Vibration measurement device and CMS device for wind power generation

Abstract

To provide a vibration measurement device that includes an acceleration sensor and an acceleration sensor fixture, suppresses occurrence of an electric discharge accompanied by a high-voltage surge because of lightning, and can suppress a failure of the acceleration sensor, and to provide a wind power generation-purpose CMS device that uses the vibration measurement device.SOLUTION: A vibration measurement device 100 comprises: an acceleration sensor 10; an acceleration sensor fixture 21; a spacer 32 that serves as an insulation member; and a thermal contraction tube 31. The acceleration sensor 10 includes an element 11. The acceleration sensor fixture 21 is arranged on a measurement object 1 side of the acceleration sensor 10. The spacer 32 is tightly sandwiched between the acceleration sensor 10 and the acceleration sensor fixture 21 so as to contact with both the acceleration sensor and the acceleration sensor fixture. The thermal contraction tube 31 covers a sensor outer edge 10a and a fixture outer edge 21a. The thermal contraction tube 31 includes an area that protrudes outward the acceleration sensor 10 and acceleration sensor fixture 21 in a plane view.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a vibration measuring device and a CMS device for wind power generation using the same. [Background technology]

[0002] A vibration measuring device for measuring vibrations of a measurement object, such as a wind turbine, includes an acceleration sensor and an acceleration sensor mounting bracket for attaching the acceleration sensor. For example, Japanese Patent Laid-Open Publication No. 7-198740 (Patent Document 1) discloses an acceleration sensor mounting bracket that supports an acceleration sensor while being fixed to the measurement object. This acceleration sensor mounting bracket suppresses transmission of base strain of the measurement object to the acceleration sensor. For example, Japanese Utility Model Laid-Open Publication No. 58-14132 (Patent Document 2) discloses an improved electrically insulating acceleration sensor mounting bracket that enables vibration measurement at high temperatures by connecting the measurement object and the acceleration sensor with fusing glass. Furthermore, Japanese Utility Model Laid-Open Publication No. 5-24025 (Patent Document 3) discloses a vibration measuring device in which a unit base with an insulating film is arranged between the measurement object and the acceleration sensor. In this vibration measuring device, the unit base with an insulating film prevents ground loops (described below) and suppresses noise contamination in measured values.

[0003] These vibration measurement devices have a problem in that if they are subjected to a high-voltage surge such as a lightning strike, they will break down and be unable to acquire vibration data. This is because the high-voltage surge applies an overvoltage to the acceleration sensor, causing an overcurrent to flow. To prevent this, for example, Japanese Patent Application Laid-Open No. 2009-289551 (Patent Document 4) introduces a discharge noise absorption element that can avoid noise in all frequency bands, including lightning, static electricity, electromagnetic waves, and magnetism, as well as a noise avoidance box that uses this element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-198740 Patent Document 2 Japanese Utility Model Publication No. 58-14132 Patent Document 3 Japanese Utility Model Publication No. 5-24025 Patent Document 4 Japanese Patent Application Laid-Open No. 2009-289551 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] In a vibration measuring device including an acceleration sensor and an acceleration sensor fixture, if the occurrence of discharge associated with a high voltage surge due to lightning strike or the like is suppressed, the failure of the acceleration sensor can be suppressed. However, none of Japanese Patent Application Laid-Open No. 7-198740, Japanese Utility Model Publication No. 58-14132, and Japanese Utility Model Publication No. 5-24025 have considered a high voltage surge due to lightning strike or the like and the associated discharge. Further, Japanese Patent Application Laid-Open No. 2009-289551 has not considered a high voltage surge and discharge due to lightning strike in a vibration measuring device including an acceleration sensor and an acceleration sensor fixture.

[0006] The present disclosure has been made in view of the above problems, and an object thereof is to provide a vibration measuring device including an acceleration sensor and an acceleration sensor fixture, which can suppress the occurrence of discharge associated with a high voltage surge due to lightning strike or the like and suppress the failure of the acceleration sensor, and a CMS device for wind power generation using the same. MEANS FOR SOLVING THE PROBLEMS

[0007] A vibration measuring device according to the present disclosure includes an acceleration sensor, an acceleration sensor fixture, an insulating member, and an acceleration sensor cable. The acceleration sensor includes an element capable of measuring the vibration of a measurement object. The acceleration sensor fixture is disposed on the position side where the measurement object of the acceleration sensor should be disposed. The insulating member is sandwiched between the acceleration sensor and the position where the measurement object should be disposed. The acceleration sensor cable includes a pair of cable wires, a shield wire, and an outer sheath that bundles the pair of cable wires and the shield wire and surrounds them from the outside. EFFECTS OF THE INVENTION

[0008] According to the present disclosure, there is provided a vibration measurement device including an acceleration sensor and an acceleration sensor fixture, which can suppress the occurrence of discharge associated with a high-voltage surge caused by lightning strike and suppress the failure of the acceleration sensor.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Embodiments for Carrying Out the Invention

[0010] Hereinafter, this embodiment will be described with reference to the drawings.

[0011] (Embodiment 1) (Configuration of Vibration Measurement Device) First, the vibration measurement device of this embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a schematic diagram showing the configuration of the vibration measurement device according to Embodiment 1. In FIG. 1 and each subsequent schematic diagram, the cross-sectional shape obtained by cutting the device along the vertical direction is schematically shown. Referring to FIG. 1, the vibration measurement device 100 according to this embodiment mainly includes an acceleration sensor 10, an acceleration sensor fixture 21, a heat shrinkable tube 31, a spacer 32, an acceleration sensor cable 40, and a stud 50.

[0012] The acceleration sensor 10 includes an element 11 capable of measuring the vibration of the measurement object 1 inside the acceleration sensor housing 10B, which is its housing. Specifically, for example, a cavity 12 may be formed inside the acceleration sensor housing 10B made of a conductive material, and the element 11 may be arranged in the cavity 12. The cavity 12 is not limited to being a void and may be filled with an insulating resin material or the like. Examples of the measurement object 1 include a windmill. Here, the measurement object 1 is assumed to be conductive. The acceleration sensor fixture 21 is arranged on the side of the measurement object 1 of the acceleration sensor 10, that is, the lower side in FIG. 1. That is, the acceleration sensor fixture 21 is arranged so as to be sandwiched between the measurement object 1 and the acceleration sensor 10.

[0013] The acceleration sensor fixture 21 is formed of a conductive material such as metal for its housing, for example. Therefore, when the acceleration sensor fixture 21 is directly in contact with the acceleration sensor 10 and the measurement object 1 in FIG. 1 that sandwich it, it can conduct electricity between them.

[0014] A spacer 32 as an insulating member is disposed between the acceleration sensor 10 and the acceleration sensor mounting fixture 21 so as to be sandwiched therebetween and in contact with both the acceleration sensor 10 and the acceleration sensor mounting fixture 21. However, the spacer 32 may be disposed so as to be sandwiched between the acceleration sensor mounting fixture 21 and the measurement object 1 and in contact with both the acceleration sensor mounting fixture 21 and the measurement object 1. The acceleration sensor 10 and the acceleration sensor mounting fixture 21 are coupled to each other by a stud 50 as an insulating fixing member via the spacer 32. The stud 50 is disposed so as to penetrate the spacer 32 between the acceleration sensor 10 and the acceleration sensor mounting fixture 21. For this reason, a missing portion may be formed in the acceleration sensor 10 and the acceleration sensor mounting fixture 21 so that a part thereof is missing and the stud 50 can be accommodated, and a through hole through which the stud 50 can penetrate may be formed in the spacer 32 between them. The stud 50 is disposed in a single space formed by connecting the missing portion and the through hole, and couples the acceleration sensor 10, the spacer 32, and the acceleration sensor mounting fixture 21 to each other. A filler 62 may be disposed in a gap between the stud 50 and the acceleration sensor 10 and the acceleration sensor mounting fixture 21 to which it is coupled. However, the filler 62 may not be disposed. The filler 62 is made of a material having a higher dielectric strength than air. Thereby, the dielectric strength around the stud 50 and its periphery is enhanced.

[0015] FIG. 2 is a schematic diagram showing individual aspects of an acceleration sensor, an acceleration sensor fixture, and a stud for coupling these. In FIG. 2, the acceleration sensor 10 and the stud 50 are shown as viewed from the same direction as in FIG. 1, and the acceleration sensor fixture 21 is shown as viewed in plan from the upper side of FIG. 1. Referring to FIG. 2, the acceleration sensor 10 (acceleration sensor housing 10B) is shown as a rectangular shape as viewed schematically from the front in FIG. 1, but may actually be, for example, in the shape of a bolt with a male thread formed thereon. The acceleration sensor 10 has a through hole 10h formed at the center of the circular surface at the lowermost end of FIG. 2. The acceleration sensor fixture 21 is, for example, square in plan view and is in the shape of a rectangular parallelepiped having a certain thickness in the depth direction of the paper surface of FIG. 2. That is, the acceleration sensor fixture 21 may be in a plate shape as described later. The acceleration sensor fixture 21 has a through hole 21h formed at the center in plan view. Although not shown, female threads are formed on the inner walls of the through holes 10h and 21h. The stud 50 has a shape close to a cylinder, and male threads are formed on its outer surface.

[0016] FIG. 3 is a schematic diagram showing the process of coupling an acceleration sensor and an acceleration sensor fixture with a stud. Referring to FIG. 3, the acceleration sensor 10 and the acceleration sensor fixture 21 are arranged so as to overlap in plan view such that the through hole 10h and the through hole 21h are continuous. The stud 50 is inserted into the through holes 10h and 21h. The male threads formed on the stud 50 and the female threads formed on the through holes 10h and 21h are fastened. Thereby, the acceleration sensor housing 10B, the stud 50, and the acceleration sensor fixture 21 are coupled to each other. At this time, in order to stabilize the frequency response characteristics, the fastening torque is adjusted by a torque wrench to be, for example, 2.7 Nm or more and 6.8 Nm or less.

[0017] Referring again to FIG. 1, the heat-shrinkable tube 31 (tube) is a single cylindrical covering material that straddles and covers both the sensor outer edge 10a, which is the outer edge (outer surface) of the acceleration sensor housing 10B, and the mounting fixture outer edge 21a, which is the outer edge (outer surface) of the acceleration sensor mounting fixture 21. The sensor outer edge 10a and the mounting fixture outer edge 21a are preferably formed so that they substantially overlap in a plan view from above in FIG. 1 (so that the acceleration sensor 10 and the acceleration sensor mounting fixture 21 have substantially the same shape and size in a plan view). The heat-shrinkable tube 31 is made of an insulating material and is bonded to the sensor outer edge 10a and the mounting fixture outer edge 21a with an adhesive 61. Specifically, the heat-shrinkable tube 31 is preferably made of, for example, polyolefin, silicone rubber, or polyvinyl chloride. Instead of the heat-shrinkable tube 31, a tube made of a material that has almost no heat-shrinkability may be used.

[0018] The heat-shrinkable tube 31 may be disposed so as to encase the acceleration sensor 10 and the acceleration sensor mounting fixture 21 in a cylindrical shape, as shown in FIG. 1 . This allows the heat-shrinkable tube 31 to include a region that protrudes outward from the acceleration sensor 10 and the acceleration sensor mounting fixture 21 when viewed from above in the direction in which the acceleration sensor 10 and the acceleration sensor mounting fixture 21 overlap (e.g., from the top of FIG. 1 ). In other words, the heat-shrinkable tube 31 includes a region that protrudes outward beyond the sensor outer edge 10a and the mounting fixture outer edge 21a in the above-described planar view. Note that insulating tape may be used instead of the heat-shrinkable tube 31, and this tape may be bonded to encase and cover the sensor outer edge 10a and the mounting fixture outer edge 21a in the same manner as the heat-shrinkable tube 31 shown in FIG. 1 . Because the heat-shrinkable tube 31 is bonded to the surfaces of the sensor outer edge 10a and the mounting fixture outer edge 21a in a manner that covers them with adhesive 61, the gap between the heat-shrinkable tube 31 and the sensor outer edge 10a and the mounting fixture outer edge 21a is filled with adhesive 61, leaving almost no gap between the heat-shrinkable tube 31 and the heat-shrinkable tube 31. Since almost no gaps are formed in this manner, the dielectric strength between the acceleration sensor 10 and the acceleration sensor mounting fixture 21 and the heat shrinkable tube 31 is increased.

[0019] In FIG. 1, the heat-shrinkable tube 31 extends from the vertical center of the outer edge 10a of the sensor to the vertical center of the outer edge 21a of the fixture. However, the heat-shrinkable tube 31 may be formed longer in the vertical direction than in FIG. 1. For example, it may extend from a position within 25% of the vertical dimension from the upper end of the outer edge 10a of the sensor to a position within 25% of the vertical dimension from the lower end of the outer edge 21a of the fixture. Alternatively, the heat-shrinkable tube 31 may extend from a position within 20% of the vertical dimension from the upper end of the outer edge 10a of the sensor to a position within 20% of the vertical dimension from the lower end of the outer edge 21a of the fixture. Further, the heat-shrinkable tube 31 may be formed in a cylindrical shape covering the entire outer edge 10a of the sensor, the outer edge of the spacer 32, and the outer edge 21a of the fixture.

[0020] The spacer 32 is disposed so as to overlap the acceleration sensor 10 and the acceleration sensor fixture 21 in a plan view from above in FIG. 1. The spacer 32 is, for example, a plate-like member formed of an insulating material. Here, the plate-like member means a member having dimensions in the left-right direction and the depth direction (of the main surface) in FIG. 1 that are twice or more the dimension of the thickness in the vertical direction in FIG. 1, and the thickness in the vertical direction in FIG. 1 is substantially the same throughout (there is no difference greater than the processing error). That is, the plate-like shape means a rectangular parallelepiped shape or a cylindrical shape (disc shape) having a cross-section along the vertical direction in FIG. 1 that is, for example, rectangular. The spacer 32 is disposed so as to be sandwiched between the two so as to contact both the lowermost surface of the acceleration sensor housing 10B in FIG. 1 and the uppermost surface of the acceleration sensor fixture 21. Note that the spacer 32 may have a through hole (hollow) formed in the central portion in a plan view, or may be a solid member in which such a through hole (hollow) is not formed.

[0021] The acceleration sensor cable 40 includes a first cable wire 41, a second cable wire 42, a shield wire 43, and an outer sheath 44 that bundles and surrounds these wires from the outside. In the figure, for ease of distinction, the first cable wire 41 is shown as a chain line, and the second cable wire 42 is shown as a dotted line. However, in reality, they also extend continuously like the shield wire 43 shown as a solid line. The first cable wire 41 and the second cable wire 42 are connected to the element 11 included in the acceleration sensor 10 via an insulating connector 59 provided to contact the acceleration sensor 10. With these two cable wires, it is possible to connect the element 11 to a power source or apply a voltage to the element 11. One end of the shield wire 43 is not connected to the acceleration sensor housing 10B and is electrically insulated from the acceleration sensor housing 10B. One end of the shield wire 43 is connected to the insulating connector 59, and the other end on the side opposite to one end is connected to the ground point G2. The measurement object 1 is connected to the ground point G1. Thereby, the measurement object 1 and the acceleration sensor housing 10B have the ground potential of the ground point G1. Note that the ends of the first cable wire 41 and the second cable wire 42 on the side opposite to the side connected to the element 11 may be connected to a data collection device (not shown). Also, the side of the shield wire 43 opposite to one end may be electrically connected to the ground point G2 via the data collection device.

[0022] FIG. 4 is an enlarged schematic view showing a first example of the joining mode between the acceleration sensor fixture and the measurement object in the region A surrounded by a dotted line in FIG. 1. FIG. 5 is an enlarged schematic view showing a second example of the joining mode between the acceleration sensor fixture and the measurement object in the region A surrounded by a dotted line in FIG. 1. Referring to FIG. 4, the acceleration sensor fixture 21 and the measurement object 1 may be joined by a generally known insulating adhesive 61. Alternatively, referring to FIG. 5, the acceleration sensor fixture 21 and the measurement object 1 may be joined by an insulating stud 50. 21 Either FIG. 4 or FIG. 5 may be applied to the joint portion between the acceleration sensor fixture and the measurement object 1. This also applies to each of the following embodiments.

[0023] (Regarding the spacer 32) The spacer 32 is preferably formed of an insulating material having a low water absorption rate and being less likely to deteriorate over time. The dielectric strength of the spacer 32 is preferably 10 kV / mm or more.

[0024] FIG. 6 is a graph showing changes in the frequency response characteristics of the acceleration sensor when the material of the acceleration sensor fixture in FIG. 1 is changed. The horizontal axis in FIG. 6 is the frequency of the vibration applied to the acceleration sensor fixture 21, and the vertical axis in FIG. 6 indicates the gain of the acceleration sensor output signal. Referring to FIG. 6, if the acceleration sensor fixture 21 is a material with a high Young's modulus such as metal (conductive material) (for example, SUS304), the gain does not increase much even as the frequency increases, and there is no frequency at which resonance occurs where the gain becomes extremely high in at least the frequency band of 8000 Hz or less. From this, when the acceleration sensor fixture 21 is made of a material with a high Young's modulus such as metal (conductive material), the frequency response characteristics are good. On the other hand, when the acceleration sensor fixture 21 is formed of a material with a relatively low Young's modulus such as a resin material (insulator), for example, polyetheretherketone (PEEK), the gain increases as the frequency increases, and resonance occurs at a frequency of about 7500 Hz. From this, if a material with a relatively low Young's modulus such as a resin material (insulator) is sandwiched between the element 11 that senses vibration and the measurement object 1, the frequency response characteristics in the high frequency band deteriorate.

[0025] However, even if the spacer 32 is a material with a low Young's modulus such as resin (insulator), the optimal spring constant of the spacer 32 is 2.0×10 9If it is set to N / m or more, the high-frequency response characteristics in the high-frequency band can be improved. This will be described below. The numerical range of the spring constant of the spacer 32 is determined as follows. FIG. 7 is a schematic diagram of a configuration prepared to determine the spring constant of the spacer. Referring to FIG. 7, the acceleration sensor 10 and the acceleration sensor fixture 21 here are the same as the acceleration sensor 10 and the acceleration sensor fixture 21 in FIG. 1. The acceleration sensor fixture 21 is arranged on the vibration table 2 side (lower side) of the acceleration sensor 10. The vibration table 2 corresponds to the measurement object 1 in FIG. 1. The insulating plate 39 corresponds to the spacer 32 in FIG. 1. However, the insulating plate 39 is arranged not between the acceleration sensor 10 and the acceleration sensor fixture 21 but between the acceleration sensor fixture 21 and the vibration table 2 (below the acceleration sensor fixture 21). The acceleration sensor cable 40 and the grounding points G1, G2 are not shown. The insulating plate 39 is formed of PEEK, and its Young's modulus is 3.6 GPa. All are plate-shaped (cuboid-shaped) with an area of 400 mm 2 In the following Table 1, three types of insulating plates 39 with different thicknesses are used, and the frequency response characteristics when each insulating plate 39 is used are examined.

[0026]

Table 1

[0027] FIG. 8 is a graph showing changes in the frequency response characteristics of the insulating plate when the thickness of the insulating plate is changed using the configuration of FIG. 7. The horizontal axis of FIG. 8 is the frequency of the vibration applied to the insulating plate 39, and the vertical axis of FIG. 8 indicates the effective value of the output signal. Referring to FIG. 8, when the insulating plate 39 with a thickness of 2 mm or 10 mm is used, resonance occurs at frequencies of approximately 7300 Hz and approximately 6300 Hz, respectively. Generally, the frequency range where resonance points are observed is not suitable for vibration measurement. For this reason, the insulating plate 39 with a thickness of 2 mm or 10 mm cannot be used for vibration measurement in the high-frequency band. On the other hand, the insulating plate 39 with a thickness of 1 mm does not have resonance points in the frequency band below 8000 Hz, so it can be used for vibration measurement in the high-frequency band. From this, it can be seen that the insulating plate 39 with a thin thickness, that is, a high spring constant, has a higher resonance point. From Table 1, the spring constant of the insulating plate 39 with a thickness of 1 mm may be 1.44×10 9 N / m. However, it is more preferable to have a slightly larger margin in the magnitude of the spring constant upward. From this perspective, as described above, the spring constant of the spacer 32 is preferably 2.0×10 9 N / m or more.

[0028] The spacer 32 may be a resin material having a high Young's modulus, that is, a Young's modulus of 2.5 GPa or more. The resin material here may contain at least one of carbon fiber and glass fiber. Alternatively, the spacer 32 may be made of a ceramic material containing at least one of silicon, aluminum, and alkaline earth metals and having a high Young's modulus, that is, a Young's modulus of 100 GPa or more. Also, the thickness of the spacer 32 in the vertical direction of FIG. 1 is preferably less than 2 mm.

[0029] (Comparative Example and Its Problems) FIG. 9 is a schematic diagram illustrating a ground loop that occurs in a vibration measuring device according to a comparative example. Referring to FIG. 9, the vibration measuring device according to the comparative example includes an acceleration sensor 10 and a shielded wire 43. The vibration measuring device may also include a data collecting device 70. In FIG. 9, no insulating member is interposed between the acceleration sensor 10 and the object to be measured 1. In FIG. 9, if the ground potentials of ground point G1 connected to the object to be measured 1 and ground point G2 connected to the data collecting device 70 differ, a current indicated by the arrows in the figure flows between ground points G1 and G2, and this current noise may be carried over to the signal measured by the vibration measuring device. This noise current circulates through a circuit that includes ground points G1 and G2 in FIG. 9. This phenomenon is called a ground loop GL. If noise is carried over to the signal measured by the vibration measuring device, the reliability of the data obtained by the measurement is reduced.

[0030] Fig. 10 is a schematic diagram showing the configuration of a vibration measuring device according to a first example of a comparative example for suppressing ground loops. Referring to Fig. 10, a vibration measuring device 900 according to the first example of the comparative example differs from the vibration measuring device 100 of Fig. 1 in the following respects. In the vibration measuring device 900, no insulating spacer 32 is sandwiched between the acceleration sensor 10 and the acceleration sensor mounting fixture 21. Furthermore, in Fig. 10, no heat-shrink tubing 31 is provided to cover the sensor outer edge 10a and the mounting fixture outer edge 21a.

[0031] However, in FIG. 10, as in FIG. 1, an insulating connector 59 is attached to the side of the acceleration sensor 10 opposite the object to be measured 1. The first cable 41 and the second cable 42 connected to the element 11 run through the insulating connector 59 and the outer sheath 44. One end of the shield wire 43 is connected to the insulating connector 59 and is not connected to the conductive housing of the acceleration sensor 10. Therefore, in the vibration measuring device 900, the acceleration sensor 10 and the shield wire 43 are not electrically connected. For this reason, in FIG. 10, even if the ground potentials of the ground points G1 and G2 are different, a ground loop GL like that in FIG. 9 does not occur.

[0032] FIG. 11 is a schematic diagram for explaining discharge due to the generation of a surge voltage in the vibration measuring device according to the first example of the comparative example in FIG. 10. Referring to FIG. 11, when a high voltage called a surge voltage SV caused by lightning strike or the like is applied to the measurement object 1 in FIG. 10, a high voltage is also applied to the acceleration sensor housing 10B electrically connected to the measurement object 1. For this reason, a high voltage is applied between the element 11 in the acceleration sensor 10 and the acceleration sensor housing 10B in which the cavity 12 for housing the element 11 is formed, and a discharge DCG occurs. Due to this discharge DCG, the element 11 may be burned out or damaged, and the acceleration sensor 10 may malfunction.

[0033] FIG. 12 is a schematic diagram showing the configuration of a vibration measuring device according to a second example of the comparative example for suppressing a ground loop. Referring to FIG. 12, the vibration measuring device 900 according to the second example of the comparative example is different from the vibration measuring device 100 in FIG. 1 in the following points. The vibration measuring device 900 has an acceleration sensor fixture 22 on the measurement object 1 side of the acceleration sensor 10 instead of the acceleration sensor fixture 21. The acceleration sensor fixture 22 has, for example, a housing formed of an insulating material. For this reason, normally, the acceleration sensor 10 and the measurement object 1 are electrically insulated. However, when a surge voltage is applied to the measurement object 1 in FIG. 12, the high voltage is transmitted from the acceleration sensor fixture 22 to the acceleration sensor 10, and there is a possibility that a discharge DCG and a failure of the acceleration sensor 10 accompanying the discharge DCG occur as in FIG. 11. This is because the creepage distance extending in the vertical direction on the left and right side surfaces of FIG. 12 from the measurement object 1 to the acceleration sensor 10 in FIG. 12 is relatively short, and discharge occurs in the air. Even if the insulating acceleration sensor fixture 22 is sandwiched, the surge voltage may be transmitted from the measurement object 1 to the acceleration sensor 10 through the fixture 22. Suppressing the failure of the element 11 and the acceleration sensor 10 due to such discharge during lightning strike or the like has been an issue. Incidentally, from the viewpoint of facilitating detection of the vibration signal, the acceleration sensor fixture is preferably more conductive than insulating.

[0034] (Function and Effect) In consideration of the above problems, a vibration measuring device 100 according to this embodiment includes an acceleration sensor 10, an acceleration sensor mounting bracket 21, a spacer 32 serving as an insulating member, and an acceleration sensor cable 40. The acceleration sensor 10 includes an element 11 capable of measuring the vibration of an object to be measured. The acceleration sensor mounting bracket 21 is placed on the acceleration sensor 10 on the side of the position where the object to be measured 1 is to be placed (the lower side in FIG. 1). The spacer 32 is sandwiched between the acceleration sensor 10 and the position where the object to be measured 1 is to be placed. The acceleration sensor cable 40 includes a pair of cable wires (a first cable wire 41 and a second cable wire 42), a shielded wire 43, and an outer sheath 44 that bundles and surrounds the first cable wire 41, the second cable wire 42, and the shielded wire 43.

[0035] By disposing the spacer 32 as an insulating member, insulation between the acceleration sensor 10 and the object to be measured 1 can be ensured even if the housing of the acceleration sensor mounting fixture 21 is made of a conductive material such as metal. This holds true both under normal conditions and when a surge voltage is applied to the object to be measured 1. As a result, the dielectric strength of the vibration measuring device 100 is improved compared to a case without the spacer 32, making the acceleration sensor 10 less likely to break down. In addition, the spacer 32 makes the acceleration sensor mounting fixture 21 conductive, which makes it possible to suppress a decrease in the accuracy of vibration measurement by the vibration measuring device 100.

[0036] In the vibration measuring device 100, a single insulating heat shrink tube 31 covers the sensor outer edge 10a of the acceleration sensor 10 and the mounting outer edge 21a of the acceleration sensor mounting fixture 21. The heat shrink tube 31 includes an area that protrudes outward (covers the outer diameters) of the acceleration sensor 10 and the acceleration sensor mounting fixture 21 when viewed in plan from the direction in which the acceleration sensor 10 and the acceleration sensor mounting fixture 21 overlap.

[0037] From a different perspective, the vibration measuring device 100 according to this embodiment includes an acceleration sensor 10, an acceleration sensor mounting fixture 21, a spacer 32 as an insulating member, and a single insulating tube (heat shrink tube 31). The acceleration sensor 10 includes an element 11 capable of measuring the vibration of a measurement target 1. The acceleration sensor mounting fixture 21 is disposed on the measurement target 1 side of the acceleration sensor 10. The spacer 32 is sandwiched between the acceleration sensor 10 and the acceleration sensor mounting fixture 21, and contacts both the acceleration sensor 10 and the acceleration sensor mounting fixture 21. The single insulating heat shrink tube 31 covers the sensor outer edge 10a of the acceleration sensor 10 and the mounting fixture outer edge 21a of the acceleration sensor mounting fixture 21. The heat shrink tube 31 includes an area that protrudes outward (covers the outer diameter) of the acceleration sensor 10 and the acceleration sensor mounting fixture 21 when viewed in a plan view from a direction in which the acceleration sensor 10 and the acceleration sensor mounting fixture 21 overlap.

[0038] Next, by covering the outer diameters (sensor outer edge 10a and attachment outer edge 21a) of the acceleration sensor 10 and the acceleration sensor attachment fixture 21 with the heat shrink tube 31, the creepage distance can be increased in the vertical direction in FIG. 1. In a configuration in which the sensor outer edge 10a and the attachment fixture outer edge 21a are not covered with the heat shrink tube 31, the spacer 32 ensures insulation between the acceleration sensor attachment fixture 21 and the acceleration sensor housing 10B. In other words, the creepage distance is the thickness of the spacer 32. However, in FIG. 1, the creepage distance between the acceleration sensor 10 and the acceleration sensor attachment fixture 21 is the creepage distance 63 indicated by the arrow in the figure. Specifically, the creepage distance 63 corresponds to the distance traveled from the acceleration sensor 10 to the acceleration sensor attachment fixture 21 along its outermost edge. In other words, if, for example, the heat shrink tube 31 is present between the acceleration sensor 10 and the acceleration sensor attachment fixture 21, the creepage distance 63 is measured by running along the surface of the heat shrink tube 31. Therefore, when a surge voltage is applied to the object to be measured 1, the application of a high voltage to the element 11, the generation of a high current, and the generation of a discharge to the acceleration sensor 10 can be suppressed, compared to a case where the heat shrink tube 31 is not provided. This is because a longer creepage distance 63 can suppress creepage discharge via the sensor outer edge 10a, etc. This can suppress breakdowns in the element 11 and the acceleration sensor 10.

[0039] In addition, in the present embodiment, the spring constant can be controlled by controlling the dimensions according to the material of the spacer 32 as the insulating member. Thereby, the spacer 32 can have good frequency response characteristics in the high frequency band. Therefore, a decrease in the accuracy of vibration measurement of the vibration measurement device 100 including the spacer 32 can be suppressed.

[0040] According to the present embodiment, a failure of the acceleration sensor 10 is prevented. Therefore, the frequency of occurrence of measurement troubles in the vibration measurement device is reduced, and the reliability of the device for monitoring the vibration measurement device is improved. This operational effect is basically the same in each of the embodiments described below.

[0041] (Embodiment 2) (Configuration of Vibration Measurement Device) FIG. 13 is a schematic diagram showing the configuration of a vibration measurement device according to Embodiment 2. Note that FIG. 13 corresponds to FIG. 1. However, in Embodiments 2 to 10, the acceleration sensor cable 40 and the grounding points G1 and G2 in FIG. 1 actually exist in the same manner as in FIG. 1, but their illustration is omitted.

[0042] Referring to FIG. 13, the vibration measurement device 100 according to the present embodiment basically has the same configuration as the vibration measurement device 100 shown in FIG. 1, and thus the description of the same content will not be repeated. However, the vibration measurement device 100 of the present embodiment does not have the heat shrinkable tube 31. Further, in the vibration measurement device 100 of the present embodiment, as the insulating member, an adapter 33 is disposed instead of the spacer 32. The adapter 33 has a circular shape when viewed in plan from the direction in which the acceleration sensor 10 and the acceleration sensor fixture 21 overlap (for example, the upper side in FIG. 13), and the thickness in the vertical direction of FIG. 13 is substantially the same throughout (there is no difference greater than the machining error). However, the planar shape of the adapter 33 is not limited to a circular shape, and may be, for example, an elliptical, rectangular, or square planar shape. The adapter 33 may be disposed between the acceleration sensor fixture 21 and the measurement object 1 and in contact with both the acceleration sensor fixture 21 and the measurement object 1.

[0043] The adapter 33 includes an area that protrudes outward from the acceleration sensor 10 and the acceleration sensor mounting fixture 21 when viewed in plan from the direction in which the acceleration sensor 10 and the acceleration sensor mounting fixture 21 overlap (for example, from the upper side in FIG. 1). In other words, the adapter 33 includes an area that protrudes outward from the sensor outer edge 10a and the mounting fixture outer edge 21a in the above-mentioned plan view. The portion of the adapter 33 that protrudes outward from the sensor outer edge 10a and the mounting fixture outer edge 21a in the plan view makes the creepage distance 63 between the acceleration sensor 10 and the acceleration sensor mounting fixture 21 longer than when there is no such protruding portion. The creepage distance 63 between the acceleration sensor 10 and the acceleration sensor mounting fixture 21 is approximately equal to the sum of twice the length that the outer edge of the adapter 33 protrudes horizontally from the sensor outer edge 10a and the thickness of the adapter 33 in the vertical direction in FIG. 13.

[0044] The horizontal length of the portion of the adapter 33 that protrudes outward from the sensor outer edge 10a and the mounting fixture outer edge 21a in a plan view is set to a length such that the dielectric breakdown voltage of air under standard conditions having the same thickness as the creepage distance 63 (via the adapter 33) between the acceleration sensor 10 and the acceleration sensor mounting fixture 21 obtained by that horizontal length is 100 kV or more. Here, air under standard conditions refers to air with a temperature of 23°C and a humidity of 50%. More specifically, the diameter (maximum dimension) of the adapter 33 in the horizontal direction (left-right direction in FIG. 13) is preferably between two and three times the horizontal dimension of the housing of the acceleration sensor 10 and the acceleration sensor mounting fixture 21.

[0045] It is preferable that the spring constant of the adapter 33 is equal to the spring constant of the insulating plate 39 of the first embodiment. In other words, the spring constant of the adapter 33 is, for example, 2.0×10 9 It is preferable that the resistance is N / m or more.

[0046] The adapter 33 includes adapter protrusions 33a for fitting with the acceleration sensor 10 and the acceleration sensor mounting fixture 21 on one surface (upper side in FIG. 13) and the other surface (lower side in FIG. 13) of a plate-like member that protrudes outward from the sensor outer edge 10a of the acceleration sensor 10 as described above. The adapter protrusions 33a are preferably made of the same material as the plate-like member of the adapter 33 (i.e., an insulating material). Recesses for fitting with the adapter protrusions 33a are formed on the surfaces of the housings of the acceleration sensor 10 and the acceleration sensor mounting fixture 21. The adapter protrusions 33a are fixed to the acceleration sensor 10 and the acceleration sensor mounting fixture 21 by inserting them into the recesses. Therefore, the entire adapter 33 is fixed to the acceleration sensor 10 and the acceleration sensor mounting fixture 21. The shape of the adapter protrusions 33a in a plan view (shape when viewed from the top and bottom in FIG. 13) may be any of a circle, an ellipse, a rectangle, and a square. In the vertical direction of FIG. 13 (the direction connecting the acceleration sensor 10 and the acceleration sensor attachment 21), the adapter protrusion 33a is Adapter 33 It may be thicker than , but it may also be thinner than . Adapter 33 The acceleration sensor 10 and the acceleration sensor attachment fixture 21 are connected to each other by an adapter 33 including an adapter protrusion 33a.

[0047] (Action and effect) In the vibration measuring device 100, the insulating member (adapter 33) includes an area that protrudes outside the acceleration sensor 10 and the acceleration sensor fixture 21 when viewed in a plan view from the direction in which the acceleration sensor 10 and the acceleration sensor fixture 21 overlap.

[0048] From a different perspective, the vibration measuring device 100 according to this embodiment comprises an acceleration sensor 10, an acceleration sensor mounting fixture 21, and an insulating member (adapter 33). The acceleration sensor 10 includes an element 11 capable of measuring vibrations of the object to be measured 1. The acceleration sensor mounting fixture 21 is disposed on the object to be measured 1 side of the acceleration sensor 10. The insulating member (adapter 33) is sandwiched between the acceleration sensor 10 and the acceleration sensor mounting fixture 21 and is in contact with both. The insulating member (adapter 33) includes a region that protrudes outward from the acceleration sensor 10 and the acceleration sensor mounting fixture 21 when viewed from above from the direction in which the acceleration sensor 10 and the acceleration sensor mounting fixture 21 overlap. Similar to the heat-shrinkable tube 31 of the first embodiment, the adapter 33, which protrudes outward beyond the acceleration sensor 10 and the like in a planar view, can increase the creepage distance 63, thereby suppressing damage to the element 11 and the acceleration sensor 10 when a surge voltage is applied to the object to be measured 1. Other functions and effects are the same as those of the first embodiment, and therefore description thereof will not be repeated.

[0049] (Embodiment 3) (Configuration of vibration measurement device) FIG. 14 is a schematic diagram showing the configuration of the vibration measuring device according to Embodiment 3. Note that FIG. 14 corresponds to FIGS. 1 and 13. Referring to FIG. 14, the vibration measuring device 100 according to the present embodiment basically has the same configuration as the vibration measuring device 100 shown in FIGS. 1 and 13, and thus the description of the same content will not be repeated. However, the vibration measuring device 100 of the present embodiment does not have the heat shrinkable tube 31. Further, in the vibration measuring device 100 of the present embodiment, as an insulating member, instead of the spacers 32 and the adapter 33, a single insulating spacer 34 is disposed. The arrangement position of the spacer 34 is the same as that of the spacers 32 and the adapter 33. The material of the spacer 34 may be the same as that of the spacer 32 in Embodiment 1. However, like the adapter 33, the spacer 34 includes a region protruding outward of the acceleration sensor 10 and the acceleration sensor fixture 21 when these are viewed in plan from the direction in which the acceleration sensor 10 and the acceleration sensor fixture 21 overlap (for example, the upper side in FIG. 1). In this regard, the spacer 34 is different from the spacer 32 whose area in plan view is substantially equal to that of the acceleration sensor 10 and the acceleration sensor fixture 21 (not protruding outward in plan view with respect to the sensor outer edge 10a, etc.). Due to the region of the spacer 34 protruding outward with respect to the acceleration sensor 10 and the like, the creepage distance 63 can be increased in the same manner as in Embodiment 2 in the present embodiment. The spring constant of the spacer 34 is preferably equivalent to that of the insulating plate 39 in Embodiment 1 and the adapter 33 in Embodiment 2. For this reason, the length of the spacer 34 protruding outward in plan view with respect to the acceleration sensor 10 and the acceleration sensor fixture 21, and the thickness thereof in the vertical direction in FIG. 14 may be substantially equal to the protruding length and thickness of the adapter 33.

[0050] (Function and Effect) In the vibration measuring device 100, the insulating member may be a single insulating spacer 34. The acceleration sensor 10 and the acceleration sensor mount 21 are joined together by an insulating fixing member (stud 50), and a filler 62 may be placed in the gap between the stud 50 and the acceleration sensor 10 or acceleration sensor mount 21. Even with this configuration, the spacer 34, which protrudes outward from the acceleration sensor 10 in a plan view, can lengthen the creepage distance 63, thereby suppressing damage to the element 11 and the acceleration sensor 10 when a surge voltage is applied to the object to be measured 1.

[0051] (Fourth embodiment) (Configuration of vibration measurement device) FIG. 15 is a schematic diagram showing the configuration of a vibration measuring device according to a fourth embodiment. FIG. 15 corresponds to FIG. 14. Referring to FIG. 15, the vibration measuring device 100 according to this embodiment has basically the same configuration as the vibration measuring device 100 shown in FIG. 14, and therefore the same description will not be repeated. The vibration measuring device 100 in FIG. 15 has three insulating members: two spacers 34 and one spacer 35. The spacer 35 is sandwiched between the upper and lower spacers 34, and the spacer 34, spacer 35, and spacer 34 stacked in this order from bottom to top are sandwiched between the acceleration sensor 10 and the acceleration sensor mounting fixture 21. The material of the spacer 35 may be the same as the material of the spacer 34. If these three stacked spacers are considered as a group, the group of spacers contacts both the acceleration sensor 10 and the acceleration sensor mounting fixture 21 by contacting the acceleration sensor 10 at the top and the acceleration sensor mounting fixture 21 at the bottom.

[0052] The spacer 35 is made of the same material as the spacer 34, but has a shorter horizontal dimension (left-right direction in FIG. 15) than the spacer 34. The horizontal dimension of the spacer 34 may be 0.5 to 0.8 times the horizontal dimension of the spacer 35, and is preferably 0.6 to 0.7 times the horizontal dimension of the spacer 34. As a result, the spacer outer edge 35a of the spacer 35 is disposed inside the spacer outer edge 34a of the spacer 34, that is, at a position closer to the center in a radial direction extending radially from the center of the acceleration sensor 10 in a plan view. However, like the spacer 34, the spacer outer edge 35a of the spacer 35 is disposed outside the sensor outer edge 10a and the mounting outer edge 21a in a plan view (at a position farther from the center of the acceleration sensor 10 in the radial direction than the spacer outer edge 34a). The three spacers 34 and 35 stacked together are connected and fixed to the acceleration sensor 10 and the acceleration sensor mounting fixture 21 by the studs 50.

[0053] 15, the spacers 34, 35, and 34 are stacked from bottom to top in this order, but this is not limiting, and for example, two spacers 35 and one spacer 34 may be stacked in the order of spacer 35, spacer 34, and spacer 35. Alternatively, two spacers 34 and two spacers 35 may be stacked alternately, or either of the spacers 34 and 35 may be stacked in the bottom layer. The number of spacers 34 and 35 to be arranged and the order in which they are arranged are arbitrary.

[0054] (Action and effect) The vibration measurement device 100 according to this embodiment includes an acceleration sensor 10, an acceleration sensor fixture 21, and one or more spacers 34 and one or more spacers 35 as insulating members. The spacers 34 and 35 include regions that protrude outside the acceleration sensor 10 and the acceleration sensor fixture 21 when viewed in a plan view from the direction in which the acceleration sensor 10 and the acceleration sensor fixture 21 overlap. The spacer 35 has smaller dimensions in the direction (left - right direction in FIG. 15) intersecting the direction (up - down direction in FIG. 15) connecting the acceleration sensor 10 and the acceleration sensor fixture 21 than the spacer 34. The spacers 34 and 35 are laminated together and sandwiched between the acceleration sensor 10 and the acceleration sensor fixture 21, and are in contact with both the acceleration sensor 10 and the acceleration sensor fixture 21. As a result, for example, a creepage distance 63 having an uneven shape in the left - right direction in FIG. 15 is obtained by two spacer outer edges 34a and one spacer outer edge 35a in FIG. 15. That is, since the spacer outer edge 34a and the spacer outer edge 35a have a difference in horizontal dimension, the creepage distance 63 from the acceleration sensor 10 to the acceleration sensor fixture 21 at the outer edge of the laminated structure of the spacer outer edge 34a and the spacer outer edge 35a becomes longer by that amount. Thereby, failures of the element 11 and the acceleration sensor 10 when a surge voltage is applied to the measurement object 1 can be suppressed. Since other operational effects are the same as those in the first embodiment, the description will not be repeated.

[0055] (Embodiment 5) (Configuration of the vibration measurement device) FIG. 16 is a schematic diagram showing the configuration of a vibration measuring device according to a fifth embodiment. FIG. 16 corresponds to FIG. 1. Referring to FIG. 16, the vibration measuring device 100 according to this embodiment has a configuration basically similar to that of the vibration measuring device 100 shown in FIG. 1, and therefore, description of the same configuration will not be repeated. The vibration measuring device 100 shown in FIG. 16 includes an acceleration sensor mounting fixture 22 whose housing is made of an insulating material, instead of the acceleration sensor mounting fixture 21 whose housing is made of a conductive material. The insulating material constituting the housing of the acceleration sensor mounting fixture 22 is preferably a material with low water absorption and resistance to deterioration over time. Furthermore, the dielectric strength of the acceleration sensor mounting fixture 22 is preferably 10 kV / mm or greater. Specifically, the insulating material constituting the housing of the acceleration sensor mounting fixture 22 may be the same as the insulating material constituting the spacer 32 in the first embodiment. In this embodiment, the acceleration sensor mounting fixture 22 has an insulating housing, and therefore neither the spacers 32, 34 nor the adapter 33 are used as insulating members.

[0056] In Fig. 16, no filler is placed in the gap between the stud 50 and the acceleration sensor 10 and acceleration sensor mounting fixture 22 to which it is joined. This is because the acceleration sensor mounting fixture 22 is insulating, so high dielectric strength can be ensured for the stud 50 and its surroundings without the need for a filler. However, in Fig. 16, as in Fig. 1, a filler 62 may be placed in the gap between the stud 50 and the acceleration sensor 10 and acceleration sensor mounting fixture 22 to which it is joined.

[0057] As described above, the acceleration sensor mounting fixture 22 of this embodiment may have a housing (entirely) made of an insulating material. However, the acceleration sensor mounting fixture 22 of this embodiment may have a housing main body made of a conductive material, and the surface of the main body may be coated (applied) with a thin film of an insulating material, as shown in FIG. 26 described later. In any case, the acceleration sensor mounting fixture 22 can electrically insulate the acceleration sensor 10 from the object to be measured 1.

[0058] (Action and effect) The vibration measurement device 100 according to this embodiment includes an acceleration sensor 10, an acceleration sensor fixture 22, and a single insulating tube (heat-shrinkable tube 31). The acceleration sensor 10 includes an element 11 capable of measuring the vibration of the measurement object 1. The acceleration sensor fixture 22 is disposed on the side of the measurement object 1 of the acceleration sensor 10. The single insulating heat-shrinkable tube 31 covers the sensor outer edge 10a of the acceleration sensor 10 and the fixture outer edge 22a of the acceleration sensor fixture 22. The heat-shrinkable tube 31 includes a region protruding outside the acceleration sensor 10 and the acceleration sensor fixture 22 when viewed in a plan view from the direction in which the acceleration sensor 10 and the acceleration sensor fixture 22 overlap. The acceleration sensor fixture 22 can electrically insulate between the acceleration sensor 10 and the measurement object 1.

[0059] First, since the acceleration sensor fixture 22 can electrically insulate between the acceleration sensor 10 and the measurement object 1, for example, the insulation withstand voltage of the vibration measurement device 100 is improved as compared with the case where a conductive acceleration sensor fixture 21 is disposed. Therefore, the acceleration sensor 10 is less likely to fail.

[0060] Further, since the heat-shrinkable tube 31 protrudes outside the acceleration sensor 10 (sensor outer edge 10a) and the acceleration sensor fixture 22 (fixture outer edge 22a), the creepage distance 63 between the acceleration sensor 10 and the measurement object 1 can be increased as compared with the case where it does not protrude outside, similar to the first embodiment. That is, the insulation withstand voltage between the acceleration sensor 10 and the measurement object 1 due to the acceleration sensor fixture 22 being insulating is further reinforced by the extension of the creepage distance 63.

[0061] In this embodiment, since the acceleration sensor fixture is insulating, unlike the first embodiment, the creepage distance 63 is from the acceleration sensor 10 to the measurement object 1. However, the operational effects due to the increase in the creepage distance 63 are the same as those in the first embodiment. That is, the insulation withstand voltage of the vibration measurement device 100 is enhanced by the insulating acceleration sensor fixture 22 and the heat-shrinkable tube 31 that protrudes outside the acceleration sensor 10 and the like to increase the creepage distance 63.

[0062] As described in the first embodiment (FIG. 6), when an insulating acceleration sensor mounting fixture is used, the frequency response characteristics are generally worse, especially in the high frequency band, than when a conductive (metallic) acceleration sensor mounting fixture is used. For this reason, it is preferable that the vibration measuring device 100 having the configuration of this embodiment is used for measurements at frequencies of about 7000 Hz or less, that is, from the low frequency band to the medium frequency band.

[0063] (Embodiment 6) (Configuration of vibration measurement device) FIG. 17 is a schematic diagram showing the configuration of a vibration measuring device according to a sixth embodiment. FIG. 17 corresponds to FIG. 14. Referring to FIG. 17, the vibration measuring device 100 according to this embodiment has basically the same configuration as the vibration measuring device 100 shown in FIG. 14, and therefore the same description will not be repeated. The vibration measuring device 100 in FIG. 17 has an acceleration sensor mounting fixture 22 whose housing is made of an insulating material instead of the acceleration sensor mounting fixture 21 whose housing is made of a conductive material. An insulating coating 64, which is either an adhesive or grease, is applied to the gap between the spacer 34 and the acceleration sensor mounting fixture 22 on the side (below) of the measurement target 1. The application of the insulating coating 64 fills the gap between the spacer 34 and the acceleration sensor mounting fixture 22.

[0064] (Action and effect) In the vibration measuring device 100, the acceleration sensor mounting fixture 22 may be capable of electrically insulating the acceleration sensor 10 from the object to be measured 1. An insulating coating material 64 such as adhesive or grease may be placed in the gap between the acceleration sensor mounting fixture 22 and the spacer 34 serving as an insulating member. In this way, as in the fifth embodiment (FIG. 16), the dielectric strength between the acceleration sensor 10 and the object to be measured 1 due to the insulating properties of the acceleration sensor mounting fixture 22 is further reinforced by the extension of the creepage distance 63 caused by the spacer 34 protruding outward from the acceleration sensor 10, etc.

[0065] (Embodiment 7) (Configuration of vibration measurement device) FIG. 18 is a schematic diagram showing the configuration of the vibration measuring device according to Embodiment 7. Note that FIG. 18 corresponds to the configuration diagrams of the vibration measuring devices in other embodiments such as FIGS. 1 and 16. Referring to FIG. 18, the vibration measuring device 100 according to the present embodiment basically has the same configuration as the vibration measuring device 100 in other embodiments such as FIGS. 1 and 16, and thus the description of the same content will not be repeated. The vibration measuring device 100 in FIG. 18 does not have the heat shrinkable tube 31. In the vibration measuring device 100 of FIG. 18, the fixture outer edge 22a, which is the outer edge of the acceleration sensor fixture 22, has a portion that protrudes outside the outer edge of the acceleration sensor (sensor outer edge 10a) in a plan view. In the cross-sectional view of FIG. 18, the portion where the fixture outer edge 22a protrudes outward extends in a direction intersecting the left-right direction of FIG. 18 along the connection surface where the acceleration sensor fixture 22 is connected to the acceleration sensor 10. That is, the fixture outer edge 22a extends in a direction having an angle with respect to the left-right direction (a direction excluding the left-right direction and a direction substantially equal thereto) as the intersecting direction. In this regard, the present embodiment is different from the above-described other embodiments in which the fixture outer edges 22a and 21a are arranged so as to substantially overlap the sensor outer edge 10a in a plan view.

[0066] The mounting outer edge 22a in FIG. 18 has a wave shape. That is, when the cross-sectional shape of the mounting outer edge 22a is viewed in a radial direction (left and right direction in FIG. 18) extending radially from the center of the acceleration sensor 10 in a plan view, it has a shape that goes back and forth between the inside close to the center of the acceleration sensor 10 and the outside far from the center of the acceleration sensor 10. As it moves from the acceleration sensor 10 side to the measurement target 1 side, the mounting outer edge 22a goes back and forth between the inside and outside of the acceleration sensor 10 in a plan view multiple times. In FIG. 18, the innermost side of the mounting outer edge 22a is a position that overlaps with the sensor outer edge 10a in a plan view, and the outermost side of the mounting outer edge 22a is outside the sensor outer edge 10a in a plan view. In addition, in the cross-sectional shape in FIG. 18, the mounting outer edge 22a is linear and bent so as to go back and forth between the inside and outside. As a result, the mounting outer edge 22a has a portion that protrudes outside the sensor outer edge 10a in a plan view. However, the present invention is not limited to such an embodiment, and for example, the innermost part of the mounting outer edge 22a may be located inside or outside the sensor outer edge 10a. The outermost part of the mounting outer edge 22a may be located inside or outside the outermost position of the mounting outer edge 22a shown in FIG. 18. Although the mounting outer edge 22a in FIG. 18 is bent in a straight line, the mounting outer edge 22a may have a cross-sectional shape that is curved to draw a curve. The outermost part of the mounting outer edge 22a may be located at a position where it overlaps with the sensor outer edge 10a in a plan view or inside the position. In this case, the mounting outer edge 22a will not have a portion that protrudes outside the sensor outer edge 10a, but there is no problem as long as the outer edge 22a has a wave shape that goes back and forth multiple times.

[0067] In Fig. 18, the outer edge 22a of the fixture has a wave shape of three wavelengths in total. However, the number of wavelengths of the wave shape is arbitrary, and it is preferable that the total length of the wave shape is equal to or greater than the creeping distance 63 in Fig. 18 (i.e., a length of three wavelengths or more).

[0068] (Action and effect) In the vibration measuring device 100, the acceleration sensor mounting bracket 22 is placed on the measurement target 1 side of the acceleration sensor 10. The acceleration sensor mounting bracket 22 is an insulating member that can electrically insulate the acceleration sensor 10 from the measurement target 1. The mounting bracket outer edge 22a has a portion that protrudes outward from the sensor outer edge 10a in a plan view. This protruding portion extends in a direction that intersects with the direction along the connection surface where the acceleration sensor mounting bracket 22 connects to the acceleration sensor 10.

[0069] From a different perspective, the vibration measuring device 100 according to this embodiment includes an acceleration sensor 10 and an acceleration sensor mounting fixture 22. The acceleration sensor 10 includes an element 11 capable of measuring vibrations of an object to be measured 1. The acceleration sensor mounting fixture 22 is disposed on the side of the acceleration sensor 10 facing the object to be measured 1. The acceleration sensor mounting fixture 22 is capable of electrically insulating the acceleration sensor 10 from the object to be measured 1. The mounting fixture outer edge 22a has a portion that protrudes outward from the sensor outer edge 10a in a plan view. Therefore, as in the fifth embodiment (FIG. 16), the dielectric strength between the acceleration sensor 10 and the object to be measured 1 due to the insulating property of the acceleration sensor mounting fixture 22 is further reinforced by the extension of the creepage distance 63 due to the mounting fixture outer edge 22a having a portion that protrudes outward from the sensor outer edge 10a.

[0070] In the vibration measuring device 100, the outer edge (attachment outer edge 22a) of the acceleration sensor attachment 22 may have a wave shape. In this way, for example, the attachment outer edge 22a extends in the vertical direction of FIG. Wave shape The creepage distance 63 along the mounting fixture outer edge 22a can be made longer than when the mounting fixture does not have such a configuration. Therefore, similarly to the fifth embodiment (FIG. 16), the dielectric strength between the acceleration sensor 10 and the object to be measured 1, which is achieved by the insulating acceleration sensor mounting fixture 22, is further reinforced by the extension of the creepage distance 63 due to the corrugated mounting fixture outer edge 22a. Note that the mounting fixture outer edge 22a protruding outward from the sensor outer edge 10a in a plan view also further extends the creepage distance 63 than when the mounting fixture does not have such a configuration.

[0071] (Embodiment 8) (Configuration of vibration measurement device) FIG. 19 is a schematic diagram showing the configuration of the vibration measuring device according to the eighth embodiment. Referring to FIG. 19, the description of the configuration similar to that in FIG. 18 in the vibration measuring device 100 according to the present embodiment will not be repeated. In the vibration measuring device 100 of FIG. 19, the outer edge of the insulating acceleration sensor fixture 22 has a portion that protrudes outside the acceleration sensor 10 in a plan view.

[0072] The acceleration sensor fixture 22 includes a first portion 22b and a second portion 22c. The first portion 22b is disposed on the side of the measurement target 1 of the acceleration sensor 10 (the lower side in FIG. 19). That is, the first portion 22b is a portion disposed between the acceleration sensor 10 and the measurement target 1, similar to the acceleration sensor fixture 22 of the vibration measurement device 100 in FIG. 18, for example. The first portion 22b extends in the direction along the contact surface where the acceleration sensor 10 and the acceleration sensor fixture 22 contact, that is, in the left - right direction in FIG. 19. Therefore, the first portion 22b also includes portions disposed outside the portion that overlaps the acceleration sensor 10 in plan view (the left and right regions of the acceleration sensor 10 in FIG. 19). The second portion 22c is continuous with the first portion 22b, and in particular, bends from the first portion 22b in the cross - sectional shape shown in FIG. 19, and is a portion that extends upward from the first portion 22b away from the first portion 22b. The second portion 22c bends at right angles at both left and right ends of the first portion 22b in the cross - sectional shape of FIG. 19 and extends upward therefrom. The second portion 22c is spaced apart from the acceleration sensor 10 in the left - right direction of the figure (radially spaced apart from the center of the acceleration sensor 10). The second portion 22c extends in the vertical direction (along the acceleration sensor 10) from the bent portion that is the boundary with the first portion 22b to, for example, the same vertical position as the uppermost part of the acceleration sensor 10. That is, the second portion 22c extends in a direction intersecting the direction (the first direction) along the connection surface between the acceleration sensor 10 and the acceleration sensor fixture 22. However, the second portion 22c may extend to a position above the uppermost part of the acceleration sensor 10 (on the side opposite to the first portion 22b). The acceleration sensor 10 is surrounded by the first portion 22b and the second portion 22c that extend in mutually perpendicular directions and are continuous with each other. In other words, the acceleration sensor fixture 22 has a shape that covers the acceleration sensor 10 from the outside.

[0073] It is preferable that the dimension in the left - right direction in FIG. 19 of the first portion 22b of the acceleration sensor fixture 22 (including the portion that overlaps the second portion 22c in plan view) along the contact surface where it contacts the acceleration sensor 10 is 2 times or more, and more preferably 3 times or more, the dimension in the left - right direction along the contact surface of the acceleration sensor 10.

[0074] (Action and effect) Similar to the seventh embodiment, the vibration measuring device 100 according to this embodiment has a mounting outer edge 22a that protrudes outward from the sensor outer edge 10a in a plan view. The acceleration sensor mounting bracket 22 includes a first portion 22b that is disposed on the measurement target 1 side of the acceleration sensor 10 and extends along the contact surface between the acceleration sensor 10 and the acceleration sensor mounting bracket 22, and a second portion 22c that bends from the first portion 22b and extends away from the first portion 22b. The acceleration sensor 10 is surrounded by the acceleration sensor mounting bracket 22 by the first portion 22b and the second portion 22c. The first portion 22b extends to an area outside the acceleration sensor 10 in a plan view, and the second portion 22c extends further from there, thereby significantly increasing the creepage distance 63 along the outer edge 22a of the acceleration sensor mounting bracket 22. This is because the creepage distance 63 is equal to or greater than the sum of the dimension by which the first portion 22b extends from the acceleration sensor 10 outward beyond the acceleration sensor 10 and the dimension by which the second portion 22c extends in the vertical direction from there (and the vertical thickness of the first portion 22b). Therefore, similar to the fifth embodiment (FIG. 16), the dielectric strength between the acceleration sensor 10 and the object to be measured 1, which is achieved by the insulating acceleration sensor mounting fixture 22, is further reinforced by the extension of the creepage distance 63 due to the insulative second portion 22c.

[0075] (Embodiment 9) (Configuration of vibration measurement device) FIG. 20 is a schematic diagram showing the configuration of the vibration measuring device according to Embodiment 9. Referring to FIG. 20, since the vibration measuring device 100 according to the present embodiment is basically the same as that in FIG. 19, the description of the same configuration as that in FIG. 19 will not be repeated. In the vibration measuring device 100 of FIG. 20, a gap filler 65 for filling the gap between the second portion 22c of the acceleration sensor fixture 22 and the acceleration sensor 10, which are spaced apart from each other, is disposed. It is preferable that the gap filler 65 is made of a material having a higher dielectric strength than air. Specifically, as the gap filler 65, any one of mortar having a high Young's modulus, a repair material (repair putty), and an adhesive may be used. Note that the dielectric strength of the gap filler 65 is preferably 3.0 kV / mm or more. The Young's modulus of the gap filler 65 is preferably 2.5 GPa or more.

[0076] (Function and effect) The vibration measuring device 100 in FIG. 20 is different from the vibration measuring device 100 in FIG. 19 in that it has the gap filler 65. For example, according to the configuration of FIG. 19, the frequency response characteristics of the acceleration sensor fixture 22 may deteriorate. However, by disposing the gap filler 65 as shown in FIG. 20, the frequency response characteristics of the acceleration sensor fixture 22 including the gap filler 65 can be improved.

[0077] (Embodiment 10) FIG. 21 is a schematic diagram showing the configuration of a vibration measuring device according to a tenth embodiment. Referring to FIG. 21, the vibration measuring device 100 according to this embodiment is basically the same as that shown in FIG. 19, and therefore the same configuration as that shown in FIG. 19 will not be described again. The vibration measuring device 100 in FIG. 21 has a configuration similar to that of the vibration measuring device 100 in FIG. 19, except that the acceleration sensor mounting bracket 22 does not have the second portion 22c and only comprises the first portion 22b. Specifically, the acceleration sensor mounting bracket 22 in FIG. 21 has a portion that protrudes outside the acceleration sensor 10 in a plan view. The acceleration sensor mounting bracket 22 as a whole extends in a direction along the contact surface between the acceleration sensor 10 and the acceleration sensor mounting bracket 22, i.e., in the left-right direction in FIG. 19. The dimension W1 of the acceleration sensor mounting bracket 22 along the contact surface between the acceleration sensor 10 and the acceleration sensor mounting bracket 22 is at least three times the dimension W2 of the acceleration sensor 10 along the contact surface. It is more preferable that the dimension W1 is at least five times the dimension W2.

[0078] (Action and effect) According to this embodiment, the acceleration sensor mounting bracket 22 is larger than the acceleration sensor 10 in a plan view. The acceleration sensor mounting bracket 22 is disposed both in an area overlapping the acceleration sensor 10 in a plan view and in an area outside of that area. This increases the contact area of the acceleration sensor mounting bracket 22 with the object to be measured 1 directly below it compared to, for example, a case in which the acceleration sensor mounting bracket 22 has the same dimension W2 as the acceleration sensor 10. Therefore, according to this embodiment, as shown in FIG. 21 , the difference between the dimension W1 and the dimension W2 is added as part of the creepage distance 63 from the acceleration sensor 10 to the object to be measured 1. Therefore, according to this embodiment, the creepage distance 63 can be made longer compared to, for example, a case in which the acceleration sensor mounting bracket 22 has the same dimension W2 as the acceleration sensor 10. As a result, similar to the fifth embodiment (FIG. 16 ), the dielectric strength between the acceleration sensor 10 and the object to be measured 1, which is due to the insulating properties of the acceleration sensor mounting bracket 22, is further reinforced by the extension of the creepage distance 63.

[0079] (Embodiment 11) FIG. 22 is a schematic diagram showing the configuration of the vibration measuring device according to Embodiment 11. Note that FIG. 22 corresponds to FIG. 1. However, in Embodiments 11 to 14, a part of the acceleration sensor cable 40 is shown. The grounding points G1 and G2 exist as in FIG. 1, but their illustration is omitted.

[0080] Referring to FIG. 22, the vibration measuring device 100 according to the present embodiment basically has the same configuration as the vibration measuring device 100 shown in FIG. 1, so the description of the same content will not be repeated. However, the vibration measuring device 100 of the present embodiment does not have the heat shrinkable tube 31 and the spacer 32, and the acceleration sensor cable 40 is electrically connected to the acceleration sensor 10. Specifically, one end of the shield wire 43 included in the acceleration sensor cable 40 is connected to the grounding terminal 81. Here, one end is the lower side of FIG. 22, that is, the acceleration sensor fixture 21 side of the acceleration sensor 10. The grounding terminal 81 is installed so as to be in contact with the acceleration sensor fixture 21 and electrically connectable to the acceleration sensor fixture 21. Note that the grounding terminal 81 may be installed so as to be in contact with the measurement object 1 and electrically conductive to the measurement object 1. That is, the shield wire 43 may be installed so as to be electrically conductive to the measurement object 1. In FIG. 22, the grounding terminal 81 is shown in contact with both the acceleration sensor fixture 21 and the measurement object 1 and electrically conductive to both, and such a configuration may be adopted.

[0081] Two current-carrying paths, a first path and a second path, are formed in the vibration measuring device 100. The first path is a path in which the shield wire 43 extends from a bundle of a plurality of cable wires covered by the outer jacket 44 of the acceleration sensor cable 40 to the grounding terminal 81. That is, the first path is constituted by the shield wire 43. The second path is a path that extends from the first cable wire 41 and the second cable wire 42 of the acceleration sensor cable 40, passes through the element 11 of the acceleration sensor 10 and the conductive acceleration sensor housing 10B, and reaches the acceleration sensor fixture 21. The first path and the second path are arranged in parallel so as to be side by side in the left-right direction of FIG. 22.

[0082] (Operation and Effect) The vibration measuring device 100 according to this embodiment includes an acceleration sensor 10, an acceleration sensor mounting fixture 21, and an acceleration sensor cable 40. The acceleration sensor 10 includes an element 11 capable of measuring the vibration of a measurement target 1. The acceleration sensor mounting fixture 22 is disposed on the side of the acceleration sensor 10 where the measurement target 1 is to be located. The acceleration sensor cable 40 includes a pair of cable wires (a first cable wire 41 and a second cable wire 42), a shield wire 43, and an outer jacket 44 that bundles and surrounds the first cable wire 41, the second cable wire 42, and the shield wire 43. A first path along which the shield wire 43 extends is disposed in parallel with a second path from the acceleration sensor cable 40 via the acceleration sensor 10 to the acceleration sensor mounting fixture 21. A ground terminal 81 is connected to the first path so as to be electrically connectable to the acceleration sensor mounting fixture 21. The shield wire 43 is not connected to the acceleration sensor 10 but is connected to the acceleration sensor mounting fixture 21 (for example, via the ground terminal 81).

[0083] The first path is a path that connects the shield wire 43 from the side of the acceleration sensor 10 opposite the acceleration sensor mounting fixture 21 (upper side in FIG. 22) to the ground terminal 81 electrically connected to the acceleration sensor mounting fixture 21. The second path is a path that passes through the acceleration sensor housing 10B from the first cable wire 41 and the second cable wire 42 and the element 11 connected thereto to the acceleration sensor mounting fixture 21. When a surge voltage is applied to the measurement object 1 in FIG. 22, the acceleration sensor mounting fixture 21 (measurement object 1) and the shield wire 43 are electrically connected via the ground terminal 81 of the first path. Therefore, the high voltage and high current of the surge voltage are immediately reduced to the ground potential. In addition, when a surge voltage is applied to the measurement object 1, almost no current flows through the second path that is parallel to the first path. The reason that almost no current flows through the second path is that there is a cavity 12 between the element 11 to which the first cable wire 41 and the like are connected and the acceleration sensor housing 10B, and they are not continuous. In other words, the second path is not electrically connected in its entirety due to the presence of cavity 12. Therefore, the second path has a much higher electrical resistance than the first path. Therefore, the surge voltage passes preferentially through the first path over the second path, so that the surge voltage can be instantly reduced in potential as described above. Since a high voltage is not applied to acceleration sensor 10 (element 11 of the second path), breakdown of acceleration sensor 10 (element 11 of the second path) can be suppressed.

[0084] (Embodiment 12) FIG. 23 is a schematic diagram showing the configuration of a vibration measuring device according to a twelfth embodiment. FIG. 23 corresponds to FIG. 22. Referring to FIG. 23, the vibration measuring device 100 according to this embodiment has basically the same configuration as the vibration measuring device 100 shown in FIG. 22, and therefore description of the same content will not be repeated. However, in the vibration measuring device 100 of FIG. 23, a surge protective device 82 is connected between one end of the first path formed by the shielded wire 43, which is connected to the ground terminal 81, and the other end on the opposite side (the acceleration sensor 10 side of the acceleration sensor mounting fixture 21). The surge protective device 82 is an SPD (Surge Protective Device). In other words, the vibration measuring device 100 of this embodiment is equipped with an SPD.

[0085] FIG. 24 is a schematic diagram showing a first example of the connection mode between the ground terminal and the acceleration sensor fixture in FIGS. 22 and 23. Referring to FIG. 24, the ground terminal 81 in Embodiment 11 and Embodiment 12 may be fixed to the acceleration sensor fixture 21 by fastening a screw. Specifically, for example, a female screw is formed on the conductive housing of the acceleration sensor fixture 21, the ground terminal 81 is attached to the female screw, and a male screw is fastened from above. Thereby, the ground terminal 81 is contact-fixed to the conductive housing of the acceleration sensor fixture 21. Such a fixing mode may be adopted.

[0086] FIG. 25 is a schematic diagram showing a second example of the connection mode between the ground terminal and the acceleration sensor fixture in FIGS. 22 and 23. Here, a mode may be adopted in which a female screw is formed on the ground terminal 81 so that the stud 50 for fixing the acceleration sensor 10 and the acceleration sensor fixture 21 penetrates the ground terminal 81 and is fastened to the male screw formed on the stud 50. That is, in FIG. 25, the stud 50 couples the acceleration sensor 10, the acceleration sensor fixture 21, and the ground terminal 81 to each other.

[0087] In any of the examples of FIGS. 24 to 25, the ground terminal 81 and either the acceleration sensor fixture 21 or the acceleration sensor 10 may be fixed by a tape or the like.

[0088] (Function and effect) The vibration measurement device 100 according to the present embodiment has the same structural features as those in Embodiment 11. In the vibration measurement device 100, one end of the shield wire 43 is connected to the ground terminal 81, and a surge protection device 82 may be connected between the other end, which is the opposite side of one end in the first path, and the one end.

[0089] If the acceleration sensor fixture 21 and the measurement target 1 are joined by an insulating adhesive 61 as shown in Fig. 4, the measurement target 1 and the acceleration sensor fixture 21 are electrically insulated from each other. In this case, during normal operation (when no surge voltage is applied to the measurement target 1), the ground loop GL in Fig. 9 does not occur. Since the surge protection device 82 does not conduct current during normal operation, no current flows through the first path of the shield wire 43. Also, since the second path passing through the acceleration sensor 10 (element 11) and the acceleration sensor fixture 21 from the acceleration sensor cable 40 is discontinuous due to the cavity 12, no current flows, and no current flows between the measurement target 1 and the acceleration sensor fixture 21 (acceleration sensor housing 10B) because they are insulated from each other.

[0090] However, when a surge voltage is applied to the measurement target 1, the surge protection device 82 operates like a conductor. For this reason, the first path of the shield wire 43 is electrically connected from the acceleration sensor fixture 21 (ground terminal 81) to the acceleration sensor 10 connected to the acceleration sensor cable 40. As a result, the potential difference between the acceleration sensor fixture 21 (and the measurement target 1 that contacts the ground terminal 81 in common therewith) and the acceleration sensor 10 disappears, and the high voltage and high current of the surge voltage immediately drop to the ground potential by the ground terminal 81. On the other hand, for the same reason as in Embodiment 11 (Fig. 22), when a surge voltage is applied to the measurement target 1, almost no current flows through the second path that is parallel to the first path. As described above, similar to Embodiment 11, since the surge voltage preferentially passes through the first path rather than the second path, the high voltage is not applied to the acceleration sensor 10 (element 11 of the second path), and a failure of the acceleration sensor 10 (element 11 of the second path) can be suppressed.

[0091] As described above, in this embodiment, since the surge protection device 82 is installed during normal operation when no surge voltage is applied to the measurement target 1, the ground loop GL (see Fig. 9) does not occur and no noise current is generated. However, when a surge voltage is applied to the measurement target 1, the surge protection device 82 electrically connects the measurement target 1 and the shield wire 43. Thereby, it is possible to suppress a high voltage from being applied to the element 11 inside the acceleration sensor 10 and a high current from flowing through the element 11.

[0092] (Embodiment 13) Fig. 26 is a schematic diagram showing the configuration of a vibration measuring device according to a thirteenth embodiment. Referring to Fig. 26, vibration measuring device 100 according to this embodiment basically has the same configuration as that shown in Fig. 22, and therefore description of the same content will not be repeated. However, unlike Fig. 22, vibration measuring device 100 of this embodiment is provided with acceleration sensor mounting fixture 22 instead of acceleration sensor mounting fixture 21. Vibration measuring device 100 of this embodiment has a conductive connector 83 connected to it so as to come into contact with acceleration sensor 10.

[0093] The conductive connector 83 is attached to the upper surface (top surface) of the acceleration sensor housing 10B in FIG. 26, which is the opposite side to the acceleration sensor mounting fixture 22 of the acceleration sensor housing 10B, so as to come into contact with the acceleration sensor housing 10B. However, the conductive connector 83 may be installed so as to come into contact with a surface other than the top surface of the acceleration sensor housing 10B. The conductive connector 83 is made of a metal material, and the acceleration sensor 10 and the conductive connector 83 are electrically connected by coming into contact with the acceleration sensor housing 10B. As will be described in a later embodiment, the shielded wire 43 may be electrically connected not only to the acceleration sensor housing 10B, but also to the acceleration sensor 10 side (upper side in FIG. 26) of the insulating member (here, the non-metallic part 22e).

[0094] The shield wire 43 is connected to the conductive connector 83. Also, in FIG. 26, the acceleration sensor fixture 22 includes an insulating member. The insulating member electrically insulates between the measurement object 1 and the acceleration sensor 10. Specifically, the acceleration sensor fixture 22 of the present embodiment includes a metal part 22d that constitutes the main body and a non-metal part 22e that is an insulating member. The metal part 22d is a member that forms the center of the acceleration sensor fixture 22 and has, for example, a rectangular parallelepiped shape (plate shape) like the entire acceleration sensor fixture 22. The metal part 22d may be conductive made of metal or the like. The non-metal part 22e is disposed on the outer surface of the metal part 22d. That is, the non-metal part 22e is coated or formed on the surface of the metal part 22d. The non-metal part 22e may be formed, for example, by anodizing or insulating coating treatment on the entire surface of the metal part 22d, or may be formed by the above treatment on only a part of the surface of the metal part 22d. For example, between the measurement object 1 and the acceleration sensor fixture 22 (the metal part 22d thereof), the non-metal part 22e may be disposed only on the lowermost surface of the metal part 22d in FIG. 26 so as to contact both the measurement object 1 and the acceleration sensor fixture 22 (the metal part 22d thereof). Alternatively, the non-metal part 22e may be disposed, for example, only on the entire surface of the surface of the metal part 22d on the acceleration sensor 10 side (the uppermost surface in FIG. 26). Due to the presence of the non-metal part 22e, the acceleration sensor fixture 22 has insulation properties.

[0095] (Function and Effect) In the vibration measurement device 100, the non-metal part 22e as an insulating member included in the acceleration sensor fixture 22 electrically insulates between the measurement object 1 and the acceleration sensor 10. The shield wire 43 may be electrically connected to the acceleration sensor 10 side of the insulating member.

[0096] Viewed from different perspectives, the vibration measuring device 100 according to the present embodiment includes an acceleration sensor 10, an acceleration sensor fixture 21, and an acceleration sensor cable 40. The acceleration sensor 10 includes an element 11 capable of measuring the vibration of the measurement object 1. The acceleration sensor fixture 22 is disposed on the measurement object 1 side of the acceleration sensor 10. The acceleration sensor cable 40 is electrically connected to the acceleration sensor 10. The acceleration sensor cable 40 includes a shield wire 43. A conductive connector 83 is connected so as to contact the acceleration sensor 10. The shield wire 43 is connected to the conductive connector 83. An insulating film (non-metal part 22e) is sandwiched between the measurement object 1 and the acceleration sensor 10.

[0097] Due to the non-metal part 22e, the measurement object 1 and the acceleration sensor 10 are electrically insulated. In this case, under normal conditions (a state where no surge voltage is applied to the measurement object 1), the ground loop GL in FIG. 9 does not occur. However, when a surge voltage is applied to the measurement object 1, for example, by surface discharge along the non-metal part 22e, the measurement object 1 and the shield wire 43 connected to the conductive connector 83 in contact with the acceleration sensor 10 are electrically connected. Almost no current flows through the second path including the element 11, which is parallel to the first path formed by the shield wire 43. This is because, similar to Embodiments 11 and 12, the second path has a higher electrical resistance than the first path. As described above, similar to Embodiment 11, since the surge voltage preferentially passes through the first path rather than the second path, a high voltage is not applied to the acceleration sensor 10 (element 11 of the second path), and a failure of the acceleration sensor 10 (element 11 of the second path) can be suppressed. As described above, the present embodiment basically has the same operational effects as Embodiment 12.

[0098] In the vibration measuring device 100, the shield wire 43 is electrically connected to the conductive connector 83, and the conductive connector 83 may electrically connect the shield wire 43 to, for example, the acceleration sensor 10. By using the conductive connector 83, unlike the case of using the insulating connector 59 (see FIG. 10), the shield wire 43 can be electrically conductive to the acceleration sensor 10 via the conductive connector 83. Thereby, the above-mentioned first path can be easily formed.

[0099] In the vibration measurement device 100, the acceleration sensor fixture 22 may include a metal part 22d and a non-metal part 22e as an insulating member. By providing the non-metal part 22e on the surface of the metal part 22d, the acceleration sensor fixture 22 can ensure the accuracy of vibration measurement due to the conductivity of the metal part 22d and improve the insulation withstand voltage of the vibration measurement device 100 (fault suppression of the acceleration sensor 10) by ensuring the insulation between the acceleration sensor 10 and the measurement object 1 due to the non-metal part 22e being an insulating member. The insulating member (non-metal part 22e) may be an insulating coating film coated on the surface of the metal part 22d. The insulating member (non-metal part 22e) may be formed of either resin or ceramics. As shown in FIG. 26, the non-metal part 22e may be in contact with the measurement object 1.

[0100] (Embodiment 14) FIG. 27 is a schematic diagram showing the configuration of the vibration measurement device according to Embodiment 14. Referring to FIG. 27, the vibration measurement device 100 according to the present embodiment basically has the same configuration as that in FIG. 26, so the description of the same content will not be repeated. However, in the present embodiment, the acceleration sensor fixture 22 includes a metal part 22d and a non-metal part 22f as an insulating member. The non-metal part 22f is, for example, a plate-like member having a rectangular shape in plan view and a thickness shown in the vertical direction in FIG. 27. The non-metal part 22f is a member having insulation such as a resin or ceramic material processed into a plate shape. As shown in FIG. 27, the uppermost surface of the non-metal part 22f and the lowermost surface of the metal part 22d may be joined by an adhesive 61. Alternatively, although not shown, the uppermost surface of the non-metal part 22f and the lowermost surface of the metal part 22d may be joined by, for example, a laser.

[0101] That is, in the present embodiment, instead of the non-metal part 22e formed on the lowermost surface of the metal part 22d as the coating film in Embodiment 13, the non-metal part 22f as a plate-like member is arranged. Even with such a configuration, basically the same operational effects as those in Embodiment 13 are achieved.

[0102] (Embodiment 15) FIG. 28 is a schematic diagram showing the configuration of a vibration measuring device according to a fifteenth embodiment. Referring to FIG. 28, the vibration measuring device 100 according to this embodiment has essentially the same configuration as that shown in FIG. 22, and therefore the same description will not be repeated. However, unlike FIG. 22, this embodiment includes an acceleration sensor mounting bracket 22 instead of the acceleration sensor mounting bracket 21. Similar to FIG. 27 of the fourteenth embodiment, the acceleration sensor mounting bracket 22 includes a metal portion 22d and a non-metal portion 22f bonded to its bottom surface with, for example, adhesive 61. Although not shown, the acceleration sensor mounting bracket 22 may also include a metal portion 22d and a non-metal portion 22e serving as an insulating coating coated on its surface, similar to FIG. 26 of the thirteenth embodiment.

[0103] 28 is different from Figures 26 and 27 in the connection position of the shield wire 43. In Figures 26 and 27, the shield wire 43 is connected to the top surface of the acceleration sensor 10 by a conductive connector 83. In contrast, in Figure 28, the shield wire 43 is connected to a ground terminal 81 that is connected to the side surface of the metal part 22d of the acceleration sensor mounting bracket 22.

[0104] 26 and 27, the shield wire 43 may be connected to the acceleration sensor 10. Alternatively, the shield wire 43 may be connected to a metal part 22d joined directly onto a non-metal part 22f (insulating member) as shown in Fig. 28. In either case, it is preferable that the shield wire 43 is electrically connected to the acceleration sensor 10 side of the insulating member (the upper side in Figs. 26 to 28).

[0105] (Embodiment 16) A wind power generating device using the vibration measuring device 100 described in each of the above embodiments will be described below.

[0106] <Configuration of wind power generation equipment> FIG. 29 is a diagram schematically showing the configuration of a wind power generator using the vibration measuring device according to each embodiment. Referring to FIG. 29, the wind power generator 1000 includes a main shaft 120, blades 130, a speed increaser 140, a generator 150, and a main bearing 160. The wind power generator 1000 includes sensors 10C to 10K and a data collection device 70. The sensors 10C to 10K are provided as acceleration sensors 10 included in the vibration measuring device 100 according to each of the above embodiments. The data collection device 70 is provided as a CMS device for wind power generation. The speed increaser 140, the generator 150, the main bearing 160, the sensors 10C to 10K, and the data collection device 70 are stored in the nacelle 190, and the nacelle 190 is supported by a tower 101.

[0107] The main shaft 120 enters the nacelle 190 and is connected to the input shaft of the speed increaser 140, and is rotatably supported by the main bearing 160. Then, the main shaft 120 transmits the rotational torque generated by the blades 130 receiving wind power to the input shaft of the speed increaser 140. The blades 130 are provided at the tip of the main shaft 120, convert wind power into rotational torque, and transmit it to the main shaft 120.

[0108] The main bearing 160 is fixedly provided in the nacelle 190 and rotatably supports the main shaft 120. The main bearing 160 is constituted by a rolling bearing, for example, an automatic aligning spherical bearing, a tapered roller bearing, a cylindrical roller bearing, a ball bearing, or the like. Note that these bearings may be single-row or multi-row.

[0109] The sensors 10C to 10K are fixedly provided on each device inside the nacelle 190. Specifically, the sensor 10J is fixedly provided on the upper surface of the main bearing 160 to monitor the state of the main bearing 160. The sensors 10K, 10C, and 10D are fixedly provided on the upper surface of the speed increaser 140 to monitor the state of the speed increaser 140. The sensors 10E and 10F are fixedly provided on the upper surface of the generator 150 to monitor the state of the generator 150. The sensor 10G is fixedly provided on the main bearing 160 to monitor misalignment and abnormal vibration of the nacelle. The sensor 10I is fixedly provided on the main bearing 160 to monitor unbalance and abnormal vibration of the nacelle.

[0110] The speed-up gear 140 is provided between the main shaft 120 and the generator 150, and increases the rotation speed of the main shaft 120 and outputs the increased rotation speed to the generator 150. As an example, the speed-up gear 140 is configured by a gear speed-up mechanism including a planetary gear, an intermediate shaft, a high-speed shaft, etc. Although not shown, the speed-up gear 140 also has a plurality of bearings that rotatably support a plurality of shafts. The generator 150 is connected to the output shaft of the speed-up gear 140, and generates electricity using the rotation torque received from the speed-up gear 140. The generator 150 is configured by, for example, an induction generator. The generator 150 also has a bearing that rotatably supports a rotor.

[0111] The data collection device 70 is provided inside the nacelle 190, and receives data such as vibrations, sounds, and AE (Acoustic emission) of each device detected by the sensors 10C to 10K. Although not shown, the sensors 10C to 10K and the data collection device 70 are connected by wired cables.

[0112] The features described in each of the above-described embodiments (each example included therein) may be applied in an appropriate combination within a range that is not technically inconsistent.

[0113] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0114] 1 Measurement object, 10 Acceleration sensor, 10a Sensor outer edge, 10h, 21h Through hole, 10B Acceleration sensor housing, 11 Element, 12 Cavity, 21, 22 Acceleration sensor fixture, 21a, 22a Fixture outer edge, 22b First part, 22c Second part, 22d Metal part, 22e, 22f Non-metal part, 31 Heat shrinkable tube, 32, 34 Spacer, 33 Adapter, 33a Adapter protrusion, 34a, 35a Spacer outer edge, 36, 39 Insulating plate, 40 Acceleration sensor cable, 41 First cable wire, 42 Second cable wire, 43 Shield wire, 44 Outer sheath, 50 Stud, 61 Adhesive, 62 Filler, 63 Creepage distance, 64 Insulating coating agent, 65 Gap filler, 70 Data collection device, 81 Ground terminal, 82 Surge protection device, 83 Conductive connector, 100, 900 Vibration measurement device, 101 Tower, 120 Main shaft, 130 Blade, 140 Speed increaser, 150 Generator, 160 Main bearing, 190 Nacelle, 1000 Wind power generation device, DCG Discharge, G1, G2 Grounding point, GL Ground loop, SV Surge voltage.

Claims

1. An acceleration sensor including an element capable of measuring vibrations of a measurement object, an acceleration sensor fixture disposed on the side of the position where the measurement object of the acceleration sensor should be disposed, an insulating member sandwiched between the acceleration sensor and the position where the measurement object should be disposed, an acceleration sensor cable including a pair of cable wires, a shield wire, and an outer covering that bundles the pair of cable wires and the shield wire and surrounds them from the outside, A vibration measurement device, wherein a spring constant of the insulating member is 2.0×10^9 N / m or more.

2. The vibration measurement device according to claim 1, wherein the insulating member includes a region protruding outside the acceleration sensor and the acceleration sensor fixture when viewed in a plan view from the direction in which the acceleration sensor and the acceleration sensor fixture overlap.

3. The insulating member is a single insulating spacer, the acceleration sensor and the acceleration sensor fixture are coupled to each other by an insulating fixing member, The vibration measurement device according to claim 1 or 2, wherein a filler is disposed in a gap between the fixing member and the acceleration sensor and the acceleration sensor fixture.

4. Comprising a single insulating tube covering an outer edge of the acceleration sensor and an outer edge of the acceleration sensor fixture, The vibration measurement device according to claim 1, wherein the tube includes a region covering an outer diameter of the acceleration sensor and the acceleration sensor fixture when viewed in a plan view from the direction in which the acceleration sensor and the acceleration sensor fixture overlap.

5. The vibration measurement device according to any one of claims 1 to 4, wherein the acceleration sensor fixture is conductive.

6. The acceleration sensor fixture can electrically insulate between the acceleration sensor and the measurement object, The vibration measurement device according to any one of claims 1 to 4, wherein either an adhesive or grease is disposed in a gap between the insulating member and the acceleration sensor fixture.

7. The acceleration sensor fixture is connected to the measurement object side of the acceleration sensor, the acceleration sensor fixture is the insulating member capable of electrically insulating between the acceleration sensor and the measurement object, The outer edge of the acceleration sensor fixture has a portion protruding outside the outer edge of the acceleration sensor in a plan view, and the protruding portion extends in a direction intersecting with the direction along the connection surface where the acceleration sensor fixture is connected to the acceleration sensor. The vibration measurement device according to claim 1.

8. The vibration measurement device according to claim 7, wherein an outer edge of the acceleration sensor fixture has a wavy shape.

9. The acceleration sensor fixture includes a first portion disposed on the measurement target side of the acceleration sensor and extending in a direction along the connection surface, and a second portion bent from the first portion and extending away from the first portion. The vibration measurement device according to claim 7, wherein the acceleration sensor is surrounded by the acceleration sensor fixture by the first portion and the second portion.

10. A gap filler is disposed in a gap between the second portion and the acceleration sensor. The vibration measurement device according to claim 9, wherein the gap filler has a higher dielectric breakdown voltage than air.

11. An insulating member included in the acceleration sensor fixture electrically insulates between the measurement target and the acceleration sensor. The vibration measurement device according to claim 1, wherein the shield wire is electrically connected to the acceleration sensor side of the insulating member.

12. The shield wire is electrically connected to a conductive connector. The vibration measurement device according to claim 11, wherein the shield wire is electrically connected to the acceleration sensor side of the insulating member by the conductive connector.

13. The vibration measurement device according to claim 11 or 12, wherein the acceleration sensor fixture includes a metal portion and a non-metal portion as the insulating member.

14. The vibration measurement device according to claim 13, wherein the insulating member is an insulating coating coated on a surface of the metal portion.

15. The vibration measurement device according to claim 13 or 14, wherein the insulating member is formed of either resin or ceramics.

16. The vibration measurement device according to any one of claims 13 to 15, wherein the insulating member is in contact with the measurement target.

17. The vibration measurement device according to claim 13, wherein the metal portion and the insulating member are joined by an adhesive.

18. A CMS device for wind power generation using the vibration measurement device according to any one of claims 1 to 17.

Images