JP4636211B1 - Magnetic flux detection sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic flux detection sensor which can be miniaturized and can improve the linearity of a detection signal with respect to the inclination angle of a posture.
An inclination sensor (1) includes a casing (2), a magnetoelectric conversion element (8), and a movable body (12). The casing 2 forms a movable body accommodating space 6 having an upward concave curved surface 5. The casing 2 is provided with a magnetoelectric conversion element 8 that is located below the deepest part 5A of the concave curved surface 5 and detects the magnetic flux density in the height direction of the casing 2. The movable body 12 is formed of a hemispherical magnet, and a sliding surface 13 formed of a downward hemispherical surface and a flat upper surface 14 have opposite polarities. The movable body 12 is accommodated in the movable body accommodating space 6 of the casing 2 with the sliding surface 13 being slidable on the concave curved surface 5. Thereby, the magnetic flux density according to the inclination angle θ of the casing 2 can be applied to the magnetoelectric conversion element 8.
[Selection] Figure 1

Description

  The present invention relates to a magnetic flux detection sensor suitable for use in, for example, detection of posture inclination.

  As a conventional magnetic flux detection sensor, an inclination sensor that detects an inclination of an attitude is known (for example, see Patent Documents 1 and 2). In Patent Document 1, a magnet having an inclined surface with a depressed central portion, a magnetic detection element such as a Hall IC disposed to face the inclined surface of the magnet, and the magnet and the magnetic detection element are located. A configuration including a spherical movable body made of a magnetic material provided on a tilted surface of a magnet so as to be able to roll is disclosed. In the tilt sensor of Patent Document 1, the movable body rolls and displaces on the tilted surface according to the tilt of the magnet, and the change in the magnetic flux density accompanying the displacement of the movable body is detected by the magnetic detection element.

  Patent Document 2 discloses a case having a concave spherical surface, a thick disk-shaped magnet slidably provided on the concave spherical surface of the case, and three or more at the side edge of the concave spherical surface. A configuration including a magnetic detection element is disclosed. In the tilt sensor of Patent Document 2, the magnet slides and displaces on the concave spherical surface according to the tilt of the case, and a change in magnetic flux density due to the displacement of the magnet is detected using a plurality of magnetic detection elements.

JP 2003-185430 A JP-A-8-261758

  By the way, in the tilt sensor according to the prior art, in order to reliably detect the displacement of the movable body and the magnet due to the tilt, it is necessary to secure a sufficiently large movable range of the movable body compared to the outer shape of the movable body or the like. For this reason, there exists a problem that the whole sensor is easy to enlarge and it is difficult to form a small sensor. In addition, since the tilt sensor outputs a detection signal according to the shape of the movable body and the positional relationship between the magnetic detection element and the movable body, the detection signal is likely to have a nonlinear characteristic with respect to the tilt angle. The range of possible tilt angles tends to be narrow.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a magnetic flux detection sensor that can be miniaturized and can improve the linearity of a detection signal with respect to the inclination angle of the posture. It is in.

In order to solve the above-described problem, the invention of claim 1 includes a sliding surface formed of a downward convex curved surface formed on the bottom side and an upper surface formed of a horizontal surface formed on the upper side of the sliding surface . A nonmagnetic container having a movable body, a movable body containing space having an upward concave curved surface that slidably supports the sliding surface of the movable body, and a magnetic flux density generated by sliding of the movable body provided in the nonmagnetic container. A magnetic flux detection sensor having a magnetic flux density detection means for detecting a change, wherein the sliding surface of the movable body and the magnetic flux density detection means are arranged to face each other, and the magnetic flux is supplied to the magnetic flux density detection means through the sliding surface. and applies, to the top rim of the sliding surface in the movable member and said upper surface intersect, a chamfer to ease the concentration of the magnetic flux density at the top rim provided, when the nonmagnetic container is inclined from the horizontal state The movable body is displaced from the steady position along the concave curved surface of the non-magnetic container, and when the non-magnetic container returns to the horizontal state, the movable body is positioned along the concave curved surface of the non-magnetic container. It is set as the structure which returns to.

  According to a second aspect of the present invention, there is provided a movable body housing having a hemispherical movable body having a sliding surface composed of a downward hemispherical surface on the bottom side, and an upward concave curved surface that slidably supports the sliding surface of the movable body. A magnetic flux detection sensor comprising: a nonmagnetic container having a space; and a magnetic flux density detection means for detecting a change in magnetic flux density provided in the nonmagnetic container and caused by the sliding of the movable body, wherein the sliding surface of the movable body The magnetic flux density detecting means is disposed oppositely, and a magnetic flux is applied to the magnetic flux density detecting means via the sliding surface, and a chamfering that reduces the concentration of the magnetic flux density at the upper peripheral edge of the movable body is provided on the upper peripheral edge of the movable body. When the non-magnetic container is tilted from the horizontal state, the movable body is displaced from the steady position along the concave curved surface of the non-magnetic container, and when the non-magnetic container returns to the horizontal state, the movable body is Body is configured so as to return to the normal position along the concave curved surface of the nonmagnetic container.

  In the third and fourth aspects of the invention, the movable body is formed using a magnetic material and is magnetized in a state in which the sliding surface and the upper surface have opposite polarities.

  In the invention of claim 5, the concave curved surface of the movable body accommodating space is formed by a spherical surface having a larger radius of curvature than the sliding surface of the movable body.

  In the invention of claim 6, at least one of the sliding surface of the movable body and the concave curved surface of the movable body housing space is subjected to a smoothing process.

  In the invention of claim 7, the magnetic flux density detecting means generates a magnetic flux in the Y-axis direction in comparison with a detection signal when the magnetic flux is tilted in the X-axis direction in the X-axis direction and the Y-axis direction orthogonal to each other on the horizontal plane. The detection signal when tilted has an anisotropy that results in a large output level, and the concave curved surface of the movable body accommodating space is compared with the X-axis direction in order to compensate for the anisotropy of the magnetic flux density detection means. It is formed by an anisotropic curved surface that greatly displaces the movable body in the Y-axis direction.

According to an eighth aspect of the present invention, there is provided a movable body having a sliding surface formed of a downward convex curved surface formed on the bottom side, and an upper surface formed of a horizontal surface formed on the upper side of the sliding surface, and sliding of the movable body A non-magnetic container having a movable body accommodating space having an upward concave curved surface that slidably supports the surface, and a magnetic flux density detecting means that is provided in the non-magnetic container and detects a change in magnetic flux density caused by the sliding of the movable body. The sliding surface of the movable body and the magnetic flux density detection means are arranged to face each other, and when the nonmagnetic container is inclined from a horizontal state, the movable body is a concave curved surface of the nonmagnetic container. When the non-magnetic container returns to the horizontal state, the movable body returns to the steady position along the concave curved surface of the non-magnetic container.

  According to a ninth aspect of the present invention, there is provided a movable body containing a hemispherical movable body having a sliding surface composed of a downward hemispherical surface on the bottom side, and an upward concave curved surface that slidably supports the sliding surface of the movable body. A magnetic flux detection sensor comprising: a nonmagnetic container having a space; and a magnetic flux density detection means for detecting a change in magnetic flux density provided in the nonmagnetic container and caused by the sliding of the movable body, wherein the sliding surface of the movable body When the non-magnetic container is tilted from a horizontal state when the magnetic flux density detecting means is arranged oppositely, the movable body is displaced from a steady position along the concave curved surface of the non-magnetic container, and the non-magnetic container is in a horizontal state. The movable body is configured to return to a steady position along the concave curved surface of the non-magnetic container when returning to step S2.

According to the first aspect of the present invention, the movable body includes a sliding surface made of a downward convex curved surface formed on the bottom side , and an upper surface made of a horizontal surface formed on the upper side of the sliding surface. . For this reason, the thickness of the movable body gradually decreases from the apex portion of the convex curved surface along the periphery of the upper surface. When a movable body is formed using a magnetic material, magnetic flux tends to concentrate on a thick portion of the movable body. For this reason, the magnetic flux density is high around the apex portion of the movable body, and the magnetic flux density is reduced in a portion near the upper surface periphery of the movable body.

  The movable body is provided in the movable body accommodation space of the nonmagnetic container. The magnetic flux density detection means is provided in the non-magnetic container and is disposed opposite to the sliding surface of the movable body. When the nonmagnetic container is tilted from the horizontal state, the sliding surface of the movable body slides on the concave curved surface, and the vertex portion of the movable body moves toward the lowest position of the concave curved surface. At this time, the relative position of the apex portion of the movable body and the magnetic flux density detection means changes according to the inclination angle of the nonmagnetic container. For this reason, the magnetic flux density applied to the magnetic flux density detecting means can be changed according to the inclination angle of the non-magnetic container.

  Moreover, since the vertex part of a movable body should just be displaced with respect to a magnetic flux density detection means, the movable body accommodation space of a nonmagnetic container should just have a volume which can be rotationally displaced by a movable body. For this reason, the volume of the movable body accommodation space can be brought close to the volume of the movable body, and the entire sensor can be reduced in size.

  Further, as the opposing positional relationship between the sliding surface of the movable body and the magnetic flux density detection means, for example, when the magnetic flux density detection means is arranged around the deepest part of the concave curved surface when the nonmagnetic container is in a horizontal state, the nonmagnetic container When the tilt angle is small, the displacement between the apex portion of the movable body and the magnetic flux density detecting means is small, and the magnetic flux density applied to the magnetic flux density detecting means is high. On the other hand, when the inclination angle of the non-magnetic container is large, the displacement between the apex portion of the movable body and the magnetic flux density detection means is large, and the magnetic flux density applied to the magnetic flux density detection means is low. Note that the magnetic flux density applied to the magnetic flux density detecting means changes according to the thickness of the movable body portion facing the magnetic flux density detecting means. For this reason, the linearity of the detection signal of the magnetic flux density detection means with respect to the inclination angle of the non-magnetic container can be improved compared to the case where the movable body is made of, for example, a thick disk shape or a small-diameter spherical shape, and can be detected. The angle range of various inclinations can be expanded.

For example, when the sliding surface and the upper surface of the movable body are magnetized in opposite polarities, the magnetic flux tends to concentrate on the upper surface periphery of the movable portion where the surfaces intersect at an acute angle. In contrast, in the present invention, because there is a sliding surface and the upper surface of the movable member provided with the cut edge on the top rim crossing can be the chamfer, to alleviate the concentration of magnetic flux at the top rim of the movable body . As a result, the magnetic flux density can be gradually decreased from the apex portion of the movable body toward the upper surface periphery, and the linearity of the change in the magnetic flux density caused by the displacement of the movable body can be enhanced.

  According to the second aspect of the present invention, since the sliding surface comprising a downward hemispherical surface is formed on the bottom side of the movable body, the thickness of the movable body gradually decreases from the apex portion of the hemispherical surface along the peripheral edge of the upper surface. For this reason, substantially the same effect as the invention of claim 1 can be obtained.

  According to the third and fourth aspects of the invention, since the movable body is formed using the magnetic material and the sliding surface and the upper surface are magnetized in opposite polarities, the magnetic flux is directed toward the normal direction of the sliding surface. Can be generated. Further, the magnetic flux density detection means is arranged to face the sliding surface of the movable body. For this reason, when the non-magnetic container is tilted from the horizontal state, the magnetic flux density detecting means also tilts substantially in line with the normal direction of the sliding surface portion of the sliding movable body facing the magnetic flux density detecting means.

  In addition, the hemispherical movable body has a high magnetic flux density at the apex portion and a low magnetic flux density near the upper surface periphery. For this reason, according to the inclination angle of the non-magnetic container, the portion of the sliding surface of the movable body facing the magnetic flux density detection means can be displaced to change the magnetic flux density applied from the movable body to the magnetic flux density detection means. In addition, the magnetic flux density detector can reliably detect the magnetic flux density according to the tilt angle. As a result, the magnetic flux density detection means can output a detection signal corresponding to the tilt angle.

  According to the invention of claim 5, since the concave curved surface of the movable body accommodating space is formed by a hemispherical surface having a larger radius of curvature than the hemispherical surface of the movable body, the vertex of the hemispherical surface is concave. It is possible to slide on the concave curved surface while being in contact with the curved surface.

  According to the invention of claim 6, since at least one of the sliding surface of the movable body and the concave curved surface of the movable body accommodating space is smoothed, the sliding surface of the movable body and the concave shape of the movable body accommodating space are provided. The frictional resistance with the curved surface can be reduced, and the movable body can be smoothly slid on the concave curved surface.

  According to the seventh aspect of the present invention, the magnetic flux density detection means has a higher output level when the magnetic flux is tilted in the Y-axis direction than the detection signal when the magnetic flux is tilted in the X-axis direction. It was set as the structure which has anisotropy. The concave curved surface of the movable body accommodating space was formed by an anisotropic curved surface that greatly displaced the movable body in the Y-axis direction compared to the X-axis direction. Therefore, if the nonmagnetic container is tilted in the Y-axis direction by the same tilt angle as when tilted in the X-axis direction, the amount of displacement of the movable body in the Y-axis direction increases, and the magnetic flux density detection means and the apex portion of the movable body The position change of can be increased.

  Here, since the magnetic flux is generated in the normal direction of the sliding surface of the movable body, the magnetic flux density is detected when the non-magnetic container is tilted in the Y-axis direction compared to when the non-magnetic container is tilted in the X-axis direction. The change in the magnetic flux density applied to the means increases. That is, the magnetic flux density applied from the movable body to the magnetic flux density detecting means is lower when tilted in the Y-axis direction than when tilted in the X-axis direction at the same tilt angle, and the output level of the detection signal is reduced. Can be small. As a result, the detection signal of the magnetic flux density detection means when the nonmagnetic container is tilted in the X-axis direction and the detection signal of the magnetic flux density detection means when the nonmagnetic container is tilted in the Y-axis direction are output with respect to the tilt angle. Levels can be made approximately equal.

According to the invention of claim 8, the movable body includes a sliding surface formed of a downward convex curved surface formed on the bottom side , and an upper surface formed of a horizontal surface formed on the upper side of the sliding surface. . For this reason, as for a movable body, the thickness of a movable body becomes small gradually along the upper surface periphery from the vertex part of a convex-shaped curved surface. In addition, the magnetic flux density detection means is provided in the non-magnetic container, and the sliding surface of the movable body and the magnetic flux density detection means are arranged to face each other, so that the apex portion of the movable body and the magnetic flux density detection according to the inclination angle of the non-magnetic container. The relative position with the means changes. For this reason, the magnetic flux density applied to the magnetic flux density detecting means can be changed according to the inclination angle of the non-magnetic container.

  In the invention of claim 8 as well, as in the invention of claim 1, the entire sensor can be reduced in size, and the linearity of the detection signal of the magnetic flux density detection means with respect to the inclination angle of the nonmagnetic container can be improved. Can do.

  According to the ninth aspect of the present invention, since the sliding surface comprising a downward hemispherical surface is formed on the bottom side of the movable body, the movable body has a thickness dimension toward the upper surface periphery centering on the apex portion of the hemispherical surface. It can be formed into a hemispherical shape that gradually decreases. Therefore, substantially the same effect as that attained by the 8th aspect can be attained.

It is a disassembled perspective view which shows the inclination sensor by the 1st Embodiment of this invention. It is sectional drawing which looked at the inclination sensor from the arrow II-II direction in FIG. It is a top view which shows the inclination sensor in FIG. 1 in the state which excluded the cover body. It is explanatory drawing which shows the positional relationship of a movable body and a magnetoelectric conversion element when the inclination sensor by 1st Embodiment is made into a horizontal state. It is explanatory drawing which shows the positional relationship of a movable body and a magnetoelectric conversion element when the inclination sensor by 1st Embodiment is made into an inclination state. It is explanatory drawing similar to FIG. 4 which shows the inclination sensor by a comparative example. In 1st Embodiment and a comparative example, it is a characteristic diagram which shows the relationship between an inclination angle and the magnetic flux density corresponding to a detection signal. It is a disassembled perspective view which shows the inclination sensor by 2nd Embodiment. It is sectional drawing which looked at the inclination sensor from the arrow IX-IX direction in FIG. It is a top view which shows the inclination sensor in FIG. 8 in the state which excluded the cover body. In 1st, 2nd embodiment, it is a characteristic diagram which shows the relationship between the inclination angle and the magnetic flux density corresponding to a detection signal. It is sectional drawing of the position similar to FIG. 2 which shows the inclination sensor by 3rd Embodiment. In 2nd, 3rd embodiment, it is a characteristic diagram which shows the relationship between an inclination angle and the magnetic flux density corresponding to a detection signal. It is sectional drawing of the position similar to FIG. 9 which shows the inclination sensor by 4th Embodiment. It is a disassembled perspective view which shows the inclination sensor by 5th Embodiment. It is sectional drawing which looked at the inclination sensor from the arrow XVI-XVI direction in FIG. It is sectional drawing which looked at the inclination sensor from the arrow XVII-XVII direction in FIG. It is a top view which shows the inclination sensor in FIG. 15 in the state which excluded the cover body. It is explanatory drawing which shows the positional relationship of the movable body in FIG. 15, and a magnetoelectric conversion element. It is a front view which shows the magnetoresistive sensor of a magnetoelectric conversion element. It is an equivalent circuit diagram which shows a magnetoelectric conversion element. It is sectional drawing of the position similar to FIG. 16 which shows the inclination sensor by 6th Embodiment. It is sectional drawing which looked at the inclination sensor from the arrow XXIII-XXIII direction in FIG. It is a top view which shows the inclination sensor in FIG. 22 in the state which excluded the cover body. It is sectional drawing of the position similar to FIG. 2 which shows the inclination sensor by a 1st modification. It is sectional drawing of the position similar to FIG. 2 which shows the inclination sensor by a 2nd modification. It is sectional drawing of the position similar to FIG. 2 which shows the inclination sensor by a 3rd modification. It is sectional drawing of the same position as FIG. 2 which shows the inclination sensor by a 4th modification.

  Hereinafter, a case where a magnetic flux detection sensor according to an embodiment of the present invention is applied to a tilt sensor will be described as an example with reference to the accompanying drawings.

  1 to 5 show a tilt sensor 1 according to the first embodiment. The tilt sensor 1 is composed of a casing 2, a magnetoelectric conversion element 8, and a movable body 12, which will be described later.

  The casing 2 is a nonmagnetic container formed using a nonmagnetic material such as an insulating resin material. The casing 2 includes a casing main body 3 formed in a substantially cylindrical shape with a bottom, and a lid body 4 that covers an upper side that serves as an opening of the casing main body 3.

  The height of the casing body 3 in the vertical direction is several mm (for example, about 9 mm), and the cross-sectional shape in the horizontal plane is a substantially circular shape with an outer diameter of several mm (for example, about 9 mm). In addition, a concave portion 3A that is recessed in a substantially hemispherical shape (bowl shape) is formed on the upper side of the casing body 3, and a cylindrical male fitting portion 3B is integrated upward at the opening edge of the concave portion 3A. Is formed.

  The surface (exposed surface) of the recess 3A is a concave curved surface 5 that opens upward. The concave curved surface 5 is formed of, for example, a hemispherical surface, and the radius of curvature r1 is larger than the radius of curvature r2 of the sliding surface 13 of the movable body 12 described later.

  The lid 4 is formed in a substantially disc shape, and a cylindrical female fitting portion 4A is integrally formed on the outer peripheral edge thereof downward. By fitting and inserting the male fitting portion 3B of the casing body 3 into the female fitting portion 4A, the lid body 4 is attached to the casing body 3, and the substantially hemispherical shape is provided between the casing body 3 and the lid body 4. The movable body accommodating space 6 is formed.

  In addition, a substantially cylindrical rod portion 7 extending downward toward the deepest portion 5 </ b> A of the concave curved surface 5 is provided at the center portion of the lid body 4. In addition, the lower end part of the rod part 7 is formed in the substantially hemispherical shape. By providing the rod portion 7, it is possible to prevent a movable body 12 (described later) from being separated from the concave curved surface 5, and to prevent the movable body 12 from being reversed upside down in the movable body accommodating space 6.

  The magnetoelectric transducer 8 composed of a magnetoresistive element, a Hall element, etc. constitutes a magnetic flux density detection means, and outputs a detection signal Vout corresponding to the magnetic flux density (magnetic field) in the height direction of the casing 2, for example. The magnetoelectric conversion element 8 is provided inside the casing body 3 positioned below the deepest part 5A of the concave curved surface 5 by a minute dimension δ. The minute dimension δ is set in the range of several hundred μm to several mm, for example, about δ = 1 mm. In addition, the magnetoelectric conversion element 8 is disposed at a position facing the sliding surface 13 of the movable body 12 accommodated in the movable body accommodating space 6. A magnetic flux φ from the movable body 12 is applied to the magnetoelectric conversion element 8 via the sliding surface 13 of the movable body 12. Thereby, the magnetoelectric conversion element 8 detects a change in magnetic flux density caused by the sliding of the movable body 12.

  The magnetoelectric transducer 8 is electrically connected to a ground terminal 9 for connection to an external ground, and is also electrically connected to a drive voltage terminal 10 for supplying a drive voltage Vdd. Furthermore, a signal output terminal 11 for outputting a detection signal Vout such as a voltage is electrically connected to the magnetoelectric conversion element 8. The ground terminal 9, the drive voltage terminal 10, and the signal output terminal 11 are formed of, for example, a conductive metal material, embedded in the casing body 3, and part of the ground terminal 9, projecting downward from the lower surface side of the casing body 3. Yes.

  The movable body 12 is formed using a magnetic material such as ferrite, for example, and is formed into a substantially hemispherical magnet (permanent magnet). A sliding surface 13 made of a downward convex curved surface is formed on the bottom side of the movable body 12, and a flat upper surface 14 is formed on the upper side of the movable body 12. As a result, the movable body 12 has a maximum thickness at the apex portion 12A of the sliding surface 13 that is substantially hemispherical, and approaches the upper surface peripheral portion 12B of the upper surface 14 from the apex portion 12A along the sliding surface 13. The thickness gradually decreases.

  The movable body 12 is magnetized so that the sliding surface 13 and the upper surface 14 have opposite polarities, for example, the sliding surface 13 has an N pole and the upper surface 14 has an S pole. As a result, a magnetic flux φ is generated in the normal direction of the sliding surface 13 of the movable body 12. The magnetic flux density around the apex portion 12A where the thickness of the movable body 12 is maximum increases, and the magnetic flux density gradually decreases as it approaches the upper peripheral portion 12B where the thickness becomes thinner.

  The movable body 12 is accommodated in the movable body accommodating space 6 of the casing 2 with the sliding surface 13 facing downward so that the concave curved surface 5 of the casing 2 and the sliding surface 13 of the movable body 12 come into contact with each other and can slide. For this reason, when the casing 2 is tilted from the horizontal state, the movable body 12 slides and displaces inside the movable body accommodating space 6 along the concave curved surface 5.

  Further, since the movable body 12 has a hemispherical shape protruding downward, the upper surface 14 is stationary in a horizontal state based on its weight balance. Therefore, the positional relationship between the apex portion 12A of the movable body 12 and the magnetoelectric conversion element 8 changes according to the inclination angle θ of the casing 2, and the magnetic flux φ applied from the movable body 12 to the magnetoelectric conversion element 8 The direction of is also changing.

  The tilt sensor 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  First, when the casing 2 is in a horizontal state, the movable body 12 is disposed on the deepest portion 5A side of the concave curved surface 5 as a steady position. Specifically, the movable body 12 is supported by the concave curved surface 5 in a state where the apex portion 12A of the movable body 12 is in contact with the deepest portion 5A of the concave curved surface 5. At this time, the apex portion 12 </ b> A having a high magnetic flux density in the movable body 12 is disposed at a position directly above the magnetoelectric conversion element 8. Therefore, a magnetic flux φ is applied to the magnetoelectric conversion element 8 by the movable body 12 along the vertical direction that is the height direction of the casing 2. For this reason, the magnetoelectric transducer 8 outputs the largest detection signal Vout according to the magnetic flux density in the Z-axis direction.

  Next, when the casing 2 is tilted and tilted from the horizontal state, the movable body 12 is displaced from the steady position along the concave curved surface 5 and moves toward the lowest position of the movable body accommodating space 6. . Therefore, the apex portion 12A having a high magnetic flux density in the movable body 12 is separated from the deepest portion 5A of the concave curved surface 5 in accordance with the inclination angle θ of the casing 2, and the uppermost peripheral portion having a low magnetic flux density is included in the deepest portion 5A. 12B approaches. Therefore, the magnetic flux density applied from the movable body 12 to the magnetoelectric conversion element 8 decreases according to the inclination angle θ.

  The magnetoelectric transducer 8 detects the magnetic flux density in the direction inclined by the inclination angle θ with respect to the vertical direction, and outputs a detection signal Vout corresponding to the magnetic flux density. As a result, the magnetoelectric transducer 8 outputs the detection signal Vout corresponding to the inclination angle θ, and the detection signal Vout gradually decreases as the inclination angle θ increases.

  Next, when the casing 2 is returned to the horizontal state, the movable body 12 is displaced toward the deepest part 5A along the concave curved surface 5, and the apex part 12A returns to the steady position where it contacts the deepest part 5A. To do. Thereby, the magnetic flux density applied to the magnetoelectric conversion element 8 increases again, and the magnetoelectric conversion element 8 outputs the largest detection signal Vout corresponding to the magnetic flux density in the vertical direction.

  In the present embodiment, the movable body 12 is formed in a hemispherical shape having a hemispherical sliding surface 13, and the sliding surface 13 is slidably supported by the concave curved surface 5 having a hemispherical surface. For this reason, the magnetic flux density applied to the magnetoelectric conversion element 8 can be changed according to the inclination angle θ of the casing 2, and the linearity of the detection signal Vout with respect to the inclination angle θ can be enhanced.

  In order to confirm the effect of improving linearity, the inclination sensor 1 according to the present embodiment was compared with the inclination sensor 21 as a comparative example shown in FIG. For the tilt sensors 1 and 21, the relationship between the tilt angle θ and the magnetic flux density in the tilt angle θ direction was measured, and the comparison result is shown in FIG.

  A casing 22 of a tilt sensor 21 as a comparative example shown in FIG. 6 includes a casing body 23 and a lid body 24 as in the tilt sensor 1 of the first embodiment, and the casing body 23 has a concave curved surface 25. It was set as the structure provided with the movable body accommodation space 26 which has. The movable body 27 is formed of a thick disk-shaped (columnar) magnet as in Patent Document 2, and the circular lower surface 27A and upper surface 27B are magnetized in opposite polarities. .

  In the case of the tilt sensor 21, as indicated by a broken line in FIG. 7, the magnetic flux density greatly changes when the tilt angle θ is 20 ° to 30 °, and the magnetic flux density has a nonlinear characteristic with respect to the tilt angle θ. This is because the movable body 27 is formed in a thick disk shape, so that the magnetoelectric conversion element 8 is in the case where the magnetoelectric conversion element 8 is located near the center portion of the lower surface 27A and in the case where it is located away from the center portion. This is because the magnetic flux density applied to is greatly changed.

  On the other hand, in the case of the tilt sensor 1, as indicated by the solid line in FIG. 7, when the tilt angle θ is in the range from 0 ° to about 50 °, the magnetic flux density decreases uniformly as the tilt angle θ increases. The magnetic flux density has a characteristic close to linear with respect to the tilt angle θ. This is because the movable body 12 is formed in a hemispherical shape, so that the magnetic flux density is high around the apex portion 12A where the thickness of the movable body 12 is maximum, and the magnetic flux density becomes closer to the upper peripheral portion 12B where the thickness is thin. This is because is gradually reduced. In the present embodiment, as the inclination angle θ of the casing 2 increases, the position of the sliding surface 13 facing the magnetoelectric conversion element 8 is displaced from the apex portion 12A toward the upper peripheral portion 12B. For this reason, the magnetic flux density can be changed according to the inclination angle θ within the angle range where the sliding surface 13 of the movable body 12 and the magnetoelectric conversion element 8 face each other, and the linearity of the detection signal Vout corresponding to the magnetic flux density is increased. Can be increased.

  In the present embodiment, the apex portion 12A of the movable body 12 only needs to be displaced with respect to the magnetoelectric conversion element 8. Therefore, the movable body accommodating space 6 of the casing 2 has a volume that allows the movable body 12 to be rotationally displaced. Anything is enough. For this reason, the volume of the movable body accommodation space 6 can be brought close to the volume of the movable body 12, and the inclination sensor 1 can be reduced in size.

  Next, FIGS. 8 to 10 show a second embodiment of the present invention. The feature of the present embodiment is that a chamfered portion is provided at the peripheral portion of the upper surface of the movable body.

  The tilt sensor 41 is configured by a casing 42, a magnetoelectric conversion element 48, and a movable body 52 in substantially the same manner as the tilt sensor 1 according to the first embodiment.

  The casing 42 is a nonmagnetic container formed using a nonmagnetic material such as an insulating resin material. The casing 42 includes a casing main body 43 formed in a substantially cylindrical shape with a bottom, and a lid body 44 that covers the upper side serving as an opening of the casing main body 43. The casing main body 43 and the lid body 44 are formed in substantially the same manner as the casing main body 3 and the lid body 4 according to the first embodiment.

  The height of the casing body 43 in the vertical direction is about several mm, and the cross-sectional shape in the horizontal plane is a substantially circular shape with an outer diameter of several mm. A concave portion 43A that is recessed in a substantially hemispherical shape is formed on the upper side of the casing body 43, and a cylindrical male fitting portion 43B is integrally formed at the opening edge of the concave portion 43A.

  The surface (exposed surface) of the recess 43A is a concave curved surface 45 that opens upward. On the deepest portion side of the concave curved surface 45, a bottom surface portion 45A which is a small circular flat surface parallel to the horizontal surface is formed. Further, the substantially hemispherical surface of the concave portion 43A and the outer periphery of the bottom surface portion 45A are connected by a bottom surface connection portion 45B having a truncated conical shape that is reduced in diameter in the downward direction. As a result, the concave curved surface 45 is formed in a substantially hemispherical shape as a whole.

  These bottom surface portion 45A and bottom surface connecting portion 45B support a sliding surface 53 of the movable body 52 described later in a state close to point contact. For this reason, even when the inclination angle θ is small, the frictional resistance between the concave curved surface 45 and the movable body 52 can be reduced, and the movable body 52 can be easily slid. In addition, since the bottom surface 45A that is a flat surface is provided on the deepest side of the concave curved surface 45, when the casing 42 is returned to the horizontal state, the movable body 52 is surely returned to the bottom surface 45A that is the steady position. Can do.

  The lid body 44 is formed in a substantially disc shape, and a cylindrical female fitting portion 44A is integrally formed on the outer peripheral edge thereof downward. By fitting and inserting the male fitting portion 43B of the casing main body 43 into the female fitting portion 44A, the lid body 44 is attached to the casing main body 43, and the substantially hemispherical shape is formed between the casing main body 43 and the lid body 44. The movable body accommodating space 46 is formed. Further, a rod portion 47 that is substantially the same as the rod portion 7 according to the first embodiment is provided at the central portion of the lid 44.

  The magnetoelectric conversion element 48 constitutes a magnetic flux density detector, and outputs a detection signal Vout corresponding to the magnetic flux density in the height direction of the casing 42, for example. The magnetoelectric conversion element 48 is provided in the casing main body 43 so as to be several hundred μm to several mm below the bottom surface portion 45 A of the concave curved surface 45, and the sliding of the movable body 52 in the movable body accommodating space 46. It is disposed at a position facing the surface 53. Then, the magnetic flux φ from the movable body 52 is applied to the magnetoelectric conversion element 48 via the sliding surface 53. Thereby, the magnetoelectric conversion element 48 detects a change in magnetic flux density caused by the sliding of the movable body 52. The magnetoelectric transducer 48 is electrically connected to a ground terminal 49, a drive voltage terminal 50, and a signal output terminal 51 attached to the casing body 43, as in the first embodiment.

  The movable body 52 is formed using a magnetic material, and is formed into a substantially hemispherical magnet (permanent magnet). In the movable body 52, a sliding surface 53 made of a downward convex curved surface is formed on the bottom side, and the upper surface 54 is a flat surface on the upper side, almost the same as the movable body 12 according to the first embodiment. Is formed. As a result, the movable body 52 has a maximum thickness at the apex portion 52A of the sliding surface 53 that is substantially hemispherical, and gradually decreases in thickness as it approaches the upper surface peripheral portion 52B of the upper surface 54 from the apex portion 52A. ing.

  The movable body 52 is magnetized so that the sliding surface 53 and the upper surface 54 have opposite polarities. Thereby, the movable body 52 generates the magnetic flux φ in the normal direction of the sliding surface 53, for example. Note that the magnetic flux density increases around the apex portion 52A where the thickness of the movable body 52 is the maximum, and the magnetic flux density gradually decreases as it approaches the upper peripheral portion 52B where the thickness is reduced.

  The movable body 52 is accommodated in the movable body accommodating space 46 of the casing 42 with the sliding surface 53 facing downward so that the concave curved surface 45 of the casing 42 and the sliding surface 53 of the movable body 52 can contact and slide. . For this reason, when the casing 42 is tilted from the horizontal state, the movable body 52 slides and displaces inside the movable body accommodation space 46 along the concave curved surface 45.

  Further, since the movable body 52 has a hemispherical shape protruding downward, the upper surface 54 is stationary in a horizontal state based on its weight balance. Therefore, the distance between the apex portion 52A of the movable body 52 and the magnetoelectric conversion element 48 changes according to the inclination angle θ of the casing 42, and the magnetic flux φ applied from the movable body 52 to the magnetoelectric conversion element 48 increases. The direction also changes.

  Further, the upper peripheral edge portion 52B of the movable body 52 is rounded in an arc shape to form a chamfered portion 55. As a result, the concentration of the magnetic flux φ at the upper peripheral portion 52B around the chamfered portion 55 is alleviated.

  Further, the movable body 52 is formed with a recessed portion 56 that is located on the center side of the upper surface 54 and is recessed in a substantially circular shape. By providing the recessed portion 56, the center of gravity of the movable body 52 moves to the apex portion 52A side, and the stability of the movable body 52 is enhanced.

  Thus, in the second embodiment, the same operational effects as those of the first embodiment can be obtained, and in particular, the chamfered portion 55 is provided on the upper peripheral portion 52B of the movable body 52. Thus, the concentration of the magnetic flux φ at the upper peripheral edge portion 52B of the movable body 52 can be relaxed, and the linearity range of the detection signal of the magnetoelectric transducer 48 with respect to the tilt angle θ can be enhanced.

  In order to confirm the effect of improving the linearity, the inclination sensors 1 and 41 according to the first and second embodiments were compared. For the tilt sensors 1 and 41, the relationship between the tilt angle θ and the magnetic flux density in the tilt angle θ direction was measured, and the comparison result is shown in FIG.

  In the case of the tilt sensor 1 of the first embodiment, as indicated by a broken line in FIG. 11, the magnetic flux density decreases as the tilt angle θ increases in a range where the tilt angle θ is smaller than 50 °, for example. On the other hand, in the range where the tilt angle θ is larger than 50 °, for example, the magnetic flux density does not decrease even if the tilt angle θ increases, and the magnetic flux density increases.

  In the movable body 12 according to the first embodiment, the magnetic flux φ is concentrated at the upper peripheral portion 12B where the sliding surface 13 and the upper surface 14 intersect at an acute angle. Therefore, in the first embodiment, when the inclination angle θ increases, the upper surface peripheral portion 12B having a high magnetic flux density approaches the magnetoelectric conversion element 8, and therefore the magnetic flux density detected by the magnetoelectric conversion element 8 increases, and the inclination angle θ However, the non-linear range becomes narrower.

  On the other hand, in the tilt sensor 41 of the second embodiment, the chamfered portion 55 is provided on the upper surface peripheral portion 52B of the movable body 52, so that the magnetic flux φ at the upper peripheral portion 52B of the movable body 52 is caused by the chamfered portion 55. Can be relaxed. For this reason, the magnetic flux density can be gradually reduced as the apex portion 52A approaches the upper peripheral portion 52B. As a result, in the case of the second embodiment, as indicated by a solid line in FIG. 11, the magnetic flux density continues to decrease uniformly as the tilt angle θ increases, even in the range where the tilt angle θ exceeds 50 °, The range of the detectable tilt angle θ can be further expanded.

  Next, FIG. 12 shows a third embodiment of the present invention. The feature of this embodiment is that the outer diameter of the movable body is set to a value close to the inner diameter of the concave curved surface. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The tilt sensor 61 includes a casing 62, a magnetoelectric conversion element 8, and a movable body 68 in substantially the same manner as the tilt sensor 1 according to the first embodiment.

  The casing 62 is composed of a casing body 63 and a lid body 64 in substantially the same manner as the casing 2 according to the first embodiment. A concave portion 63A that is recessed in a hemispherical shape is formed on the upper side of the casing body 63, and a concave curved surface 65 that is a hemispherical surface having an inner diameter dimension D1 is formed on the surface of the concave portion 63A. A cylindrical male fitting portion 63B is formed at the opening edge of the concave curved surface 65, and this male fitting portion 63B is fitted and inserted into the female fitting portion 64A of the lid 64. Thereby, a movable body accommodating space 66 is formed between the casing body 63 and the lid body 64. In addition, a rod portion 67 that is substantially the same as the rod portion 7 according to the first embodiment is provided at the center portion of the lid 64.

  Further, the casing main body 63 is provided with a magnetoelectric conversion element 8 positioned below the deepest portion 65A of the concave curved surface 65, and a ground terminal 9 and a drive voltage terminal electrically connected to the magnetoelectric conversion element 8. 10 and a signal output terminal 11 are attached.

  The movable body 68 is formed using a magnetic material, and is formed into a substantially hemispherical magnet (permanent magnet). The movable body 68 is formed in substantially the same manner as the movable body 52 according to the second embodiment. For this reason, a sliding surface 69 made of a downward convex curved surface is formed on the bottom side of the movable body 68, and a flat upper surface 70 is formed on the upper side.

  In the movable body 68, the sliding surface 69 and the upper surface 70 are magnetized in opposite polarities. The magnetic flux density around the apex portion 68A where the thickness of the movable body 68 is thick increases, and the magnetic flux density gradually decreases as it approaches the thin upper surface peripheral portion 68B.

  The upper surface peripheral portion 68B of the movable body 68 is rounded in an arc shape to form a chamfered portion 71. In addition, a recessed portion 72 that is recessed in a substantially circular shape is formed on the center side of the upper surface 70 of the movable body 68. Further, the outer diameter D2 of the movable body 68 is set to a value of about 70 to 95% of the inner diameter D1 as a value close to the inner diameter D1 of the concave curved surface 65. The movable body 68 is accommodated in the movable body accommodating space 66 of the casing 62 with the sliding surface 69 facing downward.

  Thus, the third embodiment can obtain the same effects as those of the first and second embodiments. In particular, the outer diameter D2 of the movable body 68 is a value close to the inner diameter D1 of the concave curved surface 65. Therefore, as shown in FIG. 13, the amount of change in magnetic flux density applied to the magnetoelectric transducer 8 with respect to the tilt angle θ can be increased. For this reason, the output range of the detection signal Vout of the magnetoelectric conversion element 8 can be expanded, and the detection sensitivity of the inclination angle θ can be increased.

  In addition, since the outer diameter D2 of the movable body 68 is set to a value close to the inner diameter D1 of the concave curved surface 65, the overall inclination sensor 61 can be downsized by reducing the outer diameter D2 of the movable body 68. it can.

  In the third embodiment, a movable body 68 similar to the movable body 52 according to the second embodiment is used. However, a movable body similar to the movable body 12 according to the first embodiment is used. It is good also as a structure. In the third embodiment, the concave curved surface 65 having the same shape as the concave curved surface 5 according to the first embodiment is used. However, the concave curved surface 45 according to the second embodiment has the same shape. A configuration using a concave curved surface may be adopted.

  Next, FIG. 14 shows a fourth embodiment of the present invention. The feature of this embodiment is that a coating film as a smoothing process is formed on a concave curved surface. In the present embodiment, the same components as those in the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The inclination sensor 81 is configured by a casing 42, a magnetoelectric conversion element 48, and a movable body 52 in substantially the same manner as the inclination sensor 41 according to the second embodiment. However, a thin coating film 82 made of fluorine resin, silicon resin or the like is formed on the surface of the concave curved surface 45 as a smoothing process. The coating film 82 has, for example, a smooth surface having lubricity, and reduces the contact resistance with respect to the movable body 52.

  Thus, the fourth embodiment can obtain the same effects as those of the first and second embodiments. In particular, since the coating film 82 as the smoothing process is formed on the concave curved surface 45, the concave curved surface 45 is provided. The frictional resistance between the movable body 52 and the movable body 52 can be reduced. For this reason, the responsiveness of the movable body 52 can be improved with respect to the change of the inclination angle θ, and the detection accuracy of the inclination angle θ can be improved.

  In the fourth embodiment, the case of applying to the second embodiment has been described as an example. However, the fourth embodiment may be applied to the first and third embodiments. In the fourth embodiment, the coating film 82 is formed on the surface of the concave curved surface 45. However, the coating film 82 may be formed on the sliding surface 53 of the movable body 52. A coating film 82 may be formed on both surfaces 53.

  Furthermore, in the fourth embodiment, the resin coating film 82 is used as the smoothing process. However, a metal thin film by plating or the like may be formed, and surface irregularities are reduced as in the surface polishing process. Various surface treatments that can be applied are applicable.

  Next, FIGS. 15 to 21 show a fifth embodiment of the present invention. The feature of this embodiment is anisotropy in which the detection output in the horizontal Y-axis direction is larger than the horizontal X-axis direction among the X-axis, Y-axis, and Z-axis that are orthogonal to each other. When using a magnetoelectric transducer, in order to obtain substantially the same detection output regardless of the direction, the concave curved surface of the movable body housing space is directed toward the Y axis direction compared to the X axis direction. It is formed by an anisotropic curved surface that is largely displaced.

  The tilt sensor 91 is configured by a casing 92, a magnetoelectric conversion element 98, and a movable body 102 in substantially the same manner as the tilt sensor 41 according to the second embodiment.

  The casing 92 is a nonmagnetic container formed using a nonmagnetic material such as an insulating resin material. The casing 92 includes a casing main body 93 formed in a substantially cylindrical shape with a bottom, and a lid body 94 that covers the upper side serving as an opening of the casing main body 93.

  The height of the casing body 93 in the vertical direction is about several mm, and the cross-sectional shape in the horizontal plane is a substantially circular shape with an outer diameter of several mm. Further, a concave portion 93A that is recessed in a substantially semi-ellipsoidal shape is formed on the upper side of the casing body 93, and a cylindrical male fitting portion 93B is integrally formed downward on the opening side of the concave portion 93A. Has been.

  The surface (exposed surface) of the recess 93A is a concave curved surface 95 that opens upward. The concave curved surface 95 is formed of an anisotropic curved surface having different cross-sectional shapes in the horizontal X-axis direction and the Y-axis direction among the X-axis, Y-axis, and Z-axis that are orthogonal to each other. Specifically, the concave curved surface 95 is formed by a half-shaped ellipsoidal surface in which the X-axis direction is a short axis and the Y-axis direction is a long axis.

  By forming the concave curved surface 95 by an anisotropic curved surface, the casing 92 is formed in a shape in which the detection signal Vout having the same output level can be obtained from the magnetoelectric conversion element 98 when the casing 92 is inclined in any direction of the horizontal plane (XY plane). Has been.

  The lid body 94 is formed in a substantially disc shape, and a cylindrical female fitting portion 94A is integrally formed on the outer peripheral edge thereof downward. By fitting and inserting the male fitting portion 93B of the casing main body 93 into the female fitting portion 94A, the lid body 94 is attached to the casing main body 93, and a substantially semi-ellipse is formed between the casing main body 93 and the lid body 94. A body-like movable body accommodating space 96 is formed. In addition, a rod portion 97 substantially the same as the rod portion 7 according to the first embodiment extending downward toward the deepest portion 95A of the concave curved surface 95 is provided at the center portion of the lid 94.

  Next, a case where a magnetic thin film magnetoresistive element is used as the magnetoelectric conversion element 98 serving as the magnetic flux density detecting means will be described. In order to reduce the size, the magnetoelectric conversion element 98 is configured by an AMR-IC (Anisotropic Magneto Resistance Integrated Circuit) in which a magnetoresistive sensor 98A composed of a magnetic thin film magnetoresistive element and a differential amplifier 98B are integrated. ing. The magnetoresistive sensor 98A is composed of four magnetoresistive elements R1 to R4. The magnetoresistive elements R1 to R4 are formed using means such as vapor deposition of a magnetoresistive material such as indium antimony (InSb) on the sensor substrate S. The magnetoresistive elements R1 to R4 are formed by connecting and arranging a plurality of elongated patterns in a meander shape. The magnetoresistive element R1 is arranged on the upper left side of the sensor substrate S and the magnetoresistive element R4 is arranged on the lower right side of the sensor substrate S. The magnetoresistive element R2 is arranged at the lower left of the sensor substrate S and the magnetoresistive element R3 is arranged at the upper right of the sensor substrate S.

  The magnetoresistive elements R1 to R4 are bridge-connected, and the input terminal of the differential amplifier 98B is connected to a connection point between the magnetoresistive elements R1 and R2 and a connection point between the magnetoresistive elements R3 and R4. A connection point between the magnetoresistive elements R2 and R4 is electrically connected to a ground terminal 99 for connection to an external ground GND. A driving voltage terminal 100 for supplying a driving voltage Vdd is electrically connected to a connection point between the magnetoresistive elements R1 and R3. Furthermore, the output terminal of the differential amplifier 98B is electrically connected to a signal output terminal 101 that outputs a detection signal Vout such as a voltage. The differential amplifier 98B differentially amplifies the potential difference generated between these two connection points and outputs a detection signal Vout.

  In the sensor substrate S, the direction connecting the magnetoresistive elements R1 and R2 (R3 and R4) coincides with the vertical direction (Z-axis direction), and the magnetoresistive elements R1 and R3 (R2 and R4) are connected. The direction is arranged so as to coincide with the horizontal direction (X-axis direction). The resistance values of the magnetoresistive elements R1 and R4 change according to the change in the magnetic flux density in the horizontal direction (X-axis direction). The resistance values of the magnetoresistive elements R2 and R3 change according to the change in the magnetic flux density in the vertical direction (Z-axis direction).

  When the magnetic flux density parallel to the XZ plane is applied to the sensor substrate S, the resistance values of the four magnetoresistive elements R1 to R4 all change. For this reason, when the casing 92 is tilted in the X-axis direction, the detection signal Vout changes, for example, in a positive / negative range of the drive voltage Vdd (−Vdd ≦ Vout ≦ Vdd).

  On the other hand, when a magnetic flux density parallel to the XY plane is applied to the sensor substrate S, the resistance values of the remaining two magnetoresistive elements R1, R4 change, although the resistance values of the two magnetoresistive elements R2, R3 change. Hardly changes. For this reason, when the casing 92 is tilted in the Y-axis direction, the detection signal Vout changes in the range from the ground potential to the drive voltage Vdd (0 ≦ Vout ≦ Vdd).

  As a result, the magnetoresistive sensor 98A has anisotropy in which the detection signal Vout when the magnetic flux is tilted in the Y-axis direction has a higher output level than the detection signal Vout when the magnetic flux φ is tilted in the X-axis direction. Output characteristics.

  The magnetoelectric conversion element 98 is provided inside the casing main body 93 located several hundred μm to several mm below the deepest portion 95 </ b> A of the concave curved surface 95. That is, the magnetoelectric conversion element 98 is disposed at a position facing the sliding surface 103 of the movable body 102 accommodated in the movable body accommodating space 96.

  The movable body 102 is formed using a magnetic material, and is formed into a substantially hemispherical magnet (permanent magnet). In substantially the same manner as the movable body 52 according to the second embodiment, a sliding surface 103 made of a downward convex curved surface is formed on the bottom side of the movable body 102, and an upper surface 104 having a flat surface on the upper side. Is formed. As a result, the movable body 102 has a maximum thickness at the apex portion 102A of the sliding surface 103 that is substantially hemispherical, and gradually decreases in thickness as it approaches the upper surface peripheral portion 102B of the upper surface 104 from the apex portion 102A. ing.

  The movable body 102 is magnetized so that the sliding surface 103 and the upper surface 104 have opposite polarities. As a result, a magnetic flux φ is generated in the normal direction of the sliding surface 103 of the movable body 102. Note that the magnetic flux density increases around the apex portion 102A where the thickness of the movable body 102 is maximum, and the magnetic flux density gradually decreases as it approaches the upper peripheral portion 102B where the thickness is reduced.

  The movable body 102 is accommodated in the movable body accommodating space 96 of the casing 92 with the sliding surface 103 facing downward so that the concave curved surface 95 of the casing 92 and the sliding surface 103 of the movable body 102 can contact and slide. Yes. Therefore, when the casing 92 is tilted from the horizontal state, the movable body 102 slides and displaces inside the movable body accommodating space 96 along the concave curved surface 95.

  The upper peripheral edge portion 102B of the movable body 102 is rounded in an arc shape to form a chamfered portion 105. In addition, the movable body 102 is formed with a recessed portion 106 that is located on the center side of the upper surface 104 and is recessed in a substantially circular shape.

  In the fifth embodiment, the magnetoelectric transducer has anisotropy in which the detection signal Vout when the tilt sensor is tilted in the Y-axis direction has a higher output level than the detection signal Vout when tilted in the X-axis direction. 98 was used. On the other hand, the concave curved surface 95 of the movable body accommodating space 96 is formed by an ellipsoidal surface that greatly displaces the movable body 102 in the Y-axis direction compared to the X-axis direction. Therefore, when the casing 92 is tilted in the X-axis direction, the amount of displacement of the movable body 102 with respect to the tilt angle θ is increased when the casing 92 is tilted in the Y-axis direction, and the magnetoelectric conversion element 98 and the movable body. The positional change with the vertex part 102A of 102 can be enlarged.

  For this reason, the change in the magnetic flux density applied to the magnetoelectric conversion element 98 becomes larger when the casing 92 is tilted in the Y-axis direction than when the casing 92 is tilted in the X-axis direction. That is, the magnetic flux density applied from the movable body 102 to the magnetoelectric transducer 98 is lowered when tilted in the Y-axis direction compared to when tilted in the X-axis direction at the same tilt angle θ, and the detection signal Vout. The output level can be suppressed. As a result, the detection signal Vout of the magnetoelectric conversion element 98 when the casing 92 is inclined in the X-axis direction and the detection signal Vout of the magnetoelectric conversion element 98 when the casing 92 is inclined in the Y-axis direction are relative to the inclination angle θ. The output level can be made substantially equal. In the fifth embodiment, the same effects as those in the first and second embodiments can be obtained.

  Next, FIG. 22 to FIG. 24 show a sixth embodiment of the present invention. The feature of this embodiment is that the concave curved surface of the movable body accommodating space is a combination of a half-shaped ellipsoidal surface in which the X-axis direction is the short axis and the Y-axis direction is the long axis, and a hemispherical surface. This is because it is formed by an isotropic curved surface. Note that the half-shaped ellipsoidal surface and the hemispherical surface are combined while being in contact with each other at the center of the ellipsoidal surface. In the present embodiment, the same components as those in the fifth embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The inclination sensor 111 is configured by a casing 112, a magnetoelectric conversion element 98, and a movable body 102 in substantially the same manner as the inclination sensor 91 according to the fifth embodiment.

  The casing 112 is a nonmagnetic container formed using a nonmagnetic material such as an insulating resin material. The casing 112 includes a casing main body 113 formed in a substantially cylindrical shape with a bottom, and a lid body 114 that covers an upper portion serving as an opening of the casing main body 113.

  The height of the casing body 113 in the vertical direction is about several mm, and the cross-sectional shape in the horizontal plane is a substantially circular shape with an outer diameter of several mm. A concave portion 113A that is recessed in a substantially semi-ellipsoidal shape is formed on the upper side of the casing body 113, and a cylindrical male fitting portion 113B is integrally formed at the opening edge of the concave portion 113A.

  The surface (exposed surface) of the recess 113A is a concave curved surface 115 that opens upward, and is formed by an anisotropic curved surface having different cross-sectional shapes in the X-axis direction and the Y-axis direction. Specifically, the concave curved surface 115 is shorter than the length in the longitudinal direction of the halved ellipsoidal surface 115A in which the X-axis direction is the minor axis and the Y-axis direction is the major axis, and the ellipsoidal surface 115A. It is formed by an anisotropic curved surface combined with a hemispherical surface 115B having a diameter D2b larger than the length in the hand direction. At this time, the deepest part of the ellipsoidal surface 115A and the deepest part of the hemispherical surface 115B are arranged and formed so as to coincide with the deepest part 115C of the concave curved surface 115 to be formed. As a result, the ellipsoidal surface 115A and the hemispherical surface 115B are in contact with each other at the deepest portion 115C of the concave curved surface 115 to be formed, and the concave portion 113A is formed symmetrically with respect to the XZ plane and the YZ plane.

  The major axis dimension D2a of the ellipsoidal surface 115A and the diameter dimension D2b of the hemispherical surface 115B are such that the magnetoelectric conversion is located below the deepest portion 115C of the concave curved surface 115 when the casing 112 is inclined in any direction of the XY plane. The elements 98 are selected so as to obtain a detection signal Vout having the same output level.

  The lid body 114 is formed in a substantially disc shape, and a cylindrical female fitting portion 114A is integrally formed on the outer peripheral edge thereof downward. By fitting and inserting the male fitting portion 113B of the casing main body 113 into the female fitting portion 114A, the lid body 114 is attached to the casing main body 113, and a halved shape is formed between the casing main body 113 and the lid body 114. The movable body accommodating space 116 is formed by combining the ellipsoid and the substantially hemisphere. In addition, a rod portion 117 substantially the same as the rod portion 7 according to the first embodiment is provided at the center portion of the lid body 114.

  In the sixth embodiment, since the concave curved surface 115 is formed by an anisotropic curved surface in which the ellipsoidal surface 115A and the hemispherical surface 115B are combined, the movable body 102 is compared with the case where the concave curved surface 115 is formed only by the half-shaped ellipsoidal surface. The frictional resistance can be reduced by reducing the contact area between the concave curved surface 115 and the concave curved surface 115. For this reason, the responsiveness of the movable body 102 with respect to the inclination angle θ can be improved, and the detection accuracy of the inclination angle θ can be improved. In the sixth embodiment, the same operational effects as those of the first, second, and fifth embodiments can be obtained.

  In the fifth and sixth embodiments, the movable body 102 provided with the chamfered portion 105 is used. However, as with the movable body 12 according to the first embodiment, the movable body without the chamfered portion is used. It is good also as a structure using a body. In addition, the concave curved surfaces 95 and 115 of the fifth and sixth embodiments may be smoothed in the same manner as in the fourth embodiment, and the sliding surface 103 of the movable body 102 is smoothed. May be. Also in the fifth and sixth embodiments, similarly to the concave curved surface according to the second embodiment, a bottom surface portion that is a flat surface may be formed at the deepest portion of the concave curved surface.

  Moreover, in the said 2nd-6th embodiment, it was set as the structure which provided the chamfered part 55, 71, 105 of a circular arc cross section in the upper surface peripheral part 52B, 68B, 102B of the movable body 52,68,102. However, the present invention is not limited to this. For example, as in the tilt sensor 121 according to the first modification shown in FIG. 25, the upper peripheral edge portion 122B of the movable body 122 is chamfered to provide a chamfered portion 125 having a linear cross section. It is good also as a structure which provides. In this case, the movable body 122 includes a sliding surface 123 having a vertex portion 122A protruding downward and a flat upper surface 124.

  Further, the chamfered portion 125 of the movable body 122 is configured to form a conical side surface that is inclined from the radially outer side to the inner side of the movable body 122 toward the upper side of the movable body 122. A circumferential surface parallel to the vertical direction may be formed.

  In the first to sixth embodiments, the movable bodies 12, 52, 68, 102 have a thickness dimension close to the radius of curvature of the sliding surfaces 13, 53, 69, 103 made of a hemispherical surface. . However, the present invention is not limited to this, and the movable body 132 is made of a hemispherical surface within a range in which a desired magnetic flux density distribution can be obtained, such as the tilt sensor 131 according to the second modification shown in FIG. The surface 133 may have a thickness dimension smaller than the radius of curvature (for example, about half of the radius of curvature). In this case, the movable body 132 includes a sliding surface 133 with a vertex portion 132A protruding downward and a flat upper surface 134, and the thickness dimension gradually decreases as the vertex portion 132A approaches the upper surface peripheral portion 132B. It is. Further, the movable body may have a thickness dimension larger than the radius of curvature of the sliding surface within a range in which rolling can be prevented.

  In the second to sixth embodiments, the movable bodies 52, 68, 102 are provided with recessed portions 56, 72, 106 that are located in the center of the upper surfaces 54, 70, 104 and are recessed in a cylindrical shape. The configuration. However, the present invention is not limited to this. For example, like the tilt sensor 141 according to the third modification shown in FIG. 27, the movable body 142 is located at the center of the upper surface 144 and is recessed in a bowl shape. It is good also as a structure which provides. Even in this case, it is preferable that the movable body 142 includes the sliding surface 143 formed of a hemispherical surface, and the thickness dimension thereof gradually decreases as the apex portion 142A approaches the upper peripheral portion 142B.

  In each of the above embodiments, the movable bodies 12, 52, 68, and 102 are made of magnets. However, the present invention is not limited to this, and a configuration in which a magnet 155 serving as a generation source of the magnetic flux φ is provided in the casing 2 ′ separately from the movable body 152, as in the tilt sensor 151 according to the fourth modification shown in FIG. 28. It is good. In this case, the movable body 152 is formed of a magnetic material, but does not need to be magnetized. In addition, the movable body 152 includes a sliding surface 153 formed of a hemispherical surface and a flat upper surface 154, and the thickness dimension gradually decreases as the apex portion 152A approaches the upper peripheral portion 152B. Further, the magnet 155 is provided on the lid 4 ′ of the casing 2 ′, and in order to apply a magnetic flux density to the magnetoelectric conversion element 8 via the sliding surface 153 of the movable body 152, for example, magnetoelectric conversion is sandwiched between the movable body 152. It is arranged at a position opposite to the element 8.

  Further, in each of the above embodiments, the movable bodies 12, 52, 68 and 102 are entirely formed using a magnetic material. However, the present invention is not limited to this, and the movable body may be configured such that, for example, a hemispherical outer shape is formed using a non-magnetic resin material with a magnetic material inserted.

  Furthermore, in each said embodiment, the case where the magnetic flux detection sensor is applied to the inclination sensors 1, 41, 61, 81, 91, 111 for detecting the inclination angle θ of the casings 2, 42, 62, 92, 112 is taken as an example. However, the present invention may be applied to a tilt switch that switches on and off when the casing is tilted by a desired tilt angle.

1, 41, 61, 81, 91, 111, 121, 131, 141, 151 Inclination sensor (magnetic flux detection sensor)
2,42,62,92,112,2 'casing (non-magnetic container)
5, 45, 65, 95, 115 Concave curved surface 6, 46, 66, 96, 116 Movable body accommodating space 8, 48, 98 Magnetoelectric conversion element (magnetic flux density detecting means)
12, 52, 68, 102, 122, 132, 142, 152 Movable body 12A, 52A, 68A, 102A, 122A, 132A, 142A, 152A Vertex portion 12B, 52B, 68B, 102B, 122B, 132B, 142B, 152B Peripheral portion 13, 53, 69, 103, 123, 133, 143, 153 Sliding surface 14, 54, 70, 104, 124, 134, 144, 154 Upper surface 55, 71, 105, 125 Chamfered portion 82 Coating film

Claims (9)

A movable body having a sliding surface formed of a downward convex curved surface formed on the bottom side and a top surface formed of a horizontal surface formed on the upper side of the sliding surface, and slidably supports the sliding surface of the movable body A magnetic flux detection sensor comprising a non-magnetic container having a movable body accommodating space having an upward concave curved surface, and a magnetic flux density detection means provided in the non-magnetic container for detecting a change in magnetic flux density caused by sliding of the movable body. And
The sliding surface of the movable body and the magnetic flux density detection means are arranged to face each other, and a magnetic flux is applied to the magnetic flux density detection means through the sliding surface,
A chamfered portion that relaxes the concentration of magnetic flux density at the periphery of the upper surface is provided on the periphery of the upper surface where the sliding surface and the upper surface intersect in the movable body,
When the nonmagnetic container is tilted from a horizontal state, the movable body is displaced from a steady position along the concave curved surface of the nonmagnetic container,
When the nonmagnetic container returns to a horizontal state, the movable body is configured to return to a steady position along the concave curved surface of the nonmagnetic container. A non-magnetic container comprising a hemispherical movable body having a sliding surface composed of a downward-facing hemispherical surface on the bottom side, and a movable body accommodating space having an upward concave curved surface that slidably supports the sliding surface of the movable body And a magnetic flux detection sensor provided in the nonmagnetic container and detecting a change in magnetic flux density caused by sliding of the movable body,
The sliding surface of the movable body and the magnetic flux density detection means are arranged to face each other, and a magnetic flux is applied to the magnetic flux density detection means through the sliding surface,
A chamfered portion for relaxing the concentration of magnetic flux density at the upper surface periphery is provided on the upper surface periphery of the movable body,
When the nonmagnetic container is tilted from a horizontal state, the movable body is displaced from a steady position along the concave curved surface of the nonmagnetic container,
When the nonmagnetic container returns to a horizontal state, the movable body is configured to return to a steady position along the concave curved surface of the nonmagnetic container.   The magnetic flux detection sensor according to claim 1, wherein the movable body is formed using a magnetic material and is magnetized in a state in which the sliding surface and the upper surface have opposite polarities.   The magnetic flux detection sensor according to claim 2, wherein the movable body is formed using a magnetic material and is magnetized in a state in which the sliding surface and the upper surface have opposite polarities.   5. The magnetic flux detection sensor according to claim 2, wherein the concave curved surface of the movable body housing space is formed by a spherical surface having a larger radius of curvature than the sliding surface of the movable body.   The magnetic flux detection sensor according to claim 1, wherein at least one of the sliding surface of the movable body and the concave curved surface of the movable body housing space is subjected to a smoothing process. The magnetic flux density detecting means is a detection signal when the magnetic flux is tilted in the Y-axis direction compared to a detection signal when the magnetic flux is tilted in the X-axis direction in the X-axis direction and the Y-axis direction orthogonal to each other on the horizontal plane. Has anisotropy that results in a large output level,
The concave curved surface of the movable body accommodating space is formed by an anisotropic curved surface that greatly displaces the movable body in the Y-axis direction compared to the X-axis direction in order to compensate for the anisotropy of the magnetic flux density detecting means. The magnetic flux detection sensor according to any one of claims 1 to 6. A movable body having a sliding surface formed of a downward convex curved surface formed on the bottom side and a top surface formed of a horizontal surface formed on the upper side of the sliding surface, and slidably supports the sliding surface of the movable body A magnetic flux detection sensor comprising a non-magnetic container having a movable body accommodating space having an upward concave curved surface, and a magnetic flux density detection means provided in the non-magnetic container for detecting a change in magnetic flux density caused by sliding of the movable body. And
The sliding surface of the movable body and the magnetic flux density detecting means are arranged to face each other.
When the nonmagnetic container is tilted from a horizontal state, the movable body is displaced from a steady position along the concave curved surface of the nonmagnetic container,
When the nonmagnetic container returns to a horizontal state, the movable body is configured to return to a steady position along the concave curved surface of the nonmagnetic container. A non-magnetic container comprising a hemispherical movable body having a sliding surface composed of a downward-facing hemispherical surface on the bottom side, and a movable body accommodating space having an upward concave curved surface that slidably supports the sliding surface of the movable body And a magnetic flux detection sensor provided in the nonmagnetic container and detecting a change in magnetic flux density caused by sliding of the movable body,
The sliding surface of the movable body and the magnetic flux density detecting means are arranged to face each other.
When the nonmagnetic container is tilted from a horizontal state, the movable body is displaced from a steady position along the concave curved surface of the nonmagnetic container,
When the nonmagnetic container returns to a horizontal state, the movable body is configured to return to a steady position along the concave curved surface of the nonmagnetic container.

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