Construction machine and method for using the same

Abstract

To provide a construction machine capable of achieving zero emission on site by simultaneously providing battery driving and a compact machine body, and a method for using the same.SOLUTION: An upper turning body 14 includes a frame body in which a main frame having a pivot and floor frames provided on both sides of the main frame in the upper turning body width direction are coupled. A driving cab 36 is provided in one of the floor frames. A power unit and a battery 53 which serves as its power source are provided in the other floor frame 35. The power unit includes an electric motor 39, a hydraulic pump 50 connected to the electric motor to be driven, an inverter 51 that controls the electric motor, and an electric circuit including an inverter power supply circuit for supplying power to the inverter. The inverter power supply circuit is configured to be able to switch the battery and a commercial power source to connect to the inverter, and the battery, the electric motor, and the hydraulic motor are arranged side by side in the longitudinal direction of the upper turning body.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to construction machinery and a method of using construction machinery. More specifically, the present invention relates to construction machinery provided with a hydraulic pump driven by an electric motor as a power source and a method of using the construction machinery.

Background Art

[0002] Emission regulations for construction machinery are becoming more stringent. In particular, from the perspective of zero emissions, battery-driven construction machinery may be required at the site. Instead of having an engine and a fuel tank, battery-driven construction machinery is equipped with an electric motor for driving a hydraulic pump and a power storage device such as a battery for supplying power to the electric motor. Further, when it is cable-connected to a commercial power source which is an external power source, the electric motor can be driven by the power supplied from the commercial power source, and there is an advantage that the power consumption of the battery can be suppressed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In conventional battery-driven construction machinery, by receiving the supply of commercial power, the mounting of the battery that also serves as a counterweight is minimized as much as possible, and the miniaturization of the machine body that enables so-called rearward small turning is realized. However, since this type of construction machinery is configured on the premise of working at the same location within the factory, it can only operate in a limited location. When battery drive is emphasized in the case of moving between sites or when setup for construction is involved, there is a problem that a compact machine body cannot be achieved.

[0005] Therefore, an object of the present invention is to provide a construction machine and a method of using the construction machine that can achieve both battery drive and a compact body and can achieve zero emissions at the construction site.

Means for Solving the Problems

[0006] In order to achieve the above object, a construction machine according to the present invention includes a lower traveling body, an upper slewing body rotatably provided on the upper part of the lower traveling body, a working device vertically movably provided at the front part of the upper slewing body, and a counterweight mounted on the rear end of the upper slewing body. In the construction machine, the upper slewing body includes a frame body in which a main frame having a slewing axis and floor frames provided on both sides in the width direction of the upper slewing body of the main frame are integrally coupled. A driver's cab is provided on one side floor frame, and a power unit and a battery serving as its power source are provided on the other side floor frame. The power unit includes an electric motor, a hydraulic pump driven by being connected to the electric motor, an inverter for controlling the electric motor, and an electric circuit including an inverter power supply circuit for supplying power to the inverter. The inverter power supply circuit is configured to be able to switch and connect the battery and the commercial power supply to the inverter. The battery, the electric motor, and the hydraulic pump are arranged side by side in the front-rear direction of the upper slewing body.

[0007] Further, the battery is arranged in front with respect to a vertical plane in the width direction of the upper slewing body passing through the slewing axis.

[0008] Furthermore, the power unit is provided with a hydraulic circuit connected to an external hydraulic unit for emergency escape, and the electric circuit includes a manual start switch for enabling power supply to the inverter and a manual changeover switch for invalidating the signal of the start switch to switch the power supply from a state of being possible to a state of being impossible and vice versa.

[0009] In addition, the upper revolving body is provided with jacks at four locations on the front, rear, left, and right, and a cable connection part for connecting the power transmission cable of the commercial power supply is provided at a position corresponding to one side of the two jacks on the rear side.

[0010] Moreover, the method of using the construction machine of the present invention is the method of using the construction machine, wherein the construction machine carried into the site is self-driven to the construction position, the upper revolving body is supported by grounding the jacks, and then, with the conduction path between the power transmission cable of the commercial power supply and the inverter secured via the cable connection part, the power supply to the inverter is switched from the battery to the commercial power supply.

Advantages of the Invention

[0011] According to the construction machine of the present invention, in the width direction of the upper revolving body with a counterweight mounted on the rear end, a power unit is provided on the opposite side of the driver's cab, and the battery, electric motor, and hydraulic pump for functioning the power unit are arranged side by side in the longitudinal direction of the upper revolving body. Therefore, a battery sized to match the operating time of the power unit can be arranged in a wide space without occupying the driver's cab and counterweight. That is, a construction machine that can achieve both battery drive and a compact body and achieve zero emissions at the site can be obtained.

[0012] Also, since the battery is arranged forward with respect to the vertical plane in the width direction of the upper revolving body passing through the revolving axis of the upper revolving body, the arrangement of the battery has no adverse effect on the rear end revolving radius of the upper revolving body determined by the position of the counterweight, and the battery can be arranged separately from the rear side structure at the position (vertical plane) of the revolving axis. As a result, when changing the design from the conventional engine drive type to the battery drive type, it is possible to provide the hydraulic pump at the same position, and in particular, the development and model change of small construction machines that exhibit mobility in narrow areas can proceed smoothly.

[0013] Furthermore, a hydraulic circuit is provided that connects to an external hydraulic unit for emergency escape. Since the electric circuit includes a changeover switch that invalidates the signal of the start switch to make power supply to the inverter impossible from possible and vice versa, it is possible to prevent the unintentional operation of the electric motor during the operation of the external hydraulic unit. That is, when an abnormality occurs in the system, it is possible to safely proceed with the process of obtaining hydraulic pressure from the outside and performing an emergency escape (for example, escaping from a non-self-propelled state) while protecting the hydraulic circuit by invalidating the signal of the start switch.

[0014] In addition, jacks are provided at four locations, front, rear, left, and right, of the upper slewing body, and a cable connection portion for connecting a power transmission cable of a commercial power supply is provided at a position corresponding to one side of the two jacks on the rear side. Therefore, it is possible to avoid the counterweight that easily obstructs the cable connection work, and it is possible to easily connect the power transmission cable drawn from the power transmission facility to the construction machine to the cable connection portion. In particular, at the time of construction when both the grounding state of the jack and the connection state of the power transmission cable are made, there is no risk of damaging the power transmission cable due to traveling or slewing operations, so there is an advantage that the routing of the power transmission cable can be made simple along the ground.

[0015] Also, according to the method of using the construction machine of the present invention, the construction machine transported to the site is self-propelled to the construction position, the jacks are grounded to support the upper slewing body, and then the power supply to the inverter is switched from the battery to the commercial power supply while ensuring the conduction path between the power transmission cable of the commercial power supply and the inverter via the cable connection portion. Therefore, it is possible to meet the needs of the site where battery drive is emphasized when setting up the construction. In particular, a construction machine for pile driving (for example, a pile driver) having many functions suitable for various construction needs, after moving to the construction position, grounds the jacks and stops on the spot for a long time. Depending on the site, the driving force becomes extremely large. Therefore, as a power supply selection method of using the battery during non-construction times such as movement and setup work and switching to the use of commercial power supply during main construction when driving the working device, it is particularly effective.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0017] Figures 1 to 8 show an example form in which the present invention is applied to a pile driver which is an example of a construction machine. The pile driver 11 is, as shown in FIG. 1, a dual-purpose machine capable of switching between steel pipe pile construction and ground improvement construction, and includes a lower traveling body 12 equipped with crawlers, and an upper swing body 14 rotatably provided on the lower traveling body 12 via a swing bearing 13. A base machine (airframe) 15 composed of the above, a leader 16 erected at the front of the upper swing body 14, and a hoisting cylinder 17 that supports the leader 16 from behind. Further, a leader support 18 that supports the leader 16 so as to be able to move up and down is provided at the front of the upper swing body 14. Furthermore, stabilizing jacks 19 are provided at four locations on the front, rear, left, and right of the upper swing body 14, and a counterweight 20 for balancing the pile driver 11 is mounted at the rear end of the upper swing body 14.

[0018] The leader 16 is formed by detachably connecting a plurality of leader members to each other. A top sheave 21 is attached to the upper end, and a lower guide 22 is attached to the lower end. An auger 23, which is an example of a working device, is attached to the front surface of the leader 16 so as to be movable up and down. Each leader member has flange members provided at the upper and lower ends detachably connected to each other by bolts and nuts. When transporting the pile driver 11, the upper leader member is removed according to the transport conditions and transported separately from the machine body. In this case, on the machine body side, heavy objects such as the auger 23 and the counterweight 20 are removed as necessary, and the leader 16 is set in a transport posture (not shown) where it is laid down backward.

[0019] The auger 23 is configured around a device main body 23a that rotatably supports a drive shaft 24, and a pair of left and right guide gibs 23b, 23b that are in sliding contact with the guide pipes 25, 25 of the leader 16 protrude rearward. At the upper and lower parts of the auger 23, both ends of a lifting chain 28 spanned between a drive sprocket 26 provided at the lower end of the leader 16 and a driven sprocket 27 provided at the upper end are respectively attached, constituting a chain-type auger lifting device. The auger lifting device rotationally drives the drive sprocket 26 with a hydraulic motor, and moves the lifting chain 28 wound around the drive sprocket 26 and the driven sprocket 27 in the vertical direction, thereby lifting and lowering the auger 23 along the front surface of the leader 16.

[0020] When the pile driver 11 is used for the purpose of burying a steel pipe pile, a steel pipe pile 29 is used as a construction member. The steel pipe pile 29 is connected to the lower end of the drive shaft 24 via a rod cap 30. Then, in a working start state where all four jacks 19 are grounded, the auger 23 is lowered while rotationally driving the drive shaft 24 under the drive of the hydraulic motor 23c for auger drive, thereby pressing the steel pipe pile 29 into the ground.

[0021] On the other hand, when the pile driver 11 is used for ground improvement, a hollow rod (not shown) is used as a construction member. The hollow rod is attached in a state of penetrating the apparatus main body 23a. At the upper end, a grout hose 31 for injecting a ground improvement agent is connected via a swivel, and at the lower end, an excavation head having an excavation blade and an agitation blade is attached. The injection hose 31 is a supply hose for the ground improvement agent pumped from a batcher plant (not shown). As shown in FIG. 2, it is introduced from the rear side of the pile driver 11, provided along one side of the machine body, and after rising upward at the front part of the machine body where a flow meter 32 is installed, it is routed along the leader 16. Then, in the working start state where all four jacks 19 are grounded, while rotating the hollow rod, it is lowered along the leader 16, and the ground improvement agent sent through the hollow rod is jetted from the tip of the excavation head into the excavation hole, thereby mixing the earth and sand excavated by the excavation blade of the excavation head and the ground improvement agent with the agitation blade of the excavation head.

[0022] As shown in FIG. 3, the upper swing body 14 includes a frame body in which a rectangular box-shaped main frame 33 having a swing bearing 13 attached to the lower surface and floor frames 34 and 35 framed on both sides in the width direction of the main frame 33 are integrally coupled. This frame body has a vertical swing axis PV passing through the center of the swing bearing 13 in the main frame 33, and the rear swing radius R of the upper swing body 14 is defined by this swing axis PV and the rear end position of the counterweight 20. Also, the two rear jacks 19 among the four front, rear, left, and right positions are arranged inside an arc having the rear swing radius R of the upper swing body 14. And in the state where all four jacks 19 are grounded, four support points are formed around the upper swing body 14 in the front, rear, left, and right directions, and a stable region in the shape of a rectangle in plan view connecting these is created. The center of gravity of the pile driver 11 is always placed within the stable region, but the center of gravity of the counterweight 20 is placed outside the rear part of the stable region. For example, during main construction when the auger 23 is driven, the counterweight 20 plays a role in improving the pile pulling performance.

[0023] At the front of the right floor frame 34, a driver's cab 36 is installed where the operator boards to perform driving operations. Also, at the rear of the right floor frame 34, an equipment storage room 38 for accommodating hydraulic equipment such as a hydraulic oil tank 37 is provided. On the other hand, on the left floor frame 35, a power unit (hydraulic power source device) for supplying pressure oil driven by an electric motor 39 and a housing structure 40 for accommodating it are provided.

[0024] Inside the driver's cab 36, equipment such as operation levers, operation pedals, various operation switches, and a touch panel display 41 for performing operations such as traveling, turning, raising and lowering, and rotating the jack 19 and the auger 23 are intensively arranged in the vicinity of the driver's seat 42 in consideration of operability. As shown in FIG. 5, these operation system devices are wired and connected to a controller 43 that comprehensively controls the system of the pile driver 11. The controller 43 is mainly composed of a CPU that performs various arithmetic processes based on the operator's operation commands and the state of the pile driver 11, and executes a control program stored in an internal memory (storage area) to perform predetermined controls, such as controls related to power management of the power unit.

[0025] Information acquired by various sensors included in the vehicle body control device 44 (for example, information indicating the operating state of the auger 23) is input to a construction management device installed inside the driver's cab 36 as construction-related information. The construction management device is configured to be able to execute a control program for controlling construction methods implemented based on a construction plan, such as a precast pile method, a cast-in-place pile method, or a ground improvement method, and includes an external storage device for storing various data during actual construction at the construction site, and a display 41 on which the operator can check the execution results of the control program on the display screen or input data by touch panel operation.

[0026] At the rear of the driver's seat 42 in the driver's cab 36, an air conditioner unit (air conditioning device) is provided. As shown in Fig. 3, the air conditioner unit 45 includes an electric compressor 46 (see also Fig. 5) installed on the ceiling of the equipment storage compartment 38, and a heat exchange cycle is configured to circulate refrigerant through each device of the electric compressor (compressor) 46, condenser (condenser), expansion valve (expansion valve), and evaporator (evaporator) connected by a closed pipeline. Thereby, while the refrigerant is circulating, the evaporator takes away the surrounding heat to cool the driver's cab 36. On the other hand, in the heating operation, the cooling water of the power unit is used as the heat medium. As shown in Figs. 5 and 6, an electric heater 49 is provided in a cooling water circuit (closed pipeline) 48 that operates a water pump 47 to circulate the cooling water. While the cooling water is circulating, the cooling water heated by the electric heater 49 is radiated by a heating core (air heating section) built into the air conditioner unit 45, and the air (air from the blower) passing through this heating core becomes warm air to heat the driver's cab 36.

[0027] As shown in Figs. 2 to 6, the power unit mainly includes an electric motor 39, a hydraulic pump (multi-connected pump) 50 driven by being connected to the electric motor 39, an inverter 51 that controls the electric motor 39, and an electric circuit including an inverter power supply circuit 52 that supplies power to the inverter 51, and is schematically configured to be housed in a housing structure 40 together with a high-voltage battery (hereinafter referred to as the first battery) 53 that serves as a power source.

[0028] The electric motor 39 is a water-cooled electric motor equipped with a water circuit that indirectly cools the inside with cooling water. The tip of the output shaft is directed rearward (right direction in Fig. 2) in the longitudinal direction of the upper swing body and is mounted on the floor frame 35 in a vibration-proof state. Also, as shown in Fig. 6, the water circuit of the electric motor 39 constitutes a part of the cooling water circuit 48, which is a heat medium circuit.

[0029] The cooling water circuit 48 has a first DC step-down converter (water-cooled DC-DC converter with a water circuit) 54 connected in parallel with the electric motor 39 in the discharge-side flow path of the water pump 47, and a water cooler 55 connected in parallel with the electric heater 49 in the suction-side flow path of the water pump 47. The water cooler 55 is a heat exchanger equipped with an electric fan. By passing air through the heat dissipation cooling core, it dissipates the heat of the cooling water that has passed through the electric motor 39 and the first DC step-down converter 54, and returns the cooled cooling water to the electric motor 39 and the first DC step-down converter 54, thereby maintaining the temperatures of these devices within an appropriate range.

[0030] The discharge-side flow path of the water pump 47 is provided with a flow control valve (not shown) for ensuring a certain amount of cooling water for the electric motor 39, and is configured to be shuntable into a motor-side shunt path 48a that supplies cooling water to the electric motor 39 and a step-down converter-side shunt path 48b that supplies cooling water to the first DC step-down converter 54. On the other hand, the suction-side flow path of the water pump 47 is configured to be shuntable into a cooler-side shunt path 48c that supplies the return of the cooling water to the water cooler 55 and a heater-side shunt path 48d that supplies the cooling water to the electric heater 49.

[0031] A cooling water tank (expansion tank) 56 is provided in the cooler-side shunt path 48c. When the cooling water thermally expands, the cooling water (overflow portion) is guided from the air vent flow paths 48e and 48f connected to the upstream side and the downstream side of the water cooler 55 respectively and stored. When the pressure in the cooling water tank 56 exceeds the set pressure, air is vented to the outside from an air vent cap (not shown) provided at the upper end of the cooling water tank 56. The cooling water discharged from the cooling water tank 56 merges with the return of the cooling water through the water supply flow path 48g. Although not shown in the figure, as state monitoring means, a water temperature sensor is attached to the water cooler 55, and a water level sensor is attached to the cooling water tank 56, and signals from each sensor can be input to the controller 43.

[0032] Here, the cooling water heated as it passes through the water circuits of each device 39, 54 returns to the water pump 47 through the cooler side shunt passage 48c. However, when the electric heater 49 is energized, that is, when a valve (not shown) is opened during the heating operation of the air conditioner unit 45, a flow of cooling water is generated in the heater side shunt passage 48d, and the cooling water is heated by the heat of the electric heater 49. Then, the heated cooling water is introduced into the heating core within the air conditioner unit 45, and heat exchange occurs with the air (blowing air) passing through the heating core. In this way, the cooling water circulating through the cooling water circuit 48 is utilized as the heat medium for heating.

[0033] As shown in FIG. 5 and the like, the first battery 53 is a power storage module including a plurality of rechargeable battery packs 57, a battery management unit 58, and an opener (contact) 59. In this embodiment, 21 battery packs 57 each composed of a lithium ion battery with a capacity of approximately 40 Ah are used. For example, if the battery packs 57 with a use voltage of approximately 32.4 V are connected in series, the first battery 53 can output a DC voltage of approximately 680 V. The battery management unit 58 uses, for example, a BMU (Battery Management Unit) to manage the voltage and temperature of the battery packs 57, transmits each acquired data to the controller 43, and is configured to control the opening and closing of the contacts of the opener 59 in response to commands from the controller 43.

[0034] The DC power stored in the first battery 53 is supplied to each device such as the electric compressor 46 and the electric heater 49 based on commands from the controller 43. For the electric motor 39, power converted from DC to AC by the inverter 51 is supplied. As a result, the first battery 53 is discharged. On the other hand, when the remaining capacity SOC (State Of Charge) of the first battery 53 decreases, power converted from AC to DC by the stabilization power supply (AC - DC converter) 60 is supplied while the commercial power supply (AC power supply source) and the first battery 53 are electrically connected. As a result, the first battery 53 is charged.

[0035] The use of such a commercial power source is carried out by providing a protection circuit such as a circuit breaker (breaker) 61 in the electric circuit and then, for example, taking power from a power outlet in a facility that manages the pile driver 11 or from a high-voltage line at a construction site. Specifically, in the management facility, a power transmission cable 64 is drawn from an AC step-up transformer (charger) 62 to the pile driver 11, and in the construction site, from a stationary cubicle (AC step-down transformer) 63 to the pile driver 11. Charging is performed with the power transmission cable 64 connected by a connector 65 which is a cable connection part. Note that the power transmission cable 64 is prepared separately, for example, a power supply cable for construction when supplying a large amount of power and a charging cable for charging when supplying a small amount of power. The one for construction use, although it depends on the scale of the site, is, for example, about 20 m or more in length and is used.

[0036] Also, the power supply control by the controller 43 is also performed for a lead battery (hereinafter referred to as the second battery) 66 provided separately from the first battery 53. The controller 43 selects, for example, either the first battery 53 or the stabilized power supply 60 as the power source to be used based on the remaining capacity SOC of the first battery 53, the connection state of the power transmission cable 64, an arbitrary selection by the operator, etc., and performs control to supply the DC power of the selected power source to the second battery 66.

[0037] The second battery 66 stores the DC power supplied from the first battery 53 or the stabilized power supply 60 via the first DC step-down transformer (DC-DC converter) 54, and supplies DC power as the operating power source for devices other than high-voltage devices such as the electric motor 39, for example, the water cooler 55, the oil cooler 67, the water pump 47, etc., and as the control power source for various devices such as the controller 43, the inverter 51, and the battery management unit 58 that receives power supply via the second DC step-down transformer (DC-DC converter) 68.

[0038] The inverter power supply circuit 52 includes a switch circuit that enables switching and connecting the first battery 53 and the commercial power supply to the inverter 51. As the switch circuit, for example, a plurality of relays are used to control the opening and closing of the contacts of a switch (contactor), and it is configured to switch between the AC power and the DC power input to the inverter 51. Hereinafter, the switching operation procedure based on the operator's selection will be described with reference to FIGS. 5 and 7.

[0039] FIG. 7 shows an electrical circuit of an operation input system for power management. This electrical circuit includes a start switch 69 for starting the system, a charge switch 70 for obtaining commercial power and charging the first battery 53 and the second battery 66 respectively, an operation / stop switch 71 for operating / stopping the electric motor 39, and an operation mode selection switch 72 for switching the operation mode of the power unit between battery drive and commercial power drive. Further, the electrical circuit has a main power circuit PL provided with a changeover switch 87 to be described later, and a control power supply circuit CL for operating a power relay 73 provided between the main power circuit PL and the power line 74 of the controller 43. The start switch 69 and the charge switch 70 are provided in parallel in the control power supply circuit CL.

[0040] Each of the switches 69, 70, 71, 72 is provided in the driver's cab 36. For example, the start switch 69, the charge switch 70, and the operation / stop switch 71 use self-return push-button switches, and among them, the operation / stop switch 71 uses a two-point push-button switch composed of an operation button and a stop button. Also, the operation mode selection switch 72 uses a selector switch that operates the contact portion of the switch by rotating a knob.

[0041] When the start switch 69 is pressed down to turn it on, the power relay 73 switches, and the power line 74 of the controller 43 becomes energized to start the controller 43. At this time, the lamp 69a attached to the start switch 69 lights up in response to a command from the controller 43, and the power relay 73 is held in the switched state. As a result, the inverter power supply circuit 52 (not shown in FIG. 7) incorporated in the electric circuit can be switched and controlled according to the command of the controller 43, that is, it becomes the start state in which power supply to the inverter 51 is possible. In this start state, the display screen of the display 41 displays, for example, either the transport mode or the construction mode as the operation mode selected by the operation mode selection switch 72. In this case, the transport mode corresponds to battery drive, and the construction mode corresponds to commercial power supply drive.

[0042] When the transport mode is selected, the controller 43 operates the inverter power supply circuit 52 and holds the circuit between the first battery 53 and the inverter 51 in a connected state (conductive state), and gives a command to switch the switch 59 to the closed state to the battery management unit 58. As a result, the switch 59 is switched to the closed state, and the power of the first battery 53 can be supplied to the inverter 51.

[0043] Here, when the operation button of the operation / stop switch 71 is pressed down to turn it on, an operation input is made to the controller 43, and the lamp 71a attached to the operation button lights up. Then, in the inverter 51, under the situation of receiving power supply from the first battery 53, the control circuit operates according to the command of the controller 43 to control the rotation of the electric motor 39. In this way, when the hydraulic pump 50 is driven by the electric motor 39, in the hydraulic circuit of the pile driver 11, for example, it becomes a state in which hydraulic supply can be made to the hydraulic motor of the lower traveling body 12 or the hydraulic cylinder of the jack 19, and the pile driver 11 can be self-propelled and the setup work for construction can be performed by battery drive.

[0044] On one hand, after creating the connection state of the power transmission cable 64 and when the construction mode is selected, the controller 43 activates the inverter power supply circuit 52 and maintains the circuit connection state (conductive state) between the cubicle 63 and the inverter 51. As a result, the power of the commercial power supply can be supplied to both the inverter 51 and the stabilizer power supply 60.

[0045] Here, when the operation button of the operation / stop switch 71 is pressed down to turn it on, an operation input is made to the controller 43 in the same manner as in the above-described transport mode. Then, in the inverter 51, under the situation of receiving power supply from the commercial power supply, the control circuit is activated according to the command of the controller 43 to control the rotation of the electric motor 39. In this way, when the hydraulic pump 50 is driven by the electric motor 39, in the hydraulic circuit of the pile driver 11, for example, a state where hydraulic supply can be provided to the auger drive hydraulic motor 23c is achieved, and the construction of the pile driver 11 can be performed by driving with the commercial power supply. Note that in the state where the construction mode is selected, power is distributed according to the load, and the first battery 53 and the second battery 66 can be charged via the stabilizer power supply 60 respectively.

[0046] Also, even when the pile driver 11 is placed in a resting state (for example, in a garage), by creating a state (cable connection state) where it is possible to receive the power supply of the commercial power supply, the first battery 53 and the second battery 66 can be charged respectively. In this case, when the charging switch 70 is pressed down to turn it on, the power relay 73 is switched, and the power line 74 of the controller 43 becomes energized to activate the controller 43. At this time, the lamp 70a attached to the charging switch 70 lights up upon receiving a command from the controller 43, and the power relay 73 is held in the switched state.

[0047] The controller 43 gives an instruction to the battery management unit 58 to switch the switch 59 to the closed state, whereby the switch 59 is switched to the closed state. Then, under the situation where the stabilized power supply 60 is receiving power supply from the commercial power supply, the control circuit operates according to the instruction of the controller 43 to charge the first battery 53. When the charging of the first battery 53 is completed (fully charged state), the controller 43 gives an instruction to the battery management unit 58 to switch the switch 59 to the open state and controls the first DC step-down converter 54 to charge the second battery 66 for a predetermined charging time. Thus, when the charging switch 70 is turned on, the batteries 53 and 66 can be charged by the charging current controlled by the stabilized power supply 60 and the first DC step-down converter 54, and the pile driver 11 can be continuously operated by battery drive.

[0048] Hereinafter, the arrangement of each device constituting the system will be described with reference to FIGS. 2 to 4. The housing structure 40 of the power unit is composed of a box installed on the floor frame 35. Since the ceiling part provided with a plurality of handrails 40a can also serve as a scaffold that can be raised and lowered from the front side of the upper swing body 14, the overall rigidity is enhanced by the reinforcing material. The inside of the box forms a storage space that is approximately divided into two equal parts in the front-rear direction of the upper swing body (the left-right direction in FIG. 3) with a vertical plane S in the width direction of the upper swing body passing through the swing axis PV as a boundary. Further, on the outer surface of the box, a pair of front and rear openings corresponding to each storage space are provided, and flip-up doors 40b, 40b are attached to these openings. Furthermore, the inner surface of the box (the surface on the main frame 33 side) has a structure that can be disassembled for maintenance and the like.

[0049] The front storage space is provided with an electrical chamber 75 composed of a housing with waterproof and dustproof properties ensured. The electrical chamber 75 occupies a large part of the front storage space, and the bottom of the housing is submerged inside the floor frame 35. As shown in FIG. 4, it is attached in a vibration-proof state via a bracket 76 provided with vibration-proof rubber 76a. Inside the housing, mainly the first battery 53, the inverter 51, and the stabilized power supply 60 are installed.

[0050] The size (outer shape) of the first battery 53 is such that the dimension in the width direction of the upper swing body is smaller than the dimension in the vertical direction. In the front-rear direction of the upper swing body, three battery packs 57 stacked in six layers are arranged side by side, and a battery pack 57 stacked in three layers is arranged at the foremost part, and a total of 21 battery packs 57 are integrated. Also, there is a space for two layers in the vertical direction below the battery pack 57 stacked in three layers, and a stabilization power supply 60 is arranged using this space.

[0051] The inverter 51 has an operation part 51a provided on the front surface of a rectangular parallelepiped shape and is arranged with the first battery 53 on its back at the outer part of the first battery 53. Thereby, the first battery 53 and the inverter 51 are arranged side by side in the width direction of the upper swing body. Even when the electric chamber 75 is in an installed state, if the outer surface panel constituting the outer surface of the housing is removed, it is possible to easily access the operation part 51a of the inverter 51 and the like. On the other hand, if the inner surface panel constituting the inner surface of the housing is removed, it is possible to easily access the first battery 53 and the like.

[0052] In the rear accommodation space, the electric motor 39 and the hydraulic pump 50 are arranged to fill the front-rear direction, and auxiliary machines such as a water pump 47 and a first DC step-down converter 54 are arranged around them in consideration of the connection of the water circuit. The upper part of the rear accommodation space communicates with an upper equipment accommodation space formed by covering the ceiling opening of the accommodation structure 40 with a box-shaped flat cover 77, and auxiliary machines such as a water cooler 55, a cooling water tank 56, and an oil cooler 67 are arranged in this upper equipment accommodation space. Both the water cooler 55 and the oil cooler 67 are installed with the axis of the electric fan facing the vertical direction, and an upward airflow is formed in the rear accommodation space during operation.

[0053] On the upper surface of the cover 77, there is an opening / closing hatch (not shown) that allows access to the cooling water tank 56, and on the front, rear, left, and right four side surfaces of the cover 77, there are punching metal-shaped openings with a large number of holes. During the operation of the power unit, the outside air introduced into the rear-side accommodation space of the accommodation structure 40 through the floor frame 35 passes through the cooling cores of the water cooler 55 and the oil cooler 67, becomes warm air (exhaust air), and is discharged to the outside from the openings of the cover 77.

[0054] The various devices arranged in this way are basically such that the first battery 53, the electric motor 39, and the hydraulic pump 50 are arranged side by side in the front-rear direction of the upper swing body. In these relative positional relationships, from the rear side to the front side, the hydraulic pump 50, the electric motor 39, and the first battery 53 are arranged in this order. Also, in terms of the positional relationship with the swing axis PV, the first battery 53 is arranged in front with respect to the vertical plane S, and the electric motor 39 and the hydraulic pump 50 are arranged behind. Furthermore, the first battery 53, the electric motor 39, and the hydraulic pump 50 are all arranged within the stable region formed by the four support points of the jack 19, and the weight balance in the arrangement of each part, particularly the weight balance in the front-rear direction of the upper swing body, is considered.

[0055] Also, within the accommodation structure 40, a space of a size suitable for power transmission, oil supply, etc. is secured. In this space, for example, as shown in FIG. 3, a lead-in cable 78 from the connector 65 to the power unit is installed. The connector 65 is connected in a pluggable manner to the power transmission cable 64 loop-suspended by a hanger 79 at a position corresponding to the right-side jack 19 with the operator's cab 36 among the two rear-side jacks 19, for example, at the upper part of the jack 19 (see also FIG. 2), and relays between the power transmission cable 64 and the lead-in cable 78.

[0056] The lead-in cable 78 forms a conduction path, together with the power transmission cable 64, for a stabilizing power supply 60, an inverter 51, etc. This conduction path is formed, for example, with a connector 65 attached to the outer surface of a cable introduction chamber 80 installed between the equipment accommodation chamber 38 and the counterweight 20, introduced from the outside into the cable introduction chamber 80 via the connector 65, and passing through a cable relay chamber 81 installed between the accommodation structure 40 and the counterweight 20. A circuit breaker 61 for cutting off the power supply from the power transmission cable 64 during a load short circuit or overloading is provided in this cable relay chamber 81. The specific routing method of the lead-in cable 78 crosses the front space of the counterweight 20, extends from one side (right side) to the other side (left side) in the width direction of the upper swivel body, is drawn into the interior of the accommodation structure 40 via the circuit breaker 61, and extends from the rear accommodation space to the front accommodation space where the electrical chamber 75 is located.

[0057] Hereinafter, the movement of the pile driver 11 and the usage method at the construction site will be described. First, when moving (transporting) between construction sites, select the transport mode as the operation mode of the power unit, and for example, perform the running operation when loading and unloading the power unit onto the loading platform of a transport vehicle by battery drive. That is, the power unit is operated by obtaining power from the first battery 53 mounted on the pile driver 11. After the pile driver 11 is carried into the construction site, the leader 16 is erected from the horizontal state through a predetermined procedure, and the pile driver 11 is self-driven according to the display on the guidance screen of the display 41 and moved from the current position to the construction position (target pile core position).

[0058] At the construction site, after stopping the pile driver 11 on the spot, all four jacks 19 are grounded to stably support the upper slewing body 14. Then, the power cable 64 is drawn from the cubicle 63 to the pile driver 11, and after ensuring the conduction path between the power cable 64 and the inverter 51 via the connector 65, the operation mode selection switch 72 is switched to switch from the transport mode to the construction mode. That is, the power supply to the inverter 51 is switched from the first battery 53 to the commercial power supply. And, for example, when performing steel pipe pile construction (Figure 1), the rotation and lifting operations of the auger 23 are performed by driving with the commercial power supply. That is, the power unit is operated by obtaining power from the commercial power supply which is an external power source. Thus, in the power unit, by controlling the rotation of the electric motor 39, the supply amount of the hydraulic oil to the hydraulic motor 23c for driving the auger etc. is adjusted, and thereby, the rotation state of the auger 23 is maintained at a speed suitable for the state of the ground.

[0059] Here, when adding a section to the steel pipe pile 29, each operation such as the jack 19 and slewing is performed in a predetermined procedure. During operations other than such main construction, once the connection state of the power cable 64 is released, while the connection of the power cable 64 is maintained, the first battery 53 is charged, and the remaining capacity SOC of the first battery 53 which has decreased due to self-propelling and construction setup work is restored. After going through a predetermined pile joining operation, the auger 23 is driven again to push the steel pipe pile 29 forward while applying rotation to it, so that the steel pipe pile 29 is embedded deep into the ground. At this time, in the construction management device, various acquired data (for example, construction torque for each depth) and the pile number of the construction target are associated and sequentially stored in the external storage device. When the construction is completed, the connection state of the power cable 64 is released, and after switching the operation mode from the construction mode to the transport mode, the traveling operation toward the next construction site is performed by driving with the battery. Note that the selection of the operation mode can be automatically switched and controlled by detecting the connection state of the power cable 64, for example, in addition to the manual operation by the operator.

[0060] By the way, in the pile driver 11 placed in various usage environments, when an abnormality occurs in the system for some reason and it becomes impossible to self-run, a function that allows for an emergency escape from the work location is required. Therefore, the power unit is provided with a hydraulic circuit that connects to an external hydraulic unit for emergency escape.

[0061] As shown in FIG. 8, the hydraulic circuit includes a piping connection portion 82 to which a hydraulic hose from an external hydraulic unit (not shown) is connected. The piping connection portions 82 are, for example, self-sealing couplings P1, P2, P3, P4, T provided at appropriate positions at the rear of the upper swing body 14. The self-sealing coupling has its valve held in a closed state when not connected and opens to a communicating state when connected. The external hydraulic unit supplies the hydraulic oil pressurized by a hydraulic pump to the hydraulic circuit of the power unit via a hydraulic hose, and recovers the hydraulic oil that returns via the hydraulic hose from the return circuit (T line) passing through each operation valve V1 to V4 into the hydraulic oil tank.

[0062] The oil passage connected to the hydraulic hose is connected to the corresponding discharge oil passage (P line) of the hydraulic pump (multi-pump) 50, and while preventing backflow to the hydraulic pump 50 by the sealing action of the check valves 83 to 86, it supplies hydraulic oil to the operation valves V1 to V4. As a result, the pile driver 11 can perform the same driving operations as in normal times. For example, the lower traveling body 12 can be driven to travel in the reverse direction to escape from the non-self-running state.

[0063] Also, for the purpose of protecting the hydraulic circuit during emergency escape, the electric circuit of the power unit is provided with a changeover switch 87 as shown in FIG. 7 that invalidates the signal of the start switch 69 to switch the power supply to the inverter 51 from possible to impossible and vice versa. The changeover switch 87 uses a toggle switch or the like that holds the contact switching state after the switch operation, and is provided, for example, in the driver's cab 36.

[0064] When the changeover switch 87 is switched from the normal state shown in FIG. 7, the main power circuit PL is switched to the OFF state. As a result, the controller 43, which can no longer obtain power, stops the system and turns off the power. Even in this state (the state where the main power circuit PL is OFF), the control power supply circuit CL is energized by depressing the start switch 69, and the coil can be excited to operate the power relay 73. However, since the main power circuit PL has been switched to the OFF state by the changeover switch 87, the power line 74 is not energized, and the controller 43 does not restart.

[0065] That is, when an abnormality occurs in the system and it becomes impossible to self-run, the system is stopped in response to the switching operation of the changeover switch 87. Once the system is turned off, even if the start switch 69 is turned on, the system does not start, and power is not supplied to the inverter 51 (power supply impossible state). Also, when the changeover switch 87 is switched, the attached lamp 87a lights up, and thus the switching operation state is notified via the lamp 87a. By taking such safety measures, the hydraulic power source of the pile driver 11 can be transferred to an external hydraulic unit.

[0066] As described above, according to the construction machine of the present invention, in the width direction of the upper swing body 14 equipped with the counterweight 20 at the rear end, a power unit is provided on the side opposite to the driver's cab 36, and the battery 53, electric motor 39, and hydraulic pump 50 that function the power unit are arranged side by side in the longitudinal direction of the upper swing body. Therefore, a battery 53 sized according to the operating time of the power unit can be arranged in a wide space not occupied by the driver's cab 36 and the counterweight 20. That is, a construction machine that can achieve both battery drive and a compact body and zero emissions at the site can be obtained.

[0067] In addition, since the battery 53 is disposed forward with respect to the vertical plane S in the width direction of the upper swing body 14 passing through the swing axis PV of the upper swing body 14, the arrangement of the battery 53 has no adverse effect on the rear end swing radius R of the upper swing body 14 determined by the position of the counterweight 20, and the battery 53 can be separated from the rear side structure at the position (vertical plane S) of the swing axis PV and arranged. As a result, when changing the design from the conventional engine drive type to the battery drive type, it becomes possible to provide the hydraulic pump 50 at the same position, and in particular, the development and model change of small construction machines that exhibit mobility in narrow areas can proceed smoothly.

[0068] Furthermore, a hydraulic circuit connected to an external hydraulic unit for emergency escape is provided, and the electric circuit includes a changeover switch 87 that switches between a state where the signal of the start switch 69 is invalidated and power supply to the inverter 51 is made impossible from possible and vice versa. Therefore, during the operation of the external hydraulic unit, unintentional operation of the electric motor 39 can be prevented. That is, when an abnormality occurs in the system, while protecting the hydraulic circuit by invalidating the signal of the start switch 69, it is possible to safely proceed with the process of obtaining hydraulic pressure from the outside and making an emergency escape (for example, escaping from a non-self-propelled state).

[0069] In addition, jacks 19 are provided at four locations, front, rear, left, and right, of the upper swing body 14, and a cable connection portion 65 for connecting the power transmission cable 64 of the commercial power supply is provided at a position corresponding to one side of the two rear jacks 19. Therefore, it becomes possible to avoid the counterweight 20 that easily obstructs the cable connection work, and the power transmission cable 64 drawn from the power transmission facility to the construction machine can be easily connected to the cable connection portion 65. In particular, during construction when both the grounding state of the jack 19 and the connection state of the power transmission cable 64 are made, there is no risk of damaging the power transmission cable 64 due to running or turning operations, so there is an advantage that the routing of the power transmission cable 64 can be made simple along the ground.

[0070] Also, according to the method of using the construction machine of the present invention, after the construction machine carried into the site is self-propelled to the construction position and the jack 19 is grounded to support the upper swing body 14, while ensuring the conduction path between the power transmission cable 64 of the commercial power supply and the inverter 51 via the cable connection part 65, the power supply to the inverter 51 is switched from the battery 53 to the commercial power supply. Therefore, it is possible to meet the needs of the site where battery drive is emphasized when setting up the construction. In particular, a construction machine for pile driving (for example, a pile driver 11) having many functions suitable for various construction needs, after moving to the construction position, grounds the jack 19 and stops on the spot for a long time. Depending on the site, the driving force can be extremely large. Therefore, the battery 53 is used during non-construction times such as movement and setup work, and the power supply is switched to the use of commercial power during main construction when driving the working device (for example, the auger 23). As a power selection method, it is particularly effective.

[0071] In particular, the size (outer shape) of the battery 53 is formed such that the dimension in the width direction of the upper swing body is smaller than the dimension in the vertical direction, and the integration of a plurality of battery packs 57 is attempted. Therefore, even when the battery 53 is arranged on one side of the upper swing body 14, it does not compress the arrangement of various devices such as the inverter 51. Due to the interaction with the electrical chamber 75 that houses these and the disassembled structure of the box body that constitutes the housing structure 40, a practical power unit configuration excellent in assembly and maintenance can be obtained.

[0072] Moreover, since the electric motor 39 is a water-cooled electric motor provided with a water circuit that indirectly cools the inside with cooling water, the heat transfer rate is improved at each stage compared to air cooling, and the system can be miniaturized. The space saved by miniaturization can be effectively used as a mounting space for the battery 53 and the like. That is, in a battery-driven construction machine, a more efficient layout can be realized. In particular, even when various electrical and hydraulic devices housed in the housing structure 40 are concentrated in an overcrowded state, the heat influence between the devices caused by this overcrowded state can be reduced. Therefore, it is particularly effective as a measure to improve the heat balance.

[0073] Note that the present invention is not limited to the above-described embodiment, and the specifications of the power unit can be appropriately changed according to the functions required for the construction machine. Also, the mounting position can be configured in consideration of the positional relationship with other structures and devices, such as arranging only the battery among the components in the space between the operator's cab and the counterweight. For example, in the case of a pile driver, by arranging the battery within the stable region where the center of gravity of the machine body is placed, the overall weight can be increased without pressing the arrangement of the counterweight, which also contributes to an improvement in stability. Furthermore, the arrangement of connectors, switches, etc. is also arbitrary. For example, a charging switch, a changeover switch, etc. may be provided outside the operator's cab. In addition, although a pile driver has been exemplified as the construction machine, the present invention is not limited thereto, and it is particularly effective for foundation construction machines that have a relatively long stay in one place and continue high-output work, such as an earth drill or an obstacle remover equipped with a rotary drive device (Kelly drive) of the same type as an auger, and can be applied to various construction machines equipped with a power unit as a power source for the working device, such as a self-propelled crane that raises and lowers a suspension hook with a winch.

Explanation of Signs

[0074] 11…Piling machine, 12…Lower traveling body, 13…Slewing bearing, 14…Upper slewing body, 15…Base machine, 16…Leader, 17…Lifting cylinder, 18…Leader support, 19…Jack, 20…Counterweight, 21…Top sheave, 22…Lower guide, 23…Auger, 23a…Apparatus main body, 23b…Guide gib, 23c…Hydraulic motor for auger drive, 24…Drive shaft, 25…Guide pipe, 26…Drive sprocket, 27…Driven sprocket, 28…Hoisting chain, 29…Steel pipe pile, 30…Rod cap, 31…Injection hose, 32…Flow meter, 33…Main frame, 34, 35…Floor frame, 36…Operator's cab, 37…Hydraulic oil tank, 38…Equipment storage room, 39…Electric motor, 40…Storage structure, 40a…Handrail, 40b…Door, 41…Display, 42…Driver's seat, 43…Controller, 44…Vehicle body control equipment, 45…Air conditioner unit, 46…Electric compressor, 47…Water pump, 48…Cooling water circuit, 48a…Motor side shunt path, 48b…Step-down transformer side shunt path, 48c…Cooler side shunt path, 48d…Heater side shunt path, 48e, 48f…Air bleeding flow path, 48g…Water supply flow path, 49…Electric heater, 50…Hydraulic pump, 51…Inverter, 51a…Operation part, 52…Inverter power supply circuit, 53…High voltage battery (first battery), 54…First DC step-down transformer, 55…Water cooler, 56…Cooling water tank, 57…Battery pack, 58…Battery management unit, 59…Switch, 60…Stabilized power supply (AC-DC converter), 61…Circuit breaker, 62…AC step-up transformer (charger), 63…Cubicle (AC step-down transformer), 64…Power transmission cable, 65…Connector, 66…Lead battery (second battery), 67…Oil cooler, 68…Second DC step-down transformer (DC-DC converter), 69…Start switch, 69a…Lamp, 70…Charge switch, 70a…Lamp, 71…Operation / stop switch, 71a…Lamp, 72…Operation mode selection switch, 73…Power relay, 74…Power line, 75…Electrical room, 76…Bracket, 76a…Vibration isolator rubber, 77…Cover, 78…Lead-in cable, 79…Hanger, 80…Cable lead-in room, 81…Cable relay room, 82…Pipe connection part, 83 - 86…Check valve, 87…Changeover switch, 87a…Lamp

Claims

1. In a construction machine comprising a lower traveling body, an upper slewing body rotatably provided above the lower traveling body, a working device vertically movably provided at the front of the upper slewing body, and a counterweight mounted at the rear end of the upper slewing body, the upper slewing body includes a frame body in which a main frame having a slewing axis and floor frames provided on both sides in the width direction of the upper slewing body of the main frame are integrally coupled. A driver's cab is provided on one side floor frame, and a power unit and a battery serving as its power source are provided on the other side floor frame. The power unit includes an electric motor, a hydraulic pump driven by being connected to the electric motor, an inverter for controlling the electric motor, and an electric circuit including an inverter power supply circuit for supplying power to the inverter, the inverter power supply circuit being configured to be switchably connected to the battery and a commercial power supply with respect to the inverter, wherein the battery, the electric motor, and the hydraulic pump are arranged side by side in the longitudinal direction of the upper slewing body. The construction machine is characterized by this.

2. The construction machine according to claim 1, wherein the battery is arranged forward with respect to a vertical plane in the width direction of the upper slewing body passing through the slewing axis.

3. The power unit is provided with a hydraulic circuit connected to an external hydraulic unit for emergency escape, and the electric circuit includes a manual start switch for enabling power supply to the inverter, and a manual changeover switch for invalidating the signal of the start switch to switch the power supply from an enabled state to a disabled state and vice versa. The construction machine according to claim 1 or 2 is characterized by this.

4. The upper slewing body is provided with jacks at four locations in the front, rear, left, and right directions, and a cable connection portion for connecting a power transmission cable of the commercial power supply is provided at a position corresponding to one side of the two rear jacks. The construction machine according to claim 1 or 2 is characterized by this.

5. A method of using the construction machine according to claim 4, wherein the construction machine carried into the site is self-driven to the construction position, after grounding the jacks to support the upper slewing body, while ensuring a conduction path between the power transmission cable of the commercial power supply and the inverter via the cable connection portion, switching the power supply to the inverter from the battery to the commercial power supply. The method of use is characterized by this.

Images