JP5490497B2 - measuring device - Google Patents

Description

  The present invention relates to a clamp-type measuring device having a pair of sensors for detecting electrical parameters (current, voltage, resistance, etc.) of a measuring object in a ring shape surrounding the measuring object. It is.

  As this type of measuring apparatus, a clamp sensor is disclosed in Japanese Patent Application Laid-Open No. 2009-85599. This clamp sensor includes a pair of semicircular clamp sensor structures (hereinafter also simply referred to as “structures”) that are supported by a support shaft so that one end side of each clamp can be opened and closed. A configuration is adopted in which an annular sensor portion for current detection is formed by abutting the end faces of each other. In this case, with this type of clamp sensor, it is known that the measurement accuracy is reduced in a state where the end surfaces of the magnetic cores do not normally collide with each other and a gap is formed between both end surfaces. Therefore, this clamp sensor is configured to detect whether or not both structures are normally closed by a micro switch provided on the open end side of one structure, and to issue an alarm when both structures are not closed. It has been adopted. Thereby, the situation where a measurement operation is performed in a state where a gap is generated between both end faces of the magnetic core is avoided.

JP 2009-85599 A (page 4-6, FIG. 1-7)

  However, the conventional clamp sensor has the following problems to be solved. In other words, the conventional clamp sensor employs a configuration in which a warning is issued by detecting whether or not both structures are closed by a micro switch provided in one structure. In this case, this type of clamp sensor (clamp-type measuring device) includes an urging member (spring) for urging at least one structure toward the other structure so that both structures are closed. A configuration is adopted in which the closed state is maintained by the urging force of the urging member. In the clamp sensor having such a configuration, it is necessary to greatly deform the urging member when the measurement object is clamped by both structures (when both structures are operated to be open). Therefore, in this type of clamp sensor (measuring device), the greater the force required to open both structures, the greater the operating force required, making it difficult for a less powerful user to clamp a large measurement object. Yes.

  In this case, by employing a biasing member with a small biasing force, the force required to clamp a large measurement object (the force required to open both structures greatly) can be reduced. However, in a clamp sensor configured to keep both structures closed by the biasing force of the biasing member, the biasing force of the biasing member decreases as the two structures in the open state approach the closed state. In the force member, even if the force for rotating both structures to the closed state is insufficient and a gap is formed between both end faces of the magnetic core, or both end faces of the magnetic core are normally abutted, There is a risk that the structure cannot be kept closed and opened. In this case, in the conventional clamp sensor, as described above, a warning is issued when both structures are not in the closed state. Therefore, the measurement work is performed in a state where a gap is generated between the end surfaces of the magnetic core. Can be avoided. However, when a warning is issued, for example, a complicated operation of manually rotating both structures (sensor units) to the closed state is forced.

  The present invention has been made in view of such a problem to be improved, and can be easily opened and closed even by a powerless user, and measurement is performed without causing a gap between the end portions of the sensor unit. The main object is to provide a measuring apparatus capable of performing the above.

In order to achieve the above object, the measuring apparatus according to claim 1 is configured to be able to contact and separate each end by opening and closing operations, and is configured to form an annular shape in a closed state in which the ends are joined to each other. A pair of sensors for detecting an electrical parameter of the measurement object in a state of surrounding the measurement object and forming the ring, and at least one of the sensors is directed to the other so as to be in the closed state. A biasing member for biasing, a magnet disposed on one of the two sensors, and a magnetic body disposed on the other sensor so as to be attracted by the magnet in the closed state , The magnet and the magnetic part are arranged so that a gap is formed between the magnet and the magnetic part in the closed state . In this case, the “annular” in the present invention means a shape that is closed when surrounding the measurement object, and the “annular” includes a circular shape, an elliptical shape, This includes arbitrary shapes such as a rectangular shape and a polygonal shape. In addition, the magnetic body portion in the present invention includes a magnetic body portion that itself is composed of a magnet.

Furthermore, the measuring device according to claim 2, wherein, in the measuring apparatus according to claim 1 Symbol placement, such that the at least one of the two sensors are positioned on the outer peripheral side of the two sensors in a state in which none of the annular defining The magnet and the magnetic body portion are arranged on the outer peripheral side of the end portion on the side away from the shaft portion in both sensors.

The measurement apparatus according to claim 3, wherein, in the measuring apparatus according to claim 1 or 2, wherein the magnet is composed of a permanent magnet.

According to a fourth aspect of the present invention, in the measurement apparatus according to the first or second aspect , the magnet is an electromagnet.

Furthermore, the measuring apparatus according to claim 5 is the measuring apparatus according to any one of claims 1 to 4 , wherein the magnet and the magnetic body portion are arranged around the magnetic core in each of the sensors in the annular state. Are spaced apart from the magnetic core.

  The measuring device according to claim 1 is configured to be able to contact and separate each end by an opening / closing operation, and is configured to form an annular shape in a closed state in which the ends are joined to each other, and surrounds the measurement object. A pair of sensors for detecting an electrical parameter of the measurement object in an annular state, a biasing member for biasing at least one of the two sensors toward the other so as to be in a closed state, and both sensors A magnet disposed on one of them, and a magnetic body disposed on the other sensor so as to be attracted by the magnet in the closed state.

  Therefore, according to the measuring apparatus of the first aspect, even if the urging force of the urging member is reduced (even if an urging member having a small urging force is provided), both sensors are reliably closed by the attractive force of the magnet. As a result of being able to maintain the state (that is, close contact between the end portions of both sensors), it is possible to carry out measurement without creating a gap at the tip portions of both sensors. The electrical parameters for can be accurately detected. In addition, according to this measuring device, the magnets and the magnetic body portions are separated from each other only by slightly opening the two sensors in the closed state to slightly separate the end portions, thereby reducing the attractive force of the magnet. Even a powerless user can easily open both sensors.

Further, according to the measuring apparatus of this, the end portions of each of the two sensors by which is arranged a magnet and the magnetic portion so that a gap is formed between the magnet and the magnetic portion in the closed state and joined together state Since the end surfaces of the magnet and the magnetic body portion are in contact with each other prior to becoming a gap between the two end portions of the sensors, the rotation of the sensor can be avoided. The end portions of both sensors can be reliably joined to each other.

Further, according to the measuring apparatus of claim 2 , at least one of the two sensors can be rotated about a shaft portion that is defined so as to be positioned on the outer peripheral side of the two sensors in an annular state. Even if a relatively small magnet (a magnet having a small attractive force) is disposed by arranging the magnet and the magnetic body portion on the outer peripheral side of the end portion on the side separated from the shaft portion in both sensors. Because of the lever principle, the force to turn both sensors from the open state to the closed state and the force to keep both sensors in the closed state work most effectively. Can be opened more easily.

Moreover, according to the measuring apparatus of Claim 3 , since the magnet was comprised with the permanent magnet, not only can it maintain both sensors in a closed state reliably by simple structure, but compared with comprising with an electromagnet. Thus, power consumption can be reduced.

Further, according to the measuring apparatus of the fourth aspect , since the magnet is configured by the electromagnet, a gap is generated between the end portions of both sensors when electric power is supplied to the electromagnet to operate as the magnet. As a result, the electrical parameters of the measurement object can be accurately detected, and the power supply to the electromagnet is stopped when the measurement object is clamped. As a result of the elimination of the attractive force, both sensors can be easily opened with a smaller force than a measuring device having a magnet composed of permanent magnets.

Furthermore, according to the measuring apparatus of the fifth aspect , the magnet and the magnetic part are arranged around the magnetic core in each sensor in the annular state, and the magnet and the magnetic part are separated from the magnetic core, respectively. As a result, the influence of the magnetic field lines generated from the magnet on the detection of the electrical parameter by the sensor can be made sufficiently small. As a result, the electrical parameter of the measurement object can be detected more accurately.

It is a front view of the current measuring device 1 in which the fixed side sensor 11a and the movable side sensor 11b are closed. It is a front view of the current measuring device 1 in which the fixed side sensor 11a and the movable side sensor 11b are in an open state. It is a front view of fixed side sensor 11a and movable side sensor 11b in current measuring device 1A. It is a front view of fixed side sensor 11a and movable side sensor 11b in current measuring device 1B. It is a front view of fixed side sensor 11a and movable side sensor 11b in current measuring device 1C.

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

  First, the configuration of the current measuring device 1 will be described.

  The current measuring apparatus 1 shown in FIGS. 1 and 2 is an example of a clamp-type measuring apparatus, and a current (an example of an “electrical parameter”) that flows through a conducting wire 100 as a measurement object is not contacted with the conducting wire 100. It is configured to be measurable. Specifically, the current measuring device 1 includes a clamp unit 2 and a main body unit 3 and is configured to be able to measure a current value of a current flowing through a measurement object (conductive wire 100) based on a detection signal.

  As shown in FIGS. 1 and 2, the clamp unit 2 is an example of a fixed side sensor 11 a and a movable side sensor 11 b (“a pair of sensors”) formed in a substantially semicircular shape in plan view. Sensor 11 ”). In this case, as shown in both figures, the clamp portion 2 is configured so that the distal end portions 12a and 12b of both sensors 11 (the distal end portions of coil portions 22a and 22b described later) and the proximal end portion 13a, 13b (base ends of coil portions 22a and 22b described later) are configured to be able to contact and separate from each other. In addition, the clamp portion 2 is configured to form an annular shape in a closed state in which the distal end portions 12a and 12b and the proximal end portions 13a and 13b are joined to each other, and surrounds the conducting wire 100 to form an annular shape (conducting wire) In a state where 100 is clamped), a detection signal corresponding to the current value of the current flowing through the conducting wire 100 can be output.

  The stationary sensor 11a includes a resin sensor case 21a and a coil portion 22a accommodated in the sensor case 21a. The movable sensor 11b includes a resin sensor case 21b, a coil part 22b accommodated in the sensor case 21b (hereinafter, a coil part 22a of the fixed sensor 11a, and a coil part 22b of the movable sensor 11b. When not distinguished, it is also referred to as “coil part 22”). In this case, in the current measuring device 1, the sensor case 21 a of the stationary sensor 11 a is integrally formed with the main body case 3 a of the main body 3. In the current measuring device 1, the base end portion of the sensor case 21b of the movable sensor 11b is housed inside the main body case 3a, and the pin 3b (an example of a shaft portion) inserted through the base end portion is provided. It is attached to the main body case 3a so as to be rotatable with respect to the stationary sensor 11a and the main body 3 as a rotation center.

  In this case, the coil part 22 is each provided with the magnetic core and the coil | winding (all are not shown) wound around the magnetic core. In addition, the sensor case 21b has a direction in which the tip end of the sensor case 21b comes into contact with the tip end of the sensor case 21a (the two sensors 11 are closed) by a spring 3c (an example of an “urging member”) disposed in the body case 3a. Direction to be in a state: direction of arrow A shown in FIG. In this case, when the lever 21c formed integrally with the sensor case 21b is pushed in the direction of the arrow B shown in FIG. 2, the front end of the sensor case 21b is separated from the front end of the sensor case 21a (both The sensor 11 is configured to be rotated in the opening direction. Therefore, in this current measuring device 1, the clamp portion 2 is configured such that the distal end portions and the proximal end portions of the sensor cases 21a and 21b, that is, the distal end portions 12a and 12b of both sensors 11 and The base end portions 13a and 13b are configured to contact and separate (open and close).

  As shown in FIGS. 1 and 2, in the current measuring device 1, for example, the magnet 4a is disposed in the sensor case 21a of the fixed sensor 11a, and the magnet 4b is disposed in the sensor case 21b of the movable sensor 11b. It is arranged. In this case, each of the magnets 4a and 4b constitutes a "magnet" and a "magnetic body part", and is formed in a columnar shape (cylindrical or prismatic) with permanent magnets such as ferrite magnets, neodymium magnets, and alnico magnets, for example. Has been. Further, as shown in FIG. 1, when both sensors 11 are in the closed state, the magnets 4a and 4b face each other face to face and the magnet 4a attracts the magnet 4b as a magnetic body part. In addition, the magnets 4b are disposed in a positional relationship in which the magnet 4a can be attracted as a magnetic part. Therefore, in this current measuring device 1, in addition to the biasing force of the spring 3c, the sensors 11 are maintained in the closed state by the attractive force of the magnets 4a and 4b. The spring 3c is configured by a spring having a smaller spring constant than the urging member (small urging force).

  As shown in FIG. 1, the magnets 4 a and 4 b are disposed around the magnetic core (coil portion 22) in both sensors 11 (as an example, on the outer peripheral side of both annular sensors 11). And spaced apart from the magnetic core (coil portion 22). In this case, in the current measuring device 1, the magnets 4a and 4b are disposed at positions farthest from the pin 3b that is the rotation center of the movable sensor 11b in both sensors 11 (sensor cases 21a and 21b). Despite the fact that the magnets 4a and 4b are composed of relatively small magnets (magnets having a small attraction force), the force for rotating both sensors 11 from the open state to the closed state according to the lever principle, and both sensors 11 The force for maintaining the closed state acts most effectively. Magnets 4a and 4b have a positional relationship such that when both sensors 11 are in a closed state, the end surfaces thereof face each other and a gap S (about 0.5 mm as an example) is generated between the end surfaces. The sensor cases 21a and 21b are fixed.

  As shown in FIGS. 1 and 2, the main body unit 3 includes a main body case 3a in which an operation unit and a display unit are disposed, and a measurement unit and a control unit (not shown) are accommodated in the main body case 3a. ing. In addition, about the main-body part 3, it is not limited to the structure formed integrally with the clamp part 2 like this electric current measurement apparatus 1, The main-body part 3 and the clamp part 2 are comprised separately, and it is signal cable etc. A configuration (not shown) that is electrically connected to each other may be employed.

  Next, a method of using the current measuring device 1 will be described with reference to the attached drawings.

  When measuring the current value of the current flowing through the conducting wire 100 using the current measuring device 1, first, the conducting wire 100 is clamped by the clamp portion 2. Specifically, as shown in FIG. 2, first, the lever 21c is pushed into the main body 3 in the direction of the arrow B, whereby the movable sensor 11b is rotated with respect to the fixed sensor 11a around the pin 3b. It is made to move and the front-end | tip parts 12a and 12b of both the sensors 11 and base end parts 13a and 13b are mutually separated. At this time, in the current measuring device 1, when both the sensors 11 are in the closed state, the magnets 4a and 4b are attracted to each other so as to maintain the closed state. Therefore, immediately after the start of the opening operation, a certain amount of force is required to push in the lever 21c, but the end surfaces of the magnets 4a and 4b are moved to a certain extent as the movable sensor 11b rotates with respect to the fixed sensor 11a. When the magnets 4a and 4b are separated from each other by a distance or more, the force with which the magnets 4a and 4b attract each other becomes weak. As a result, the movable sensor 11b can be rotated with respect to the fixed sensor 11a by pushing the lever 21c with a relatively small force. It has become.

  Next, the pushing of the lever 21c is released in a state where the conducting wire 100 is surrounded by both the sensors 11. At this time, the movable side sensor 11b is rotated with respect to the fixed side sensor 11a by the urging force (elastic return force) of the spring 3c in the direction of the arrow A shown in FIG. 12b and base end part 13a, 13b mutually join. In this case, in the current measuring device 1, the spring 3c is greatly deformed in a state where the distal end portions 12a and 12b and the proximal end portions 13a and 13b of both sensors 11 are greatly separated from each other. The biasing force of the spring 3c acting in the direction in which the distal end portions 12a, 12b and the proximal end portions 13a, 13b of the sensor 11 are joined to each other is increased. Therefore, immediately after the start of the closing operation for releasing the pushing of the lever 21c, the movable sensor 11b is reliably rotated in the direction of the arrow A with respect to the fixed sensor 11a by the large biasing force of the main body 3c.

  On the other hand, when the movable sensor 11b rotates with respect to the fixed sensor 11a and the distal end portions 12a and 12b and the proximal end portions 13a and 13b of the sensors 11 approach each other to some extent, the deformation amount of the spring 3c. Is reduced, the urging force of the spring 3c acting in the direction in which the distal end portions 12a, 12b and the proximal end portions 13a, 13b of both sensors 11 are joined to each other is reduced. However, when the tip portions 12a and 12b of both sensors 11 and the base end portions 13a and 13b come close to a certain distance, the end surfaces of the magnets 4a and 4b come close to each other and the magnets 4a and 4b attract each other. As a result, the attractive force of the magnets 4a and 4b is added to the biasing force of the spring 3c, and the movable sensor 11b is reliably rotated in the direction of the arrow A with respect to the fixed sensor 11a. Thereby, as shown in FIG. 1, the front end portions 12a and 12b and the base end portions 13a and 13b of both sensors 11 are joined to each other.

  In this case, in the current measuring device 1, as described above, in the state where the front end portions 12a and 12b and the base end portions 13a and 13b of both sensors 11 are joined to each other, between the opposing end surfaces of the magnets 4a and 4b. Magnets 4a and 4b are arranged so that a gap S is generated. Accordingly, the end surfaces of the magnets 4a and 4b come into contact with each other before the distal end portions 12a and 12b of both sensors 11 and the proximal end portions 13a and 13b are joined to each other, and the distal end portions 12a of both sensors 11 are brought into contact with each other. , 12b and in a state where a gap is generated between the base end portions 13a, 13b, a situation in which the rotation of the movable sensor 11b with respect to the fixed sensor 11a is stopped is avoided. Thereby, clamping of the conducting wire 100 by the clamp part 2 is completed.

  Thereafter, by operating the operation unit of the main body unit 3 and instructing the start of measurement, the control unit in the main body unit 3 controls the measurement unit to execute measurement processing. At this time, the current value of the current flowing through the conducting wire 100 is measured based on the detection signals output from both sensors 11, and the measurement result is displayed on the display unit. In addition, since the measurement principle of the current value by this type of current measuring device is publicly known, detailed description is omitted. At this time, the current measuring device 1 is positioned so as to be separated from the magnetic cores (coil portions 22) of the two sensors 11 (in this example, positioned on the outer peripheral side of the magnetic cores with respect to the magnetic cores of the two sensors 11). Magnets 4a and 4b are arranged so as to be separated from each other. Therefore, the influence of the lines of magnetic force generated from the magnets 4a and 4b on the detection of current by both sensors 11 is sufficiently small. Thereby, a series of measurement processes is completed.

  As described above, the current measuring device 1 is configured so that the distal end portions 12a and 12b and the proximal end portions 13a and 13b can be brought into contact with and separated from each other by opening and closing operations, and the distal end portions 12a and 12b and the proximal end portions 13a and 13b. An electrical parameter (in this example, the measurement object) of the measurement object in the closed state in which the objects are joined to each other, and is configured to form an annulus in a closed state surrounding the measurement object (for example, the conductive wire 100). A pair of fixed side sensor 11a and movable side sensor 11b for detecting a current flowing through the body), a spring 3c for biasing the movable side sensor 11b toward the fixed side sensor 11a so as to be in a closed state, and a fixed side A magnet 4a disposed on the sensor 11a and a magnet 4b disposed on the movable sensor 11b so as to be attracted by the magnet 4a in the closed state are provided. That.

  Therefore, according to the current measuring device 1, even if the urging force of the spring 3c is reduced (even if the spring 3c having a small urging force is provided), the sensors 11 are securely closed by the attractive force of the magnets 4a and 4b. The state can be maintained (that is, the end portions of the front end portions 12a and 12b of both sensors 11 and the end portions of the base end portions 13a and 13b can be brought into close contact with each other). As a result of being able to carry out the measurement without causing a gap between the end portions and between the end portions of the base end portions 13a and 13b, the electrical parameters of the measurement object (in this example, the current of the current flowing through the conductor 100) Value) can be accurately measured (detected). Further, according to the current measuring device 1, the magnet 4a, the opening of the sensor 11 in the closed state is separated by slightly separating the end portions of the distal end portions 12a and 12b and the end portions of the base end portions 13a and 13b. As a result of the end surfaces of 4b being separated from each other and the attractive force of the magnets 4a and 4b being reduced, both the sensors 11 can be easily opened even by a weak user.

  In addition, according to the current measuring device 1, the magnets 4a and 4b are disposed so that the gap S is formed between the magnets 4a and 4b in the closed state, so that the front ends 12a and 12b of both sensors 11 Prior to the end portions 13a and 13b being joined to each other, the end surfaces of the magnets 4a and 4b come into contact with each other, and a gap is formed between the distal end portions 12a and 12b and between the proximal end portions 13a and 13b. Since it is possible to avoid a situation where the rotation of the movable sensor 11b with respect to the fixed sensor 11a stops, the distal end portions 12a and 12b and the proximal end portions 13a and 13b can be reliably joined. .

  Furthermore, according to the current measuring device 1, at least one of the two sensors 11 (in this example, the movable sensor 11b) is defined to be positioned on the outer peripheral side of the two sensors 11 in an annular state. It is configured to be rotatable about the pin 3b as a rotation center, and the magnets 4a and 4b are disposed on the outer peripheral side of the end portions (in this example, the front end portions 12a and 12b) of the two sensors 11 that are separated from the pin 3b. As a result, even if the magnets 4a and 4b are constituted by relatively small magnets (magnets having a small attraction force), the force for rotating both sensors 11 from the open state to the closed state according to the lever principle, and both sensors 11 Since the force for maintaining the closed state acts most effectively, even a non-powerful user can open both sensors 11 more easily.

  Further, according to the current measuring device 1, since the magnets 4a and 4b are composed of permanent magnets, the sensors 11 can be reliably maintained in a closed state with a simple structure, and can be composed of electromagnets. As a result, power consumption can be reduced.

  Furthermore, according to this current measuring device 1, by arranging the magnets 4a and 4b around the magnetic core in each sensor 11 in the annular state and separating the magnets 4a and 4b from the magnetic core, The influence of the magnetic lines generated from the magnets 4a and 4b on the detection of the electrical parameter (current in this example) by the sensor 11 can be made sufficiently small. As a result, the electrical parameter of the conductor 100 is measured more accurately ( Can be detected).

  Note that the configuration of the clamp-type measuring device is not limited to the above configuration. For example, the configuration and method of use of the measuring device have been described by taking the current measuring device 1 in which the magnets 4a and 4b made of permanent magnets are arranged in both the sensors 11 as an example, but at least when both the sensors 11 are in the closed state. If the magnet can attract the magnetic part, the measuring device can be configured by employing an electromagnet instead of the permanent magnet. In this case, the configuration “at least when both sensors 11 are closed, the magnet can attract the magnetic part” means that “the magnet can attract the magnetic part only when both sensors 11 are in the closed state”. In addition to the “configuration”, in addition to the “closed state”, “when the both sensors 11 in the open state are operated to the closed state, the state immediately before the closed state is changed to the closed state”, and “the closed state” This includes a configuration in which the magnet can attract the magnetic body portion during the period from when the sensors 11 are opened to the state immediately after the sensors 11 are opened. In addition, in the following description, about the component similar to said electric current measurement apparatus 1, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  In this case, when the configuration in which both sensors 11 are maintained in the closed state by the attractive force (magnetic force) of the magnets 4a and 4b formed of electromagnets, power is consumed while the magnets 4a and 4b are functioning as magnets. The Therefore, power is supplied to the magnets 4a and 4b at least during the current value measurement process (when both sensors 11 should be in the closed state), and the lead wire 100 is clamped by the clamp unit 2 when the measuring device is not used. When performing the operation (when opening the clamp portion 2: when both sensors 11 are in the open state), a configuration is adopted in which the power supply to the magnets 4a and 4b is stopped by operating a switch (not shown). preferable. Further, it is also possible to provide a detection mechanism for detecting the open / closed state of the clamp unit 2 so that power is supplied to the magnets 4a and 4b only when the clamp unit 2 is in the closed state to control the supply of power to the magnets 4a and 4b. it can.

  As described above, by configuring the magnets 4a and 4b with electromagnets to supply power to the magnets 4a and 4b and operating them as electromagnets, the current measuring device having the magnets 4a and 4b composed of permanent magnets. 1 can be obtained, and at the time of clamping the conducting wire 100, the supply of electric power to the magnets 4a and 4b is stopped, so that the attraction force of the magnets 4a and 4b disappears. , 4b, both sensors 11 can be easily opened with a smaller force than the current measuring device 1 having.

In addition, the current measuring device 1 in which the magnets 4a and 4b are disposed on both the fixed side sensor 11a and the movable side sensor 11b has been described as an example, but either one of the magnets 4a and 4b in the above example is a permanent magnet. or while constituted by electromagnets, the magnet 4a, 4b the other of can be changed to ferromagnetic metal plate. Specifically, as an example, a magnet 4a composed of a permanent magnet or an electromagnet is disposed on the fixed sensor 11a, and a metal plate (magnetic part) is disposed on the movable sensor 11b instead of the magnet 4b. Further, it is possible to adopt a configuration in which both sensors 11 are maintained in a closed state by an attractive force (magnetic force) by which the magnet 4a attracts the metal plate. Even when such a configuration is adopted, the same effects as those of the current measuring device 1 can be obtained.

  Furthermore, although the current measuring device 1 in which the magnets 4a and 4b are arranged at the position farthest from the pin 3b that is the rotation center of the movable sensor 11b has been described as an example, the magnets 4a and 4b (magnets and magnetic bodies) are described. The arrangement position of the (part) is not limited to this. For example, in the current measuring device 1A shown in FIG. 3, on the side of the tip 12a, 12b away from the pin 3b that is the rotation center of the movable sensor 11b, around the magnetic core of both sensors 11 and within the magnetic core. Magnets 4a and 4b are arranged so as to be located on the circumferential side and away from the magnetic core. Further, in the current measuring device 1B shown in FIG. 4, on the base end portions 13a and 13b side close to the pin 3b that is the rotation center of the movable sensor 11b, around the magnetic cores of both sensors 11 and within the magnetic cores. Magnets 4a and 4b are arranged so as to be located on the circumferential side and away from the magnetic core. Further, in the current measuring device 1C shown in FIG. 5, on the base end portions 13a and 13b side close to the pin 3b which is the rotation center of the movable sensor 11b, the outer periphery of the magnetic core is around the magnetic cores of both sensors 11. Magnets 4a and 4b are arranged so as to be located on the side and away from the magnetic core. In any of these current measuring devices 1A to 1C, the magnets 4a and 4b are arranged around the magnetic cores of the two sensors 11 in the annular state, are separated from the magnetic cores, and both the sensors 11 In the closed state, a gap S is provided between the end faces of the magnets 4a and 4b. Therefore, the same effect as the current measuring device 1 described above can be obtained.

  Furthermore, the number of magnets and magnetic parts provided in one measuring device is not limited to one set, and any number of two or more sets can be provided. In addition, the configuration in which only one of the two sensors 11 (movable sensor 11b) rotates about the pin 3b serving as a shaft by the opening / closing operation is described as an example. It is also possible to adopt a configuration in which both of them rotate around the shaft portion as a rotation center.

  Furthermore, although the current measuring devices 1 and 1A to 1C for detecting the current flowing through the conductor 100 as “electrical parameters” have been described as examples, the current measuring device 1 described above is used for various measuring devices other than the current measuring device. , 1A to 1C can be applied. Specifically, a resistance measuring device that clamps the measurement object by a pair of sensors and applies a voltage for inspection to the measurement object, detects a current flowing through the measurement object in that state, and measures a resistance value For a voltage measuring device that clamps a measurement object with a pair of sensors and detects the voltage in a non-contact manner via a coupling capacitor, a magnet and a magnet are used in the same manner as the current measuring devices 1 and 1A to 1C. A body part can be disposed. By comprising in this way, the effect similar to the electric current measuring apparatus 1 mentioned above can be show | played.

DESCRIPTION OF SYMBOLS 1,1A-1C Current measuring apparatus 2 Clamp part 3 Main part 3b Pin 3c Spring 4a, 4b Magnet 11a Fixed side sensor 11b Movable side sensor 12a, 12b Tip part 13a, 13b Base end part 100 Conductor S Crevice

Claims (5)

Each end is configured to be able to contact and separate by opening and closing operations, and is configured to form an annular shape in a closed state in which the ends are joined to each other. A pair of sensors for detecting electrical parameters of the measurement object, a biasing member that biases at least one of the two sensors toward the other so as to be in the closed state, and A magnet disposed on one side and a magnetic body portion disposed on the other sensor so as to be attracted by the magnet in the closed state ;
The measuring apparatus in which the magnet and the magnetic body portion are arranged so that a gap is formed between the magnet and the magnetic body portion in the closed state . At least one of the two sensors is configured to be rotatable about a shaft portion that is defined to be positioned on the outer peripheral side of the two sensors in the annular state,
Said magnet and said magnetic body, said side of said end portion according to claim 1 Symbol placement of the measuring device is disposed on the outer peripheral side of the remote from the shaft portion in both sensors. The magnet measuring apparatus according to claim 1 or 2, wherein is composed of permanent magnets. The magnet measuring apparatus according to claim 1 or 2, wherein is composed of an electromagnet. Said magnet and said magnetic body is according to any one of claims 1 to 4, which is disposed around the magnetic core are then respectively separated from the magnetic core at the respective sensors in a state where none of the annular measuring device.

Images