JP3998849B2 - EMC countermeasure structure of electronic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an EMC countermeasure structure for an electronic device such as a telephone exchange.
[0002]
[Prior art]
In an electronic device such as a conventional telephone exchange, electromagnetic noise generated by a printed circuit board or a power supply housed in a housing has an adverse effect on surrounding electronic devices, so that these electromagnetic noise leaks to the outside of the housing. In order to prevent this, a casing with EMC countermeasures is used.
[0003]
Further, as a case of a conventional electronic device with EMC countermeasures, for example, those shown in FIGS. 6 to 8 are known.
[0004]
The case of the above-mentioned conventional EMC countermeasure structure has a pair of support columns c whose lower ends are fixed to the left and right ends of the base by a fixing tool b, and a shelf plate d is disposed between these support columns c, for example, in two stages. It is horizontal.
[0005]
A plurality of guide rails e are provided on the opposite surface of the shelf plate d so that the upper and lower ends of the printed boards f and f ′ on which electronic components are mounted can be removably inserted into the guide rails e. A motherboard h on which a connector g for connecting the printed circuit board f is mounted is detachably fixed to the rear surface side of the shelf board d by a fixture b, and a front panel i is attached to the front side of the shelf board d. Is detachably fixed by the fixing tool b.
[0006]
Further, an MDF substrate j constituting a wiring relay terminal block (hereinafter referred to as “MDF”) for connecting the telephone office and the electronic exchange and between the electronic exchange and the telephone is attached to one column c. In addition, a side plate k is detachably attached to the side surface of each support column c by a fixing tool b.
[0007]
In the case of the above conventional EMC countermeasure structure, the base a, the support column c, the shelf d, the front plate i, and the both side plates k are formed of metal in order to prevent leakage of electromagnetic wave noise to the outside of the case. And has a structure for shielding electromagnetic noise.
[0008]
A signal transmitted from the telephone office is transmitted from the line m to the motherboard h via the MDF board j, the connection cable n, and the printed board f, and further from the motherboard h to the printed board f ′, the connection cable n, the MDF board j, and It is sent to the telephone set p via the connection cable o.
[0009]
[Problems to be solved by the invention]
However, in the case of the conventional EMC countermeasure structure, electromagnetic noise generated from the printed circuit boards f and f ′, the power supply q, etc. rides on the connection cable n that connects the printed circuit boards f and f ′ and the MDF board j, and the connection cable. Since the electromagnetic noise generated from the printed circuit board f, f ′, the power supply q, etc. leaks directly from the wiring hole r to the outside of the casing through the wiring hole r for pulling out j, the electromagnetic noise is moved out of the casing. There was a problem that leakage could not be prevented reliably.
[0010]
The present invention has been made in order to improve such a conventional defect, and provides an EMC countermeasure structure for an electronic device that can reliably prevent electromagnetic noise generated from a printed circuit board, a power supply, etc. from leaking out of the casing. It is intended to do.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an MDF frame in which a plurality of MDF substrate mounting holes are opened between at least one of the support columns provided in the housing and the side plate, and is provided in the MDF substrate mounting hole of the MDF frame. Attaching multiple MDF boards with connectors on both sides , shielding the ground around these connectors with metal, and selectively connecting cables from multiple printed boards to the connectors inside the multiple MDF boards Connected to the connector on the outside of the selected MDF board, and the wiring from the external device or telephone line is connected. Electromagnetic noise generated from the printed circuit board or power supply in the housing is connected to the cable or wiring. be leaked from the hole is shielded by the MDF frame and MDF board attached thereto, it is reached inside the connector Since the connector is shielded, it is possible to electromagnetic noise to an external device or a telephone line connected to the outside of the connector is reliably prevented from leaking.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The invention according to claim 1 of the present invention is, in the casing constituted by the front plate, the rear plate and the both side plates, provided with support columns spaced apart from each other left and right, and provided with a plurality of shelves between these support columns, In an EMC countermeasure structure for an electronic device in which a plurality of printed boards are detachably mounted between these shelf boards, an MDF frame having a plurality of MDF board mounting holes is provided between at least one of the support columns and the side plate, and A plurality of MDF boards having connectors provided on both sides thereof are attached to the MDF board mounting holes of the MDF frame, and the periphery of these connectors is shielded with metal and grounded, and a plurality of MDF boards are connected to the connectors inside the plurality of MDF boards. A configuration in which a connection cable from a printed circuit board is selectively connected, and wiring from an external device or a telephone line is connected to a connector outside the selected MDF board; Those were.
[0013]
With the above configuration, even if electromagnetic wave noise generated from the printed circuit board in the housing or the power source gets on the connection cable connecting the printed circuit board and the MDF circuit board or leaks from the wiring hole opened in the support column, Even if it is shielded by the MDF board attached to it and reaches the inner connector, the connector is shielded, so it is possible to reliably prevent electromagnetic noise from leaking to external devices and telephone lines connected to the outer connector. can do.
[0016]
The invention according to claim 2 of the present invention, the MDF frame respectively on left and right posts Rutotomoni selectively attach the MDF board MDF board mounting hole of MDF frame, MDF board mounting hole that does not attach the MDF board A metal cover is attached to the connector, and a connection cable from the printed board is selectively connected to a connector inside the MDF board .
[0017]
With the above configuration, wiring processing can be performed from either the left side or the right side of the casing, so that workability is improved and electromagnetic noise can be prevented from leaking outside through the MDF substrate mounting hole of the MDF frame .
[0022]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings shown in FIGS.
[0023]
1 is an exploded perspective view of an electronic device adopting an EMC countermeasure structure, FIG. 2 is a perspective view of an assembled state, FIG. 3 is an enlarged view of a main part, FIG. 4 is a side view of an MDF substrate, and FIG. FIG.
[0024]
In these drawings, reference numeral 1 denotes a housing of an electronic device. The lower ends of a pair of support columns 2 are fixed to the left and right ends of a base 1a by a fixing tool 3. Between these support columns 2, for example, two shelf boards 4 is horizontally spaced apart vertically.
[0025]
A plurality of guide rails 5 are provided on the opposing surfaces of the shelf plates 4 with a space in the left-right direction, and a plurality of printed circuit boards 6 are arranged between the upper and lower guide rails 5 from the front side of the housing 1. , 7 can be removably inserted, and the printed circuit boards 6, 7 can be connected to electronic components (not shown) or the connectors 9 of the motherboard 8. A connector (not shown) is mounted.
[0026]
The mother board 8 has a connector 9 for each printed circuit board 6, 7, and is detachably attached to the rear surface side of each shelf board 4 by a fixing tool 3.
[0027]
Further, an MDF frame 12 is attached to one support column 2.
[0028]
As shown in FIG. 3, the MDF frame 12 has a flat box shape that can be attached to the inside of the column 2 and has a large opening 12a on one side surface.
[0029]
A plurality of mounting pieces 12b project from the inner peripheral edge of the opening 12a. The mounting pieces 12b are attached to the support column 2 by the fixing tool 3, and the other side surface of the MDF frame 12 is A plurality of, for example, six MDF substrate mounting holes 12c are opened in two upper and lower stages.
[0030]
An MDF substrate 13 is detachably attached to one or a plurality of these MDF substrate attachment holes 12c by a fixing tool 3.
[0031]
The MDF board 13 has a connector 13a for connecting the line 14 from the telephone office and the telephone 15 on the outer side, and a wiring connector 13b for connecting the printed boards 6 and 7 on the inner side. 4, one end of the wiring connector 13b is connected to the connectors 6a and 7a of the printed circuit boards 6 and 7, and is drawn into the MDF frame 12 from the wiring hole 2a opened in the support column 2. The other end of the connected connection cable 16 is connected.
[0032]
Each connector 13a, 13b attached to the MDF board 13 is shielded with metal around it, and the shield part is grounded to the MDF frame 12 via the ground pattern (not shown) of the MDF board 13, The connectors 13a and 13b are structured so as not to receive electromagnetic wave noise, and a metal cover 18 is attached to the MDF substrate attachment hole 12c to which the MDF substrate 13 is not attached by the fixing tool 3, and these MDF substrate attachments are made. Electromagnetic noise is prevented from leaking to the outside through the hole 12c.
[0033]
On the other hand, a rear plate 19 is attached to the rear surface of the mother board 8, a front plate 20 is attached to the front surface of the shelf plate 4, and a side plate 21 is detachably attached to the side surface of the support column 2 by the fixing tool 3. The stand 1 a, the support 2, the shelf plate 4, the front and rear surface plates 20 and 19, and the both side plates 21 are formed of metal in order to prevent electromagnetic wave noise from leaking outside the housing 1.
[0034]
Next, the operation of the casing 1 configured as described above will be described. When the MDF substrate 13 is attached, the MDF frame 12 is first fixed to one support column 2 by the fixing tool 3, and then the MDF substrate of the MDF frame 12. In attaching the MDF substrate 13 to the mounting hole 12c, first, the other end of the connection cable 16 having one end connected to the printed circuit boards 6 and 7 and the other end pulled out from the wiring hole 2a of the support column 2 is connected to the MDF substrate. 13 is connected to a wiring connector 13b provided on the inside.
[0035]
In this state, the MDF board 13 is attached to the MDF board attachment hole 12c of the MDF frame 12 by the fixing tool 3, and the line 14 from the telephone office and the telephone 15 are connected to the connector 13a provided on the outside of the MDF board 13. .
[0036]
Further, the cover 18 is attached to the MDF substrate mounting hole 12c to which the MDF substrate 13 is not mounted so that electromagnetic wave noise does not leak.
[0037]
When the attachment of the MDF substrate 13 is completed as described above, the side plate 21 is attached to the side surface of the support column 2 and the front and rear surface plates 20 and 19 are attached to the front and rear surfaces to complete the assembly of the housing 1. Even when electromagnetic noise generated from the power source 6 or 7 or the power source 23 rides on the connection cable 16 and reaches the MDF substrate 13, it is shielded by the MDF frame 12 and the cover 18 and is prevented from leaking to the outside. The electromagnetic noise directly leaking from 2a is also shielded by the MDF frame 12 and the cover 18 and prevented from leaking outside.
[0038]
As a result, electromagnetic noise generated in the housing 1 can be reliably prevented from leaking to the outside of the housing 1.
[0039]
When the MDF substrate 13 is attached to the MDF frame 12, the number of the fixing tools 3 to be used is reduced by fixing the intermediate portion of the adjacent MDF substrates 13 with a common fixing tool 3 'as shown in FIG. Therefore, workability at the time of assembly is improved.
[0040]
In the above-described embodiment, the MDF frame 12 and the MDF substrate 13 are attached to one of the pillars 2.
[0041]
【The invention's effect】
As the invention has been described in detail above, by providing a MDF frame between at least one of the struts and the side plate of the housing, to the MDF frame, attaching a plurality of MDF substrate provided with connectors on both sides, around these connectors Is shielded with metal and grounded, and connection cables from a plurality of printed circuit boards are selectively connected to connectors on the inside of the plurality of MDF boards, and external devices or telephone lines are connected to the connectors on the outside of the selected MDF boards. Even if electromagnetic noise generated from the printed circuit board or power supply gets on the connection cable connecting the printed circuit board and the MDF board or leaks from the wiring hole opened in the support column, the MDF frame It is shielded or MDF board, is reached inside the connector, since the connector is shielded, the outer connector Electromagnetic noise to connected external device or a telephone line can be reliably prevented from leaking.
[0042]
Further, by providing each MDF frame to the left and right post, selectively attaching the metal cover to the MDF board mounting hole is not attached Rutotomoni, the MDF board mounting the MDF board MDF board mounting hole of MDF frame, printed Since the connection cable from the board is selectively connected to the connector inside the MDF board, wiring processing can be performed from either the left side or the right side of the housing, so that workability is improved and electromagnetic noise is generated by MDF. It is possible to prevent leakage from the MDF substrate mounting hole of the frame to the outside .
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an EMC countermeasure structure of an electronic apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing an EMC countermeasure structure of an electronic apparatus according to an embodiment of the invention. FIG. 4 is a side view of an MDF substrate used in an EMC countermeasure structure for an electronic device according to an embodiment of the present invention. FIG. 6 is an exploded perspective view showing the EMC countermeasure structure of the conventional electronic device. FIG. 7 is a perspective view showing the EMC countermeasure structure of the conventional electronic device. 8] Perspective view of MDF board used in EMC countermeasure structure of conventional electronic equipment
DESCRIPTION OF SYMBOLS 1 Case 1a Base 2 Support | pillar 2a Wiring hole 3 Fastening tool 4 Shelf board 5 Guide rail 6, 7 Printed circuit board 6a, 7a Connector 8 Mother board 9 Connector 12 MDF frame 12a Opening part 12b Mounting piece 12c MDF board mounting hole 13 MDF board 13a Connector 13b Wiring connector 14 Line 15 Telephone 16 Connection cable 18 Cover 19 Rear panel 20 Front panel 21 Side panel 23 Power supply

Claims (2)

Within a housing composed of a front plate, a rear plate, and both side plates, support columns are provided apart from each other left and right, and a plurality of shelf plates are provided between the support columns, and a plurality of printed circuit boards are inserted and removed between the shelf plates. In an EMC countermeasure structure for a freely mounted electronic device, an MDF frame having a plurality of MDF substrate mounting holes is provided between at least one of the support columns and a side plate, and the MDF substrate mounting holes of the MDF frame are provided on both sides. A plurality of MDF boards provided with connectors are attached , and the periphery of these connectors is shielded with metal and grounded, and connection cables from the plurality of printed boards are selectively connected to the connectors inside the plurality of MDF boards. connect, an electronic device, characterized in that the configuration of connecting the wiring from the external device or telephone line to the outside of the connector of MDF substrate selected EMC countermeasure structure of. An MDF frame is provided on each of the left and right columns, and an MDF board is selectively attached to the MDF board mounting holes of these MDF frames, and a metal cover is attached to the MDF board mounting hole to which the MDF board is not attached. The EMC countermeasure structure for an electronic device according to claim 1 , wherein a connection cable is selectively connected to a connector inside the MDF substrate .

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