Electric work machinery

Abstract

The present invention provides an electric work machine that can easily discharge air stagnating in at least one of the first cooling channel built into the first battery unit and the second cooling channel built into the second battery unit. [Solution] The hydraulic excavator, as an electric work machine, comprises a first battery unit incorporating a first cooling passage through which a refrigerant flows, a second battery unit incorporating a second cooling passage connected in parallel to the first cooling passage, a selector valve connected to the first and second cooling passages, and a heat exchanger for cooling the refrigerant. The selector valve selectively directs the refrigerant to at least one of the first and second cooling passages.

Description

Technical Field

[0001] The present invention relates to an electric working machine.

Background Art

[0002] Patent Document 1 discloses a working machine including a cooling circuit that cools a capacitor as a power storage device while circulating a refrigerant cooled by a radiator as a heat exchanger.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, electric working machines equipped with a plurality of battery units (for example, lithium-ion battery units) as power storage devices have also been proposed. In such an electric working machine, cooling of each battery unit may be achieved by allowing a refrigerant to flow through a cooling channel built into each battery unit. Here, for example, when air is mixed into the cooling circuit when the refrigerant is injected into the cooling circuit during manufacturing, maintenance, etc., this mixed air may stay in at least one cooling channel of the cooling circuit (even if the refrigerant circulates through the cooling circuit). In this case, in order to avoid non-uniform temperature of the battery unit and the progression of deterioration of the battery unit, it is desirable to eliminate the retention of air. However, particularly when each cooling channel is connected in parallel to each other, the flow rate of the refrigerant flowing through each cooling channel tends to be small, so there is a risk that it may be difficult to eliminate the retention of air.

[0005] The present invention was made to solve the above-mentioned problems, and its objective is to provide an electric work machine that can easily discharge air stagnating in at least one of the cooling passages (a first cooling passage built into the first battery unit and a second cooling passage built into the second battery unit) built into multiple battery units. [Means for solving the problem]

[0006] A working machine according to one aspect of the present invention comprises a first battery unit incorporating a first cooling channel through which a refrigerant flows, a second battery unit incorporating a second cooling channel connected in parallel to the first cooling channel, a selector valve connected to the first cooling channel and the second cooling channel, and a heat exchanger for cooling the refrigerant, wherein the selector valve selectively guides the refrigerant to at least one of the first cooling channel and the second cooling channel. [Effects of the Invention]

[0007] With the above configuration, air accumulating in at least one of the first cooling channel built into the first battery unit and the second cooling channel built into the second battery unit can be easily discharged. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view showing the schematic configuration of a hydraulic excavator, which is an example of an electric work machine according to one embodiment of the present invention. [Figure 2] This is a schematic block diagram showing the electrical and hydraulic system configurations of the above-mentioned hydraulic excavator. [Figure 3] This is a block diagram schematically showing the configuration of the cooling system of the hydraulic excavator described above. [Figure 4] This is a perspective view from the left rear showing the configuration of the selector valve installed in the hydraulic excavator described above. [Figure 5] This is a left side view showing the arrangement and structure of the cooling system described above. [Figure 6] This is a plan view showing the arrangement and structure of the cooling system described above. [Figure 7] This is a rear view showing the arrangement structure of the cooling system described above. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings.

[0010] [1. Outline configuration of an electric power machine] Figure 1 is a side view showing the schematic configuration of a hydraulic excavator 1, which is an example of an electric work machine according to one embodiment of the present invention. The hydraulic excavator 1 (also called an electric excavator) comprises a lower traveling body 2, a work machine 3, and an upper rotating body 4.

[0011] Here, the directions in this embodiment are defined as follows: The direction in which the operator (driver, operator) seated in the driver's seat 41a located in the control section 41 of the upper slewing body 4 faces forward is defined as "forward," and the opposite direction is defined as "rear." When the upper slewing body 4 is not slewing relative to the lower traveling body 2 (slewing angle 0 degrees), the front-rear direction of the upper slewing body 4 coincides with the front-rear direction of the lower traveling body 2. The drawing shows the hydraulic excavator 1 in the state where the upper slewing body 4 is not slewing relative to the lower traveling body 2. Also, the left side as seen from the perspective of the operator seated in the driver's seat 41a is defined as "left," and the right side as "right." Furthermore, the direction of gravity perpendicular to the front-rear and left-right directions is defined as the up-down direction, with the upstream side of the direction of gravity being defined as "up," and the downstream side being defined as "down." In the drawings, the front is indicated by the symbol "F", the rear by "B", the left by "L", the right by "R", the top by "U", and the bottom by "D", as needed.

[0012] The lower travel body 2 comprises a pair of left and right crawlers 21 and a pair of left and right travel motors 22. Each travel motor 22 is a hydraulic motor. The left and right travel motors 22 drive the left and right crawlers 21 respectively, allowing the hydraulic excavator 1 to move forward and backward. The lower travel body 2 is provided with a blade 23 for leveling work and a blade cylinder 23a. The blade cylinder 23a is a hydraulic cylinder that rotates the blade 23 in the vertical direction.

[0013] The work machine 3 comprises a boom 31, an arm 32, and a bucket 33. By independently driving the boom 31, arm 32, and bucket 33, excavation work such as soil and sand can be performed.

[0014] The boom 31 is rotated by the boom cylinder 31a. The boom cylinder 31a is supported at its base end on the front of the upper slewing body 4 and is movable in an extendable and retractable manner. The arm 32 is rotated by the arm cylinder 32a. The arm cylinder 32a is supported at its base end on the boom 31 and is movable in an extendable and retractable manner. The bucket 33 is rotated by the bucket cylinder 33a. The bucket cylinder 33a is supported at its base end on the arm 32 and is movable in an extendable and retractable manner. The boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a are each composed of hydraulic cylinders.

[0015] The upper rotating body 4 is an example of the machine body 11. The upper rotating body 4 is located above the lower running body 2 and is mounted to rotate relative to the lower running body 2 via a rotating bearing (not shown). The upper rotating body 4 houses a control unit 41, a rotating frame 42, a rotating motor 43, a machine room 44, and the like.

[0016] The upper rotating body 4 rotates relative to the lower traveling body 2 by the drive of a rotating motor 43 located on the rotating frame 42. The rotating frame 42 is composed of multiple metal members joined together by welding or the like, and is located at the bottom 11D of the machine body 11 (upper rotating body 4). The rotating motor 43 is a hydraulic motor.

[0017] In the upper swing body 4, a hydraulic pump 71 (see FIG. 2) is further arranged. The hydraulic pump 71 is driven by an electric motor 61 (see FIG. 2) inside the machine room 44. The hydraulic pump 71 supplies hydraulic oil (pressure oil) to hydraulic motors (for example, left and right travel motors 22, swing motor 43) and hydraulic cylinders (for example, blade cylinder 23a, boom cylinder 31a, arm cylinder 32a, bucket cylinder 33a). The hydraulic motors and hydraulic cylinders driven by the supply of hydraulic oil from the hydraulic pump 71 are collectively referred to as a hydraulic actuator 73 (see FIG. 2).

[0018] In the control section 41, a driver's seat 41a is arranged. Various control members 41b are arranged around the driver's seat 41a. The various control members 41b include a lever, a switch, a pedal, etc. When the operator sits on the driver's seat 41a and operates the various control members 41b, the hydraulic actuator 73 is driven. Thereby, the lower traveling body 2 can travel, the leveling work by the blade 23 can be performed, the excavation work by the working machine 3 can be performed, the upper swing body 4 can swing, etc.

[0019] In the machine room 44, a battery unit BU is arranged. The battery unit BU is composed of, for example, a lithium-ion battery unit and stores electric power. The battery unit BU may be composed of a plurality of batteries unitized, or may be composed of a single battery cell. Further, the upper swing body 4 is provided with a power supply port (not shown). The above power supply port and a commercial power supply 51 which is an external power source are connected via a power supply cable 52. Thereby, the battery unit BU can be charged.

[0020] Note that the hydraulic excavator 1 may have a configuration in which hydraulic devices such as the hydraulic actuator 73 and an actuator driven by electric power are used in combination. Examples of the actuator driven by electric power include an electric travel motor, an electric cylinder, and an electric swing motor.

[0021] [2. Configuration of Electrical System, Hydraulic System, and Cooling System] This section describes the electrical, hydraulic, and cooling systems of hydraulic excavator 1. First, the electrical and hydraulic systems of hydraulic excavator 1 will be described based on Figure 2. Figure 2 is a schematic block diagram showing the electrical and hydraulic systems of hydraulic excavator 1.

[0022] The hydraulic excavator 1 is equipped with an electric motor 61, a charger 62, an inverter 63, a PDU (Power Drive Unit) 64, a junction box 65, a DC-DC converter 66, a lead-acid battery 67, and a system controller 68. The system controller 68 is an electronic control unit also called an ECU (Electronic Control Unit) and performs electrical control of each part of the hydraulic excavator 1.

[0023] The electric motor 61 is driven by power supplied from the battery unit BU via the junction box 65 and inverter 63. That is, the battery unit BU stores the power to drive the electric motor 61. The electric motor 61 is composed of a synchronous motor or an induction motor, etc. The electric motor 61 is located inside the machine room 44 (see Figure 1), particularly on the slewing frame 42 (see Figure 1).

[0024] The charger 62 converts the AC voltage supplied from the commercial power supply 51 via the power supply cable 52 (see Figure 1) into a DC voltage. The inverter 63 converts the DC voltage supplied from the battery unit BU into an AC voltage and supplies it to the electric motor 61. This causes the electric motor 61 to rotate. The supply of AC voltage (current) from the inverter 63 to the electric motor 61 is performed based on a rotation command output from the system controller 68.

[0025] The PDU64 is a battery control unit that controls the input and output of the battery unit BU by controlling its internal battery relay. The junction box 65 is composed of a charger relay, an inverter relay, a fuse, etc. The voltage output from the charger 62 is supplied to the battery unit BU via the junction box 65 and the PDU64. The voltage output from the battery unit BU is supplied to the inverter 63 via the PDU64 and the junction box 65.

[0026] The DC-DC converter 66 steps down the high-voltage (e.g., 300V) DC voltage supplied from the battery unit BU via the junction box 65 to a low-voltage (e.g., 12V). The lead-acid battery 67 stores the power of the low-voltage DC voltage. The lead-acid battery 67 also outputs the stored power. The low-voltage DC voltage output from the DC-DC converter 66 and the lead-acid battery 67 is supplied to the system controller 68, the circulation pump 102 (see Figure 3 below), the blower fan 104F (see Figure 5 below), etc.

[0027] Multiple hydraulic pumps 71 are connected to the rotating shaft (output shaft) of the electric motor 61. The multiple hydraulic pumps 71 include variable displacement pumps and fixed displacement pumps. In Figure 2, only one hydraulic pump 71 is shown as an example. Each hydraulic pump 71 is connected to a hydraulic fluid tank 74 that contains (stores) hydraulic fluid. The hydraulic pumps 71 supply hydraulic fluid from the hydraulic fluid tank 74 to the hydraulic actuator 73 via a control valve 72. This drives the hydraulic actuator 73. The control valve 72 is a directional control valve that controls the flow direction and flow rate of the hydraulic fluid supplied to the hydraulic actuator 73.

[0028] Next, the configuration of the cooling system of hydraulic excavator 1 (particularly the cooling system of battery unit BU) will be explained based on Figure 3. Figure 3 is a schematic block diagram showing the configuration of the cooling system of hydraulic excavator 1. In Figure 3, the direction in which the refrigerant circulates (circulation direction) is indicated by an arrow.

[0029] The hydraulic excavator 1 is equipped with a cooling circuit 100. The cooling circuit 100 cools the battery unit BU by circulating a coolant. In this embodiment, cooling water is used as the coolant, but it is not limited to this, and for example, cooling oil may be used as the coolant. In addition to the function of cooling the battery unit BU, the cooling circuit 100 also has the function of warming (heating) the battery unit BU.

[0030] In this embodiment, four battery units BU are provided. Specifically, each battery unit BU consists of a first battery unit BU1 and a second battery unit BU2, with two first battery units BU1 and two second battery units BU2 provided. That is, the hydraulic excavator 1 comprises multiple (two in this embodiment) first battery units BU1 and multiple (two in this embodiment) second battery units BU2. Note that the hydraulic excavator 1 only needs to have at least one first battery unit BU1 and one second battery unit BU2. For example, it may have one first battery unit BU1 and three second battery units BU2, or it may have three first battery units BU1 and one second battery unit BU2. Furthermore, the number of battery units BU is not limited to four; for example, it may have two, three, or five or more.

[0031] Each battery unit BU is identical to the others. That is, the first battery unit BU1 and the second battery unit BU2 are the same battery unit BU. However, the first battery unit BU1 and the second battery unit BU2 may be different battery units BU. For example, each battery unit BU has the same rectangular box shape (see Figures 5 to 7 described later). However, each battery unit BU may be different in size from the others, or may have an external shape other than a rectangular box.

[0032] A coolant flows inside each battery unit BU. More specifically, the first battery unit BU1 incorporates a first cooling channel BU1a, and the second battery unit BU2 incorporates a second cooling channel BU2a. The first cooling channel BU1a and the second cooling channel BU2a constitute a cooling circuit 100. Therefore, the coolant circulating in the cooling circuit 100 flows through the first cooling channel BU1a and the second cooling channel BU2a. In other words, the coolant flows through the first cooling channel BU1a and the second cooling channel BU2a.

[0033] The first battery unit BU1 is cooled by heat exchange with the refrigerant flowing through the first cooling channel BU1a, which is built into the first battery unit BU1. The second battery unit BU2 is cooled by heat exchange with the refrigerant flowing through the second cooling channel BU2a, which is built into the second battery unit BU2. Hereafter, the multiple first cooling channels BU1a and the multiple second cooling channels BU2a may be collectively referred to as the cooling channel group BUa.

[0034] The cooling circuit 100 includes a cooling flow path group BUa, a circulation path 101, a circulation pump 102, a heater 103, a radiator 104, a selector valve 105, and a connecting section 106. In other words, the hydraulic excavator 1 is equipped with a circulation path 101, a circulation pump 102, a heater 103, a radiator 104, a selector valve 105, and a connecting section 106. The circulation path 101 is a flow path (water channel) for circulating refrigerant (cooling water). The configuration of the circulation path 101 will be described later.

[0035] The circulation path 101 is connected to a circulation pump 102, a heater 103, a radiator 104, a selector valve 105, a communication section 106, and a group of cooling flow paths BUa. More specifically, the circulation pump 102, the heater 103, and the radiator 104 are connected in series with each other. In particular, the circulation pump 102 is located between the heater 103 and the radiator 104. Between the heater 103 and the radiator 104, on the side of the heater 103 (or radiator 104) away from the circulation pump 102, two first cooling flow paths BU1a and two second cooling flow paths BU2a are connected in parallel with each other. That is, the second cooling flow paths BU2a are connected in parallel with the first cooling flow paths BU1a.

[0036] The two first cooling channels BU1a and the two second cooling channels BU2a are interconnected via a selector valve 105 and a communication section 106. The selector valve 105 is provided between the heater 103 and the cooling channel group BUa, and the communication section 106 is provided between the cooling channel group BUa and the radiator 104.

[0037] The circulation pump 102 is an electric pump and is driven by (low-voltage) power supplied from a DC-DC converter 66 and a lead-acid battery 67 (both see Figure 2). When the circulation pump 102 is driven, the refrigerant circulates through the circulation path 101. More specifically, the refrigerant discharged from the circulation pump 102 flows into the heater 103. The heater 103 enables heating (heating) of the refrigerant. Specifically, when the heater 103 is set to the ON state (energized state), the heater 103 heats the refrigerant that flows into it. When the heater 103 is set to the OFF state (unenergized state), heating of the refrigerant by the heater 103 stops. For example, the heater 103 is used in cold weather. The refrigerant that has passed through the heater 103 flows into the selector valve 105. The selector valve 105 controls the flow direction of the refrigerant that flows into it. The configuration of the selector valve 105 will be described later.

[0038] The refrigerant that has passed through the selection valve 105 flows into the cooling channel group BUa. As described above, the refrigerant flows through the cooling channel group BUa, and heat exchange takes place between the refrigerant and each battery unit BU, thereby cooling each battery unit BU.

[0039] The refrigerant that has passed through the cooling channel group BUa flows into the radiator 104 via the connecting section 106. Specifically, the refrigerant that has passed through one first cooling channel BU1a, the refrigerant that has passed through the other first cooling channel BU1a, the refrigerant that has passed through one second cooling channel BU2a, and the refrigerant that has passed through the other second cooling channel BU2a merge at the connecting section 106 and flow into the radiator 104. The connecting section 106 is composed of a joint member that connects the two first cooling channels BU1a, the two second cooling channels BU2a, and the radiator 104 to each other. In other words, the connecting section 106 connects the first cooling channel BU1a and the second cooling channel BU2a.

[0040] The radiator 104 is an example of a heat exchanger HE. The radiator 104 cools the refrigerant flowing through it by exchanging heat with the wind (air) that blows on it. In other words, the hydraulic excavator 1 is equipped with a heat exchanger HE (radiator 104 in this embodiment) that cools the refrigerant circulating in the cooling circuit 100. Air is supplied to the radiator 104 by driving a blower fan 104F (see Figures 5 to 7, described later) which is positioned opposite the radiator 104. The blower fan 104F is an electric fan and is driven by (low-voltage) power supplied from a DC-DC converter 66 and a lead battery 67 (both see Figure 2). Note that the cooling of the refrigerant by the radiator 104 may also be achieved by heat exchange between the refrigerant flowing through the radiator 104 and another refrigerant flowing separately through the radiator 104.

[0041] The connection structure of the circulation pump 102, heater 103, radiator 104, selector valve 105, communication section 106, and cooling channel group BUa is not limited to the above. For example, the heater 103 may be provided upstream of the circulation pump 102 in the direction of refrigerant flow, and the radiator 104 may be provided downstream of the circulation pump 102 in the direction of refrigerant flow. Also, the communication section 106 may be provided upstream of the cooling channel group BUa in the direction of refrigerant flow, and the selector valve 105 may be provided downstream of the cooling channel group BUa in the direction of refrigerant flow.

[0042] Here, the configuration of the circulation path 101 will be described. Each waterway between the selector valve 105 and the cooling flow path group BUa in the circulation path 101 is composed of a first piping group P1. In this embodiment, since there are four of the above-mentioned waterways, the first piping group P1 has four first pipes P11. The number of first pipes P11 can be set according to the number of the above-mentioned waterways and is not limited to four. Each first pipe P11 is composed of a piping member such as a hose and constitutes the above-mentioned waterway. Specifically, one end of each first pipe P11 is connected to the selector valve 105, and the other end is connected to either the first cooling flow path BU1a or the second cooling flow path BU2a. Therefore, the hydraulic excavator 1 is equipped with a first piping group P1, and this first piping group P1 extends from the selector valve 105 toward the first cooling flow path BU1a and the second cooling flow path BU2a.

[0043] Each waterway between the cooling channel group BUa and the communication section 106 in the circulation path 101 is composed of a second piping group P2. In this embodiment, since there are four of the above-mentioned waterways, the second piping group P2 has four second pipes P21. The number of second pipes P21 can be set according to the number of the above-mentioned waterways and is not limited to four. Each second pipe P21 is composed of a piping member such as a hose and constitutes the above-mentioned waterway. Specifically, one end of each second pipe P21 is connected to the communication section 106, and the other end is connected to the first cooling channel BU1a or the second cooling channel BU2a. Therefore, the hydraulic excavator 1 is equipped with a second piping group P2, and this second piping group P2 extends from the communication section 106 toward the first cooling channel BU1a and the second cooling channel BU2a.

[0044] The waterway between the radiator 104 and the selector valve 105 in the circulation path 101 (the waterway that passes through the circulation pump 102) includes a third pipe P3. The third pipe P3 is made up of piping members such as hoses and constitutes the above-mentioned waterway. One end of the third pipe P3 is connected to the selector valve 105, and the other end extends toward the radiator 104. Therefore, the hydraulic excavator 1 is equipped with a third pipe P3, which extends from the selector valve 105 toward the heat exchanger HE (radiator 104 in this embodiment).

[0045] The waterway between the communication section 106 and the radiator 104 in the circulation path 101 (the waterway on the opposite side from the waterway passing through the circulation pump 102) includes a fourth pipe P4. The fourth pipe P4 is made up of piping members such as hoses and constitutes the above-mentioned waterway. One end of the fourth pipe P4 is connected to the communication section 106, and the other end extends toward the radiator 104. Therefore, the hydraulic excavator 1 is equipped with a fourth pipe P4, which extends from the communication section 106 toward the heat exchanger HE (radiator 104 in this embodiment).

[0046] [3. Configuration of the Selector Valve] The configuration of the selector valve 105 will be explained with reference to Figure 4. Figure 4 is a perspective view from the left rear showing the configuration of the selector valve 105. The selector valve 105 has a valve body 105a, a valve element 105b, and an operating member 105c.

[0047] The valve body 105a is constructed by closing the lower end of a cylindrical metal member that extends in the vertical direction. The valve body 105a has a first connection port 105a1, a second connection port 105a2, a third connection port 105a3, a fourth connection port 105a4, and a fifth connection port 105a5.

[0048] The first connection port 105a1, the second connection port 105a2, the third connection port 105a3, the fourth connection port 105a4, and the fifth connection port 105a5 each protrude outward from the outer circumferential surface of the valve body 105a in the radial direction. Specifically, the first connection port 105a1 protrudes to the right rearward on the lower side of the valve body 105a. The second connection port 105a2 is above the first connection port 105a1 and is positioned circumferentially offset from the first connection port 105a1 on the valve body 105a, protruding to the left front. The third connection port 105a3 is above the second connection port 105a2 and protrudes to the left front. The fourth connection port 105a4 is approximately above the first connection port 105a1 and protrudes to the right rear. The fifth connection port 105a5 opens between the first connection port 105a1 and the fourth connection port 105a4 in the vertical direction, protruding toward the rear right.

[0049] The third pipe P3 (see Figure 3) is connected to the first connection port 105a1. As described above, the third pipe P3 extends from the selector valve 105 toward the radiator 104. That is, the third pipe P3 extends toward the circulation pump 102. Therefore, the inflow of refrigerant discharged from the circulation pump 102 (after passing through the heater 103) into the selector valve 105 occurs through the first connection port 105a1.

[0050] The first piping group P1 (see Figure 3) is connected to the second connection port 105a2, the third connection port 105a3, the fourth connection port 105a4, and the fifth connection port 105a5. Specifically, the first piping P11 (see Figure 3), which is connected to the first cooling channel BU1a, is connected to the second connection port 105a2 and the fourth connection port 105a4, respectively (see also Figure 5 described later). The first piping P11, which is connected to the second cooling channel BU2a, is connected to the third connection port 105a3 and the fifth connection port 105a5, respectively (see also Figure 5 described later). Therefore, the selector valve 105 is connected to the first cooling channel BU1a and the second cooling channel BU2a via the first piping group P1 (see also Figure 3).

[0051] The valve body 105a also has a sensor mounting port 105a6 and an outlet (not shown). A temperature sensor 107 is attached to the sensor mounting port 105a6 to detect the temperature of the refrigerant circulating in the cooling circuit 100 (flowing through the selector valve 105). However, a sensor other than the temperature sensor 107 may be attached to the sensor mounting port 105a6. An example of a sensor other than the temperature sensor 107 is a pressure sensor that detects the pressure of the refrigerant. The outlet is used when replacing the refrigerant, etc. Specifically, the refrigerant in the valve body 105a is discharged to the outside of the cooling circuit 100 through the outlet. The outlet is sealed by a plug (not shown) that is detachably attached to the outlet.

[0052] The valve body 105b is composed of a cylindrical metal member extending in the vertical direction. A communication passage (not shown) is formed in the valve body 105b. The valve body 105b is housed in the valve casing 105a so as to be rotatable around an axis along the vertical direction. By operating the operating member 105c connected to the upper end of the valve body 105b, the valve body 105b can be rotated around an axis along the vertical direction. However, the rotation of the valve body 105b may be performed by means other than operating the operating member 105c. For example, the rotational position of the valve body 105b may be electrically controlled by a control motor, a control solenoid valve (neither shown), etc. That is, rotational control (position control) of the valve body 105b may be performed.

[0053] The operating member 105c is composed of a metal plate-like member extending in one direction within the horizontal direction. One side of the operating member 105c in that direction (the right side in Figure 4) is connected to the valve body 105b. The other side of the operating member 105c in that direction (the left side in Figure 4) is provided with a through hole 105c1 that penetrates in the vertical direction.

[0054] The operation of the operating member 105c is performed using a plurality of vertically penetrating markers MK provided on a fixing plate 105d fixed to the upper end of the valve body 105a. In this embodiment, five markers MK are provided. Here, if we are to distinguish the five markers MK in particular, they will be referred to as the first marker MK1, the second marker MK2, the third marker MK3, the fourth marker MK4, and the fifth marker MK5, in order from the front left in a counterclockwise direction in a plan view.

[0055] For example, the operating member 105c is operated to a position where the through hole 105c1 and the first marker MK1 overlap in a plan view. Then, the communication passage of the valve body 105b connects the first connection port 105a1, the second connection port 105a2, the third connection port 105a3, the fourth connection port 105a4, and the fifth connection port 105a5 to each other. Therefore, in this case, a portion of the refrigerant that flows into the selector valve 105 via the first connection port 105a1 flows toward the two first cooling passages BU1a via the second connection port 105a2 and the fourth connection port 105a4. At the same time, the remaining refrigerant that flows into the selector valve 105 flows toward the two second cooling passages BU2a via the third connection port 105a3 and the fifth connection port 105a5. In other words, the selector valve 105 allows the refrigerant to be directed to either the first cooling channel BU1a or the second cooling channel BU2a.

[0056] When the operating member 105c is operated to a position where the through hole 105c1 and the second marker MK2 overlap in a plan view, the communication passage of the valve body 105b connects the first connection port 105a1 and the third connection port 105a3. Therefore, in this case, the refrigerant that flows into the selector valve 105 via the first connection port 105a1 flows (all of it) towards one of the second cooling channels BU2a via the third connection port 105a3.

[0057] When the operating member 105c is operated to a position where the through hole 105c1 and the third marker MK3 overlap in a plan view, the communication passage of the valve body 105b connects the first connection port 105a1 and the fourth connection port 105a4. Therefore, in this case, the refrigerant that flows into the selector valve 105 through the first connection port 105a1 flows (all of it) towards the other first cooling channel BU1a through the fourth connection port 105a4.

[0058] When the operating member 105c is operated to a position where the through hole 105c1 and the fourth marker MK4 overlap in a plan view, the communication passage of the valve body 105b connects the first connection port 105a1 and the second connection port 105a2. Therefore, in this case, the refrigerant that flows into the selector valve 105 via the first connection port 105a1 flows (all of it) towards one of the first cooling channels BU1a via the second connection port 105a2.

[0059] When the operating member 105c is operated to a position where the through hole 105c1 and the fifth marker MK5 overlap in a plan view, the communication passage of the valve body 105b connects the first connection port 105a1 and the fifth connection port 105a5. Therefore, in this case, the refrigerant that flows into the selector valve 105 via the first connection port 105a1 flows (all of it) towards the other second cooling channel BU2a via the fifth connection port 105a5.

[0060] Thus, the selector valve 105 not only guides the refrigerant to either the first cooling channel BU1a or the second cooling channel BU2a, but also enables the refrigerant to be guided to either the first cooling channel BU1a or the second cooling channel BU2a. Furthermore, by operating the operating member 105c to a predetermined position (for example, the position where the through hole 105c1 and the first marker MK1 overlap in a plan view, the position where the through hole 105c1 and the second marker MK2 overlap in a plan view, etc.), the channel through which the refrigerant is guided (through which the refrigerant flows) can be selected. In other words, the selector valve 105 selectively guides the refrigerant to at least one of the first cooling channel BU1a or the second cooling channel BU2a.

[0061] With the above configuration, by selecting a state in the selector valve 105 in which the refrigerant is guided to both the first cooling passage BU1a and the second cooling passage BU2a (first state), both the first battery unit BU1 and the second battery unit BU2 can be reliably cooled. In particular, even if the temperature of the refrigerant rises as the first battery unit BU1 and the second battery unit BU2 are cooled, the heat exchanger HE (radiator 104 in this embodiment) can cool the refrigerant. Therefore, the first battery unit BU1 and the second battery unit BU2 can be continuously cooled.

[0062] On the other hand, by selecting a state in the selection valve 105 where the refrigerant is guided to either the first cooling channel BU1a or the second cooling channel BU2a (second state), the flow velocity of the refrigerant flowing through the first cooling channel BU1a or the second cooling channel BU2a can be made greater than in the first state. The greater the flow velocity of the refrigerant, that is, the faster the refrigerant flows, the less likely air is to stagnate in the refrigerant. Therefore, even if air mixed into the cooling circuit 100 during the injection of refrigerant into the cooling circuit 100 during manufacturing, maintenance, etc., stagnates in at least one of the first cooling channel BU1a or the second cooling channel BU2a, the stagnate air can be easily discharged. As a result, air stagnates in at least one of the first cooling channel BU1a built into the first battery unit BU1 and the second cooling channel BU2a built into the second battery unit BU2 can be easily discharged.

[0063] Furthermore, the selection of the first state in the selection valve 105 is suitable for situations such as when the hydraulic excavator 1 is in operation (driven) or when the first battery unit BU1 and the second battery unit BU2 are being charged. The selection of the second state in the selection valve 105 is suitable for situations such as when the hydraulic excavator 1 is being manufactured or when the cooling circuit 100 is being maintained.

[0064] [4. Cooling system layout] The arrangement structure of the cooling system of the hydraulic excavator 1 (particularly the cooling system of the battery unit BU), that is, the arrangement structure of the equipment, components, etc. (e.g., selector valve 105, communication part 106) that constitute the cooling circuit 100, will be explained based on Figures 5, 6, and 7. Figures 5, 6, and 7 are the left side view, top view, and rear view, respectively, showing the arrangement structure of the equipment, etc. that constitute the cooling circuit 100. In Figure 6, for convenience, the top view of the fixing mechanism 80, which will be described later, is omitted.

[0065] The two first battery units BU1 and the two second battery units BU2 are fixed to the slewing frame 42 by a fixing mechanism 80. Specifically, the fixing mechanism 80 fixes the two first battery units BU1 and the two second battery units BU2 near the center in the left-right direction at the rear of the slewing frame 42. However, the fixing mechanism 80 may also fix the two first battery units BU1 and the two second battery units BU2 to positions other than the above-mentioned position on the slewing frame 42 (e.g., the front or side). The fixing mechanism 80 is supported by the slewing frame 42 via a plurality of vibration-damping members (not shown). As the vibration-damping members, a vibration-damping structure combining vibration-damping rubber, stays, housings, etc., can be used.

[0066] The two first battery units BU1 and the two second battery units BU2 are positioned parallel to each other in one direction and aligned in a direction perpendicular to that direction. In this embodiment, the two first battery units BU1 and the two second battery units BU2 are positioned parallel to each other in the left-right direction, which is the one direction mentioned above, and aligned in the front-rear direction perpendicular to that left-right direction. Specifically, from front to back, one first battery unit BU1, one second battery unit BU2, the other first battery unit BU1, and the other second battery unit BU2 are positioned in that order. A PDU 64 is positioned in front of one of the first battery units BU1.

[0067] A selector valve 105 is located to the left of the two first battery units BU1 and the two second battery units BU2, specifically to the left of the other first battery unit BU1 and the other second battery unit BU2. The selector valve 105 is positioned below the vertical center of each battery unit BU and is fixed to the slewing frame 42.

[0068] The communication portion 106 is located to the upper left of the other first battery unit BU1 and to the rear upper of the other second battery unit BU2. Therefore, the communication portion 106 is located above the selector valve 105. In other words, the selector valve 105 is positioned on one side (downward in this embodiment) in the vertical direction relative to the communication portion 106. The communication portion 106 is fixed to the upper surface of the fixing mechanism 80.

[0069] In this embodiment, since cooling water is used as the refrigerant, the specific gravity of the air is lower than that of the refrigerant, and the air in the refrigerant tends to flow upward. Therefore, if the selector valve 105, located upstream of the first cooling passage BU1a and the second cooling passage BU2a, is positioned below the communication section 106, located downstream of the first cooling passage BU1a and the second cooling passage BU2a, stagnant air can be more easily discharged.

[0070] Here, let us assume, for example, that the selector valve 105 is provided downstream of the first cooling passage BU1a and the second cooling passage BU2a, and the communication section 106 is provided upstream of the first cooling passage BU1a and the second cooling passage BU2a. In this assumption, in order to facilitate the discharge of stagnant air, the communication section 106 should be positioned below the selector valve 105. That is, in this case, it is desirable that the selector valve 105 be positioned above the communication section 106. Thus, from the viewpoint of smoothly discharging stagnant air from at least one of the first cooling passage BU1a and the second cooling passage BU2a, the following configuration is desirable. That is, as in this embodiment, it is desirable that the selector valve 105 be positioned on one side (downward in this embodiment) in the vertical direction relative to the communication section 106.

[0071] The radiator 104 is located to the right of the two first battery units BU1 and the two second battery units BU2, specifically to the right of one of the first battery units BU1 and one of the second battery units BU2. In other words, the heat exchanger HE (radiator 104 in this embodiment) is located on one side (to the right in this embodiment) of the first battery units BU1 and the second battery units BU2. Therefore, the radiator 104 and the selector valve 105 are located on either side of the first battery units BU1 and the second battery units BU2. In other words, the selector valve 105 is located on the opposite side of the heat exchanger HE from the first battery units BU1 and the second battery units BU2.

[0072] The heat exchanger HE tends to be large in order to ensure cooling performance that can reliably suppress the temperature rise of the refrigerant due to the cooling of the first battery unit BU1 and the second battery unit BU2. Because the enlarged heat exchanger HE requires a large installation space, the installation space for the selector valve 105 is limited on the same side as the heat exchanger HE relative to the first battery unit BU1 and the second battery unit BU2. Therefore, from the viewpoint of easily installing the selector valve 105, it is desirable that the selector valve 105 be installed on the opposite side of the heat exchanger HE relative to the first battery unit BU1 and the second battery unit BU2, as in this embodiment.

[0073] Similar to the selector valve 105, the communication section 106 is also located on the opposite side of the heat exchanger HE from the first battery unit BU1 and the second battery unit BU2. Therefore, the heat exchanger HE and the communication section 106 are located with the first battery unit BU1 and the second battery unit BU2 in between.

[0074] The radiator 104 is fixed to the swivel frame 42 via a support (not shown) having a duct. Specifically, the radiator 104 is housed in the duct together with a blower fan 104F positioned opposite the radiator 104. A circulation pump 102 is also fixed to the support via a support bracket (not shown). The circulation pump 102 is positioned below and rear of the radiator 104.

[0075] An inlet 104a is provided at the top of the radiator 104, which protrudes upward and opens. The inlet 104a is used when injecting refrigerant into the cooling circuit 100, which includes a first cooling channel BU1a and a second cooling channel BU2a. That is, the heat exchanger HE (radiator 104 in this embodiment) has an inlet 104a for injecting refrigerant into the first cooling channel BU1a and the second cooling channel BU2a. More specifically, during the refrigerant injection process, a worker (e.g., an operator) removes a cap 104b that is detachably provided on the inlet 104a and pours the refrigerant into the inlet 104a. The refrigerant then passes through the inlet 104a and flows into the cooling circuit 100. As a result, the cooling circuit 100 is filled with refrigerant.

[0076] The inlet 104a is located at the highest point among the components of the cooling circuit 100. For example, the inlet 104a is located above the connecting section 106, which is located above the selector valve 105. In other words, the inlet 104a is positioned above both the selector valve 105 and the connecting section 106.

[0077] As described above, in this embodiment, the air in the refrigerant flows more easily upward, so the air discharged from at least one of the first cooling channel BU1a and the second cooling channel BU2a tends to collect at the inlet 104a. When the above air collects at the inlet 104a, the upper surface (liquid level) of the refrigerant in the cooling circuit 100, which is visible from the inlet 104a, moves downward. That is, the water level in the cooling circuit 100 decreases. Therefore, it becomes easier to confirm that the stagnant air has been discharged, making it easier for the worker to perform the refrigerant injection work (especially the discharge of stagnant air). Furthermore, by effectively utilizing the inlet 104a as a collection point for stagnant air, it becomes unnecessary to provide the above collection point separately from the inlet 104a, thus suppressing an increase in the number of parts in the cooling circuit 100. From this perspective, in a configuration such as that of this embodiment, where the heat exchanger HE has an inlet 104a for injecting refrigerant into the first cooling channel BU1a and the second cooling channel BU2a, it is desirable that the inlet 104a be positioned above the selector valve 105 and the communication section 106.

[0078] In addition, to allow refrigerant to be injected into the cooling circuit 100, an opening other than the inlet 104a may be provided in the cooling circuit 100, either in place of or in addition to the inlet 104a.

[0079] Of the multiple (four in this embodiment) first pipes P11 that constitute the first piping group P1 connected to the selector valve 105, those connected to the first cooling channel BU1a are connected to the first cooling channel inlet BU1b, which constitutes the upstream end of the first cooling channel BU1a. The first cooling channel inlet BU1b is provided on the left side of the first battery unit BU1.

[0080] Of the multiple first pipes P11, those connected to the second cooling channel BU2a are connected to the second cooling channel inlet BU2b, which constitutes the upstream end of the second cooling channel BU2a. The second cooling channel inlet BU2b is located on the left side of the second battery unit BU2.

[0081] Of the multiple (four in this embodiment) second pipes P21 that constitute the second piping group P2 connected to the communication section 106, those connected to the first cooling passage BU1a are connected to the first cooling passage outlet section BU1c, which constitutes the downstream end of the first cooling passage BU1a. The first cooling passage outlet section BU1c is provided on the left side of the first battery unit BU1, similar to the first cooling passage inlet section BU1b. The first cooling passage inlet section BU1b and the first cooling passage outlet section BU1c are arranged side by side in the vertical direction. In particular, the first cooling passage outlet section BU1c is positioned above the first cooling passage inlet section BU1b.

[0082] Of the multiple second pipes P21, those connected to the second cooling channel BU2a are connected to the second cooling channel outlet BU2c, which constitutes the downstream end of the second cooling channel BU2a. The second cooling channel outlet BU2c, like the second cooling channel inlet BU2b, is provided on the left side of the second battery unit BU2. The second cooling channel inlet BU2b and the second cooling channel outlet BU2c are arranged side by side in the vertical direction. In particular, the second cooling channel outlet BU2c is positioned above the second cooling channel inlet BU2b.

[0083] Therefore, the multiple second pipes P21 extending from the communication section 106 toward the first cooling passage BU1a or the second cooling passage BU2a are located above the multiple first pipes P11 extending from the selector valve 105 toward the first cooling passage BU1a or the second cooling passage BU2a. In other words, the first group of pipes P1 is positioned on one side (downward in this embodiment) in the vertical direction relative to the second group of pipes P2.

[0084] Furthermore, the connection of each first pipe P11 to the first cooling passage BU1a (specifically, the inlet BU1b of the first cooling passage) or the second cooling passage BU2a (specifically, the inlet BU2b of the second cooling passage) is made to the left of the first battery unit BU1 and the second battery unit BU2. The connection of each second pipe P21 to the first cooling passage BU1a (specifically, the outlet BU1c of the first cooling passage) or the second cooling passage BU2a (specifically, the outlet BU2c of the second cooling passage) is made to the left of the first battery unit BU1 and the second battery unit BU2. In other words, the first piping group P1 and the second piping group P2 are connected to the first cooling passage BU1a and the second cooling passage BU2a on the side opposite to the heat exchanger HE (radiator 104 in this embodiment) relative to the first battery unit BU1 and the second battery unit BU2.

[0085] Even if the hydraulic excavator 1 is configured to include a first piping group P1 and a second piping group P2, it is desirable to ensure that the air stagnating in at least one of the first cooling passage BU1a and the second cooling passage BU2a is smoothly discharged. From this viewpoint, it is desirable that the first piping group P1 be arranged on one side (downward in this embodiment) in the vertical direction relative to the second piping group P2, as in this embodiment.

[0086] It is desirable to consolidate the connection points between the first piping group P1 and the second piping group P2 and the first cooling channel BU1a and the second cooling channel BU2a, respectively, in order to improve the ease of assembly of the first piping group P1 and the second piping group P2. It is also desirable to avoid the heat exchanger HE (radiator 104 in this embodiment) interfering with the connection (connection work) between the first cooling channel BU1a and the second cooling channel BU2a of the first piping group P1 and the second piping group P2. In these respects, it is desirable that the first piping group P1 and the second piping group P2 are connected to the first cooling channel BU1a and the second cooling channel BU2a on the side opposite to the heat exchanger HE relative to the first battery unit BU1 and the second battery unit BU2, as in this embodiment.

[0087] The third pipe P3, which connects to the selector valve 105, is routed along the outer peripheral edge 42B1 of the rear 42B of the slewing frame 42, below the two first battery units BU1 and the two second battery units BU2. More specifically, the third pipe P3 is routed between the outer peripheral edge 42B1, which is formed to widen in the lateral direction as it moves from rear to front, and the other second battery unit BU2 in the longitudinal direction. As described above, the other second battery unit BU2 is located behind the two first battery units BU1. Therefore, the third pipe P3 is routed behind the first battery units BU1 and the second battery units BU2.

[0088] Even when the selector valve 105 and the heat exchanger HE (radiator 104 in this embodiment) are located on either side of the first battery unit BU1 and the second battery unit BU2, it is desirable to reliably achieve a configuration that connects the selector valve 105 and the heat exchanger HE. Furthermore, it is desirable to efficiently route the third piping P3 by making effective use of the dead space behind the first battery unit BU1 and the second battery unit BU2. From this viewpoint, it is desirable that the third piping P3 be routed behind the first battery unit BU1 and the second battery unit BU2, as in this embodiment.

[0089] Specifically, the outer edge 42B1 is formed in an arc shape when viewed from above. However, the shape of the slewing frame 42 is not limited to the above. For example, when viewed from above, the slewing frame 42 may be circular, elliptical, rectangular, square, or a polygon with sides other than a rectangle and a square.

[0090] The third pipe P3 is connected to the fifth pipe P5 via the first joint member PJ1, in addition to the selector valve 105. One end of the fifth pipe P5 is connected to the first joint member PJ1, and the other end is connected to the heater 103. In a plan view, the heater 103 is located to the left front of the radiator 104 and to the right front of one of the first battery units BU1, and is fixed to the swing frame 42. The heater 103 is also connected to the circulation pump 102 via the sixth pipe P6.

[0091] The fourth pipe P4, which is connected to the communication section 106, is positioned above the two first battery units BU1 and the two second battery units BU2. In particular, the fourth pipe P4 is routed along the upper surface of the other first battery unit BU1. That is, the fourth pipe P4 is routed on the other side (above in this embodiment) in the vertical direction relative to the first battery units BU1 and the second battery units BU2.

[0092] As described above, the third pipe P3 is located below the two first battery units BU1 and the two second battery units BU2. Therefore, the fourth pipe P4 is located above the third pipe P3. In other words, the third pipe P3 is positioned on one side (downward in this embodiment) in the vertical direction relative to the fourth pipe P4.

[0093] Even if the hydraulic excavator 1 is configured to include a third pipe P3 and a fourth pipe P4, it is desirable to ensure that the air stagnating in at least one of the first cooling passage BU1a and the second cooling passage BU2a is smoothly discharged. From this viewpoint, it is desirable that the third pipe P3 be positioned on one side (downward in this embodiment) in the vertical direction relative to the fourth pipe P4, as in this embodiment.

[0094] Even when the communication section 106 and the heat exchanger HE (radiator 104 in this embodiment) are located on either side of the first battery unit BU1 and the second battery unit BU2, it is desirable to reliably achieve a configuration that connects the communication section 106 and the heat exchanger HE. Furthermore, it is desirable to efficiently route the fourth piping P4 by effectively utilizing the dead space above the first battery unit BU1 and the second battery unit BU2. From this viewpoint, as in this embodiment, it is desirable that the fourth piping P4 is routed on the other side in the vertical direction (above in this embodiment) relative to the first battery unit BU1 and the second battery unit BU2.

[0095] The fourth pipe P4 is connected to the seventh pipe P7 via the second joint member PJ2, in addition to the communication section 106. One end of the seventh pipe P7 is connected to the second joint member PJ2, and the other end is connected to the radiator 104. A reserve tank 104c is connected to the radiator 104. The reserve tank 104c stores refrigerant. When the amount of refrigerant circulating in the cooling circuit 100 becomes insufficient, refrigerant is replenished from the reserve tank 104c.

[0096] [5. Supplement] In this embodiment, the case where the lower side is considered "one side in the vertical direction" and the upper side is considered "the other side in the vertical direction" has been described, but the embodiment is not limited to this. For example, the upper side may be considered "one side in the vertical direction" and the lower side may be considered "the other side in the vertical direction." In other words, the vertical orientation may be reversed.

[0097] In this embodiment, the case in which the right side of the first battery unit BU1 and the second battery unit BU2 is defined as "one side of the first battery unit BU1 and the second battery unit BU2" has been described, but the embodiment is not limited to this. For example, the left side of the first battery unit BU1 and the second battery unit BU2 may be defined as "one side of the first battery unit BU1 and the second battery unit BU2". In other words, the left and right sides of the first battery unit BU1 and the second battery unit BU2 may be reversed.

[0098] In this embodiment, a hydraulic excavator 1, which is a construction machine, was used as an example of an electric work machine. However, the electric work machine is not limited to a hydraulic excavator 1, and may be a construction machine such as a wheel loader. Furthermore, the electric work machine may be an agricultural machine such as a combine harvester or tractor.

[0099] [6. Addendum] The hydraulic excavator 1 described in this embodiment can also be described as an electric work machine as shown in the following appendix.

[0100] The electric work machines mentioned in Appendix (1) are: A first battery unit incorporating a first cooling channel through which a refrigerant flows, A second battery unit incorporating a second cooling channel connected in parallel to the first cooling channel, A selector valve connected to the first cooling channel and the second cooling channel, The system comprises a heat exchanger for cooling the refrigerant, The selection valve selectively directs the refrigerant to at least one of the first cooling channel and the second cooling channel.

[0101] The electric work machine in Appendix (2) is the same as the electric work machine described in Appendix (1), It includes a connecting section that connects the first cooling channel and the second cooling channel, The selector valve is positioned on one side in the vertical direction relative to the communication portion.

[0102] The electric work machines in Appendix (3) are the electric work machines described in Appendix (2), The heat exchanger has an inlet for injecting the refrigerant into the first cooling channel and the second cooling channel. The inlet is positioned above the selector valve and the communication section.

[0103] The electric work machine in Appendix (4) is the electric work machine described in Appendix (2) or (3), The heat exchanger is located on one side of the first battery unit and the second battery unit. The selection valve is positioned on the opposite side of the heat exchanger from the first battery unit and the second battery unit.

[0104] The electric work machines in Appendix (5) are the electric work machines described in Appendix (4), A first group of pipes extending from the selection valve toward the first cooling channel and the second cooling channel, The system comprises a second group of pipes extending from the aforementioned communication section toward the first cooling channel and the second cooling channel, The first group of pipes is arranged on one side in the vertical direction relative to the second group of pipes.

[0105] The electric work machines in Appendix (6) are the electric work machines described in Appendix (5), The first group of piping and the second group of piping are connected to the first cooling channel and the second cooling channel on the side opposite to the heat exchanger relative to the first battery unit and the second battery unit.

[0106] The electric work machine in Appendix (7) is an electric work machine described in any of Appendix (2) to (6), A third pipe extending from the selector valve toward the heat exchanger, The system includes a fourth pipe extending from the aforementioned communication section toward the heat exchanger, The third pipe is positioned on one side in the vertical direction relative to the fourth pipe.

[0107] The electric work machines in Appendix (8) are the electric work machines described in Appendix (7), The third piping is routed behind the first battery unit and the second battery unit.

[0108] The electric work machine in Appendix (9) is the electric work machine described in Appendix (7) or (8), The fourth piping is routed through the other side in the vertical direction relative to the first battery unit and the second battery unit.

[0109] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and it can be expanded or modified without departing from the spirit of the invention. [Industrial applicability]

[0110] This invention can be used, for example, in work machinery such as construction machinery and agricultural machinery. [Explanation of Symbols]

[0111] 1. Hydraulic excavator (electric work machine) 104a Inlet 105 Selector valve 106 Communication section BU1 First Battery Unit BU1a First cooling channel BU2 Second Battery Unit BU2a Second cooling channel HE heat exchanger P1 1st piping group P2 2nd piping group P3 Third Piping P4 4th pipe

Claims

1. A first battery unit incorporating a first cooling channel through which a refrigerant flows, A second battery unit incorporating a second cooling channel connected in parallel to the first cooling channel, A selector valve connected to the first cooling channel and the second cooling channel, The system comprises a heat exchanger for cooling the refrigerant, The selection valve is an electrically operated work machine that selectively guides the refrigerant to at least one of the first cooling passage and the second cooling passage.

2. It includes a connecting section that connects the first cooling channel and the second cooling channel, The electric work machine according to claim 1, wherein the selection valve is arranged on one side in the vertical direction with respect to the communication portion.

3. The heat exchanger has an inlet for injecting the refrigerant into the first cooling channel and the second cooling channel. The electric work machine according to claim 2, wherein the inlet is positioned above the selector valve and the communication section.

4. The heat exchanger is positioned on one side of the first battery unit and the second battery unit. The electric work machine according to claim 2, wherein the selection valve is located on the opposite side of the heat exchanger from the first battery unit and the second battery unit.

5. A first group of pipes extending from the selection valve toward the first cooling channel and the second cooling channel, The system comprises a second group of pipes extending from the aforementioned communication section toward the first cooling channel and the second cooling channel, The electric work machine according to claim 4, wherein the first group of pipes is arranged on one side in the vertical direction relative to the second group of pipes.

6. The electric work machine according to claim 5, wherein the first group of piping and the second group of piping are connected to the first cooling channel and the second cooling channel on the opposite side of the heat exchanger from the first battery unit and the second battery unit.

7. A third pipe extending from the selector valve toward the heat exchanger, The system includes a fourth pipe extending from the aforementioned communication section toward the heat exchanger, The electric work machine according to any one of claims 2 to 6, wherein the third pipe is arranged on one side in the vertical direction relative to the fourth pipe.

8. The electric work machine according to claim 7, wherein the third piping is routed behind the first battery unit and the second battery unit.

9. The electric work machine according to claim 7, wherein the fourth piping is routed to the first battery unit and the second battery unit through the other side in the vertical direction.

Images