JPH0787629A - Ventilator for switchboard - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent warm air from staying on the ceiling of the switchboard. [Structure] A hood 9 in the shape of a ridge on the ceiling of the panel body 2 of the switchboard
Is installed and the ventilation fan 3 is installed on the top thereof. This allows
The upper side of the current transformer 6 and the bus bar 7 arranged near the ceiling is opened, ventilation is improved, and warm air does not stay in the ceiling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation device for a switchboard, which cools the inside of the switchboard by a ventilation fan.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional switchboard (transformer board) equipped with a ventilation fan, in which (A) is a side sectional view.
(B) is a front sectional view. In the figure, a ventilation fan 3 is provided on a ceiling portion of a board 2 accommodating a transformer 1, and a cover 4 is arranged above the ventilation fan 3. The ventilation fan 3 has a structure in which an impeller 3b is housed in a frame body 3a having a square cross section.
Ventilation holes 5 are opened in the front and rear surfaces of the lower part of the board 2,
When the ventilation fan 3 is operated, cold outside air taken in through the ventilation hole 5 flows as shown by an arrow, and cools the inside of the panel.
The ventilating fan 3 is on / off controlled by a thermostat (not shown) installed in the panel, and is operated when the temperature inside the panel rises to a specified value (for example, 40 ° C.), but is stopped otherwise.

[0003]

However, in the past, warm air often stayed near the ceiling even when the ventilation fan 3 was operating, which adversely affected the current transformer 6 and other devices. that is,
The busbar 7 is routed around the ceiling in a complicated manner, and although the insulator 8 and other devices supporting the busbar 7 are arranged and crowded, the busbar 7 and the devices and the ceiling plate 2a are not provided.
This is because when the air in the board that has risen is narrow, and when the air in the board that has risen hits the ceiling board 2a, it cannot pass through the ventilation fan 3 unless it changes its direction horizontally, so the ventilation passages are intricate and the ventilation in this part is not performed sufficiently. It was

Further, while the ventilation fan 3 is stopped, it is ventilated by natural convection, but since the gap between the frame 3a and the impeller 3b is small, the ventilation is insufficient and the temperature inside the panel tends to rise to a high level. During that time, it had a bad effect on the equipment inside the board. Therefore, an object of the present invention is to provide a ventilation device for a switchboard, which improves ventilation in the vicinity of the ceiling during operation of the ventilation fan and promotes natural convection while the ventilation fan is stopped to protect the equipment inside the panel. Is.

[0005]

In order to achieve the above object, according to the present invention, a roof-shaped hood is provided on the ceiling of a board and a ventilation fan is installed on the top of the hood. Further, in that case, a ventilation window opened in the hood when the ventilation fan is stopped is opened, and a shutter that automatically opens and closes in conjunction with the operation of the ventilation fan is provided in the ventilation window to promote natural convection during the stop of the ventilation fan. To do. An appropriate actuator such as a solenoid that is turned on and off at the same time as the ventilation fan can be used to automatically open and close the shutter, but if the shutter is composed of a flapper that has one end openably supported and an opening spring that holds this flapper in the open position, The structure is simple because it is not necessary to separately provide means for driving the shutter.

[0006]

[Function] By providing a hood in the shape of a ridge on the ceiling of the board and installing a ventilation fan on the top of the hood, the space above the busbars and equipment located near the ceiling is opened and the rising air is guided to the hood. Since it reaches the ventilation fan smoothly, warm air does not stay near the ceiling. In addition, natural convection is facilitated by opening a ventilation window in the hood that opens when the ventilation fan is stopped. This ventilation window must be closed during operation of the ventilation fan, but if a shutter is provided from this flapper, one end of which is openably and closably supported, and a spring that holds this flapper in the open position, the ventilation window can be operated at the same time. Due to the negative pressure on the suction side, the flapper is sucked against the spring to automatically close the ventilation window.

[0007]

1 and 2 show an embodiment of the present invention. (A) of FIG. 1 is a side sectional view of a switchboard showing the flow of air during operation of a ventilation fan, and (B) is a front sectional view thereof. Further, FIG. 2 is an enlarged cross-sectional view of an essential part showing natural convection of air while the ventilation fan is stopped. The same reference numerals are used for the parts corresponding to those of the conventional example. In FIG. 1, a hood 9 is provided on the ceiling of the board 2, and a ventilation fan 3 is installed on the top thereof. The hood 9 is attached to the ceiling plate 2a so as to cover a large rectangular opening, leaving only a peripheral portion thereof,
The structure is in the shape of a ridge, where four roof plates 9a from four sides are gathered in the center with an appropriate slope, and a ventilation fan 3 is installed in a square opening at the top.

Further, a rectangular ventilation window 10 (FIG. 2) is formed in the roof plate 9a on four sides of the hood 9, and the ventilation window 10 is provided with a shutter 11. As shown in FIG.
The shutter 11 has a hinge 12 at the upper end and a roof plate 9 of the hood 9.
A flapper 11a that is openably and closably supported by a, and an opening spring 1 that includes a compression coil spring that holds the flapper 11a in the open position shown in the drawing.
It consists of 1b. The opening spring 11b is the flapper 11
It is provided at two places on the left and right so as to push the middle side of the a, and the lower end thereof is housed in the spring receiving recess 13 of the roof panel 9a.
The opening of the flapper 11a pushed from the inside by the opening spring 11b is regulated by the stopper piece 14 fixed to the roof plate 9a. The other structure is the same as that of the conventional example of FIG.

In such a switchboard, when the ventilation fan 3 is operated, a negative pressure on the suction side causes a pressure difference between the inside and outside of the ventilation window 10. Therefore, the flapper 11a is attracted to the roof plate 9a side against the opening spring 11b, and closes the ventilation window 10 as shown by the solid line in FIG. In this state, the outside air sucked into the board from the ventilation holes 5 flows as indicated by the arrow, and cools the board. At that time, since the hood 9 is provided on the ceiling in the illustrated configuration, the space above the busbar 7, the insulator 8, or the current transformer 6 is opened, and the air that has exited the board 2 is hood 9 Since the air is guided to the ventilation fan 3 by the gradient of, the ventilation is smoother than that of the conventional configuration, and warm air does not stay on the ceiling.

On the other hand, when the ventilation fan 3 is stopped, the ventilation window 10a
There is no pressure difference between the inside and outside of the flapper 11a
The force of 1b pushes it open as shown in FIG. As a result, a large amount of air convection occurs in the panel between the ventilation hole 5 and the ventilation window 10. As a result, the temperature inside the panel during the stop of the ventilation fan 3 becomes lower than before, which has a favorable effect on the equipment and reduces the operating opportunities of the ventilation fan 3 to save energy.

[0011]

As described above, according to the present invention, by providing the hood in the shape of a ridge on the ceiling of the board and installing the ventilation fan on the top of the hood, warm air near the ceiling is not retained and the hood is eliminated. There is no need to worry about deterioration of the attached equipment due to heat. Further, by opening a ventilation window in the hood that is opened when the ventilation fan is stopped, and providing a shutter that automatically opens and closes in conjunction with the operation of the ventilation fan in this ventilation window, natural convection is promoted and ventilation efficiency when the ventilation fan is stopped is increased. Further in that case,
If the shutter is composed of a flapper whose one end is openably and closably supported and an opening spring that holds the flapper in the open position, a special driving means is not required for opening and closing the shutter, and the structure is simplified.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, in which (A) is a side sectional view of a switchboard during operation of a ventilation fan, and (B) is a front sectional view thereof.

2 is an enlarged front cross-sectional view of a main part of the switchboard of FIG. 1 when a ventilation fan is stopped.

FIG. 3 shows a conventional example, in which (A) is a side sectional view of a switchboard and (B) is a front sectional view thereof.

[Explanation of symbols]

 2 board body 3 ventilation fan 5 ventilation hole 9 hood 10 ventilation window 11 shutter 11a flapper 11b opening spring

Claims (3)

[Claims] 1. A ventilating device for a switchboard, wherein a switchboard is provided with a ventilating fan on the ceiling of the switchboard, and a roof-shaped hood is provided on the ceiling of the switchboard, and the ventilating fan is installed on the top thereof. 2. A ventilation window opened in the hood when the ventilation fan is stopped, and a shutter which automatically opens and closes in conjunction with the operation of the ventilation fan is provided in the ventilation window.
Ventilation device for the listed switchboard. 3. A ventilation device for a switchboard according to claim 2, wherein the shutter is composed of a flapper whose one end is openably and closably supported, and an opening spring which holds the flapper in an open position.