JP2001308575A - Shield structure for electronic unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of components for shielding an electronic unit, to simplify a structure, and to reduce the cost of manufacturing components. SOLUTION: A front cover 3 which is formed with a size for covering all electronic units 2 mounted in a cabinet 1 is fixed on unit mounting frames 2a. Thus, shield members 4 attached to the front cover 3 are pressed and are in contact with the unit mounting frames 2a to electrically bring the front cover 3 and the unit mounting frames 2a into conduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure in which an electronic unit mounted on a general-purpose cabinet that is not shielded against electromagnetic waves is shielded against electromagnetic interference (EMI).

[0002]

2. Description of the Related Art When an electronic unit configured by mounting a plurality of electronic circuit packages in a predetermined housing or the like is mounted in a general-purpose cabinet that is not shielded against electromagnetic waves, a noise source in each unit is determined. It may be necessary to take measures against electromagnetic interference caused by noise or the like generated from an electronic circuit package.

In such a case, a shielding material such as an EMI gasket is conventionally attached to the back surface of a front plate provided in each electronic circuit package, and a shield between the electronic circuit packages is shielded by this shielding material to perform electromagnetic wave shielding. ing.

[0004]

However, in the above-mentioned prior art, since shielding is performed for each electronic unit in each electronic circuit package, a large number of shielding materials are required and the front plate of each electronic circuit package is required. Must have a structure that allows a shield material to be attached, and therefore the number of parts increases, the structure becomes complicated, and the cost of manufacturing parts increases.

An object of the present invention is to solve such a problem.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention is a shield structure in which an electronic unit is mounted on a cabinet which is not shielded against electromagnetic waves via a unit mounting frame, wherein a front cover is mounted on the cabinet. By forming a shield material on one of the front cover and the unit mounting frame, and fixing the front cover to the unit mounting frame. The front cover and the unit mounting frame are electrically connected via the shield material.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a shield structure of an electronic unit according to the present invention. FIG. 1 is a perspective view showing a first embodiment, and FIG. 2 is a perspective view of a main part of FIG. In FIG. 1, reference numeral 1 denotes a general-purpose cabinet that is not shielded against electromagnetic waves. In the cabinet 1, a plurality of (three in FIG. 1) electronic units 2 are mounted vertically by a unit mounting frame 2a. The electronic unit 2 is configured by mounting a plurality of packages (not shown) serving as noise sources in a predetermined housing.

Reference numeral 3 denotes a front cover which is formed to have a size capable of covering all the electronic units 2 mounted on the cabinet 1 at a time, and which can be fixed to the unit mounting frame 2a by screws (not shown). ing. Reference numeral 4 denotes a shielding material for preventing electromagnetic wave interference. As the shielding material 4, an EMI gasket made of conductive rubber or conductive resin fiber or the like is used. As shown in FIG. It is provided so as to face each unit mounting frame 2a along both sides.

Next, the operation will be described. A plurality of electronic units 2 are mounted on a cabinet 1 each in a unit mounting frame 2a.
When the front cover 3 is fixed to the unit mounting frame 2a with a screw (not shown) in a state where the front panel 3 is mounted, the shield member 4 attached to the inner surface of the front cover 3 comes into pressure contact with each unit mounting frame 2a.

As a result, the front cover 3 and all of the unit mounting frames 2a are electrically connected to each other through the shield member 4 to have the same potential, and a large space between each electronic unit 2 and the front cover 3 is provided with a shield measure. And the electronic unit 2 is collectively shielded. Also,
All the unit mounting frames 2a mounted on the front cover 3 and the cabinet 1 fall to the same frame ground, and the grounding conditions can be made the same.

As described above, in the first embodiment, the shields 4 provided on the front cover 3 are pressed into contact with the unit mounting frames 2a, so that the electronic units 2 can be collectively shielded. It is possible to reduce the number of components when mounting a plurality of electronic units 2 that are not subjected to shielding measures in an unshielded cabinet, simplify the structure, and reduce the component manufacturing cost.

In the above description, the shield material 4 is provided on the front cover 3 and is brought into pressure contact with each unit mounting frame 2a. However, the shielding material 4 is brought into contact with each unit mounting frame 2a collectively. If the front cover 1 is pressed into contact with the shield member 4, the shield can be similarly provided, and the same effect can be expected. FIG. 3 is a perspective view showing the second embodiment, and the same components as those in the first embodiment are denoted by the same reference numerals.

In this embodiment, shielding is performed on the rear side of the electronic unit 2. In the figure, reference numeral 5 denotes a shield fitting, which is fixed to each unit mounting frame 2a on which the electronic unit 2 is mounted on the cabinet 1 by screws. The shield fitting 1 and the unit mounting frame 2a The surfaces contacting each other are subjected to a treatment such as plating for electrical conduction.

Reference numeral 6 denotes a rear cover, which is formed to have a size capable of covering all the electronic units 2 mounted on the cabinet 1 at a time. The rear covers 6 are provided at four corners of the shield fitting 5 and the like. It can be fixed to a plurality of protrusions with screws. Next, the operation will be described.
When a plurality of electronic units 2 are mounted on the cabinet 1 by the unit mounting frames 2a, respectively, when the shield fitting 5 is fixed to both sides of the unit mounting frame 2a by screws so as to contact the respective unit mounting frames 2a, each unit becomes Since the mounting frame 2a and the shield metal 5 are electrically connected to each other and have the same potential, the rear cover 6 is fixed to a plurality of protrusions provided on the shield metal 5 with screws and the rear cover 6
Is pressed against the shield member 4 attached to the shield fitting 5.

As a result, the rear cover 6 and all the unit mounting frames 2a are electrically connected to each other via the shield member 4 to have the same potential, and a large space between each electronic unit 2 and the rear cover 6 is provided with a shield measure. And the electronic unit 2 is collectively shielded. Also,
All the unit mounting frames 2a mounted on the rear cover 6 and the cabinet 1 fall to the same frame ground, and the grounding conditions can be made the same.

In the second embodiment described above, the first
The same effect as that of the embodiment can be expected. In the second embodiment, the rear cover 6 is pressed against the shield member 4 attached to the shield fitting 5 fixed to each unit mounting frame 2a.
Shielding material 4 is provided on the end face of the device, and the shielding material 4 can be pressed against the shielding fitting 5 to provide a similar shield, and the same effect can be expected.

Incidentally, the cabinet and the electronic unit in the present invention are not limited to those having the shapes shown in the drawings, and it is a matter of course that the present invention can be applied to general-purpose cabinets and electronic units having other shapes.

[0018]

As described above, according to the present invention, the front cover or the rear cover is formed in such a size that all the electronic units mounted on the cabinet can be covered at a time, and this cover and the shielding material are used. Since each electronic unit can be collectively shielded, the number of parts can be reduced and the structure can be reduced even when mounting multiple electronic units that are not shielded in an unshielded general-purpose cabinet. The effect is obtained that the simplification can be made and the part manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part of FIG.

FIG. 3 is a perspective view showing a second embodiment of the invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cabinet 2 Electronic unit 2a Unit mounting frame 3 Front cover 4 Shielding material 5 Shield metal fitting 6 Rear cover

Claims (2)

[Claims] 1. A shield structure in which an electronic unit is mounted on a cabinet which is not shielded against electromagnetic waves via a unit mounting frame, wherein a front cover is provided for all the electronic units mounted on the cabinet. The front cover and the unit mounting frame are formed by providing a shield material on one of the front cover and the unit mounting frame and fixing the front cover to the unit mounting frame. Is electrically conducted through the shield material. 2. A shield structure in which an electronic unit is mounted on a cabinet which is not shielded against electromagnetic waves via a unit mounting frame, wherein a rear cover is provided for all the electronic units mounted on the cabinet. A shield member that is formed in a size that can be covered by the unit mounting frame and is electrically connected to the unit mounting frame is fixed to the unit mounting frame, and a shield material is provided on one of the rear cover and the shield metal. And fixing the rear cover to the shield fitting, thereby electrically connecting the rear cover and the unit mounting frame via the shield material and the shield fitting.