HK1195363B - Current detector and electricity meter - Google Patents

Description

Current detection device and electricity meter

Technical Field

The present invention relates to a current detection device that detects the magnitude of a current flowing through a conductor by magnetoelectric conversion, and an electricity meter using the current detection device.

Background

Conventionally, a current detection device for detecting a load current in a general household, a factory, an office, or the like is widely known. The current detection device includes, for example: a primary conductor that generates a magnetic field by a flow of a load current, and a magneto-electric conversion unit that detects the magnetic field generated by the primary conductor (see, for example, patent document 1).

The magnetoelectric conversion unit is formed by a coil in which a wire such as an enameled wire is wound around an annular magnetic core called a toroidal core, and the operation of winding the wire around the magnetic core takes time, which raises a problem that the current detection device is expensive.

In order to solve such a problem, patent document 2 discloses a current detection device in which a plurality of coil portions that detect a magnetic field generated by a primary conductor 11 and a support portion that supports the plurality of coil portions and is made of a magnetic material in which the plurality of coil portions are connected in magnetic series by a wire are provided around the primary conductor that generates a magnetic field proportional to a measurement current; the electric signals generated by the plurality of coil portions based on the magnetic field generated by the primary conductor are output from the output terminal via the wiring.

Fig. 1 is a schematic diagram showing a configuration of a conventional general current detection device disclosed in patent document 2. The current detection device is provided with a1 st coil 12 and a 2 nd coil 13 for detecting a magnetic field generated by a primary conductor 11, and a1 st magnetic body 14 and a 2 nd magnetic body 15 for supporting the 1 st coil 12 and the 2 nd coil 13 and magnetically short-circuiting the coils, around the primary conductor 11 generating a magnetic field according to the magnitude of a measurement current, and outputs an electric signal generated by the 1 st coil 12 based on the magnetic field generated by the primary conductor 11 from an output terminal 17 via a wiring, and outputs an electric signal generated by the 2 nd coil 13 from an output terminal 18 via a wiring.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-37297

Patent document 2: japanese patent application laid-open No. 2010-256141

Summary of the invention

Problems to be solved by the invention

However, the conventional current detection device described above has a structure in which the 1 st coil 12 to the output terminal 17 and the 2 nd coil 13 to the output terminal 18 need to be wired, and therefore, there is a problem that the manufacturability is deteriorated by the operation for wiring, and the cost is increased.

Disclosure of Invention

The invention provides a current detection device and an electricity meter which are excellent in manufacturability and are cheap.

Means for solving the problems

In order to solve the above problem, a current detection device according to the present invention includes: a conductor through which a current to be measured flows; a plurality of coils disposed around the conductor; a1 st magnetic body which is provided to face one end surfaces of the plurality of coils and magnetically short-circuits the plurality of coils; and a 2 nd magnetic body which is provided so as to face the other end surfaces of the plurality of coils, magnetically short-circuits the plurality of coils, and has through holes through which coil wires from the plurality of coils pass, the through holes being provided at positions facing the other end surfaces of the plurality of coils.

Further, the electricity meter of the present invention includes: the current detection device described above; a voltage detection unit that detects a voltage generated in the conductor; and a power calculation unit for calculating the amount of electricity based on the current detected by the current detection device and the voltage detected by the voltage detection unit.

Drawings

Fig. 1 is a diagram for explaining a conventional current detection device.

Fig. 2 is a schematic diagram showing a configuration of a current detection device according to embodiment 1 of the present invention.

Fig. 3 is a schematic diagram showing a configuration of a current detection device according to embodiment 2 of the present invention.

Fig. 4 is a schematic diagram showing the configuration of a current detection device according to embodiment 3 and a modification thereof.

Fig. 5 is a schematic diagram showing the configuration of a current detection device according to embodiment 4 of the present invention.

Fig. 6 is a block diagram showing the configuration of an electricity meter according to embodiment 5 of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding components as those of the conventional current detection device described in the background section are given the same reference numerals as those used in the background section.

(example 1)

Fig. 2 is a schematic diagram showing a configuration of a current detection device according to embodiment 1 of the present invention. The current detection device includes: a linear primary conductor 11, a1 st coil 12, a 2 nd coil 13, a1 st magnetic body 14, and a 2 nd magnetic body 15 disposed around the primary conductor 11.

The primary conductor 11 corresponds to the "conductor" of the present invention, and is made of a conductive metal such as iron or copper. The primary conductor 11 generates a magnetic field by the flow of a load current as a measured current.

The 1 st coil 12 and the 2 nd coil 13 correspond to the "plurality of coils" of the present invention, and are formed by winding a wire such as an enamel wire around a nonconductive core material such as phenol or a phenol resin. Electromotive forces corresponding to currents flowing through the primary conductor 11 are induced in each of the 1 st coil 12 and the 2 nd coil 13, and are output as electric signals.

The 1 st coil 12 and the 2 nd coil 13 may be core materials having a hollow structure or may be core materials having a material filled therein. In addition, a magnetic body such as ferrite or permalloy may be used as the core material. The 1 st coil 12 and the 2 nd coil 13 may be formed by bonding coil wires to each other with a bonding agent such as a fusion bonding agent or an adhesive, without providing a core material.

The 1 st magnetic body 14 and the 2 nd magnetic body 15 are made of ferrite, permalloy, or the like, and are disposed at positions sandwiching the 1 st coil 12 and the 2 nd coil 13.

With such a configuration, the 1 st magnetic body 14 is disposed to face one end surfaces (lower end surfaces in fig. 2) of the 1 st coil 12 and the 2 nd coil 13, and magnetically short-circuits the 1 st coil 12 and the 2 nd coil 13.

The 2 nd magnetic body 15 is provided so as to face the other end surfaces (upper end surfaces in fig. 2) of the 1 st coil 12 and the 2 nd coil 13, and magnetically short-circuits the 1 st coil 12 and the 2 nd coil 13. A through hole 21 for guiding the coil wiring from the 1 st coil 12 to the output terminal 17 is provided at a predetermined position of the 2 nd magnetic body 15, specifically, at a position facing the other end surface of the 1 st coil 12, and a through hole 22 for guiding the coil wiring from the 2 nd coil 13 to the output terminal 18 is provided at a position facing the other end surface of the 2 nd coil 13.

The output terminal 17 outputs an electric signal generated in the 1 st coil 12 in accordance with the current flowing through the primary conductor 11. The output terminal 18 outputs an electric signal generated in the 2 nd coil 13 in accordance with the current flowing through the primary conductor 11.

Next, the operation of the current detection device configured as described above will be described. The 1 st coil 12 and the 2 nd coil 13 receive a magnetic field generated by a current flowing through the primary conductor 11, and generate an electric signal corresponding to the current on the coil wire. The coil wire of the 1 st coil 12 is connected to the output terminal 17, and outputs an electric signal corresponding to the current flowing through the primary conductor 11 to the output terminal 17. Similarly, the coil wire of the 2 nd coil 13 is connected to the output terminal 18, and an electric signal corresponding to the current flowing through the primary conductor 11 is output to the output terminal 18. The electric signals output to these output terminals 17 and 18 indicate the magnitude of the current flowing through the primary conductor 11.

In the current detection device according to embodiment 1, the connection between the 1 st coil 12 and the 2 nd coil 13 and the 1 st magnetic body 14 and the 2 nd magnetic body 15 may be formed by forming a recess in the 1 st magnetic body 14 and the 2 nd magnetic body 15, and fitting the 1 st coil 12 and the 2 nd coil 13 into the recess. The 1 st coil 12 and the 2 nd coil 13 may be fixed to the 1 st magnetic body 14 and the 2 nd magnetic body 15 with an adhesive or the like. The 1 st coil 12 and the 2 nd coil 13 do not have to be in contact with the 1 st magnetic body 14 and the 2 nd magnetic body 15, and these components may be mounted in a resin case or the like and fixed.

As described above, according to the current detection device of embodiment 1 of the present invention, the through holes 21 and 22 for passing the coil wiring are formed in the 2 nd magnetic body 15, and the coil wires from the 1 st coil 12 and the 2 nd coil 13 are connected to the output terminals 17 and 18 through the through holes 21 and 22, respectively, so that the routing operation is facilitated, and the time required for manufacturing can be reduced. As a result, the manufacturability can be improved and the cost can be reduced.

(example 2)

Fig. 3 is a schematic diagram showing a configuration of a current detection device according to embodiment 2 of the present invention. The current detection device of embodiment 1 is the same as the current detection device of embodiment 1 except that the structure of the 2 nd magnetic body 15 of the current detection device of embodiment 1 is changed and the 2 nd magnetic body 15a is used. Hereinafter, the description will be focused on the differences from the current detection device of example 1.

The 2 nd magnetic body 15a is provided so as to face the other end surfaces (upper end surfaces in fig. 3) of the 1 st coil 12 and the 2 nd coil 13, and magnetically short-circuits the 1 st coil 12 and the 2 nd coil 13. A through hole 23 for guiding the coil wiring from the 1 st coil 12 to the output terminal 17 and guiding the coil wiring from the 2 nd coil 13 to the output terminal 18 is provided at a predetermined position of the 2 nd magnetic body 15a, specifically, at a position other than a position facing the other end surface of the 1 st coil 12 and other than a position facing the other end surface of the 2 nd coil 13.

According to the current detection device of embodiment 2 of the present invention, since the one through hole 23 through which the coil wiring passes is formed in the 2 nd magnetic body 15a, and the coil leads from the 1 st coil 12 and the 2 nd coil 13 pass through the through hole 23 and are connected to the output terminals 17 and 18, the routing operation is facilitated, the time required for manufacturing can be reduced, and as a result, the manufacturability can be improved and the cost can be reduced.

Further, since the through-hole 23 through which the coil wiring from the 1 st coil 12 and the 2 nd coil 13 passes is provided at a position other than a position facing the other end surfaces of the 1 st coil 12 and the 2 nd coil 13, the other end portions of the 1 st coil 12 and the 2 nd coil 13 are covered with the magnetic material, and the interference resistance performance can be improved.

In the current detection device according to embodiment 2, only one through-hole 23 is formed in the 2 nd magnetic body 15a, but a plurality of through-holes may be provided if the through-hole is located at a position other than a position facing the other end surface of the 1 st coil 12 and other than a position facing the other end surface of the 2 nd coil 13.

(example 3)

Fig. 4 (a) is a schematic diagram showing the configuration of a current detection device according to embodiment 3 of the present invention. The current detection device of embodiment 1 is the same as the current detection device of embodiment 1 except that the coil leads of the 1 st coil 12 and the 2 nd coil 13 of the current detection device of embodiment 1 are changed to be wound around the bobbin and the 1 st coil 12a and the 2 nd coil 13a are used. Hereinafter, the description will be focused on the differences from the current detection device of example 1.

The 1 st coil 12a and the 2 nd coil 13a correspond to the "plurality of coils" of the present invention. The 1 st coil 12a is formed of a bobbin-wound coil in which a coil wire is wound around a bobbin 31, and a winding head and a winding tail of the coil wire are bound by a pin terminal 24. Similarly, the 2 nd coil 13a is formed of a coil wound around a bobbin in which a coil wire is wound around a bobbin 32, and a winding head and a winding tail of the coil wire are bound by a pin terminal 25. The bobbins 31 and 32 are made of, for example, PBT (polybutylene terephthalate) resin.

According to the current detection device of embodiment 3 of the present invention, since the 1 st coil 12a and the 2 nd coil 13a are bobbin-wound coils, no wire is required, and the time required for manufacturing can be reduced. As a result, the manufacturability can be improved and the cost can be reduced.

The current detection device of embodiment 3 can be modified as follows. Fig. 4 (b) is a schematic diagram showing the configuration of a current detection device according to a modification example of embodiment 3 of the present invention. The current detection device of example 3 is the same as the current detection device of example 3, except that the bobbin 31a and 32a is used instead of the bobbin 31a and 32a in which the flange shape of the bobbin 31 and 32 included in the 1 st coil 12a and the 2 nd coil 13a is changed, and the 1 st coil 12a and the 2 nd coil 13a are used as the 1 st coil 12b and the 2 nd coil 13b, respectively. Hereinafter, the description will be focused on the differences from the current detection device of example 3.

The 1 st coil 12b and the 2 nd coil 13b correspond to the "plurality of coils" of the present invention. A part of the flange on the 2 nd magnetic body 15a side of the bobbin 31a of the 1 st coil 12b extends to a position facing the through hole 23 of the 2 nd magnetic body 15a, and the coil wire of the 1 st coil 12b is connected to the output terminal 24 from the extended portion 33 of the flange through the through hole 23.

A part of the 2 nd magnetic body 15a side flange of the bobbin 32a of the 2 nd coil 13b extends to a position facing the through hole 23 of the 2 nd magnetic body 15a, and the coil wire of the 2 nd coil 13b is connected to the output terminal 25 from the extending portion 34 of the flange through the through hole 23.

According to the current detection device of the modification of embodiment 3, in addition to the effects produced by the current detection device of embodiment 3, the time taken for manufacturing can be reduced. As a result, the manufacturability can be improved and the cost can be reduced.

(example 4)

Fig. 5 is a schematic diagram showing the configuration of a current detection device according to embodiment 4 of the present invention. The current detection device has the same shape as the 1 st magnetic body and the 2 nd magnetic body of the current detection devices of embodiments 1 to 3. Hereinafter, the description will be given mainly on the differences from the current detection devices of embodiments 1 to 3.

Fig. 5 (a) is a diagram in which the 1 st magnetic body 14 of the current detection device of example 1 is changed to a1 st magnetic body 14a having the same shape as the 2 nd magnetic body 15.

Fig. 5 (b) is a diagram in which the 1 st magnetic body 14 of the current detection device of example 2 is changed to a1 st magnetic body 14b having the same shape as the 2 nd magnetic body 15 a.

Fig. 5 (c) is a diagram in which the 1 st magnetic body 14 of the current detection device of example 3 is changed to a1 st magnetic body 14a having the same shape as the 2 nd magnetic body 15.

Fig. 5 (d) is a diagram in which the 1 st magnetic body 14 of the current detection device according to the modification of embodiment 3 is changed to a1 st magnetic body 14b having the same shape as the 2 nd magnetic body 15 a.

With the above configuration shown in fig. 5 (a) to 5 (d), the 1 st magnetic body and the 2 nd magnetic body can be shared, and therefore, the number of types of parts can be reduced, and the cost can be reduced.

(example 5)

Embodiment 4 of the present invention is an electricity meter using the current detection device of embodiments 1 to 4 described above. Fig. 6 is a block diagram showing the configuration of the electricity meter of embodiment 4. The electricity meter is provided with: a current detection device 51, a voltage detection unit 52, a power calculation unit 53, and a display unit 54.

As the current detection device 51, any one of the current detection devices of embodiments 1 to 4 described above is used. The current detection device 51 detects a use current (a 1) used by the load of the user, converts the use current into an electric signal corresponding to the use current, and outputs the electric signal.

The voltage detection unit 52 is a part for detecting the voltage of the system under test, and is configured by a voltage dividing resistor such as a transformer and an attenuator, and the like, and detects the use voltage (V1) used by the load of the user, converts the use voltage into a low-level voltage signal proportional to the use voltage, and outputs the voltage signal.

The power calculation unit 53 calculates the electric power based on the current flowing through the conductor 11 detected by the current detection device 51 and the voltage detected by the voltage detection unit 52. Specifically, the power calculation unit 53 is configured by a digital multiplier circuit, a DSP (digital signal processor), or the like, and multiplies the signal relating to the use current (a 1) output from the current detection device 51 and the signal relating to the use voltage (V1) output from the voltage detection unit 52, and converts the multiplication result into data (a 1 · V1) proportional to the use power of the user.

The power calculation unit 53 edits and outputs the calculation result of the data (a 1 · V1) proportional to the power used as the data of the amount of use. The usage data referred to herein is data on the power used by the user, such as the total cumulative amount of power used by the user's load and the amount of power used per time slot.

In addition, since the signal of the use current (a 1) output from the current detection device 51 is proportional to the signal obtained by differentiating the use current (a 1) except for the case where the core material of the coil is a magnetic material, the signal is integrated by the power calculation unit 53 before being converted into data (a 1 · V1) proportional to the power used by the user. The display unit 54 is configured by a liquid crystal display or the like, and displays usage data.

As described above, according to the electricity meter of the embodiment 5 of the present invention, it is possible to realize an electricity meter having a current detection device which does not take time in manufacturing, is excellent in manufacturing efficiency, and can reduce cost.

According to the present invention, the routing operation becomes easy, the manufacturability can be improved, and the cost can be reduced.

Claims (2)

1. A current detection device is provided with:

a conductor through which a current to be measured flows;

2 coils wound around the bobbin and disposed around the conductor;

a1 st magnetic body which is provided to face one end surface of the 2 bobbin-wound coils and magnetically short-circuits the 2 bobbin-wound coils, and has a through hole in the middle of 2 short-circuits of the 2 bobbin-wound coils; and

a 2 nd magnetic body which is provided to face the other end surface of the 2 bobbin-wound coil and magnetically short-circuits the 2 bobbin-wound coil, and has a through hole in the middle of 2 short-circuits of the 2 bobbin-wound coil,

the 2 bobbin-wound coils are of the same shape,

the 1 st magnetic body and the 2 nd magnetic body have the same shape,

the output terminal from the coil wound by the 2 bobbins is inserted into the through hole of either the 1 st magnetic body or the 2 nd magnetic body.

2. An electricity meter is provided with:

the current detection device of claim 1;

a voltage detection unit that detects a voltage generated in the conductor; and

and a power calculation unit that calculates power or electric power based on the current detected by the current detection device and the voltage detected by the voltage detection unit.