JP2565277Y2 - Noise absorber - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise absorbing device mounted on an input / output cable of an electronic device or the like.

[0002]

2. Description of the Related Art In electronic devices such as measuring instruments, there are many inconveniences that noise enters through an input / output cable or radiates from the device to the outside via an input / output cable. To solve this inconvenience, FIG.
(a), as shown in FIG. 6 (a), a tubular noise absorbing device 4 or 6 made of a magnetic material such as ferrite was attached to input / output cables 3 and 5 of an electronic device.

[0005] The noise absorbing device 4 shown in FIG.
The input / output cable 3 is inserted through a through hole of the magnetic ferrite tube 4 as shown in FIG.

[0006] The noise absorbing device 6 shown in FIG.
The magnetic ferrite square tube 6 shown in FIG.
As shown in (c), a pair of divided pieces 7-1 and 7-
After the cable 5 (FIG. 6A) is sandwiched between the pair of split pieces 7-1 and 7-2, the fastener 8 (FIG.
(c)) has a structure in which the divided pieces 7-1 and 7-2 are attached to both ends, joined to each other, and held.

[0005]

However, a main part of the electronic device where noise is generated or a part which is easily affected by noise entering from the outside is a cable routing part. In many cases, the level of noise generation and the level of noise immunity at such parts are not known at the time of the initial design. In most cases, the noise level is determined based on the results of various noise tests performed on actual electronic devices. Removal measures are often taken.

In this case, the above-described noise absorbing device having impedance-frequency characteristics corresponding to the noise level is selected and attached to a cable. When a ferrite magnetic material is used as a noise absorbing device, the factors that determine the frequency band are the frequency characteristics of the magnetic permeability μ and the complex magnetic permeability μ ′ of the ferrite, but the impedance level depends on the breaking of the magnetic path of the noise absorbing device. It depends on the area and the length through which the cable passes, ie the length of the ferrite tube.

The conventional noise absorbing device shown in FIGS. 5 and 6 is a device having a structure in which a magnetic tube having an appropriate length or a tube divided into two in the longitudinal direction is connected with a fastener. Therefore, each device has a certain impedance.

If the noise cannot be sufficiently absorbed by using one absorbing device, two or three additional devices must be installed. In this case, the entire length of the ferrite tube of the entire mounted apparatus is often longer than the length of the ferrite tube necessary to obtain a sufficient noise absorbing effect. In such a case, a portion of the ferrite tube that is unnecessary for noise absorption is actually attached to the cable, and a problem arises in that the cable must bear the weight of the portion. In order to solve such a problem, it is conceivable to prepare various ferrite tubes having different lengths in advance, and attach them to a cable in combination with a length that can obtain a sufficient noise absorbing effect.

However, it is economically inefficient to prepare various ferrite tubes of different lengths.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a noise absorbing device comprising a magnetic tube having a minimum length necessary for obtaining the noise absorbing device without inefficiency in terms of economy.

[0011]

According to the present invention, there is provided a noise absorbing device made of a tube-shaped magnetic material, which is inserted through a cable to absorb noise. A noise absorbing device characterized in that a plurality of folding grooves are provided at an arbitrary pitch in the direction.

Also, in a noise absorbing device for absorbing noise by closely joining a pair of half-pieces made of a half-tube-shaped magnetic material in the longitudinal direction with a cable interposed therebetween, an outer periphery of the pair of half-tubes is provided. The noise absorbing device is characterized in that a plurality of fold grooves are provided in the portion at an arbitrary pitch in the longitudinal direction.

Further, a noise absorbing device is provided, wherein a slit is provided in a part of the folding groove.

[0014]

The impedance close to the optimum impedance for absorbing noise can be obtained by folding a plurality of folds provided at an arbitrary pitch or the folds and slits while appropriately selecting the folds. It is obtained by changing the length of the tube. Therefore,
An optimum noise absorbing effect can be obtained, and a light noise absorbing device can be obtained, and the mechanical influence on the cable can be minimized.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 (a) shows an embodiment of a non-divided round tubular noise absorbing device. The outer peripheral surface of the round tube 9 has a structure in which folding grooves 11 are provided at an arbitrary pitch.

FIG. 1B shows an embodiment of a split-type round tubular noise absorbing device. It is composed of a pair of semi-circular split pieces 9-1 and 9-2 in a half-split shape, and has a structure in which folding grooves 11 are provided at an arbitrary pitch on the outer peripheral surface.

FIG. 2A shows an embodiment of a non-split type rectangular tubular noise absorbing device. It has a structure in which folding grooves 11 are provided at an arbitrary pitch on the outer peripheral surface of the rectangular tube 10.

FIG. 2 (b) shows an embodiment of a split type rectangular tubular noise absorbing device. It is composed of a pair of half-divided pieces 10-1 and 10-2, and has a structure in which folding grooves 11 are provided at an arbitrary pitch on the outer peripheral surface. .

In the non-segmented tubular noise absorbers shown in FIGS. 1 (a) and 2 (a), specifically, an impedance value which is as close as possible to an optimum value for generating noise or noise immunity. The tubes 9 and 10 are bent while appropriately selecting a plurality of fold grooves 11 provided at an arbitrary pitch so that the length can be obtained, so that the noise is absorbed by attaching the noise absorbing device to the cable. can do.

The split-type tubular noise absorbing device shown in FIGS. 1 (b) and 2 (b) is, specifically, a pair of split pieces 9-.
1, 9-2, 10-1 and 10-2 are used in close contact with a cable (not shown), and the impedance is optimal for noise generation or noise immunity as in the non-segmented tubular noise absorber. Of the pair of split pieces 9- so that the impedance value is as close as possible to the value of
1, 9-2, 10-1, and 10-2 can be obtained by appropriately selecting a plurality of fold grooves 11 provided at an arbitrary pitch.

In actual use, each of the divided pieces 9-
1, 9-2, 10-1, and 10-2 are used in close contact with each other, but are separately illustrated in FIGS. 1B and 2B for easy understanding. Further, at the time of close contact bonding to a cable (not shown), as shown in FIG. 6 (c), close contact bonding is performed using a fastener 8, but is omitted in the figure.

FIG. 3 is a view showing a state in which the tube 9 of the present invention is cut by folding grooves having an arbitrary pitch. Tube 9
Is cut by bending at a position where a sufficient absorbing effect can be obtained by the folding groove 11 and used as a noise absorbing device.
Get 3. The remaining tube 14 can be used for a noise absorbing device of another device. The depth and shape of the fold groove provided in the tube are appropriately changed depending on the shape and thickness of the tube so that the tube can be easily cut off. For example, when the groove of the tube is V-shaped, the width / cutting angle can be changed, and when the groove is U-shaped, the width / depth, etc. can be appropriately changed so as to be easily cut off.

FIG. 4 (a) is a plan view showing a state in which a slit is provided in a part of the groove of the tube, and FIG. 4 (b) is a front view of FIG. 4 (a).

4 (a) and 4 (b), the rectangular tubular noise absorbing device 10 at any arbitrary pitch is
A slit 12 is provided on two opposing sides, and a folding groove 11 is provided on the other two sides. Thus, the fold groove 11 and the slit 1
The structure of the combination of the two is highly effective in the operation of cutting a part of the absorber having a large thickness.

The same effect can be obtained even if a folding groove and a slit exist in the same side.

In this embodiment, the ferrite magnetic material has been described as an example. However, similar effects can be obtained with a magnetic material made of a material other than ferrite.

[0028]

According to the present invention, since the magnetic tube is provided with a fold groove or the like at an arbitrary pitch, the length of the fold groove is set to an appropriate impedance value for obtaining a sufficient absorption effect. It is possible to provide a noise absorbing device that can be cut, is very efficient in the manufacturing process, does not need to attach a magnetic portion of an unnecessary length to a cable, and is economically excellent.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view showing one embodiment of a non-divided round tubular noise absorbing device of the present invention, and FIG.
(b) is a perspective view showing one embodiment of the split round tubular noise absorbing device of the present invention.

FIG. 2 (a) is a perspective view showing an embodiment of the non-segmented rectangular tubular noise absorbing device of the present invention, and FIG.
(b) is a perspective view showing an embodiment of the split square tubular noise absorbing device of the present invention.

FIG. 3 is a view showing a state in which the tube 9 of the present invention is cut by folding grooves having an arbitrary pitch.

4 (a) is a plan view showing a state in which a slit is provided in a part of the folding groove of the tube of the present invention, and FIG. 4 (b) is a front view of FIG. 4 (a).

5 (a) is a perspective view showing a state in which a conventional round noise absorbing device is attached to a cable, and FIG. 5 (b) is an enlarged perspective view of the conventional round noise absorbing device.

6 (a) is a perspective view showing a state in which a conventional rectangular noise absorbing device is attached to a cable, and FIG. 6 (b) is an enlarged perspective view of the conventional rectangular noise absorbing device. FIG. 6C is a perspective view showing a state in which the cable is sandwiched between a pair of divided pieces of the noise absorbing device in FIG. 6B and the fasteners are attached to both ends.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Printed board (or apparatus main body) 2 Connector 3,5 Lead wire cable 4,6,9,10 Magnetic tube 7-1,7-2,9-1,9-2,10-1,10-2
Magnetic tube split piece 8 Fastener 11 Fold groove 12 Slit

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shuichi Tateya 21-1, Taishido, Taishiro-ku, Sendai-shi, Miyagi Pref. Tokin Co., Ltd. -200479 (JP, A) Fully open sho 61-76626 (JP, U) Fully open sho 53-29250 (JP, U) Fully open sho 63-115297 (JP, U)

Claims (3)

(57) [Scope of request for utility model registration] 1. A noise absorbing device made of a tube-shaped magnetic material, which absorbs noise by being inserted into and attached to a cable, wherein a plurality of bent grooves are formed at an arbitrary pitch in a longitudinal direction on an outer peripheral portion of the tube-shaped ferrite. A noise absorbing device comprising: 2. A noise absorbing device for absorbing noise by closely joining a pair of half-pieces made of a half-tubular magnetic material in the longitudinal direction with a cable interposed therebetween. A noise absorbing device, wherein a plurality of fold grooves are provided at an arbitrary pitch in a longitudinal direction in a portion. 3. The noise absorbing device according to claim 1, wherein a slit is provided in a part of the folding groove.