JPH09182259A - Noise absorber for power supply duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb noise by having a surge absorbing element which connects coupling conductive parts with one another, and the coupling conductive parts with an earth coupling conductive part. SOLUTION: For a noise absorber 1 for a power supply duct, a case earth conductive part 11b is inserted into the step part 4a of an earth coupling conductive part 4 for coupling thereby making a conductor and a case earth electrically conductive, at the same time when inserting the ends 12a of the conductor 12 of the power supply duct 10. When power is supplied and surge noise voltage larger than the rated voltage is applied to the conductor 12 of the power supply duct 10, a part of its energy is earthed, being returned to the side of power source through the varistor element 6 between the coupling conductive parts 3 of a noise absorber 1 for power supply duct, and further other energy is earthed through the varistor elements 6 of the coupling conductive part 3 and the earth coupling conductive part 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise absorber, and more particularly to a noise absorber for a power supply duct having a noise absorption circuit housed inside a connector of the power supply duct.

[0002]

2. Description of the Related Art Conventionally, in a factory or the like, when a large number of machine layout changes are expected in the future, a power supply duct system is used as a wiring system that can easily cope with such changes. This power supply duct system is shown in FIGS. 5 to 7, and is configured to have a power supply duct 10 and a terminal plug 13. 5 is a perspective view showing the power supply duct system, FIG. 6 is a sectional view of the power supply duct 10, and FIG.
4 is a perspective view of the terminal plug 13. FIG.

The power supply duct 10 is formed having a case 11 and three conductors 12 inside the case 11. The case 11 is made of a composite material having a steel plate material as a core material and a surface coated with a synthetic resin material, and has a hexagonal cross section, for example, and has an opening 11a at the bottom and extends long in a tubular shape. A steel plate as a core material of a composite material has case earth conductive parts 11b and 11b which are exposed by projecting from a synthetic resin material coating on both sides in a longitudinal direction of both sides, and a plate member having a predetermined length. It is bent and formed. The conductor 12
Is made of a conductive material such as a copper material, has a circular cross section, extends in a cylindrical shape, and is formed by extrusion to a length substantially the same as that of the case 11. A predetermined number of the conductors 12 are held and arranged inside the case 11 at a predetermined interval by a long conductor holding portion 12a having a long opening 11b at a predetermined position. Set up.
In addition, a plurality of the power supply ducts 10 each having a predetermined length are generally formed in a circular cylindrical cross section of an end 12a of the conductor 12 of one power supply duct 10 and the conductor 12 of the other power supply duct 10. They are connected by a connecting piece having a circular cross section of the same size and a predetermined length, and installed by being installed from the ceiling by a hanger.

The terminal plug 13 is a power supply duct 10.
Is used by inserting it into the opening 11a extending in the longitudinal direction of the case 11, and the opening 12b of the conductor holding portion 12a.
The contact conductive portion 1 for contacting and conducting the conductor 12 by the
3a. And this terminal plug 13
The conductor 1 is inserted into the opening 11a of the case 11 and rotated 90 degrees in the horizontal direction, and the contact conductive portion 13a is pressed by a predetermined pressure to each conductor 1.
2 is contacted, and power is supplied to a machine or the like by the cord 13b.

By the way, in an electronic device, in order to protect an internal electronic circuit from a lightning surge and a power-source superposed noise which enter through a power line, a surge absorbing circuit or a noise filter circuit is generally inserted in an input part of the power source. Done. Further, the surge voltage induced on the outdoor distribution line by lightning or the like is first absorbed by the varistor or the like built in the earth leakage breaker provided on the distribution board. However, electromagnetic noise is also induced in the wiring of the indoor branch circuit by surge voltage caused by lightning, or equipment used indoors using a switching power supply. Therefore, a surge absorbing circuit and a noise filter circuit are inserted into the input part of the power supply in order to protect the internal electronic circuit on the device side against these surge voltage and electromagnetic noise.

[0006]

However, the above-mentioned power supply duct supplies power to a machine or the like through a conductor arranged in a case having an opening on one surface of a steel plate material. Since the case is also installed by being erected by a hanger, it is more susceptible to electromagnetic noise propagating in the air, as compared with general branch wiring that is installed in a steel conduit and is embedded. Recently, especially in factories and the like, machines using microcomputers such as industrial robots or measuring devices have been increasing, but these machines also have various protection measures against surge voltage and electromagnetic noise. Therefore, even in the power supply duct system, consideration is being demanded to prevent the electromagnetic noise from affecting the connected machine.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a noise absorber for a power supply duct that absorbs noise on the power supply duct system side to protect electric equipment. is there.

[0008]

In order to achieve the above object, the noise absorber for a power supply duct according to claim 1 is electrically conductive by connecting a casing having an inner cavity and a conductor of the power supply duct. A connection conductive part, a ground connection conductive part for connecting and conducting the case earth of the power supply duct, and a surge absorbing element connecting between the connection conductive parts and between the connection conductive part and the ground connection conductive part. There is. This allows
The surge noise voltage propagating through the power supply duct is applied to this surge absorbing element.

Further, in the noise absorber for the power supply duct according to claim 2, the surge absorbing element according to claim 1 is used as a varistor element. As a result, the surge noise voltage propagating through the power supply duct is applied to this varistor element.

Further, in the noise absorber for the power supply duct according to a third aspect of the present invention, there is provided a casing having an inner cavity, a connecting conductive portion for connecting and conducting the conductor of the power supply duct, and a case ground of the power supply duct. An earth connection conductive part that connects and conducts electricity,
A capacitor connecting the connecting conductive parts and between the connecting conductive part and the ground connecting conductive part, and an annular or cylindrical ferrite core that is penetrated by the connecting conductive part are provided. As a result, noise is grounded based on the resonance frequency determined by the capacitance of the capacitor and the inductance of the ferrite core.

Further, a noise absorber for a power supply duct according to a fourth aspect is provided with the earth connecting conductive portion according to the first to third aspects.
It is a plate material. As a result, noise is grounded from the connecting conductive portion through the plate material.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of a noise absorber for a power supply duct of the present invention will be described below with reference to FIGS. The noise absorber 1 for the power supply duct is, for example, 3
A connector for connecting the power supply ducts 10 and 10 for supplying the power of the phase is formed, and a noise absorbing circuit is provided inside the connector. The housing 2, the connecting conductive portion 3, and the earth connecting conductive member. The part 4, the support 5, and the surge absorbing element 6 are main constituent members.

The housing 2 is an outer shell that generally encloses the constituent members of the noise absorber 1 for the power supply duct, and is made of, for example, a steel plate material having conductivity and magnetism as a core material and an outer surface coated with a synthetic resin material. The composite plate material is formed by bending a plate material having a predetermined length. Also. The housing 2 is a cylindrical body having a hexagonal cross section that is substantially the same as the case 11 of the power supply duct 10 described in the section of the related art, and has a through hole 2a for fixing the earth connecting conductive portion 4 described later, Through holes 2b, 2b for fixing the support bodies 5, 5 are provided at predetermined positions. Through hole 2a
Is a through hole for simultaneously fixing one of the earth connecting conductive portion 4 and the support body 5, and a female screw is engraved on the steel plate portion of the inner wall thereof, and is fixed to the housing 2 by the steel fixing screw 7. The ground connection conductive portion 4 is fixed and electrically connected.

The connecting conductive portion 3 is a portion for connecting and conducting the conductors 12 of the power supply ducts 10 and 10 having a predetermined length, and is made of a conductive material such as a copper material to form a hemispherical end face 3a and a predetermined length. And a circular cross section having the outer dimensions of, and is formed to have substantially the same length as the housing 2. The connecting conductive portion 3 has a hemispherical end surface 3a which is inserted into the cylindrical end portion 12a of the conductor 12 of the power supply duct 10 described in the section of the prior art to connect the two power supply ducts 10 and 10 and conduct electricity. To do.

The earth connecting conductive portion 4 is connected to the power supply duct 10,
10 is a portion that connects the case grounds 10b and 10b and conducts electricity, for example, by a steel plate material having conductivity and magnetism,
It has a predetermined width and a length dimension substantially the same as that of the housing 2, and has a case ground conductive portion 10 of the power supply duct 10 at both ends in the longitudinal direction.
b has step portions 4a and 4a for contacting it, and a through hole 4b for simultaneously fixing the housing 2 and the supports 5, 5 and one end of a surge absorbing element 6 described later are fixed by soldering, for example. The through hole 4c for conducting is formed at a predetermined position. The step portion 4a is a portion for holding the case 11 of the power supply duct 10 by the facing portion 2c of the housing 2 facing the ground connecting conductive portion 4. In the direction orthogonal to the direction, a bent step portion is formed having a dimension substantially the same as the thickness of the composite material forming the case 11 of the power supply duct 10. The through holes 4b have an inner diameter dimension slightly larger than the outer diameter of the male screw of the steel fixing screw 9, and a predetermined number is formed at a predetermined position facing the through hole 2a of the housing 2.

The support 5 is a portion for holding and arranging the connecting conductive portions 3 with a predetermined interval, and is made of synthetic resin and has an outer diameter slightly smaller than the inner diameter of the hexagonal cross section of the housing 2. It has a hexagonal shape having a diameter dimension, and has a holding hole 5a for holding and arranging the three connecting conductive parts 3 inside the housing 2 so as to have a predetermined interval on the plane. The support 5 is provided with a screw 9 for fixing the housing 2 and the grounding conductive portion 4 to each other.
A female screw having a predetermined depth is attached to the inside of the housing 2 by the screw 9 so that the female screw is fixed at a predetermined position.
The holding hole 5a has an inner diameter substantially the same as the circular outer diameter of the connecting conductive portion 3 so that the connecting conductive portion 3 can be press-fitted and fixed, and the hemispherical end surface 3a is the end surface of the housing 2. The power supply ducts 10 and 10 which are press-fitted and fixed so as to be substantially the same as the above and are connected at the peripheral edge 5b are positioned.

The surge absorbing element 6 is an element for forming the surge absorbing circuit having the structure shown in FIG. 3B, and is a varistor element, for example, and is provided inside the noise absorber 1 for the power supply duct. The varistor element is a voltage non-linear element, which is used in a surge absorbing circuit of a power supply circuit of a general electronic device, and is a surge absorbing element having a characteristic of being particularly excellent in high-speed response. The surge absorbing element 6 is connected between the three connecting conductive portions 3 alternately and between the three connecting conductive portions 3 and the ground connecting conductive portion 4 to form a surge absorbing circuit. . In order to facilitate the connection, for example, a plate made of a conductive metal material having a spring property, such as a phosphor bronze material, is curved at a portion connecting the surge absorbing element 6 and the three connecting conductive portions 3. The formed connecting body 6b is fixed to the tip of the lead wire, and the connecting body 6b is locked to the connecting conductive portion 3 by the spring property. For connection between the surge absorbing element 6 and the grounding conductive portion 4, the tip of the lead wire is directly fixed by soldering.

The noise absorber 1 for the power supply duct is composed of the above-mentioned members. To assemble the noise absorber 1, first, the three connecting conductive portions 3 are inserted into the support members 5 and 5 to predetermined positions, respectively.
Next, the six surge absorbing elements 6 each having the connecting body 6b fixed at a predetermined position are locked to the connection conductive portion 3 and the ground connection conductive portion 4, respectively, and then the housing 2 is arranged at the predetermined position. The screws 9 are fixed to the through holes 2a and 2b of the housing 2 by tightening the screws.

In the noise absorber 1 for the power feeding duct constructed as described above, at the same time as inserting the end portions 12a of the conductors 12 of the power feeding ducts 10 and 10 into the connecting conductive portions 3a on both sides, the case ground conductive portion 11b. Is inserted into the step portion 4a of the earth connecting conductive portion 4 and connected to electrically connect the conductor to the case earth. Then, the power is supplied, and the conductor 1 of the power supply duct 10
When a surge noise voltage higher than the rated voltage is applied to 2, the energy of a part of the surge noise voltage is applied to the noise absorber 1 for the power supply duct.
Is circulated to the power supply side via the varistor element between the connecting conductive portions 3 and grounded, and the other energy is grounded via the varistor elements of the connecting conductive portion 3 and the earth connecting conductive portion 4.

Therefore, even if countermeasures against various surge noise voltages are taken for each machine fed from the power supply duct, a uniform surge noise countermeasure can be realized for these machines in the coupler of the power supply duct. Becomes In addition, by appropriately connecting the power supply duct noise absorber 1 at the coupler, the surge noise voltage is absorbed in the vicinity of the machine connected from the terminal plug 13 to ensure reliability. It is possible to take measures against surge noise. In addition, the surge absorber 6
Is a varistor element, the surge noise voltage propagating through the power supply duct 10 is applied to this varistor element. Due to the fast response of this varistor element,
Particularly, it is possible to more effectively absorb a relatively low surge voltage caused by arc discharge such as electric welding that occurs in a factory. Further, this varistor element is most often used in general electronic equipment, and a surge noise countermeasure can be achieved at a lower cost. Further, by using the plate member for the earth connection conductive portion 4, the surge noise voltage is grounded with a lower impedance, and a more reliable countermeasure against surge noise is achieved.

Next, a second embodiment of the noise absorber for the power supply duct of the present invention will be described with reference to FIG. The noise absorber 1 for the power supply duct includes a housing 2 having a cavity inside, a connecting conductive portion 3 for connecting and conducting the conductors 12, 12 of the two power supply ducts 10, 10, and the power supply duct 10 described above.
2. A ground connecting conductive portion 4 for connecting and conducting the case ground 9a, a capacitor 8a for connecting between the connecting conductive portion 3 and the ground connecting conductive portion 4, and an annular shape or a cylinder penetrated by the connecting conductive portion 3. And a ferrite core 8b in the shape of a circle. The circuit configuration of this is shown in FIG. 4B, and is provided inside the noise absorber 1 for the power supply duct. Further, the same casing 2, connecting conductive portion 3, earth connecting conductive portion 4, support 5 and connecting body 6b as those of the first embodiment are used.

The capacitor 7 is, for example, a ceramic capacitor having a good noise absorption characteristic especially in a high frequency band of about 100 MHz or more. Power supply duct 10
The electromagnetic noise superposed on the power supply voltage fed by the conductor 12 passes through the connecting conductive portion 3 and is grounded by the capacitor 7 through the earth connecting conductive portion 4.

The ferrite core 8 makes the connecting conductive portion 3 have an inductance characteristic in order to form a resonance circuit together with the capacitor 7, and is a cylindrical core made of a ferrite material having a predetermined magnetic permeability. The ferrite core 8 has a cylindrical shape having a predetermined length with an inner diameter slightly larger than the circular outer shape of the connecting conductive portion 3.
Is inserted and fixed in place with an adhesive, for example.

In the noise absorber 1 for the power supply duct configured as described above, by making the circuit configuration as described above, noise is grounded based on the resonance frequency determined by the capacitance of the capacitor 7 and the inductance of the ferrite core 8. The connection conductive portion 4 is grounded. Then, it is grounded via the case ground conductive portion 11b of the power supply duct 10, and electromagnetic noise is absorbed by the power supply duct near the machine connected from the terminal plug 13, so that a more reliable countermeasure against electromagnetic noise. Will be possible. By using an annular or cylindrical ferrite core as the inductance of this noise absorbing circuit, the inductance characteristic can be easily obtained. Further, by using the earth connecting conductive portion 4 as a plate material, the electromagnetic noise is also grounded with a lower impedance like the surge noise voltage described above, and a more reliable countermeasure against electromagnetic noise is achieved.

In the above description, the surge absorbing element is described as the varistor in the first embodiment, but the surge absorbing element is not limited to the varistor element, and other types such as a gap type surge absorbing element may be used. It may be a surge absorbing element. Here, the gap type surge absorber discharges and absorbs the surge noise voltage through the air gap, and has excellent withstand voltage characteristics. Further, the number of conductors of the power supply duct is not limited to three.

[0026]

In the noise absorber for the power supply duct according to the first aspect of the present invention, since the surge noise voltage propagating through the power supply duct is applied to the surge absorbing element, the noise absorber is connected near the machine connected from the terminal plug. By absorbing the surge noise voltage, it is possible to take reliable measures against surge noise.

Further, the noise absorber for the power supply duct according to claim 2 is cheaper because the surge noise voltage propagating through the power supply duct is applied to the varistor element in addition to the effect of the first aspect. Surge noise countermeasures can be achieved at a cost.

Further, in the noise absorber for the power supply duct according to the third aspect, since noise is grounded based on the resonance frequency determined by the capacitance of the capacitor and the inductance of the ferrite core, more reliable electromagnetic noise countermeasures can be taken. Become.

In addition to the effect of the noise absorber for the power supply duct according to the fourth aspect, in addition to the effect of the first aspect, the noise is grounded from the connecting conductive portion through the plate material, so that it is lower. It will be grounded by impedance, and more reliable measures against surge noise and electromagnetic noise will be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a noise absorber for a power supply duct of the present invention.

FIG. 2 is an exploded perspective view thereof.

3A is a sectional view and FIG. 3B is a circuit diagram.

4A and 4B are explanatory views showing a second embodiment of the noise absorber for the power supply duct of the present invention, in which FIG. 4A is a sectional view and FIG. 4B is a circuit diagram.

FIG. 5 is a perspective view showing a power supply duct system using the noise absorber for the power supply duct of the present invention.

FIG. 6 is a cross-sectional view of a power supply duct that is a main part thereof.

FIG. 7 is a perspective view of a terminal plug which is a main part thereof.

[Explanation of symbols]

 2 case 3 connection conductive part 4 ground connection conductive part 5 support 6 surge absorber 7 capacitor 8 ferrite core 10 power supply duct

Claims (4)

[Claims] 1. A housing having an inner cavity, a connecting conductive portion for connecting and conducting a conductor of a power supply duct, a ground connecting conductive portion for connecting and conducting a case ground of the power supply duct, and the connection. A noise absorber for a power supply duct, comprising: a surge absorbing element connecting between conductive parts and between a connecting conductive part and a ground connecting conductive part. 2. The noise absorber for a power supply duct according to claim 1, wherein the surge absorbing element is a varistor element. 3. A housing having an inner cavity, a connecting conductive portion for connecting and conducting a conductor of a power supply duct, a ground connecting conductive portion for connecting and conducting a case earth of the power supply duct, and the connection. Noise absorption for a power supply duct, comprising: a capacitor connecting between the conductive parts and between the connection conductive part and the ground connection conductive part; and an annular or cylindrical ferrite core penetrated by the connection conductive part. vessel. 4. The noise absorber for a power supply duct according to claim 1, wherein the ground connecting conductive portion is a plate member.