JP2017009576A - Voltage detection probe and measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make mountable to a measurement object electric wire that is present in a state extremely close to other electric wires.SOLUTION: A voltage detection probe comprises: a first shield cylindrical element 21 formed in a cylindrical shape made of a conductive material and having an insertion recess 33 formed at the tip into which a measurement object electric wire 6 can be inserted; and a detection electrode 23 formed in a columnar shape made of a conductive material, with a tip face 23a and an outer circumferential face 23b covered with an insulation coating 24, and housed inside the first shield cylindrical element 21 so as to be able to move relatively to the cylindrical element 21 along the direction of an axis L. The detection electrode 23 is constructed so that when it is moved relatively to the first shield cylindrical element 21 and the tip face 23a reaches the insertion recess 33, the tip face 23a can be capacitive coupled via the insulation coating 24 with the measurement object electric wire 6 being inserted in the insertion recess 33.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a voltage detection probe configured to be able to detect the voltage of an electric wire to be measured, and a measurement apparatus including the voltage detection probe.

  As this type of voltage detection probe, the applicant of the present application discloses various types of voltage detection probes (hereinafter also simply referred to as “detection probes”) in Patent Documents 1 to 3 below. For example, Patent Document 1 discloses a detection probe that includes a clamp portion in which a magnetic core that surrounds an electric wire to be measured and forms an annular closed magnetic path in a closed state is incorporated. In Patent Document 2, a sensor substrate housing portion that houses a voltage measurement sensor substrate, and a sensor substrate housing portion that is pivotally supported by a sensor substrate housing portion via a rotation shaft, and a measurement target conductor is connected to the sensor substrate housing portion. The detection probe of the structure provided with the measurement object electric wire pressing part clamped between is disclosed. Moreover, in patent document 3, it has a voltage detection part by which the detection electrode for a voltage detection and a magnet are arrange | positioned inside, and is measuring object, positioning the front-end | tip part of the measurement probe provided with the voltage detection part with the magnetic force of a magnet A detection probe configured to be pressed against an electric wire is disclosed. Each of these detection probes is a detection probe (so-called non-contact type) that can detect the voltage of the conductive portion by simply capacitively coupling the detection electrodes to each other without directly contacting the conductive portion of the electric wire to be measured. Voltage detection probe).

Japanese Unexamined Patent Publication No. 2012-137496 (5th page, FIG. 1) JP 2014-52329 A (page 5-8, FIG. 1-3) JP 2014-163670 A (page 5-8, Fig. 1-3)

  However, each of the detection probes described above has the following problems to be improved. In other words, these detection probes have a configuration in which a magnetic core, a mechanism for clamping and clamping, or a magnet is arranged in the vicinity of the voltage detection electrode. In particular, the shape of the part including the electrode for voltage detection is large.

  Therefore, these detection probes are in the vicinity (periphery) of the portion where the detection probe is mounted, such as an overhead wire, a lead-in wire from the overhead wire to the indoor, an electric wire used for indoor wiring (usually a covered electric wire). However, it is possible to use it for a measuring object electric wire in which a certain amount of space exists. However, these detection probes are, for example, electric wires having a small diameter (for example, a diameter of 2 mm or less) for supplying an operating voltage to a circuit board disposed in an electronic device, and are usually similar to other electric wires. It is difficult to attach to one electric wire that is in close proximity to other electric wires, such as one electric wire routed in a state of being bundled together with a small diameter electric wire. There is a problem that should be improved.

  The present invention has been made in order to improve such a problem, and a voltage detection probe that can be attached to a measurement target electric wire existing in a state of being very close to other electric wires, and a measurement provided with this voltage detection probe The main purpose is to provide a device.

  In order to achieve the above object, the voltage detection probe according to claim 1 is formed of a cylindrical body made of a conductive material and is cut out along a direction in which a part of the outer peripheral wall at the tip intersects the axis. The axial direction is formed by a shield cylinder having an insertion recess into which the measurement target electric wire can be inserted is formed at the tip, and a columnar body made of a conductive material whose tip and outer peripheral surfaces are covered with an insulating coating. And a detection electrode accommodated in the shield cylinder so as to be movable relative to the shield cylinder, the detection electrode being moved relative to the shield cylinder When the distal end surface is positioned in the insertion recess, the distal end surface is configured to be capable of capacitive coupling through the measurement target electric wire inserted into the insertion recess and the insulating coating.

  The voltage detection probe according to claim 2 is the voltage detection probe according to claim 1, wherein the notch surface located on the tip end side of the notch surface of the shield cylinder constituting the insertion recess is Inclined toward the base end with respect to a reference plane orthogonal to the axis.

  The voltage detection probe according to claim 3 is the voltage detection probe according to claim 2, wherein the base side cutout located on the base end side of the cutout surface of the shield cylindrical body constituting the insertion recess. The surface is inclined to the base end side with respect to the notch surface on the tip side with respect to the reference plane.

  The voltage detection probe according to claim 4 is the voltage detection probe according to any one of claims 1 to 3, further comprising a biasing member that constantly biases the detection electrode in the direction of the insertion recess. The distal end side located on the distal end side of the cutout surface of the shield cylindrical body that is slid in the direction of the insertion concave portion in the shield cylindrical body by the biasing force of the biasing member and constitutes the insertion concave portion The measurement target electric wire inserted in the insertion recess is sandwiched between the notch surface and the distal end surface.

  The voltage detection probe according to claim 5 is the voltage detection probe according to any one of claims 1 to 4, wherein the distal end surface is inclined toward the distal end portion with reference to a reference plane orthogonal to the axis. .

  A voltage detection probe according to a sixth aspect is the voltage detection probe according to any one of the first to fifth aspects, wherein the measurement target electric wire and the tip end surface are between the detection electrode and the shield cylinder. A shield material for a detection electrode made of a conductive material is further provided to further cover the insulating coating covering the outer peripheral surface of the detection electrode exposed from the insertion recess to the outside of the shield cylinder in the capacitive coupling state.

  A voltage detection probe according to a seventh aspect is the voltage detection probe according to the sixth aspect, wherein the shield material for the detection electrode is formed of a cylindrical body.

  The voltage detection probe according to an eighth aspect of the present invention is the voltage detection probe according to the sixth aspect, wherein the detection electrode shielding material is formed of a conductor layer formed on a surface of the insulating coating.

  The voltage detection probe according to claim 9 is the voltage detection probe according to any one of claims 1 to 5, wherein the measurement target electric wire and the tip end surface are in a capacitively coupled state outside the shield cylinder. A detection electrode shielding material made of a conductive material is provided to further cover the insulating coating covering the outer peripheral surface of the detection electrode exposed from the insertion recess to the outside of the shield cylinder.

  The voltage detection probe according to claim 10 is the voltage detection probe according to any one of claims 6 to 9, wherein the detection electrode shield material has the tip of the detection electrode shield material in the capacitive coupling state. The detection electrode is configured so as to be in a state where it is flush with the distal end surface and a state where the distal end portion is located closer to the proximal end portion side of the shield cylinder along the axial direction than the distal end surface. Has been.

  A measurement apparatus according to claim 11 is provided with the voltage detection probe according to any one of claims 1 to 10, a main body unit to which the voltage detection probe is connected, and the core wire disposed in the main body unit. A voltage detection unit that detects a voltage of the measurement target electric wire through the detection electrode and outputs a voltage signal that changes in accordance with the voltage, and is disposed in the main body unit, and based on the voltage signal, A voltage generation unit that generates a voltage that follows the voltage of the measurement target wire and that is applied to the shield conductor; and the measurement unit that is disposed in the main body unit and that is generated based on the voltage generated by the voltage generation unit. A processing unit that measures the voltage of the target electric wire, and the voltage detection unit operates with a floating voltage based on the potential of the voltage generated by the voltage generation unit.

  In the voltage detection probe according to claim 1 and the measurement apparatus according to claim 11, the measurement target electric wire in a state in which the detection electrode is moved relative to the shield cylinder and inserted in the insertion recess The tip end surface of the detection electrode is configured to be capable of capacitive coupling via an insulating coating.

  Therefore, according to this voltage detection probe and measurement apparatus, an insertion recess into which a single wiring material to be measured can be inserted is formed at the tip, and the detection electrode covered with an insulating coating is accommodated inside. As long as it can be obtained, the shield cylinder can be formed of a thin cylindrical rigid body, which allows capacitive coupling between the measurement target electric wire inserted into the insertion recess and the tip surface of the detection electrode, and the shield cylinder. Since the detection electrode can be shielded, it can be used to measure wires that are in close proximity to other conductors that were difficult to mount (clamp) with the various detection probes described in the background art. However, while the influence of the disturbance on the detection electrode (for example, the influence from other conductors) is reduced by the shield cylinder, it is inserted into the insertion recess and the voltage can be measured reliably and easily. Can.

  According to the voltage detection probe according to claim 2 and the measurement apparatus according to claim 11, since the distal-side notch surface is inclined toward the base end side, the measurement target electric wire inserted into the insertion recess is the detection electrode. Thus, the measurement target electric wire can be made difficult to come off from the insertion recess in a state where it is pressed against the front end side notch surface by the front end surface (a state sandwiched between the front end surface of the detection electrode and the front end side notch surface).

  According to the voltage detection probe according to claim 3 and the measurement device according to claim 11, the distal end as described above is configured so that the proximal notch surface is inclined toward the proximal end side with respect to the distal end notch surface. While maintaining the effect of tilting the side notch surface (the effect of making it difficult to remove the measurement target wire from the insertion recess), the distance along the axial direction between the notch surfaces is the depth that forms the insertion recess. Since it can be configured to gradually widen as it is separated from the cut-out surface on the side (configuration in which the opening width of the insertion recess is gradually increased), the ease of insertion of the measurement target electric wire into the insertion recess can be enhanced.

  According to the voltage detection probe according to claim 4 and the measurement device according to claim 11, the measurement target electric wire inserted into the insertion recess is moved from the notch surface of the shield cylinder by the urging force of the urging member. Since it can be clamped with the tip surface of the detection electrode, the voltage of the measurement target wire is maintained as a result of maintaining the state where the measurement target wire is positioned in the insertion recess even when the voltage detection probe is released. The workability of the measurement work can be improved.

  According to the voltage detection probe according to claim 5 and the measurement device according to claim 11, the detection electrode is inserted into the insertion recess by forming the distal end surface of the detection electrode on the inclined surface inclined toward the distal end side of the shield cylinder. In the state where the measurement target wire is pressed against the notch surface on the tip side by the tip surface of the detection electrode (the state where it is sandwiched between the tip surface of the detection electrode and the notch surface on the tip side), the measurement target wire is further removed from the insertion recess. Can be difficult.

  According to the voltage detection probe according to claim 6 and the measurement device according to claim 11, since the detection electrode shielding material is disposed between the detection electrode and the shield cylindrical body, Insulating cover that covers the outer peripheral surface of the detection electrode that is exposed to the outside of the shield cylinder from the insertion recess in the capacitive coupling state can be further covered with the shield material for the detection electrode, thereby sufficiently reducing the influence of disturbance on the detection electrode. Can do.

  According to the voltage detection probe according to claim 7 and the measurement device according to claim 11, the detection electrode is inserted into the cylinder by forming the detection electrode shield material with the cylinder, and the cylinder is used as the shield cylinder. Since the cylinder as the shield material for the detection electrode can be disposed between the detection electrode and the shield cylinder by a simple process that is simply inserted into the electrode, the assembly efficiency of the voltage detection probe can be sufficiently improved. it can.

  According to the voltage detection probe according to claim 8 and the measurement apparatus according to claim 11, the detection electrode shield material is made thin by forming the detection electrode shield material with the conductor layer formed on the surface of the insulating coating. As a result, the shield cylinder that accommodates the detection electrode covered with the detection electrode shielding material can be configured to be thin. As a result, only one measurement target electric wire from among the plurality of electric wires that are close to each other can be obtained. It is possible to easily perform the operation of attaching the to the tip of the shield cylinder (inserting it into the insertion recess formed in the tip).

  According to the voltage detection probe according to claim 9 and the measurement device according to claim 11, in the capacitive coupling state between the measurement target electric wire and the distal end surface, the shield material for the detection electrode is disposed outside the shield cylinder. Since the insulating coating covering the outer peripheral surface of the detection electrode exposed from the insertion recess to the outside of the shield cylinder can be further covered with the detection electrode shielding material, the influence of disturbance on the detection electrode can be sufficiently reduced.

  According to the voltage detection probe of claim 10 and the measurement device of claim 11, in the capacitive coupling state, the tip of the detection electrode shield is flush with the tip of the detection electrode and the tip is from the tip. Since the detection electrode shield material is configured to be either in the state of being located on the proximal end side of the shield cylinder along the axial direction, the distal end portion of the detection electrode shield material is moved from the distal end surface of the detection electrode. Since it can be prevented from projecting, the measurement target wire is damaged by the tip of the shield material for the detection electrode when the measurement target wire is sandwiched between the notch surface constituting the insertion recess and the tip surface of the detection electrode. It is possible to reliably prevent the situation of being received or disconnected.

2 is a perspective view showing a configuration of a detection probe 1. FIG. 1 is a cross-sectional view taken along the line WW of the detection probe 1 in a state where the grip portion 2 is cut along a plane including the axis L in FIG. 1 (a cross-sectional view in a state where the insertion recess 33 is closed by the detection electrode 23). . It is sectional drawing of the detection electrode unit 3 cut | disconnected along the plane containing the axis line L of FIG. FIG. 2 is a cross-sectional view taken along the line WW of the detection probe 1 in a state where the grip portion 2 is cut along a plane including the axis L in FIG. 1 (a cross-sectional view in a state where an insertion recess 33 is opened). FIG. 5 is a cross-sectional view of the detection electrode unit 3 cut along a plane including the axis L in FIG. 4. 1 is a cross-sectional view taken along the line W-W of the detection probe 1 in a state where the grip portion 2 is cut along a plane including the axis L (a front end side notch surface 33a of the insertion recess 33 and a front end surface 23a of the detection electrode 23). Is a cross-sectional view in a state in which the measurement target electric wire 6 is sandwiched between them. FIG. 4 is an enlarged cross-sectional view of a main part for explaining the configuration of the distal end portion of the first shield cylinder 21 (enlarged cross-sectional view in a state where an insertion recess 33 is opened). It is a principal part expanded sectional view for demonstrating the structure of the front-end | tip part of the 1st shield cylinder 21 (enlarged sectional view in the state by which the measuring object electric wire 6 is clamped). It is a block diagram of measuring apparatus MD. It is a principal part expanded sectional view for demonstrating the other structure of the front end surface 23a of the detection electrode 23 (enlarged sectional view in the state by which the measuring object electric wire 6 is clamped). FIG. 6 is an enlarged cross-sectional view of a main part for explaining a configuration of still another tip portion of the first shield cylinder 21 (enlarged cross-sectional view in a state where an insertion recess 33 is opened). It is a principal part expanded sectional view for demonstrating the other structure of the front-end | tip part of the detection electrode 23 (enlarged sectional view in the state by which the measuring object electric wire 6 is clamped). 4 is an enlarged cross-sectional view of a main part showing a configuration of a tip portion of a detection electrode unit 3 including a cylindrical body 37. FIG. It is a side view of the detection probe 101 in a state where the half of the grip part 2 (the front half in the figure) is removed. Detection of a state in which the first shield cylinder 21 is moved toward the distal end side (direction away from the base end portion) of the grip portion 2 in a state where the half portion of the grip portion 2 (the front half portion in the figure) is removed. 2 is a side view of a probe 101. FIG. FIG. 3 is a side view of the detection probe 101 in a state where a measurement target electric wire 6 is sandwiched in a state where a half of the grip portion 2 (a front half in the drawing) is removed. 4 is an enlarged cross-sectional view of a main part showing a configuration of a distal end portion of detection electrode unit 103. 4 is an enlarged cross-sectional view of a main part showing a configuration of a distal end portion of a detection electrode unit 103 provided with a cylindrical body 37. FIG. FIG. 6 is an enlarged cross-sectional view of a main part showing another configuration of a tip end portion of a detection electrode unit 103 including a cylindrical body 37.

  Hereinafter, embodiments of a voltage detection probe and a measurement apparatus will be described with reference to the accompanying drawings.

  First, the configuration of the voltage detection probe 1 (hereinafter also simply referred to as “detection probe 1”) as the voltage detection probe shown in FIG. 1 will be described with reference to the drawings.

  As an example, the detection probe 1 includes a grip portion 2 and a detection electrode unit 3 as shown in FIG. 1, and constitutes a measuring device MD together with a main body unit 4 (see FIG. 9) described later. Further, the detection probe 1 is connected to the main unit 4 via the shield cable 5 and the measurement target electric wire 6 (see FIG. 4) is inserted into an insertion recess 33 described later provided at the tip of the detection electrode unit 3. Used. The shielded cable 5 in the present embodiment is a cable provided with a signal transmission wiring and a shield conductor that shields the wiring, for example, a core wire as a signal transmission wiring and a shield covering the core wire. It includes shielded wires (including coaxial cables) with conductors and twisted pair wires. In this example, as an example, as illustrated in FIG. 2, a shield wire including a core wire 5 a and a shield conductor 5 b covering the core wire 5 a will be described as an example of the shield cable 5.

  The grip portion 2 is a member that is gripped by a user, and as an example, as shown in FIGS. 1 and 2, a material having electrical insulation properties such as a synthetic resin material (hereinafter also simply referred to as an insulating material). It is formed in a hollow columnar body that can be used to accommodate the detection electrode unit 3. Further, a through hole 11a through which a first shield cylinder 21 (described later) of the detection electrode unit 3 is inserted is formed on the end surface 11 on the tip end portion (left end portion in FIGS. 1 and 2) of the grip portion 2. Yes. Moreover, as shown in FIG. 2, the through-hole 13a is formed in the end surface 13 by the side of the base end part (right side edge part in FIG. 1, 2) of the grip part 2. As shown in FIG. The shielded cable 5 is connected to the base end portion of the grip portion 2 by fitting a universal bush 5c integrally attached to the shielded cable 5 into the through hole 13a.

  Moreover, the long groove 15 extended along the length direction (direction parallel to the axis line L (refer FIG. 1, FIG. 1) mentioned later) of the grip part 2 is formed in the outer surface of the outer peripheral wall of the grip part 2 as an example. In addition, a first guide hole 16 extending along the length direction of the grip portion 2 is formed through the bottom wall in the bottom wall of the long groove 15 (a part of the outer peripheral wall of the grip portion 2). ing.

  As an example, as shown in FIGS. 2 to 6, the detection electrode unit 3 includes a first shield cylinder (shield cylinder) 21, a second shield cylinder 22, a detection electrode 23, an insulating coating 24, and a first lid 25. , A second lid 26, a third lid 27, an insulating cylinder 28, a guide cylinder 29, a connecting pin 30, an urging member 31, and an operation lever 32.

  As shown in FIGS. 3 and 5, the first shield cylinder 21 is made of a cylindrical rigid body having a diameter of about 3 mm to 5 mm as an example using a conductive material (a metal material having conductivity). As a cylindrical body), and the tip portion (the left end portion in FIGS. 2 to 6) has a direction in which a part of the outer peripheral wall at the tip portion intersects the axis L (in this example, orthogonal) The insertion recess 33 into which the measurement target electric wire 6 (see FIGS. 4, 6, and 8) is inserted is formed along a cutting direction by a method such as cutting. Moreover, as shown in FIGS. 2-6, as for the 1st shield cylinder 21, the base end part (right end part in FIGS. 2-6) is accommodated in the grip part 2 (2nd shield cylinder 22). In addition, as shown in FIG. 8, the measurement target electric wire 6 in this example is a covered electric wire in which the core wire 6a is covered with an insulating coating 6b.

  As shown in FIGS. 2 and 5 (in detail, as shown in FIG. 7 which is an enlarged view of the main part of FIG. 5), the insertion recess 33 is formed as an example in this example. Of the cut-out surface 33a, the base-end-side cut-out surface 33b, and the back-side cut-out surface 33c, the front-end-side cut-out surface 33a located on the front end side of the first shield cylinder 21 is a reference plane PL orthogonal to the axis L. With respect to the base end portion side of the first shield cylinder 21 (that is, a configuration in which the angle θ1 between the axis L (a virtual plane including the axis L) and the notch surface 33a is an acute angle). ing. With this configuration, the measurement target electric wire 6 inserted into the insertion recess 33 is formed on the distal end side notch surface 33a by the end surface 23a (hereinafter also referred to as the distal end surface 23a) of the detection electrode 23 as described later. In the pressed state (see FIGS. 6 and 8), it is difficult for the insertion recess 33 to come off.

  In this example, as an example, the proximal-side notch surface located on the proximal-end side of the first shield cylinder 21 among the distal-side notch surface 33a, the proximal-side notch surface 33b, and the back-side notch surface 33c. 33b is configured to be inclined to the proximal end portion side of the first shield cylindrical body 21 with respect to the reference-side plane PL (see FIG. 7) orthogonal to the axis L (see FIG. 7). The angle θ2 between the imaginary plane including L) and the front-side notch surface 33a is an acute angle in a state where the angle θ2 is smaller than the angle θ1. With this configuration, the tip side notch surface 33a and the base are maintained while maintaining the effect when the tip side notch surface 33a is inclined as described above (the effect that it is difficult to remove the measurement target wire 6 from the insertion recess 33). Configuration in which the distance along the axis L direction between the end-side notch surface 33b is gradually increased as the distance from the back-side notch surface 33c (the back-side notch surface constituting the insertion recess 33) increases (insertion recess) Therefore, the ease of insertion of the measurement target electric wire 6 into the insertion recess 33 can be enhanced.

  Moreover, in this example, although the back side notch surface 33c is a structure used as a plane substantially parallel to the axis line L as an example, it is not limited to this structure, The structure formed in an arcuate surface is employ | adopted. You can also.

  The measurement target electric wire 6 in which the detection probe 1 of the present example is used is a conductor that has been difficult to mount with the various detection probes described in the background art, for example, normally with other similar small-diameter wiring materials. One small-diameter wiring material (covering) that exists in close proximity to other conductors (other wiring materials, etc.), such as one small-diameter wiring material that is routed in a bundled state Electric wire).

  For this reason, in the detection electrode unit 3 of the detection probe 1, an insertion recess 33 having a width and a depth at which such a small-diameter wiring member can be inserted as the measurement target electric wire 6 is formed as the first shield cylinder 21 at the distal end. As long as it can be formed, a thinner cylindrical rigid body can be used. Further, in order to enable the measurement target electric wire 6 to be selectively inserted into the insertion recess 33 even when the distance between the measurement target electric wire 6 and another wiring material adjacent to the measurement target electric wire 6 is short. However, the cylindrical rigid body used for the first shield cylinder 21 is preferably as thin as possible. For example, in order to accommodate a wiring material having a small diameter (diameter of about 2 mm) as described above, the insertion recess 33 is, for example, a depth slightly deeper than 2 mm and a width slightly wider than 2 mm (opening width). Need to be formed. For this reason, as above-mentioned, it is preferable to form the 1st shield cylinder 21 with the cylindrical rigid body about 3 mm-5 mm in diameter as an example.

  As shown in FIGS. 3 and 5, the second shield cylinder 22 is a cylindrical rigid body having an outer diameter of about 7 mm to 10 mm as an example using a conductive material (a metal material having conductivity). As a cylindrical body) and is fixed to the grip portion 2 while being accommodated in the grip portion 2. In addition, a second guide hole (through hole) 34 extending along the length direction (axis L direction) of the second shield cylinder 22 is formed in the outer peripheral wall of the second shield cylinder 22.

  As shown in FIGS. 3 and 5, the detection electrode 23 is made of a conductive material (a metal material having conductivity) and the outer shape is a columnar body (a columnar body having a cross-sectional shape that matches the cross-sectional shape of the first shield cylinder 21. In this example, it is formed in a cylindrical body) as an example. In addition, as an example, the detection electrode 23 has other surfaces (a distal end surface 23a (left end surface) and an outer peripheral surface 23b) other than an end surface (right end surface in FIGS. 3 and 5) to which the connecting pin 30 is connected. ) Is covered with an insulating coating 24. The insulating coating 24 is formed with a thickness of, for example, less than 0.1 mm (for example, about 0.05 mm) using a synthetic resin material having electrical insulation as an example.

  In addition, the detection electrode 23 having the insulating coating 24 formed on the surface in this manner is movable relative to the first shield cylinder 21 along the axis L direction as shown in FIGS. It is accommodated in the first shield cylinder 21 (slidably). Further, as shown in FIG. 3, the detection electrode 23 is in a state where the distal end surface 23 a abuts on the first lid 25 attached to the opening on the distal end side of the first shield cylinder 21 as will be described later. The base end side is defined as a length protruding from the base end side of the first shield cylinder 21. In this example, the tip surface 23a of the detection electrode 23 is formed in a plane parallel to the reference plane PL as shown in FIG.

  The first lid 25 is formed using a conductive material (a metal material having conductivity), and is press-fitted into an opening on the distal end portion (left end portion in FIGS. 2 and 3) side of the first shield cylinder 21. The opening is closed by being attached by a technique such as welding (electrically connected technique). The second lid 26 is formed using a conductive material (a metal material having conductivity), and is press-fitted into an opening on the tip (left end in FIGS. 2 and 3) side of the second shield cylinder 22. It is attached by a technique such as welding (electrically connected technique). Further, the second lid body 26 has a through hole 26a formed in the center portion. The first shield cylindrical body 21 is inserted (fixed) to the second lid body 26 by a method capable of securing a conduction state such as welding while the base end side is inserted into the through hole 26a. .

  The third lid 27 is formed using a conductive material (a metal material having conductivity), and is press-fitted into an opening of the second shield cylinder 22 on the base end (right end in FIGS. 2 and 3) side. It is mounted by a technique such as welding or a technique (electrically connected technique). Further, the third lid 27 has a through hole 27a formed at the center. In this example, as an example, the first shield cylinder 21 and the first lid 25 are formed separately, and the second shield cylinder 22, the second lid 26, and the third lid 27 are separated. Although the structure formed in a body is employ | adopted, the structure which forms the 1st shield cylinder 21 and the 1st cover body 25 integrally, and at least one of the 2nd cover body 26 and the 3rd cover body 27 A configuration in which only the second lid body 26, only the third lid body 27, or both the second lid body 26 and the third lid body 27 are formed integrally with the second shield cylinder 22 may be employed. .

  As shown in FIGS. 3 and 5, the insulating cylinder 28 is formed into a cylindrical body (in this example, a cylindrical body as an example) using an insulating material, and is mounted in the through hole 27 a of the third lid body 27. Has been. The insulating cylinder 28 is for electrically insulating the guide cylinder 29 and the third lid 27 inserted into the insulating cylinder 28 as will be described later. Therefore, in the configuration shown in the figure, the insulating cylinder 28 is formed to have a length that also contacts the inner surface of the second shield cylinder 22 on the proximal end side, but is arranged only in the through hole 27a. Of course.

  As shown in FIGS. 3 and 5, the guide cylinder 29 is opened at one end side (left end side in FIG. 3) using a conductive material (a metal material having conductivity) and the other end side (in FIG. 3). Is formed into a cylindrical body that is closed (in this example, a cylindrical body as an example). In this example, a cylindrical protrusion 29a for inserting and soldering the core wire 5a of the shielded cable 5 is formed on the end surface of the guide cylinder 29 on the other end side. Formation is arbitrary. In addition, the guide cylinder 29 is fixed to the third lid 27 with the insulating cylinder 28 interposed by being press-fitted into the insulating cylinder 28 from the open end side.

  3 and 5, the connecting pin 30 is a columnar body (a columnar body having a cross-sectional shape that matches the cross-sectional shape of the guide cylinder 29 using a conductive material (a metal material having conductivity). As an example, it is formed in a cylindrical body). The connecting pin 30 has one end side (left end side in FIG. 3) protruding from the guide cylinder 29 and the other end side (right end side in FIG. 3) is slidable in the guide cylinder 29. Has been inserted. The connection pin 30 is connected in a state where one end side is connected to the base end side of the detection electrode 23 in a conductive state.

  The urging member 31 is constituted by a spring (for example, a coil spring) made of a conductive material (conductive metal material) as an example, and as shown in FIGS. The cylindrical body 29 is accommodated in a contracted state (a compressed state) between the closed inner surface on the other end side and the end surface on the other end side of the connecting pin 30. With this configuration, the urging member 31 urges the connecting pin 30 in a direction in which one end thereof always protrudes from the guide cylinder 29 (the direction of the distal end portion of the first shield cylinder 21). As a result, the urging member 31 also allows the detection electrode 23 connected to the connection pin 30 and the operation lever 32 connected to the detection electrode 23 as will be described later, to the tip of the first shield cylinder 21. Always energized in the part direction.

  As shown in FIGS. 3 and 5, the operation lever 32 protrudes from the second guide hole 34 in the rectangular parallelepiped column 32 a inserted into the second guide hole 34 of the second shield cylinder 22 and the column 32 a. A flange portion 32b formed in a state extending along the outer surface of the second shield cylindrical body 22 at the portion, and a knob portion formed at the tip of the portion protruding outward from the second guide hole 34 in the column portion 32a 32c, and these members are integrally formed using an insulating material. Further, the operation lever 32 has an end portion (lower end portion in FIGS. 3 and 5) that extends to the inside of the second shield cylindrical body 22 in the support column portion 32 a at the detection electrode 23 (the first shield cylindrical body 21 in the detection electrode 23). To the base end side protruding from the base).

  With this configuration, for example, when the knob 32c receives an external force F1 (see FIGS. 4 and 5) in the direction of the proximal end of the second shield cylinder 22 from the thumb of the user holding the grip 2, the operation lever 32 is operated. In the state where the flange portion 32b is in contact with the outer surface of the second shield cylinder 22 and the column portion 32a is guided by the second guide hole 34, the detection electrode 23 and It moves together with the connecting pin 30 in the direction of the proximal end of the second shield cylinder 22. On the other hand, when the external force F1 is released, the operation lever 32 moves toward the distal end portion of the second shield cylindrical body 22 together with the detection electrode 23 and the connecting pin 30 by the biasing force F2 (see FIG. 6) of the biasing member 31. Then, the tip of the detection electrode 23 moves until it contacts the first lid 25.

  Further, in the detection electrode unit 3 having this configuration, the detection electrode 23, the connection pin 30 connected to the detection electrode 23, and the guide cylinder 29 into which the connection pin 30 is inserted are substantially the same in potential (shield). The first shield cylinder 21, the second shield cylinder 22, and the first lid 25 inserted into the opening on the distal end side of the first shield cylinder 21 defined by the potential of the shield conductor 5 b of the cable 5. The second shield body 22 is covered with the second lid body 26 that closes the opening on the distal end side, and the third lid body 27 that closes the opening on the proximal end side of the second shield cylinder 22. It has a configuration (that is, a configuration shielded by the potential of the shield conductor 5b).

  As shown in FIGS. 2, 4, and 6, the detection electrode unit 3 configured in this way has a first shield cylinder 21 inserted through a through hole 11 a formed in the end surface 11 of the grip portion 2, and an operation lever. The 32 column portions 32 a are inserted into the first guide holes 16 of the grip portion 2, and the knob portions 32 c are accommodated in the grip portion 2 in a state where the knob portions 32 c are disposed in the long grooves 15 of the grip portion 2. Therefore, the 1st shield cylinder 21 is the composition accommodated in the grip part 2 in the state which the base end part was being fixed to the 2nd cover body 26 of the detection electrode unit 3 accommodated in the grip part 2. FIG. Therefore, this is equivalent to a state in which the base end portion is connected to the grip portion 2 when viewed as the entire detection probe 1.

  In addition, the end portion of the shield cable 5 is fitted to the end surface 13 of the grip portion 2 as shown in FIGS. 2, 4, and 6, and the free bush 5 c is fitted into the through hole 13 a formed in the end surface 13. Connected with. Further, at the end portion of the shielded cable 5 located in the grip portion 2, the core wire 5a of the shielded cable 5 is connected to the guide cylinder 29 by being soldered to the cylindrical projection 29a, and the shield of the shielded cable 5 is shielded. The conductor 5b is soldered to the third lid 27 constituting the detection electrode unit 3 (that is, the first shield cylinder 21 is composed of the second lid 26, the second shield cylinder 22 and the third lid 27). And is connected to the shield conductor 5b).

  As shown in FIG. 9, the main unit 4 includes, as an example, a main power circuit 51, a DC / DC converter (hereinafter also simply referred to as “converter”) 52, a voltage detection unit 53, a resistor 54 for current / voltage conversion, a voltage A generation unit 55, a voltmeter 56, a processing unit 57, and a display unit 58 are provided.

  The main power supply circuit 51 has a positive voltage Vdd and a negative voltage Vss (actual values generated with reference to the potential of the ground G1 as the first reference potential) for operating the above-described components 53 to 58 of the main unit 4. The same DC voltages with different polarities are output. For example, the converter 52 includes an insulated transformer having a primary winding and a secondary winding that are electrically insulated from each other, a drive circuit that drives the primary winding of the transformer, and a secondary winding of the transformer. And a DC converter (not shown) that rectifies and smoothes the AC voltage that is applied, and is configured as an insulated power source in which the secondary side is electrically insulated from the primary side.

  In this converter 52, the drive circuit operates based on the input positive voltage Vdd and negative voltage Vss, and drives the primary winding of the transformer in a state where the positive voltage Vdd is applied, and the AC voltage is applied to the secondary winding. Induces. The direct current converter rectifies and smoothes the alternating voltage. Thereby, from the secondary side of converter 52, positive voltage Vf + and negative voltage Vf− with reference to internal reference potential (second reference potential) G2 on the secondary side are in a floating state (ground G1, positive voltage Vdd and negative voltage Vf−). In a state electrically separated from the voltage Vss). The positive voltage Vf + and the negative voltage Vf− as floating voltages generated in this way are supplied to the voltage detection unit 53 together with the second reference potential G2. The positive voltage Vf + and the negative voltage Vf− are generated as direct current voltages having substantially the same absolute value and different polarities.

  The voltage detection unit 53 includes a current-voltage conversion circuit 53a, an integration circuit 53b, a drive circuit 53c, and an insulation circuit 53d (a photocoupler driven by the drive circuit 53c is illustrated as an example. In the state where the reference potential in the voltage detection unit 53 is defined by the second reference potential G2, the converter can be used. It operates by receiving a positive voltage Vf + and a negative voltage Vf− from 52.

  In the current-voltage conversion circuit 53a, as an example, the non-inverting input terminal is connected to a portion defined by the second reference potential G2 in the voltage detection unit 53 via a resistor (hereinafter also referred to as “connected to the second reference potential G2”). ) And the inverting input terminal is connected to the core wire 5a of the shielded cable 5 (that is, the detection electrode 23 of the detection probe 1 via the core wire 7a), and the feedback resistor is connected between the inverting input terminal and the output terminal. The first operational amplifier is connected. In the current-voltage conversion circuit 53a, the first operational amplifier operates with the positive voltage Vf + and the negative voltage Vf−, and the voltage V1 of the measurement target wire 6 and the second reference potential G2 (the voltage signal output from the voltage generation unit 55). The detection current (current signal) I flowing between the measurement target wire 6 and the detection electrode 23 at a current value corresponding to the potential difference Vdi due to the potential difference Vdi (refer to FIG. 9). It converts into detection voltage signal V2 and outputs it. In this case, the amplitude of the detection voltage signal V2 changes in proportion to the amplitude of the current signal I.

  For example, the integrating circuit 53b has a non-inverting input terminal connected to the second reference potential G2 via a resistor, an inverting input terminal connected to the output terminal of the first operational amplifier via an input resistor, and feedback. The capacitor includes a second operational amplifier connected between the inverting input terminal and the output terminal. In the integrating circuit 53b, the second operational amplifier operates with the positive voltage Vf + and the negative voltage Vf− and integrates the detection voltage signal V2, whereby the integration signal V3 whose voltage value changes in proportion to the potential difference Vdi. Is generated and output.

  The drive circuit 53c drives the insulation circuit 53d in the linear region according to the level of the integration signal V3, and the driven insulation circuit 53d electrically separates the integration signal V3 to generate a new integration signal (first signal). ) Output as V3a. That is, the voltage detection unit 53 outputs an integration signal V3a indicating the voltage V1 of the measurement target wire 6 in combination with the detection probe 1.

  The current / voltage converting resistor 54 has one end connected to the negative voltage Vss and the other end connected to a corresponding insulating circuit 53d in the voltage detection unit 53 (in this example, the collector terminal of the phototransistor in the photocoupler). ing.

  The voltage generation unit 55 receives and amplifies the integration signal V3a to generate a voltage signal V4 and applies the voltage signal V4 to a portion defined by the second reference potential G2 in the voltage detection unit 53. The voltage signal V4 changes according to the voltage V1 of the measurement target electric wire 6 as described later. As a result, the positive voltage Vf + and the negative voltage Vf−, which are floating voltages based on the second reference potential G2, become floating voltages that change according to the voltage of the voltage signal V4.

  As an example, the voltage generation unit 55 includes a second reference potential G2 of the voltage detection unit 53 (shield conductor 5b of the shield cable 5 having the same potential as the second reference potential G2), a detection electrode 23, and a voltage detection unit 53 (current voltage). By forming a feedback loop together with the conversion circuit 53a, the integration circuit 53b, the drive circuit 53c and the insulation circuit 53d (photocoupler in this example), an amplification operation is performed to amplify the integration signal V3a so as to reduce the potential difference Vdi. The voltage signal V4 is generated.

  In this example, as an example, the voltage generation unit 55 includes an amplifier circuit 55a, a phase compensation circuit 55b, and a booster circuit 55c as shown in FIG. Here, the amplification circuit 55a generates the voltage signal V4a by inputting and amplifying the integration signal V3a. In this case, the amplifier circuit 55a generates a voltage signal V4a in which the absolute value of the voltage value changes in accordance with the increase / decrease of the absolute value of the voltage value of the integration signal V3a by an amplification operation. The phase compensation circuit 55b receives the voltage signal V4a, adjusts its phase, and outputs it as the voltage signal V4b in order to stabilize the feedback control operation (prevent oscillation). The booster circuit 55c is configured using a booster transformer as an example, and generates a voltage signal V4 by boosting the voltage signal V4b at a predetermined magnification (by increasing the absolute without changing the polarity). 2 Applied to reference potential G2. The voltmeter 56 measures the voltage signal V4 with reference to the potential of the ground G1, converts the voltage value into digital data, and outputs it as voltage data Dv.

  The processing unit 57 includes a CPU and a memory (both not shown), and executes a voltage calculation process for calculating the voltage V1 of the measurement target wire 6 based on the voltage data Dv output from the voltmeter 56. To do. Further, the processing unit 57 displays the voltage V1 calculated in the voltage calculation process on the display unit 58 in the form of a table or a graph. For example, the display unit 58 includes a monitor device such as a liquid crystal display.

  When measuring the voltage V <b> 1 of the measurement target electric wire 6 using the measuring device MD including the detection probe 1 and the main body unit 4, the measurement is performed in the insertion recess 33 formed at the distal end portion of the first shield cylinder 21. The target electric wire 6 is inserted.

  Specifically, first, by applying an external force F1 in the direction of the arrow shown in FIG. 4 to the knob portion 32c of the operation lever 32 by hand (specifically, a finger), the knob portion 32c (that is, the entire operation lever 32) is applied. By sliding against the biasing force of the biasing member 31 from the position shown in FIG. 2 to the position shown in FIG. 4 (sliding in the arrow direction), the detection electrode 23 slides in the first shield cylinder 21 ( Slide). As a result, the detection probe 1 is shifted from the state where the insertion recess 33 is closed by the detection electrode 23 as shown in FIG. 2 to the state where the insertion recess 33 is opened as shown in FIG. Next, the measurement target electric wire 6 is inserted into the insertion recess 33 that has been opened. In this case, since the measurement target electric wire 6 is a covered electric wire, the core wire 6a of the measurement target electric wire 6 and the first shield cylinder 21 are maintained in an electrically insulated state.

  In particular, in the detection probe 1, as shown in FIGS. 1 to 6 and specifically in FIG. 8, the proximal-side notch surface 33b constituting the insertion recess 33 is a first shield than the distal-side notch surface 33a. It is a structure which inclines to the base end part side of the cylinder 21, and the distance along the axis L direction between the front end side notch surface 33a and the base end side notch surface 33b is an opening part from the back side of the insertion recessed part 33. Since it becomes the structure which becomes gradually wide toward the side, it becomes possible to insert the measuring object electric wire 6 in the insertion recessed part 33 easily.

  Subsequently, the hand (finger) is released from the knob portion 32c. As a result, the external force F1 applied to the knob portion 32c is eliminated, and the connecting pin 30 is pushed toward the first shield cylinder 21 in the guide cylinder 29 by the urging force F2 of the urging member 31. Further, the detection electrode 23 is pushed by the connecting pin 30 so that the inside of the first shield cylindrical body 21 is directed toward the first lid 25, and as shown in FIGS. And a position where the measurement target electric wire 6 is sandwiched between the first shield cylinder 21 and the front end side cutout surface 33a. Thus, the clamping operation (mounting operation) of the detection probe 1 to the measurement target electric wire 6 is completed.

  In the detection probe 1, the state in which the measurement target electric wire 6 is inserted into the insertion recess 33 is maintained by holding the measurement target electric wire 6 in this manner. Therefore, even when the detection probe 1 is released, it is formed between the core wire 6a of the measurement target electric wire 6 and the distal end surface 23a of the detection electrode 23 that are important when measuring the voltage V1 of the measurement target electric wire 6. The occurrence of a situation in which the capacitance value of the electrostatic capacitance C0 (see FIG. 8) fluctuates greatly is sufficiently avoided. As a result, the detection probe 1 accurately detects the voltage V1 of the measurement target electric wire 6 only by capacitively coupling the detection electrodes 23, which are detection electrodes, without directly contacting the core wire 6a of the measurement target electric wire 6. It is configured to be able to function as a so-called conductor (metal) non-contact type voltage detection probe that can detect the current.

  In particular, in the detection probe 1, as shown in FIG. 8 and the like, the front end side notch surface 33a that sandwiches the measurement target electric wire 6 is inclined toward the base end side of the first shield cylindrical body 21 with respect to the reference plane PL. (That is, a configuration in which the angle θ1 between the axis L and the notch 33a on the front end side is an acute angle), and therefore, combined with the front end surface 23a of the detection electrode 23 formed on a plane parallel to the reference plane PL. Thus, the gap between the front end side notch surface 33a and the front end surface 23a that sandwich the measurement target electric wire 6 can be gradually narrowed from the back side of the insertion recess 33 toward the opening side. Thereby, in this detection probe 1, it is possible to maintain the state in which the measurement target electric wire 6 is inserted into the insertion recess 33 more reliably.

  In this state, the voltage V1 of the measurement target electric wire 6 and the voltage of the second reference potential G2 of the voltage detection unit 53 (the shield conductor 5b of the shield cable 5 having the same potential as the second reference potential G2 and the first of the detection electrode unit 3). The potential difference Vdi from the respective voltages of the three lid bodies 27, the second shield cylinder body 22, the second lid body 26, the first shield cylinder body 21 and the first lid body 25 (that is, the voltage of the voltage signal V4) increases. When the voltage difference Vdi is increased due to the rise of the voltage V1 (for example, when the potential difference Vdi is increased), the voltage detection unit 53 of the main body unit 4 causes the current-voltage conversion circuit from the measurement target wire 6 via the detection electrode 23. The amount of current signal I flowing into 53a increases. In this case, the current-voltage conversion circuit 53a reduces the voltage value of the output detection voltage signal V2. In the integrating circuit 53b, the current flowing from the output terminal of the second operational amplifier toward the inverting input terminal via the capacitor increases due to the decrease in the detection voltage signal V2. Therefore, the integration circuit 53b increases the voltage of the integration signal V3. As the voltage of the integration signal V3 rises, the transistor of the drive circuit 53c shifts to a deep on state. Thereby, in the insulating circuit 53d (photocoupler), the current flowing through the light emitting diode increases, and the resistance of the phototransistor decreases. Therefore, the voltage value of the integrated signal V3a generated by dividing the potential difference (Vdd−Vss) between the resistance value of the resistor 54 and the resistance value of the phototransistor is decreased.

  In the main unit 4, the voltage generation unit 55 increases the voltage value of the generated voltage signal V4 based on the integration signal V3a. In this measurement apparatus MD, the current-voltage conversion circuit 53a, the integration circuit 53b, the drive circuit 53c, the insulation circuit 53d, and the voltage generation unit 55 that constitute the feedback loop in this way detect an increase in the voltage V1 of the measurement target wire 6. Then, by executing the feedback control operation for increasing the voltage value of the voltage signal V4, the voltage (voltage of the voltage signal V4) such as the second reference potential G2 of the voltage detection unit 53 is made to follow the voltage V1.

  Further, when the potential difference Vdi increases due to the decrease in the voltage V1, the amount of current of the current signal I that flows out (flows out) from the current-voltage conversion circuit 53a to the measurement target wire 6 via the detection electrode 23 increases. At this time, voltage detection is performed by the current-voltage conversion circuit 53a and the like constituting the feedback loop performing a feedback control operation opposite to the above-described feedback control operation to reduce the voltage of the voltage signal V4. A voltage (voltage of the voltage signal V4) such as the second reference potential G2 of the unit 53 is made to follow the voltage V1.

  In this way, in the measuring apparatus MD, the feedback control operation for causing the voltage (voltage of the voltage signal V4) such as the second reference potential G2 of the voltage detector 53 to follow the voltage V1 is executed in a short time, and the voltage detector 53, such as the second reference potential G2 (which is also the voltage of the detection electrode 23 due to a virtual short circuit of the first operational amplifier of the current-voltage conversion circuit 53a) is made to coincide with (converge) the voltage V1. The voltmeter 56 measures the voltage value of the voltage signal V4 in real time and outputs voltage data Dv indicating the voltage value. In addition, after the voltage signal V4 once converges to the voltage V1 of the measurement target electric wire 6, each component constituting the feedback loop operates as described above to follow the fluctuation of the voltage V1. Therefore, voltage data Dv indicating the voltage V <b> 1 of the measurement target electric wire 6 is continuously output from the voltmeter 56.

  The processing unit 57 receives the voltage data Dv output from the voltmeter 56 and stores it in the memory. Next, the processing unit 57 executes a voltage calculation process, calculates the voltage V1 of the measurement target electric wire 6 based on the voltage data Dv, and stores it in the memory. Finally, the processing unit 57 causes the display unit 58 to display the measurement result (voltage V1) stored in the memory. Thereby, the measurement of the voltage V1 of the measuring object electric wire 6 by the measuring device MD is completed.

  Subsequently, when measuring the voltage V1 of the other electric wires 6 to be measured, first, an external force F1 in the direction of the arrow shown in FIG. 4 is applied to the knob portion 32c of the operation lever 32, so that the operation lever 32 is moved to the grip portion 2. By sliding toward the base end direction and sliding (sliding) the detection electrode 23 in the same direction, the front end side notch surface 33a of the insertion recess 33 and the front end surface 23a of the detection electrode 23 are moved. The clamping state of the measurement target electric wire 6 is eliminated. Next, the measurement target electric wire 6 is removed from the insertion recess 33 (the clamp state of the measurement target electric wire 6 is eliminated). As a result, the detection probe 1 can be attached (clamped) to the next measurement target electric wire 6.

  As described above, in the detection probe 1 and the measuring apparatus MD including the detection probe 1, the insertion recess 33 is formed at the distal end portion, the proximal end portion is fixed to the grip portion 2, and the shield conductor 5 b of the shield cable 5. The first shield cylinder 21 connected to the front end 23a, the front end face 23a and the outer peripheral face 23b are covered with an insulating coating 24 and are slidably accommodated in the first shield cylinder 21, and are attached to the core 5a of the shield cable 5. The detection electrode 23 is connected to the measurement target electric wire 6 in a state where the detection electrode 23 slides in the first shield cylinder 21 toward the insertion recess 33 and is inserted into the insertion recess 33. The front end surface 23 a is configured to be capable of capacitive coupling through the coating 24.

  Therefore, according to the detection probe 1 and the measuring device MD provided with the detection probe 1, the insertion recess 33 into which one wiring material to be measured electric wire 6 can be inserted is formed at the distal end portion, and the insulating coating 24 is provided. As long as the detection electrode 23 covered with can be accommodated inside, the first shield cylinder 21 can be formed of a thin cylindrical rigid body, and thereby the measurement target electric wire 6 inserted into the insertion recess 33. Since the capacitive coupling between the detection electrode 23 and the front end surface 23a of the detection electrode 23 and the shielding of the detection electrode 23 by the first shield cylinder 21 are possible, the various detection probes described in the background art are attached (clamped). The influence of the disturbance on the detection electrode 23 (for example, the influence from other conductors) is also applied to the measurement target electric wire 6 that exists in the state of being very close to the other conductors that are difficult to measure. While reducing by the shielding cylinder 21 and insert and (wearing) into the insertion concave portion 33 can be the voltage V1 reliably and easily measured.

  Further, in the detection probe 1 and the measuring apparatus MD provided with the detection probe 1, the front end side notch surface 33 a, the base end side notch surface 33 b, and the back side notch that form the insertion recess 33 of the first shield cylinder 21. The front end side notch surface 33a located on the front end side of the notch surface 33c is configured to be inclined toward the base end side with respect to the reference plane PL. Therefore, according to the detection probe 1 and the measurement apparatus MD, the measurement target electric wire 6 inserted into the insertion recess 33 is pressed against the front end side notch surface 33a by the front end surface 23a of the detection electrode 23 (front end surface). 23a and the front end side notch surface 33a), it is possible to make it difficult to remove the measurement target electric wire 6 from the insertion recess 33.

  Further, in the detection probe 1 and the measuring apparatus MD provided with the detection probe 1, the front end side notch surface 33 a, the base end side notch surface 33 b, and the back side notch that form the insertion recess 33 of the first shield cylinder 21. The base end side notch surface 33b located on the base end side of the notch surface 33c is configured to be inclined to the base end side with respect to the front end notch surface 33a with reference to the reference plane PL. Therefore, according to this detection probe 1 and this measuring device MD, the effect (the effect that it is difficult to remove the measurement target electric wire 6 from the insertion recess 33) when the tip side notch surface 33a is inclined as described above is maintained. However, the configuration in which the distance along the axis L direction between the cut-out surfaces 33a and 33b is gradually increased as the distance from the back-side cut-out surface 33c (the back-side cut-out surface constituting the insertion recess 33) increases (insertion). Since the opening width of the concave portion 33 can be gradually increased), the ease of insertion of the measurement target electric wire 6 into the insertion concave portion 33 can be enhanced.

  In addition, according to the detection probe 1 and the measuring apparatus MD including the detection probe 1, the first shield cylinder 21 is placed on the measurement target electric wire 6 inserted into the insertion recess 33 by the urging force of the urging member 31. Therefore, even when the detection probe 1 is released, the measurement target electric wire 6 is positioned in the insertion recess 33. As a result of maintaining the state, the workability of the voltage V1 measurement work can be improved.

  Further, in the detection probe 1 described above, the distal end surface 23a of the detection electrode 23 is formed in a plane parallel to the reference plane PL, but as shown in FIG. 10, it is inclined toward the distal end side of the first shield cylinder 21. It is also possible to adopt a configuration that is formed on an inclined surface. According to the detection probe 1 having this configuration and the measurement apparatus MD including the detection probe 1, the measurement target electric wire 6 inserted into the insertion recess 33 is pressed against the distal-side notch surface 33a by the distal-end surface 23a of the detection electrode 23. In the held state (a state sandwiched between the distal end surface 23 a and the distal end side notch surface 33 a), the measurement target electric wire 6 can be further prevented from coming off from the insertion recess 33.

  In addition, the detection probe 1 employs a configuration in which the notch surfaces 33a and 33b are inclined toward the proximal end portion of the first shield cylinder 21 with respect to the reference plane PL. However, the detection probe 1 is limited to this configuration. For example, as shown in FIG. 11, the notch surfaces 33a and 33b are both parallel to the reference plane PL, and although not shown, the tip side notch surface 33a is parallel to the reference plane PL, and A configuration in which the base end side notch surface 33b is inclined toward the base end portion side, or a configuration in which the distal end side notch surface 33a is inclined toward the base end portion side and the base end side notch surface 33b is parallel to the reference plane PL. Can also be adopted.

  In the detection probe 1 (that is, the detection electrode unit 3), as shown in FIGS. 8 and 10, the tip surface 23a of the detection electrode 23 and the core wire 6a of the measurement target electric wire 6 are capacitively coupled ( (Capacitive coupling state), that is, in a state where the measurement target electric wire 6 is sandwiched between the distal end side notch surface 33a and the distal end surface 23a in the insertion recess 33, a shield member (a member having the same potential as the potential of the shield conductor 5b) Through the opening portion of the insertion recess 33 where there is no presence, there is a configuration that may be slightly affected by disturbance.

  As a configuration for reducing the influence of disturbance on the detection electrode 23 as described above, detection is exposed from the insertion recess 33 to the outside of the first shield cylinder 21 in the capacitive coupling state as in the detection electrode unit 3 shown in FIG. A conductor layer 36 is formed on the insulating coating 24 covering the outer peripheral surface 23b of the electrode 23 (the conductor layer 36 is disposed between the detection electrode 23 and the first shield cylinder 21), and the detection electrode 23 A configuration in which the outer peripheral surface 23b and the insulating coating 24 are further covered with the conductor layer 36 can be employed. In this case, the conductor layer 36 is formed on the surface of the insulating coating 24 with a thickness of, for example, less than 0.1 mm (for example, about 0.01 mm) using a conductive material (for example, a metal material). Further, in this configuration, the conductor layer 36 has the same potential as that of the first shield cylinder 21 due to contact (electrical contact) with the inner surface of the first shield cylinder 21, so that the conductor layer 36 is used for the detection electrode. Functions as a shielding material.

  According to this configuration, by forming the conductor layer 36 functioning as the detection electrode shield material on the outer peripheral surface 23b of the detection electrode 23 exposed from the insertion recess 33 to the outside of the first shield cylinder 21 in the capacitive coupling state. The influence of disturbance on the detection electrode 23 can be sufficiently reduced.

  In addition, according to this configuration, since the detection electrode shield material is configured by the conductor layer 36, the detection electrode shield material can be thinned, and therefore, the detection electrode shield material is covered with the conductor layer 36. As a result, the first shield cylinder 21 that accommodates the broken detection electrode 23 can be configured to be thin. As a result, only one measurement target electric wire 6 is connected to the first shield cylinder 21 from among a plurality of adjacent wires. It is possible to easily perform the operation of attaching to the distal end (inserting into the insertion recess 33 formed in the distal end).

  As another configuration for reducing the influence of disturbance in the capacitive coupling state, a metal (made of conductive material) cylinder 37 is used instead of the conductor layer 36 as in the detection electrode unit 3 shown in FIG. An outer peripheral surface 23b of the detection electrode 23 and the outer peripheral surface 23b that are disposed between the detection electrode 23 and the first shield cylindrical body 21 and are exposed to the outside of the first shield cylindrical body 21 from the insertion recess 33 in the capacitive coupling state. It is also possible to employ a configuration in which the insulating coating 24 to be covered is further covered with a cylindrical body 37. In this configuration, the cylindrical body 37 is also in contact with the inner surface of the first shield cylindrical body 21 (electrical contact). By having the same potential as the body 21, the cylinder 37 functions as a shield material for the detection electrode. For this reason, also in this structure, the influence of the disturbance with respect to the detection electrode 23 can fully be reduced.

  Further, according to this configuration, the detection electrode 23 is inserted into the cylindrical body 37 and the cylindrical body 37 is only inserted into the first shield cylindrical body 21 by forming the detection electrode shielding material with the cylindrical body 37. Since the cylindrical body 37 as the detection electrode shielding material can be disposed between the detection electrode 23 and the first shield cylindrical body 21 by a simple process, the assembly efficiency of the detection probe 1 can be sufficiently improved. it can.

  Further, in the detection electrode unit 3 in which the cylindrical body 37 is disposed between the detection electrode 23 and the first shield cylindrical body 21, as shown in FIG. 13, the distal end portion 37a of the cylindrical body 37 is the detection electrode in the capacitive coupling state. The distal end surface 23a of the first shield cylindrical body 21 is located on the same side as the distal end surface 23a (insulating coating 24 covering the distal end surface 23a) and the distal end portion 37a is closer to the proximal end side of the first shield cylinder 21 along the axis L direction. A configuration in which one of the states located on the right side in FIG. According to this configuration, since the distal end portion 37 a of the cylindrical body 37 does not protrude from the distal end surface 23 a of the detection electrode 23, measurement is performed at the distal end side notch surface 33 a constituting the insertion recess 33 and the distal end surface 23 a of the detection electrode 23. When sandwiching the target electric wire 6, it is possible to reliably prevent the measurement target electric wire 6 from being damaged or cut by the distal end portion 37a of the cylindrical body 37.

  Further, the measuring device MD may be configured to have a current measuring function in addition to the voltage measuring function, and further measure a resistance measuring function and power for measuring resistance based on the measured voltage value and current value. The configuration may include other measurement functions such as a power measurement function.

  Next, a voltage detection probe 101 (hereinafter also simply referred to as “detection probe 101”) shown in FIGS. 14 and 15 as another example of the detection probe will be described. In addition, in the following description, the same code | symbol is attached | subjected about the component similar to the above-mentioned detection probe 1, and the overlapping description is abbreviate | omitted. The detection probe 101 includes the grip portion 2 and the detection electrode unit 103. In this detection electrode unit 103, as shown in FIGS. 14 and 15, the detection electrode 23 is fixed to the second shield cylinder 22 (grip part 2), and the first shield cylinder 21 is second along the axis L direction. The shield cylinder 22 is configured to be movable. That is, also in this configuration, the detection electrode 23 is accommodated in the first shield cylinder 21 so as to be movable relative to the first shield cylinder 21.

  In this case, as shown in FIG. 14, when the first shield cylinder 21 is moved to the base end portion (the right end portion in the figure) of the grip portion 2, the front end surface 23a of the detection electrode 23 is The insertion recess 33 is closed by being positioned on the distal end portion (first lid body 25) side of the first shield cylinder 21. Further, as shown in FIG. 15, when the first shield cylinder 21 is moved to the distal end portion (the left end portion in the figure) of the grip portion 2, the distal end surface 23a of the detection electrode 23 is the first. The insertion recess 33 is opened away from the tip of the shield cylinder 21.

  Moreover, in this detection electrode unit 103, as shown in FIGS. 14 and 15, the urging member 131 (as an example) disposed on the distal end side (the left end side in both drawings) in the second shield cylindrical body 22 is used. The first shield cylinder 21 is urged toward the base end side of the grip portion 2 by a compression coil spring made of a conductive material (for example, a metal material). In addition, the structure which arrange | positions the biasing member 131 comprised with the tension coil spring in the base end part side (the right end part side in both figures) in the 2nd shield cylinder 22 is also employable.

  When measuring the voltage V1 of the measurement target electric wire 6 using the measuring device MD including the detection probe 101, first, an external force F1 in the direction of the arrow shown in FIG. 14 is applied to the knob portion 32c of the operation lever 32 with a finger. The knob portion 32c is moved from the position shown in FIG. 15 to the position shown in FIG. 15 against the urging force of the urging member 131 (moving operation on the operation lever 32). At this time, the first shield cylinder 21 is moved in the direction of the arrow shown in FIG. 14 according to this moving operation. As a result, the insertion recess 33 shifts from the state closed by the detection electrode 23 (state shown in FIG. 14) to the opened state (state shown in FIG. 15). Next, as shown in FIG. 16, the measurement target electric wire 6 is inserted into the insertion recess 33 that has been opened.

  Subsequently, the finger is released from the knob portion 32c. At this time, as shown in FIG. 16, the first shield cylinder 21 is pushed toward the proximal end side of the grip portion 2 by the biasing force F <b> 2 of the biasing member 31. And the measurement object electric wire 6 is clamped by the front end side notch surface 33a of the insertion recess 33. Thus, the clamping operation (mounting operation) of the measurement target electric wire 6 by the detection probe 101 is completed. Next, the voltage V <b> 1 of the measurement target electric wire 6 is measured by each part of the main unit 4 performing each process.

  In the detection probe 101 and the measuring device MD including the detection probe 101, the first shield cylinder 21 is configured to be movable along the axis L direction. In this case, in the configuration in which the detection electrode 23 is moved, a guide hole (second guide hole 34 of the second shield cylindrical body 22) through which the support column 32 a is inserted in order to connect the support column 32 a of the operation lever 32 to the detection electrode 23. It is necessary to form the same guide hole) and the like in the first shield cylinder 21 and the shield effect is reduced accordingly. On the other hand, in the detection probe 101 and the measuring apparatus MD that move the first shield cylinder 21, there is no need to form a guide hole in the first shield cylinder 21, so that the detection electrode 23 is moved accordingly. The shield effect can be enhanced more.

  Also in this detection probe 101, in order to reduce the influence of disturbance in the capacitive coupling state, as shown in FIG. 17, the first shield from the insertion recess 33 is capacitively coupled as shown in FIG. A conductor layer 36 that functions as a shield material for the detection electrode is formed on the insulating coating 24 that covers the outer peripheral surface 23b of the detection electrode 23 exposed to the outside of the cylindrical body 21 (the detection electrode 23 and the first shield cylindrical body 21). The conductor layer 36 is disposed between the outer peripheral surface 23 b and the insulating coating 24 of the detection electrode 23 and the conductor layer 36 further covers the outer peripheral surface 23 b and the insulating coating 24. For this reason, also in this configuration, the influence of disturbance on the detection electrode 23 can be sufficiently reduced.

  Further, as another configuration for reducing the influence of disturbance in the capacitive coupling state, a metal (conductivity) functioning as a shield material for the detection electrode instead of the conductor layer 36 as in the detection electrode unit 103 shown in FIG. A cylindrical body 37 made of a material is disposed between the detection electrode 23 and the first shield cylinder 21, and the outer periphery of the detection electrode 23 exposed from the insertion recess 33 to the outside of the first shield cylinder 21 in the capacitive coupling state. A configuration in which the insulating coating 24 covering the surface 23b and the outer peripheral surface 23b thereof is further covered with the cylindrical body 37 may be employed. Also in this configuration, the influence of disturbance on the detection electrode 23 can be sufficiently reduced.

  Further, in the detection electrode unit 103 in which the cylindrical body 37 is disposed between the detection electrode 23 and the first shield cylindrical body 21, as shown in FIG. 18, the distal end portion 37a of the cylindrical body 37 is the detection electrode in the capacitive coupling state. The distal end surface 23a of the first shield cylindrical body 21 is located on the same side as the distal end surface 23a (insulating coating 24 covering the distal end surface 23a) and the distal end portion 37a is closer to the proximal end side of the first shield cylinder 21 along the axis L direction than the distal end surface 23a. Any of the states located on the right side in FIG. According to this configuration, since the distal end portion 37 a of the cylindrical body 37 does not protrude from the distal end surface 23 a of the detection electrode 23, measurement is performed at the distal end side notch surface 33 a constituting the insertion recess 33 and the distal end surface 23 a of the detection electrode 23. When sandwiching the target electric wire 6, it is possible to reliably prevent the measurement target electric wire 6 from being damaged or cut by the distal end portion 37a of the cylindrical body 37.

  As still another configuration for reducing the influence of disturbance in the capacitive coupling state, a cylindrical body 37 that functions as a shield material for the detection electrode is provided outside the first shield cylindrical body 21 as in the detection electrode unit 103 shown in FIG. The outer peripheral surface 23b of the detection electrode 23 exposed to the outside of the first shield cylindrical body 21 from the insertion recess 33 in the capacitive coupling state and the insulating coating 24 covering the outer peripheral surface 23b are further covered with the cylindrical body 37. Can also be adopted. Also in this configuration, the influence of disturbance on the detection electrode 23 can be sufficiently reduced.

  Further, in the detection electrode unit 103 in which the cylinder 37 is disposed between the detection electrode 23 and the first shield cylinder 21, or the cylinder 37 is disposed outside the first shield cylinder 21, As shown in FIGS. 18 and 19, in the capacitive coupling state, the distal end portion 37a of the cylindrical body 37 is flush with the distal end surface 23a of the detection electrode 23 (insulating coating 24 covering the distal end surface 23a) and the distal end portion 37a It is possible to adopt a configuration in which one of the states located on the proximal end side (the right side in the figure) of the first shield cylinder 21 along the axis L direction from the distal end surface 23a can be employed. Also in this configuration, since the distal end portion 37a of the cylindrical body 37 does not protrude from the distal end surface 23a of the detection electrode 23, the measurement target is the front end side notch surface 33a constituting the insertion recess 33 and the distal end surface 23a of the detection electrode 23. When the electric wire 6 is clamped, it is possible to reliably prevent the measurement target electric wire 6 from being damaged or cut by the distal end portion 37a of the cylindrical body 37.

  Further, although the example in which the detection probe 1 or 101 is configured with the grip portion 2 has been described above, a detection probe that does not include the grip portion 2 (a detection probe configured only with the detection electrode unit 3) may be employed. . In this configuration, for example, the detection probe (detection electrode unit 3) is used while being fixed to a housing in which the main unit 4 is accommodated, or the detection probe (detection electrode unit 3) is used while being fixed to a moving mechanism. The present invention can be applied to a usage pattern in which the measurement target electric wire 6 is clamped by operating the moving mechanism.

1,101 detection probe
5 Shielded cable 5a Core wire 5b Shield conductor
6 Measurement target wire 21 First shield cylinder 23 Detecting electrode 24 Insulation coating 33 Insertion recess 33a Tip side notch surface 33b Base end notch surface 36 Conductor layer 37 Tube 37a Tip
L axis PL Reference plane

Claims (11)

An insertion recess that is formed of a cylindrical body made of a conductive material and in which a part of the outer peripheral wall at the tip is cut out along the direction intersecting the axis and into which the measurement target electric wire can be inserted is formed at the tip. A formed shield cylinder;
The front end surface and the outer peripheral surface are formed of a columnar body made of a conductive material covered with an insulating coating, and are housed in the shield cylinder so as to be movable relative to the shield cylinder along the axial direction. A detection electrode,
When the detection electrode is moved relative to the shield cylinder and the tip surface is positioned in the insertion recess, the measurement target electric wire and the insulation coating in a state of being inserted in the insertion recess A voltage detection probe in which the distal end surface is configured to be capable of capacitive coupling via a pin.   Of the cut-out surfaces of the shield cylindrical body constituting the insertion recess, the front-end cut-out surface located on the front-end portion side is inclined toward the base end portion with reference to a reference plane orthogonal to the axis. The voltage detection probe according to claim 1.   Of the cut-out surfaces of the shield cylindrical body constituting the insertion recess, a base-side cut-out surface located on the base end side is more than the base-side cut-out surface with respect to the reference plane. The voltage detection probe according to claim 2, wherein the voltage detection probe is inclined toward the end side. A biasing member that constantly biases the detection electrode in the direction of the insertion recess;
The detection electrode is slid in the direction of the insertion recess in the shield cylinder by the biasing force of the biasing member, and is on the tip end side of the cutout surface of the shield cylinder that constitutes the insertion recess. The voltage detection probe according to any one of claims 1 to 3, wherein the measurement target electric wire inserted into the insertion recess is sandwiched between a front end side notch surface located at the front end and the front end surface.   5. The voltage detection probe according to claim 1, wherein the tip surface is inclined toward the tip portion with reference to a reference plane orthogonal to the axis.   Between the detection electrode and the shield cylinder, the outer peripheral surface of the detection electrode exposed from the insertion recess to the outside of the shield cylinder is covered in a capacitive coupling state between the measurement target electric wire and the tip surface. The voltage detection probe according to any one of claims 1 to 5, wherein a shield material for a detection electrode made of a conductive material that further covers the insulating coating is disposed.   The voltage detection probe according to claim 6, wherein the detection electrode shield member is formed of a cylindrical body.   The voltage detection probe according to claim 6, wherein the detection electrode shielding material is formed of a conductor layer formed on a surface of the insulating coating.   The insulating coating that covers the outer peripheral surface of the detection electrode that is exposed from the insertion recess to the outside of the shield cylinder in a capacitive coupling state between the measurement target electric wire and the tip surface is further provided on the outer side of the shield cylinder. The voltage detection probe according to claim 1, wherein a shielding material for a detection electrode made of a conductive material is disposed.   In the capacitively coupled state, the detection electrode shield material is in a state in which the distal end portion of the detection electrode shield material is flush with the distal end surface of the detection electrode, and the distal end portion is closer to the axial direction than the distal end surface. The voltage detection probe according to any one of claims 6 to 9, wherein the voltage detection probe is configured to be in any of the states positioned on the proximal end side of the shield cylinder. A voltage detection probe according to any one of claims 1 to 10,
A main unit to which the voltage detection probe is connected;
A voltage detection unit disposed in the main body unit for detecting a voltage of the measurement target electric wire via the core wire and the detection electrode and outputting a voltage signal that changes in accordance with the voltage;
A voltage generator disposed in the main body unit, generating a voltage following the voltage of the measurement target wire based on the voltage signal and applying the voltage to the shield conductor;
A processing unit disposed in the main unit and measuring the voltage of the measurement target wire based on the voltage generated by the voltage generation unit;
The voltage detector is a measuring device that operates with a floating voltage based on the potential of the voltage generated by the voltage generator.

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