JP2861873B2 - High frequency equipment shield case - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield case frame base and a cover used in high-frequency equipment such as a cordless phone.

[0002]

2. Description of the Related Art A shield case used for a high-frequency device is formed by assembling a frame base and a cover, which are formed by bending a thin surface-treated steel sheet having a thickness of about 0.3 to 1.0 mm by a punching sheet metal technique and assembling. As shown in FIG. 6, the inside of the rectangular frame base is divided into parts of the high-frequency circuit, and this partition plate 3 is also used as the outer frame base 1.
It is made by bending a steel plate connected to The connected portion is called a connecting portion 4 and serves as a reinforcing member and a cover receiver for the frame base 1. A cover is fitted to the frame base 1 from above and below to form a shield case.

Conventionally, a shield case of a high-frequency device such as a cordless phone has been designed such that an upper edge of a frame base 1 and a connecting portion 4 are flush with each other as shown in a sectional view of FIG. 4 and the entire upper edge of the frame base 1.

However, slight deformation and dimensional errors in processing when the frame base 1 is assembled cannot be avoided, and a difference occurs in the height between the upper edge of the frame base 1 and the connecting portion 4, so that the upper edge of the frame base 1 is not removed. In some cases, a gap may be partially formed between the cover 2 and the cover 2, or incomplete fitting may occur. on the other hand,
In a high-frequency device, the grounding method is very important, and several ground patterns (not shown) of the circuit board housed in the shield case are pulled out to the end of the circuit board at several places, and ground terminals (not shown) of the frame base 1 are drawn. ) Was bent close to and soldered to make the frame base function as a ground, and it was necessary to pay attention so that the electrical connection state would not change.

[0005]

However, noise may occur at the time of vibration or percussion of an inspection. It is a problem that a cordless phone generates noise due to vibration, and the present invention has been made in view of such a situation. It is an object of the present invention to provide a shield case of a high-frequency device which does not generate noise.

[0006]

A shield case for a high-frequency device comprising a frame base and a cover fitted to the frame base, wherein a portion of the upper and lower edges of the frame base which is not in contact with the cover is framed. Provided is a shield case for a high-frequency device that is 60% or more of the total length of the upper and lower edges of a base. Also, a shield case of a high-frequency device comprising a frame base and a cover fitted to the frame base, wherein a portion of the upper and lower edges of the frame base surrounding the local oscillator, which is not in contact with the cover, is formed on each of the upper and lower edges of the frame base. Provided is a shield case for a high-frequency device having a length of 80% or more. The present invention also provides a shield case for a high-frequency device in which a gap between a non-contact portion of the frame base and the cover is 0.3 to 0.8 mm. Further, the present invention provides a shield case for a high-frequency device in which upper and lower edges of a frame base are cut out to form a non-contact portion. Further, the present invention provides a shield case of a high-frequency device in which a cover side is deformed to form a non-contact portion.

[0007]

The contact area between the upper and lower edges of the frame base of the shield case and the cover is mainly limited to the connecting section and the projection, so that the contact range does not change at the time of impact. Further, since the gap between the non-contact portions is 0.3 mm or more, even if the cover vibrates at the time of striking, the cover and the upper edge of the frame base side plate do not come into contact with each other to generate noise. Also, even if the frame base is slightly deformed during assembly or the cover has a dimensional error, the non-contact between the frame base and the cover is reliably maintained, and the shielding effect can be maintained because the gap is 0.8 mm or less. .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is an exploded perspective view of the shield case of the present invention. The shield case 100 has a structure in which an upper cover 20 is fitted from the upper part of the frame base 10 and a lower cover 21 is fitted from the lower part of the frame base 10 divided for each part of the high frequency circuit. FIG. 2 is a cross-sectional view of the shield case 100 assembled with FIG. Reference numeral 40 denotes a connecting portion, 41 denotes a protruding portion, and 42 denotes a non-contact portion. FIG. 3 is a perspective view of the frame base 10.
0 and 60 are frame base side plates, 51 is a caulking hole, 61
Is a caulking terminal. FIG. 5 is a development view of the punching die before assembly including a frame-based partial partition plate.

The shield case 100 is 0.3 to 1.0 m
As shown in FIG. 1, it is made up of a frame base 10, an upper cover 20 and a lower cover 21 fitted to the frame base. In this case, a 0.4mm thick solder plated steel plate (turn metal = Nippon Steel Corporation)
It was used. The contact portion between the frame base side plates 50 and 60 of the frame base 10, the upper cover 20 and the lower cover 21 is a connecting portion 40 and a contact portion 41 as shown in FIG. 2, and the contact between the frame base side plates 50 and 60 and the cover. If the part is only a corner joint, the non-contact part is long, so several projections 41 may be provided between the joints. However, in this case, since the frame base is small, only one projection is provided at the center. 41 are provided. If the non-contact portion is at least 60% of the entire length of the edge of the frame base, the range of noise falls within the standard range, and the fit between the frame base and the cover becomes strong. As shown in FIG. 4, in particular, the hot part of the circuit or local oscillator 70 is sensitive to vibration contact, and the surrounding frame base 71 has an upper or / and lower edge cover 80 which is not in contact with the cover. % Is desirable.

As shown in FIG. 3, the frame base of the shield case is partitioned by partition plates 30 for dividing each part of the circuit, and these partition plates 30 are connected to the frame base side plate by connecting portions 40. The method of manufacturing the frame base is as follows. First, the developed view shown in FIG. 5 is punched out from one piece of solder-plated steel sheet, and the partition (only a part is shown) of each part on the middle side is bent along the dotted line in the figure.
Next, the outer frame base side plates 50 and 60 are also bent along the dotted lines, and the crimping terminals 61 are inserted into the crimping holes 51 of the frame base side plates 50 and 60 to form a rectangular frame base 10 by crimping. The connecting portion 40 formed in the bent portion serves as a reinforcing material not only for the cover but also for the frame base. The upper cover 20 is fitted to the frame base 10 from above and the lower cover 21 is fitted from below to complete the shield case 100.

The frame base 10 of the shield case 100 for a high-frequency device such as a cordless phone according to the present invention has a non-contact portion 42 having a height of 0.8 mm as shown in the sectional view of FIG.
So that the height of the upper and lower edges of the frame base 10 is lower than the height of the connecting portion 40 and the protruding portion 41.
When the lower cover 21 and the lower cover 21 are covered, only the upper surface of the connecting portion 40 and the protrusion 41 of the frame base 10 are in contact with the covers 20 and 21. For this reason, even if there is a slight deformation or dimensional error in the processing when the frame base 10 and the upper cover 20 and the lower cover 21 are assembled, they are absorbed, and the upper and lower portions of the covers 20, 21 and the frame base 10 are absorbed. Since the edge can be kept in a non-contact state, noise is not generated at the time of vibration or percussion. On the other hand, since the height of the non-contact part on the side of the frame base is at most about 0.8 mm,
There is no loss of shielding effect. In this case, the frame base 10 is notched and the non-contact portion 42 is provided, but the covers 20 and 21 are processed by a press or the like to form a similar non-contact portion 4.
2 may be provided. Also, the gap is formed between the covers 20 and 21.
Is determined by the relationship between the thickness of the non-contact portion 42 and the length of the non-contact portion 42, but a certain effect can be obtained even in the range of 0.3 to 2 mm.

[0012]

According to the present invention, the contact portion between the upper and lower edges of the frame base of the shield case and the cover is mainly limited to the connecting portion and the projecting portion. Further, since the contact portion is not large, the fitting between the frame base and the cover is performed firmly without being hindered by the contact portion.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a shield case of the present invention.

FIG. 2 is a side sectional view of the shield case of the present invention.

FIG. 3 is a perspective view of a frame base of the present invention.

FIG. 4 is a perspective view of a portion surrounding a local oscillator of the shield case of the present invention.

FIG. 5 is a development view of a cutting die including a partial partition plate of the frame base of the present invention.

FIG. 6 is a perspective view of a conventional frame base.

FIG. 7 is a side sectional view of a conventional shield case.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Frame base 20 Cover (upper cover) 21 Cover (lower cover) 42 Non-contact part with cover 100 Shield case

Claims (5)

(57) [Claims] 1. A frame base having a shielding function in which a steel plate is assembled by assembling a partition for each middle part and a frame base side plate on the outside in which a connection part formed of a plane parallel to an opening surface is formed by punching and bending a steel plate. A cover parallel to the opening surface and an upper edge and / or a lower edge of the frame base, and a cover having a shielding function to be fitted to the frame base. A high-frequency wave, wherein a portion of the frame base that is not in contact with an upper edge and / or a lower edge excluding the connecting portion is at least 60% of a total length of each of the upper edge and / or the lower edge of the frame base. Equipment shield case. 2. A frame base having a shielding function in which a partition of each middle part and a frame base side plate on an outer side are formed by forming a connecting part formed of a plane parallel to an opening surface by punching and bending a steel plate, and said connecting part. And a cover having a shielding function that is received only on a surface parallel to the opening surface and is fitted to the frame base. 3. A frame base having a shielding function in which a partition of each middle part and a frame base side plate on an outer side are formed by punching and bending a steel plate to form a connection part formed of a plane parallel to an opening surface, and the connection part. And a cover having a shield function to receive the upper edge and / or lower edge of the frame base and to be fitted to the frame base, and accommodate the local oscillator in the partition of the middle part. Upper and / or lower edges of the frame base surrounding the local oscillator, wherein the upper and / or lower edges of the frame base partition surrounding the local oscillator are not in contact with the cover. 80% or more of the entire length of the shield case of the high-frequency device. 4. The shield according to claim 1, wherein a gap between the frame base and the cover in the non-contact portion is 0.3 to 0.8 mm. Case. 5. The shield according to claim 1, wherein an upper edge and / or a lower edge of the frame base is cut off to form the non-contact portion. Case.