JP3564774B2 - switchboard - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a switchboard for natural ventilation cooling, and particularly to a means for promoting natural ventilation.
[0002]
[Prior art]
For example, in a switchboard (control panel) in which electrical devices and appliances having a relatively large amount of heat, such as a transformer, a resistor, and a rectifier, are housed in the panel, cooling is also important. If electrical equipment and appliances that are heat sources are installed in places with insufficient ventilation, the temperature inside the panel will rise abnormally, resulting in problems such as shortening the service life and causing burnout. For this reason, consideration is given to increasing the cooling power due to natural ventilation, such as by increasing the air supply and exhaust ports, and in some cases, a fan is installed to provide forced ventilation.
[0003]
[Problems to be solved by the invention]
However, in the case of the former (natural ventilation cooling), there is a problem that some concerns remain in terms of safety, and the system cannot be installed in a place with a bad atmosphere. In the case of the latter (forced ventilation), in addition to equipment costs, costs are also required for maintenance such as failure detection and repair thereof.
[0004]
Therefore, an object of the present invention is to provide a switchboard that can increase the cooling effect with a low-cost and simple structure.
[0005]
[Means for Solving the Problems]
According to the present invention, in a distribution board in which electric devices and appliances are housed in a panel, an exhaust port is formed into a shape exhibiting a chimney effect, and a plurality of plate-like magnetic bodies are formed below the exhaust port so as to form an air passage. And that the wires of some of the wires penetrated through them, that an iron plate was used as the plate-like magnetic material, that the size of the hole for wire penetration of the plate-like magnetic material was made variable, In addition, folds or fins are provided on the plate-shaped magnetic body.
[0006]
[Action]
When an alternating current flows through an electric wire penetrating the plate-shaped magnetic material, an alternating magnetic field is generated around the electric current, and an eddy current is generated in the magnetic material. When an eddy current is generated, a loss (eddy current loss) occurs and heat is generated. With this heat generation, an ascending airflow is generated around the magnetic body and accelerated by a chimney effect. As a result, the airflow toward the exhaust port in the panel is increased, and the heat generated by the electric equipment is quickly discharged to the outside of the panel. As a result, a rise in the temperature of the electric device or appliance is suppressed.
[0007]
【Example】
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
[0008]
1 and 2 show a first embodiment of a switchboard according to the present invention. FIG. 1 is a cross-sectional view of a state cut parallel to a side surface, and FIG. 2 is a cross-sectional view of a state cut parallel to a front face. In the figure, reference numeral 1 denotes a box, and 2 denotes electrical equipment and appliances (transformers, resistors, rectifiers, etc.) housed therein, which are main heat sources in the panel. The box 1 has an exhaust port 1A having a chimney effect on its upper surface. A large number of plate-like magnetic materials, for example, iron plates 3, are arranged below the exhaust port 1A so as to form a ventilation path toward the exhaust port 1A, and a part of the electric wire 4 of the wiring penetrates these. In the illustrated example, three sets of several sheets are arranged in parallel at a certain interval and arranged in one row, and three rows are arranged in parallel, and a space between the iron plates 3 is a ventilation path toward the exhaust port 1A. As shown in FIG. 3, the iron plate 3 is formed with a hole 3A for penetrating the electric wire. Although not shown, an air supply port is provided in a lower portion of the box 1. In addition, each iron plate 3 has its mounting leg fixed to an insulating rod or the like so as to maintain a mutual interval and to be firmly supported at a predetermined position.
[0009]
Next, the operation will be described. When an alternating current is flowing through the electric wire 4 penetrating the iron plate 3, an alternating magnetic field is generated around the electric current, and an eddy current is generated in the iron plate 3. For this reason, resistance loss due to eddy current, so-called eddy current loss, occurs, and heat is generated. In addition, the generation of the alternating magnetic field causes a hysteresis loss in the iron plate 3, which also generates heat. As a result of the heat generation, an upward airflow (convection) is generated around each iron plate 3 and accelerated by the chimney effect. As a result, the airflow toward the exhaust port 1A increases in the vicinity of the electric device / apparatus 2 in the panel, and the heat generated by the electric apparatus / appliance 2 is quickly discharged to the outside of the panel. Thereby, the temperature rise of the electric device / apparatus 2 is suppressed.
[0010]
Examples 2 to 7 are shown in FIGS. Example 2 (FIG. 4) uses a bus bar 4A for wiring in the board, and a hole 3B for wire penetration having a sufficient insulation distance with the bus bar 4A of a bare conductor is formed in the iron plate 3. Provided. Example 3 (FIG. 5) is a case where the insulating plate 5 is interposed between the bus bar 4A and the iron plate 3-1 to be integrated. The insulating plate 5 also serves as a support for the iron plate 3-1. 1 eliminates the need for mounting legs. Further, the hole 3C for penetrating the electric wire is smaller than the hole 3B of the second embodiment.
[0011]
Example 4 (FIG. 6) is a case in which the size of the hole 3D for electric wire penetration is variable, and two iron plates 3-21 and 3-22 having a U-shaped notch on one side are partially overlapped. A hole 3D for electric wire penetration is formed. The two iron plates 3-21 and 3-22 are fixed and integrated with a screw 6, and a long hole 7 is formed on one side and a screw hole is formed on the other side so that the size of the hole 3D can be adjusted. I have. The amount of heat generated can be changed by adjusting the size of the hole 3D.
[0012]
Example 5 (FIG. 7) is a case in which a hole 3E for electric wire penetration and a fold 8 are formed in the iron plate 3-3. Example 6 (FIG. 8) is a case where a hole 3 </ b> E for penetrating an electric wire is formed in an iron plate 3-4 and a radiation fin 9 is attached. In each of Example 5 and Example 6, heat radiation from the iron plates 3-3 and 3-4 is promoted, and the attraction effect is enhanced.
[0013]
Example 7 (FIG. 9) is a case where the double cylindrical body 10 is formed of an iron plate, and the electric wire 4 is penetrated in the axial direction. Also in this embodiment, as in the other embodiments, the cylindrical body 10 generates heat due to the eddy current loss, and the ventilation is promoted by the attraction effect due to the convection at the time of heat radiation. It should be noted that the present invention is not limited to the double cylinder, and may be a single cylinder or a triple cylinder or more. Further, it may be a rectangular cylinder.
[0014]
【The invention's effect】
As described above, according to the present invention, the alternating magnetic field around the wires securely wired in the panel is utilized, and eddy current loss and the like are generated in the plate-shaped magnetic body near the exhaust port having a chimney effect. And a large air flow is induced by a convection effect caused by heat generation, so that natural ventilation can be promoted with a simple structure, and stable ventilation cooling can be expected. In addition, since an iron plate is used as the plate-shaped magnetic body, it can be manufactured at low cost. Further, by making the size of the hole for electric wire penetration variable, the calorific value can be adjusted, and ventilation cooling suitable for the situation can be performed. Further, by providing the folds and the radiation fins, it is possible to enhance the attraction effect by convection, and to further promote natural ventilation.
[Brief description of the drawings]
FIG. 1 is a sectional view of a switchboard according to a first embodiment of the present invention, which is cut in parallel with a side surface.
FIG. 2 is a cross-sectional view of the switchboard according to the first embodiment of the present invention, which is cut in parallel to the front.
FIG. 3 is a perspective view of a main part according to the first embodiment.
FIG. 4 is a perspective view showing a main part of a switchboard according to a second embodiment of the present invention.
FIG. 5 is a perspective view showing a main part of a third embodiment of the switchboard according to the present invention.
FIG. 6 is a perspective view showing a main part of a switchboard according to a fourth embodiment of the present invention.
FIG. 7 is a perspective view showing a main part of a switchboard according to a fifth embodiment of the present invention.
FIG. 8 is a perspective view showing a main part of a switchboard according to a sixth embodiment of the present invention.
FIG. 9 is a perspective view showing a main part of a switchboard according to a seventh embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Box 2 ... Electric equipment and appliances 3, 3-1, 3-21, 3-22, 3-3, 3-4 ... Iron plate 3A, 3B, 3C, 3D, 3E ... Hole 4 for electric wire penetration ... Electric wire 4A ... Bus bar 5 ... Insulating plate 6 ... Screw 7 ... Elongated hole 8 ... Pleat 9 ... Heat radiation fin 10 ... Double cylindrical body

Claims (4)

In a switchboard in which electric devices and appliances are housed in the panel, the exhaust port is formed into a shape exhibiting a chimney effect, and a plurality of plate-shaped magnetic bodies are arranged below the exhaust port to form a ventilation path toward the exhaust port, A switchboard characterized in that some of the wires are passed through them. The switchboard according to claim 1, wherein an iron plate is used as the plate-shaped magnetic body. The switchboard according to claim 1 or 2, wherein the size of the hole for penetrating the electric wire of the plate-shaped magnetic material is variable. The switchboard according to claim 1, 2, or 3, wherein a fold or a fin is provided on the plate-shaped magnetic body.

Images