JPS6244558Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention provides an engaging piece on each of at least two plate-like parts constituting the case, and a first engaging piece provided on one plate-like part adjacent to each other and a first engaging piece provided on the other plate-like part adjacent to each other. The second engaging piece provided on the plate-shaped part is rolled up together with the second engaging piece provided on the plate-shaped part in a state where they are overlapped with each other, thereby forming an engaging part having a rolled-up shape in cross section, and The present invention relates to a shield case configured such that the one and the other plate-shaped portions are joined to each other by an engaging portion.

In electronic equipment such as television receivers and video tape recorders, electronic components such as those mentioned above are used to effectively prevent magnetic flux leakage from transformers, DC-DC converters, etc. from adversely affecting surrounding circuits. It is stored inside a shield case.

FIG. 1 shows a conventional shielding case 1 of this kind. This shielding case 1 is a box with an open bottom made by bending a sheet of iron, for example. Along with composing the body,
For example, a pair of protrusions integrally molded at the joint portions (seam portions) of the side plates 2, 3, 4, and 5 are bent to form bent pieces 6, and these bent pieces 6 form the side plate. 2, 3, 4, and 5 are joined to each other. Further, two pairs of cut and raised pieces 7 cut and raised on the inside of the case are provided on each of the side plate 3 and the side plate 5 of the shielding case 1 so as to form pairs with each other. Each of these cut and raised pieces 7 has a gap of a predetermined width, into which an edge of a printed wiring board (not shown) or the like can be inserted. Therefore, within the shielding case 1, a printed wiring board or the like is securely held at four locations by the four pairs of cut and raised pieces 7. Also, as shown in Figure 1,
A closing plate 8 that closes the bottom opening of the shielding case 1 is held by claw pieces 11, and terminals of various electric circuit components are pulled out from a plurality of holes 9 formed in this closing plate 8. . In FIG. 1, 10 is a side plate 3, for attaching the shielding case 1 to a printed wiring board, chassis, etc.
5 are mounting protrusions provided at the lower ends of each.

However, although such a shielding case 1 is easy to manufacture and inexpensive, it is very difficult to join the seams between the side panels 2 to 5 with the bent pieces 6 in a completely sealed state without any gaps. . Therefore, even if the above-described shielding case 1 is used, there is a drawback that it is not possible to effectively prevent the adverse effects caused by electromagnetic leakage phenomena. In particular, when a magnetic shield is required, such a shielding case 1 cannot be used.

Therefore, conventionally, when a magnetic shield is required, a shielding case 1 as shown in Fig. 2 is usually used.
2 is used. Case 12 for this shield
is made by drawing a single iron plate or the like, and is provided with cut and raised pieces 7 and mounting protrusions 10, respectively, as in the case of the shield case 1 described above, and a closing plate 8 is provided at the bottom. Claw piece 1 with the opening closed
It is held at 1. According to such a shielding case 12, since it is formed by drawing process, it is possible to obtain a completely sealed state, but since the process of drawing process is troublesome, the shielding case 12
The problem was that it was very expensive to manufacture. Moreover, if the depth of the drawing and thus the depth of the shielding case 12 is to be made deeper, the manufacturing cost will increase in proportion to the depth, and the depth of the drawing will also be limited due to processing constraints. The reality is that it can only be processed to a certain extent.

In addition, in the shield cases 1 and 12 shown in FIGS. 1 and 2, respectively, it is necessary to cut and bend a part of the case at several places in order to form the cut and bend pieces 7. A number of holes 7a are created by raising the material. Therefore, electromagnetic leakage occurs from these holes 7a, so that shielding by the shielding cases 1 and 12 cannot be performed effectively.

The present invention was devised in view of the above-mentioned actual situation, and can be manufactured at low cost, configured to a desired size (especially depth), and is extremely easy to install a printed wiring board inside the shielding case. It is an object of the present invention to provide a shielding case that can be attached to a shield and that can obtain a sufficient shielding effect.

Embodiments of a shielding case to which the present invention is applied will be described below with reference to FIGS. 3 to 8. Note that parts common to those in FIGS. 1 and 2 are designated by the same reference numerals and their explanations will be omitted. Further, in order to simplify the drawings, illustrations of the cut-and-raised piece 7 and the hole 7a are omitted in FIGS. 4 to 8.

The shielding case 20 of this embodiment is made by bending a single sheet metal, for example, made of iron, and has a substantially rectangular parallelepiped shape as a whole, as shown in FIG. The seams 25, 26, 27, 28 of the four side views 21, 22, 23, 24 of the shielding case 20 are shown in FIG.
The engaging portions 29, 3 have a rolled-up cross section as shown in FIG.
0, 31, and 32 are formed, respectively, and these engaging portions 29 to 32 allow the above-mentioned side plate 21
-24 are engaged with each other.

Here, in order to further clarify the structure of the shielding case 20, the manufacturing procedure of the shielding case 20 will be described.

First, a cross-shaped plate member 34 as shown in FIG. 4A is punched out of an iron plate or the like. By this punching process, the side plates 21, 22 of the shield case 20,
Plate parts 21' and 2 corresponding to 23 and 24, respectively
2', 23', 24' are formed, and four cuts 35 are formed between them. Next, as shown in FIG. 4B, both end portions of the plate portions 21 to 24' are bent at right angles in a predetermined direction along the bending line 36, thereby forming the engaging pieces 21a and 22.
a, 23a, and 24a are formed, respectively. Then, as shown in FIG. 4C, the side plates 22, 24 are bent by bending the plate parts 22', 24' along the bending line 37 so as to be perpendicular to the plate parts 21', 23'. Form. Thereafter, as shown in FIG. 4D, the plate portions 21', 23' are bent at right angles along the bending line 38 to form the side plates 21, 23. As a result, as shown in FIGS. 4D and 4E, these side plates 21 and 23 are brought into contact with the right-angled engagement pieces 22a and 24a of the side plates 22 and 24, respectively, and the side plates 21 and 23 engaging pieces 21a, 23a are in a state perpendicular to the engaging pieces 22a, 24a.

Next, as shown by the arrow in FIG.
The engaging pieces 22a and 24a of 2 and 24 are wrapped in a substantially U-shaped cross section. In this state, as shown in FIG.
Fold each in the direction of the arrow. As a result, the engaging pieces 22a, 24a of the side plates 22, 24 are attached to the side plates 22, 24.
The engagement pieces 21a, 23a of 1 and 23 are wound into a substantially U-shape, and the engagement pieces 21a, 23
The tip portions 21b, 23b of a are held between the engagement pieces 22a, 24a, which are substantially U-shaped. In this way, the engaging portion 2 with a rolled-up cross section
9 to 32 are formed, and these engaging parts 29 to 32
The joint part 25 between the side plates 21 to 24 is
28 are joined in a completely sealed state.

The shielding case 20 is manufactured by the steps shown in FIGS. 4A to 4G described above.
During the process shown in FIGS. 4A to 4F, which precedes the winding process shown in FIG. By cutting and raising portions near 22a and 24a inside the case 20, two pairs of cut and raised pieces 7 for attaching printed wiring boards are provided. In this case, holes 7a are formed by providing the above-mentioned cut and raised pieces 7, but these holes 7a are closed by the winding process shown in FIG. 4G, as clearly shown in FIG. 3. The joint portions 30 and 31 are closed at the tip portions 23b.

Shield case 2 configured in this way
For example, a DC-DC converter and the like are housed inside the housing 0 together with a printed wiring board, and the bottom opening is closed by a closing plate 8.

According to the shield case 20 as described above, the joint portions 25 to 2 between the side plates 21 to 24
8 can be joined to each other in a completely sealed state with the engaging parts 29 to 32 having a rolled-up cross section, and since the hole 7a can be closed by the engaging parts 30 and 31, electromagnetic This makes it possible to effectively provide magnetic shielding against leakage phenomena, especially leakage magnetic flux. Moreover, since the shielding case 20 can be easily manufactured by only punching and bending, the cost of the shielding case 20 can be reduced.

In addition, with the conventional manufacturing method using drawing processing, the depth of the shield case could only be processed to a certain extent, but if the shield case 20 is manufactured using the bending process as described above, it is possible to The shield case 20 can be manufactured to any depth and has the shape and size as required.
can be obtained.

Although one embodiment of the shielding case of the present invention has been described above, the structure is not limited to the one shown in FIG. 3, and for example, the structure shown in FIGS. good. First, the shield case 20 shown in FIG. 5 is constructed in a similar shape to that shown in FIG.
It is formed on the 23 side.

The shielding case 20 shown in FIG. 6 is made by bending a single plate-like member, and is made by bending the shield case 20 at right angles along four bending lines 40, so that the shield case 20 has an open bottom. It is constructed in the form of a rectangular parallelepiped box. The above-mentioned engaging portions 30 are provided at the joints between the top plate 41 and the side plates 21, 22, 24 and the joints between the side plates 22 and 23 of the shield case 20, respectively. There is.

Further, FIG. 7 shows an example in which the number of engaging parts 30 is reduced to two, and in this case too, the shielding case 20 is composed of a single plate-like member. . That is, this shielding case 20 is bent along the bending line 40 to form a substantially rectangular parallelepiped box as described above. And the top plate 4 of the shield case 20
Engagement portions 30 as described above are formed at the seams between 1 and the side plates 23 and the side plates 22 and 23, respectively. The upper ends of the side plates 22 and 24 are bent at right angles along a bending line 43, and a bent piece 44 is disposed in close contact with the lower side of the top plate 41. FIG. 8 shows a modification of the shielding case 20 shown in FIG. 7. In the shielding case 20 shown in FIG. Engagement portions 30 as described above are formed at the seam portions, respectively.

In addition, the shield case 2 shown in FIGS. 5 to 8
Even in the case of 0, the engagement piece and the hole (not shown) are connected so that the hole 7a as described above is closed by the engagement portion 30.
The shape and positional relationship between the shield case 20 and the shield case 20 shown in FIG.
Further, since the size of the engaging portion 30 is not so large, the placement location of the shielding case 20 is not restricted, which is advantageous in terms of spacing factor. Moreover, since the location where the engaging portion 30 is formed is not limited to the locations described above and can be changed arbitrarily, there is an advantage that the shape can be configured according to the location where the shield case 20 is used.

Although the present invention has been described above with reference to embodiments, the present invention is not limited to these embodiments, and various modifications can be made based on the technical idea of the present invention.

For example, in each of the embodiments described above, the shielding case 20 is constructed from a single plate-like member, but two or more independent plate-like members may be combined to form a shield case 20 between them. By forming the engaging portion 30 at the seam portion, it is also possible to configure these so as to be joined to each other. Further, the shape of the engaging portion 30 is not limited to the above-mentioned embodiments, and may have a triangular cross-section, a square cross-section, a curled cross-section (spiral shape), or the like.

As described above, the present invention provides a first engagement piece provided on one of the at least two plate-like parts adjacent to each other and a first engagement piece provided on the other plate-like part of at least two plate-like parts constituting the case. By rolling the first and second engaging pieces together with the second engaging piece superimposed on each other, an engaging portion having a rolled-up cross section is formed, and the engaging portion is used to form one of the first and second engaging pieces. Since the plate-shaped portions and the other plate-shaped portion are configured to be joined to each other, the joint portion of the one plate-shaped portion and the other plate-shaped portion can be completely sealed at the engagement portion, and for this reason, the above-mentioned Magnetic shielding of the seam portion, etc. can be performed extremely effectively.

Furthermore, when manufacturing the shield case, the first and second engaging pieces are provided on one and the other plate-shaped portions, respectively, and the first and second engaging pieces are simply rolled together. Not only can it be manufactured extremely easily and inexpensively by bending without using expensive manufacturing methods such as drawing, but
It is possible to obtain a shielding case having a desired depth.

In addition, by cutting and raising the portion of the plate-shaped portion near the engaging piece to the inside of the case, a plurality of cut-and-raised pieces for holding the printed wiring board housed inside the case are provided, making it easy to use. Despite this configuration, the printed wiring board can be attached extremely easily inside the shielding case.

In addition, the first and second engaging pieces are connected to each other so that the holes formed in the plate-like portion by cutting and bending to form the plurality of cutting and bending pieces are closed by the front side wrap-shaped engaging portions. After selecting the shape and positional relationship with the hole,
Although the printed wiring board can be installed extremely easily due to its simple structure, not only the seam between one and the other plate parts but also the holes created to form the cut and raised pieces are completely sealed. The shielding case can be kept in a sealed state, and therefore the entire shielding case can be magnetically shielded very effectively.

[Brief explanation of drawings]

FIGS. 1 and 2 are exploded perspective views showing conventional shielding cases, respectively. Figures 3 to 8 are for explaining an embodiment of a shield case to which the present invention is applied. Figure 3 is an exploded perspective view of the shield case, and Figure 4 is a fabrication of the shield case. Figure 4A shows the procedure for
~D is a perspective view of the shield case, Figures 4E~G
FIG. 5 is an enlarged sectional view of a main part showing an engaging portion of a shield case, and FIGS. 5 to 8 are perspective views showing modifications of the shield case of the present invention. In addition, in the symbols used in the drawings, 7...
... Cut and raised piece, 7a ... Hole, 20 ... Shield case, 21, 22, 23, 24 ... Side plate, 21
a, 22a, 23a, 24a... engaging piece, 25,
26, 27, 28... seam part, 29, 3
0, 31, 32... are engaging portions.

Claims (1)

[Claims for Utility Model Registration] At least two plate-like parts constituting the case are each provided with an engaging piece, and the first engaging piece provided on one of the plate-like parts adjacent to each other and the other plate-like part are provided. An engaging portion having a rolled-up shape in cross section is formed by rolling the first and second engaging pieces together with the second engaging piece provided on the top of the second engaging piece placed on top of each other; In the shielding case configured to join the one and the other plate-shaped portions to each other, by cutting and raising a portion of the plate-shaped portion near the engagement piece to the inside of the case. A plurality of cut and raised pieces are provided for holding a printed wiring board to be housed, and a hole formed in the plate-like portion by the cut and raised pieces for forming the plurality of cut and raised pieces is formed in the cross-sectional area. The first
and a shield case, characterized in that the shape and positional relationship between the second engagement piece and the hole are selected.