JPH0423357Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a shield case used for electronic devices such as front ends and tuner packs.

[Technical background and conventional technology]

Metal shield cases are used in high frequency equipment such as front ends and tuner packs that have local oscillators and RF high frequency stages.

FIG. 8 (side view) and FIG. 9 (cross-sectional view in FIG. 8) show a conventional shield case of this type. Reference numeral 1 denotes a metal frame having four sides, the upper part of which is covered by an upper cover 2 and the lower part by a lower cover 3. A circuit board 4 is housed inside the frame 1. A plurality of pressure contact pieces 2a are provided on the peripheral edge of the upper cover 2.
However, a plurality of pressure-welding pieces 3a are respectively bent and formed on the peripheral edge of the lower cover 3, and each pressure-welding piece 2a
and 3a are in pressure contact with the side surface of the frame 1. The frame body 1, the upper cover 2, and the lower cover 3 are electrically connected to each other by the elastic pressure of the pressure contact pieces 2a and 3a.

[Problems with conventional technology]

As shown in FIG. 8, in the conventional shield case, the pressure contact piece 2a of the upper cover 2 and the pressure contact piece 3a of the lower cover 3 are formed in a state facing each other. The height dimension l is less than half the height of the entire shield case.

However, although recent high-frequency equipment is required to be thinner, if the conventional structure is simply made thinner, the height l of the pressure contact pieces 2a and 3a will become even shorter. These pressure contact pieces 2a and 3a
If the height dimension l of
The pressure force between a and the frame 1 becomes insufficient. If the contact between the frame 1, the upper cover 2, and the lower cover 3 becomes insufficient in this way, the shielding characteristics will deteriorate and problems such as howling will easily occur.

[Purpose of invention]

The present invention has been made by focusing on the above-mentioned conventional problems, and provides a shield case that can be made thinner, has reliable contact between the frame and each cover, and has good shielding properties. The purpose is to

[Means for solving problems]

The shield case according to the present invention includes a metal frame having four sides, and a metal upper cover and lower cover that cover the upper and lower parts of the frame, in which each of the upper cover and the lower cover is The pressure-welding pieces are bent at the edges, and the pressure-welding pieces of each cover are elastically attached to the side of the frame with the pressure-welding pieces of the other cover inserted between the pressure-welding pieces of one cover. It is characterized by being pressed into contact with the

[Effect]

In the above means, even if the frame is thin and the width dimension of the frame is small, the length of the pressure-welding pieces can be reduced because the pressure-welding pieces of one cover are inserted between the pressure-welding pieces of the other cover. The pressure contact piece can be sufficiently secured and the pressure contact piece is pressed against the side surface of the frame body with sufficient elastic force. Therefore, the contact between the frame and the cover becomes good, and the shielding performance can be improved.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings of FIGS. 1 to 7.

FIG. 1 is a side view showing a first embodiment of a shield case according to the present invention, and FIG. 2 is a sectional view thereof.

This shielded case is suitable for local oscillators and RF
It can be used in various high-frequency electronic devices such as front aids, tuner packs, FM tuners, and TV tuners that have a high-frequency stage.

Reference numeral 11 is a metal frame having four sides, and a circuit board 14 is housed inside the frame.
The upper part of the frame 11 is covered by an upper cover 12, and the lower part is covered by a lower cover 13. A pressure contact piece 12a is bent and formed on the peripheral edge of the upper cover 12, and a pressure contact piece 13a is bent and formed on the peripheral edge of the lower cover 13. 1st
As shown in the figure, the pressure contact piece 12a of the upper cover 12
The pressure contact pieces 13a of the lower cover 13 extend in an alternating manner. A V-shaped pressure contact portion 12b is formed at the tip of the pressure contact piece 12a. Similarly, a pressure contact portion 13b is formed on the pressure contact piece 13a.

In this shield case, the pressure contact pieces 12a of the upper cover 12 and the pressure contact pieces 13a of the lower cover 13 extend alternately, so that the dimension L thereof can be made sufficiently long. Therefore, the degree of freedom in elastic deformation is increased, and the pressure contact portions 12b and 13b are pressed against the side surface of the frame 11 with sufficient elastic force.

FIG. 3 is a side view showing a second embodiment of the shield case according to the present invention, and FIG. 4 is a sectional view thereof.

In this embodiment, the pressure contact piece 12 of the upper cover 12 is
a and the pressure contact piece 13a of the lower cover 13 are bent at approximately right angles. Actually, this pressure welding piece 12
Since a and 13a are bent at an even more acute angle than a right angle, when the upper cover 12 and lower cover 13 are fitted to the frame 11, the pressure welding pieces 12a and 13
a is adapted to press against the side surface of the frame body 11.

Further, a projection 11a is formed on the side surface of the frame 11, and a round hole 12 is formed in each pressure contact piece 12a and 13a.
c and 13c are drilled. By fitting the round holes 12c and 13c into the protrusions 11a, the frame 11 and each cover 12, 13 are reliably fitted.

FIG. 5 is a perspective view showing a third embodiment of the shield case according to the present invention, FIG. 6 is a view in the direction of the arrow in FIG.
FIG. 7 is a view taken along the arrows in FIG.

In this embodiment, the pressure contact piece 12 of the upper cover 12 is
a and the pressure contact piece 13a of the lower cover 13 have the same structure as the embodiment shown in FIGS.
b and 13b are formed. Furthermore, a plurality of protrusions 11b having a predetermined width are formed on the side surface of the frame 11. The pressure contact portions 12b at the tips of the upper pressure contact pieces 12a and the pressure contact portions 13b of the lower pressure contact pieces 13a, which extend alternately, are connected to the upper protrusion portions 1, respectively.
1b, the frame body 11 and each cover 12, 13
The fit is secure.

In the embodiments shown in FIGS. 5 to 7, a recess may be formed instead of the protrusion 11b, and the pressure contact parts 12b and 13b may be fitted into the recess.

[Effect of idea]

As described above, according to the present invention, the following effects can be achieved.

(1) Since the pressure contact pieces of the upper cover and the pressure contact pieces of the lower cover are extended in an alternating manner, the dimensions of the pressure contact pieces can be made sufficiently long. Therefore, the pressing piece can be pressed against the frame with sufficient elastic force, and the frame and each cover can be reliably joined. Therefore, the shielding characteristics of the case are improved, and the high frequency characteristics of the device can be improved.

(2) Even if the width and height of the frame are small, the pressure welding pieces can be made longer by combining them with each other, so the contact pressure between the pressure welding pieces and the frame can be maintained at the same level as with conventional large width dimensions. can. Therefore, the shielding characteristics of the case can be improved.

(3) As stated in claim (2), if the press-fitting piece and the frame are fitted with unevenness, the frame and each cover can be fitted more reliably. It becomes like this.

[Brief explanation of the drawing]

1 to 7 show embodiments of the present invention, FIG. 1 is a side view showing the first embodiment of the shield case according to the present invention, and FIG. 2 is a side view of the shield case shown in FIG.
3 is a side view showing the second embodiment of the shield case, FIG. 4 is a sectional view taken from the side shown in FIG. 3, FIG. 5 is a perspective view showing the third embodiment of the shield case, and FIG. 7 is a view taken in the direction of the arrows in FIG. 5, FIG. 8 is a side view showing a conventional shield case, and FIG. 9 is a cross-sectional view taken in the direction of FIG. 8. 11...Frame body, 12...Top cover, 12a...
... Pressure contact piece, 13 ... Lower cover, 13a ... Pressure contact piece, 14 ... Circuit board.

Claims (1)

[Claims for Utility Model Registration] (1) In a shield case consisting of a metal frame having four sides, and a metal upper cover and lower cover that cover the upper and lower parts of this frame, the upper cover and the lower Pressure-welding pieces are bent and formed on each edge of the cover, and with the pressure-welding piece of one cover inserted between the pressure-welding pieces of the other cover, the pressure-welding pieces of each cover are bent and formed on the frame body. A shield case characterized by elastic pressure contact on the sides. (2) The shield case according to claim (1) of the utility model registration, wherein the pressure-welding piece and the side surface of the frame are pressure-welded with a concave-convex fitting portion.