Sensors

Abstract

To avoid a fall in detection accuracy of an amount to be detected caused by a difference in diameter (external diameter) of a detection object wire.SOLUTION: Abutting surfaces F1 and F2 formed respectively in a plane parallel with an insertion direction of a detection object wire with respect to a notch 21a and across a tubular length direction of a wire insertion part 4 and an electrode holding part 3 are provided on a tip part 4a side within the notch part 21a of the wire insertion part 4. The abutting surfaces F1 and F2 are inclined respectively so that a first virtual extension plane of the abutting surface F1 and a second virtual extension plane of the abutting surface F2 are across each other on a virtual plane passing through a center part of an electrode in a direction orthogonal to both the insertion direction and tubular length direction and parallel with both the insertion direction and tubular length direction, and are located gradually closer to the tip part 4a side toward an intersection portion of the first virtual extension plane and the second virtual extension plane.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a sensor capable of detecting a quantity to be detected in an electric wire to be detected without contacting the conductor of the electric wire to be detected. [Background technology]

[0002] As this type of sensor, the applicant has disclosed a voltage detection probe (hereinafter simply referred to as a "detection probe") capable of detecting the voltage of a measurement target electric wire (detection target electric wire) without contacting the core wire in the following patent document.

[0003] This detection probe is configured to include a grip portion held by a user, and a detection electrode unit connected to the main unit via a shielded cable. The detection electrode unit also includes a first shield cylinder having an insertion recess (notch) into which a measurement target electric wire can be inserted, a detection electrode whose surface is covered with an insulating coating and inserted slidably into the first shield cylinder, a second shield cylinder fixed to the inside of the grip portion and through which the first shield cylinder is inserted, an operation lever connected to the detection electrode and for sliding the detection electrode relative to the first shield cylinder, the second shield cylinder, and the grip portion, and a biasing member for biasing the detection electrode toward the tip portion.

[0004] When using this detection probe to detect the voltage of the core wire of the electric wire to be measured, the detection probe is attached to the electric wire to be measured. Specifically, first, the operating lever is pulled toward the user while holding the grip portion, and the detection electrode is slid toward the user within the first shield cylinder. This makes it possible to insert the electric wire to be measured into the insertion recess. Next, the user inserts the electric wire to be measured into the insertion recess while holding the operating lever, and then releases the operating lever. At this time, the detection electrode is slid toward the tip side of the first shield cylinder by the biasing force of the biasing member, and the electric wire to be measured is sandwiched between the tip surface of the detection electrode and the tip side notched surface (inner end surface) of the first shield cylinder. This completes the attachment of the detection probe to the electric wire to be measured, and the core wire of the electric wire to be measured and the detection electrode of the detection probe are capacitively coupled, making it possible to detect the voltage of the electric wire to be measured (core wire).

[0005] In this case, in the detection probe disclosed by the applicant, the above-mentioned insertion recess is formed by three surfaces, the tip-side notch surface, the base-side notch surface, and the back-side notch surface. The tip-side notch surface is inclined so that the end of the mouth side of the insertion recess is located on the base end side of the first shield cylinder, and is located closer to the tip end side of the first shield cylinder as it approaches the back-side notch surface. Therefore, when the detection electrode is moved relative to the first shield cylinder toward the tip end of the first shield cylinder, the measurement target electric wire inserted in the insertion recess is pressed against the tip-side notch surface by the tip end surface of the detection electrode, and is moved inside the insertion recess toward the back-side notch surface while being guided by the tip-side notch surface, so that the measurement target electric wire is held (positioned) at three points, the tip-side notch surface, the back-side notch surface, and the tip end surface of the detection electrode. As a result, in the detection probe disclosed by the applicant, the measurement target electric wire is less likely to come off the insertion recess. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-009576 A (Pages 7-20, Figures 1-19) Summary of the Invention [Problem to be solved by the invention]

[0007] However, the detection probe disclosed by the applicant in the above patent document has the following problems to be solved. Specifically, the detection probe disclosed by the applicant employs a configuration in which the core wire of the electric wire to be measured and the detection electrode are capacitively coupled by pressing the tip face of the detection electrode against the electric wire to be measured that is inserted into the insertion recess (notch) of the first shield cylinder (electric wire insertion portion), thereby detecting the voltage of the electric wire to be measured (core wire).

[0008] In addition, in the detection probe disclosed by the applicant, as described above, the tip-side notched surface constituting the insertion recess is inclined so that its edge on the rim side is located on the base end side of the first shielding cylinder, and is located closer to the tip of the first shielding cylinder as it approaches the back-side notched surface, so that when the detection electrode presses the electric wire to be measured against the tip-side notched surface, the electric wire to be measured is moved within the insertion recess toward the back-side notched surface as if guided by the tip-side notched surface, and the electric wire to be measured is held (positioned) at three points: the tip-side notched surface, the back-side notched surface, and the tip surface of the detection electrode. In this case, in the detection probe disclosed by the applicant, the back-side notched surface is configured as a plane parallel to the moving direction of the detection electrode relative to the first shielding cylinder (the cylinder length direction of the first shielding cylinder).

[0009] Therefore, in this detection probe in which the electric wire to be measured is held at three points as described above, when detecting the voltage of an electric wire to be measured that has a large diameter (outer diameter), the distance between the center of the electric wire to be measured (core wire) and the rear notched surface of the insertion recess becomes large, so that the center of the electric wire to be measured (core wire) is not positioned on an imaginary plane that passes through the center of the tip surface of the detection electrode and is parallel to both the insertion direction of the electric wire to be measured into the insertion recess and the tube length direction of the first shield cylinder (movement direction of the detection electrode). Also, when detecting the voltage of an electric wire to be measured that has a small diameter (outer diameter), the distance between the center of the electric wire to be measured (core wire) and the rear notched surface of the insertion recess becomes small, so that the center of the electric wire to be measured (core wire) is not positioned on the imaginary plane. In other words, in the detection probe disclosed by the applicant, the positional relationship between the core of the electric wire to be measured and the center of the tip surface of the detection electrode varies depending on the diameter (outer diameter) of the electric wire to be measured, and due to this difference in positional relationship, the state of capacitive coupling between the core and the detection electrode varies for each type (each diameter (outer diameter)) of the electric wire to be measured. Therefore, it is preferable to improve this point in order to improve the detection accuracy for electric wires to be measured having various diameters (outer diameters).

[0010] On the other hand, this type of detection probe (sensor) is also used when detecting a detectable quantity such as voltage for one of a plurality of electric wires arranged close to each other as the electric wire to be measured, or when detecting a detectable quantity for an electric wire arranged close to a board, casing, or the like as the electric wire to be measured. In this case, the detection probe disclosed by the applicant is configured to insert a detection electrode formed in a thin cylindrical shape into a first shielding cylinder formed in a thin cylindrical shape, so that the tip side part of the detection probe (the part where the insertion recess is formed) is in a thin rod shape. As a result, even when detecting a detectable quantity for an electric wire with other nearby objects such as other electric wires, boards, and casings as the electric wire to be measured, it is possible to insert the tip side part of the detection probe (first shielding cylinder) into the gap between the nearby objects and the electric wire to be measured, and insert the electric wire to be measured into the insertion recess.

[0011] However, in today's world where electronic devices are becoming smaller and the number of electric wires used is increasing, the gap between the nearby object and the electric wire to be measured may be narrower than the diameter of the tip end portion of the detection probe disclosed by the applicant. In such a case, for example, it is necessary to push aside either or both of the electric wire to be measured and the nearby object with one hand to enlarge the gap between the electric wire to be measured and the nearby object, and in that state, insert the tip end of the detection probe (first shield cylinder) held in the other hand into the gap to insert the electric wire to be measured into the insertion recess. For this reason, when the gap between the nearby object and the electric wire to be measured is narrow, the current situation is that the attachment work of the detection probe to the electric wire to be measured is complicated.

[0012] In this case, by modifying the configuration of the detection probe disclosed by the applicant to further reduce the diameter of the first shielding cylinder, it becomes possible to easily insert the tip of the detection probe (first shielding cylinder) even when the gap between the nearby object and the electric wire to be measured is narrow. However, in order to reduce the diameter of the first shielding cylinder, it is necessary to reduce the diameter of the detection electrode inserted into the first shielding cylinder. As a result, the electrode surface of the detection electrode that faces the core wire of the conductor to be measured becomes narrow, and the detection sensitivity of the measured quantity decreases.

[0013] In addition, if the outer diameter of the first shielding cylinder is reduced without reducing the diameter of the detection electrode, the first shielding cylinder becomes thin, making it difficult to ensure sufficient physical strength and susceptible to disturbances (intrusion of noise into the detection electrode inside the first shielding cylinder). Furthermore, by reducing the diameter only of the tip side of the first shielding cylinder from the insertion recess, it becomes possible to easily insert the tip of the detection probe (first shielding cylinder) into the gap between the nearby object and the electric wire to be measured without reducing the diameter of the detection electrode or reducing the thickness of the first shielding cylinder. However, since the portion of the first shielding cylinder that shields the electrode surface of the detection electrode (the portion facing the electrode surface in the first shielding cylinder) becomes small, it becomes susceptible to disturbances (intrusion of noise into the detection electrode).

[0014] The present invention has been made in consideration of the above-mentioned problems to be solved, and has as its main object to provide a sensor that can suitably avoid a decrease in the detection accuracy of the detection quantity caused by differences in the diameter (outer diameter) of the electric wire to be detected. Another object of the present invention is to provide a sensor that can easily insert the electric wire to be detected, with a small gap between it and a nearby object, into the notch without causing a decrease in physical strength, detection sensitivity, and shielding performance. [Means for solving the problem]

[0015] In order to achieve the above object, the sensor according to claim 1 includes an electrode, an electrode holding section formed in a cylindrical shape into which the electrode can be inserted, and an electric wire insertion section formed in a cylindrical shape from a conductive material into which the electrode holding section can be inserted and configured to allow a detection target electric wire to be inserted into a notch formed by cutting out a part of a peripheral wall at a tip end portion, the sensor being configured to be able to move the electric wire insertion section relatively to the electrode holding section along the cylindrical length direction of the electrode holding section and the electric wire insertion section, and to be able to detect a detection amount of the detection target electric wire via the electrode in a non-contact state with a conductor within an insulating coating of the detection target electric wire by bringing the electrode held by the electrode holding section relatively close to the detection target electric wire inserted into the electric wire insertion section. The wire insertion portion has a first wire abutment surface and a second wire abutment surface, each formed on a plane parallel to the insertion direction of the electric wire to be detected into the notch and intersecting the tube length direction, provided on the tip side of the wire insertion portion within the notch, and the first wire abutment surface and the second wire abutment surface are inclined so that on a virtual plane that passes through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction and is parallel to both the insertion direction and the tube length direction, a first virtual extension plane of the first wire abutment surface and a second virtual extension plane of the second wire abutment surface intersect with each other and are positioned closer to the tip side as they approach the intersection point between the first virtual extension plane and the second virtual extension plane.

[0016] The sensor of claim 2 is the sensor of claim 1, wherein the first wire abutment surface and the second wire abutment surface are formed so that the first virtual extension plane and the second virtual extension plane intersect with each other on the virtual plane passing through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction.

[0017] The sensor according to claim 3 is the sensor according to claim 1 or 2, wherein the first electric wire abutting surface and the second electric wire abutting surface are arranged such that a first intersection angle between the first imaginary extension plane and the imaginary plane, and The second virtual extension plane and the virtual plane are inclined such that a second intersection angle between them is equal to each other.

[0018] The sensor according to claim 4 includes an electrode, an electrode holding section formed in a cylindrical shape so that the electrode can be inserted therein, and an electric wire insertion section formed in a cylindrical shape from a conductive material so that the electrode holding section can be inserted therein and configured so that a detection target electric wire can be inserted into a notch formed by cutting out a part of a peripheral wall at a tip end side portion, and configured so that the electric wire insertion section can be moved relatively to the electrode holding section along a cylindrical length direction of the electrode holding section and the electric wire insertion section, and configured so that the electrode held by the electrode holding section can be brought relatively close to the detection target electric wire inserted into the electric wire insertion section, thereby detecting a detection amount of the detection target electric wire via the electrode in a non-contact state with a conductor within an insulating coating of the detection target electric wire. a first electric wire abutment surface and a second electric wire abutment surface, each formed on a surface parallel to the insertion direction of the electric wire to be detected into the notch and intersecting the tube length direction, are provided in the electric wire insertion portion within the notch on the tip side of the electric wire insertion portion, the first electric wire abutment surface and the second electric wire abutment surface are inclined such that the first electric wire abutment surface and the second electric wire abutment surface are in contact with each other on an imaginary plane that passes through a center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction and is parallel to both the insertion direction and the tube length direction, and the distance between the first electric wire abutment surface and the second electric wire abutment surface along the tube diameter direction of the electric wire insertion portion becomes shorter toward the tip side.

[0019] The sensor of claim 5 is the sensor of claim 4, wherein the first wire abutment surface and the second wire abutment surface are formed to be in contact on the imaginary plane passing through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction.

[0020] The sensor of claim 6 is the sensor of claim 5, wherein the first wire abutment surface and the second wire abutment surface are formed to be linearly symmetrical with respect to the imaginary plane when the electrode holding portion is viewed along the insertion direction.

[0021] The sensor of claim 7 is a sensor of any one of claims 1 to 6, wherein the wire insertion portion has a maximum width along the insertion direction within a first range along the tube length direction from the tip to an edge of the notch on the tip side that is smaller than a maximum height along a direction perpendicular to both the tube length direction and the insertion direction, and a portion is provided in a second range along the tube length direction from the edge of the notch on the tip side to an edge of the notch on the rear end side of the wire insertion portion in the notch where the width along the insertion direction gradually increases, and the tip side portion is formed such that within a third range toward the rear end side of the edge of the notch on the rear end side, the minimum width along the insertion direction and the minimum height along a direction perpendicular to both the tube length direction and the insertion direction are both greater than the maximum width in the first range.

[0022] The sensor of claim 8 is the sensor of claim 7, wherein the tip side portion of the electric wire insertion portion is formed so that the maximum width in the first range is greater than or equal to the width along the insertion direction of the electrode surface of the electrode that is brought close to the electric wire to be detected. Effect of the Invention

[0023] In the sensor described in claim 1, a first electric wire abutment surface and a second electric wire abutment surface, each formed on a plane parallel to the insertion direction of the electric wire to be detected into the notch and intersecting the tube length direction, are provided on the tip side of the electric wire insertion portion within the notch, and a first imaginary extension plane of the first electric wire abutment surface and a second imaginary extension plane of the second electric wire abutment surface intersect on an imaginary plane that passes through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction and is parallel to both the insertion direction and the tube length direction, and are each inclined so as to be located closer to the tip side as it approaches the intersection point of the two imaginary extension planes.

[0024] In the sensor described in claim 4, a first electric wire abutment surface and a second electric wire abutment surface, each formed on a surface parallel to the insertion direction of the electric wire to be detected into the notch and intersecting the tube length direction, are provided on the tip side of the electric wire insertion portion within the notch, and the first electric wire abutment surface and the second electric wire abutment surface are in contact on an imaginary plane that passes through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction and is parallel to both the insertion direction and the tube length direction, and are each inclined so that the distance between the first electric wire abutment surface and the second electric wire abutment surface along the tube diameter direction of the electric wire insertion portion becomes shorter toward the tip side.

[0025] Therefore, according to the sensor described in claims 1 and 4, when the electric wire to be detected inserted into the notch is moved relatively within the notch toward the tip side in accordance with the relative movement of the electrode with respect to the wire insertion portion, the electric wire to be detected is guided toward the other by either the first electric wire abutting surface or the second electric wire abutting surface whichever it comes into contact with first, and is ultimately held in a state of contact with three points, namely the tip surface of the electrode, the first electric wire abutting surface, and the second electric wire abutting surface. This makes it possible to preferably prevent the electric wire to be detected from being held in a state where its center (center of the core wire) is significantly misaligned from an imaginary plane that is parallel to the movement direction of the electrode with respect to the wire insertion portion and passes through the center of the tip surface of the electrode. As a result, for various types of electric wires to be detected that have different diameters (outer diameters), the positional relationship between the core wire and the center of the tip surface of the electrode can be maintained without significant difference, so that the detectable quantity of the electric wire to be detected (core wire) can be detected with high accuracy without causing a situation in which the state of capacitive coupling between the core wire of the electric wire to be detected and the electrode differs due to the above-mentioned difference in positional relationship.

[0026] In the sensor of claim 2, the first electric wire abutting surface and the second electric wire abutting surface are formed so that the first imaginary extension plane and the second imaginary extension plane intersect with each other on an imaginary plane passing through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction. In the sensor of claim 5, the first electric wire abutting surface and the second electric wire abutting surface are formed so as to be in contact with each other on an imaginary plane passing through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction. Therefore, the sensors of claims 2 and 5 can suitably prevent the electric wire to be detected from being held in a state in which the center of the electric wire to be detected (the center of the core wire) is significantly shifted from the imaginary plane passing through the center of the tip surface of the electrode. As a result, for various types of electric wires to be detected that have different diameters (outer diameters), the positional relationship between the core wire and the center of the tip surface of the electrode can be maintained without significant difference, so that the detectable quantity of the electric wire to be detected (core wire) can be detected with even greater accuracy without causing a situation in which the state of capacitive coupling between the core wire of the electric wire to be detected and the electrode differs due to the above-mentioned difference in positional relationship.

[0027] In the sensor described in claim 3, the first electric wire contact surface and the second electric wire contact surface are inclined so that the first intersection angle between the first imaginary extension plane and the imaginary plane and the second intersection angle between the second imaginary extension plane and the imaginary plane are equal to each other. In the sensor described in claim 6, the first electric wire contact surface and the second electric wire contact surface are formed so as to be symmetrical with respect to the imaginary plane when the electrode holder is viewed along the insertion direction. Therefore, the sensors described in claims 3 and 6 can reliably position the centers (centers of the cores) of various types of detection target electric wires having different diameters (outer diameters) on the imaginary plane. This makes it possible to detect the amount of the detection target electric wire (core) with higher accuracy.

[0028] In the sensor described in claim 7, within a first range along the tube length direction from the tip to the rim of the tip side of the notch, the maximum width along the insertion direction of the electric wire to be detected relative to the notch is smaller than the maximum height along the direction perpendicular to both the tube length direction and the insertion direction, and within a second range along the tube length direction from the rim of the tip side of the notch to the rim of the rear end side of the electric wire insertion portion in the notch, a portion is provided in which the width along the insertion direction gradually increases, and the tip side portion of the electric wire insertion portion is formed so that within a third range toward the rear end side of the rim of the rear end side of the notch, both the minimum width along the insertion direction and the minimum height along the direction perpendicular to both the tube length direction and the insertion direction are greater than the maximum width in the first range.

[0029] Therefore, according to the sensor of claim 7, even when the sensor is attached to a detection target electric wire with an extremely small gap between the sensor and the nearby object, the wire insertion part can be inserted into the gap so that the separation direction between the nearby object and the detection target electric wire is aligned with the width direction of the tip side part, thereby allowing the detection target electric wire to be inserted smoothly (i.e. easily) without applying a large stress to the detection target electric wire, etc. Also, even when the wire insertion part is inserted between the detection target electric wire and the nearby object until the detection target electric wire, etc. is positioned to the side of the notch, since a part whose width along the insertion direction gradually increases is provided within the second range, the tip side part can be inserted so as to gradually separate the detection target electric wire from the nearby object, allowing the detection target electric wire to be inserted smoothly (i.e. easily) without applying a large stress to the detection target electric wire, etc. Furthermore, since the width and height of the wire insertion portion in the third range are sufficiently large, the physical strength of the wire insertion portion is sufficiently high to effectively prevent noise from being mixed into the electrode in the wire insertion portion (i.e., without causing a decrease in shielding performance), and further, by arranging an electrode of sufficient thickness together with the electrode holding portion in the wire insertion portion, the detection sensitivity of the detectable quantity can be sufficiently increased.

[0030] According to the sensor of claim 8, the tip side part of the wire insertion part is formed so that the maximum width in the first range is equal to or greater than the width in the insertion direction of the electrode surface of the electrode that is brought close to the electric wire to be detected, so that the tip side part of the wire insertion part can suitably prevent the intrusion of noise from the extending direction of the electrode (direction perpendicular to the electrode surface). Also, the width in the insertion direction of the first electric wire abutting surface and the second electric wire abutting surface can be made sufficiently large, so that a sufficiently wide range in the length direction of the electric wire to be detected can be held by the tip part of the electrode and both electric wire abutting surfaces, so that it is possible to suitably avoid a situation in which a large stress is applied to the electric wire to be detected when the sensor is attached to the electric wire to be detected (when the electric wire to be detected is held by the sensor). [Brief description of the drawings]

[0031] [Figure 1] FIG. 2 is an external perspective view of the voltage sensor 1. [Diagram 2] 2 is another external perspective view of the voltage sensor 1. FIG. [Diagram 3] 2 is an enlarged perspective view of a tip portion of the voltage sensor 1. FIG. [Figure 4] 2 is another enlarged perspective view of the tip portion of the voltage sensor 1. FIG. [Diagram 5] 2 is an explanatory diagram for explaining the shape of an insertion portion main body 21 and the size of each portion of the electric wire insertion portion 4. FIG. [Figure 6] 13 is another explanatory diagram for explaining the shape of the insertion portion main body 21 and the size of each portion in the electric wire insertion portion 4. FIG. [Figure 7] 13 is still another explanatory diagram for explaining the shape of the insertion portion main body 21 and the size of each portion of the electric wire insertion portion 4. FIG. [Figure 8] 11 is an explanatory diagram for explaining guiding of the insulated electric wire Xa by the contact surfaces F1 and F2. FIG. [Figure 9] 2 is an enlarged side view of the tip of the voltage sensor 1 when not in use. [Figure 10]FIG. 1 is an explanatory diagram for explaining an operation of holding the insulated electric wire Xa arranged adjacent to the insulated electric wire Xb by the voltage sensor 1 (attaching the voltage sensor 1 to the insulated electric wire Xa). [Figure 11] FIG. 11 is another explanatory diagram for explaining the operation of holding the insulated electric wire Xa by the voltage sensor 1 (attaching the voltage sensor 1 to the insulated electric wire Xa). [Figure 12] 1 is an explanatory diagram for explaining a state in which the insulated electric wire Xa is held by the voltage sensor 1 (the voltage sensor 1 is attached to the insulated electric wire Xa). FIG. [Figure 13] 10 is an explanatory diagram for describing the shape of contact surfaces F1A, F2A in an electric wire insertion portion 4A of a voltage sensor 1A and guiding of an insulated electric wire Xa by the contact surfaces F1A, F2A. FIG. [Figure 14] 11 is an explanatory diagram for explaining the shape of contact surfaces F1B, F2B in an electric wire insertion portion 4B of a voltage sensor 1B and guiding of an insulated electric wire Xa by the contact surfaces F1B, F2B. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, an embodiment of the sensor will be described with reference to the accompanying drawings.

[0033] 1 and 2 is an example of a "sensor" and is configured to detect a voltage (an example of a "detectable quantity of the electric wire to be detected") supplied to a conductor (core) of a covered electric wire Xa (an example of an "electric wire to be detected": see Figs. 8, 10 to 12) whose conductor (core) is covered with an insulating coating and insulated, without contacting the conductor. This voltage sensor 1 includes an electrode 2, an electrode holding section 3, an electric wire insertion section 4 and a signal cable 5, and is configured so as to be attachable to the covered electric wire Xa to be detected (so that the covered electric wire Xa can be inserted therein), and is also configured so as to be connectable to a measuring device (not shown) via the signal cable 5.

[0034] The electrode 2 is an example of an "electrode" and is formed in a columnar shape (cylindrical in this example) from a conductive metal material as shown in FIG. 3. In a state where a tip 2a (tip surface) is pressed against the insulated electric wire Xa inserted into the electric wire insertion portion 4 as described later (an example of a state of "being brought close to a conductor in an insulating coating of an electric wire to be detected"), the electrode 2 is capacitively coupled with the conductor of the insulated electric wire Xa via the insulating coating of the insulated electric wire Xa. The electrode 2 is inserted into the holding portion main body 11 described later in the electrode holding portion 3 so that the tip 2a (tip surface) is exposed from the holding portion main body 11 and integrated with the holding portion main body 11 (an example of a configuration of "being held by the electrode holding portion in a state of being inserted into the electrode holding portion"), and a signal cable 5 is connected to the rear end portion within the holding portion main body 11. In this case, the signal cable 5 to which the electrode 2 is connected has a conductor (core wire) shielded by a shield wire (mesh wire) to prevent noise from being mixed into the conductor.

[0035] The electrode holding part 3 is an example of an "electrode holding part" and is formed in a tubular shape (cylindrical shape in this example) as a whole. The electrode holding part 3 includes a holding part main body 11 and an insulator 12, and is configured to be able to hold the electrode 2 such that the tip 2a (tip surface) of the electrode 2 is exposed from the tip of the holding part main body 11, and a holding part 11a (a grip part for a user to hold the voltage sensor 1 when using the voltage sensor 1) is provided on the rear end side of the holding part main body 11 as shown in Figs. 1 and 2.

[0036] In this case, the holding body 11 is formed of, for example, a metal material having electrical conductivity. The gripping portion 11a is formed in a tubular (cylindrical) shape from an insulating material (for example, insulating resin) so that the signal cable 5 can be inserted therethrough. The insulator 12 is formed in a tubular (cylindrical) shape so that the electrode 2 can be held relative to the holding body 11 while insulating the electrode 2 from the holding body 11 from each other.

[0037] 1 and 2, the electric wire insertion portion 4 is an example of an "electric wire insertion portion" and includes an insertion portion main body 21 disposed on the tip end 4a side and an operation knob 22 disposed on the rear end 4b side. In this case, the voltage sensor 1 of this example is configured, as an example, so that the electric wire insertion portion 4 (operation knob 22) can be slid relative to the electrode holding portion 3 (gripping portion 11a) along the tube length direction of the electrode holding portion 3 and the electric wire insertion portion 4 (an example of a configuration in which "the electric wire insertion portion can be moved relatively to the electrode holding portion along the tube length direction").

[0038] 3 to 7, the insertion portion main body 21 is formed, for example, in a tubular shape (cylindrical in this example) made of stainless steel (an example of a "material having electrical conductivity") into which the electrode holding portion 3 holding the electrode 2 can be inserted. The insertion portion main body 21 is a member that constitutes the "circumferential wall" in the area on the tip portion 4a side (an example of a "tip portion side area"), and is partially cut out to provide a notch 21a (an example of a "notch"), and is configured so that the coated electric wire Xa or the like can be inserted into the notch 21a.

[0039] 5 and 6, the insertion portion main body 21 is formed such that within a "first range (range of arrow Ca)" along the "tube length direction (left-right direction in both figures)" from the tip 4a of the wire insertion portion 4 (position of dashed line B1 in both figures) to the rim of the notch 21a on the tip 4a side (position of dashed line B2 in both figures), the "maximum width (in this example, width Wa in FIG. 6)" along the "insertion direction (up-down direction in FIG. 6)" of the insulated wire Xa relative to the notch 21a is smaller than the "maximum height (in this example, height Ha in FIG. 5)" along the direction perpendicular to both the "tube length direction" and the "insertion direction" (up-down direction in FIG. 5: hereinafter, this direction is also referred to as the "first direction").

[0040] Furthermore, the insertion portion main body 21 has a portion within a "second range (range of arrow Cb)" along the "tube length direction" from the edge of the notch 21a on the tip end 4a side (position of dashed line B2) to the edge of the notch 21a on the rear end 4b side of the wire insertion portion 4 (position of dashed line B3 in both figures), where the width of the insertion portion main body 21 along the "insertion direction" becomes larger toward the rear end 4b side.

[0041] In this case, the insertion portion main body 21 of this example is formed so that the width of the insertion portion main body 21 along the "insertion direction" from a position (the position of dashed line B2a in both figures) slightly closer to the rear end portion 4b than the rim portion (the position of dashed line B2) on the tip end 4a side of the notch 21a within the "second range (the range of arrow Cb)" is gradually increased toward the rear end portion 4b. In addition, in the insertion portion body 21 of this example, the portion on the rear end 4b side of the notch 21a is formed cylindrically, and as shown in Figures 3 to 5, the edge of the rear end 4b side of the notch 21a in side view is inclined so that it is positioned closer to the rear end 4b as it approaches the open end (upper end in Figure 5) of the notch 21a. As shown in Figure 6, in the "second range (range of arrow Cb)", at a position closer to the tip end 4a (the position of dashed line B3a in both figures) than the edge on the rear end 4b side of the notch 21a (the position of dashed line B3), the width of the insertion portion body 21 along the "insertion direction" is equal to the width Wb of the insertion portion body 21 at the edge on the rear end 4b side of the notch 21a (the position of dashed line B3). In other words, in the wire insertion portion 4 (insertion portion main body 21) of this example, the range along the "tube length direction" from the position of dashed line B2a to the position of dashed line B3a corresponds to the "region whose width gradually increases along the insertion direction."

[0042] In addition, the insertion body 21 is formed at a portion on the tip 4a side such that both the "minimum width (width Wb shown in FIG. 6 in this example)" along the "insertion direction" and the "minimum height (height Hb shown in FIG. 5 in this example)" along the "first direction" are larger than the aforementioned "maximum width (width Wa shown in FIG. 6)" in the "first range" within a "third range (range of arrow Cc)" on the rear end 4b side of the rim (position of arrow B3) on the rear end 4b side of the notch 21a. Furthermore, the insertion body 21 is formed at a portion on the tip 4a side such that the above-mentioned "maximum width (width Wa shown in FIG. 6)" in the "first range" is equal to or larger than the width along the "insertion direction" of the "electrode surface (end surface on the tip 2a side)" of the electrode 2 that is brought close to the coated electric wire Xa or the like (diameter R2 shown in FIG. 6 in this example where the electrode 2 is cylindrical). In this case, in the voltage sensor 1 of this example, the center in the "insertion direction" of the tip portion 4a of the wire insertion portion 4 and the center in the "insertion direction" of the electrode 2 inserted into the wire insertion portion 4 while being held by the electrode holding portion 3 are configured to coincide in the tube length direction of the electrode holding portion 3 and the wire insertion portion 4.

[0043] Moreover, the insertion section main body 21 is formed such that the width along the "insertion direction" in the above-mentioned "first range" decreases from the part of the maximum width Wa toward the tip 4a, and the tip 4a side part is located at the center in the width direction in a plan view (or bottom view). Moreover, the insertion section main body 21 is configured such that both side surfaces in a plan view (or bottom view) of the part on the tip 4a side are tapered surfaces that intersect with the "tube length direction". In this case, in the insertion section main body 21 of this example, the length along the "tube length direction" from the tip 4a to the part of the above-mentioned "maximum width (width Wa shown in FIG. 6)" in the "first range" (length L1 shown in FIG. 6) is greater than 1 / 2 of the "maximum width" in the "first range" (length L2 shown in FIG. 6).

[0044] In addition, in the insertion portion body 21 of this example, in which both side surfaces of the tip portion 4a side are formed as linear tapered surfaces in a plan view (or bottom view), and the tip portion 4a is formed to be located at the center in the width direction in a plan view (or bottom view), the tip portion 4a is sharply pointed in a plan view (or bottom view). In addition, in the insertion portion body 21 of this example, the tip portion 4a is formed to have a rounded shape as shown in Figs. 3 and 6 in order to avoid a situation in which the insulated electric wire Xa, nearby objects, or the hand of an operator is injured.

[0045] 5, the insertion section main body 21 is formed such that the height in the "first direction" in the "first range" decreases from the portion of maximum height Ha toward the tip 4a. In this case, the insertion section main body 21 of this example is formed such that the tip side of the portion on the tip 4a side has a semicircular shape in side view.

[0046] 4, 5 and 7, the insertion portion main body 21 (wire insertion portion 4) has an abutment surface F1, which is an example of a "first wire abutment surface," and an abutment surface F2, which is an example of a "second wire abutment surface," provided on the tip portion 4a side within the notch 21a. In this case, the abutment surfaces F1 and F2 are each formed on a plane that is parallel to the "insertion direction" of the insulated wire Xa into the notch 21a and intersects with the "tube length direction" of the electrode holding portion 3 and the wire insertion portion 4 (the relative movement direction of the electrode 2 with respect to the wire insertion portion 4). As shown in FIG. 7, the contact surfaces F1 and F2 are inclined such that on a virtual plane (plane shown by dashed line Lc: an example of an "imaginary plane") that passes through the center (as an example, the center: the axis of the electrode 2 in this example where the electrode 2 is cylindrical) in the "first direction (the vertical direction in the same figure)" of the electrode 2 inserted into the wire insertion portion 4 (insertion portion main body 21) together with the electrode holding portion 3 and is parallel to the "insertion direction" and the "cylinder length direction", a virtual extension plane of the contact surface F1 (plane shown by dashed line F1a in the same figure: an example of a "first virtual extension plane") and a virtual extension plane of the contact surface F2 (plane shown by dashed line F2a in the same figure: an example of a "second virtual extension plane") intersect, and the intersecting portion of both virtual extension planes (position shown by point Fx in the same figure: a linear portion extending in the depth direction in the same figure at the position of point Fx) is positioned closer to the tip portion 4a.

[0047] Furthermore, as shown in FIG. 7, the abutment surfaces F1 and F2 are inclined so that the angle of intersection θ1 (an example of a "first intersection angle") between the virtual extension plane of the abutment surface F1 (the plane shown by the dotted line F1a in the same figure) and the virtual plane (the plane shown by the dashed line Lc) of the abutment surface F1 and the angle of intersection θ2 (an example of a "second intersection angle") between the virtual extension plane of the abutment surface F2 (the plane shown by the dotted line F2a in the same figure) and the virtual plane (the plane shown by the dashed line Lc) of the abutment surface F2 are equal to each other.

[0048] In addition, the operation knob 22 is a part that is operated by the user when moving (sliding) the wire insertion portion 4 relative to the electrode holding portion 3 (grip portion 11a), and as an example, is formed in a tubular shape (cylindrical in this example) made of insulating resin material into which the electrode holding portion can be inserted, and is integrated with the insertion portion main body 21.

[0049] In addition, in this voltage sensor 1, as an example, a coil spring (not shown) is housed together with the electrode holding portion 3 in the electric wire insertion portion 4, and as shown in Fig. 9, the electric wire insertion portion 4 is urged in the direction of arrow D1 (direction from the tip to the rear end of the voltage sensor 1) against the electrode holding portion 3 (electrode 2) by the elastic restoring force (urging force in the extension direction) of the coil spring. As a result, in the voltage sensor 1 of this example, when not in use, the tip portion 2a of the electrode 2 is positioned on the tip portion 4a side of the notch 21a in the electric wire insertion portion 4 (insertion portion main body 21), and the electrode holding portion 3 holding the electrode 2 can be seen through the notch 21a.

[0050] In addition, when attaching the voltage sensor 1 to the insulated electric wire Xa or removing it from the insulated electric wire Xa, the wire insertion portion 4 can be moved (slid) in the direction of arrow D2 relative to the electrode holding portion 3 along the tube length direction of the electrode holding portion 3 and the wire insertion portion 4, making it possible to insert the insulated electric wire Xa, etc. into the notch 21a of the wire insertion portion 4 or to remove the insulated electric wire Xa, etc. inserted into the notch 21a from the notch 21a.

[0051] Next, a method of detecting a voltage using the voltage sensor 1 will be described with reference to the accompanying drawings.

[0052] As described above, this type of "sensor" may be used to detect one of a number of electric wires arranged close to each other, or to detect an electric wire arranged close to a board, a casing, etc. As an example, a description will be given of an example of detecting a "detection amount" for a "detection target electric wire" in a state where the gap between the adjacent solid insulated electric wire Xb (proximate object) is very narrow, such as the insulated electric wire Xa shown by a solid line in Fig. 10.

[0053] In this case, as shown in Fig. 9, in the voltage sensor 1 of this example, the wire insertion part 4 is biased in the direction of the arrow D1 relative to the electrode holding part 3 by a coil spring (not shown) disposed in the wire insertion part 4, and the electrode holding part 3 holding the electrode 2 is visible through the notch 21a, that is, the insulated wire Xa or the like cannot be inserted into the notch 21a. Therefore, when mounting the voltage sensor 1 on the insulated wire Xa (holding the insulated wire Xa by the voltage sensor 1), first, the wire insertion part 4 (operation knob 22) is slid in the direction of the arrow D2 relative to the electrode holding part 3 (gripping part 11a) against the biasing force of the coil spring, and the tip part 2a of the electrode 2 held by the electrode holding part 3 is positioned on the rear end part 4b side of the notch 21a (the right side in the figure) as shown in Fig. 10. This makes it possible to insert the insulated wire Xa or the like into the notch 21a.

[0054] Next, while maintaining the state in which the electric wire insertion portion 4 is slid relative to the electrode holding portion 3 as described above, the tip portion 4a of the electric wire insertion portion 4 (insertion portion main body 21) is inserted into the gap between the insulated electric wires Xa, Xb. Specifically, the tip portion 4a is inserted into the gap between the insulated electric wires Xa, Xb such that the direction of the width Wa of the portion of the electric wire insertion portion 4 on the tip portion 4a side is aligned with the direction in which the insulated electric wires Xa, Xb are separated (the direction of the height Ha is aligned with the extension direction of the insulated electric wires Xa, Xb).

[0055] In this case, in the voltage sensor 1 of this example, as described above, the portion on the tip 4a side of the wire insertion portion 4 (insertion portion main body 21) is formed so that the height of the portion on the tip 4a side (within the "first range") becomes smaller from the portion of maximum height Ha toward the tip 4a. In other words, in the voltage sensor 1 of this example, a part (the most extreme end) in the height direction of the portion on the tip 4a side of the wire insertion portion 4 protrudes. Therefore, unlike a configuration in which the height of the "electric wire insertion portion" within the "first range" is constant, that is, a configuration in which the tip of the "electric wire insertion portion" is linear along the radial direction of the "electric wire insertion portion" in a side view, even if insertion is attempted with the direction of the height Ha of the electric wire insertion portion 4 slightly tilted with respect to the extending direction of the two insulated electric wires Xa, Xb, the tip 4a (the portion with the smallest height) is inserted between the two insulated electric wires Xa, Xb before both ends (upper and lower ends) in the height Ha direction at the part on the tip 4a side of the electric wire insertion portion 4 come into contact with the two insulated electric wires Xa, Xb. This makes it possible to smoothly insert the electric wire insertion portion 4 between the two insulated electric wires Xa, Xb.

[0056] As described above, in the voltage sensor 1 of this embodiment, the wire insertion section 4 (insertion section main body 21) is formed such that the width of the portion (within the "first range") on the tip end 4a side of the wire insertion section 4 becomes smaller from the portion of the maximum width Wa toward the tip end 4a. In addition, in the voltage sensor 1 of this embodiment, the portion on the tip end 4a side is formed such that the length along the "tube length direction" from the tip end 4a to the portion of the maximum width Wa in the "first range" is larger than 1 / 2 of the maximum width Wa in the "first range", and the portion on the tip end 4a side is sharply pointed. Therefore, even if the two insulated electric wires Xa, Xb are arranged very close to each other as shown by the solid lines in FIG. 10, the tip end 4a can be easily inserted into a very small gap without the operator having to push the two insulated electric wires Xa, Xb away with his or her hands to widen the gap. Furthermore, in the voltage sensor 1 of this example, the tip 4a has a rounded shape, so that even if the tip 4a comes into contact with either of the two insulated electric wires Xa, Xb, it is possible to preferably avoid a situation in which the two insulated electric wires Xa, Xb are damaged.

[0057] Furthermore, in the electric wire insertion portion 4, which is formed so that the width of the portion on the tip end 4a side becomes smaller from the portion of width Wa toward the tip end 4a as described above, the width of the portion on the tip end 4a side becomes larger toward the rear end portion 4b. Therefore, when the voltage sensor 1 is moved in the direction of arrow D2 relative to the two insulated electric wires Xa, Xb from a state in which the tip end 4a is inserted between the two insulated electric wires Xa, Xb shown by the solid lines, the two insulated electric wires Xa, Xb are guided in the separation direction by the portion on the tip end 4a side of the electric wire insertion portion 4 so as to be separated from each other, and the voltage sensor 1 (electric wire insertion portion 4) can be smoothly inserted until the two insulated electric wires Xa, Xb reach the position of the maximum width Wa at the portion on the tip end 4a side, as shown by the dashed and dotted lines in the figure.

[0058] In reality, the voltage sensor 1 is moved with respect to both insulated electric wires Xa, Xb. However, in this figure and in Figures 11 and 12 which will be referred to later, in order to facilitate understanding of the positional relationship between the voltage sensor 1 (wire insertion portion 4) and both insulated electric wires Xa, Xb, the relative positions of both insulated electric wires Xa, Xb at each point in time during the installation work are shown with respect to the voltage sensor 1 which is shown fixed.

[0059] In the voltage sensor 1 of this example, the maximum width Wa of the portion (within the "first range") on the tip 4a side of the wire insertion portion 4 (insertion portion main body 21) is smaller than the maximum height Ha as described above, and the width of the portion on the tip 4a side is sufficiently small. Therefore, the separation distance between the two insulated electric wires Xa, Xb when the portion on the tip 4a side is inserted is smaller when the tip 4a side portion is inserted with the direction of the width Wa of the portion on the tip 4a side aligned with the separation direction of the two insulated electric wires Xa, Xb (with the direction of the height Ha aligned with the extension direction of the two insulated electric wires Xa, Xb) as in this example than when the tip 4a is inserted into the gap between the two insulated electric wires Xa, Xb with the direction of the height Ha of the portion on the tip 4a side aligned with the separation direction of the two insulated electric wires Xa, Xb (with the direction of the width Wa aligned with the extension direction of the two insulated electric wires Xa, Xb). This makes it possible to suitably avoid a situation in which a large stress is applied to both covered electric wires Xa, Xb when the electric wire insertion portion 4 is inserted.

[0060] In this case, although it is different from the present example in which the voltage sensor 1 (wire insertion portion 4) is inserted between the two insulated electric wires Xa, Xb shown by the solid lines in Fig. 10, when the insulated electric wire Xa to be detected and the insulated electric wire Xb arranged nearby are present at the position of the dashed lines shown in the figure (for example, when they are present at the same distance as the two insulated electric wires Xa, Xb shown by the dashed lines separated from each other by the insertion of the voltage sensor 1), if the voltage sensor 1 of this example has a sufficiently small maximum width Wa at the portion on the tip end 4a side, the wire insertion portion 4 can be inserted without significantly deforming the two insulated electric wires Xa, Xb. However, for example, when a "sensor" (not shown) is used whose "maximum width of the tip end portion in the wire insertion portion" is approximately the same as the "maximum height of the tip end portion in the wire insertion portion (height Ha in the voltage sensor 1)," it is necessary to significantly deform both insulated electric wires Xa, Xb in order to insert the "tip end portion" between the two insulated electric wires Xa, Xb shown by the solid lines. For this reason, even if the width of the portion on the tip 4a side (within the “first range”) does not decrease from the portion of maximum width Wa toward tip 4a, as in the voltage sensor 1 of this example, by making the “maximum width” sufficiently smaller than the “maximum height”, it can be seen that the “tip side portion” can be easily inserted between the two insulated electric wires Xa, Xb that are arranged closely to each other.

[0061] On the other hand, in order to insert the insulated electric wire Xa into the notch 21a from a state in which the insulated electric wires Xa, Xb are guided by inserting the tip 4a side portion of the wire insertion portion 4 so that the relative position with respect to the voltage sensor 1 becomes the position shown by the dashed line in Fig. 10, the voltage sensor 1 is further moved in the direction of arrow D2 relative to the insulated electric wires Xa, Xb. At this time, since there is no portion with a width larger than the above-mentioned maximum width Wa within the "first range" of the wire insertion portion 4, the voltage sensor 1 (wire insertion portion 4) can be smoothly moved relative to the insulated electric wires Xa, Xb from the position shown by the dashed line in the same figure to the position shown by the two-dot chain line in the same figure and in Fig. 11 (the position where the insulated electric wires Xa, Xb reach the rim of the notch 21a on the tip 4a side).

[0062] Next, the voltage sensor 1 (wire insertion portion 4) is rotated clockwise as viewed from the gripping portion 11a side, with the center of the electrode holding portion 3 and the wire insertion portion 4 in the cylindrical diameter direction as the rotation center, so that the open end of the notch 21a (the upper end in FIG. 11) approaches the insulated electric wire Xa. At this time, the insulated electric wire Xa, which was located at the rim of the tip portion 4a side of the notch 21a as shown by the two-dot chain line in FIG. 11, enters the notch 21a as shown by the one-dot chain line, and then moves by its own restoring force to the position shown by the dashed line so as to approach the insulated electric wire Xb shown by the two-dot chain line.

[0063] Next, the force applied to the operation knob 22 (the operating force for moving the electric wire insertion part 4 in the direction of the arrow D2 relative to the electrode holding part 3) is weakened. At this time, the electric wire insertion part 4 is slid in the direction of the arrow D1 shown in FIG. 11 relative to the electrode holding part 3 by the biasing force (restoring force) of a coil spring (not shown). In addition, as the electric wire insertion part 4 slides relative to the electrode holding part 3, the electrode 2 held by the electrode holding part 3 is moved relatively in the direction of the arrow D2 relative to the electric wire insertion part 4. As a result, the insulated electric wire Xa, which was located at the position shown by the dashed line in FIG. 12 and FIG. 13, is moved in the notch 21a together with the electrode 2 in the direction of the arrow D2 relative to the electric wire insertion part 4 after contacting the electrode 2, and is sandwiched between the electric wire insertion part 4 and the electrode 2 as shown by the solid line in FIG. 13. As a result, the tip part 2a of the electrode 2 is pressed against the insulated electric wire Xa, and the electrode 2 is capacitively coupled to the conductor of the insulated electric wire Xa. This completes the attachment of the voltage sensor 1 to the insulated electric wire Xa.

[0064] In the above example of the installation work, when the insulated electric wires Xa, Xb reach the rim of the notch 21a on the tip end 4a side by inserting the wire insertion part 4 between the insulated electric wires Xa, Xb, the voltage sensor 1 (wire insertion part 4) is rotated with respect to the insulated electric wires Xa, Xb to insert the insulated electric wire Xa into the notch 21a. Instead of this operation method, it is also possible to insert a part of the wire insertion part 4 on the tip end 4a side between the insulated electric wires Xa, Xb until the insulated electric wires Xa, Xb reach a position closer to the rear end 4b than the rim of the notch 21a on the tip end 4a side, and then rotate the voltage sensor 1 (wire insertion part 4) to insert the insulated electric wire Xa into the notch 21a.

[0065] Specifically, the tip 4a side portion is inserted between the two insulated electric wires Xa, Xb until the wire insertion portion 4 is inserted at the position indicated by the three-dot chain line in Fig. 10 (the two insulated electric wires Xa, Xb are positioned within the "second range"). Next, the voltage sensor 1 (wire insertion portion 4) is rotated clockwise as viewed from the gripping portion 11a side, with the center of the electrode holding portion 3 and the wire insertion portion 4 in the cylindrical diameter direction as the rotation center, so that the open end of the notch 21a (the upper end in Fig. 11) approaches the insulated electric wire Xa. At this time, as indicated by the three-dot chain line in Fig. 10, the insulated electric wire Xa, which was positioned to the side of the notch 21a (within the "second range"), is smoothly inserted into the notch 21a without coming into contact with the rim of the notch 21a on the tip 4a side.

[0066] In this case, as described above, in the voltage sensor 1 of this example, within the "second range (the range of arrow Cb shown in Figs. 5 and 6)," a portion is provided on the front end 4a side where the width along the "insertion direction (vertical direction in Fig. 6)" of the wire insertion portion 4 (insertion portion main body 21) gradually increases toward the rear end 4b. Therefore, when the relative positions of the two insulated electric wires Xa, Xb with respect to the voltage sensor 1 (wire insertion portion 4) are changed from the position shown by the two-dot chain line in Fig. 10 toward the rear end 4b by inserting the wire insertion portion 4, the two insulated electric wires Xa, Xb need to be spaced apart further. However, when the voltage sensor 1 is moved in the direction of arrow D2 with respect to the two insulated electric wires Xa, Xb (when the two insulated electric wires Xa, Xb are moved in the direction of arrow D1 relative to the voltage sensor 1), the two insulated electric wires Xa, Xb are gradually moved apart by the guidance of the wire insertion portion 4 to reach the position shown by the three-dot chain line. Therefore, it is possible to smoothly move the wire insertion portion 4 relative to the two insulated electric wires Xa, Xb, which were arranged in close proximity to each other before the insertion of the wire insertion portion 4, until the two insulated electric wires Xa, Xb are positioned to the sides of the above-mentioned “second range” in the wire insertion portion 4.

[0067] Thereafter, in the same manner as in the example of the installation work described above, the insulated electric wire Xa is clamped between the electrode 2 and the wire insertion portion 4 (the tip portion 2a of the electrode 2 is pressed against the insulated electric wire Xa), whereby the electrode 2 is capacitively coupled to the conductor of the insulated electric wire Xa, and installation of the voltage sensor 1 to the insulated electric wire Xa is completed.

[0068] In addition, an example has been described in which the detection target is the insulated electric wire Xa which has an extremely small gap with the insulated electric wire Xb arranged nearby, and the insulated electric wire Xa moves by its own restoring force to the position shown by the dashed line in FIG. 11 (the position closest to the insulated electric wire Xb within the notch 21a) when it is inserted into the notch 21a, and then the electrode 2 presses the insulated electric wire Xa against the tip portion 4a of the notch 21a. However, depending on the positional relationship between the insulated electric wire Xa and the wire insertion portion 4 when the voltage sensor 1 (wire insertion portion 4) is inserted into the gap between the insulated electric wires Xa, Xb, the position of the insulated electric wire Xa when it is inserted into the notch 21a (before the electrode 2 is moved relative to the wire insertion portion 4) may differ from the position in the above example. However, in the voltage sensor 1 (wire insertion portion 4) of this example, by providing the abutment surfaces F1, F2 on the tip portion 4a side within the insertion portion main body 21 as described above, it is possible to hold the insulated wire Xa with its center (conductor) positioned on the axis of the electrode 2, regardless of where the insulated wire Xa is positioned within the notch 21a.

[0069] Specifically, when the insulated electric wire Xa inserted into the notch 21a is closest to the insulated electric wire Xb (when the insulated electric wire Xa is located at the back of the notch 21a) as in the above example, the insulated electric wire Xa is located at the lower broken line position in the left diagram of Fig. 8 with respect to the abutment surfaces F1, F2. When the insulated electric wire Xa is located at such a position, the insulated electric wire Xa is pressed by the tip 2a of the electrode 2 and moved in the notch 21a in the direction of the arrow D2 as the electrode 2 (not shown) moves relative to the electric wire insertion portion 4 in the direction of the arrow D2 (hereinafter, also simply referred to as "movement of the electrode 2 relative to the electric wire insertion portion 4"), and is brought into abutment with the abutment surface F2 as shown by the two-dot chain line in the figure. Furthermore, when the electrode 2 is further moved in the direction of the arrow D2, the insulated electric wire Xa is moved toward the abutment surface F1, as guided by the abutment surface F2, and is positioned in a state in which it abuts against three points, namely the tip end 2a of the electrode 2, the abutment surface F2, and the abutment surface F1, as shown by solid lines in the figure.

[0070] On the other hand, unlike the previous example, when the insulated electric wire Xa inserted into the notch 21a is separated from the insulated electric wire Xb (when the insulated electric wire Xa is located closer to the rim of the notch 21a), the insulated electric wire Xa is located at the upper dashed line position in the left diagram of Fig. 8 with respect to the abutment surfaces F1, F2. When the insulated electric wire Xa is located at such a position, as the electrode 2 moves in the direction of the arrow D2 relative to the wire insertion portion 4, the insulated electric wire Xa is pressed by the tip 2a of the electrode 2 and moved in the notch 21a in the direction of the arrow D2, and is brought into contact with the abutment surface F1 as shown by the dashed line in the figure. Furthermore, when the electrode 2 is further moved in the direction of the arrow D2, the insulated electric wire Xa is moved toward the abutment surface F2, as guided by the abutment surface F1, and is positioned in a state in which it abuts against three points, namely the tip end 2a of the electrode 2, the abutment surface F2, and the abutment surface F1, as shown by solid lines in the figure.

[0071] In this case, as described above, in the voltage sensor 1 (wire insertion portion 4) of this example, the angle θ1 of intersection between the virtual extension plane of the abutment surface F1 (the plane shown by the dotted line F1a in Figures 7 and 8) and the virtual plane (a plane parallel to the relative movement direction of the electrode 2 with respect to the wire insertion portion 4 and overlapping with the axis of the electrode 2: the plane shown by the dashed line Lc in Figures 7 and 8) and the angle θ2 of intersection between the virtual extension plane of the abutment surface F2 (the plane shown by the two-dot dash line F2a in Figures 7 and 8) and the above virtual plane are inclined so that they are equal. Therefore, regardless of whether the insulated electric wire Xa inserted into the notch 21a is moved toward the tip end 4a by the electrode 2 and guided by either the abutment surface F1 or the abutment surface F2, the insulated electric wire Xa is similarly moved to a position where it contacts three points, namely the tip end 2a of the electrode 2 and the abutment surfaces F1 and F2 (the detection position where the “detectable amount” is detected: the position shown by the solid line in the left diagram of Figure 8).

[0072] In the voltage sensor 1 (wire insertion portion 4) of this example in which the angles θ1 and θ2 are equal, the center of the insulated electric wire Xa is held so as to be located on the imaginary plane, regardless of the diameter of the insulated electric wire. Specifically, as shown in the right diagram of Fig. 8, when the insulated electric wire Xa is in contact with three points, the tip portion 2a of the electrode 2 and the contact surfaces F1 and F2, the center (point Xc) of the insulated electric wire Xa shown by the solid line, the center (point Xc) of the small-diameter insulated electric wire Xa shown by the dashed line, and the center (point Xc) of the large-diameter insulated electric wire Xa shown by the dashed line are all located on the imaginary plane (the plane shown by the dashed line Lc). In this manner, in this voltage sensor 1 (wire insertion portion 4), even if the diameter (outer diameter) of the insulated wire Xa differs, the positional relationship between the center of the insulated wire Xa (core wire) and the central portion (center in this example) of the tip portion 2a (tip surface) of the electrode 2 does not change (it is located on the axis of the electrode 2), so that a situation in which the state of capacitive coupling between the insulated wire Xa (core wire) and the electrode 2 changes due to a difference in the positional relationship is avoided.

[0073] On the other hand, when the attachment of the voltage sensor 1 to the insulated electric wire Xa is completed as in any of the examples of the attachment work, the measurement process is started by operating an operation unit (not shown) of the measuring device connected via the signal cable 5. Note that a method of measuring voltage using this type of sensor is well known, so a detailed description will be omitted. This completes the detection of the voltage of the insulated electric wire Xa as the detection target. Also, when the detection of the voltage is completed, the voltage sensor 1 is removed from the insulated electric wire Xa in a procedure reverse to the procedure of the attachment work described above. Furthermore, when a new voltage is to be detected for a "detection target electric wire" other than the insulated electric wire Xa, the attachment work and the like are performed in a procedure similar to the above series of work for the insulated electric wire Xa as the detection target. This allows the voltage to be detected for various "detection target electric wires" other than the insulated electric wire Xa in the same manner as for the insulated electric wire Xa.

[0074] In this case, in the voltage sensor 1 of this embodiment, as described above, the portion on the tip 4a side is formed so that both the minimum width Wb along the "insertion direction" and the minimum height Hb along the "first direction" in the "third range (the range of the arrow Cc shown in Figs. 5 and 6)" are larger than the above-mentioned maximum width Wa in the "first range". Therefore, compared to a configuration in which the "third range" is formed narrow like the portion on the tip 4a side of the electric wire insertion portion 4 (the portion where the notch 21a is formed: in the "first range" and "second range"), the physical strength of the electric wire insertion portion 4 is sufficiently high, and the shielding effect of the electrode 2 by the electric wire insertion portion 4 is also sufficiently high. In addition, by configuring the electric wire insertion portion 4 to insert the electrode holding portion 3 (electrode 2) into a portion (in the "third range") in the electric wire insertion portion 4 that has a sufficiently large width and height, the diameter R2 of the electrode 2 is sufficiently large, and the voltage detection sensitivity is sufficiently high.

[0075] In addition, in the voltage sensor 1 of this example, the portion on the tip 4a side is formed so that the maximum width Wa in the "first range" of the wire insertion portion 4 is equal to or larger than the width (diameter R2 shown in FIG. 6 in this example) in the "insertion direction" of the "electrode surface (end surface on the tip 2a side)" of the electrode 2 that is brought close to the insulated electric wire Xa or the like, and the center of the portion on the tip 4a side of the wire insertion portion 4 in the "insertion direction" and the center (center in this example) of the electrode 2 inserted into the wire insertion portion 4 while being held by the electrode holding portion 3 are aligned in the tube length direction of the electrode holding portion 3 and the wire insertion portion 4. Therefore, since the shielding effect by the vicinity of the tip 4a of the wire insertion portion 4 is sufficiently high, even if a noise source is present on the left side in FIGS. 10 to 12 (in front of the tip 4a of the wire insertion portion 4 of the voltage sensor 1), the noise is preferably prevented from being detected by the electrode 2.

[0076] Furthermore, in the voltage sensor 1 of this example, by forming the maximum width Wa of the "first range" of the electric wire insertion portion 4 to be sufficiently large as described above, the widths of both contact surfaces F1, F2 can also be made sufficiently large (approximately the same as the width of the tip portion 2a of the electrode 2), and thus a sufficiently wide range along the length of the insulated electric wire Xa can be held by the tip portion 2a of the electrode 2 and the contact surfaces F1, F2. This makes it possible to suitably avoid a situation in which a large stress is applied to the insulated electric wire Xa in a state in which the voltage sensor 1 is attached to the insulated electric wire Xa (a state in which the insulated electric wire Xa is held by the voltage sensor 1).

[0077] In this manner, in this voltage sensor 1, the abutment surfaces F1, F2, each formed on a plane parallel to the “insertion direction” of the insulated electric wire Xa into the notch 21a and intersecting with the “tube length direction” of the wire insertion portion 4 and the electrode holding portion 3, are provided on the tip portion 4a side of the wire insertion portion 4 within the notch 21a, and the “first imaginary extension plane” of the abutment surface F1 and the “second imaginary extension plane” of the abutment surface F2 intersect on an “imaginary plane” that passes through the center of the electrode 2 in a “first direction” perpendicular to both the “insertion direction” and the “tube length direction” and is parallel to both the “insertion direction” and the “tube length direction”, and are inclined so as to be positioned closer to the tip portion 4a as they approach the intersection point of both “imaginary extension planes”.

[0078] Therefore, according to this voltage sensor 1, when the insulated electric wire Xa inserted into the notch 21a is moved relatively within the notch 21a toward the tip 4a as the electrode 2 moves relative to the wire insertion portion 4, the insulated electric wire Xa is guided toward the other of the abutment surfaces F1, F2 whichever it comes into contact with first, and is ultimately held in a state of contact with three points, namely the tip 2a of the electrode 2 and the abutment surfaces F1, F2. This makes it possible to preferably prevent the insulated electric wire Xa from being held in a state where the center (center of the core wire) of the insulated electric wire Xa is significantly misaligned from an imaginary plane that is parallel to the movement direction of the electrode 2 relative to the wire insertion portion 4 and passes through the central portion (center in this example) of the tip 2a of the electrode 2. As a result, for various types of insulated electric wires Xa having different diameters (outer diameters), the positional relationship between the core wire and the center of the tip portion 2a of the electrode 2 can be maintained without significant difference, and the voltage of the insulated electric wire Xa (core wire) can be detected with high accuracy without causing a situation in which the state of capacitive coupling between the core wire of the insulated electric wire Xa and the electrode 2 differs due to the above-mentioned difference in positional relationship.

[0079] In addition, in this voltage sensor 1, the abutment surfaces F1 and F2 are formed so that the "first virtual extension plane" and the "second virtual extension plane" intersect with each other on the "virtual plane" passing through the center of the electrode 2 in the direction perpendicular to both the "insertion direction" and the "tube length direction". Therefore, according to this voltage sensor 1, it is possible to suitably prevent the insulated electric wire Xa from being held in a state in which the center (center of the core wire) of the insulated electric wire Xa is significantly displaced from the "virtual plane" passing through the center of the tip portion 2a of the electrode 2. As a result, for various insulated electric wires Xa having different diameters (outer diameters), the positional relationship between the core wire and the center of the tip portion 2a of the electrode 2 can be held without significantly changing, and therefore the voltage of the insulated electric wire Xa (core wire) can be detected with higher accuracy without causing a situation in which the state of capacitive coupling between the core wire of the insulated electric wire Xa and the electrode 2 differs due to the difference in the positional relationship.

[0080] Furthermore, according to this voltage sensor 1, the contact surfaces F1, F2 are inclined so that the "first intersection angle" between the "first imaginary extension plane" and the "imaginary plane" and the "second intersection angle" between the "second imaginary extension plane" and the "imaginary plane" are equal to each other, so that the center (center of the core wire) of various insulated electric wires Xa having different diameters (outer diameters) can be reliably positioned on the above imaginary plane. This makes it possible to detect the voltage of the insulated electric wire Xa (core wire) with even higher accuracy.

[0081] Furthermore, in this voltage sensor 1, within a "first range" along the "tube length direction" from the tip 4a to the rim of the notch 21a on the tip 4a side, the maximum width Wa of the insulated wire Xa along the "insertion direction" relative to the notch 21a is smaller than the maximum height Ha along the "first direction" perpendicular to both the "tube length direction" and the "insertion direction", and within a "second range" along the "tube length direction" from the rim of the notch 21a on the tip 4a side to the rim of the rear end side of the wire insertion portion 4 in the notch 21a, a region is provided in which the width along the "insertion direction" gradually increases, and the portion on the tip 4a side of the wire insertion portion 4 is formed so that within a "third range" toward the rear end side of the rim of the rear end side of the notch 21a, the minimum width Wb along the "insertion direction" and the minimum height Hb along the "first direction" are both greater than the maximum width Wa in the "first range".

[0082] Therefore, according to this voltage sensor 1, even when the voltage sensor 1 is attached to the insulated electric wire Xa with an extremely small gap between it and a nearby object (e.g., the insulated electric wire Xb), the insulated electric wire Xa can be smoothly (i.e., easily) inserted into the gap by aligning the separation direction between the nearby object and the insulated electric wire Xa with the width direction of the part on the tip end 4a side. Also, even when the insulated electric wire Xa or the like is inserted between the insulated electric wire Xa and the nearby object until it is positioned to the side of the notch 21a, since a part whose width along the "insertion direction" gradually increases is provided within the "second range", the part on the tip end 4a side can be inserted so as to gradually separate the insulated electric wire Xa from the nearby object, and as a result, the insulated electric wire Xa or the like can be smoothly (i.e., easily) inserted without applying large stress. Furthermore, since the width and height of the wire insertion portion 4 in the "third range" are sufficiently large, the physical strength of the wire insertion portion 4 is sufficiently high to effectively prevent noise from being mixed into the electrode 2 in the wire insertion portion 4 (i.e., without causing a decrease in shielding performance), and by arranging the electrode 2 of sufficient thickness together with the electrode holding portion 3 in the wire insertion portion 4, the detection sensitivity of the "detectable quantity (voltage in this example)" can be sufficiently increased.

[0083] Moreover, according to this voltage sensor 1, the portion on the tip 4a side of the wire insertion portion 4 is formed so that the maximum width Wa in the "first range" is equal to or greater than the width along the "insertion direction" of the "electrode surface (tip 2a)" of the electrode 2 that is brought close to the insulated electric wire Xa (in this example, the diameter R2 of the electrode 2), so that the tip 4a side portion of the wire insertion portion 4 can suitably prevent the intrusion of noise from the extension direction of the electrode 2 (the direction perpendicular to the electrode 2 surface). Furthermore, the width along the "insertion direction" of the abutment surfaces F1, F2 can be made sufficiently large, and thus a sufficiently wide range along the length of the insulated electric wire Xa can be held by the tip 4a of the electrode 2 and both abutment surfaces F1, F2, so that it is possible to suitably avoid a situation in which a large stress is applied to the insulated electric wire Xa in a state in which the voltage sensor 1 is attached to the insulated electric wire Xa (a state in which the insulated electric wire Xa is held by the voltage sensor 1).

[0084] The configuration of the "sensor" is not limited to the above-mentioned example of the voltage sensor 1. For example, the configuration has been described by taking as an example a configuration in which the contact surfaces F1 and F2 are inclined so that the intersection angle θ1 between the imaginary extension plane of the contact surface F1 (plane shown by dashed line F1a in Figs. 7 and 8) and the imaginary plane (parallel to both the insertion direction of the insulated electric wire Xa into the notch 21a and the tube length direction of the electric wire insertion portion 4 and the electrode holding portion 3 (relative movement direction of the electrode 2 with respect to the electric wire insertion portion 4) and overlapping with the axis of the electrode 2: plane shown by dashed line Lc in Figs. 7 and 8) and the intersection angle θ2 between the imaginary extension plane of the contact surface F2 (plane shown by dashed line F2a in Figs. 7 and 8) and the imaginary plane are equal, but a configuration in which both angles θ1 and θ2 are slightly different may be adopted. In this case, even if the angles θ1, θ2 are different, by inclining the abutment surfaces F1, F2 so that the imaginary extension planes of the abutment surfaces F1, F2 intersect with the above-mentioned imaginary plane, it is possible to preferably prevent the center of the insulated electric wire Xa (core wire) from being held in a state where it is significantly misaligned with the imaginary plane.

[0085] In addition, the configuration of the voltage sensor 1 has been described as an example, in which the wire insertion portion 4 has a contact surface F1 (first wire abutment surface) and a contact surface F2 (second wire abutment surface) formed so that the "first virtual extension plane" and the "second virtual extension plane" intersect with each other on an "imaginary plane" passing through the center of the electrode 2 (an example of the "center") in a direction perpendicular to both the "insertion direction" and the "tube length direction". However, the "wire insertion portion" can also be configured by forming the "first wire abutment surface" and the "second wire abutment surface" so that the "first virtual extension plane" and the "second virtual extension plane" intersect with each other on an "imaginary plane" passing through a portion (another example of the "center") that is slightly displaced from the center of the "electrode" in a direction perpendicular to both the "insertion direction" and the "tube length direction" (not shown). Even when such a configuration is adopted, it is possible to preferably avoid holding the "target electric wire" in a state in which its center is significantly shifted from the "imaginary plane" that is parallel to the movement direction of the "electrode" relative to the "wire insertion portion" and passes through the center of the tip of the "electrode", thereby making it possible to detect the "detectable quantity" of the "target electric wire" with high accuracy.

[0086] In addition, the configuration of the voltage sensor 1 having the electric wire insertion portion 4 in which the abutment surface F1 as the "first electric wire abutment surface" and the abutment surface F2 as the "second electric wire abutment surface" are configured in a plane parallel to the "insertion direction" of the insulated electric wire Xa into the notch 21a and intersecting with the "tube length direction" of the electric wire insertion portion 4 and the electrode holding portion 3 have been described as an example, but the "first electric wire abutment surface" and the "second electric wire abutment surface" formed in the "electric wire insertion portion" can also be configured as a "surface" other than a "plane". As an example, the voltage sensors 1A and 1B shown in Figures 13 and 14 are another example of a "sensor" and are configured to detect the voltage supplied to the conductor (core) of the insulated electric wire Xa in a non-contact state with the conductor, similar to the above-mentioned voltage sensor 1. In this case, voltage sensor 1A includes an electric wire insertion portion 4A instead of electric wire insertion portion 4 in voltage sensor 1, and voltage sensor 1B includes an electric wire insertion portion 4B instead of electric wire insertion portion 4 in voltage sensor 1.

[0087] Note that components of voltage sensors 1A, 1B other than wire insertion portions 4A, 4B are similar to the corresponding components of voltage sensor 1, and therefore detailed description thereof will be omitted. Furthermore, portions of wire insertion portions 4A, 4B other than contact surfaces F1A, F1B and contact surfaces F2A, F2B, which will be described later, are formed in the same manner as the corresponding portions of wire insertion portion 4, and therefore illustrations and detailed description thereof will be omitted.

[0088] The wire insertion portion 4A in the voltage sensor 1A is another example of an "electric wire insertion portion," and as shown in FIG. 13, abutment surfaces F1A (another example of a "first wire abutment surface") and abutment surface F2A (another example of a "second wire abutment surface") are provided on the tip side of the wire insertion portion 4A within the notch 21a, and are formed of surfaces (in this example, "curved surfaces" curved in a direction protruding toward the tip side of the wire insertion portion 4A (the left side in the same figure)) that are parallel to the "insertion direction" of the insulated electric wire Xa into the notch 21a and intersect with the "tube length direction" of the wire insertion portion 4A and the electrode holding portion 3. In this case, the abutment surfaces F1A, F2A are formed so as to contact each other on an "imaginary plane (plane indicated by dashed line Lc)" that passes through the center of the electrode 2 in a direction perpendicular to both the above-mentioned "insertion direction" and "tube length direction" (as an example, the center: the axis of the electrode 2) and is parallel to both the "insertion direction" and the "tube length direction".

[0089] In addition, in this electric wire insertion portion 4A, the abutment surfaces F1A and F2A are inclined so that the distance between the abutment surfaces F1A and F2A along the cylindrical diameter direction (the vertical direction in the figure) of the electric wire insertion portion 4A and the electrode holding portion 3 becomes shorter toward the tip end side (the left side in the figure) of the electric wire insertion portion 4. Furthermore, in this electric wire insertion portion 4A, when viewed along the "insertion direction" of the insulated electric wire Xa into the notch 21a, the abutment surfaces F1A and F2A are formed so as to be line-symmetrical with respect to the axis of the above-mentioned "virtual plane (broken line Lc)."

[0090] In the voltage sensor 1A having the wire insertion portion 4A having such abutment surfaces F1A and F2A, when the electrode 2 is moved relative to the wire insertion portion 4A in the direction of the arrow D2 with the insulated wire Xa located at the back side of the notch 21a (the insulated wire Xa located at the lower broken line position in the left diagram of FIG. 13), the insulated wire Xa is pressed by the tip 2a of the electrode 2 and moved in the notch 21a in the direction of the arrow D2, and abuts against the abutment surface F2A as shown by the two-dot chain line in the same diagram. When the electrode 2 is further moved in the direction of the arrow D2, the insulated wire Xa is moved toward the abutment surface F1A while being guided by the abutment surface F2A, and is positioned in a state of abutment against three points, that is, the tip 2a of the electrode 2, the abutment surface F2A, and the abutment surface F1A, as shown by the solid line in the same diagram.

[0091] When the electrode 2 is moved relative to the wire insertion portion 4A in the direction of the arrow D2 with the insulated electric wire Xa positioned close to the rim of the notch 21a (when the insulated electric wire Xa is positioned at the upper broken line position in the left diagram of FIG. 13), the insulated electric wire Xa is pressed by the tip 2a of the electrode 2 and moved in the notch 21a in the direction of the arrow D2, and abuts against the abutment surface F1A as shown by the dashed line in the diagram. When the electrode 2 is further moved in the direction of the arrow D2, the insulated electric wire Xa is moved toward the abutment surface F2A while being guided by the abutment surface F1A, and is positioned in a state of abutment against three points, that is, the tip 2a of the electrode 2, the abutment surface F1A, and the abutment surface F2A, as shown by the solid line in the diagram.

[0092] In this case, in this voltage sensor 1A (wire insertion portion 4A), as described above, the abutment surfaces F1A, F2A are inclined so that the distance between the abutment surfaces F1A, F2A along the cylindrical diameter direction of the wire insertion portion 4A becomes shorter toward the tip end of the wire insertion portion 4A. Therefore, regardless of whether the insulated electric wire Xa inserted into the notch 21a is moved toward the tip end 4a by the electrode 2 and guided by either the abutment surface F1A or the abutment surface F2A, the insulated electric wire Xa is moved in the same manner to a position where it comes into contact with three points, the tip end 2a of the electrode 2 and the abutment surfaces F1A, F2A (a detection position for detecting the "detectable amount": a position indicated by a solid line in the left diagram of FIG. 13).

[0093] In addition, in this voltage sensor 1A (wire insertion portion 4A) in which the contact surfaces F1A and F2A are formed to be symmetrical about the "imaginary plane (dashed line Lc)" when viewed along the "insertion direction," the center of the insulated electric wire Xa is held so as to be located on the above-mentioned "imaginary plane" regardless of the difference in diameter. Specifically, as shown in the right diagram of Fig. 13, when the insulated electric wire Xa is in contact with three points, the tip portion 2a of the electrode 2 and the contact surfaces F1A and F2A, the center (point Xc) of the insulated electric wire Xa shown by the solid line, the center (point Xc) of the thin-diameter insulated electric wire Xa shown by the dashed line, and the center (point Xc) of the thick-diameter insulated electric wire Xa shown by the dashed line are all located on the imaginary plane (plane shown by dashed line Lc). In this manner, in this voltage sensor 1A (wire insertion portion 4A), even if the diameter (outer diameter) of the insulated wire Xa differs, the positional relationship between the center of the insulated wire Xa (core wire) and the central portion (center in this example) of the tip portion 2a (tip surface) of the electrode 2 does not change (it is located on the axis of the electrode 2), so that a situation in which the state of capacitive coupling between the insulated wire Xa (core wire) and the electrode 2 changes due to a difference in the positional relationship is avoided.

[0094] On the other hand, the wire insertion portion 4B in the voltage sensor 1B is yet another example of an "electric wire insertion portion," and as shown in FIG. 14, a contact surface F1B (another example of a "first electric wire abutment surface") and a contact surface F2B (another example of a "second electric wire abutment surface") are formed by surfaces (in this example, "curved surfaces" curved in a direction protruding toward the base end side (the right side in the same figure) of the wire insertion portion 4B) that are parallel to the "insertion direction" of the insulated electric wire Xa into the notch 21a and intersect with the "tube length direction" of the wire insertion portion 4B and the electrode holding portion 3, and are provided on the tip side of the wire insertion portion 4B within the notch 21a. In this case, the abutment surfaces F1B, F2B are formed so as to contact each other on an "imaginary plane (plane indicated by dashed line Lc)" that passes through the center of the electrode 2 in a direction perpendicular to both the above-mentioned "insertion direction" and "tube length direction" (as an example, the center: the axis of the electrode 2) and is parallel to both the "insertion direction" and the "tube length direction".

[0095] In addition, in this electric wire insertion portion 4B, the abutment surfaces F1B and F2B are inclined so that the distance between the abutment surfaces F1B and F2B along the cylindrical diameter direction (the vertical direction in the figure) of the electric wire insertion portion 4B and the electrode holding portion 3 becomes shorter toward the tip end side (the left side in the figure) of the electric wire insertion portion 4. Furthermore, in this electric wire insertion portion 4B, when viewed along the "insertion direction" of the insulated electric wire Xa into the notch 21a, the abutment surfaces F1B and F2B are formed so as to be line-symmetrical with respect to the axis of the above-mentioned "virtual plane (broken line Lc)."

[0096] In the voltage sensor 1B having the wire insertion portion 4B having such abutment surfaces F1B, F2B, similarly to the voltage sensor 1A having the wire insertion portion 4A described above, when the electrode 2 is moved relatively to the wire insertion portion 4B in the direction of arrow D2 with the insulated wire Xa inserted in the notch 21a, the insulated wire Xa is pressed by the tip 2a of the electrode 2 and moved within the notch 21a in the direction of arrow D2. Note that the guidance of the insulated wire Xa by the abutment surfaces F1B, F2B accompanying the relative movement of the electrode 2 is similar to the guidance of the insulated wire Xa by the abutment surfaces F1, F1A and the abutment surfaces F2, F2B in the voltage sensors 1, 1A (wire insertion portions 4, 4A), and therefore a detailed description thereof will be omitted. The insulated wire Xa guided by the contact surfaces F1B and F2B is positioned in a state of contact with three points of the tip 2a of the electrode 2, the contact surface F1B, and the contact surface F2B, as shown by solid lines in the figure.

[0097] In this case, in this voltage sensor 1B (wire insertion portion 4B), as described above, the abutment surfaces F1B, F2B are inclined so that the distance between the abutment surfaces F1B, F2B along the cylindrical diameter direction of the wire insertion portion 4B becomes shorter toward the tip end of the wire insertion portion 4B. Therefore, in this voltage sensor 1B (wire insertion portion 4B), even if the insulated electric wire Xa inserted into the cutout 21a is moved toward the tip end 4a by the electrode 2 and guided by either the abutment surface F1B or the abutment surface F2B, the insulated electric wire Xa is similarly moved to a position where it comes into contact with three points, the tip end 2a of the electrode 2 and the abutment surfaces F1B, F2B (a detection position for detecting the "detectable amount": a position shown by a solid line in the left diagram of FIG. 14).

[0098] Furthermore, in this voltage sensor 1B (wire insertion portion 4B) in which the contact surfaces F1B, F2B are formed to be symmetrical about the axis of the "imaginary plane (dashed line Lc)" when viewed along the "insertion direction," the center of the insulated electric wire Xa is held to be located on the above-mentioned "imaginary plane" regardless of the difference in diameter. Therefore, in this voltage sensor 1B (wire insertion portion 4B), similarly to the above-mentioned voltage sensor 1A (wire insertion portion 4A), even if the diameter (outer diameter) of the insulated electric wire Xa is different, the positional relationship between the center of the insulated electric wire Xa (core wire) and the central portion (center in this example) of the tip portion 2a (tip surface) of the electrode 2 does not change (it is located on the axis of the electrode 2), and therefore a situation in which the state of the capacitive coupling between the insulated electric wire Xa (core wire) and the electrode 2 changes due to a difference in the positional relationship is avoided.

[0099] In this manner, in this voltage sensor 1A, 1B, abutment surfaces F1A, F1B and abutment surfaces F2A, F2B, respectively formed on surfaces parallel to the “insertion direction” of the insulated electric wire Xa into the notch 21a and intersecting the “tube length direction” of the wire insertion portions 4A, 4B and the electrode holding portion 3, are provided on the tip portion 4a side of the wire insertion portions 4A, 4B within the notch 21a, and the abutment surfaces F1A, F1B and F2A, F2B are in contact with each other on an “imaginary plane” that passes through the center of the electrode 2 in a direction perpendicular to both the “insertion direction” and the “tube length direction” and is parallel to both the “insertion direction” and the “tube length direction”, and are inclined such that the separation distance between the abutment surfaces F1A, F1B and F2A, F2B along the “tube diameter direction” of the wire insertion portions 4A, 4B and the electrode holding portion 3 becomes shorter toward the tip portion 4a.

[0100] Therefore, according to this voltage sensor 1A, 1B, when the insulated electric wire Xa inserted into the notch 21a is relatively moved within the notch 21a toward the tip end 4a in accordance with the relative movement of the electrode 2 with respect to the wire insertion portion 4A, 4B, the insulated electric wire Xa is guided toward the other of the abutment surfaces F1A, F2A and the abutment surfaces F1B, F2B, whichever comes into contact with it first, and is ultimately held in a state of contact with three points of the tip end 2a of the electrode 2, the abutment surfaces F1A, F2A and the abutment surfaces F1B, F2B. This makes it possible to preferably prevent the insulated electric wire Xa from being held in a state where the center (center of the core wire) of the insulated electric wire Xa is significantly misaligned from an imaginary plane that is parallel to the movement direction of the electrode 2 with respect to the wire insertion portion 4 and passes through the central portion (center in this example) of the tip end 2a of the electrode 2. As a result, for various types of insulated electric wires Xa having different diameters (outer diameters), the positional relationship between the core wire and the center of the tip portion 2a of the electrode 2 can be maintained without significant difference, and the voltage of the insulated electric wire Xa (core wire) can be detected with high accuracy without causing a situation in which the state of capacitive coupling between the core wire of the insulated electric wire Xa and the electrode 2 differs due to the above-mentioned difference in positional relationship.

[0101] In addition, in the voltage sensors 1A and 1B, the contact surfaces F1A, F2A and the contact surfaces F1B, F2B are formed so as to be in contact with each other on an "imaginary plane" passing through the center of the electrode 2 in a direction perpendicular to both the "insertion direction" and the "tube length direction". Therefore, the voltage sensors 1A and 1B can suitably avoid holding the insulated electric wire Xa in a state in which the center (center of the core wire) of the insulated electric wire Xa is significantly displaced from the "imaginary plane" passing through the center of the tip portion 2a of the electrode 2. As a result, for various insulated electric wires Xa having different diameters (outer diameters), the positional relationship between the core wire and the center of the tip portion 2a of the electrode 2 can be held without significantly changing, and the voltage of the insulated electric wire Xa (core wire) can be detected with higher accuracy without causing a situation in which the state of capacitive coupling between the core wire of the insulated electric wire Xa and the electrode 2 differs due to the difference in the positional relationship.

[0102] Furthermore, in the voltage sensors 1A and 1B, the contact surfaces F1A, F2A and F1B, F2B are formed to be symmetrical about an "imaginary plane" when the wire insertion portions 4A, 4B are viewed along the "insertion direction." Therefore, with the voltage sensors 1A and 1B, the centers (centers of the core wires) of various insulated electric wires Xa having different diameters (outer diameters) can be reliably positioned on the "imaginary plane." This makes it possible to detect the voltage of the insulated electric wire Xa (core wire) with even higher accuracy.

[0103] In addition, the "first electric wire abutment surface" and the "second electric wire abutment surface" that contact on the "virtual plane" are not limited to "curved surfaces" such as the above-mentioned abutment surfaces F1A, F1B and abutment surfaces F2A, F2B, and can be composed of various "surfaces" that become free curved or broken line-like when viewed along the "insertion direction".

[0104] In addition, the configuration of voltage sensors 1A, 1B has been described as an example, having wire insertion portions 4A, 4B formed so that abutment surfaces F1A, F1B and abutment surfaces F2A, F2B are in contact on an "imaginary plane" passing through the center of electrode 2 (an example of the "center") in a direction perpendicular to both the "insertion direction" and the "tube length direction". However, the "wire insertion portion" can also be configured (not shown) by forming the "first wire abutment surface" and the "second wire abutment surface" to be in contact on an "imaginary plane" passing through a portion (another example of the "center") slightly shifted from the center of the "electrode" in a direction perpendicular to both the "insertion direction" and the "tube length direction". Even when such a configuration is adopted, it is possible to preferably avoid holding the "target electric wire" in a state in which its center is significantly shifted from the "imaginary plane" that is parallel to the movement direction of the "electrode" relative to the "wire insertion portion" and passes through the center of the tip of the "electrode", thereby making it possible to detect the "detectable quantity" of the "target electric wire" with high accuracy.

[0105] Although the configuration has been described as an example in which the insulated electric wire Xa can be inserted into the notch 21a and removed from the notch 21a by sliding the electric wire insertion portion 4 (operation knob 22) relative to the electrode holding portion 3 (gripping portion 11a), it is also possible to adopt a configuration in which the insulated electric wire Xa can be inserted or removed by sliding the "electrode holding portion" relative to the "electric wire insertion portion" or by sliding both the "electrode holding portion" and the "electric wire insertion portion". Furthermore, the voltage sensor 1 has been described as an example in which the cylindrical electrode 2 is held by the cylindrical electrode holding portion 3 and the cylindrical electrode holding portion 3 is inserted into the cylindrical electric wire insertion portion 4, but the "electrode" can be formed into a square pillar shape, and the "electrode holding portion" and the "electric wire insertion portion" can be formed into a square tube shape.

[0106] In addition, although the configuration of the voltage sensor 1 that can be used to detect the voltage of the insulated electric wire Xa as the "detectable amount" has been described as an example, a configuration similar to that of the voltage sensor 1 can also be adopted in a "sensor" that can detect any electrical parameter other than voltage as the "detectable amount" (not shown). Also, although the voltage sensor 1 configured to detect the "detectable amount" via the electrode 2 in a state of capacitive coupling with the conductor of the insulated electric wire Xa has been described as an example, the configuration of the present invention can also be adopted in a sensor configured to detect the "detectable amount" via an "electrode" in a state of electromagnetic inductive coupling with the conductor, or a sensor configured to detect the "detectable amount" via an "electrode" in a state of electric field coupling with the conductor. [Explanation of symbols]

[0107] 1,1A,1B Voltage Sensor 2 electrodes 2a Tip 3 Electrode holding part 4, 4A, 4B Wire insertion part 4a Tip 4b Rear end 5 Signal Cable 11 Holding unit body 11a Grip part 12 Insulators 21 Insertion section body 21a Notch 22 Operation knob F1,F1A,F1B,F2,F2A,F2B Contact surface F1a dashed line F2a dashed line Fx points Ha,Hb height L1, L2 length Lc dashed line R2 diameter Wa, Wb Width Xa, Xb coated wire θ1,θ2 angle

Claims

1. An electrode; an electrode holding portion formed in a cylindrical shape into which the electrode can be inserted; an electric wire insertion portion formed in a cylindrical shape from a conductive material into which the electrode holding portion can be inserted, and configured so that an electric wire to be detected can be inserted into a notch formed by cutting out a part of a peripheral wall at a tip portion side portion, a sensor configured to allow the electric wire insertion portion to be moved relatively to the electrode holding portion along a tube length direction of the electrode holding portion and the electric wire insertion portion, and configured to allow the electrode held by the electrode holding portion to be brought relatively close to the detection target electric wire inserted into the electric wire insertion portion, thereby allowing a detection amount of the detection target electric wire to be detected via the electrode in a non-contact state with a conductor within an insulating coating of the detection target electric wire, a first electric wire abutment surface and a second electric wire abutment surface, each of which is formed on a plane parallel to an insertion direction of the electric wire to be detected into the notch and intersecting with the tube length direction, are provided on a tip end side of the electric wire insertion portion within the notch; The first wire contact surface and the second wire contact surface are inclined so that on a virtual plane that passes through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction and is parallel to both the insertion direction and the tube length direction, a first virtual extension plane of the first wire contact surface and a second virtual extension plane of the second wire contact surface intersect with each other and are positioned closer to the tip end as they approach the intersection point between the first virtual extension plane and the second virtual extension plane.

2. The sensor according to claim 1, wherein the first wire abutment surface and the second wire abutment surface are formed such that the first virtual extension plane and the second virtual extension plane intersect with each other on the virtual plane passing through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction.

3. 3. The sensor according to claim 1 or 2, wherein the first wire abutment surface and the second wire abutment surface are each inclined so that a first intersection angle between the first imaginary extension plane and the imaginary plane, and a second intersection angle between the second imaginary extension plane and the imaginary plane are equal to each other.

4. An electrode; an electrode holding portion formed in a cylindrical shape into which the electrode can be inserted; an electric wire insertion portion formed in a cylindrical shape from a conductive material into which the electrode holding portion can be inserted, and configured so that an electric wire to be detected can be inserted into a notch formed by cutting out a part of a peripheral wall at a tip portion side portion, a sensor configured to allow the electric wire insertion portion to be moved relatively to the electrode holding portion along a tube length direction of the electrode holding portion and the electric wire insertion portion, and configured to allow the electrode held by the electrode holding portion to be brought relatively close to the detection target electric wire inserted into the electric wire insertion portion, thereby allowing a detection amount of the detection target electric wire to be detected via the electrode in a non-contact state with a conductor within an insulating coating of the detection target electric wire, a first electric wire abutment surface and a second electric wire abutment surface, each of which is formed by a surface parallel to an insertion direction of the electric wire to be detected into the notch and intersecting with the tube length direction, are provided on a tip end side of the electric wire insertion portion within the notch; the first wire abutment surface and the second wire abutment surface are inclined such that, on a virtual plane that passes through a center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction and that is parallel to both the insertion direction and the tube length direction, the first wire abutment surface and the second wire abutment surface are in contact with each other, and a distance between the first wire abutment surface and the second wire abutment surface along a tube diameter direction of the wire insertion portion becomes shorter toward the tip end.

5. The sensor according to claim 4, wherein the first wire contact surface and the second wire contact surface are formed to be in contact on the imaginary plane passing through the center of the electrode in a direction perpendicular to both the insertion direction and the tube length direction.

6. The sensor according to claim 5 , wherein the first wire contact surface and the second wire contact surface are formed to be symmetrical with respect to the imaginary plane when the electrode holding portion is viewed along the insertion direction.

7. 7. The sensor according to claim 1, wherein the wire insertion portion has a maximum width along the insertion direction within a first range along the tube length direction from the tip to an edge of the notch on the tip side that is smaller than a maximum height along a direction perpendicular to both the tube length direction and the insertion direction, and a portion is provided in which the width along the insertion direction gradually increases within a second range along the tube length direction from the edge of the notch on the tip side to an edge of the notch on the rear end side of the wire insertion portion, and the tip side portion is formed such that within a third range toward the rear end side of the edge of the notch on the rear end side, both the minimum width along the insertion direction and the minimum height along a direction perpendicular to both the tube length direction and the insertion direction are larger than the maximum width in the first range.

8. 8. The sensor according to claim 7, wherein the tip side portion of the wire insertion portion is formed so that the maximum width in the first range is greater than or equal to the width along the insertion direction of the electrode surface of the electrode that is brought close to the electric wire to be detected.

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