JP3493524B2 - Water-cooled cooler in electric vehicle transformer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled cooler mainly used for cooling a transformer in an electric vehicle. 2. Description of the Related Art In general, a fan is used as a cooler of a transformer in an industrial machine, which is a so-called air cooling system. On the other hand, transformers for electric vehicles also
With the recent improvement in the performance of electric vehicles, there has been an increasing demand to actively cool the transformer to suppress its temperature rise, but the actual situation is that no specific cooling means has been taken. [0004] An electric vehicle may be air-cooled by using a fan as in the case of the above-mentioned industrial machines. Dust and dirt tend to adhere to the transformer, which is expected to lower the cooling performance. An object of the present invention is to provide a cooler for a transformer of an electric vehicle which can prevent dust and dirt from adhering to the transformer and can maintain stable cooling performance. SUMMARY OF THE INVENTION The present invention relates to a cooler for a transformer in which windings are applied to legs of a substantially rectangular annular core as viewed from the front, wherein the coolers are respectively provided on upper and lower portions of the annular core. A flat tube made of a hollow extruded member having a plurality of cooling water passages disposed therein and extending in a longitudinal direction, headers provided at both ends of each flat tube, and a connection for connecting upper and lower headers together. Each flat tube has a U-shape having bent portions bent at substantially right angles at both ends or both edges, and the upper flat tube is in contact with the upper surface of the annular core. In addition, both bent portions of the flat tube are in contact with the upper end portions of both side surfaces of the annular core, the lower flat tube is in contact with the lower surface of the annular core, and both bent portions of the flat tube are formed of the annular core. It is in contact with the lower end portions of both side surfaces. According to the water-cooled cooler in the transformer of the present invention, the cooling water flowing in from the header on one side of the upper flat tube passes through the cooling water passage inside the upper flat tube and the other end. After flowing into the header on one side of the lower flat tube via the connecting pipe, it flows into the header on the other end through the cooling water passage inside the lower flat tube. Then, the transformer can be cooled by the circulation of the cooling water. In the cooler of the present invention, in addition to the flat tubes being in contact with the upper and lower surfaces of the annular core, the bent portions of the flat tubes are in contact with the upper and lower ends of both sides of the annular core. To
The cooling area by the cooling water is enlarged. In addition, since the bent portion of the flat tube restricts the movement of the flat tube in the left-right direction, the flat tube can be stably arranged on the upper and lower surfaces of the annular core. Further, in the case of the water-cooled cooler of the present invention, a closed cooling water circulation path can be formed as described above. An embodiment of a water-cooled cooler in a transformer of an electric vehicle according to the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, a cooling device in a transformer (T) in which windings (2) are applied to legs (1a) of a substantially rectangular annular core (1) when viewed from the front. A flat tube (4) (5) made of a hollow extruded section, which is disposed at the upper and lower portions of the annular core (1) and has a plurality of cooling water passages (3) extending in the length direction therein; It is composed of headers (6a) (6b) (7a) (7b) provided at both ends of each flat tube, and a connecting tube (8) connecting the header (6b) and the header (7a). Flat tube (4)
(5) is a bent part (4b) (5
It has a U shape having b), and has bent portions (4b) (5b) and flat plate portions (4a) (5a) between both bent portions. The flat tube (4) on the upper side has its flat plate (4a) on the upper surface of the annular core (1) and both bent portions (4
b) are in contact with the upper ends of both sides of the annular core (1), respectively, and the flat tube (5) on the lower side has its flat plate (5a) on the lower surface of the annular core (1). Bent part (5b) is annular core (1)
Are respectively in contact with the lower end portions of both side surfaces. As shown in FIG. 3, the flat tubes (4) and (5) are fixed to the upper and lower portions of the annular core (1) by brackets (9) having U-shaped cross sections on both sides. According to the water-cooled cooler having the above structure, the cooling water flowing from the header (6a) on one side of the upper flat tube (4) is
It flows into the header (6b) at the other end through the cooling water channel (3) inside the upper flat tube (4), and further flows through the connecting tube (8) to one side of the lower flat tube (5). After flowing into the header (7a), it flows into the header (7b) at the other end through the cooling water passage (3) inside the lower flat tube (5). Then, the transformer is cooled by the circulation of the cooling water. FIGS. 4 to 6 show another embodiment of the water-cooled cooler of the present invention, and a flat tube made of a hollow extruded member shown in FIG.
By bending the flat tube (21) from the slits (22) formed near both side edges of (21), flat tubes (24) and (25) having a U-shaped cross section are formed. As shown in FIG. 4, the flat tubes (24) and (25) are disposed above and below a substantially rectangular annular core (26) as viewed from the front, and are fixed by bands (not shown). In the drawing, reference numeral (23) denotes a cooling water passage of the flat tubes (24) and (25), and (27) is provided at both ends of the flat tubes (24) and (25) and communicates with the cooling water passage (23). Indicates the header. According to the water-cooled cooler in the transformer of the present invention, the cooling water is circulated in the upper and lower portions of the annular core of the transformer and in the portions near the upper and lower ends of both side surfaces, respectively.
The temperature rise of the transformer is effectively suppressed. Moreover,
Since it is a so-called hermetic type cooler, stable cooling can be performed without any danger that the cooling performance is reduced due to dust or dust accompanying the running of the electric vehicle. In addition, since the flat tube in the cooler of the present invention is restricted from moving in the left-right direction by the bent portion of the flat tube, the electric vehicle can be stably disposed against vibrations during traveling of the electric vehicle. In an electric vehicle, it is necessary to cool a motor, a power drive unit (PDU), a downverter, and the like. When the water-cooled cooler of the present invention is used, cooling water is sequentially supplied to each of the above members. So-called series cooling in which a series of circulation is performed becomes possible. In addition, since the cooler of the present invention is of a compact form that can be integrally disposed in the upper and lower portions of the transformer, there is no need to secure a separate space in an electric vehicle, and various other advantages are obtained. It has practical advantages.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a cooler in a transformer according to the present invention. FIG. 2 is a side view of the same. FIG. 3 is a sectional view showing an attached state of a flat tube in the cooler of the present invention. FIG. 4 is a front view showing another embodiment of the cooler of the present invention. FIG. 5 is a side view showing a state before the flat tube of the cooler in FIG. 4 is formed. 6 is a side view showing a state after the flat tube of the cooler in FIG. 4 is formed. [Explanation of symbols] (1) Annular core (1a) Leg (2) Winding (3) Cooling channel (4) Flat tube (4b) Bend (5) Flat tube (5b) Bend (6a) (6b ) Header (7a) (7b) Header (T) Transformer

Claims (1)

(57) [Claims] [Claim 1] A cooler in a transformer (T) in which a winding (2) is wound on each leg (1a) of a substantially rectangular annular core (1) as viewed from the front. A flat tube (4) (5) made of a hollow extruded member having a plurality of cooling water passages (3) formed in the upper and lower portions of the annular core (1) and extending in the longitudinal direction, respectively. Headers provided at both ends of each flat tube (6a) (6b) (7a) (7b),
Each of the flat tubes (4) and (5) has a bent portion (4b) (5b) whose both ends or both edges are bent at substantially right angles. ), The upper flat tube (4) is in contact with the upper surface of the annular core (1), and both bent portions (4b) of the flat tube (4) are on both side surfaces of the annular core (1). Of the lower flat tube
(5) is an electric vehicle in which the bent portion (5b) of the flat tube (5) is in contact with the lower surface of the annular core (1) and the lower end of both sides of the annular core (1) is in contact with the lower surface of the annular core (1). Water-cooled cooler in transformer.