 94 that is not internally connected are provided. The plug-type connector 90 provided at the other end of the power cable 60 having one end connected to the assist generator motor 23 is normally connected to the socket-type connector 91.

  In the present embodiment, for example, when any abnormality or failure occurs in the electric system, in particular, a short-circuit failure or the like occurs in a place other than the motor, the plug-type connector 90 for the assist power generation motor 23 is connected to the power control unit 55 side. It is removed from the socket-type connector 91 and connected to a dummy connector 94 for the assist generator motor 23. Similarly, for the swing electric motor 25, the plug-type connector 92 for the swing electric motor 25 is removed from the socket-type connector 93 on the power control unit 55 side and connected to the dummy connector 95 for the swing electric motor 25. As a result, the assist power generation motor 23, the swing electric motor 25, and the power control unit 55 can be completely separated from each other. Therefore, regeneration of the power generation energy of the assist power generation motor 23, the swing electric motor 25 does not occur.

  Since the dummy connectors 94 and 95 are provided with caps (not shown), the live parts of the socket type connectors 91 and 93 can be protected by changing the caps to the outside of the socket type connectors 91 and 93. In addition, a dustproof / waterproof function can be secured.

  Further, a plug-type connector 92 provided at the other end of the power cable 59 connected at one end to the swing electric motor 25 and a plug-type provided at the other end of the power cable 60 connected at one end to the assist power generation motor 23. Even if both the connector 90 and the other connector 90 are not attached, the monitoring control means in the first embodiment monitors the internal temperature and the rotational speed of the electric motors 25 and 27. It has a function.

  According to the second embodiment of the present invention described above, in the hybrid construction machine that uses the electric motor to drive the swing body 20, the electric system such as the swing electric motor 25, the inverter 52, and the power storage device 24 fails. Even when the swing body 20 is driven by the swing hydraulic motor 27 alone, the temperature and current of the electric system can be monitored and the electric motor and the inverter are electrically insulated. Can prevent accidents. In addition, even if the electric system fails, as long as the temperature and current of the electric system to be monitored are within a certain range, the swivel body can continue to be driven by the hydraulic motor alone, so the operator can work for a long time with peace of mind. it can. As a result, the operating efficiency of the hybrid construction machine can be improved.

  Next, a hydraulic excavator according to a third embodiment of the hybrid construction machine of the present invention will be described with reference to FIG. FIG. 21 is a system configuration diagram of the electric / hydraulic equipment constituting the third embodiment of the hybrid construction machine of the present invention. In FIG. 21, the same reference numerals as those shown in FIGS. 1 to 20 are the same or corresponding parts, and the description thereof is omitted.

  In the first embodiment shown in FIG. 2, the inverter control circuit is provided in a part of the controller 80. However, in the present embodiment, instead of the configuration, the inverter control circuit 52a, 53a is provided. In the first embodiment, the controller 80 performs various processes based on the detection signals from the temperature sensors Se1, Se2, and the current sensors 65, 66. In the present embodiment, the inverter control circuits 52a, 53a are used. In FIG.

  Next, a hydraulic excavator according to a fourth embodiment of the hybrid construction machine of the present invention will be described with reference to FIG. FIG. 22 is a system configuration diagram of the electric / hydraulic equipment constituting the fourth embodiment of the hybrid construction machine of the present invention. In FIG. 22, the same reference numerals as those shown in FIGS. 1 to 21 are the same or corresponding parts, and the description thereof is omitted.

  In the first embodiment shown in FIG. 2, the assist generator motor 23 connected to the drive shaft of the engine 22 is used. However, in this embodiment, instead of the configuration, the discharge oil of the hydraulic pump 41 is used. A hydraulic motor 101 to be driven and an electric motor 100 connected to a drive shaft of the hydraulic motor 101 are used. In addition to the electric double layer capacitor 24, any power storage device such as a lithium ion capacitor, a lithium ion battery, or a nickel metal hydride battery can be used as the power storage device. In the embodiment shown in FIG. The battery 103 is used.

  Next, a hydraulic excavator according to a fifth embodiment of the hybrid construction machine of the present invention will be described with reference to FIG. FIG. 23 is a system configuration diagram of the electric / hydraulic equipment constituting the fifth embodiment of the hybrid construction machine of the present invention. In FIG. 23, the same reference numerals as those shown in FIGS. 1 to 22 denote the same or corresponding parts, and the description thereof is omitted.

  In the present embodiment, in order to perform initial charging of the capacitor 24, the voltage is boosted by using the DC / DC converter 112 from the electrical system battery line including the alternator 110 and the electrical equipment battery 111. However, in this case, when surplus energy is generated in the capacitor 24, energy cannot be released freely to the electric system battery line. Therefore, the energy management control unit 82 keeps the charged amount of the capacitor constant to some extent only by acceleration / deceleration of the turning operation. It is necessary to control so that

  Next, hydraulic excavators according to sixth and seventh embodiments of the hybrid construction machine of the present invention will be described with reference to FIGS. 24 and 25. FIG. FIG. 24 is a system configuration diagram of an electric / hydraulic device constituting the sixth embodiment of the hybrid construction machine of the present invention, and FIG. 25 is an electric configuration constituting the seventh embodiment of the hybrid construction machine of the present invention. -It is a system block diagram of hydraulic equipment. In FIGS. 24 and 25, the same reference numerals as those shown in FIGS. 1 to 23 are the same or corresponding parts, and the description thereof is omitted.

  In the embodiments so far, the hydraulic excavator using the engine 22 as the prime mover has been shown, but there is no problem even if the present invention is applied to another prime mover, for example, a hydraulic excavator using an electric motor. In the embodiment shown in FIG. 24, a hydraulic excavator using an electric motor 120 driven by AC power from a commercial AC power supply 121, and in the embodiment shown in FIG. 25, the electric motor 120 driven by a large capacity battery 130. The system block diagram of the hydraulic excavator using is shown. In the embodiment shown in FIG. 24, as in the embodiment of FIG. 23, the voltage is boosted from the commercial AC power supply 121 using the DC / DC converter 122 in order to perform the initial charging of the capacitor 24.

  When applying the present invention to the hydraulic excavator using the electric motor 120 as the prime mover, it should be noted that if the electric power line and the power control unit are shared by the electric motor for turning and the electric motor for the prime mover, these failures occur. If this happens, there is a possibility that even the operation in the hydraulic single swing mode cannot be performed.

  In the embodiment shown in FIG. 24, the main electric motor 120 is a three-phase AC induction motor, and the electric motor for rotation 25 that is directly driven by the three-phase AC of the commercial power supply 121 and uses the energy stored in the capacitor 24 is: It is a separate power supply line. In the embodiment shown in FIG. 25, when the power control units 132 and 133 are separated for main and turning, and an abnormality such as a short circuit failure occurs in the turning electric motor 25 or turning power control unit 133, the turning electric unit By disconnecting with the interruption | blocking relay 134, it is set as the structure which can be operate | moved in hydraulic single rotation mode.

  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 swing electric motor 53 Inverter for assist generator motor 54 Smoothing capacitor 55 Power control unit 56 Main contactor 57 Main relay 58 Inrush current prevention circuit 65 Current sensor 80 Controller 81 Abnormality monitoring / abnormality processing control block 82 Energy management control block 83 Hydraulic / electric combined swing control block 84 Hydraulic single control block 8 5 Control switching block Se1 Temperature sensor

Claims (10)

A prime mover, a hydraulic pump driven by the prime mover, a turning body, an electric motor for driving the turning body, a hydraulic motor for driving the turning body driven by the hydraulic pump, and the electric motor. A hybrid construction machine comprising: a power storage device; a first inverter that transfers power between the power storage device and the electric motor; and a turning operation lever device that commands driving of the swivel body.
A temperature sensor that detects an internal temperature of the electric motor; a temperature sensor that detects an internal temperature of the first inverter;
When the operation lever device for turning is operated, both the electric motor and the hydraulic motor are driven, and the swivel body is driven by the total torque of the electric motor and the hydraulic motor. A control device for switching between a mode and a hydraulic single swing mode in which only the hydraulic motor is driven when the swing operation lever device is operated, and the swing body is driven with torque of only the hydraulic motor And
The control device includes: a control switching unit that switches to the hydraulic single swing mode when a failure or abnormality occurs in a first electric system including the electric motor, the power storage device, and the first inverter; Monitoring control means for limiting and controlling the number of revolutions of the prime mover in order to limit the number of revolutions of the hydraulic motor so that the detection value from each temperature sensor is within a preset regulation value set in advance in the turning mode; A hybrid construction machine characterized by comprising: A prime mover, a hydraulic pump driven by the prime mover, a turning body, an electric motor for driving the turning body, a hydraulic motor for driving the turning body driven by the hydraulic pump, and the electric motor. A hybrid construction machine comprising: a power storage device; a first inverter that transfers power between the power storage device and the electric motor; and a turning operation lever device that commands driving of the swivel body.
A current sensor for detecting an output current of the electric motor;
When the operation lever device for turning is operated, both the electric motor and the hydraulic motor are driven, and the swivel body is driven by the total torque of the electric motor and the hydraulic motor. A control device for switching between a mode and a hydraulic single swing mode in which only the hydraulic motor is driven when the swing operation lever device is operated, and the swing body is driven with torque of only the hydraulic motor And
The control device includes: a control switching unit that switches to the hydraulic single swing mode when a failure or abnormality occurs in a first electric system including the electric motor, the power storage device, and the first inverter; And a monitoring control means for stopping the prime mover in order to stop the hydraulic motor when a detected value from the current sensor exceeds a preset limit value in a turning mode. Hybrid construction machine. Driven by the prime mover, the hydraulic pump driven by the prime mover, the swing body, the electric motor for driving the swing body, the hydraulic motor for driving the swing body driven by the hydraulic pump, and the prime mover An assist power generation motor, an electric storage device connected to the electric motor and the assist power generation motor, a first inverter that transfers electric power between the electric storage device and the electric motor, the electric storage device, and the assist electric power generation In a hybrid construction machine including a second inverter that transmits and receives power to and from a motor, and a turning operation lever device that commands driving of the turning body,
A temperature sensor that detects an internal temperature of the assist generator motor; a temperature sensor that detects an internal temperature of the second inverter;
When the operation lever device for turning is operated, both the electric motor and the hydraulic motor are driven, and the swivel body is driven by the total torque of the electric motor and the hydraulic motor. A control device for switching between a mode and a hydraulic single swing mode in which only the hydraulic motor is driven when the swing operation lever device is operated, and the swing body is driven with torque of only the hydraulic motor And
The control device includes: a control switching unit that switches to the hydraulic single swing mode when a failure or abnormality occurs in a second electric system including the assist power generation motor, the power storage device, and the second inverter; In the single turning mode, a hybrid control system comprising: a monitoring control means for limiting and controlling the number of revolutions of the prime mover so that a detection value from each of the temperature sensors is within a preset limit value. Construction machinery. Driven by the prime mover, the hydraulic pump driven by the prime mover, the swing body, the electric motor for driving the swing body, the hydraulic motor for driving the swing body driven by the hydraulic pump, and the prime mover An assist power generation motor, an electric storage device connected to the electric motor and the assist power generation motor, a first inverter that transfers electric power between the electric storage device and the electric motor, the electric storage device, and the assist electric power generation In a hybrid construction machine including a second inverter that transmits and receives power to and from a motor, and a turning operation lever device that commands driving of the turning body,
A current sensor for detecting an output current of the assist generator motor;
When the operation lever device for turning is operated, both the electric motor and the hydraulic motor are driven, and the swivel body is driven by the total torque of the electric motor and the hydraulic motor. A control device for switching between a mode and a hydraulic single swing mode in which only the hydraulic motor is driven when the swing operation lever device is operated, and the swing body is driven with torque of only the hydraulic motor And
The control device includes: a control switching unit that switches to the hydraulic single swing mode when a failure or abnormality occurs in a second electric system including the assist power generation motor, the power storage device, and the second inverter; A hybrid construction machine, comprising: a monitoring control unit that stops the prime mover when a detection value from the current sensor exceeds a preset limit value in a single turning mode. The hybrid construction machine according to claim 1 or 2,
A first cable having one end connected to the electric motor and a connector at the other end to which the first inverter is connected;
A first connector connected to the first inverter and detachable from the connector of the first cable;
Wherein when a failure or abnormality occurs in the first electric system, a hybrid construction machine, characterized in that removing the connector of the first cable from the first connector. The hybrid construction machine according to claim 3 or 4,
A first cable having one end connected to the electric motor and a connector at the other end to which the first inverter is connected;
A second cable having one end connected to the assist generator motor and a connector at the other end to which the second inverter is connected;
A first connector connected to the first inverter and detachable from the connector of the first cable;
A second connector connected to the second inverter and detachable from the connector of the second cable;
When the failure in the first electric system comprising an electric motor and the energy storage device and said first inverter or a failure, disconnect the connector of the first cable from the first connector,
Or, when said failure or abnormality occurs in the second electric system, a hybrid construction machine, characterized in that removing the connector of the second cable from the second connector. The hybrid construction machine according to claim 5,
A first dummy connector provided in the first inverter, having no internal connection line, wherein the connector of the first cable is detachable;
Wherein when a failure or abnormality occurs in the first electric system, a hybrid construction machine, which comprises attaching a connector of the first cable to the first dummy connector. The hybrid construction machine according to claim 6,
A first dummy connector provided in the first inverter, having no internal connection line, to which the connector of the first cable can be attached and detached;
A second dummy connector provided in the second inverter, having no internal connection line, to which the connector of the second cable can be attached and detached,
When the fault or abnormality in the first electric system occurs, fitted with connectors of the first cable to the first dummy connector,
Or, when said failure or abnormality occurs in the second electric system, a hybrid construction machine, which comprises attaching the connector of the second cable to the second dummy connector. The hybrid construction machine according to claim 6 or 8 ,
The monitoring control means is configured to determine the internal temperature and the number of rotations of the electric motor even when both the connector of the first cable and the connector of the second cable are not attached to any other connector. A hybrid construction machine characterized by monitoring. The hybrid construction machine according to claim 5 or 7,
The monitoring control unit, the connector of the first cable, even if the both other one of the connector not mounted, a hybrid construction, which comprises monitoring the engine speed and the internal temperature of the electric motor machine.

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