JP2000244172A - Suppression structure for radiant noise with reference to wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a radiant noise with reference to a wire by a method wherein a recess is formed on the surface of a case having an electromagnetic shielding property and the wire which is connected to an electric circuit is arranged in the recess. SOLUTION: A groove 3a whose cross-sectional shape is U-shaped is formed on the surface of a case 3 having an electromagnetic shielding property. Then, a hole 3b into and through which a wire harness 2 is inserted and passed is formed in the front end of the groove 3a. Then, the wire harness 2 is passed through the groove 3a, the wire harness 2 is inserted into, and passed through, the inside of the case 3 from the hole 3b which is formed in the front end of the groove 3a, and it is connected to the input electrode of an input/output connector 5 which is attached to the front part of a circuit board 4. As a result, in a part in which the wire harness 2 is parallel to the circuit board 4, a distance which is separated from the circuit board 4 becomes large. In addition, since the case 3 has the electromagnetic shielding property, a noise level at which a noise generated from the circuit board 4 is radiated to the wire harness 2 becomes extremely small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation noise suppressing structure for suppressing noise generated from an electric circuit from being radiated to electric wires connected to the electric circuit.

[0002]

2. Description of the Related Art Conventionally, a 12 volt DC voltage is input from a battery mounted on a vehicle, and the input voltage is set to 100 volts,
A vehicle may be provided with a power supply device that converts the voltage into an AC voltage of 0 or 60 Hz and outputs the converted AC voltage. FIG. 2 is a perspective view of a power supply device 62 including a switching regulator circuit and an inverter circuit formed on a circuit board 63. As shown in FIG. 2, in the case of this power supply device 62, an input connector 6 to which a wire harness 61 for supplying a 12-volt DC voltage from a battery (not shown) is connected.
4 is attached to the rear of the circuit board 63, and 100
An output connector 66 connected to an outlet 65 for supplying an AC voltage of 50 or 60 Hz is attached to the front of the circuit board 63. However,
In the case of the power supply device 62, since two connectors, an input connector 64 and an output connector 66, are required, the cost is increased due to an increase in the number of components. Further, a space for mounting the input connector 64 and the output connector 66 is required on the circuit board 63, so that it is necessary to increase the depth of the circuit board 63 and the depth of the case 67. Therefore, the circuit board 63
However, there is a problem that the cost associated with an increase in the area of the case 67 and the cost associated with an increase in the volume of the case 67 increase.

The power supply device 51 shown in FIG. 3 uses an input / output connector 54 in which two connectors of the input connector 64 and the output connector 66 are integrated in order to avoid the cost increase. The power supply device 51 includes a case 52
The input / output connector 54 is attached to a circuit board 53 housed in the connector. A 12 volt DC voltage from a battery (not shown) is supplied to the input / output connector 54 via a wire harness 55, and is input from the input / output connector 54 to the circuit board 53. A switching regulator circuit and an inverter circuit are formed on the circuit board 53, and these circuits convert the 12 volt DC voltage into an AC voltage of 100 volts, 50 or 60 Hz. This AC voltage is applied to the input / output connector 5
Outlet 56 attached to case 52 via
Supplied to An L-shaped noise shield plate 57 made of a steel plate is provided between the wire harness 55 and the circuit board 53 in order to suppress noise generated during switching control in the switching regulator circuit and the inverter circuit from being radiated to the wire harness 55. It is provided in. The noise shielding plate 57 allows the wire harness 5
Radiation noise to the wire harness 5 is suppressed.
5 prevents noise from entering other electronic devices.

[0004]

However, in the case of the conventional power supply device 51, since the noise shielding plate 57 is required, the material cost of the noise shielding plate 57 itself and the cost for mounting the noise shielding plate 57 are reduced. However, there is a problem that the cost of the power supply device 51 increases due to the increase in cost.

Accordingly, the present invention provides a radiation noise suppressing structure capable of suppressing radiation noise to electric wires at low cost without increasing the area of a circuit board, increasing the volume of a case, or increasing the number of parts. Is to be solved.

[0006]

In order to solve the above problems, the present invention is to provide a radiation noise suppressing structure for electric wires as described in claim 1. Claim 1
According to the invention described in (1), since the electric wire connected to the electric circuit is arranged in the concave portion formed on the surface of the case having the electromagnetic shielding property, the electric wire is separated from the electric circuit. Further, since noise generated from the electric circuit is electromagnetically shielded in the case, the level of radiation noise to the electric wire is suppressed. In this case, since only a concave portion for arranging electric wires is formed on the surface of the case, there is no increase in the area of the circuit board, an increase in the volume of the case, or an increase in the number of parts, and it is possible to suppress radiation noise to the electric wires at low cost. it can.

[0007]

Next, an embodiment of the present invention will be described. FIG. 1 shows a state in which a 12 volt DC voltage is input from a vehicle battery (not shown) through a wire harness (wire) 2 having a connector 2a attached to a tip thereof, and the input voltage is changed to 100 volt, 50 or 60 Hz. 1 DIN size power supply 1 for converting to AC voltage and outputting
Is shown in a perspective view. In addition, this power supply device 1 is attached to a center console box or the like of a vehicle,
For example, a power supply voltage for watching television in a car is supplied.

[0008] As shown in FIG.
The circuit board 4 is housed in the housing 1, and an input / output connector 5 is attached to a front portion of the circuit board 4. A 12 volt DC voltage from a battery (not shown) is supplied to the input electrode of the input / output connector 5 via the wire harness 2, and is input to the circuit board 4 from the input electrode of the input / output connector 5. A switching regulator circuit and an inverter circuit are formed on the circuit board 4, and the 12 volt DC voltage is reduced to 100 volts and 50 volts by these circuits.
Alternatively, it is converted to an AC voltage of 60 Hz. This AC voltage is supplied to an outlet 6 attached to the case 3 via an output electrode of the input / output connector 5. As described in the section of the related art, noise generally occurs during switching control in the switching regulator circuit and the inverter circuit. When this noise is radiated to the wire harness 2, the noise may enter another electronic device mounted on the vehicle via the wire harness 2 and cause the other electronic device to malfunction. Therefore, noise generated at the time of the switching control is generated by the wire harness 2.
Therefore, means for minimizing radiation from the vehicle are required.

The case 3 is made of, for example, a thin steel plate having an electromagnetic shielding property, and as shown in FIG.
A groove (a cross-sectional shape is concave) 3 a for passing the wire harness 2 is formed on the upper surface of the case 3. A hole 3b for inserting the wire harness 2 into the case 3 is formed at the front end of the groove 3a.

As described above, the groove 3a is formed on the upper surface of the case 3, the wire harness 2 is passed through the groove 3a, and the wire harness 2 is inserted into the case 3 from the hole 3b formed at the front end of the groove 3a. And the wire harness 2 is connected to the input electrode of the input / output connector 5 attached to the front part of the circuit board 4, so that the portion where the wire harness 2 is parallel to the circuit board 4 has a large distance from the circuit board 4. In addition, since the case 3 has the electromagnetic shielding property as described above, the noise level at which the noise generated from the circuit board 4 is radiated to the wire harness 2 becomes extremely low.
When the power supply device 1 is mounted on a center console box or the like of a vehicle, the power supply device 1 needs to be 1 DIN size and the upper surface needs to be flat because it is arranged so as to overlap with other audio equipment. Because
The groove 3 a was formed on the upper surface of the case 3. In addition, in a state where the wire harness 2 is passed through the groove 3a, if necessary, the wire harness 2 may be fixed using a band clamper or the like.

As described above, since the radiation noise to the wire harness 2 is suppressed, the level of the noise entering the other electronic devices via the wire harness 2 is reduced, thereby preventing the problem that the other electronic devices malfunction. can do.

In the embodiment of the present invention, the groove 3a
Has been described on the upper surface of the case 3, but the groove 3a is not limited to the upper surface of the case 3, but may be formed on the side surface or the lower surface. Further, a concave portion having an L-shaped cross section for disposing the wire harness 2 may be formed at a corner of the case 3. Further, in the embodiment of the present invention, the radiation noise suppressing structure in the power supply device 1 has been described.
The present invention is not limited to the power supply device, and is applied to all electronic devices having an electric circuit in which noise is generated and having a wire harness (including electric wires, cables, and the like) connected to the electric circuit.

[0013]

According to the first aspect of the present invention, it is possible to suppress radiation noise to electric wires at low cost without increasing the area of the circuit board, increasing the volume of the case, or increasing the number of parts. effective.

[Brief description of the drawings]

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

FIG. 2 is a perspective view for explaining a problem of the related art.

FIG. 3 is a perspective view for explaining another problem of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply device 2 Wire harness 3 Case 3a groove 4 Circuit board 5 Input / output connector 6 Outlet

Claims (1)

[Claims] 1. A radiation noise suppression structure for an electric wire in which a concave portion for arranging an electric wire connected to an electric circuit as a noise generating source is formed on a surface of an electromagnetic shielding case for housing the electric circuit.