JPH0638546A - Forcedly-air-cooled inverter apparatus - Google Patents

Abstract

PURPOSE:To provide a low-cost inverter apparatus having the structure of cooling fins to make the number of fan minimum. CONSTITUTION:In the radiation fins of a forced-air-cooled inverter, the height of both side-end ribs 6 is the same on air-inflow side and air-discharge side, and the height of inside ribs 5 other than the side-end ribs 6 on the air-inflow side is lower than that on the air-discharge side. As a result, a negative pressure is generated in the rib part without cooling fan 3 on the air-discharge side and forced air by the cooling fan 3 flows the whole rib part so that a cooling efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device,
In particular, the present invention relates to a forced air cooling type inverter device in which a cooling fan for forced air cooling is incorporated in a fin.

[0002]

2. Description of the Related Art Conventionally, a forced air cooling type inverter device in which a cooling fan for forced air cooling is incorporated in fins generally adopts the cooling fin shape and the cooling fan arrangement method shown in FIGS. Was there. In these figures, 1 is a cooling fin, 2 is a rib of the cooling fin, and 3 is a cooling fan.

FIG. 9 shows a so-called rectification method in which the ribs 2 of the cooling fins 1 are narrowed at the portion L1 in accordance with the width dimension L0 of the cooling fan 3.

FIG. 10 shows that the distance L2 between the cooling fan 3 and the rib 2 is at least equal to or larger than the diameter of the cooling fan 3.

FIG. 11 shows a method of providing a plurality of cooling fans 3.

Further, in the example of the cooling method for the inverter device of Japanese Patent Laid-Open No. 1-204498, a turbulent flow plate is provided on each of the base portions between the ribs to generate a turbulent flow to reduce the velocity boundary layer of the wind. The method of increasing the amount of heat radiation was used.

[0007]

In the prior art shown in FIG. 9, the size of the narrowed portion L1 of the rib for rectifying the wind is required. Further, in the conventional example of FIG. 10, the dimension of L2 is similarly required. Both of the conventional examples shown in FIGS. 9 and 10 have a drawback that the size of the entire cooling fin becomes large. Figure 1
In the conventional example of No. 1, since a plurality of cooling fans 3 are required so as to cover the entire air inflow portion of the rib 2, the number of parts, the number of wiring steps, the cost, and the reliability are lowered. Etc. and the amount of heat generation that does not require a plurality of fans is not effective. In Japanese Patent Laid-Open No. 1-204498, it is premised that the airflow of the fan is flowing in all the flow paths, so a plurality of fans are required to cover the entire area of the inflow part of the airflow. In addition to the same drawbacks as in FIG. 11, it was necessary to install a turbulent flow plate.

An object of the present invention is to improve the cooling efficiency by allowing the fan flow also in the natural convection portion where the fan air flow does not flow in the conventional cooling structure, and to reduce the size of the entire cooling fin. is there. Still another object is to provide a small-sized inverter device having a cooling fin which is inexpensive and has a high cooling efficiency without installing a plurality of fans.

[0009]

The ribs on the inside excluding the ribs on both ends of the cooling fin have a shape in which the height of the rib on the wind outflow side is lower than the height of the rib on the wind inflow side.

[0010]

[Function] By making the height of the rib different between the inflow side and the outflow side of the wind, negative pressure is generated on the outflow side of the rib not facing the cooling fan, and the conventional cooling fin causes natural convection. Even in the both side flow paths, the flow of the wind by the cooling fan becomes the forced wind, and the wind flow becomes even faster than the wind speed during natural convection. As a result, forced air flows over the entire surface of the cooling fin to improve the cooling performance.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.

Reference numeral 3 denotes a cooling fan, and 4 denotes an entire cooling fin. Reference numeral 5 is a rib inside the cooling fin 4, and 6 is an outside rib.

When the component mounting surface 7 of the cooling fin 4 has a heating element and is forcedly cooled by the cooling fan 3, cooling fins having parallel ribs are used, and the rib 5 is used to reduce the size of the cooling fin. It is conceivable to adopt a method that does not take an extra distance L1 or L2 between the cooling fan 3 and the cooling fan 3. However, in this case, when the number of cooling fins is one, the ribs within the width of the cooling fan 3 have a large flow rate of air flow, so that the cooling performance is good. There is a problem that the cooling performance deteriorates because the wind does not flow and it becomes the same as in the case of natural air cooling.

Therefore, in the embodiment shown in FIG. 1, the ribs of the cooling fins are inclined to the inner ribs 5 excluding the ribs 6 on both sides, so that the air can be sent to the areas where the air from the fans on both sides does not flow. I have to.

FIG. 2 shows a side view of the fin shape shown in FIG. FIG. 3 is a view on arrow A in FIG. A description will be given with reference to FIGS. As shown in the figure, only the ribs 6 on both side ends are parallel fins, and by sloping all of the inner ribs 5 as shown by the broken line, the region of interference with other flow passages becomes wider toward the air discharge side. . For this reason, negative pressure is generated on the air discharge side of the rib portion outside the width of the cooling fan 3, and the flow of the wind portion of the rib portion outside the width of the cooling fan 3 is promoted.
In this way, in the parallel fins, the wind is forcibly flown even in the region where the fan does not flow, the region in which the wind of the cooling fan 3 flows is expanded, and the cooling efficiency is improved. Therefore, the heat dissipation area for suppressing the same temperature rise as in the conventional case can be made smaller than that of the parallel fin, and the cooling fin can be made small. Further, since the negative pressure is generated by the cooling fan 3 on the air discharge side of the rib portion outside the width of the cooling fan 3, the air inflow portion of the inner rib portion outside the width of the cooling fan 3 is shown in FIG. As described above, the cooling effect can be improved by extending the cooling fan 3 to a surface substantially the same as the air inflow surface.

The effect of the present invention will be described based on the measured data shown in FIGS. 4 to 6 and Table 1. FIG. 4 shows the shape of a conventional parallel rib (a view seen from the direction corresponding to the arrow A in FIG. 2) and the measured value of the wind speed corresponding thereto. FIG. 4 shows that the fan is divided into a part where the wind is flowing and a part where almost no air is flowing. The fact that the center of the wind speed is deviated from the center of the cooling fan is due to the influence of the rotation direction of the fan.

FIG. 5 shows the rib shape according to the present invention (corresponding to the view in the direction of arrow A in FIG. 2) and the actual measurement value of the wind speed in the same manner as in FIG. As an effect of the present invention, it can be seen that the wind of the cooling fan 3 also flows in the flow passages on both sides and flows in all the flow passages. Therefore, the cooling performance is improved as compared with the case of only natural convection. Also in this case, the center of the wind speed is deviated from the center of the cooling fan.

FIG. 6 shows cooling fin shapes and temperature measurement points (a) to (d) for comparing the effects of the present invention. Reference numerals 8 and 9 denote heating elements to be cooled of the main circuit components of the inverter device. Table 1 shows the test results. According to the actual measurement results, the rib shape of the embodiment of the present invention reduces the temperature rise by about 3 ° C to 5 ° C. As a result, it was demonstrated that the cooling effect was further enhanced by the fact that the air flowed through the flow path where the forced air cooling did not flow until now.

As shown in FIGS. 7 and 8, since the center of the wind speed is deviated from the center of the cooling fan, the cooling fan may be installed so as to deviate from the center of the heating element.

Further, by forming the fin portion by the integral shaping by aluminum die casting, it is possible to use a single fan and obtain an inverter device having a small and inexpensive cooling fin. FIG. 7 is a perspective view showing an arrangement of a cooling device portion of an inverter device integrally molded by aluminum die casting.

FIG. 8 shows another embodiment of the present invention, showing an inner rib shape (the outer rib 6 is omitted in the drawing). Instead of inclining the inner ribs,
The inner ribs are all cut out as shown in the figure to the extent that a negative pressure is generated on the air discharge side of the ribs outside the width of the cooling fan. Even in this case, on the discharge side of the wind, interference occurs between the other flow passages, a negative pressure is similarly generated in the rib portion outside the width of the cooling fan 3, and the wind is forced to flow. is there. The air inlets of the inner ribs of the cooling fan that do not face each other do not need to be cut out as shown in the figure.

According to the above-described embodiment, among the device in which it is necessary to bring the ribs of the cooling fan and the cooling fin close to each other in order to reduce the size of the device, and the heating element mounted on the cooling fin, It is particularly effective for a cooling method for effectively cooling the heating element installed in a portion of the cooling fan that is less affected by the wind.

According to the present invention, even if the cooling fin is large and a plurality of cooling fans need to be provided, it is not necessary to provide the cooling fan over the entire rib area. Even if the cooling fans are sparsely provided, the negative pressure effect on the exhaust side of the wind causes the air to forcibly flow to the rib portion where the cooling fan is not provided. Therefore, the number of cooling fans can be reduced.

[0024]

According to the present invention, the flow of the fan is generated in the natural convection part where the air of the fan does not flow in the conventional cooling structure, the cooling efficiency is improved, and the size of the entire cooling fin is reduced. There is an effect that can be. Further, there is an effect that it is possible to provide a small-sized inverter device having an inexpensive cooling device with good cooling efficiency by using only one fan.

[Brief description of drawings]

FIG. 1 is a view showing an outer shape of an embodiment of a cooling fin according to the present invention.

FIG. 2 is a side view of the cooling fin of the embodiment of FIG. 1 according to the present invention.

FIG. 3 is a view on arrow A of FIG. 2 according to the present invention.

FIG. 4 is a diagram showing an example of measured values of wind speed in a conventional parallel fin.

5 is a diagram showing an example of actually measured wind speeds in the cooling fin of the embodiment of FIG. 1 according to the present invention.

FIG. 6 is a diagram showing temperature test measurement points of an example according to the present invention.

FIG. 7 is a view showing another embodiment integrally formed by aluminum die casting according to the present invention.

FIG. 8 is a diagram showing another embodiment according to the present invention.

FIG. 9 is a view showing an external view of a conventional cooling fin.

FIG. 10 is a view showing an external view of a conventional cooling fin.

FIG. 11 is a view showing an external view of a conventional cooling fin.

Table 1 shows the temperature test results of one example of the present invention.

[Explanation of symbols]

1 ... Cooling fin, 2 ... Rib, 3 ... Cooling fan, 4
... Cooling fins, 5 ... Inner ribs, 6 ... Side end ribs, 7
... Component mounting surface, 8 ... Heating element, 9 ... Heating element.

Claims (4)

[Claims] 1. A forced air-cooling type inverter device having a cooling fan and cooling fins having heat radiating ribs, wherein the heat radiating ribs provided at both ends are substantially constant in height from a wind inflow side to a wind outflow side. A forced air-cooled inverter device, which is a rib, wherein the height of the heat dissipation rib provided inside the side end rib is lower than the height of the side end rib at least on the air outflow side. . 2. The forced air-cooled inverter device according to claim 1, wherein the heat radiation rib and the cooling fan are mounted in close contact with each other. 3. A forced air cooling type inverter device comprising a cooling fan and a cooling fin having a heat radiating rib, wherein the heat radiating ribs provided at both ends are substantially constant in height from a wind inflow side to a wind outflow side. The heat dissipation rib provided inside the side end rib is an inner rib whose height is substantially the same as that of the side end rib on the air inflow side and whose air outflow side is lower than the air inflow side. A forced air-cooled inverter device characterized in that 4. The forced air-cooled inverter device according to claim 3, wherein the height of the inner rib gradually decreases from the air inflow side to the air outflow side.