Construction machine

Abstract

To provide a construction machine equipped with a heating medium circuit capable of exhibiting an energy-saving effect simultaneously while supplementing a shortage of a heat quantity required for heating.SOLUTION: An upper turning body is provided with an electric motor 39, a hydraulic pump 50 connected to the electric motor to be driven, and a battery that supplies power to the electric motor. The electric motor is a water-cooled type using cooling water which circulates through a cooling water circuit 48. The cooling water circuit includes an electric heater 49, a water cooler 55 connected in parallel to the electric heater, an air-conditioner unit (air conditioner) 45 equipped with an air heating part 45a that dissipates heat from the cooling water heated by the electric heater, and a valve 45b opened in the energized state of the electric heater to introduce the cooling water to the air heating part.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to construction machinery, and more particularly to construction machinery having a hydraulic pump driven by an electric motor as a power source.

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. Battery-driven construction machinery is provided with a power storage device such as an electric motor that drives a hydraulic pump and a battery that supplies power to the electric motor, instead of an engine and a fuel tank. Since this type of construction machinery cannot use the cooling water of the engine as a heat medium for heating, when performing a heating operation, the water stored in the water tank is heated by an electric heater and taken into the air conditioner unit in the cab (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] However, relying solely on an electric heater to heat the heat medium (water) increases the power consumption, which shortens the driving time of the battery. In addition, the original advantages of battery-driven construction machinery, such as increased overall energy consumption, increased running costs, and increased environmental impact, cannot be fully realized.

[0005] Therefore, an object of the present invention is to provide a construction machine having a heat medium circuit that can obtain an energy-saving effect while compensating for a shortage of heat required for heating.

Means for Solving the Problems

[0006] In order to achieve the above object, a construction machine of the present invention is a construction machine including a lower traveling body, an upper revolving body rotatably provided on the upper part of the lower traveling body, and a working device vertically movably provided at the front part of the upper revolving body. The upper revolving body is provided with an electric motor, a hydraulic pump driven by being connected to the electric motor, and a battery for supplying power to the electric motor. The electric motor is a water-cooled type using cooling water circulating in a cooling water circuit. The cooling water circuit includes an electric heater, a water cooler connected in parallel with the electric heater, an air conditioner including an air heating part for dissipating the cooling water heated by the electric heater, and a valve that opens in an energized state of the electric heater to introduce the cooling water into the air heating part. It is characterized by having these components.

[0007] Further, the upper revolving body is provided with a stabilized power supply for converting alternating current from a commercial power supply into direct current, and a DC step-down converter for stepping down the direct current converted by the stabilized power supply to a set voltage. The DC step-down converter is characterized by being a water-cooled type using the cooling water. Furthermore, the battery is characterized by being a water-cooled type using the cooling water.

Advantages of the Invention

[0008] According to the construction machine of the present invention, since the electric motor, which is a heat source, is a water-cooled type and the stored cooling water flowing through the cooling water circuit is used as a heat medium for heating, the heating amount of the cooling water by the electric heater can be effectively suppressed. That is, by regenerating and effectively using the heat energy that was released to the outside air in the prior art for heating, while compensating for the shortage of heat required for heating, at the same time, an energy-saving effect can be expected.

[0009] Moreover, since the cooling water circuit has a valve that opens in the energized state of the electric heater and introduces cooling water into the air heating section, in combination with the operation of the shunt path in which the electric heater and the water cooler are connected in parallel to each other, when the valve is opened during heating use (for example, in winter), a state where the balance between the heat dissipation amount in the air heating section and the heat dissipation amount in the water cooler is maintained can be obtained. On the other hand, when the valve is closed during non-heating use (for example, in summer), a state where the heat dissipation of the cooling water is promoted by using the water cooler alone can be obtained. Since it can contribute to energy-saving measures while protecting the electric motor from heat in any temperature environment, it is excellent in practicality.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0011] Figs. 1 to 9 show an exemplary embodiment in which the present invention is applied to a pile driver, which is an example of construction machinery. As shown in Fig. 1, the pile driver 11 is a multi-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 slewing body 14 rotatably provided on the lower traveling body 12 via a slewing bearing 13. A base machine (airframe) 15 composed of the above, a leader 16 erected at the front of the upper slewing body 14, and a hoisting cylinder 17 that supports the leader 16 from the rear. Further, a leader support 18 that supports the leader 16 so as to be able to be raised and lowered is provided at the front of the upper slewing body 14. Furthermore, stabilizing jacks 19 are provided at four locations, front, rear, left, and right of the upper slewing body 14, and a counterweight 20 for balancing the pile driver 11 is mounted at the rear end of the upper slewing body 14.

[0012] 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 able to move 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. The leader 16 formed in this way, when transporting the pile driver 11, the upper leader member is removed according to the transportation conditions and transported separately from the airframe. In this case, on the airframe side, heavy objects such as the auger 23 and the counterweight 20 are removed as necessary, and the leader 16 is set in a transportation posture (not shown) where it lies down backward.

[0013] The auger 23 is configured around a device body 23a that rotatably holds 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 project rearward. Above and below the auger 23, both ends of a lifting chain 28 that is 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 looped around the drive sprocket 26 and the driven sprocket 27 in the vertical direction, thereby raising and lowering the auger 23 along the front surface of the leader 16.

[0014] When the pile driver 11 is used for the purpose of driving 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 auger drive hydraulic motor 23c, thereby pressing the steel pipe pile 29 into the ground.

[0015] On one 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 stirring blades 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, so that the earth and sand excavated by the excavation blade of the excavation head and the ground improvement agent are mixed by the stirring blades of the excavation head.

[0016] As shown in FIG. 3, the upper swing body 14 includes a frame body in which a rectangular box-shaped main frame 33 with 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 at the front, rear, left, and right of the upper swing body 14, and a stable region in the shape of a rectangle in plan view connecting between them 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, at the main construction time when the auger 23 is driven, the counterweight 20 plays a role in improving the pile pulling performance.

[0017] At the front of the right floor frame 34, a driver's cab 36 is installed where the operator rides and performs 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.

[0018] Inside the driver's cab 36, equipment such as operation levers, operation pedals, various operation switches, and a touch panel type 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.

[0019] Information obtained 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 for the operator to confirm the execution results of the control program on the display screen and input data by touch panel operation.

[0020] 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 chamber 38, and a heat exchange cycle is configured to circulate refrigerant through each device of the electric compressor (compressor) 46, condenser (condenser), expansion valve, and 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 to 7, 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) 45a built into the air conditioner unit 45, and the air (air from the blower) passing through this heating core 45a becomes warm air to heat the driver's cab 36.

[0021] As shown in FIGS. 2 to 7, 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.

[0022] 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 in the front-rear direction of the upper swing body (right direction in FIG. 2) and is mounted on the floor frame 35 in an anti-vibration 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.

[0023] 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. For example, T-shaped joints T1, T2, T3, and T4 with three-way branches are used at the branch points and the confluence points for connecting the devices 39, 54, 49, and 55 in parallel. The water cooler 55 is a heat exchanger equipped with an electric fan 55a. By passing the cooling air through the heat dissipation cooling core 55b, the heat of the cooling water that has passed through the electric motor 39 and the first DC step-down converter 54 is dissipated, and the cooled cooling water is returned to the electric motor 39 and the first DC step-down converter 54, thereby maintaining the temperatures of these devices (heat sources) within an appropriate range (see also FIG. 7).

[0024] The discharge-side flow path of the water pump 47 is provided with a flow control valve 48a for ensuring a certain amount of cooling water for the electric motor 39, and is configured to be able to branch into a motor-side shunt path 48b for supplying the cooling water to the electric motor 39 and a step-down converter-side shunt path 48c for supplying the cooling water to the first DC step-down converter 54.

[0025] On one hand, the suction side flow path of the water pump 47 is configured to be divergeable into a cooler side shunt path 48d that supplies the return of the cooling water to the water cooler 55 and a heater side shunt path 48e that supplies the electric heater 49. The flow rate control valve 48a is provided in the pressure reducer side shunt path 48c and includes, for example, a throttle valve whose opening degree can be adjusted by a handle operation (manual). A cooling water tank (expansion tank) 56 is provided in the cooler side shunt path 48d. When the cooling water thermally expands, the cooling water (overflow portion) is guided from the air vent flow paths 48f and 48g 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 the air vent cap 56a 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 48h. Further, as state monitoring means, a water temperature sensor 55c is attached to the water cooler 55, and a water level sensor (not shown) is attached to the cooling water tank 56, and signals from each sensor are configured to be inputtable to the controller 43. In the controller 43, for example, the electric fan 55a of the water cooler 55 is controlled (ON / OFF) according to the temperature of the cooling water.

[0026] Here, the cooling water heated as it passes through the water circuits of the respective devices 39 and 54 returns to the water pump 47 through the cooler side shunt path 48d. However, when the electric heater 49 is energized, that is, when the valve 45b is opened during the heating operation of the air conditioner unit 45, a flow of cooling water is generated in the heater side shunt path 48e, 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 45a, and heat exchange is performed with the air (blowing air) passing through the heating core 45a. In this way, the cooling water circulating in the cooling water circuit 48 is used as the heat medium for heating.

[0027] 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 a switch (contact) 59. In this embodiment, 21 battery packs 57 each composed of a lithium ion battery with a capacity of about 40 Ah are used. For example, when battery packs 57 with an operating voltage of about 32.4 V are connected in series, the first battery 53 can output a DC voltage of about 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 switch 59 in response to commands from the controller 43.

[0028] 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 a command from the controller 43, and power converted from DC to AC by the inverter 51 is supplied to the electric motor 39. 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.

[0029] The use of such commercial power supplies 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 through power distribution. 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 to a connector 65 which is a cable connection part. Note that the power transmission cable 64 is prepared separately, for example, into a power supply cable for construction work that supplies a large amount of power and a charging cable that supplies a small amount of power. The one for construction work is, depending on the scale of the site, for example, about 20 m or longer in length and is used.

[0030] 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 supply 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 supply to the second battery 66.

[0031] 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 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 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. Note that each of the DC step-down transformers 54, 68 steps down the voltage of the input DC power supply to the set voltage and outputs it. The first DC step-down transformer 54, for example, steps down the input DC 600V to DC 26V and outputs it. On the other hand, the second DC step-down transformer 68, for example, steps down the input DC 24V to DC 12V and outputs it.

[0032] 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 the AC power and DC power input to the inverter 51. Hereinafter, the procedure of the switching operation based on the selection of the operator will be described with reference to FIGS. 5 and 8.

[0033] FIG. 8 shows an electric circuit of an operation input system for power management. This electric 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 electric circuit has a power main circuit PL and a control power supply circuit CL that operates a power relay 73 provided between the power main 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.

[0034] 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 part of the switch by rotating a knob.

[0035] 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 is 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. 8) incorporated in the electric circuit can be switched and controlled according to the command of the controller 43, that is, it enters the start state where power can be supplied to the inverter 51. 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.

[0036] 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 with respect 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.

[0037] 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 condition 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, the hydraulic motors of the lower traveling body 12 and the hydraulic cylinders of the jack 19 can be supplied with hydraulic pressure, and the pile driver 11 can be self-propelled and the setup work for construction can be performed by battery drive.

[0038] On the other 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 a circuit-connected state (conductive state) between the cubicle 63 and the inverter 51. Thereby, the power of the commercial power supply can be supplied to both the inverter 51 and the stabilizer power supply 60.

[0039] 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. Thus, 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 pile driver 11 can be operated by the commercial power supply drive. 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.

[0040] 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) in which 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 in response to a command from the controller 43, and the power relay 73 is held in the switched state.

[0041] 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 continuous operation of the pile driver 11 can be performed by battery drive.

[0042] Hereinafter, the arrangement of each device constituting the system will be described with reference to FIGS. 2 to 4 and the like. The housing structure 40 of the power unit is composed of a box installed on the floor frame 35. Since the ceiling part with a plurality of handrails 40a can also serve as a scaffold that can move up and down 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 bisected 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. In addition, 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.

[0043] 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, and 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.

[0044] 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 longitudinal 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, a space equivalent to two layers in the vertical direction is provided below the battery pack 57 stacked in three layers, and a stabilization power supply 60 is arranged using this space. By integrating such a plurality of battery packs 57, even when the first battery 53 is arranged on one side of the upper swing body 14, the arrangement of various devices such as the inverter 51 is not restricted.

[0045] 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 at its back on the outer side 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 part of the housing is removed, easy access can be achieved to the operation part 51a of the inverter 51 and the like. On the other hand, if the inner surface panel constituting the inner surface part of the housing is removed, easy access can be achieved to the first battery 53 and the like.

[0046] In the rear accommodation space, the electric motor 39 and the hydraulic pump 50 are arranged to fill the longitudinal direction, and auxiliary machines such as a water pump 47 and a first DC step-down converter 54 are arranged around these, particularly in the vicinity of the electric motor 39, in consideration of the connection of the cooling water circuit 48. As also shown in FIG. 7, for example, the water pump 47 is placed on the upper part of the rear end of the electric motor 39, while the first DC step-down converter 54 is installed side by side with the electric motor 39 in the width direction of the upper swing body and is placed vertically (facing the outer surface of the main body of the electric motor 39).

[0047] The upper part of the rear accommodation space communicates with the upper equipment accommodation space formed by covering the ceiling opening of the accommodation structure 40 with a box-shaped flat cover 77. In this upper equipment accommodation space, auxiliary equipment such as a water cooler 55, a cooling water tank 56, and an oil cooler 67 are arranged side by side in the front-rear direction. Both the water cooler 55 and the oil cooler 67 are installed with the axes of the electric fans 55a, 67a facing vertically. When each electric fan 55a, 67a operates, an upward airflow (the flow of air from the bottom to the top in FIG. 7) is formed in the rear accommodation space. Thereby, heat accumulation in the accommodation structure 40 can be avoided, and heat dissipation performance is enhanced.

[0048] Also, joints T1, T2, T3, T4 for connecting the respective shunt paths 48b, 48c, 48d, 48e of the cooling water circuit 48 are arranged in the space between the electric motor 39 and the water cooler 55 in the vertical direction (FIG. 7). In this way, the compactly grouped shunt paths 48b to 48e have the heater-side shunt path 48e drawn out to the outside of the accommodation structure 40 and extending to the driver's cab 36 where the air conditioner unit 45 is located.

[0049] An opening and closing hatch (not shown) accessible to the cooling water tank 56 is provided on the upper surface of the cover 77, and punching metal-shaped openings with a large number of holes are provided on the front, rear, left, and right four side surfaces of the cover 77. During the operation of the power unit, the outside air introduced into the rear accommodation space of the accommodation structure 40 through the floor frame 35 passes through the respective cooling cores 55b, 67b of the water cooler 55 and the oil cooler 67, becomes warm air (exhaust air), and is discharged to the outside through the openings of the cover 77.

[0050] With the various devices arranged in this manner, basically, the first battery 53, the electric motor 39, and the hydraulic pump 50 are arranged side by side in the longitudinal direction of the upper swing body. In their relative positional relationship, 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. As a result, a first battery 53 with a size corresponding to the operating time of the power unit can be arranged in a wide space without the occupation of the cab 36 and the counterweight 20. Also, in terms of the positional relationship with the slewing axis PV, the first battery 53 is arranged in front and the electric motor 39 and the hydraulic pump 50 are arranged behind with respect to the vertical plane S. Thereby, the arrangement of the battery 53 has no adverse effect on the rear swing radius R of the upper swing body 14 determined by the position of the counterweight 20, and the battery 53 can be arranged separately from the rear structure of the position (vertical plane S) of the slewing axis PV. Further, 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 longitudinal direction of the upper swing body, is considered.

[0051] Also, within the housing structure 40, a space of a size suitable for power transmission and oil supply 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 to the power transmission cable 64 loop-suspended by the hanger 79 at a position corresponding to the right jack 19 with the cab 36 among the two rear jacks 19, for example, at the upper part of the jack 19, so that it can be inserted and removed (see also FIG. 2), and relays between the power transmission cable 64 and the lead-in cable 78. Thereby, it becomes possible to avoid the counterweight 20 that is likely to obstruct the cable connection work, and the power transmission cable 64 drawn from the power transmission facility to the pile driver 11 can be easily connected to the cable connection portion 65.

[0052] The lead-in cable 78 forms a conduction path, together with the power transmission cable 64, for a stabilized 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 an equipment accommodation chamber 38 and a 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 a housing 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 housing 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.

[0053] 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 perform the traveling operation, for example, when loading and unloading the power unit on 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-propelled according to the display on the guidance screen of the display 41 and moves from the current position to the construction position (target pile core position).

[0054] After stopping the pile driver 11 on-site at the construction location, 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 securing 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 driven by 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. In this way, 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 ground condition.

[0055] By the way, for the operator of the pile driver 11 who is exposed to the environment of hot sun or severe cold, it is extremely desirable that the cab 36 is air-conditioned. Especially in cold regions, since the temperature of the cooling water becomes excessively low, the power consumption of the electric heater 49 becomes larger to raise the temperature of the cooling water. As a result, in the case of battery drive, the operating time of the pile driver 11 becomes shorter. Also, in such a low-temperature environment, it leads to energy loss for heating the electric heater 49, which is not preferable from the perspective of energy conservation. Therefore, in the cooling water circuit 48, the water pump 47 is in an operating state following the startup of the system, and while circulating the cooling water between each heat source of the electric motor 39 and the first DC step-down converter 54 and the water cooler 55, control is performed so that a part of the cooling water can be taken into the air conditioner unit 45 when heating is used.

[0056] In this case, when the heating switch (not shown) attached to the air conditioner unit 45 is turned on, the valve 45b of the heater side bypass passage 48e is opened, and the electric heater 49 is energized in response to a command from the controller 43. At this time, the flow of the cooling water does not bypass the water cooler 55, that is, the flow rate of the cooler side bypass passage 48d does not become zero, and is distributed to each of the bypass passages 48d and 48e according to the difference in the flow path resistance between the cooler side bypass passage 48d and the heater side bypass passage 48e (joint T3). As a result, as shown in FIG. 6, the cooling water flowing through the cooler side bypass passage 48d is introduced into the cooling core 55b and exchanges heat (radiates heat) with the air (blowing air) passing through the cooling core 55b. On the other hand, the cooling water flowing through the heater side bypass passage 48e is heated by the heat of the electric heater 49 and then introduced into the heating core 45a, and exchanges heat (radiates heat) with the air (blowing air) passing through the heating core 45a.

[0057] In this way, in the case of the heating operation for heating the air for air conditioning, the flow of the cooling water merges after passing through each heat exchanger of the heating core 45a and the water cooler 55 (joint T4), and the return of this cooling water is suppressed from excessive temperature rise by the cooling action of the water cooler 55. That is, even if a part of the cooling water flows through the heater side bypass passage 48e, it does not adversely affect the cooling of each heat source of the electric motor 39 and the first DC step-down converter 54.

[0058] As described above, according to the construction machine of the present invention, since the electric motor 39, which is a heat source, is water-cooled and the stored cooling water flowing through the cooling water circuit 48 is used as a heat medium for heating, the heating amount of the cooling water by the electric heater 49 can be effectively suppressed. That is, by regenerating and effectively using the heat energy that was conventionally released to the outside air for heating, it is possible to compensate for the shortage of the amount of heat required for heating and at the same time expect an energy-saving effect.

[0059] Moreover, since the cooling water circuit 48 has a valve 45b that opens in the energized state of the electric heater 49 to introduce cooling water into the air heating section 45a, in combination with the operation of the shunt paths 48d and 48e in which the electric heater 49 and the water cooler 55 are connected in parallel to each other, when heating is in use with the valve 45b open (for example, in winter), a state in which the balance between the heat dissipation amount in the air heating section 45a and the heat dissipation amount in the water cooler 55 is maintained can be obtained. On the other hand, when heating is not in use with the valve 45b closed (for example, in summer), a state in which the heat dissipation of the cooling water is promoted by using the water cooler 55 alone can be obtained. Since it is possible to contribute to energy-saving measures while protecting heat-generating sources such as the electric motor 39 and the first DC step-down converter 54 from heat in any temperature environment, it is excellent in practicality.

[0060] Moreover, due to the configuration of the water-cooled electric motor 39, the heat transfer rate is improved at each stage compared to the air-cooled type, and the system can be miniaturized and integrated. For example, a relative arrangement (an arrangement in which they are arranged side by side in the vertical direction) of the electric motor 39, the water cooler 55, the cooling water circuit 48, etc., as shown in FIG. 7, can be achieved, and the resulting free space in the front-rear direction can be effectively utilized as a mounting space for the first battery 53 or the like. Also, due to the interaction with the configuration of the water-cooled first DC step-down converter 54, the power consumption of the electric heater 49 can be suppressed, and a further energy-saving effect can be expected. At the same time, it contributes to further integration and space saving in the equipment and circuit layout. That is, in the battery-driven construction machine, a more compact and efficient layout can be realized. In particular, even when various electric and hydraulic devices housed in the housing structure 40 are concentrated and in an overcrowded state, since the heat influence between the devices caused by this overcrowded state can be reduced, it is particularly effective as a measure to improve the heat balance.

[0061] FIG. 9 shows a modified example of a construction machine equipped with the cooling water circuit of the present invention. In the following description, the same components as those shown in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0062] In this modified example, it has the same configuration of the cooling water circuit as in the above-described example, and on the cooling water circuit 91, a first battery (heat source) 53 to be cooled is provided. The first battery 53 is a water-cooled type equipped with a pipe-shaped cooling structure (not shown) for cooling the power storage module (such as the battery pack 57, the battery management unit 58, and the switch 59) in the above-described example, and is provided in parallel with each of the electric motor 39 and the first DC step-down converter 54. Thereby, for example, a battery-side shunt path 48i connected in parallel with the step-down converter-side shunt path 48c is formed using the joints T5 and T6. A flow control valve 48j is provided in this battery-side shunt path 48i. As the structure of the flow control valve 48j, the same manual throttle valve as the flow control valve 48a of the step-down converter-side shunt path 48c is used.

[0063] And also in this modified example configured as described above, the same effects as those when using the above-described cooling water circuit 48 can be exhibited. Furthermore, in the case of this modified example, since the cooling water stored by each of the electric motor 39, the first DC step-down converter 54, and the first battery 53 as heat sources is used as the heat medium for heating, the power consumption of the electric heater 49 can be suppressed and a further energy-saving effect can be expected. In particular, compared with the air-cooling method, the heat of the first battery 53 can be radiated efficiently, and the entire first battery 53 can be cooled evenly, so that the performance degradation due to the high-temperature state of the power storage module can be prevented. Also, combined with the cooling structure by piping with an easy layout, on one side of the upper swivel body 14, each device can be easily and efficiently incorporated into the floor frame 35 or the housing structure 40.

[0064] Note that the present invention is not limited to the above-described embodiment. The configuration of the cooling water circuit only needs to include a diversion path that diverts the flow of the cooling water to the heater side and the cooler side, and various control methods can be applied within the necessary range for starting and stopping the water pump, opening and closing the valve, adjusting the flow rate, and the like. In addition, devices such as an inverter may be added to the object to be cooled (heat source) by the cooling water. Furthermore, the length of the pipeline of the cooling water circuit, the position of the branch point (joint), and the like can be appropriately changed according to the relative positional relationship between devices such as the power unit and the air conditioner unit. For example, when only an electric motor with a large heat generation amount during operation is configured to be water-cooled and other devices are configured to be air-cooled, a DC step-down converter with a smaller heat generation amount compared to the electric motor is arranged at a position where air can easily flow (side by side and vertically with the electric motor), so it can also be expected to be cooled by the outside air taken into the housing structure.

[0065] In addition, although a pile driver has been exemplified as the construction machine, the present invention is not limited thereto, and it can be applied to various construction machines equipped with an air conditioner unit for heating and cooling in the operator's cab, particularly, an earth drill, an obstacle removal machine, and a self-propelled crane that lifts and lowers a suspension hook with a winch, which are equipped with a rotary drive device (Kelly drive) of the same type as the auger, and various construction machines equipped with a hydraulic pump driven by an electric motor as a power source for the working device.

Description of Reference Numerals

[0066] 11…Piling machine, 12…Lower traveling body, 13…Slewing bearing, 14…Upper slewing body, 15…Base machine, 16…Leader, 17…Luffing cylinder, 18…Leader support, 19…Jack, 20…Counterweight, 21…Top sheave, 22…Lower guide, 23…Auger, 23a…Equipment main body, 23b…Guide gib, 23c…Hydraulic motor for auger drive, 24…Drive shaft, 25…Guide pipe, 26…Drive sprocket, 27…Driven sprocket, 28…Chain for lifting, 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, 45a…Heating core (air heating section), 45b…Valve, 46…Electric compressor, 47…Water pump, 48…Cooling water circuit, 48a…Flow control valve, 48b…Motor side shunt path, 48c…Reducer side shunt path, 48d…Cooler side shunt path, 48e…Heater side shunt path, 48f,48g... Air bleeding passage, 48h... Water supply passage, 48i... Battery side shunt passage, 48j... Flow control valve, 49... Electric heater, 50... Hydraulic pump, 51... Inverter, 51a... Operation unit, 52... Inverter power supply circuit, 53... High voltage battery (first battery), 54... First DC step-down converter, 55... Water cooler, 55a... Electric fan, 55b... Cooling core, 55c... Water temperature sensor, 56... Cooling water tank, 56a... Air bleeding cap, 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 converter), 64... Power transmission cable, 65... Connector, 66... Lead battery (second battery), 67... Oil cooler, 67a... Electric fan, 67b... Cooling core, 68... Second DC step-down converter (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 entry room, 81... Cable relay room, 91... Cooling water circuit,

Claims

1. In a construction machine comprising a lower traveling body, an upper revolving body rotatably provided on the upper part of the lower traveling body, and a working device vertically movably provided at the front part of the upper revolving body, the upper revolving body is provided with an electric motor, a hydraulic pump driven by being connected to the electric motor, and a battery for supplying power to the electric motor, the electric motor is a water-cooled type using cooling water circulating in a cooling water circuit, the cooling water circuit has an electric heater, a water cooler connected in parallel with the electric heater, an air conditioner having an air heating part for radiating the cooling water heated by the electric heater, and a valve that opens in an energized state of the electric heater to introduce the cooling water into the air heating part, and is characterized by the above.

2. The upper revolving body is provided with a stabilized power supply for converting alternating current from a commercial power supply into direct current, and a DC step-down converter for stepping down the direct current converted by the stabilized power supply to a set voltage, and the DC step-down converter is a water-cooled type using the cooling water, and is characterized by the construction machine according to Claim 1.

3. The battery is a water-cooled type using the cooling water, and is characterized by the construction machine according to Claim 1 or 2.

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