Pincer sensor and measuring device

Abstract

Provided is a tongs sensor and a measuring device that seek to reduce manufacturing costs and reliably and easily perform holding and opening / closing operations. The tongs sensor and the measuring device are provided with holding arms (11, 12) that form a ring in a closed state, and are configured to rotate the two holding arms (11, 12) about a rotation shaft (30) disposed near the end portions (11b, 12b) of the two holding arms (11, 12) in such a way that the end portions (11a, 12a) contact / separate from each other, and are provided with operation arms (21, 22) that are respectively disposed extending from the end portions (11b, 12b) of the two holding arms (11, 12) and are configured to rotate about the rotation shaft (30) in such a way that the two holding arms (11, 12) change to an open state, and when the operation arms (21, 22) are viewed in the axial direction of the rotation shaft (30), the outer edge portion (E21o) of the operation arm (21) and the outer edge portion (E22o) of the operation arm (22) are both formed in a curved shape that curves in the same direction.

Description

TECHNICAL FIELD

[0001] The present application relates to a clamp sensor provided with a pair of holding arms that constitute a ring-shaped sensor portion in a closed state in which the tip end portions are close to each other, and configured to be able to rotate the two holding arms so that the tip end portions are brought into contact with and separation from each other, and a measuring device configured to be provided with such a clamp sensor. BACKGROUND

[0002] As such a clamp sensor, the applicant has disclosed a clamp sensor provided with a pair of holding portions that are opened and closed freely in the following patent document.

[0003] In the clamp sensor disclosed by the applicant, the base end portions of the two holding portions are pivotally supported by a pair of support shafts in a housing portion (main body portion), and a spiral spring always applies a force to the two holding portions so that the tip end portions are brought into abutting relation (closed state) with each other. In addition, the clamp sensor disclosed by the applicant is provided with a pair of operation levers for bringing the tip end portions of the two holding portions into separation (open state) with each other. In this case, the two operation levers of the clamp sensor are configured to be disposed on the left and right side portions of the housing portion (main body portion), are pivotally supported by a pair of support shafts in the housing portion, and are pivoted with respect to the housing portion so that the end portions (hereinafter also referred to as "operation side end portions") on the side opposite to the side pivotally supported by the support shafts are brought into close relation with each other, thereby enabling the two holding portions to be brought into open state.

[0004] Further, the clamp sensor disclosed by the applicant is provided with a lock mechanism for preventing the two holding portions in the closed state from being brought into open state by accident. In this case, the lock mechanism in the clamp sensor is provided with an operation piece and an opening preventing piece, etc. In the lock mechanism, with a sliding operation of the operation piece with respect to the housing portion, the opening preventing piece is moved to between the base end portions of the two holding portions in the closed state, thereby restricting the pivoting of the two holding portions (i.e., from the closed state to the open state). In addition, with a sliding operation of the operation piece with respect to the housing portion in the opposite direction, the opening preventing piece is avoided from between the base end portions of the two holding portions, thereby allowing the two holding portions to be pivoted (brought into open state).

[0005] In the use of the tongs-type sensor, the two clamping portions which have been turned to the closed state are turned to the open state. At this time, when the turning to the open state is restricted by the locking mechanism, the operation piece is slid to cause the opening preventing piece to avoid from between the two clamping portions, thereby releasing the restriction. Then, the operation side end portions are made to approach each other to turn the two operation levers with respect to the outer housing portion. At this time, the base end portions of the two clamping portions are pressed by the two operation levers, and the two clamping portions are turned against the force of the coil springs, thereby turning to the open state. In this state, the clamping object (the measured conductor) is located between the two clamping portions in such a manner that it passes between the front end portions of the two clamping portions.

[0006] Then, the operation force applied to the two operation levers is weakened. At this time, the two clamping portions are turned by the force of the coil springs to turn to the closed state. Then, the operation piece is slid to move the opening preventing piece to between the two clamping portions. Thus, the turning of the two clamping portions is restricted by the locking mechanism (the opening preventing piece), and the turning from the closed state to the open state is restricted. By the above steps, even if the hand holding the tongs-type sensor touches the two operation levers, the two clamping portions can be maintained in the closed state. Thereafter, based on the signal detected by the tongs-type sensor, the measured quantity of the clamping object is measured. Further, when the measurement work is finished, the two clamping portions are turned to the open state in the same manner as the above operation method, and the tongs-type sensor is released from the clamping object. Thus, a series of work is completed.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-125410 (pages 3 to 6, FIGS. 1 to 3) Figures 1-5 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] However, the tongs-type sensor disclosed by the applicant still has the following problems to be improved.

[0012] Specifically, in the tongs-type sensor disclosed by the applicant, the two clamping portions are supported by independent support shafts in the outer housing portion, and the two operation levers are also supported by independent support shafts in the outer housing portion. That is, in the above tongs-type sensor, in order to be able to open and close the two clamping portions, a pair of operation levers which are formed independently of the two clamping portions, and four support shafts for respectively supporting the two clamping portions and the two operation levers are required. Therefore, in the above tongs-type sensor, the number of constituent parts is large, and the assembly work at the time of manufacturing is complicated, thereby resulting in the present situation that it is difficult to reduce the manufacturing cost.

[0013] ​Further, in the applicant's disclosed pinch sensor, one configuration example is as follows: the ball of the thumb is attached to one of the two operating levers, and the ball of the index finger (or the balls of the index finger and middle finger) is attached to the other of the two operating levers, in this state the pinch sensor is held by one hand, and the two operating levers are operated in such a way that the ball of the thumb and the ball of the index finger (or the balls of the index finger and middle finger) approach each other, thereby enabling the two clamping portions to be changed from the closed state to the open state. Further, in the above-described pinch sensor, the outer edge portions of the two operating levers (the portions to which the balls of the thumb and index finger (or the balls of the thumb, index finger, and middle finger) are attached), and the side outer edge portions of the outer housing portion (the portions to which the balls of the little finger, ring finger, and middle finger (or the balls of the little finger and ring finger), and the ball of the thenar eminence of the thumb (the base of the thumb) are attached) are each formed in a straight line shape when viewed in the axial direction of the above-described support shafts.

[0014] In this case, in the applicant's disclosed pinch sensor, the outer edge portions of the two operating levers, and the side outer edge portions of the outer housing portion are provided with anti-slip roughening. However, depending on the size of the user's hand, the manner in which it is held when in use, and the force applied when operating the two operating levers, it is possible that the thumb and index finger (or the thumb, index finger, and middle finger) will slip with respect to the two operating levers, or that the little finger, ring finger, and middle finger (or the little finger and ring finger), and the thenar eminence of the thumb will slip with respect to the outer housing portion. Therefore, it is preferable to improve this aspect.

[0015] The present application was formed in view of the above-described problems to be improved, and its main object is to provide a pinch sensor and measurement device that can reduce manufacturing costs, and reliably and easily perform holding and opening / closing operations.

[0016] Technical solution adopted to solve the technical problem

[0017] The pinch sensor of the present application is configured with a pair of clamping arms that are formed in an arc shape and constitute a ring-shaped sensor portion in a closed state in which the tip end portions abut each other, and is configured to rotate the two clamping arms about a rotation shaft disposed near the base end portions of the two clamping arms in such a way that the tip end portions approach / desert from each other, the pinch sensor is provided with a pair of operating arms that are each disposed extending from the base end portions of the two clamping arms, and is configured to rotate the two clamping arms about the rotation shaft in such a way that the tip end portions approach each other, thereby changing the two clamping arms to an open state in which the tip end portions are separated from each other, when viewed in the axial direction of the rotation shaft, a first outer edge portion on the side opposite the other operating arm of the one operating arm and a second outer edge portion on the side opposite the one operating arm of the other operating arm are each formed in a curved shape that curves in the same direction.

[0018] Further, in the tongs-type sensor of the present application, the two operation arms are formed such that a first distance between an end portion on the side opposite to the clamping arm side of the one operation arm and the rotation axis is shorter than a second distance between an end portion on the side opposite to the clamping arm side of the other operation arm and the rotation axis.

[0019] Further, in the tongs-type sensor 2 of the present application, when the two operation arms are viewed in the axial direction, the first outer edge portion and the second outer edge portion are formed in a curved shape that curves in the direction from the one operation arm toward the other operation arm.

[0020] Further, in the tongs-type sensor of the present application, a connection cable for connecting the tongs-type sensor to the outside is drawn from the end portion on the side opposite to the clamping arm side of the other operation arm.

[0021] Further, in the tongs-type sensor 2 of the present application, when the two operation arms are viewed in the axial direction, a third outer edge portion on the side of the other operation arm of the one operation arm and a fourth outer edge portion on the side of the one operation arm of the other operation arm are both formed in a curved shape that curves in the same direction as the first outer edge portion and the second outer edge portion.

[0022] Further, in the tongs-type sensor of the present application, when the two operation arms are viewed in the axial direction, a portion of the third outer edge portion opposite to the fourth outer edge portion and a portion of the fourth outer edge portion opposite to the third outer edge portion are formed in the same shape.

[0023] Further, the measuring apparatus of the present application is provided with the above-described tongs-type sensor and a measuring section that measures a measured amount regarding a clamping object clamped by the tongs-type sensor.

[0024] Effects of the Invention

[0025] In the tongs-type sensor of the present application, a pair of operation arms are provided, the pair of operation arms are respectively provided so as to extend from base end portions of two clamping arms and are configured to be rotatable about a rotation axis in a manner that the two clamping arms are brought into an open state in which the front end portions thereof are separated from each other, and when the two operation arms are viewed in the axial direction of the rotation axis, a first outer edge portion on the side opposite to the side of the other operation arm of the one operation arm and a second outer edge portion on the side opposite to the side of the one operation arm of the other operation arm are both formed in a curved shape that curves in the same direction. Further, in the measuring apparatus of the present application, the above-described tongs-type sensor and a measuring section are provided.

[0026] Therefore, according to the tongs sensor and the measuring device of the present application, by integrally forming one clamping arm and one operating arm, and integrally forming the other clamping arm and the other operating arm, the number of components of the tongs sensor can be sufficiently reduced, and thus the manufacturing cost and the assembly cost of the components can be sufficiently reduced, and as a result, the manufacturing cost of the tongs sensor can be sufficiently reduced. Further, by making the first outer edge portion of one operating arm and the second outer edge portion of the other operating arm be curved in the same direction, when the tongs sensor is held with one hand (for example, five fingers), each finger can be attached to the first outer edge portion and the second outer edge portion in a natural posture, and thus the tongs sensor can be reliably and easily held, and accidental dropping can be prevented. Further, when operating the two operating arms, each finger can be appropriately prevented from slipping with respect to the first outer edge portion and the second outer edge portion, and thus the opening and closing operation of the two clamping arms can be reliably and easily performed. Furthermore, when the two operating arms are brought close to each other to change the two clamping arms to an open state, since the distance between the first outer edge portion and the second outer edge portion in the entire length direction of the two operating arms is sufficiently short, even a small hand can reliably and easily maintain the state in which the two operating arms are close to each other (the open state of the two clamping arms). Thus, the clamping of the clamped object (the attachment of the tongs sensor to the clamped object) and the detachment of the tongs sensor from the clamped object can be reliably and easily performed. Further, by making the distance between the first outer edge portion and the second outer edge portion sufficiently short, the tongs sensor can be reliably and easily held in a state in which the two operating arms are pinched with the thumb and the index finger (or pinched with the thumb, the index finger, and the middle finger), and the clamping arms can be reliably and easily opened and closed in this state. Thus, compared to the case in which the tongs sensor is held with one hand in a state in which five fingers are attached to the two operating arms, the wrist and the elbow are not forcibly bent and stretched when the clamped object is clamped and detached, and the tongs sensor can be held in various postures and opened and closed. Therefore, even for a clamped object present in a narrow place, a clamped object present at a high place or a low place, the clamping and the detachment can be reliably and easily performed. Further, unlike a structure in which the first outer edge portion and the second outer edge portion are bent in opposite directions at a central portion of the length direction of the two operating arms, and a structure in which the first outer edge portion and the second outer edge portion are formed in a straight line along the length direction of the two operating arms, by making the first outer edge portion and the second outer edge portion be curved in the same direction, even when the tongs sensor is held with only two or three fingers, the fingers attached to the inside of the curved shape are not easily slipped with respect to the operating arms, and thus the fingers attached to the outside of the curved shape are not easily slipped with respect to the operating arms. Thus, the tongs sensor can be reliably held with only two or three fingers, and thus accidental dropping of the tongs sensor can be appropriately prevented.

[0027] Further, the tongs-type sensor and the measurement apparatus provided with the same according to the present application are configured such that a first distance between an end portion on the opposite side of the holding arm side of one of the operation arms and the rotation shaft is shorter than a second distance between an end portion on the opposite side of the holding arm side of the other of the operation arms and the rotation shaft, and when the tongs-type sensor is held by one hand, the thumb can be attached to the end portion on the opposite side of the holding arm side of the first outer edge portion of one of the operation arms in a natural posture while the index finger, the middle finger, the ring finger, and the little finger are attached to the second outer edge portion of the other of the operation arms. Thus, the opening and closing operation of the two holding arms can be performed more reliably and easily.

[0028] Further, the tongs-type sensor and the measurement apparatus provided with the same according to the present application are configured such that the first outer edge portion and the second outer edge portion are formed in a curved shape that curves in a direction from one of the operation arms toward the other of the operation arms when viewed in the axial direction, and thus, when the tongs-type sensor is held by one hand, the thumb can be attached to the first outer edge portion of one of the operation arms in a natural posture, and the index finger, the middle finger, the ring finger, and the little finger can be attached to the second outer edge portion of the other of the operation arms in a natural posture. Thus, the opening and closing operation of the two holding arms can be performed more reliably and easily.

[0029] Further, the tongs-type sensor and the measurement apparatus provided with the same according to the present application are configured such that a connection cable for connecting the tongs-type sensor to the outside is drawn from the end portion on the opposite side of the holding arm side of the other of the operation arms, and thus, unlike a configuration in which the connection cable is drawn from the end portion on the opposite side of the holding arm side of one of the operation arms, the connection cable drawn from the end portion on the opposite side of the holding arm side of the other of the operation arms does not interfere with the operation of the two operation arms, and thus, the opening and closing operation of the two holding arms can be performed more reliably and easily.

[0030] Further, the tongs-type sensor and the measurement apparatus provided with the same according to the present application are configured such that, when viewed in the axial direction, both the third outer edge portion on the side of the other of the operation arms of one of the operation arms and the fourth outer edge portion on the side of one of the operation arms of the other of the operation arms are curved in the same direction as the first outer edge portion and the second outer edge portion, and thus, the width between the first outer edge portion and the third outer edge portion can be made large enough in the entire length direction of one of the operation arms, the width between the second outer edge portion and the fourth outer edge portion can be made large enough in the entire length direction of the other of the operation arms, and a tongs-type sensor in which the first outer edge portion, the second outer edge portion, the third outer edge portion, and the fourth outer edge portion are curved in the same direction can be provided, which is excellent in terms of appearance.

[0031] Further, the tongs-type sensor according to the present application and the measurement device provided with the tongs-type sensor are formed in such a manner that the portions of the third outer edge portion opposite the fourth outer edge portion and the portions of the fourth outer edge portion opposite the third outer edge portion are of the same shape when viewed in the axial direction, and thus, when operated in the direction in which the two operating arms approach each other, the two operating arms become in a state in which they abut against a sufficiently large area of the third outer edge portion and the fourth outer edge portion, and thus, even if an excessively large force is applied, breakage or deformation of the two operating arms and the rotation shaft can be appropriately avoided. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a configuration view of the measurement device 1 viewed from the front side.

[0033] Figure 2 is an appearance perspective view of the tongs-type sensor 2 in a state in which the transition of the sensor portion 10 to the open state is restricted.

[0034] Figure 3 is an appearance perspective view of the tongs-type sensor 2 in a state in which the transition of the sensor portion 10 to the open state is permitted.

[0035] Figure 4 is an appearance perspective view of the tongs-type sensor 2 in a state after the transition of the sensor portion 10 to the open state.

[0036] Figure 5 is a cross-sectional view of the operating portion 20 of the tongs-type sensor 2 in a state in which the transition of the sensor portion 10 to the open state is permitted.

[0037] Figure 6 is a cross-sectional view of the operating portion 20 of the tongs-type sensor 2 in a state in which the transition of the sensor portion 10 to the open state is restricted.

[0038] Figure 7 is an appearance view of the tongs-type sensor 2 in a state in which the transition of the sensor portion 10 to the open state is permitted, viewed in the axial direction of the rotation shaft 30.

[0039] Figure 8 is an appearance view of the tongs-type sensor 2 in a state after the transition of the sensor portion 10 to the open state, viewed in the axial direction of the rotation shaft 30.

[0040] Figure 9 is an appearance view of the tongs-type sensor 2 in a state in which the transition of the sensor portion 10 to the open state is restricted, viewed in the axial direction of the rotation shaft 30.

[0041] (EXPLANATION OF SYMBOLS)

[0042] 1 MEASUREMENT DEVICE

[0043] 2 TONGS-TYPE SENSOR

[0044] 3 measuring device main body

[0045] 10 sensor portion

[0046] 11, 12 clamping arms

[0047] 11a, 11b, 12a, 12b end portions

[0048] 20 operation portion

[0049] 21, 22 operation arms

[0050] 21a, 21b, 22a, 22b end portions

[0051] 23 rotation restriction member

[0052] 23a, 23b end portions

[0053] 30 rotation shaft

[0054] 40 signal cable

[0055] E21o, E21i, E22o, E22i outer edge portions

[0056] F22 abutment surface

[0057] F23 abutment surface

[0058] L1 one-dot chain line

[0059] L2 two-dot chain line

[0060] L21, L22 distances

[0061] M21 to M23 magnets

[0062] W10, W20 widths

[0063] X clamped object DETAILED DESCRIPTION

[0064] Hereinafter, an embodiment of a clamp-on sensor and a measuring device will be described with reference to the drawings.

[0065] Figure 1 The measuring device 1 illustrated is a non-contact type current measuring device that is one example of a "measuring device" configured to detect a magnetic field generated around a clamped object X (an electric wire or the like) by causing a current to flow in the clamped object X, and based on the magnitude of the detected magnetic field, be able to measure a current value of the current flowing in the clamped object X ("a measured quantity" is one example). Specifically, the measuring device 1 is configured to have a clamp-on sensor 2 and a measuring device main body 3.

[0066] The clamp-on sensor 2 is one example of a "clamp-on sensor" and is configured to have a pair of clamping arms 11 and 12 that are capable of being opened and closed, and a pair of operation arms 21 and 22 that are capable of being opened and closed.Figures 2-4 As shown in FIG. 1, the sensor unit 10, the operation unit 20, the rotation shaft 30 (see FIG. 2), and the signal cable 40 are provided. The sensor unit 10 is provided with the clamping arms 11, 12 (one example of "a pair of clamping arms") formed in an arc shape, as shown in FIG. 1. Figures 5-9 As shown in FIG. 1, the sensor unit 10, the operation unit 20, the rotation shaft 30 (see FIG. 2), and the signal cable 40 are provided. The sensor unit 10 is provided with the clamping arms 11, 12 (one example of "a pair of clamping arms") formed in an arc shape, as shown in FIG. 1. Figure 2 Figure 3 As shown in FIG. 1, the sensor unit 10, the operation unit 20, the rotation shaft 30 (see FIG. 2), and the signal cable 40 are provided. The sensor unit 10 is provided with the clamping arms 11, 12 (one example of "a pair of clamping arms") formed in an arc shape, as shown in FIG. 1.

[0067] The operation unit 20 is provided with the operation arm 21 extending from the end portion 11b of the clamping arm 11 (integrally formed with the clamping arm 11) and the operation arm 22 extending from the end portion 12b of the clamping arm 12 (integrally formed with the clamping arm 12) (one example of "a pair of operation arms"). That is, in the tongs sensor 2 of the present example, one rod-shaped member is configured in such a manner that the end portion 11b of the clamping arm 11 is continuous with the end portion 21a of the operation arm 21, and another rod-shaped member is configured in such a manner that the end portion 12b of the clamping arm 12 is continuous with the end portion 22a of the operation arm 22.

[0068] In this case, in the tongs sensor 2 of the present example, as shown in FIG. 1, the two clamping arms 11, 12 and the operation arms 21, 22 are configured to be rotatable about the rotation shaft 30 (one example of "a rotation shaft") disposed near the end portions 21a, 22a of the operation arms 21, 22 (one example of "the base end portions of the two clamping arms"). Figures 7-9 Figure 4 Figure 8 In this case, in the tongs sensor 2 of the present example, as shown in FIG. 1, the two clamping arms 11, 12 and the operation arms 21, 22 are configured to be rotatable about the rotation shaft 30 (one example of "a rotation shaft") disposed near the end portions 21a, 22a of the operation arms 21, 22 (one example of "the base end portions of the two clamping arms").

[0069] In addition, in the tongs sensor 2 of the present example, the end portions 21b, 22b correspond to "end portions on the side opposite to the clamping arm side". Furthermore, in the actual tongs sensor 2, a biasing member that biases the two operation arms 21, 22 in a direction in which they are separated from each other is housed in the operation arms 21, 22, and a sensor substrate disposed between the magnetic detection circuit of the sensor unit 10 and the signal cable 40 is housed in the operation arm 22, but the illustration and detailed description of these members are omitted in order to facilitate understanding of the configuration of the tongs sensor 2.

[0070] ​​​Further, in the tongs sensor 2, as shown in Figure 7 the distance L21 ("one example of a first distance") between the end portion 21b of the operating arm 21 ("one example of an operating arm on one side") and the rotation axis 30 is shorter than the distance L22 ("one example of a second distance") between the end portion 22b of the operating arm 22 ("one example of an operating arm on the other side") and the rotation axis 30.

[0071] In this case, as shown in Figures 7-9 when the operating arms 21, 22 of the tongs sensor 2 of the present example are viewed in the axial direction of the rotation axis 30, both the outer edge portion E21o ("one example of a first outer edge portion") on the side opposite the operating arm 22 of the operating arm 21, and the outer edge portion E22o ("one example of a second outer edge portion") on the side opposite the operating arm 21 of the operating arm 22 are formed in curved shapes that curve in the same direction. Specifically, when the operating arms 21, 22 are viewed in the axial direction, the outer edge portions E21o, E22o are formed in curved shapes that curve downward from the operating arm 21 toward the operating arm 22. Figures 7-9

[0072] In this case, in the tongs sensor 2 of the present example, the outer edge portion E22o of the operating arm 22 is curved with a relatively gentle curvature corresponding to the arc-shaped position of the middle phalanges of the four fingers of the adult's hand when the tongs sensor 2 is held with one hand. Further, the outer edge portion E21o of the operating arm 21 is gently curved in substantially the same shape (substantially the same curvature) as the outer edge portion E22o of the operating arm 22.

[0073] Further, when the operating arms 21, 22 of the tongs sensor 2 of the present example are viewed in the axial direction, the outer edge portion E21i ("one example of a third outer edge portion") on the side of the operating arm 22 of the operating arm 21, and the outer edge portion E22i ("one example of a fourth outer edge portion") on the side of the operating arm 21 of the operating arm 22 are formed in curved shapes that curve in the same direction (in the present example, the direction from the operating arm 21 toward the operating arm 22) as the outer edge portion E21o of the operating arm 21 and the outer edge portion E22o of the operating arm 22.

[0074] Further, when the operating arms 21, 22 of the present example are viewed in the axial direction, the portion of the outer edge portion E21i opposite the outer edge portion E22i, and the portion of the outer edge portion E22i opposite the outer edge portion E21i are in the same shape, and the two clamping arms 11, 12 constitute complementary shapes. As a result, in the tongs sensor 2 of the present example, as shown in Figure 8 ​As shown, when the two holding arms 11, 12 are caused to change to the open state (when the two operating arms 21, 22 are caused to approach each other), the outer edge portion E21i of the operating arm 21 substantially abuts the outer edge portion E22i of the operating arm 22 to become a state in which there is no gap between the two operating arms 21, 22.

[0075] Further, as shown in Figures 2-4 In the tongs-type sensor 2 of this example, a rotation restricting member 23 is attached to the operating arm 21. Specifically, as one example, an end portion 23a of the rotation restricting member 23 is pivotally supported to an intermediate portion of the two end portions 21a, 21b of the operating arm 21.

[0076] As shown in Figure 7 , Figure 8 This rotation restricting member 23, in a state in which the end portion 23b does not abut the operating arm 22 (non-locked state: as one example, a state in which the end portion 23b is pivoted to the side of the end portion 21b of the operating arm 21), allows the operating arm 21 to relatively pivot with respect to the operating arm 22 in a direction in which the holding arms 11, 12 change from the closed state to the open state.

[0077] In this case, in the tongs-type sensor 2 of this example, the rotation restricting member 23 is pivotally supported to the operating arm 21 in such a manner that the end portion 23b is positioned at the end portion 21b of the operating arm 21 in the non-locked state. Further, in the tongs-type sensor 2 of this example, as shown in Figure 5 In this case, in the tongs-type sensor 2 of this example, the rotation restricting member 23 is pivotally supported to the operating arm 21 in such a manner that the end portion 23b is positioned at the end portion 21b of the operating arm 21 in the non-locked state. Further, in the tongs-type sensor 2 of this example, as shown in

[0078] Further, as shown in Figure 9 This rotation restricting member 23, in a state in which the end portion 23b does not abut the operating arm 22 (non-locked state: as one example, a state in which the end portion 23b is pivoted to the side of the end portion 21b of the operating arm 21), allows the operating arm 21 to relatively pivot with respect to the operating arm 22 in a direction in which the holding arms 11, 12 change from the closed state to the open state.

[0079] In this case, in the tongs-type sensor 2 of this example, as shown in Figure 6As shown, when viewed along the axial direction of the rotation axis 30, an imaginary straight line passes through the two ends 23a, 23b of the rotation limiting member 23 in the locked state. Figure 6 The dotted line L1 shown is relative to the abutting surface F22 (along the end 23b (abutting surface F23) of the operating arm 22 that abuts against the rotation limiting member 23. Figure 6 The rotation limiting component 23 and the operating arm 22 are formed in a manner that is orthogonal (or approximately orthogonal) to the plane of the two dashed lines L2 shown.

[0080] Furthermore, in the clamp sensor 2 of this example, such as Figure 5 As shown, a magnet M21 is disposed at the end 21b of the operating arm 21, and a magnet M23 is disposed at the end 23b of the rotation limiting member 23. Thus, the clamp sensor 2 in this example is configured such that when the rotation limiting member 23 is switched to the unlocked state, the attractive force of the two magnets M21 and M23 is used to maintain the state in which the end 23b of the rotation limiting member 23 is pulled toward the end 21b of the operating arm 21, thereby limiting the rotation of the rotation limiting member 23 relative to the operating arm 21.

[0081] Furthermore, in the clamp sensor 2 of this example, such as Figure 6 As shown, a magnet M22 is disposed in the middle of the two ends 22a and 22b of the operating arm 22. Thus, the clamp sensor 2 in this example is configured such that when the rotation limiting member 23 is switched to the locked state, the attractive force between the magnet M22 and the magnet M23 of the rotation limiting member 23 is used to maintain the state in which the end 23b of the rotation limiting member 23 is pulled toward the E22i of the operating arm 22, thereby restricting the rotation of the rotation limiting member 23 relative to the operating arm 21 (i.e., releasing the locked state).

[0082] Furthermore, in the clamp sensor 2 of this example, such as Figure 7 , Figure 9 As shown, the lengths and shapes of the two clamping arms 11 and 12 and the two operating arms 21 and 22 are defined such that the operating part 20 exists within the range of the maximum width W10 of the sensor part 10 in the closed state (the maximum width W20 of the operating part 20 is less than or equal to the maximum width W10 of the sensor part 10).

[0083] Furthermore, in the clamp sensor 2 of this example, the signal cable 40 (an example of a "connection cable") used to connect the clamp sensor 2 to the measuring device body 3 is connected to the aforementioned sensor substrate within the operating arm 22, and, as... Figures 2-4 As shown, the signal cable 40 extends from the end 22b of the operating arm 22 to the outside of the operating arm 22. Furthermore, a connector (not shown) for connecting to the measuring device body 3 is connected to the front end of the signal cable 40.

[0084] On the other hand, as one example, the measurement device main body 3 is integrally configured by the components corresponding to the "external portion" and the "measurement portion", an "operation portion" having a plurality of operation switches for setting measurement conditions and the like, and a "display portion" for displaying measurement results, and is configured to be able to attach / detach the signal cable 40 of the clamp-on sensor 2. The measurement device main body 3 houses therein a measurement circuit of the sensor portion 10 (magnetic detection circuit) connected to the clamp-on sensor 2 via the sensor substrate, and the signal cable 40. Alternatively, the components corresponding to the "external portion" and the "measurement portion" can be configured separately from the "operation portion", the "display portion", and the like.

[0085] In the measurement device 1, when stored and transported, as one example, the clamp-on sensor 2 (signal cable 40) is detached from the measurement device main body 3, and, as shown in Figs. 9A and 9B, the rotation restricting member 23 is changed to the locked state. By this, the clamp-on sensor 2 can be stored and transported in the state where the operation portion 20 exists within the maximum width W10 of the sensor portion 10 in the closed state as described above, and the unexpected change of the sensor portion 10 to the open state is restricted, so that the deformation or breakage of the two clamping arms 11, 12 due to the foreign matter being caught between the end portions 11a, 12b of the two clamping arms 11, 12 can be properly avoided. Figure 2 Figure 9

[0086] On the other hand, when the current value of the current flowing through the clamping object X is measured using the measurement device 1, first, the clamp-on sensor 2 (signal cable 40) is attached to the measurement device main body 3. Then, when the rotation restricting member 23 is changed to the locked state as described above, the rotation restricting member 23 is rotated with respect to the operation arm 21, and, as shown in Figs. 10A and 10B, is changed to the unlocked state. By this, the operation of changing the two clamping arms 11, 12 from the closed state to the open state is allowed. Figure 3 Figure 7

[0087] In this case, in the clamp-on sensor 2 of the present example, the rotation restricting member 23 is rotated with respect to the operation arm 21 until the end portion 23b of the rotation restricting member 23 is positioned at the end portion 21b of the operation arm 21, and, by this, the unexpected rotation of the rotation restricting member 23 with respect to the operation arm 21 is restricted by the attractive force of the magnet M21 arranged at the end portion 21b and the magnet M23 arranged at the end portion 23b. By this, the case where the rotation restricting member 23 in the unlocked state is unexpectedly rotated with respect to the operation arm 21 to hinder the operation of bringing the two operation arms 21, 22 close to each other, which will be described later, can be avoided.

[0088] ​​​​Next, as an example, the palm is attached to the operation section 20 of the forceps-type sensor 2, and the index finger, the middle finger, the ring finger, and the little finger are bent, the portions of the middle phalanges of the respective fingers are attached to the outer edge portion E22o of the operation arm 22, and the ball of the thumb is attached to the outer edge portion E21o of the operation arm 21, and the forceps-type sensor 2 is held with one hand. Next, the operation arm 21 is operated so that the thumb is close to the index finger. At this time, the operation arm 21 is rotated about the rotation shaft 30 against the force of an unillustrated urging member, and the operation arm 21 is brought close to the operation arm 22. Further, as the operation arm 21 is rotated relative to the operation arm 22, the holding arm 11 formed integrally with the operation arm 21 is rotated relative to the holding arm 12 formed integrally with the operation arm 22. Thus, as shown in Figs. 2 and 3, the sensor section 10 is changed from the closed state to the open state, and becomes a state in which the end portion 11a of the holding arm 11 and the end portion 12a of the holding arm 12 are separated from each other, and the end portion 11b of the holding arm 11 and the end portion 12b of the holding arm 12 are separated from each other. Figure 4 、 Figure 8

[0089] In this case, in the forceps-type sensor 2 of the present example, the outer edge portion E22o of the operation arm 22 is gently curved with a curvature corresponding to the arc-like positions at which the middle phalanges of the four fingers, the index finger, the middle finger, the ring finger, and the little finger, are located. Therefore, when the operation arm 21 is rotated relative to the operation arm 22, the force (the restoring force of the above-mentioned urging member) applied to the operation arm 22 is received by the four fingers substantially equally, and therefore, even a person with a poor grip can sufficiently support the operation arm 21, and can appropriately maintain the state in which the four fingers are attached to the outer edge portion E22o of the operation arm 22 (appropriately prevent the four fingers from slipping relative to the operation arm 22).

[0090] Further, in the forceps-type sensor 2 of the present example, the outer edge portion E21o of the operation arm 21 is gently curved in the same direction with substantially the same shape (substantially the same curvature) as the outer edge portion E22o of the operation arm 22. Therefore, when the operation arm 21 is rotated relative to the operation arm 22, the force (the restoring force of the above-mentioned urging member) applied to the operation arm 21 can be received substantially equally over a sufficiently large area of the ball of the thumb, and therefore, the ball of the thumb does not feel pain, can appropriately support the operation arm 21, and can appropriately maintain the state in which the thumb is attached to the outer edge portion E21o of the operation arm 21 (appropriately prevent the thumb from slipping relative to the operation arm 21). Further, by curving the outer edge portions E21o, E22o in the same direction identically, the distance between the outer edge portions E21o, E22o becomes sufficiently short in the entire longitudinal direction of the two operation arms 21, 22 when the two operation arms 21, 22 are brought close to each other. Thus, even a small hand can reliably and easily maintain the state in which the two operation arms 21, 22 are close to each other.​

[0091] Moreover, in the tongs sensor 2, as described above, the portions of the outer edge portion E21i of the operation arm 21 and the outer edge portion E22i of the operation arm 22 that are opposite each other, and the portions of the outer edge portion E22i and the outer edge portion E21i that are opposite each other, are the same shape, and when the operation to change the sensor portion 10 to the open state is performed, the two outer edge portions E21i and E22i substantially abut and become a state in which there is no gap between the two operation arms 21 and 22. Therefore, even if unnecessary force is applied in a direction in which the two operation arms 21 and 22 approach each other, since a state in which a sufficiently large area of the outer edge portion E21i of the operation arm 21 and the outer edge portion E22i of the operation arm 22 are in contact is achieved, the force applied to the contact portions of the outer edge portion E21i and the outer edge portion E22i is dispersed, and thus breakage or deformation of the operation arms 21 and 22 can be appropriately avoided.

[0092] In this case, unlike the tongs sensor 2 of the present example, in a configuration in which the shapes of the opposite portions of the outer edge portions E21i and E22i are different, that is, a configuration in which the outer edge portions E21i and E22i become a point contact state at an arbitrary portion in the length direction of the operation arms 21 and 22 when the two operation arms 21 and 22 approach each other (not shown), if a force to separate the shaft support portions of the two operation arms 21 and 22 supported by the rotation shaft 30 is applied with the point contact portions of the outer edge portions E21i and E22i as fulcrums, deformation or breakage of the rotation shaft 30 can occur. In contrast, in the tongs sensor 2 of the present example, the opposite portions of the outer edge portions E21i and E22i are configured to be the same shape, and when the two operation arms 21 and 22 approach each other, a portion corresponding to the above-described "fulcrum" does not occur, and the outer edge portions E21i and E22i become a surface contact state, and thus deformation or breakage of the rotation shaft 30 can be appropriately avoided.

[0093] Next, the clamped object X is positioned between the clamping arms 11 and 12 in a manner that passes between the end portions 11a and 12a of the two clamping arms 11 and 12 (the tongs sensor 2 is moved in a manner that the clamped object X is positioned between the clamping arms 11 and 12). Then, the force of the thumb that operates the operation arm 21 is weakened.

[0094] At this time, the operation arm 21 is rotated about the rotation shaft 30 in a direction opposite to the operation to change to the above-described open state by the force of a force applying member not shown, and the operation arm 21 is separated from the operation arm 22. In addition, as the operation arm 21 rotates in the opposite direction with respect to the operation arm 22, the clamping arm 11 that is formed integrally with the operation arm 21 rotates in a direction opposite to the operation to change to the open state with respect to the clamping arm 12 that is formed integrally with the operation arm 22. Thus, as shown in FIG. 6, the clamped object X is released from the tongs sensor 2. Figure 3 ,Figure 7 As shown, the sensor portion 10 changes from the open state to the closed state, and the end portion 11a of the holding arm 11 and the end portion 12a of the holding arm 12 come into contact with each other, and the end portion 1 lb of the holding arm 11 and the end portion 12b of the holding arm 12 come into contact with each other, and a magnetic detection circuit in a ring shape is formed in the sensor portion 10.

[0095] Next, the rotation restricting member 23 is rotated with respect to the operation arm 21 against the attractive force of the magnets M21, M23, and as shown in Figure 2 Figure 9 the rotation restricting member 23 is rotated with respect to the operation arm 21. Thereby, the operation in the direction in which the two operation arms 21, 22 are brought close to each other is restricted, and the sensor portion 10 is maintained in the closed state. In this case, in the tongs-type sensor 2 of the present example, the state in which the end portion 23b of the rotation restricting member 23 is in abutment with the outer edge portion E22i of the operation arm 22 is maintained by the attractive force of the magnet M22 arranged on the operation arm 22 and the magnet M23 arranged on the rotation restricting member 23.

[0096] Furthermore, in the tongs-type sensor 2 of the present example, when the tongs-type sensor 2 is viewed in the axial direction of the rotation axis 30 with the rotation restricting member 23 changed to the locked state, an imaginary straight line (an imaginary straight line in the extending direction of the rotation restricting member 23: Figure 6 as shown in the one-dot chain line L1) passing through both end portions 23a, 23b of the rotation restricting member 23 is orthogonal (or substantially orthogonal) with respect to the abutment surface F22 of the operation arm 22 with which the end portion 23b of the rotation restricting member 23 is in abutment (as shown in the two-dot chain line L2). Figure 6 Therefore, when a force in the direction in which the two operation arms 21, 22 are brought close to each other is applied, the abutment surface F23 of the rotation restricting member 23 is pressed perpendicularly (or substantially perpendicularly) on the abutment surface F22 of the operation arm 22, and thus slippage of the abutment surface F23 along the abutment surface F22 (i.e., slippage of the end portion 23b with respect to the operation arm 22) is less likely to occur. As a result, the state in which the end portion 23b of the rotation restricting member 23 is in abutment with the outer edge portion E22i of the operation arm 22 is more appropriately maintained.

[0097] ​Thus, in the tongs sensor 2 of the present example, it is possible to appropriately avoid the situation in which the rotation restricting member 23 that has shifted to the locked state unexpectedly rotates with respect to the operation arm 21, and operation in the direction in which the two operation arms 21, 22 are brought closer to each other is performed. Thereby, operation to shift the two clamping arms 11, 12 from the closed state to the open state is restricted, and the sensor portion 10 is maintained in the closed state. Through the above, clamping of the clamping object X by the tongs sensor 2 is completed.

[0098] Then, the operation portion of the measurement device main body 3 is operated to start the measurement process. At this time, the tongs sensor 2 is used to detect the magnetic field that is generated around the clamping object X (an electric wire or the like) due to the current flowing in the clamping object X, and the measurement device main body 3 calculates (measures) the current value of the current flowing in the clamping object X on the basis of the detected magnetic field size. Thereby, the current value as the measurement result is displayed on the display portion of the measurement device main body 3, and a series of measurement operations is completed.

[0099] Further, when the measurement operations are completed, the clamping object X is moved from between the two clamping arms 11, 12 (the tongs sensor 2 is detached from the clamping object X) in the order opposite to the above-described clamping operations. Also, at the time of conveyance and storage, as described above, the rotation restricting member 23 is shifted to the locked state, and the tongs sensor 2 is detached from the measurement device main body 3. Through the above steps, a series of operations is completed.

[0100] In addition, in the tongs sensor 2 of the present example, instead of the operation method in which the five fingers are attached to the two operation arms 21, 22 to hold the tongs sensor 2 with one hand as described above, it is possible to hold in a manner in which the two operation arms 21, 22 are pinched with the thumb and the index finger (or the thumb, the index finger, and the middle finger). In this case, in the tongs sensor 2 of the present example, since the distance between the outer edge portions E21o, E22o is sufficiently short, it is possible to reliably and easily hold the tongs sensor 2 in a manner in which the two operation arms 21, 22 are pinched with two or three fingers, and it is possible to reliably and easily open and close the clamping arms 11, 12. Thereby, compared to the case in which the tongs sensor 2 is held with one hand in a manner in which the five fingers are attached to the two operation arms 21, 22, the wrist, the elbow, or the like is not forcibly bent and stretched at the time of clamping of the clamping object X or at the time of detachment from the clamping object X, and it is possible to hold the tongs sensor 2 in various postures and perform opening and closing. Thus, even if the clamping object X exists in a narrow place, or the clamping object X exists in a high place or a low place, it is possible to approach and separate the tongs sensor 2 in various postures, and to open and close in various postures, and thus it is possible to reliably and easily clamp or detach with respect to various clamping objects X.

[0101] Further, in the tongs sensor 2 of the present example, unlike the structure in which the outer edge portions E21o, E22o are bent in opposite directions in a large separation manner at the central portions in the length direction of the two operation arms 21, 22, and the structure in which the outer edge portions E21o, E22o are formed in a straight line shape along the length direction of the two operation arms 21, 22, by making the outer edge portions E21o, E22o be curved in a curved shape bent in the same direction, even when the tongs sensor 2 is held with only two or three fingers, it is less likely that the fingers attached on the inner side of the curved shape slip with respect to the operation arm (in the present example, the operation arm 21). Therefore, it is also less likely that the fingers attached on the outer side of the curved shape slip with respect to the operation arm (in the present example, the operation arm 22). Thus, the tongs sensor 2 can be reliably held with only two or three fingers, and thus, it is possible to appropriately avoid the accidental dropping of the tongs sensor 2.

[0102] As such, in the tongs sensor 2, the pair of operation arms 21, 22 are provided which are configured to be respectively extended at the end portions 11b, 12b of the two clamping arms 11, 12 and rotatable about the rotation axis 30 in a manner of approaching each other to thereby change the two clamping arms 11, 12 into the open state in which the end portions 11a, 12a are separated from each other, and in which, when the two operation arms 21, 22 are observed in the axis direction of the rotation axis 30, the outer edge portion E21o on the side opposite to the operation arm 22 of the operation arm 21 and the outer edge portion E22o on the side opposite to the operation arm 21 of the operation arm 22 are formed in a curved shape bent in the same direction. Further, in the above-described measurement device 1, the tongs sensor 2 and the measurement device main body 3 are configured to be provided.

[0103] Therefore, according to the above-described tongs sensor 2 and the measurement device 1, by integrally forming the holding arm 11 and the operation arm 21, and integrally forming the holding arm 12 and the operation arm 22, the number of components of the tongs sensor 2 can be sufficiently reduced, and thus the manufacturing cost and the assembly cost of the components can be sufficiently reduced, and thus the manufacturing cost of the tongs sensor 2 can be sufficiently reduced. Further, by making the outer edge portion E21o of the operation arm 21 and the outer edge portion E22o of the operation arm 22 have a curved shape that curves in the same direction, when the tongs sensor 2 is held with one hand (for example, five fingers), each finger can be attached to the outer edge portions E21o, E22o in a natural posture, and thus the tongs sensor 2 can be reliably and easily held, and accidental dropping can be prevented. Further, even when the two operation arms 21, 22 are operated, slippage of the fingers with respect to the outer edge portions E21o, E22o can be appropriately prevented, and thus the opening and closing operation of the two holding arms 11, 12 can be reliably and easily performed. Furthermore, when the two operation arms are brought close to each other to change the two holding arms to the open state, the distance between the outer edge portions E21o, E22o becomes sufficiently short in the entire length direction of the two operation arms 21, 22, and thus even if the hand is small, the close state of the two operation arms 21, 22 (the open state of the two holding arms 11, 12) can be reliably and easily maintained. Thus, the holding of the holding object X (the attachment of the tongs sensor 2 to the holding object) and the detachment of the tongs sensor 2 from the holding object X can be reliably and easily performed. Further, by making the distance between the outer edge portions E21o, E22o sufficiently short, the tongs sensor 2 can be reliably and easily held in a state in which the two operation arms 21, 22 are pinched with the thumb and the index finger (or pinched with the thumb, the index finger, and the middle finger), and the holding arms 11, 12 can be reliably and easily opened and closed in this state. Thus, compared to the case in which the tongs sensor 2 is held with one hand in a state in which the five fingers are attached to the two operation arms 21, 22, when the holding object X is held and when the tongs sensor 2 is detached from the holding object X, the wrist, the elbow, and the like are not forcibly bent and stretched, and the tongs sensor 2 can be held in various postures and opened and closed. Therefore, even for the holding object X present in a narrow place, the holding object X present in a high place, or the holding object X present in a low place, the holding and the detachment can be reliably and easily performed. Further, unlike a structure in which the outer edge portions E21o, E22o are bent in opposite directions at a central portion of the length direction of the two operation arms 21, 22, or a structure in which the outer edge portions E21o, E22o are formed in a straight line along the length direction of the two operation arms 21, 22, by making the outer edge portions E21o, E22o have a curved shape that curves in the same direction, even when the tongs sensor 2 is held with only two or three fingers, slippage of the fingers attached to the inside of the curved shape with respect to the operation arm (in this example, the operation arm 21) is less likely to occur, and slippage of the fingers attached to the outside of the curved shape with respect to the operation arm (in this example, the operation arm 22) is also less likely to occur.Thus, the forceps sensor 2 can be reliably held with only two or three fingers, and thus, accidental dropping of the forceps sensor 2 can be appropriately avoided.

[0104] Further, according to the forceps sensor 2 and the measuring apparatus 1, the two operation arms 21, 22 are formed in such a manner that a "first distance" (distance L21) between the end portion 21b of the operation arm 21 on the side opposite to the holding arm 11 and the rotation shaft 30 is shorter than a "second distance" (distance L22) between the end portion 22b of the operation arm 22 on the side opposite to the holding arm 12 and the rotation shaft 30, and thus, when the forceps sensor 2 is held with one hand, the thumb can be attached to the end portion 21b side of the outer edge portion E21o of the operation arm 21 in a natural posture in a state where the index finger, the middle finger, the ring finger, and the little finger are attached to the outer edge portion E22o of the operation arm 22. Thus, the opening and closing operation of the two holding arms 11, 12 can be performed more reliably and more easily. Figure 7

[0105] Further, according to the forceps sensor 2 and the measuring apparatus 1, the two operation arms 21, 22 are formed in such a manner that the outer edge portion E21o and the outer edge portion E22o become curved shapes curved in a direction from the operation arm 21 toward the operation arm 22 when viewed in the axial direction, and thus, when the forceps sensor 2 is held with one hand, the thumb can be attached to the outer edge portion E21o of the operation arm 21 in a natural posture, and the index finger, the middle finger, the ring finger, and the little finger can be attached to the outer edge portion E22o of the operation arm 22 in a natural posture. Thus, the opening and closing operation of the two holding arms 11, 12 can be performed more reliably and more easily.

[0106] Further, according to the forceps sensor 2 and the measuring apparatus 1, the signal cable 40 for connecting the forceps sensor 2 to the measuring apparatus main body 3 (outside) is drawn from the end portion 22b of the operation arm 22 on the side opposite to the holding arm 12, and thus, unlike the structure in which the signal cable 40 is drawn from the end portion 21b of the shorter operation arm 21, the signal cable 40 drawn from the end portion 22b of the longer operation arm 22 does not interfere with the operation of the two operation arms 21, 22, and thus, the opening and closing operation of the two holding arms 11, 12 can be performed more reliably and more easily.

[0107] ​Further, according to the tongs-type sensor 2 and the measuring device 1, the two operation arms 21, 22 are formed in such a manner that, when viewed in the axial direction, the outer edge portion E21i of the operation arm 21 on the operation arm 22 side and the outer edge portion E22i of the operation arm 22 on the operation arm 21 side are curved in the same direction as the outer edge portions E21o, E22o. Thus, the width between the outer edge portions E21o, E21i in the entire length direction of the operation arm 21 and the width between the outer edge portions E22o, E22i in the entire length direction of the operation arm 22 can be made sufficiently large, and a tongs-type sensor 2 in which the outer edge portions E21o, E21i, E22o, E22i are curved in the same direction can be provided.

[0108] Further, according to the tongs-type sensor 2 and the measuring device 1, the two operation arms 21, 22 are formed in such a manner that, when viewed in the axial direction, the outer edge portion E21i of the operation arm 21 on the operation arm 22 side and the outer edge portion E22i of the operation arm 22 on the operation arm 21 side are curved in the same direction as the outer edge portions E21o, E22o. Thus, the width between the outer edge portions E21o, E21i in the entire length direction of the operation arm 21 and the width between the outer edge portions E22o, E22i in the entire length direction of the operation arm 22 can be made sufficiently large, and a tongs-type sensor 2 in which the outer edge portions E21o, E21i, E22o, E22i are curved in the same direction can be provided.

[0109] Further, the configuration of the "tongs-type sensor" and the "measuring device" is not limited to the example of the tongs-type sensor 2 and the measuring device 1 described above.

[0110] For example, in the configuration of the tongs-type sensor 2 described above, the two operation arms 21, 22 are formed in such a manner that, when viewed in the axial direction of the rotation shaft 30, the outer edge portions E21i, E22i of the operation arms 21, 22 are curved in the same direction as the outer edge portions E21o, E22o, but either one or both of the "third outer edge portion" and the "fourth outer edge portion" can be formed in a curved shape curved in the opposite direction with respect to the "first outer edge portion" and the "second outer edge portion" or a non-curved shape (straight line shape or angular shape, etc.) (not shown).

[0111] Further, in the configuration of the clamp sensor 2 illustrated as an example, the two operation arms 21, 22 are formed so that the distance L21 between the end portion 21b of the operation arm 21 and the rotation shaft 30 is shorter than the distance L22 between the end portion 22b of the operation arm 22 and the rotation shaft 30, but the two operation arms (not illustrated) can be formed so that the "first distance" of one of the operation arms is equal to the "second distance" of the other operation arm. Further, in the configuration of the clamp sensor 2 illustrated as an example, the rotation limiting member 23 is provided to limit the operation in the direction in which the two operation arms 21, 22 approach each other, but the clamp sensor can be configured without the rotation limiting member 23.

[0112] Further, the example in which the signal cable 40 is connected to the measurement device main body 3 as the "external" and used has been described, but the signal cable 40 can be connected to and used with an extension cable, a signal amplifier, a noise filter, or the like as the "external". Further, the structure of the measurement device 1 and the clamp sensor 2 in which the current value of the current flowing in the clamped object X is measured as the "measured quantity" has been described as an example, but the same structure as the measurement device 1 and the clamp sensor 2 described above can be adopted in the "measurement device" and the "clamp sensor" in which various electrical parameters other than the current value are measured as the "measured quantity".

Claims

1. A clamp sensor comprising a pair of clamping arms, the pair of clamping arms being arc-shaped and forming an annular sensor portion in a closed state where their front ends abut against each other, and the clamp sensor being configured to allow the two clamping arms to rotate about a rotation axis disposed near the base ends of the two clamping arms, such that the front ends contact / separate from each other. The clamp sensor has a pair of operating arms, which extend from the base ends of the two clamping arms and are configured to rotate about the rotation axis in a mutually approaching manner, thereby turning the two clamping arms into an open state where their front ends are separated from each other. The two operating arms are configured such that, when viewed along the axial direction of the rotation axis, the first outer edge of one operating arm opposite to the side of the other operating arm and the second outer edge of the other operating arm opposite to the side of the first operating arm are both curved in the same direction. Furthermore, the first distance between the end of one operating arm opposite to the side of the clamping arm and the rotation axis is shorter than the second distance between the end of the other operating arm opposite to the side of the clamping arm and the rotation axis.

2. The clamp sensor according to claim 1, wherein, When the two operating arms are viewed along the axial direction, the first outer edge and the second outer edge are formed into a curved shape that bends from one operating arm toward the other operating arm.

3. The clamp sensor according to claim 1, wherein, A connecting cable is led out from the end of the operating arm of the other party on the side opposite to the clamping arm side, the connecting cable being used to connect the clamp sensor to the outside.

4. The clamp sensor according to claim 2, wherein, A connecting cable is led out from the end of the operating arm of the other party on the side opposite to the clamping arm side, the connecting cable being used to connect the clamp sensor to the outside.

5. The clamp sensor according to any one of claims 1 to 4, wherein, When the two operating arms are viewed along the axial direction, the third outer edge of one operating arm on the side of the other operating arm and the fourth outer edge of the other operating arm on the side of the first operating arm are both formed into a curved shape that bends in the same direction as the first outer edge and the second outer edge.

6. The clamp sensor according to claim 5, wherein, When the two operating arms are viewed along the axial direction, the portion of the third outer edge that is opposite to the fourth outer edge and the portion of the fourth outer edge that is opposite to the third outer edge are formed to have the same shape.

7. A measuring device comprising: The clamp sensor according to any one of claims 1 to 6; and The measuring unit measures the quantity to be measured with respect to the clamped object held by the clamp sensor.

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