JP2018077183A - Clamp sensor and measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve detection accuracy, as improving workability.SOLUTION: A clamp sensor comprises: a main body part 10; clamp parts 11a and 11b that are rotatably disposed in the main body part 10, surround an electric wire 50 and detect an amount to be detected about the electric wire 50 in a closed state where each contact part provided in each of tip end surfaces of tip end parts 21a and 21b of the clamp parts is in contact with each other; and an urging unit that urges the clamp parts 11a and 11b in a revolving direction A where the clamp parts 11a and 11b are put into the closed state. In the tip end parts 21a and 21b of the clamp parts 11a and 11b, guide parts 25a and 25b are provided that are configured to be gradually spaced apart from each other as heading for a tip end, and guide the electric wire 50, and when the guide parts 25a and 25b are pushed against the electric wire 50, the clamp parts 11a and 11b are configured to resist urging force of the urging unit to revolve in a revolving direction B reverse to the revolving direction A.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a clamp sensor that detects an amount to be detected for a detection target, and a measurement apparatus including the clamp sensor.

  As this type of measuring apparatus, a non-contact current measuring instrument (hereinafter also referred to as “current measuring instrument”) disclosed in Patent Document 1 below is known. This current measuring device is an open type current measuring device, and is configured to be able to measure the current flowing through the measuring object without clamping the measuring object (measuring conductor). Specifically, the current measuring device includes a magnetic flux capturing core having a gap portion (gap) and formed in a substantially U shape, and Hall elements disposed at both ends of the gap of the magnetic flux capturing core. The sensor part which has this. In this current measuring instrument, when the measuring object is positioned inside the magnetic flux capturing core, the magnetic flux generated by the current flowing through the measuring object is converged on the magnetic flux capturing core, and the Hall element detects this magnetic flux, It is possible to measure the current flowing through the measurement object. In this case, since the current measuring device can measure the current by positioning the measuring object in the ring of the magnetic flux capturing core without clamping the measuring object, for example, a pair of sensor units are rotated. Compared with a measuring apparatus that moves and clamps a measurement object, it is possible to improve workability because a clamping operation is unnecessary.

Japanese Patent Laid-Open No. 2002-5967 (page 2-3, FIGS. 1 and 5)

  However, the current measuring instrument has the following problems to be improved. Specifically, since the current measuring instrument uses a magnetic flux capturing core having a gap, the workability is improved, but the detection accuracy may be lowered. More specifically, in the above current measuring device, when the measurement object is located at the “U-shaped” straight portion of the magnetic flux capturing core defined as an appropriate conductor position of the magnetic flux capturing core, the current measuring device is marked. Although a large detection error does not occur, a detection error may occur when the measurement target is not positioned at an appropriate conductor position (for example, when it is positioned at the bottom or opening of the “U” shape). Therefore, in this current measuring device, it is difficult to achieve both improvement in workability and improvement in detection accuracy, and development of a technique capable of improving this point is desired.

  The present invention has been made in view of such a problem, and a main object of the present invention is to provide a clamp sensor and a measuring apparatus that can improve the detection accuracy while improving workability.

  In order to achieve the above object, the clamp sensor according to claim 1 is provided on the front end surface of each of the front end portions, and at least one of the main body portion is rotatably disposed on the main body portion and surrounds the detection target. A pair of clamp portions that detect a detection amount for the detection target in a closed state in which the contact portions are in contact with each other, and the rotation in the first rotation direction in which the clamp portions are in the closed state. A clamp sensor including a biasing portion that biases a movable clamp portion, wherein each tip portion of each clamp portion is configured to be separated from each other toward the tip, and the detection target is Each of the guide portions for guiding is provided, and the rotatable clamp portion is adapted to resist the biasing force of the biasing portion when the guide portion is pressed against the detection target. Opposite to the direction of movement Kino is configured to be rotatable in a second rotational direction.

  According to a second aspect of the present invention, the clamp sensor according to the first aspect is capable of performing an operation of rotating the rotatable clamp portion in the second rotational direction against the biasing force. An operation unit is provided.

  A clamp sensor according to a third aspect is the clamp sensor according to the first or second aspect, wherein both of the clamp portions are rotatably disposed on the main body portion.

  According to a fourth aspect of the present invention, in the clamp sensor according to any one of the first to third aspects, the magnetism as the detected amount is detected in the tip portion of at least one of the clamp portions. The magnetic detection element is arranged, and either one of the clamp portions is formed in a convex shape in which the contact portion protrudes from the tip end surface, and a protrusion portion that protrudes from the convex contact portion. Provided in the vicinity of the convex contact portion, the other of the clamp portions is formed in a concave shape in which the contact portion is recessed from the distal end surface and can be fitted to the convex contact portion, and the closed portion is closed. In the state, the accommodating portion for accommodating the protruding portion is provided in the vicinity of the concave contact portion.

  According to a fifth aspect of the present invention, there is provided a measuring apparatus that measures a measured amount of the detection target based on the clamp sensor according to any of the first to fourth aspects and the detected amount detected by the clamp sensor. And a measuring unit to perform.

  According to the clamp sensor according to claim 1 and the measuring device according to claim 5, a guide portion configured to guide the detection target by being separated from each other toward the tip is provided at each tip portion of each clamp portion. As a result, it is possible to surround (clamp) the detection target with each clamp unit simply by pressing each guide unit against the detection target, and thus the workability can be sufficiently improved. Further, according to the clamp sensor and the measuring apparatus, for example, in the configuration in which the core is disposed in the clamp portion, the detection target can be surrounded by each core when the detection target is clamped by each clamp portion. Unlike the conventional configuration, which detects a magnetic field in the state and may cause a detection error depending on the position of the detection target inside the core having the gap portion, regardless of the position of the detection target on the inner periphery of each clamp portion The magnetism can be accurately detected. Therefore, according to the clamp sensor and the measuring apparatus, it is possible to sufficiently improve detection accuracy while improving workability.

  Moreover, according to the clamp sensor of Claim 2, and the measuring apparatus of Claim 5, operation which can be operated to rotate the clamp part which can be rotated in the 2nd rotation direction against biasing force Since the detection target is thin or soft due to the provision of the portion, the reaction force is not applied to each guide portion so that the tip portions of the clamp portions are separated from each other when the guide portions are pressed against the detection target. Even in the case, the detection target can be reliably clamped at each clamp portion.

  Further, in the clamp sensor according to claim 3 and the measuring apparatus according to claim 5, both of the clamp portions are rotatably disposed on the main body portion. In this case, in the configuration in which only one of the clamp portions is rotatable, for example, when the detection target is arranged in the vicinity of the wall surface, when one clamp portion is positioned on the wall surface side, the detection target is Even if each guide portion is pressed against the wall, rotation of one of the clamp portions is hindered by the wall surface, making it difficult to clamp the detection target. On the other hand, in the clamp sensor and the measuring apparatus, since both of the clamp portions can be rotated, even if the rotation of one clamp portion is obstructed, the other clamp portion can be rotated. As a result, the detection target can be reliably clamped even in such a situation.

  Moreover, according to the clamp sensor of Claim 4, and the measuring apparatus of Claim 5, while forming any one contact part of each clamp part in the convex shape which protrudes from a front end surface, a convex contact part Protruding part that protrudes more in the vicinity of the convex contact part, and the other contact part of each clamp part is formed in a concave shape that is recessed from the tip surface, so that the detection target and each contact when clamping the detection target Wear of each contact portion due to sliding with the portion can be reliably prevented. Therefore, according to the clamp sensor and the measuring apparatus, for example, in the configuration in which the core is disposed in the clamp portion, the positional relationship between the core and the magnetic detection element in the closed state changes due to wear of each contact portion. It is possible to reliably prevent a situation in which the detection accuracy is lowered due to the above.

1 is a configuration diagram showing a configuration of a current measuring device 1. FIG. It is a perspective view of clamp sensor 2 when clamp parts 11a and 11b are in a closed state. It is a perspective view of clamp sensor 2 when clamp parts 11a and 11b are in an open state. It is the perspective view which looked at the clamp sensor 2 when the clamp parts 11a and 11b are in an open state from the opposite side to FIG. 3 is an exploded perspective view of the clamp sensor 2. FIG. It is the 1st explanatory view explaining how to use clamp sensor 2. It is the 2nd explanatory view explaining how to use clamp sensor 2. It is the 3rd explanatory view explaining how to use clamp sensor 2. It is the 4th explanatory view explaining how to use clamp sensor 2. It is a 5th explanatory view explaining how to use clamp sensor 2.

  Hereinafter, embodiments of a clamp sensor and a measuring apparatus will be described with reference to the accompanying drawings.

  First, the configuration of the current measuring device 1 shown in FIG. 1 will be described. The current measuring device 1 is an example of a measuring device, and is configured to be able to measure a current (an example of an amount to be measured) flowing in an electric wire 50 (an example of a detection target) shown in FIG. Has been. Specifically, as shown in FIG. 1, the current measurement device 1 includes a clamp sensor 2, a measurement unit 3, and a display unit 4.

  The clamp sensor 2 is an example of a clamp sensor, and as shown in FIGS. 2 to 5, as shown in FIG. 2 to FIG. 5, a main body portion 10 and a pair of clamp portions 11 a and 11 b (hereinafter also referred to as “clamp portion 11”). It is configured with.

  The main body 10 is a part that is gripped by the user during measurement, and as an example, is formed in a substantially rectangular parallelepiped shape as shown in FIGS. Further, as shown in FIG. 5, the main body 10 is configured to include cases 10a and 10b that can be fitted to each other, and accommodates the spring 16 and the substrate 18 shown in FIG. As shown in FIGS. 2 to 4, operation portions 17 a and 17 b are respectively arranged on both side surfaces of the main body portion 10, and on the distal end side (upper end side in each drawing) of the main body portion 10, Clamp portions 11a and 11b are provided.

  As shown in FIGS. 2 to 4, the clamp portions 11 a and 11 b are each formed in a substantially arc shape in plan view. The clamp portions 11a and 11b are pivotally supported on the distal end side of the main body portion 10 by the pins 14a and 14b shown in FIG. 5 on the base end portions 22a and 22b side, and the base end portions 22a and 22b side (pins 14a and 14b). 14b) is disposed in the main body 10 so as to be rotatable about the rotation center. In addition, the clamp portions 11a and 11b are pressed in a direction in which the base end portions 22a and 22b are separated from each other by the urging force of the spring 16 disposed in the main body portion 10, and thereby the tip ends of the respective tip end portions 21a and 21b. A state in which two contact portions 24a and 24b (see FIGS. 3 and 4) provided on the surfaces 23a and 23b are in contact with each other (a state shown in FIG. 6; hereinafter, this state is also referred to as a “closed state”). The first rotation direction (the rotation direction A shown in FIGS. 6, 9, and 10) is urged.

  In this case, as shown in FIG. 3, the two contact parts 24b of the clamp part 11b (one of the clamp parts 11) are formed in a convex shape protruding from the tip surface 23b. Further, as shown in FIG. 4, the two contact portions 24a of the clamp portion 11a (the other of the clamp portions 11) are recessed from the tip surface 23a, and the corresponding contact portions 24b (convex contact portions) of the clamp portion 11b. ) And a concave shape that can be fitted.

  As shown in FIG. 3, two protrusions 26 that protrude from the contact portion 24b are provided in the vicinity of the contact portion 24b (convex contact portion) at the distal end portion 21b of the clamp portion 11b. Further, as shown in FIG. 4, in the vicinity of the contact portion 24a (concave contact portion) at the distal end portion 21a of the clamp portion 11a, the corresponding protrusions 26 of the clamp portion 11b in the closed state of the clamp portions 11 are provided. Two accommodating portions 27 to be accommodated are provided.

  Moreover, as shown in FIGS. 2-4, the electric wire 50 (detection object) is guided to each front-end | tip part 21a, 21b in clamp part 11a, 11b toward the contact part 24a, 24b of clamp part 11a, 11b. Guide portions 25a and 25b are provided. In this case, as shown in FIG. 6, the guide portions 25 a and 25 b are separated from each other toward the tip (expanded) in the closed state of each clamp portion 11, and are opposed to each other. Are inclined with respect to the length direction of the clamp sensor 2 (vertical direction in the figure). By providing the guide portions 25a and 25b, in the clamp sensor 2, when the guide portions 25a and 25b are pressed against the electric wire 50 (detection target) as shown in FIGS. 11 a and 11 b can be rotated in the rotation direction B (second rotation direction opposite to the first rotation direction) against the biasing force of the spring 16.

  In the clamp sensor 2, the clamp portions 11 a and 11 b are moved by pushing the operation portions 17 a and 17 b (see FIG. 6) disposed in the main body portion 10 against the urging force of the spring 16. It is possible to rotate in a second rotation direction (rotation direction B shown in the figure) opposite to the rotation direction A (first rotation direction).

  Moreover, as shown in FIG. 5, the clamp parts 11a and 11b are respectively provided with cases 12a and 12b, and substantially arc-shaped cores 13a and 13b are accommodated in the cases 12a and 12b, respectively. Further, as shown in the figure, a magnetic detection element 15 for detecting magnetism and outputting a detection signal is disposed inside the distal end portion 21a of the clamp portion 11a (an example of at least one of the clamp portions 11a and 11b). Has been. In this case, the magnetic detection element 15 is comprised with the Hall element as an example. Further, the magnetic detection element 15 is connected to a substrate 18 for processing (for example, amplification processing and AD conversion processing) a detection signal output from the magnetic detection element 15 via a wiring substrate 15a disposed in the case 12a. Has been.

  As shown in FIG. 10, the clamp portions 11 a and 11 b surround the electric wire 50 (clamp) and are in a closed state, so that the cores 13 a and 13 b that surround the electric wire 50 by the current flowing through the electric wire 50. The magnetic detection element 15 detects the magnetic field generated at, and outputs a detection signal.

  The measuring unit 3 measures the current value of the current flowing through the electric wire 50 (an example of the amount to be measured) based on the detection signal output from the clamp sensor 2. The display unit 4 displays the current value measured by the measurement unit 3.

  Next, a method for measuring the current value of the current flowing through the electric wire 50 as a detection target using the current measuring device 1 will be described with reference to the drawings. In the initial state, as shown in FIG. 2, the clamp portions 11a and 11b of the clamp sensor 2 are closed (the contact portions 24a and 24b (see FIGS. 3 and 4) are in contact). To do.

  First, the start of measurement is instructed by operating an operation unit (not shown). Next, the electric wire 50 is clamped by the clamp portions 11 a and 11 b of the clamp sensor 2. Specifically, as illustrated in FIG. 6, the clamp sensor 2 is configured such that the electric wire 50 is positioned between the guide portions 25 a and 25 b provided at the tip portions 21 a and 21 b of the clamp portions 11 a and 11 b in the clamp sensor 2. 2 is moved toward the electric wire 50.

  Subsequently, as shown in FIG. 7, the clamp sensor 2 is further moved toward the electric wire 50, and the guide portions 25 a and 25 b are pressed against the electric wire 50. At this time, the reaction force of the pressing force applied to the electric wire 50 by pressing the guide portions 25a and 25b against the electric wire 50 is applied to the opposing surfaces 31a and 31b of the guide portions 25a and 25b. In this case, since the opposing surfaces 31a and 31b are inclined with respect to the length direction of the clamp sensor 2, the reaction force from the electric wire 50 is applied to the opposing surfaces 31a and 31b in the rotation direction B (second rotation). In the direction of movement). As a result, the clamp portions 11a and 11b rotate in the rotation direction B against the urging force of the spring 16 as shown in FIG. Further, the tip portions 21a and 21b are separated from each other by the rotation of the clamp portions 11a and 11b in the turning direction B, and contact portions 24a and 24b (respectively provided on the tip surfaces 23a and 23b of the tip portions 21a and 21b). 3) is released (the closed state is released).

  Next, as shown in FIG. 8, the clamp sensor 2 is further moved, and the electric wire 50 is passed through the gap between the tip portions 21 a and 21 b of the clamp portions 11 a and 11 b generated by the rotation in the rotation direction B.

  Here, in this clamp sensor 2, as shown in FIG. 4, the contact portion 24a of the clamp portion 11a is formed in a concave shape recessed from the tip surface 23a. The electric wire 50 passing through the gap between the portions 21a and 21b slides with the distal end surface 23a without sliding with the contact portion 24a. Further, as shown in FIG. 3, the contact portion 24b of the clamp portion 11b is formed in a convex shape protruding from the tip surface 23b, but the protruding portion 26 protruding from the contact portion 24b is located in the vicinity of the contact portion 24b. Is provided. For this reason, as shown in FIGS. 7 and 8, the electric wire 50 passing through the gap between the tip portions 21a and 21b slides with the protrusion 26 without sliding with the contact portion 24b. In other words, in the clamp sensor 2, the contact portion 24a is formed in a concave shape and the protrusion 26 is provided, so that the contact portions 24a, 24b by sliding between the electric wire 50 and the contact portions 24a, 24b when the electric wire 50 is clamped are provided. It is possible to reliably prevent the wear of 24b.

  Next, as shown in FIG. 9, when the electric wire 50 passes through the gap between the tip portions 21a and 21b, the reaction force from the electric wire 50 against the tip portions 21a and 21b is released, as shown in FIGS. Further, the clamp portions 11 a and 11 b are rotated in the rotation direction A (first rotation direction) by the biasing force of the spring 16. At this time, as shown in FIG. 10, the protruding portion 26 of the clamp portion 11b is accommodated in the accommodating portion 27 of the clamp portion 11a, and the contact portions 24a and 24b (see FIGS. 3 and 4) are brought into contact with each other. The parts 11a and 11b are closed. Thereby, the electric wire 50 is clamped by the clamp portions 11a and 11b, and the electric wire 50 is surrounded by the cores 13a and 13b of the clamp portions 11a and 11b.

  As described above, in this clamp sensor 2, it is possible to press the guide portions 25 a and 25 b provided at the tip portions 21 a and 21 b of the clamp portions 11 a and 11 b against the electric wire 50 without operating the operation portions 17 a and 17 b. 50 can be clamped. For this reason, in this clamp sensor 2, workability | operativity can fully be improved.

  Next, the magnetic detection element 15 disposed in the clamp portion 11a detects a magnetic field generated in the cores 13a and 13b of the clamp portions 11a and 11b by the current flowing through the electric wire 50, and outputs a detection signal. In addition, the detection signal is processed (for example, amplification processing and AD conversion processing) by the substrate 18 connected to the magnetic detection element 15 via the wiring substrate 15 a and is output to the measurement unit 3. Next, the measurement unit 3 measures a current value based on the detection signal. Subsequently, the display unit 4 displays the measurement value measured by the measurement unit 3.

  In this case, in the conventional configuration using the core having the gap portion, there is a possibility that a detection error may occur depending on the position of the electric wire 50 inside the core. On the other hand, in this clamp sensor 2, the electric wire 50 is clamped by the clamp portions 11 a and 11 b and the magnetic field is detected in a state where the electric wires 50 are surrounded by the cores 13 a and 13 b. Regardless of the position of the electric wire 50, it is possible to accurately detect magnetism.

  Further, in the clamp sensor 2, as described above, the contact portion 24a is formed in a concave shape and the protrusion 26 is provided, so that the electric wire 50 and the contact portions 24a and 24b slide when the electric wire 50 is clamped. It is possible to reliably prevent the contact portions 24a and 24b from being worn. For this reason, in this clamp sensor 2, the positional relationship between the core 13b and the magnetic detection element 15 in the closed state changes due to wear of the contact portions 24a and 24b, and a situation in which the detection accuracy decreases due to this change is ensured. It is possible to prevent.

  Next, when the measurement is completed, the clamp sensor 2 is moved in the direction opposite to the direction of movement (front side) so that the electric wire 50 is positioned between the tip portions 21a and 21b. Next, when the electric wire 50 is brought into contact with the tip portions 21a and 21b and the clamp sensor 2 is further moved, the reaction force of the pressing force applied to the electric wire 50 is applied to the tip portions 21a and 21b, and the clamp portions 11a and 11b are moved. It rotates in the rotation direction B against the urging force of the spring 16 (see FIG. 8). Further, the tip portions 21a and 21b are separated from each other by the rotation of the clamp portions 11a and 11b in the rotation direction B. Next, the clamp sensor 2 is further moved, and the electric wire 50 is passed through the gap between the tip portions 21a and 21b. Also in this case, since the electric wire 50 passing through the gap slides with the tip surface 23a and the protrusion 26 without sliding with the contact portions 24a and 24b, wear of the contact portions 24a and 24b is prevented.

  Next, when the electric wire 50 passes through the gap between the tip portions 21a and 21b, the clamp portions 11a and 11b are rotated in the rotation direction A by the biasing force of the spring 16, and the clamp portions 11a and 11b are in the closed state. (See FIG. 6). Thus, the measurement of the current value for the electric wire 50 is completed.

  In the clamp sensor 2, the electric wires 50 can be clamped by operating the operation portions 17 a and 17 b. For example, when the electric wire 50 is thin or soft and when the guide portions 25a and 25b are pressed against the electric wire 50, the reaction force that separates the tip portions 21a and 21b is not applied to the guide portions 25a and 25b. An operation of pushing the operating portions 17a and 17b against the urging force of the spring 16 is performed. At this time, the base end portions 22a and 22b of the clamp portions 11a and 11b engaged with the operation portions 17a and 17b are pressed toward each other (inward) against the biasing force of the spring 16, and this As a result, the clamp portions 11a and 11b rotate in the rotation direction B (second rotation direction: see FIG. 6), and the tip portions 21a and 21b are separated from each other. In this state, the electric wire 50 is passed through the gap between the distal end portions 21a and 21b, and then the pushing of the operation portions 17a and 17b is released. At this time, the clamp portions 11a and 11b are rotated in the rotation direction A (first rotation direction: see FIG. 10) by the biasing force of the spring 16, and the electric wire 50 is clamped by the clamp portions 11a and 11b. . Further, when the measurement is finished, the operation parts 17a and 17b are pushed in to rotate the clamp parts 11a and 11b in the rotation direction B, and the electric wire 50 is passed through the gap between the tip parts 21a and 21b, thereby the clamp parts 11a and 11b. Then, the operation parts 17a and 17b are released from being pushed away.

  As described above, according to the clamp sensor 2 and the current measuring device 1, the guide portions 25a and 25b configured to be separated from each other toward the distal end and guide the electric wire 50 are replaced with the distal end portions 21a and 21b of the clamp portions 11a and 11b. By providing each on 21b, the electric wire 50 can be clamped by the clamp portions 11a and 11b only by pressing the guide portions 25a and 25b against the electric wire 50, so that workability can be sufficiently improved. Further, according to the clamp sensor 2 and the current measuring device 1, when the electric wire 50 is clamped by the clamp portions 11a and 11b, the electric wire 50 can be surrounded by the cores 13a and 13b, and the magnetic field is detected in this state. Unlike the conventional configuration that may cause a detection error depending on the position of the electric wire 50 inside the core having the gap portion, the magnetism is accurately detected regardless of the position of the electric wire 50 on the inner periphery of the clamp portions 11a and 11b. can do. Therefore, according to the clamp sensor 2 and the current measuring device 1, it is possible to sufficiently improve the detection accuracy while improving workability.

  Further, according to the clamp sensor 2 and the current measuring device 1, it is possible to rotate the clamp portions 11a and 11b in the rotation direction B (second rotation direction) against the urging force of the spring 16. By providing the operation portions 17a and 17b, the electric wire 50 is thin or soft, and when the guide portions 25a and 25b are pressed against the electric wire 50, a reaction force that separates the tip portions 21a and 21b is guided. Even when not joining the portions 25a and 25b, the electric wire 50 can be reliably clamped by the clamp portions 11a and 11b.

  Further, in the clamp sensor 2 and the current measuring device 1, both the clamp portions 11a and 11b are rotatably disposed on the main body portion 10. In this case, in the configuration in which only one of the clamp portions 11a and 11b (for example, the clamp portion 11a) is rotatable, for example, when the electric wire 50 is disposed in the vicinity of the wall surface, the clamp portion 11a is positioned on the wall surface side. In this case, even if the guide portions 25a and 25b are pressed against the electric wire 50, rotation of the clamp portion 11a is hindered by the wall surface, making it difficult to clamp the electric wire 50. On the other hand, in the clamp sensor 2 and the current measuring device 1, since both the clamp portions 11a and 11b are rotatable, the clamp portion 11b is rotated even if the rotation of the clamp portion 11a is obstructed. As a result, the electric wire 50 can be reliably clamped even in such a situation.

  Further, according to the clamp sensor 2 and the current measuring device 1, the contact portion 24b of the clamp portion 11b is formed in a convex shape that protrudes from the distal end surface 23b, and the protrusion portion 26 that protrudes from the contact portion 24b is formed in the contact portion 24b. , The contact portion 24a of the clamp portion 11a is formed in a concave shape recessed from the distal end surface 23a, so that the contact portion 24a by sliding between the electric wire 50 and the contact portions 24a, 24b when clamping the electric wire 50 is provided. The wear of 24b can be reliably prevented. For this reason, according to the clamp sensor 2 and the current measuring device 1, the positional relationship between the core 13b and the magnetic detection element 15 in the closed state changes due to wear of the contact portions 24a and 24b, and the detection accuracy is thereby increased. The situation where it falls can be prevented reliably.

  Note that the configurations of the clamp sensor and the measuring apparatus are not limited to the above configurations. For example, although an example in which both the clamp portions 11a and 11b are configured to be rotatable has been described above, a configuration in which only one of the clamp portions 11a and 11b can be rotated may be employed.

  In addition, the example in which the magnetic detection element 15 is provided only in the clamp portion 11a has been described above. However, a configuration in which the magnetic detection element 15 is provided in both the clamp portions 11a and 11b may be employed.

  Further, although an example in which a Hall element is used as the magnetic detection element 15 has been described above, a magnetic detection element such as a magnetoresistive effect element, a magnetic impedance element, or a fluxgate sensor can be used as the magnetic detection element 15.

  Moreover, although the configuration example including the operation units 17a and 17b has been described above, a configuration not including the operation units 17a and 17b may be employed.

  In addition, the clamp sensor 2 detects the magnetic field as the amount to be detected, and the measurement unit 3 measures the current as the amount to be measured. However, the amount to be detected and the amount to be measured are limited to the magnetic field and the current. In addition, various physical quantities such as voltage, power and resistance are included.

DESCRIPTION OF SYMBOLS 1 Current measuring apparatus 2 Clamp sensor 3 Measuring part 10 Main body part 11a, 11b Clamp part 15 Magnetic detection element 16 Spring 17a, 17b Operation part 21a, 21b Tip part 23a, 23b Tip surface 24a, 24b Contact part 25a, 25b Guide part 26 Projection part 27 Housing part 50 Electric wire A Rotating direction B Rotating direction

Claims (5)

In a closed state in which at least one of the main body and the main body is rotatably disposed on the main body and surrounds the detection target and the respective contact portions provided on the front end surfaces of the respective front end portions are in contact with each other. A pair of clamp portions for detecting a detected amount of a detection target, and a biasing portion for biasing the pivotable clamp portion in a first rotation direction in which each clamp portion is in the closed state. A clamp sensor,
Each tip portion of each clamp portion is provided with a guide portion configured to be separated from each other toward the tip and guide the detection target.
The rotatable clamp part is a second opposite to the first turning direction against the urging force of the urging part when the guide part is pressed against the detection target. A clamp sensor configured to be rotatable in the direction of rotation.   The clamp sensor according to claim 1, further comprising an operation unit capable of performing an operation of rotating the rotatable clamp unit in the second rotation direction against the biasing force.   The clamp sensor according to claim 1 or 2, wherein both of the clamp portions are rotatably disposed on the main body portion. A magnetic detection element for detecting magnetism as the amount to be detected is disposed inside the tip portion of at least one of the clamp portions,
Either one of the clamp portions is formed in a convex shape in which the contact portion protrudes from the distal end surface, and a protruding portion that protrudes from the convex contact portion is in the vicinity of the convex contact portion. Provided,
The other of each of the clamp portions is formed with a concave shape in which the contact portion is recessed from the distal end surface and can be fitted with the convex contact portion, and a receiving portion in which the protruding portion is accommodated in the closed state. The clamp sensor according to claim 1, wherein the clamp sensor is provided in the vicinity of the concave contact portion.   5. A measuring apparatus comprising: the clamp sensor according to claim 1; and a measurement unit that measures a measurement amount for the detection target based on the detection amount detected by the clamp sensor.

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