JPH08200911A - Cooler for electric vehicle - Google Patents

Abstract

PURPOSE: To achieve higher cooling efficiency by making it compatible to set a cooling liquid path just below a heating part with a less space between the heating part and the cooling liquid path. CONSTITUTION: A cooler 1 is provided with a heat sink 5 through which a cooling liquid flows and the heat sink 5 has a path 6 inside to pass the cooling liquid therethrough. An outlet pipe is fixed at one end of the heat sink 5 communicating with the path 6 while an outlet pipe fixed at the other end thereof communicating with the path 6. A female thread member 15 is made cylindrical of aluminum, for instance and a female thread part 15a is formed in the internal wall thereof. The female thread part 15a is allowed to be screwed on a thread formed on a bolt 8 for fixing a base 7. The female thread member 15 is inserted into a hole 5c of the heat sink 5 to be joined on the heat sink 5 by soldering.

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 electric parts mounted on an electric vehicle.

[0002]

2. Description of the Related Art Conventionally, in an electric vehicle, air cooling is generally used as a cooling method for electric parts including heat-generating parts such as power transistors. However, this air cooling is
It is not suitable for cooling electric parts that need to be cooled promptly at the time of starting in summer when the outside temperature is high, for example, electric parts having important functions such as semiconductor element units.

On the other hand, as a liquid cooling type cooling device, for example, as disclosed in Japanese Patent Laid-Open No. 6-24279, heat generated from an electric component is transferred from a heat radiating portion of the electric component through a heat transfer member and an outer wall of a tube. It is known that heat is transferred to the cooling liquid flowing in the tube to heat the cooling liquid, thereby cooling the electric parts.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the cooling device for an electric vehicle disclosed in Japanese Patent Publication No. 79, vibration of an automobile is caused by interposing a heat transfer material having high thermal conductivity between the outer wall surface of the tube through which the cooling liquid flows and the heat radiation portion of the electric component. The influence on the heat transfer performance due to the fluctuation of the clearance between the outer wall surface of the tube and the heat radiation part due to the external force such as twisting or the like can be suppressed to a small level.

In the case of such a liquid-cooling type cooling device, it is desirable to arrange a flow path for the cooling liquid to flow immediately below an electric component as a heating element in order to improve cooling efficiency, and the heating element and the cooling liquid are also provided. The thickness of the wall interposed between the channel and the channel is preferably as thin as possible. However, when a female screw is cut on the thin wall, the screw penetrates the flow path portion, causing a coolant leakage. Therefore, conventionally, it has been difficult to achieve both the provision of the cooling liquid flow path immediately below the heat generating portion and the thinning of the wall.

According to the present invention, a cooling device for an electric vehicle is provided in which the cooling liquid passage is provided immediately below the heat generating portion and the wall thickness between the heat generating portion and the cooling liquid passage is made thin to improve the cooling efficiency. To provide.

[0007]

According to a first aspect of the present invention, there is provided a cooling device for an electric vehicle according to the present invention, which is a cooling device for an electric component mounted on an electric vehicle. A heat sink having an electric component provided on the other side of the substrate and having a flow path through which a cooling liquid flows, a male screw member for fixing the substrate to the heat sink, and a component fixed to the heat sink. And a female screw member that screw-connects the male screw member.

The cooling device for an electric vehicle according to a second aspect of the present invention is the cooling device for an electric vehicle according to the first aspect, wherein the female screw member is joined to the heat sink by brazing. To do. Further, the cooling device for an electric vehicle according to claim 3 of the present invention is the cooling device for an electric vehicle according to claim 1 or 2,
The flow path is divided into a plurality of flow paths inside the heat sink by a plurality of wall bodies.

[0009]

According to the cooling device for an electric vehicle of the present invention, the female screw member that is screwed to the male screw member that fixes the substrate to the heat sink is a component that is fixed to the heat sink. Therefore, the female screw that is fixed to the heat sink. When the male screw member is screwed to the member, the male screw member can be prevented from penetrating the heat sink. As a result, there is an effect of preventing the leakage of the cooling liquid caused by the male screw member penetrating the heat sink.

Further, according to the cooling device for an electric vehicle of the present invention, since the female screw member and the heat sink are separate members, the wall thickness of the heat sink is increased in order to form the female screw portion in the heat sink as in the conventional case. No need. As a result, the wall thickness of the heat sink located between the electric component and the cooling liquid can be reduced, and the cooling efficiency of the electric component by the cooling liquid can be improved. Therefore, it is possible to reduce the flow rate of the cooling liquid, and for example, it is possible to reduce the capacity and lengthen the life of the cooling liquid pressure pump.

Further, according to the cooling device for an electric vehicle of the present invention, since the flow path inside the heat sink is divided into the plurality of flow paths by the plurality of wall bodies, the heat transfer area by the plurality of wall bodies is increased. To do. This has the effect of further improving the cooling efficiency of the electric component with the cooling liquid.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 and 2 show a cooling device for an electric vehicle (hereinafter referred to as “cooling device”) according to a first embodiment of the present invention.
Shown in

The cooling device 1 cools the electric parts 3a, 3b and 3c as heat generating elements mounted on an electric vehicle, and is provided with a heat sink 5 in which a cooling liquid such as an antifreezing liquid or silicon oil flows. There is. The heat sink 5 has a rectangular cross section and is formed in a plate shape made of, for example, aluminum, and has a passage 6 therein for allowing a cooling liquid to flow therethrough. An inlet pipe 18 communicating with the passage 6 is fixed to one end of the heat sink 5, and an outlet pipe 19 communicating with the passage 6 is also fixed to the other end. As a result, the internal passage of the inlet pipe 18, the passage 6 and the internal passage of the outlet pipe 19 communicate with each other. Further, a hole 5c for mounting the female screw member 15 is formed on the heating element mounting surface 5a of the heat sink 5, and the hole 5c communicates with the passage 6.

The female screw member 15 is formed in a cylindrical shape made of, for example, aluminum, and the female screw portion 1 is formed on the inner wall thereof.
5a is formed. The female screw portion 15a can be screwed with a screw thread formed on bolts 8, 9, 10 and 11 for fixing a base 7, which will be described later. Female screw member 15
Is inserted into the hole 5c of the heat sink 5 and is joined to the heat sink 5 by brazing. At this time, the tip of the female screw member 15 is located in the recess 5 d formed in the inner wall of the passage 6. The female screw member 15 may be attached by brazing, fixing by welding, screws, or the like.

The electric components 3a, 3b and 3c are mounted on a flat base 7. The base 7 is formed in a plate shape made of, for example, copper, and bolt insertion holes are formed at its four corners. The bolts 8 and 9 inserted into the bolt insertion holes,
Reference numerals 10 and 11 denote the female screw portion 15a of the female screw member 15 described above.
The base 7 and the electric components 3 are screwed to the base 7.
a, 3b, and 3c are fixed to the heating element mounting surface 5a of the heat sink 5.

With the above-described structure, the wall of the heat sink 5 on the heating element mounting surface 5a side can be thinned. That is, the electric components 3 attached to the base 7
The heat conduction distance between a, 3b, 3c and the cooling liquid flowing in the passage 6 becomes short. Therefore, the electrical components 3a, 3
The cooling efficiency of b and 3c is improved. Next, FIGS. 5 and 6 show conventional cooling devices according to Comparative Example 1 and Comparative Example 2, respectively.

Comparative Example 1 shown in FIG. 5 is a conventional example in which the bolts 8 and 11 are directly screwed to the heat sink 25.
In this example, in order to prevent the female screws 26 and 27 from penetrating into the passage 6, the passage 6 cannot be arranged immediately below the electric components 3a and 3b, and the cooling efficiency of the electric components 3a and 3b is poor. There is. In addition, Comparative Example 2 shown in FIG.
The upper wall of the heat sink 35 is made thick so that the bolts 8 and 11 do not penetrate, and the female screw 3 is provided from the upper surface of this thick wall.
6 and 37 are formed, and the bolts 8 and
This is an example in which 11 is screwed. In Comparative Example 2, since the heat sink 35 is formed with a thick wall, the heat transfer efficiency between the passage 6 through which the cooling liquid flows and the electric components 3a, 3b, 3c is low, so the cooling efficiency is reduced. There is a drawback that

In contrast to these comparative examples, according to the cooling device 1 of the first embodiment, the bolt 8 for fixing the board 7 on which the electric components 3a, 3b, 3c are mounted by the female screw member 15 which is a separate member from the heat sink 5. Are screwed together. As a result, the bolt 8 does not directly penetrate the heat sink 5, and while preventing the coolant flowing through the passage 6 of the heat sink 5 from leaking out due to the penetration of the bolt, the flow path is formed immediately below the electric components 3a and 3b. It can be provided, and the cooling efficiency of the electric components 3a and 3b can be improved. In addition, the wall of the heat sink 5 that defines the passage 6 is formed by the base 7
Since it is formed by a thin wall between and, there is an effect that the heat transfer efficiency can be improved by thinning and the cooling efficiency of the electric components 3a, 3b, 3c can be improved.

(Second Embodiment) FIG. 3 shows a cooling device according to a second embodiment of the present invention. The second embodiment shown in FIG. 3 is an example in which the passage inside the heat sink 45 is divided into a plurality of parts by walls. Inside the heat sink 45, walls 46, 4
7, 48, 49 by passages 51, 52, 53, 54,
It is divided into 55.

According to this second embodiment, the walls 46, 4
7 and 48 increase the heat transfer area, which has the effect of improving the cooling efficiency. (Third Embodiment) FIG. 4 shows a cooling device according to a third embodiment of the present invention. The third embodiment shown in FIG. 4 is an example in which the female screw member 15 is sealed by an O-ring. Heat sink 55
Place the O-rings 58 and 59 on a part of the
The flange 1 of the first female screw member 15 is provided on the opposite side of 8, 59.
5a and the flange portion 60a of the second female screw member 60
This is an example in which is provided. Male screw part 1 of the first female screw member 15
5b is screwed to the second female screw member 60, and the first female screw member 15 is fastened and fixed to the heat sink 55.

In the third embodiment, the O-rings 58 and 59 are provided so that the cooling liquid in the passage 6 through which the cooling liquid flows does not leak outside.
To make it liquid-tight. This prevents the coolant from leaking to the outside. As a result, the electric component 3
A channel can be arranged directly under a and 3b,
By reducing the thickness between the electric components 3a, 3b, 3c and the passage 6, it is possible to effectively cool the electric components 3a, 3b, 3c with the cooling liquid.

[Brief description of drawings]

1 is a sectional view of the cooling device according to the first exemplary embodiment of the present invention taken along the line I-I shown in FIG.

FIG. 2 is a plan view of the cooling device according to the first exemplary embodiment of the present invention.

FIG. 3 is a sectional view of a cooling device according to a second exemplary embodiment of the present invention.

FIG. 4 is a sectional view of a cooling device according to a third exemplary embodiment of the present invention.

5 is a sectional view of a conventional cooling device according to Comparative Example 1. FIG.

FIG. 6 is a sectional view of a conventional cooling device according to a second comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling device 3a, b, c Electric component 5 Heat sink 6 Passage (flow path) 7 Base (board) 8, 9, 10, 11 Bolt (male screw member) 15 Female screw member 18 Inlet pipe 19 Outlet pipe 45 Heat sink 46, 47 , 48, 49 Walls 51, 52, 53, 54, 55 Passages

Claims (3)

[Claims] 1. A cooling device for an electric component mounted on an electric vehicle, comprising: an electric component provided on one side surface of a substrate; and another side surface of the substrate on which a flow path for a cooling liquid flows. A cooling device for an electric vehicle, comprising: a heat sink having; a male screw member that fixes the substrate to the heat sink; and a female screw member that is a component that is fixed to the heat sink and that screw-connects the male screw member. 2. The cooling device for an electric vehicle according to claim 1, wherein the female screw member is joined to the heat sink by brazing. 3. The cooling device for an electric vehicle according to claim 1, wherein the flow passage is divided into a plurality of flow passages by a plurality of wall bodies inside the heat sink.