JP2019105492A - Electrodynamic detector and method for manufacturing the same - Google Patents

Abstract

To provide an electrodynamic detector which enables highly accurate adjustment in a short time, and a method for manufacturing the same.SOLUTION: The electrodynamic detector comprises: a columnar part with one end fixed to one surface of a lid, to which a magnetic field generation part for generating a magnetic field is fixed; a movable part which is elastically supported to the columnar part by an elastic support member so as to displace along the movement of the columnar part and to which a coil is fixed; a holding member fastened to the other end of the columnar part by a fastening member, so as to hold the elastic support member together with the columnar part; and a cylindrical side plate which is fastened to the lid by the fastening member, so as to store the columnar part and the movable part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrokinetic detector and a method of manufacturing the same.

  The electrokinetic detector is a device that measures the movement of the object to be measured, such as the velocity and acceleration, by using an induced electromotive force generated in a conductor moving in a magnetic field. Such an electrodynamic detector includes a movable body that is displaced with the movement of a measured object, a conductor attached to the movable body, a magnetic field generation unit that applies a magnetic field to the conductor, and an induced electromotive force generated in the conductor And an electric circuit for outputting the signal (see, for example, Patent Document 1).

JP-A-9-325067

  In the above-mentioned electrodynamic detector, each member is accommodated in a housing. In such a configuration, for example, it is conceivable to fix each member in the casing by housing each member in a bottomed cylindrical casing and fixing the upper lid to the casing. However, in this case, when the movable portion is to be adjusted to the neutral position, the upper lid is removed and adjusted, and then the upper lid is attached again. In this case, while taking time for adjustment, there is a possibility that variation may occur in adjustment accuracy.

  In one aspect, the present invention aims to provide an electrokinetic detector that enables high-precision adjustment in a short time and a method of manufacturing the same.

  In one aspect, the electrodynamic detector according to the present invention is displaced along the movement of the columnar part, one end of which is fixed to one surface of the lid and the magnetic field generating unit that generates the magnetic field is fixed. As described above, the elastic supporting member is held between the columnar portion and the movable portion which is elastically supported on the columnar portion by the elastic supporting member and is fastened to the other end of the columnar portion by the fastening portion and the movable portion to which the coil is fixed. It is characterized by including: a holding member; and a cylindrical side plate that accommodates the columnar portion and the movable portion by being fastened to the lid by a fastening member.

  In the above-described electrodynamic detector, even if the lid and the side plate together with the second lid define a space for accommodating the columnar portion and the movable portion by being fastened to the side plate by a fastening member. Good.

  In one aspect, in the method of manufacturing an electrodynamic detector according to the present invention, a columnar portion to which a magnetic field generation unit that generates a magnetic field is fixed is fixed to one surface of a lid, and a movable portion to which a coil is fixed is The flexible support member elastically supports the movable portion to the columnar portion by an elastic support member so as to be displaced along the movement of the columnar portion, adjusts the position of the movable portion, and fastens a clamping member to an upper portion of the columnar portion by a fastening member. Thus, the elastic supporting member is held between the columnar portion and the holding member, and the cylindrical side plate is fastened to the lid by the fastening member, thereby accommodating the columnar portion and the movable portion in the side plate. To be characterized.

  It is possible to provide an electrokinetic detector that enables high-precision adjustment in a short time and a method of manufacturing the same.

(A) is typical sectional drawing of the electrodynamic detector which concerns on Example 1, (b) is a detailed view of a magnetic field production | generation part. It is a top view of a diaphragm spring. FIG. 5 is a schematic cross-sectional view illustrating the configuration of an electrodynamic detector according to a comparative embodiment. It is a flowchart showing the manufacturing method of the electrodynamic-type detector which concerns on embodiment. It is a figure which illustrates another magnetic field generation part.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1A is a schematic cross-sectional view of the electrodynamic detector 100 according to the first embodiment. FIG. 1B is a detailed view of a magnetic field generation unit 30 described later. In FIG. 1 (b), hatches showing cross sections are omitted. The sensitivity axis of the electrodynamic detector 100 is set in the substantially vertical direction. In the present embodiment, the vertically upper side is referred to as the upper side, and the vertically lower side is referred to as the lower side.

  As illustrated in FIG. 1A, the main part of the electrokinetic detector 100 is housed in a closed and bottomed cylindrical (for example, cylindrical in this embodiment) casing. The housing is provided with a lower lid 11, an upper lid 12 and a side plate 13. The lower lid 11 and the upper lid 12 have, for example, a substantially circular shape, and have substantially the same shape. Further, in each of the lower lid 11 and the upper lid 12, a hole is formed in a substantially central portion. The side plate 13 has a cylindrical shape. The axis of the side plate 13 is along the sensitivity axis. The side plate 13 is fastened to the lower lid 11 by a fastening member 14 such as a screw. For example, the inner peripheral surface of the lower end of the side plate 13 is fastened to the end surface (side surface) of the lower lid 11. The side plate 13 is fastened to the upper lid 12 by a fastening member 15 such as a screw. For example, the inner peripheral surface of the upper end of the side plate 13 is fastened to the end surface (side surface) of the upper lid 12.

  In the housing, a substantially cylindrical support post is provided along the sensitivity axis. The post includes a lower member 21, a columnar portion 22, and an upper member 23. The lower member 21, the columnar portion 22 and the upper member 23 have a substantially cylindrical shape and are concentric with the cylinder formed by the side plate 13. The lower surface of the lower member 21 is disposed at the center of the upper surface of the lower lid 11 and is fastened to the lower lid 11 by a fastening member 24 such as a screw inserted into a hole of the lower lid 11. The columnar portion 22 is disposed such that the lower surface faces the upper surface of the lower member 21. The columnar portion 22 is fixed to the lower member 21 by fitting to the lower member 21 or the like. The upper member 23 is disposed such that the lower surface faces the upper surface of the columnar portion 22. The upper member 23 is fastened to the columnar portion 22 by a fastening member 25 such as a screw.

  A magnetic field generation unit 30 is fixed to a central portion of the columnar portion 22 in the sensitivity axis direction. As illustrated in FIG. 1B, the magnetic field generation unit 30 is configured by the permanent magnet 31, the first cylindrical portion 32a, the second cylindrical portion 32b, the third cylindrical portion 33, and the connection portion 34. The permanent magnet 31 has a cylindrical shape, is fixed to the outer peripheral surface of the columnar portion 22, and is concentric with the columnar portion 22. The permanent magnet 31 has different magnetic poles on the upper side and the lower side. The first cylindrical portion 32 a and the second cylindrical portion 32 b are fixed to the outer peripheral surface of the columnar portion 22 and are concentric with the columnar portion 22 to sandwich the permanent magnet 31 from above and below. The first cylindrical portion 32 a is located above the permanent magnet 31, and the second cylindrical portion 32 b is located below the permanent magnet 31. The third cylindrical portion 33 is disposed between the permanent magnet 31, the first cylindrical portion 32a and the second cylindrical portion 32b, and the side plate 13, and is concentric with the columnar portion 22, and the permanent magnet 31, the first cylindrical portion 32a And the second cylindrical portion 32 b and the side plate 13. The permanent magnet 31, the first cylindrical portion 32a and the second cylindrical portion 32b, and the third cylindrical portion 33 are arranged to face each other. The permanent magnet 31 and the third cylindrical portion 33 are connected by a ring-shaped connecting portion 34. With the above configuration, the magnetic field generation unit 30 has a structure in which two Hs are arranged in the horizontal direction in the cross-sectional view of FIG.

  The first cylindrical portion 32a, the second cylindrical portion 32b, and the third cylindrical portion 33 are made of magnetic material. The connection portion 34 is made of a nonmagnetic material. In FIG. 1 (b), each arrow represents an example of the direction of the magnetic flux. In the example of FIG. 1 (b), the magnetic flux is directed from the permanent magnet 31 to the first cylindrical portion 32a, from the first cylindrical portion 32a to the third cylindrical portion 33, and downward to the third cylindrical portion 33, From the cylindrical portion 33 to the second cylindrical portion 32 b, from the second cylindrical portion 32 b to the permanent magnet 31. Thus, the magnetic field generation unit 30 functions as an internal magnet type magnetic circuit. Also, the upper and lower air gaps of the connection portion 34 function as one magnetic circuit. The permanent magnet 31, the first cylindrical portion 32a, the second cylindrical portion 32b, the third cylindrical portion 33, and the connecting portion 34 constituting the magnetic field generating unit 30 are electrically connected to each other. Further, the magnetic field generation unit 30 is electrically connected to the columnar portion 22.

  The magnetic field generation unit 30 according to the present embodiment is configured of one magnet and one magnetic circuit, and the dimensions of the respective parts are substantially the same on the upper and lower sides of the connection part 34. The magnetic flux density between the first cylindrical portion 32a and the third cylindrical portion 33 and the magnetic flux density between the second cylindrical portion 32b and the third cylindrical portion 33 below the connection portion 34 are substantially the same. It has become.

  Referring again to FIG. 1A, the diaphragm spring 40a as an elastic supporting member is held and fixed by the upper surface of the columnar portion 22 and the lower surface of the upper member 23. Further, a diaphragm spring 40b as an elastic supporting member is held and fixed by the upper surface of the lower member 21 and the lower surface of the columnar portion 22. FIG. 2 is a plan view of the diaphragm springs 40a and 40b. The diaphragm springs 40 a and 40 b include an inner ring 41, an outer ring 42, and a spring portion 43 connecting the inner ring 41 and the outer ring 42. The inner ring 41 and the outer ring 42 are concentric with the columnar portion 22. The inner ring 41 of the diaphragm spring 40 a is sandwiched by the upper surface of the columnar portion 22 and the lower surface of the upper member 23. The inner ring 41 of the diaphragm spring 40 b is sandwiched by the upper surface of the lower member 21 and the lower surface of the columnar portion 22.

  The movable portion (pendulum) 50 has a cylindrical shape and is disposed between the third cylindrical portion 33 and the side plate 13. The movable portion 50 extends above the upper end of the third cylindrical portion 33 and extends below the lower end of the third cylindrical portion 33. The outer ring 42 of the diaphragm spring 40 a is connected to the upper end portion of the inner peripheral surface of the movable portion 50. The outer ring 42 of the diaphragm spring 40 b is connected to the lower end portion of the inner cylindrical surface of the movable portion 50. Since the spring portion 43 has elasticity, the movable portion 50 is elastically supported by the columnar portion 22. Thereby, the movable portion 50 is displaced along the movement of the columnar portion 22. Further, the movable portion 50 is electrically connected to the diaphragm springs 40a and 40b.

  An upper coil bobbin 60 a is provided on the upper inner peripheral surface of the movable portion 50. The upper coil bobbin 60a is fixed to the inner circumferential surface of the movable portion 50 and is fixed to the lower surface of the ring-shaped portion concentric with the columnar portion 22 and the lower surface of the end of the ring-shaped portion 22 side concentric with the columnar portion 22 And a cylindrical portion. A coil 70 a concentric with the columnar portion 22 is provided on the outer peripheral surface of the cylindrical portion. That is, the coil 70 a is wound around the columnar portion 22. The ring-shaped portion is located above the upper end of the third cylindrical portion 33 and below the diaphragm spring 40 a. The lower end of the cylindrical portion is located above the connection portion 34 in a region where the first cylindrical portion 32 a and the third cylindrical portion 33 face each other. The ring-shaped portion and the cylindrical portion are separated from the first cylindrical portion 32 a, the third cylindrical portion 33 and the connecting portion 34. The coil 70 a displaces in the magnetic field generated by the first cylindrical portion 32 a and the third cylindrical portion 33 above the connection portion 34 when the movable portion is displaced in the vertical direction.

  A lower coil bobbin 60 b is provided on the lower inner cylindrical surface of the movable portion 50. The lower coil bobbin 60b is fixed to the inner peripheral surface of the movable portion 50 and fixed to the upper surface of the ring-shaped portion concentric with the columnar portion 22 and the upper end of the ring-shaped portion 22 at the columnar portion 22 side And a cylindrical portion. A coil 70 b concentric with the columnar portion 22 is provided on the outer peripheral surface of the cylindrical portion. That is, the coil 70 b is wound around the columnar portion 22. The ring-shaped portion is located below the lower end of the third cylindrical portion 33 and above the diaphragm spring 40b. The upper end of the cylindrical portion is located below the connection portion 34 in a region where the second cylindrical portion 32 b and the third cylindrical portion 33 face each other. The ring-shaped portion and the cylindrical portion are separated from the second cylindrical portion 32 b, the third cylindrical portion 33, and the connecting portion 34. The coil 70b displaces in the magnetic field generated by the second cylindrical portion 32b and the third cylindrical portion 33 below the connection portion 34 when the movable portion is displaced in the vertical direction.

  The coil length of the coil 70a and the coil length of the coil 70b are set to be substantially the same. As described above, the direction of the magnetic flux generated between the first and second cylindrical portions 32a and 32b and the third cylindrical portion 33 is horizontal. The displacement direction of the movable portion 50 is the sensitivity axis direction of the substantially vertical direction. The coil 70 a and the coil 70 b move integrally with the movable unit 50. Therefore, coil 70a and coil 70b are relatively displaced at substantially the same speed in the direction substantially perpendicular to the direction in which the magnetic flux penetrates and the winding direction of coils 70a and 70b, ie the direction in which the electromotive force is generated. .

  An output connector 80 is inserted into the hole of the upper lid 12. The output connector 80 includes at least two terminals of a first terminal and a second terminal. By connecting the wire connecting the coil 70a and the coil 70b to the two terminals of the output connector 80, the output of the output connector 80 is used to output the induced electromotive force induced in the coils 70a and 70b. it can. Therefore, by measuring the potential between the terminals of output connector 80, the induced electromotive force induced in coils 70a and 70b can be measured.

  When vibration is applied to the electrokinetic detector 100 from a measurement target (not shown), the movable portion 50 is elastically displaced along the sensitivity axis direction while being supported by the diaphragm springs 40a and 40b. In addition, a ground etc. correspond to this, when observing the activity state of crustal activity with a to-be-measured body.

The coils 70a and 70b fixed to the movable portion 50 are displaced in a direction substantially perpendicular to the magnetic flux generated by the magnetic field generation unit 30, respectively. As a result, Lorentz force according to the speed of the object to be measured acts on the charge in the conductive wire constituting the coils 70a and 70b. Therefore, an induced electromotive force is generated in the coils 70a and 70b according to the movement of the object to be measured. The induced electromotive force induced in each of the coils 70a and 70b is expressed by the following equation (1).
E = B × L × V × sin θ (1)

  In the above equation (1), E represents the induced electromotive force induced in the coils 70a and 70b, B represents the magnetic flux density of the magnetic field generated by the magnetic field generation unit 30, and L represents the conductive wire constituting the coils 70a and 70b. V represents the relative velocity between the coils 70a and 70b and the magnetic field generating unit 30, θ represents the direction in which the coils 70a and 70b are relatively displaced, and the magnetic flux is magnetized in the coils 70a and 70b. Indicates the angle between the direction. In the present embodiment, when the magnetic field generating unit 30 is fixed to the object to be measured and the object to be measured vibrates, the natural frequency is determined by the mass of the movable portion 50 and the spring constants of the diaphragm springs 40a and 40b. In the upper frequency band, the relative velocity V is substantially equivalent to the velocity of the magnetic field generation unit 30. In addition, since (theta) is about 90 degrees, the said Formula (1) can be represented by E = BxLxV.

  Here, in order to explain the effect of the electrodynamic detector 100 according to the present embodiment, the electrodynamic detector 200 according to the comparative embodiment will be described. FIG. 3 is a schematic cross-sectional view illustrating the configuration of the electrodynamic detector 200. As shown in FIG. As illustrated in FIG. 3, the electrokinetic detector 200 is provided with a housing and a post different from the embodiment.

  In the comparative embodiment, the housing includes the lower lid 11, the upper lid 12a, and the side plate 13. In the comparative embodiment, the support includes the lower member 21a and the columnar portion 22a, and does not include the upper member. The diaphragm spring 40a is sandwiched by the upper surface of the columnar portion 22a and the lower surface of the upper lid 12a. In addition, about the member same as embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  In this configuration, each member is accommodated in a bottomed cylinder formed of the lower lid 11 and the side plate 13 before the position of the movable portion 50 is adjusted. After that, the diaphragm spring 40a is fixed by attaching the upper lid 12a. Therefore, by determining whether the output from the output connector 80 satisfies the reference, it is determined whether the movable portion 50 is positioned at the neutral position. If the output from the output connector 80 does not satisfy the standard, remove the upper lid 12a, take out each member in the bottomed cylinder composed of the lower lid 11 and the side plate 13, and adjust the position of the movable portion 50. become.

  In this case, while taking time for adjustment, there is a possibility that variation may occur in adjustment accuracy. Specifically, since it is not possible to adjust the position of the movable portion 50 without the upper lid 12a, a jig having the same shape as the upper lid 12a and having a hole so that the inside can be seen (adjusting from this hole) Install and adjust instead. However, since the upper lid 12a and the jig are separate members, and the dimensions of the respective portions vary within the tolerance range, a difference occurs in the force for fixing the diaphragm spring 40a, resulting in variation in adjustment accuracy.

  On the other hand, in the electrodynamic detector 100 according to the present embodiment, after the lower member 21 is fixed to the lower lid 11, the diaphragm spring 40b is sandwiched between the lower member 21 and the columnar portion 22, and the columnar portion The diaphragm spring 40 a can be held between the upper and lower members 22 and 23. In this case, the lower lid 11 can be used as a jig for stabilizing the position of the movable body 50. As described above, with the position of the movable body 50 stabilized, the position of the movable portion 50 can be adjusted to the neutral position. Therefore, the adjustment accuracy is improved. In addition, it is not necessary to take out the movable portion 50 from the inside of the case each time of adjustment. Therefore, the time required for adjustment can be shortened. As described above, in the electrodynamic detector 100 according to the present embodiment, highly accurate adjustment can be performed in a short time.

  FIG. 4 is a flowchart showing a method of manufacturing the electrodynamic detector 100. As shown in FIG. As illustrated in FIG. 4, the lower member 21 is fixed to the lower lid 11 (step S1). Next, the diaphragm spring 40b is sandwiched between the lower part 21 and the columnar part 22 to which the magnetic field generation unit 30 is fixed, the movable part 50, the upper coil bobbin 60a, and the lower coil bobbin 60b are attached, and the columnar part 22 and the upper member 23 It clamps by the fastening member 25 on both sides of the diaphragm spring 40a (step S2).

  Next, the position of the movable unit 50 is adjusted (step S3). Next, the side plate 13 is fixed to the lower lid 11 by the fastening member 14 (step S4). Thereafter, the upper lid 12 is fixed to the side plate 13 by the fastening member 15, and the output connector 80 is attached to the upper lid 12 (step S5).

  According to the manufacturing method of the present embodiment, after the lower member 21 is fixed to the lower lid 11, the diaphragm spring 40 b is sandwiched between the lower member 21 and the columnar portion 22, and the diaphragm is formed by the columnar portion 22 and the upper member 23. The spring 40a can be held. Thus, the position of the movable portion 50 can be adjusted to the neutral position while the position of the movable body 50 is stabilized. Therefore, the adjustment accuracy is improved. In addition, it is not necessary to take out the movable portion 50 from the inside of the case each time of adjustment. Therefore, the time taken for adjustment can be shortened. As described above, according to the manufacturing method according to the present embodiment, highly accurate adjustment can be performed in a short time.

  The arrangement location and number of the permanent magnets 31 are not particularly limited. For example, FIG. 5 is another example of the magnetic field generation unit 30. In the example of FIG. 5, the third cylindrical portion 33 has a cylindrical shape, is fixed to the outer peripheral surface of the columnar portion 22, and is concentric with the columnar portion 22. The permanent magnet 31, the first cylindrical portion 32a and the second cylindrical portion 32b are disposed between the third cylindrical portion 33 and the side plate 13, have substantially the same radius, and are concentric with the columnar portion 22, and the third cylinder It is separated from the portion 33 and the side plate 13. The permanent magnet 31 has different magnetic poles on the upper side and the lower side. The first cylindrical portion 32 a and the second cylindrical portion 32 b sandwich the permanent magnet 31 from above and below. The first cylindrical portion 32 a is located above the permanent magnet 31, and the second cylindrical portion 32 b is located below the permanent magnet 31. The permanent magnet 31, the first cylindrical portion 32a and the second cylindrical portion 32b, and the third cylindrical portion 33 are arranged to face each other. The permanent magnet 31 and the third cylindrical portion 33 are connected by a ring-shaped connecting portion 34.

  In FIG. 5, each arrow represents an example of the direction of the magnetic flux. In the example of FIG. 5, the magnetic flux is directed from the permanent magnet 31 to the second cylindrical portion 32b, from the second cylindrical portion 32b to the third cylindrical portion 33, and directed upward to the third cylindrical portion 33, and the third cylindrical portion 33b. From the first cylindrical portion 32 a to the permanent magnet 31. Thus, the magnetic field generation unit 30 of FIG. 5 functions as an external magnet type magnetic circuit. Also, the upper and lower air gaps of the connection portion 34 function as one magnetic circuit. The permanent magnet 31, the first cylindrical portion 32a, the second cylindrical portion 32b, the third cylindrical portion 33, and the connecting portion 34 constituting the magnetic field generating unit 30 are electrically connected to each other. Further, the magnetic field generation unit 30 is electrically connected to the columnar portion 22.

  In the above embodiment, one end of the columnar portion 22 is fixed to one surface of the lid, and the columnar portion 22 functions as an example of the columnar portion to which the magnetic field generation unit that generates a magnetic field is fixed. The movable portion 50 is elastically supported on the columnar portion by the elastic support member so as to be displaced along the movement of the columnar portion, and functions as an example of the movable portion to which the coil is fixed. The upper member 23 is fastened to the other end of the columnar part by a fastening member, thereby functioning as an example of a sandwiching member that sandwiches the elastic support member with the columnar part. When the side plate 13 is fastened to the lid by a fastening member, the side plate 13 functions as an example of a cylindrical side plate that accommodates the columnar portion and the movable portion. The upper lid 12 is fastened to the side plate by a fastening member, thereby functioning as a second lid which defines a space for accommodating the columnar portion and the movable portion together with the lid and the side plate.

  As mentioned above, although the embodiment of the present invention has been described in detail, the present invention is not limited to the specific embodiment, and various modifications may be made within the scope of the present invention described in the claims. Changes are possible.

DESCRIPTION OF SYMBOLS 11 lower lid 12 upper lid 13 side plate 14, 15 fastening member 21 lower member 22 columnar part 23 upper member 24, 25 fastening member 30 magnetic field generation part 31 permanent magnet 32a 1st cylindrical part 32b 2nd cylindrical part 33 3rd cylindrical part 40a, 40b diaphragm spring 50 movable part 60a upper coil bobbin 60b lower coil bobbin 70a, 70b coil 80 output connector 100 electrodynamic detector

Claims (3)

A columnar part having one end fixed to one surface of the lid and a magnetic field generation unit generating a magnetic field fixed;
A movable portion elastically supported on the columnar portion by an elastic support member so as to be displaced along the movement of the columnar portion, and a coil fixed thereto;
A clamping member configured to clamp the elastic supporting member with the columnar portion by being fastened to the other end of the columnar portion by a clamping member;
An electrodynamic detector comprising: a cylindrical side plate that accommodates the columnar portion and the movable portion by being fastened to the lid by a fastening member.   The second lid according to claim 1, further comprising: a second lid which, together with the lid and the side plate, delimits a space for housing the columnar portion and the movable portion by being fastened to the side plate by a fastening member. Electric detector. The columnar part to which the magnetic field generation part which generates a magnetic field is fixed is fixed to one side of the lid,
An elastic supporting member elastically supporting the movable portion on the columnar portion such that the movable portion to which the coil is fixed is displaced along the movement of the columnar portion;
Adjust the position of the movable part,
The elastic supporting member is nipped between the columnar portion and the nipping member by fastening the nipping member to the upper portion of the columnar portion by a fastening member.
A manufacturing method of an electrodynamic detector, wherein the columnar portion and the movable portion are accommodated in the side plate by fastening a cylindrical side plate to the lid by a fastening member.