JP4943398B2 - Heat sink - Google Patents

Description

  The present invention relates to a heat radiating plate in which a plurality of radiating fins are formed on a base surface of a base substrate, and in particular, intersects with a rotating shaft of a rotating body so that the length direction of the radiating fins is directed to the rotating shaft of the rotating body. A heat dissipating plate that is attached to the surface and rotates with the rotating body, or a heat dissipating member that is attached to the peripheral surface of the rotating body so that the length direction of the heat dissipating fins is substantially parallel to the rotating shaft of the rotating body and rotates with the rotating body. The present invention relates to a plate and a rotating body to which one or both of these heat radiating plates are attached.

  Conventionally, in a rotating body 10 that rotates itself, such as a motor that rotationally drives a load such as a blower or a pump, or a motor coupling that transmits torque to the load 30 as shown in FIGS. In order to do this, there is a surface 16 intersecting with the rotating shaft of the rotating body, a side peripheral surface of the rotating body, or a cooling means such as a heat radiating plate 1 or heat radiating fins attached to both of them. Since the cooling means rotates together with the rotating body 10, when the diameter of the rotating body is large or the rotation speed is high, noise may be emitted from the cooling means, and it is an urgent issue to solve this. It has become.

  In particular, when a heat radiating plate is attached to the surface that intersects the rotating shaft of the rotating body so that the length direction of the radiating fin is directed to the rotating shaft of the rotating body, or the length direction of the radiating fin is substantially parallel to the rotating shaft of the rotating body. It is known that when a heat radiating plate is attached to the side peripheral surface of the rotating body, the noise generated by the rotation of the rotating body becomes larger. However, no technology has been developed so far to solve the above problem without impairing the cooling performance of the cooling means.

As a technique similar to this, Patent Document 1 discloses a technique for suppressing noise generated by a rotary drive machine (motor) used in a railway vehicle or the like.
This relates to a motor including a fan (groove) that generates wind in the radial direction when the rotor rotates and cooling means that includes cooling fins that receive wind blown from the fan and enhance the cooling effect inside the motor. Since the fins amplify the noise generated by the fan when the rotor rotates, the noise generated by the fan is suppressed by making the number of fans different from the number of fins.

However, although the technology is provided with cooling means on the surface that intersects the rotation axis of the rotating body, the fan is provided on the rotating rotor and the fins are provided on the non-rotating stator. The technology cannot be applied to a motor, a motor coupling, or the like provided with a cooling means that is attached to the body and rotates together with the rotating body. Similarly, the technique cannot be applied to cooling means such as a heat radiating plate or a heat radiating fin attached to the rotating body and rotating together with the rotating body.
JP 2003-324894 A

  The problem to be solved by the present invention is that a heat radiating plate which is attached to a surface intersecting with the rotating shaft of the rotating body so that the length direction of the radiating fin faces the rotating shaft of the rotating body and rotates together with the rotating body, or With respect to heat sinks that are attached to the side peripheral surface of the rotating body so that the length direction is substantially parallel to the rotating shaft of the rotating body and rotate together with the rotating body, without affecting the cooling performance originally provided by these heat sinks By providing a heat radiating plate that can be attached to the rotator and can suppress noise generated by rotating together with the rotator, and a quiet rotator equipped with one or both of these heat radiating plates. is there.

The present inventor has obtained the following technical knowledge as a result of various experimental studies and theoretical studies to solve the above problems.
(A) As shown in FIGS. 1 and 5, a heat radiating plate 1 in which a plurality of heat radiating fins 2 are formed in a substantially parallel shape on a base surface of a substrate 5 serving as a base, and the length direction of the heat radiating fins is a rotating body. If the rotating body 10 is rotated by being attached to the surface 16 that intersects the rotating shaft of the rotating body so as to face the rotating shaft 15 of the rotating body 15, it will inevitably be in a direction substantially perpendicular to the row of the radiating fins 2, in other words, in the width direction of the radiating fins. Air flows.
Similarly, the heat radiating plate 1 in which a plurality of heat radiating fins 2 are formed in a substantially parallel shape on the base surface of the base substrate 5 is arranged so that the length direction of the heat radiating fins is substantially parallel to the rotating shaft 15 of the rotating body. When the rotating body 10 is rotated by being attached to the side peripheral surface 17 of the rotating body, air inevitably flows in a direction substantially orthogonal to the rows of the radiation fins 2, in other words, in the width direction of the radiation fins.

  The main cause of the noise is that air column vibration is generated between the radiation fins 2 and 2 due to the air flowing in a direction substantially orthogonal to the rows of the radiation fins 2 in this way. is there. In addition, when the heights of all the radiation fins as shown in FIGS. 1 and 7 are the same, air column vibrations occur between all the radiation fins and the frequency of all the air column vibrations. Since this becomes the same, this becomes the dominant frequency and the noise becomes larger. Therefore, noise can be suppressed by suppressing the generation of air column vibrations or by dispersing the frequency of air column vibrations.

(B) As a method for suppressing the occurrence of air column vibrations, it is desirable to form slits 3 in the radiating fins 2 that penetrate the radiating fins in the width direction as shown in FIG. This is because by forming the slit 3, a part of the air flowing in the direction substantially orthogonal to the row of the radiating fins flows through the slit and the air flow is disturbed. Moreover, it is more desirable that the depth of the slit formed in the radiating fin is 2.5 mm or more.

(C) On the other hand, as a method for dispersing the frequency of the air column vibration, the height of all the radiation fins as shown in FIGS. It is desirable that the height is made different and the side surface shape of the heat sink is inclined. This is because the frequency of occurrence of air column vibration is determined by the height of the heat radiating fins, and therefore, if the height of the heat radiating fins is different and uneven, the frequency of air column vibration is dispersed. Moreover, as shown to FIGS. 13-14, it is more desirable to make the side surface shape of a heat sink into a mountain shape.

(D) And even if slits are formed in the radiating fins, or even if the radiating fins are formed to have different heights and the side surfaces of the radiating plates are inclined, the cooling performance of the radiating plates is originally provided. Has little effect.

Based on the above findings, the inventor is able to suppress the noise generated by rotating with the rotating body attached to the rotating body without affecting the cooling performance originally provided by the heat sink, And it came up with the rotary body which mounts the said heat sink. The gist is as follows.
(1) A heat radiating plate in which a plurality of plate-like radiating fins each having a thickness, height and length are formed on a base surface of a base substrate, and the thickness and height of the plate-like radiating fins. A heat radiating plate that is attached to a surface that intersects with the rotating shaft of the rotating body so that one surface of the surface is directed to the rotating shaft of the rotating body and rotates together with the rotating body, and is formed on the base surface of the base substrate A slit that penetrates the heat dissipating fin in the thickness direction is formed in a part or all of the heat dissipating fin , and the slit has a depth of 2.5 mm or more, an interval of 15 to 32 mm, and a width of 0.7 to 4 mm. Heat sink.

( 2 ) A heat radiating plate in which a plurality of plate-like radiating fins having a thickness, height and length are formed in a substantially parallel shape on the base surface of the base substrate, and the thickness and height of the plate-like radiating fins. A heat radiating plate that is attached to a surface that intersects with the rotating shaft of the rotating body so that one surface of the surface is directed to the rotating shaft of the rotating body and rotates together with the rotating body, and is formed on the base surface of the base substrate The heat radiating plate is characterized in that the heat radiating fins are formed so as to have different heights, and the side surface shape of the heat radiating plate as viewed from the surface composed of the thickness and height of the heat radiating fins is inclined.

( 3 ) The heat radiation plate according to ( 2 ), wherein the side surface of the heat radiation plate has a mountain shape.

( 4 ) A rotating body to which the radiator plate according to any one of (1) to ( 3 ) is attached.

  According to the heat radiating plate of the present invention, it is possible to suppress noise generated by being attached to the rotating body and rotating together with the rotating body without affecting the cooling performance that the heat radiating plate originally has. Moreover, since such a heat sink is attached to the rotating body according to the present invention, noise can be suppressed in the same manner as the heat sink according to the present invention.

Hereinafter, with reference to FIGS. 1 to 17 illustrating the best mode for carrying out the present invention.
FIG. 1 is a perspective view of a non-contact type motor coupling using a permanent magnet, which is an example of a rotating body 10 to which a heat radiating plate 1 according to the present invention is attached. As shown in the figure, the motor coupling includes a heat radiating plate 1 in which a plurality of heat radiating fins 2 are formed in a substantially parallel shape on a base surface of a substrate 5 serving as a base, and the length direction of the heat radiating fins is the motor cup. It is attached to a surface 16 that intersects the rotation axis of the motor coupling so as to face the direction of the rotation axis 15 of the ring, that is, the radial direction.
The substantially parallel shape includes a shape of a row extending radially from the rotary shaft 15 when attached to the surface 16 that intersects the rotary shaft of the rotating body, such as the heat sink shown in FIG. 7 to 10, and includes the case where adjacent radiating fins 2 are formed to be parallel to each other as in the radiating plate shown in FIGS.

  FIG. 2 is a schematic diagram showing the operation principle of the motor coupling. When the electric disk (conductor) 11 is rotated by the rotational driving force of the motor 20, an eddy current is generated in the electric disk (conductor) 11 and electromagnetic waves are generated. The force acts in the direction of rotating the permanent magnet disk (magnet rotor) 12 in the same direction as the rotation direction of the motor. Therefore, the load 30 side also rotates in the same direction as the motor 20.

  Since the motor coupling controls the transmission torque by expanding or contracting the gap 13 between the electric disk (conductor) 11 and the permanent magnet disk (magnet rotor) 12, the conventional motor and load are directly connected. Compared to contact type motor coupling, energy saving effect is high. Further, since the gap 13 absorbs vibrations and shocks, the transmission of vibrations and shocks is small, and wear and misalignment failures are also small. For this reason, in recent years, it has attracted attention as a new variable speed device.

  However, although it is a motor coupling having such excellent properties, as shown in FIGS. 1 and 2, the motor coupling also cools itself, so that the surface 16 intersecting with the rotating shaft 15, that is, the electric motor Since the heat sink 1 is attached to the outer peripheral surface of the disk 11, there is a problem that noise is emitted from the heat sink 1 when the motor coupling rotates.

  As described above, the noise is generated by cutting the air in the direction substantially orthogonal to the rows of the radiating fins, in other words, in the direction of rotation of the electric disk 11 (the direction of arrow A in FIG. 1). The main factor is the occurrence of air column vibration. This is because the inventor has estimated that the cause of noise generation is air column vibration, and as a result of performing a test to verify the estimation, the technical knowledge obtained by verifying that the estimation is correct It is.

In addition, it was estimated that the cause of noise generation was air column vibration, while the dominant frequency of noise emitted from motor coupling (hereinafter referred to as an actual machine) is 3550-5600 Hz, This is because the generation frequency f of the air column vibration calculated from the above coincides with 4525 Hz.
f = c / 4h
Here, c is the speed of sound and is calculated here as 362 m / s (at 50 ° C.). Further, h is the height of the heat radiating fin, and is calculated here as 20 mm.

Here, the air column vibration refers to a resonance phenomenon that occurs in the tube, and an example of the phenomenon is a phenomenon in which sound is produced by blowing the mouth of a bottle.
The dominant frequency is a frequency analysis of noise composed of various frequency components, when the sound pressure level at a specific frequency is extremely high compared to the sound pressure level at other frequencies. In this case, a specific frequency having a large sound pressure level is called a dominant frequency.

  Next, a verification method will be described. The verification method simulates the air flow received by the heat sink mounted on the actual machine when the actual machine is rotating by air blowing to the test heat sink using the air nozzle 40 as shown in FIG. This is to verify whether or not the dominant frequency generated when the height of the fin of the test heat sink is changed matches the calculated frequency of air column vibration. Note that the air blowing direction is a direction substantially orthogonal to the rows of the radiation fins, in other words, the width direction of the radiation fins, in order to simulate the flow of air received by the actual heat sink.

  The specifications of the test heat sink are shown in Table 1, and the results of the test are shown in FIG. The plot data in the figure is a measurement (measured value) of a sound pressure level generated when air blows toward a test heat sink with fin heights of 10, 20, and 30 mm. Moreover, the downward arrow in the figure indicates the frequency (calculated value) at which air column vibration occurs. From the figure, it can be confirmed that the peak frequency (dominant frequency) of the measured value and the calculated value almost coincide with each other for the heights of the three types of fins. In other words, it was possible to verify that the dominant frequency matches the frequency of air column vibration by changing the fin height of the test heat sink.

  The verification simulates the air flow received by the heat sink mounted on the actual machine when the actual machine is rotating, but the fin height of the heat sink mounted on the actual machine is 20 mm, and the actual machine Since the dominant frequency of the noise generated when rotating is 3550 to 5600 Hz, the dominant frequency substantially coincides with the dominant frequency of the test heat sink having a fin height of 20 mm shown in FIG. This proves that the cause of the noise generated by the rotation of the actual machine is air column vibration caused by air flowing in a direction substantially orthogonal to the rows of the radiation fins.

From the above results, the present inventor who has obtained confirmation that the noise can be suppressed by suppressing the generation of air column vibrations or dispersing the frequency of the air column vibrations, next, the rotary test machine shown in FIG. 43, the following tests were conducted.
The test machine 43 has a simple structure in which the rotary disk 44 rotates around the rotary shaft 45. The purpose of the test is to make the length direction of the radiating fins face the rotary axis 45 of the rotary disk 44. In addition, whether or not the noise state of the actual machine can be accurately reproduced when the test heat sink shown in FIG. 7 is attached to the surface 47 intersecting with the rotation axis of the rotation disk and the rotation disk 44 is rotated. Is to confirm. If the test machine can accurately reproduce the noise state of the actual machine, use the test machine for research and development of a heat sink that can suppress the generation of air column vibration or disperse the frequency of air column vibration. Can do.

  Table 2 shows the specifications of the actual machine and the test machine, and Table 3 shows the specifications of the heat sink of the actual machine and the test heat sink. As shown in Table 2, the distance between the heat sinks is different between the actual machine and the test machine, and as shown in Table 3, the number of heat sinks is different between the actual machine and the test machine. The noise state of the actual machine is built in.

  The result of the test is shown in FIG. From these results, when the flow velocity of the test machine 43 is set to 41 m / s, the dominant frequency matches that of the actual machine, and the overall noise tendency can also be reproduced. Has been confirmed to be accurately reproduced. Therefore, the rotary test machine can be used for research and development of a heat sink that can suppress the generation of air column vibration or disperse the frequency of air column vibration. The flow rate of 41 m / s corresponds to a rotational speed of 1570 rpm.

  Here, FIG. 7 is a schematic view showing a test heat sink used in the above-described test. As shown in the figure, this heat sink is a substrate 5 that is simply a base, like the heat sink according to the prior art. A heat radiating plate in which a plurality of heat radiating fins 2 are formed in parallel on the base surface.

As a result of various experiments using the rotary test machine, the present inventor has arrived at the following technical knowledge.
As a method for suppressing the occurrence of air column vibrations, it is desirable to form slits 3 in the radiating fins 2 that penetrate the radiating fins in the width direction, as shown in FIG. This is because when the rotating body is rotated by attaching a heat dissipating plate having the shape shown in FIG. 7 to the surface intersecting with the rotating shaft of the rotating body so that the length direction of the heat dissipating fins is directed to the rotating shaft of the rotating body, the air is dissipated. It flows in the width direction (thickness direction) of the radiation fins along the upper surface of the fin 2. And when the length of a radiation fin is long, the center part of the length direction of a radiation fin does not receive the influence of the both ends of the length direction of a radiation fin, and acts like a closed tube. When air flows along the upper surface of the closed tube, air column vibrations are generated, and outstanding noise is generated. Therefore, if the slit 3 which penetrates a radiation fin to the width direction (thickness direction) is formed in the center part of the length direction of a radiation fin especially in a radiation fin, the air flow of the center part of the length direction of a radiation fin This is because the generation of air column vibration is suppressed.

The depth of the slit is desirably 2.5 mm or more. FIG. 17 is a diagram showing the relationship between the depth of the slit and the sound pressure level of the dominant frequency (4000 Hz band and 5000 Hz band). From the figure, the slit depth is set to 2.5 mm or more, so that the 4000 Hz band. It can be confirmed that the sound pressure level of the dominant frequency in the 5000 Hz band can be greatly reduced. Further, it can be confirmed that the thickness less than 2.5 mm hardly contributes to the suppression of the occurrence of air column vibration .
The test conditions in the figure are as follows: the rotational speed of the rotary test machine is 1570 rpm, the number of radiating fins is 34 (17 × 2), the spacing between the radiating fins is 3 mm, the height of the radiating fins is 20 mm, and The slits formed in the heat radiating fins are cut in a straight line shown in FIG. 8, and the slit interval is 25 mm and the slit width is 1 mm.

  The slit interval is preferably 15 to 32 mm. If the slit interval is 32 mm or less, the sound pressure level of the dominant frequency in the 4000 Hz band can be reduced, but if it is less than 15 mm, the strength of the heat radiating fins may be affected.

  The width of the slit is preferably 0.7 to 4 mm. If it is less than 0.7 mm, it hardly contributes to suppression of the occurrence of air column vibration, and if it exceeds 4 mm, the heat transfer area of the radiating fin is reduced, which may affect the cooling performance originally provided in the radiating plate.

  As shown in FIG. 8, the slit is formed at the center in the lengthwise direction of the radiation fins, in the direction orthogonal to the rows of the radiation fins, that is, in the width direction (thickness direction) of the radiation fins. Although it is desirable to form all the radiation fins of the plurality of radiation fins formed on the base surface of the substrate to be formed, it is not limited to this form. For example, the form shown to Fig.9 (a)-(d) and the form shown to Fig.10 (a)-(b) may be sufficient.

The form shown in FIG. 9A is a form in which the slit 3 is formed at a position deviated from the center instead of forming the slit at the center in the lengthwise direction of the radiating fin.
The form shown in FIG. 9B is a form in which slits 3 are not formed in all of the plurality of radiating fins formed on the base surface of the base substrate, but slits 3 are formed in a part of the plurality of radiating fins. It is.
The form shown in FIG. 9C is a form in which the slits 3 are formed so that the slits are arranged in a staggered manner.
The form shown in FIG. 9D is a form in which the slits 3 are formed not to always have the same width but to have different widths.

In the form shown in FIG. 10A, each of the plurality of radiating fins 2 formed on the base surface of the base substrate is formed with slits 3 penetrating the radiating fins in the width direction. The slits 3 are formed in such a manner that the rows formed by are not in the direction perpendicular to the rows of radiating fins, but in a substantially orthogonal direction that is slightly inclined from the orthogonal direction.
The form shown in FIG. 10B is a form in which the slits 3 are formed so that the slits 3 are randomly arranged.

The shape of the slit is not limited to the form in which the cut reaches the base surface of the substrate 5 serving as the base as shown in FIG. 8 and is perpendicular to the base surface of the substrate. For example, the form shown to Fig.11 (a)-(d) may be sufficient.
The form shown in FIG. 11A is a form formed so that the slit does not reach the base surface of the substrate 5 serving as the base.
The form shown in FIG. 11B is a form in which the slit is formed in a V shape.
The form shown in FIG. 11C is a form in which the bottom of the slit is rounded.
The form shown in FIG. 11D is a form in which the shape of the slit is formed into an ellipse.

  The heat radiating plate 1 described above is a heat radiating plate that is attached to a surface that intersects with the rotating shaft of the rotating body so that the length direction of the radiating fins faces the rotating shaft of the rotating body, and rotates together with the rotating body. 1. Although it is a heat sink formed so that the adjacent heat sink fins 2 may become parallel like the heat sink shown in FIGS. 7-11, the heat sink which concerns on this invention is limited to this form is not. For example, like the heat radiating plate shown in FIG. 12, it includes a row shape of radiating fins extending radially from the rotating shaft 15 when attached to a surface intersecting with the rotating shaft of the rotating body.

  On the other hand, as a method of dispersing the frequency of the air column vibration, the plurality of radiating fins 2 formed on the base surface of the base substrate are formed so as to have different heights and inclined to the side surface shape of the radiating plate. It is desirable to have This is because the frequency of occurrence of air column vibration is determined by the height of the radiating fins as shown in the above formula. This is because the generation of noise is suppressed.

The side surface shape of the heat sink in this case is preferably the mountain shape shown in FIG. 13, but is not limited to this, for example, the mountain shape shown in FIGS. 14 (a) to (d). It may be shaped.
The form shown in FIG. 14A differs from the mountain shape shown in FIG. 13 in that the heights of the adjacent radiating fins are different.
The form shown in FIGS. 14 (b) and 14 (c) is such that the side surface of the heat radiating plate has a curved slope.
In the form shown in FIG. 14D, the height of the heat dissipating fins is asymmetric on the left and right.

  Moreover, although it is desirable that the side surface shape of the heat radiating plate is a mountain shape, the shape may be a slope shape shown in FIGS. 15 (a) and 15 (b). Although not shown, the slope shape shown in FIGS. 15 (a) and 15 (b) may be a slope shape having a slope formed by curves as shown in FIGS. 14 (b) and 14 (c).

  Although the top of the mountain shape shown in FIG. 13 is flat, the step in the other inclined portion, that is, the step in the inclined portion of the heat sink shown in FIG. 13, and the heat sink shown in FIGS. About a level | step difference, it is desirable to set it as 0.5-10 mm. If the step, which is the difference in height between adjacent radiating fins, is less than 0.5 mm, it can hardly contribute to dispersing the frequency at which air column vibration occurs. Also, even if the level difference exceeds 10 mm, the sound pressure reduction effect is saturated, and when a large number of radiating fins are formed on the base surface of the base substrate, the radiating fins are very high and low. This is not preferable in terms of equipment.

  The heat radiating plate according to the present invention described above serves as a base and a heat radiating plate in which slits that penetrate the heat radiating fins in the width direction are formed in a part or all of the plurality of radiating fins formed on the base surface of the base substrate. A plurality of heat dissipating fins formed on the base surface of the substrate is a heat dissipating plate formed so as to have different heights, and the side surface shape of the heat dissipating plate is inclined. FIG. Needless to say, the heat radiation plate of the form shown can suppress the occurrence of air column vibrations and can disperse the frequency of the air column vibrations, so that noise can be further suppressed.

In order to finally confirm the technical knowledge by using the test machine 43, the present inventor uses a test heat radiation plate having the form shown in FIGS. 8, 13, and 16 in which the length direction of the heat radiation fins is a rotating disk. The sound pressure level was measured when it was attached to a surface 47 intersecting with the rotating shaft of the rotating disk so as to face the rotating shaft 45 of 44 and rotated.
The test machine setting conditions are as shown in Table 2. However, the flow velocity is set to 41 m / s to accurately reproduce the noise state in the actual machine.

Also, the conditions of the test heat sink are as shown in Table 3 except for the form of the heat sink. However, the fin height in the form shown in FIGS. 13 and 16 is set so that the center of the row and its neighbors are 26 mm, and the neighbors are 24 mm, and the height is lowered by 2 mm as it goes to the end of the row. . Therefore, the fin height at both ends of the row is 12 mm.
In addition, in order to confirm the effect of the heat sink according to the present invention relatively, a heat sink in which a plurality of heat radiation fins 2 are formed in parallel on the base surface of the substrate 5 as a simple base shown in FIG. It evaluated as an example (comparative example). The results are shown in Table 4.

About the heat sink which formed the slit shown in FIG. 8, it can confirm that the sound pressure level of a dominant frequency falls significantly.
Moreover, about the heat sink which formed the side surface shape shown in FIG. 13 in the shape of a mountain, although the effect of reducing the sound pressure level of the dominant frequency is not as good as that of the heat sink having the slit, the sound pressure level of the entire noise is greatly increased. It can confirm that it falls.
In addition, it is confirmed that both the sound pressure level of the dominant frequency and the sound pressure level of the entire noise are significantly reduced for the heat sink having the slits shown in FIG. 16 and the side surface formed in a mountain shape. be able to.
In addition, the heat-transfer area in a table | surface is a relative value when a prior art example (comparative example) is set to 100. FIG. The heat sink having the slits shown in FIG. 8 is 105.2%, the heat sink having the side surface shape shown in FIG. 13 is 97.3%, and the slit shown in FIG. 16 is formed. The heat radiation plate having the side surface formed in a mountain shape is 102.3%, which is almost the same as the conventional example, and the heat transfer area hardly affects the cooling performance of the heat radiation plate.

  From the above results, according to the heat radiating plate according to the present invention, it is possible to suppress noise generated by being attached to the rotating body and rotating together with the rotating body without substantially affecting the cooling performance that the heat radiating plate originally has. I was able to confirm.

It is a perspective view of the non-contact type motor coupling using a permanent magnet which is an example of the rotary body which attaches the heat sink which concerns on this invention. It is a schematic diagram which shows the operation principle of an example of a rotary body. It is a schematic diagram which shows the test equipment using an air nozzle, (a) is a top view, (b) is a side view. It is a graph which shows the test result using an air nozzle. It is a schematic diagram which shows the test equipment using a rotary test machine. It is a graph which shows the test result using a rotary type test machine. It is a schematic diagram which shows the heat sink which concerns on a prior art, (a) is a top view, (b) is a front view, (c) is a side view. It is a schematic diagram which shows an example of the heat sink which formed the slit which concerns on this invention, (a) is a top view, (b) is a front view, (c) is a side view. It is a schematic diagram which shows an example of the heat sink which formed the slit which concerns on this invention, and all of (a)-(d) are top views. It is a schematic diagram which shows an example of the heat sink which formed the slit which concerns on this invention, and all of (a)-(b) are top views. It is a schematic diagram which shows an example of the heat sink which formed the slit which concerns on this invention, and all of (a)-(d) are front views. It is a top view which shows an example of the heat sink which concerns on this invention. It is a schematic diagram which shows an example of the heat sink which formed the side surface shape which concerns on this invention in the mountain shape, (a) is a top view, (b) is a front view, (c) is a side view. It is a schematic diagram which shows an example of the heat sink which formed the side surface shape which concerns on this invention in the mountain shape, and (a)-(d) all are side views. It is a schematic diagram which shows an example of the heat sink which gave inclination to the side surface shape which concerns on this invention, All of (a)-(b) are side views. It is a schematic diagram which shows an example of the heat sink which concerns on this invention, (a) is a top view, (b) is a front view, (c) is a side view. It is a figure which shows the relationship between the depth of a slit, and the sound pressure level of a dominant frequency.

Explanation of symbols

1 Heat sink
2 Radiation fin 2a Radiation fin length 2b Radiation fin width 2c Radiation fin height 2d Radiation fin spacing 3 Slit 3a Slit depth 3b Slit spacing 3c Slit width 5 Substrate 6 Air flow 10 Rotating body 11 Electric disk 12 Permanent magnet disk 13 Gap 14 Spacer 15 Rotating shaft 16 Surface intersecting the rotating shaft 17 Side surface 20 of the rotating body Motor 30 Load 40 Air nozzle 41 Sound collecting microphone 42 Noise analyzer 43 Test machine 44 Rotating disk 45 Rotating shaft 46 Distance between heat sinks 47 Surface intersecting the rotation axis

Claims (4)

A heat radiating plate in which a plurality of plate-like radiating fins each having a thickness, height and length are formed on a base surface of a base substrate, and a surface comprising the thickness and height of the plate-like radiating fins. A heat sink that is attached to a surface that intersects with the rotating shaft of the rotating body so that one side of the rotating member faces the rotating shaft of the rotating body and rotates together with the rotating body,
A slit that penetrates the heat radiating fin in the thickness direction is formed in a part or all of the plurality of heat radiating fins formed on the base surface of the base substrate , and the slit has a depth of 2.5 mm or more, an interval of 15 to 32 mm, and a width. A heat sink characterized by being 0.7 to 4 mm . A heat radiating plate in which a plurality of plate-like radiating fins each having a thickness, height and length are formed on a base surface of a base substrate, and a surface comprising the thickness and height of the plate-like radiating fins. A heat sink that is attached to a surface that intersects with the rotating shaft of the rotating body so that one side of the rotating member faces the rotating shaft of the rotating body and rotates together with the rotating body,
A plurality of heat dissipating fins formed on the base surface of the base substrate are formed so as to have different heights, and the side surface shape of the heat dissipating plate as viewed from the surface consisting of the thickness and height of the heat dissipating fins is inclined. A heat sink characterized by The heat radiating plate according to claim 2 , wherein the side surface of the heat radiating plate has a mountain shape. Rotating body radiator plate is mounted according to any one of claims 1-3.

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