JP2001102504A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device which can effectively allow heat generated by a power module to escape. SOLUTION: This device is related to performance improvement for a control device which is provided with warped fins 4a and 4b provided in a radial state by standing and with cooling parts 8a and 8b forming spaces 5a and 5b, which are enclosed by internal terminals of each said fins 4a and 4b, provided on a single surface of a heat sink base 1. Through this means virtual cooling performance for the heat generated by the power module 7 is improved, and the cooling performance for a same volume as a heat sink device 7 is improved significantly. Additionally, air flow which deviates near a fin base surface is moved to the upper of the fins 4a and 4b and a flow velocity distribution between fins is equalized, so that a heat conductive area is maintained effectively over the whole height direction and the cooling performance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for driving a servomotor used for a machine tool or an industrial robot, and more particularly to a control device capable of efficiently releasing heat from a power module. It is about.

[0002]

2. Description of the Related Art FIG. 12 shows a heat sink device used in a conventional control device. FIG.
No. 49700, a conventional heat sink,
Heat sink base 21 and heat sink base 2
A drive motor 22 directly fixed to the drive motor 1;
An axial fan 23 rotating more than 2 and fins 24 having a uniform thickness and directly surrounding at least a part of the side surface of the fan and surrounding the fan 23 are provided. In this conventional example, while the airflow driven by the fan 23 passes through the air path formed by the adjacent fins 24, heat exchange is performed between the fins 24 and the heat sink base 21 is cooled.

According to the conventional example described in Japanese Patent Application Laid-Open No. 9-254214, the heat sink of the control device is housed in a casing which also serves as a duct, so that the number of fans to be installed can be reduced and the size of the device can be reduced. It is planned. According to this, a heat sink, a servo amplifier fixed to the heat sink, a drive motor, a fan,
It is composed of a casing, and the casing also serves as a duct having an air intake and an air exhaust.

Further, Japanese Patent Application Laid-Open No.
Japanese Patent Publication No. 1770 proposes a high-efficiency cooling device having a plurality of curved radiating fins arranged radially and having a blower fan facing a blower opening surrounded by an inner end surface of the fins.

[0005]

According to the conventional example shown in FIG. 12, the airflow driven by the fan 23 is deflected in the direction along the heat sink base surface after colliding with the heat sink base 21 immediately below the fan. However, since the gas flows away toward the end of the heat sink base, there is a problem that the airflow does not basically occur immediately below the motor disposed in the center portion of the fan 24, and the cooling performance in this portion cannot be secured. Was.

Further, when the air flow collides with the heat sink base 21 and is deflected, the air flow contracts toward the heat sink base surface side due to the action of the centrifugal force to increase the speed, thereby reducing the substantial air flow passage cross section. Therefore, considering the flow velocity distribution in the height direction among the air paths surrounded by the fins 24 in FIG. 12, the air flow actually exists only in the vicinity of the heat sink base 21, and the substantial heat transfer area is small. . Therefore, even if the height of the fins 24 is increased, the substantial heat transfer area cannot be increased, and there is a problem that the performance improvement is limited.

[0007] In order to increase the substantial surface area, the number of fins is increased, or the thickness of the fins is increased to relatively reduce the width of the air path and increase the frictional drag. Can be considered,
There is a limit because the number of fins is limited because dust or the like existing in the use environment may accumulate on the fin surface and block the air passage between the fins. Further, if the width of the air passage is reduced uniformly, the pressure loss becomes large as a whole, and the air volume is reduced. As a result, satisfactory performance cannot be obtained.

Further, when the number of fins is increased, there is a limitation in manufacturing. That is, the heat sink is generally manufactured by die casting or brazing, but a die casting method is used for inexpensive manufacturing. However, as is well known, the die casting method is performed by injecting a molten aluminum into a mold, so that the number of fins increases, that is, when the fin pitch becomes narrow, the pitch of the mold also becomes narrow, and the thickness of the mold becomes thin. Become. As a result, there is a problem that the mold is damaged by the heat cycle by the molten aluminum, and the production cost is greatly increased, and the advantage of die casting is lost.

Further, according to the conventional example shown in FIG. 12, although the number of motor fans installed is reduced, it is necessary to increase the surface area of the fins in order to increase the amount of heat radiation in response to the increase in the amount of heat generated by the power module. As a result, the fin height is increased, and it has not been possible to sufficiently meet the demand for miniaturization.

[0010] The present invention has been made in view of the above problems, and has as its object to provide a control device capable of efficiently releasing heat generated by a power module.

[0011]

According to the present invention, there is provided a control device comprising: a power module; a heat sink base adjacent to the power module on a back surface thereof; and a plurality of fans disposed opposite to a surface of the heat sink base.
And a plurality of fins erected on the surface of the heat sink base so that the plurality of fans on the surface of the heat sink base extend while curving from positions facing each other.

The position on the surface of the heat sink base where the plurality of fans face each other deviates from the region where the temperature becomes maximum when the power module on the surface of the heat sink base is operated alone.

[0013] Further, a partition plate extending from an edge of each suction port of the plurality of fans and covering the plurality of fins is provided.

The rotation direction of a pair of adjacent fans among the plurality of fans is opposite to each other, and the plurality of fins are opposite to each other from the position on the heat sink base surface where the pair of fans face each other. It extends while bending.

A fin extending from a position where one of a pair of adjacent fans of the plurality of fans faces the heat sink base surface, and a fin extending from a position where the other of the pair of fans faces the heat sink base surface. The fins for rectification are provided between the fins.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a schematic diagram illustrating a control device according to a first embodiment of the present invention.
FIG. 1A is a schematic cross-sectional view of the control device, and FIG. 1B shows the control device with the fans 3a and 3b and the motors 2a and 2b removed for convenience of explanation.
FIG. 3 is a schematic plan view seen from a side opposite to a side on which the power module 7 is mounted.

In this embodiment, fins 4a, 4 and spaces 5a, 5
b, a pair of cooling units 8a and 8b
Fans 3a, 3b and motors 2a, 2b are provided opposite to the respective cooling units 8a, 8b, and the power module 7 is directly or thermally mounted on the opposite side of the heat sink base 1 from the cooling units 8a, 8b. It is fixed via conductive grease (not shown).

Here, the fins 4a, 4b are respectively curved and erected radially, and the spaces 5a, 5b surrounded by the ends of the inner surfaces of the fins 4a, 4b are provided at the center of the cooling portions 8a, 8b. Are formed. The cooling units 8a and 8b, which are composed of the fins 4a and 4b and the spaces 5a and 5b, which are erected radially, are arranged side by side with a gap of about 10 mm therebetween.

Next, the operation will be described. Fan 3a,
The airflow blown out from 3b collides with the heat sink base 1 immediately below the fan, changes its direction, flows in from the inner periphery between the fins, and flows toward the outer periphery. At this time, since the air flows directionally in the rotation direction of the motors 2a and 2b, the air is not radially directed to the central axes of the motors 2a and 2b so that the air can be guided without resistance. It is deflected as shown in FIG.

Further, the airflow blown out from the fans 3a, 3b basically flows outward at the fin outlets along the curved fins 4a, 4b, but is adjacent to the cooling portions 8a, 8b. On the side where the air flows from the cooling units 8b and 8a collide, a region without the fins 4a and 4b is provided between the juxtaposed cooling units 8a and 8b as described above. Therefore, the airflow escapes sideways.

Next, the heat radiation characteristics of the cooling units 8a and 8b will be described. As described above, first, the airflow collides with the heat sink base 1 immediately below the fan, so that the heat sink takes away nearly 100 W / m ² K of heat from the heat sink base 1 here. After colliding with the heat sink base 1, the airflow collides with the inner surface end of the fin toward the fin side, again at 100 W / m ² K.
Can take away a degree of heat. Furthermore, the airflow is fin 4
a, and heat of about several tens of W / m ² K can be taken from the fin side surface and the heat sink base 1. In addition, since the airflow does not flow directly under the motor, the heat radiation characteristic is extremely deteriorated as compared with other parts.

As described above, it has been clarified that the heat radiation characteristics differ depending on the positions of the cooling units 8a and 8b. In particular, when the heat radiation structure having a high heat generation density such as the power module 7 and directly below the semiconductor chip affects a transient temperature rise of the semiconductor chip, the relative arrangement of the cooling units 8a and 8b with respect to the power module 7 is limited. By
The destruction of the semiconductor chip 7 can be prevented.

Hereinafter, the relative positional relationship between the cooling unit and the power module will be described in detail. As shown in FIG.
When the power module is operated alone, the temperature in the central portion becomes higher than that in the peripheral portion, resulting in a mountain-shaped temperature distribution shape. Here, FIG. 2 is a graph showing the temperature distribution with respect to the position of the power module.

Although the temperature is lowered by fixing the cooling portion, the cooling efficiency of the portion located in the space region of the cooling portion is poor. Therefore, when the center portion of the power module and the center portion of the cooling portion are substantially matched, the most. The part to be cooled is a space area immediately below the motor, and only the central part of the power module may overheat and exceed the operating temperature, which is a problem.

However, by arranging two cooling parts near the area where the temperature of the power module reaches the maximum, and arranging a part having good heat radiation efficiency, that is, the end of the inner surface of the fan in the cooling part, it is possible to achieve a uniform temperature. Hopefully the above problem can be solved. Here, two fans and two motors are required. However, since an inexpensive smaller fan having a small air volume can be used, this does not pose a major industrial problem.

In FIG. 1, the fans 3a, 3b are provided so as to face substantially the centers of the cooling portions 8a, 8b, and the fins 4a, 4b are formed so that spaces 5a, 5b are formed thereunder.
, But as shown in FIG.
b may be provided not at the center of the cooling units 8c and 8d but at a deviated position. In particular, the power module 7 includes a cooling unit 8c,
If the power module 7 is larger than 8d, as shown in FIG. 3, the fan 3 is mounted so that the power module 7 is attached to the rear surface of the fins 4c, 4d corresponding to the inner surface ends.
The cooling performance is further improved by symmetrically displacing the mounting positions of a and 3b outward. In FIG. 3B, for convenience of description, a schematic plan view is shown with the fans 3a and 3b and the motors 2a and 2b removed.

Further, in FIG. 1A showing the present embodiment, the fans 3a and 3b are installed further above the uppermost portions of the fins 4a and 4b, but as shown in FIG. It goes without saying that the same effect can be obtained even if the vertical position of the surface of the fan 3a facing the heat sink base 1 is lower than the uppermost position of the fin 4a. Further, the present invention is not limited to the method of installing the fans shown in FIGS. 1 and 2, and the fan 3a may be provided to be inclined with respect to the heat sink base 1 as shown in FIG.
Further, as described above, it is needless to say that three or more cooling units may be provided, instead of the structure in which two cooling units are provided on the heat sink base.

In the first embodiment, no particular restrictions are imposed on the fin shape and the thickness of the heat sink base. However, as described in the following second to fifth embodiments, the fin shape and the heat sink base By restricting the thickness of the air passage, the air flow can also flow above the air passage, and therefore, the flow velocity distribution in the air passage becomes uniform, so that the cooling performance can be improved. Hereinafter, restrictions on the fin shape and the thickness of the heat sink base for further improving the cooling performance will be sequentially described in Embodiments 2 to 5.

Embodiment 2 FIG. 5 is a schematic sectional view showing a fin shape according to the second embodiment. FIG. 5A shows the shape of the fin on the inner peripheral side (that is, the upstream side of the air path).
(B) shows the fin shape on the outer peripheral side (that is, the downstream side of the air path). The present embodiment is the same as the first embodiment except for the fin shape.

In the present embodiment, the thickness of the fin 4 decreases linearly as the distance from the heat sink base increases. In addition, the ratio of the fin thickness between the tip and the bottom of the fin changes toward the outer periphery, and the thickness of the bottom of the fin becomes larger on the outer periphery.

More specifically, the relationship between the air path width dt ₁ at the uppermost part of the fin on the inner peripheral side and the air path width db _{1 at} the lowermost part of the fin is dt ₁ > 1.5 × db ₁ , and the fin on the outer peripheral side and satisfies the condition dt _2> 1.5 × db ₂ also the relationship between the top of the air passage width dt ₂ and the fins at the bottom of the air passage width db _2. In this embodiment, the fin length is 70 mm and the fin height is 30 m
m, the average wind speed of the fin-to-fin air path is 4 m / s at the most downstream position,
The maximum value of the width of the air passage between the fins at the most downstream position is 5 mm.

At this time, the width of the air path formed between the adjacent fins increases in accordance with the vertical distance from the heat sink base 1 and dt ₁ / db _{1 in} the direction along the air path.
And the enlargement ratio such as dt ₂ / db ₂ increases as the distance from the inner end of the fin on the upstream side increases.

Next, the operation will be described. The airflow blown from the fan collides with the heat sink base immediately below the fan, changes its direction, flows in from the inner peripheral portion between the fins, and flows toward the outer periphery. In the prior art, the wind speed distribution along the fin height direction of the airflow flowing toward the outer periphery is locally high near the heat sink base, but in the present embodiment, the inter-fin air path is as described above. Since the width is narrower at the bottom and wider at the tip, and the ratio of the width between the bottom and the tip of the air passage toward the outer periphery increases toward the downstream, the fluid resistance due to the frictional force generated on the fin side surface is The airflow concentrated near the narrow bottom increased, and the airflow concentrated near the bottom diffused in the fin height direction in the fin-to-fin air passage, and the wind speed near the heat sink bottom decreased and the wind speed near the heat sink tip increased. And the wind speed distribution becomes uniform.

Further, even if dust existing in the use environment accumulates on the fin surface and the inter-fin air passage is closed, an air passage is secured above the fin, and the air flow bypasses the upper air passage. At the downstream of the flow, it spreads again over the entire fin and flows.

Since the present embodiment is configured as described above, the airflow that has been deviated near the heat sink base surface in the airflow path between the fins is also diffused and supplied above the fins, and the wind speed distribution between the fins becomes uniform. Since the heat transfer area is effectively secured throughout the height direction of the fins, the cooling performance is substantially improved, and the cooling performance of the heat sink having the same volume is significantly improved. In addition, an air path that bypasses the air path due to dust accumulation is ensured, and the degree of performance degradation is small.

In the present embodiment, the relationship between the air path width dt at the top of the fin and the air path width db at the bottom of the fin is as follows.
It is set so as to satisfy the condition of dt> 1.5 × db, but it is appropriate according to the conditions such as the fin height, the average value of the inter-fin air passage width, the average value of the inter-fin wind speed, and the air passage length. Needless to say, the range of values varies.

Embodiment 3 FIG. 6 is a schematic diagram of one cooling unit according to the third embodiment. FIG. 6A is a plan view, and FIG. 6B is an enlarged perspective view of the cooling unit viewed from above the side surface. As shown in the figure, as means for expanding the air path width in accordance with the vertical distance from the heat sink base, the number of fins is increased from the upstream side along the air path to the downstream side, and the fin height from the heat sink base is increased. The fins are changed for each fin. The present embodiment is the same as the first embodiment except for the fin shape.

In the present embodiment, the fins have two heights, and the fins 40 having a high height and the fins 41 having a short height are alternately provided. In addition, the length toward the outer periphery of the fin is set so that the tall fin 40 is longer than the short fin 41. As in the second embodiment,
The fin thickness is set to decrease linearly as the distance from the heat sink base increases, and the air passage width is set to be smaller near the fin bottom than at the fin tip.

Next, the operation will be described. The airflow flowing through the air passage between the fins is smaller on the inner peripheral side as the air passage width due to the linear change in the fin thickness is closer to the fin bottom,
As shown in the second embodiment, the wind speed distribution in the fin height direction is improved. Furthermore, on the outer peripheral side, the short fins 4
1 is additionally provided, the resistance is large at a position near the heat sink base where the number of fins is large in the air path, and the air flow is reduced. The air volume increases at the top of the fin with a wide inter-wind path.

Since the present embodiment is configured as described above, the airflow that has been biased in the vicinity of the heat sink base surface moves above the fins, and the wind speed distribution between the fins becomes uniform. Since the heat transfer area is effectively ensured over the entire area, the cooling performance is substantially improved, and the cooling performance with the same volume is significantly improved.

In this embodiment, the fins have two kinds of heights, but fins having a plurality of kinds of heights may be alternately provided as needed. Further, in the embodiment of the present embodiment, in order to make the distribution of the cross-sectional area of the air path in the fin height direction close to a constant value from the inner peripheral side to the outer peripheral side, the short fin 41 having a constant height is provided on the inner peripheral side (ie, Although a method of providing the fin 41 only on the outer peripheral side (downstream side) without providing it on the upstream side) is adopted, by gradually increasing the height of the increased fin 41 from the inner peripheral side to the outer peripheral side, Further, it may be provided from the inner peripheral side.

Embodiment 4 FIG. 7 is a schematic cross-sectional view illustrating the shape of a heat sink base in one cooling unit according to the fourth embodiment. In the present embodiment, a substantially conical wind guiding slope 90 is provided by increasing the thickness of the heat sink base immediately below the fan. still,
The present embodiment is the same as Embodiment 1 except for the fin shape.

Next, the operation will be described. The airflow from the fan 3 toward the heat sink base 1 is a conical wind guiding slope 9.
It flows from the inner peripheral part of the flow fin along 0 and is introduced into the air passage between the fins. At this time, since the airflow is pushed to the outer peripheral side by the wind guide slope 90, the velocity vector flowing toward the outer circumference is formed more upstream, and the airflow to the upper part of the fin 4 is higher than the case where the wind guide slope 90 is not provided. Is promoted.

Since the present embodiment is configured as described above, the airflow that has been biased in the vicinity of the heat sink base surface moves above the fins 4 so that the wind speed distribution between the fins becomes uniform, and the height of the fins 4 increases. Since the heat transfer area is effectively secured over the entire height direction, there is an effect that the cooling performance is substantially improved and the cooling performance with the same volume is significantly improved.

In addition, the thickness of the heat sink base 1 without the fins 4 immediately below the fan 3 increases, so that the heat sink base surface is moved from the rear surface to the power module 7.
Even if the heat is locally heated by the heat sink base, the heat sink base has a large thickness, so that the heat conductivity in the direction along the heat sink base becomes good, and the heat is efficiently diffused to the region where the surrounding fins 4 exist. This has the effect that it is difficult to cause a significant temperature rise.

Embodiment 5 FIG. FIG. 8A is a schematic cross-sectional view showing the shape of a heat sink base in one cooling unit according to the fifth embodiment. In the present embodiment, an enclosed slope 91 having a substantially truncated cone shape is formed directly below the drive motor 2 of the fan 3 in the heat sink base 1, and the thickness of the heat sink base 1 at the bottom of the truncated cone-shaped projection 91. The thickness is configured to decrease stepwise toward the outer peripheral portion. The present embodiment is the same as the first embodiment except for the fin shape.

Since the present embodiment is configured as described above, the airflow that has been deflected near the heat sink base surface moves above the fins, the wind speed distribution between the fins becomes uniform, and the entire fin height direction is increased. Since the heat transfer area is effectively ensured over the entire area, the cooling performance is substantially improved, and the cooling performance with the same volume is significantly improved. Further, there is an effect that the problem that the airflow from the fan is caught immediately below the motor to generate a vortex and the characteristics of the fan are deteriorated and the air volume is reduced does not occur.

In addition, due to the structure in which the thickness of the heat sink base gradually decreases from the center of the heat sink toward the outer peripheral portion, heat is easily conducted toward the outer peripheral portion where a large number of fins 4 are provided. This has the effect of further improving the heat radiation performance in the area where the wind does not hit the part. Needless to say, the thickness of the heat sink base 1 is increased in accordance with an increase in the amount of heat to be cooled.

In the present embodiment, the thickness of the heat sink base is changed in a stepwise manner.
It goes without saying that the thickness may be reduced in a polygonal line as shown in FIG.

Also, as shown in the first embodiment, when there are a plurality of cooling units, when manufacturing the heat sink device by the die casting method, the conical shape or the conical shape as in the fourth and fifth embodiments is used. Trapezoidal projections 90, 91, 92
Is effective in improving productivity. That is, when the heat sink base 1 starts to coagulate and contract in the die casting process, fins and other protrusions prevent the contraction. When the heat sink base 1 starts to cool, the fins are firmly fixed to the mold.
At this time, projections 90 and 9 having a conical shape or a truncated cone shape
By forming 1, 92 at the center of the cooling portions 8a, 8b, the contraction force of the heat sink base acts as a normal force to the slope of the projection, and as a result, the fin receives the force separating from the mold and receives heat. The base 1 can be easily released from the mold without distortion. In order to facilitate release from the mold, it is preferable that the angle between the inclined surface and the heat sink base is 85 degrees or less.

Embodiment 6 FIG. FIG. 9 is a schematic diagram showing a control device according to the sixth embodiment of the present invention. FIG. 9 (a)
FIG. 9 is a schematic cross-sectional view showing the control device, and FIG. 9B is a schematic plan view thereof. In the present embodiment, partition plates are fixed to the suction ports of the fans. Other points are the same as those of the first embodiment except for the number of cooling units.

Next, the operation will be described. Fan 3a ~
The airflow blown out from 3c collides with the heat sink base 1 immediately below the fan, changes the direction, flows in from the inner periphery between the fins, and flows toward the outer periphery, similarly to the other embodiments. At this time, since the fin shape is set so that the air flow is diffused to the upper part of the fins 4a to 4c on the outer peripheral side, the partition plates 9a to 9c are formed.
c can prevent the air flow from excessively diffusing and the wind speed from decreasing.

Further, by using the partition plates 9a to 9c, the air heated by heat exchange goes around to the upper part,
It is possible to prevent the air from being sucked in again from the suction port of the fan and the temperature of the air rising to lower the heat exchange efficiency.

Air flows from the cooling units 8a to 8c arranged side by side along the fins 4a to 4c, but one side between the cooling units generates an air flow collision as described in the first embodiment. Therefore, in addition to a flow parallel to the heat sink base 1, an upward airflow is generated. The partition plates 9a to 9c can prevent the raised airflow from being sucked into the suction port of the fan, and as a result, a reduction in cooling efficiency can be prevented.

Embodiment 7 FIG. FIG. 10 is a schematic plan view showing an arrangement of fins in a cooling unit according to the seventh embodiment. This embodiment is the same as Embodiment 1 except for the arrangement of the fins and the rotation direction of the motor. Note that FIG. 10 illustrates a state in which the fans 3a and 3b and the motors 2a and 2b are removed for convenience of explanation.

As shown in FIG. 1, in the first embodiment, the bending directions of the fins are the same, but in the present embodiment, as shown in FIG. By reversing the direction of rotation of the fan drive motor and the direction of rotation of the fan at the same time, the flow of air flows in adjacent sides becomes the same direction, so that pressure loss can be suppressed and high cooling performance can be secured.

Embodiment 8 FIG. FIG. 11 is a schematic plan view showing a control device according to the eighth embodiment. In FIG. 11, for convenience of explanation, the fans 3a and 3b and the motor 2
a and 2b are removed.

In the present embodiment, the rectifying fins 10 are provided between the cooling units as shown in FIG.
, The air flow coming out of the curved fins collides with the rectifying fins. In particular, when the rectifying fins are made of a material having good heat conduction similar to that of the heat sink base, efficient heat transfer can be achieved. As a result, the power module can be more uniformly heated. Needless to say, even when the drive motors are in the same rotational direction, the rectifying fins also have a heat radiation effect due to airflow collision.

[0059]

According to the present invention, there is provided a control device comprising: a power module; a heat sink base adjacent to the power module on the back surface; a plurality of fans installed facing the surface of the heat sink base; And a plurality of fins erected on the surface of the heat sink base so that the plurality of fans extend while curving from the opposing positions, so that the temperature distribution in the power module becomes small, Is cooled well, and the performance of the power module can be sufficiently exhibited.

Further, the position where the plurality of fans face each other on the heat sink base surface is out of the region where the temperature of the heat sink base surface reaches the maximum temperature when the power module is operated alone. This has the effect of cooling.

Further, since a partition plate extending from the edge of each suction port of the plurality of fans and covering the plurality of fins is provided, an airflow whose temperature has increased due to heat exchange is sucked again from the fan suction port. This has the effect that the cooling efficiency can be prevented from lowering.

The rotation direction of a pair of adjacent fans among the plurality of fans is opposite to each other, and the plurality of fins are opposite to each other from the position on the heat sink base surface where the pair of fans face each other. Since it extends while bending, the airflow of each other flows in the same direction,
Pressure loss can be suppressed and high cooling performance can be secured.

A fin extending from a position where one of a pair of adjacent fans of the plurality of fans faces the heat sink base surface, and a fin extending from a position where the other of the pair of fans faces the heat sink base surface. Since the rectifying fins are provided between the fins and the fins, high cooling performance can be secured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a first embodiment.

FIG. 2 is a schematic diagram illustrating an effect of the first embodiment.

FIG. 3 is another schematic diagram illustrating the first embodiment.

FIG. 4 is another schematic cross-sectional view illustrating the first embodiment.

FIG. 5 is a schematic sectional view of a fin according to a second embodiment.

FIG. 6 is a schematic diagram illustrating a third embodiment.

FIG. 7 is a schematic sectional view showing a fourth embodiment.

FIG. 8 is a schematic diagram illustrating a fifth embodiment.

FIG. 9 is a schematic diagram illustrating a sixth embodiment.

FIG. 10 is a schematic diagram illustrating a seventh embodiment.

FIG. 11 is a schematic diagram illustrating an eighth embodiment.

FIG. 12 is a schematic diagram illustrating a conventional example.

[Explanation of symbols]

1 heat sink base, 2a, 2b motor, 3, 3a, 3b, 3c fan, 4, 4a, 4
b, 4c, 4d fin, 5a, 5b, 5c, 5d space, 6 heat sink device, 7 power module,
8a, 8b, 8c, 8d Cooling unit, 9a, 9
b, 9c partition plate, 21 heat sink base,
22 motor, 23 fan, 24
Fins, 40 tall fins,
41 short fins, 90, 91, 92
Protrusions.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Hiroshi Chiba, 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsui Electric Co., Ltd. (72) Mitsuyasu Kachi 2-3-2, Marunouchi, Chiyoda-ku, Tokyo No. Mitsubishi Electric Corporation F-term (reference) 5F036 BB05

Claims (5)

[Claims] A power module, a heat sink base adjacent to the power module on the back surface, a plurality of fans installed facing the surface of the heat sink base, and a plurality of fans on the surface of the heat sink base. And a plurality of fins erected on the heat sink base surface so as to extend while bending from a position. 2. The heat sink base surface according to claim 2, wherein the position where the plurality of fans oppose each other is outside a region where the temperature rises to a maximum when the power module alone is operated on the heat sink base surface. 1
The control device as described. 3. The control device according to claim 1, further comprising a partition plate extending from an edge of each suction port of the plurality of fans and covering the plurality of fins. 4. A pair of adjacent fans among the plurality of fans have rotation directions opposite to each other, and a plurality of fins are arranged in opposite directions from positions on the heat sink base surface where the pair of fans face each other. The control device according to any one of claims 1 to 3, wherein the control device extends while being curved. 5. A fin extending from a position where one of a pair of adjacent fans of the plurality of fans faces the heat sink base surface, and a fin extending from a position where the other of the pair of fans faces the heat sink base surface. The control device according to any one of claims 1 to 4, wherein a rectifying fin is provided between the fin and the fin.