Vibration measurement device

Abstract

To provide a vibration measuring apparatus that suppresses occurrence of discharge due to a high-voltage surge caused by lightning, suppresses failures of a vibration sensor, and can be easily attached to a measurement target.SOLUTION: In a vibration measurement device, a vibration sensor 10 includes an element capable of measuring vibration of a measurement target 1. A first base 22A is attached to the lower side of the vibration sensor 10. A second base 21 is disposed on the lower side of the first base 22A. A first fixing part 50A fixes the vibration sensor 10 and the first base 22A. At least one of the first base 22A and the second base 21 is insulating in at least a partial region. A second fixing part 50B protrudes from the second base 21, thereby allowing the measurement target 1 to be fixed to the second base 21.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vibration measuring device. [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 Application Publication No. 58-14132 [Patent Document 3] Publication number 5-24025 [Patent Document 4] Japanese Patent Application Laid-Open No. 2009-289551 Summary of the Invention [Problem to be solved by the invention]

[0005] In a vibration measuring device equipped with an acceleration sensor and an acceleration sensor mounting fixture, failure of the acceleration sensor can be prevented by suppressing discharges caused by high-voltage surges due to lightning strikes, etc. However, none of the above-mentioned Japanese Patent Laid-Open No. 7-198740, Japanese Utility Model Laid-Open No. 58-14132, and Japanese Utility Model Laid-Open No. 5-24025 discusses high-voltage surges caused by lightning strikes, etc., and the accompanying discharges. Furthermore, Japanese Patent Laid-Open No. 2009-289551 does not discuss high-voltage surges and discharges caused by lightning strikes in a vibration measuring device equipped with an acceleration sensor and an acceleration sensor mounting fixture.

[0006] It is also conceivable that there may be cases where it is necessary to provide two base members between the acceleration sensor and the object to be measured while suppressing discharges associated with high-voltage surges. For example, there may be cases where it is desirable to provide both a conductive base member and an insulating base member. In such cases, it is desirable to easily fasten the object to be measured and the base members, for example, by a female screw provided on the object to a fastening portion such as a stud with a male screw. However, none of the above patent documents disclose such content.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a vibration measuring device that suppresses the occurrence of discharges associated with high-voltage surges caused by lightning strikes and the like, prevents failure of the vibration sensor, and is easy to attach to the object to be measured. [Means for solving the problem]

[0008] A vibration measuring device according to the present disclosure includes a vibration sensor, a first base, a second base, a first fixing part, and a second fixing part. The vibration sensor includes an element capable of measuring vibrations of an object to be measured. The first base is attached to the vibration sensor on the side where the object to be measured is located. The second base is installed on the first base on the opposite side from the vibration sensor. The first fixing part fixes the vibration sensor to the first base. At least one of the first base and the second base is insulating in at least a partial area. The second fixing part protrudes from the second base, allowing the object to be fixed to the second base. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a vibration measuring device that suppresses the occurrence of discharges associated with high voltage surges caused by lightning strikes and the like, suppresses failure of vibration sensors, and is easy to attach to an object to be measured. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing the overall configuration of a vibration measuring device according to a first embodiment. [Figure 2] 2 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 according to the first embodiment. [Figure 3] 10 is a schematic diagram showing individual aspects of a vibration sensor, a base, and a stud that connects them. FIG. [Figure 4] 10A and 10B are schematic diagrams showing a process of connecting the vibration sensor and the insulating base with a stud. [Figure 5] FIG. 10 is a schematic diagram for explaining a ground loop that occurs in a vibration measuring device in a comparative example. [Figure 6] 1 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. FIG. [Figure 7] 7 is a schematic diagram for explaining discharge caused by a surge voltage generated in the vibration measuring device according to the first example of the comparative example of FIG. 6. FIG. [Figure 8]FIG. 10 is a schematic diagram showing the configuration of a vibration measuring device according to a second example of a comparative example for suppressing ground loops. [Figure 9] 1. FIG. 4 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a first example of the second embodiment. [Figure 10] 1. FIG. 4 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a second example of the second embodiment. [Figure 11] FIG. 10 is a schematic perspective view showing an assembly process of the members that constitute the vibration measuring device according to the third embodiment. [Figure 12] 10 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 according to a third embodiment. FIG. [Figure 13] FIG. 10 is a schematic perspective view showing an assembly process of the members that constitute the vibration measuring device according to the fourth embodiment. [Figure 14] 1. FIG. 4 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a first example of the fourth embodiment. [Figure 15] 10 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a second example of the fourth embodiment. FIG. [Figure 16] FIG. 10 is a schematic perspective view showing an assembly process of the components that constitute the vibration measuring device according to the fifth embodiment. [Figure 17] 10 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a first example of the fifth embodiment. FIG. [Figure 18] 10 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a second example of the fifth embodiment. FIG. [Figure 19] FIG. 10 is a schematic perspective view showing a modified example of the assembly process of the members that make up the vibration measuring device according to the fifth embodiment. [Figure 20] 10 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a first example of the sixth embodiment. FIG. [Figure 21] 10 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a second example of the sixth embodiment. FIG. [Figure 22]10 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 according to a seventh embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present embodiment will be described below with reference to the drawings. Note that hereinafter, the acceleration sensor will be referred to as a vibration sensor.

[0012] (Embodiment 1) (Configuration of vibration measurement device) First, a vibration measuring device according to this embodiment will be described with reference to Figures 1 to 4. Figure 1 is a schematic diagram showing the overall configuration of a vibration measuring device according to embodiment 1. Note that Figure 1 and the subsequent schematic diagrams show a cross-sectional shape of the device cut along the vertical direction. Referring to Figure 1, a vibration measuring device 100 according to this embodiment mainly comprises a vibration sensor 10, a base 20, a vibration sensor cable 40, and a stud 50.

[0013] The vibration sensor 10 includes an element 11 capable of measuring vibrations of a measurement object 1 inside a vibration sensor housing 10B, which is the housing of the vibration sensor 10. Specifically, a cavity 12 may be formed inside the vibration sensor housing 10B, which may be made of a conductive material, and the element 11 may be disposed inside the cavity 12. The cavity 12 is not limited to being an air gap, and may be filled with an insulating resin material or the like. An example of the measurement object 1 is a wind turbine. Here, the measurement object 1 is assumed to be conductive.

[0014] FIG. 2 is an enlarged schematic diagram showing the configuration of an area A surrounded by a dotted line in FIG. 1 in the first embodiment. With reference to FIGS. 1 and 2, the base 20 is disposed on the side of the vibration sensor 10 where the measurement target 1 is disposed. In other words, the base 20 is disposed immediately below the vibration sensor 10. The base 20 is disposed between the vibration sensor 10 and the measurement target 1. The base 20 is insulating in at least a portion of its area in the vertical direction of the vibration sensor 10. In other words, when considering the vertical coordinate, the base 20 has a portion that is insulating in the entire horizontal and depth directions at least at some coordinate positions (areas). The insulating base 22A is a member of the base 20 that is insulating in the entire horizontal and depth directions in FIG. 2 at at least some vertical coordinate positions. The insulating portion of the insulating base 22A is formed of an insulating material.

[0015] The insulating material constituting the insulating base 22A is a material that can insulate from the adhesive surface with the adhesive 61 described below. The insulating base 22A only needs to have a portion that is insulating in the entire lateral and depth directions at least in a portion of the coordinate position (area) in the vertical direction. The insulating base 22A is insulating as a whole in a plan view from above, for example, at least at the surface position that comes into contact with the adhesive 61. The insulating base 22A may also have insulating side surfaces.

[0016] In this embodiment, the base 20 includes a first base and a second base. The first base is attached directly to the lower side of the vibration sensor 10. In other words, the insulating base 22A in FIGS. 1 and 2 corresponds to the first base. In this embodiment, the base 20 includes a conductive base 21 in addition to the insulating base 22A. The conductive base 21 is arranged closer to the position where the measurement object 1 is placed than the insulating base 22A (lower side: farther from the vibration sensor 10), and serves as a second base that can be attached to the measurement object 1. In this embodiment, it is sufficient that only a portion of the vertical region of the base 20 is insulating. Therefore, as shown in FIGS. 1 and 2, only one of the first base and the second base may be insulating.

[0017] Alternatively, both the first base and the second base may be insulating. Furthermore, the second base (conductive base 21) may be attached to the vibration sensor 10, and the first base (insulating base 22A) may be attached to the object to be measured 1, inversely to that shown in Figure 2. In other words, the conductive base 21 may be disposed above the insulating base 22A.

[0018] The housing of conductive base 21 is made of, for example, a metal material. Specifically, the metal material constituting conductive base 21 is stainless steel or iron. However, the housing of conductive base 21 may be made of a conductive material other than a metal material.

[0019] 1 and 2, as an example, the insulating base 22A has an insulating housing whose entire body is insulating. However, the insulating base 22A of this embodiment may have a configuration in which an insulating thin film is formed or applied to the surface of a conductive housing, for example. When considering coordinates in the up-down direction, the insulating thin film is formed over the entire width and depth directions at least in (a region of) a part of the coordinate position.

[0020] The studs 50 include a first stud and a second stud. The first stud 50A secures the vibration sensor 10 to the insulating base 22A. The first stud 50A may be an insulating fixing member. The first stud 50A is a member separate from the insulating base 22A. The first stud 50A is installed so as to straddle the gap between the vibration sensor 10 and the insulating base 22A. The second stud 50B may be insulating. The second stud 50B (second fixing portion) protrudes downward from the conductive base 21.

[0021] FIG. 3 is a schematic diagram showing the vibration sensor, the base, and the studs connecting them. In FIG. 3, the vibration sensor 10 and the stud 50 are shown as viewed from the same direction as in FIG. 1, and the insulating base 22A is shown as viewed from above in a plan view. Referring to FIG. 3, the vibration sensor 10 (vibration sensor housing 10B) is shown in FIG. 1 as being generally rectangular when viewed from the front, but in practice, it may have a shape similar to that of a bolt with a male thread. The vibration sensor 10 has a recess 10h formed at the center of the circular surface at the bottom of FIG. 3, at the bottom in the vertical direction. The insulating base 22A has, for example, a square shape in a plan view and is a rectangular parallelepiped with a certain thickness in the depth direction of the paper in FIG. 3. In other words, the insulating base 22A may be plate-shaped. The insulating base 22A has a recess 22h formed at the center of the insulating base 22A in a plan view, at the top in the vertical direction. Although not shown, female threads are formed on the inner walls of the recesses 10h and 22h. The first stud 50A has a shape similar to a cylinder, and has a male thread formed on its outer surface.

[0022] FIG. 4 is a schematic diagram showing the process of connecting the vibration sensor and insulating base with a stud. Referring to FIG. 4, the vibration sensor 10 and insulating base 22A are arranged so that they overlap in a plan view, with recesses 10h and 22h connected to each other. A first stud 50A is inserted into the recesses 10h and 22h. The male threads formed on the first stud 50A are fastened to the female threads formed on the recesses 10h and 22h. This connects the vibration sensor housing 10B, the stud 50, and the insulating base 22A to each other. To stabilize the frequency response characteristics, the fastening torque is adjusted with a torque wrench to, for example, 2.7 Nm or more and 6.8 Nm or less.

[0023] Referring again to FIG. 2, similarly to the above, the measurement object 1 and the conductive base 21 are coupled by the second stud 50B. A recess 21h (base recess) is formed in the center of the conductive base 21 in a plan view and at the bottom in the vertical direction. A recess 1h is formed in the measurement object 1 at the top in the vertical direction, at a position that should overlap the recess 21h in a plan view. Female threads are formed on the inner walls of the recesses 21h and 1h. The conductive base 21 and the measurement object 1 are arranged so that the recesses 21h and 1h are continuous and overlap in a plan view. The second stud 50B is inserted into the recesses 21h and 1h. The male thread formed on the second stud 50B and the female thread formed on the recesses 21h and 1h are fastened together. As a result, the second stud 50B is fixed to the conductive base 21 at the recess 21h. The second stud 50B protrudes downward from the bottom surface of the conductive base 21 in FIG. 2. The second stud 50B is a second fixing portion. The conductive base 21 and the object to be measured 1 are coupled to each other.

[0024] The vibration sensor cable 40 includes a first cable 41, a second cable 42, a shielded cable 43, and an outer sheath 44 that bundles and surrounds these cables. In the figure, the first cable 41 is shown with a chain line and the second cable 42 with a dotted line for ease of distinction. However, in reality, these cables 41 and 42 extend continuously, just like the shielded cable 43, shown with a solid line. A conductive connector 83 is provided so as to contact the vibration sensor 10. The conductive connector 83 may contact the outer sheath 44. The conductive connector 83 is interposed between the outer sheath 44 and the vibration sensor 10. The first cable 41 and the second cable 42 are connected to the element 11 included in the vibration sensor 10 via the conductive connector 83. These two cables allow the element 11 to be connected to a power source or to apply a voltage to the element 11. One end of the shielded cable 43 may not be directly connected to the vibration sensor housing 10B but may be embedded in the conductive connector 83. As a result, the shielded wire 43 is connected to the vibration sensor housing 10B via the conductive connector 83. One end of the shielded wire 43 is connected to the conductive connector 83, and the other end opposite the one end is connected to the ground point G2. The object to be measured 1 is connected to the ground point G1. As a result, the object to be measured 1 and the vibration sensor housing 10B are at the ground potential of the ground point G1. Note that the ends of the first cable wire 41 and the second cable wire 42 opposite to the end connected to the element 11 may be connected to a data collecting device (not shown). Furthermore, the other end of the shielded wire 43 opposite to the one end may be electrically connected to the ground point G2 via the data collecting device.

[0025] (Comparative Examples and Their Problems) FIG. 5 is a schematic diagram illustrating a ground loop that occurs in a vibration measuring device according to a comparative example. Referring to FIG. 5, the vibration measuring device according to the comparative example includes a vibration sensor 10 and a shielded cable 43. The vibration measuring device may also include a data collecting device 70. In FIG. 5, no insulating member is interposed between the vibration sensor 10 and the object to be measured 1. In FIG. 5, 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. 5. 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.

[0026] Fig. 6 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. 6, 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, an insulating base 22A is not sandwiched between the vibration sensor 10 and the object to be measured 1. In Fig. 6, only a conductive base 21 is sandwiched between the vibration sensor 10 and the object to be measured 1 as a vibration sensor mounting fixture.

[0027] 6, unlike FIG. 1, an insulating connector 59 is attached to the side of the vibration sensor 10 opposite the measurement target 1. The first cable 41 and second cable 42 connected to the element 11 run through the insulating connector 59 and the outer sheath 44. One end of the shielding wire 43 is connected to the insulating connector 59 and is not connected to the conductive housing of the vibration sensor 10. Therefore, in the vibration measuring device 900, the vibration sensor 10 and the shielding wire 43 are not electrically connected. For this reason, in FIG. 6, even if the ground potentials of the grounding points G1 and G2 are different, a ground loop GL like that in FIG. 5 does not occur.

[0028] 7 is a schematic diagram illustrating a discharge caused by a surge voltage in a vibration measuring device according to a first example of the comparative example of FIG. 6. Referring to FIG. 7, when a high voltage called a surge voltage SV caused by a lightning strike or the like is applied to the object to be measured 1 in FIG. 6, a high voltage is also applied to the vibration sensor housing 10B electrically connected to the object to be measured 1. As a result, a high voltage is applied between the element 11 in the vibration sensor 10 and the vibration sensor housing 10B in which the cavity 12 for accommodating the element 11 is formed, causing a discharge DCG. This discharge DCG may burn or damage the element 11, resulting in a malfunction of the vibration sensor 10.

[0029] FIG. 8 is a schematic diagram showing the configuration of a second comparative vibration measuring device for suppressing ground loops. Referring to FIG. 8, the second comparative vibration measuring device 900 differs from the vibration measuring device 100 of FIG. 1 in the following respects. The vibration measuring device 900 includes an insulating base 22, instead of a conductive base 21, as a vibration sensor mounting fixture on the measurement target 1 side of the vibration sensor 10. The insulating base 22 has a housing made of an insulating material, for example. Therefore, the vibration sensor 10 and the measurement target 1 are typically electrically insulated. If a surge voltage is applied to the measurement target 1 shown in FIG. 8, the insulating base 22 may be able to prevent the high voltage from discharging the DCG and resulting damage to the vibration sensor 10. However, from the perspective of making it easier to detect vibration signals, a conductive base is preferable over an insulating base. Furthermore, consideration must be given to how the insulating base 22 and the measurement target 1 should be attached. For these reasons, there are cases where it is desirable to provide both a conductive base member and an insulating base member. For example, this is the case when it is desired to obtain both the effect of preventing ground loops by using an insulating base member (insulating base 22) and the effect of improving the accuracy of vibration measurement by using a conductive base member (conductive base 21).

[0030] (Action and effect) In view of the above problems, a vibration measuring device 100 according to this embodiment includes a vibration sensor 10, an insulating base 22A (first base), a conductive base 21 (second base), a first stud 50A (first fixing portion), and a second stud 50B (second fixing portion). The vibration sensor 10 includes an element 11 capable of measuring vibrations of an object to be measured 1. The insulating base 22A is attached to the vibration sensor 10 on the side where the object to be measured 1 is located (the lower side in FIG. 2). The conductive base 21 is installed on the insulating base 22A on the opposite side from the vibration sensor 10 (the lower side in FIG. 2). The first stud 50A secures the vibration sensor 10 to the insulating base 22A. At least a partial region of at least one of the insulating base 22A and the conductive base 21 (the insulating base 22A) is insulating. The second stud 50B protrudes from the conductive base 21, allowing the object to be measured 1 to be fixed to the conductive base 21.

[0031] The insulating base 22A, which serves as an insulating member, ensures insulation between the vibration sensor 10 and the object to be measured 1, even if the conductive base 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. Therefore, the presence of the insulating base 22A improves the dielectric strength of the vibration measuring device 100 compared to a device that does not have the insulating base 22A, making the vibration sensor 10 less susceptible to failure. In other words, even if a surge voltage is applied to the vibration measuring device 100 or a lightning strike occurs, the vibration sensor 10 is less likely to fail. Furthermore, the presence of the insulating base 22A can suppress the occurrence of ground loops, at least compared to a device that does not have the insulating base 22. This suppresses the introduction of noise from the vibration measuring device due to ground loops.

[0032] On the other hand, if the conductive base 21 is conductive, it is possible to suppress a decrease in the accuracy of vibration measurement by the vibration measuring device 100. For this reason, the vibration measuring device 100 has both a first base (insulating base 22A) attached to the vibration sensor 10 and a second base (conductive base 21) attached to the measurement target 1. The insulating base 22A may be insulating in its entirety, or only a portion thereof may be insulating. The conductive base 21 may be conductive in its entirety, or only a portion thereof may be conductive. The vibration measuring device 100 can obtain both the effect of suppressing failures and ground loops in the vibration sensor 10 by the insulating base 22A, and the effect of suppressing a decrease in the accuracy of vibration measurement by the conductive base 21.

[0033] The second stud 50B (second fixing portion) protrudes from the conductive base 21, so that the measurement target 1 can be fixed to the conductive base 21. The second stud 50B allows the vibration measuring device 100 to be easily installed on a female screw or the like provided on the measurement target 1, even when the measurement target 1 has a two-layer base consisting of the insulating base 22A and the conductive base 21. The measurement target 1 is often provided with a female screw (corresponding to the recess 1h described above) for mounting the measuring device. Therefore, the improvement in the mountability of the vibration measuring device 100 by the second stud 50B is useful.

[0034] In the vibration measuring device 100, a first stud 50A is installed so as to straddle the gap between the vibration sensor 10 and the insulating base 22A. The first stud 50A is a separate member from the insulating base 22A. This configuration may also be used. The first stud 50A stably fixes the vibration sensor 10 to the insulating base 22A.

[0035] In the vibration measuring device 100, a recess 21h may be formed in the conductive base 21. The second fixing portion may be a second stud 50B fixed to the conductive base 21 at the recess 21h. The second stud 50B has a male thread. Therefore, the vibration measuring device 100 can be easily attached to a female thread included in the measurement object 1 using the second stud 50B.

[0036] It is more preferable that the vibration measuring device 100 further includes a conductive connector 83 interposed between the vibration sensor 10 and an outer cover 44 surrounding the shielded wire 43 connected to the ground potential G2 so as to come into contact with the vibration sensor 10. The shielded wire 43 is connected to the conductive connector 83.

[0037] In this way, under normal circumstances (when no surge voltage SV is applied to the object to be measured 1), the insulating base 22A prevents the ground loop shown in Figure 5 from occurring. However, when a surge voltage SV is applied to the object to be measured 1, such as during a lightning strike, creeping discharge occurs along the insulating base 22A (the insulating material portion on its surface). This establishes electrical continuity between the object to be measured 1 and the shielded wire 43 via the conductive connector 83, which contacts the vibration sensor 10. Almost no current flows through the second path, which includes the element 11 and is parallel to the first path through the shielded wire 43. This is because the second path has higher electrical resistance than the first path. As a result, current due to the surge voltage preferentially passes through the first path over the second path. Therefore, high-voltage discharge does not occur in the vibration sensor 10 (the element 11 on the second path), and current can flow from the vibration sensor housing 10B to the ground point G2 via the conductive connector 83. This protects the vibration sensor 10 from lightning strikes.

[0038] Consider a case where an insulating connector 59 such as that shown in FIGS. 6 to 8 is used instead of the conductive connector 83 in FIG. 1. In this case, when a surge voltage is applied, it is not possible for current to flow from the vibration sensor housing 10B to the ground point G2 through the insulating connector 59. On the other hand, if the conductive connector 83 is used, it is possible for current to flow from the vibration sensor housing 10B to the ground point G2 through the conductive connector 83 when a surge voltage is applied. This protects the element 11 included in the vibration sensor 10 from lightning strikes, further enhancing the effect of suppressing breakdowns in the vibration sensor 10.

[0039] (Embodiment 2) In the following embodiments, components having the same configuration as those of the vibration measuring device 100 shown in FIGS. 1 and 2 of the first embodiment are denoted by the same reference numerals, and descriptions thereof will not be repeated unless there are particular differences from FIGS. 1 and 2. FIG. 9 is an enlarged schematic diagram showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a first example of the second embodiment. Referring to FIG. 9, the vibration measuring device 100 according to the first example of the present embodiment basically has the same configuration as the vibration measuring device 100 of the first embodiment (FIG. 2). However, in the first example of the present embodiment, a conductive base 21 is provided as the first base, and an insulating base 22B is provided as the second base. In other words, the vertical relationship between the conductive base 21 and the insulating base 22B is reversed from that shown in FIG. 2 of the first embodiment. The vibration measuring device 100 may have a configuration in which the first base is conductive and the second base is insulating. The insulating base 22B is made of the same material as the insulating base 22A. Like the insulating base 22A, at least a portion of the insulating base 22B in the vertical direction is insulating.

[0040] In a first example of this embodiment, the insulating base 22B includes, as a second fixing portion, an insulating member that can be filled into a recess 1h (measurement object recess) formed in the object to be measured 1. In other words, the insulating base 22B does not have a recess 22h. Furthermore, the insulating base 22B does not have a second stud 50B (as a second fixing portion) that protrudes from the recess 22h. Instead of having the second stud 50B, in the first example of this embodiment, the insulating base 22B has a filling portion 22P as a second fixing portion. A recess 1h is formed in the object to be measured 1. The filling portion 22P is an insulating member (part of the insulating base 22B) that can fill the recess 1h of the object to be measured 1 to which the insulating base 22B is attached. The filling portion 22P is integral with the main body portion of the insulating base 22B (the portion other than the filling portion 22P).

[0041] Filling portion 22P protrudes from insulating base 22B and is housed in recess 1h. This allows measurement object 1 to be fixed to insulating base 22B. In this embodiment, filling portion 22P protruding from insulating base 22B is part of insulating base 22B. In other words, the "second fixing portion" in the "second fixing portion protruding from the second base" in this specification may be integral with the second base (part of the second base), as in embodiment 2. Alternatively, the "second fixing portion" may be a separate member (a stud) from the second base, as in embodiment 1.

[0042] In this embodiment, the insulating base 22B is formed by pouring a resin material into, for example, the recess 1h of the object to be measured 1. As a result, a flat member made of the resin material is formed on the surface of the area adjacent to the recess 1h. This flat member is used as the insulating base 22B attached to the object to be measured 1. In this case, the recess 1h does not need to be provided with a female thread. The flat member (insulating base 22B) and the conductive base 21 attached to the vibration sensor 10 are bonded together with an adhesive 61.

[0043] FIG. 10 is an enlarged schematic diagram showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a second example of the second embodiment. Referring to FIG. 10, the vibration measuring device 100 according to the second example of the present embodiment has a configuration basically similar to that of the vibration measuring device 100 according to the first embodiment (FIG. 2). However, in the second example of the present embodiment, the insulating base 22B includes, as a first fixing portion, an insulating member that can be filled into the recess 10h formed in the vibration sensor 10. In other words, the insulating base 22B does not have the recess 22h. Furthermore, the insulating base 22B does not have the first stud 50A (as the first fixing portion) that protrudes from the recess 22h. Instead of having the first stud 50A, in the second example of the present embodiment, the insulating base 22B has a filling portion 22P as the first fixing portion. The vibration sensor 10 has a recess 10h. The filling portion 22P is an insulating member (part of the insulating base 22B) that can be filled into the recess 1h where the insulating base 22B is attached. The filling portion 22P is integral with the main body portion of the insulating base 22B (the portion other than the filling portion 22P).

[0044] 10, an insulating base 22B having a filling portion 22P is fixed to the vibration sensor 10 in place of the measurement object 1 in FIG.

[0045] The filling portion 22P protruding from the insulating base 22B allows the vibration sensor 10 to be fixed to the insulating base 22B. In this embodiment, the filling portion 22P protruding from the insulating base 22B is part of the insulating base 22B. In other words, in this specification, the "first fixing portion" in the phrase "the first fixing portion protruding from the first base" may be integral with the first base (part of the first base). Alternatively, as in the first embodiment, the "first fixing portion" may be a separate member (a stud) from the first base.

[0046] The insulating base 22B in FIG. 10 is formed by the same process as that for the insulating base 22B in FIG.

[0047] Furthermore, although not shown, an insulating fixing portion such as the first fixing portion may be fixed integrally with the vibration sensor 10. In this case, the insulating fixing portion is housed in a recess provided in a first base (for example, conductive base 21) attached directly below the vibration sensor 10. In this way, the vibration sensor 10 and the first base may be fixed together.

[0048] (Action and effect) The configuration of this embodiment can also achieve the same effects as those of the first embodiment.

[0049] (Embodiment 3) Fig. 11 is a schematic perspective view showing an assembly process of the components constituting the vibration measuring device according to embodiment 3. Referring to Fig. 11, in vibration measuring device 100 according to this embodiment, insulating base 22A and conductive base 21 have, for example, a regular hexagonal planar shape.

[0050] The insulating base 22A and the conductive base 21 are in contact with each other so that a pair of opposing faces of the regular hexagon are clamped by a wrench. In this manner, a rotation torque is applied to the insulating base 22A and the conductive base 21 by the wrench. This causes the insulating base 22A and the conductive base 21 to rotate, allowing them to be fixed to the vibration sensor 10 and the measurement target 1 by the studs 50.

[0051] In Fig. 11, insulating base 22A is attached to vibration sensor 10. Also in Fig. 11, conductive base 21 is being attached to object to be measured 1 via second stud 50B. Therefore, in Fig. 11, which shows these states, first stud 50A is hidden within vibration sensor 10 and insulating base 22A and cannot be seen, but second stud 50B is exposed on the object to be measured 1 side of conductive base 21.

[0052] FIG. 12 is an enlarged schematic diagram showing the configuration of region A surrounded by a dotted line in FIG. 1 in the third embodiment. Referring to FIGS. 12 and 11, in this embodiment, the size of conductive base 21 in a plan view is larger than the size of insulating base 22A in a plan view. Therefore, the size and plan area of ​​each side of the regular hexagon of conductive base 21 in a plan view are larger than the size and plan area of ​​each side of the regular hexagon of insulating base 22A in a plan view. Therefore, in the cross-sectional shape of FIG. 12, the conductive base 21 has a larger left-right dimension (the distance between a pair of opposing faces of the regular hexagon) than the insulating base 22A. The left-right dimension of insulating base 22A and conductive base 21 in FIG. 12 is equal to the width across flats of a tool, such as a wrench, used to rotate base 20. The width across flats is the dimension between two parallel faces of a tool, such as a wrench, that are used to clamp an object to be rotated. A first dimension in the left-right direction of the conductive base 21 in Fig. 12 is preferably larger than a second dimension in the left-right direction of the insulating base 22A in Fig. 12. For example, the first dimension is 1.05 to 3 times the second dimension.

[0053] (Action and effect) In the vibration measuring device 100 of this embodiment, the size of the conductive base 21 (second base) in a plan view is larger than the size of the insulating base 22A (first base) in a plan view. If both the conductive base 21 and the insulating base 22A are hexagonal, the distance between a pair of opposing faces of the hexagon is a dimension that allows a tool such as a wrench used to apply rotation to be clamped therebetween. With this dimensional relationship, the step of bonding the insulating base 22A and the conductive base 21 with adhesive 61 can be omitted when attaching the conductive base 21 and the like to the measurement target 1 on site.

[0054] Consider a case where the size of the conductive base 21 in a plan view is smaller than the size of the insulating base 22A in a plan view. In this case, it is difficult to bond the insulating base 22A and the conductive base 21 with adhesive 61 before attaching them to the measurement target 1 on-site, as described above. During the screw tightening work on-site, the hexagonal shape of the second base on the measurement target 1 side is fitted to a wrench. If the first base adjacent to the second base is larger than the second base, the first base will come into contact with the wrench. This causes interference with the first base. This makes it difficult to fit the wrench to the second base and rotate it. Because this work is difficult, the bases are tightened one by one on-site without being bonded together. In this case, there is a concern that an operator may make an error, such as accidentally gluing a first base to a second base when it should not be glued.

[0055] Therefore, the present embodiment is as described above. This allows the insulating base 22A and the conductive base 21 to be bonded in advance before heading to the site where the vibration measuring device 100 will be attached to the measurement target 1. Therefore, at the site, it is sufficient to simply screw the measurement target 1 and the conductive base 21 together via the second studs 50B. This shortens the work time and reduces the chance of work errors.

[0056] (Fourth embodiment) FIG. 13 is a schematic perspective view showing the assembly process of the components constituting the vibration measuring device according to the fourth embodiment. FIG. 14 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a first example of the fourth embodiment. Referring to FIGS. 13 and 14, the vibration measuring device 100 according to the first example of this embodiment has an insulating base 22C as a first base and a conductive base 21D as a second base. The insulating base 22C is made of the same material as the insulating base 22A. Like the insulating base 22A, at least a portion of the insulating base 22C in the vertical direction is insulating. The conductive base 21D is made of the same material as the conductive base 21. The insulating base 22C is partially removed upward from its bottom surface on the conductive base 21D side. This partially removed portion is a recessed portion 22CV having an inner wall surface and a bottom surface. The horizontal dimension of the recessed portion 22CV is slightly smaller than the horizontal dimension of the entire insulating base 22C. The vertical dimension of the recessed portion 22CV is slightly smaller than the vertical dimension of the entire insulating base 22C.

[0057] The conductive base 21D has a step on its outer surface. Specifically, the conductive base 21D in FIG. 14 has a larger left-right dimension in the lower region than in the upper region. Therefore, the upper region of the conductive base 21D in FIG. 14, which has a smaller left-right dimension, can be inserted into the recessed portion 22CV. The upper region of the conductive base 21D in FIG. 14, which has a smaller left-right dimension, is the convex portion 21DP. The convex portion 21DP is inserted into the recessed portion 22CV. This allows the convex portion 21DP to fit into the recessed portion 22CV.

[0058] The bottom surface of the recessed portion 22CV (the uppermost surface in FIG. 14) and the uppermost surface of the protruding portion 21DP are fixing surfaces 23. At fixing surface 23, the recessed portion 22CV can come into contact with the inserted protruding portion 21DP. As a result, the inserted protruding portion 21DP is fixed to the recessed portion 22CV. From this viewpoint, it is preferable that the dimension L2 of the protruding portion 21DP be larger than the dimension L1 of the recessed portion 22CV in the extension direction of the vibration measuring device 100 (the vertical direction in FIG. 14). Specifically, it is preferable that dimension L2 be larger than dimension L1 by 3% to 5%. In this way, the insulating base 22C and the conductive base 21D come into contact with each other and are bonded to each other at fixing surface 23.

[0059] Adhesive 61 may be applied to fixing surfaces 23 that contact each other and fix the two bases together. This fixes concave portion 22CV and convex portion 21DP at fixing surfaces 23. Additionally, it is preferable that concave portion 22CV be slightly larger than convex portion 21DP in the left-right direction (radial direction) of FIG. 14 . Specifically, it is preferable that concave portion 22CV be 3% to 5% larger than convex portion 21DP in the left-right direction of FIG. 14 . In this way, when convex portion 21DP is fitted into concave portion 22CV as shown in FIG. 14 , a small gap is formed between the outer surface of convex portion 21DP and the inner wall surface of concave portion 22CV. Adhesive 61 is filled in this gap. This bonds insulating base 22C and conductive base 21D to each other.

[0060] Fig. 15 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in Fig. 1 in a second example of embodiment 4. Referring to Fig. 15, the vibration measuring device according to the second example of the present embodiment has a conductive base 21D as a first base and an insulating base 22C as a second base.

[0061] Insulating base 22C is partially removed downward from its top surface on the conductive base 21D side. This partially removed portion is recessed portion 22CV having an inner wall surface and a bottom surface. Conductive base 21D is columnar and does not have a stepped outer surface like the first example in FIG. 14. However, conductive base 21D may also have a stepped outer surface in the second example in FIG. 15.

[0062] At least a portion (for example, a lower portion) of conductive base 21D having a columnar shape can be inserted into recessed portion 22CV. When conductive base 21D does not have a step on the outer surface as shown in FIG. 15, the entire conductive base 21D can be considered as convex portion 21DP. In this way, convex portion 21DP can be fitted into recessed portion 22CV in FIG. 15 as in FIG. 14. At fixing surface 23, recessed portion 22CV can come into contact with inserted convex portion 21DP. As a result, inserted convex portion 21DP is fixed to recessed portion 22CV.

[0063] 15, as indicated by the parenthesized reference characters in the figure, an insulating base 22D may be provided as a first base, and a conductive base 21C may be provided as a second base. In this case, a recessed portion 21CV is formed in the conductive base 21C. Also in this case, the portion of the insulating base 22D that is inserted into the recessed portion 21CV is a protruding portion 22DP. The configuration of the recessed portion 21CV and the protruding portion 22DP is the same as the configuration of the recessed portion 22CV and the protruding portion 21DP described above.

[0064] In this embodiment, as shown in Fig. 14, the first base may be insulating base 22C and the second base may be conductive base 21D. Alternatively, as shown in Fig. 15, the first base may be conductive base 21D and the second base may be insulating base 22C. Furthermore, in this embodiment, as shown in Fig. 14, the first base may have concave portion 22CV and the second base may have convex portion 21DP. Alternatively, as shown in Fig. 15, the first base may have convex portion 21DP and the second base may have concave portion 22CV.

[0065] In both Figs. 14 and 15, the second base is larger in size than the first base in a plan view, as described in the third embodiment.

[0066] (Issues and Effects) In the first to third embodiments, the insulating base 22A and the conductive base 21 are bonded to each other on a flat surface with adhesive 61. In this case, the task of fixing the insulating base 22A and the conductive base 21 to each other with adhesive 61 can be difficult. For example, if the worker's hands shake, it can be difficult to position the surfaces where the insulating base 22A and the conductive base 21 are bonded in the desired position. If there is a misalignment between the insulating base 22A and the conductive base 21, the process of bonding them together cannot be carried out smoothly.

[0067] Therefore, in this embodiment, as in the first example, one (first base) of the insulating base 22C (first base) and the conductive base 21D (second base) has a concave portion 22CV. The other (second base) has a convex portion 21DP that can fit into the concave portion 22CV. In this way, the conductive base 21D and the insulating base 22C can be bonded together with a portion of the conductive base 21D fitted into the concave portion of the insulating base 22C. Therefore, even if the worker's hands are shaky, the bonding process can be carried out without any problems as long as the bases are fitted together. The process of fitting the convex portion 21DP into the concave portion 22CV can be carried out relatively easily even by manual labor. Therefore, according to this embodiment, the process of fixing the insulating base 22C and the conductive base 21D can be completed in a shorter time than in examples such as the first embodiment.

[0068] Furthermore, in this embodiment, in addition to the fixing surfaces 23, which are the vertical end surfaces, the inner wall surfaces of the concave portion 22CV and the outer surface of the convex portion 21DP are also bonded with adhesive 61. This increases the adhesive strength compared to bonding only at the vertical end surfaces. Therefore, in this embodiment, even if an impact is applied to the vibration sensor 10 during use of the vibration measuring device 100, peeling of the adhesive surfaces between the insulating base 22C and the conductive base 21D can be prevented. The second example also provides the same effects as the first example.

[0069] (Embodiment 5) FIG. 16 is a schematic perspective view showing the assembly process of the components constituting the vibration measuring device according to the fifth embodiment. FIG. 17 is an enlarged schematic view showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a first example of the fifth embodiment. With reference to FIGS. 16 and 17, the vibration measuring device 100 according to this embodiment has a first through hole 24 formed in the insulating base 22C and a second through hole 25 formed in the conductive base 21D. One pin 26 can pass through each of these through holes. In having this additional feature, the vibration measuring device 100 of this embodiment differs in configuration from the vibration measuring device 100 of the fourth embodiment (FIGS. 13 and 14).

[0070] 17, when the convex portion 21DP and the concave portion 22CV are fitted together, the first through hole 24 and the second through hole 25 overlap each other when viewed from the outside in the radial direction of the vibration sensor 10. The first through hole 24 and the second through hole 25 are formed at positions where this overlap occurs.

[0071] Two first through holes 24 are formed in total, one at a first position on the inner wall surface (outer surface) of concave portion 22CV and one at a second position opposite the first position. In other words, for example, if concave portion 22CV has a circular planar shape, the first position and the second position are 180 degrees out of phase with each other. One second through hole 25 is formed so as to penetrate from a third position on the outer surface of solid convex portion 21DP to a fourth position opposite the third position. In other words, for example, if convex portion 21DP has a circular planar shape, the third position and the fourth position are 180 degrees out of phase with each other. With the above positional relationship in place, convex portion 21DP is inserted into concave portion 22CV as shown in FIG. 16. Then, the first position and the third position come close to each other and overlap, and the second position and the fourth position come close to each other and overlap. As a result, the pin 26 is inserted so as to penetrate all of the two first through-holes 24 and one second through-hole 25 from the first position to the second position via the third position and the fourth position.

[0072] For example, the size (diameter) of a circular cross section of one second through hole 25 may be larger than that of two first through holes 24. Conversely, as shown in FIG. 18, the size (diameter) of a circular cross section of one second through hole 25 may be smaller than that of two first through holes 24. Furthermore, the cross sections of the first through holes 24 and the second through holes 25 may be equal in size. FIG. 18 is an enlarged schematic diagram showing the configuration of an area A surrounded by a dotted line in FIG. 1 in a second example of embodiment 5. Referring to FIG. 18, the configuration shown in this figure is the same as that of FIG. 17 except for the size relationship of the through holes, and therefore description thereof will not be repeated.

[0073] Furthermore, the first stud 50A that secures the vibration sensor 10 to the first base may be initially fixed to a recess in the first base and then fitted into the recess in the vibration sensor 10, as shown in FIG. 16. However, conversely, as shown in FIG. 19, the first stud 50A may be initially fixed to a recess in the vibration sensor 10 and then fitted into the recess in the first base. FIG. 19 is a schematic perspective view showing a modified example of the assembly process of the components that make up the vibration measuring device according to embodiment 5. Referring to FIG. 19, the configuration shown in this figure is such that the first stud 50A before assembly is attached to the vibration sensor 10 instead of the first base. Except for this point, FIG. 19 is the same as FIG. 16, and therefore its description will not be repeated. The possibility of the embodiment shown in FIG. 19 also applies to the other embodiments.

[0074] Pin 26 may be made of a conductive material. In this case, an insulating sleeve 27 is preferably provided on the inner wall of second through hole 25. Insulating sleeve 27 is made of an insulating material, such as polyolefin, silicone rubber, or polyvinyl chloride. Insulating sleeve 27 is disposed so as to fill the area between the inner wall surface of second through hole 25 and pin 26 passing through second through hole 25 in the radial direction. In other words, insulating sleeve 27 is cylindrical. This makes it possible to prevent an electrical short circuit due to contact between pin 26 and conductive base 21D.

[0075] The pins 26 may be made of an insulating material. Alternatively, the pins 26 may be made of a conductive material with an insulating coating formed on their surfaces. In this embodiment, the insulating base and the conductive base may be reversed upside down as in the fourth embodiment. Even when the bases are reversed upside down, the size relationship of the through holes formed in each base does not matter, as in the case described above.

[0076] Furthermore, first through hole 24 and second through hole 25 of this embodiment may be formed in the first base and second base that do not have concave and convex portions as in embodiment 1. For example, in Fig. 2, through holes may be formed to penetrate insulating base 22A, adhesive 61, and conductive base 21 in the vertical direction of the figure, and one pin 26 may be inserted across these through holes.

[0077] (Action and effect) In the vibration measuring device 100 of this embodiment, a first through-hole 24 is formed in the insulating base 22C (first base), and a second through-hole is formed in the conductive base 21D (second base). One pin 26 can pass through both the first through-hole 24 and the second through-hole 25.

[0078] If a person or object hits the insulating base 22C and conductive base 21D of the vibration measuring device 100 and applies external force, the adhesive 61 may peel off, potentially causing the two to become unattached. Furthermore, if the insulating base 22C and conductive base 21D are simply secured together with the adhesive 61, it is known that the adhesive 61 will peel off over time. Therefore, a single pin 26 is configured to penetrate between the first through-hole 24 of the insulating base 22C and the second through-hole 25 of the conductive base 21D. By allowing the single pin 26 to penetrate between the through-holes 24 and 25, the insulating base 22C and the conductive base 21D can be secured in a mated state, as shown in FIG. 17 , even if the adhesive 61 peels off. This increases the securing force compared to when only the adhesive 61 is used. Furthermore, the vibration measuring device 100 can be used for a longer period of time compared to when only the adhesive 61 is used. This means that vibration data of the measurement target can be obtained over a longer period of time.

[0079] (Sixth embodiment) Fig. 20 is an enlarged schematic diagram showing the configuration of region A surrounded by a dotted line in Fig. 1 in a first example of embodiment 6. Referring to Fig. 20, vibration measuring device 100 according to this embodiment has through-hole 28A formed as a hole in insulating base 22C, and protrusion 29 formed on conductive base 21D. Protrusion 29 is arranged at a position where it can be inserted so as to pass through through-hole 28A when convex portion 21DP is fitted into concave portion 22CV. In having these characteristics, vibration measuring device 100 of this embodiment differs in configuration from vibration measuring device 100 of embodiment 5 (Fig. 17).

[0080] In a first example of this embodiment, through-hole 28A is formed so as to extend radially from the inner wall surface to the outer wall surface of the cylindrical portion forming recessed portion 22CV of insulating base 22C and penetrate the same. A total of two through-holes 28A may be formed at the positions shown in Fig. 20. In the figure, for example, when recessed portion 22CV has a circular planar shape, through-holes 28A are formed in two locations that are 180 degrees out of phase with each other. However, the number of through-holes 28A formed is arbitrary.

[0081] Protrusion 29 is attached to a position on conductive base 21D that can be inserted into through-hole 28A when the two bases are fitted together as shown in Fig. 20. In Fig. 20, protrusions 29 are attached to two locations on the outer surface of convex portion 21DP that are 180 degrees out of phase with each other.

[0082] Preferably, protrusion 29 is configured so that the length of its extension from the surface of conductive base 21D can be freely adjusted. For example, a spring (not shown) is preferably attached to the base of protrusion 29. This allows protrusion 29 to freely expand and contract relative to the surface of conductive base 21D. In this way, for example, when convex portion 21DP is inserted into concave portion 22CV and the tip of protrusion 29 contacts the inner wall surface of concave portion 22CV, protrusion 29 can be contracted to smoothly insert convex portion 21DP into concave portion 22CV. When protrusion 29 is inserted into through-hole 28A, the tip of protrusion 29 is released from the interference force of the inner wall surface, and protrusion 29 extends again. At this time, protrusion 29 can pass through through-hole 28A.

[0083] It is preferable that protrusion 29 is longer in the radial direction than through hole 28A. This allows protrusion 29 to pass through the entire through hole 28A. Note that protrusion 29 is made of an insulating material. This allows electrical insulation between protrusion 29 and conductive base 21D to which it is attached.

[0084] Alternatively, protrusion 29 may be formed from a conductive material. In such a case, although not shown, it is preferable to sandwich an insulating material between protrusion 29 in Fig. 20 and the outer surface of convex portion 21DP to which it is attached.

[0085] Fig. 21 is an enlarged schematic view showing the configuration of region A surrounded by a dotted line in Fig. 1 in a second example of embodiment 6. Referring to Fig. 21, the vibration measuring device according to the second example of this embodiment is basically the same as the first example in Fig. 20. However, in Fig. 21, protrusion 29 is formed on insulating base 22C, and hole 28B is formed in conductive base 21D.

[0086] In a second example of the present embodiment, hole 28B is formed so as to extend a certain length radially inward from the outer surface of convex portion 21DP of conductive base 21D. A total of two hole 28B may be formed at the positions shown in Fig. 21. This position is in the same phase as through hole 28A in Fig. 20.

[0087] Protrusion 29 is attached to conductive base 21D at a position that allows it to be inserted into hole 28B when the two bases are fitted together, as shown in FIG. 21 . In FIG. 21 , protrusions 29 are attached to two locations on the inner wall surface of recessed portion 22CV that are 180 degrees out of phase with each other. Similar to FIG. 20 , protrusion 29 in FIG. 21 is preferably configured such that the length of its extension from the inner wall surface of recessed portion 22CV can be freely adjusted, for example, by a spring. For example, when protrusion 21DP is inserted into recessed portion 22CV and the tip of protrusion 29 contacts the outer surface of protrusion 21DP, protrusion 29 can be contracted to allow protrusion 21DP to be smoothly inserted into recessed portion 22CV. When protrusion 29 is inserted into hole 28B, the tip of protrusion 29 is released from the interference force of the outer surface, and protrusion 29 extends again.

[0088] Although protrusion 29 may be shorter than hole 28B in the radial direction, it is preferable that the length of protrusion 29 be, for example, 80% or more of the length of hole 28B. In this way, inserted protrusion 29 is fully accommodated within hole 28B.

[0089] In this embodiment, as shown in Fig. 20, through-hole 28A may be formed in insulating base 22C and protrusion 29 may be formed in conductive base 21D. Alternatively, as shown in Fig. 21, protrusion 29 may be formed in insulating base 22C and hole 28B may be formed in conductive base 21D. Although not shown, in this embodiment, the insulating base and the conductive base may be upside down as in embodiment 4. Even when the insulating base and the conductive base are upside down, the hole and the protrusion may be formed in either of the bases.

[0090] Furthermore, the holes (through hole 28A, hole 28B) and protrusion 29 of this embodiment may be formed in the first base and the second base that do not have the concave and convex portions as in embodiment 1. For example, in Fig. 2, protrusion 29 extending downward from insulating base 22A and through hole 28A passing through conductive base 21 in the up-down direction may be formed, and protrusion 29 may pass through through hole 28A.

[0091] (Action and effect) In this embodiment, as in the first example, a hole (through hole 28A) is formed in one (first base) of insulating base 22C (first base) and conductive base 21D (second base), and protrusion 29 is formed in the other (second base). With convex portion 21DP fitted into concave portion 22CV, protrusion 29 is disposed at a position where it can be inserted into the hole.

[0092] Depending on the configuration of this embodiment, protrusion 29 may function similarly to pin 26 in embodiment 5. Furthermore, the holes may function similarly to first through-hole 24 and second through-hole 25 in embodiment 5. This allows this embodiment to achieve the same effects as embodiment 5. Specifically, if protrusion 29 penetrates through-hole 28A, even if adhesive 61 peels off, conductive base 21D can remain engaged with insulating base 22C as shown in FIGS. 20 and 21 . In other words, protrusion 29 functions as a pin to prevent conductive base 21D from slipping out of insulating base 22C. This increases the fixing strength compared to when only adhesive 61 is used. Furthermore, vibration measuring device 100 can be used for a longer period of time compared to when only adhesive 61 is used. This means that vibration data of the measurement target can be obtained for a longer period of time. Inserting protrusion 29 into hole 28B in the second example also achieves the same effects as the first example.

[0093] (Embodiment 7) FIG. 22 is an enlarged schematic diagram showing the configuration of an area A surrounded by a dotted line in FIG. 1 in accordance with the seventh embodiment. Referring to FIG. 22, the vibration measuring device 100 according to this embodiment differs from the previous embodiments in the number of components used as a base. Specifically, the vibration measuring device 100 according to this embodiment has only one third base (insulating base 22E) as the base 20. In other words, the vibration measuring device 100 according to this embodiment does not have a conductive base. The insulating base 22E is placed on the side of the vibration sensor 10 where the measurement target 1 is placed. The insulating base 22E is made of the same material as the insulating base 22A. Like the insulating base 22A, the insulating base 22E is insulating in at least a portion of its area in the vertical direction of the vibration sensor 10. In other words, the insulating base 22E has insulating properties in at least a portion of its area in the horizontal and depth directions.

[0094] The third stud 50C, which serves as a third fixing portion, is installed so as to straddle the gap between the vibration sensor 10 and the insulating base 22E. The third stud 50C is made of an insulating material. A male thread similar to that of the first stud 50A and the second stud 50B is formed on the third stud 50C. This allows the third stud 50C to secure the vibration sensor 10 to the insulating base 22E. The third stud 50C further extends downward from there to protrude from the insulating base 22E, and is attached to the object to be measured 1 via a recess 1h in the object to be measured 1. In other words, the third stud 50C straddles the gap between the vibration sensor 10, the insulating base 22E, and the object to be measured 1, connecting them together.

[0095] A base through-hole 22k is formed between a recess 10h formed at the bottom of the vibration sensor 10 and a recess 1h formed at the top of the object to be measured 1. The base through-hole 22k penetrates the insulating base 22E in the vertical direction. The base through-hole 22k connects the recess 10h and the recess 1h. The inner wall of the base through-hole 22k may be formed with a female thread similar to that of the recesses 10h and 1h. However, the inner wall of the base through-hole 22k does not have to be formed with a female thread similar to that of the recesses 10h and 1h. If a female thread is formed in the base through-hole 22k, the female thread is fastened to the male thread of the third stud 50C. This fixes the insulating base 22E to the vibration sensor 10. However, even if a female thread is not formed in the base through-hole 22k, the third stud 50C fastened to the recess 10h will pass through the base through-hole 22k. This restrains the insulating base 22E to the vibration sensor 10 and fixes it to the vibration sensor 10 as one of the components of the vibration measuring device 100. Here we think like this.

[0096] A single large space is formed by the recesses 10h and 1h and the base through-hole 22k between them. A third stud 50C is provided so as to be housed within this space. The male threads of the third stud 50C are fastened to the female threads of the recesses 10h and 1h. This joins the vibration sensor 10, insulating base 22E, and measurement target 1 together as a single unit.

[0097] Instead of the third stud 50C, the third fixing portion may be similar to the filling portion 22P as part of the insulating base 22B in the second embodiment. In this case, the filling portion 22P integrated with the insulating base 22E straddles the gap between the recess 10h of the vibration sensor 10 and the insulating base 22E, and further reaches the recess 1h of the object to be measured 1. The filling portion 22P fills the recesses 10h, 1h and the base through-hole 22k.

[0098] (Action and effect) The vibration measuring device 100 according to this embodiment includes a vibration sensor 10 and an insulating base 22E (third base). The vibration sensor 10 includes an element 11 capable of measuring vibrations of a measurement object 1. The insulating base 22E is attached to the vibration sensor 10 on the side where the measurement object 1 is to be disposed (the lower side in FIG. 22). At least a portion of the region (the entire region in a plan view) (in the vertical direction of the vibration sensor 10) of the insulating base 22E is insulating. An insulating third stud 50C (third fixing portion) is installed between the vibration sensor 10 and the insulating base 22E to fix the vibration sensor 10 to the insulating base 22E. The third stud 50C protrudes from the insulating base 22E on the side opposite to the vibration sensor 10, thereby fixing the measurement object 1 to the insulating base 22E. This embodiment can also achieve the same effects as the first embodiment.

[0099] Various aspects of the present disclosure are summarized below as appendices.

[0100] (Appendix 1) a vibration sensor including an element capable of measuring vibrations of a measurement object; a first base attached to the vibration sensor on a side where the measurement object is placed; a second base installed on the opposite side of the first base from the vibration sensor; a first fixing portion that fixes the vibration sensor and the first base; a second fixing portion; At least one of the first base and the second base is insulating in at least a portion thereof; The vibration measuring device, wherein the second fixing portion projects from the second base, thereby making it possible to fix the measurement object to the second base.

[0101] (Appendix 2) a first stud as the first fixing portion is installed so as to straddle the vibration sensor and the first base; 2. The vibration measuring device according to claim 1, wherein the first stud is a separate member from the first base.

[0102] (Appendix 3) a base recess formed in the second base; 3. The vibration measuring device according to claim 1, wherein the second fixing portion is a second stud fixed to the second base in the base recess.

[0103] (Appendix 4) 3. The vibration measuring device according to claim 1, wherein the second base includes, as the second fixing portion, an insulating member that can be filled into a measurement object recess formed in the measurement object.

[0104] (Appendix 5) 5. The vibration measuring device according to claim 1, wherein the second base has a larger size in a plan view than the first base.

[0105] (Appendix 6) The vibration measuring device according to any one of appendixes 1 to 5, wherein one of the first base and the second base has a concave portion, and the other base, which is different from the first base, has a convex portion that can fit into the concave portion.

[0106] (Appendix 7) a hole is formed in one of the first base and the second base, and a protrusion is formed in the other; 7. The vibration measuring device according to claim 6, wherein the protrusion is positioned so that it can be inserted into the hole when the convex portion is fitted into the concave portion.

[0107] (Appendix 8) a first through hole is formed in the first base, and a second through hole is formed in the second base; 7. The vibration measuring device according to any one of claims 1 to 6, wherein one pin can pass through both the first through hole and the second through hole so as to straddle both the first through hole and the second through hole.

[0108] (Appendix 9) a conductive connector is further provided between an outer cover surrounding a shielded wire connected to a ground potential and the vibration sensor, the conductive connector being in contact with the vibration sensor; 9. The vibration measuring device according to claim 1, wherein the shielded wire is connected to the conductive connector.

[0109] (Appendix 10) a vibration sensor including an element capable of measuring vibrations of a measurement object; a third base attached to the vibration sensor on a side where the measurement target is placed, the third base is insulating in at least a portion thereof; an insulating third fixing portion is provided to bridge the gap between the vibration sensor and the third base and fix the vibration sensor to the third base; The vibration measuring device, wherein the third fixing portion protrudes from the third base on the opposite side to the vibration sensor, thereby enabling the measurement object to be fixed to the third base. [Explanation of symbols]

[0110] 1 Measurement object, 1h, 10h, 21h, 22h Recess, 10 Vibration sensor, 10B Vibration sensor housing, 11 Element, 12 Cavity, 20 Base, 21, 21C, 21D Conductive base, 21CV, 22CV Recessed portion, 21DP, 22DP Convex portion, 22, 22A, 22B, 22C, 22D, 22E Insulating base, 22k Base through hole, 22P Filling portion, 23 Fixing surface, 24 First through hole, 25 Second through hole, 26 Pin, 27 Insulating sleeve, 28A Through hole, 28B Hole portion, 29 Protrusion portion, 40 Vibration sensor cable, 41 First cable wire, 42 Second cable wire, 43 Shield wire, 44 Outer sheath, 50 Stud, 50A First stud, 50B Second stud, 50C Third stud, 59 Insulating connector, 61 adhesive, 70 data collection device, 100 vibration measurement device, G1, G2 grounding points.

Claims

1. a vibration sensor including an element capable of measuring vibrations of a measurement object; a first base attached to a side of the vibration sensor where the measurement target is located; a second base installed on the opposite side of the first base from the vibration sensor; a first fixing portion that fixes the vibration sensor and the first base; a second fixing portion, At least one of the first base and the second base is insulating in at least a portion thereof; The vibration measuring device, wherein the second fixing portion protrudes from the second base, thereby making it possible to fix the measurement target to the second base.

2. a first stud as the first fixing portion is installed so as to straddle the vibration sensor and the first base; 2. The vibration measuring device according to claim 1, wherein the first stud is a separate member from the first base.

3. a base recess formed in the second base; 3. The vibration measuring device according to claim 1, wherein the second fixing portion is a second stud fixed to the second base in the base recess.

4. 3. The vibration measuring device according to claim 1, wherein the second base includes, as the second fixing portion, an insulating member that can be filled into a measurement object recess formed in the measurement object.

5. The vibration measuring device according to claim 1 , wherein the second base has a size larger than the first base in a plan view.

6. 3. The vibration measuring device according to claim 1, wherein one of the first base and the second base has a concave portion, and the other base has a convex portion that can be fitted into the concave portion.

7. a hole is formed in one of the first base and the second base, and a protrusion is formed in the other; The vibration measuring device according to claim 6 , wherein the protrusion is disposed at a position where it can be inserted into the hole in a state where the convex portion is fitted into the concave portion.

8. a first through hole is formed in the first base, and a second through hole is formed in the second base; The vibration measuring device according to claim 1 , wherein a single pin can pass through both the first through hole and the second through hole so as to straddle both the first through hole and the second through hole.

9. a conductive connector is further provided between an outer cover surrounding a shielded wire connected to a ground potential and the vibration sensor, the conductive connector being in contact with the vibration sensor; The vibration measuring device according to claim 1 , wherein the shielded wire is connected to the conductive connector.

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