JPH02899Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a ballast case for a discharge lamp.

As is well known, this type of case is used to house the ballast body inside, and is also filled with a filler. Normally, this type of case is constructed by rolling a metal plate, such as a steel plate, into a cylindrical shape, overlapping the side edges, and then welding or fixing the overlapping parts with rivets. There is. However, with this configuration, welding, rivets, etc. are used to fix the overlapping side edges, so the fixing work is troublesome. Further, the inner surface of the overlapping portion is stepped and cannot be flat. Therefore, the stepped portion comes to protrude from the inner surface. If the stepped portion is located on the top surface of the case, the distance from the ballast body housed inside will be shorter than other parts by the thickness of the stepped portion. In other words, the insulation distance becomes shorter and there is a risk of insulation failure. In order to prevent this, the distance between the stepped portion and the ballast body may be made as long as necessary;
If this is done, the cross section of the case will eventually become larger, leading to an increase in the size of the case.

If you want to avoid increasing the size of the case, you can reduce the cross-sectional area of the ballast itself, especially its core.
However, if this is done, the vertical width of the ballast body must be increased. However, increasing the vertical width of the ballast body causes an increase in noise.

The purpose of this idea is to simplify the structure of the case and reduce noise.

An embodiment of this invention will be described with reference to the drawings. As shown in the figure, the ballast case is made of rolled steel plate into a cylindrical shape, which is not much different from the conventional case described above.
In the figure, 1 is a bottom wall, 2 and 3 are side walls, and 4 is a top wall. The abutting portions of the edges 5 and 6 of the rolled steel plate are located on the upper wall 4 in the illustrated example. In other words, the upper wall 4 is held near both end edges of the steel plate.
is constructed. As described above, in the past, the edges 5 and 6 were overlapped with each other, and the overlapped portion was fixed by welding, rivets, or the like.

In this invention, both end edges 5 and 6 are connected and fixed like a fastener, and FIG. 2 shows an enlarged view thereof. One edge 5 has a protrusion 7 and a recess 8, and the other edge 6 has a recess 9 into which the projection 7 can fit, and a projection 10 into which the recess 8 can fit. A large number of these are consecutively provided so that they are alternately located. Each protrusion has a slightly bulged tip, similar to a normal fastener. In order to connect the edges 5 and 6 with such a protrusion and a recess,
The protruding part of one edge into the recessed part of the other edge,
Alternatively, after facing the recessed portion of one end edge with the protruding portion of the other end edge, external force may be applied to insert the tip of each protruding portion into the recessed portion. When first inserted, the tip of the protrusion is expanded, so it is difficult to insert it into the recess.
You can easily insert it by pressing it firmly. By this insertion, the binding of both end edges 5, 6 to each other is completed.

When the protrusion 10 is sufficiently larger than the depression 9, the edges 5 and 6 may be joined together by fitting the protrusion 10 from the upper surface of the depression 9.

When the edges are fixed together as described above, there is no overlap between the edges in the fixed portion, so this overlap does not cause any increase in the cross-sectional shape. In addition, fixing can be accomplished by simply inserting the protrusion into the recess, and there is no need for welding, rivets, etc. as in the conventional case, so the fixing is extremely easy. Once they are tied together, the bulge at the tip of the protrusion is fitted into the recess, so there is no risk of the bond coming off even if an external tensile force is applied.

Furthermore, as described above, the fixed portions of the edges do not overlap and are flat, so there is no need to reduce the cross-sectional area of the iron core of the ballast body, making it possible to reduce noise.

Specifically, for a ballast with the same VA capacity, when a case with a conventional configuration was used, the noise was 27 horns, but when a case with this invention was used, the noise was reduced to 23 to 24 horns. It has been confirmed that it has decreased.

As detailed above, according to this invention, this type of ballast case can be manufactured inexpensively and easily, and the cross-sectional shape does not have to be enlarged at all, and the edges are close to each other. It has the advantage of being able to bond sufficiently firmly and further reducing noise.

Since this invention does not require welding or riveting, a colored steel plate may be used as the steel plate.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an embodiment of this invention;
The figure is an enlarged perspective view of main parts. 5, 6... Edge, 7, 10... Protrusion, 8, 9
... hollow part.

Claims (1)

[Scope of Claim for Utility Model Registration] A ballast case for a discharge lamp in which a metal plate is rolled into a cylindrical shape, the edges of the metal plate are fixed together, a ballast body is housed inside, and a filler is filled. On one of the edges, a large number of protrusions and depressions each having a bulging tip are arranged in succession, and on the other edge, a depression into which the protrusions can fit, and the depressions are provided on the other edge. A large number of protrusions having bulged tips that can be fitted into the parts are arranged in succession in the same way,
A ballast case for a discharge lamp, which is formed by fitting protrusions on both ends into recessed portions of both ends and bonding the ends together.