JPH0745023Y2 - Clamp sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a clamp sensor, and more specifically,
When measuring the current of the conductor to be measured introduced into the space formed by the pair of magnetic cores that can be opened and closed, the characteristics brought about by the difference in the positional relationship of the conductor to be measured in the space of the magnetic core. The present invention relates to a clamp sensor that can be stabilized by minimizing adverse effects.

[Prior Art] A clamp sensor is used by incorporating it into a clamp type ammeter that encloses and measures a conductor to be measured such as an electric wire in a live state.

FIG. 5 shows an example of a conventional type structure of a so-called current transformer type clamp sensor, which includes a pair of magnetic cores 1 and 2 that can be opened and closed, and windings around the magnetic cores 1 and 2. Formed with windings 5 and 6
The magnetic cores 1 and 2 themselves have a structure in which thin plates made of a high-permeability magnetic material such as permalloy are laminated in order to suppress the generation of eddy currents.

[Problems to be Solved by the Invention] By the way, in a clamp sensor made of a high-permeability magnetic material such as silicon steel plate or permalloy which is relatively inexpensive, a magnetic core is usually formed as the frequency becomes higher. The magnetic permeability of the core material is lowered, and the positional relationship between the conductor W to be measured and the clamp sensor is broken as shown in FIG. 5, and it is as if the air-core coil encloses the conductor W to be measured. As a result, there was the fact that it became unclear what kind of magnetic coupling they had with each other.

Therefore, especially in the high frequency band, the magnetic cores 1, 2
There is an inconvenience that a large change appears in the phase characteristic and the amplitude characteristic depending on the position of the conductor W to be measured introduced into the space portion 7 surrounded by.

[Means for Solving the Problem] The present invention has been made in view of the above-described inconvenience of the conventional clamp sensor, and its characteristic feature is that the butted end faces are mutually connected so as to allow the lead wires to be measured to come and go. A pair of magnetic cores that can be opened and closed together, and a winding wound around each of these magnetic cores, and the magnetic core formed by the winding is made of a conductive material. A clamp sensor formed so as to be housed in a core cover with a coating layer interposed, wherein the conductive coating layer is formed by winding a conductive tape material around the wound magnetic core. It was formed in. In this case, the conductive coating layer may be formed by applying a conductive paint on the side of the core cover that houses the wound magnetic core.

[Operation] Therefore, by interposing the conductive coating layer made of a conductive material between the magnetic core having the winding and the core cover, a one-turn coil is formed around the magnetic core, and the magnetic field is increased in the high frequency band. The magnetic flux generated in the core can be suppressed, and the magnetic coupling state between the measured wire and the winding of the clamp sensor can be improved.

Therefore, it is possible to suppress the unnatural peak characteristic that tends to occur due to the relationship with the specific position of the measured conductor in the space surrounded by the pair of magnetic cores, and to measure the phase of the measured conductor during current measurement. It is possible to stabilize the characteristics and the amplitude characteristics.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, in which a pair of magnetic members which are combined so that the butt end surfaces 13 and 14 can be opened and closed to each other so that a measured wire W such as an electric wire can be put in and taken out. The cores 11 and 12 are made of, for example, a high-permeability magnetic material such as permalloy.
A space 19 formed by 1 and 12 is formed so that a conductor W to be measured such as an electric wire can be introduced therein.

In addition, these magnetic cores 11 and 12 have windings 15 and 16 respectively.
And is formed so that it can be housed in a core cover (not shown).

Furthermore, between the pair of magnetic cores 11 and 12 provided with the windings 15 and 16 thus formed and the core cover,
Conductive coating layers 17 and 18 made of a conductive material are interveningly formed.

This will be described in more detail with reference to the example shown in FIG. 1. The conductive coating layers 17 and 18 are formed between the pair of magnetic cores 11 and 12 having the windings 15 and 16 and the core cover. Is formed by winding an aluminum foil tape material on each of the portions of the magnetic cores 11 and 12 having the windings 15 and 16 and covering them. In this case, it is preferable to cover as many surfaces as possible of the magnetic cores 11 and 12 including the windings 15 and 16.
The conductive coating layers 17 and 18 may be formed by winding a tape material made of a suitable conductive material such as a copper foil tape material instead of the aluminum foil tape material. By thus winding the tape material, the conductive coating layers 17 and 18 are formed.
When forming, the work can be performed relatively easily, and the workability can be improved.

Further, the conductive coating layers 17 and 18 are formed by applying the tape material made of a suitable conductive material to the inner peripheral surface of the core cover (not shown) in which the magnetic cores 11 and 12 having the windings 15 and 16 are housed. It can also be formed by sticking or by applying a paint having equivalent conductivity. In this way, when the conductive coating layers 17 and 18 are formed in advance on the inner peripheral surface side of the core cover, the magnetic cores 11 and 12 having the windings 15 and 16 are simply placed at predetermined positions in the core cover. It can be intervened by being housed, and the assembling work can be made simpler.

Since this device is constructed as described above,
By interposing the conductive coating layers 17 and 18 made of a conductive material between the magnetic cores 11 and 12 having the windings 15 and 16 and the core cover, one turn coil is formed around the magnetic cores 11 and 12. The magnetic flux generated in the magnetic cores 11 and 12 in the high frequency band can be suppressed, and the magnetic coupling state between the conductor W to be measured and the windings 15 and 16 in the clamp sensor can be improved.

Therefore, it is possible to suppress the unnatural peak characteristic that tends to occur due to the relationship with the specific position of the conductor W to be measured in the space 19 surrounded by the pair of magnetic cores 11 and 12, and the conductor W to be measured can be suppressed. It is possible to stabilize the phase characteristics and the amplitude characteristics when measuring the W current.

Therefore, even if the magnetic cores 11 and 12 are made of a relatively low-cost silicon steel plate or a core material made of a high-permeability magnetic material such as permalloy, a conductive coating layer 17,1 is provided between the core cover and the core cover.
Since 8 is interposed, it is possible to suppress the occurrence of an unfavorable phenomenon such as that seen in the conventional example of FIG. 5 in which the magnetic permeability decreases as the frequency increases.

FIGS. 2 (a) and (b) and FIGS. 3 (a) and (b) show a clamp sensor (fifth example) consisting of a magnetic core having windings.
(See FIG. 1) as a comparative example, and a clamp sensor (see FIG. 1) according to the present invention in which a conductive coating layer made of an aluminum foil tape material is formed on a magnetic core having windings is used as an example. Space 1 surrounded by 1) and 12 (2)
The measured conductor W introduced into 9 (7) is positioned at three points A, B and C as shown in FIG. 4, and the characteristic comparison between the comparative example and the example shown at each position is made. It is a graph figure obtained by performing.

Of these, FIG. 2 is a comparison of phase characteristics,
According to the comparative example of (a), when the frequency is 10 KHz or more, the A and B positions are abruptly unstable in the negative direction, and the C positions are abruptly unstable in the positive direction. On the other hand, according to the embodiment of (b), even though the gradual instability is observed at the positions of A and B, the characteristic becomes stable at the position of C even when the frequency reaches 100 KHz. Was confirmed to be in a stable state.

On the other hand, FIG. 3 is a comparison of amplitude characteristics,
According to the comparative example of (a), the characteristics at frequencies A and B from around 10 KHz suddenly become unstable in the positive direction, whereas according to the example of (b), It was confirmed that the characteristics were stable even when the frequency reached 100 KHz at both B and C positions.

[Advantage of the Invention] As described above, according to the present invention, since the conductive coating layer is interposed between the magnetic core having the winding and the core cover, one turn is made around the magnetic core. By forming a coil, it is possible to suppress the magnetic flux generated in the magnetic core in the high frequency band and improve the magnetic coupling state between the conductor under test and the winding in the clamp sensor, so that it is surrounded by the magnetic core. Regardless of the position of the conductor to be measured when introducing the conductor to be measured into the space part to be measured,
Both the phase characteristic and the amplitude characteristic can be made stable.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and FIG.
FIG. 3 and FIG. 3 are graphs comparing the characteristics obtained by the comparative example and the example, FIG. 4 is an explanatory view showing the arrangement pattern of the conductors to be measured with respect to the magnetic core at that time, and FIG. FIG. 7 is a schematic configuration diagram showing a conventional example. 11,12 …… Magnetic core, 13,14 …… Mating end face, 15,16 ……
Winding, 17,18 ... Conductive coating layer, 19 ... Space, W ... Conductor to be measured

Claims (2)

[Scope of utility model registration request] 1. A pair of magnetic cores, which are combined so as to open and close abutting end faces of each other so as to allow a conducting wire to be measured in and out, and a winding wound around each of the magnetic cores. In a clamp sensor formed so that the wound magnetic core can be housed in a core cover with a conductive coating layer formed of a conductive material interposed, the conductive coating layer is formed by winding. A clamp sensor is formed by winding a conductive tape material around the magnetic core. 2. A pair of magnetic cores, which are combined so as to open and close abutting end faces of each other so as to allow a conducting wire to be measured in and out, and a winding wound around each of these magnetic cores, In a clamp sensor formed so that the wound magnetic core can be housed in a core cover with a conductive coating layer formed of a conductive material interposed, the conductive coating layer is formed by winding. A clamp sensor is formed by applying a conductive paint to the side of a core cover that accommodates the magnetic core.