JP2002151874A - Power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of storing board with a drip-proof structure for storing a power converter unit, while high-temperature wind discharged from the power converter unit in a forced cooling state is prevented from adversely, affecting the apparatus. SOLUTION: A cooling fin 2 for a transistor is provided in a ventilation path 1, formed on the inner rear side in an inverter unit 10. Upward cooling wind generated from a cooling fan 3 is caused to flow in the ventilation path 1. A control printed board 6 is provided on the inner front side of the inverter unit 10, and the front side thereof is covered with a front cover 7, having a slit 8. When the inverter unit 10 is stored in a storage board with a drip-proof structure, the upper edge of the ventilation path is blocked with a roof plate 4, and a side-face exhaustion hole 24 is formed on both side faces of the upper part of the ventilation path. In addition, a drip-proof type side-face exhaust hole 31 is provided at a position corresponding to the side-face exhaust hole 24, and a side-face gallery 33 is provided at the front face of the storage board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion device having a structure in which high-temperature cooling air discharged from a power conversion unit housed in a storage board is smoothly discharged from the storage board.

[0002]

2. Description of the Related Art For example, there is an inverter as an example of a device for converting DC to AC power. This inverter consists of, for example, a semiconductor switch element such as a transistor, a cooling fin for removing heat generated by the transistor, a cooling fan for sending cooling air to the cooling fin, a control printed board for controlling the operation of the transistor, and the like. In many cases, these are collectively arranged in a box shape, and this is referred to as an inverter unit. The inverter unit as a power conversion unit is installed in various places according to the purpose of use, such as being housed in a switchboard or constituting a control device collectively with other devices. Units are often provided with a simple cover to protect their internal equipment.

FIG. 5 is a structural diagram showing a configuration of a conventional inverter unit. In this inverter unit, devices such as transistors and capacitors are arranged in front of it,
A ventilation path 1 through which cooling air flows is provided on the rear side. Heat generated when the transistor operates is transmitted to the cooling fins 2 projecting into the ventilation path 1. The cooling fan 3 installed in the upper part of the ventilation path 1 draws heat from the cooling fins 2 by the air flow which is drawn from the lower part of the ventilation path 1 and flows in the direction of the arrow. Since the upper end of the ventilation passage 1 is closed by the top plate 4, the cooling air whose temperature has been increased by the heat taken from the cooling fins 2 is:
It is discharged from the front opening 5 directly below the top plate 4 in the direction of the arrow, that is, forward. Or, unlike this illustration,
If the top plate 4 is removed and the front side opening 5 is closed, the high-temperature cooling air is discharged upward as it is, that is, in the direction of the dashed arrow. It is also possible to arrange the cooling fan 3 on the inlet side of the ventilation path 1 differently from the illustration and to push the cooling air into the ventilation path 1.

Since the control printed board 6 is also provided with functions for setting the operating conditions of the inverter, adjusting and displaying the operation state, it is arranged at a position where adjustment operation and monitoring are easy, that is, at the upper front of the inverter unit. In order to protect the control printed board 6, a front cover 7 is provided on the front side. Further, in order to suppress a rise in temperature due to self-heating of the control printed board 6 by natural ventilation, a slit 8 is formed in the front cover 7 as a ventilation opening.

[0005] As described above, since it is not known where and how the inverter unit is to be used, only a simple covering is applied. Therefore, when the inverter unit is, for example, for speed control of an induction motor and is installed on the machine side of the motor, it is stored in a drip-proof storage box, but when installed on the machine side of the motor, it is wide. It is often difficult to secure an installation space, and it is desirable that the storage panel be small.

[0006]

FIG. 6 is an outline drawing showing a conventional example of a drip-proof storage box for storing an inverter unit having a structure for discharging a high-temperature cooling air upward.
If the built-in inverter unit has a structure that discharges high-temperature cooling air upward, providing an exhaust port on the ceiling of the storage panel is the most effective way to discharge cooling air to the outside of the storage panel. Structure. However, in order to have a drip-proof structure even if the discharge opening is on the ceiling plate, a draining plate (not shown) that is raised upward is provided around the entire periphery of the opening. Since it is necessary to cover the portion with the drip-proof cover 11, it takes time and effort to make the drip-proof structure, and there is a drawback that the height of the storage board becomes large. Reference numeral 12 denotes a drip-proof exhaust port called a gallery provided on the outer cover on the front side of the storage panel, and a slit 8 provided on the front cover 7 of the stored inverter unit (see FIG. 5).
And has a function of discharging heat generated by the control printed board 6 from the storage board to the outside.

FIG. 7 is a cross-sectional view showing a conventional example of a drip-proof storage board in which an inverter unit for closing the upper end of the ventilation passage shown in FIG. The cooling air discharged from the inverter unit 10
The top plate 4 closing the upper end of the ventilation passage 1 hits the top plate 4 as shown by the arrow, and the front opening 5 at the top of the inverter unit.
Through the gallery 12 provided on the upper front side of the storage board. That is, since the cooling air is not discharged upward, the discharge port and the drip-proof cover 1 are provided on the ceiling portion of the storage panel.
1, and the height of the storage board can be reduced.

However, not all of the cooling air discharged from the inverter unit 10 is discharged from the gallery 12 provided on the upper front side of the storage panel. Through the slit 8 (see FIG. 5) of the front cover 7 installed on the front side. Since the cooling air is at a high temperature as described above, the components mounted on the control printed board 6 may be exposed to the high temperature and cause problems such as breakage or deterioration of the function.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drip-proof structure in which a high-temperature cooling air discharged from a power conversion unit in which forced air cooling is performed does not adversely affect equipment and a power conversion unit is housed. The purpose is to reduce the size of the storage board.

[0010]

In order to achieve the above object, a power converter according to the present invention comprises a box-shaped power supply containing a semiconductor switch element and its cooling fins, a control printed board and a cooling fan. A ventilation path is formed on the rear side of the inside of the conversion unit, the cooling fins are installed in the ventilation path, and upward cooling air generated by the cooling fan flows through the ventilation path, and the inside of the power conversion unit is The control printed board is installed on the front side, and the power conversion unit configured to cover the front side with a front cover having a ventilation opening is stored in a drip-proof storage panel. Close and provide an exhaust opening on the other side of the ventilation path except the control printed board installation side, and provide a drip-proof exhaust port on the side of the storage board corresponding to the exhaust opening. , The revenue It shall provide a drip-proof type outlet to the front corresponding to the ventilation opening of the panel.

[0011]

FIG. 1 is an external view showing the appearance of a power conversion unit according to a first embodiment of the present invention. In FIG. 1, a cooling air intake 21 is provided at a lower end on the rear side of an inverter unit as a power conversion unit. The cooling air sucked from the cooling air cools the condenser 22 and the like installed at the inlet of the cooling air intake 21 and further cools the cooling fins of the transistor which cannot be shown because they are installed inside the ventilation passage. In the present invention, the upper end of the ventilation passage is closed by the top plate 4 (see FIG. 5), and the front surface of the upper end is also closed by the front plate 23. Therefore, the cooling air that has risen in the ventilation path is discharged from the side exhaust ports 24 provided at the upper portions on both sides of the inverter unit. Note that an exhaust port can be provided at the upper portion of the back surface of the inverter unit, but this is limited to the case where a space is provided on the back surface when a storage panel for storing the inverter unit is installed. That is, when the storage panel is a wall-mounted type, no exhaust port is provided on the upper part of the back surface of the inverter unit. Reference numeral 7 denotes a front cover, and the slit 8 opened in the front cover is for dissipating heat generated by a control printed board (not shown) in the interior by natural ventilation as described above.

FIG. 2 is a first external view showing the external shape of a storage panel according to a first embodiment of the present invention which stores the power conversion unit shown in FIG. In FIG. 2, drip-proof type side exhaust ports 31 are provided on both side surfaces of the storage board, and the position of the drip-proof type side exhaust ports 31 is determined by the side exhaust ports 24 (see FIG. ), The cooling air that has passed through the ventilation path of the inverter unit and has become hot is cooled by the drip-proof side exhaust port 3.
Emitted from 1. The position of the front gallery 32 as a drip-proof exhaust port provided on the front surface of the storage panel is provided by a slit 8 for ventilating heat generated by the control printed board 6 installed in the built-in inverter unit (see FIG. 1). ).

FIG. 3 is a second external view showing another external shape of the storage panel according to the first embodiment of the present invention which stores the power conversion unit shown in FIG. In FIG. 3, a side gallery 33 as a drip-proof exhaust port is provided on both sides of the storage board. The side gallery 33 has the effect of reducing the width of the storage panel as compared with the drip-proof type side exhaust port 31 shown in FIG. 2, and the ventilation area increases or decreases depending on the number of steps in the gallery.
The provision of the front gallery 32 on the front side is similar to the case of the first external view described above with reference to FIG.

FIG. 4 is a sectional view showing a second embodiment of the present invention by cutting the storage board shown in FIG. 2 along a horizontal plane.
As described above, the outer dimensions of the inverter unit 10 are reduced as much as possible by storing the inverter unit 10 in a storage panel having a slightly larger drip-proof structure. Some gap is required between them. Most of the high-temperature cooling air discharged from the side exhaust port 24 (see FIG. 1) of the inverter unit 10 is drip-proof side exhaust port 31 of the storage board (see FIG. 2).
When a part of the high-temperature cooling air flows around the front side of the inverter unit 10 through the above-mentioned gap, the control printed board built in the inverter unit 10 is exposed to high temperature as described above. Causes a malfunction.
Therefore, in the second embodiment shown in FIG. 4, the wind shield plate 3 that prevents the high-temperature cooling air from flowing to the front side of the inverter unit 10.
5 is provided between the inside of the storage board and the inverter unit 10.

The air shield plate 35 is provided with a drip-proof side exhaust port 3 provided on the side of the storage board.
It is only necessary that the air resistance is larger than the air resistance when the cooling air is discharged from 1, so that there is no need to completely separate the inverter unit 10 and the storage board with the wind shield plate 35.

[0016]

According to the present invention, when the power conversion unit is stored in the drip-proof storage box, the internal equipment of the power conversion unit is conventionally forcibly cooled to discharge the high-temperature cooling air. Due to the large size or inappropriate discharge of cooling air, inconveniences such as exposure of internal devices such as printed circuit boards for control to high-temperature cooling air have occurred. On the other hand, in the present invention, the high-temperature cooling air is discharged from an outlet provided on a surface other than the front surface of the power conversion unit, but the drip-proof storage panel housing the power conversion unit includes: By providing a drip-proof exhaust port at a position corresponding to the discharge port provided in the power conversion unit, the effect of reducing the outer dimensions without damaging the drip-proof structure of the storage board can be obtained, and the control printed board can be heated to a high temperature. This has the effect of avoiding the problem of being exposed to the cooling air that has become unstable.

[Brief description of the drawings]

FIG. 1 is an external view showing an external appearance of a power conversion unit according to a first embodiment of the present invention.

FIG. 2 is a first external view showing an external shape of a storage panel according to the first embodiment of the present invention which stores the power conversion unit shown in FIG. 1;

FIG. 3 is a second external view showing another external shape of the storage panel according to the first embodiment of the present invention which stores the power conversion unit shown in FIG. 1;

FIG. 4 is a sectional view showing a second embodiment of the present invention by cutting the storage board shown in FIG. 2 along a horizontal plane.

FIG. 5 is a structural diagram showing a configuration of a conventional inverter unit.

FIG. 6 is an outline view showing a conventional example of a drip-proof storage panel that stores an inverter unit configured to discharge a high-temperature cooling air upward.

FIG. 7 is a cross-sectional view showing a conventional example of a drip-proof storage panel in which an inverter unit that closes an upper end of a ventilation path illustrated in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ventilation path 2 Cooling fin 3 Cooling fan 4 Top plate 5 Front side opening part 6 Control printed board 7 Front cover 8 Slit as ventilation opening 10 Inverter unit as power conversion unit 11 Drip-proof cover 12 Gallery 21 Cooling air Inlet 23 Front panel 24 Side exhaust port as exhaust opening 31 Drip-proof side exhaust port 32 Front gallery as drip-proof exhaust port 33 Side gallery as drip-proof side exhaust port 35 Windshield

Claims (2)

[Claims] 1. A ventilation path is formed on the inside rear side of a box-shaped power conversion unit accommodating a semiconductor switch element and its cooling fin, a control printed board and a cooling fan, and the cooling fin is formed in the ventilation path. Is installed, the upward cooling air generated by the cooling fan is caused to flow through the ventilation path, the control printed board is installed on the inside front side of the power conversion unit, and a front cover having a ventilation opening is provided. In a power conversion device in which a power conversion unit configured to cover its front side is stored in a drip-proof storage panel, an upper end of the ventilation path is closed, and an upper side of the ventilation path except for the control printed board installation side is removed. Provide an exhaust opening on the other side,
A drip-proof exhaust port is provided on a side surface of the storage panel corresponding to the exhaust opening, and a drip-proof exhaust port is provided on a front surface of the storage panel corresponding to the ventilation opening. Power converter. 2. The power converter according to claim 1, wherein cooling air discharged from an exhaust opening at an upper portion of a ventilation path of the power conversion unit is discharged from a drip-proof exhaust port on a front surface of the storage board. A power converter, wherein a partition for preventing the power conversion is provided between the storage board and the power conversion unit.