JP2010048749A - Vibration sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration sensor device capable of detecting vibration over a long period of time.
SOLUTION: A rectangular parallelepiped space 2 in which a pair of opposing surfaces provided in an insulating base 1 are square is filled with an insulating liquid, and the space 2 is subjected to vibration of the space 2. A rectangular parallelepiped dielectric block 3 having a square shape that is opposed to each of the opposing set of surfaces that can move inside is housed, and each of the opposing set of surfaces of the space 2 The length of one side is the same as the length of one side of the dielectric block 3, and the distance in plan view between the outer side and the end of the surface of the space 2 is smaller than the length of one side of the dielectric block 3. This is a vibration sensor device 9 in which the capacitive electrode 4 is formed except for the square-shaped region S having dimensions. Since the capacitance between the capacitive electrodes 4 and 4 changes with the movement of the dielectric block 3 according to the vibration of the space 2, the vibration can be detected while suppressing the wear of the capacitive electrode 4 and the like.
[Selection] Figure 1

Description

  The present invention relates to a vibration sensor device that detects vibrations associated with operation or abnormality of various devices such as pumps and compressors, and vibrations associated with human movements.

  Conventionally, as a vibration sensor device for detecting vibrations due to the operation or abnormality of various devices such as pumps and compressors, vibrations due to human movement, etc., depending on the vibration of conductive spheres, electrode plates, etc. A device including a movable body capable of moving and displacing, and an electrode capable of detecting the presence or absence of conduction by the movable body and a change in capacitance for detecting the movement of the movable body is known (for example, (See Patent Documents 1 and 2.)

  Such a vibration sensor device includes, for example, a conductive sphere as a movable body, and includes a comb-shaped first electrode and a second electrode disposed in parallel with the movable body interposed therebetween as an electrode. Yes. And by repeating the conductive sphere between the first electrode and the second electrode in response to vibration, the state where the first electrode and the second electrode are conductive is repeated and the state where the conductive sphere is not conductive is repeated. By detecting this change in conduction, vibration is detected.

In the case of a vibration sensor device that detects vibration by a change in capacitance, for example, a movable electrode that can be displaced (deflection or the like) according to vibration and a fixed electrode that faces the movable electrode are provided. Yes. Then, the movable electrode bends in response to the vibration, the distance between the movable electrode and the fixed electrode changes, and the capacitance between the two changes, and the vibration is detected by detecting this change in capacitance. The
JP-A-10-9944 JP 2007-205851

  However, in the conventional vibration sensor device, since the direct contact between the movable body such as the conductive sphere and the electrode is repeated, there is a problem that the electrode and the conductive sphere are likely to suffer from problems such as wear and damage. . Further, since the movable electrode repeats displacement (deformation) such as deflection, there is a problem that a crack or the like starting from the displaced portion is likely to occur.

  In particular, when the vibration is intense and the speed of the displacement of the conductive sphere or the displacement of the movable electrode, the number of times, the amount of displacement, etc. are large, the above-described problems are more likely to occur.

  The present invention has been completed in view of such conventional problems, and an object of the present invention is to provide a highly reliable vibration sensor device that can stably detect vibration over a long period of time. It is in.

  According to the vibration sensor device of the present invention, an insulating liquid is filled in a rectangular parallelepiped space in which a pair of opposing surfaces provided in an insulating base is a square shape, and the vibration sensor device responds to the vibration of the space. A rectangular parallelepiped-shaped dielectric block having a square shape that is movable in the space and facing each of the opposing set of surfaces is accommodated, and the opposing set of the space Each of the surfaces has a square shape in which the length of one side is the same as the length of one side of the dielectric block, and the distance in plan view between the outer side and the end of the surface of the space is one side of the dielectric block The capacitor electrode is formed except for a square region having a dimension smaller than the length of the capacitor.

  In the vibration sensor device according to the aspect of the invention, in the above configuration, the dielectric block has a relative dielectric constant of a portion of the insulating base located between the capacitive electrode and the space and the liquid. It is characterized by being larger than the relative dielectric constant.

  In the vibration sensor device according to the aspect of the invention, in the configuration described above, the space and the dielectric block are each in a cubic shape, and at least one of two opposing surfaces different from the opposing surface of the space. In addition, the length of one side is the same square as the length of one side of the dielectric block, and the distance in plan view between the outer side and the end of the surface of the space is one side of the dielectric block. The capacitor electrode is formed except for a square region having a dimension smaller than the length of the capacitor.

  According to the vibration sensor device of the present invention, since the above-described configuration is provided, one side is provided on each of a pair of faces of the space according to the position of the dielectric block that moves in the space according to the vibration of the space. A square whose length is the same as the length of one side of the dielectric block and whose distance in plan view between the outer side and the edge of the space is smaller than the length of one side of the dielectric block The range of the dielectric block interposed between the capacitive electrodes formed excluding the shaped region changes, and the capacitance between the capacitive electrodes changes accordingly. In addition, when the space is not vibrating, the dielectric block is stationary at some point in the space according to the difference between the density and the density of the liquid, so that the capacitance between the capacitive electrodes changes. do not do. Therefore, the presence or absence of vibration can be detected by detecting the presence or absence of this change in capacitance.

  Further, according to the vibration sensor device of the present invention, the dielectric block is not in direct contact with the capacitor electrode, and deformation such as deflection does not occur in the dielectric block itself. Therefore, it is possible to provide a highly reliable vibration sensor device capable of effectively suppressing the occurrence of defects such as wear and cracks in the dielectric block and the capacitor electrode and capable of detecting vibration stably over a long period of time. be able to.

  Note that the space, the dielectric block, and the capacitive electrode in the vibration sensor device of the present invention have the above-described configuration in order to reliably change the capacitance between the capacitive electrodes in accordance with the movement of the dielectric block.

  That is, for example, when a dielectric block having a square shape with the same size as the opposing surface is interposed in the entire area between the square regions of a pair of opposing surfaces (dielectric between the capacitor electrodes). The capacitance generated between the capacitive electrodes (when no body block is present) is minimized. If the dielectric block moves from this state, the range of the dielectric block interposed between the capacitive electrodes increases, and the capacitance generated between the capacitive electrodes gradually increases. In addition, when the square dielectric block is located at the corner of the space when viewed from the capacitive electrode side, the range of the dielectric block interposed between the capacitive electrodes is the maximum, and electrostatic capacitance generated between the capacitive electrodes Capacity is maximized. If the dielectric block is moved from this state, the range of the dielectric block interposed between the square regions where the capacitor electrodes are not formed increases (the range of the dielectric block interposed between the capacitor electrodes is increased). The capacitance generated between the capacitive electrodes gradually decreases. When the square dielectric block moves along one outer side of the square region, the distance in plan view between the outer side and the end of the surface of the space is the length of one side of the dielectric block. The dielectric block is in a rectangular (including square) range corresponding to the difference in length between the square regions provided in each of the pair of opposing surfaces of the space having a dimension smaller than Depending on this range, the capacitance generated between the capacitive electrodes decreases. Further, the intervening range gradually changes according to the movement of the dielectric block. Thus, since the capacitance between the capacitive electrodes changes according to the movement of the dielectric block accompanying the vibration of the space, the presence or absence of the vibration of the space can be detected based on the presence or absence of the change of the capacitance.

  In the vibration sensor device of the present invention, in the configuration described above, the relative permittivity of the dielectric block is higher than the relative permittivity of the portion located between the capacitive electrode and the space in the insulating base and the relative permittivity of the liquid. If it is large, the change in capacitance when the dielectric block is interposed between the capacitance electrodes can be increased more effectively. Therefore, it is possible to provide a vibration sensor device that can more reliably detect the change in capacitance between the capacitance electrodes, that is, the presence or absence of the movement of the dielectric block.

  Further, in the vibration sensor device of the present invention, the space and the dielectric block are each in the shape of a cube, and the length of one side is also set on at least one of two opposing surfaces different from the opposing surface of the space. Is a square-shaped region having the same length as one side of the dielectric block, and the distance in plan view between the outer side and the end of the surface of the space is smaller than the length of one side of the dielectric block. In the case where a capacitive electrode is formed, since two different sets of surfaces are orthogonal to each of the opposing set of surfaces, the capacitance formed on at least one of the two sets of surfaces. By detecting a change in the capacitance between the electrodes, it is also possible to detect vibration in a direction orthogonal to a pair of surfaces in the space.

  In this case, the space has a cubic shape, and each surface constituting the space has the same square shape, and the capacitive electrodes are formed on each of them except for a similar square region. In the capacitive electrode formed on at least one of the two sets of opposed surfaces different from the surface, the movement of the dielectric block in response to the vibration is performed as in the case of the capacitive electrode formed on the one set of surfaces described above. Can be detected.

  Therefore, in this case, it is possible to provide a vibration sensor device that can effectively detect vibrations in space in three directions that are so-called front and rear, right and left, and top and bottom, which are orthogonal to each other over a long period of time.

  The vibration sensor device of the present invention will be described with reference to the accompanying drawings.

  FIGS. 1A and 1B are a side view and a top view (both are perspective views) showing an example of an embodiment of the vibration sensor device of the present invention, respectively, and FIG. 2 is a vibration sensor device 9 shown in FIG. It is a perspective view (perspective view). 1 and 2, 1 is an insulating substrate, 2 is a space, 3 is a dielectric block, and 4 is a capacitive electrode. A space 2 provided inside the insulating base 1 is filled with an insulating liquid (not shown), and a dielectric block 3 is accommodated. The capacitive electrode 4 is formed except for the square region S, and the vibration sensor device 9 of the present invention is basically configured. In FIG. 2, the insulating substrate 1 is omitted for the sake of clarity.

  The vibration sensor device 9 is mounted on a device having a movable part such as a pump, a compressor, or an engine, for example, and is used as a detector that detects a movable state or abnormal vibration of the movable part (for example, a pump motor). The vibration sensor device 9 is also used for measuring instrument parts that detect vibrations associated with movements such as walking of a person.

  The vibration sensor device 9 includes a dielectric block 3 that moves between the capacitive electrodes 4 and 4 when the dielectric block 3 moves in the space 2 according to the vibration of the space 2 caused by the vibration of the device in which the vibration sensor device 9 is mounted. The presence or absence of vibration is detected by utilizing the fact that the area of the body block 3 (the area viewed from the capacitive electrode 4 side) changes and the capacitance between the capacitive electrodes 4 and 4 changes according to this change. Is.

  That is, according to the vibration sensor device 9, the length of one side of each of the opposing surfaces of the space 2 is equal to that of the dielectric block 3 according to the position of the dielectric block 3 moving in the space 2. Except for a square region having the same square shape as the length of one side, and the distance in plan view between the outer side and the end of the surface of the space 2 is smaller than the length of one side of the dielectric block 3 The range of the dielectric block 3 interposed between the formed capacitive electrodes 4 and 4 changes, and the capacitance between the capacitive electrodes 4 and 4 changes accordingly. Further, when the space 2 is not vibrating, the dielectric block 3 is stationary at any place in the space 2 according to the difference between the density and the density of the liquid. Does not change the capacitance. Therefore, the presence or absence of vibration can be detected by detecting the presence or absence of a change in capacitance between the capacitance electrodes 4 and 4.

  In the example shown in FIG. 1 and FIG. 2, the capacitive electrode 4 is extended to the outer edge of the opposing set of surfaces of the insulating base 1 outside the set of opposing square surfaces of the space 2. Although formed, the capacitive electrode 4 may be formed only in a portion of the insulating base 1 that faces each other with the space 2 in between. In addition, the capacitive electrode 4 may be formed in a member constituting the insulating base 1 (so as not to be exposed to the space 2 and the outside).

  Further, according to the vibration sensor device 9, the dielectric block 3 is not in direct contact with the capacitive electrode 4, and deformation such as deflection is not caused in the dielectric block 3 itself. Therefore, the occurrence of defects such as wear and cracks in the dielectric block 3 and the capacitor electrode 4 is effectively suppressed, and the highly reliable vibration sensor device 9 capable of stably detecting vibration for a long period of time. Can be provided.

  In this case, since the liquid can also function as a so-called cushioning material, the dielectric block 3 is also effective in preventing the dielectric block 3 from colliding with the inner surface of the insulating base 1 constituting the space 2 and being damaged.

  When the space 2 is not vibrating, the dielectric block 3 stops at the lower end portion in the space 2 when the density is higher than the density of the liquid, and stops at the upper end portion of the space 2 when the density is smaller. To do. Further, when the density of the dielectric block 3 is the same as the density of the liquid, the dielectric block 3 stands still at an arbitrary place in the space 2.

  The difference between the density of the dielectric block 3 and the density of the liquid may be arbitrarily set in consideration of, for example, the use, productivity, cost, and the like of the vibration sensor device 9. If the vibration sensor device 9 is used for an application in which a large acceleration accompanying the vibration occurs mainly in the vertical direction, such as an application for detecting the vibration accompanying walking of a person, the density of the dielectric block 3 is set to the liquid density. Larger than that. In this case, when a large acceleration is generated in the downward direction, the dielectric block 3 moves to the upper part of the space 2 due to the inertial force, so that a sufficient space for the downward movement of the dielectric block 3 is secured. When a large acceleration is generated in the upward direction, vibration due to a change in capacitance between the capacitive electrodes 4 and 4 corresponding to the movement of the dielectric block 3 is more reliably detected.

Note that if the difference between the density of the dielectric block 3 and the density of the liquid becomes too large, the influence of buoyancy and gravity due to the density difference may increase, making it difficult to detect vibration. Is preferably set to about 5 g / cm ³ or less.

  The insulating base 1 is formed in a shape and a dimension capable of providing a space 2 in which a pair of opposing surfaces are square in shape. As such an insulating substrate 1, for example, a rectangular parallelepiped shape or a cubic shape having the same shape as the space 2 and a large outer dimension, or an outer surface such as an upper surface or a lower surface is curved or uneven in some portions in these shapes. Shape. Further, the insulating substrate 1 may have a shape (outer shape) different from the space 2 such as a spherical shape or an elliptical spherical shape as long as the space 2 can be provided inside. In the example shown in FIGS. 1 and 2, the insulating base 1 is formed in a rectangular parallelepiped shape having a slightly larger outer dimension than the space 2.

  Since the space 2 is filled with a liquid, the space 2 needs to have a structure that can be filled with the liquid and that does not cause problems such as leakage of the liquid.

  As the insulating base 1 provided with such a space 2, for example, a rectangular parallelepiped lower insulator (not indicated) having a recess on the upper surface and a flat plate joined to the upper surface of the lower insulator so as to close the recess. And an upper insulator having a shape (not indicated).

  The insulating substrate 1 is made of, for example, an aluminum oxide sintered body, a glass ceramic sintered body, a mullite sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a silicon nitride sintered body, or the like. It can be made of an electrically insulating material such as a ceramic material, a resin material such as an epoxy resin, a polyimide resin, or an acrylic resin, or a composite material of an inorganic material such as a ceramic material and a resin material.

  For example, if the insulating base 1 is made of an aluminum oxide sintered body, the insulating base 1 can be manufactured by joining a lower insulator and an upper insulator made of an aluminum oxide sintered body. The manufacturing method in this case is, for example, as follows.

  First, a raw material powder composed mainly of aluminum oxide powder and added with silicon oxide or calcium oxide is processed into a sheet shape with an organic solvent and a binder to produce a plurality of ceramic green sheets. A ceramic green sheet is punched into a frame-shaped green sheet, and then the frame-shaped green sheet is laminated on the ceramic green sheet that has not been punched, and the laminate is fired to insulate the bottom. Create a body. Next, a plurality of flat ceramic green sheets similar to those described above are laminated as necessary, and then fired to produce an upper insulator. Then, after filling the recess with the liquid, the upper insulator is joined to the upper surface of the lower insulator by a joining means such as brazing or bonding, so that the space 2 filled with the liquid is provided inside. The substrate 1 is manufactured.

  Further, if the insulating substrate 1 is made of a resin material such as an epoxy resin or a polyimide resin, the uncured material of these resin materials is shaped into a predetermined lower insulator or upper insulator using a mold. The lower insulator and the upper insulator can be produced by molding and curing, and these can be produced by joining them with a joining means such as a resin adhesive.

  The liquid filled in the space 2 is insulative and has the same or different density from the dielectric block 3 described later. Such a liquid is preferably, for example, a liquid that does not have a corrosive action on the insulating substrate 1 or a liquid having a low viscosity that does not hinder the movement of the dielectric block 3. What is necessary is just to select suitably according to the density of the dielectric material block 3. As will be described later, the density of the dielectric block 3 may be adjusted in accordance with the density of the liquid after selecting the liquid in consideration of the characteristics and the like.

  As such a liquid, for example, pure water, hydrocarbon solvents such as n-hexane, cyclohexane, n-heptane, methyl iodide, or the like can be used. Pure water is produced by subjecting water such as tap water to a treatment such as an ion exchange method or a reverse osmosis membrane method. When the insulating substrate 1 is filled, conductive impurities such as salts are present. Care must be taken not to mix.

  The space 2 is for accommodating the dielectric block 3 and moving the dielectric block 3 according to the vibration of the space 2.

  In addition, the dielectric block 3 moves in the space 2, so that each side of the pair of surfaces of the space 2 has a square shape in which the length of one side is the same as the length of one side of the dielectric block 3. A set of capacitive electrodes 4 formed excluding the square region S in which the distance in plan view between the side and the end of the surface of the space 2 is smaller than the length of one side of the dielectric block 3 This is for changing the capacitance between four.

  Capacitance electrodes 4 and 4 respectively formed on a pair of opposing square-shaped surfaces of the space 2 detect the movement of the dielectric block 3 according to the vibration of the space 2 by a change in capacitance, This is for detecting vibrations in the space 2. The pair of capacitive electrodes 4 and 4 are formed on a pair of surfaces parallel to each other to form a so-called parallel plate capacitor.

  The square region S is for changing the capacitance between the capacitive electrodes 4 and 4 according to the movement of the dielectric block 3. That is, since the square area S is provided on each of the pair of square surfaces of the space 2 with the same size and position, they are opposed to each other. Then, the range of the dielectric block 3 interposed between the capacitive electrodes 4 and 4 changes according to the range of the dielectric block 3 located in the portion where the square regions S face each other, and the capacitance is changed accordingly. The dielectric constant between the electrodes 4 and 4 changes, and the capacitance changes.

  In order to suppress such a malfunction in the detection of vibration in the space 2 (for example, when it is determined that the vibration is vibrating but not vibrating), the space 2 has a pair of opposed surfaces. The dielectric block 3 has a rectangular parallelepiped shape, and the dielectric block 3 has a rectangular parallelepiped shape in which one set of surfaces facing each other is a square shape. Each of the pair of opposing surfaces has a square shape in which the length of one side is the same as the length of one side of the dielectric block 3, and the distance in plan view between the outer side and the end of the surface of the space 2 is a dielectric. The block 3 is formed except for a square region S having a dimension smaller than the length of one side.

  That is, for example, as shown in FIG. 3 (a), the dielectric block 3 having a square shape with the same size on the opposite surface is interposed between the opposing square regions S. When (when the dielectric block 3 is not interposed between the capacitive electrodes 4 and 4), the capacitance generated between the capacitive electrodes 4 and 4 is minimized, and if the dielectric block 3 moves from this state, the capacitance The range of the dielectric block 3 interposed between the electrodes 4 and 4 increases, and the capacitance generated between the capacitive electrodes 4 and 4 gradually increases. Further, for example, as shown in FIG. 3B, when the square-shaped dielectric block 3 is located at the corner of the space 2 when viewed from the capacitive electrode 4 side, it is interposed between the capacitive electrodes 4 and 4. The range of the dielectric block 3 is the maximum, and the capacitance generated between the capacitive electrodes 4 and 4 is the maximum. If the dielectric block 3 moves from this state, the range of the dielectric block 3 interposed between the square regions S where the capacitive electrode 4 is not formed increases (intervened between the capacitive electrodes 4 and 4). The range of the dielectric block 3 to be reduced), and the capacitance generated between the capacitive electrodes 4 and 4 gradually decreases. For example, as shown in FIG. 3C, when the square dielectric block 3 moves in the direction of the arrow along one outer edge of the square area, the outer edge and the end of the surface of the space 2 The dielectric block 3 has a rectangular shape (square) according to the difference in length between the square regions S having a dimension in plan view that is smaller than the length of one side of the dielectric block 3. In this range, the capacitance generated between the capacitive electrodes 4 and 4 is reduced. The intervening range gradually changes (increases / decreases) according to the movement of the dielectric block 3.

  Therefore, the capacitance between the capacitive electrodes 4 and 4 is changed by the movement of the dielectric block 3 according to the vibration of the space 2, and the presence or absence of vibration can be detected. FIGS. 3A to 3C are side views (perspective views) showing examples of operating states of the vibration sensor device 9 shown in FIGS. 1 and 2, respectively. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals. FIG. 3 shows an example in which the capacitor electrode 4 is formed only on a portion of the insulating base 1 corresponding to a pair of opposing square surfaces of the space 2.

  The distance in plan view between the outer side of the square region S and the end of the surface of the space 2 may be set to be slightly smaller than the length of one side of the dielectric block 3. For example, if the dielectric block 3 has a square shape with a side length of about 0.5 to 2 cm in plan view, the plane between the outer side of the square region S and the end of the surface of the space 2. The viewed distance may be set to a size smaller by about 0.1 to 0.2 cm. With such a size, a sufficient space in which the dielectric block 3 can move in the space 2 is secured, so that the movement of the dielectric block 3 accompanying the vibration of the space 2 is easy. It is easy to detect a change in capacitance between 4 and 4, that is, to detect vibration.

  In addition, as shown in FIG. 4A, for example, the rectangular parallelepiped space 2 has a length SW between a pair of square surfaces, and the length of one side of the square surface of the dielectric block 3. In the case of a rectangular parallelepiped shape shorter than the length BL, the rotation of the dielectric block 3 in the space 2 can be suppressed. In this case, the range of the dielectric block 3 located between the square regions S is changed to more reliably detect the change in the capacitance between the capacitive electrodes 4 and 4 due to vibration. Can do. In the example shown in FIG. 4A, the distance SW between the pair of square surfaces of the space 2 is closer to the distance BW between the pair of square surfaces of the dielectric block 3. It is also possible to suppress the rotation of the dielectric block 3 more effectively by making the dimensions.

  On the other hand, for example, as shown in FIG. 4B, the length SW between a pair of square surfaces of the space 2 is the length of one side of the square surface of the dielectric block 3. When the length is longer than BL, the dielectric block 3 may rotate in the space 2. In such a case, for example, the length BW between a pair of square surfaces of the dielectric block 3 is between the outer side of the square region S and the end of the square surface of the space 2. If the distance is shorter than the distance in plan view, there is a possibility that the dielectric block 3 moves between the square regions S and moves in a state where the whole is interposed between the capacitive electrodes 4 and 4. Therefore, it becomes difficult to reliably detect the movement of the dielectric block 3 due to the vibration of the space 2 as a change in capacitance between the capacitive electrodes 4 and 4.

  Even in such a case, as shown in FIG. 4C, for example, the dielectric block 3 has a length BW between a pair of square surfaces such as a cube or a rectangular parallelepiped close to a cube. If the dimension is approximately the same as the length BL of one side of the square surface, the dielectric block 3 moves in the space 2 with more certain change in the range interposed between the square regions S. Can be made. This is because the distance between the end of the square surface of the space 2 and the outer side of the square region S is smaller than the length BL of one side of the square surface of the dielectric block 3. It depends on.

  Thus, in order to suppress unnecessary rotation of the dielectric block 3, the space 2 has a length SW between a pair of square-shaped surfaces that is equal to one side of the square-shaped surface of the dielectric block 3. The rectangular parallelepiped shape is preferably shorter than the length BL. When the distance SW between the pair of square surfaces of the space 2 is longer than the length BL of one side of the square surface of the dielectric block 3, the dielectric block 3 responds to the movement. In order to make the change in the range interposed between the capacitive electrodes 4 and 4 more reliable, a cubic shape or a rectangular parallelepiped shape having dimensions close thereto is preferable.

  4 (a) and 4 (c) are top views (perspective views) showing an example (modified example) when the vibration sensor device 9 shown in FIGS. 1 and 2 is viewed from above, respectively. FIG. 9 is a top view (perspective view) of a vibration sensor device 9b which is a comparative example with respect to (a). 4A to 4C, parts similar to those in FIGS. 1 and 2 are denoted by the same reference numerals.

  The dielectric block 3 is made of, for example, a ceramic material such as barium titanate, strontium titanate, magnesium titanate or a mixed material thereof, or a resin such as an epoxy resin, a styrene resin, a polypropylene resin, or a polyphenylene sulfide resin. It is made of a material having a high relative dielectric constant such as a material. The relative dielectric constant of these resin materials is about 3 to 5 (20 ° C.), and the relative dielectric constant of barium titanate is about 500 or more (20 ° C.). The dielectric block 3 is preferably made of a dielectric material such as barium titanate having a relative dielectric constant of about 500 or more or a mixed system thereof in order to effectively change the capacitance between the capacitive electrodes 4 and 4. .

  The rectangular parallelepiped dielectric block 3 is formed, for example, by processing barium titanate powder into a sheet shape together with an organic solvent and a binder to produce a plurality of ceramic green sheets, cutting into a predetermined square plate shape, and stacking to form a rectangular parallelepiped shape. It can be produced by firing after forming into a shape.

  In this case, the density of the dielectric block 3 can be adjusted by means of, for example, a material having a density different from that of the liquid or a hollow shape.

For example, when pure water (density is about 1 g / cm ³ ) is used as the liquid, a ceramic material having a density higher than that of pure water, such as barium titanate (density is about 6 g / cm ³ ), is used. If the dielectric block 3 is manufactured, the density of the dielectric block 3 can be made larger than the density of the liquid. If a resin material having a density lower than that of pure water (for example, a polypropylene resin having a density of about 0.9 g / cm ³ ) is used, the density of the dielectric block 3 can be made smaller than the density of the liquid.

  Even when the dielectric block 3 is made of a ceramic material, if the inside of the dielectric block 3 is hollow, the density can be adjusted to the same level as the liquid.

For example, in the case of the dielectric block 3 made of barium titanate and having a side length of 1 cm and formed hollow and filled with air, the following may be performed. That is, if the volume of the hollow portion of the dielectric block 3 is xcm ³ , the density of air is about 1.2 × 10 ⁻³ g / cm ³ , and thus (1.2 × 10 ⁻³ × x + (1− x) × 6) / 1 = 1, and x≈0.83 (cm ³ ), that is, a cubic shape with one side length of 1 cm such that the volume of the hollow portion inside is about 0.83 cm. If the dielectric block 3 is manufactured, the dielectric block 3 and the liquid have the same density.

  In order to form the dielectric block 3 in a hollow shape from barium titanate, for example, a method such as punching out the central portion of the ceramic green sheet that becomes an intermediate layer when laminating is used as a frame shape. Can do. The dielectric block 3 can also be produced by bonding two barium titanate laminates (fired) (not shown) having recesses on the surface so that the recesses face each other.

  The capacitive electrode 4 is formed of a metal material such as tungsten, molybdenum, manganese, copper, silver, palladium, gold, or platinum. The capacitor electrode 4 made of such a metal material is attached to the insulating substrate 1 in the form of, for example, a metallized layer, a plating layer, a vapor deposition layer, a metal foil, etc. Each is formed except for the square region S.

  If the capacitor electrode 4 is made of, for example, a tungsten metallized layer, the capacitor electrode 4 is printed in a predetermined pattern of the capacitor electrode 4 on the outer surface of the laminate of ceramic green sheets to be the insulating substrate 1 (lower insulator). It can be formed by co-firing with the laminate.

  Further, if the capacitor electrode 4 is made of a copper metal foil and a plating layer, the metal foil is bonded to the outer surface or inner surface (surface constituting the recess) of the lower insulator formed by curing the resin material. At the same time, it can be formed by etching to form a pattern of a predetermined capacity electrode 4 and depositing a copper plating layer on the surface thereof by means such as electroless plating.

  Such a vibration sensor device 9 can be manufactured as follows, for example.

  First, the insulating base 1 composed of the lower insulator and the upper insulator is manufactured together with the capacitor electrode 4. Next, the dielectric block 3 is put in the recess of the lower insulator, and a liquid such as pure water is put up to the upper end of the recess, and then the upper insulator is joined to the upper surface of the lower insulator via a resin adhesive. Thus, the vibration sensor device 9 is manufactured.

  Also, a through hole (not shown) is provided in advance in the upper insulator or the lower insulator, and the upper and lower insulators are put through resin adhesive, glass or the like with only the dielectric block 3 in the recess. The joining may be performed by a joining method such as joining, brazing, or welding, and then the through hole may be closed with glass or a ceramic material.

  The manufactured vibration sensor device 9 is mounted on various devices, measuring instruments, and the like as described above, and detects movements such as abnormal vibration of a machine and walking of a person based on whether or not there is a change in capacitance. The detected vibration is transmitted, for example, to an electric circuit constituting the device or measuring instrument as an electric signal indicating that the capacitance has changed. In the vibration sensor device 9, a conductor such as a wiring conductor (not shown) for easily transmitting such an electric signal may be formed on the inside or the outer surface of the insulating base 1.

  Further, in the vibration sensor device 9, in the configuration described above, the relative dielectric constant of the dielectric block 3 is such that the relative dielectric constant of the portion of the insulating substrate 1 located between the capacitive electrode 4 and the space 2 and the relative dielectric constant of the liquid. When the ratio is larger than the ratio, the change in capacitance when the dielectric block 3 is interposed between the capacitive electrodes 4 and 4 can be increased more effectively. Therefore, the vibration sensor device 9 that can more reliably detect the change in the capacitance between the capacitive electrodes 4, 4, that is, the presence or absence of the movement of the dielectric block 3 can be obtained.

  For example, when pure water (relative permittivity is about 80) is used as the liquid, the dielectric block 3 is formed of a ceramic material (relative permittivity is about 500 or more) such as barium titanate or strontium titanate. You just have to do it.

  Further, for example, as shown in FIG. 5, the vibration sensor device 9 has a space 2 and a dielectric block 3 each having a cubic shape, and has two sets of facing surfaces different from the one set of facing surfaces of the space 2. At least one of them has a square shape in which the length of one side is the same as the length of one side of the dielectric block 3, and the distance in plan view between the outer side and the end of the surface of the space 2 is When the capacitive electrode 4a is formed except for the square-shaped region Sa having a dimension smaller than the length of one side, since two different sets of surfaces are orthogonal to one set of surfaces, By detecting a change in capacitance between the capacitive electrodes 4a and 4a formed on at least one of them, it is also possible to detect a vibration in a direction B perpendicular to a pair of surfaces of the space 2. FIG. 5 is a perspective view (perspective view) showing another example of the embodiment of the vibration sensor device 9 of the present invention. 5, parts similar to those in FIGS. 1 and 2 are denoted by the same reference numerals. Further, for the sake of easy viewing, the dielectric block 3 is shown in a state where it is exposed outside the space 2.

  In this case, since the space 2 has a cubic shape and each surface constituting the space 2 has the same square shape, the space 2 is formed on at least one of two opposing surfaces different from the opposing surface pair. Also in the capacitive electrodes 4a and 4a, as in the case of the capacitive electrodes 4 and 4 formed on the set of surfaces described above, the movement of the dielectric block 3 in response to vibration can be detected.

  Therefore, in this case, it is possible to provide a vibration sensor device 9 with higher accuracy that can effectively detect vibration in the space 2 in three directions orthogonal to each other, so-called front and rear, right and left, and top and bottom.

  Further, the dielectric block 3 has a cubic shape, and the length of one side thereof is longer than the distance in plan view between the outer side of the square region S (Sa) and the end of the surface of the space 2. For example, even if the dielectric block 3 rotates in the space 2, the dielectric block 3 can be interposed between the capacitive electrodes 4 and 4 (4a and 4a), so that the vibration due to the change in capacitance can be detected more. A reliable vibration sensor device 9 can be obtained.

  The vibration sensor device of the present invention is not limited to the example of the above embodiment, and various modifications are possible within the scope of the gist of the present invention.

  For example, the dielectric block 3 may have its corners (ridges) chamfered in an arc shape so as to more effectively suppress chipping and wear. Further, the capacitive electrode 4 may be formed inside the insulating substrate 1, or the exposed surface may be coated with a plating layer such as nickel or gold to more effectively suppress oxidative corrosion or the like. Good.

(A) And (b) is the side view and top view (both are perspective views) which respectively show an example of the embodiment of the vibration sensor device of the present invention. FIG. 2 is a perspective view (perspective view) of the vibration sensor device shown in FIG. 1. (A)-(c) is a side view (perspective view) which shows typically the operating state of the vibration sensor apparatus of this invention, respectively. (A) And (c) is a top view (perspective view) which shows an example (perspective view) when the vibration sensor apparatus shown in FIG. 1 is seen from the top, respectively, (b) is a comparative example with respect to (a). It is a top view (perspective view) of a certain vibration sensor device. It is a perspective view (perspective view) which shows the other example of embodiment of the vibration sensor apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulation base | substrate 2 ... Space 3 ... Dielectric block 4, 4a ... Capacitance electrode S, Sa ... Square area 9, 9b ... Vibration sensor apparatus

Claims (3)

A rectangular parallelepiped space in which a pair of facing surfaces provided inside the insulating base is square, is filled with an insulating liquid, and can move in the space in response to vibration of the space. A rectangular parallelepiped-shaped dielectric block in which a pair of surfaces opposed to the pair of opposed surfaces is square is accommodated, and a length of one side is provided on each of the pair of opposed surfaces of the space. Is the same square shape as the length of one side of the dielectric block, and the distance in plan view between the outer side and the end of the surface of the space is smaller than the length of one side of the dielectric block. A vibration sensor device, wherein a capacitive electrode is formed except for a square region. 2. The relative dielectric constant of the dielectric block is larger than a relative dielectric constant of a portion of the insulating substrate located between the capacitive electrode and the space and a relative dielectric constant of the liquid. The vibration sensor device according to the description. The space and the dielectric block are each in the shape of a cube, and the length of one side of each of the two opposing faces different from the opposing pair of faces of the space is the dielectric block. Except for a square region having the same square shape as the length of one side and having a dimension in which the distance in plan view between the outer side and the end of the surface of the space is smaller than the length of one side of the dielectric block. The vibration sensor device according to claim 1, wherein a capacitance electrode is formed.

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