BATTERY-POWERED WORK MACHINE

Abstract

For suppressing the power consumption of a battery-powered work machine. An electric excavator includes a main body, a battery 37 located in the main body and temperature-controlled by a temperature-control fluid, an electric motor 40 driven by current from the battery 37, a hydraulic pump 43 driven by the electric motor 40, and a hydraulic actuator driven by hydraulic oil supplied by the hydraulic pump 43. The electric excavator heats the battery 37 using the hydraulic oil when the temperature of the hydraulic oil is higher than that of the temperature-control fluid.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a battery-powered work machine. STATE OF THE ART

[0002] JP 11-229430 A (Patent Document 1) discloses a battery-powered hydraulic excavator. Electricity is supplied from a battery mounted on an upper rotating body to an electric motor, a hydraulic pump is driven by the electric motor, and a hydraulic actuator is actuated by a delivery flow from the hydraulic pump. LIST OF COUNTERPOINTS Patent Literature

[0003] Patent Document 1: JP 11-229430 A BRIEF DESCRIPTION OF THE INVENTION Technical Problem

[0004] When a battery-powered machine is warmed up in a cold region, the battery, in addition to the hydraulic oil, must also be heated. Since the energy source for this warming process is electricity drawn from the battery, the efficiency of the power consumption decreases, and the continuous operating time of the machine is reduced.

[0005] The present disclosure proposes a battery-powered working machine capable of suppressing power consumption. Solution to the problem

[0006] A battery-powered working machine according to the present disclosure includes a main body, an energy storage device provided in the main body and configured to be temperature-controlled by a temperature-controlling fluid, an electric motor configured to be driven by current from the energy storage device, a hydraulic pump configured to be driven by the electric motor, and a hydraulic actuator configured to be driven by hydraulic oil supplied by the hydraulic pump. The battery-powered working machine heats the energy storage device using the hydraulic oil when the temperature of the hydraulic oil is higher than the temperature of the temperature-controlling fluid. Advantageous effects of the invention

[0007] The battery-powered machine described in this disclosure can suppress power consumption. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view that schematically illustrates a configuration of an electric excavator. Fig. 2 is a block scheme that represents a system configuration of the in Fig. 1 illustrated electric excavator illustrated. Fig. Figure 3 is a perspective view illustrating a schematic configuration of a battery. Fig. Figure 4 is a flowchart illustrating the process of regulating the temperature of a battery. Fig. Figure 5 is a schematic view illustrating another example of the arrangement of a heat exchanger. DESCRIPTION OF EXECUTION FORMS

[0008] The following descriptions detail embodiments with reference to the drawings. In the following description, identical components and elements are designated by the same reference numerals. The names and functions of these components are also identical. Accordingly, a detailed description of these is not repeated. Initially, the extraction of any configuration from the embodiments and any combination thereof is also considered.

[0009] In the following description, the terms “top”, “bottom”, “front”, “back”, “left” and “right” are directions based on an operator seated in a 4S operator seat in a 4 cabin. Configuration of the working machine

[0010] Fig. Figure 1 is a perspective view that schematically illustrates a configuration of an electric excavator 100 as an example of a battery-powered work machine in one embodiment. As in Fig. As illustrated in Figure 1, the electric excavator 100 includes a main body 1 and a hydraulically operated working unit 2. The main body 1 includes a rotating unit 3 and a travel unit 5.

[0011] The undercarriage 5 includes a pair of crawler tracks 5Cr and a drive motor 5M. The electric excavator 100 can move by rotating the crawler tracks 5Cr. The drive motor 5M serves as a power source for the undercarriage 5. The drive motor 5M is a hydraulically actuated motor. It should be noted that the undercarriage 5 can include wheels (tires).

[0012] The rotating body 3 is arranged on the transport body 5 and is supported by the transport body 5. The rotating body 3 can be rotated by a rotary motor 24 ( Fig. 2) rotated about a pivot axis RX as its center point relative to the drive body 5. The rotary motor 24 is a hydraulically operated motor. The drive motor 5M or the rotary motor 24 can be an electric motor. The pivot axis RX is a virtual straight line that serves as the center of rotation of the drive body 3.

[0013] The rotating body 3 encloses an operator compartment (cabin) 4. The cabin 4 is located, for example, on the front left side of the rotating body 3 (the front of the vehicle). Inside the cabin 4, a driver's seat 4S is provided, in which an operator sits. An operator (personnel) in the cabin 4 can perform an operation of the work tool 2, a rotation operation of the rotating body 3 relative to the drive unit 5, and a driving operation of the electric excavator 100 by the drive unit 5.

[0014] The rotating body 3 has an outer cover 9. The outer cover 9 covers a machine room. The machine room is located at the rear of the rotating body 3 in relation to the cabin 4 (the rear of the vehicle). The machine room contains a battery 37, an inverter 31, an electric motor 40, a hydraulic pump 43, the rotary motor 24, a main valve 41, and a hydraulic oil tank 42 (all in Fig. 2) and the like.

[0015] The working device 2 is supported, for example, by the rotating body 3 at the front of the rotating body 3 and the right side of the cabin 4. The working device 2 includes a boom 6, an arm 7, and a bucket 8.

[0016] The boom 6 is pivotally connected to the main body 1. In particular, a base end section of the boom 6, with a lower boom pin 13 as a support point, is rotatably connected to the rotating body 3. The arm 7 is pivotally connected to the boom 6. In particular, a base end section of the arm 7, with an upper boom pin 14 as a support point, is pivotally connected to a front end section of the boom 6. The bucket 8 is rotatably connected to the arm 7. In particular, a base end section of the bucket 8, with an upper arm pin 15 as a support point, is pivotally connected to a front end section of the arm 7.

[0017] The boom 6 can be driven relative to the main body 1 by a boom cylinder 10. This drive enables the boom 6 to pivot upwards and downwards with the lower boom pin 13 as its support point relative to the rotating body 3. One end of the boom cylinder 10 is connected to the rotating body 3, and the other end is connected to the boom 6.

[0018] The arm 7 can be driven relative to the boom 6 by an arm cylinder 11. This drive enables the arm 7 to pivot upwards and downwards or forwards and backwards with the upper boom pin 14 as a support point in the direction of the boom 6. One end of the arm cylinder 11 is connected to the boom 6 and the other end is connected to the arm 7.

[0019] The bucket 8 can be driven relative to the arm 7 by a bucket cylinder 12. This drive allows the bucket 8 to pivot upwards and downwards with the upper arm pin 15 as a support point relative to the arm 7. One end of the bucket cylinder 12 is connected to the arm 7 and the other end is connected to a bucket connection 17.

[0020] Each of the boom cylinder 10, arm cylinder 11 and bucket cylinder 12 is a hydraulic cylinder and is hydraulically driven. System configuration

[0021] Fig. 2 is a block scheme that represents a system configuration of the in Fig. Figure 1 illustrates the electric excavator 100. The electric excavator 100 includes the electric motor 40 as a power source. In the electric excavator 100, the electric motor 40 generates a driving force to power the working tool 2. The electric motor 40 can drive the working tool 2. Each of the boom 6, arm 7, and excavator bucket 8 is driven by the electric motor 40. Thus, the working tool 2 can be operated.

[0022] The electric motor 40 is driven by alternating current supplied by the inverter 31, with the battery 37 serving as the current source. The speed of the electric motor 40 is controlled by the frequency of the alternating current supplied by the inverter 31.

[0023] Battery 37 is in the one with the in Fig. The outer cover (1) and the covered engine room (9) are arranged and provided in the main body (1, the rotating body 3) of the electric excavator 100. The battery 37 is located at a rear end section of the rotating body 3. The battery 37 is mounted on the rotating body 3. The battery 37 is supported by a frame of the rotating body 3.

[0024] Battery 37 is an energy storage device that stores electrical energy. Battery 37 extracts the stored electrical energy as electromotive force. Battery 37 is a secondary battery, such as a lithium-ion battery or a nickel-metal hydride battery. Battery 37 comprises, for example, a multitude of battery packs. Each of these battery packs contains a multitude of battery cells. A battery cell is configured, for example, by stacking a positive and a negative electrode with a separator positioned between them.

[0025] A temperature sensor 39 detects the temperature of the battery 37. Data relating to the temperature of the battery 37, as detected by the temperature sensor 39, are entered into a control unit 30.

[0026] The inverter 31 converts a direct current output from the battery 37 into an alternating current with a controlled frequency, etc. The inverter 31 supplies the electric motor 40 with alternating current via an electrical wiring line. The inverter 31 controls the operation of the electric motor 40 according to a control signal input from the control unit 30. In this way, the electrical energy stored in the battery 37 is supplied to the electric motor 40.

[0027] The electric excavator 100 powers the electric motor 40, which is driven by electricity stored in the battery 37. The high-capacity battery 37 is mounted on the electric excavator 100. The electric excavator 100 does not include an internal combustion engine. The battery-powered electric excavator 100 can operate without carbon dioxide emissions and can reduce vibrations and noise during operation.

[0028] The battery 37 and the inverter 31 are electrically connected via a power distribution unit (PUD) 35 and a high-voltage junction box (HVJB) 36. The power distribution unit 35 includes a function to distribute the power stored in the battery 37 to all equipment, including the inverter 31. The battery 37 is connected to the high-voltage junction box 36, and a charging port 38 is also connected to it. An external power source or generator is connected to the charging port 38. Thus, the battery 37 is charged. The battery 37 stores externally supplied electrical energy.

[0029] The inverter 31, the power distribution unit 35, the high-voltage junction box 36, the battery 37, the charging port 38, and the electric motor 40 are connected via a high-voltage cable. The battery 37 supplies the inverter 31 with power via a high-voltage cable. The inverter 31, the power distribution unit 35, the high-voltage junction box 36, and the high-voltage cable connecting these components form an electrical circuit that is electrically connected to the battery 37.

[0030] An output shaft of the electric motor 40 is mechanically connected to a drive shaft of the hydraulic pump 43. When the electric motor 40 is driven, a driving force from the electric motor 40 is transmitted to the hydraulic pump 43, thus driving the hydraulic pump 43.

[0031] The hydraulic oil tank 42 serves to store hydraulic oil and to supply it to the hydraulic pump 43. When the hydraulic pump 43 is driven, the hydraulic oil is drawn from the hydraulic oil tank 42. A hydraulic line 44 is connected to the hydraulic pump 43. One end of the hydraulic line 44 is immersed in the hydraulic oil in the hydraulic oil tank 42. A filter 45 is attached to the end of the hydraulic line 44. The hydraulic oil in the hydraulic tank 42 passes through the filter 45, flows into the hydraulic line 44, and is drawn into the hydraulic pump 43.

[0032] The hydraulic oil delivered by the hydraulic pump 43 is supplied to the main valve 41 via the hydraulic line 44. The main valve 41 is located in an oil path between the hydraulic pump 43 and a hydraulic actuator. The main valve 41 is configured as an assembly consisting of several control valves, pilot valves, and the like. The main valve 41 supplies the hydraulic oil, which is drawn from the hydraulic oil tank 42 while the hydraulic pump 43 is driven, to the hydraulic actuator and discharges it.

[0033] The hydraulic actuator includes the rotary motor 24 as well as the boom cylinder 10, the arm cylinder 11, the excavator bucket cylinder 12 and the travel motor 5M, which are also in Fig. Figure 1 illustrates this. The rotary motor 24 and the drive motor 5M are hydraulic motors that are hydraulically driven.

[0034] In response to an operation performed by an operator on board cabin 4 ( Fig. 1) The opening / closing of each of the valves is controlled in the main valve 41. In response to a drive operation by the operator, the main body 1 and the working device 2 of the electric excavator 100 can be actuated. In particular, the operator can actuate the working device 2 by actuating the hydraulic cylinders 10, 11 and 12, perform a rotation operation of the rotating body 3 relative to the travel body 5 by actuating the rotary motor 24 and perform a travel operation of the electric excavator 100 by actuating the travel motor 5M.

[0035] The hydraulic oil discharged from the hydraulic actuator is returned to the hydraulic oil tank 42 via the main valve 41 and a hydraulic line 46. The hydraulic oil flowing from the hydraulic actuator towards the hydraulic oil tank 42 flows through the hydraulic line 46.

[0036] The hydraulic line 46 is provided with an air-cooled cooler 47. The air-cooled cooler 47 includes a heat exchanger, a fan that blows air onto the heat exchanger, and a motor that drives the fan. In the heat exchanger, heat is exchanged between the hydraulic oil and the airflow supplied by the fan, and the hydraulic oil is cooled by dissipating heat into the air.

[0037] The hydraulic line 46 is equipped with a pressure relief valve 48. The pressure relief valve 48 releases the pressure of the hydraulic oil in the hydraulic line 46 when the pressure becomes equal to or higher than a set pressure, thereby regulating the maximum pressure of the hydraulic line 46.

[0038] A temperature sensor 49 detects the temperature of the hydraulic oil flowing through the hydraulic line 46. A bypass line 50 branches off from the hydraulic line 46. The temperature sensor 49 detects the temperature of the hydraulic oil upstream of the flow path with respect to a branch point with the bypass line 50. The temperature sensor 49 detects the temperature of the hydraulic oil immediately downstream of the main valve 41 in the path of the hydraulic oil flowing from the hydraulic actuator towards the hydraulic oil tank 42.

[0039] The bypass line 50 is equipped with a changeover valve 51. The changeover valve 51 switches between opening and closing the bypass line 50. When the changeover valve 51 opens the bypass line 50, some of the hydraulic oil flowing from the hydraulic actuator towards the hydraulic oil tank 42 diverts from the hydraulic line 46 and flows through the bypass line 50. When the changeover valve 51 closes the bypass line 50, the hydraulic oil does not flow through the bypass line 50.

[0040] The main valve 41, the hydraulic oil tank 42, the hydraulic lines 44 and 46 and the bypass line 50 form a hydraulic oil circuit through which the hydraulic oil flows.

[0041] The bypass line 50 is equipped with a heat exchanger 52. The heat exchanger 52 exchanges heat between the hydraulic oil flowing through the bypass line 50 and a temperature control fluid flowing through the fluid line 64. The temperature control fluid is a fluid, for example, water.

[0042] A fluid line 64, which is in Fig. The path, illustrated by a dashed line 2, extends between battery 37 and a battery thermal management system 60. The temperature control fluid flowing through fluid line 64 circulates through battery 37 and the battery thermal management system 60. The temperature of battery 37 is regulated by the temperature control fluid. When battery 37 is at a low temperature, heat is transferred from the temperature control fluid to battery 37, and battery 37 is heated. When battery 37 is at a high temperature, heat is released from battery 37 to the temperature control fluid, and battery 37 is cooled.

[0043] The battery thermal management system 60 includes a heater 61 and a cooler 62. The battery thermal management system 60 serves to heat and cool the temperature control fluid. The heater 61 is, for example, an electric heater. The temperature control fluid is heated by the heat generated by the heater 61. The cooler 62 is, for example, an evaporator that forms a refrigeration cycle. The cooler 62 cools the temperature control fluid.

[0044] The battery thermal management system 60 includes a changeover valve 63. The changeover valve 63 reverses the flow of the temperature control fluid. The changeover valve 63 is provided in a bypass path that bypasses the fluid line 64 in the battery thermal management system 60. When the changeover valve 63 is closed, it causes the temperature control fluid to flow from the battery thermal management system 60 toward the heat exchanger 52. When the changeover valve 63 is open, the flow of the temperature control fluid to the heat exchanger 52 is suppressed.

[0045] The battery thermal management system 60 includes a pump 65. The pump 65 generates energy to circulate the temperature control fluid through the fluid line 64. The battery thermal management system 60 regulates the temperature of the battery 37 by causing the temperature control fluid, heated by the heater 61 or cooled by the cooler 62, to flow through the battery 37. A temperature sensor 69 detects the temperature of the temperature control fluid discharged from the pump 65. The temperature sensor 69 detects the temperature of the temperature control fluid before the temperature is regulated by the battery thermal management system 60.

[0046] The control unit 30 is configured to include a central processing unit (CPU), memory, and similar components. The memory stores a program for controlling the operations of the electric excavator 100 and various types of data required to execute the program. The memory also temporarily stores work data generated in connection with the operation of the electric excavator 100. The control unit 30 controls the operations of the hydraulic excavator 100 by executing a control program stored in memory.

[0047] The control unit 30 transmits a control signal to the changeover valve 51 to control the opening degree of the changeover valve 51. Data relating to the temperature of the hydraulic oil, detected by the temperature sensor 49, is input to the control unit 30. The control unit 30 transmits a control signal to the changeover valve 63 to control the opening degree of the changeover valve 63. Data relating to the temperature control fluid, detected by the temperature sensor 69, is input to the control unit 30. The control unit 30 operates the heater 61 or the cooler 62 appropriately based on the reading from the temperature sensor 69. Accordingly, the temperature of the temperature control fluid supplied to the battery 37 from the battery thermal management system 60 is appropriately regulated. Temperature control of the power storage device

[0048] Fig. Figure 3 is a perspective view illustrating a schematic configuration of battery 37. Battery 37 includes a variety of battery packs 37A to 37F. The variety of battery packs 37A to 37F are stacked in an upward and downward direction. Although in Fig. As 3 six battery packs 37A to 37F are illustrated, the number of battery packs that make up battery 37 is of course arbitrary.

[0049] Each of the multiple battery packs 37A to 37F is provided with a supply port and a return port. Battery pack 37A has a supply port 37AS and a return port 37AR. Battery pack 37F has a supply port 37FS and a return port 37FR. Fluid line 64 is connected to the supply ports of the respective battery packs 37A to 37F. Fluid line 64 is also connected to the return ports of the respective battery packs 37A to 37F.

[0050] The temperature control fluid is supplied from fluid line 64 to each of the battery packs 37A to 37F via the supply port. The temperature control fluid flows through the interior of each battery pack 37A to 37F, thereby regulating the temperature of each battery cell enclosed within battery 37. After being used to regulate the temperature of battery 37, the temperature control fluid flows out of each battery pack 37A to 37F via the return port and is returned to fluid line 64.

[0051] Fig. Figure 4 is a flowchart illustrating the process of regulating the temperature of battery 37. The diagram is in Fig. 4. The illustrated process in each step is controlled by the control unit 30 ( Fig. 2) executed.

[0052] In step S1, the control unit 30 determines whether the hydraulic oil temperature is higher than the setpoint temperature of the temperature control fluid. The hydraulic oil temperature refers to the temperature of the hydraulic oil flowing through the hydraulic line 46 after it has been used to operate the hydraulic actuator. The hydraulic oil temperature is measured by the temperature sensor 49 and input to the control unit 30. The setpoint temperature of the temperature control fluid is stored in the control unit 30's memory. The control unit 30 compares the input hydraulic oil temperature with the setpoint temperature of the temperature control fluid read from the memory and determines whether the hydraulic oil temperature is higher than the setpoint temperature of the temperature control fluid.

[0053] If it is determined that the hydraulic oil temperature is higher than the setpoint temperature of the temperature control fluid (YES in step S1), the control unit 30 determines in step S2 whether the ambient temperature is equal to or lower than a threshold value. In this case, the ambient temperature includes at least one of the outside air temperature, the temperature of battery 37, and the temperature of the temperature control fluid. An ambient temperature threshold value is stored in the memory of the control unit 30. For example, the ambient temperature threshold value could be a lower limit of the operating temperature range of battery 37.

[0054] The control unit 30 compares the input ambient temperature with the ambient temperature threshold read from memory and determines whether the ambient temperature is equal to or lower than the threshold. The control unit 30 also determines whether the temperature of the battery 37 is equal to or lower than a preset temperature, or whether the temperature of the temperature control fluid is equal to or lower than a preset temperature.

[0055] If the ambient temperature is determined to be equal to or lower than the threshold (YES in step S2), the control unit 30 initiates a process in step S3 of heating the temperature control fluid using the hydraulic oil. The control unit 30 controls the opening degree of the changeover valve 51 to generate a flow of hydraulic oil that returns to the hydraulic oil tank 42 via the bypass line 50. Additionally, the control unit 30 controls the opening degree of the changeover valve 63 to generate a flow of the temperature control fluid towards the heat exchanger 52. In the heat exchanger 52, heat is transferred from the high-temperature hydraulic oil to the low-temperature temperature control fluid, and the temperature of the temperature control fluid increases.

[0056] By supplying the temperature control fluid, which has been heated by the hydraulic oil, to the battery 37, the battery 37 can be heated by the temperature control fluid. Since the temperature control fluid is heated by the hydraulic oil, the amount of heat generated by the heater 61 required to heat the temperature control fluid to a temperature suitable for heating the battery 37 can be reduced. This reduces the power consumption of the heater 61.

[0057] If the temperature of the hydraulic oil is equal to or lower than the setpoint temperature of the temperature control fluid (NO in step S1), the temperature control fluid cannot be heated by the hydraulic oil, and therefore the process proceeds to step S4, and the process of heating the temperature control fluid using the hydraulic oil is not carried out. If the temperature of battery 37 is higher than the setpoint temperature (NO in step S2), it is not necessary to heat battery 37 using the temperature control fluid, and therefore the process proceeds to step S4, and the process of heating the temperature control fluid using the hydraulic oil is not carried out.If the temperature of the temperature control fluid used to regulate the temperature of battery 37 is higher than the specified temperature and the temperature control fluid is sufficiently heated (NO in step S2), the process proceeds to step S4 and the process of heating the temperature control fluid using the hydraulic oil is not carried out.

[0058] During the investigation in step S1, it may be determined that a temperature difference between the hydraulic oil and the temperature control fluid is equal to or greater than a specified value. Even if the temperature of the hydraulic oil is higher than the setpoint temperature of the temperature control fluid, a small temperature difference may not sufficiently increase the amount of heat transferred from the hydraulic oil to the temperature control fluid, and it may be difficult to heat the temperature control fluid efficiently. If the temperature control fluid is heated by the hydraulic oil, whose temperature is sufficiently higher than that of the temperature control fluid, the temperature control fluid can be heated efficiently.

[0059] Fig. Figure 5 is a schematic view illustrating another example of the arrangement of the heat exchanger 52. The heat exchanger 52 can be located at any point in the hydraulic oil circuit through which the hydraulic oil flows, as long as the heat exchanger can exchange heat between the hydraulic oil and the temperature control fluid. As shown in Fig. As illustrated in Figure 5, the heat exchanger 52 can be arranged inside the hydraulic oil tank 42.

[0060] The control unit 30 transmits a control signal to the changeover valve 63 to control the opening degree of the changeover valve 63. If the in Fig. When the changeover valve 63 shown in section 5 is opened, a flow of the temperature control fluid is generated towards the heat exchanger 52, and the temperature control fluid can be heated by the hydraulic oil. When the in Fig. When the changeover valve 63 shown in Figure 5 is closed, the flow of the temperature control fluid towards the heat exchanger 52 can be suppressed.

[0061] In the embodiment described above, an electric excavator 100 is given as an example of the working machine. However, the embodiment is not limited to the electric excavator 100 and is applicable to other types of working machines that include the battery 37 (the power storage device). For example, the working machine can include other types of battery-powered working machines such as an electric wheel loader, an electric bulldozer, and an electric dump truck. Steps and effects

[0062] Although some parts overlap with the description provided above, the characteristic configurations, actions, and effects of the present embodiment are summarized as follows.

[0063] As in Fig. As illustrated in Figure 4, battery 37 is heated by the hydraulic oil when the temperature of the hydraulic oil is higher than the temperature of the temperature control fluid that regulates the temperature of battery 37. In the case of the electric excavator 100, which includes the hydraulic actuator, a significant amount of heat is absorbed by the hydraulic oil when the hydraulic actuator is driven, and it is likely that the temperature of the hydraulic oil will rise. The heat from the hydraulic oil can be used to keep battery 37 warm. The waste heat from the hydraulic oil after the hydraulic actuator has been driven can be redirected to heat battery 37, thus warming the battery 37.The amount of heat generated by the heater 61 to warm the temperature control fluid can be reduced, and if the temperature control fluid can be heated to the set temperature or higher by the hydraulic oil, the heater 61 does not need to be operated, thus suppressing its power consumption. Even in cold regions, the continuous operating time of the electric excavator 100 can be ensured.

[0064] As in Fig. As illustrated in Figure 4, battery 37 can be heated by the hydraulic oil if the temperature of battery 37 or the temperature of the temperature control fluid is equal to or lower than a predetermined temperature. Battery 37 has an operating temperature range (for example, 15 °C or more and 35 °C or less), and battery 37 can degrade in temperatures below the lower limit of this operating temperature range. If the temperature of battery 37 is equal to or lower than the predetermined temperature, or if the temperature of the temperature control fluid used to regulate the temperature of battery 37 is equal to or lower than the predetermined temperature, battery 37 can be heated by the hydraulic oil, the temperature of which is higher than the temperature of the temperature control fluid.This makes it possible to warm the battery 37 to the operating temperature range at an early stage while simultaneously suppressing power consumption.

[0065] As in Fig. 2 and Fig. As illustrated in Figure 5, the heat exchanger 52, which exchanges heat between the hydraulic oil and the temperature control fluid, can be provided within the hydraulic oil circuit through which the hydraulic oil flows. To heat the battery 37 using the hydraulic oil, the hydraulic oil can circulate through the battery 37 to transfer heat directly from the hydraulic oil to the battery 37. However, in this case, a separate coolant path is required for cooling the battery 37, distinct from a separate hydraulic oil path for heating the battery 37. In the battery-powered electric work machine, the battery 37 has a large capacity and contains a large number of battery packs (battery cells). Therefore, if a separate hydraulic oil path and a separate temperature control coolant path are provided for all battery cells, the structure becomes complex and difficult to implement due to space constraints and cost.The heat exchanger 52 exchanges heat between the hydraulic oil and the temperature control fluid, and the temperature control fluid heated by the heat of the hydraulic oil is supplied to the battery 37, so that a structure for heating the battery 37 using the hydraulic oil can be easily implemented.

[0066] As in Fig. As illustrated in Figure 2, the heat exchanger 52 can be located in the bypass line 50, through which the hydraulic oil flows from the hydraulic actuator towards the hydraulic oil tank 42. Accordingly, the temperature of the temperature control fluid can be increased by the high-temperature hydraulic oil after the hydraulic actuator has been driven.

[0067] As in Fig. As illustrated in Figure 5, the heat exchanger 52 can be arranged inside the hydraulic oil tank 42. This allows the temperature of the temperature control fluid to be increased by the high-temperature hydraulic oil that is returned to the hydraulic oil tank 42 after the hydraulic actuator has been driven. Since the heat exchanger 52 can be arranged without affecting the Fig. By providing the illustrated bypass line 50, the configuration can be simplified, space saved and energy for transferring the hydraulic oil via the bypass line 50 avoided.

[0068] As in Fig. As illustrated in Figure 3, battery 37 can encompass the multitude of stacked battery packs 37A to 37F, and the temperature control fluid can flow through the interior of each of the multitude of battery packs 37A to 37F. In this way, the temperature of each of the multitude of battery packs 37A to 37F can be set to a suitable temperature.

[0069] It is understood that the embodiment disclosed herein is in every respect illustrative and not limiting. The scope of protection of the present invention is not limited to the description given above and is defined by the claims and is intended to include all modifications within the meaning and scope of protection that correspond to the claims. Reference symbol list 1 main body, 2 working machine, 3 bodies of revolution, 5 vehicles, 5M drive motor, 6 outriggers 7 Arm, 8 shovels, 10 boom cylinders, 11 arm cylinders, 12 paddle cylinders, 24 rotary motor, 30 control unit, 31 inverters, 35 Power distribution unit, 36 high-voltage junction boxes, 37 Battery, 37A to 37F battery pack, 37AR, 37FR return connection, 37AS, 37FS feed connection, 38 charging ports, 39, 49, 69 Temperature sensor, 40 electric motor, 41 Main valve, 42 Hydraulic oil tank, 43 Hydraulic pump, 44, 46 Hydraulic line, 50 bypass lines, 51.63 Diverter valve, 52 heat exchangers, 60 Battery thermal management system, 61 Heating, 62 coolers, 64 Fluid line, 65 pump, 100 electric excavators QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 11-229430 A [0002, 0003]

Claims

[1] Battery-powered working machine, comprising: a main body; a power storage device provided in the main body and configured to be temperature-controlled by a temperature control fluid; an electric motor configured to be powered by electricity from the energy storage device; a hydraulic pump configured to be driven by the electric motor; and a hydraulic actuator configured to be driven by the hydraulic oil delivered from the hydraulic pump, the energy storage device is heated by the hydraulic oil if the temperature of the hydraulic oil is higher than the temperature of the temperature control fluid. [2] Battery-powered working machine according to claim 1, wherein the power storage device is heated by the hydraulic oil when the temperature of the power storage device or the temperature of the temperature control fluid is equal to or lower than a predetermined temperature. [3] Battery-powered working machine according to claim 1 or 2, further comprising a heat exchanger provided in a hydraulic oil circuit through which the hydraulic oil flows and which is configured to exchange heat between the hydraulic oil and the temperature control fluid. [4] Battery-powered working machine according to claim 3, wherein the hydraulic oil circuit includes a hydraulic oil tank in which the hydraulic oil is stored, and the heat exchanger is provided in the hydraulic oil circuit, through which the hydraulic oil flows from the hydraulic actuator towards the hydraulic oil tank. [5] Battery-powered working machine according to claim 3, wherein the hydraulic oil circuit includes a hydraulic oil tank in which the hydraulic oil is stored, and The heat exchanger is located inside the hydraulic oil tank. [6] Battery-powered working machine according to claim 3, wherein The energy storage device comprises a large number of stacked battery packs and The temperature control fluid flows through the interior of each of the multiple battery packs.

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