JP6197794B2 - Vibration sensor unit - Google Patents

Description

  The present invention relates to a vibration sensor unit used for detecting leakage of pipes and diagnosing deterioration of structures such as buildings and bridges.

  Diagnosis techniques using various sensors have been proposed and put into practical use. For example, for fluid leakage diagnosis due to deterioration or destruction of piping such as water pipes, a method of detecting vibrations transmitted through piping caused by fluid leakage with a vibration sensor unit is generally performed (Patent Documents 1 and 2). . Since piping is buried underground or installed in a high-rise building, the method of installing a vibration sensor unit for a long period of time and inspecting by wireless communication is more efficient than manual inspection. Increase.

  As a vibration sensor unit, there is a type having an antenna for wireless communication. Generally, the antenna of this type of vibration sensor unit is externally attached to the housing of the vibration sensor unit via a waterproof connector.

  Patent Document 3 describes a rock fall / sediment collapse detection device in which a sensor, a control circuit, a battery, a wireless device, an antenna, and the like are built in a resin casing.

JP-A-6-34478 JP-A-8-166315 JP 2011-47252 A

  A vibration sensor unit must be installed for a long period of time for inspection of fluid leakage in piping and deterioration of structures such as buildings and bridges. For this reason, the vibration sensor unit is required to have environmental durability that can be used for a long period of installation, in particular, waterproofness and robustness.

  A general vibration sensor unit has a configuration in which an antenna is externally attached to a housing as described above. Therefore, when an external force is applied to the antenna, stress concentrates on the connector portion between the antenna and the housing, so that it is difficult to maintain the shape of the connector portion, and there is room for improvement in waterproofness and robustness.

  In the technique of Patent Document 3, the housing is made of resin. For this reason, it is difficult to detect minute vibrations because it is not only inferior in robustness due to its low rigidity compared to a metal housing, but also because the mechanical resistance is high and the attenuation of vibrations in the housing is large. It is. Further, since the moisture content of the resin is higher than that of the metal, it is difficult to maintain the waterproof property of the resin casing for a long period of time compared to the metal casing.

  An object of the present invention is to provide a vibration sensor unit excellent in waterproofness and robustness.

The present invention provides a vibration sensor unit.
The first vibration sensor unit of the present invention comprises:
A metallic housing apertures are formed,
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
I have a,
The insulator is formed in a flat plate shape.
The second vibration sensor unit of the present invention includes:
A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
The partition is
A first surface diagonally facing the antenna;
And a second surface that is diagonally opposed to the antenna and intersects the first surface.
The third vibration sensor unit of the present invention is
A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
The housing is
A first housing having the antenna therein;
A second housing having the vibration sensor and the control unit therein;
Including
The first housing is provided with the opening and the insulator.
The first housing and the second housing are detachable from each other,
The first housing and the second housing can be electrically connected to each other via external connection terminals formed in each.
The fourth vibration sensor unit of the present invention is:
A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
A wireless circuit board attached to the insulator;
The antenna is provided on the wireless circuit board.
The fifth vibration sensor unit of the present invention is:
A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
Resin is filled in the internal space of the casing.
The sixth vibration sensor unit of the present invention includes:
A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
A radio wave absorber is formed on a surface of the partition that is opposite to the surface facing the antenna.
The seventh vibration sensor unit of the present invention is
A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
A rib is formed on a surface of the partition portion opposite to the surface facing the antenna.
The eighth vibration sensor unit of the present invention is:
A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
The vibration sensor unit is configured such that the bottom of the housing is attached to an installation target surface on which the vibration sensor unit is installed,
The insulator is formed in a flat plate shape and is inclined with respect to the bottom surface of the housing.

  According to the present invention, the vibration sensor unit can be excellent in waterproofness and robustness.

  The above-described object and other objects, features, and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.

It is a typical front sectional view of the vibration sensor unit concerning a 1st embodiment. It is a typical front sectional view of a vibration sensor unit concerning a 2nd embodiment. It is a typical top view of a vibration sensor unit concerning a 2nd embodiment. It is a schematic diagram which shows the example of the radiation directivity of the antenna of the vibration sensor unit which concerns on 2nd Embodiment, (a) is a top view among these, (b) is a side view. It is a typical front sectional view of a vibration sensor unit concerning a 3rd embodiment. It is a typical front sectional view of a vibration sensor unit concerning a 4th embodiment. It is a typical front sectional view of a vibration sensor unit concerning a 5th embodiment. It is a figure which shows the example of the relationship between the distance from an antenna to a partition part, and the absolute gain of an antenna. It is a schematic diagram of the vibration sensor unit which concerns on 6th Embodiment, Among these, (a) is front sectional drawing, (b) is a bottom view of the electromagnetic wave absorber provided in the partition part. It is a schematic diagram of the vibration sensor unit which concerns on 7th Embodiment, Among these, (a) is front sectional drawing, (b) is a bottom view of a partition part. It is the schematic diagram of the vibration sensor unit which concerns on 8th Embodiment, among these, (a) is front sectional drawing, (b) is the figure which looked at the vibration sensor unit in the arrow A direction of (a). It is a schematic diagram of the vibration sensor unit which concerns on 9th Embodiment, (a) is front sectional drawing, (b) is a top view among these. It is typical front sectional drawing of the vibration sensor unit which shows the example of the attachment structure of an insulator and a partition part. It is a typical front sectional view of the vibration sensor unit which shows other examples of the attachment structure of an insulator. It is a schematic diagram which shows the other example of the attachment structure of an antenna, Among these, (a) is front sectional drawing of a vibration sensor unit, (b) is a top view of an antenna.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate. In the drawings, for convenience of explanation, the structure of each part may be simplified as appropriate, and the dimensional ratio of each part may be schematically shown, unlike the actual case.

[First Embodiment]
FIG. 1 is a schematic front sectional view of a vibration sensor unit 100 according to the first embodiment.

  The vibration sensor unit 100 according to the present embodiment includes a metal housing 10 in which an opening 11 is formed, an insulator 20 that closes the opening 11, an antenna 30, a partition portion 40 made of a conductor, and a vibration sensor 50. And a control unit 60. The antenna 30 is disposed in the closed space 5 surrounded by the insulator 20 and the housing 10. The vibration sensor 50 and the control unit 60 are disposed on the opposite side of the insulator 20 with respect to the antenna 30 in the closed space 5. The partition portion 40 is disposed so as to partition the first region 5a in which the antenna 30 is disposed in the closed space 5 and the second region 5b in which the vibration sensor 50 and the control unit 60 are disposed. Furthermore, the vibration sensor unit 100 includes a battery 80 disposed in the second region 5b. The vibration sensor unit 100 is used for water leak detection in a water supply network, gas leak detection in a gas pipe, leak detection of various pipes in a chemical plant, and diagnosis of deterioration of structures such as buildings and bridges. Details will be described below.

  The housing 10 is made of a corrosion-resistant metal or a metal subjected to a corrosion-resistant process. More specifically, the casing 10 is configured by molding a corrosion-resistant conductive material such as aluminum or stainless steel by pressing or die casting. Further, after the housing 10 is molded, corrosion resistance processing such as anodizing, fluorine processing, or insert molding may be performed.

  The insulator 20 is insulative with high transparency to radio waves output from the antenna 30. Examples of the material of the insulator 20 include a resin such as epoxy, or a ceramic such as glass. The insulator 20 functions as a radiation window that radiates radio waves output from the antenna 30 to the outside of the enclosed space 5. The shape of the insulator 20 is, for example, a flat plate shape. However, the insulator 20 may have any other shape.

  An insulator 20 is attached to the opening 11 of the housing 10 to close the opening 11, thereby forming a closed space 5 surrounded by the insulator 20 and the housing 10. The closed space 5 is waterproofed from the outside. For example, as shown in FIG. 1, the insulator 20 is fitted to the housing 10 and is brazed to the housing 10. Alternatively, the insulator 20 may be attached to the housing 10 by screwing or the like via a waterproof packing (O-ring). By attaching the insulator 20 to the housing 10 in this manner, waterproofing of the joint portion between the insulator 20 and the housing 10 is achieved.

  The vibration sensor unit 100 includes a wireless circuit board 70 having a printed pattern, and the antenna 30 is disposed on the printed pattern of the wireless circuit board 70. For example, the wireless circuit board 70 is fixed to the surface of the insulator 20 on the closed space 5 side.

  The partition 40 may be formed integrally with the housing 10, or the partition 40 formed separately from the housing 10 may be fixed to the housing 10.

  The entire housing 10 may include a plate-like bottom portion 12 and may be integrally formed. The bottom portion 12 is formed separately from a portion of the housing 10 excluding the bottom portion 12 (hereinafter referred to as a housing body). Later, it may be joined to the casing body by welding or adhesion.

  The bottom 12 of the housing 10 is fixed to a surface to be installed such as a water pipe. The vibration sensor unit 100 includes, for example, a fixing portion (not shown) (permanent magnet or the like) for attracting and fixing the bottom portion 12 to a water pipe or the like with a strong magnetic force.

  The vibration sensor 50 is configured by, for example, a piezoelectric element. The vibration sensor 50 is fixed to the bottom 12 by adhesion or the like. The detection result of vibration by the vibration sensor 50 is output to the control unit 60. Specifically, the vibration sensor 50 converts mechanical vibration of the vibration sensor unit 100 into an alternating electrical signal and outputs the electrical signal to the control unit 60.

  The control unit 60 has a sensor circuit and a power supply circuit. Among these, the sensor circuit digitizes the magnitude of the vibration of the vibration sensor unit 100 based on the electric signal input from the vibration sensor 50, determines the state of vibration with a predetermined threshold, and the determination result is wirelessly transmitted. It transmits to an external apparatus via the circuit board 70 and the antenna 30. The power supply circuit supplies power supplied from the battery 80 to the wireless circuit board 70.

The antenna 30 is a known current antenna having strong directivity in the direction of the insulator 20 or in the direction of the inside of the housing 10 facing the insulator 20. The antenna 30 is, for example, a λ / 4 monopole antenna. However, the antenna 30 is not limited to this example, and may be an antenna similar in directivity to the λ / 4 monopole antenna, such as a meander dipole antenna, a dipole antenna, or a one-wavelength loop antenna.
Further, the antenna 30 may be an antenna having a large directivity gain, such as a microstrip antenna. However, in this case, it is desirable to form the antenna 30 so that the main lobe faces the insulator 20.
The frequency of the radio wave output from the antenna 30 is desirably a 400 MHz band or a 900 MHz band for specific low power that can be used by a user without requiring a license.

The partition part 40 consists of a conductor (it is electrically conductive). It is preferable that the partition part 40 is metal. In this case, examples of the metal material constituting the partition 40 include silver, copper, or aluminum having high conductivity. In addition, the partition part 40 may be resin etc. which provided electroconductivity by surface processing. Further, if the housing 10 is conductive, the partition 40 may be made of the same material as the housing 10.
Since partition 40 is made of a conductor, it functions as a reflector for radio waves of a desired frequency output from antenna 30. The partition part 40 is arranged so that the directivity of the radio wave reflected by the partition part 40 faces the direction of the insulator 20. The partition 40 is disposed at a predetermined distance d from the antenna 30. This distance d will be described later.

An example of the shape of the partition 40 is a flat plate shape. In this case, it is preferable that the partition part 40 and the antenna 30 are arrange | positioned mutually parallel. The thickness of the partition portion 40 (vertical dimension in FIG. 1) is preferably 1/2 or more of the thickness of the housing 10.
In the case of this embodiment, the partition part 40 is opposed to the insulator 20 in parallel, for example. In addition, the partition 40 is provided in the housing 10 so as to substantially close the cross section (planar cross section) of the housing 10 (for example, so as to close a region excluding a formation region of a through hole 40a described later). It is preferable that they are arranged.

  The partition 40 may have a shape that forms a so-called corner reflector having two reflecting surfaces, as will be described later.

  The partition 40 is formed with a through hole 40a that allows the first region 5a and the second region 5b to communicate with each other. The control unit 60 and the radio circuit board 70 separated by the partition unit 40 are electrically connected to each other by the covered wire 7 or the like through the through hole 40a. Here, by filling the through hole 40a with an epoxy resin or arranging a rubber packing in the through hole 40a, the covered wire 7 or the like is fixed to the through hole 40a, and the covered wire 7 or the like is vibrated. It is preferable to suppress.

According to the first embodiment as described above, since the partition portion 40 made of a conductor is provided in the metal housing 10, the rigidity of the vibration sensor unit 100 can be increased. Therefore, the robustness of the vibration sensor unit 100 can be improved and the occurrence of unnecessary vibration in the vibration sensor unit 100 can be reduced. Furthermore, the presence of the partition portion 40 can enhance the waterproof performance of the second region 5b. Further, by attaching the insulator 20 functioning as a radiation window for outputting the radio wave output from the antenna 30 to the outside, the insulator 30 is built in the casing 10 with the insulator 20 as a lid. It becomes possible to do. In addition, since the insulator 20 closes the opening 11 of the housing 10, the closed space 5 surrounded by the insulator 20 and the housing 10 is formed. Can be secured. Further, since the housing 10 is made of metal and has a low mechanical resistance, the vibration sensor 50 can reliably detect minute vibrations.
Therefore, it is possible to obtain a vibration sensor unit with high vibration detection accuracy and excellent long-term waterproofness and robustness against external impacts.
For the same reason that minute vibrations can be reliably detected by the vibration sensor 50, when the vibration power generator is mounted on the vibration sensor unit 100, high electric conversion efficiency can be obtained, so that high power generation efficiency can be realized.
Furthermore, the partition part 40 made of a conductor also functions as an electromagnetic shield that electromagnetically shields the first region 5a and the second region 5b from each other. For this reason, it can suppress that the electromagnetic waves emitted from the control part 60 act on the radio | wireless circuit board 70 and the antenna 30, and induce the malfunctioning of the radio | wireless circuit board 70 and the antenna 30. FIG. At the same time, electromagnetic waves emitted from the radio circuit board 70 and the antenna 30 can be prevented from acting on the control unit 60 and inducing a malfunction of the control unit 60.

  Moreover, since the radio circuit board 70 is attached to the insulator 20 and the antenna 30 is provided on the radio circuit board 70, the radio wave output from the antenna 30 can be efficiently output to the outside through the insulator 20. it can.

  Further, by forming the partitioning portion 40 in a flat plate shape and arranging the partitioning portion 40 and the antenna 30 in parallel with each other, radio waves output from the antenna 30 can be efficiently reflected by the partitioning portion 40. .

[Second Embodiment]
FIG. 2 is a schematic front sectional view of a vibration sensor unit 200 according to the second embodiment. FIG. 3 is a schematic plan view of the vibration sensor unit 200. FIG. 4 is a schematic diagram showing an example of radiation directivity of the antenna 30 of the vibration sensor unit 200, in which (a) is a plan view and (b) is a side view.

  The vibration sensor unit 200 according to the present embodiment is different from the vibration sensor unit 100 according to the first embodiment in the points described below, and is configured similarly to the vibration sensor unit 100 in other points. Yes.

  The housing 10 is formed in, for example, a cylindrical shape (specifically, for example, a cylindrical shape). The housing 10 has a flange-shaped flange portion 14 formed at the peripheral edge of the opening 11. The insulator 20 is fastened to the flange portion 14 by bolts 9a and nuts 9b. A waterproof packing (O-ring) 8 is interposed between the insulator 20 and the flange portion 14 so that the joint between the insulator 20 and the flange portion 14 is waterproofed.

  As shown in FIG. 4B, the antenna 30 is an antenna having strong directivity in the direction of the insulator 20 and the direction inside the casing 10 facing the insulator 20 (upward and downward in FIG. 2).

  According to the second embodiment as described above, the same effect as in the first embodiment can be obtained.

[Third Embodiment]
FIG. 5 is a schematic front sectional view of a vibration sensor unit 300 according to the third embodiment.

  The vibration sensor unit 300 according to the present embodiment is different from the vibration sensor unit 100 according to the first embodiment or the vibration sensor unit 200 according to the second embodiment in other points as described below. The configuration is the same as that of the vibration sensor unit 100 or 200.

  In the case of this embodiment, the resin 310 is filled in the closed space (internal space) 5 (the first region 5 a and the second region 5 b) of the housing 10. As the resin 310, for example, a two-component liquid epoxy resin (relative dielectric constant 7.2) that cures at a low temperature of about 100 ° C. is used.

According to the third embodiment, in addition to the same effects as the first or second embodiment, the following effects can be obtained.
By filling the inside of the housing 10 with the resin 310, the distance d is shortened by the wavelength shortening effect as compared with the second embodiment, so that the vibration sensor unit 200 can be lowered in height. Since the housing 10 does not have a hollow structure, the rigidity of the housing 10 is also improved.

[Fourth Embodiment]
FIG. 6 is a schematic front sectional view of a vibration sensor unit 400 according to the fourth embodiment.

  The vibration sensor unit 400 according to the present embodiment is different from the vibration sensor units 100, 200, and 300 according to the first to third embodiments in the points described below, and is otherwise the vibration sensor unit. The configuration is the same as 100, 200, and 300.

  In the case of this embodiment, the housing 10 includes a first housing 411 having the antenna 30 and the radio circuit board 70 therein, and a second housing 412 having the vibration sensor 50 and the control unit 60 inside. It is configured. An opening 11 is formed in the first housing 411, and an insulator 20 is provided so as to close the opening 11. The first area 5a that is the internal space of the first housing 411 is a sealed space. On the other hand, the second region 5b which is the internal space of the second housing 412 is also a sealed space. A battery 80 is also arranged in the second housing 412.

  The first housing 411 and the second housing 412 are detachable from each other. Specifically, for example, a flange portion 411a is formed at the lower end of the first housing 411, and a flange portion 412a that abuts the flange portion 411a is formed at the upper end of the second housing 412. And the flange part 411a and the flange part 412a are fastened by the volt | bolt 9a and the nut 9b in the state in which the flange part 411a and the flange part 412a were faced | matched mutually. Thereby, the first housing 411 and the second housing 412 are integrated with each other.

  The first housing 411 and the second housing 412 can be separated from each other by removing the bolt 9a that fastens the flange portion 411a and the flange portion 412a from the nut 9b.

In the case of this embodiment, the partition 40 is continuously formed with the first portion 41 formed continuously with the flange 411 a at the lower end of the first housing 411 and with the flange 412 a at the upper end of the second housing 412. A second portion 42 formed. The first portion 41 is located on the same plane as the flange portion 411a, and the second portion 42 is located on the same plane as the flange portion 412a. The first portion 41 and the second portion 42 are abutted against each other.
An external connection terminal 421 is provided on the lower surface of the first portion 41, and an external connection terminal 422 is provided on the upper surface of the second portion 42. The external connection terminal 421 is electrically connected to the wireless circuit board 70 by the covered wire 7 or the like through the through hole 40 a formed in the first portion 41. Similarly, the external connection terminal 422 is electrically connected to the control unit 60 by the covered wire 7 or the like through the through hole 40a formed in the second portion 42. That is, the first housing 411 and the second housing 412 can be electrically connected to each other via the external connection terminals 421 and 422 formed in each.

  In a state where the first housing 411 and the second housing 412 are integrated with each other, the external connection terminal 421 and the external connection terminal 422 come into contact with each other, whereby the wireless circuit board 70 and the control unit 60 are mutually connected. Electrically connected.

  A waterproof packing (O-ring) 8 is interposed between the flange portion 411 a and the flange portion 412 a and around the external connection terminals 421 and 422. Thereby, waterproofing of the external connection terminals 421 and 422, and hence the first region 5a and the second region 5b is achieved.

According to the fourth embodiment as described above, the following effects can be obtained in addition to the same effects as the first to third embodiments.
The housing 10 includes a first housing 411 having the antenna 30 and the radio circuit board 70 therein, and a second housing 412 having the vibration sensor 50 and the control unit 60 inside. The first housing 411 The second housing 412 can be attached to and detached from each other. Therefore, it is possible to exchange only the second housing 412 while sharing the first housing 411. Therefore, for example, when the vibration sensor 50 or the control unit 60 fails, only the second housing 412 can be replaced. Further, for example, when a second housing 412 having a pyroelectric sensor is separately manufactured, the second housing 412 can be easily replaced. Further, by adopting a structure in which the battery 80 is arranged in the second housing 412, it is possible to replace only the second housing 412 when the battery 80 is exhausted.

[Fifth Embodiment]
FIG. 7 is a schematic front sectional view of a vibration sensor unit 500 according to the fifth embodiment.

  The vibration sensor unit 500 according to the present embodiment is different from the vibration sensor units 100, 200, 300, and 400 according to the first to fourth embodiments described above in the points described below. The sensor units 100, 200, 300, and 400 are configured in the same manner.

  In the case of this embodiment, the partition part 40 has comprised the corner reflector shape. The partition 40 has a first surface 45 that obliquely opposes the antenna 30 and a second surface 46 that obliquely opposes the antenna 30 and intersects the first surface 45. The first surface 45 and the second surface 46 of the partition portion 40 are also opposed obliquely to the insulator 20.

According to the fifth embodiment as described above, in addition to the same effects as in the first to fourth embodiments, the following effects can be obtained.
Since the partition part 40 has a corner reflector shape, the directivity of the radio wave reflected by the partition part 40 in the direction of the insulator 20 is high. Therefore, the radiation efficiency of the radio wave from the vibration sensor unit 500 can be improved.

Here, the distance d from the antenna 30 to the partition part 40 in each of the above embodiments will be described.
FIG. 8 is a diagram illustrating an example of the relationship between the distance d and the absolute gain of the antenna 30. Of these, FIG. 8A shows the relationship when the reflecting surface of the partition portion 40 (surface facing the antenna 30 side) is a plane, and FIG. 8B shows the reflecting surface of the partition portion 40 facing the antenna 30 side. The relationship when the surface) has a corner reflector shape is shown. In FIG. 8B, the curve indicated by the solid line indicates the relationship when the angle θ formed by the first surface 45 and the second surface 46 is 60 degrees, and the curve indicated by the dotted line indicates that the angle θ is 90 degrees. The relationship in the case of is shown. The wavelength λ is the wavelength of the fundamental resonance frequency output from the antenna 30.

  When the reflecting surface of the partition 40 is a flat surface, the distance d is set to about 0.1 to 0.4 times the wavelength λ, or about 0.6 to 0.9 times the wavelength λ. It is preferable.

  When the reflecting surface of the partition 40 has a corner reflector shape, the distance d is preferably about 0.1 to 0.9 times the wavelength λ.

[Sixth Embodiment]
FIG. 9 is a schematic view of a vibration sensor unit 600 according to the sixth embodiment, in which FIG. 9A is a front cross-sectional view, and FIG. 9B is a diagram of a radio wave absorber 610 provided in the partition 40. It is a bottom view.

  The vibration sensor unit 500 according to the present embodiment is different from the vibration sensor units 100, 200, 300, 400, and 500 according to the first to fifth embodiments in the points described below. The vibration sensor units 100, 200, 300, and 400 are configured in the same manner.

  In the case of the present embodiment, a radio wave absorber 610 is formed on the surface of the partitioning portion 40 opposite to the surface facing the antenna 30. Thereby, it can suppress that the electromagnetic waves which generate | occur | produce from the control part 60 (for example, power supply circuit of the control part 60) act on the radio | wireless circuit board 70 and the antenna 30. FIG. Examples of the material of the radio wave absorber 610 include magnetic materials such as ferrite. The radio wave absorber 610 is, for example, in the form of a sheet.

  The radio wave absorber 610 has a through hole 610a formed at a position facing the through hole 40a of the partition 40. The controller 60 and the radio circuit board 70 are electrically connected to each other by the covered wire 7 or the like through the through hole 610a and the through hole 40a.

  According to the sixth embodiment as described above, the same effects as those of the first to fifth embodiments can be obtained, and electromagnetic waves generated from the control unit 60 act on the radio circuit board 70 and the antenna 30. This can be suppressed.

[Seventh Embodiment]
10A and 10B are schematic views of a vibration sensor unit 700 according to the seventh embodiment, in which FIG. 10A is a front sectional view and FIG. 10B is a bottom view of the partition portion 40.

  The vibration sensor unit 700 according to the present embodiment is different from the vibration sensor units 100, 200, 300, 400, 500, and 600 according to the first to fifth embodiments in the points described below. In this respect, the vibration sensor units 100, 200, 300, 400, 500, and 600 are configured in the same manner.

  In the present embodiment, ribs 710 are formed on the surface of the partitioning portion 40 opposite to the surface facing the antenna 30, and the partitioning portion 40 is reinforced by the ribs 710. The ribs 710 are preferably formed in, for example, a lattice shape extending vertically and horizontally. However, the rib 710 may be striped. The rib 710 may have other shapes.

  According to the seventh embodiment as described above, the same effects as those of the first to fifth embodiments can be obtained, and the partition portion 40 is reinforced by the ribs 710. The reinforcing effect can be improved. Therefore, the robustness of the vibration sensor unit 500 can be enhanced. Alternatively, it is possible to reduce the thickness of the metal constituting the housing 10 and reduce the weight of the housing 10.

[Eighth Embodiment]
11A and 11B are schematic views of a vibration sensor unit 800 according to the eighth embodiment, in which FIG. 11A is a front sectional view, and FIG. 11B is a view showing the vibration sensor unit 800 in the direction of arrow A in FIG. FIG.

  The vibration sensor unit 800 according to the present embodiment is the vibration sensor unit 100, 200, 300, 400, 600, 700 according to the first to fourth, sixth, or seventh embodiment described above in the following points. In other respects, the vibration sensor units 100, 200, 300, 400, 600, and 700 are configured in the same manner.

As described in the first embodiment, the vibration sensor unit 800 is configured such that the bottom 12 (see FIGS. 1 and 2) of the housing 10 is attached to the installation target surface. The insulator 20 is formed in a flat plate shape and is inclined with respect to the bottom surface of the housing 10. Although the inclination angle of the insulator 20 with respect to the bottom surface of the housing 10 is arbitrary, for example, it is preferably 45 degrees.
In the case of the present embodiment, the housing 10 has, for example, a cylindrical shape, and the insulator 20 is also inclined with respect to the cylindrical axis.

  The insulator 20 is fixed to the housing 10 by screwing bolts 9 a into the housing 10 through the insulator 20. The waterproofing between the insulator 20 and the housing 10 is achieved by the waterproof packing 8 as in the above embodiments.

The partition 40 is disposed in parallel to the installation target surface on which the vibration sensor unit 800 is installed.
Also in this embodiment, the radio circuit board 70 and the antenna 30 are fixed to the insulator 20.
For this reason, the antenna 30 is disposed to be inclined (for example, inclined 45 degrees) with respect to the partition portion 40.

  In the case of this embodiment, since the insulator 20 is inclined with respect to the bottom surface of the housing 10, an antenna radiated from the vibration sensor unit 800 is obtained by rotating the housing 10 around its cylindrical axis. The directivity of 30 radio waves can be easily changed. Therefore, the vibration sensor unit 800 can be easily installed on the installation target surface in such a posture that the communication state of the wireless communication between the vibration sensor unit 800 and the external device is good.

  In the case of the present embodiment, by making the partition portion 40 and the inner side surface 19 of the housing 10 have the same shape as the corner reflector shape, the radio wave radiation efficiency from the vibration sensor unit 800 can be improved. .

[Ninth Embodiment]
12A and 12B are schematic views of a vibration sensor unit 900 according to the ninth embodiment, in which FIG. 12A is a front sectional view and FIG. 12B is a plan view.

  The vibration sensor unit 900 according to the present embodiment is different from the vibration sensor unit 800 according to the eighth embodiment described above, and is configured in the same manner as the vibration sensor unit 800 in other points.

In the case of this embodiment, the housing 10 includes a first housing 411 having the antenna 30 and the radio circuit board 70 therein, and a second housing 412 having the vibration sensor 50 and the control unit 60 inside. It is configured.
An opening 11 is formed in the first housing 411, and an insulator 20 is provided so as to close the opening 11. The insulator 20 is fixed to the casing 10 (first casing 411) with bolts 9a, as in the eighth embodiment.
The first area 5a that is the internal space of the first housing 411 is a sealed space. On the other hand, the second region 5b which is the internal space of the second housing 412 is also a sealed space.

  For example, a flange portion 411 a and a first portion 41 are formed at the lower end of the first housing 411, and a flange portion 412 a that abuts the flange portion 411 a and a second portion that abuts the first portion 41 are formed in the second housing 412. A portion 42 is formed. And the flange part 411a and the flange part 412a are fastened by the volt | bolt 9a and the nut 9b in the state in which the flange part 411a and the flange part 412a were faced | matched mutually. Thereby, the first housing 411 and the second housing 412 are integrated with each other. A convex portion 41 a that protrudes downward is formed on the lower surface of the first portion 41, and a concave portion 42 a that is recessed downward is formed on the upper surface of the second portion 42. The convex portion 41a is fitted into the concave portion 42a.

  In the case of this embodiment, the vibration sensor unit 900 is configured such that the bottom surface of the second housing 412 (not shown: similar to the bottom surface of the bottom portion 12 shown in FIGS. 1 and 2) is attached to the installation target surface. Yes.

  The insulator 20 is formed in a flat plate shape and is inclined with respect to the bottom surface of the second housing 412.

  The first casing 411 and the second casing 412 can rotate around a rotation axis 920 orthogonal to the bottom surface of the second casing 412.

  In order to enable such rotation operation, as shown in FIG. 12B, for example, the flange portion 411a of the first housing 411 has an arcuate shape extending along the circumferential direction of the flange portion 411a. A guide hole 910 is formed through the front and back of the flange portion 411a. The plurality of guide holes 910 are arranged along the same circumference. The bolt 9a passes through the guide hole 910 and fastens the flange portion 411a and the flange portion 412a in cooperation with the nut 9b.

  Therefore, the first casing 411 is rotated around the rotation axis 920 relative to the second casing 412 while maintaining the first casing 411 and the second casing 412 connected to each other. Can do. During this rotation, the bolt 9 a moves while being guided by the guide hole 910, and the first housing 411 rotates relative to the second housing 412 against friction with the waterproof packing 8. Note that the first housing 411 rotates with respect to the second housing 412 in a state where the convex portion 41a is fitted in the concave portion 42a.

  In the case of the present embodiment, the insulator 20 is disposed to be inclined with respect to the bottom surface of the housing 10 (the bottom surface of the second housing 412), and the first housing 411 and the second housing 412 are: The second casing 412 can rotate around the rotation axis 920 orthogonal to the bottom surface. Therefore, the directivity of the radio wave of the antenna 30 radiated from the vibration sensor unit 900 can be easily changed by rotating the first casing 411 around the rotation axis 920 with respect to the second casing 412.

  FIG. 13 is a schematic front cross-sectional view of a vibration sensor unit showing an example of an attachment structure of the insulator 20 and the partition 40 in each of the above embodiments.

  As shown in FIG. 13, a step 17 is formed on the inner surface of the housing 10, and an insulator 20 is fitted into the step 17 so that the insulator 20 is attached to the housing 10. Further, the insulator 20 may be bonded to the housing 10 via the brazing portion 15.

  Similarly, a step 18 is formed on the inner surface of the housing 10, and a partition 40 is fitted into the step 18, and the partition 40 is attached to the housing 10. Moreover, the partition part 40 may be adhere | attached with respect to the housing | casing 10, and may be brazed.

  FIGS. 14A and 14B are schematic front sectional views of a vibration sensor unit showing another example of the mounting structure of the insulator 20 in each of the above embodiments.

  As shown in FIG. 14 (a), the protrusion 20 a formed on the lower surface of the insulator 20 is fitted into the step 17 on the inner surface of the housing 10, and the insulator 20 is brazed to the housing 10. Also good. In this case, the brazing part 15 can be formed on the upper surface of the housing 10.

  As shown in FIG. 14B, the insulator 20 may be formed in a curved surface having a cross-sectional arc shape. The insulator 20 may be brazed to the housing 10 or may be fastened to the housing 10 with a bolt 9a.

  In addition, it is preferable that the metallization layer of the brazing part 15 is corrosion resistance. Specifically, for example, as the metallized layer, tungsten, stainless steel (SUS316), or the like can be given.

  FIG. 15 is a schematic view showing another example of the mounting structure of the antenna 30 in each of the above embodiments, in which (a) is a front sectional view of the vibration sensor unit, and (b) is a plan view of the antenna 30. .

  In each of the above embodiments, the example in which the antenna 30 is fixed to the insulator 20 has been described. However, the antenna 30 may be disposed away from the insulator 20. As shown in FIG. 15A, in this example, the wireless circuit board 70 is disposed in the housing 10 so as to be separated from the insulator 20, and the antenna 30 is provided on the wireless circuit board 70.

  Here, if the antenna 30 is too close to the housing 10, the radiation efficiency is lowered. Therefore, the clearance C between the antenna 30 and the housing 10 is not less than 0.15λ times the wavelength λ. It is preferable.

Example 1
As an example, a vibration sensor unit 200 having the configuration shown in FIG. 2 was produced. A metal casing 10 having an outer diameter of 90φ × height of 90 mm and a distance d of 60 mm was produced by die casting using an aluminum material having a thickness of 10 mm. The radio circuit board 70 and the insulator 20 were attached to each other with a tape or the like, and arranged so that the component mounting surface of the radio circuit board 70 faced the partition 40. Further, a 75.6 mm × 1.0 mm linear λ / 4 monopole antenna resonating at 955 MHz was formed on the wireless circuit board 70, and the RFIC and its peripheral circuits were installed on the wireless circuit board 70. At this time, the distance d is 1/5 wavelength. Further, a control unit 60 and a battery 80 mounted with a power supply circuit and MCU are arranged in the casing 10, and a vibration sensor 50 having an outer diameter of 15 mm and a thickness of 5 mm using piezoelectric ceramics is fixed to the bottom 12 of the casing 10. 12 was bonded to the housing body by welding, and the housing 10 was sealed. Further, the partition portion 40 is provided with a through hole 40a, and the wireless circuit board 70 and the control portion 60 are connected by a covered wire.

  Note that the configurations in the above embodiments can be combined with each other.

This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2012-215175 for which it applied on September 27, 2012, and takes in those the indications of all here.
1. A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
A vibration sensor unit.
2. The insulator is formed in a flat plate shape. The vibration sensor unit described in 1.
3. The partition is formed in a flat plate shape,
1. The partition and the antenna are arranged in parallel to each other. Or 2. The vibration sensor unit described in 1.
4). The partition is
A first surface diagonally facing the antenna;
A second surface that is diagonally opposed to the antenna and intersects the first surface;
Having 1. Or 2. The vibration sensor unit described in 1.
5. The housing is
A first housing having the antenna therein;
A second housing having the vibration sensor and the control unit therein;
Including
The first housing is provided with the opening and the insulator.
The first casing and the second casing are detachable from each other. To 4. The vibration sensor unit according to any one of the above.
6). 4. The first housing and the second housing can be electrically connected to each other via external connection terminals formed on each. The vibration sensor unit described in 1.
7). 4. The battery further includes a battery disposed in the second housing. Or 6. The vibration sensor unit described in 1.
8). A wireless circuit board attached to the insulator;
The antenna is provided on the wireless circuit board. To 7. The vibration sensor unit according to any one of the above.
9. A wireless circuit board disposed in the housing apart from the insulator;
The antenna is provided on the wireless circuit board. To 7. The vibration sensor unit according to any one of the above.
10. 1. The interior space of the casing is filled with resin. Thru 9. The vibration sensor unit according to any one of the above.
11. A radio wave absorber is formed on a surface of the partitioning portion opposite to the surface facing the antenna. To 10. The vibration sensor unit according to any one of the above.
12 1. Ribs are formed on the surface of the partition portion opposite to the surface facing the antenna. To 11. The vibration sensor unit according to any one of the above.
13. The vibration sensor unit is configured such that the bottom of the housing is attached to an installation target surface on which the vibration sensor unit is installed,
The insulator is formed in a flat plate shape and is inclined with respect to the bottom surface of the housing. To 12. The vibration sensor unit according to any one of the above.
14 The housing is
A first housing having the antenna therein;
A second housing having the vibration sensor and the control unit therein;
Including
The first housing is provided with the opening and the insulator.
The vibration sensor unit is configured such that the bottom surface of the second housing is attached to the installation target surface,
The insulator is disposed to be inclined with respect to a bottom surface of the second housing;
12. The first housing and the second housing are rotatable relative to each other around a rotation axis orthogonal to the bottom surface of the second housing. The vibration sensor unit described in 1.

Claims (11)

A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
I have a,
Vibration sensor unit and the insulator that have been formed in a plate shape. A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
The partition is
A first surface diagonally facing the antenna;
A second surface that is diagonally opposed to the antenna and intersects the first surface;
Vibration sensor unit that have a. A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
The housing is
A first housing having the antenna therein;
A second housing having the vibration sensor and the control unit therein;
Including
The first housing is provided with the opening and the insulator.
The first housing and the second housing are detachable from each other,
Wherein the first housing and the second housing, movement sensor unit vibration Ru electrically connectable der to each other via an external connection terminal formed on each. The vibration sensor unit according to claim 3 , further comprising a battery disposed in the second housing. A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
A wireless circuit board attached to the insulator;
Movement sensor unit vibration wherein the antenna that provided on the radio circuit board. A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
Movement sensor unit vibration which resin is filled into the internal space of the housing. A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
The vibration movement sensor units that have wave absorber is formed in the surface opposite to the antenna surface facing the partition portion. A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
The antenna and the vibration sensor unit that is formed rib on the opposite side of the opposing surfaces in the partition portion. A metal case with an opening, and
An insulator that closes the opening;
An antenna disposed in a closed space surrounded by the insulator and the housing;
A vibration sensor and a control unit disposed on the opposite side of the insulator with respect to the antenna in the enclosed space;
A partition portion made of a conductor that partitions the first region where the antenna is disposed in the closed space and the second region where the vibration sensor and the control unit are disposed;
Have
The vibration sensor unit is configured such that the bottom of the housing is attached to an installation target surface on which the vibration sensor unit is installed,
The insulator is formed into a flat plate shape, and the casing of the vibration sensor unit that is disposed inclined with respect to the bottom surface. The housing is
A first housing having the antenna therein;
A second housing having the vibration sensor and the control unit therein;
Including
The first housing is provided with the opening and the insulator.
The vibration sensor unit is configured such that the bottom surface of the second housing is attached to the installation target surface,
The insulator is disposed to be inclined with respect to a bottom surface of the second housing;
The vibration sensor unit according to claim 9 , wherein the first housing and the second housing are capable of rotating with respect to each other around a rotation axis orthogonal to the bottom surface of the second housing.   A wireless circuit board disposed in the housing apart from the insulator;
  The vibration sensor unit according to claim 1, wherein the antenna is provided on the wireless circuit board.

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