JP6679408B2 - Voltage detection probe and measuring device - Google Patents

Description

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

  As this type of voltage detection probe, the applicant of the present application discloses various forms of voltage detection probe (hereinafter, also simply referred to as “detection probe”) in Patent Documents 1 to 3 below. For example, Patent Document 1 discloses a detection probe that includes a clamp portion that includes a magnetic core that surrounds an electric wire to be measured in a closed state to form an annular closed magnetic circuit. Further, in Patent Document 2, a sensor substrate housing portion that houses a voltage measuring sensor substrate, and a measurement target conductor wire that is rotatably supported by the sensor substrate housing portion via a pivot shaft and serves as a sensor substrate housing portion. Disclosed is a detection probe having a configuration in which a measurement target electric wire pressing portion is sandwiched between the detection probes. Further, in Patent Document 3, a voltage detection unit in which a detection electrode for voltage detection and a magnet are arranged is provided, and the measurement target while positioning the tip of the measurement probe provided with the voltage detection unit by the magnetic force of the magnet. A detection probe configured to press against an electric wire is disclosed. All of these detection probes are capable of detecting the voltage of the conductive part of the electric wire to be measured (so-called non-contact type) by capacitively coupling the electrode for detection to the conductive part of the electric wire to be measured without directly contacting the conductive part. Voltage detection probe).

  Here, the above-mentioned detection probe, in the vicinity of the electrode for voltage detection, a magnetic core is arranged, a mechanism for clamping or clamping is arranged, or a structure in which a magnet is arranged, The outer shape, in particular, the shape of the portion including the electrode for voltage detection is large. Therefore, in the above detection probe, for example, when measuring the voltage of one of the bundled electric wires, it is not possible to hold only one electric wire. Measurement is difficult.

  As a means for solving such a problem, the applicant has developed the following detection probe. This detection probe includes a grip portion made of an insulating material, a shield cylinder body having an insertion recess formed at the tip end portion and a base end portion connected to the grip portion, and a metal having a tip end surface and an outer peripheral surface covered with an insulating coating. And a detection electrode slidably housed in a shield cylinder formed of a columnar body made of aluminum. Further, the detection electrode is slid (moved) in response to an operation on an operation lever slidably arranged on the grip portion. In this case, the detection electrode is connected to the tip of the column of the operating lever that is inserted into the second guide hole formed in the shield cylinder. In this detection probe, the operation lever is operated to slide the detection electrode toward the tip of the shield cylinder to bring the tip of the detection electrode into contact with the wire inserted in the insertion recess. It is possible to measure the voltage of. For this reason, in this detection probe, by forming the shield cylinder and the detection electrode to be thin, it is possible to reliably and easily hold only one of the bundled electric wires. It is possible to reliably measure the voltage of the wire.

Japanese Patent Laid-Open No. 2012-137496 (page 5, FIG. 1) Japanese Patent Laid-Open No. 2014-52329 (pages 5-8, FIGS. 1-3) Japanese Unexamined Patent Publication No. 2014-163670 (pages 5-8, FIGS. 1-3)

  However, the above-mentioned detection probe developed by the applicant also has the following problems to be improved. That is, in the detection probe developed by the applicant (the detection probe in which the electric wire is sandwiched by the tip portion of the shield cylinder), the tip of the column portion of the operation lever inserted into the second guide hole formed in the shield cylinder. The detection electrode is connected to the section. Therefore, in this detection probe, the presence of the second guide hole may be affected by disturbance, which may reduce the accuracy of voltage measurement, and improvement of this point is desired.

  The present invention has been made in order to improve such a problem, and a main object of the present invention is to provide a voltage detection probe and a measurement device capable of accurately measuring the voltage by sufficiently reducing the influence of disturbance.

In order to achieve the above object, the voltage detection probe according to claim 1 is provided with an insertion concave portion into which a measurement target electric wire can be inserted by cutting out a part of an outer peripheral wall at a tip end along a direction intersecting the axis. Conductive tubular first shield body formed at the tip portion, conductive tubular second shield body into which the base end side of the first shield body is inserted, tip surface and outer peripheral surface Is formed of a conductive columnar body covered with an insulating coating and is housed in the first shield body, and one of the first shield body and the detection electrode is an operating lever. Is configured to be movable along the direction of the axis according to the moving operation of the insertion concave portion when the insulating coating of the distal end surface comes into contact with the measurement target electric wire inserted into the insertion concave portion. Due to the tip surface The said front end surface while clamping the measured wires are inserted is the inserted measurable target wire and the capacitive coupling is configured through the insulating coating Te, the operating lever includes a handle portion, said first A support part that is inserted into a guide hole formed in the two shield body and is connected to one of the two, and at least one of an inner side and an outer side of the second shield body is attached to the support part. A third shield body is provided that is movable according to the movement operation of the operation lever and that shields the guide hole when the inserted measurement target electric wire is sandwiched.

  The voltage detection probe according to a second aspect is the voltage detection probe according to the first aspect, wherein the first shield body is configured to be movable along the direction of the axis.

  According to a third aspect of the voltage detection probe of the first or second aspect, the third shield body is arranged inside the second shield body.

  A voltage detection probe according to a fourth aspect is the voltage detection probe according to any of the first to third aspects, wherein the third shield body is formed in a cylindrical shape.

  The voltage detection probe according to claim 5 is the voltage detection probe according to any one of claims 1 to 4, wherein the voltage detection probe is located on the tip end side of the cutout surface of the first shield body that forms the insertion recess. The front end side cutout surface is inclined toward the base end portion side with reference to a reference plane orthogonal to the axis.

  The voltage detection probe according to claim 6 is the voltage detection probe according to claim 5, wherein a base end side cut located on the base end side of the cutout surface of the first shield body forming the insertion recess. The notch surface is inclined toward the base end side with respect to the tip side notch surface with the reference plane as a reference.

The voltage detection probe according to claim 7 is the voltage detection probe according to any one of claims 1 to 6, further comprising a biasing member that constantly biases the detection electrode in the insertion recess direction, and the detection electrode includes: The first shield body is slid in the insertion recess direction by the urging force of the urging member, and is positioned on the tip end side of the cutout surface of the first shield body forming the insertion recess. in between the tip side cutout surface the front end surface, to clamp the constant target wire measurement that have been the insertion.

  The voltage detection probe according to claim 8 is the voltage detection probe according to any one of claims 1 to 7, wherein the tip end surface is inclined toward the tip end side with reference to a reference plane orthogonal to the axis. .

Voltage detection probe according to claim 9, wherein, in the voltage detection probe according to any one of claims 1 to 8, from the insertion recess of the first shield member in capacitive coupling state between the measured wire being the insertion The outer peripheral surface of the detection electrode that is exposed to the outside and is covered with the insulating coating is covered with a conductor layer that is in electrical contact with the first shield body.

A measuring device according to claim 10 is the voltage detecting probe according to any one of claims 1 to 9, a main body unit connected to the voltage detecting probe, and the measuring electrode disposed in the main body unit. A voltage detection unit that detects the voltage of the inserted electric wire to be measured through and outputs a voltage signal that changes according to the voltage, and is provided in the main body unit, and based on the voltage signal. A voltage generator that generates a voltage that follows the voltage of the inserted electric wire to be measured, and the voltage generator that is disposed in the main body unit and that is inserted based on the voltage generated by the voltage generator. And a processing unit that measures the voltage of the electric wire to be measured, and the voltage detection unit operates at 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 device according to claim 10, when the electric wire to be measured is clamped, the voltage detection probe is attached to a support column of the operation lever and is movable according to a movement operation on the operation lever. A third shield body that shields the guide hole of the second shield body is disposed on at least one of the inside and the outside of the second shield body. Therefore, according to the detection probe and the measurement device, the influence of the disturbance on the detection electrode can be sufficiently reduced as compared with the configuration in which the guide hole is not shielded when the measurement target wire is sandwiched. It is possible to accurately measure the voltage of the electric wire.

  In the voltage detection probe according to claim 2 and the measurement device according to claim 10, the first shield body is configured to be movable along the direction of the axis. In this case, in the configuration in which the detection electrode is moved, a guide hole (a guide hole similar to the guide hole of the second shield body) through which the support column is inserted in order to connect the support column of the operation lever to the detection electrode is provided. It is necessary to form the shield body, and the shield effect is reduced accordingly. On the other hand, in this detection probe and measurement device that moves the first shield body, since it is not necessary to form guide holes or the like in the first shield body, the shield effect is increased by that amount as compared with the configuration in which the detection electrode is moved. be able to.

  According to the voltage detection probe of claim 3 and the measuring device of claim 10, the third shield body is provided inside the second shield body, so that the third shield body is provided outside the second shield body. The detection probe can be downsized as compared with the configuration provided.

  According to the voltage detection probe of the fourth aspect and the measuring device of the tenth aspect, since the third shield body is formed in a cylindrical shape, the detection electrode can be surrounded by the third shield body. The shield effect of the body can be further enhanced.

  According to the voltage detection probe of claim 5 and the measurement device of claim 10, since the tip-side cutout surface is inclined toward the base end side, the electric wire to be measured inserted in the insertion recess is the detection electrode. It is possible to prevent the electric wire to be measured from coming off from the insertion recessed portion in a state in which it is pressed against the tip-side cutout surface by the tip end surface (state where it is sandwiched between the tip end surface of the detection electrode and the tip-side cutout surface).

  According to the voltage detection probe of claim 6 and the measuring device of claim 10, the proximal cutout surface is inclined toward the proximal end side with respect to the distal cutout surface. While maintaining the effect of tilting the side cutout surface (the effect that it is difficult to detach the measurement target wire from the insertion recessed portion), the distance along the axial direction between the cutout surfaces constitutes the insertion recessed portion. Since it can be configured to gradually widen with increasing distance from the notch surface on the far side (the configuration in which the opening width of the insertion recess is gradually widened), the ease of inserting the measurement target wire into the insertion recess can be enhanced. .

  According to the voltage detection probe of claim 7 and the measuring device of claim 10, the measurement target electric wire inserted in the insertion concave portion is notched by the urging force of the urging member. Since it can be sandwiched between the probe and the tip surface of the detection electrode, the measurement target wire is maintained in the insertion recess even when the voltage detection probe is released. It is possible to improve workability in voltage measurement work.

  According to the voltage detection probe of claim 8 and the measuring device of claim 10, the tip end surface of the detection electrode is formed into an inclined surface that is inclined toward the tip end side of the first shield body, so that it is inserted into the insertion recess. When the electric wire to be measured is pressed against the notch surface on the tip side by the tip surface of the detection electrode (sandwiched between the tip surface of the detection electrode and the notch surface on the tip side), the electric wire to be measured is further removed from the insertion recess. It can be hard to come off.

  According to the voltage detection probe of claim 9 and the measurement device of claim 10, the inner surface of the first shield body is configured by further covering the outer peripheral surface (surface of the insulating coating) of the detection electrode with a conductor layer. A part of the opening portion of the insertion recess is exposed at a portion exposed from the opening portion of the insertion recess in this conductor layer that functions as a shield member by being brought into contact with (electrical contact with) the same potential as the first shield body. It is possible to further reduce the influence of disturbance on the electric wire to be measured by closing (reducing the area of the region where the shield member does not exist in the opening portion of the insertion recess).

It is a perspective view showing a configuration of a detection probe 1. FIG. 2 is a sectional view taken along line WW of the detection probe 1 in a state in which the grip portion 2 is cut along a plane including the axis L in FIG. 1 (a sectional view in a state in which 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 sectional view taken along line WW of the detection probe 1 (a sectional view in a state in which an insertion recess 33 is open) in a state in which the grip portion 2 is cut along a plane including the axis L in FIG. 1. FIG. 5 is a cross-sectional view of the detection electrode unit 3 taken along a plane including the axis L of FIG. 4. 1 is a sectional view taken along line WW of the detection probe 1 in a state where the grip portion 2 is cut along a plane including the axis L (a tip-side cutout surface 33a of the insertion recess 33 and a tip surface 23a of the detection electrode 23). It is sectional drawing in the state in which the electric wire 6 for measurement is clamped between. FIG. 4 is an enlarged cross-sectional view of an essential part (an enlarged cross-sectional view in a state where an insertion recess 33 is opened) for explaining a configuration of a tip portion of the first shield tubular body 21. FIG. 4 is an enlarged cross-sectional view of an essential part (an enlarged cross-sectional view in a state where a measurement target electric wire 6 is held) for explaining a configuration of a tip end portion of a first shield tubular body 21. It is a block diagram of measuring device MD. FIG. 6 is an enlarged cross-sectional view of an essential part (an enlarged cross-sectional view in a state where the measurement target electric wire 6 is held) for explaining another configuration of the tip end surface 23a of the detection electrode 23. FIG. 6 is an enlarged cross-sectional view of an essential part (an enlarged cross-sectional view in a state where an insertion recess 33 is open) for explaining the configuration of still another tip portion of the first shield tubular body 21. FIG. 6 is an enlarged cross-sectional view of an essential part (an enlarged cross-sectional view in a state where the measurement target electric wire 6 is held) for explaining another configuration of the tip end portion of the detection electrode 23. FIG. 3 is a side view of the detection probe 101 with a half body (front half body in the figure) of the grip portion 2 removed. Detection of the state in which the first shield cylinder 21 is moved to the tip end side of the grip part 2 (direction away from the base end part) in a state where the half part of the grip part 2 (front half in the figure) is removed 3 is a side view of the probe 101. FIG. FIG. 6 is a side view of the detection probe 101 in a state in which the measurement target electric wire 6 is sandwiched in a state in which a half body (a front half body in the same figure) of the grip portion 2 is removed.

  Hereinafter, embodiments of a voltage detection probe and a measuring device 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 body unit 4 via the shielded 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. Then used. The shielded cable 5 in the present embodiment is a cable provided with wiring for signal transmission and a shield conductor that shields this wiring, and includes, for example, a core wire as wiring for signal transmission 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 shown in FIG. 2, a shield wire including a core wire 5a and a shield conductor 5b that covers the core wire 5a will be described as an example of the shield cable 5.

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

  Further, on the outer surface of the outer peripheral wall of the grip portion 2, as an example, a long groove 15 extending along the length direction of the grip portion 2 (direction parallel to an axis L (see FIGS. 1 and 2) described later) is formed. At the same time, a first guide hole 16 extending along the length direction of the grip portion 2 is formed in the bottom wall of the long groove 15 (a part of the outer peripheral wall of the grip portion 2) so as to penetrate the bottom wall. ing.

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

  As shown in FIGS. 3 and 5, the first shield tube body 21 is made of a conductive material (metal material having conductivity) and has an outer shape of, for example, a cylindrical rigid body having a diameter of about 3 mm to 5 mm (in this example, an example). As a cylindrical body), and at the tip portion (the left end portion in FIGS. 2 to 6), a part of the outer peripheral wall at the tip portion intersects the axis L (in this example, it is orthogonal. Insertion direction 33, into which the electric wire 6 to be measured (see FIGS. 4, 6 and 8) is inserted by being cut out by a method such as cutting. The electric wire 6 to be measured in this example is a covered electric wire in which the core wire 6a is covered with an insulating coating 6b as shown in FIG. Further, as shown in FIGS. 3 and 5, the first shield tube body 21 is fixed to the second shield tube body 22 with the base end side (right side in both figures) being accommodated in the second shield tube body 22. Has been done.

  The insertion recess 33 is, as an example in this example, as shown in FIGS. 2 and 5 (in detail, as shown in FIG. 7, which is an enlarged view of a main part of FIG. 5), the first shield forming the insertion recess 33. Of the respective cutout surfaces 33a, 33b, 33c of the tubular body 21, the tip-side cutout surface 33a located on the tip end side of the first shield tubular body 21 is first based on the reference plane PL orthogonal to the axis L. The shield cylinder 21 is inclined toward the base end side (that is, the angle θ1 between the axis L (virtual plane including the axis L) and the tip-side cutout surface 33a is an acute angle). With this configuration, the electric wire 6 to be measured inserted into the insertion recess 33 is formed on the tip-side notch surface 33a by the end surface 23a (hereinafter, also referred to as the tip surface 23a) on the tip end side 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 the present example, as an example, the base end side notch surface 33b located on the base end side of the first shield tubular body 21 among the notch surfaces 33a, 33b, 33c is a reference plane PL (which is orthogonal to the axis L). With reference to FIG. 7) as a reference, a configuration (that is, an axis L (a virtual plane including the axis L)) and a tip-side notch surface that are inclined toward the base end side of the first shield tubular body 21 with respect to the tip-side notch surface 33a The angle θ2 with respect to 33a is made acute when the angle θ2 is smaller than the angle θ1). With this configuration, while maintaining the effect of tilting the tip-side notch surface 33a as described above (the effect of making it difficult to detach the measurement target electric wire 6 from the insertion recess 33), the gap between the notch surfaces 33a and 33b is maintained. A configuration in which the distance along the direction of the axis L is gradually widened as the distance from the rear side cutout surface 33c (the rear side cutout surface forming the insertion recess 33) is increased (the opening width of the insertion recess 33 is gradually increased. Therefore, it is possible to increase the ease of inserting the electric wire 6 to be measured into the insertion recess 33.

  Further, in the present example, the rear side notch surface 33c is, for example, a configuration that is a plane substantially parallel to the axis L, but the configuration is not limited to this configuration, and a configuration in which it is formed in an arcuate surface is adopted. You can also

  The electric wire 6 to be measured, in which the detection probe 1 of this example is used, is a conductor that is difficult to mount with the various detection probes described in the background art, for example, together with other similar small diameter wiring materials. One small-diameter wiring material that exists in close proximity to other conductors (such as other wiring materials), such as one small-diameter wiring material that is drawn around in a bound state Electric wire).

  Therefore, in the detection electrode unit 3 of the detection probe 1, as the first shield tube body 21, the insertion recess 33 having a width and a depth into which the wiring material having such a small diameter can be inserted as the electric wire 6 to be measured is provided at the tip. It is possible to use a thinner tubular rigid body as long as it can be formed. In addition, in order to allow 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 member adjacent to the measurement-target electric wire 6 is short. However, it is preferable that the tubular rigid body used for the first shield tubular body 21 be as thin as possible. For example, in order to accommodate a wiring member having a small diameter (diameter of about 2 mm) as described above, the insertion recessed portion 33 has, for example, a depth slightly deeper than 2 mm and a width (opening width) slightly wider than 2 mm. Need to be formed. Therefore, as described above, the first shield tubular body 21 is preferably formed of a tubular rigid body having a diameter of about 3 mm to 5 mm, for example.

  As shown in FIGS. 3 and 5, the second shield cylinder 22 is made of a conductive material (metal material having conductivity) and has an outer shape of, for example, a cylindrical rigid body having a diameter of about 7 mm to 10 mm (in this example, an example). And is fixed to the grip portion 2 while being accommodated in the grip portion 2 as shown in FIGS. Further, a second guide hole (through hole) 34 (corresponding to a guide hole) extending along the length direction (direction of the axis L) of the second shield tubular body 22 is provided on the outer peripheral wall of the second shield tubular body 22. Are formed.

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

  Further, the detection electrode 23 having the insulating coating 24 formed on the surface in this manner is slidable (movable with respect to the grip portion 2) along the direction of the axis L, as shown in FIGS. It is housed in the first shield tubular body 21. Further, as shown in FIG. 3, the detection electrode 23 is in a state in which the front end surface 23a is in contact with the first lid body 25 attached to the front end side opening of the first shield tube body 21 as described later, The base end side is defined to have a length protruding from the base end side of the first shield cylinder 21. Further, in this example, the tip end surface 23a of the detection electrode 23 is formed by a plane parallel to the reference plane PL, as shown in FIG.

  The first lid 25 is formed of a conductive material (metal material having conductivity), and is press-fitted into the opening of the first shield cylinder 21 on the tip (left end in FIGS. 2 and 3) side. The opening is closed by being attached by a method such as welding (electrically connected method). The second lid 26 is formed of a conductive material (metal material having conductivity), and is press-fitted into the opening portion of the second shield cylinder 22 on the tip end side (the left end side in FIGS. 2 and 3). It is attached by a technique such as welding (a technique of electrically connecting). Further, the second lid 26 has a through hole 26a formed in the central portion. The first shield cylinder body 21 is inserted (fixed) to the second cover body 26 by a method such as welding, in which the base end portion side is inserted into the through hole 26a and a conductive state can be secured. .

  The third lid 27 is formed of a conductive material (metal material having conductivity), and is press-fitted into the opening of the second shield cylinder 22 on the base end (right end in FIGS. 2 and 3) side. It is attached by a method such as welding or welding (a method of electrically connecting). Further, the third lid 27 has a through hole 27a formed in the central portion. In this example, as an example, the first shield tubular body 21 and the first lid body 25 are separately formed, and the second shield tubular body 22, the second lid body 26, and the third lid body 27 are separately provided. Although the configuration of forming the body is adopted, the configuration of integrally forming the first shield tubular body 21 and the first lid body 25, or at least one of the second lid body 26 and the third lid body 27. It is also possible to adopt a configuration in which (only the second lid 26, only the third lid 27, or both the second lid 26 and the third lid 27) is integrally formed with the second shield tubular body 22. .

  As shown in FIGS. 3 and 5, the insulating cylindrical body 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 done. The insulating tubular body 28 is for electrically insulating the guide tubular body 29 inserted into the insulating tubular body 28 from the third lid body 27 as described later. Therefore, in the configuration shown in the figure, the insulating tubular body 28 is formed to have a length that also contacts the inner surface of the second shield tubular body 22 on the proximal end side, but is arranged only in the through hole 27a. Needless to say,

  As shown in FIGS. 3 and 5, the guide tubular body 29 is made of a conductive material (metal material having conductivity) and has one end side (left end side in FIG. 3) opened and the other end side (see FIG. 3). Is formed in a tubular body (a cylindrical body as an example in this example) which is closed at the right end side thereof. In this example, a cylindrical projection 29a for inserting and soldering the core wire 5a of the shielded cable 5 is formed on the end surface on the other end side of the guide cylindrical body 29. Formation is arbitrary. The guide cylinder 29 is fixed to the third lid body 27 with the insulation cylinder 28 interposed by being press-fitted into the insulation cylinder 28 from the opening end side.

  As shown in FIGS. 3 and 5, the connecting pin 30 is made of a conductive material (a metal material having conductivity) and has a columnar body (a columnar body having a cross-sectional shape that matches the cross-sectional shape of the guide tubular body 29. In the present example. As an example, it is formed in a columnar body). Further, the connecting pin 30 is slidable in the guide cylinder 29 on the other end side (right end side in FIG. 3) while one end side (left end side in FIG. 3) protruding from the guide cylinder 29. Has been inserted. Further, the connecting pin 30 is connected to the base end side of the detection electrode 23 at one end side in a state where electrical continuity is secured.

  The urging member 31 is composed of a compression coil spring made of a conductive material (metal material having conductivity) as an example, and as shown in FIGS. It 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 side of the connecting pin 30 always projects from the guide tubular body 29 (a tip end direction of the first shield tubular body 21). Further, as a result, the biasing member 31 causes the tip of the first shield cylinder body 21 to detect the detection electrode 23 connected to the connection pin 30 and further the operation lever 32 connected to the detection electrode 23 as described later. Always bias in the direction of the section.

  As shown in FIGS. 3 and 5, the operation lever 32 is positioned outside the rectangular parallelepiped support portion 32a inserted into the second guide hole 34 of the second shield tubular body 22 and the second guide hole 34 in the support portion 32a. A knob portion 32c formed at the tip of the portion projecting inward is provided, and these members are integrally formed by using an insulating material. Further, in the operation lever 32, the end portion (the lower end portion in FIGS. 3 and 5) of the support portion 32a extending inside the second shield tubular body 22 is the detection electrode 23 (the first shield tubular body 21 in the detection electrode 23). It is connected to the base end side protruding from).

  With this configuration, for example, when the knob 32c from the user's thumb holding the grip 2 receives the external force F1 (see FIGS. 4 and 5) toward the base end of the second shield cylinder 22, the operation lever 32 is operated. Moves toward the base end portion of the second shield cylinder 22 together with the detection electrode 23 and the connecting pin 30 against the urging force of the urging member 31 in a state where the column portion 32a is guided by the second guide hole 34. To do. On the other hand, when the external force F1 is released, the operation lever 32 is moved by the urging force F2 of the urging member 31 (see FIG. 6) together with the detection electrode 23 and the connecting pin 30 toward the tip end portion of the second shield cylinder 22. First, the tip of the detection electrode 23 moves until it comes into contact with the first lid 25.

  Further, in the detection electrode unit 3 having this configuration, as shown in FIGS. 3 and 5, the flange portion 32b is arranged outside the second shield cylinder 22 (along the outer surface of the second shield cylinder 22). The flange portion 32b is attached to a portion of the support portion 32a of the operation lever 32 that protrudes from the second guide hole 34. Therefore, the flange portion 32b is moved (slipped) along the outer surface of the second shield tubular body 22 in a state of being in contact with the outer surface of the second shield tubular body 22 in response to a moving operation on the operation lever 32. In this case, the flange portion 32b is formed of a conductive material (for example, the same material as the material forming the second shield cylinder 22) in an arc shape (gutter shape) in cross section, and the second shield cylinder body is formed. By being in contact with 22, the second shield cylinder 22 has the same potential. The flange portion 32b is formed to be slightly longer than the length of the second guide hole 34 in the second shield tubular body 22 (the length along the moving direction of the operation lever 32 (the direction of the axis L)). The flange portion 32b shields the second guide hole 34 when the measurement target electric wire 6 is sandwiched by the tip-side cutout surface 33a of the insertion recess 33 and the end surface 23a of the detection electrode 23 (the state shown in FIG. 6). Functions as a third shield body.

  In addition, 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 entirely the same potential (shield). The first shield cylinder body 21, the second shield cylinder body 22, and the first lid body 25 inserted into the opening on the tip end side of the first shield cylinder body 21 defined by the potential of the shield conductor 5b of the cable 5). , Covered with a second lid 26 that closes the opening on the tip end side of the second shield cylinder 22 and a third lid 27 that closes the opening on the base end side of the second shield cylinder 22. It is configured (that is, shielded by the potential of the shield conductor 5b).

  In the detection electrode unit 3 configured as described above, as shown in FIGS. 2, 4 and 6, the first shield tube body 21 is inserted into the through hole 11 a formed in the end surface 11 of the grip portion 2 and the operation lever is provided. The support column 32 a of 32 is inserted into the first guide hole 16 of the grip part 2, and the knob part 32 c is arranged in the long groove 15 of the grip part 2 and is accommodated in the grip part 2. Therefore, the first shield tube body 21 is housed in the grip part 2 in a state where the base end part thereof is fixed to the second lid body 26 of the detection electrode unit 3 housed in the grip part 2. Therefore, when the detection probe 1 as a whole is viewed, it is equivalent to a state in which the base end portion is connected to the grip portion 2.

  Further, the end portion of the shielded cable 5 is fitted to the end surface 13 of the grip portion 2 as shown in FIGS. 2, 4 and 6 in which the universal bush 5c is fitted in the through hole 13a formed in the end surface 13. Connected by. At the end portion of the shielded cable 5 located inside the grip portion 2, the core wire 5a of the shielded cable 5 is soldered to the tubular protrusion 29a to be connected to the guide tubular body 29, and the shielded cable 5 is shielded. The conductor 5b is soldered to the third lid body 27 that constitutes the detection electrode unit 3 (that is, the first shield tubular body 21 includes the second lid body 26, the second shield tubular body 22, and the third lid body 27). Is connected to the shield conductor 5b via.

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

  The main power supply circuit 51 has a positive voltage Vdd and a negative voltage Vss for operating the above-described respective constituent elements 53 to 58 of the main body unit 4 (absolute values generated with reference to the potential of the ground G1 as the first reference potential). In the same way, DC voltages with mutually different polarities) are output. The converter 52 includes, for example, an insulating transformer having a primary winding and a secondary winding electrically insulated from each other, a drive circuit for driving the primary winding of the transformer, and a secondary winding of the transformer. And a DC converter (not shown) for rectifying and smoothing the generated AC voltage, and 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 to drive the primary winding of the transformer in the state where the positive voltage Vdd is applied, and the AC voltage is applied to the secondary winding. Induce. Further, the DC converter rectifies and smoothes this AC voltage. As a result, from the secondary side of converter 52, positive voltage Vf + and negative voltage Vf− based on this internal reference potential (second reference potential) G2 on the secondary side are in a floating state (ground G1, positive voltage Vdd and negative). It is generated in a state of being electrically separated from the voltage Vss. The positive voltage Vf + and the negative voltage Vf− as the floating voltage 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 DC 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 driving circuit 53c, and an insulating circuit 53d (a photo coupler driven by the driving circuit 53c is shown as an example, but, for example, although not shown, (Various other configurations such as a configuration using an insulating transformer in place of the coupler can be adopted), and the converter in a state where the reference potential in the voltage detection unit 53 is regulated to the second reference potential G2. The positive voltage Vf + and the negative voltage Vf- are supplied from 52 to operate.

  In the current-voltage conversion circuit 53a, as an example, the non-inverting input terminal is connected via a resistor to the portion of the voltage detection unit 53 defined by the second reference potential G2 (hereinafter, also referred to as “connected to the second reference potential G2”). In addition, 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 5a), and the feedback resistor is provided between the inverting input terminal and the output terminal. It is configured with a first operational amplifier connected. In the current-voltage conversion circuit 53a, the first operational amplifier operates at 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). Due to a potential difference Vdi (which is also the voltage of V4) (see FIG. 9), a detection current (current signal) I flowing between the measurement target electric wire 6 and the detection electrode 23 is obtained at a current value corresponding to the potential difference Vdi. The detected voltage signal V2 is converted and output. In this case, the amplitude of the detection voltage signal V2 changes in proportion to the amplitude of the current signal I.

  In the integrating circuit 53b, for example, the non-inverting input terminal is connected to the second reference potential G2 via a resistor, the inverting input terminal is connected to the output terminal of the first operational amplifier via the input resistor, and the feedback is performed. The capacitor comprises 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 detected voltage signal V2, so that the integrated signal V3 whose voltage value changes in proportion to the above potential difference Vdi. Is generated and output.

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

  One end of the current-voltage converting resistor 54 is connected to the negative voltage Vss, and the other end is connected to the corresponding insulating circuit 53d in the voltage detecting section 53 (in this example, the collector terminal of the phototransistor in the photocoupler). ing.

  The voltage generator 55 inputs and amplifies the integrated signal V3a to generate a voltage signal V4, and applies the voltage signal V4 to a portion of the voltage detector 53 defined by the second reference potential G2. This 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 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), the detection electrode 23, and the 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), by performing an amplification operation for amplifying the integration signal V3a so as to reduce the potential difference Vdi. , Voltage signal V4 is generated.

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

  The processing unit 57 includes a CPU and a memory (neither of which is shown), and executes a voltage calculation process of calculating the voltage V1 of the measurement target electric wire 6 based on the voltage data Dv output from the voltmeter 56. To do. The processing unit 57 also causes the display unit 58 to display the voltage V1 calculated in the voltage calculation process in the form of a table or a graph. The display unit 58 is composed of, for example, a monitor device such as a liquid crystal display.

  When the voltage V1 of the electric wire 6 to be measured is measured 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 tip of the first shield cylinder 21. Insert the target electric wire 6.

  Specifically, first, by applying an external force F1 in the arrow direction 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 moved. By sliding from the position shown in FIG. 2 to the position shown in FIG. 4 against the biasing force of the biasing member 31 (sliding in the direction of the arrow), the detection electrode 23 is slid in the first shield cylinder 21 ( Slide). As a result, the detection probe 1 is moved from the state in which the insertion recess 33 is closed by the detection electrode 23 as shown in FIG. 2 to the state in which the insertion recess 33 is opened as shown in FIG. Next, the electric wire 6 to be measured is inserted into the insertion recess 33 that has been opened. In this case, since the electric wire 6 to be measured is a covered electric wire, the core wire 6a of the electric wire 6 to be measured and the first shield tubular body 21 are maintained in an electrically insulated state.

  In addition, particularly in this detection probe 1, as shown in FIGS. 1 to 6 and in detail in FIG. 8, the base end side cutout surface 33b forming the insertion recess 33 is more than the front end side cutout surface 33a than the first shield. It is configured to incline toward the base end side of the tubular body 21, and the distance along the direction of the axis L between the notch surfaces 33a and 33b gradually increases from the inner side of the insertion recess 33 toward the opening side. Because of the configuration, the electric wire 6 to be measured can be easily inserted into the insertion recess 33.

  Then, the hand (finger) is released from the knob portion 32c. As a result, the external force F1 applied to the knob portion 32c disappears, and thus the urging force F2 of the urging member 31 pushes the connecting pin 30 in the guide cylinder 29 toward the first shield cylinder 21. Further, the detection electrode 23 is pushed by the connecting pin 30 so that the inside of the first shield cylinder 21 is directed toward the first lid 25, and as shown in FIGS. And slides to the position where the electric wire 6 to be measured is sandwiched between the and the notch surface 33a on the tip side. By the above, the clamping work (mounting work) of the detection probe 1 to the measurement target electric wire 6 is completed.

  Here, in this detection probe 1, as shown in FIG. 6, when the measurement target electric wire 6 is sandwiched between the tip surface 23a of the detection electrode 23 and the tip side notch surface 33a, it is formed on the second shield cylinder 22. The formed second guide hole 34 is shielded by the flange portion 32b arranged outside the second shield tubular body 22. Therefore, in this detection probe 1, the influence of disturbance on the detection electrode 23 (for example, the influence from another conductor) is compared with the configuration in which the second guide hole 34 is not shielded in the state where the measurement target electric wire 6 is sandwiched. It is possible to reduce it sufficiently.

  In this detection probe 1, the electric wire 6 to be measured is thus sandwiched, so that the electric wire 6 to be measured is maintained in the insertion recess 33. 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 tip surface 23a of the detection electrode 23, which is 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) varies greatly is sufficiently avoided. As a result, the detection probe 1 can accurately detect the voltage V1 of the measurement target electric wire 6 only by capacitively coupling the detection electrode 23, which is an electrode for the detection, to each other without directly contacting the core wire 6a of the measurement target electric wire 6 with each other. It is configured so that it can function as a so-called conductor (metal) non-contact type voltage detection probe that can detect a voltage.

  Further, particularly in this detection probe 1, as shown in FIG. 8 and the like, the tip-side cutout surface 33a for sandwiching the measurement target electric wire 6 is inclined toward the base end side of the first shield tubular body 21 with reference to the reference plane PL. (That is, the angle θ1 between the axis L and the tip-side notch surface 33a is an acute angle), it cooperates with the tip surface 23a of the detection electrode 23 formed on a plane parallel to the reference plane PL. Thus, the gap between the tip-side cutout surface 33a that holds the measurement target electric wire 6 and the tip surface 23a can be gradually narrowed from the inner side of the insertion recess 33 toward the opening side. As a result, in the detection probe 1, it is possible to more reliably maintain the state in which the measurement target electric wire 6 is inserted into the insertion recess 33.

  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, the detection electrode unit 3 The respective voltages of the third lid 27, the second shield cylinder 22, the second lid 26, the first shield cylinder 21 and the first lid 25. That is, the potential difference Vdi from the voltage of the voltage signal V4) increases. When the potential difference Vdi is increasing due to the increase of the voltage V1 (for example, when the potential difference Vdi is increasing), the voltage detecting unit 53 of the main body unit 4 causes the current-voltage conversion circuit from the measurement target electric wire 6 via the detection electrode 23. The current amount of the 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 to the inverting input terminal via the capacitor increases due to the decrease in the detected voltage signal V2. Therefore, the integration circuit 53b raises the voltage of the integration signal V3. Further, as the voltage of the integrated signal V3 rises, the transistor of the drive circuit 53c shifts to the deep ON state. As a result, in the insulating circuit 53d (photocoupler), the current flowing through the light emitting diode increases and the resistance of the phototransistor decreases. Therefore, 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 has a reduced voltage value.

  Further, in the main body unit 4, the voltage generation unit 55 increases the voltage value of the generated voltage signal V4 based on the integrated signal V3a. In this measurement device 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 form the feedback loop in this way detect an increase in the voltage V1 of the measurement target electric wire 6. Then, by performing the feedback control operation of increasing the voltage value of the voltage signal V4, the voltage of the second reference potential G2 or the like of the voltage detection unit 53 (the voltage of the voltage signal V4) is made to follow the voltage V1.

  Further, when the potential difference Vdi increases due to the decrease in the voltage V1, the current amount of the current signal I flowing out (flowing out) from the current-voltage conversion circuit 53a to the measurement target electric wire 6 via the detection electrode 23 increases. At this time, the current-voltage conversion circuit 53a or the like forming the feedback loop executes a feedback control operation that is the reverse of the above feedback control operation to reduce the voltage of the voltage signal V4, thereby performing voltage detection. The voltage of the second reference potential G2 or the like of the portion 53 (the voltage of the voltage signal V4) is caused to follow the voltage V1.

  In this way, in the measuring device MD, the feedback control operation of causing the voltage of the second reference potential G2 or the like of the voltage detection unit 53 (the voltage of the voltage signal V4) to follow the voltage V1 is executed in a short time, and the voltage detection unit is executed. The voltage such as the second reference potential G2 of 53 (which is also the voltage of the detection electrode 23 due to the virtual short circuit of the first operational amplifier of the current-voltage conversion circuit 53a) is matched (converged) with 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 on the voltage V1 of the electric wire 6 to be measured, each constituent element of the feedback loop operates as described above to follow the fluctuation of the voltage V1. Therefore, the voltage data Dv indicating the voltage V1 of the electric wire 6 to be measured is continuously output from the voltmeter 56.

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

  Here, in the detection probe 1, as described above, the second guide hole 34 of the second shield tubular body 22 is shielded by the flange portion 32b when the measurement target electric wire 6 is held (the state shown in FIG. 6). Therefore, the influence of the disturbance on the detection electrode 23 (for example, the influence from other conductors) is sufficiently reduced. Therefore, the detection probe 1 can accurately measure the voltage V1.

  Subsequently, when measuring the voltage V1 of the other electric wire 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 to move the operation lever 32 to the grip portion 2. By sliding (sliding) in the same direction as the detection electrode 23 by sliding toward the base end direction, the tip side notch surface 33a of the insertion recess 33 and the tip end surface 23a of the detection electrode 23 are formed. The clamped state of the electric wire 6 to be measured is eliminated. Then, the electric wire 6 to be measured is removed from the inside of the insertion recess 33 (the clamped state of the electric wire 6 to be measured is released). This allows the detection probe 1 to be attached (clamped) to the next electric wire 6 to be measured.

  As described above, the detection probe 1 and the measuring device MD are attached to the column portion 32a of the operation lever 32 and configured to be movable according to the movement operation on the operation lever 32, and when the measurement target electric wire 6 is clamped. A flange portion 32 b that shields the second guide hole 34 of the second shield tubular body 22 is arranged outside the second shield tubular body 22. Therefore, according to the detection probe 1 and the measurement device MD, the influence of the disturbance on the detection electrode 23 is sufficiently reduced as compared with the configuration in which the second guide hole 34 is not shielded while the measurement target electric wire 6 is sandwiched. As a result, the voltage V1 of the measurement target electric wire 6 can be accurately measured.

  Further, in the detection probe 1 and the measuring device MD equipped with the detection probe 1, the detection probe 1 is located on the tip end side of the cutout surfaces 33a, 33b, 33c of the first shield cylindrical body 21 forming the insertion recess 33. The notch surface 33a on the tip end side is configured to be inclined toward the base end portion with reference to the reference plane PL. Therefore, according to this detection probe 1 and this measurement device MD, the measurement target electric wire 6 inserted into the insertion recess 33 is pressed against the tip side notch surface 33a by the tip surface 23a of the detection electrode 23 (tip surface). It is possible to make it difficult for the electric wire 6 to be measured to come off from the insertion concave portion 33 in a state where it is sandwiched between 23a and the notch surface 33a on the tip side.

  In addition, in the detection probe 1 and the measuring device MD including the detection probe 1, the position is located on the proximal end side of the cutout surfaces 33a, 33b, 33c of the first shield cylindrical body 21 forming the insertion recess 33. The base end side cutout surface 33b is inclined toward the base end side with respect to the front end side cutout surface 33a with reference to the reference plane PL. Therefore, according to this detection probe 1 and this measuring device MD, the effect when the tip side notch surface 33a is tilted as described above (the effect that the measurement target electric wire 6 cannot be easily removed from the insertion recess 33) is maintained. At the same time, the distance between the cutout surfaces 33a and 33b along the direction of the axis L is gradually increased as the distance from the backside cutout surface 33c (the backside cutout surface forming the insertion recess 33) is increased. Since the opening width of the insertion recess 33 can be gradually increased, the ease of inserting the measurement target electric wire 6 into the insertion recess 33 can be improved.

  Further, according to the detection probe 1 and the measuring device MD equipped with the detection probe 1, the electric wire 6 to be measured inserted in the insertion recess 33 is moved by the urging force of the urging member 31 to the first shield cylindrical body 21. Since it can be sandwiched between the tip-side cutout surface 33a of the device and the tip surface 23a of the detection electrode 23, the electric wire 6 to be measured is located in the insertion recess 33 even when the detection probe 1 is released. As a result of the state being maintained, workability in measuring the voltage V1 can be improved.

  Further, in the detection probe 1 described above, the tip 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 tip end side of the first shield tubular body 21. It is also possible to adopt a configuration in which it is formed on a slope. According to the detection probe 1 of this configuration and the measuring device MD equipped with this detection probe 1, the measurement target electric wire 6 inserted into the insertion recess 33 is pressed against the tip-side cutout surface 33a by the tip surface 23a of the detection electrode 23. In this state (the state in which the measurement target electric wire 6 is sandwiched between the front end surface 23a and the front end side cutout surface 33a), the electric wire 6 to be measured can be further prevented from coming off from the insertion recess 33.

  Further, in the detection probe 1 described above, each notch surface 33a, 33b is configured to be inclined toward the base end side of the first shield tubular body 21 with the reference plane PL as a reference, but is not 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, or although not shown, the tip-side notch surface 33a is parallel to the reference plane PL, and A configuration in which the proximal cutout surface 33b is inclined toward the proximal end portion, or a configuration in which the distal cutout surface 33a is inclined toward the proximal end portion and the proximal cutout surface 33b is parallel to the reference plane PL. Can also be adopted.

  Further, in the detection probe 1 (that is, the detection electrode unit 3), as shown in FIGS. 8 and 10, the tip end surface 23a of the detection electrode 23 and the core wire 6a of the measurement target electric wire 6 are capacitively coupled ( (Capacitively coupled state), that is, in a state where the electric wire 6 to be measured is sandwiched between the tip-side notch surface 33a and the tip surface 23a in the insertion recess 33, a shield member (a member having the same potential as the shield conductor 5b). Although there is a possibility that the electric wire 6 to be measured may be slightly affected by the disturbance through the opening portion of the insertion concave portion 33 in which there is no such a possibility, it is preferable to reduce this possibility as much as possible.

  Therefore, like the detection electrode unit 3 having the configuration shown in FIG. 12, the outer peripheral surface of the detection electrode 23 that is in contact with the inner surface of the first shield cylinder 21 (in this example, the detection covered with the insulating coating 24). By adopting a structure in which the outer peripheral surface of the electrode 23 (the surface of the insulating coating 24) is further covered with the conductor layer 36, the first shield cylinder 21 is brought into contact (electrical contact) with the inner surface of the first shield cylinder 21. A part of the opening portion of the insertion recess 33 is closed at a portion exposed from the opening portion of the insertion recess 33 in the conductor layer 36 that functions as the above-mentioned shield member by having the same potential as the insertion recess 33 (the insertion recess 33 (The area of the area where the shield member does not exist in the opening portion of 1) can be reduced) to further reduce the influence of disturbance on the measurement target electric wire 6. In this case, the conductor layer 36 is made of a conductive metal material. With, it can be formed on the surface of the insulating coating 24 with a thickness of for example less than 0.1 mm (about 0.01mm as one example).

  Further, the measuring device MD may be configured to have a current measuring function in addition to the voltage measuring function, and further, to measure resistance based on the measured voltage value and current value and to measure power. It may be configured to have another measurement function such as a power measurement function.

  Next, a voltage detection probe 101 (hereinafter, also simply referred to as “detection probe 101”) shown in FIGS. 13 and 14 as another example of the detection probe will be described. In addition, in the following description, the same components as those of the detection probe 1 described above will be denoted by the same reference numerals, and redundant description will be omitted. In this detection probe 101, the second shield tubular body 22 is fixed to the grip portion 2. Moreover, in this detection probe 101, as shown in both figures, the first shield cylinder 21 is movable with respect to the second shield cylinder 22 (that is, with respect to the grip portion 2) along the direction of the axis L. Is configured. Further, in this detection probe 101, the detection electrode 23 is fixed to the grip portion 2.

  In this case, as shown in FIG. 13, when the first shield tubular body 21 is moved to the base end portion (the right end portion in the figure) side of the grip portion 2, the tip end surface 23a of the detection electrode 23 is The insertion recess 33 is closed at the tip end (first lid 25) side of the first shield cylinder 21. Further, as shown in FIG. 14, when the first shield tubular body 21 is moved toward the tip end portion (the left end portion in the figure) of the grip portion 2, the tip end surface 23a of the detection electrode 23 is the first end. The insertion recess 33 is opened apart from the tip of the shield cylinder 21.

  Further, in this detection probe 101, as shown in FIGS. 13 and 14, the operation lever 32 is formed at the column portion 32a inserted into the second guide hole 34 of the second shield cylinder 22 and at the tip of the column portion 32a. And a knob portion 32c that has been formed. These members are integrally formed by using an insulating material. In addition, the end portions (the lower end portions (not shown) in FIGS. 13 and 14 on the lower side in FIGS. 13 and 14) of the column portion 32a extending inward of the second shield tubular body 22 and the third shield tubular body 123 described later are the first shield tubular bodies. It is connected to 21.

  In addition, in this detection probe 101, as shown in FIGS. 13 and 14, inside the second shield cylinder 22 (the second shield cylinder 22 is shown by a broken line in both figures) (the second shield cylinder). A tubular (cylindrical as an example) third shield tubular body 123 is disposed along the inner surface of 22. The third shield tubular body 123 is attached to the column portion 32 a of the operation lever 32. Therefore, the third shield tubular body 123 is moved (slipped) along the inner surface of the second shield tubular body 22 in a state of being in contact with the inner surface of the second shield tubular body 22 in response to a moving operation on the operation lever 32. In this case, the third shield tubular body 123 is formed in a tubular shape (for example, a cylindrical shape) using a conductive material (for example, the same material as the material forming the second shield tubular body 22). By contacting the shield cylinder 22, the potential is the same as that of the second shield cylinder 22. The length of the third shield cylinder 123 is similar to the length of the second guide hole 34 in the second shield cylinder 22 (the length along the moving direction of the operation lever 32 (the direction of the axis L)). Is formed in. The third shield cylinder 123 has the second guide hole 34 in a state where the electric wire 6 to be measured is sandwiched by the tip-side cutout surface 33a of the insertion recess 33 and the end surface 23a of the detection electrode 23 (the state shown in FIG. 15). And functions as a third shield body that shields.

  Further, in this detection probe 101, as shown in FIGS. 13 and 14, a biasing member 131 is arranged between the second lid body 26 and the third shield tubular body 123 in the second shield tubular body 22. ing. The urging member 131 is composed of a compression coil spring made of a conductive material (for example, a metal material) as an example, and is accommodated in a contracted state (a compressed state). With this configuration, the third shield tubular body 123, the operation lever 32 attached to the third shield tubular body 123, and the first shield tubular body 21 connected to the column portion 32a of the operation lever 32 are the biasing members. It is urged toward the base end side of the grip portion 2 by 131. It is also possible to adopt a configuration in which the biasing member 131 formed of a tension coil spring is arranged between the third lid body 27 and the third shield tubular body 123 in the second shield tubular body 22.

  When measuring the voltage V1 of the electric wire 6 to be measured using the measuring device MD equipped with this detection probe 101, first, an external force F1 in the direction of the arrow shown in FIG. 13 is applied to the knob portion 32c of the operating lever 32 with a finger. , The knob portion 32c is moved from the position shown in the figure to the position shown in FIG. 14 against the urging force of the urging member 131 (moving operation with respect to the operation lever 32). At this time, the first shield cylinder 21 is moved in the direction of the arrow shown in the figure in accordance with this moving operation. As a result, the insertion recess 33 shifts from the state in which the detection electrode 23 is closed (the state shown in FIG. 13) to the state in which it is opened (the state shown in FIG. 14). Next, as shown in FIG. 15, the electric wire 6 to be measured is inserted into the insertion recess 33 that is in the open state.

  Then, the finger is released from the knob portion 32c. At this time, as shown in FIG. 15, the third shield cylinder 123, the operating lever 32, and the first shield cylinder 21 are pushed toward the base end side of the grip portion 2 by the urging force F2 of the urging member 31. To be made. As a result, as shown in the figure, the electric wire 6 to be measured is clamped by the tip end surface 23a of the detection electrode 23 and the tip end side notch surface 33a of the insertion recess 33. By the above, the clamping work (mounting work) of the electric wire 6 to be measured by the detection probe 101 is completed. Then, each unit of the main body unit 4 executes each process, and thereby the voltage V1 of the measurement target electric wire 6 is measured.

  Here, in this detection probe 1, as shown in FIG. 15, when the electric wire 6 to be measured is sandwiched between the tip surface 23a of the detection electrode 23 and the tip side notch surface 33a of the insertion recess 33, the second shield tube The second guide hole 34 formed in the body 22 is shielded by the third shield cylindrical body 123 arranged inside the second shield cylindrical body 22. For this reason, even in the detection probe 101 and the measurement device MD including the detection probe 101, the disturbance to the detection electrode 23 is reduced as compared with the configuration in which the second guide hole 34 is not shielded in the state where the measurement target electric wire 6 is held. As a result of being able to sufficiently reduce the influence (for example, the influence from other conductors), the voltage V1 of the measurement target electric wire 6 can be accurately measured.

  Further, in the detection probe 101 and the measuring device MD provided with the detection probe 101, the first shield cylinder 21 is configured to be movable along the direction of the axis L. In this case, in the configuration in which the detection electrode 23 is moved, in order to connect the support column 32a of the operation lever 32 to the detection electrode 23, a guide hole through which the support column 32a is inserted (the second guide hole 34 of the second shield cylinder 22). It is necessary to form a guide hole similar to the above) 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 device MD that move the first shield cylinder 21, it is not necessary to form the guide hole in the first shield cylinder 21, so the detection electrode 23 is moved by that amount. The shield effect can be enhanced more than that.

  Further, according to the detection probe 101 and the measuring device MD equipped with the detection probe 101, the third shield cylinder 123 is disposed inside the second shield cylinder 22 so that the third shield cylinder 123 is removed. Unlike the configuration in which the third shield cylinder 123 is arranged outside the second shield cylinder 22, a space for disposing the third shield cylinder 123 outside the second shield cylinder 22 is provided in the second shield cylinder 22 and the grip portion 2. Since it is not necessary to provide it between the second shield cylindrical body 123 and the third shield cylindrical body 123, the detection probe 101 can be downsized as compared with the configuration in which the third shield cylindrical body 123 is arranged outside the second shield cylindrical body 22.

  Further, according to the detection probe 101 and the measuring device MD including the detection probe 101, the detection electrode 23 can be surrounded by the third shield cylindrical body 123 by forming the third shield cylindrical body 123 in a cylindrical shape. Therefore, the shield effect of the third shield cylinder 123 can be further enhanced.

  The configuration of the voltage detection probe is not limited to the above configuration. For example, in the above-described voltage detection probe 1 (configuration in which the detection electrode 23 is moved along the direction of the axis L), the flange portion 32b functioning as the third shield body is arranged inside the second shield tubular body 22. Alternatively, it is possible to adopt a configuration in which the second shield tubular body 22 is provided both inside and outside. Further, in the voltage detection probe 1 described above, a tubular (cylindrical) third shield body may be employed instead of the flange portion 32b. Further, in the above-described detection probe 101 (the configuration in which the first shield tubular body 21 is moved along the direction of the axis L), the configuration in which the third shield tubular body 123 is arranged outside the second shield tubular body 22 and the inside It is also possible to adopt a configuration in which it is arranged both on the outside and outside. Further, in the above-described detection probe 101, a third shield body having a circular arc section (trough shape) can be adopted instead of the third shield tube body 123 having a tubular shape.

  Further, although the example in which the detection probes 1 and 101 are provided with the grip portion 2 is described above, a detection probe not provided with the grip portion 2 (a detection probe configured only with the detection electrode unit 3) can be adopted. . In this configuration, for example, the detection probe (detection electrode unit 3) is used by being fixed to the housing that houses the main body unit 4, or the detection probe (detection electrode unit 3) is used by being fixed to the moving mechanism. The present invention can be applied to a usage mode in which the moving mechanism is operated to clamp the electric wire 6 to be measured.

1,101 Detection probe
2 grip part
5 Shielded cable 5a Core wire 5b Shield conductor
6 Wire to be Measured 16 First Guide Hole 21 First Shield Cylindrical Body 22 Second Shield Cylindrical Body 23 Detecting Electrode 24 Insulation Coating 32 Operation Lever 32a Support Part 32c Knob 33 Insertion Recess 33a Tip Cutout 33b Base Cut Notch surface 34 Second guide hole 123 Third shield cylinder
L axis PL Reference plane

Claims (10)

A cylindrical first shield having conductivity, in which a part of the outer peripheral wall at the tip portion is cut out along the direction intersecting the axis to insert an insertion recess into which the electric wire to be measured can be inserted is formed. Body and
A tubular second shield body having conductivity, into which the base end side of the first shield body is inserted;
A detection electrode which is formed of a conductive columnar body having a tip end surface and an outer peripheral surface covered with an insulating coating and is housed in the first shield body;
One of the first shield body and the detection electrode is configured to be movable along the direction of the axis according to a movement operation of an operation lever, and is connected to the measurement target electric wire inserted in the insertion recess. A measurement in which the inserted electric wire to be measured is sandwiched between the insertion concave portion and the tip surface when the insulation coating on the tip surface abuts, and the tip surface is inserted through the insulation coating . It is configured so that it can be capacitively coupled to the target wire,
The operation lever includes a knob portion and a column portion that is inserted into a guide hole formed in the second shield body and is connected to one of the two.
At least one of the inner side and the outer side of the second shield body is attached to the column portion and configured to be movable according to the moving operation of the operation lever, and when the inserted electric wire to be measured is clamped. A voltage detection probe in which a third shield body that shields the guide hole is provided.   The voltage detection probe according to claim 1, wherein the first shield body is configured to be movable along the direction of the axis.   The voltage detection probe according to claim 1, wherein the third shield body is arranged inside the second shield body.   The voltage detection probe according to claim 1, wherein the third shield body is formed in a cylindrical shape.   Of the cutout surfaces of the first shield body forming the insertion recessed portion, a tip side notch surface located on the tip end side is inclined toward the base end side with reference to a reference plane orthogonal to the axis. The voltage detection probe according to any one of claims 1 to 4.   Of the cutout surfaces of the first shield body forming the insertion recessed portion, the proximal end side cutout surface located on the proximal end portion side is more than the distal end side cutout surface with respect to the reference plane. The voltage detection probe according to claim 5, which is inclined toward the base end side. A biasing member that constantly biases the detection electrode in the insertion recess direction,
The detection electrode is slid in the first shield body in the insertion recess direction by the urging force of the urging member, and the tip of the cutout surface of the first shield body forming the insertion recess is formed. between the front end side cutout surface located on part side of the front end surface, the voltage detection probe according to any one of claims 1 to 6 for holding the constant target wire measurement that have been the insertion.   The voltage detection probe according to claim 1, wherein the tip end surface is inclined toward the tip end side with reference to a reference plane orthogonal to the axis. The outer peripheral surface of the detection electrode exposed from the insertion recess to the outside of the first shield body in the capacitively coupled state with the inserted electric wire to be measured is covered with the first shield body. The voltage detection probe according to any one of claims 1 to 8, which is covered with a conductor layer that electrically contacts. The voltage detection probe according to any one of claims 1 to 9,
A main unit connected to the voltage detection probe,
A voltage detection unit disposed in the main body unit, which detects the voltage of the inserted measurement target electric wire via the detection electrode and outputs a voltage signal that changes according to the voltage,
A voltage generator disposed in the main body unit, which generates a voltage that follows the voltage of the inserted electric wire to be measured based on the voltage signal;
A processing unit disposed in the main body unit, for measuring the voltage of the inserted electric wire to be measured based on the voltage generated by the voltage generation unit,
The voltage detection unit is a measuring device that operates with a floating voltage based on a potential of the voltage generated by the voltage generation unit.

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