Patent Description:
Conventionally, various electric work machines such as electric hydraulic excavators have been proposed. For example, Patent Document <NUM> discloses an electric hydraulic excavator separately having a fan for cooling a radiator and a fan for cooling an oil cooler.

For example, in a small-sized electric work machine of backward small-swivel type such as a mini-excavator, a space for arranging each member in an engine room is limited. Therefore, it is usually difficult to individually provide cooling fans corresponding to a radiator and an oil cooler in a small-sized electric work machine as in Patent Document <NUM>. Another electric work machine is shown in <CIT>. Accordingly, it is desirable to cool the radiator and the oil cooler in a compact layout in a small-sized electric work machine.

The present invention has been made to solve the above-described problem, and an object of the present invention is to provide an electric work machine capable of cooling a radiator (first heat exchanger) and an oil cooler (second heat exchanger) in a compact layout.

An electric work machine according to one aspect of the present invention includes a plurality of electric devices, a first heat exchanger that cools a refrigerant passing through at least one of the plurality of electric devices, a hydraulic pump that is driven by any one of the plurality of electric devices and discharges hydraulic oil, a second heat exchanger that cools the hydraulic oil, and a fan that takes outside air into an interior of a machine body, and the first heat exchanger is arranged on an upstream side of the fan in a flow direction of the outside air flown by the fan, and the second heat exchanger is arranged on a downstream side of the fan in the flow direction of the outside air.

According to the above configuration, the first heat exchanger and the second heat exchanger can be cooled in a compact layout.

The following is a description of an embodiment of the present invention based on the drawings.

<FIG> is a side view illustrating a schematic configuration of a hydraulic excavator (electric excavator) <NUM> provided as an example of an electric work machine according to the present embodiment. The hydraulic excavator <NUM> includes a lower traveling body <NUM>, a work instrument <NUM>, and an upper swivel body <NUM>. In the present embodiment, the hydraulic excavator <NUM> or the upper swivel body <NUM> (particularly, an engine room <NUM>) is also referred to as a "machine body".

Here, directions are defined as follows. A forward direction is a direction in which an operator (manipulator, driver) seated on a driver's seat 41a of the upper swivel body <NUM> faces front, and a backward direction is a direction opposite to the forward direction. Therefore, in a state where the upper swivel body <NUM> does not swivel with respect to the lower traveling body <NUM> (<NUM>-degree swivel angle), a front-back direction of the upper swivel body <NUM> coincides with a direction in which the lower traveling body <NUM> moves forward and backward. As viewed from the operator seated on the driver's seat 41a, a left side is defined as "left" and a right side is defined as "right". A gravity direction perpendicular to the front-back direction and a left-right direction is defined as an up-down direction, in which an upstream side of the gravity direction is defined as "up", and a downstream side thereof is defined as "down". In the drawings, the hydraulic excavator <NUM> is illustrated in a state where the upper swivel body <NUM> does not swivel with respect to the lower traveling body <NUM>. In addition, in the drawings, if necessary, forward is denoted by a symbol "F", likewise, backward by "B", rightward by "R", leftward by "L", upward by "U", and downward by "D".

The lower traveling body <NUM> is provided with a pair of left and right crawlers <NUM> and a pair of left and right traveling motors <NUM>. Each of the traveling motors <NUM> is a hydraulic motor. The left and right traveling motors <NUM> drive the left and right crawlers <NUM>, respectively, thereby allowing the hydraulic excavator <NUM> to move forward and backward. The lower traveling body <NUM> is provided with a blade <NUM> for performing a ground leveling work and a blade cylinder 23a. The blade cylinder 23a is a hydraulic cylinder to rotate the blade <NUM> in the up-down direction.

The work instrument <NUM> has a boom <NUM>, an arm <NUM>, and a bucket <NUM>. The boom <NUM>, the arm <NUM>, and the bucket <NUM> are independently driven, thereby to make it possible to perform excavation work of earth, sand, and the like.

The boom <NUM> is rotated by a boom cylinder 31a. The boom cylinder 31a has a base end portion thereof supported by a front part of the upper swivel body <NUM>, and is movable freely in an extendable and retractable manner. The arm <NUM> is rotated by an arm cylinder 32a. The arm cylinder 32a has a base end portion thereof supported by the boom <NUM>, and is movable freely in an extendable and retractable manner. The bucket <NUM> is rotated by a bucket cylinder 33a. The bucket cylinder 33a has a base end portion thereof supported by the arm <NUM>, and is movable freely in an extendable and retractable manner. The boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a each include a hydraulic cylinder.

The upper swivel body <NUM> is positioned above the lower traveling body <NUM>, and is so provided as to be swivelable via a swivel bearing (not illustrated) relative to the lower traveling body <NUM>. In the upper swivel body <NUM>, a steering part <NUM>, a swivel frame <NUM>, a swivel motor <NUM>, the engine room <NUM> and the like are arranged. By driving of the swivel motor <NUM> that is a hydraulic motor, the upper swivel body <NUM> swivels via a swivel bearing.

A hydraulic pump <NUM> (see <FIG>) is arranged in the upper swivel body <NUM>. The hydraulic pump <NUM> is driven by an electric motor <NUM> (see <FIG>) inside the engine room <NUM>. The hydraulic pump <NUM> supplies a hydraulic oil (pressure oil) to hydraulic motors (for example, the left and right traveling motors <NUM> and the swivel motor <NUM>), and hydraulic cylinders (for example, the blade cylinder 23a, the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a). The hydraulic motors and the hydraulic cylinders that are driven with the hydraulic oil supplied from the hydraulic pump <NUM> are collectively referred to as hydraulic actuators <NUM> (see <FIG>).

The driver's seat 41a is arranged in the steering part <NUM>. Various levers 41b are arranged around the driver's seat 41a. The operator is seated on the driver's seat 41a and operates the levers 41b, thereby driving the hydraulic actuators <NUM>. As a result, traveling of the lower traveling body <NUM>, the ground leveling work by the blade <NUM>, the excavating work by the work instrument <NUM>, the swiveling of the upper swivel body <NUM> and the like can be performed.

A battery unit <NUM> is arranged in the upper swivel body <NUM>. The battery unit <NUM> is composed of, for example, a lithium-ion battery unit, and stores electric power for driving the electric motor <NUM>. The battery unit <NUM> may be composed of a plurality of batteries as a unit or may be composed of a single battery cell. The upper swivel body <NUM> has a power feed port which is not illustrated. The power feed port and a commercial power source <NUM>, which is an external power source, are connected via a power feed cable <NUM>. This allows charging of the battery unit <NUM>.

The upper swivel body <NUM> is further provided with a lead battery <NUM>. The lead battery <NUM> outputs a low-voltage (<NUM> V, for example) DC voltage. The output from the lead battery <NUM> is supplied as a control voltage to, for example, a system controller <NUM> (see <FIG>), a drive unit of a fan <NUM> (see <FIG>), and the like.

The hydraulic excavator <NUM> may be so configured as to be a combination of hydraulic devices such as the hydraulic actuators <NUM> and actuators driven by electric power. As the actuators driven by electric power, for example, an electric traveling motor, an electric cylinder, and an electric swivel motor are included.

<FIG> is a block diagram schematically illustrating the configuration of electric and hydraulic systems of the hydraulic excavator <NUM>. The hydraulic excavator <NUM> includes the electric motor <NUM>, a charger <NUM>, an inverter <NUM>, a power drive unit (PDU) <NUM>, a junction box <NUM>, a DC-DC converter <NUM>, and the system controller <NUM>.

Electric devices EL include the electric motor <NUM>, the charger <NUM>, the inverter <NUM>, the PDU <NUM>, the junction box <NUM>, the DC-DC converter <NUM>, the battery unit <NUM>, and the lead battery <NUM>. That is, the hydraulic excavator <NUM> includes a plurality of the electric devices EL. The plurality of electric devices EL include a water-cooled electric device EL-W and an air-cooled electric device EL-A, details of which are described below. The system controller <NUM> is composed of an electronic control unit (ECU) for electrically controlling individual parts of the hydraulic excavator <NUM>.

The electric motor <NUM> is driven by electric power supplied from the battery unit <NUM> via the junction box <NUM> and the inverter <NUM>. The electric motor <NUM> includes a permanent magnet motor or an induction motor. The electric motor <NUM> is arranged on the swivel frame <NUM>.

The charger <NUM> (also referred to as a power feeder) converts an AC voltage supplied from the commercial power source <NUM>, illustrated in <FIG>, via the power feed cable <NUM> into a DC voltage. The inverter <NUM> converts a DC voltage supplied from the battery unit <NUM> into an AC voltage and supplies the AC voltage to the electric motor <NUM>. Thus, the electric motor <NUM> is rotated. The AC voltage (current) is supplied from the inverter <NUM> to the electric motor <NUM> based on a rotation command output from the system controller <NUM>.

The PDU <NUM> is a battery control unit that controls an internal battery relay to control inputting and outputting of the battery unit <NUM>. The junction box <NUM> is so configured as to include a charger relay, an inverter relay, a fuse and the like. The voltage output from the above-mentioned charger <NUM> is supplied to the battery unit <NUM> via the junction box <NUM> and the PDU <NUM>. Further, the voltage output from the battery unit <NUM> is supplied via the PDU <NUM> and the junction box <NUM> to the inverter <NUM>.

The DC-DC converter <NUM> lowers a high-voltage (<NUM> V, for example) DC voltage supplied from the battery unit <NUM> via the junction box <NUM> to a low voltage (<NUM> V, for example). Like the output from the lead battery <NUM>, the voltage output from the DC-DC converter <NUM> is supplied to the system controller <NUM>, the drive unit of the fan <NUM>, etc..

A plurality of the hydraulic pumps <NUM> is connected to a rotation axis (output shaft) of the electric motor <NUM>. The plurality of hydraulic pumps <NUM> include a variable displacement pump and a fixed displacement pump. <FIG> illustrates only one hydraulic pump <NUM> as an example. Each hydraulic pump <NUM> is connected to a hydraulic oil tank <NUM> that contains (stores) hydraulic oil. When the hydraulic pump <NUM> is driven by the electric motor <NUM>, the hydraulic oil in the hydraulic oil tank <NUM> is supplied to the hydraulic actuator <NUM> via a control valve <NUM>. Thus, the hydraulic actuator <NUM> is driven. The control valve <NUM> is a direction switch valve that controls a flow direction and a flow rate of the hydraulic oil supplied to the hydraulic actuator <NUM>. As described above, the hydraulic excavator <NUM> includes the hydraulic pump <NUM> that is driven by any one of the plurality of electric devices EL (for example, the electric motor <NUM>) and discharges the hydraulic oil.

<FIG> and <FIG> are a plan view and a right side view, respectively, illustrating the configuration of the interior of the engine room <NUM> of the hydraulic excavator <NUM>. <FIG> is a cross-sectional view of the interior of the engine room <NUM> illustrated in <FIG> taken along the line A-A ' in the up-down direction. <FIG> is an enlarged perspective view illustrating a configuration of a main portion of the interior of the engine room <NUM>. In <FIG> and <FIG>, an upper surface 90a of a housing <NUM> (see <FIG> and <FIG>) and an upper surface 100a of an air guide portion <NUM> (see <FIG>) are not illustrated for a purpose of clarifying a configuration of an interior of the housing <NUM> and the air guide portion <NUM>.

As illustrated in <FIG>, in the present embodiment, four battery units <NUM> are arranged side by side in the front-back direction on the swivel frame <NUM> via a vibration-proofing member <NUM> (see <FIG>) and the like. The battery unit <NUM> located at the most backward position is positioned at a center in the right-left direction on the swivel frame <NUM>. The remaining three battery units <NUM> are arranged in such a manner to be shifted in the left direction with respect to the battery unit <NUM> located at the most backward position. Thus, the plurality of battery units <NUM> are efficiently arranged in a limited narrow space near a rear end edge of the swivel frame <NUM> formed in a semicircular shape in a plan view. The number and arrangement of the battery units <NUM> are not limited to the example of the present embodiment.

As illustrated in <FIG>, the electric motor <NUM>, the hydraulic pump <NUM>, and the like are arranged on a right side of the plurality of battery units <NUM> on the swivel frame <NUM>. Hereinafter, the configuration of the interior of the engine room <NUM> will be described in detail.

As illustrated in <FIG>, the hydraulic excavator <NUM> includes the fan <NUM>. The fan <NUM> is rotatably supported inside the housing <NUM> and takes outside air into an interior of the machine body by rotation. That is, the fan <NUM> of the present embodiment is of a suction type. The housing <NUM> has a frame shape, and both ends in the left-right direction are open. A rotation axis CA of the fan <NUM> extends in the left-right direction. The hydraulic pump <NUM> is located below the fan <NUM> (housing <NUM>). The hydraulic pump <NUM> is connected to the hydraulic oil tank <NUM> via a hydraulic hose H (see <FIG>).

The air guide portion <NUM> is arranged on a left side of the housing <NUM>, that is, between the housing <NUM> and the battery units <NUM> (in particular, the battery unit <NUM> located at the most forward position). The air guide portion <NUM> will be described in detail below. The electric devices EL such as the inverter <NUM> and the DC-DC converter <NUM> described above are attached to the air guide portion <NUM> (particularly, a second flow path portion <NUM> described below).

As illustrated in <FIG> and <FIG>, the charger <NUM> is arranged on a back side of the fan <NUM> (housing <NUM>) and the hydraulic pump <NUM>.

The hydraulic excavator <NUM> further includes a radiator <NUM> and an oil cooler <NUM>. The radiator <NUM> is a first heat exchanger that cools a refrigerant passing through at least one of the plurality of electric devices EL (for example, the battery unit <NUM>) illustrated in <FIG> and the like. The battery unit <NUM> can be cooled (water-cooled) by cooling the refrigerant through heat exchange at the radiator <NUM> and supplying the refrigerant from the radiator <NUM> to the battery unit <NUM>. The refrigerant is, for example, cooling water.

The oil cooler <NUM> is a second heat exchanger connected with an oil path circulating via the hydraulic pump <NUM> and the hydraulic actuator <NUM> (see <FIG>), etc. The oil cooler <NUM> cools, through heat exchange, the hydraulic oil flowing in the oil path by driving of the hydraulic pump <NUM>.

As illustrated in <FIG>, the radiator <NUM> is positioned on a right side of the fan <NUM>. That is, the radiator <NUM> is positioned on an outer side of machine body than the fan <NUM> in the left-right direction. Since the fan <NUM> is of a suction type as described above, when the fan <NUM> is rotated, outside air is sucked into the interior of the machine body from an outside of the machine body. The outside air flows from the right side toward the left side in the interior of the machine body. That is, the outside air flows from the radiator <NUM> toward the fan <NUM>. From this, it can be said that the radiator <NUM> is arranged, on an upstream side of the fan <NUM> in a flow direction of the outside air flown by the fan <NUM>.

On the other hand, the oil cooler <NUM> is positioned on a left side of the fan <NUM>. That is, the oil cooler <NUM> is positioned on an inner side of the machine body with respect to the fan <NUM> in the left-right direction. Therefore, when the fan <NUM> is rotated, the outside air sucked into the interior of the machine body from the outside of the machine body flows from the right side (radiator <NUM> side) to the left side (oil cooler <NUM> side) via the fan <NUM>. Thus, it can be said that the oil cooler <NUM> is arranged, with respect to the fan <NUM>, on a downstream side in the flow direction of the outside air.

In this way, the radiator <NUM> and the oil cooler <NUM> are arranged, with respect to the fan <NUM>, on sides opposite to each other in the left-right direction. Thus, by driving of a single fan <NUM>, the outside air taken into the interior of the machine body from the outside of the machine body hits the radiator <NUM> and the oil cooler <NUM> in this order, and both the radiator <NUM> and the oil cooler <NUM> can be cooled. Thus, as compared with a configuration in which cooling fans are provided corresponding to the radiator <NUM> and the oil cooler <NUM>, respectively, a compact layout advantageous for the small-sized hydraulic excavator <NUM> can be realized. In other words, both the radiator <NUM> and the oil cooler <NUM> can be cooled in a compact layout.

In addition, since the outside air hit the radiator <NUM> can also be hit the oil cooler <NUM>, it can be said that the outside air used for cooling the radiator <NUM> can be effectively used for cooling the oil cooler <NUM>. Further, since the radiator <NUM> is arranged on the upstream side in the flow direction of the outside air flown by the fan <NUM>, it is possible to prevent a hand of a person (for example, a maintenance person) as well as foreign matter such as earth and sand from accidentally entering the fan <NUM> from the outside of the machine body by the radiator <NUM>. Accordingly, it is possible to easily prevent entry of the foreign matter or the like without installing a dedicated member (for example, a mesh-like fence) that blocks the entry of foreign matter or the like.

In the present embodiment, as illustrated in <FIG> and <FIG>, the oil cooler <NUM> is arranged to face a part of the fan <NUM> (in a stationary state). That is, in the front-back direction, a length of occupation (width) of the oil cooler <NUM> is shorter than a length of occupation (width) of the fan <NUM>. Since the fan <NUM> is of a suction type as described above, when the fan <NUM> is rotated, a part of the outside air taken into the interior of the machine body flows toward the oil cooler <NUM>, and the rest flows off the oil cooler <NUM>. The high-temperature oil cooler <NUM> is cooled by the outside air flowing from the fan <NUM> toward the oil cooler <NUM>. On the other hand, the outside air flowing off the oil cooler <NUM> from the fan <NUM> does not hit the high-temperature oil cooler <NUM>, and thus has a relatively low temperature compared to the outside air hitting the oil cooler <NUM> (the outside air used for cooling the oil cooler <NUM>). From a viewpoint of effectively using the outside air having a relatively low temperature for cooling the electric device EL (for example, the electric motor <NUM>), it is desirable that the oil cooler <NUM> is arranged to face a part of the fan <NUM> as in the present embodiment.

Next, details of the air guide portion <NUM> provided in the engine room <NUM> will be described. <FIG> are perspective views of the air guide portion <NUM> as viewed from different directions.

The air guide portion <NUM> has a first flow path portion <NUM> and a second flow path portion <NUM>. That is, the hydraulic excavator <NUM> has the first flow path portion <NUM> and the second flow path portion <NUM>. The first flow path portion <NUM> and the second flow path portion <NUM> are partitioned by a partition plate <NUM>. In other words, the first flow path portion <NUM> and the second flow path portion <NUM> share the partition plate <NUM>.

As illustrated in <FIG>, the air guide portion <NUM> is arranged on the left side with respect to the housing <NUM> having the fan <NUM> and the like, that is, on the inner side of the machine body. Therefore, the outside air that has passed through the interior of the housing <NUM> by the fan <NUM> passes through an exit-side opening portion 90b of the housing <NUM>, is guided to the air guide portion <NUM>, and flows through an interior of any one of the first flow path portion <NUM> and the second flow path portion <NUM> of the air guide portion <NUM>.

The first flow path portion <NUM> has a first opening portion <NUM> at an upstream end portion in the flow direction of the outside air and a second opening portion <NUM> at a downstream end portion in the flow direction of the outside air. That is, the first flow path portion <NUM> has the first opening portion <NUM> at one end portion and the second opening portion <NUM> at the other end portion. The first opening portion <NUM> is positioned on a side opposite to the oil cooler <NUM> with respect to the exit-side opening portion 90b of the housing <NUM>, and opens toward the right side in the left-right direction. In the first flow path portion <NUM>, the flow path is bent from the left-right direction to the front-back direction by the partition plate <NUM>. As a result, the second opening portion <NUM> of the first flow path portion <NUM> opens toward the front in the front-back direction (see <FIG>, <FIG>, and <FIG>). The shape of first flow path portion <NUM> is not limited to the bent shape described above.

In this configuration, by the fan <NUM>, the outside air flowing toward the oil cooler <NUM> in the housing <NUM> hits the oil cooler <NUM> to cool the oil cooler <NUM>, and then becomes a relatively high-temperature wind to flow into an interior of the first flow path portion <NUM> via the first opening portion <NUM>. Then, the relatively high-temperature wind flowing through the interior of the first flow path portion <NUM> is discharged through the second opening portion <NUM>. Therefore, in view of smoothly discharging the relatively high-temperature air after cooling the oil cooler <NUM> to the outside of the machine body via the second opening portion <NUM>, as illustrated in <FIG>, it is desirable that the first opening portion <NUM> be positioned on a side opposite to the fan <NUM> with respect to the oil cooler <NUM>.

The second flow path portion <NUM> has a third opening portion <NUM> at the upstream end portion in the flow direction of the outside air and a fourth opening portion <NUM> at the downstream end portion in the flow direction of the outside air. That is, the second flow path portion <NUM> has the third opening portion <NUM> at one end portion and the fourth opening portion <NUM> at the other end portion. The third opening portion <NUM> is positioned on a side opposite to the fan <NUM> with respect to the exit-side opening portion 90b of the housing <NUM>, and opens toward the right side in the left-right direction. In the second flow path portion <NUM>, the flow path is bent from the right-left direction to the up-down direction by an inclined surface 100b which is inclined downward from a left end portion of the upper surface 100a toward the inner side of the machine body (the left side in the right-left direction). As a result, the fourth opening portion <NUM> of the second flow path portion <NUM> opens downward. The shape of second flow path portion <NUM> is not limited to the bent shape described above.

In addition, the third opening portion <NUM> of the second flow path portion <NUM> is positioned side by side with the first opening portion <NUM> of the first flow path portion <NUM> (in the F-B direction in <FIG> and the like) when viewed from the direction of the rotation axis CA of the fan <NUM>, and is connected to the first opening portion <NUM>. Accordingly, one large opening portion is formed on the housing <NUM> side of the air guide portion <NUM>. Further, as illustrated in <FIG>, the third opening portion <NUM> is positioned so as to be shifted from the oil cooler <NUM> (in the F-B direction) when viewed from the direction of the rotation axis CA of the fan <NUM>. Therefore, the third opening portion <NUM> does not overlap with the oil cooler <NUM> when viewed from the direction of the rotation axis CA of the fan <NUM>.

With this configuration, out of the outside air taken into the interior of the housing <NUM> via the radiator <NUM> by the fan <NUM>, the outside air flowing off the oil cooler <NUM> is guided into an interior of the second flow path portion <NUM> via the third opening portion <NUM>. Then, the outside air flowing through the interior of the second flow path portion <NUM> is discharged from the fourth opening portion <NUM>. Since the outside air flowing off the oil cooler <NUM> does not hit the high-temperature oil cooler <NUM>, the outside air has a relatively low temperature compared to the outside air hitting the oil cooler <NUM> (the outside air used for cooling the oil cooler <NUM>). From a viewpoint of effectively using the outside air having a relatively low temperature for cooling the electric device EL (for example, the electric motor <NUM>), it is desirable that the third opening portion <NUM> serving as an inlet for guiding the outside air having a relatively low temperature to the interior of the second flow path portion <NUM> is positioned to be shifted from the oil cooler <NUM> when viewed from the direction of the rotation axis CA of the fan <NUM> as in the present embodiment.

As illustrated in <FIG>, the plurality of electric devices EL included in the hydraulic excavator <NUM> include the water-cooled device EL-W through which the above-described refrigerant passes and the air-cooled device EL-A. The water-cooled device EL-W is, for example, the battery unit <NUM>. That is, the plurality of electric devices EL include the battery unit <NUM> through which the refrigerant passes.

The air-cooled devices EL-A include, for example, the electric motor <NUM>, the charger <NUM>, the inverter <NUM>, the PDU <NUM>, the junction box <NUM>, the DC-DC converter <NUM>, and the lead battery <NUM>. That is, the plurality of air-cooled devices EL-A include the electric motor <NUM> that drives the hydraulic pump <NUM>.

The air-cooled device EL-A can be efficiently cooled (air-cooled) if the air-cooled device EL-A can be directly hit by a relatively low-temperature wind that flows off the oil cooler <NUM> (through the outside of the oil cooler <NUM>) after cooling the radiator <NUM> by the fan <NUM>, enters the interior of the second flow path portion <NUM> from the third opening portion <NUM>, and is discharged from the fourth opening portion <NUM>. Therefore, from the viewpoint of improving the cooling efficiency of the air-cooled device EL-A, it is desirable that any one of the plurality of air-cooled devices EL-A is arranged at the fourth opening portion <NUM> of the second flow path portion <NUM>.

In the present embodiment, the electric motor <NUM>, which is the air-cooled device EL-A, is arranged at the fourth opening portion <NUM>. In this case, since the relatively low-temperature wind discharged from the fourth opening portion <NUM> directly hits the electric motor <NUM>, the cooling efficiency of the electric motor <NUM> is improved.

In addition, from the viewpoint of realizing a compact layout by fitting the air-cooled device EL-A (for example, the electric motor <NUM>) from downward to the fourth opening portion <NUM> of the second flow path portion <NUM>, it is desirable that the fourth opening portion <NUM> opens downward as in the present embodiment.

From the viewpoint of efficiently cooling the other air-cooled devices EL-A (other than the electric motor <NUM>) by the relatively low-temperature wind flowing through the interior of the second flow path portion <NUM>, it is desirable that any another one of the plurality of air-cooled devices EL-A is arranged on a wall surface 120W (see <FIG> and <FIG>) of the second flow path portion <NUM>.

In the present embodiment, the inverter <NUM> is arranged on a side surface 120W1 (see <FIG>) on the back side in the front-back direction of the second flow path portion <NUM>. The DC-DC converter <NUM> is arranged on a back surface 120W2 (see <FIG>), which constitutes the second flow path portion <NUM>, of the inclined surface 100b of the air guide portion <NUM>. In this case, the relatively low-temperature wind flows through the interior of the second flow path portion <NUM>, whereby the inverter <NUM>, which is the air-cooled device EL-A arranged on the side surface 120W1, is efficiently cooled, and the DC-DC converter <NUM>, which is the air-cooled device EL-A arranged on the back surface 120W2, is efficiently cooled.

The air-cooled devices EL-A arranged on the wall surface 120W of the second flow path portion <NUM> may include a heat dissipation portion such as fins. In addition, the heat dissipation portion may be positioned protruding into the interior of the second flow path portion <NUM>. In this case, the relatively low-temperature wind flowing through the interior of the second flow path portion <NUM> hits the heat dissipation portion, thereby further improving the cooling efficiency of the air-cooled device EL-A arranged on the wall surface 120W.

From the viewpoint of cooling the other air-cooled devices EL-A by using the relatively low-temperature wind discharged from the fourth opening portion <NUM> of the second flow path portion <NUM>, any another one of the plurality of air-cooled devices EL-A may be arranged outside the second flow path portion <NUM>.

In the present embodiment, as illustrated in <FIG>, other air-cooled devices EL-A such as the charger <NUM> and the junction box <NUM> are arranged outside the second flow path portion <NUM>. In this case, the relatively low-temperature wind discharged from the fourth opening portion <NUM> of the second flow path portion <NUM> hits the charger <NUM> and the like around the second flow path portion <NUM>, thereby cooling the charger <NUM> and the like. That is, the relatively low-temperature wind discharged from the fourth opening portion <NUM> is effectively used to cool the charger <NUM> and the like.

From the viewpoint of effectively utilizing a narrow (limited) space in the engine room <NUM> while individually cooling the electric motor <NUM>, which is the air-cooled device EL-A, and the battery unit <NUM>, which is the water-cooled device EL-W, it is desirable that the electric motor <NUM> be arranged near the water-cooled device EL-W in the engine room <NUM>. In this regard, it is desirable that the electric motor <NUM> be arranged side by side with the water-cooled device EL-W.

In addition, from the viewpoint of effectively utilizing the narrow (limited) space in the engine room <NUM> while separately cooling the water-cooled device EL-W and the plurality of air-cooled devices EL-A, it is desirable that the battery unit <NUM> which is the water-cooled device EL-W be arranged near the second flow path portion <NUM> (in which the plurality of air-cooled devices EL-A are arranged on the wall surface 120W) in the engine room <NUM>. In this regard, as illustrated in <FIG>, it is desirable that the battery unit <NUM> is arranged side by side with the second flow path portion <NUM>.

In the present embodiment, as illustrated in <FIG>, the example in which the oil cooler <NUM> is arranged so as to overlap a part of the radiator <NUM> when viewed from the direction of the rotation axis CA of the fan <NUM> has been described, but the oil cooler <NUM> may be arranged so as not to overlap the radiator <NUM>. For example, as viewed from the direction of the rotation axis CA, the radiator <NUM> may be arranged so as to overlap with the left half of the fan <NUM>, and the oil cooler <NUM> may be arranged so as to overlap with the right half of the fan <NUM>. Even in this case, there is no change in the fact that both the radiator <NUM> and the oil cooler <NUM> can be cooled by the driving of the single fan <NUM>, and the radiator <NUM> and the oil cooler <NUM> can be cooled in a compact layout.

The hydraulic excavator <NUM> which is the construction machine has been described heretofore as the example of the electric work machine, but the electric work machine is not limited to the hydraulic excavator <NUM> and may be any other construction machine such as a wheel loader. The electric work machine may be an agricultural machine such as a combine harvester or a tractor.

Claim 1:
An electric work machine (<NUM>) comprising:
a plurality of electric devices;
a first heat exchanger (<NUM>) that cools a refrigerant passing through at least one of the plurality of electric devices;
a hydraulic pump (<NUM>) that is driven by any one of the plurality of electric devices and discharges hydraulic oil;
a second heat exchanger (<NUM>) that cools the hydraulic oil;
and
a fan (<NUM>) that takes outside air into an interior of a machine body, body (<NUM>), characterised in that
the first heat exchanger (<NUM>) is arranged on an upstream side of the fan (<NUM>) in a flow direction of the outside air flown by the fan, and
the second heat exchanger (<NUM>) is arranged on a downstream side of the fan in the flow direction of the outside air.