EP4092370A1

EP4092370A1 - Vehicle-mounted transformer

Info

Publication number: EP4092370A1
Application number: EP20914198.5A
Authority: EP
Inventors: Shiki HAYAMIZU
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2020-01-14
Filing date: 2020-01-14
Publication date: 2022-11-23
Anticipated expiration: 2040-01-14
Also published as: WO2021144837A1; EP4092370A4; JP6771701B1; JPWO2021144837A1; EP4092370B1

Abstract

An object of the present disclosure is to provide an on-vehicle transformer including a cooler in which the interior of air flow portions can be efficiently cleaned. In an on-vehicle transformer (100), a cooler (140) includes a heat exchange unit (141), an air intake unit (142) and an air intake filter (143). The air intake unit (142) is integrally connected to the heat exchange unit (141). The heat exchange unit (141) has a plurality of oil flow portions (141A) and a plurality of air flow portions (141B). The air intake unit (142) has an air intake fan (142A). The air intake fan (142A) suctions outdoor air into the air intake unit (142) through the air flow portions (141B). A sliding mechanism (170) is provided between each of the plurality of oil flow portions (141A) and a corresponding one of the plurality of air flow portions (141B) adjacent to each of the plurality of oil flow portions (141A). The sliding mechanism (170) is configured to allow each of the plurality of air flow portions (141B) to slide in a direction along an air flow direction of the outdoor air in the plurality of air flow portions (141B).

Description

TECHNICAL FIELD

The present disclosure relates to an on-vehicle transformer.

BACKGROUND ART

Japanese Patent Laying-Open No. S54-47153 (PTL 1) discloses a configuration of a cooler. The cooler disclosed in PTL 1 is a heat exchanger used in general air conditioners such as refrigerators and fan coil units for cooling and heating. The heat exchanger includes a pipe and a fin. The fin is divided into fin blocks. The heat exchanger includes a member that presses the fin blocks against the pipe. The fin blocks are detachably mounted.

CITATION LIST

PATENT LITERATURE

PTL 1: Japanese Patent Laying-Open No. S54-47153

SUMMARY OF INVENTION

TECHNICAL PROBLEM

In order to cool an insulating oil, a cooler having air flow portions through which the suctioned outdoor air can flow is also used in a conventional on-vehicle transformer. As for the cooler used in the on-vehicle transformer, when the on-vehicle transformer is continuously used, dust accumulates in the air flow portions. This leads to a decrease in cooling performance and an increase in temperature of the insulating oil cooled by the cooler.
Therefore, in the on-vehicle transformer, it is necessary to clean the dust by, for example, blowing air onto the dust accumulated in the air flow portions. In this case, it is conceivable to perform cleaning of the interior of the air flow portions from the edge side of the air flow portions through which the outdoor air flows in. However, when the air is blown from the above-described edge side, an air blowing direction is a forward direction with respect to an air flow direction in the air flow portions during the use of the cooler. Therefore, the accumulated dust cannot be sufficiently cleaned. In addition, it is also conceivable to perform cleaning of the interior of the air flow portions from the side of the air flow portions opposite to the edge side through which the outdoor air flows in. However, on the side opposite to the above-described edge side, an air intake fan is located near the air flow portions, and thus, the cleaning work is not easy, which leads to a decrease in efficiency of the cleaning work.
Thus, it is conceivable to configure the air flow portions to be completely removable from the cooler as in the cooler described in PTL 1. However, the cooler used in the on-vehicle transformer is comparatively large in size, and thus, it is not easy to put the air flow portions completely removed from the cooler back into the cooler. When such cooler is used in the on-vehicle transformer, the efficiency of the above-described cleaning work rather decreases.
The present disclosure has been made in light of the above-described problems, and an object of the present disclosure is to provide an on-vehicle transformer including a cooler in which the interior of air flow portions can be efficiently cleaned.

SOLUTION TO PROBLEM

An on-vehicle transformer based on the present disclosure includes: a transformer main body; a tank; an insulating oil; a cooler; a connection pipe; and a pump. The tank houses the transformer main body. The insulating oil is filled into the tank to cool the transformer main body. The cooler cools the insulating oil. The connection pipe connects the tank and the cooler to each other. The pump is placed in the connection pipe. The pump circulates the insulating oil between the tank and the cooler. The cooler includes a heat exchange unit and an air intake unit. The air intake unit is integrally connected to the heat exchange unit. The heat exchange unit has a plurality of oil flow portions and a plurality of air flow portions. The plurality of oil flow portions allow the insulating oil to flow in one direction. Each of the plurality of air flow portions is located between two of the plurality of oil flow portions adj acent to each of the plurality of air flow portions. Each of the plurality of air flow portions allows outdoor air to flow toward an interior of the air intake unit in a direction that crosses an oil flow direction of the insulating oil in the plurality of oil flow portions. The air intake unit has an air intake fan. The air intake fan is located in the air intake unit. The air intake fan suctions the outdoor air into the air intake unit through the air flow portions. A sliding mechanism is provided between each of the plurality of oil flow portions and a corresponding one of the plurality of air flow portions adjacent to each of the plurality of oil flow portions. The sliding mechanism is configured to allow each of the plurality of air flow portions to slide in a direction along an air flow direction of the outdoor air in the plurality of air flow portions. By sliding each of the plurality of air flow portions along the sliding mechanism, each of the plurality of air flow portions can move such that in the air flow direction, an edge of each of the plurality of air flow portions on an air intake unit side is located, toward an opposite side of the air intake unit side, at a distance from an edge of each of the plurality of oil flow portions on the opposite side of the air intake unit side.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, at the time of cleaning of the interior of the plurality of air flow portions in the cooler, the cleaning can be performed from the edge side of each of the plurality of air flow portions on the air intake unit side, and thus, dust in the plurality of air flow portions can be easily removed. Furthermore, after the above-described cleaning, each of the plurality of air flow portions can be easily housed between two of the plurality of oil flow portions adjacent to each of the plurality of air flow portions by the sliding mechanism. Therefore, the interior of the plurality of air flow portions in the cooler can be efficiently cleaned.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 shows a configuration of an on-vehicle transformer according to a first embodiment.
Fig. 2 is a diagram of a cooler and a part of a connection pipe in the on-vehicle transformer in Fig. 1, when viewed from an arrow II direction.
Fig. 3 is a cross-sectional view of the cooler and a part of the connection pipe in the on-vehicle transformer in Fig. 1, when viewed from a III-III line arrow direction.
Fig. 4 is a diagram of the cooler in Fig. 2, when viewed from an arrow IV direction.
Fig. 5 is a diagram of the cooler in Fig. 2, when viewed from an arrow V direction.
Fig. 6 is a diagram of the cooler in Fig. 2, when viewed from an arrow VI direction.
Fig. 7 shows a state in which a plurality of air flow portions have been moved by sliding mechanisms in the on-vehicle transformer according to the first embodiment.
Fig. 8 is a cross-sectional view showing a part of a cooler in an on-vehicle transformer according to a second embodiment.
Fig. 9 shows a state in which a plurality of air flow portions have been moved by sliding mechanisms in the on-vehicle transformer according to the second embodiment.
Fig. 10 shows a part of a cooler in an on-vehicle transformer according to a third embodiment.
Fig. 11 shows a state in which a plurality of air flow portions have been moved by sliding mechanisms in an on-vehicle transformer according to a fourth embodiment.

DESCRIPTION OF EMBODIMENTS

An on-vehicle transformer according to each embodiment will be described hereinafter with reference to the drawings. In the embodiments described below, the same or corresponding portions in the drawings are denoted by the same reference characters and description thereof will not be repeated.

First Embodiment

Fig. 1 shows a configuration of an on-vehicle transformer according to a first embodiment. As shown in Fig. 1, an on-vehicle transformer 100 according to the first embodiment includes a transformer main body 110, a tank 120, an insulating oil 130, a cooler 140, a connection pipe 150, and a pump 160.
Transformer main body 110 is housed in tank 120. Insulating oil 130 is filled into tank 120 to cool transformer main body 110. Cooler 140 cools insulating oil 130. Connection pipe 150 connects tank 120 and cooler 140 to each other. Pump 160 is placed in connection pipe 150. Pump 160 circulates insulating oil 130 between tank 120 and cooler 140.
Fig. 2 is a diagram of the cooler and a part of the connection pipe in the on-vehicle transformer in Fig. 1, when viewed from an arrow II direction. Fig. 3 is a cross-sectional view of the cooler and a part of the connection pipe in the on-vehicle transformer in Fig. 1, when viewed from a III-III line arrow direction.
As shown in Figs. 1 to 3, cooler 140 includes a heat exchange unit 141, an air intake unit 142 and an air intake filter 143. Air intake unit 142 is integrally connected to heat exchange unit 141.
As shown in Fig. 3, heat exchange unit 141 has a plurality of oil flow portions 141A and a plurality of air flow portions 141B. The plurality of oil flow portions 141A allow insulating oil 130 to flow in one direction.
Heat exchange unit 141 is provided with an oil inflow header 141C and an oil outflow header 141D. Oil inflow header 141C is connected to one side of connection pipe 150. Oil inflow header 141C is provided at upstream ends of the plurality of oil flow portions 141A in the oil flow direction of insulating oil 130. Oil outflow header 141D is connected to the other side of connection pipe 150. Oil outflow header 141D is provided at downstream ends of the plurality of oil flow portions 141A in the oil flow direction of insulating oil 130.
Fig. 4 is a diagram of the cooler in Fig. 2, when viewed from an arrow IV direction. Fig. 5 is a diagram of the cooler in Fig. 2, when viewed from an arrow V direction. Fig. 6 is a diagram of the cooler in Fig. 2, when viewed from an arrow VI direction. Oil inflow header 141C and oil outflow header 141D are not shown in Figs. 4 to 6.
As shown in Figs. 3 to 6, each of the plurality of air flow portions 141B is located between two of the plurality of oil flow portions 141A adjacent to each of the plurality of air flow portions 141B. A cooling fin 141F is provided in each of the plurality of air flow portions 141B in order to enhance the heat exchange efficiency.
Each of the plurality of air flow portions 141B allows outdoor air to flow toward an interior of air intake unit 142 in a direction that crosses the oil flow direction of insulating oil 130 in the plurality of oil flow portions 141A. In the present embodiment, in each of the plurality of air flow portions 141B, insulating oil 130 flows through each of a plurality of oil flow holes partitioned by cooling fin 141F. Specifically, the oil flow direction of insulating oil 130 and the above-described air flow direction of the outdoor air are orthogonal to each other, when viewed from a direction of alignment of the plurality of oil flow portions 141A.
Air intake unit 142 has an air intake fan 142A. Air intake fan 142A is located in air intake unit 142.
Air intake fan 142A suctions the outdoor air into air intake unit 142 through air flow portions 141B. The outdoor air suctioned into air intake unit 142 by air intake fan 142A is discharged through an air discharge port 142B. In the present embodiment, air discharge port 142B is located on one side of air intake unit 142 in the oil flow direction of insulating oil 130.
In the present embodiment, air intake filter 143 is located on the side of heat exchange unit 141 opposite to the air intake unit 142 side. Air intake filter 143 is configured to allow the outdoor air to flow therethrough, and is provided to cover the air-intake-side edges in the air flow direction in the plurality of air flow portions 141B. Air intake filter 143 is configured to be removable from air intake unit 142.
Cooler 140 further includes an air discharge filter 144. Air discharge filter 144 has, for example, a grid-like outer shape. Air discharge filter 144 is configured to allow the outdoor air to flow therethrough, and is provided to cover air discharge port 142B. Air discharge filter 144 can suppress contact of rotating air intake fan 142A with a foreign object. Air discharge filter 144 is configured to be removable from air intake unit 142.
As shown in Figs. 3 to 6, a sliding mechanism 170 is provided between each of the plurality of oil flow portions 141A and a corresponding one of the plurality of air flow portions 141B adjacent to each of the plurality of oil flow portions 141A.
Fig. 7 shows a state in which the plurality of air flow portions have been moved by the sliding mechanisms in the on-vehicle transformer according to the first embodiment. In Fig. 7, cooler 140 is shown from the same direction as that in Fig. 4, and oil inflow header 141C and oil outflow header 141D are not shown.
As shown in Figs. 3, 4 and 7, sliding mechanism 170 is configured to allow each of the plurality of air flow portions 141B to slide in a direction along the air flow direction of the outdoor air in the plurality of air flow portions 141B. When the plurality of air flow portions 141B are slid, air intake filter 143 is removed.
In the present embodiment, sliding mechanism 170 has a sliding contact portion 171 and a rail portion 172. Sliding contact portion 171 is provided on each of the plurality of oil flow portions 141A. In the present embodiment, a plurality of sliding contact portions 171 are provided as sliding contact portions 171 for each of the plurality of oil flow portions 141A. Although sliding contact portion 171 has a rail shape extending in the above-described air flow direction in the present embodiment, sliding contact portion 171 may be formed of a plurality of rotatable rollers.
In addition, in the present embodiment, sliding contact portion 171 is also in sliding contact with air flow portion 141B adjacent to oil flow portion 141A of the plurality of oil flow portions 141A provided with sliding contact portion 171. As a result, the efficiency of heat exchange between the plurality of air flow portions 141B and the plurality of oil flow portions 141A can be enhanced.
Rail portion 172 is provided on each of the plurality of air flow portions 141B so as to be in sliding contact with sliding contact portion 171 directly or indirectly. Rail portion 172 extends in the direction along the above-described air flow direction.
In the present embodiment, a not-shown grease is provided between rail portion 172 and sliding contact portion 171. Thus, rail portion 172 can smoothly slide with respect to sliding contact portion 171, and the efficiency of heat exchange between the plurality of air flow portions 141B and the plurality of oil flow portions 141A can be enhanced. Rail portion 172 may also be in sliding contact with oil flow portion 141A adjacent to air flow portion 141B of the plurality of air flow portions 141B provided with rail portion 172. As a result, the efficiency of heat exchange between the plurality of air flow portions 141B and the plurality of oil flow portions 141A can be enhanced.
As shown in Figs. 4 and 7, in on-vehicle transformer 100 according to the first embodiment, by sliding each of the plurality of air flow portions 141B along sliding mechanism 170, each of the plurality of air flow portions 141B can move such that in the above-described air flow direction, an edge E1 of each of the plurality of air flow portions 141B on the air intake unit 142 side is located, toward an opposite side of the air intake unit 142 side, at a distance from an edge E3 of each of the plurality of oil flow portions 141A on the opposite side of the air intake unit 142 side.
Therefore, at the time of cleaning of the interior of the plurality of air flow portions 141B in cooler 140, the cleaning can be performed from the edge E1 side of each of the plurality of air flow portions 141B on the air intake unit 142 side, and thus, dust in the plurality of air flow portions 141B can be easily removed. Furthermore, after the above-described cleaning, each of the plurality of air flow portions 141B can be easily housed between two of the plurality of oil flow portions 141A adjacent to each of the plurality of air flow portions 141B by sliding mechanism 170. Therefore, the interior of the plurality of air flow portions 141B in cooler 140 can be efficiently cleaned. Furthermore, it is unnecessary to clean each of the plurality of air flow portions 141B from the inside of air intake unit 142, which can lead to a reduction in internal volume of air intake unit 142 and a reduction in size of air intake unit 142.
In addition, in the first embodiment, sliding mechanism 170 has sliding contact portion 171 and rail portion 172. Sliding contact portion 171 is provided on each of the plurality of oil flow portions 141A. Rail portion 172 is provided on each of the plurality of air flow portions 141B so as to be in sliding contact with sliding contact portion 171 directly or indirectly. Rail portion 172 extends in the direction along the above-described air flow direction. Thus, sliding mechanism 170 can be provided in a simple configuration.
In addition, in the first embodiment, cooler 140 further includes air intake filter 143 located on the side of heat exchange unit 141 opposite to the air intake unit 142 side. Thus, accumulation of dust in air flow portions 141B can be suppressed.

Second Embodiment

An on-vehicle transformer according to a second embodiment will be described below. The on-vehicle transformer according to the second embodiment is different in configuration of the sliding mechanisms from on-vehicle transformer 100 according to the first embodiment. Therefore, description of features similar to those of on-vehicle transformer 100 according to the first embodiment will not be repeated.
Fig. 8 is a cross-sectional view showing a part of a cooler in the on-vehicle transformer according to the second embodiment. Fig. 9 shows a state in which a plurality of air flow portions have been moved by sliding mechanisms in the on-vehicle transformer according to the second embodiment. In Fig. 8, a part of the cooler is shown in the same cross-sectional view as that of cooler 140 in the first embodiment shown in Fig. 3, and only one of the plurality of air flow portions 141B is shown, and only oil flow portions 141A of the plurality of oil flow portions 141A adjacent to above-described one air flow portion 141B are shown. In Fig. 9, the state is shown from the same direction as the direction of illustration of cooler 140 in the first embodiment shown in Fig. 7.
As shown in Figs. 8 and 9, in the second embodiment, a sliding mechanism 270 further has an intermediate rail portion 273. Intermediate rail portion 273 is provided between sliding contact portion 171 and rail portion 172. Intermediate rail portion 273 is slidable with respect to each of sliding contact portion 171 and rail portion 172. Intermediate rail portion 273 extends in the direction along the above-described air flow direction.
The above-described configuration makes it possible to increase a spacing distance when in the above-described air flow direction, edge E1 of each of the plurality of air flow portions 141B on the air intake unit 142 side is spaced, toward the opposite side of the air intake unit 142 side, apart from edge E3 of each of the plurality of oil flow portions 141A on the opposite side of the air intake unit 142 side. Thus, the interior of air flow portions 141B can be cleaned more easily.
It is preferable that a grease should also be provided between sliding contact portion 171 and intermediate rail portion 273 and between rail portion 172 and intermediate rail portion 273.

Third Embodiment

An on-vehicle transformer according to a third embodiment will be described below. The on-vehicle transformer according to the third embodiment is different from on-vehicle transformer 100 according to the first embodiment in that a cooler further includes a pressing unit. Therefore, description of features similar to those of on-vehicle transformer 100 according to the first embodiment will not be repeated.
Fig. 10 shows a part of a cooler in the on-vehicle transformer according to the third embodiment. In Fig. 10, a part of the cooler is shown from the same direction as the direction of illustration of cooler 140 in the first embodiment shown in Fig. 4.
As shown in Fig. 10, in the third embodiment, cooler 140 further includes a pressing unit 345. Pressing unit 345 presses heat exchange unit 141 from outside. Pressing unit 345 engages with heat exchange unit 141 to press heat exchange unit 141 from both sides in a direction of alignment of the plurality of oil flow portions 141A in heat exchange unit 141.
Therefore, the plurality of air flow portions 141B and the plurality of oil flow portions 141A can be brought into closer contact with each other, with sliding mechanisms 170 being interposed. Thus, the heat exchange efficiency in heat exchange unit 141 can be enhanced.
In the present embodiment, pressing unit 345 has a pair of pressing portions 345A, a coupling member 345B and a support portion 345C. Each of the pair of pressing portions 345A is located outside a corresponding one of both ends of heat exchange unit 141 in the direction of alignment of the plurality of oil flow portions 141A. Each of the pair of pressing portions 345A is pressed against and coupled to a corresponding one of both ends of heat exchange unit 141 by coupling member 345B. Each of the pair of pressing portions 345A is coupled to a corresponding one of both ends of heat exchange unit 141 such that coupling can be released. Although a specific member of coupling member 345B is not particularly limited, examples of coupling member 345B include a bolt and the like. In the present embodiment, support portion 345C is connected to each of the pair of pressing portions 345A. As described above, pressing unit 345 is configured to be removable from heat exchange unit 141. Thus, when pressing unit 345 is removed, the plurality of air flow portions 141B can be slid and moved. Support portion 345C is located so as not to cover the whole of each of the plurality of air flow portions 141B.

Fourth Embodiment

An on-vehicle transformer according to a fourth embodiment will be described below. The on-vehicle transformer according to the fourth embodiment is different from on-vehicle transformer 100 according to the first embodiment in that a heat exchange unit is provided with a handle portion. Therefore, description of features similar to those of on-vehicle transformer 100 according to the first embodiment will not be repeated.
Fig. 11 shows a state in which a plurality of air flow portions have been moved by sliding mechanisms in the on-vehicle transformer according to the fourth embodiment. In Fig. 11, the state is shown from the same direction as the direction of illustration of cooler 140 according to the first embodiment shown in Fig. 7.
As shown in Fig. 11, in the fourth embodiment, a handle portion 441G is connected to an edge of each of the plurality of air flow portions 141B on an opposite side of the air intake unit 142 side. Handle portion 441G connects the plurality of air flow portions 141B to each other. Therefore, by pulling out handle portion 441G to the opposite side of the air intake unit 142 side, the plurality of air flow portions 141B can be slid at a time. Thus, the work efficiency of cleaning of the interior of the plurality of air flow portions 141B can be enhanced.
Handle portion 441G is located so as not to cover the whole of each of the plurality of air flow portions 141B. In addition, although handle portion 441G has a bar-like outer shape extending along a direction of alignment of the plurality of air flow portions 141B in the present embodiment, the outer shape of handle portion 441G is not particularly limited. Handle portion 441G may have a frame-like outer shape that covers a part of cooler 140.
In the description of the embodiments above, the combinable features may be combined with each other.
It is noted that the embodiments disclosed herein are illustrative in every respect, and do not form a basis for restrictive interpretation. Therefore, the technical scope of the present disclosure should not be interpreted based on the foregoing embodiments only, but is defined by the terms of the claims. Further, any modifications within the meaning and scope equivalent to the terms of the claims are encompassed.

REFERENCE SIGNS LIST

100 on-vehicle transformer; 110 transformer main body; 120 tank; 130 insulating oil; 140 cooler; 141 heat exchange unit; 141A oil flow portion; 141B air flow portion; 141C oil inflow header; 141D oil outflow header; 141F cooling fin; 142 air intake unit; 142A air intake fan; 142B air discharge port; 143 air intake filter; 144 air discharge filter; 150 connection pipe; 160 pump; 170, 270 sliding mechanism; 171 sliding contact portion; 172 rail portion; 273 intermediate rail portion; 345 pressing unit; 345A pressing portion; 345B coupling member; 345C support portion; 441G handle portion.

Claims

An on-vehicle transformer comprising:
a transformer main body;

a tank that houses the transformer main body;

an insulating oil filled into the tank to cool the transformer main body;

a cooler that cools the insulating oil;

a connection pipe that connects the tank and the cooler to each other; and

a pump placed in the connection pipe to circulate the insulating oil between the tank and the cooler, wherein

the cooler includes a heat exchange unit, and an air intake unit integrally connected to the heat exchange unit,

the heat exchange unit has a plurality of oil flow portions and a plurality of air flow portions, the plurality of oil flow portions allowing the insulating oil to flow in one direction, each of the plurality of air flow portions being located between two of the plurality of oil flow portions adjacent to each of the plurality of air flow portions to allow outdoor air to flow toward an interior of the air intake unit in a direction that crosses an oil flow direction of the insulating oil in the plurality of oil flow portions,

the air intake unit has an air intake fan located in the air intake unit to suction the outdoor air into the air intake unit through the air flow portions,

a sliding mechanism is provided between each of the plurality of oil flow portions and a corresponding one of the plurality of air flow portions adjacent to each of the plurality of oil flow portions, the sliding mechanism being configured to allow each of the plurality of air flow portions to slide in a direction along an air flow direction of the outdoor air in the plurality of air flow portions, and

by sliding each of the plurality of air flow portions along the sliding mechanism, each of the plurality of air flow portions can move such that in the air flow direction, an edge of each of the plurality of air flow portions on an air intake unit side is located, toward an opposite side of the air intake unit side, at a distance from an edge of each of the plurality of oil flow portions on the opposite side of the air intake unit side.
The on-vehicle transformer according to claim 1, wherein
the sliding mechanism has a sliding contact portion and a rail portion, the sliding contact portion being provided on each of the plurality of oil flow portions, the rail portion being provided on each of the plurality of air flow portions so as to be in sliding contact with the sliding contact portion directly or indirectly, and extending in the direction along the air flow direction.
The on-vehicle transformer according to claim 2, wherein
an intermediate rail portion is further provided between the sliding contact portion and the rail portion, the intermediate rail portion being slidable with respect to each of the sliding contact portion and the rail portion, and extending in the direction along the air flow direction.
The on-vehicle transformer according to any one of claims 1 to 3, wherein
the cooler further includes a pressing unit that presses the heat exchange unit from outside, and

the pressing unit engages with the heat exchange unit to press the heat exchange unit from both sides in a direction of alignment of the plurality of oil flow portions in the heat exchange unit.
The on-vehicle transformer according to any one of claims 1 to 4, wherein
the cooler further includes an air intake filter located on a side of the heat exchange unit opposite to the air intake unit side.