JP7682060B2 - Sensors - Google Patents

Description

The present invention relates to a sensor that can detect the amount of a detection target electric wire without contacting the conductor of the detection target electric wire.

As one such type of sensor, the applicant has disclosed in the following patent documents a voltage detection probe (hereinafter simply referred to as a "detection probe") that can detect the voltage of a measurement target electric wire (detection target electric wire) without contacting the core wire.

This detection probe is configured with a grip portion that is held by the user, and a detection electrode unit that is connected to the main unit via a shielded cable. The detection electrode unit also includes a first shield cylinder formed with an insertion recess (notch) into which the electric wire to be measured 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 that is fixed to the inside of the grip portion and through which the first shield cylinder is inserted, an operating lever that is connected to the detection electrode and slides the detection electrode relative to the first shield cylinder, the second shield cylinder, and the grip portion, and a biasing member that biases the detection electrode toward the tip.

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, while holding the grip portion, the operating lever is pulled toward the user, and the detection electrode is slid toward the user inside the first shield cylinder. This makes it possible to insert the electric wire to be measured into the insertion recess. Next, while holding the operating lever, the electric wire to be measured is inserted into the insertion recess, and the operating lever is released. 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 clamped between the tip surface of the detection electrode and the tip side cutout 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).

In this case, in the detection probe disclosed by the applicant, the above-mentioned insertion recess is composed of 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 rim 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 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, resulting in a state in which the measurement target electric wire is held (positioned) at three points: the tip-side notch surface, the back-side notch surface, and the tip 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.

JP 2017-009576 A (pages 7-20, Figures 1-19)

However, the detection probe disclosed by the applicant in the above patent document has the following problems that need to be improved. Specifically, the detection probe disclosed by the applicant employs a configuration in which the tip face of the detection electrode is pressed against the electric wire to be measured while it is inserted into the insertion recess (notch) of the first shield cylinder (electric wire insertion portion), thereby capacitively coupling the core wire of the electric wire to be measured and the detection electrode, thereby detecting the voltage of the electric wire to be measured (core wire).

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

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 notch surface of the insertion recess becomes large, so that the center of the electric wire to be measured (core wire) is not located 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 notch surface of the insertion recess becomes small, so that the center of the electric wire to be measured (core wire) is not located 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. For this reason, it is preferable to improve this point in order to improve the detection accuracy for electric wires to be measured of various diameters (outer diameters).

On the other hand, this type of detection probe (sensor) is also used when detecting a detectable quantity such as voltage using one of multiple electric wires arranged close to each other as the measured electric wire, or when detecting a detectable quantity using an electric wire arranged near a board or casing as the measured electric wire. 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 shield 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 thin and rod-shaped. As a result, even when detecting a detectable quantity using an electric wire that has other nearby objects such as other electric wires, boards, and casings as the measured electric wire, it is possible to insert the tip side part of the detection probe (first shield cylinder) into the gap between the nearby objects and the measured electric wire and insert the measured electric wire into the insertion recess.

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 the electric wire to be measured or the nearby object, or both, with one hand to widen the gap between the electric wire to be measured and the nearby object, and then 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 task of attaching the detection probe to the electric wire to be measured is complicated.

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 also 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.

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

The present invention was made in consideration of the above-mentioned problems to be solved, and its main objective is to provide a sensor that can effectively avoid a decrease in the detection accuracy of the quantity to be detected due to differences in the diameter (outer diameter) of the electric wire to be detected. Another objective 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.

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 so that the electrode can be inserted, and an electric wire insertion section formed in a cylindrical shape from a conductive material so that the electrode holding section can be inserted, and configured so that a detection target electric wire can be inserted into a notch formed by cutting out a part of the peripheral wall at the tip side portion, and configured so that the electric wire insertion section can be moved relatively to the electrode holding section along the 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 in the electric wire insertion section, thereby detecting the detection amount of the detection target electric wire via the electrode in a non-contact state with the conductor within the insulating coating of the detection target electric wire. The wire insertion section has a first wire contact surface and a second wire contact surface formed on a plane parallel to the insertion direction of the wire to be detected into the notch and intersecting with the tube length direction, and the first wire contact surface and the second wire contact surface are provided on the tip side of the wire insertion section within the notch, and 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, the first virtual extension plane of the first wire contact surface and the second virtual extension plane of the second wire contact surface intersect with each other, and are inclined so that they are located closer to the tip side as they approach the intersection of the first virtual extension plane and the second virtual extension plane.

The sensor according to claim 2 is the sensor according to claim 1, in which the first electric wire contact surface and the second electric wire contact 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.

The sensor of claim 3 is the sensor of 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.

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, and an electric wire insertion section formed in a cylindrical shape from a conductive material so that the electrode holding section can be inserted, and configured so that a detection target electric wire can be inserted into a notch formed by cutting out a part of the peripheral wall at the tip side portion, and configured so that the electric wire insertion section can be moved relatively to the electrode holding section along the cylindrical length direction of the electrode holding section and the electric wire insertion section, and configured so that the amount to be detected of the detection target electric wire can be detected through the electrode in a non-contact state with the conductor in the 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 in the electric wire insertion section. A sensor, in which the wire insertion section has a first wire abutment surface and a second wire abutment surface formed on a surface parallel to the insertion direction of the wire to be detected into the notch and intersecting the tube length direction, and the first wire abutment surface and the second wire abutment surface are provided on the tip side of the wire insertion section within the notch, and the first wire abutment surface and the second wire abutment surface are inclined so that the first wire abutment surface and the second 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 the distance between the first wire abutment surface and the second wire abutment surface along the tube diameter direction of the wire insertion section becomes shorter toward the tip side.

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

The sensor according to claim 6 is the sensor according to claim 5, in which the first electric wire contact surface and the second electric 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.

The sensor according to claim 7 is a sensor according to any one of claims 1 to 6, in which 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 the rim 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 rim of the notch on the tip side to the rim of the rear end side of the wire insertion portion in the notch, and the tip side portion is formed so that 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.

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

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 with the tube length direction, are provided on the tip side of the electric wire insertion part in 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 inclined so as to be located closer to the tip side as they approach the intersection point of both imaginary extension planes.

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 in 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 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.

Therefore, according to the sensor of claims 1 and 4, when the electric wire to be detected inserted into the notch is relatively moved within the notch toward the tip side in accordance with the relative movement of the electrode with respect to the electric wire insertion portion, the electric wire to be detected is guided toward the other of the first electric wire abutting surface and the second electric wire abutting surface, whichever comes into contact with it 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 avoid holding the electric wire to be detected in a state in which the center of the electric wire (center of the core wire) is significantly displaced from an imaginary plane that is parallel to the direction of movement of the electrode with respect to the electric wire insertion portion and passes through the center of the tip surface of the electrode. This allows the positional relationship between the core wire and the center of the tip surface of the electrode to be maintained without significant differences for various types of electric wires to be detected that have different diameters (outer diameters), and therefore allows the amount to be detected of the electric wire to be detected (core wire) to 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.

In the sensor of claim 2, the first and second electric wire abutment surfaces are formed so that the first and second virtual extension planes 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 and second electric wire abutment surfaces 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, according to the sensors of claims 2 and 5, it is possible to preferably avoid the detection target electric wire being held in a state in which the center (center of the core wire) of the detection target electric wire is significantly displaced from the imaginary plane passing through the center of the tip surface of the electrode. This allows the positional relationship between the core wire and the center of the tip surface of the electrode to be maintained without significant differences for various types of electric wires to be detected that have different diameters (outer diameters), and therefore allows the amount to be detected of the electric wire to be detected (core wire) to 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.

In the sensor of 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 of 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, according to the sensors of claims 3 and 6, the center (center of the core wire) of various types of detection target electric wires having different diameters (outer diameters) can be reliably positioned on the above imaginary plane. This makes it possible to detect the amount of the detection target electric wire (core wire) with even higher accuracy.

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 detection target electric wire 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 on 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 larger than the maximum width in the first range.

Therefore, according to the sensor of claim 7, even when the sensor is attached to a detection target electric wire with a very small gap between the adjacent object and the detection target electric wire, the electric wire insertion part can be inserted into the gap so that the separation direction between the adjacent object and the detection target electric wire is aligned with the width direction of the tip side part, so that the detection target electric wire can be inserted smoothly (i.e. easily) without applying large stress to the detection target electric wire, etc. Also, even when the electric wire insertion part is inserted between the detection target electric wire and the adjacent object until the detection target electric wire, etc. is positioned to the side of the notch, a part whose width along the insertion direction gradually increases is provided within the second range, so that the tip side part can be inserted so as to gradually separate the detection target electric wire from the adjacent object, and as a result, the detection target electric wire can be inserted smoothly (i.e. easily) without applying large stress to the detection target electric wire, etc. Furthermore, because 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 entering the electrode in the wire insertion portion (i.e., without causing a decrease in shielding performance), and by disposing an electrode of sufficient thickness together with the electrode holding portion in the wire insertion portion, the detection sensitivity of the amount to be detected can be sufficiently increased.

According to the sensor described in claim 8, the tip side portion of the wire insertion portion 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 that is brought close to the detection target electric wire in the electrode, and therefore the tip side portion of the wire insertion portion can suitably prevent the intrusion of noise from the extension direction of the electrode (direction perpendicular to the electrode surface). In addition, the width of the first electric wire abutment surface and the second electric wire abutment surface in the insertion direction can be made sufficiently large, and thus a sufficiently wide range along the length of the detection target electric wire can be held by the tip of the electrode and both electric wire abutment surfaces, so that it is possible to suitably avoid a situation in which a large stress is applied to the detection target electric wire when the sensor is attached to the detection target electric wire (when the detection target electric wire is held by the sensor).

FIG. 2 is an external perspective view of the voltage sensor 1. FIG. 2 is another external perspective view of the voltage sensor 1. FIG. 2 is an enlarged perspective view of a tip portion of the voltage sensor 1. 4 is another enlarged perspective view of the tip portion of the voltage sensor 1. FIG. 4 is an explanatory diagram for explaining the shape of an insertion portion main body 21 and the size of each portion of the wire insertion portion 4. FIG. 11 is another explanatory diagram for explaining the shape of the insertion portion main body 21 and the size of each portion of the wire insertion portion 4. FIG. 11 is still another explanatory diagram for describing the shape of the insertion portion main body 21 and the size of each portion of the wire insertion portion 4. FIG. 10 is an explanatory diagram for explaining guidance of the insulated electric wire Xa by the abutment surfaces F1 and F2. FIG. 2 is an enlarged side view of a tip portion of the voltage sensor 1 when not in use. FIG. 10 is an explanatory diagram for explaining an operation of holding a coated electric wire Xa arranged adjacent to a coated electric wire Xb by a voltage sensor 1 (attaching the voltage sensor 1 to the coated electric wire Xa). 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). FIG. 1 is an explanatory diagram for illustrating a state in which a coated electric wire Xa is held by a voltage sensor 1 (the voltage sensor 1 is attached to the coated electric wire Xa). FIG. 11 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 guidance of an insulated electric wire Xa by the contact surfaces F1A, F2A. FIG. 11 is an explanatory diagram for describing the shape of contact surfaces F1B, F2B in an electric wire insertion portion 4B of a voltage sensor 1B and guidance of an insulated electric wire Xa by the contact surfaces F1B, F2B. FIG.

The following describes an embodiment of the sensor with reference to the attached drawings.

The voltage sensor 1 shown in Figures 1 and 2 is an example of a "sensor" and is configured to detect the voltage (an example of the "quantity to be detected for the electric wire to be detected") supplied to the conductor (core) of a coated electric wire Xa (an example of a "electric wire to be detected": see Figures 8, 10-12), 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 portion 3, an electric wire insertion portion 4, and a signal cable 5, and is configured so as to be attachable to the coated electric wire Xa to be detected (so that the coated 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.

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 the tip 2a (tip surface) is pressed against the insulated electric wire Xa inserted into the electric wire insertion section 4 as described later (an example of a state of "being brought close to the conductor in the insulating coating of the electric wire to be detected"), the electrode 2 is capacitively coupled with the conductor of the insulated electric wire Xa through the insulating coating of the insulated electric wire Xa. The electrode 2 is inserted into the holding section main body 11 described later in the electrode holding section 3 so that the tip 2a (tip surface) is exposed from the holding section main body 11 and integrated with the holding section main body 11 (an example of a configuration of "being held by the electrode holding section in a state of being inserted into the electrode holding section"), and a signal cable 5 is connected to the rear end within the holding section 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.

The electrode holding part 3 is an example of an "electrode holding part" and is formed into a tubular shape (cylindrical in this example). 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 so that the tip 2a (tip surface) of the electrode 2 is exposed from the tip of the holding part main body 11, and as shown in Figures 1 and 2, a grip part 11a (a grip part for a user to grip the voltage sensor 1 when using the voltage sensor 1) is disposed on the rear end side of the holding part main body 11.

In this case, the holding body 11 is formed, for example, from 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. Furthermore, the insulator 12 is formed in a tubular (cylindrical) shape so that the electrode 2 can be held against the holding body 11 while insulating the electrode 2 from the holding body 11 from each other.

The wire insertion section 4 is an example of an "electric wire insertion section" and, as shown in Figs. 1 and 2, includes an insertion section 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 wire insertion section 4 (operation knob 22) can be slid relative to the electrode holding section 3 (gripping section 11a) along the tube length direction of the electrode holding section 3 and the wire insertion section 4 (an example of a configuration in which "the wire insertion section can be moved relatively to the electrode holding section along the tube length direction").

As shown in Figures 3 to 7, the insertion section main body 21 is formed, for example, from stainless steel (an example of a "conductive material") in a tubular shape (cylindrical in this example) into which the electrode holding section 3 holding the electrode 2 can be inserted. This insertion section main body 21 is a member that constitutes the "periphery" in the area on the tip section 4a side (an example of a "tip section"), and is partially cut out to provide a notch 21a (an example of a "notch"), and is configured so that the insulated electric wire Xa or the like can be inserted into this notch 21a.

As shown in Figs. 5 and 6, the insertion 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 section 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 into 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").

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

In this case, the insertion portion body 21 of this example is formed so that the width of the insertion portion body 21 along the "insertion direction" from a position (the position of dashed line B2a in both figures) slightly closer to the rear end 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)" gradually increases toward the rear end 4b. In addition, in the insertion body 21 of this example, the portion of the insertion body 21 closer to the rear end 4b than the notch 21a is formed cylindrically, and as shown in Figures 3 to 5, the edge of the notch 21a on the rear end 4b side 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 insertion body 21 of this example, at a position closer to the tip 4a than the edge (position of dashed line B3) on the rear end 4b side of the notch 21a within the "second range (range of arrow Cb)" (position of dashed line B3a in both figures), the width of the insertion body 21 along the "insertion direction" is equal to the width Wb of the insertion body 21 at the edge (position of dashed line B3) on the rear end 4b side of the notch 21a. In other words, in the present example of the electric wire insertion section 4 (insertion section main body 21), the range along the "tube length direction" from the position of the dashed line B2a to the position of the dashed line B3a corresponds to the "area where the width along the insertion direction gradually increases."

In addition, the insertion body 21 is formed such that the "minimum width (in this example, width Wb shown in FIG. 6)" along the "insertion direction" and the "minimum height (in this example, height Hb shown in FIG. 5)" along the "first direction" are both greater than the aforementioned "maximum width (width Wa shown in FIG. 6)" in the "first range" within the "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 such that the "maximum width (width Wa shown in FIG. 6)" in the "first range" is greater than the width (diameter R2 shown in FIG. 6 in this example where the electrode 2 is cylindrical) along the "insertion direction" of the "electrode surface (end surface on the tip 2a side)" that is brought close to the coated electric wire Xa or the like in the electrode 2. In this case, the voltage sensor 1 of this example is configured so that the center in the "insertion direction" of the tip 4a side 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 coincide with each other in the tube length direction of the electrode holding portion 3 and the wire insertion portion 4.

The insertion body 21 is formed such that the width along the "insertion direction" in the above-mentioned "first range" decreases from the maximum width Wa toward the tip 4a, and the tip 4a side is located at the center of the width direction in a plan view (or bottom view). The insertion body 21 is also formed with tapered surfaces on both sides of the tip 4a side in a plan view (or bottom view) that intersect with the "tube length direction". In this case, in the insertion body 21 of this example, the length along the "tube length direction" from the tip 4a to 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).

In addition, in the present example, the insertion body 21 has both side surfaces on the tip 4a side that are linearly tapered in plan view (or bottom view), and the tip 4a is formed to be located at the center in the width direction in plan view (or bottom view), so the tip 4a is sharply pointed in plan view (or bottom view). In addition, in the present example, the insertion body 21 has the tip 4a formed to have a rounded shape as shown in Figures 3 and 6 in order to avoid injury to the coated electric wire Xa, nearby objects, or the operator's hands.

Furthermore, as shown in FIG. 5, the insertion 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 body 21 in this example is formed such that the tip side of the portion on the tip 4a side is semicircular in side view.

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," 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 relative to 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 relative to the wire insertion portion 4). As shown in FIG. 7, the contact surfaces F1 and F2 are inclined so that the imaginary extension plane of the contact surface F1 (plane shown by dashed line F1a in FIG. 7: an example of the "first imaginary extension plane") and the imaginary extension plane of the contact surface F2 (plane shown by dashed line F2a in FIG. 7: an example of the "second imaginary extension plane") intersect on an imaginary plane (plane shown by dashed line F1a in FIG. 7: an example of the "first imaginary extension 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 (vertical direction in FIG. 7)" of the electrode 2 inserted into the electric 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" (plane shown by dashed line Lc in FIG. 7: an example of the "first imaginary extension plane"), and are positioned closer to the tip portion 4a as they approach the intersection portion of the two imaginary extension planes (position shown by point Fx in FIG. 7: a linear portion extending in the depth direction at point Fx in FIG. 7).

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

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

In addition, as an example, in this voltage sensor 1, a coil spring (not shown) is housed in the wire insertion portion 4 together with the electrode holding portion 3, and as shown in FIG. 9, the elastic restoring force (biasing force in the extension direction) of the coil spring biases the wire insertion portion 4 against the electrode holding portion 3 (electrode 2) in the direction of arrow D1 (direction from the tip to the rear end of the voltage sensor 1). As a result, in the voltage sensor 1 of this example, when not in use, the tip 2a of the electrode 2 is positioned on the tip 4a side of the notch 21a in the 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.

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 is moved (slid) in the direction of the 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, so that the insulated electric wire Xa, etc. can be inserted into the notch 21a of the wire insertion portion 4 and the insulated electric wire Xa, etc. inserted into the notch 21a can be removed from the notch 21a.

Next, the method of detecting voltage using the voltage sensor 1 will be explained with reference to the attached drawings.

As mentioned above, this type of "sensor" may be used to detect one of multiple electric wires arranged close to each other, or to detect an electric wire arranged near a board, casing, or the like. As an example, we will explain an example of detecting the "detectable amount" of a "detection target electric wire" with a very narrow gap between it and an adjacent solid-line insulated electric wire Xb (proximate object), such as the insulated electric wire Xa shown by a solid line in Figure 10.

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) arranged 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 attaching the voltage sensor 1 to 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 as shown in FIG. 10, 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). This makes it possible to insert the insulated wire Xa or the like into the notch 21a.

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

In this case, as described above, in the voltage sensor 1 of this example, the tip 4a side portion of the wire insertion portion 4 (insertion portion main body 21) is formed so that the height of the portion (within the "first range") on the tip 4a side of the wire insertion portion 4 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 of the tip 4a side portion of the wire insertion portion 4 in the height direction (the most distal end portion) is in a protruding state. Therefore, unlike a configuration in which the height of the "wire insertion portion" is constant within the "first range," that is, a configuration in which the tip of the "wire insertion portion" is linear along the radial direction of the "wire insertion portion" in a side view, even if the wire insertion portion 4 is inserted with the height Ha of the wire insertion portion 4 slightly tilted relative to the extension direction of the two insulated electric wires Xa and Xb, the tip 4a (the portion with the smallest height) is inserted between the two insulated electric wires Xa and Xb before both ends (upper and lower ends) in the height Ha direction at the tip 4a side of the wire insertion portion 4 come into contact with the two insulated electric wires Xa and Xb. This makes it possible to smoothly insert the wire insertion portion 4 between the two insulated electric wires Xa and Xb.

In addition, in the voltage sensor 1 of this example, as described above, the wire insertion section 4 (insertion section main body 21) is formed so 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 maximum width Wa toward the tip end 4a. In addition, in the voltage sensor 1 of this example, the portion on the tip end 4a side is formed so that the length along the "tube length direction" from the tip end 4a to the portion of maximum width Wa in the "first range" is greater 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 and Xb are arranged very close to each other as shown by the solid lines in Figure 10, the operator can easily insert the tip end 4a into a very small gap without having to push the two insulated electric wires Xa and Xb away with his or her hands to widen the gap. In addition, in this example of the voltage sensor 1, the tip 4a has a rounded shape, so even if the tip 4a comes into contact with either of the two insulated electric wires Xa, Xb, it is possible to effectively avoid a situation in which the insulated electric wires Xa, Xb are damaged.

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

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

In addition, in the voltage sensor 1 of this example, as described above, the maximum width Wa of the portion on the tip 4a side (within the "first range") of the wire insertion portion 4 (insertion portion main body 21) is smaller than the maximum height Ha, and the width of the portion on the tip 4a side is sufficiently small. Therefore, the separation distance between the two insulated wires Xa and Xb when the portion on the tip 4a side is inserted is smaller when the direction of the width Wa of the portion on the tip 4a side is aligned with the separation direction of the two insulated wires Xa and Xb (the direction of the height Ha is aligned with the extension direction of the two insulated wires Xa and Xb) as in this example than when the tip 4a is inserted into the gap between the two insulated wires Xa and Xb with the direction of the height Ha of the portion on the tip 4a side aligned with the separation direction of the insulated wires Xa and Xb (the direction of the width Wa is aligned with the extension direction of the insulated wires Xa and Xb). This effectively prevents the application of large stress to both coated wires Xa and Xb when inserting the wire insertion section 4.

In this case, unlike the present example in which the voltage sensor 1 (wire insertion section 4) is inserted between the two insulated electric wires Xa and Xb shown by solid lines in Fig. 10, when the insulated electric wire Xa to be detected and the insulated electric wire Xb arranged nearby are located at the position of the dashed lines shown in the same figure (for example, when they are located at the same distance as the insulated electric wires Xa and Xb shown by the dashed lines that are separated 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 tip 4a side, the wire insertion section 4 can be inserted without significantly deforming the insulated electric wires Xa and Xb. However, for example, when a "sensor" (not shown) is used whose "maximum width of the tip side part in the wire insertion section" is about the same as the "maximum height of the tip side part in the wire insertion section (height Ha in the voltage sensor 1)," it is necessary to significantly deform both insulated electric wires Xa and Xb in order to insert the "tip side part" between the insulated electric wires Xa and Xb shown by solid lines. Therefore, even if the width of the portion on the tip 4a side (within the "first range") does not decrease from the portion with the maximum width Wa toward the tip 4a as in the voltage sensor 1 of this example, by making the "maximum width" sufficiently smaller than the "maximum height," it is possible to easily insert the "tip side portion" between the two closely arranged insulated electric wires Xa, Xb.

On the other hand, in order to insert the insulated electric wire Xa into the notch 21a from the state in which the insulated electric wires Xa and Xb are guided by inserting the tip 4a side of the electric wire insertion section 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 the arrow D2 relative to the insulated electric wires Xa and Xb. At this time, since there is no part with a large width exceeding the above-mentioned maximum width Wa within the "first range" of the electric wire insertion section 4, the voltage sensor 1 (electric wire insertion section 4) can be smoothly moved relative to the insulated electric wires Xa and Xb from the position shown by the dashed line in the figure to the position shown by the two-dot chain line in the figure and in Fig. 11 (the position where the insulated electric wires Xa and Xb reach the edge of the tip 4a side of the notch 21a).

Then, the voltage sensor 1 (wire insertion section 4) is rotated clockwise as viewed from the gripping section 11a side, with the center of the electrode holding section 3 and the wire insertion section 4 in the cylindrical direction as the rotation center, so that the open end of the notch 21a (the upper end in FIG. 11) approaches the insulated wire Xa. At this time, the insulated wire Xa, which was located at the rim of the tip 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, approaching the insulated wire Xb shown by the two-dot chain line.

Next, the force applied to the operation knob 22 (the operating force that moves the wire insertion part 4 in the direction of the arrow D2 relative to the electrode holding part 3) is weakened. At this time, the 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 the coil spring (not shown). In addition, as the 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 wire insertion part 4. As a result, the coated wire Xa, which was located at the position shown by the dashed line in the same figure and FIG. 12, is moved in the notch 21a together with the electrode 2 in the direction of the arrow D2 relative to the wire insertion part 4 after contacting the electrode 2, and is clamped between the wire insertion part 4 and the electrode 2 as shown by the solid line in the same figure. As a result, the tip 2a of the electrode 2 is pressed against the coated wire Xa, and the electrode 2 is capacitively coupled to the conductor of the coated wire Xa. This completes the installation of the voltage sensor 1 onto the insulated wire Xa.

In the above example of the installation work, when the wire insertion part 4 is inserted between the two insulated electric wires Xa, Xb and the two insulated electric wires Xa, Xb reach the edge of the notch 21a on the tip end 4a side, the voltage sensor 1 (wire insertion part 4) is rotated with respect to the two insulated electric wires Xa, Xb to insert the insulated electric wire Xa into the notch 21a. Instead of this method of operation, the part of the wire insertion part 4 on the tip end 4a side can be inserted between the two insulated electric wires Xa, Xb until the two insulated electric wires Xa, Xb reach a position closer to the rear end 4b than the edge of the notch 21a on the tip end 4a side, and then the voltage sensor 1 (wire insertion part 4) can be rotated to insert the insulated electric wire Xa into the notch 21a.

Specifically, the tip 4a side is inserted between the two insulated electric wires Xa and Xb until the wire insertion portion 4 is inserted at the position of the three-dot chain line shown in FIG. 10 (the state where both insulated electric wires Xa and Xb are located 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 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 to the side of the notch 21a (within the "second range") as shown by the three-dot chain line in FIG. 10, is smoothly inserted into the notch 21a without contacting the edge of the notch 21a on the tip 4a side.

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 tip 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 wire insertion portion 4 is inserted to change the relative positions of the two insulated wires Xa, Xb with respect to the voltage sensor 1 (wire insertion portion 4) from the position shown by the two-dot chain line in Fig. 10 toward the rear end 4b, the two insulated wires Xa, Xb need to be spaced apart further. However, when the voltage sensor 1 is moved in the direction of arrow D2 relative to the two insulated wires Xa, Xb (when the two insulated wires Xa, Xb are moved in the direction of arrow D1 relative to the voltage sensor 1), the two insulated 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 section 4 relative to the two insulated wires Xa and Xb, which were placed very close to each other before the wire insertion section 4 was inserted, until they are positioned to the sides of the above-mentioned "second range" in the wire insertion section 4.

After this, 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 electric wire insertion portion 4 (the tip portion 2a of the electrode 2 is pressed against the insulated electric wire Xa), so that 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.

In addition, by detecting a coated electric wire Xa that has a very small gap with a nearby coated electric wire Xb, an example has been described in which the coated electric wire Xa moves by its own restoring force to the position shown by the dashed line in Figure 11 (the position closest to the coated electric wire Xb within the notch 21a) when inserted into the notch 21a, and is then pressed against the tip 4a of the notch 21a by the electrode 2. However, depending on the positional relationship between the coated 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 coated electric wires Xa, Xb, the position of the coated electric wire Xa when inserted into the notch 21a (before the electrode 2 is moved relative to the wire insertion portion 4) may differ from the position shown in the example above. However, in the voltage sensor 1 (wire insertion portion 4) of this example, the contact surfaces F1 and F2 are provided on the tip portion 4a side within the insertion portion main body 21 as described above, so that no matter where the insulated wire Xa is located within the notch 21a, it is possible to hold the center (conductor) of the insulated wire Xa in a position aligned with the axis of the electrode 2.

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 dashed line position in the left diagram of Fig. 8 with respect to the abutment surfaces F1 and F2. When the insulated electric wire Xa is located in such a position, the electrode 2 (not shown) moves relative to the electric wire insertion portion 4 in the direction of the arrow D2 (hereinafter simply referred to as "movement of the electrode 2 relative to the electric wire insertion portion 4"), and the insulated electric wire Xa is pressed by the tip 2a of the electrode 2 and moves in the notch 21a in the direction of the arrow D2, and abuts against 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 wire Xa is moved toward the contact surface F1, as guided by the contact surface F2, and is positioned in contact with three points, the tip 2a of the electrode 2, the contact surface F2, and the contact surface F1, as shown by the solid lines in the figure.

On the other hand, unlike the above 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 relative to the abutment surfaces F1, F2. When the insulated electric wire Xa is located in 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 moves in the notch 21a in the direction of the arrow D2, and is brought into abutment against 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 wire Xa is moved toward the contact surface F2, as guided by the contact surface F1, and is positioned in contact with three points, the tip 2a of the electrode 2, the contact surface F2, and the contact surface F1, as shown by the solid lines in the figure.

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 imaginary extension plane of the abutment surface F1 (the plane shown by the dashed line F1a in Figures 7 and 8) and the imaginary 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 imaginary extension plane of the abutment surface F2 (the plane shown by the dashed line F2a in Figures 7 and 8) and the above imaginary plane are inclined so that they are equal. Therefore, regardless of whether the insulated wire Xa inserted into the notch 21a is moved toward the tip 4a by the electrode 2 and guided by the abutment surface F1 or the abutment surface F2, the insulated wire Xa is moved in the same way to a position where it contacts the tip 2a of the electrode 2 and three points of 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).

In addition, 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 wire Xa is held so as to be located on the imaginary plane, regardless of the difference in diameter. Specifically, as shown in the right diagram of FIG. 8, when the insulated wire Xa is in contact with three points, the tip 2a of the electrode 2 and the contact surfaces F1 and F2, the center (point Xc) of the insulated wire Xa shown by the solid line, the center (point Xc) of the thin insulated wire Xa shown by the dashed line, and the center (point Xc) of the thick insulated wire Xa shown by the dashed line are all located on the imaginary plane (plane shown by the dashed line Lc). In this manner, in this voltage sensor 1 (wire insertion section 4), even if the diameter (outer diameter) of the coated wire Xa differs, the positional relationship between the center of the coated wire Xa (core wire) and the central portion (in this example, the center) 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 a situation in which the state of the capacitive coupling between the coated wire Xa (core wire) and the electrode 2 changes due to differences in positional relationship is avoided.

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 attachment work examples, the measurement process is started by operating the operation unit (not shown) of the measurement device connected via the signal cable 5. Note that the 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 voltage detection 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 newly detecting the voltage of a "detection target electric wire" other than the insulated electric wire Xa, the attachment work etc. are performed in the same procedure as the above series of work in which the insulated electric wire Xa is 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 way as for the insulated electric wire Xa.

In this case, in the voltage sensor 1 of this example, 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 Figures 5 and 6)" are larger than the maximum width Wa described above in the "first range". Therefore, compared to a configuration in which the "third range" is formed narrower like the portion on the tip 4a side of the wire insertion portion 4 (the portion where the notch 21a is formed: within the "first range" and "second range"), the physical strength of the wire insertion portion 4 is sufficiently high, and the shielding effect of the electrode 2 by the wire insertion portion 4 is also sufficiently high. In addition, by configuring the electrode holding portion 3 (electrode 2) to be inserted into a portion of the wire insertion portion 4 with a sufficiently large width and height (within the "third range"), the diameter R2 of the electrode 2 is sufficiently large, and the voltage detection sensitivity is sufficiently high.

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 greater than the width (diameter R2 in this example shown in FIG. 6) 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, etc., 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 configured to coincide 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 to the left in FIGS. 10 to 12 (in front of the tip 4a of the wire insertion portion 4 of the voltage sensor 1), the situation in which the noise is detected by the electrode 2 is suitably avoided.

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

In this manner, in this voltage sensor 1, the abutment surfaces F1 and F2, each formed on a plane parallel to the "insertion direction" of the coated 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, are provided on the tip 4a side of the electric wire insertion portion 4 within the notch 21a, and the "first virtual extension plane" of the abutment surface F1 and the "second virtual extension plane" of the abutment surface F2 intersect on an "imaginary plane" that passes through the center of the electrode 2 in the "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 that they are positioned closer to the tip 4a side as they approach the intersection of both "imaginary extension planes".

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 in accordance with the relative movement of the electrode 2 with respect 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 contact with three points, the tip 2a of the electrode 2 and the abutment surfaces F1, F2. This makes it possible to preferably avoid the insulated electric wire Xa being held in a state in which 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 direction of movement 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 2a of the electrode 2. This allows the positional relationship between the core wire and the center of the tip 2a of the electrode 2 to be maintained without significant differences for various types of coated electric wires Xa with different diameters (outer diameters), and allows the voltage of the coated electric wire Xa (core wire) to be detected with high accuracy without causing a situation in which the state of capacitive coupling between the core wire of the coated electric wire Xa and the electrode 2 differs due to the above-mentioned differences in positional relationship.

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 preferably 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 "virtual plane" passing through the center of the tip portion 2a of the electrode 2. As a result, for various insulated electric wires Xa with 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, so that the voltage of the insulated electric wire Xa (core wire) can be detected with higher accuracy without inviting 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 above-mentioned positional relationship.

In addition, with this voltage sensor 1, the contact surfaces F1 and F2 are inclined so that the "first intersection angle" between the "first virtual extension plane" and the "virtual plane" and the "second intersection angle" between the "second virtual extension plane" and the "virtual plane" are equal to each other. This makes it possible to reliably position the center (center of the core wire) of various types of insulated electric wires Xa with different diameters (outer diameters) on the above-mentioned virtual plane. This makes it possible to detect the voltage of the insulated electric wire Xa (core wire) with even higher accuracy.

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

Therefore, according to this voltage sensor 1, even when the voltage sensor 1 is attached to the insulated electric wire Xa with a very small gap between it and a nearby object (e.g., the insulated electric wire Xb), the wire insertion part 4 can be inserted into the gap so that the separation direction between the nearby object and the insulated electric wire Xa is aligned with the width direction of the part on the tip 4a side, allowing the insulated electric wire Xa, etc. to be inserted smoothly (i.e., easily) without applying significant stress to the insulated electric wire Xa, etc. Also, even when the wire insertion part 4 is inserted between the insulated electric wire Xa and the nearby object until the insulated electric wire Xa, etc. is positioned to the side of the notch 21a, a part in which the width along the "insertion direction" gradually increases is provided within the "second range", so that the part on the tip 4a side can be inserted so as to gradually separate the insulated electric wire Xa from the nearby object, allowing the insulated electric wire Xa, etc. to be inserted smoothly (i.e., easily) without applying significant stress to the insulated electric wire Xa, etc. Furthermore, because the width and height of the electric wire insertion portion 4 in the "third range" are sufficiently large, the physical strength of the electric wire insertion portion 4 is sufficiently high, and the intrusion of noise into the electrode 2 inside the electric wire insertion portion 4 can be effectively prevented (i.e., without causing a decrease in shielding performance), and by disposing the electrode 2 of sufficient thickness together with the electrode holding portion 3 inside the electric wire insertion portion 4, the detection sensitivity of the "quantity to be detected (voltage in this example)" can be sufficiently increased.

In addition, according to this voltage sensor 1, the tip 4a side portion 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 (in this example, the diameter R2 of the electrode 2) along the "insertion direction" of the "electrode surface (tip 2a)" that is brought close to the insulated electric wire Xa in the electrode 2. This allows the tip 4a side portion of the wire insertion portion 4 to suitably prevent noise from entering from the extension direction of the electrode 2 (the direction perpendicular to the electrode 2 surface). In addition, the width of the abutment surfaces F1 and F2 along the "insertion direction" 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 and F2. This makes it possible to suitably avoid a situation in which a large stress is applied to the insulated electric wire Xa when the voltage sensor 1 is attached to the insulated electric wire Xa (when the insulated electric wire Xa is held by the voltage sensor 1).

The configuration of the "sensor" is not limited to the above-mentioned example of the voltage sensor 1. For example, the contact surfaces F1 and F2 are inclined so that the 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 coated 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 relative 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) is equal to the 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, but a configuration in which the angles θ1 and θ2 are slightly different can also be adopted. In this case, even if the angles θ1 and θ2 are different, by tilting the contact surfaces F1 and F2 so that the imaginary extension planes of the contact surfaces F1 and F2 intersect with the imaginary plane, it is possible to preferably avoid holding the center of the insulated electric wire Xa (core wire) in a state where it is significantly misaligned from the imaginary plane.

In addition, the configuration of the voltage sensor 1 having the wire insertion portion 4 in which the abutment surface F1 (first wire abutment surface) and the abutment surface F2 (second wire abutment surface) are 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 the direction perpendicular to both the "insertion direction" and the "tube length direction", has been described as an example. 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 the 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 effectively avoid holding the "detection target electric wire" in a state where its center is significantly misaligned from the "imaginary plane" that is parallel to the movement direction of the "electrode" relative to the "electric wire insertion portion" and passes through the center of the tip of the "electrode," so the "detection amount" of the "detection target electric wire" can be detected with high accuracy.

In addition, the configuration of the voltage sensor 1 having the wire insertion section 4 in which the abutment surface F1 as the "first wire abutment surface" and the abutment surface F2 as the "second wire abutment surface" are configured on a plane parallel to the "insertion direction" of the insulated wire Xa relative to the notch 21a and intersecting with the "tube length direction" of the wire insertion section 4 and the electrode holding section 3 has been described as an example, but the "first wire abutment surface" and the "second wire abutment surface" formed on the "wire insertion section" 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 other examples of "sensors", and are configured to detect the voltage supplied to the conductor (core) of the insulated wire Xa in a non-contact state with the conductor, similar to the voltage sensor 1 described above. In this case, voltage sensor 1A has a wire insertion section 4A instead of the wire insertion section 4 in voltage sensor 1, and voltage sensor 1B has a wire insertion section 4B instead of the wire insertion section 4 in voltage sensor 1.

The components of the voltage sensors 1A, 1B other than the wire insertion portions 4A, 4B are similar to the corresponding components of the voltage sensor 1, so detailed descriptions are omitted. In addition, the parts of the wire insertion portions 4A, 4B other than the contact surfaces F1A, F1B and contact surfaces F2A, F2B described below are formed in the same manner as the corresponding parts of the wire insertion portion 4, so illustrations and detailed descriptions are omitted.

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 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 on 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 figure)) that are parallel to the "insertion direction" of the insulated 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 and F2A are formed to contact each other on an "imaginary plane (plane indicated by dashed line Lc)" that passes through the center of electrode 2 in a direction perpendicular to both the "insertion direction" and the "cylinder length direction" (as an example, the center: the axis of electrode 2) and is parallel to both the "insertion direction" and the "cylinder length direction".

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 (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 (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 "imaginary plane (dashed line Lc)" described above.

In a voltage sensor 1A having a wire insertion section 4A with such abutment surfaces F1A and F2A, when the electrode 2 is moved relative to the wire insertion section 4A in the direction of the arrow D2 with the insulated wire Xa positioned at the back of the notch 21a (the insulated wire Xa positioned 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 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 as guided by the abutment surface F2A, and is positioned in a state of abutment against three points, the tip 2a of the electrode 2, the abutment surface F2A, and the abutment surface F1A, as shown by the solid line in the diagram.

When the electrode 2 is moved relative to the wire insertion section 4A in the direction of the arrow D2 with the insulated wire Xa positioned near the edge of the notch 21a (the insulated wire Xa positioned at the upper dashed line 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 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 wire Xa is moved toward the abutment surface F2A, as guided by the abutment surface F1A, and is positioned in a state of abutment against three points, 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.

In this case, as described above, in this voltage sensor 1A (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 of the wire insertion portion 4A becomes shorter toward the tip end of the wire insertion portion 4A. Therefore, even if the insulated 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 wire Xa is moved in the same way to a position where it contacts the tip end 2a of the electrode 2 and the abutment surfaces F1A and F2A at three points (detection position for detecting the "detectable amount": position shown by solid lines in the left diagram of Figure 13).

In addition, in this voltage sensor 1A (wire insertion section 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 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 Figure 13, when the insulated wire Xa is in contact with three points, the tip 2a of the electrode 2 and the contact surfaces F1A and F2A, the center (point Xc) of the insulated wire Xa shown by the solid line, the center (point Xc) of the thin-diameter insulated wire Xa shown by the dashed line, and the center (point Xc) of the thick-diameter insulated 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 section 4A), even if the diameter (outer diameter) of the coated wire Xa differs, the positional relationship between the center of the coated wire Xa (core wire) and the central portion (in this example, the center) 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 a situation in which the state of the capacitive coupling between the coated wire Xa (core wire) and the electrode 2 changes due to differences in the positional relationship is avoided.

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, abutment surfaces F1B (yet another example of a "first wire abutment surface") and F2B (yet another example of a "second wire abutment surface") are formed on a surface (in this example, a "curved surface" curved in a direction protruding toward the base end side (right side in the same figure) of the wire insertion portion 4B) 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 wire insertion portion 4B and the electrode holding portion 3, respectively, and are provided on the tip side of the wire insertion portion 4B within the notch 21a. In this case, the abutment surfaces F1B and F2B are formed to contact each other on an "imaginary plane (plane indicated by dashed line Lc)" that passes through the center of electrode 2 in a direction perpendicular to both the "insertion direction" and the "cylinder length direction" (as an example, the center: the axis of electrode 2) and is parallel to both the "insertion direction" and the "cylinder length direction".

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 (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 (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 "imaginary plane (dashed line Lc)" described above.

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 relative to the wire insertion portion 4B in the direction of the arrow D2 with the insulated wire Xa inserted into 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 the 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. In addition, the insulated wire Xa, guided by the contact surfaces F1B and F2B, is positioned in contact with three points on the tip 2a of the electrode 2, the contact surface F1B, and the contact surface F2B, as shown by solid lines in the figure.

In this case, as described above, in this voltage sensor 1B (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 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 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 F1B or the abutment surface F2B, the insulated wire Xa is similarly moved to a position where it contacts the tip end 2a of the electrode 2 and the abutment surfaces F1B and F2B at three points (detection position where the "detectable amount" is detected: position shown by solid lines in the left diagram of FIG. 14).

In addition, in this voltage sensor 1B (wire insertion section 4B), in which the contact surfaces F1B and 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 section 4B), as in the above-mentioned voltage sensor 1A (wire insertion section 4A), even if the diameter (outer diameter) of the insulated electric wire Xa differs, 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), so that 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.

In this manner, in the voltage sensors 1A and 1B, the abutment surfaces F1A, F1B and F2A, F2B, which are formed on surfaces 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 4A, 4B and the electrode holding portion 3, are provided on the tip portion 4a side of the electric wire insertion portion 4A, 4B in 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 so that the distance between the abutment surfaces F1A, F1B and F2A, F2B along the "tube diameter direction" of the electric wire insertion portion 4A, 4B and the electrode holding portion 3 becomes shorter toward the tip portion 4a.

Therefore, according to the voltage sensors 1A and 1B, when the insulated electric wire Xa inserted into the notch 21a is relatively moved within the notch 21a toward the tip 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 F1B, F2B, whichever comes into contact with it first, and is ultimately held in contact with three points of the tip 2a of the electrode 2, the abutment surfaces F1A, F2A and the abutment surfaces F1B, F2B. This makes it possible to preferably avoid the insulated electric wire Xa being held in a state in which the center (center of the core wire) of the insulated electric wire Xa is significantly displaced from an imaginary plane that is parallel to the direction of movement 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 2a of the electrode 2. This allows the positional relationship between the core wire and the center of the tip 2a of the electrode 2 to be maintained without significant differences for various types of coated electric wires Xa with different diameters (outer diameters), and allows the voltage of the coated electric wire Xa (core wire) to be detected with high accuracy without causing a situation in which the state of capacitive coupling between the core wire of the coated electric wire Xa and the electrode 2 differs due to the above-mentioned differences in positional relationship.

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 contact 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, with the voltage sensors 1A and 1B, it is possible to preferably 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 with 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, so that 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 above-mentioned positional relationship.

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 wires Xa with different diameters (outer diameters) can be reliably positioned on the "imaginary plane." This makes it possible to detect the voltage of the insulated wire Xa (core wire) with even higher accuracy.

The "first electric wire contact surface" and the "second electric wire contact surface" that meet on the "imaginary plane" are not limited to "curved surfaces" such as the above-mentioned contact surfaces F1A, F1B and contact surfaces F2A, F2B, but can be configured with various "surfaces" that form free curves or broken lines when viewed along the "insertion direction".

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 F2A, F2B are in contact on an "imaginary plane" passing through the center of electrode 2 (an example of a "center") in a direction perpendicular to both the "insertion direction" and the "tube length direction". However, the "wire insertion portion" can also be configured so that the "first wire abutment surface" and the "second wire abutment surface" are in contact on an "imaginary plane" passing through a portion (another example of a "center") 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 effectively avoid holding the "detection target electric wire" in a state where its center is significantly misaligned from the "imaginary plane" that is parallel to the movement direction of the "electrode" relative to the "electric wire insertion portion" and passes through the center of the tip of the "electrode," so the "detection amount" of the "detection target electric wire" can be detected with high accuracy.

In addition, the configuration has been described as an example in which the insulated wire Xa can be inserted into the notch 21a and removed from the notch 21a by sliding the wire insertion section 4 (operation knob 22) relative to the electrode holding section 3 (grip section 11a), but it is also possible to adopt a configuration in which the insulated wire Xa can be inserted and removed by sliding the "electrode holding section" relative to the "wire insertion section" or by sliding both the "electrode holding section" and the "wire insertion section". In addition, the voltage sensor 1 has been described as an example in which the cylindrical electrode 2 is held by the cylindrical electrode holding section 3 and the cylindrical electrode holding section 3 is inserted into the cylindrical wire insertion section 4, but the "electrode" can be formed into a square column, and the "electrode holding section" and the "wire insertion section" can be formed into a square tube.

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 quantity" 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 quantity" (not shown). Also, although the voltage sensor 1 that detects the "detectable quantity" via the electrode 2 that is capacitively coupled to 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 that detects the "detectable quantity" via an "electrode" that is electromagnetically inductively coupled to the conductor, or that detects the "detectable quantity" via an "electrode" that is electric field coupled to the conductor.

1, 1A, 1B Voltage sensor 2 Electrode 2a Tip part 3 Electrode holding part 4, 4A, 4B Wire insertion part 4a Tip part 4b Rear end part 5 Signal cable 11 Holding part body 11a Grip part 12 Insulator 21 Insertion part body 21a Notch 22 Operation knob F1, F1A, F1B, F2, F2A, F2B Contact surface F1a One-dot chain line F2a Two-dot chain line Fx Point Ha, Hb Height L1, L2 Length Lc Broken line R2 Diameter Wa, Wb Width Xa, Xb Covered wire θ1, θ2 Angle

Claims (8)

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. The sensor according to claim 1, wherein the first electric wire contact surface and the second electric wire contact 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. 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. 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. The sensor according to claim 4, wherein the first electric wire contact surface and the second electric 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. The sensor according to claim 5, wherein 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 holding portion is viewed along the insertion direction. The sensor according to any one of claims 1 to 6, wherein the maximum width along the insertion direction within a first range along the tube length direction from the tip to the rim of the notch on the tip side is smaller than the maximum height along the 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 rim of the notch on the tip side to the rim of the rear end side of the wire insertion portion in the notch, and the tip side portion is formed such that 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 larger than the maximum width in the first range within a third range toward the rear end side of the rim of the rear end side of the notch. 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 equal to or greater than the width along the insertion direction of the electrode surface that is brought close to the electric wire to be detected.

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