JP5778570B2 - Construction machinery - Google Patents

Description

  The present invention relates to a construction machine, and more particularly to a construction machine provided with an electric motor and a power storage device.

  For example, in a construction machine such as a hydraulic excavator, a fuel such as gasoline or light oil is used as a power source, and a hydraulic pump is driven by an engine to generate hydraulic pressure to drive a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder. Hydraulic actuators are small and light and capable of high output, and are widely used as construction machine actuators.

  On the other hand, in recent years, a construction machine has been proposed that uses an electric motor and an electricity storage device (battery, electric double layer capacitor, etc.) to improve energy efficiency and save energy compared to conventional construction machines that use only hydraulic actuators. (For example, refer to Patent Document 1).

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

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

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

  By the way, a capacitor which is a power storage device in such a construction machine is likely to be deteriorated by being used for a long time in a harsh environment. Capacitor degradation reduces the work capacity of construction machinery, so there is a power storage device degradation determination device that can determine the degradation state of a capacitor in advance in a state where a power storage device such as a capacitor is mounted on a vehicle (for example, a patent) Reference 2).

JP 2001-016704 A JP 2009-227044 A

  According to the above-described prior art disclosed in Patent Document 2, it is possible to perform capacitor deterioration determination in advance. However, for example, when a failure occurs in any of the electrical components such as a power storage device and a voltage converter in a construction machine, charging of the capacitor and supply of electric power from the capacitor cannot be performed normally. The above-described prior art of Patent Document 2 does not consider the determination of the failure part in the entire electrical component. Therefore, in such a case, the failure part is quickly determined, and the repair and the replacement of parts are promptly performed. It was difficult to do.

  The present invention has been made on the basis of the above-described matters, and an object of the present invention is to automatically detect the occurrence of a failure of an electrical system component including a capacitor and the failure part during operation of the machine in a construction machine including a capacitor as a power storage device. The present invention provides a construction machine that has a failure diagnosis function that can be discriminated quickly and quickly, and that can improve maintenance such as repair and replacement of parts.

In order to achieve the above object, the first invention includes an electric motor, a capacitor as an electric storage device, an inverter and a DC voltage converter provided between the electric motor and the capacitor, and the DC voltage conversion. And a relay provided between the capacitor and the capacitor, wherein the DC voltage conversion is performed on the relay side of the DC voltage converter in a construction machine capable of transferring power between the electric motor and the capacitor. A voltage sensor for detecting a primary side voltage of the detector, and a change rate of a detection voltage of the voltage sensor after the DC voltage converter and the capacitor are connected by the relay, and using the change rate, and a determining failure determining means the failure of the electrical system parts including a DC voltage converter and said capacitor, said failure determining means, the DC voltage variable by the relay A change rate calculating means for calculating a change rate of a detection voltage of the voltage sensor after a predetermined time has elapsed since the capacitor and the capacitor are connected, and the electrical component including the DC voltage converter and the capacitor at the time of failure. The DC voltage converter and the capacitor can be obtained by comparing the change rate of the primary voltage of the DC voltage converter in advance with the storage means, and the change rate calculated by the change rate calculation means and the change rate in the storage means. And a determination unit for determining a failure of an electrical system component including

According to a second aspect of the present invention, in the first aspect, the failure determination means is a rate of change of a detection voltage of the voltage sensor after a lapse of a predetermined time after the DC voltage converter and the capacitor are connected by the relay. A rate of change calculating means for calculating the DC voltage converter and a storage means for preliminarily storing the rate of change of the primary voltage of the DC voltage converter at each failure site at the time of failure of the electrical system component including the capacitor; A determination unit that determines a failure site of an electric system component including the DC voltage converter and the capacitor by comparing the change rate calculated by the change rate calculation unit and the change rate in the storage unit. Features.

Further, according to a third invention, in the second invention, the storage means has a first set value which is a rate of change of a primary side voltage of the DC voltage converter when the DC voltage converter fails. A cable that connects the DC voltage converter and the capacitor or a second set value that is a rate of change of the primary voltage of the DC voltage converter when the capacitor fails is stored in advance. When the change rate calculated by the change rate calculating means exceeds the first set value, it is determined that the cable connecting the DC voltage converter and the capacitor or a failure of the capacitor, and the change rate calculation is performed. When the change rate calculated by the means is less than the second set value, it is determined that the DC voltage converter has failed .

According to a fourth aspect of the present invention, in any one of the first to third aspects, the failure determination unit outputs an output signal indicating a failure of the electrical system component and / or a failure part to a notification device and / or a host computer. It outputs to the radio | wireless communication terminal which carries out radio transmission to.

  According to the present invention, in a construction machine including an electric motor and a capacitor as a power storage device, the occurrence and failure of an electric system component including a capacitor and a voltage converter can be quickly and reliably determined when the machine is started. Therefore, maintainability such as repair and replacement of parts is improved.

It is a side view which shows one Embodiment of the construction machine of this invention. 1 is a system configuration diagram of main electric / hydraulic equipment constituting an embodiment of a construction machine according to the present invention. FIG. It is a power circuit diagram of the main electric system which constitutes one embodiment of the construction machine of the present invention. It is a functional block diagram which shows the structure of the failure determination means which comprises one Embodiment of the construction machine of this invention. It is a characteristic view which shows the characteristic of the capacitor voltage of each failure part in the failure determination means which comprises one embodiment of the construction machine of the present invention. It is a table | surface figure which shows the relationship between the change rate of a capacitor voltage in the failure determination means which comprises one embodiment of the construction machine of this invention, and a failure location. It is a flowchart figure of the failure diagnosis in the failure determination means which comprises one Embodiment of the construction machine of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking as an example a hybrid excavator provided with a hydraulic device and an electric motor as a construction machine. The present invention can be applied to all construction machines (including work machines), and the application of the present invention is not limited to hydraulic excavators. FIG. 1 is a side view showing an embodiment of the construction machine of the present invention, FIG. 2 is a system configuration diagram of main electric / hydraulic equipment constituting the embodiment of the construction machine of the present invention, and FIG. It is a power circuit diagram of the main electric system which constitutes one embodiment of a construction machine.

  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. An electric double layer capacitor 24 connected to the generator motor 23 and the swing electric motor 25, a speed reduction mechanism 26 for reducing the rotation of the swing electric motor 25 and the swing hydraulic motor 27, and the like. Since the driving force of the swing electric motor 25 and the swing hydraulic motor 27 is transmitted to the swing body 20 (the swing frame 21) via the speed reduction mechanism 26, the swing body 20 (the swing frame 21) rotates with respect to the traveling body 10. To drive.

  Further, an excavator mechanism (front device) 30 is mounted on the revolving unit 20. The shovel mechanism 30 includes a boom 31 provided on the revolving body frame 21 so as to be able to move up and down, a boom cylinder 32 for driving the boom 31, an arm 33 pivotally supported near the tip of the boom 31, An arm cylinder 34 for driving the arm 33, 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 arm 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 main 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 a turning operation lever device (not shown). The control valve 42 is a pressure supplied to the boom cylinder 32, the arm cylinder 34, the bucket cylinder 36 and the traveling hydraulic motors 13 and 14 in response to an operation command (hydraulic pilot signal) from an operation lever device other than turning. Control oil flow and direction.

  The main electric system includes the assist generator motor 23, the swing electric motor 25, the power control unit 55 composed of electric components that drive and control them, a main controller 80, and an electric double layer capacitor 24. And a capacitor unit 56 including a relay or the like for controlling electrical connection with the control unit 55.

  The DC power from the capacitor 24 is boosted to a predetermined bus voltage by a DC voltage converter (chopper) 51 and input to an inverter 52 for driving the swing electric motor 25 and an inverter 53 for driving the assist power generation motor 23. Is done. 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 connected 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.

  The controller 80 is a control device composed of a microcomputer and an electric circuit, and is activated by an engine key switch (not shown) and uses signals not shown in FIG. 2 such as operation command signals, pressure signals, and rotation speed signals. Control commands for the control valve 42, the power control unit 55, and the capacitor unit 56 are generated to control the hydraulic pressure, the electric system, and the engine 22. Further, as will be described later, when starting the hybrid excavator, a failure determination means 81 (see FIG. 4) that executes failure diagnosis for automatically and promptly determining the occurrence and failure location of the electrical system components including the capacitor 24. It has. The occurrence and the failure part of the electrical system component determined by the failure determination unit 81 are notified to the operator by the notification device 82 and also output to the wireless communication terminal 100. The wireless communication terminal 100 wirelessly transmits the device data collected by the controller 80, the occurrence of the failure of the electrical system component described above, and the failure site to the host computer or the like. The electromagnetic proportional valve 75 converts an electric signal from the main controller 80 into a hydraulic pilot signal, and the control valve 42 is controlled by the hydraulic pilot signal.

Next, the power circuit of the main electric system constituting one embodiment of the construction machine of the present invention will be described with reference to FIG. In FIG. 3, the same reference numerals as those shown in FIGS. 1 and 2 are the same parts, and detailed description thereof is omitted.
The capacitor unit 56 includes a positive relay 57 b as an open / close switch that opens and closes an electrical connection between the positive electrode of the capacitor 24 and the positive electrode on the primary side of the DC voltage converter 51, and the negative electrode of the capacitor 24 and the DC voltage converter 51. Negative relays 57c are provided as open / close switches for opening and closing the electrical connection with the negative electrode of each bus bar. The inrush current prevention circuit includes an inrush current prevention relay 57a and an inrush current prevention resistor 58 so as to bypass the contact of the positive side relay 57b. Specifically, one fixed contact of the inrush current prevention relay 57a is connected to the fixed contact on the capacitor 24 side of the positive side relay 57b, and the other fixed contact of the inrush current prevention relay 57a is one end of the inrush current prevention resistor 58. And the other end of the inrush current prevention resistor 58 is connected to a fixed contact on the DC voltage converter 51 side of the positive side relay 57b.

  The inrush current prevention circuit prevents generation of excessive current that flows when the DC voltage converter 51 and the capacitor 24 are connected in a state where the smoothing capacitor 88 in the DC voltage converter 51 is not charged. Specifically, before the positive side relay 57b is closed, the inrush current prevention relay 57a is closed, and the current is limited by the path of the inrush current prevention circuit to charge the capacitor 88 in the DC voltage converter 51. To do.

  The DC voltage converter 51 includes two power transistors 1IGBT and 2IGBT indicated by 85 and 86, a reactor 87, and a smoothing capacitor 88.

  Reactor 87 has one end connected to the positive electrode of capacitor 24 via terminal 91, connection cable 92, and positive relay 57 b, and the other end connected to the source of 1 IGBT 85 and the drain of 2 IGBT 86. The drain of the 1 IGBT 85 is connected to one end of the main smoothing capacitor 54, one end of the assist power generation motor inverter 53, and one end of the electric swing motor inverter 52. The source of the 2IGBT 86 is connected to the negative electrode of the capacitor 24, the other end of the main smoothing capacitor 54, the assist generator motor inverter 53, and the other end of the electric swing motor inverter 52 via the negative relay 57c. One end of the reactor 87 is connected to one end of the smoothing capacitor 88, and the other end of the smoothing capacitor 88 is connected to the source of the 2 IGBT 86.

  In response to a command from the controller 80, the 1IGBT 85 and the 2IGBT 86 are alternately opened and closed, thereby boosting the voltage of the capacitor 24 to a predetermined bus voltage and controlling the bus voltage to a predetermined constant value.

  A voltage sensor 89, which is a voltage detection means for measuring the voltage (primary side voltage) V1 of the capacitor side terminal of the DC voltage converter 51, and the voltage (secondary side voltage) V2 of the bus side terminal of the DC voltage converter 51 are measured. A voltage sensor 90 which is a voltage detecting means is provided on the primary side and the secondary side of the DC voltage converter 51, respectively. The voltage values V1 and V2 measured by the voltage sensors 89 and 90 are respectively input to the controller 80 in order to determine the occurrence of failure of the electric system parts and the failure part at the start of the hybrid hydraulic excavator. The controller 80 is provided with failure determination means 81 (see FIG. 4) described later.

  The main smoothing capacitor 54 smoothes the DC voltage. The assist power generation motor inverter 53 and the electric swing motor inverter 52 are connected to the DC voltage converter 51 and the main smoothing capacitor 54 on one side and to the assist power generation motor 23 and the electric swing motor 25 on the other side, respectively. .

  The assist power generation motor inverter 53 and the swing electric motor inverter 52 are configured by a bridge circuit including six switching elements such as an IGBT. The assist generator motor inverter 53 and the swing electric motor inverter 52 perform bidirectional power conversion.

  When driving the assist power generation motor 23 and the swing electric motor 25, the secondary side of the DC power converter 51 is received by changing the pulse width by repeating ON / OFF of the current in response to a command from the controller 80. Power running control to generate three-phase alternating current from the bus. On the other hand, when charging the electric power from the assist generator motor 23 and the swing electric motor 25 to the capacitor 24, in response to a command from the controller 80, ON / OFF of the current is repeated and the pulse width is changed to change the three phases. Regenerative control is performed by generating DC power from the AC to the secondary side bus of the DC power converter 51. The capacitor 24 is charged by supplying this DC power.

  Next, failure determination means for determining the occurrence of a failure of an electric system component and the failure part at the start of the hybrid excavator executed by the controller 80 will be described with reference to FIGS. FIG. 4 is a functional block diagram showing the configuration of the failure determination means constituting one embodiment of the construction machine of the present invention, and FIG. 5 shows each failure part in the failure determination means constituting one embodiment of the construction machine of the present invention. FIG. 6 is a table showing the relationship between the rate of change of the capacitor voltage and the failure location in the failure determination means constituting one embodiment of the construction machine of the present invention. 4 to FIG. 6, the same reference numerals as those shown in FIG. 1 to FIG. 3 are the same parts, and detailed description thereof will be omitted.

  As shown in FIG. 4, the failure determination unit 81 includes a storage unit 81a, a change rate calculation unit 81b, a voltage comparison unit 81c, a change rate comparison unit 81d, and a determination unit 81e. Further, the primary side voltage V1 of the DC voltage converter 51 detected by the voltage sensor 89 and the secondary side voltage V2 of the DC voltage converter 51 detected by the voltage sensor 90 are input to the failure determination means 81. Further, the failure determination means 81 outputs a signal for notifying the occurrence of a failure of the electrical system component and the failure site to the wireless communication terminal 100 and the notification device 82.

  The storage unit 81a includes threshold values KV1SL1 and KV1SL2 of a change rate of a primary side voltage V1 of a DC voltage converter 51 described later, a threshold value KV2SL of a secondary side voltage V2 of the DC voltage converter 51, and a DC voltage converter 51 A threshold value KVIG1S of the primary side voltage V1 is stored.

  The primary voltage V1 of the DC voltage converter 51 detected by the voltage sensor 89 is input to the change rate calculation unit 81b. The change rate calculation means 81b calculates the change rate of the primary side voltage V1 by a calculation method described later. The calculated change rate is output to the change rate comparison unit 81d.

  The voltage comparison means 81c includes a primary voltage V1 of the DC voltage converter 51 detected by the voltage sensor 89, a secondary voltage V2 of the DC voltage converter 51 detected by the voltage sensor 90, and a threshold value from the storage means 81a. KV2SL and KVIG1S are input. The voltage comparison unit 81c compares these input signals and outputs the result to the determination unit 81e.

  The change rate comparison means 81d receives the output signal from the change rate calculation means 81b and the threshold values KV1SL1 and KV1SL2 from the storage means 81a. The change rate comparison unit 81d compares these input signals and outputs the result to the determination unit 81e.

  The determination unit 81e receives an output signal from the voltage comparison unit 81c and an output signal from the change rate comparison unit 81d. The determination unit 81e determines the occurrence of the failure of the electric system component and the failure part from these input signals, and outputs this determination signal to the wireless communication terminal 100 and the notification device 82.

Next, processing contents of the failure determination means 81 will be described.
In the start of the hydraulic excavator according to the embodiment of the construction machine of the present invention, first, the engine 22 and the hydraulic pump 41 are started by changing an ignition key (not shown) from the ON position to the start position. Thereafter, initial charge / discharge control of the capacitor 24 by the controller 80 is executed. In the initial charge / discharge control of the capacitor 24, the power control unit 55 is started, the initial charge processing of the inverters 52 and 53 and the main smoothing capacitor 54 and the connection processing of the relays 57a to 57c are performed, and the initial charge of the capacitor 24 is performed. It is.

  The failure determination means 81 of the controller 80 monitors the behavior of the primary side voltage V1 of the DC voltage converter 51 after the connection processing of the relays 57a to 57c in the initial charge / discharge control of the capacitor 24. It is possible to determine the occurrence of a component failure and the location of the failure.

  In FIG. 5, the horizontal axis indicates time, and the vertical axis indicates the primary voltage V <b> 1 of the DC voltage converter 51. In addition, the solid lines (a) to (c) of the characteristic lines indicate the characteristics of the primary side voltage V1 of the DC voltage converter 51 when the electrical parts such as the capacitor unit 56 are normal, and the dotted lines indicate the inside of the capacitor unit 56. The characteristics of the primary side voltage V1 of the DC voltage converter 51 when the so-called capacitor unit side disconnection such as the disconnection of the cable, the relay, the disconnection of the connection cable 92 to the capacitor unit, the contact failure of the terminal 91, etc. The chain lines (a ′) to (c ′) are the DC voltage converter 51 when the 1 IGBT 85 and the reactor 87 of the DC voltage converter 51 are disconnected, or when the 2 IGBT 86 of the DC voltage converter 51 is short-circuited. The characteristics of the primary side voltage V1 are respectively shown. Time T1 indicates the time when the inrush current prevention relay 57a is connected and the 1 IGBT 85 of the DC voltage converter 51 is gated on.

  First, the case where the electrical components such as the DC voltage converter 51 and the capacitor unit 56 and their connections are normal will be described. At time T1, the inrush current prevention relay 57a is connected and the 1 IGBT 85 of the DC voltage converter 51 is gated on, so that current suddenly flows from the capacitor 24 to the smoothing capacitor 88 of the DC voltage converter 51. As a result, the primary side voltage V1 of the DC voltage converter 51 immediately rises to the voltage (initial voltage) of the capacitor 24 as indicated by solid lines (a) to (c). This initial voltage varies depending on the state of charge of the capacitor 24. The solid line (a) shows the characteristics when the charge amount of the capacitor 24 is large, the solid line (b) shows the characteristic when the charge amount of the capacitor 24 is small, and the solid line (c) shows the characteristic when the charge amount of the capacitor 24 is almost not. Respectively.

  After the primary voltage V1 of the DC voltage converter 51 rises to the initial voltage, the power from the assist power generation motor 23 flows into the capacitor 24 via the assist power generation motor inverter 53 and the DC voltage converter 51, The capacitor 24 is charged. For this reason, the primary voltage V1 of the DC voltage converter 51 gradually increases from the initial voltage. The rate of change of the primary side voltage V1 of the DC voltage converter 51 at this time is determined by the capacitance of the capacitor 24 and the charging current to the capacitor 24.

  Here, the time after the primary side voltage V1 of the DC voltage converter 51 rises to the initial voltage is set as T2, and the time after the elapse of a predetermined time from the time T2 is set as T3. Here, the time T2 is a time that defines a voltage lower limit value for obtaining the rate of change, and the time ΔT1 between the time T2 and the time T1 is, for example, 10 ms.

  Time T3 is a time that defines the voltage upper limit value for obtaining the rate of change, and is the time before the change characteristic of the primary side voltage V1 is saturated in the state where the cable in the capacitor unit 56 is disconnected. A time ΔT2 between time T3 and time T2 is, for example, 50 ms.

  On the other hand, when a so-called capacitor unit side disconnection such as disconnection of the cable in the capacitor unit 56, the relays 57a to 57c, disconnection of the connection cable 92 to the capacitor unit 56, contact failure of the terminal 91, etc. occurs, inrush current prevention After the time T1 when the relay 57a is connected and the 1 IGBT 85 of the DC voltage converter 51 is gated on, the current from the assist generator motor 23 does not flow into the capacitor 24 but flows into only the smoothing capacitor 88 of the DC voltage converter 51. Since the capacitance of the smoothing capacitor 88 of the DC voltage converter 51 is sufficiently smaller than the capacitance of the capacitor 24, the primary voltage V1 of the DC voltage converter 51 starts from 0 as indicated by a dotted line (d). It rises rapidly.

  Further, when the 1 IGBT 85 of the DC voltage converter 51 and the reactor 87 are disconnected, the primary side of the DC voltage converter 51 is connected by connecting the inrush current prevention relay 57a and gate-on the 1 IGBT 85 of the DC voltage converter 51. The voltage V1 immediately rises to the voltage (initial voltage) of the capacitor 24 as indicated by alternate long and short dash lines (a ′) to (c ′), but thereafter, the current from the assist power generation motor 23 does not flow into the capacitor 24. It will not change from the initial voltage. The alternate long and short dash line (a ′) indicates the characteristics when the capacitor 24 has a large amount of charge, the alternate long and short dash line (b ′) indicates the characteristic when the capacitor 24 has a small amount of charge, and the alternate long and short dash line (c ′) indicates the amount of charge of the capacitor 24. The characteristics when there is almost no are shown.

  Further, when the 2IGBT 86 of the DC voltage converter 51 is short-circuited, the primary voltage V1 of the DC voltage converter 51 remains 0 as indicated by a one-dot chain line (c ′).

  Therefore, by connecting the inrush current prevention relay 57a and monitoring the rate of change of the primary side voltage V1 of the DC voltage converter 51 from time T2 after time T1 when the 1 IGBT 85 of the DC voltage converter 51 is gated on to time T3. It is possible to determine the occurrence of the failure of the electric system part and the failure part. In the present embodiment, the change rate calculation means 81b of the failure determination means 81 calculates the change rate of the primary side voltage V1 of the DC voltage converter 51 from time T2 to time ΔT2 from time T2 to change the change rate. In the rate comparison unit 81d, the failure part can be determined by comparing with the table showing the relationship between the change rate of the capacitor voltage and the failure part, for example, shown in FIG. 6 and stored in the storage unit 81a.

  In FIG. 6, KV1SL1 is a predetermined change rate threshold value and indicates the maximum value when the electrical system component is normal, and KV1SL2 is a predetermined change rate threshold value and the electrical system component is normal. Indicates the minimum value at a certain time. These values are stored in the storage means 81a. In the change rate comparison unit 81d, if the change rate output from the change rate calculation unit 81b exceeds KV1SL1, the determination unit 81e determines that the capacitor unit 56 is disconnected, and similarly, the change output from the change rate calculation unit 81b. If the rate is less than KV1SL2, the determination unit 81e determines that the DC voltage converter 51 has an internal failure. If the change rate output from the change rate calculating means 81b is KV1SL1 or less and KV1SL2 or more, the determination unit 81e determines that the electrical system component is normal.

  The table shown in FIG. 6 is converted into data in the form of a storage table and stored in the storage unit 81a, and the change rate calculation unit 81b detects the DC voltage converter 51 detected by the voltage sensor 89 at preset times T2 and T3. A change rate corresponding to the primary side voltage V1 is calculated, the change rate comparison unit 81d performs a comparison operation with the data in the storage unit 81a, and the determination unit 81e determines the failure site.

  Next, in the embodiment of the construction machine of the present invention, a failure diagnosis flow in the failure determination means will be described with reference to FIG. FIG. 7 is a flowchart of failure diagnosis in the failure determination means constituting one embodiment of the construction machine of the present invention. In FIG. 6, the same reference numerals as those shown in FIGS. 1 to 6 are the same parts, and detailed description thereof is omitted.

  First, in step (S101) of FIG. 7, it is determined whether or not the engine 22 has been started. Specifically, for example, the determination is made based on whether or not an ignition key (not shown) is operated to the start position. If the engine 22 has been started, it is determined YES, and the process proceeds to step (S102). If the engine has not been started, NO is determined, and the process returns to step (S101).

  In step (S102), it is determined whether or not the rotational speed signal of the engine 22 is equal to or greater than a predetermined set value KNE. Specifically, the rotation speed signal of the engine 22 taken into the controller 80 is compared with the set value KNE stored in advance in the storage unit. The set value KNE is an engine speed at which the electric power from the assist power generation motor 23 can charge the capacitor 24, and is set to, for example, 800 rpm that is an idle speed. If the rotational speed of the engine 22 is equal to or greater than the set value KNE, it is determined YES, and the process proceeds to step (S103). .

  In step (S103), it is determined whether or not control of the bus voltage of the power control unit 55 by the assist power generation motor 23 is being executed. Specifically, determination is made based on whether or not the controller 80 is performing regenerative control of the inverter 53 for the assist power generation motor. If step (S102) and step (S103) are determined as YES, it can be determined that electric power necessary for charging capacitor 24 by assist power generation motor 23 is obtained. If the controller 80 performs regenerative control of the assist generator motor inverter 53, it is determined YES, and the process proceeds to step (S104). If it is not regeneratively controlled, NO is determined, and the process returns to step (S101).

  In step (S104), it is determined whether or not the secondary voltage V2 of the DC voltage converter 51, which is the bus voltage of the power control unit 55, is equal to or higher than a predetermined threshold value KV2SL. Specifically, the voltage comparison unit 81c of the failure determination unit 81 compares the secondary side voltage V2 of the DC voltage converter 51 detected by the voltage sensor 90 with the threshold value KV2SL stored in advance in the storage unit 81a. The threshold value KV2SL is a bus voltage at which the electric power from the assist power generation motor 23 can charge the capacitor 24, and is set to 300 V, for example. If the secondary voltage V2 of the DC voltage converter 51 is greater than or equal to the threshold value KV2SL, the determination is YES, and the process proceeds to step (S106). If the secondary voltage V2 of the DC voltage converter 51 is less than the threshold value KV2SL, NO is determined. After the determination, the process proceeds to step (S105).

  In step (S105), the determination unit 81e determines that the assist power generation motor 23 or the assist power generation motor inverter 53 is abnormal. This is because power generation is not normally performed unless the secondary voltage V2 of the DC voltage converter 51 is equal to or higher than a predetermined threshold in step (S104). For example, the determination unit 81e of the failure determination unit 81 notifies the operator of an abnormality by using a notification device 82 such as a monitor screen and displays the failure part, and wirelessly transmits this information to the host computer or the like via the wireless communication terminal 100. Send.

  In step (S106), it is determined whether or not the primary voltage V1 of the DC voltage converter 51 is equal to or lower than a predetermined threshold value KVIG1S. In the voltage comparison unit 81c of the failure determination unit 81, the primary voltage V1 detected by the voltage sensor 89 is compared with the threshold value KVIG1S stored in the storage unit 81a. At this timing, since the relays 57a to 57c are not connected and the 1 IGBT 85 of the DC voltage converter 51 is not gated on, the primary voltage V1 of the DC voltage converter 51 is approximately 0V if it is normal. Therefore, the threshold value KVIG1S is a minimum voltage assumed from a noise voltage or the like, and is set to 20V, for example. If the primary voltage V1 of the DC voltage converter 51 is equal to or lower than the threshold value KVIG1S, the determination is YES, and the process proceeds to step (S108). If the primary voltage V1 of the DC voltage converter 51 exceeds the threshold value KVIG1S, NO is determined. The process proceeds to step (S107).

  In step (S107), the determination unit 81e determines that the 1 IGBT 85 of the DC voltage converter 51 is short-circuited or the relays 57a to 57c of the capacitor unit 56 are short-circuited. This is because, in step (S106), if the primary voltage V1 of the DC voltage converter 51 is not less than or equal to a predetermined threshold value, an abnormal circuit is configured and a voltage is generated. For example, the determination unit 81e of the failure determination unit 81 notifies the operator of an abnormality by using a notification device 82 such as a monitor screen and displays the failure part, and wirelessly transmits this information to the host computer or the like via the wireless communication terminal 100. Send.

  In step (S108), inrush current prevention relay 57a is connected, and 1 IGBT 85 of DC voltage converter 51 is gated on. Specifically, the controller 80 outputs a close command to the inrush current prevention relay 57 a of the capacitor unit 56, and outputs a gate-on signal to the 1 IGBT 85 of the DC voltage converter 51 of the power control unit 55. As a result, charging of the capacitor 24 is started.

  In step (S109), the rate of change of the primary side voltage V1 of the DC voltage converter 51 is measured. Specifically, in change rate calculation means 81b of failure determination means 81, DC voltage converter 51 at time ΔT2 from time T2 to time T3 after time T1 when 1 IGBT 85 of DC voltage converter 51 shown in FIG. The change rate of the primary side voltage V1 is calculated and calculated.

  In step (S110), it is determined whether or not the rate of change of the primary voltage V1 of the DC voltage converter 51 calculated in step (S109) exceeds a predetermined threshold value KV1SL1. Specifically, in the change rate comparison unit 81d of the failure determination unit 81, the change rate of the primary voltage V1 of the DC voltage converter 51 calculated by the change rate calculation unit 81b and the threshold value KV1SL1 stored in advance in the storage unit 81a Compare If the rate of change of the primary side voltage V1 of the DC voltage converter 51 exceeds the threshold value KV1SL1, it is determined YES, and the process proceeds to step (S111), where the rate of change of the primary side voltage V1 of the DC voltage converter 51 is less than the threshold value KV1SL1. If it is present, NO is determined and the process proceeds to step (S112).

  In step (S111), the determination is made by the capacitor unit 56 side disconnection and the determination unit 81e. For example, the determination unit 81e of the failure determination unit 81 notifies the operator of an abnormality by using a notification device 82 such as a monitor screen and displays the failure part, and wirelessly transmits this information to the host computer or the like via the wireless communication terminal 100. Send.

  In step (S112), it is determined whether or not the rate of change of the primary voltage V1 of the DC voltage converter 51 calculated in step (S109) is less than a predetermined threshold value KV1SL2. Specifically, in the change rate comparison means 81d of the failure determination means 81, the change rate of the primary voltage V1 of the DC voltage converter 51 calculated by the change rate calculation means 81b and the threshold value KV1SL2 stored in advance in the storage means 81a Compare If the rate of change of the primary side voltage V1 of the DC voltage converter 51 is less than the threshold value KV1SL2, the determination is YES, and the process proceeds to step (S113), where the rate of change of the primary side voltage V1 of the DC voltage converter 51 is greater than or equal to the threshold value KV1SL2. If there is, it is determined as NO, and the process proceeds to END, assuming that there is no failure site.

  In step (S113), the determination unit 81e determines that there is an internal failure of the DC voltage converter 51. For example, the determination unit 81e of the failure determination unit 81 notifies the operator of an abnormality by using a notification device 82 such as a monitor screen and displays the failure part, and wirelessly transmits this information to the host computer or the like via the wireless communication terminal 100. Send.

  The failure part of the electrical system component can be determined promptly and reliably by the above failure diagnosis flow. When it is determined in step (S111) that the capacitor unit 56 is disconnected, the capacitor unit 56 or its connection cable 92 may be repaired or replaced. If it is determined in step (S113) that the DC voltage converter 51 has an internal failure, the DC voltage converter 51 may be repaired or the power control unit 55 including the DC voltage converter 51 may be replaced.

  According to the above-described embodiment of the construction machine of the present invention, the construction machine including the assist power generation motor 23, the electric swing motor 25, and the capacitor 24 as the power storage device includes the capacitor 24, the DC voltage converter 51, and the like. Occurrence and failure location of electrical parts can be quickly and reliably determined when the machine is started, so that maintenance such as repair and parts replacement is improved. Further, along with this, the machine stop time can be shortened, so that the work capacity can be increased and the productivity is improved.

  In the embodiment of the present invention, the failure determination unit 81 outputs a signal for notifying the occurrence of a failure of an electrical system component and the failure site to the wireless communication terminal 100 and the notification device 82, but the present invention is not limited to this. It is not a thing. It may be output to either the wireless communication terminal 100 or the notification device 82.

  In the embodiment of the present invention, a hybrid excavator provided with a hydraulic device and an electric motor has been described as an example. However, the present invention is not limited to this. The present invention can be applied to general construction and work machines having an electric motor and a capacitor.

DESCRIPTION OF SYMBOLS 10 Running body 20 Turning body 21 Turning frame 22 Engine 23 Assist electric power generation motor 24 Capacitor 25 Turning electric motor 40 Hydraulic system 41 Hydraulic pump 42 Control valve 51 DC voltage converter 52 Inverter for turning electric motor 53 Inverter 54 for assist electric power generation motor Main smoothing Capacitor 55 Power control unit 56 Capacitor unit 57a Inrush current prevention relay 57b Positive side relay 57c Negative side relay 80 Controller 81 Failure determination means 81a Storage means 81b Change rate calculation means 81c Voltage comparison means 81d Change rate comparison means 81e Determination section 82 Notification device 85 1IGBT
86 2IGBT
87 Reactor 88 Smoothing capacitor 89 Voltage sensor 90 Voltage sensor 100 Wireless communication terminal

Claims (4)

An electric motor, a capacitor as an electricity storage device, an inverter and a DC voltage converter provided between the electric motor and the capacitor, and a relay provided between the DC voltage converter and the capacitor, In a construction machine capable of transferring power between the electric motor and the capacitor,
A voltage sensor for detecting a primary side voltage of the DC voltage converter on the relay side of the DC voltage converter;
The change rate of the voltage detected by the voltage sensor after the DC voltage converter and the capacitor are connected by the relay is calculated, and the DC voltage converter and the electric system component including the capacitor are calculated using the change rate. and a failure determination means for determining a failure,
The failure determination means includes a change rate calculation means for calculating a change rate of a detection voltage of the voltage sensor after a lapse of a predetermined time after the DC voltage converter and the capacitor are connected by the relay.
Storage means for storing in advance the rate of change of the primary voltage of the DC voltage converter at the time of failure of an electrical system component including the DC voltage converter and the capacitor;
A determination unit that determines a failure of an electrical system component including the DC voltage converter and the capacitor by comparing the change rate calculated by the change rate calculation unit and the change rate in the storage unit; And construction machinery. The construction machine according to claim 1,
The failure determination means includes a change rate calculation means for calculating a change rate of a detection voltage of the voltage sensor after a lapse of a predetermined time after the DC voltage converter and the capacitor are connected by the relay.
Storage means for storing in advance the rate of change of the primary voltage of the DC voltage converter for each faulty part at the time of failure of the electrical system component including the DC voltage converter and the capacitor;
A determination unit that determines a failure part of an electrical system component including the DC voltage converter and the capacitor by comparing the change rate calculated by the change rate calculation unit and the change rate in the storage unit. A featured construction machine. The construction machine according to claim 2 ,
The storage means includes a first setting value that is a rate of change of a primary side voltage of the DC voltage converter when the DC voltage converter fails, a cable that connects the DC voltage converter and the capacitor, or A second set value that is a rate of change of the primary side voltage of the DC voltage converter when the capacitor fails;
When the rate of change calculated by the rate-of-change calculating means exceeds the first set value, the determining unit determines that a cable connecting the DC voltage converter and the capacitor or a failure of the capacitor is present. A construction machine characterized in that it is determined that the DC voltage converter has failed when the rate of change calculated by the rate-of-change calculating means is less than the second set value . The construction machine according to any one of claims 1 to 3 ,
Before Symbol failure determination means, a construction machine and outputs an output signal indicative of the failure and / or failure area of the electrical system components to the alarm device and / or the host computer or the like to the wireless communication terminal for wirelessly transmitting.

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