POWER SUPPLY

A power supply includes a battery; an inverter that controls an output voltage of the battery; an air-cooler that cools the battery and the inverter with cooling air; and a case that houses the battery, the inverter, and the air-cooler.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Japanese Patent Application No. 2021-110823 filed on Jul. 2, 2021 and to Japanese Patent Application No. 2022-083047 filed on May 20, 2022. The entire contents of this application are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a power supply that is mounted on, for example, an industrial machine such as a working vehicle.

2. Description of the Related Art

Conventionally, a power supply disclosed in Japanese Unexamined Patent Application Publication No. 2016-172507 is known.

The power supply disclosed in Japanese Unexamined Patent Application Publication No. 2016-172507 includes a battery box that houses a battery, an inverter that controls an output voltage of the battery, a cooler that cools the battery and the inverter, and so forth. The cooler includes a battery fan for cooling the battery and a water pump for cooling the inverter and so forth.

SUMMARY OF THE INVENTION

In the power supply described above, the battery and the inverter are cooled by the separate coolers (the battery fan and the water pump) independent of each other. Hence, the power supply requires a case having a large internal space to house the coolers. Thus, it is difficult to reduce the size of this power supply, and a large space is required for installation. Moreover, since the number of components increases, there is also a problem that manufacturing cost increases.

The present invention has been made in view of the above-described problems, and provides a power supply that can efficiently cool a battery and an inverter, can be reduced in size, and can be reduced in manufacturing cost.

Technical measures taken by the present invention to address the above-described problems are characterized in the following points.

A power supply according to an aspect of the present invention includes a battery; an inverter that controls an output voltage of the battery; an air-cooler that cools the battery and the inverter with cooling air; and a case that houses the battery, the inverter, and the air-cooler.

The power supply may include an air guide plate disposed inside the case. The air-cooler may include a cooling fan and a heat exchanger. The air guide plate may guide air blown from the cooling fan to the battery and the inverter. The heat exchanger may cool the air that has passed through the battery and the inverter.

The air guide plate may guide the air blown from the cooling fan to the battery and then to the inverter.

The air guide plate may guide the air blown from the cooling fan to the inverter and then to the battery.

The air guide plate may have a first portion disposed above the battery. The battery may include a plurality of battery modules disposed side by side in a planar manner. The first portion may have a slit formed to guide the air blown from the cooling fan to a gap between the plurality of battery modules.

The plurality of battery modules may be disposed side by side in a direction orthogonal to a blowing direction of the air from the cooling fan. The slit may be formed so as to extend in the blowing direction.

The air guide plate may have a second portion extending from an edge of the air guide plate close to the cooling fan toward the first portion. The second portion may be inclined so as to have an upward gradient from the edge of the air guide plate close to the cooling fan toward the first portion.

The inverter may be disposed below the second portion.

The air guide plate may have a guide part that guides the air blown from the cooling fan to the slit. The guide part may have a pair of guide plates disposed with the slit therebetween, and extending from an upstream side toward a downstream side in a blowing direction of the air from the cooling fan. A distance between the pair of guide plates may decrease from the upstream side toward the downstream side.

The power supply may include a support part that is erected from an inner bottom portion of the case and that supports the air guide plate at a position above the battery. The battery may have a first side surface disposed on a downstream side in a blowing direction of the air from the cooling fan. The support part may close a gap between the plurality of battery modules, the gap being formed in the first side surface.

The battery may have a second side surface disposed on one side in a direction orthogonal to a direction in which the slit extends, and a third side surface disposed on the other side in the direction orthogonal to the direction in which the slit extends. The battery modules may each include a plurality of cells, and the air guided from the slit to the gap may pass between the plurality of cells to flow in the direction orthogonal to the direction in which the slit extends and may be discharged from the second side surface and the third side surface.

The power supply may include a junction box that houses a relay capable of electrically connecting the battery and the inverter to each other; and a DC-DC converter that boosts the output voltage of the battery. The junction box and the DC-DC converter may be housed in the case.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a power supply according to an embodiment of the present invention will be described with reference to the drawings.

As illustrated inFIGS.1to4, a power supply1includes a battery (secondary battery)2, a power converter3, an air-cooler4, and a case5. The battery2, the power converter3, and the air-cooler4are housed in an internal space of the common (one) case5.

For the orientation of the power supply1, arrows are illustrated inFIGS.1to4and other drawings for the convenience of explanation. The direction of an arrow A1is defined as forward, the direction of an arrow A2is defined as rearward, the direction of an arrow B1is defined as leftward, the direction of an arrow B2is defined as rightward, the direction of an arrow C1is defined as upward, and the direction of an arrow C2is defined as downward. The direction of an arrow A0is referred to as a front-rear direction, the direction of an arrow B0is referred to as a width direction or a left-right direction, and the direction of an arrow C0is referred to as an up-down direction. A direction from the left or the right toward the center in the width direction is referred to as inward in the width direction, and a direction from the center in the width direction toward the left or the right is referred to as outward in the width direction.

As illustrated inFIG.5, the battery2includes a plurality of battery modules20A and20B. In the present embodiment, the battery2includes two battery modules20A and20B. However, the number of battery modules included in the battery2is not limited to two, and may be three or more, or may be one.

One battery module includes a plurality of battery cells21. The plurality of battery cells21are electrically connected to each other. InFIG.5, one battery module includes four battery cells21. However, the number of battery cells21included in one battery module is not limited to four, and may be five or more, or three or less. In the following description, a battery cell may be simply referred to as a cell.

Each of the battery cells21is, for example, a lithium-ion secondary battery, a nickel-hydrogen secondary battery, or an organic radical battery. In the present embodiment, each of the battery cells21and the battery modules20A and20B has a rectangular-parallelepiped shape.

The plurality of battery cells21included in the battery module20A are housed in an exterior case16. The plurality of battery cells21included in the battery module20B are housed in another exterior case16. In the present embodiment, the exterior cases16each have a rectangular parallelepiped shape. Outer surfaces (upper surfaces, lower surfaces, and side surfaces) of the exterior cases16define outer surfaces (upper surfaces, lower surfaces, and side surfaces) of the battery modules20A and20B. Among the outer surfaces of the battery modules20A and20B, surfaces other than surfaces facing each other (surfaces disposed with an inter-module passage10therebetween) define outer surfaces of the battery2.

As illustrated inFIGS.2and5, the plurality of battery modules20A and20B are disposed in a planar manner. In the present embodiment, the two battery modules20A and20B are disposed side by side in the width direction B0. The inter-module passage10is formed between the two battery modules20A and20B. The inter-module passage10extends in the front-rear direction A0.

The plurality of battery cells21are disposed side by side in a planar manner. In the present embodiment, the plurality of (four) battery cells21are disposed side by side in the front-rear direction A0in one battery module. Each pair of battery cells21adjoining each other have each inter-cell passage11therebetween. The inter-cell passages11extend in the width direction (left-right direction) B0.

Alternatively, although not illustrated, the battery2may have a configuration in which a plurality of battery modules20A and20B disposed in a planar manner are stacked in a plurality of stages in the up-down direction. Still alternatively, each of the plurality of battery modules20A and20B may have a configuration in which a plurality of battery cells21disposed in a planar manner are stacked in a plurality of stages in the up-down direction.

As illustrated inFIG.5, the battery2has a rectangular parallelepiped shape as a whole, and has an upper surface, side surfaces, and a lower surface. Specifically, the battery2has an upper surface2a, a first side surface2b, a second side surface2c, a third side surface2d, a fourth side surface2e, and a lower surface2f. The first side surface2bis disposed to face rearward. The second side surface2cis disposed to face leftward. The third side surface2dis disposed to face rightward. The fourth side surface2eis disposed to face forward.

The upper surface2a, the first side surface2b, the fourth side surface2e, and the lower surface2fof the battery2are divided into two by the inter-module passage10. In other words, the inter-module passage10is continuously open in the upper surface2a, the first side surface2b, the fourth side surface2e, and the lower surface2fof the battery2.

The inter-cell passages11are open in the second side surface2cand the third side surface2dof the battery2, and also open in portions facing the inter-module passage10. In other words, inner end portions of the inter-cell passages11in the width direction communicate with the inter-module passage10, and outer end portions thereof in the width direction are open.

As illustrated inFIG.5, each of the exterior cases16is formed with vents16aat positions facing the respective inter-cell passages11. The vents16aare formed in inner surfaces in the width direction and outer surfaces in the width direction of the exterior cases16. The vents16acommunicate with the respective inter-cell passages11. The vents16aformed in the inner surfaces in the width direction of the exterior cases16serve as inlets for guiding cooling air (described later) from the outside of the battery2(the outside of the exterior cases16) to the inter-cell passages11. The vents16aformed in the outer surfaces in the width direction of the exterior cases16serve as outlets for guiding cooling air (described later) from the inter-cell passages11to the outside of the battery2(the outside of the exterior cases16).

The power converter3is a device that converts electric power (electric energy) output from the battery2into electric power in a form suitable for being supplied to a drive device (such as a motor) that is driven by the power supply1. As illustrated inFIGS.2and3, in the present embodiment, the power converter3includes an inverter31and a DC-DC converter32. In the illustrated example, the inverter31and the DC-DC converter32are constituted as an integrated unit. Specifically, the inverter31and the DC-DC converter32are housed inside a common housing33.

However, the inverter31and the DC-DC converter32need not be integrated. In this case, the inverter31and the DC-DC converter32are disposed side by side at positions close to each other. The inverter31and the DC-DC converter32may be disposed side by side in the front-rear direction, may be disposed side by side in the width direction, or may be disposed side by side in the up-down direction.

The inverter31controls an output voltage of the battery2. Specifically, the inverter31converts a direct-current voltage output from the battery2into an alternating-current voltage and outputs the alternating-current voltage. The direct-current voltage output from the battery2is supplied to the inverter31via the DC-DC converter32. The DC-DC converter32boosts the direct-current voltage output from the battery2. The inverter31converts the direct-current voltage boosted by the DC-DC converter32into an alternating-current voltage and outputs the alternating-current voltage. However, the power converter3may include at least the inverter31, and need not include the DC-DC converter32. When the power converter3does not include the DC-DC converter32, the “power converter3” in the following description may be read as the “inverter31”.

As illustrated inFIGS.1to3, the air-cooler4includes a cooling fan41and a heat exchanger42.

The cooling fan41has a blowing portion41afor blowing air (cooling air) by rotation of a fan, and a suction portion41bfor sucking air toward the fan. In the present embodiment, the cooling fan41is a centrifugal fan (sirocco fan). The cooling fan41can be driven by using electric power stored in the battery2.

The heat exchanger42cools air flowing through the internal space of the case5by heat exchange. The heat exchanger42cools the air that has passed through the battery2and the power converter3. In the present embodiment, an evaporator is used as the heat exchanger42. The heat exchanger42includes a pipe through which a refrigerant flows, and a fin for heat radiation provided so as to be thermally conductive with the pipe. Air passing through the heat exchanger42is cooled by heat exchange between the refrigerant flowing in the pipe of the heat exchanger42and the air passing around the pipe and the fin. An inlet portion42aand an outlet portion42b(seeFIG.2) of the pipe of the heat exchanger42protrude to the outside of the case5.

As illustrated inFIGS.1and2, the power supply1includes a junction box6. The junction box6houses a relay capable of electrically connecting the battery2and the inverter31to each other. The junction box6is housed inside the case5.

As illustrated inFIG.1, the case5includes a main body51and a cover body52. In the present embodiment, the case5has a substantially rectangular parallelepiped shape, and the length in the front-rear direction A0is larger than the length in the width direction B0. Moreover, the length (height) in the up-down direction C0is smaller than the length in the front-rear direction A0and the length in the width direction B0. However, the shape of the case5can be appropriately changed.

The main body51has a bottom plate51a, a side wall51b, and a first flange51c. The bottom plate51adefines a bottom surface of the case5. The side wall51bincludes a first side wall511, a second side wall512, a third side wall513, and a fourth side wall514. The first side wall511extends upward from a front edge of the bottom plate51a. The second side wall512extends upward from a rear edge of the bottom plate51a. The third side wall513extends upward from a left edge of the bottom plate51aand connects a left edge of the first side wall511and a left edge of the second side wall512to each other. The fourth side wall514extends upward from a right edge of the bottom plate51aand connects a right edge of the first side wall511and a right edge of the second side wall512to each other. The first flange51cextends outward (in a direction away from the internal space of the case5) from an upper edge of the side wall51b.

The cover body52has a top plate52a, a side plate52b, and a second flange52c. The top plate52adefines an upper surface of the case5. The side plate52bincludes a first side plate521, a second side plate522, a third side plate523, and a fourth side plate524. The first side plate521extends downward from a front edge of the top plate52a. The second side plate522extends downward from a rear edge of the top plate52a. The third side plate523extends downward from a left edge of the top plate52aand connects a left edge of the first side plate521and a left edge of the second side plate522to each other. The fourth side plate524extends downward from a right edge of the top plate52aand connects a right edge of the first side plate521and a right edge of the second side plate522to each other. The second flange52cextends outward (in the direction away from the internal space of the case5) from a lower edge of the side plate52b.

A plurality of first through holes51dare formed in the first flange51c. A plurality of second through holes52dare formed in the second flange52c. The first flange51cand the second flange52care fixed to each other by superposing the first through holes51dand the second through holes52d, inserting bolts, and screwing nuts to the bolts. Thus, the cover body52and the main body51are fixed to each other. A space surrounded by the cover body52and the main body51defines the internal space of the case5. The internal space of the case5is a hermetically sealed space into which outside air is not introduced.

As illustrated inFIGS.1to3, the battery2is disposed in a rear portion of the internal space of the case5. The cooling fan41is disposed in a front portion of the internal space of the case5. The blowing portion41ais disposed to face rearward (to face the battery2). Thus, the cooling fan41can blow air (cooling air) rearward (toward the battery2) from the blowing portion41a. Moreover, the blowing portion41ais disposed at a position shifted outward (rightward) in the width direction from the center in the width direction of the case5. The suction portion41bis disposed to face downward. Thus, the cooling fan41can suck air from below.

As illustrated inFIG.3, the position of the battery2and the position of the blowing portion41aof the cooling fan41overlap each other in the up-down direction. An upper end (the upper surface2a) of the battery2is disposed at a position higher than the blowing portion41aof the cooling fan41. A lower end (the lower surface2f) of the battery2is disposed at a position lower than the blowing portion41aof the cooling fan41.

As illustrated inFIG.3and other drawings, the heat exchanger42is disposed below the cooling fan41. Specifically, the heat exchanger42is disposed below the suction portion41bof the cooling fan41. Accordingly, air cooled by passing through the heat exchanger42is sucked from the suction portion41bof the cooling fan41, and the air is blown from the blowing portion41aas cooling air.

As illustrated inFIG.3, the power converter3is disposed between the battery2and the heat exchanger42in the front-rear direction. Thus, the inverter31and the DC-DC converter32are disposed between the battery2and the heat exchanger42in the front-rear direction. As illustrated inFIG.3, an upper end of the power converter3is disposed at a position lower than an upper end of the blowing portion41aof the cooling fan41. Moreover, the upper end of the power converter3is disposed at a position lower than an upper end of the battery2.

As illustrated inFIGS.1and2, the junction box6is disposed in rear of the battery2. However, the junction box6may be disposed at another position. For example, the junction box6may be disposed between the power converter3and the battery2. Alternatively, the junction box6may be disposed above a second portion72of an air guide plate7.

As illustrated inFIGS.1and2, the power supply1includes a battery management unit (BMU)15. The battery management unit15is housed inside the case5. The battery management unit15is a control unit that monitors the state of the battery2(the remaining charge amount of the battery2, the temperature of the battery2, and so forth). The battery management unit15is disposed side by side with the air-cooler4(the cooling fan41and the heat exchanger42) in the width direction.

As illustrated inFIGS.1to4, the power supply1includes an air guide plate7. The air guide plate7is disposed inside the case5. The air guide plate7is a plate for guiding air (cooling air) blown from the cooling fan41in a desirable direction. The air guide plate7can guide the air blown from the cooling fan41to the battery2and the power converter3.

The air guide plate7is made of, for example, a metal plate or a resin plate coated with an insulating material. Thus, it is possible to prevent an electrical short circuit from occurring between the battery2and the air guide plate7.

As illustrated inFIG.6and other drawings, the air guide plate7has a first portion71and a second portion72.

The first portion71is disposed such that one surface faces upward and the other surface faces downward. That is, the first portion71is constituted as a flat plate disposed in a horizontal plane. The first portion71has a quadrangular (rectangular) shape in plan view. As illustrated inFIGS.1to4, the first portion71is disposed above the battery2. The first portion71is disposed so as to cover the upper surface2aof the battery2. The first portion71is disposed parallel to the upper surface2aof the battery2.

A slit74is formed in the first portion71. The slit74is a hole whose length in the front-rear direction is larger than the length thereof in the width direction. That is, the slit74extends in the front-rear direction. In other words, the slit74extends in a blowing direction of the air from the cooling fan41(a direction of an arrow D1inFIGS.2and3). The length of the slit74in the front-rear direction is equal to the length of the inter-module passage10in the front-rear direction or is smaller than the length of the inter-module passage10in the front-rear direction. The width (the length in the width direction B0) of the slit74is equal to the width of the inter-module passage10or is larger than the width of the inter-module passage10.

The first side surface2bof the battery2is disposed on one side (rear side) in a direction (front-rear direction) in which the slit74extends. In other words, the first side surface2bis disposed on a downstream side in the blowing direction D1of the air from the cooling fan41. The fourth side surface2eis disposed on the other side (front side) in the direction (front-rear direction) in which the slit74extends. In other words, the fourth side surface2eis disposed on an upstream side in the blowing direction D1of the air from the cooling fan41. The second side surface2cis disposed on one side (left side) in a direction (width direction) orthogonal to the direction in which the slit74extends. The third side surface2dis disposed on the other side (right side) in the direction (width direction) orthogonal to the direction in which the slit74extends.

As illustrated inFIG.2, the slit74is disposed at a position at which the slit74overlaps a gap (the inter-module passage10) between the plurality of battery modules20A and20B in plan view. Thus, the slit74can guide the air (cooling air) blown from the cooling fan41to the gap (the inter-module passage10) between the plurality of battery modules20A and20B.

As illustrated inFIGS.1,3and6, the second portion72extends obliquely forward and downward from a front edge of the first portion71. As illustrated inFIGS.1and3, the second portion72is inclined so as to have an upward gradient from an edge of the second portion72close to the cooling fan41(front) toward an edge of the second portion72close to the first portion71(rear) inside the case5. A third portion73extending forward in the horizontal direction is provided in a front portion of the second portion72. The first portion71, the second portion72, and the third portion73are integrally formed.

As illustrated inFIG.3, the air (cooling air) blown from the blowing portion41aof the cooling fan41flows along an upper surface of the second portion72of the air guide plate7(see an arrow D2), reaches a gap above the first portion71disposed above the battery2, and flows rearward along an upper surface of the first portion71(see an arrow D3).

As illustrated inFIG.3, the distance between the upper surface of the first portion71and an inner upper surface of the case5(a lower surface of the top plate52a) is smaller than the distance between the upper surface of the second portion72and the inner upper surface of the case5. Hence, when the cooling air is guided from the gap above the second portion72to the gap above the first portion71, the air velocity increases. Hence, the cooling air can be reliably guided to a rear portion of the second portion72. Moreover, since the sectional area (air passage sectional area) orthogonal to the flow direction of the cooling air decreases in the gap above the first portion71, the pressure of the cooling air increases, and thus the cooling air is more likely to be guided to the slit74.

As illustrated inFIGS.1to3, the power converter3is disposed below the second portion72. When the power converter3includes the inverter31and the DC-DC converter32, the inverter31and the DC-DC converter32are disposed below the second portion72. When the power converter3includes the inverter31but does not include the DC-DC converter32, the inverter31is disposed below the second portion72, but the DC-DC converter32is not disposed.

As illustrated inFIG.3and other drawings, a front portion (the third portion73) of the air guide plate7is disposed in contact with or close to a lower portion of the blowing portion41aof the cooling fan41. A rear portion (the first portion71) of the air guide plate7is disposed at a position higher than the blowing portion41a. An intermediate portion (the second portion72) in the front-rear direction of the air guide plate7is disposed in a manner inclined with an upward gradient so as to extend from the lower portion of the blowing portion41ato the position higher than the blowing portion41a.

As illustrated inFIGS.1to4, the power supply1includes a support part8that supports the air guide plate7. As illustrated inFIG.6and other drawings, the support part8includes a first support portion81provided at a rear portion of the first portion71and a second support portion82provided at a front portion of the first portion71. The first support portion81is disposed in rear of the slit74. The second support portion82is disposed in front of the slit74. The widths of the first support portion81and the second support portion82each are equal to the width of the slit74or each are smaller than the width of the slit74. The first support portion81and the second support portion82extend downward from the first portion71. The lengths (heights) of the first support portion81and the second support portion82are set to be equal to the height of the battery2or are set to be larger than the height of the battery2.

A lower end of the support part8is fixed to an inner bottom portion (an upper surface of the bottom plate51a) of the case5. That is, the support part8is erected upward from the inner bottom portion (the upper surface of the bottom plate51a) of the case5. Since the lower end of the support part8is fixed to the case5, the air guide plate7is fixed to the case5. However, the method of fixing the air guide plate7to the case5may be another method such as fixing the air guide plate7to the first flange51cor the second flange52c. When the other method is employed, the lower end of the support part8may be separated from the inner bottom portion (the upper surface of the bottom plate51a) of the case5.

As illustrated inFIGS.1to3, the first support portion81is disposed at a position close to the first side surface2bof the battery2. As illustrated inFIGS.1and2, the first support portion81closes a gap between the plurality of battery modules20A and20B, the gap being formed in the first side surface2bof the battery2. The second support portion82is disposed at a position close to the fourth side surface2eof the battery2. As illustrated inFIGS.2and4, the second support portion82closes a gap between the plurality of battery modules20A and20B, the gap being formed in the fourth side surface2eof the battery2. Hence, a front portion and a rear portion of the gap between the plurality of battery modules20A and20B are closed with the support part8. In other words, a front portion and a rear portion of the inter-module passage10are closed with the support part8. Thus, air (cooling air) is prevented from flowing into the inter-module passage10from the front and the rear of the inter-module passage10. As a result, the air (cooling air) can intensively flow into the inter-module passage10from above (from the slit74).

In the present embodiment, the support part8has a columnar shape; however, the support part8may have a plate shape. When the support part8has a plate shape, the plate-shaped first support portion81is disposed to cover the first side surface2bof the battery2, and the plate-shaped second support portion82is disposed to cover the fourth side surface2eof the battery2. This configuration can also prevent air from flowing into the inter-module passage10from the front and the rear of the inter-module passage10.

As illustrated inFIG.7, the power supply1may have a configuration in which a guide part9is provided on an upper surface of the air guide plate7. The guide part9is provided to guide the air blown from the cooling fan41to the slit74. The guide part9has a pair of guide plates9L and9R disposed with the slit74therebetween. The guide plate9L is disposed at the left of the slit74. The guide plate9R is disposed at the right of the slit74.

The pair of guide plates9L and9R are erected upward from the upper surface of the air guide plate7. The pair of guide plates9L and9R extend from the upstream side to the downstream side in the blowing direction D1(from the front to the rear) of the cooling fan41. Front end portions of the pair of guide plates9L and9R are disposed in front of a front end portion of the slit74. Rear end portions of the pair of guide plates9L and9R are disposed in rear of a rear end portion of the slit74. The distance between the pair of guide plates9L and9R (the distance between the guide plate9L and the guide plate9R) decreases from the upstream side toward the downstream side in the blowing direction D1of the cooling fan41. The rear end portion of the guide plate9L and the rear end portion of the guide plate9R are connected to each other in rear of the slit74.

As illustrated inFIG.7, in the present embodiment, the pair of guide plates9L and9R are disposed in a V-shape in plan view. In the pair of guide plates9L and9R, an open section of the V-shape is disposed on the upstream side in the blowing direction D1, and a closed section of the V-shape is disposed on the downstream side in the blowing direction D1.

By providing the guide part9on the air guide plate7, the air (cooling air) blown from the cooling fan41can be collected toward the slit74by the guide part9(see an arrow E1). Moreover, the air blown from the cooling fan41can be prevented from flowing over the slit74to the rear of the battery2. Thus, the air (cooling air) blown from the cooling fan41can be efficiently guided to the slit74.

Hereinafter, a flow of air (cooling air) inside the case5of the power supply1will be described in detail.

As illustrated inFIGS.2and3, air (cooling air) blown from the blowing portion41aof the cooling fan41flows from the front to the rear in the internal space of the case5(see the arrow D1). The blown air flows along the upper surface of the air guide plate7(see the arrows D2and D3). Specifically, the air flows sequentially along the upper surface of the third portion73and the upper surface of the second portion72, and reaches the gap above the first portion71. In this case, since the second portion72of the air guide plate7is gently inclined toward the first portion71, it is possible to reduce a pressure loss that may occur when the air flows from the gap above the second portion72toward the gap above the first portion71.

The air that has reached the gap above the first portion71flows along the upper surface of the first portion71, and is guided from the slit74provided in the first portion71to the gap (the inter-module passage10) between the plurality of battery modules20A and20B (see an arrow D4). The air guided to the gap between the plurality of battery modules20A and20B passes between the plurality of cells (the inter-cell passages11) included in the battery modules20A and20B, flows in a direction orthogonal to the slit74(see an arrow D5), and is discharged from the second side surface2cand the third side surface2dof the battery2. Thus, the plurality of battery cells21included in the plurality of battery modules20A and20B are efficiently cooled with the cooling air.

The air discharged from the second side surface2cof the battery2flows forward through a gap between the second side surface2cand an inner surface of the case5(inner surfaces of the third side wall513and the third side plate523) (see an arrow D6). The air discharged from the third side surface2dof the battery2flows forward through a gap between the third side surface2dand an inner surface of the case5(inner surfaces of the fourth side wall514and the fourth side plate524) (see an arrow D7). The air flowing forward further flows forward while cooling the power converter3by passing around the power converter3(see an arrow D8).

Since the second portion72of the air guide plate7is inclined downward from the rear toward the front, the air (cooling air) flowing forward is prevented from rising and is collected downward toward the front. Thus, the cooling air can reliably flow around the power converter3, and the power converter3can be efficiently cooled.

The air that has passed around the power converter3is cooled by passing through the heat exchanger42(see an arrow D9), and the cooled air is sucked from the suction portion41binto the cooling fan41and then is blown from the blowing portion41a(see the arrow D1). Thus, the air (cooling air) blown from the blowing portion41acools the battery2and the power converter3(the inverter31and the DC-DC converter32) while circulating inside the case5.

As described above, the air guide plate7guides the air blown from the cooling fan41to the battery2and then to the inverter31(the power converter3). In general, the heat-resistant temperature of the battery2is lower than the heat-resistant temperature of the inverter31. For example, the heat-resistant temperature of the battery2is about 60° C., and the heat-resistant temperature of the inverter31is about 80° C. Thus, the battery2having the low heat-resistant temperature can be cooled more preferentially than the inverter31having the high heat-resistant temperature by first applying the air, which is immediately after being blown from the cooling fan41and which is not warmed yet (at low temperature), to the battery2.

However, the air guide plate7may be configured to guide the air blown from the cooling fan41to the inverter31(the power converter3) and then to the battery2. This configuration can be obtained by, for example, interchanging the positions of the power converter3(the inverter31and the DC-DC converter32) and the battery2. This configuration can also be obtained by disposing the power converter3(the inverter31and the DC-DC converter32) above the second portion72of the air guide plate7without changing the disposition of the battery2. This configuration is suitably employed when the heat-resistant temperature of the inverter31is lower than the heat-resistant temperature of the battery2.

In the above-described embodiment, the battery2includes the battery modules20A and20B. However, the battery2may include only the plurality of battery cells21without including the battery module. In this case, the battery cells21are disposed side by side in the front-rear direction and the width direction. Thus, the inter-cell passages11include an inter-cell passage extending in the front-rear direction and an inter-cell passage extending in the width direction. The inter-cell passage extending in the front-rear direction is disposed below the slit74.

The power supply1can be used as, for example, a device for supplying electric power to a motor (including a motor/generator) for driving an agricultural machine, a construction machine, a utility vehicle, a mower, or the like. Specifically, the power supply1can be suitably used as a device that is mounted on an electric vehicle driven by using an electric motor or a hybrid vehicle driven by using both an electric motor and an engine to supply electric power to the electric motor. Specifically, the power supply1can be used by being mounted on a working vehicle such as a tractor, a compact track loader, or a skid-steer loader.

With the power supply1according to the above-described embodiment, the following advantageous effects are attained.

A power supply1includes a battery2; an inverter31that controls an output voltage of the battery2; an air-cooler4that cools the battery2and the inverter31with cooling air; and a case5that houses the battery2, the inverter31, and the air-cooler4.

With this configuration, since the battery2, the inverter31, and the air-cooler4are housed in the common case5, the battery2and the inverter31can be efficiently cooled with the cooling air from the air-cooler4. Moreover, since the battery2and the inverter31can be cooled by the common air-cooler4, the power supply1can be reduced in size. Thus, the power supply1can be installed even in a limited narrow space. Furthermore, since connectors, harnesses, and refrigerant pipes are not required unlike in a case where a plurality of coolers are provided, it is possible to reduce the number of components and hence reduce manufacturing cost. Furthermore, by housing the battery2, the inverter31, and the air-cooler4in the common (one) case5, it is possible to secure high waterproof performance and dust-proof performance. Thus, an expensive waterproof case or dustproof case is not required.

The power supply1includes an air guide plate7disposed inside the case5, the air-cooler4includes a cooling fan41and a heat exchanger42, the air guide plate7guides air blown from the cooling fan41to the battery2and the inverter31, and the heat exchanger42cools the air that has passed through the battery2and the inverter31.

With this configuration, the air blown from the cooling fan41can be guided to the battery2and the inverter31by the air guide plate7to cool the battery2and the inverter31, and warmed air after cooling the battery2and the inverter31can be cooled by the heat exchanger42. Hence, the battery2and the inverter31can always be cooled with the cooling air having a low temperature, and a temperature rise of the battery2and the inverter31can be suppressed for a long time. Thus, the power supply1can maintain a high output for a long time.

The air guide plate7guides the air blown from the cooling fan41to the battery2and then to the inverter31.

With this configuration, in a case where the heat-resistant temperature of the battery2is lower than the heat-resistant temperature of the inverter31, the air blown from the cooling fan41in a low-temperature state in which the air is not warmed yet can be brought into contact with the battery2. Thus, the battery2having the low heat-resistant temperature can be efficiently cooled preferentially to the inverter31having the high heat-resistant temperature.

The air guide plate7guides the air blown from the cooling fan41to the inverter31and then to the battery2.

With this configuration, in a case where the heat-resistant temperature of the inverter31is lower than the heat-resistant temperature of the battery2, the air blown from the cooling fan41in a low-temperature state in which the air is not warmed yet can be brought into contact with the inverter31. Thus, the inverter31having the low heat-resistant temperature can be efficiently cooled preferentially to the battery2having the high heat-resistant temperature.

The air guide plate7has a first portion71disposed above the battery2, the battery2includes a plurality of battery modules20A and20B disposed side by side in a planar manner, and the first portion71has a slit74formed to guide the air blown from the cooling fan41to a gap between the plurality of battery modules20A and20B.

With this configuration, by guiding the air blown from the cooling fan41to the gap between the plurality of battery modules20A and20B through the slit74, the plurality of battery modules20A and20B can be efficiently cooled.

The plurality of battery modules20A and20B are disposed side by side in a direction orthogonal to a blowing direction D1of the air from the cooling fan41, and the slit74is formed so as to extend in the blowing direction D1.

With this configuration, since the cooling air having the same temperature can be brought into contact with the plurality of battery modules20A and20B, the plurality of battery modules20A and20B can be uniformly and efficiently cooled. Moreover, the air blown from the cooling fan41can be introduced into the slit74in a long distance range extending in the blowing direction D1.

The air guide plate7has a second portion72extending from an edge of the air guide plate7close to the cooling fan41toward the first portion71, and the second portion72is inclined so as to have an upward gradient from the edge of the air guide plate7close to the cooling fan41toward the first portion71.

With this configuration, since the cooling air blown from the cooling fan41can be smoothly guided to the first portion71along the inclination of the air guide plate7, a pressure loss of the cooling air can be reduced.

The inverter31is disposed below the second portion72.

With this configuration, a rise of the cooling air can be suppressed by the second portion72, and a flow of the cooling air can be concentrated in the vicinity of the inverter31(below the second portion72). Thus, the inverter31can be efficiently cooled.

The air guide plate7has a guide part9that guides the air blown from the cooling fan41to the slit74; the guide part9has a pair of guide plates9L and9R disposed with the slit74therebetween, and extending from an upstream side toward a downstream side in a blowing direction D1of the air from the cooling fan41; and a distance between the pair of guide plates9L and9R decreases from the upstream side toward the downstream side in the blowing direction D1of the air.

With this configuration, the air blown from the cooling fan41can be efficiently and reliably guided to the slit74by the pair of guide plates9L and9R.

The power supply1includes a support part8that is erected from an inner bottom portion of the case5and that supports the air guide plate7at a position above the battery2; the battery2has a first side surface2bdisposed on a downstream side in a blowing direction D1of the air from the cooling fan41; and the support part8closes a gap between the plurality of battery modules20A and20B, the gap being formed in the first side surface2b.

With this configuration, the support part8can prevent the cooling air from entering from the gap between the plurality of battery modules20A and20B formed in the first side surface2b. Thus, the cooling air can be guided in a concentrated manner toward the slit74. Accordingly, since the cooling air is intensively introduced into the gap between the battery modules20A and20B from above, the cooling efficiency of the battery modules20A and20B can be improved.

The battery2has a second side surface2cdisposed on one side in a direction orthogonal to a direction in which the slit74extends, and a third side surface2ddisposed on the other side in the direction orthogonal to the direction in which the slit74extends; and the battery modules20A and20B each include a plurality of cells21, and the air guided from the slit74to the gap passes between the plurality of cells21to flow in the direction orthogonal to the direction in which the slit74extends and is discharged from the second side surface2cand the third side surface2d.

With this configuration, since the cooling air introduced from the gap between the plurality of battery modules20A and20B can be discharged through the gap between the plurality of cells21, the plurality of cells21can be efficiently and reliably cooled.

The power supply1includes a junction box6that houses a relay capable of electrically connecting the battery2and the inverter31to each other; and a DC-DC converter32that boosts the output voltage of the battery2. The junction box6and the DC-DC converter32are housed in the case5.

With this configuration, since the DC-DC converter32is housed in the case5, the DC-DC converter32can be cooled together with the battery2and the inverter31by the air-cooler4. Thus, it is not necessary to provide another cooler for cooling the DC-DC converter32, and it is possible to efficiently cool the DC-DC converter32, the battery2, and the inverter31by the one air-cooler4. Moreover, since the junction box6is housed in the case5, the battery2and the inverter31can be connected to each other by the relay housed in the junction box6inside the case5.