Electric construction machine
View Patent ↗Provided is an electric construction machine adapted to prevent an electric current, after flowing in via a junction at which power transmission systems join together, from flowing into at least one connector to which an external power supply is not connected. Power transmission systems 71 A, 71 B, 71 C connected to connectors 59 A, 59 B, 59 C are all caused to join with a common system 73 at a junction before being connected to a control unit 35 . The power transmission systems 71 A, 71 B, and 71 C include switches 74 Aa, 74 Ab, 74 Ba, 74 Bb, 74 Ca, 74 Cb. In relay circuits 75 A, 75 B, 75 C, when a plug for an external power supply is connected to corresponding one of the connectors 59 A, 59 B, 59 C, connection of the corresponding connector connection detecting terminals and plug connection detecting terminals energizes a coil of the corresponding control relay (either 76 A, 76 B, or 76 C), then after switching contact points of the corresponding control relay to a closed state, energizes coils of the corresponding switches via the contact points, and switches contact points of the corresponding switches to a closed state.
1. An electric construction machine comprising:
an electric motor;
a hydraulic pump driven by the electric motor;
hydraulic actuators, each driven by a hydraulic fluid delivered from the hydraulic pump;
an internal battery that is an electric power supply source for the electric motor;
a plurality of connectors to which respective plugs for a plurality of kinds of external power supplies are adapted to be connected;
a sliding plate disposed that while selectively opening one of the plurality of connectors so as to be connectable to the corresponding one of the plugs for the external power supplies, blocks the remaining connectors so as to be unconnectable to the plugs for the external power supplies;
a plurality of power transmission systems each connected to one of the plurality of connectors; and
a battery charger to which the plurality of power transmission systems are connected via one common system, the battery charger being configured so that when any one of the plurality of connectors is connected to corresponding one of the plugs for the external power supplies, the battery charger supplies, to the internal battery, electric power supplied from the corresponding external power supply,
wherein the electric construction machine further comprises:
a plurality of switches, each disposed in one of the plurality of power transmission systems and each associated with one of the plurality of connectors;
a detection block that detects whether one of the plurality of connectors has been connected to corresponding one of the plugs for the external power supplies or whether one of the connectors has been selected for connection to corresponding one of the plugs for the external power supplies; and
a switching control block that conducts switching control so that among the plurality of switches, only the switches associated with the connector detected by the detection block will close and all the other switches will open,
wherein the detection block includes connector connection detecting terminals each disposed in one of the plurality of connectors and each connected to one of plug connection detecting terminals disposed in the plugs for the external power supplies;
wherein the switching control block is a plurality of relay circuits that each include a control relay associated with a combination of one of the connectors and one of the switches; and
wherein the plurality of relay circuits are each constructed so that when the plug for one of the external power supplies is connected to the corresponding one of the plurality of connectors, a coil of the corresponding relay is energized through connection of the corresponding connector connection detecting terminals and plug connection detecting terminals, then a contact point of the corresponding control relay changes to a closed state, then coils of the corresponding switches are energized via the contact point, and contact points of the corresponding switches are switched to a closed state.
2. An electric construction machine comprising:
an electric motor;
a hydraulic pump driven by the electric motor;
hydraulic actuators, each driven by a hydraulic fluid delivered from the hydraulic pump;
an internal battery that is an electric power supply source for the electric motor;
a plurality of connectors to which respective plugs for a plurality of kinds of external power supplies are adapted to be connected;
a sliding plate is disposed that while selectively opening one of the plurality of connectors so as to be connectable to the corresponding one of the plugs for the external power supplies, blocks the remaining connectors so as to be unconnectable to the plugs for the external power supplies;
a plurality of power transmission systems each connected to one of the plurality of connectors; and
a battery charger to which the plurality of power transmission systems are connected via one common system, the battery charger being configured so that when any one of the plurality of connectors is connected to corresponding one of the plugs for the external power supplies, the battery charger supplies, to the internal battery, electric power supplied from the corresponding external power supply,
wherein the electric construction machine further comprises:
a plurality of switches, each disposed in one of the plurality of power transmission systems and each associated with one of the plurality of connectors;
a detection block that detects whether one of the plurality of connectors has been connected to corresponding one of the plugs for the external power supplies or whether one of the connectors has been selected for connection to corresponding one of the plugs for the external power supplies; and
a switching control block that conducts switching control so that among the plurality of switches, only the switches associated with the connector detected by the detection block will close and all the other switches will open,
wherein the detection block includes a limit switch that detects a sliding position of the sliding plate; and
wherein the switching control block is a controller that conducts switching control so that among the plurality of switches, only the switches associated with a connector determined to be connectable to the corresponding plug for the external power supply will close and all the other switches will open.