JP2012147543A - Sound deadening type air cooling device of electrical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound deadening type air cooling device which prevents noise occurrence and achieves sound deadening effect in both an inlet port and an outlet port of a cooling fan to reduce noise from an electrical apparatus and the air cooling device.SOLUTION: In a sound deadening type air cooling device 1 cooling electric apparatuses 3, 4 by cooling air circulated by a cooling fan 10, silencers 13, 15 are provided at both an inlet port 12 and an outlet port 14 of the cooling fan. Further, the silencer 15 having a rectification function is provided in at least either one of the inlet port and the outlet port.

Description

  The present invention relates to an air-cooling device for an electric device, and relates to a silencer type air-cooling device that can reduce noise from the electric device and the air-cooling device.

Large electric devices, for example, large AC motors and their inverter panels are necessary when operating industrial machines such as machine tools and are often used in factory facilities.
However, many of these electric devices themselves generate noise and vibration, and generate heat and require cooling.

Therefore, the AC motor is accommodated in the housing, or the inverter circuit is accommodated in the casing of the inverter panel to suppress noise, and air is cooled by circulating cooling air from the cooling fan of the air cooling device. .
In other words, the heat radiation corresponding to the calorific value of the electric equipment is calculated, and air cooling using a cooling fan that is advantageous in terms of facility costs and maintenance costs is adopted.
However, the cooling fan for cooling the heat generated by these electric devices generates a rotating sound or a wind noise and releases it to the outside to become a noise source, which may cause environmental problems.

On the other hand, in response to a noise reduction request, water cooling with cooling water may be employed instead of improving while employing a cooling fan.
However, the water-cooled type requires water supply and drainage facilities, and may cause water supply and drainage troubles such as condensation, rust, clogging of cooling water circulation pipes due to adhering minerals, etc., and secondary troubles such as equipment failures. However, the problem of increasing the cost of equipment and management labor to prevent it is likely to occur, and it was not a sufficient solution.

Therefore, in order to achieve both cost reduction and environmental measures, there is a demand for an air cooling device that can reduce noise.
For example, Patent Document 1 below discloses a case where a silencer duct is provided at one or both of the cooling air inlet and / or the cooling air outlet of the casing of the inverter panel. The silencer duct is only connected to the side, and the other side directly faces the inverter circuit or the like in the housing.
Therefore, the turbulent airflow that flows around the devices such as the circuits in the housing is sucked into the cooling fan with vibration caused by the turbulent flow. Alternatively, the turbulent air as it is sent from the cooling fan is sent into the housing and generates noise due to the turbulent air, so it cannot be said that the noise reduction is sufficient.

Moreover, although the following patent document 2 shows about the muffling function of the ventilation fan (the sending side and the discharge side) of an elevator, only the noise reduction in the elevator car is intended.
Therefore, the ventilation ducts on the car side of each ventilation fan on both the inlet side and the outlet side are provided with an active noise control device as a main noise reduction means, and are lined with a sound absorbing material. The outside side of the ventilation fan is open directly into the elevator hoistway and does not have any noise reduction measures.
That is, the noise countermeasures for the outside of each ventilation fan as contemplated by the present invention are not shown.

JP-A-9-84255 (FIGS. 1 to 10) JP-A-6-247669 (FIGS. 1 and 2)

  In view of the above prior art, the present invention provides a muffler type air cooling device that can prevent noise generation and muffle noise at both the suction port and the discharge port of a cooling fan, and can reduce noise from electrical equipment and air cooling devices. The issue is to provide.

  In order to solve the above-described problems, the invention according to claim 1 is directed to a silencer type air-cooling device that cools an electric device with cooling air circulated by a cooling fan, and includes both a suction port and a discharge port of the cooling fan. A silencer type air-cooling device for electrical equipment, characterized in that a silencer is provided.

  According to a second aspect of the present invention, in the silencer type air cooling device for an electric device according to the first aspect, a silencer having a rectifying function is provided in at least one of the suction port and the discharge port. To do.

  According to a third aspect of the present invention, in the silencer type air cooling device for an electric device according to the first or second aspect, the suction port or the discharge port is connected to at least one of the suction port or the discharge port. The present invention is characterized in that a silencer is provided in which the inner peripheral surface of the cooling air flow path is formed of a perforated plate and the periphery thereof is surrounded by a sound absorbing material.

  According to a fourth aspect of the present invention, in the silencer type air cooling device for an electric device according to the first aspect, the silencer type air cooling device sucks the cooling air by connecting the suction port to the electric device side. The cooling air is discharged to the outside from the discharge port, and a silencer having a rectifying function is provided at the discharge port.

  According to a fifth aspect of the present invention, in the silencer type air cooling device for an electric device according to the fourth aspect, an inner peripheral surface of a cooling air flow channel connected to the suction port is formed of a porous plate at the suction port. In addition, a silencer is provided that surrounds it with a sound absorbing material.

  According to a sixth aspect of the present invention, in the silencer type air cooling device for an electric device according to the fourth or fifth aspect, the electric device is an inverter panel, and the silencer type air cooling device is provided from within the inverter panel. The cooling air is discharged to the outside.

  The invention according to claim 7 is the silencing type air cooling apparatus for electric equipment according to claim 4 or claim 5, wherein the electric equipment is an AC motor housed in a housing, and the silencing type air cooling apparatus is The cooling air is discharged from the inside of the housing to the outside.

According to the silencer type air cooling device for an electrical apparatus of the first aspect of the present invention, since silencers are provided at both the suction port and the discharge port of the cooling fan, noise is generated at both the suction port and the discharge port of the cooling fan. Prevention and silencing.
In other words, when cooling air is sucked from the electrical equipment side and discharged outside, the noise from the electrical equipment and the noise of the cooling air that has passed through the electrical equipment are reduced by the silencer of the suction port, and the cooling fan Since the noise generated from the exhaust air is reduced by the silencer at the discharge port, the noise released to the outside from the electrical equipment and the cooling fan is suppressed together with the discharge of the cooling air to the outside, and a noise reduction effect is obtained.

  In addition, when cooling air is sucked in from the outside and supplied to the electrical equipment side, the noise generated from the cooling fan is reduced by the silencer at the suction port and is prevented from being released to the outside. Noise and noise of cooling air that passes through electrical equipment are reduced by the silencer at the exhaust port and are prevented from being transmitted to the cooling fan, thus suppressing noise emitted from the electrical equipment and cooling fan to the outside And a silencing effect is obtained.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, at least one of the suction port and the discharge port is provided with a silencer having a rectification function, that is, a silencer that functions as a rectification device. The turbulent flow of the cooling air passing through the fan is rectified, noise based on the turbulent flow is reduced, noise emitted to the outside from the electric equipment and the cooling fan is more effectively suppressed, and a noise reduction effect is obtained.

  According to the invention of claim 3, in addition to the effect of the invention of claim 1 or 2, in addition to the effect of the invention of claim 1 or claim 2, at least one of the suction port or the discharge port, the cooling air flow path connected to the suction port or the discharge port The silencer is made of a perforated plate and surrounded by a sound-absorbing material, so that the silencer is highly sound-absorbing and the pressure vibration of the cooling air passing through the cooling fan is absorbed. Since the noise is reduced, the noise emitted to the outside from the electric device and the cooling fan is more effectively suppressed, and a silencing effect is obtained.

  According to the invention of claim 4, when the cooling air sucked from the electrical equipment side by the cooling fan through the suction port is discharged from the discharge port to the outside, the rectifying silencer is provided at the discharge port of the cooling fan. Therefore, since the cooling air including the turbulent flow and rotation of the cooling fan discharge port is rectified, the noise based on the turbulent flow is reduced, and the silencer having the rectifying ability is particularly effectively utilized. The effect of the invention is exhibited.

According to the invention of claim 5, in addition to the effect of the invention of claim 4, since a silencer with high sound absorption is provided at the inlet of the cooling fan, noise generated from the electrical equipment and cooling that passes through the electrical equipment Since the noise of the working air, that is, the pressure vibration of the cooling air is absorbed, a silencer having a high sound absorbing property is utilized particularly effectively.
That is, the operational effects of both silencers are preferably combined with each other, and noise that is released to the outside from the electrical equipment and the cooling fan is particularly effectively suppressed, thereby obtaining a silencing effect.

  According to the invention of claim 6, the inverter circuit and the like in the inverter panel are air-cooled by the outside air as the cooling air introduced into the inverter panel when the cooling air is discharged by the cooling fan. 4 or the effect of the invention of claim 5 effectively suppresses noise emitted to the outside from the inverter panel and the cooling fan to obtain a silencing effect, thereby reducing the cooling cost of the inverter panel and solving environmental problems. Can contribute.

  According to the invention of claim 7, the AC motor in the housing is air-cooled by the outside air as the cooling air introduced into the housing as the cooling air is discharged by the cooling fan. Due to the effect of the invention of item 5, the noise emitted to the outside from the AC motor, its housing and the cooling fan is effectively suppressed, and a silencing effect is obtained, reducing the cooling cost of the AC motor and solving the environmental problems Can contribute.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic front view of an inverter panel equipped with a muffler type air cooling device according to Embodiment 1 of the present invention. It is a typical side view of the inverter board which attached the silencing type air cooling device by the II-II arrow in FIG. FIG. 3 is a structural explanatory diagram of a silencer in which an inner peripheral surface of a cooling air flow path in part III in FIG. 1 is formed of a perforated plate and surrounded by a sound absorbing material. It is explanatory drawing of the square circle connection duct of IV part in FIG. It is a typical elevation view of an AC motor and its housing to which a muffler type air cooling device according to Embodiment 2 of the present invention is attached. FIG. 6 is a schematic plan view of an AC motor and its housing, to which a muffler type air cooling device is attached, as viewed in the direction of arrows VI-VI in FIG. 5. FIG. 7 is a schematic side elevational view of an AC motor and its housing with a muffled air cooling device attached, as viewed in the direction of arrows VII-VII in FIG. 5. The comparison of the noise level measurement result of Example 3 of this invention and the example 4 of a prior art is shown.

Hereinafter, a silencer type air cooling device for an electric apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS.
In the present embodiment, the “electric device” to which the silencer type air cooling device 1 is attached is the inverter panel 3.

As shown in FIG. 1, the inverter panel 3 that is erected contains an inverter circuit 32 in a casing 30 and is connected to an input / output power line (not shown).
The silencer type air cooling device 1 is attached to the upper surface of the housing 30, the inlet silencer 13 is provided at the inlet 12 of the cooling fan 10, and the outlet silencer 15 is provided at the outlet 14.
The inlet silencer 13 communicates with the upper space 33 in the housing 30 via the cooling air duct 16.
The discharge port silencer 15 is opened to the outside through the blowout port 17.

  In the figure, the inlet silencer 13, the cooling fan 10, and the outlet silencer 15 are simply shown standing on a simple column 31, but have a structure having sufficient rigidity so as to prevent vibrations. It is assumed that the support 31 is supported by a horizontal beam member (not shown).

The cooling fan 10 of the muffler type air cooling device 1 is an axial fan, and driving power supply and control are performed by a power source and a control circuit (not shown).
When the cooling fan 10 is driven, cooling air is discharged from the inside of the inverter panel 3, and the outside air as cooling air introduced into the inverter panel 3 as the cooling air is discharged causes The inverter circuit 32 and the like are air-cooled.
The casing 30 of the inverter panel 3 is provided with an outside air inflow path (not shown). The outside air inflow path includes a labyrinth flow path or the like, and the noise in the casing 30 is traced back to the outside air flowing in from the outside air inflow path. It is preferable not to leak outside.

The inlet silencer 13 is connected to the inlet 12 and forms a cooling air flow path 18 having a circular cross section having an inner diameter substantially the same as the diameter of the cooling fan 10 so that the flow of the intake air is not disturbed. .
As shown in FIG. 3, the inner peripheral surface 18 a of the cooling air flow path 18 is formed of a porous plate 19, and its periphery is surrounded by a sound absorbing material 20. In order to protect from the hole 19a, a ventilation fiber body 21 is disposed. Further, the outside is covered with a suction port silencer casing 13a.

  The hole 19a of the perforated plate 19 is a radial hole formed in the inner peripheral surface 18a of the cooling air flow path 18 together with the sound absorbing material 20 on the outer peripheral side thereof, and is capable of absorbing abnormal noise due to air expansion. It is. The inlet silencer 13 using the perforated plate 19 and the sound absorbing material 20 absorbs the pressure vibration of the cooling air and becomes a silencer with high sound absorption.

The perforated plate 19 can be easily constituted by a metal plate or a resin plate, but can also be constituted by a fiber reinforced gypsum board or the like to improve the sound absorption effect.
As the sound absorbing material 20, an appropriate material such as glass wool, rock wool, metal fiber, urethane foam, porous ceramics or the like can be selected and used.
Glass fiber or the like can be used for the ventilation fiber body 21, but it is not necessary depending on the type of the sound absorbing material 20.

In the present embodiment, the cooling air duct 16 has a bend portion 16a. The bend portion 16a can freely set the exhaust direction from the inverter panel 3, that is, the connection direction with the muffler type air cooling device 1.
In the bend portion 16a, the flow direction of the cooling air passing therethrough changes, so that the flow resistance increases and turbulence may occur. However, the flow of air flowing through the bend portion 16a is provided with a rectifying plate 23. By guiding the flow direction and obtaining a uniform flow, the generation of noise due to uneven flow, compression, and collision of the cooling air flow is suppressed.

When the rectifying plate 23 is provided in the bend portion 16a, it may be difficult to manufacture with a circular cross-section duct. In this embodiment, the bend portion 16a is a rectangular cross-section duct.
However, in this case, when connecting to a circular cross-section duct or the like, in this embodiment, when connecting to the cooling air flow path 18 having a circular cross section of the inlet silencer 13, a square-circular connection duct 24 as shown in FIG. It is interposed so that the flowing air smoothly flows from the rectangular cross section to the circular cross section, thereby suppressing the generation of noise due to the flow disturbance.

On the other hand, the discharge port silencer 15 provided in the discharge port 14 is a silencer having a rectifying ability. That is, the silencer works as a rectifier, and in the present embodiment, the silencer is composed of a honeycomb structure 27 including a number of tubular passages 26 parallel to the discharge direction of the cooling fan 10.
Therefore, the turbulent flow of the cooling air discharged from the cooling fan 10 is rectified, and noise generation based on the turbulent flow is reduced.

The honeycomb structure 27 can be easily made of metal, resin or the like, but can also be made of fiber-reinforced gypsum board, porous ceramics or the like in order to enhance the sound absorption effect.
The outer peripheral side of the honeycomb structure 27 is covered with a discharge port silencer casing 15a. A protective frame (not shown) is attached to the outlet port 17 of the discharge port silencer 15 to protect the honeycomb structure 27. .

When the sound deadening air cooling device 1 of the inverter panel 3 of the present embodiment configured as described above is operated, the cooling fan 10 rotates to cool air (cooling air) from the upper space 33 in the inverter panel 3. It sucks out via the air duct 16 (including the bend portion 16a and the square connection duct 24), the inlet silencer 13, and the inlet 12.
The sucked air is discharged from the discharge port 14 to the outside.

With the discharge of the cooling air, outside air as cooling air is introduced into the inverter panel 3 from an outside air inflow passage (not shown) provided in the casing 30 of the inverter panel 3. The cooling air passes around the inverter circuit 32 in the housing 30, and the inverter circuit 32 is air-cooled.
In this embodiment, the inverter panel 3 having only the inverter circuit 32 is illustrated as an example. However, the present invention is not limited to this, and the inverter panel 3 includes a converter, a transformer, and a discharge that cooperate with the inverter circuit 32. A resistor or the like may be provided, and they are similarly air-cooled.
Further, it is preferable that the outside air inflow path is provided with a labyrinth channel or the like so as to trace the outside air flowing in from the outside air inflow path so that the noise in the housing 30 does not leak to the outside.

The cooling air that has passed through the inverter panel 3 contacts the internal inverter circuit 32 and the like, and the flow is disturbed, causing pressure vibration due to compression, collision, etc., and generating noise. It also conveys noise generated from the devices such as the inverter circuit 32 itself.
However, when such cooling air flows into the cooling fan 10 of the muffler type air cooling device 1, pressure vibration is absorbed by the suction silencer 13 provided at the suction port 12, and noise is reduced.

That is, in the cooling air flow path 18 of the inlet silencer 13, the pressure wave of the air in the cooling air flow path 18 that has entered the sound absorbing material 20 behind the hole 19a of the porous plate 19 on the inner peripheral surface 18a is Energy is attenuated by friction with the sound absorbing material 20, vibration, etc., and pressure vibration is absorbed. Therefore, the inlet silencer 13 in which the inner peripheral surface 18a of the cooling air flow path 18 is formed by the perforated plate 19 and the periphery thereof is surrounded by the sound absorbing material 20, has a high sound absorbing property.
Such a sound absorption silencer is generally more excellent in sound absorption in a high frequency range, and is suitable for noise reduction of the inverter panel 3 and the like that easily generate high frequency vibrations.

The cooling air duct 16 is sucked out from the inverter panel 3 by the rectifying plate 23 of the bend portion 16a and the rectangular connection duct 24 for connecting to the cooling air flow path 18 of the inlet silencer 13. Since the flow of the cooling air is rectified and flows smoothly, the disturbance is prevented and the generation of noise is suppressed.
Further, the reason why the inner diameter of the cooling air flow path 18 is set to be substantially the same as the diameter of the cooling fan 10 is the same effect.
Furthermore, the generation of noise from the inverter panel 3 and the cooling fan 10 can be further reduced by laying a vibration-proof rubber on the fixed part of the inverter panel 3 or lining a sound absorbing material on the inner surface of the casing 30 of the inverter panel 3. .

On the other hand, the discharge port 14 of the cooling fan 10 is provided with a discharge port silencer 15 having a rectifying function, and the cooling air in the inverter panel 3 sucked out by the cooling fan 10 is discharged to the outside through the discharge port silencer 15. Is done.
The discharge port silencer 15 includes a honeycomb structure 27 provided with a number of parallel tubular passages 26 aligned in the discharge direction of the cooling fan 10.

The discharge port 14 is provided with a connection portion 14a for smoothly connecting to the cross-sectional shape of the honeycomb structure 27 (usually a rectangle, but may be a circle, a polygon, or the like). The discharged cooling air is distributed to each tubular passage 26 of the honeycomb structure 27.
The discharged cooling air is rectified in the flow direction by passing through each tubular passage 26, and is turbulent without colliding with each other from the downstream end of the honeycomb structure 27, that is, the outlet 17 of the outlet silencer 15. It is discharged outside while being prevented from flowing.
Therefore, even if the cooling air discharged from the cooling fan 10 includes turbulent flow, rotation, and the like, it is rectified by the exhaust silencer 15, and noise generation based on the turbulent flow is suppressed.

The features of the first embodiment described above can be summarized as follows.
First, in the muffler type air cooling apparatus 1 that cools the inverter panel 3 with the cooling air circulated by the cooling fan 10, the suction silencer 13 and the discharge silencer are respectively provided in both the suction port 12 and the discharge port 14 of the cooling fan 4. 15 is provided, it is possible to prevent noise generation and to mute both the inlet 12 and the outlet 14 of the cooling fan 10.
That is, when the cooling air is sucked from the inverter panel 3 side and discharged to the outside, the noise from the inverter panel 3 and the noise of the cooling air that has passed through the inverter panel 3 are reduced by the inlet silencer 13. Since the noise generated from the cooling fan 10 is reduced by the exhaust silencer 15, the noise released to the outside from the inverter panel 3 and the cooling fan 10 is suppressed as the cooling air is discharged to the outside, and a silencing effect is obtained. It is done.

In addition, the same can be said for the case of using the reverse cooling air flow as illustrated in the first embodiment.
That is, even when cooling air is sucked in from the outside and supplied to the inverter panel 3 side, the noise generated from the cooling fan 10 is reduced by the inlet silencer 13 and prevented from being released to the outside. 3 and the noise of the cooling air passing through the inverter panel 3 are reduced by the exhaust silencer 15 and prevented from being transmitted to the cooling fan 10. Noise emitted to the outside is suppressed, and a silencing effect is obtained.

In addition to the above, the exhaust port 14 is provided with the exhaust port silencer 15 having a rectifying function, that is, the silencer made of the honeycomb structure 27 that functions as a rectifier, so that the turbulent flow of the cooling air passing through the cooling fan 10 is rectified. The noise based on the turbulent flow is reduced, the noise released to the outside from the inverter panel 3 and the cooling fan 10 is more effectively suppressed, and the noise reduction effect is obtained.
Contrary to Embodiment 1, the same is true if the inlet 12 is provided with a silencer having a rectifying ability.

In addition to the above, the suction port 12 is provided with a suction port silencer 13 in which the inner peripheral surface 18a of the cooling air flow path 18 connected to the suction port 12 is formed of a perforated plate 19 and surrounded by a sound absorbing material 20. Therefore, the suction port silencer 13 has a high sound absorption property, and the pressure vibration of the cooling air passing through the cooling fan 10 is absorbed to reduce the noise, so that it is discharged from the inverter panel 3 and the cooling fan 10 to the outside. Noise is suppressed more effectively and a silencing effect is obtained.
Contrary to Embodiment 1, even if the discharge port 14 is provided with a discharge port silencer in which the inner peripheral surface of the cooling air flow path connected to the discharge port 14 is formed of a porous plate and surrounded by a sound absorbing material. It is the same.

  Then, as in the first embodiment, in the silencer type air cooling device 1 of the inverter panel 3, the silencer type air cooling device 1 connects the suction port 12 to the inverter panel 3 side and sucks cooling air from the discharge port 14. The cooling air is exhausted to the outside, and the exhaust port 14 is provided with a silencer having a rectifying function, that is, the exhaust port silencer 15 made of the honeycomb structure 27. When the cooling air sucked from the inverter panel 3 side through the silencer 13 is discharged from the discharge port 14 to the outside, the turbulent flow and rotation of the discharge port 14 of the cooling fan 10 are performed by the discharge silencer 15 having a rectifying function. Since the cooling air containing air is rectified, noise based on turbulent flow is reduced, and a silencer having a rectifying ability is particularly effectively utilized.

In addition to this, the suction port silencer 13 having an inner peripheral surface 18a of a cooling air flow path 18 connected to the suction port 12 formed of a perforated plate 19 and surrounded by a sound absorbing material 20 is formed in the suction port 12. Since the suction silencer 13 having high sound absorption absorbs the noise generated from the inverter panel 3 and the noise of the cooling air passing through the inverter panel 3, that is, the pressure vibration of the cooling air. A highly effective silencer is utilized particularly effectively.
That is, the operational effects of both silencers are preferably combined with each other, and the noise released from the inverter panel 3 and the cooling fan 10 to the outside is particularly effectively suppressed, thereby obtaining a silencing effect.

  The noise reduction type air cooling device 1 of the first embodiment is the noise reduction type air cooling device 1 of the inverter panel 3 and discharges cooling air from the inverter panel 3 to the outside. The outside air as cooling air introduced into the inverter panel 3 along with the discharge causes the inverter circuit 32 and the like in the inverter panel 3 to be air-cooled, and noise released from the inverter panel 3 and the cooling fan 10 to the outside. It can be effectively suppressed to obtain a silencing effect, and can contribute to the reduction of the cooling cost of the inverter panel 3 and the elimination of environmental problems.

Next, a silencer type air cooling device for an electric apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS.
In the second embodiment, the “electric device” to which the silencer type air cooling device 1 is attached is the AC motor 4 accommodated in the housing 40.
In the second embodiment, parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted or simplified, and differences from the first embodiment are mainly described below.

Even if the noise of the cooling fan 3 is reduced, if the noise reduction is insufficient, for example, when the noise from the AC motor 4 as the electric device main body is high, the AC motor 4 is housed in the housing 40 to mute the noise. The mold air cooling device 1 can achieve air cooling that efficiently contacts and circulates cooling air to the AC motor 4 in the housing 40 and noise reduction.
As shown in FIGS. 5 to 7, in the second embodiment, the AC motor 4 is accommodated in a housing 40, and a driving power line (not shown) and necessary control wiring are connected.

The silencer type air cooling device 1 is attached to the upper surface of the housing 40, the suction port silencer 13 is provided at the suction port 12 of the cooling fan 10, and the discharge port silencer 15 is provided at the discharge port 14.
The inlet silencer 13 communicates with the upper space 43 in the housing 40 via the cooling air duct 16.
The discharge port silencer 15 is opened to the outside through the blowout port 17.

  In the figure, the inlet silencer 13, the cooling fan 10, and the outlet silencer 15 are simply shown standing on a simple column 41, but have a structure having sufficient rigidity so as to prevent vibrations. It is assumed that the support 41 is supported by a horizontal beam member (not shown).

The cooling fan 10 of the muffler type air cooling device 1 is an axial fan, and driving power supply and control are performed by a power source and a control circuit (not shown).
When the cooling fan 10 is driven, the cooling air is discharged from the housing 40, and the AC motor 4 in the housing 40 is discharged by the outside air as the cooling air introduced into the housing 40 as the cooling air is discharged. Etc. are air-cooled.
The housing 40 of the AC motor 4 is provided with an outside air inflow passage (not shown). The outside air inflow passage is provided with a labyrinth passage or the like so that the outside air flowing in from the outside air inflow passage can be traced back to the outside. It is preferable not to leak.

The structures and operational effects of the cooling fan 10, the inlet silencer 13, and the outlet silencer 15 are the same as those described in the first embodiment, and a description thereof will be omitted.
In the present embodiment, the cooling fan 10, the inlet silencer 13, and the outlet silencer 15 are connected to the AC motor in the housing 40 in the same manner as the inverter circuit 32 and the like in the casing 30 of the inverter panel 3 are air-cooled in the first embodiment. 4 is air-cooled, and noise emitted to the outside from the AC motor 4, the housing 40, and the cooling fan 10 is suppressed, and a silencing effect is obtained.

When the AC motor 4 of the electric equipment body to be cooled emits a high noise as in the present embodiment, the housing 40 that accommodates it simply allows the cooling air to contact and circulate the AC motor 4 efficiently. It is not limited to things, but has an aggressive structure for noise suppression.
That is, the housing 40 has a sound insulation wall structure.

  Although the sound insulation wall structure can be made of a member having a high mass such as concrete, which is often used in general, the structure makes it difficult to install, dismantle, and relocate and increase the cost, and it is difficult to maintain the accommodated AC motor 4 and the like. , May cause operational flexibility problems.

Therefore, the sound insulation wall structure of the present embodiment is a sound insulation wall having a simple structure in which a sound absorbing member such as a foam member, a porous material, glass wool or the like is inserted between double walls such as a double plate member such as a plaster board. As 42, it is lightweight, easy to install, dismantle, and relocate, the cost is suppressed, maintenance of the accommodated AC motor 4 and the like can be facilitated, and operational flexibility can be achieved.
The housing 40 that accommodates the AC motor 4 of the present embodiment includes the sound insulation wall 42 having such a simple structure.

In order to improve the sound insulation by the housing 40, in the case where the sound insulation wall 42 is constituted by a double wall, the double plate-like members are directly connected to each other so that the acoustic coupling by structural coupling is reduced. The thing which suppressed is preferable.
Moreover, it is preferable that the opening 44 of the housing 40 through which the shaft portion 4a of the AC motor 4 is inserted, and terminals such as a motive power line and a control wiring (not shown) have a seal structure.
Furthermore, the vibration generation from the AC motor 4 and the cooling fan 10 can be further reduced by placing anti-vibration rubber on the fixed portion of the AC motor 4 or lining a sound absorbing material on the inner surface of the housing 40.

  The features of the second embodiment are summarized as described above with respect to the first embodiment, and repeated description is omitted. However, the second embodiment is connected to the inlet 12 of the muffler type air cooling device 1. Since the electric device is the AC motor 4 accommodated in the housing 40, the following can be said particularly.

  That is, in the silencing type air cooling device 1 of the AC motor 4 accommodated in the housing 40, the silencing type air cooling device 1 connects the suction port 12 to the housing 40 side, sucks cooling air, and cools it from the discharge port 14 to the outside. Since the exhaust port 14 is provided with a silencer having a rectifying function at the discharge port 14, that is, the discharge port silencer 15 comprising the honeycomb structure 27, the cooling fan 10 is connected to the suction port silencer 13 at the suction port 12. When the cooling air sucked from the housing 40 side is discharged from the discharge port 14 to the outside, the discharge silencer 15 having a rectifying function is used for cooling including turbulent flow and rotation of the discharge port 14 of the cooling fan 10 Since air is rectified, noise based on turbulent flow is reduced, and a silencer having a rectifying ability is used particularly effectively.

In addition to this, the suction port silencer 13 having an inner peripheral surface 18a of a cooling air flow path 18 connected to the suction port 12 formed of a perforated plate 19 and surrounded by a sound absorbing material 20 is formed in the suction port 12. Since the suction silencer 13 having high sound absorption is provided, noise generated from the AC motor 4 and noise of cooling air passing through the housing 40 housing the AC motor 4, that is, pressure vibration of the cooling air are absorbed. Therefore, a silencer with high sound absorption is used particularly effectively.
That is, the operational effects of both silencers are preferably combined with each other, and the noise emitted to the outside from the AC motor 4 and its housing 40 and the cooling fan 10 is particularly effectively suppressed, and a silencing effect is obtained.

  The silencing type air cooling device 1 of the second embodiment is the silencing type air cooling device 1 of the AC motor 4 accommodated in the housing 40 and discharges cooling air from the inside of the housing 40 to the outside. The AC motor 4 and the like in the housing 40 are cooled by the outside air introduced into the housing 40 as the cooling air is discharged by the AC, and the AC motor 4 and the housing 40 and the cooling fan 10 Noise emitted to the outside is effectively suppressed and a silencing effect is obtained, which can contribute to the reduction of the cooling cost of the AC motor 4 and the elimination of environmental problems.

Example 1
A cooling fan manufactured by a fan manufacturer was modified by the present inventors with the silencer of the present invention and attached to the inverter panel. (Equivalent to Embodiment 1)
(Example 2)
A cooling fan manufactured by a fan manufacturer with a design change with the silencer of the present invention is attached to the inverter panel. (Equivalent to Embodiment 1)
(Example 3)
A fan manufactured by a fan manufacturer with a design change with the silencer of the present invention is installed in a housing that houses an AC motor and has a sound insulation wall. (Equivalent to Embodiment 2)
(Conventional example 1)
A cooling fan made by a fan manufacturer is attached to the inverter panel.
(Conventional example 2)
A fan manufactured by a fan manufacturer is mounted on a housing that houses an AC motor and has a sound insulation wall.
(Conventional example 3)
A fan manufactured by a fan manufacturer is mounted on a housing that houses an AC motor and has a sound insulation wall.
(Conventional example 4)
A fan manufactured by a fan manufacturer is mounted on a housing that houses an AC motor and has a sound insulation wall.

The results of measuring the noise level at a position 1 m away from the above example and the conventional example are collectively shown in FIG.
As shown in FIG. 8, in Example 1 where the noise level was the highest, the noise level was reduced by about 8 dB and an environment of less than 80 dB was ensured as compared with Conventional Example 1 where the noise level was the lowest.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the aspect of said Embodiment 1, 2, It can implement in a various aspect in the range of the summary of this invention. Of course.

  DESCRIPTION OF SYMBOLS 1 ... Silent type air cooling device, 3 ... Inverter panel, 4 ... AC motor, 10 ... Cooling fan, 12 ... Inlet, 13 ... Inlet silencer, 14 ... Outlet, 15 ... Outlet silencer, 16 ... Air duct for cooling , 16a ... Bend part, 17 ... Air outlet, 18 ... Air flow path for cooling, 18a ... Inner peripheral surface, 19 ... Perforated plate, 19a ... Hole, 20 ... Sound absorbing material, 23 ... Rectifying plate, 24 ... Square circle connection duct , 26 ... tubular passage, 27 ... honeycomb structure, 30 ... housing, 32 ... inverter circuit, 40 ... housing, 42 ... sound insulation wall

Claims (7)

  A silencer type air cooling apparatus for cooling an electric device with cooling air circulated by a cooling fan, wherein the silencer is provided at both the suction port and the discharge port of the cooling fan. .   The silencer type air cooling device for an electric device according to claim 1, wherein a silencer having a rectifying function is provided in at least one of the suction port and the discharge port.   At least one of the suction port and the discharge port is provided with a silencer in which an inner peripheral surface of a cooling air flow path connected to the suction port or the discharge port is formed of a perforated plate and surrounded by a sound absorbing material. The silencer type air cooling apparatus for an electric device according to claim 1 or 2, wherein The muffler type air cooling device is configured to connect the suction port to the electric device side and suck the cooling air, and discharge the cooling air from the discharge port to the outside.
The silencer type air cooling device for electric equipment according to claim 1, wherein a silencer having a rectifying function is provided at the discharge port.   5. A silencer comprising an inner peripheral surface of a cooling air flow path connected to the suction port formed of a perforated plate and surrounded by a sound absorbing material at the suction port. Silent air cooling device for electrical equipment.   6. The electric device according to claim 4, wherein the electric device is an inverter board, and the muffler type air cooling device discharges the cooling air from the inside of the inverter board. Silent air cooling device.   6. The electric device is an AC motor housed in a housing, and the muffler type air cooling device discharges the cooling air from the inside of the housing to the outside. Silent air-cooling device for electrical equipment as described.

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