JPS6114247Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a power distribution board, and in particular, the structure of the gusset used in the connection between the ceiling frame, bottom frame, and column frame of a steel plate power distribution board that is made of steel plates and assembled by processing and forming. The purpose of this improvement is to increase the weight of parts that can be installed inside the panel and strengthen the rigidity.

BACKGROUND ART Conventionally, a steel plate switchboard made of steel plates, which are processed and formed and assembled together, is generally constructed as shown in FIGS. 1 to 6. To explain this in the current figure, 1, 1... are the column frames, 2 is the ceiling frame, and 3 is the bottom frame. These column frames 1, ceiling frame 2, and bottom frame 3 are molded separately, and each frame is The space between them is connected by a gusset 4 as shown in FIG. In the example shown in FIG. 2, the gusset 4 is appropriately spot welded 5 to the bottom frame 3.
The column frame 1 is attached with blind rivets 6.

The structure of the gusset 4 itself is as shown in FIG. That is, the gusset 4 has a bottom plate 4a formed in a substantially isosceles triangular shape, and a side wall 4 bent upward at a right angle is provided on the equilateral side edge of the bottom plate 4a.
b, 4b are consecutive. The corner portions of the reinforcing frames 4b, 4b form rising portions 4c having an L-shaped cross section, and the lower end of the column frame 1 is fitted and fixed to the rising portions 4c. FIG. 4 shows a state in which the column frame 1 is fitted.

The housing 7 of the switchboard configured as described above is further provided with a middle frame 8 as shown in FIG.
A device plate 9 is attached to the holder, and electrical equipment 10 such as a reactor capacitor, which is quite heavy, is attached.
However, in this case, the instrument plate 9 serves as reinforcement and the fifth
Although the deformation in the direction of X--X in the figure is reduced, it does not serve as reinforcement in the direction of Y--Y, and the mounting structure of the gusset 4 does not have sufficient strength.

Further, as shown in FIG. 6, a shelf 11 may be provided on the housing 7 and the electrical equipment 10 may be placed on it. In this case, the shelf 11 is It is not reinforced in either the direction or the Y-Y direction.

According to experience and experiments, the displacement of the ceiling with respect to the foundation of the power distribution board explained above is very rarely caused by the curved deformation of the column frame 1, and is hardly a problem, and most of the displacement is caused by connecting each frame. It is clear that this is due to a very slight deformation of the gusset section to achieve this, or to a relative displacement between the parts at the fastening section. Further, as described above, the influence of the mounting means of the electrical devices 10, 10, . . . is small.

Generally, the height of a switchboard is quite high at 2350 mm, including the base height of 50 mm, and slight deformation or relative displacement of the gusset that connects the ceiling frame 2 or bottom frame 3 and column frame 1 is magnified, and the ceiling This will result in a large displacement. Furthermore, from the structural point of view, a large moment is applied to the gusset portion, and it can be inferred that deformation is likely to occur in this portion, and any relative displacement or excessive deformation that occurs will result in permanent deformation.

Therefore, according to the conventional switchboard, the following problems arise.

When moving and transporting a switchboard, deformation tends to occur at the gusset. In particular, when moving and transporting the product, it is fine if it is hung vertically, but when it is being pulled down or raised when it is placed on its side and transported by forklift, an excessive moment is applied to the gusset, which can cause permanent deformation. Easy to occur.

In order to mount heavier electrical equipment inside the switchboard, it is necessary to use a gusset that is strong enough to be less susceptible to deformation.

The amount of deformation is large relative to the weight of the electrical equipment installed in the switchboard, which means that the rigidity is small.
The natural frequency is low, and there are problems with vibration resistance.

The present invention eliminates the above-mentioned conventional drawbacks, and will be described in detail below along with embodiments shown in the drawings.

FIG. 7 and subsequent figures illustrate one embodiment of the present invention. In each figure, the same or corresponding parts as in FIGS. 1 to 6 are designated by the same reference numerals, and their explanations will be omitted.

In this embodiment, the rising portion 4c of the gusset 4
A first reinforcing frame 12 having an L-shaped cross section is fixed to the inside of the base plate 4b, and both side ends of the base end of the reinforcing frame 12 are butted together, and both side edges are connected to the bottom plate 4a and the side wall 4b.
In this structure, a second reinforcing frame 13 is fixed by spot welding in contact with b.

That is, as is clear from FIGS. 8 to 10, the first
The reinforcing frame 12 is bent into an L-shape, and the side end of one side 12a thereof is placed in contact with the inside of one end of the rising part 4c of the gusset 4, while the tip of the other side 12b is bent into an L-shape. The column frame 1 is provided with a gap large enough to fit the bent portion 1a of the column frame 1 between the raised portion 4c and the other end of the raised portion 4c.

Therefore, as shown in FIG.
The two first reinforcing frames 12 together form a hollow column with a substantially quadrilateral cross section. 1st
Of course, the lower end of the reinforcing frame 12 is gusseted 4.
It is fixed to the bottom plate 4a by spot welding.

The gusset structure according to the present invention is reinforced by the first and second reinforcing frames 12 and 13 as described above, and the column frame 1, which is fitted and fixed to the rising portion 4c, is connected to the reinforcing frame 12. It is fixed by spot welding 5.

Further, the gusset 4 itself is fixed to the bottom frame 3 with blind rivets 6, and the gusset 4, the bottom frame 3, and the underframe 14 are fastened together with bolts 15 and fixed.

In the switchboard having the above structure, the attachment part of the gusset to the column frame 1 is formed in a square shape in cross section, so the moment of inertia of the area increases,
Strength was significantly improved.

That is, as shown in Figs. 11 and 12, if the external force applied to the casing 7 is Fx, and the amount of deformation dx is the amount of deformation at that time, Fx = 130Kg for the conventional structure.
When dx = 90 mm, the structure of the present invention improved to dx = 45 mm when Fx = 130 kg. The natural frequency of the conventional structure was 4Hz, but now it is 6.5Hz. Furthermore, compared to the conventional structure, the moment of inertia of area has increased, the section modulus has also increased, and the stress generated in the gusset has been reduced, so the possibility of permanent deformation has been reduced. Furthermore, since blind rivets attached to the gusset of the column frame or screw fastening have been changed to welding, relative displacement between the gusset and the column frame due to gaps between holes and screws or the outside diameter of the rivet will not occur. Summer.

As is clear from the above description, according to the present invention, it is possible to obtain a switchboard that has high strength, has a large resistance to external forces, and is less likely to undergo permanent deformation.

[Brief explanation of the drawing]

Figures 1 to 6 explain the conventional structure.
Figure 1 is an exploded perspective view of the switchboard housing, Figure 2 is a perspective view illustrating how the column frame is attached, Figure 3 is a perspective view of the gusset, and Figure 4 is a cross-sectional plane explaining how the column frame is attached. Figures 5 and 6 are perspective views for explaining the deformed state with the inner frame and shelf board attached, and Figures 7 to 12 are for explaining one embodiment of the present invention. The figure is an exploded perspective view of the switchboard casing, Figure 8 is a perspective view explaining how the column frame is attached, Figure 9 is a perspective view explaining how the reinforcing frame is attached, and Figure 10 is the state with the column frame attached. FIGS. 11 and 12 are a side view and a cross-sectional plan view illustrating the deformed state. 1... Column frame, 2... Ceiling frame, 3... Bottom frame, 4...
... Gusset, 4c... Rising part, 5... Spot welding, 6... Blind rivet, 7... Housing,
12...first reinforcing frame, 13...second reinforcing frame.

Claims (1)

[Scope of utility model registration request] In a power distribution board in which column frames are arranged at the four corners of a ceiling frame and a bottom frame through gussets, a bottom plate 4a is attached to the four corners of the ceiling frame 2 and a bottom frame 3, and side walls 4b are attached to two sides located at right angles to each other. Furthermore, a gusset 4 having a rising portion 4b having an L-shaped cross section is fixed to the corner portion, and a first reinforcing frame 12 having an L-shaped cross section fixed to the inner side of the corner of the gusset 4 is combined with the rising portion 4c. The upper and lower ends of the column frame 1, which has a substantially C-shaped cross section, are aligned along the outside of each rising portion 4c of the gusset 4 attached to the ceiling frame 2 and the bottom frame 3. The bent portion 1a at one end of the column frame 1 is fitted into the gap formed between one end of the rising portion 4c and the side 12b of the first reinforcing frame 12, and the column frame 1 and the rising portion 4c are connected. The lower part 2 of the first reinforcing frame 12 is fixed between the
A switchboard characterized in that the sides are reinforced with a pair of left and right second reinforcing frames 13 fixed to the bottom plate of the gusset 4.