JP-7855551-B2 - Electric work equipment and method for starting electric work equipment

Inventors

• 丹波 大樹
• 伊井 常泰
• 高瀬 竣也

Assignees

• 株式会社クボタ

Dates

Publication Date

20260508

Application Date

20230622

Claims (8)

1. Electrical equipment and, An electrical circuit electrically connected to the aforementioned electrical equipment, A plurality of battery packs, each having an internal relay that opens and closes an internal circuit, the plurality of battery packs being sequentially connected in parallel to the electrical equipment via the electrical circuit, It comprises a control unit and, The aforementioned electrical circuit is Each of the aforementioned plurality of battery packs corresponds to a plurality of external relays, which include a plurality of external relays that open and close a circuit connecting the corresponding battery pack to the electrical equipment, The control unit, With the first battery pack, which is the first battery pack among the plurality of battery packs to be connected to the electrical equipment, electrically connected to the electrical equipment, the first downstream process closes the internal relay of the second battery pack, which is the second or later battery pack among the plurality of battery packs. A second downstream process that closes the external relay corresponding to the second battery pack, which has the internal relay in a closed state, An electric work machine that performs this task.
2. At least the first battery pack is, The circuit comprises a first internal relay as the internal relay, and a pre-charge circuit in which a pre-charge resistor and a pre-charge relay are connected in series in parallel to the first internal relay. The control unit, When connecting the first battery pack to the electrical equipment, A first pre-processing step that closes the external relay corresponding to the first battery pack, A second pre-processing step that closes the pre-charge relay of the first battery pack, After the first and second pre-processing steps, a third pre-processing step is performed to close the first internal relay of the first battery pack. The electric work machine according to claim 1, which performs the following:
3. Each of the plurality of battery packs has a battery cell and, as an internal relay, a first internal relay arranged on the path on one pole side of the battery cell and in parallel with the pre-charge circuit, and a second internal relay arranged on the path on the other pole side of the battery cell. The control unit, The electric work machine according to claim 2, wherein in the second pre-processing stage, the first internal relay is kept open, and the second internal relay and the pre-charge relay are closed.
4. The system further comprises a junction box that houses part or all of the aforementioned electrical circuits. The electric work machine according to claim 3, wherein the plurality of external relays are installed in a replaceable manner within the junction box.
5. The device further includes a work apparatus for performing a predetermined task, The electric work machine according to claim 4, wherein the electrical equipment directly or indirectly drives the work device.
6. The control unit, The electric work machine according to any one of claims 1 to 5, wherein the battery pack corresponding to the external relay with the most cumulative switching counts among the plurality of external relays is set to the first battery pack.
7. The control unit, The electric work machine according to any one of claims 1 to 5, wherein the battery pack set as the first battery pack is sequentially changed each time the process of connecting the plurality of battery packs to the electrical equipment is performed.
8. Electrical equipment and, An electrical circuit electrically connected to the aforementioned electrical equipment, A plurality of battery packs, each having an internal relay for opening and closing an internal circuit, the plurality of battery packs being sequentially connected in parallel to the electrical equipment via the electrical circuit, The aforementioned electrical circuit A method for starting an electric work machine, comprising a plurality of external relays corresponding to each of the plurality of battery packs, each of which switches open and closes a circuit connecting the corresponding battery pack to the electrical equipment, With the first battery pack, which is the first battery pack in the sequence of being connected to the electrical equipment, electrically connected to the electrical equipment, a first downstream process is performed to close the internal relay of the second battery pack, which is the second or later battery pack in the sequence of being connected to the electrical equipment, A method for starting an electric work machine, comprising: a second downstream process that closes the external relay corresponding to the second battery pack, which has the internal relay in a closed state.

Description

This invention relates to an electric work machine that operates using power supplied from multiple battery packs. Conventionally, electric work machines that operate using power supplied from multiple battery packs (battery assemblies) have been provided. This type of electric work machine comprises a work device, an electrical device that operates the work device, an electrical circuit electrically connected to the electrical device, and multiple battery packs, each having an internal relay, connected in parallel to the electrical device via the electrical circuit. This type of electric work machine electrically connects the multiple battery packs to the electrical device by simultaneously switching the internal relays of the multiple battery packs from an open state to a closed state when the work device is activated (starting the electrical device) (see, for example, Patent Documents 1 and 2). International Publication No. 2015/167024Japanese Patent Publication No. 2011-188789 Figure 1 is a side view of an electric work machine according to one embodiment of the present invention.Figure 2 is a schematic diagram of the hydraulic and electrical systems of the electric work machine according to the same embodiment.Figure 3 is an electrical system diagram of an electric work machine according to the same embodiment.Figure 4 is a flowchart illustrating the process for diagnosing whether parallel connection is possible for the battery packs of an electric work machine according to the same embodiment.Figure 5 is a processing flow diagram of the parallel connection process of the battery pack of the electric work machine according to the same embodiment.Figure 6 is a table showing the diagnostic conditions and results for each diagnostic process in the diagnosis of the opening and closing operation of the internal relay of the battery pack of the electric work machine according to the same embodiment.Figure 7 is a flowchart illustrating the process for fault diagnosis of an electric work machine according to the same embodiment.Figure 8 is a processing flow diagram of the single connection process for the battery pack of the electric work machine according to the same embodiment.Figure 9 is a processing flow diagram of the charging mode for charging the battery pack of an electric work machine according to the same embodiment. The following description of an electric work machine according to one embodiment of the present invention will be made with reference to the drawings. As shown in Figure 1, the electric work machine 1 is a self-propelled, mobile work machine equipped with a mobile device 10. The traveling device 10 comprises a traveling frame 100 and a traveling mechanism 101. The traveling frame 100 is a structure to which the traveling mechanism 101 is attached. The travel mechanism 101 is provided on the left and right sides of the travel frame 100, respectively. That is, the travel mechanism 101 is arranged in pairs in the left-right width direction, perpendicular to the forward and reverse directions. In this embodiment, the travel mechanism 101 is a crawler-type travel mechanism. Specifically, the travel mechanism 101 comprises an idler 102, a drive wheel 103, a plurality of road wheels 104, an endless annular crawler belt 105, and a travel motor 106. The idler 102 is located at the front of the running frame 100, on the leading side in the forward direction. The drive wheel 103 is located at the rear of the running frame 100, on the leading side in the reverse direction. Multiple road wheels 104 are provided between the idler 102 and the drive wheel 103. The crawler belt 105 is wrapped around the idler 102, the drive wheel 103, and the road wheels 104. The travel motor 106 rotates the drive wheels 103. In this embodiment, a hydraulic motor is used for the travel motor 106. Each of the left and right travel mechanisms 101 rotates the crawler belt 105 by rotating the drive wheels 103. The electric work machine 1 according to this embodiment includes a work device 11 for performing a predetermined task. The electric work machine 1 also includes a turntable 12 fixed to a travel frame 100, a machine body 13 supported by the turntable 12, and a cabin 14 supported by the machine body 13. In this embodiment, the electric work machine 1 comprises a dozer device 11a and a shovel device 11b as the work device 11. The dozer device 11a is mounted in front of the traveling device 10. Specifically, the dozer device 11a comprises a dozer plate 110a, a support arm 111a to which the dozer plate 110a is connected at its tip, the support arm 111a being connected to the traveling frame 100 via a laterally extending shaft and capable of swinging vertically around the shaft, and a hydraulic cylinder 112a for swinging the support arm 111a. The shovel device 11b comprises a boom 110b, an arm 111b, a bucket 112b (a working tool), and hydraulic cylinders 113b, 114b, and 115b. The boom 110b has a base end and a tip end. The