JP2001008468A - Inverter cooler for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooler capable by enhancing cooling efficiency to supply required current, and decreasing the installation volume. SOLUTION: This cooler is formed by arranging a radiating plate 5 brought into close contact with and fixed on a pair of inverter chips which arranged back to back. The inverter chips are disposed so as not to be overlapped with each other. Radiating fins 53 of a prescribed number are attached only to the back of the radiating plate 5, on the side where the respective inverter chips are disposed, thereby passing a cooling medium along the radiating fins 53.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an inverter used in an electric vehicle including a so-called hybrid car, and more particularly to an improvement in the arrangement of heat radiation fins.

[0002]

2. Description of the Related Art In an electric car or a hybrid car, an inverter is used to generate an AC voltage for operating a motor for driving a vehicle from a battery. FIG. 7 shows an inverter chip 11 in the conventional inverter module 1.
It is explanatory drawing showing the arrangement | positioning situation of. This inverter has 1
Inverter module 1 provided corresponding to one drive motor is included. The inverter module 1 includes a substrate on which a plurality of inverter chips 11 such as power transistors are mounted, and a heat radiation plate 2 serving as a cooling device.
Is attached.

Each inverter chip 11 easily generates heat, and the amount of current that can be supplied is suppressed due to excessive heat generation.
That is, in order to maintain the electrical performance and allow the required current to flow, it is necessary to bring the heat radiating surface into close contact with the heat radiating plate 2 and perform sufficient cooling.

[0004] In the inverter module 1, as shown in FIG.
), And are arranged in a line, and a plurality of such sets are arranged at regular intervals.
Arranged with an interval between each inverter chip 1
1 and the inverter chip 11
This is because if the heat is concentrated, generated heat is not efficiently dissipated.

The conventional heat radiation plate 2 has one surface as a flat surface to which the inverter chip 11 is fixed, and a heat radiation fin 21 standing upright on the back surface (back surface side). In addition, an LLC (Long L
cooling medium such as ife Coolant). The heat radiating plate 2 is manufactured by cutting a material having a high thermal conductivity such as a metal.

[0008] The conventional heat radiating plate 2 will be described with reference to FIG. FIG. 8 is a cross-sectional view of a conventional heat dissipation plate 2. The conventional heat dissipation plate 2 shown in FIG. 8 has a plane (A) for tightly fixing the inverter chip 11. Radiation fins 21 are provided upright on the back surface (B) of the plane A, and projections 22 are formed on at least two sides of the outer edge of the surface B. Further, the heat radiation plate 2 includes a flow path lid 23 that covers the surface B on which the heat radiation fins 21 are provided with the convex portion 22 as a wall. LLC as a cooling medium flows along the heat radiation fins 21 in the hollow portion surrounded by the flow path lid 23, the convex portion 22, and the surface B.

In the conventional heat dissipation plate 2, the heat generated by the inverter chip 11 propagates from the plane A of the heat dissipation plate 2 to the heat dissipation fins 21. The radiation fins 21 are cooled by LLC flowing through the hollow portion. Thus,
The cooling of the inverter chip 11 is performed.

[0008] The partition ribs are alternately arranged adjacent to each other in the width direction, and a coolant is circulated along the partition ribs to cool the heating elements mounted on the respective outer surfaces.
A cooling structure having a pair of cooling blocks is disclosed in
No. 38025, “Cooling structure”.

[0009]

However, in the above-mentioned conventional cooling device for an electric vehicle inverter, in order to supply an AC voltage to each of the two driving motors, two or more motors are required.
A set of inverter modules and a heat radiating plate must be installed, and there is a problem that the installation volume is increased.

Therefore, with the structure described in Japanese Patent Application Laid-Open No. 7-38025, it is possible to arrange the inverter modules on both sides to reduce the installation volume. However, it is known that much of the heat from the chip propagates to the fin immediately behind the chip, but not much to the surrounding fins. Since the corresponding ribs are alternately combined, if a predetermined sufficient number of fins are to be provided immediately behind the chip, the spacing between the ribs will be narrow, and the cooling fluid will not flow smoothly, and cooling efficiency will be reduced. There is a problem that the required current cannot be supplied due to limitations.

The present invention has been made in view of the above circumstances, and provides a cooling device for an inverter for an electric vehicle, which can cool a pair of inverter modules with sufficient cooling efficiency to supply a required current and reduce the installation volume. The purpose is to provide.

[0012]

According to a first aspect of the present invention, there is provided a heat radiation plate which is fixed to a heat radiation surface of an inverter chip and back to back. On at least one back surface, a radiating fin is provided, and in a cooling device of an inverter for an electric vehicle in which a cooling medium is circulated between both radiating plates, each inverter chip has a radiating plate arranged back to back. A plurality of radiating fins are provided only on the rear surface of the radiating plate on the side where each inverter chip is disposed, where the radiating fins are arranged so as not to overlap with each other.

[0013]

Embodiments of the present invention will be described with reference to the drawings. The components having the same configuration as the conventional one are denoted by the same reference numerals, and the detailed description is omitted.

FIG. 1 is a perspective view of a cooling device for an inverter for an electric vehicle according to an embodiment of the present invention. As shown in FIG. 1, the cooling device according to the present embodiment is fixed in close contact with the heat radiation surfaces of two inverter modules 1a and 1b provided corresponding to the two drive motors, respectively, and is arranged back to back. It is basically composed of a pair of radiating plates (heat sinks) 5a and 5b. Further, each inverter module 1 includes a plurality of inverter chips 11 for generating an AC voltage.

In each inverter module 1, four inverter chips 11 are provided as in the conventional one shown in FIG.
A set of ~ 5 is arranged in a row, and a plurality of the rows are arranged at regular intervals. Also,
A heat dissipation plate 5 is fixedly attached to the heat dissipation surface of the inverter chip 11.

Here, the shape of the heat radiation plate 5, which is a feature of the present invention, will be described. When the rear surface of the heat radiating plate 5 is viewed from the front, as shown in FIG. 2, a convex portion 51 is formed at a peripheral edge portion. A discharge path 42 is formed. In the center of the back surface of the heat radiating plate 5, a linear flow path 43 of the cooling medium partitioned by the partition wall 52 is provided.
Are formed, and the straight flow paths 43 are connected by a semi-circular flow path (hereinafter, referred to as a “semi-circular flow path”) 45 having a width equal to a radius. Here, the portion connecting the straight flow paths 43 is formed in a semicircular shape in order to make the cross-sectional area of the flow paths constant and to make the flow resistance of the cooling medium constant.

Here, the width of each linear flow path 43 is at least the chip width of the inverter chip 11 (the width of l in FIG. 7).
And a plurality of heat dissipating fins 53 are arranged at a predetermined interval to be substantially half of the width of the heat dissipating fins 53 in parallel with the partition wall 52 so that the pair of heat dissipating plates can be combined back to back. Is formed.

Looking at a cross section of the heat radiation plate 5 when the straight flow path 43 is cut along the line AA in FIG. 2, as shown in FIG. 3, the convex portion 51 and the partition wall 52 have substantially the same height. The radiating fins 53 are formed at a height approximately twice as high as these. In addition, when a cross section of the semicircular flow path 45 of the heat radiation plate 5 taken along the line BB in FIG.
As shown in FIG. 4, a semicircular partition wall 55 is formed in the semicircular channel 45 at substantially the same height as the partition wall 52.

Further, the feature of the present invention is that
As shown in FIG. 3, the plurality of radiation fins 53 are
That is, the inverter chips 11 are arranged just behind the rear surface of the row. By arranging in this way, most of the heat generated by the inverter chip 11 propagates to a predetermined plurality of radiating fins 53. Therefore, the inverter chip 11 can be efficiently cooled through the plurality of predetermined radiating fins 53.

When a pair of the heat radiating plates 5 are arranged back to back, the heat radiating fins 53 formed on each of the heat radiating plates 5a and 5b are replaced with the heat radiating fins of the linear flow path 43 of the mating member, as shown in FIG. When the perspective view is taken along a line C-C, the projection 51 is inserted into the portion where the projection 51 is not provided, as shown in FIG.
The a and 51b abut each other to form an outer peripheral wall, and the partition walls 52a and 52b also abut each other to form a wall that partitions the straight flow path 43. The radiation fins 53 are combined in this manner, and the inverter chip 11 is disposed on the front surface side of the position where the radiation fins 53 are provided. That is, as shown in FIG.
Inverter chips 11 that are in close contact with each of 5b are arranged at positions that do not overlap each other.

Next, a description will be given of a state when LLC is circulated as a cooling medium in the cooling device for an electric vehicle inverter according to the embodiment of the present invention. LLC as a cooling medium is introduced from the introduction path 41 shown in FIG. 5, flows through the linear flow path 43a, and takes heat from the radiation fins 53 formed here. Further, the LLC has a semicircular flow path 4.
After passing through 5a, it is further led to a linear flow path 43b in the lower part of the figure, and removes heat from the radiation fins 53 formed here.
Hereinafter, similarly, LLC sequentially circulates through the linear flow path 43 in the lower part of the drawing, and the radiation fins 53 formed in each flow path.
The heat is removed from the discharge passage 42 and discharged from the discharge passage 42.

According to the cooling device for an inverter for an electric vehicle of the present embodiment, the heat generated by the inverter chips 11 of the pair of inverter modules 1 is transferred to the heat dissipation plate 5 tightly fixed to each inverter chip 11, especially to the inverter. Propagation to a plurality of predetermined radiation fins 53 formed immediately behind the position where the chip 11 is fixed,
The cooling medium, such as, removes heat from these radiating fins 53 with sufficient efficiency. Therefore, the inverter chip 11 is cooled with sufficient efficiency, and the required current can be supplied. Moreover, since the heat radiation fins 53 are provided only on the back surface (the back side immediately behind the inverter chip 11) on the side where the inverter chip 11 is provided, the space between the heat radiation fins 53 is not narrowed, and the LLC flows smoothly, The cooling efficiency can be further improved.

Further, in the present embodiment, since the radiation plates 5 thus formed can be combined back to back, a pair of inverter modules 1 respectively corresponding to two driving motors and a pair of inverter modules 1 The installation volume of the pair of heat radiation plates 5 corresponding to 1 can be reduced.

The pair of heat radiating plates 5a and 5b are connected to each other by the pair of heat radiating fins 53,
3. Enter the part where the heat radiation fins are not provided,
If the combination is possible, the number of sets of the radiation fins 53 is not necessarily the same, and it is not necessary to make the shape the same. However, since the manufacturing cost can be reduced by manufacturing in the same process, the same shape should be used. It is suitable.

[0025]

According to the first aspect of the present invention, the heat radiating plates closely adhered to the heat radiating surfaces of the inverter chips are arranged back to back, and the heat radiating fins are provided on at least one back surface of both the heat radiating plates. The cooling medium is circulated between the heat radiating plates, and the inverter chips are arranged at positions where they do not overlap each other when the heat radiating plates are arranged back to back, and the back of the heat radiating plate on the side where the inverter chips are arranged. The cooling device of the inverter for an electric vehicle provided with a plurality of radiating fins only in the above-mentioned configuration allows the inverter chip to be cooled with sufficient efficiency, to enable the required current to flow, and to reduce the installation volume.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cooling device for an inverter for an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a front view of a back surface of the heat radiation plate 5;

FIG. 3 is a sectional view of a heat radiation plate 5;

FIG. 4 is a sectional view of a heat radiation plate 5;

FIG. 5 is a perspective view when a pair of heat radiation plates 5 are combined.

FIG. 6 is a cross-sectional view illustrating a state when a pair of heat radiation plates 5 are combined.

FIG. 7 is an explanatory diagram showing an arrangement state of inverter chips 11 in a conventional inverter module 1.

FIG. 8 is a cross-sectional view of a conventional heat dissipation plate 2.

[Explanation of symbols]

1 Inverter module, 2,5 heat dissipation plate,
11 inverter chip, 21,53 radiating fin,
22, 51 convex portion, 23 channel cover, 41 introduction path, 4
2 discharge channel, 43 straight channel, 45 semicircular channel, 5
2 Partition walls, 55 semicircular partition walls.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Katsuya Shikada 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Takahisa 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F Terms (reference) 5H007 AA06 BB06 CC03 HA03 HA04 HA05 5H115 PG04 PI13 PI29 PU01 PV09 PV23 TR01 TU12 UI27

Claims (1)

[Claims] A heat radiating plate closely fixed to a heat radiating surface of an inverter chip is disposed back to back, and a heat radiating fin is provided on at least one back surface of both heat radiating plates, and a cooling medium flows between both heat radiating plates. In the cooling device for an electric vehicle inverter, each inverter chip is arranged at a position where they do not overlap each other when the heat radiating plates are arranged back to back, and only on the rear surface of the heat radiating plate on the side where each inverter chip is arranged. A cooling device for an inverter for an electric vehicle, comprising a plurality of predetermined radiating fins.