JP5810741B2 - Electrical signal detection terminal and power measuring device using the same - Google Patents

Description

  The present invention relates to an electric signal detection terminal capable of detecting a voltage of a single core covered electric wire and a current flowing through the electric wire, and an electric power measurement for calculating power consumption of a load connected to the electric wire using the electric signal detection terminal. Relates to the device.

  Conventionally, a voltage measurement probe for detecting the voltage of a single-core coated electric wire by specific contact, a current measurement probe for detecting a current flowing through the electric wire, and a load connected to the electric wire based on the detected voltage and current There is known a power measuring device that includes a main body unit that calculates the power consumption (for example, Patent Document 1). Further, as a probe (electrical signal detection terminal) of such a power measuring device, a pressing which presses the measurement target electric wire clamped by the fixed sensor arm, the movable sensor arm, and the fixed sensor arm and the movable sensor arm against the fixed sensor arm. A probe including an arm is known (for example, Patent Document 2). One end of the fixed sensor arm is fixed to the support and the detection electrode is disposed inside. One end of the movable sensor arm is rotatably attached to the support, and the other end is configured to be able to contact and separate from the other end of the fixed sensor arm. The fixed sensor arm and the movable sensor arm include a magnetic core, and form a closed magnetic circuit by clamping the measurement target electric wire. One end of the holding arm is pivotally attached to the support together with one end of the movable sensor arm, and is disposed between the fixed sensor arm and the movable sensor arm. Press near the position where the detection electrode is placed.

JP 2006-343109 A JP 2009-041925 A

  By using such a probe, it is possible to reduce fluctuations in the capacitance value of the capacitance formed between the measurement target wire and the detection electrode, which is important when measuring the voltage of the measurement target wire in a non-contact manner. Is possible. However, a non-contact type probe having a simpler structure would be preferable.

  An object of the present invention is to provide a non-contact type electric signal detection terminal having a simpler structure and a power measuring device including the electric signal detection terminal.

According to one aspect of the present invention, by combining, a pair of magnetic cores that define a clamp region that surrounds a single core covered electric wire, a coil wound around a part of the pair of magnetic cores, and the pair A core case that supports the magnetic core and the coil and can maintain a state in which the pair of magnetic cores are combined, an electrode disposed in the clamp region, and the pair of magnetic cores disposed in the clamp region An elastic member that presses the electric wire surrounded by the electrode and press- contacts the electrode, and the core case holds one of the pair of magnetic cores and the electrode disposed in the clamp region. A first housing mechanism for supporting and pressing the electrode via the electric wire by the elastic member; a second housing mechanism for holding the other of the pair of magnetic cores; The pair of magnetic cores are combined into a coupling mechanism that maintains a state in which the pair of magnetic cores supported by the second housing mechanism are combined, and the pair of magnetic cores supported by the first and second housing portions. The second housing mechanism supports the elastic member disposed in the clamp region, and generates a repulsive pressure caused by the pressing of the electric wire by the elastic member. There is provided an electric signal detection terminal provided with an elastic member support that suppresses propagation to the other of the pair of magnetic cores .

According to another aspect of the present invention, an electric signal detection terminal for detecting a voltage of a single core covered electric wire and a current flowing through the electric wire, and a power measuring unit for calculating electric power consumed by a load connected to the electric wire, The electrical signal detection terminal is wound around a part of the pair of magnetic cores and a pair of magnetic cores that define a clamp region that surrounds the electric wire by combining the electrical signal detection terminals. A coil case, a core case that supports the pair of magnetic cores and the coil and can maintain a state in which the pair of magnetic cores are combined, an electrode disposed in the clamp region, and a coil region disposed in the clamp region An elastic member that presses the electric wire surrounded by the pair of magnetic cores and presses the electric wire against the electrode, and the power measurement unit is configured to detect a voltage corresponding signal detected by the electrode, Based on the detected current corresponding signal by the fine said coil comprises a control unit for calculating the power of the pair of magnetic core load connected to the electric wire to be clamped to consume, the core case, the A first housing mechanism for holding one of a pair of magnetic cores and supporting the electrode disposed in the clamp region and receiving a pressure on the electrode via the electric wire by the elastic member; While holding the other of the pair of magnetic cores and supporting the elastic member disposed in the clamp region, the repulsive pressure accompanying the pressing of the electric wire by the elastic member to the other of the pair of magnetic cores A second housing mechanism that suppresses propagation of the magnetic field; a coupling mechanism that holds a pair of magnetic cores supported by the first and second housing mechanisms; and the first and first A pair of magnetic cores supported on the housing portion, a power measuring device comprising a spring mechanism, the urging in the direction in which said pair of magnetic cores coalesce, is provided.

  It becomes possible to perform power measurement with high reliability more easily.

1A and 1B are perspective views showing an electrical signal detection terminal according to the first embodiment. 2A and 2B are XY plan views showing the bottom surface of the upper housing mechanism and the top surface of the lower housing mechanism. 3A and 3B are XZ side views showing a state where the measurement target electric wire is clamped by the electric signal detection terminal of the first embodiment. 4A and 4B are an XZ side view and a YZ sectional view showing a state in which a measurement target electric wire having a relatively large diameter is clamped by the first electric signal detection terminal. 5A to 5C are XZ sectional views showing a spring mechanism of the electric signal detection terminal according to the second embodiment. 6A to 6C are plan views showing the lower surface of the upper housing mechanism of the electric signal detection terminal according to the third embodiment, and a YZ cross section showing how the electric wire to be measured having a relatively large diameter is clamped by the electric signal detection terminal. FIG. 7A and 7B are YZ cross-sectional views showing a state in which a measurement target electric wire having a relatively thick diameter is clamped by the electric signal detection terminal according to the fourth embodiment. FIG. 8 is an XZ side view showing an electrical signal detection terminal used in the power measuring apparatus according to the embodiment. FIG. 9 is a block diagram illustrating the configuration of the power measurement apparatus according to the embodiment. FIG. 10 is a block diagram illustrating a configuration example of the voltage measurement unit of the main unit. FIG. 11 is a block diagram illustrating a configuration example of the current measurement unit of the main unit. 12A to 12C are graphs schematically showing temporal changes of the pressing signal, the current effective value, and the voltage effective value measured by the power measuring device according to the example. FIG. 13 is a graph illustrating an example of a voltage waveform and a current waveform measured by the power measuring apparatus according to the example.

  With reference to FIGS. 1-2, the basic composition of the electric signal detection terminal by an Example is demonstrated.

  1A and 1B are perspective views showing an electrical signal detection terminal according to the first embodiment. As shown in FIG. 1A, the electrical signal detection terminal 10 is formed by combining the upper magnetic core 12a and the lower magnetic core 12b that define the clamp region 11 that surrounds the single core covered electric wire 40, and the lower magnetic core 12b. A coil 13 wound around a part. The coil 13 may be wound around the upper magnetic core 12a. The pair of magnetic cores 12a and 12b are formed of ferrite, permalloy, or the like, which is a magnetic material having high permeability, and has, for example, a semi-annular shape. The coil 13 is made of, for example, a copper wire covered with an insulator.

  The pair of magnetic cores 12a and 12b and the coil 13 are accommodated in the core case 20, as shown in FIG. 1B. The core case 20 includes an upper housing mechanism 21a and a lower housing mechanism 21b. The upper housing mechanism 21a encloses the upper magnetic core 12a, and the lower housing mechanism 21b encloses the lower magnetic core 12b (FIG. 1A) and the coil 13 (FIG. 1A).

  The core case 20 is further disposed on the upper surface of the upper housing mechanism 21a, which is a coupling mechanism disposed on the side surfaces of the upper and lower housing mechanisms 21a and 21b, that is, the hinge mechanism 22 (FIGS. 2A and 2B) and the lock mechanism 23. And a spring mechanism 24. The hinge mechanism 22 is disposed on the side surfaces of the housing mechanisms 21a and 21b, and connects the housing mechanisms 21a and 21b so as to be freely opened and closed. The hinge mechanism 22 can move the upper housing mechanism 21a in the direction of the block arrow shown in FIG. 1B, for example. The locking mechanism 23 is, for example, a locking claw 23a (FIGS. 2A and 2B) provided on a side surface facing the hinge mechanism 22 of the upper housing mechanism 21a, and a side surface facing the hinge mechanism 22 of the lower housing mechanism 21b. The lock hook 23b is provided (FIGS. 2A and 2B). The lock mechanism 23 can hold the housing mechanisms 21a and 21b in a closed state. The coupling mechanism including the hinge mechanism 22 and the lock mechanism 23 can maintain a state in which the pair of magnetic cores 12a and 12b held by the housing mechanisms 21a and 21b are combined. The spring mechanism 24 is made of, for example, a leaf spring formed integrally with the housing mechanism 21a, and biases the magnetic core 12a held by the upper housing mechanism 21a in a direction in which the pair of magnetic cores 12a and 12b are combined. To do. Core case 20 is integrally formed of a resin such as plastic.

  The electric signal detection terminal 10 further has an electrode 14 disposed on the clamp region 11 so that the main surface thereof is orthogonal to the direction in which the magnetic cores 12a and 12b are combined, and the clamp region 11 faces the main surface of the electrode 14. The elastic member 15 is disposed. The electrode 14 is made of a conductive member, for example, a copper foil tape, and the elastic member 15 is made of a non-magnetic member having a variable volume, for example, sponge rubber. The arrangement of the electrode 14 and the elastic member 15 in the clamp region 11 will be described in more detail with reference to FIG.

  It should be noted that the direction in which the pair of magnetic cores 12a and 12b are combined is the Z direction, the direction in which the measurement target electric wire 40 is inserted through the clamp region 11 defined by the pair of magnetic cores 12a and 12b is the Y direction, and the directions are orthogonal to each other. An XYZ orthogonal coordinate system in which the direction is the X direction is defined.

  2A and 2B are XY plan views showing the bottom surface of the upper housing mechanism 21a and the top surface of the lower housing mechanism 21b. As shown in FIG. 2A, the upper magnetic core 12a supported by the presser claw 25 is exposed on the bottom surface of the upper housing mechanism 21a, and an elastic member 15 fixed by double-sided tape or the like is disposed in the concave portion of the upper magnetic core 12a. It is installed. On the upper surface of the lower housing mechanism 21b, as shown in FIG. 2B, the lower magnetic core 12b is exposed, and the electrode 14 is disposed on the electrode support portion 26 that fills the recess. The electrode support portion 26 and the electrode 14 supported by the electrode support portion 26 have a hollow shape so as to stably accommodate the measurement target electric wire 40 (FIG. 1A). Clamp region 11 (FIG. 2A) in which merged surfaces 12aI and 12aII of upper magnetic core 12a shown in FIG. 2A and merged surfaces 12bI and 12bII of lower magnetic core 12b shown in FIG. 1A) is defined. When clamping the measurement target electric wire 40, the elastic member 15 presses the clamped measurement target electric wire 40 (FIG. 1A) and changes its shape to absorb the repulsive pressure of the measurement target electric wire 40, while measuring the measurement target electric wire 40. 40 is brought into pressure contact with the electrode 14. This will be described in more detail with reference to FIG.

  3A and 3B are XZ side views showing a state where the measurement target electric wire is clamped by the electric signal detection terminal of the first embodiment. Hereinafter, for convenience, illustration of a coupling mechanism (hinge mechanism and lock mechanism) provided in the core case is omitted.

  First, as shown in FIG. 3A, it is assumed that the measurement target electric wire 40 is disposed on the electrode 14 and the pair of magnetic cores 12a and 12b are to be combined. The upper magnetic core 12a is supported by a presser claw 25 (FIG. 2A) provided in the upper housing mechanism 21a so as not to drop off from the housing mechanism 21a, and its one end side and the other end side protrude from the housing mechanism 21a. To be supported. In this way, by projecting the tip of the magnetic core 12a from the housing mechanism 21a, the combined surfaces of the pair of magnetic cores 12a and 12b can be reliably brought into contact with each other. At this time, the spring mechanism 24 provided on the upper surface of the housing mechanism 21a maintains a steady state without contacting the upper magnetic core 12a.

  Next, as shown in FIG. 3B, a case where a pair of magnetic cores 12a and 12b are combined is assumed. The combined surfaces of one end and the other end of each of the pair of magnetic cores 12a and 12b are in contact with each other, and the state is maintained. At this time, the spring mechanism 24 provided on the upper surface of the upper housing mechanism 21a biases the upper magnetic core 12a in the direction in which the pair of magnetic cores 12a and 12b are united (Z-axis negative direction). The elastic member 15 presses the measurement target electric wire 40 and changes the shape thereof to absorb the repulsive pressure of the measurement target electric wire 40 and press the measurement target electric wire 40 against the electrode 14.

  By using the electric signal detection terminal having such a simple configuration, the measurement target electric wire to be clamped can be easily brought into contact with the electrode disposed in the clamp region. Thereby, it becomes possible to reduce the fluctuation | variation of the capacitance value of the capacitor | condenser formed between the core wire and electrode which are important when measuring the voltage of a measuring object electric wire non-contactingly. .

  The pair of magnetic cores 12 a and 12 b are combined to form a closed magnetic circuit, and efficiently induce a magnetic flux generated by the current flowing through the measurement target electric wire 40 to the coil 13. The coil 13 wound around a part of the magnetic cores 12a and 12b induces a voltage corresponding to the magnetic flux penetrating the inside of the annular coil. This voltage signal is output to the subsequent measuring apparatus as signals SI1 and SI2 corresponding to the current flowing through the measurement target electric wire 40. Further, the electrode 14 in pressure contact with the measurement target electric wire 40 constitutes a capacitor together with the core wire of the measurement target electric wire 40, and is connected to a charge supply source (for example, a capacitor with one end grounded), whereby the voltage of the measurement target electric wire is measured. Can be charged and discharged. This charge / discharge signal (that is, a voltage signal) of the electric charge is output to a subsequent measurement apparatus as a signal SV corresponding to the voltage of the measurement target electric wire 40.

  FIG. 4A is an XZ side view illustrating a state in which a measurement target electric wire having a relatively large diameter is clamped by the first electric signal detection terminal. Moreover, FIG. 4B shows the IVB-IVB cross section in FIG. 4A. The outer diameter of a commonly used single-core coated electric wire is, for example, about 2 mm for a rated 10 A electric wire and about 25 mm for a rated 500 A electric wire. Assume that a relatively thick wire is to be clamped by using an electric signal detection terminal having a distance between the elastic member and the electrode when the pair of magnetic cores are combined and a relatively thin wire. In such a case, as shown in FIGS. 4A and 4B, the elastic member 15 may exceed the range in which the repulsive pressure of the electric wire 40 can be absorbed, and a gap (gap G) may occur between the magnetic cores 12a and 12b. There is sex. When the gap G exists between the magnetic cores 12a and 12b, the magnetic resistance of the magnetic path formed by the magnetic cores 12a and 12b increases, and the coil 13 cannot accurately detect the current flowing through the electric wire 40.

  In such a case, it is preferable to use a spring mechanism in which the elastic coefficient is different between the tip portion that contacts one of the pair of magnetic cores and the root portion that engages with the housing mechanism. You may use the housing mechanism which comprises an elastic member support part which supports an elastic member and suppresses the propagation to the one of a pair of magnetic core of the repulsive pressure accompanying the press of an electric wire. Or you may use the elastic member which has a part which penetrates a clamp area | region and has a shape from which thickness differs according to a position in a normal pressure state.

  5A to 5C are XZ sectional views showing a spring mechanism of the electric signal detection terminal according to the second embodiment. In this embodiment, as shown in FIG. 5A, the spring mechanism 24 provided in the core case 20 (FIG. 1B) includes a tip portion that contacts the upper side surface of the upper magnetic core 12a and a root portion that engages with the housing mechanism 21a. And the thickness is different. That is, it includes a tip portion having a first elastic constant and a root portion having a second elastic constant larger than the first elastic constant. For example, as shown in FIG. 5B, the spring mechanism 24 is relatively moved by the distal end portion of the spring mechanism 24 until the housing mechanisms 21 a and 21 b are locked in the closed state by the lock mechanism 23 (FIG. 1B) of the core case 20. The upper magnetic core 12a is biased with a weak force. When a repulsive pressure is applied to clamp the relatively thick wire 40 and move the upper magnetic core 12a further upward in the Z-axis, the magnetic core 12a is urged by a relatively strong force by the root portion of the spring mechanism 24. To do.

  By providing such a spring mechanism, generation of a gap between a pair of magnetic cores that can occur when a relatively thick electric wire is clamped can be suppressed, and the current flowing through the electric wire can be accurately detected. As shown in FIG. 5C, the spring mechanism 24 may have a shape with continuously different thicknesses from the tip portion to the root portion.

  6A to 6C are plan views showing the bottom surface of the upper housing mechanism 21a of the electric signal detection terminal according to the third embodiment, and a part of the electric signal detection terminal that clamps the measurement target electric wire having a relatively large diameter. It is YZ sectional drawing which shows a mode. In the present embodiment, the upper housing mechanism 21a is disposed between the inner bottom portion of the concave upper magnetic core 12a and the elastic member 15 as shown in the bottom view shown in FIG. 6A and the sectional view shown in FIG. 6B. The elastic member support part 27 arrange | positioned so that the both-sides edge part may be passed is comprised. The elastic member support portion 27 supports the magnetic core 12a so as not to drop off, and fixes the elastic member 15 via a double-sided tape or the like. When the elastic member 15 presses the relatively thick electric wire 40 against the electrode 14 by the elastic member 15, the elastic member support portion 27 bypasses the repulsive pressure of the electric wire 40 due to the press contact to both end portions of the upper housing mechanism 21a, and the upper side of the repulsive pressure. Propagation to the magnetic core 12a is suppressed.

  By providing such an elastic member support portion, it is possible to suppress the occurrence of a gap between a pair of magnetic cores that can occur when a relatively thick electric wire is clamped, and to accurately detect the current flowing through the electric wire. . 6C, the elastic member support portion 27 is separated from the upper housing mechanism 21a and may be disposed so as to engage with both side ends or the presser claws 25 (FIG. 2A). It doesn't matter.

  7A and 7B are YZ sectional views showing a part of a state in which a measurement target electric wire having a relatively large diameter is clamped by the electric signal detection terminal according to the fourth embodiment. In this embodiment, as shown in FIG. 7A, the elastic member 15 has a cylindrical shape that surrounds the bottom portion of the concave upper magnetic core 12a, and the peripheral portion has a thickness that varies depending on the position. In addition, when the elastic member support part 27 is provided in the upper housing mechanism 21a, the elastic member support part 27 preferably has a shape corresponding to the elastic member 15. By using the elastic member 15 having such a shape, the elastic member 15 is rotated in accordance with the thickness of the electric wire 40 to be clamped, and the thickness of the elastic member 15 is adjusted so that the electric wire 40 is appropriately pressed against the electrode 14. It becomes possible to adjust. Further, as shown in FIG. 7B, the elastic member 15 is formed in a triangular shape, and the elastic member 15 is slid by providing the elastic member support portion 27 corresponding to the shape, so that the electric wire 40 is appropriately pressed against the electrode 14. It is also possible to adjust the thickness of the elastic member 15.

  By using an elastic member having such a shape, it is possible to suppress the occurrence of a gap between a pair of magnetic cores that can occur when a relatively thick electric wire is clamped, and to accurately detect the current flowing through the electric wire. . The elastic member may be a foldable structure that extends through the clamp region, or may be a multilayer structure that can be peeled off. Even when such an elastic member is used, it is possible to adjust the thickness of the elastic member so that the electric wire is in pressure contact with the electrode.

  By using the electric signal detection terminal having a simple configuration as shown in the first to fourth embodiments, the voltage of the measurement target electric wire clamped on the electric signal detection terminal and the current flowing through the electric wire can be accurately determined. It becomes possible to detect. However, it will be difficult to visually confirm that the pair of magnetic cores are reliably united. In addition, it may be difficult to visually confirm that the electric wire to be clamped is surely in contact with the electrode. When the pair of magnetic cores are not combined, or when the electric wire to be clamped is not in contact with the electrode, it is difficult to accurately measure the power consumed by the load connected to the electric wire.

  In such a case, it is preferable that the operator who performs the measurement monitors the detected voltage value and current value while pressing the pair of magnetic cores in the united direction, and confirms the clamp state of the electric signal detection terminal. Will. However, it would be still preferable if there is a means for automatically determining such confirmation of the clamp state. Such a determination is based on the electrical signal detection terminal including a means for detecting the press for confirming the clamp state, the press detection, and the change of the voltage / current signal. It can be realized by using a power measuring device including a main body unit that automatically determines. Hereinafter, with reference to FIGS. 8-12, the electric power measurement apparatus which determines automatically the quality of the clamp state of an electric signal detection terminal is demonstrated.

  FIG. 8 is an XZ side view showing an electrical signal detection terminal used in the power measuring apparatus according to the embodiment. The electrical signal detection terminal 10 according to the present embodiment detects a pressure applied in the direction in which the magnetic cores 12a and 12b are combined on the outer surface intersecting with the direction in which the pair of magnetic cores 12a and 12b are combined, that is, on the upper side surface of the upper magnetic core 12a. A pressure sensor 16 is provided. Other configurations are the same as those of the electrical signal detection terminal of the third embodiment, for example. In the measurement, the operator presses the upper magnetic core 12a through the pressure sensor 16 in the direction in which the pair of magnetic cores 12a and 12b are combined. The pressure sensor 16 outputs a pressing signal SP to the subsequent measuring device in response to the pressing by the operator. The pressure sensor 16 is constituted by a piezo element, for example. It is assumed that the pressure sensor 16 does not react to the urging by the spring mechanism 24.

  FIG. 9 is a block diagram illustrating the overall configuration of the power measuring apparatus according to the embodiment. The power measuring apparatus according to the embodiment includes an electric signal detection terminal 10 provided with a pressure sensor, and a main body unit 30. The main unit 30 is configured to include, for example, a voltage measurement unit 31, a current measurement unit 32, a control unit 33, a storage unit 34, a communication unit 35, and a display unit 36.

  The electric signal detection terminal 10 clamps one of the electric wires connected to the single-phase AC power source, for example, the live line 40. The electrical signal detection terminal 10 outputs the voltage corresponding signal SVa detected by the electrode 14 (FIG. 8) to the voltage measuring unit 31 of the main unit. Moreover, the current corresponding signals SIa1 and SIa2 detected by the coil 13 (FIG. 8) are output to the current measuring unit 32 of the main unit. Furthermore, the pressing signal SP detected by the pressure sensor 16 (FIG. 8) is output to the control unit 33 of the main unit.

  The voltage measuring unit 31 and the current measuring unit 32 perform analog-digital conversion on the input voltage corresponding signal SVa and the current corresponding signals SIa1 and SIa2, and then output the voltage corresponding signal SVd and the current corresponding signal SId to the control unit 33.

  The control unit 33 calculates, for example, effective power of a load connected to the measurement target electric wire 40 based on the input voltage corresponding signal SVd and current corresponding signal SId. Also, parameter settings for each module, for example, the sampling frequency of the voltage measuring unit 31 and the current measuring unit 32 are set.

  The memory | storage part 34 is connected with the control part 33, for example, memorize | stores the voltage and electric current corresponding | compatible signal acquired by the control part 33 in time series. The storage unit 34 is configured by, for example, a random access memory or a hard disk drive.

  The communication unit 35 is connected to the control unit 33 and transmits / receives various settings and data to / from an external device.

  The display unit 36 is connected to the control unit 33 and displays a status indicating the status of the control unit 33, calculated power consumption, or a waveform indicating a time change in voltage / current of the measurement target electric wire.

  10 and 11 are block diagrams showing specific configuration examples of the voltage measuring unit 31 and the current measuring unit 32 of the main unit. For example, as shown in FIG. 10, voltage measuring unit 31 includes a load capacitor C1, an input resistor R1, an amplifier circuit Cir1 including an operational amplifier Op1 and amplification factor defining resistors R2 and R3, and an analog-digital converter AD1. It is a configuration. The electrode 14 constituting the capacitor together with the measurement target electric wire 40 can charge and discharge the electric charge corresponding to the voltage of the measurement target electric wire 40 by connecting to the load capacitance C1 whose one end is grounded. The charge / discharge signal (voltage corresponding signal SVa) of the charge is input to the amplifier circuit Cir1 having a predetermined amplification factor via the input resistor R1. The voltage corresponding signal amplified by the amplifier circuit Cir1 is analog-digital converted at a predetermined sampling frequency f by the analog-digital converter AD1. The analog-to-digital converted voltage corresponding signal SVd is output to the subsequent control unit 33 (FIG. 9).

  For example, as shown in FIG. 11, the current measuring unit 32 includes a load resistor R4, an amplifier circuit Cir2 including an operational amplifier Op2 and amplification factor defining resistors R5 and R6, and an analog-digital converter AD2. The current corresponding signal SIa1 output from the coil 13 of the electric signal detection terminal is connected to a reference potential (ground, common ground), and the current corresponding signal SIa2 is input to the amplifier circuit Cir2 having a predetermined amplification factor via the load resistor R4. Is done. The current corresponding signal amplified by the amplifier circuit Cir2 is analog-digital converted at a predetermined sampling frequency f by the analog-digital converter AD2. The analog-to-digital converted current corresponding signal SId is output to the control unit 33 (FIG. 9) at the subsequent stage.

  Hereinafter, a combination state determination flow of the pair of magnetic cores and a contact state determination flow between the measurement target electric wire and the electrode will be described with reference to FIGS. 8 and 9.

  FIG. 12A is a graph showing a time change of the pressing signal detected by the pressure sensor provided in the electric signal detection terminal. At the time of measurement, the operator clamps the electric wire to be measured connected to the AC power source and the load by the electric signal detection terminal, and presses the pair of magnetic cores in the uniting direction via the pressure sensor. The control unit 33 sequentially stores the alternating voltage and alternating current data output from the voltage measuring unit 31 and the current measuring unit 32, or the effective value data calculated from these data, in the storage unit 34. When the pressing signal output from the pressure sensor is input to the control unit 33, the control unit 33 determines the voltage and voltage within a certain time (−t 1 to t 1) before and after the time (t 0) when the pressing signal is input. Current effective value data is read from the storage unit 34.

  FIG. 12B is a graph showing a time change of the effective current value measured by the power measuring device according to the example. The control unit 33 calculates the average value Ieff1 of the current effective value within the time (-t1 to t0) read from the storage unit 34 and the average value Ieff2 of the current effective value within the time (t0 to t1), Compare these average values. At this time, when the ratio of Ieff1 and Ieff2 (Ieff1 / Ieff2) is relatively small, specifically 70% or less, for example, as shown by a waveform indicated by WF1 in the figure, there is a gap between the pair of magnetic cores. Determine that there is a significant gap. This result is notified to the operator via, for example, an external device connected to the communication unit 35 of the main unit or the display unit 36.

  On the other hand, for example, when Ieff1 / Ieff2 is relatively large, specifically greater than 70%, as shown by the waveform indicated by WF2 in the figure, the pair of magnetic cores are combined to a degree satisfying a predetermined measurement accuracy and closed magnetically. It is determined that a road is formed. At this time, the control unit 33 automatically starts power measurement, for example. Various parameters such as the time width of (−t1 to t0) and (t0 to t1) and the determination value of Ieff1 / Ieff2 can be set as appropriate from an external device connected to the communication unit 35, for example.

  FIG. 12C is a graph showing a change with time of the voltage effective value measured by the power measuring apparatus according to the example. The contact state between the measurement target electric wire 40 and the electrode 14 is generally defined when the housing mechanisms 21 a and 21 b are locked in the closed state by the lock mechanism 23 (FIG. 1B) of the core case 20. For this reason, the control unit 33 calculates the average value of the voltage effective value independently of the pressing signal, compares the average value with a predetermined determination value, and determines the contact state between the measurement target electric wire 40 and the electrode 14. What is necessary is just to perform a quality determination. However, an average value of effective voltage values within a certain time before and after the pair of magnetic cores are pressed may be calculated using the pressing signal.

  For example, as shown by the waveform WF3 in the figure, the average value Veff1 of the voltage effective value within the time (−t1 to t1) is compared with a predetermined determination value Vref, and when Veff1 <Vref, It is determined that 40 and the electrode 14 are not in contact. This result is notified to the operator via, for example, an external device connected to the communication unit 35 of the main unit or the display unit 36. Further, for example, as shown by the waveform WF4 in the figure, the average value Veff2 of the voltage effective value within the time (−t1 to t1) is compared with the predetermined determination value Vref, and when Veff2> Vref, the measurement target It determines with the electric wire 40 and the electrode 14 contacting. At this time, the control unit 33 automatically starts power measurement, for example. In addition, when the amplitude value of the AC power source connected to the measurement target wire is known, for example, when the AC voltage is 100 V of the domestic standard, the voltage corresponding signal detected when calculating the power is only the phase information. The amplitude information may be a known amplitude value.

  FIG. 13 is a graph illustrating an example of a voltage waveform and a current waveform measured by the power measuring apparatus according to the example. The AC power source connected to the measurement target wire is, for example, 50 Hz 100V. The control unit of the main unit can sequentially calculate the voltage effective value, the current effective value, and the apparent power from the measurement waveform as shown in FIG. Further, it is possible to calculate the power factor from the phase difference between the voltage waveform and the current waveform, and to sequentially calculate the active power from the apparent power and the power factor.

  By providing such a flow in the control unit of the main unit, it is possible to easily confirm the clamped state of the electric signal detection terminal. For example, when monitoring power consumption over a long period of time, highly reliable measurement data can be obtained by checking the combined state of the pair of magnetic cores and the contact state between the measurement target wire and the electrode by the flow as described above. It becomes possible. By using such a power measuring device including the electrical signal detection terminal and the main unit, it is possible to easily perform highly reliable power measurement.

  As mentioned above, although this invention was demonstrated using the Example, this invention is not restrict | limited to these. For example, in the embodiment, the power consumption measurement of the load connected to the single-phase AC power supply has been described. However, the power consumption measurement can be performed similarly in the case of a three-phase AC power supply. In the case of a three-phase AC power source, an electric signal detection terminal that clamps each of the three wires, and a voltage measuring unit that measures the voltage and current of each of the three wires and a current measuring unit may be used. If the voltage / current waveform of each of the three wires is obtained, it is possible to calculate the power, power factor, etc. by a known calculation formula. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

10 Electrical signal detection terminal,
11 Clamping area,
12a upper magnetic core,
12aI, II Upper magnetic core combined surface,
12b lower magnetic core,
12bI, II Lower magnetic core combined surface,
13 coils,
14 electrodes,
15 elastic member,
16 pressure sensor,
21a, 21b housing part,
22 hinge part,
23 Lock part,
23a locking claw,
23b locking hook,
24 Spring part,
25 Presser claw,
26 electrode support,
27 elastic member support,
30 power measurement unit,
31 Voltage measurement unit,
32 Current measurement unit,
33 control unit,
34 storage unit,
35 Communication Department,
36 Display unit 40 Electric wire.

Claims (7)

A pair of magnetic cores that define a clamping region that surrounds the single core coated wire by combining;
A coil wound around a part of the pair of magnetic cores;
A core case that supports the pair of magnetic cores and the coil and can maintain a state in which the pair of magnetic cores are combined;
An electrode disposed in the clamp region;
An elastic member disposed in the clamp region and pressed against the electrode by pressing an electric wire surrounded by the pair of magnetic cores;
Including
The core case is
A first housing mechanism for holding one of the pair of magnetic cores and supporting the electrode disposed in the clamp region and receiving a pressure on the electrode via the electric wire by the elastic member;
A second housing mechanism for holding the other of the pair of magnetic cores;
A coupling mechanism for holding a state in which a pair of magnetic cores supported by the first and second housing mechanisms are combined;
A spring mechanism for urging a pair of magnetic cores supported by the first and second housing portions in a direction in which the pair of magnetic cores are combined;
With
The second housing mechanism supports the elastic member disposed in the clamp region, and suppresses propagation of a repulsive pressure accompanying the pressing of the electric wire by the elastic member to the other of the pair of magnetic cores. An electric signal detection terminal provided with an elastic member supporting portion . The spring mechanism has a first elastic constant, has a tip portion that contacts the outer surfaces of the pair of magnetic cores, a second elastic constant larger than the first elastic constant, and the housing mechanism claim 1, wherein the electric signal detection terminal including a base portion that engages, the said. The elastic member has a shape that varies in thickness depending on the position in a normal pressure state, and moves a portion disposed in the clamp region according to an outer diameter of the electric wire surrounded by the pair of magnetic cores. The electrical signal detection terminal according to claim 1 or 2, wherein A power measuring device comprising a voltage of a single core covered electric wire, an electric signal detection terminal for detecting a current flowing in the electric wire, and a power measuring unit for calculating electric power consumed by a load connected to the electric wire,
The electrical signal detection terminal is
By combining, a pair of magnetic cores defining a clamping region surrounding the wire;
A coil wound around a part of the pair of magnetic cores;
A core case that supports the pair of magnetic cores and the coil and can maintain a state in which the pair of magnetic cores are combined;
An electrode disposed in the clamp region;
An elastic member disposed in the clamp region and pressed against the electrode by pressing the electric wire surrounded by the pair of magnetic cores;
Including
The power measurement unit includes:
A control unit that calculates power consumed by a load connected to the electric wire clamped to the pair of magnetic cores based on a voltage corresponding signal detected by the electrodes and a current corresponding signal detected by the coil; ,
Including
The core case is
A first housing mechanism for holding one of the pair of magnetic cores and supporting the electrode disposed in the clamp region and receiving a pressure on the electrode via the electric wire by the elastic member;
While holding the other of the pair of magnetic cores and supporting the elastic member disposed in the clamp region, the other of the pair of magnetic cores of the repulsive pressure accompanying the pressing of the electric wire by the elastic member A second housing mechanism for suppressing propagation to the
A coupling mechanism for holding a state in which a pair of magnetic cores supported by the first and second housing mechanisms are combined;
A spring mechanism for urging a pair of magnetic cores supported by the first and second housing portions in a direction in which the pair of magnetic cores are combined;
A power measuring device comprising: The spring mechanism has a first elastic constant, has a tip portion that contacts the outer surfaces of the pair of magnetic cores, a second elastic constant larger than the first elastic constant, and the housing mechanism The power measuring device according to claim 4 , further comprising a root portion engaged with the power. The elastic member has a shape that varies in thickness depending on the position in a normal pressure state, and moves a portion disposed in the clamp region according to an outer diameter of the electric wire surrounded by the pair of magnetic cores. The power measuring device according to claim 4 or 5, wherein The electrical signal detection terminal is further disposed on an outer surface of the pair of magnetic cores that intersects a direction in which the pair of magnetic cores are joined, and detects a pressure applied in the direction in which the pair of magnetic cores are combined. And including
The power measurement unit further includes a storage unit that stores the current corresponding signal in time series,
The control unit provided in the power measurement unit reads out a current corresponding signal within a predetermined time before and after the time when the pair of magnetic cores are pressed from the storage unit based on the pressing signal by the pressure sensor, and the storage unit The power measuring device according to any one of claims 4 to 6 , wherein the power calculation is determined based on a comparison of the current correspondence signals read before and after pressing.

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