Electric wire physical quantity measurement device

Abstract

To stably maintain a fitting state of an electric wire physical quantity measurement device to an electric wire.SOLUTION: An electric wire physical quantity measurement device comprises: a sensor which is fitted to an electric wire containing first metal to measure a physical quantity of the electric wire; a body part which acquires data of the physical quantity measured by the sensor; a housing part which houses at least a part of the body part; and a clamp which contains second metal different from the first metal to hold the electric wire and to fix the housing part to the electric wire, wherein the clamp comprises: a clamp body part which contains the second metal and is tightened in a state of holding the electric wire; and a collar which is constituted as a cylindrical member and is arranged between the electric wire and the clamp body part, and the collar comprises: a first metal layer which contains the first metal and is arranged to cover an outer periphery of the electric wire; and a resin layer which contains a resin and a plurality of pieces of intermediate metal powder containing intermediate metal having corrosion potential between corrosion potential of the first metal and corrosion potential of the second metal and dispersed in the resin, and is provided to cover an outer periphery of the first metal layer.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an electric wire physical quantity measuring device. [Background technology]

[0002] BACKGROUND ART In order to measure physical quantities such as the temperature of an electric wire or the current flowing through the electric wire, an electric wire physical quantity measuring device is sometimes attached to the electric wire (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-58960 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to stably maintain the attachment state of an electric wire physical quantity measuring device to an electric wire. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided an electric wire physical quantity measuring device including: a sensor attached to an electric wire including a first metal and measuring the physical quantity of the electric wire; a main body that acquires data of the physical quantity measured by the sensor; a housing that houses at least a portion of the main body; and a clamp that includes a second metal different from the first metal and grips the electric wire and secures the housing to the electric wire, wherein the clamp has a clamp main body that includes the second metal and is tightened while gripping the electric wire; and a collar that is configured as a tubular member and is disposed between the electric wire and the clamp main body, wherein the collar includes: a first metal layer that includes the first metal and is disposed to cover an outer periphery of the electric wire; and a resin layer that is provided to cover the outer periphery of the first metal layer, the resin layer including a resin and a plurality of intermediate metal powders that contain an intermediate metal having a corrosion potential between the corrosion potentials of the first metal and the second metal and are dispersed in the resin. [Effects of the Invention]

[0006] According to the present disclosure, the attachment state of an electric wire physical quantity measuring device to an electric wire can be stably maintained. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic perspective view showing an electric wire physical quantity measuring device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a block diagram illustrating an electric wire physical quantity measuring device according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an electric wire physical quantity measuring device according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional view of the clamp taken perpendicular to the axial direction of the wire. [Figure 5] FIG. 5 is a schematic enlarged cross-sectional view of the clamp taken along the axial direction of the electric wire. [Figure 6] FIG. 6 is a schematic diagram showing the gripping force test. [Figure 7] FIG. 7 is a schematic diagram showing a vibration test. [Figure 8] FIG. 8 is a schematic diagram showing the corrosion resistance test. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Description of the embodiments of the present disclosure] <Knowledge gained by the inventors> First, the findings of the inventors will be explained.

[0009] In recent years, the construction of data centers or semiconductor factories in areas of high demand for electricity has led to the need to increase the capacity of power lines. In such cases, it is possible to address congestion on the PH lines using a power line physical quantity measuring device without replacing the existing single-strand hard-wired copper wire (PH wire). In other words, as a congestion management measure, it is possible to increase the current capacity that the PH lines can transmit by measuring the temperature and current of the PH lines using a power line physical quantity measuring device.

[0010] However, the electrical wire physical quantity measuring devices developed by the inventors so far have been designed to be applied mainly to aluminum-stranded steel core wire (ACSR), and therefore, the application of electrical wire physical quantity measuring devices to PH electrical wires has not been considered.

[0011] Specifically, the entire wire physical quantity measuring device, including the clamp that holds the wire, contains an aluminum alloy. Therefore, when attaching an aluminum alloy-containing wire physical quantity measuring device to a copper-containing PH wire, corrosion (electrical corrosion, galvanic corrosion) may occur between the clamp and the PH wire due to dissimilar metal contact.

[0012] Therefore, the inventors have considered the following configurations (i) to (iii) as countermeasures against the above-mentioned electrolytic corrosion.

[0013] (i) A collar, a cylindrical member containing copper, was interposed between the clamp body that grips the electric wire and the electric wire. The collar was in direct contact (close contact) with the clamp body. This was thought to suppress electrolytic corrosion of the electric wire. However, in this case, rainwater penetrated between the clamp body and the collar, and the water spread to the interface due to capillary action. As a result, electrolytic corrosion occurred between the clamp body and the collar. As a result, the gripping force of the clamp body was reduced.

[0014] (ii) In the configuration of (i), the clamp body and collar are tightly attached, and the outer periphery of the clamp body and collar is covered with resin. This is thought to prevent rainwater from penetrating between the clamp body and collar during installation. However, in this case, cracks occurred in the resin covering the outer periphery of the clamp body and collar due to at least one of ultraviolet degradation, oxidation degradation, and aging degradation. As a result, rainwater penetrated through the cracks in the resin, causing electrolytic corrosion between the clamp body and collar. As a result, the gripping force of the clamp body was reduced in the configuration of (ii) as well.

[0015] (iii) In the configuration of (i), the clamp body containing an aluminum alloy and the collar made of copper were welded (brazed) with a tin-zinc alloy as an intermediate metal with a corrosion potential intermediate between the two. This was thought to improve the gripping force and suppress electrolytic corrosion during installation due to the presence of the intermediate metal between the clamp body and the collar. However, in this case, when torque was applied to the clamp in the circumferential direction of the electric wire or when vibration was applied to the clamp, the weld on the intermediate metal peeled off, causing the collar to come off from the clamp body. As a result, the attachment of the electric wire physical quantity measuring device to the electric wire could not be maintained.

[0016] As described above, new problems have arisen in the configurations (i) to (iii). Therefore, a configuration has been desired that can stably maintain the attachment state of an electric wire physical quantity measuring device to an electric wire even when the clamp of the electric wire physical quantity measuring device and the electric wire contain different types of metals.

[0017] The present disclosure below is based on the above-mentioned new problem discovered by the inventors.

[0018] <Embodiments of the present disclosure> Next, embodiments of the present disclosure will be listed and described.

[0019] [1] An electric wire physical quantity measuring device according to one aspect of the present disclosure includes: a sensor attached to an electric wire containing a first metal and measuring a physical quantity of the electric wire; a main body that acquires data of the physical quantity measured by the sensor; a housing portion that houses at least a portion of the main body portion; a clamp including a second metal different from the first metal, which clamps the electric wire and fixes the housing portion to the electric wire; Equipped with The clamp is a clamp body portion including the second metal and configured to be fastened while gripping the electric wire; a collar configured as a tubular member and disposed between the electric wire and the clamp body; and The color is a first metal layer including the first metal and arranged to cover an outer periphery of the electric wire; a resin layer including a resin and a plurality of intermediate metal powders dispersed in the resin, the intermediate metal having a corrosion potential between the corrosion potential of the first metal and the corrosion potential of the second metal, the resin layer being provided so as to cover an outer periphery of the first metal layer; It has. According to this configuration, even if the clamp of the electric wire physical quantity measuring device and the electric wire contain different types of metals, the attachment state of the electric wire physical quantity measuring device to the electric wire can be stably maintained.

[0020] [2] In the electric wire physical quantity measuring device described in [1] above, The collar further includes a second metal layer that includes the second metal and is provided so as to surround the outer periphery of the resin layer and is configured to fit inside the clamp body portion. According to this configuration, the collar can be configured to be easily detachable from the clamp body.

[0021] [3] In the electric wire physical quantity measuring device according to [1] or [2] above, The resin layer is a first resin layer including a first resin and a plurality of first metal powders containing the first metal dispersed in the first resin, the first resin layer being provided so as to cover an outer periphery of the first metal layer; an intermediate resin layer including an intermediate resin and the plurality of intermediate metal powders dispersed in the intermediate resin, the intermediate resin layer being provided so as to cover an outer periphery of the first resin layer; a second resin layer including a second resin and a plurality of second metal powders including the second metal dispersed in the second resin, the second resin layer being provided so as to cover an outer periphery of the intermediate resin layer; It has. According to this configuration, the occurrence of electrolytic corrosion can be stably suppressed.

[0022] [4] In the electric wire physical quantity measuring device according to any one of [1] to [3] above, When the wire physical quantity measuring device is attached to the wire and a predetermined torque is applied to the clamp in the circumferential direction of the wire, the maximum allowable torque before the wire physical quantity measuring device begins to move is 9.8 Nm or more. According to this configuration, even if the clamp of the electric wire physical quantity measuring device and the electric wire contain different types of metals, the attachment state of the electric wire physical quantity measuring device to the electric wire can be stably maintained.

[0023] [5] In the electric wire physical quantity measuring device according to any one of [1] to [4] above, A pair of constant tension devices that pull the electric wire with a constant tension, a fixed end that fixes a part of the electric wire between the pair of constant tension devices, and a vibration device that vibrates the electric wire between the fixed end and one of the pair of constant tension devices, were used, and with the electric wire physical quantity measuring device attached to the electric wire between the fixed end and the vibration device, a vibration was performed at a frequency of 30 Hz for 10 s so that a strain of ±0.01% was applied to the electric wire at the fixed end. 7 After a vibration test is performed in which the electric wire is vibrated by the vibration device, the electric wire is not broken and the wires contained in the electric wire are not cut at the portion where the clamp holds the electric wire. According to this configuration, even if the clamp of the electric wire physical quantity measuring device and the electric wire contain different types of metals, the attachment state of the electric wire physical quantity measuring device to the electric wire can be stably maintained.

[0024] [6] In the electric wire physical quantity measuring device according to any one of [1] to [5] above, The wire physical quantity measuring device is attached to the wire, and a current is passed through the wire, maintaining the wire at 90°C. After a corrosion test is performed for 720 hours, which repeats a cycle including spraying a corrosive solution of pH 5 onto the wire and the wire physical quantity measuring device and stopping the spraying of the corrosive solution, no corrosion occurs in the portion of the wire where the clamp grips the wire. According to this configuration, even if the clamp of the electric wire physical quantity measuring device and the electric wire contain different types of metals, the attachment state of the electric wire physical quantity measuring device to the electric wire can be stably maintained.

[0025] [Details of the embodiments of the present disclosure] Next, one embodiment of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0026] <One embodiment of the present disclosure> (1) Overview of the electrical wire physical quantity measuring device An outline of an electric wire physical quantity measuring device 10 according to an embodiment of the present disclosure will be described with reference to Figures 1 to 3. Figure 3 is a cross-sectional view of the electric wire physical quantity measuring device 10 taken along the direction in which an electric wire 100 is inserted, with the electric wire 100 and a collar 800, which will be described later, omitted. In the figures other than Figure 2, some of the wiring is omitted.

[0027] Hereinafter, the "axial direction" of the electric wire 100 refers to the direction along the central axis of the electric wire 100, and in some cases may be referred to as the longitudinal direction of the electric wire 100. The "radial direction" of the electric wire 100 refers to the direction from the central axis of the electric wire 100 toward the outer periphery, i.e., the direction perpendicular to the axial direction of the electric wire 100. The "circumferential direction" of the electric wire 100 refers to the direction along the outer periphery of the electric wire 100. Terms similar to those described above may also be used for cylindrical members, columnar members, cylindrical portions, columnar portions, and the like included in the electric wire physical quantity measuring device 10. "Suppressing" a specific phenomenon such as electrolytic corrosion means preventing the occurrence of the specific phenomenon, reducing the occurrence probability, amount, or density of the phenomenon, or reducing the range of occurrence of the phenomenon.

[0028] 1 to 3, the electric wire physical quantity measuring device 10 of this embodiment is configured to be attached to, for example, an electric wire 100 and measure the physical quantity of the electric wire 100. Specifically, the electric wire physical quantity measuring device 10 includes, for example, a sensor 20, a main body 40, a housing 30, and a clamp (holding portion) 700.

[0029] (Electric wire) In this embodiment, the electric wire 100 to be measured by the electric wire physical quantity measuring device 10 is configured as, for example, a so-called overhead power transmission line. In this embodiment, the electric wire 100 includes a first metal. Examples of the first metal include copper (Cu) or a Cu alloy. Specifically, the electric wire 100 is, for example, a hard-stranded copper wire (PH electric wire), which is a single-stranded wire.

[0030] (sensor) The sensor 20 is attached to, for example, the electric wire 100 and configured to measure a physical quantity of the electric wire 100. The "physical quantity of the electric wire 100" here includes the temperature of the electric wire 100, the current flowing through the electric wire 100, and the like.

[0031] 2 and 3, at least one sensor 20 is configured, for example, as a current measurement current transformer unit (current measurement CT unit) 520. The current measurement CT unit 520 is arranged, for example, in a ring shape so as to surround the electric wire 100. The current measurement CT unit 520 is configured, for example, to output an induced voltage corresponding to the current flowing through the electric wire 100. The current measurement CT unit 520 is connected to a current measurement unit 540, which will be described later.

[0032] Alternatively, as shown in FIGS. 1 and 2, at least one sensor 20 is configured as, for example, a temperature sensor unit 200. The temperature sensor unit 200 is configured to be in contact with, for example, an electric wire 100 and measure the temperature of the electric wire 100. Specifically, the temperature sensor unit 200 has, for example, a thermocouple that outputs a voltage according to the temperature. Hereinafter, information related to the temperature of the electric wire 100 measured by the temperature sensor unit 200 will be referred to as "temperature data." The temperature sensor unit 200 is connected to, for example, a wireless unit 600 (described later) via a lead wire 280.

[0033] (Main body) The main body 40 is configured to acquire data on the physical quantities of the electric wire 100 measured by the sensor 20, for example.

[0034] Specifically, the main body 40 has, for example, a current measurement unit (current measurement circuit) 540, a radio unit (transmitter / receiver, communication unit) 600, a power supply current transformer unit (power supply CT unit, power generation CT unit) 420, and a power supply unit (power supply circuit) 440.

[0035] (Current measurement section) 2, the current measuring unit 540 is configured to be connected to the current measuring CT unit 520, for example, and to acquire data on the current of the electric wire 100 by measuring the current flowing through the electric wire 100 based on the induced voltage output by the current measuring CT unit 520. Hereinafter, the data on the current of the electric wire 100 acquired by the current measuring unit 540 will also be referred to as "current data." The current measuring unit 540 may be considered to be part of the sensor 20.

[0036] (Radio Department) The wireless unit 600 is configured to, for example, acquire data on the physical quantities of the electric wire 100 and transmit the data wirelessly to the outside.

[0037] 2, the wireless unit 600 is connected to, for example, the current measuring unit 540 and configured to acquire current data of the electric wire 100 from the current measuring unit 540. The wireless unit 600 is connected to, for example, the temperature sensor unit 200 and configured to acquire temperature data of the electric wire 100 measured by the temperature sensor unit 200. The wireless unit 600 is connected to, for example, the power supply CT unit 420 via the power supply unit 440 (described later) and configured to wirelessly transmit various data including temperature data, current data, etc. to the outside using power supplied from the power supply unit 440.

[0038] As shown in FIGS. 1 to 3, the wireless unit 600 has, for example, an antenna 620, and is configured to transmit and receive various data to and from the outside via the antenna 620.

[0039] (Power supply current transformer section) 2 and 3, the power supply CT unit 420 is arranged, for example, in a ring shape so as to surround the electric wire 100. The power supply CT unit 420 is configured, for example, to generate electric power by electromagnetic induction from a magnetic field generated around the electric wire 100 based on a current flowing through the electric wire 100.

[0040] (Power supply part) As shown in FIG. 2, the power supply unit 440 is configured to be connected to, for example, the power supply CT unit 420, and to convert the power generated by the power supply CT unit 420 into power suitable for each unit, such as the above-mentioned wireless unit 600, and supply it to each unit.

[0041] (Storage section) The housing portion 30 houses, for example, at least a part of the main body portion 40. The housing portion 30 includes, for example, the same metal (second metal) as the clamp 700 described below.

[0042] In this embodiment, the storage section 30 is divided into, for example, two sections. Specifically, the storage section 30 has a first storage section 310 and a second storage section 320.

[0043] (First storage section) As shown in FIGS. 1 to 3, the first housing section 310 houses, outside the electric wire 100, for example, the power supply CT section 420, the power supply section 440, the current measuring section 540, and the radio section 600.

[0044] (Second storage section) As shown in FIGS. 1 to 3, the second housing portion 320 houses, for example, the current measuring CT portion 520 outside the electric wire 100.

[0045] (clamp) The clamp 700, for example, grips the electric wire 100 and fixes the accommodating portion 30 to the electric wire 100. In this embodiment, the clamp 700 is provided, for example, between the first accommodating portion 310 and the second accommodating portion 320, and is connected to both the first accommodating portion 310 and the second accommodating portion 320.

[0046] The clamp 700 includes, for example, a second metal that is different from the first metal included in the electric wire 100. Examples of the second metal include aluminum (Al) and Al alloys.

[0047] The construction of clamp 700 is described in more detail below.

[0048] (2) Clamp configuration The configuration of the clamp 700 of this embodiment will be described in detail with reference to Figures 4 and 5. In Figure 4, the electric wire 100 is omitted.

[0049] As shown in FIG. 4, the clamp 700 of this embodiment includes, for example, a clamp main body 720 and a collar 800.

[0050] (Clamp body) Clamp body 720 is configured to be tightened while gripping electric wire 100, for example. Specifically, clamp body 720 has, for example, a lower clamp body 722 and an upper clamp body 724. Lower clamp body 722 and upper clamp body 724 have semi-cylindrical recesses 722a and 724a, respectively, through which electric wire 100 is inserted. Lower clamp body 722 and upper clamp body 724 are fastened together with bolts (reference numerals not shown) and nuts (reference numerals not shown) with electric wire 100 inserted into recesses 722a and 724a.

[0051] The clamp body 720 contains, for example, Al or an Al alloy as the second metal.

[0052] (color) The collar 800 is configured as, for example, a cylindrical member and is disposed between the electric wire 100 and the clamp main body 720. Specifically, the collar 800 has, for example, a pair of half-cylindrical members, a lower collar 800a and an upper collar 800b. The lower collar 800a and the upper collar 800b are fitted inside the clamp main body lower 722 and the clamp main body upper 724, for example, with the outer circumferential surface of the lower collar 800a abutting against the recess 722a of the clamp main body lower 722 and the outer circumferential surface of the upper collar 800b abutting against the inner circumferential surface of the recess 724a of the clamp main body upper 724. The inner circumferential surfaces of the lower collar 800a and the upper collar 800b are configured to abut against the outer circumferential surface of the electric wire 100, for example, when the clamp main body 720 is tightened.

[0053] The collar 800 has, for example, at least a first metal layer 820 and a resin layer 840. In this embodiment, the collar 800 has, for example, a first metal layer 820, a resin layer 840, and a second metal layer 860.

[0054] (1st metal layer) The first metal layer 820 contains, for example, Cu or a Cu alloy as the first metal. The first metal layer 820 is disposed so as to cover the outer periphery of the electric wire 100. That is, the inner periphery of the first metal layer 820 is in direct contact with the outer periphery of the electric wire 100. However, since the first metal layer 820 contains the first metal like the electric wire 100, the occurrence of electrolytic corrosion between the first metal layer 820 and the electric wire 100 can be suppressed.

[0055] There are no particular limitations on the thickness of first metal layer 820. However, from the viewpoint of maintaining strength when fastening electric wire 100, the thickness of first metal layer 820 may be approximately 3 mm or more and 5 mm or less.

[0056] (resin layer) The resin layer 840 is provided, for example, so as to cover the outer periphery of the first metal layer 820, and is disposed between the first metal layer 820 and the clamp main body 720. In this embodiment, the resin layer 840 is provided, for example, between the first metal layer 820 and a second metal layer 860 described below, and bonds the first metal layer 820 and the second metal layer 860 together.

[0057] The resin layer 840 includes, for example, at least a resin (an intermediate resin 845 described below) and a plurality of intermediate metal powder particles (an intermediate metal powder particle 846 described below).

[0058] 5, the resin layer 840 of this embodiment has, for example, a three-layer structure. That is, the resin layer 840 has, for example, a first resin layer 841, an intermediate resin layer 844, and a second resin layer 847 in this order from a position close to the first metal layer 820 toward the outer side in the radial direction of the collar 800 (the second metal layer 860).

[0059] (1st resin layer) The first resin layer 841 includes, for example, a first resin 842 and a plurality of first metal powder particles 843. The first resin 842 includes, for example, an epoxy resin or a polyurethane resin. The first resin 842 may be, for example, a thermosetting resin.

[0060] First metal powder 843 contains, for example, Cu or a Cu alloy as a first metal, similar to electric wire 100. The plurality of first metal powder particles 843 are dispersed in first resin 842. At least some of the plurality of first metal powder particles 843 are in contact with each other.

[0061] The first resin layer 841 is provided, for example, so as to cover the outer periphery of the first metal layer 820 and is in close contact with the first metal layer 820.

[0062] (intermediate resin layer) The intermediate resin layer 844 includes, for example, an intermediate resin 845 and a plurality of intermediate metal powder particles 846. The intermediate resin 845 includes, for example, the same resin as the first resin 842.

[0063] The intermediate metal powder 846 contains, for example, an intermediate metal having a corrosion potential between the corrosion potential of the first metal and the corrosion potential of the second metal. The "corrosion potential" here is also called "natural potential" and refers to the potential of a predetermined metal in seawater with respect to a saturated calomel electrode (SCE) as a standard electrode.

[0064] Specifically, for example, when a saturated calomel electrode is used as a standard electrode, the corrosion potential of Cu or a Cu alloy as the first metal contained in the electric wire 100 is approximately −0.38 or more and −0.3 or less (V vs. SCE). The corrosion potential of Al or an Al alloy as the second metal contained in the clamp main body 720 is approximately −1.0 or more and −0.75 or less (V vs. SCE). Therefore, the intermediate metal contained in the intermediate metal powder 846 may be, for example, a metal having a corrosion potential greater than −0.75 and less than −0.38 (V vs. SCE). Specifically, the intermediate metal may be a tin (Sn)-zinc (Zn) alloy. For example, when an Sn-Zn alloy has a mass ratio of Sn:Zn=80:20, the corrosion potential of the Sn-Zn alloy is approximately −0.58 (V vs. SCE) based on the corrosion potential of Sn being −0.42 (V vs. SCE) and the corrosion potential of Zn being −1.03 (V vs. SCE).

[0065] The plurality of intermediate metal powder particles 846 are dispersed in the intermediate resin 845. At least some of the plurality of intermediate metal powder particles 846 are in contact with each other. Furthermore, at least some of the plurality of intermediate metal powder particles 846 may be in contact with the first metal powder 843 described above.

[0066] The intermediate resin layer 844 is provided so as to cover the outer periphery of the first resin layer 841 and is in close contact with the first resin layer 841, for example.

[0067] (2nd resin layer) The second resin layer 847 includes, for example, a second resin 848 and a plurality of second metal powder particles 849. The second resin 848 includes, for example, the same resin as the first resin 842 and the intermediate resin 845.

[0068] The second metal powder 849 contains, for example, Al or an Al alloy as the second metal, similarly to the clamp main body 720. The plurality of second metal powder particles 849 are dispersed in the second resin 848. At least some of the plurality of second metal powder particles 849 are in contact with each other. Furthermore, at least some of the plurality of second metal powder particles 849 may be in contact with the intermediate metal powder 846 described above.

[0069] The second resin layer 847 is provided, for example, so as to cover the outer periphery of the intermediate resin layer 844, and is in close contact with the intermediate resin layer 844 and a second metal layer 860, which will be described later.

[0070] As described above, the collar 800 arranged between the electric wire 100 and the clamp main body 720 has a resin layer 840 containing at least intermediate metal powder 846, thereby making it possible to suppress electrolytic corrosion caused by dissimilar metal contact between the electric wire 100 and the clamp main body 720.

[0071] (Dimensions of the resin layer) There are no particular limitations on the dimensions of the resin layer 840. However, the dimensions of the resin layer 840 may be set as follows.

[0072] For example, in the first resin layer 841, the volume average particle size of the first metal powder 843 is 30 μm or more and 100 μm or less, and the content of the first metal powder 843 in the first resin layer 841 is 70 mass% or more and 80 mass% or less (when the entire first resin layer 841 is 100 mass%).

[0073] For example, in the intermediate resin layer 844, the volume average particle size of the intermediate metal powder 846 is 30 μm or more and 100 μm or less, and the content of the intermediate metal powder 846 in the intermediate resin layer 844 is 70 mass% or more and 80 mass% or less (when the entire intermediate resin layer 844 is 100 mass%).

[0074] For example, in the second resin layer 847, the volume average particle size of the second metal powder 849 is 30 μm or more and 100 μm or less, and the content of the second metal powder 849 in the second resin layer 847 is 70 mass% or more and 80 mass% or less (when the entire second resin layer 847 is 100 mass%).

[0075] The "volume average particle size (MV)" referred to here is calculated by the following formula, where di is the particle diameter of the particles and Vi is the particle volume. MV=Σ(Vidi) / ΣVi The volume average particle size is measured using a dynamic light scattering particle size / particle size distribution measuring device.

[0076] For example, the thickness of the first resin layer 841 is 150 μm or more and 250 μm or less, the thickness of the intermediate resin layer 844 is 150 μm or more and 250 μm or less, and the thickness of the second resin layer 847 is 150 μm or more and 250 μm or less.

[0077] By having the resin layer 840 satisfy the above-mentioned dimensions between the first metal layer 820 and the clamp main body 720, it is possible to stably obtain conductivity via the metal powder while maintaining the adhesiveness of each resin.

[0078] (2nd metal layer) The second metal layer 860 includes, for example, Al or an Al alloy as the second metal. The second metal layer 860 is provided so as to surround the outer periphery of the resin layer 840 and is disposed between the resin layer 840 and the clamp main body 720. The second metal layer 860 is configured, for example, to fit inside the clamp main body 720 (recesses 722a and 724a). By interposing such second metal layer 860 between the resin layer 840 and the clamp main body 720, the collar 800 can be configured to be easily attached to and detached from the clamp main body 720.

[0079] There are no particular limitations on the thickness of second metal layer 860. However, from the viewpoint of maintaining strength when fastening electric wire 100, the thickness of second metal layer 860 may be approximately 7 mm or more and 10 mm or less.

[0080] (3) Characteristics of the electrical wire physical quantity measuring device The electric wire physical quantity measuring device 10 having the above-described configuration has the following characteristics.

[0081] (Gripping force test) The gripping force test will be described with reference to Fig. 6. In Fig. 6, one of the storage sections 30 is omitted for the sake of simplicity.

[0082] As shown in FIG. 6 , in the gripping force test, first, the electric wire physical quantity measuring device 10 is attached to the electric wire 100. Furthermore, a portion of a long angle iron 912 is fixed to the clamp 700 of the electric wire physical quantity measuring device 10 so that it is perpendicular to the electric wire 100. After the angle iron 912 is fixed, a weight 914 is attached to the angle iron 912 at a position a predetermined distance away from the electric wire physical quantity measuring device 10. This applies a predetermined torque to the clamp 700 in the circumferential direction of the electric wire 100. By gradually increasing the weight of the weight 914, the torque on the clamp 700 is gradually increased. This measures the maximum allowable torque before the electric wire physical quantity measuring device 10 begins to move.

[0083] In this embodiment, the collar 800 has the resin layer 840, which improves the adhesion between the first metal layer 820 and the clamp main body 720 (in this embodiment, the adhesion between the first metal layer 820 and the second metal layer 860). This makes it possible to prevent the clamp 700 from shifting relative to the electric wire 100.

[0084] Specifically, in a gripping force test of the electric wire physical quantity measuring device 10 of this embodiment, when the electric wire physical quantity measuring device 10 is attached to the electric wire 100 and a predetermined torque is applied to the clamp 700 in the circumferential direction of the electric wire 100, the maximum allowable torque before the electric wire physical quantity measuring device 10 starts to move is, for example, 9.8 Nm or more.

[0085] (Vibration test) The vibration test will be described with reference to FIG.

[0086] As shown in Fig. 7, a vibration test apparatus 92 is used in the vibration test. The vibration test apparatus 92 includes, for example, a pair of constant tension devices 922, a fixed end 924, and a vibrating device 926. The pair of constant tension devices 922 are arranged at a predetermined distance from each other and configured to pull the electric wire 100 with a constant tension. The fixed end 924 is configured to fix a portion of the electric wire 100 between the pair of constant tension devices 922. The vibrating device 926 is configured to vibrate the electric wire 100 between the fixed end 924 and one of the pair of constant tension devices 922.

[0087] In the vibration test, the above-mentioned vibration test device 92 is used, and the electric wire physical quantity measuring device 10 is attached to the electric wire 100 between the fixed end 924 and the vibration excitation device 926. In this state, the electric wire 100 is vibrated by the vibration excitation device 926 so that a predetermined strain is applied to the electric wire 100 at the fixed end 924.

[0088] In this case, the "strain applied to the electric wire 100" (%) is calculated by {(L1-L0) / L0} x 100, where L0 is the length of the minute portion of the metal wire (copper wire) that constitutes the electric wire 100 near the fixed end 924, and L1 is the length of the minute portion of the metal wire when vibrated.

[0089] After the above-described vibration, the presence or absence of damage to the electric wire 100 is confirmed at the portion where the clamp 700 of the electric wire physical quantity measuring device 10 grips the electric wire 100.

[0090] In this embodiment, it is possible to suppress the occurrence of displacement of the clamp 700 relative to the electric wire 100 at the portion where the clamp 700 grips the electric wire 100, and it is also possible to suppress the occurrence of electrolytic corrosion between the clamp 700 and the electric wire 100. As a result, even if the electric wire 100 vibrates, it is possible to suppress the occurrence of damage to the electric wire 100.

[0091] Specifically, in a vibration test on the electric wire physical quantity measuring device 10 of this embodiment, the above-mentioned vibration test device 92 was used, and in a state where the electric wire physical quantity measuring device 10 was attached to the electric wire 100 between the fixed end 924 and the vibrating device 926, a vibration test was performed at a frequency of 30 Hz for 10 seconds so that a strain of ±0.01% (100 μst) was applied to the electric wire 100 at the fixed end 924. 7 After a vibration test is performed in which the electric wire 100 is vibrated by the vibrator 926, the electric wire 100 does not break and the wires contained in the electric wire 100 do not break at the portion where the clamp 700 grips the electric wire 100.

[0092] (Corrosion test) The corrosion test will be described with reference to FIG.

[0093] As shown in FIG. 8 , a corrosion test apparatus 93 is used in the corrosion test. The corrosion test apparatus 93 includes, for example, a pair of electric wire fixing portions 932, a power source (not shown), and a solution spraying device 934. The pair of electric wire fixing portions 932 are arranged at a predetermined interval from each other and are configured to fix the electric wire 100 in a state where it is pulled with a constant tension via an insulator (reference number not shown). The electric wire physical quantity measuring device 10 is fixed to the electric wire 100 between the pair of electric wire fixing portions 932. The power source is configured to pass a predetermined current through the electric wire 100. The electric wire 100 fixed by the pair of electric wire fixing portions 932 is inserted into the solution spraying device 934. The solution spraying device 934 is configured to spray a corrosive solution onto the electric wire 100 and the electric wire physical quantity measuring device 10 fixed as described above.

[0094] The corrosion test includes a preparation step and a step of repeating a cycle including a solution spraying step and a spraying stopping step. In the preparation step, the wire physical quantity measuring device 10 is attached to the wire 100, and a current is passed through the wire 100 to maintain the wire 100 at 90°C. In the solution spraying step, an acidic corrosive solution is sprayed onto the wire 100 and the wire physical quantity measuring device 10 while the wire 100 is maintained at 90°C. In the spraying stopping step, the spraying of the corrosive solution is stopped. The cycle including the solution spraying step and the spraying stopping step is repeated. After repeating the above cycle for a predetermined time, the presence or absence of corrosion in the wire 100 is confirmed.

[0095] In this embodiment, the clamp 700 has the collar 800 described above, so that electrolytic corrosion caused by contact between the electric wire 100 and the clamp main body 720 can be suppressed.

[0096] Specifically, in this embodiment, the wire physical quantity measuring device 10 is attached to the wire 100, and a current is passed through the wire 100 to maintain the wire 100 at 90°C. After a corrosion test is performed for 720 hours, which repeats a cycle including a step of spraying a corrosive solution of pH 5 onto the wire 100 and the wire physical quantity measuring device 10 and a step of stopping the spraying of the corrosive solution, no corrosion occurs in the wire 100 at the portion where the clamp 700 grips the wire 100.

[0097] (4) Summary of this embodiment According to this embodiment, one or more of the following effects are achieved.

[0098] (a) In this embodiment, the collar 800 has a first metal layer 820 that includes the same first metal as the electric wire 100. The first metal layer 820 is in direct contact with the electric wire 100. This makes it possible to suppress the occurrence of electrolytic corrosion between the first metal layer 820 of the collar 800 and the electric wire 100.

[0099] In this embodiment, the collar 800 has a resin layer 840 between a first metal layer 820 containing a first metal and a clamp main body 720 containing a second metal. This makes it possible to prevent the occurrence of voids between the first metal layer 820 and the clamp main body 720 (in this embodiment, between the first metal layer 820 and the second metal layer 860). As a result, it is possible to prevent water from penetrating and spreading (water running) between the first metal layer 820 and the clamp main body 720, i.e., between the different metals.

[0100] Furthermore, in this embodiment, between the first metal layer 820 of the collar 800 and the clamp main body 720, the resin layer 840 contains a plurality of intermediate metal powders 846 containing an intermediate metal having a corrosion potential between the corrosion potential of the first metal and the corrosion potential of the second metal. This allows the corrosion potential of the metal to be distributed in stages from the first metal layer 820 of the collar 800 through the resin layer 840 toward the clamp main body 720. As a result, the occurrence of electrolytic corrosion between the first metal layer 820 of the collar 800 and the clamp main body 720 can be suppressed.

[0101] With this configuration, in this embodiment, it is possible to suppress the occurrence of electrolytic corrosion in the clamp 700 and the electric wire 100.

[0102] (b) In this embodiment, the collar 800 has a resin layer 840 between a first metal layer 820 containing a first metal and a clamp main body 720 containing a second metal.

[0103] Consider the case where collar 800 containing Cu or a Cu alloy as the first metal and clamp body 720 containing Al or an Al alloy as the second metal are welded with an intermediate metal having a corrosion potential intermediate between these metals, as in the above-described configuration (iii). In this case, when torque is applied to clamp 700 in the circumferential direction of electric wire 100 or when vibration is applied to clamp 700, the weld of the intermediate metal peels off.

[0104] When the intermediate metal peels off, the rough peeled surface of the intermediate metal reduces the adhesion between the collar 800 and the clamp main body 720. This causes the clamp 700 to easily slip off the electric wire 100. In other words, the gripping force of the clamp 700 on the electric wire 100 decreases.

[0105] Furthermore, when the intermediate metal peels off, a gap is created between the collar 800 and the clamp main body 720, making it easier for water to penetrate into the gap, which makes it easier for electrolytic corrosion to occur between the first metal layer 820 of the collar 800 and the clamp main body 720.

[0106] In contrast, in the present embodiment, the collar 800 has a resin layer 840 between the first metal layer 820 containing the first metal and the clamp main body 720 containing the second metal. This improves the adhesion between the first metal layer 820 and the clamp main body 720 (in the present embodiment, the adhesion between the first metal layer 820 and the second metal layer 860) compared to the above-described configuration (iii) in which the first metal layer 820 and the clamp main body 720 are welded together using an intermediate metal. This makes it possible to prevent the clamp 700 from shifting relative to the electric wire 100. In other words, it is possible to improve the gripping force of the clamp on the electric wire.

[0107] Furthermore, by improving the adhesion between the first metal layer 820 and the clamp main body 720, it is possible to suppress the intrusion of water between the first metal layer 820 and the clamp main body 720 (between the first metal layer 820 and the second metal layer 860 in this embodiment). This makes it possible to suppress the occurrence of electrolytic corrosion between the first metal layer 820 and the clamp main body 720.

[0108] As described above in (a) and (b), according to this embodiment, even if the clamp 700 and the electric wire 100 contain different types of metals, the attachment state of the electric wire physical quantity measuring device to the electric wire 100 can be stably maintained.

[0109] (c) In this embodiment, the resin layer 840 contains at least conductive intermediate metal powder particles 846 between the first metal layer 820 of the collar 800 and the clamp main body 720. At least some of the conductive intermediate metal powder particles 846 are in contact with one another. Such conductive intermediate metal powder particles 846 can electrically connect the first metal layer 820 and the clamp main body 720. This allows the electric wire physical quantity measuring device 10 attached to the electric wire 100 to be at the same potential as the electric wire 100. As a result, the occurrence of electrical malfunctions in the circuit of the electric wire physical quantity measuring device 10 can be suppressed.

[0110] (d) In this embodiment, the collar 800 has not only the first metal layer 820 and the resin layer 840, but also the second metal layer 860. That is, the second metal layer 860 is interposed between the first metal layer 820 and the clamp main body 720, and the resin layer 840 is not bonded to the clamp main body 720. This allows the collar 800 to be configured to be easily detachable from the clamp main body 720.

[0111] (e) In this embodiment, the resin layer 840 of the collar 800 has a three-layer structure. That is, the resin layer 840 has, for example, a first resin layer 841 containing a first metal powder 843, an intermediate resin layer 844 containing an intermediate metal powder 846, and a second resin layer 847 containing a second metal powder 849, in this order from a position close to the first metal layer 820 toward the radially outer side of the collar 800 (the second metal layer 860). This allows the corrosion potential of the metal to be distributed in stages from the first metal layer 820 toward the second metal layer 860 within the resin layer 840 of the collar 800. As a result, the occurrence of electrolytic corrosion between the first metal layer 820 and the second metal layer 860 of the collar 800 can be stably suppressed.

[0112] <Other Embodiments of the Present Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the present disclosure.

[0113] In the above embodiment, a case has been described in which the electric wire physical quantity measuring device 10 is configured to measure the current flowing through the electric wire 100 and the temperature of the electric wire 100 as physical quantities of the electric wire 100, but the present disclosure is not limited to this case. The electric wire physical quantity measuring device 10 may be configured to measure other physical quantities in addition to the current flowing through the electric wire 100 and the temperature of the electric wire 100. Examples of other physical quantities include vibration of the electric wire 100 and sag of the electric wire 100.

[0114] In the above embodiment, the case where collar 800 has not only first metal layer 820 and resin layer 840 but also second metal layer 860 has been described, but collar 800 does not have to have second metal layer 860; that is, resin layer 840 of collar 800 may be adhered to clamp main body 720. However, from the viewpoint of ease of attachment and detachment of collar 800 described above, collar 800 may have second metal layer 860.

[0115] In the above embodiment, the resin layer 840 of the collar 800 has been described as having a three-layer structure, but the resin layer 840 may also be composed of only an intermediate resin layer 844 containing intermediate metal powder 846. However, from the viewpoint of stably suppressing the above-mentioned electrolytic corrosion, the resin layer 840 of the collar 800 may also have a three-layer structure.

[0116] In the above embodiment, the collar 800 is fitted to the clamp body 720, but the collar 800 may be further fixed (fastened) to the clamp body 720 by a bolt. [Example]

[0117] Next, examples according to the present disclosure will be described. These examples are examples of the present disclosure, and the present disclosure is not limited to these examples.

[0118] (1) Fabrication of clamp for electrical wire physical quantity measurement device The following Sample A and Sample B were prepared as electrical wire physical quantity measuring devices.

[0119] (Sample A) The clamp of Sample A was configured as in the above-described embodiment. That is, the collar of the clamp of Sample A had a first metal layer containing Cu as the first metal, a resin layer, and a second metal layer containing Al as the second metal. The resin layer had a first resin layer containing a first metal powder containing Cu, an intermediate resin layer containing an intermediate metal powder containing an Sn-Zn alloy, and a second resin layer containing a second metal powder containing Al, in this order from a position close to the first metal layer toward the radially outer side of the collar (the second metal layer).

[0120] The specific dimensions were set as follows: Thickness of first metal layer: 4mm Thickness of the first resin layer: 200 μm Volume average particle size of the first metal powder in the first resin layer: 50 μm Content of first metal powder in first resin layer: 75% by mass Thickness of the intermediate resin layer: 200 μm Volume average particle size of intermediate metal powder in the intermediate resin layer: 50 μm Content of intermediate metal powder in the intermediate resin layer: 75% by mass Thickness of the second resin layer: 200 μm Volume average particle size of the second metal powder in the second resin layer: 50 μm Content of second metal powder in second resin layer: 75% by mass Thickness of second metal layer: 8mm

[0121] (Sample B) Sample B was constructed in the same manner as Sample A, except that the collar contained Cu as the first metal and the clamp body contained Al as the second metal, and were welded with a Sn-Zn alloy as an intermediate metal with a corrosion potential intermediate between the two.

[0122] The configuration of the electrical wire physical quantity measuring device was the same for Sample A and Sample B, except for the clamp.

[0123] (2) Evaluation The wire physical quantity measuring devices for each of the above-described Sample A and Sample B were attached to a PH wire having a cross-sectional area of ​​150 sq as the wire 100, and the following evaluations were carried out.

[0124] (Gripping force test) As shown in Fig. 6, in the gripping force test, with the electric wire physical quantity measuring device 10 attached to the electric wire 100, a weight 914 was attached to an angle bar 912 fixed to the clamp 700, and a predetermined torque was applied to the clamp 700 in the circumferential direction of the electric wire 100. At this time, the maximum allowable torque until the electric wire physical quantity measuring device 10 began to move was measured. A maximum allowable torque of 9.8 Nm or more was evaluated as "good," and a maximum allowable torque of less than 9.8 Nm was evaluated as "poor."

[0125] (Vibration test) As shown in Fig. 7, using the vibration test device 92 described above, the electric wire physical quantity measuring device 10 was attached to the electric wire 100 between the fixed end 924 and the vibration exciter 926. In this state, the electric wire 100 was vibrated by the vibration exciter 926 so that a predetermined strain was applied to the electric wire 100 at the fixed end 924. At this time, the electric wire 100 was vibrated at a frequency of 30 Hz for 10 seconds so that a strain of ±0.01% (100 µst) was applied to the electric wire 100 at the fixed end 924. 7 The electric wire 100 was vibrated by the vibrating device 926 once. After the above-mentioned vibration, the presence or absence of damage to the electric wire 100 was confirmed at the portion where the clamp 700 of the electric wire physical quantity measuring device 10 gripped the electric wire 100. When the electric wire 100 and the wires contained in the electric wire 100 did not break at the portion where the clamp 700 gripped the electric wire 100, the evaluation was made as "good", and when at least one of the breakage of the electric wire 100 and the wires contained in the electric wire 100 occurred, the evaluation was made as "poor".

[0126] (Corrosion test) 8, the corrosion test was carried out using a corrosion test apparatus 93, which included a preparation step and a step of repeating a cycle including a solution spraying step and a spraying stopping step. In the preparation step, the electric wire physical quantity measuring device 10 was attached to the electric wire 100, and a current was passed through the electric wire 100 to maintain the electric wire 100 at 90°C.

[0127] In the solution spraying step, an acidic corrosive solution was sprayed onto the electric wire 100 and the electric wire physical quantity measuring device 10 while the electric wire 100 was maintained at 90°C. The corrosive solution was an aqueous solution containing 15 mass% sodium chloride (NaCl). The pH of the corrosive solution was adjusted to 4.8 by adding sulfuric acid (H2SO4) to the corrosive solution.

[0128] In the spraying stopping step, the spraying of the corrosive solution was stopped. A cycle including the solution spraying step and the spraying stopping step was repeated. At this time, the time for the solution spraying step was 40 minutes, and the time for the spraying stopping step was 80 minutes. The above cycle was repeated for 720 hours.

[0129] After repeating the above cycle, the presence or absence of corrosion in the electric wire 100 was checked. When no corrosion occurred in the electric wire 100 at the portion where the clamp 700 gripped the electric wire 100, the result was evaluated as "good," and when corrosion occurred in the electric wire 100, the result was evaluated as "poor."

[0130] (3) Results The above evaluation yielded the following results:

[0131] (Sample B) In the results of a gripping force test on Sample B, when a torque of less than 9.8 Nm was applied to the clamp in the circumferential direction of the wire, the intermediate metal welded between the collar and the clamp body peeled off. As a result, the clamp shifted in the circumferential direction of the wire, causing the collar to come off the clamp body.

[0132] Sample B was not subjected to vibration testing or corrosion testing due to the poor results of the gripping force testing as described above.

[0133] (Sample A) In contrast, the results of the gripping force test on sample A showed that the clamp did not shift from the wire even when a torque of 9.8 Nm or more was applied to the clamp in the circumferential direction of the wire. Specifically, even when a torque of 49 Nm was applied, the resin layer of the collar did not peel off, and the clamp did not shift from the wire.

[0134] The results of the vibration test on Sample A showed that there was no peeling of the collar's resin layer and no excessive displacement of the clamp relative to the wire. It is believed that no abnormal vibrations were occurring where the clamp gripped the wire. Therefore, there was no breakage of the wire or cutting of the wires contained within the wire where the clamp gripped the wire.

[0135] The corrosion test on Sample A showed that no corrosion occurred on the wire where the clamp gripped it. In addition, no corrosion occurred on the clamp either.

[0136] As described above, it was confirmed that the sample A electric wire physical quantity measuring device was able to stably maintain the attachment state of the electric wire physical quantity measuring device to the electric wire even when the clamp and the electric wire contained different types of metals.

[0137] <Additional Notes> The following appendix describes aspects of the present disclosure. The aspects referenced by the numbers in brackets [ ] to which the appendix depends correspond to the aspects described in <Embodiments of the present disclosure>.

[0138] [7] The first metal powder has a volume average particle size of 30 μm or more and 100 μm or less, the content of the first metal powder in the first resin layer is 70% by mass or more and 80% by mass or less; The intermediate metal powder has a volume average particle size of 30 μm or more and 100 μm or less, The content of the intermediate metal powder in the intermediate resin layer is 70% by mass or more and 80% by mass or less, The second metal powder has a volume average particle size of 30 μm or more and 100 μm or less, The content of the second metal powder in the second resin layer is 70% by mass or more and 80% by mass or less. [3] The electrical wire physical quantity measuring device according to [3].

[0139] [8] the thickness of the first resin layer is 150 μm or more and 250 μm or less; The thickness of the intermediate resin layer is 150 μm or more and 250 μm or less, The thickness of the second resin layer is 150 μm or more and 250 μm or less. [3] or [7], the electric wire physical quantity measuring device.

[0140] [9] The collar is fixed to the clamp body by a bolt. [1] to [8]. A wire physical quantity measuring device according to any one of [1] to [8]. [Explanation of symbols]

[0141] 10 Wire physical quantity measuring device 20 sensors 30 Storage section 40 Main body 92 Vibration Test Equipment 93 Corrosion Test Equipment 100 wire 200 Temperature sensor section 280 lead wire 310 First Storage Unit 320 Second Storage Unit 420 Power supply CT section 440 Power supply section 520 CT section for current measurement 540 Current measurement section 600 Radio Department 620 Antenna 700 Clamp 720 Clamp body 722 Lower part of clamp body 722a Recess 724 Upper part of clamp body 724a Recess 800 colors 800a Color Lower 800b color top 820 1st metal layer 840 Resin layer 841 1st resin layer 842 First Resin 843 First metal powder 844 Intermediate resin layer 845 Intermediate Resin 846 Intermediate Metal Powder 847 Second resin layer 848 Second Resin 849 Secondary metal powder 860 2nd metal layer 912 Angle iron 914 Weight 922 Constant tension device 924 Fixed end 926 Vibration Device 932 Wire fixing part 934 Solution spraying device

Claims

1. An electric wire physical quantity measuring device, a sensor attached to an electric wire including a first metal and measuring a physical quantity of the electric wire; a main body that acquires data of the physical quantity measured by the sensor; a housing portion that houses at least a portion of the main body portion; a clamp including a second metal different from the first metal, the clamp gripping the electric wire and fixing the housing to the electric wire; Equipped with The clamp is a clamp body portion including the second metal and configured to be fastened while gripping the electric wire; a collar configured as a tubular member and disposed between the electric wire and the clamp body; and The color is a first metal layer including the first metal and arranged to cover an outer periphery of the electric wire; a resin layer including a resin and a plurality of intermediate metal powders dispersed in the resin, the intermediate metal having a corrosion potential between the corrosion potential of the first metal and the corrosion potential of the second metal, the resin layer being provided so as to cover an outer periphery of the first metal layer; have Wire physical quantity measuring device.

2. The collar further includes a second metal layer that includes the second metal and is provided so as to surround the outer periphery of the resin layer and is configured to fit inside the clamp body. The electrical wire physical quantity measuring device according to claim 1 .

3. The resin layer is a first resin layer including a first resin and a plurality of first metal powders containing the first metal dispersed in the first resin, the first resin layer being provided so as to cover an outer periphery of the first metal layer; an intermediate resin layer including an intermediate resin and the plurality of intermediate metal powders dispersed in the intermediate resin, the intermediate resin layer being provided so as to cover an outer periphery of the first resin layer; a second resin layer including a second resin and a plurality of second metal powders including the second metal dispersed in the second resin, the second resin layer being provided so as to cover an outer periphery of the intermediate resin layer; have The electrical wire physical quantity measuring device according to claim 1 or 2.

4. When a predetermined torque is applied to the clamp in the circumferential direction of the electric wire with the electric wire physical quantity measuring device attached to the electric wire, the maximum allowable torque until the electric wire physical quantity measuring device starts to move is 9.8 Nm or more. The electrical wire physical quantity measuring device according to claim 1 or 2.

5. A pair of constant tension devices that pull the electric wire with a constant tension, a fixed end that fixes a part of the electric wire between the pair of constant tension devices, and a vibration device that vibrates the electric wire between the fixed end and one of the pair of constant tension devices, were used, and in a state where the electric wire physical quantity measuring device was attached to the electric wire between the fixed end and the vibration device, a vibration was applied at a frequency of 30 Hz for 10 seconds so that a strain of ±0.01% was applied to the electric wire at the fixed end. ７ After a vibration test is performed in which the electric wire is vibrated by the vibration device, the electric wire is not broken and the wires contained in the electric wire are not cut at the portion where the clamp holds the electric wire. The electrical wire physical quantity measuring device according to claim 1 or 2.

6. The electric wire physical quantity measuring device was attached to the electric wire, and a current was passed through the electric wire while the electric wire was maintained at 90° C. A corrosion test was carried out for 720 hours, in which a cycle including a step of spraying a corrosive solution of pH 5 onto the electric wire and the electric wire physical quantity measuring device and a step of stopping the spraying of the corrosive solution was repeated. After that, no corrosion occurred in the electric wire at the portion where the clamp gripped the electric wire. The electrical wire physical quantity measuring device according to claim 1 or 2.

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