JPH10200278A - Cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooler for enhancing performance by improving cooling capability per unit area without increasing a predetermined volume of the cooler. SOLUTION: The cooler comprises a heat sink 2 having a plurality of flat plate-like fins 22 formed of a metal board 2 having a contact surface with a radiator of a heater 1 and metals fixed to the board 2 and disposed in a row state, thereby radiating heat of the heater 1 by forcibly supplying cooling air from one to the other between the fins 22. In this case, the fins 22 have fins 221 each having a shape continued and bent in a waveform state to a flow direction of the air, and flat plate-like fins 220 at both ends. The air is collided with the fins 221 to form turbulance, and hence heat transfer of the entire fan 22 to the air is improved to improve cooling as the cooler.

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 radiating heat generated by a heating element mounted on a control panel, an electronic device or the like to a fluid through fins.

[0002]

2. Description of the Related Art Conventionally, for example, electronic devices such as inverter control devices used for robots and machine tools are equipped with large heating elements such as power devices such as transistors and power supply modules. As shown in FIGS. 6A and 6B, a cooling device to which a heat sink that dissipates heat generated by a heating element to a surrounding fluid is known as these electronic devices.
FIGS. 6 and 7 show a first conventional example. Reference numeral 1 denotes a heating element (for example, a power module), and 2 denotes a heat sink fixedly in contact with the heating element 1. Flat metal fins 22 are arranged in a row on a metal substrate 21. The members are spaced and integrated, and both members are made of a material having good thermal conductivity. Reference numeral 3 denotes a cooling fan for generating forced air, and the direction of the cooling air sent from the cooling fan 3 is represented by A. In such a configuration, the heat generated by the heating element 1 is transmitted to the metal substrate 21 via the contact surface between the heating element 1 and the metal substrate 21, and the heat spreads in the metal substrate 21 by heat conduction. Heat is transmitted to the fins 22 integrated with the metal substrate 21. Heat is transmitted to the cooling air by forced convection between the metal substrate 21 and the fins 22 and the cooling air. As a result, the heat of the heating element 1 is radiated by the cooling air. As a second conventional example, as shown in FIGS. 8 and 9, the heating element 1 is, for example, a power supply device (1a to 1a) including a plurality of modules.
f), in which a plurality of fins 22 are mounted on the upper side of the metal substrate 21 of the heat sink 2 mounted on the back of the heating element 1 via the base portion 8. The cooling fan 3 is provided at a predetermined interval so as to face the front end 22a of the heat sink 2, and the mounting surface of the fin 22 of the metal substrate 21 linearly moves toward the rear end 22b away from the cooling fan 3. It has a shape that is inclined to be higher. Further, the heat sink 2 is provided with the cooling fan 3.
Some are formed in a fan shape toward the rear end 22b away from the rear end (for example, JP-A-7-249885). In such a configuration, the cooling air from the cooling fan 3 is not blocked by the front end side 22a of the heating element 1 located in the vicinity of the cooling fan 3 and is directed to the rear end side 22b away from the cooling fan 3. Will also hit directly. Thus, the heat radiation effect of the entire heat sink 2 is sufficiently enhanced.

[0003]

In order to reduce the size of such a cooling device which occupies a relatively large volume in electronic equipment which is required to be reduced in size, it is essential to improve the cooling performance per unit volume. However, in the first prior art of the prior art, the only way to improve the cooling performance without increasing the surface area of the fins is to increase the speed of the cooling air flowing between the fins 22 as shown in FIG. Due to the limitation of miniaturization, it is not possible to increase the number of cooling fans, and the size of the cooling fan that can be installed is limited, so it is difficult to obtain a high wind speed, and it is not possible to expect a dramatic improvement in cooling performance. there were. In the second conventional example, as shown in FIG. 8, forced air is generated from a cooling fan 3 provided opposite to a front end 22a of a heat sink 2, and the forced air is directed toward a rear end 22b away from the cooling fan 3. Fin 2 of metal substrate 21
Or a configuration where the mounting surface of 2 is linearly higher,
Further, in the configuration having a fan-like shape toward the rear end portion 22b, the rising effect of the wind between the fins is suppressed to increase the cooling effect. Looking at their abilities, there was a problem that they had not improved. Therefore, an object of the present invention is to provide a cooling device capable of improving the cooling capacity per unit volume without increasing the required volume of the cooling device, and achieving high performance and high reliability. .

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a metal substrate having a contact surface with a heat radiating portion of a heating element, and a metal fixed to the metal substrate and arranged in a row. A heat sink having a plurality of plate-like fins comprising: a heat sink having a plurality of flat fins; Have a shape that is continuously bent in a wave shape with respect to the flow direction of the fluid. Further, the plurality of fins are arranged in a staggered or V-shape formed such that adjacent intervals repeatedly fluctuate in the flow direction of the fluid.

Since the cooling air collides with the fin at the bent portion of the fin by the above means, turbulent cooling air is generated at the collision location due to the collision phenomenon. The turbulent cooling air exploits the boundary portion of the velocity boundary layer to make the velocity boundary layer thin, thereby improving the heat transfer capability between the fins and the cooling air, thereby improving the cooling performance of the cooling device. In addition, the arrangement of the fins is staggered or C-shaped, and the cross-sectional area between each flow path is constantly fluctuating by gradually increasing or decreasing with respect to the flow direction of the fluid. By passing through each flow path, the turbulence of the cooling air is promoted, and the cooling performance is further improved.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS. FIG. 1 is a perspective view of a cooling device showing a first embodiment of the present invention. FIG. 2A is a plan view of the cooling device of FIG. 1 as viewed from above, and FIG.
FIG. 4 is a diagram showing a flow of cooling air between fins. In FIG. 1, a heat sink 2 in which a metal substrate 21 and a flat fin 22 are integrated is fixed on the upper surface of a heating element 1, and cooling air is sent between the fins 22 by a cooling fan 3. This configuration is the same as the conventional example. The difference from the conventional example is that, among the fins 22, the fins 221 inside the flat fins 220 on both sides are arranged in a row with respect to the flow direction of the cooling air and bent continuously in a wave shape. It has the shape which was made. FIG.
(A), the intervals between adjacent bent fins in the width direction of the metal substrate 21 are equal. In such a configuration, the flat fin 2
Fin 22 composed of 20 and bent fin 221
The cooling air is sent between the fluid flow passages of the fins 220, and the heat generated by the heating element 1 is transferred to the fins 220 and 220 by the heat conduction of the metal substrate 21 through the contact surface with the metal substrate 21.
When the heat is transmitted to the cooling air 221, heat is transmitted by forced convection between the fins 220 and 221 and the cooling air to be radiated to the cooling air. Next, the operation will be described. Since the fin 221 has a bent shape in the flow direction of the cooling air, a portion where the cooling air collides with the fin 221 is formed.
Due to the collision phenomenon between the fins 221 and the cooling air, turbulent cooling air is generated at the collision location as shown in FIG. The flow of the turbulent cooling air is regulated by the fins 221 as it goes downstream, so that the degree of the turbulent flow gradually decreases. Turbulence occurs and fin 2
2 will be turbulent throughout. FIG. 3A shows a comparison between the developed velocity boundary layer on the fins along the flow of the cooling air and the change of the velocity boundary layer due to the turbulent cooling air in FIG. 3B. As a result, as shown in FIG. 3B, the turbulent cooling air flows into the velocity boundary layer B.
Thinning the velocity boundary layer B _V by exploiting the boundary portion of the _V. As the velocity boundary layer B _V becomes thinner, the heat transfer capacity between the fins 22 and the cooling air is improved, and as a result, the cooling capacity per unit volume of the cooling device is improved. Next, other embodiments will be described. The fins 221 arranged so as to have a shape continuously bent in a wave shape when viewed from above with respect to the flow direction of the cooling air are arranged in the width direction of the metal substrate 21 as shown in FIGS. Adjacent intervals may be formed so as to gradually increase or decrease with respect to the flow direction of the cooling air, and may be arranged in a C-shaped structure or a staggered structure. A cooling device having such an arrangement structure has the same effect as a cooling device having bent fins arranged at equal intervals in the width direction of the metal substrate 21. In the case of the shape of a square, the cross-sectional area between the flow paths constantly fluctuates by repeatedly increasing or decreasing in the flow direction of the fluid. For this reason, the refrigerant passes through each flow path while repeating expansion and contraction. The expansion and contraction promotes the turbulence of the refrigerant, and a higher turbulence effect can be obtained.

[0007]

As described above, according to the present invention, in a cooling device having a plurality of fins continuously bent in a wave shape provided on a metal substrate, the cooling air flowing between the fins is turbulent. The cooling capacity per unit volume can be improved without increasing the required volume of the cooling device as compared with the conventional cooling device having fins, thereby achieving higher performance and higher reliability. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cooling device according to a first embodiment of the present invention.

2A is a plan view of the cooling device of FIG. 1 as viewed from above, and FIG. 2B is a diagram illustrating a flow of cooling air between fins.

3A is a diagram showing a developed velocity boundary layer on a fin along a flow of cooling air, and FIG. 3B is a diagram showing a change of the velocity boundary layer due to turbulent cooling air.

FIG. 4 is a plan view seen from above of a cooling device showing another embodiment of the present invention.

FIG. 5 is a plan view seen from above of a cooling device showing another embodiment of the present invention.

FIG. 6 is a perspective view of a cooling device showing a first conventional example.

FIG. 7 is a diagram showing a flow of cooling air between fins in FIG. 6;

FIG. 8 is a perspective view of a cooling device showing a second conventional example.

FIG. 9 is a perspective view of a cooling device showing a second other conventional example.

[Explanation of symbols]

1: the heating element 2: heat - sink 21: Metal substrate 22: Fin 220: fins (flat plate) 221: fin (bent shape) 3: Cooling Fan A: cooling air B _V: velocity boundary layer

Claims (2)

[Claims] 1. A heat sink comprising: a metal substrate having a contact surface with a heat radiating portion of a heating element; and a plurality of plate-like fins made of metal fixed to the metal substrate and arranged in rows. A cooling device that forcibly circulates fluid from one fin to the other between the fins and radiates heat of the heating element, wherein the plurality of fins are continuous in a wavy shape in a fluid flowing direction. A cooling device having a bent shape. 2. The plurality of fins are arranged in a zigzag or C-shape formed so that adjacent intervals repeatedly change in the direction of fluid flow. The cooling device according to claim 1.