JP7638549B2 - Vibration Meter - Google Patents

Description

This invention relates to a vibration meter.

Vibrometers that measure vibrations have been known for some time. The vibrometer described in Patent Document 1 includes an acceleration sensor as a vibration sensor, and a recording device. The acceleration sensor is provided separately from the recording device. The acceleration sensor and the recording device are connected by a cable (wiring). The detection output from the acceleration sensor is provided to the recording device via the cable.

JP 2011-202961 A

Vibration measurements are performed at various measurement points. When measuring vibrations with a vibration meter, the worker (measurer) needs to transport the vibration meter to the measurement point.

However, in the above vibration meter, the vibration sensor (acceleration sensor) is provided separately from the storage device, so the vibration sensor and the storage device must be carried separately. This makes it unsuitable for carrying around. In other words, there is a problem in that it lacks portability.

In addition, when vibration measurement is performed, the vibration sensor must be connected to the recording device in preparation for the measurement. In other words, each time a vibration measurement is performed, the vibration sensor must be connected via a cable and the cable must be disconnected. This makes the preparation for vibration measurement cumbersome.

Furthermore, because the cable is routed outside the case, the following problems may occur. That is, if the measurement location is a factory or the like, there is a possibility that noise such as stray currents may be received as a signal if the cable is routed on the ground or floor. Also, because the cable is routed outside the case, there is a possibility that a failure such as a broken cable may occur. Furthermore, when connecting the vibration sensor and recording device with multiple types of cables, there is a risk that operators may make connection errors.

Therefore, the object of this invention is to provide a vibration meter that is highly portable and reduces the hassle of preparation work for measurement.

One embodiment of the present invention provides a vibrometer having the following features:

1. A vibrometer for measuring vibration, comprising:
A case having an internal space;
A vibration sensor accommodated in the internal space;
a processing unit that is accommodated in the internal space and performs measurement processing based on a detection output output from the vibration sensor.

With this configuration, the vibration sensor is housed in the internal space. Therefore, the vibration sensor and the processing unit can be carried together. This improves the portability of the vibration meter.

In addition, there is no need to connect the vibration sensor to a case or processing unit each time a vibration measurement is performed. This simplifies the preparation work for vibration measurement and reduces the hassle of the preparation work. Furthermore, because no cables are routed outside the case, problems resulting from this can be avoided.

This makes it possible to provide a vibration meter that is highly portable and reduces the hassle of preparation work for measurement.

2. The vibration meter according to claim 1, further comprising a base that supports the vibration sensor and that can support the vibration sensor housed in the internal space independently of the case.

If the vibration sensor is housed in the internal space of the case, the following problems arise. That is, if the measurement location is outdoors, the case may be affected by wind and other factors, causing slight vibrations. The case may also vibrate slightly due to vibrations from other devices housed in the internal space. If these slight vibrations are transmitted to the vibration sensor through the case, the vibration sensor may detect these vibrations as well, which may cause errors in the detection output of the vibration sensor. This may reduce the accuracy of the vibration measurement.

According to the above configuration, the base supporting the vibration sensor can support the vibration sensor housed in the internal space independently from the case. When the base supports the vibration sensor independently from the case, not only is the vibration sensor not in contact with the case, but the vibration sensor and the case are not connected. In other words, the vibration sensor is physically separated from the case. Therefore, vibrations are not transmitted from the case to the vibration sensor. This allows vibrations to be measured with high accuracy. Therefore, a vibrometer that is highly portable and capable of achieving high-accuracy vibration measurement can be provided.

The base may have legs that contact the placement surface.
The base may be movable up and down together with the vibration sensor relative to the case and the processing unit.
The base may be circular in a plan view. The base may include a plurality of legs. The plurality of legs may be arranged at intervals in a circumferential direction of the base at positions excluding a center of the base in a plan view.
3. The case has a through hole that passes through the bottom wall of the case in the vertical direction,
3. The vibrometer according to claim 2, wherein a lower end of the base is capable of protruding below the case through the through hole.

With this configuration, the lower end of the base can abut against the mounting surface through a through hole formed in the bottom wall of the case. This allows for a simple configuration in which the vibration sensor housed in the internal space is supported by the base independently of the case.

4. A first engagement portion formed on the case;
a second engaging portion formed on the base and engageable with the first engaging portion;
4. The vibrometer according to item 2 or 3, wherein a first distance from a first bottom end of the case to the first engagement portion is shorter than a second distance from a second bottom end of the base to the second engagement portion.

According to this configuration, the first distance of the first engagement portion from the first bottom end of the case is shorter than the second distance of the second engagement portion from the second bottom end of the base. Therefore, in a placed state in which the case and base are placed on the placement surface, the first engagement portion and the second engagement portion do not engage with each other. Therefore, in this placed state, the vibration sensor can be reliably physically separated from the case. Vibration measurement by the vibrometer is performed with the vibrometer in the placed state. Therefore, vibration measurement can be performed using the vibrometer with the vibration sensor reliably physically separated from case 2.

In addition, when the case of the vibration meter is raised, the vibration sensor and the base may be suspended and supported by the case due to the engagement between the first and second engagement parts. This allows the vibration sensor, the base and the case to be carried together, further improving the portability of the vibration meter.

The vibration meter may further include a grip for lifting the case. This can further improve portability.

5. The vibrometer according to item 4, wherein the first engagement portion and the second engagement portion include a first contact surface and a second contact surface that contact each other vertically.

6. The vibrometer according to item 5, wherein the first contact surface and the second contact surface are truncated cones.

With this configuration, because the first and second contact surfaces are frustum-shaped, when the first and second contact surfaces are in contact with each other, lateral movement of the base relative to the case is restricted. This makes it possible to prevent the vibration sensor and base from moving relative to the case when the vibrometer is lifted. Therefore, the vibration meter can be carried while effectively restricting movement of the vibration sensor and base relative to the case.

The vibrometer may include a first engagement portion formed on the case and a second engagement portion formed on the base and engageable with the first engagement portion. The first engagement portion and the second engagement portion may have a case-side abutment surface and a base-side abutment surface that face each other vertically. The base-side abutment surface may be a base-side abutment surface that is formed on the base and tapered downward toward the inside of the base. The case-side abutment surface may be a case-side abutment surface that is formed on the case and tapered to match the base-side abutment surface. When the vibrometer is separated from the mounting surface, the base-side abutment surface and the case-side abutment surface may be in surface contact. When the vibrometer is placed on the mounting surface, the vibration sensor and the base may not be supported by the case.
7. The vibrometer according to any one of items 4 to 6, further comprising a viscous sheet disposed between the vibration sensor and the base.

Accelerometers are sometimes used as vibration sensors. Accelerometers are sensitive to shocks. Therefore, it is desirable to minimize the transmission of shocks to the case when transporting the vibration meter to the vibration sensor.

According to the above configuration, a viscous sheet is placed between the vibration sensor and the base. The viscous sheet absorbs vibrations. Therefore, even if a large impact is applied to the case, the impact is absorbed by the viscous sheet. This makes it possible to reduce or eliminate the impact transmitted from the case to the vibration sensor. This makes it possible to protect the vibration sensor. Therefore, even if a large impact is applied to the case, the impact can be suppressed or prevented from being transmitted to the vibration sensor.

8. The vibration meter according to any one of claims 1 to 7, wherein the vibration sensor is a sensor for measuring minute vibrations (micromotion acceleration).

Vibrometers for measuring minute vibrations are used at various measurement points. Therefore, they need to be highly portable.

According to the above configuration, the vibration sensor for measuring minute vibrations is housed in the internal space. Therefore, the vibration sensor and the processing unit can be carried together. This improves the portability of the vibrometer for measuring minute vibrations.

9. The vibrometer according to any one of claims 2 to 7, further comprising a protective cover that covers the bottom of the case and can be coupled to the base by screw fastening.

With this configuration, the protective cover covers the bottom of the case, thereby protecting the bottom of case 2 and reducing or preventing shocks from being transmitted to the vibration sensor.

In addition, by screwing the protective cover to the base, the base can be pressed against the case by the screwing, and the base can be positioned in the case. This makes it possible to suppress or prevent the vibration sensor from wobbling in the internal space. This makes it easy to transport the vibration meter.

1 is a schematic cross-sectional view of a main part of a vibrometer according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view taken along the line II-II in FIG. 1 . FIG. 3 is a cross-sectional view of the vibrometer in a lifted state, the cross-sectional view corresponding to FIG. 2 . FIG. 2 is a schematic perspective view of the vibrometer with its cover open; FIG. 5 is a schematic perspective view of the vibrometer, showing a state in which a processing unit is removed from the state shown in FIG. 4; FIG. 6 is a schematic perspective view of the vibrometer, showing a state in which a sensor housing unit is removed from FIG. 5 . FIG. 2 is a perspective view of the sensor housing unit. FIG. 2 is a block diagram showing an electrical configuration of the vibrometer. 4 is a flowchart showing a flow of a vibration measurement process using the vibrometer. FIG. FIG. 3 is a schematic cross-sectional view of a main part of a vibrometer according to a second embodiment of the present invention, and corresponds to FIG. 2 . 1 is a graph illustrating the characteristics of a viscous sheet.

The following describes in detail an embodiment of the present invention with reference to the drawings.

Figure 1 is a schematic cross-sectional view of the main parts of a vibration meter 1 according to a first embodiment of the present invention. Figure 2 is a schematic cross-sectional view taken along the cutting line II-II in Figure 1. Figure 3 is a cross-sectional view of the vibration meter 1 in a lifted state, and corresponds to Figure 2. Figures 4 to 6 are perspective views of the vibration meter 1. Figure 7 is a perspective view of the sensor housing unit 8.

The left-right direction of the paper surface of FIG. 1 coincides with the left-right direction X of the vibration meter 1, the direction approximately perpendicular to the paper surface of FIG. 1 coincides with the front-rear direction Y of the vibration meter 1, and the up-down direction of the paper surface of FIG. 1 coincides with the up-down direction Z of the vibration meter 1. The left-right direction X and the front-rear direction Y are included in the horizontal direction.

With reference to Figures 1 to 3, the vibration meter 1 is placed at a predetermined measurement point and is used to measure vibrations at the measurement point. Specifically, the vibration meter 1 may be used to measure microtremors (or at least one of normal microtremors and seismic motion) at the measurement point. The vibration meter 1 is placed on a support surface 100 (see Figures 1 to 3) such as the ground, a floor, a desk, etc. at the measurement point and measures the vibrations of the support surface 100 (i.e. the ground or a floor). The support surface 100 is preferably a flat surface.

Referring to Figs. 1 to 6, the vibration meter 1 includes a case 2, a vibration sensor 3, a battery 4, a display unit 5, a handle (grip) 6, a processing unit 7, and a sensor housing unit 8. In addition to the vibration sensor 3, the vibration meter 1 also includes a geomagnetic sensor, a GPS sensor, a temperature sensor, a humidity sensor, and the like (see Fig. 8). Fig. 4 shows a state in which the lid 11 of the case 2 is open and the battery 4 is removed, that is, a state in which the vibration sensor 3, the processing unit 7, and the sensor housing unit 8 are housed in the case body 10. Fig. 5 shows a state in which the vibration sensor 3 and the processing unit 7 have been removed from the state shown in Fig. 4, and Fig. 6 shows a state in which the sensor housing unit 8 has been removed from the state shown in Fig. 5.

Referring to Figs. 1 to 6, the case 2 includes a case body 10, a lid 11 attached to the case body 10, a locking section 12 (see Fig. 4, etc.), and a bottom ring 13 (see Figs. 1 to 3) attached to the bottom 10a (bottom wall 14) of the case body 10. The lid 11 is connected to the case body 10 via a hinge H (see Fig. 2, etc.). The lid 11 closes the top surface of the case body 10 so that it can be opened in one direction. The locking section 12 fixes the lid 11 to the case body 10 so that it can be opened and closed. When the lid 11 is fixed to the case body 10 by the locking section 12, the lid 11 cannot rotate relative to the case body 10. The display unit 5 is built into the lid 11. Note that the battery 4 may be arranged on the lid 11 side (for example, in the space between the top surface of the lid 11 and the display unit 5) instead of the case body 10.

Referring to Figs. 1 to 6 (particularly Fig. 6), the case body 10 is formed in a hollow box shape. The case body 10 has an internal space 20. The case body 10 is box-shaped and has a bottom 10a and four side walls 10b. The bottom 10a includes a bottom wall 14 and a plurality (e.g., four) first legs 15. The bottom wall 14 is flat. A circular first through hole 16 (particularly see Fig. 6) is formed in the center of the bottom wall 14. The plurality of first legs 15 are arranged at the four corners of the bottom wall 14 on the underside of the bottom wall 14. The bottom surface of each first leg 15 is referred to as a first lower end 15a.

With reference to Figures 1 to 3, the bottom ring 13 is a circular ring in plan view. The bottom ring 13 is formed using a non-magnetic metal or synthetic resin material. The bottom ring 13 is fitted into the first through hole 16 from below. The bottom ring 13 has a second through hole 18. The inner peripheral wall of the second through hole 18 is the inner peripheral surface of the bottom ring 13. A first abutment surface (first engagement portion) 19 is formed on the inner peripheral wall of the second through hole 18. The first abutment surface 19 faces the second abutment surface (second engagement portion) 47 of the base 41 described below in the vertical direction. The first abutment surface 19 is a tapered surface that becomes lower toward the inside. The first abutment surface 19 is inclined with respect to the horizontal plane at an inclination angle of, for example, 30° to 60° (for example, 45° in the example of Figure 1, etc.). The first abutment surface 19 is a smooth surface. The first contact surface 19 is frustum-shaped. The bottom ring 13 is attached to an outer frame plate 51 of the outer frame 48 of the sensor housing unit 8, which will be described later. The bottom ring 13 may be fixed to the outer frame plate 51 using a fastening member such as a screw (not shown).

Referring to Figures 1 to 3 and 6, the case body 10 has a hollow rectangular parallelepiped internal space 20. The internal space 20 contains the vibration sensor 3, the processing unit 7, and the sensor housing unit 8.

Referring to Figures 1 to 3, the vibration sensor 3 is, for example, an acceleration sensor, for example, a three-axis acceleration sensor that detects the magnitude of acceleration in three directions of the sensor axis. More specifically, the vibration sensor 3 is, for example, an acceleration sensor that uses a piezoelectric element or a quartz crystal. The vibration sensor 3 measures micro-acceleration (fine vibration). The magnitude of acceleration from the vibration sensor 3 may be output as a digital value. The vibration sensor 3 is connected to the processing unit 7 via a cable 21 (see Figure 1). The detection output of the vibration sensor 3 is provided via the cable 21 to the control device 70 (see Figure 8), which will be described next, of the processing unit 7.

The battery 4 is, for example, a lithium ion battery. The battery 4 may be a primary battery or a secondary battery. The battery 4 is disposed in the uppermost part of the internal space 20. The battery 4 may be disposed in another position, but is disposed in a position where the weight of the battery does not affect the position of the center of gravity of the vibration meter 1 (where the vibration meter 1 is not eccentric).

The display unit 5 has, for example, a liquid crystal display panel. This liquid crystal display panel has a liquid crystal display section 17a on the underside (front surface). The liquid crystal display section 17a is, for example, an 8-inch liquid crystal display section. The display unit 5 is formed over the entire inner surface of the lid 11. Therefore, as shown in Figures 4 to 6, when the lid 11 is open, the liquid crystal display section 17a of the display unit 5 is exposed.

The handle 6 is, for example, a grip, and is attached to the top surface of the lid 11. The vibrometer 1 can be carried by grasping the handle 6 when the lid 11 is closed. The handle 6 is a tiltable grip as shown in Figures 1 to 3. By hanging the vibrometer 1 by the handle 6, the bottom surface of the vibrometer 1 becomes horizontal, and it can be placed (installed) as is on the placement surface 100.

The case 2 is small, and the battery 4 and display unit 5 are also small in size. This allows the vibration meter 1 to be small and lightweight. As a result, the vibration meter 1 is highly portable and easy to carry. In addition, the handle 6 is included, further improving portability.

Referring to Figs. 1 to 4, the processing unit 7 (also see Fig. 8) is configured to include a vibration meter control board 22 (also see Fig. 8) and a sheet metal member 23 on the bottom and top, respectively. The vibration meter control board 22 includes a wiring board 24 and components 25 mounted on the wiring board 24. The components 25 include electrical components, terminal blocks, and the like. The electrical components include a control device 70 (see Fig. 8), a memory unit 72 (see Fig. 8), a geomagnetic sensor, a GPS sensor, a temperature sensor, a humidity sensor, a start button 74 (see Fig. 8), an end button 75 (see Fig. 8), and the like, which will be described later. The sheet metal member 23 covers the entire area above the vibration meter control board 22 (above the wiring board 24). The sheet metal member 23 is a sheet metal member mainly for suppressing heat generation from the electrical components. The vibration meter control board 22 and the sheet metal member 23 are integrally joined using a fixing means.

With reference to Figures 1 to 3, 5 and 6, the sensor housing unit 8 includes a base 41 that supports the vibration sensor 3 (acceleration sensor) from below, and a housing frame 42 that houses the vibration sensor 3 and the base 41. The sensor housing unit 8 houses the vibration sensor 3. The sensor housing unit 8 is housed in approximately the lower half of the internal space 20.

Referring to Figures 1 to 3, 5 and 7, the base 41 is circular in plan view. The base 41 is attached to the bottom wall 14 of the case body 10 so as to be freely movable up and down. The base 41 abuts against the inner frame 49 of the housing frame 42, which will be described later, thereby restricting its upper limit position relative to the case 2. The base 41 abuts against the bottom ring 13, thereby restricting its lower limit position relative to the case 2. In other words, the base 41 is freely movable up and down between its upper limit position and lower limit position relative to the case 2. The base 41 includes a base body 43 on which the vibration sensor 3 is placed, a case-facing portion 44 that contacts the bottom ring 13, and, for example, three second legs 45.

The base body 43 is circular in plan view. The upper surface of the base body 43 is a sensor placement surface 46 on which the vibration sensor 3 is placed. The vibration sensor 3 is fixed to the sensor placement surface 46 using a fastening member (not shown) such as a screw. The base body 43 is formed using a non-magnetic metal or synthetic resin material.

The case facing portion 44 is circular in plan view. A ring-shaped second abutment surface (second engagement portion) 47 is formed on the peripheral portion of the lower surface of the case facing portion 44. The second abutment surface 47 is a tapered surface that becomes lower toward the inside. The second abutment surface 47 is inclined with respect to the horizontal plane at an inclination angle of, for example, 30° to 60° (for example, 45° in the example of FIG. 1, etc.). The second abutment surface 47 is a smooth surface. The second abutment surface 47 is frustum-shaped. The second abutment surface 47 is parallel to the first abutment surface 19. The case facing portion 44 is formed using a non-magnetic metal or synthetic resin material.

In this embodiment, the case facing portion 44 and the base body 43 are integrally formed. The base body 43 and the case facing portion 44 may be formed from separate members and connected to the base body 43 using a fastening member (not shown) such as a screw.

The three second legs 45 are arranged on the underside of the case facing portion 44 at equal intervals in the circumferential direction of the base 41. The three second legs 45 have the same height. The lower ends of the second legs 45 are referred to as second lower ends 45a. The three second legs 45 are fixed to the case facing portion 44 from below by screws, pins, or the like. The base 41 is movable up and down between a lower limit position relative to the case 2 and an upper limit position relative to the case 2. The second lower ends 45a of the second legs 45, i.e., the second lower end 45a of the base 41, can protrude downward from the bottom surface of the bottom wall 14 of the case 2 through the second through hole 18.

Referring to Figs. 5 and 7, the housing frame 42 includes an outer frame 48 and an inner frame 49. The outer frame 48 and the inner frame 49 are formed from separate metal sheets. The housing frame 48 may be fixed to the case 2 by a fastening member (not shown) such as a screw. The outer frame 48 and the inner frame 49 may be joined together using a fastening member (not shown) such as a screw.

7, the outer frame 48 is a box-shaped structure with an open top and a bottom, and includes a rectangular outer frame plate 51 in a plan view, four support columns 52 rising from the four corners of the outer frame plate 51, a left side plate 53, and a right side plate 54. Each support column 52 is L-shaped in cross section. The left side plate 53 is connected to the two support columns 52 on the left side. The right side plate 54 is connected to the two support columns 52 on the right side. The outer frame plate 51, the four support columns 52, the left side plate 53, and the right side plate 54 are integrally formed from sheet metal. The outer frame 48 is made of aluminum, for example. In this embodiment, the upper ends of the four support columns 52 and the upper end of the right side plate 54 are all at the same height. The upper ends of the four support columns 52 and the upper end of the right side plate 54 constitute the upper end of the storage frame 42. Although not shown, the outer frame 48 may further include a connecting plate that connects the upper ends of the four posts 52.

Referring to Figures 5 and 7, the processing unit 7 is accommodated above the accommodation frame 42 in the internal space 20. The accommodation frame 42 supports the processing unit 7 from below. When the accommodation frame 42 and the processing unit 7 are accommodated in the internal space 20, the upper end of the accommodation frame 42 abuts against the lower end (lower surface) of the processing unit 7. By abutting the upper end of the accommodation frame 42 against the processing unit 7, a sufficient space can be secured above the base 41 for disposing the vibration sensor 3. In other words, by abutting the upper ends of the four supports 52 against the processing unit 7, the processing unit 7 can be prevented from abutting against the vibration sensor 3.

Referring to FIG. 7, the inner frame 49 is arranged so as to cover a portion of the upper surface of the base 41. The inner frame 49 has a pair of inner frame plates 56 on the left and right. The inner frame plates 56 are arranged so as to face each other in the front-to-rear direction Y. Each inner frame plate 56 forms a protruding portion on the upper side midway in the front-to-rear direction Y.

7, the sensor housing unit 8 further has a restricting portion 57 for restricting the lateral movement and rotation of the base 41 relative to the housing frame 42. The restricting portion 57 includes an engagement protrusion 58 coupled to the upper surface of the base 41 and an engagement recess 59 formed in each inner frame plate 56. The engagement recess 59 is an engagement hole in the example of FIG. 7, but may be an engagement groove. The engagement protrusion 58 and the engagement recess 59 engage with each other to restrict the lateral movement and rotation of the base 41 relative to the housing frame 42 within a predetermined range. The engagement protrusion 58 and the engagement recess 59 are kept engaged with each other regardless of the vertical position of the base 41 (whether the base 41 is in the position shown in FIG. 1 and FIG. 2 or in the position shown in FIG. 3). Although not shown, the engagement recess 59 may be formed in the outer frame 48 instead of the inner frame 49. Although not shown, the engagement protrusion 58 may be formed on the housing frame 42 side, and the engagement recess 59 may be formed on the base 41 side.

Referring to Figures 1 to 3 (particularly Figure 3), the first distance H1 between the first contact surface 19 and the first lower end 15a is several mm to several tens of mm (for example, about 5 mm) shorter than the second distance H2 between the second contact surface 47 and the second lower end 45a. Specifically, the first distance H1 between a predetermined position on the first contact surface 19 and a position on the second contact surface 47 where the predetermined position can contact the first contact surface 19 is shorter than the second distance H2 between the second contact surface 47 and the second lower end 45a.

The state of the vibrometer 1 placed on the mounting surface 100 (the state shown in Figs. 1 and 2) is referred to as the mounting state. The base 41 is movable up and down between its upper limit position and its lower limit position relative to the case 2. In this mounting state, the second lower end 45a of the base 41 abuts against the mounting surface 100 through the second through hole 18. In this mounting state, the first lower end 15a of the case 2 and the second lower end 45a of the base 41 are at the same height. As described above, the first distance H1 between the first abutment surface 19 and the first lower end 15a is shorter than the second distance H2 between the second abutment surface 47 and the second lower end 45a. Therefore, in a mounted state where the case 2 and the base 41 are placed on the mounting surface 100 (the state shown in FIGS. 1 and 2), the first contact surface 19 and the second contact surface 47 do not contact (engage) each other, and a gap S (see FIG. 3) is formed between the first contact surface 19 and the second contact surface 47. This gap S may be several millimeters to several tens of millimeters (the distance in the vertical direction Z). When the vibrometer 1 is placed, the base 41 is not in contact with the case facing portion 44, and therefore the base 41 is not supported by the case facing portion 44.

In addition, in this mounted state, the sensor placement surface 46 of the base 41 does not abut against the inner frame 49 (inner frame plate 56). The size of the inner frame plate 56 is adjusted so that in the mounted state, the sensor placement surface 46 does not abut against the inner frame 49 (inner frame plate 56).

In this mounted state (the state shown in Figures 1 and 2), the base 41 supports the vibration sensor 3 housed in the internal space 20 independently from the case 2. In this mounted state, not only is the vibration sensor 3 not in contact with the case 2, but the vibration sensor 3 and the case 2 are not connected. In other words, the vibration sensor 3 is physically separated from the case 2.

When transporting the vibration meter 1, the worker lifts the vibration meter 1. In this case, the worker lifts the vibration meter 1 by grasping the handle 6. As the case 2 is lifted upward, the bottom ring 13 of the case 2 moves upward relative to the base 41. Then, the first abutment surface 19 of the bottom ring 13 of the case 2 abuts against the second abutment surface 47 of the base 41, and as a result, the bottom ring 13 comes into contact with the base 41 as shown in FIG. 3. Then, the case 2 is lifted further upward. In other words, as the worker lifts the vibration meter 1 by holding the handle 6, the base 41 can be placed in the bottom ring 13 without shifting.

The state of the vibration meter 1 in which the case 2 is lifted upward (the state shown in FIG. 3) is referred to as the lifted state. In this lifted state, the first abutment surface 19 and the second abutment surface 47 are in contact with each other. In the lifted state of the vibration meter 1 (the state shown in FIG. 3), the base 41 is supported in contact with the bottom ring 13 of the case 2. That is, in the lifted state of the vibration meter 1 (the state shown in FIG. 3), the vibration sensor 3 and the base 41 are supported by the case 2. In other words, the vibration sensor 3 and the base 41 are supported by being suspended from the case 2.

As described above, the pedestal 41 can move up and down relative to the case 2. The height position of the pedestal 41 relative to the case 2 differs between the placed state of the vibration meter 1 (the state shown in Figs. 1 and 2) and the raised state of the vibration meter 1 (the state shown in Fig. 3). When the vibration meter 1 is placed (the state shown in Figs. 1 and 2), the pedestal 41 is in a lower position. When the vibration meter 1 is raised (the state shown in Fig. 3), the pedestal 41 is in an upper position.

Figure 8 is a block diagram showing the electrical configuration of the vibration meter 1. The vibration meter 1 includes a control device 70. The control device 70 includes a microcomputer. More specifically, the control device 70 includes an arithmetic unit 71, a memory unit, a timer, and the like. The arithmetic unit 71 includes a processor. The processor includes a GPU (Graphic Processing Unit), a CPU (Central Processing Unit), and the like. The memory unit includes a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The control device 70 is connected to a memory unit 72. The memory unit 72 is composed of a storage device such as a non-volatile memory or a hard disk drive. The memory unit 72 stores various information. The memory unit 72 stores a program that can be executed by the arithmetic unit 71 of the control device 70.

The vibration sensor 3 is connected to the control device 70. The control device 70 stores the detection output of the vibration sensor 3 in the memory unit 72 as recorded data 73. The detection output of the vibration sensor 3 is stored in the recorded data 73 in a form linked to the detection time and other measurement conditions. In addition, a geomagnetic sensor, a GPS sensor, a temperature sensor, a humidity sensor, etc. are connected to the control device 70.

In this embodiment, the control device 70 converts the three-direction output values of the vibration sensor 3 (acceleration sensor) from the coordinate system of the three sensor axes into a predetermined orthogonal coordinate system (second orthogonal coordinate system) so that the direction of gravitational acceleration coincides with the Z axis. The control device 70 also converts the converted acceleration values into a predetermined orthogonal coordinate system (first orthogonal coordinate system) different from the above orthogonal coordinate system so that the sensor axis (y-axis) of the vibration sensor 3 (acceleration sensor) faces north (magnetic north).

A start button 74 and an end button 75 are connected to the control device 70. The control device 70 starts measurement by the vibration sensor 3 based on the input of an operation signal from the start button 74. The control device 70 ends measurement by the vibration sensor 3 based on the input of an operation signal from the end button 75.

In this embodiment, the acceleration sensor 13 is configured as a three-axis acceleration sensor. The acceleration sensor 13 measures acceleration including gravitational acceleration. Therefore, the vibrometer 1 can grasp the inclination of the acceleration sensor 3 based on the acceleration values in the three sensor axis directions output by the acceleration sensor 3. The vibrometer 1 also includes a geomagnetic sensor. Therefore, the vibrometer 1 can grasp the horizontal orientation of the vibrometer 1. The control device 70 converts the acceleration values in the coordinate system in the three sensor axis directions output by the acceleration sensor 3 into a predetermined orthogonal coordinate system. This coordinate conversion of the acceleration is performed using the method disclosed in JP 2022-171245 A. As a result, the magnitude of acceleration acting on the vibrometer 1 in the three directions, the north-south direction, the east-west direction, and the vertical direction, can be measured well regardless of the inclination or orientation of the vibrometer 1.

Figure 9 is a flow diagram showing the flow of vibration measurement processing using the vibration meter 1. The flow of vibration measurement processing using the vibration meter 1 will be explained with reference to Figures 1 to 3, 8 and 9.

At a predetermined measurement point, an operator installs (places) the vibration meter 1 on a mounting surface 100 such as the ground, a floor, or a desk. The cable 21 connected to the vibration sensor 3 is already housed in the internal space 20. Therefore, there is no need to insert or remove the cable 21 each time the vibration meter 1 is installed. Since the direction of acceleration is converted to horizontal/vertical, no level adjustment is required to make the vibration meter 1 horizontal, and there is no need to adjust the direction of the vibration meter 1 to match magnetic north. This simplifies the preparation work for installing the vibration meter 1, and reduces the hassle of the preparation work. And because the cable 21 is not routed outside the case 2, problems resulting from this can be avoided.

When the vibration meter 1 is placed (as shown in Figures 1 and 2), the base 41 supports the vibration sensor 3 housed in the internal space 20 independently from the case 2. When the vibration meter 1 is placed, the vibration sensor 3 is physically separated from the case 2, and therefore vibrations are not transmitted from the case 2 to the vibration sensor 3. This allows the vibration meter 1 to measure vibrations with high accuracy. Therefore, it is possible to provide a vibration meter 1 that is highly portable and can achieve high-accuracy vibration measurement.

During vibration measurement, it is possible that the case 2 may vibrate slightly due to the influence of wind or other equipment. However, even in such a case, the minute vibrations are not transmitted from the case 2 to the vibration sensor 3, so no error occurs in the detection output of the vibration sensor 3. This allows the accuracy of vibration measurement by the vibration meter 1 to be maintained at a high level.

In addition, the first distance H1 between the first contact surface 19 and the first lower end 15a is shorter than the second distance H2 between the second contact surface 47 and the second lower end 45a. Therefore, in a mounted state (the state shown in FIGS. 1 and 2) in which the case 2 and the base 41 are mounted on the mounting surface 100 consisting of a horizontal plane, a gap S is formed between the first contact surface 19 and the second contact surface 47. Therefore, in a mounted state in which the case 2 and the base 41 are mounted on the mounting surface 100, the vibration sensor 3 can be reliably physically separated from the case 2. The vibration measurement by the vibration meter 1 is performed in the mounted state of the vibration meter 1. Therefore, vibration measurement can be performed in a state in which the vibration sensor 3 is reliably physically separated from the case 2.

After placing the vibration meter 1, the worker operates the start button 74. When the start button 74 is operated (YES in step S1 in FIG. 9), the control device starts outputting the detection output of the vibration sensor 3 (step S2 in FIG. 9). The control device 70 does not immediately start recording the detection output even when the start button 74 is operated. Then, when 30 seconds have elapsed since the start button 74 was operated (YES in step S3 in FIG. 9), the control device 70 starts recording the detection output of the vibration sensor 3 (step S4 in FIG. 9). The detection output is recorded in the recorded data 73. At this time, the control device 70 starts recording not only the detection output of the vibration sensor 3, but also the detection outputs of other sensors (geomagnetic sensor, GPS sensor, temperature sensor, humidity sensor, etc.) in the recorded data 73.

Furthermore, recording of the detection output starts after a predetermined period (e.g., 30 seconds) has elapsed since the start button 74 was operated. As described above, when the vibration meter 1 is placed (the state shown in Figs. 1 and 2), the vibration sensor 3 is physically separated from the case 2. However, there is a risk that the impact caused by the operation of the start button 74 by the operator or the vibration caused by the operator's walking may be transmitted from the case 2 through the mounting surface 100 to the base 41, and from the base 41 to the vibration sensor 3. In this case, the vibration sensor 3 may detect this vibration, and an error may occur in the detection output of the vibration sensor 3. Therefore, if recording of the detection output starts immediately after the start button 74 is operated, the detection output with an error may be recorded in the recorded data 73.

In this embodiment, a predetermined period of time is waited from when the start button 74 is operated until recording of the detection output begins. Then, after the impact caused by operating the start button 74 has subsided, recording of the detection output begins. This makes it possible to obtain recorded data 73 that is free of the effects of operating the start button 74.

When it is time to end the measurement process, the operator operates the end button 75. When the end button 75 is operated (YES in step S5 of FIG. 9), the control device 70 ends the detection output of the vibration sensor 3 and ends the storage of the detection output (step S6 of FIG. 9).

The worker then grasps the handle 6, lifts the vibration meter 1, and carries it to the next measurement position.

In the lifted state of the vibration meter 1 (as shown in FIG. 3), the first contact surface 19 and the second contact surface 47 come into contact (engage). Since the first contact surface 19 and the second contact surface 47 are frustum-shaped, the movement of the base 41 in the lateral direction (left-right direction X and front-back direction Y) relative to the case 2 is restricted when the first contact surface 19 and the second contact surface 47 are in contact. This makes it possible to restrict the movement of the vibration sensor 3 and the base 41 relative to the case 2 when the vibration meter 1 is lifted (see FIG. 7). Therefore, the vibration meter 1 can be carried while effectively restricting the movement of the vibration sensor 3 and the base 41 relative to the case 2. This further improves the portability of the vibration meter 1.

However, since the vibration sensor 3 of the vibration meter 1 is housed in the case 2, the following problem occurs when transporting the vibration meter 1. That is, due to vibrations during transport of the vibrometer 1, the vibration sensor 3 may wobble within the case 2 and collide with other components inside the case 2. If the impact is large, the vibration sensor 3 may be damaged. This problem becomes particularly evident when a crystal type (quartz type) acceleration sensor or a piezoelectric element type sensor is used as the vibration sensor 3, as these sensors are vulnerable to impacts. In order to prevent such problems from occurring, the vibration meter 1 is provided with a protective cover 80 that is attached during transport. Figure 10 is a perspective view of the protective cover 80.

Referring to Figs. 3 and 10, when the vibration meter 1 is transported, a protective cover 80 is attached to the bottom 10a of the vibration meter 1. The protective cover 80 includes a rectangular frame 81 that is rectangular in plan view, four spacer ribs 82, four third legs 83, and a fastening bolt 84 (see Fig. 3). In Fig. 3, the protective cover 80 is indicated by a two-dot chain line. The protective cover 80 has two functions: a function of positioning (fixing) the base 41 (i.e., the base 41 and the vibration sensor 3) to the bottom ring 13, and a function of protecting the bottom 10a of the vibration meter 1.

1 to 3, the bottom ring 13 is a circular ring in plan view. The bottom ring 13 is formed using a non-magnetic metal or synthetic resin material. The bottom ring 13 is fitted into the first through hole 16 from below. The bottom ring 13 has a second through hole 18. The inner peripheral wall of the second through hole 18 is the inner peripheral surface of the bottom ring 13. A first abutment surface ( case-side abutment surface, first engagement portion) 19 is formed on the inner peripheral wall of the second through hole 18. The first abutment surface 19 faces a second abutment surface ( base-side abutment surface, second engagement portion) 47 of the base 41 described below in the vertical direction. The first abutment surface 19 is a tapered surface that becomes lower toward the inside. The first abutment surface 19 is inclined with respect to the horizontal plane at an inclination angle of, for example, 30° to 60° (for example, 45° in the example of FIG. 1, etc.). The first abutment surface 19 is a smooth surface. The first abutment surface 19 is shaped like a truncated cone. The bottom ring 13 is attached to an outer frame plate 51 of an outer frame 48 (described later) of the sensor housing unit 8. The bottom ring 13 may be fixed to the outer frame plate 51 using a fastening member (not shown) such as a screw.

When the vibration meter 1 is transported, a protective cover 80 is attached to cover the entire bottom 10a of the vibration meter 1, as shown by the two-dot chain line in FIG. 3. By protecting the bottom 10a of the vibration meter 1 with the protective cover 80, it is possible to suppress or prevent the transmission of shock to the vibration sensor 3.

When the protective cover 80 is attached, the four first legs 15 are accommodated in the corresponding leg accommodating recesses 88. When the protective cover 80 is attached, the bolt holes 89 of the base 41 face the bolt insertion holes 87 of the metal plate 85 in the vertical direction. Then, the bolts 84 are screwed into the bolt holes 89 through the bolt insertion holes 87. As a result, the bolts 84 are fastened to the bolt holes 89. When the amount of screwing of the bolts 84 increases, the heads of the bolts 84 and the base 41 approach each other while the distance between the metal plate 85 and the bolt holes 89 is kept constant by the spacer ribs 82. Therefore, the base 41 is pressed against the bottom ring 13, and the base 41 can be positioned (fixed) at the bottom of the case 2. Therefore, the vibration sensor 3 can be suppressed or prevented from wobbling in the internal space 20. Therefore, the vibration meter 1 can be easily transported.

Figure 11 is a schematic cross-sectional view of the main parts of a vibrometer 201 according to a second embodiment of the present invention, and corresponds to Figure 2. Figure 12 is a graph for explaining the characteristics of a viscous sheet 211. In the second embodiment, parts corresponding to those shown in the first embodiment are indicated with the same reference numerals as in Figures 1 to 10, and their explanations are omitted. The vibrometer 201 differs from the vibrometer 1 in that a viscous sheet 211 is disposed between each of the vibration sensors 3 and the base 41.

A first viscous sheet 211 is disposed between the vibration sensor 3 and the base 41. The first viscous sheet 211 is disposed over the entire area between the vibration sensor 3 and the base 41.

The viscous sheet 211 is a sheet with high viscosity. The viscous sheet 211 is a sheet that absorbs vibrations and is a shock absorbing sheet. The viscous sheet 211 is formed, for example, using urethane gel.

According to the second embodiment, even if a large impact is applied to the case 2, the impact is absorbed by the viscous sheet 211. This makes it possible to reduce or eliminate the impact transmitted from the case 2 to the vibration sensor 3. This makes it possible to protect the vibration sensor 3. Therefore, even if a large impact is applied to the case 2, it is possible to suppress or prevent the impact from being transmitted to the vibration sensor 3, thereby preventing damage to the vibration sensor 3.

The viscous sheet 211 is, for example, a Hypergel sheet (manufactured by Exseal Co., Ltd.). Any one of Sample 1, Sample 2, and Sample 3 in FIG. 12 is used as the viscous sheet 211. Sample 1, Sample 2, and Sample 3 may be "Hypergel 30" (product name), "Hypergel 50" (product name), and "Hypergel 70" (product name) of Hypergel sheets (manufactured by Exseal Co., Ltd.), respectively. As shown in FIG. 12, in all of Samples 1 to 3, the vibration transmissibility is high at 30 Hz or less and low at 50 Hz or more. The frequency range to be measured using the vibrometer 201 is 10 Hz or less. On the other hand, the frequency range due to impact is 50 Hz or more. In other words, by using the viscous sheet 211 having a low vibration transmissibility in the frequency range due to impact (50 Hz or more) and a high vibration transmissibility in the frequency range to be measured (10 Hz or less), damage to the vibration sensor 3 can be prevented while maintaining high accuracy of vibration measurement by the vibrometer 201.

Although several embodiments of the present invention have been described above, the present invention can also be embodied in other forms.

For example, the first contact surface 19 and the second contact surface 47 have been described as having a truncated cone shape, but as long as they are both annular tapered surfaces, they do not have to have a truncated cone shape.

In addition, the first contact surface 19 and the second contact surface 47 have been described as being tapered surfaces, but the first contact surface 19 and the second contact surface 47 may have a horizontal surface rather than a tapered surface. In this case, the first contact surface 19 and the second contact surface 47 may be circular in plan view or may have another annular shape.

This invention is not limited to the above embodiments, and various modifications are possible within the scope of the claims.

1: Vibration meter 2: Case 3: Vibration sensor 6: Handle (grip)
7: Processing unit 10a: Bottom portion 15a: First lower end 19: First contact surface (first engagement portion)
20: Internal space 41: Base 45a: Second lower end 47: Second contact surface (second engagement portion)
80: Protective cover 201: Vibration meter 211: Viscous sheet H1: First distance H2: Second distance

Claims (7)

A vibrometer for measuring vibrations while being placed on a mounting surface, comprising:
A case having an internal space;
A vibration sensor accommodated in the internal space;
a processing unit that is accommodated in the internal space and performs measurement processing based on a detection output output from the vibration sensor;
a base for supporting the vibration sensor, the base having legs that come into contact with a mounting surface, the base being movable up and down together with the vibration sensor accommodated in the internal space relative to the case and the processing unit ;
a base-side contact surface formed on the base and tapered downward toward the inside of the base;
a tapered case-side abutment surface formed on the case, facing the base-side abutment surface from above and below and matching with the base-side abutment surface ;
When the vibrometer is separated from the mounting surface, the base contact surface and the case contact surface are in surface contact with each other,
A vibrometer, wherein the vibration sensor and the base are not supported by the case when the vibrometer is placed on the placement surface . A through hole is formed in the case, the through hole vertically penetrating a bottom wall of the case,
The vibrometer according to claim 1 , wherein a lower end of the base is capable of protruding below the case through the through hole. The vibrometer according to claim 1 , wherein a first distance from a first lower end of the case-side contact surface is shorter than a second distance from a second lower end of the base-side contact surface . The vibrometer according to claim 1 , wherein the case-side contact surface and the base- side contact surface are frustum-shaped. The vibrometer of claim 1 or 4 , further comprising a viscous sheet disposed between the vibration sensor and the base. The base is circular in plan view,
The legs are multiple;
The vibrometer according to claim 1 , wherein the legs are arranged at intervals in a circumferential direction of the base in a plan view except at a center of the base. A vibrometer for measuring vibrations, comprising:
A case having an internal space;
A vibration sensor accommodated in the internal space;
a processing unit that is accommodated in the internal space and performs measurement processing based on a detection output output from the vibration sensor;
a base for supporting the vibration sensor, the base being capable of supporting the vibration sensor housed in the internal space independently from the case;
The vibration meter further includes a protective cover that covers a bottom of the case and is connectable to the base in a screw-tight manner.

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