JP2009264809A - Acceleration sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acceleration sensor device which has a simple structure, is easy to manufacture and has high reliability and accuracy in detection of acceleration. <P>SOLUTION: The acceleration sensor device has a plurality of coiled conductors 2 which are arranged in the length direction outside a columnar space 1 and surround the space 1, respectively, elastic members 4 which are disposed respectively from the opposite ends of the space 1 toward the central part and a high permeability material block 3 which is held between the elastic members 4 in the space 1. The high permeability material block 3 comes to a standstill at a position where the inertial force according to acceleration and a stress working from the elastic member 4 are in balance, and changes the inductance of the coiled conductor 2. By measuring beforehand the stress associated with a change in the shape of the elastic member 4, therefore, the acceleration can be easily detected by calculation based on the position of the high permeability material block 3 and the mass of the block 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an acceleration sensor device that detects the position of a high-permeability body block that moves according to the magnitude of acceleration based on a change in inductance of a coiled conductor, and detects acceleration based on that position.

  Conventionally, as an acceleration sensor device for detecting acceleration, a mechanism for changing the capacitance between capacitive electrodes according to the magnitude of acceleration is provided, and the acceleration is detected by the change in capacitance. (For example, refer to Patent Documents 1 and 2).

  Such an acceleration sensor device generally includes a mass portion (weight portion) supported by a beam and a fixed electrode disposed to face the mass portion. A movable electrode is formed on the mass portion so as to face the fixed electrode, and an electrostatic capacity is generated between the capacitive electrode composed of the fixed electrode and the movable electrode.

  When acceleration occurs in the acceleration sensor device, the beam bends in accordance with the magnitude of the acceleration, and the distance between the capacitance electrodes varies to change the capacitance. By detecting this change in capacitance, the acceleration generated in the acceleration sensor device, that is, the acceleration of a device such as an automobile equipped with the acceleration sensor device is detected.

Such an acceleration sensor device usually applies a fine processing technique such as etching to a semiconductor substrate such as a silicon substrate to provide mechanical movable parts such as a beam part and a mass part and electric wiring parts such as capacitive electrodes. It is manufactured by forming.
JP 2006-250910 A JP 2007-85747

  However, in the conventional acceleration sensor device, when an excessive acceleration occurs, there is a possibility that mechanical destruction such as bending occurs in the beam portion. In particular, if the beam is made thinner or longer in order to increase the accuracy of acceleration detection, the strength of the beam may be reduced or the stress generated when it bends will increase. Becomes higher.

  In addition, since the semiconductor substrate is manufactured by applying a fine processing technique such as etching, a high level of technology is required for the manufacturing, and it is difficult to ensure processing accuracy.

  The present invention has been completed in view of such conventional problems, and an object of the present invention is to provide an acceleration sensor device that is easy to manufacture with a simple structure and has high reliability and high accuracy of acceleration detection. There is to do.

  The acceleration sensor device according to the present invention is arranged in a length direction outside the columnar space, each of which is arranged with a plurality of coiled conductors surrounding the space, and from both ends of the space toward the central portion. And a high permeability block housed between the elastic members in the space.

  The acceleration sensor device according to the present invention is characterized in that, in the above configuration, the space is formed in an insulating container.

  Further, the acceleration sensor device of the present invention is the above-described configuration, wherein the plurality of coiled conductors have an interval between adjacent ones smaller than the outer dimension in the length direction of the space of the high permeability block, It is characterized by being larger than half of the outer dimension.

  Moreover, the acceleration sensor device according to the present invention is characterized in that, in the above configuration, the plurality of coiled conductors have different numbers of turns and are connected in series.

  The acceleration sensor device according to the present invention includes a plurality of coiled conductors that are arranged in the longitudinal direction outside the columnar space, each surrounding the space, and an elasticity that is disposed from both ends of the space toward the center. Provided with an acceleration sensor device that is easy to manufacture with a simple structure and has high reliability and acceleration detection accuracy, because it comprises a member and a high permeability block housed between elastic members in the space can do.

  That is, when acceleration occurs in the space, an inertial force corresponding to the magnitude of the acceleration acts on the high permeability body block, and the high permeability body block that tries to move in the space by this inertial force has an elastic member. Stress (elastic force) is applied. The high-permeability body block is stationary with respect to the space at a position where the inertial force and stress are balanced (position where the inertial force and stress are the same magnitude and in the opposite direction), and the space is surrounded at this position. The inductance of the coiled conductor is changed.

  Therefore, it is possible to easily detect at which position in the space, that is, at which position the elastic member is deformed (compressed), the inertial force and the stress are balanced. Therefore, by measuring the force required to deform the elastic member (stress applied from the elastic member) in advance, the inertial force acting on the high-permeability body block is detected at its stationary position (coiled conductor position). The magnitude of acceleration can be calculated from the inertial force and the mass of the high permeability block.

  Such an acceleration sensor device has a simple structure and forms a fine movable part such as a beam part because the high magnetic permeability body block is only accommodated in the space surrounding the outside of the coiled conductor. Microfabrication is not particularly necessary and is easy to manufacture. In addition, since there are no fine movable parts, mechanical destruction that hinders the function of the acceleration sensor device hardly occurs, and the reliability is high. Further, since the inertial force resulting from the acceleration can be detected as the stress from the elastic member with high accuracy using the change in the inductance of the coiled conductor, the accuracy of the acceleration detection is high. Therefore, according to the acceleration sensor device of the present invention, it is possible to provide an acceleration sensor device that is easy to manufacture with a simple structure and that has high reliability and high accuracy of acceleration detection.

  In the acceleration sensor device of the present invention, in the above configuration, when the space is formed in the insulating container, the high permeability body block is sealed in the space in the insulating container, and each of the plurality of the elements surrounds the space. The following effects can be obtained by arranging the coiled conductors in the lengthwise direction inside the insulating container (outside the space).

  That is, the high magnetic permeability body block can be reliably stored in the space, and a part of the insulating container is interposed between the high magnetic permeability body block and the coiled conductor so that the coiled conductor has a high height. Wear, chipping, etc. due to direct contact with the magnetic permeability body block can be effectively prevented. In addition, it is possible to form a plurality of coiled conductors while ensuring good electrical insulation between adjacent objects in the insulating container. Therefore, in this case, reliability and productivity as an acceleration sensor device can be improved.

  In the acceleration sensor device of the present invention, in the above-described configuration, the plurality of coiled conductors have an interval between adjacent ones that is smaller than the outer dimension in the length direction of the space of the high permeability block. If it is larger than half, an acceleration sensor device with higher detection accuracy can be obtained.

  That is, when the interval between the adjacent coiled conductors is smaller than the outer dimension in the length direction of the space of the high permeability body block, the high permeability body block moved according to the acceleration (inertial force) It is effectively prevented that the coil enters between adjacent coiled conductors and no change in inductance occurs in any of the coiled conductors. In addition, when this interval is larger than half of the outer dimensions, for example, it is possible to prevent the high permeability body block from entering inside across three or more adjacent coiled conductors. It is effectively prevented that the inductance is changed by the conductor and the detection accuracy of the position of the high permeability block is lowered.

  Therefore, in spite of the acceleration occurring in the space, the inductance does not change in any coiled conductor, and it is erroneously detected that no acceleration occurs, and the position of the high permeability body block It is possible to effectively prevent a decrease in the acceleration detection accuracy based on the acceleration sensor device, and to obtain an acceleration sensor device with higher detection accuracy.

  Further, in the acceleration sensor device of the present invention, the plurality of coiled conductors have different numbers of turns and, when connected in series, the plurality of coiled conductors connected in series. By detecting the degree of change in the total inductance, it is possible to detect in which coiled conductor the inductance is changing, that is, in which position in the space the high permeability block is moved. The acceleration generated in the space can be detected from the position of the high permeability block. Therefore, it is not necessary to measure the inductance of each of the plurality of coiled conductors, and the acceleration sensor device can detect the acceleration more easily.

  That is, the inductance of each coiled conductor is proportional to the relative permittivity and cross-sectional area of the inner part of the coiled conductor, and is proportional to the square of the number of turns, so that there is no high permeability block The inductances of the plurality of coiled conductors are different from each other. Further, the amount of increase in inductance when the high permeability body block moves inside the coiled conductor differs in proportion to the square of the number of turns of the coiled conductor. The total inductance of the plurality of coiled conductors is the sum of the inductances of the plurality of coiled conductors. Therefore, by detecting the amount of change in the total inductance of a plurality of coiled conductors, which coiled conductor has its inner permeability changed, that is, where the high permeability block is located. Can be easily detected.

  Therefore, in this case, it is not necessary to measure the inductances of the plurality of coiled conductors, and the acceleration sensor device can detect the acceleration more easily.

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

  Fig.1 (a) is a top view (perspective view) which shows an example of embodiment of the acceleration sensor apparatus of this invention, FIG.1 (b) is sectional drawing in the AA line. 2 is a perspective view (perspective view) of the acceleration sensor device shown in FIG. 1 and 2, 1 is a space provided inside the insulating container 5, 2 is a coiled conductor, 3 is a high permeability block accommodated in the space 1, 4 is an elastic member, 5 (5 a, 5b) is an insulating container, and 9 is an acceleration sensor device. For ease of viewing, the elastic member 4 and the insulating container 5 are omitted in FIG.

  The acceleration sensor device 9 is mounted on a device such as an automobile, a game machine, a camera shake prevention device, or a conveyor belt, detects acceleration of the device, and sends an electric signal to a display device such as a display as necessary. It has a function of sending the numerical value of the acceleration and controlling the stop of the device on which the acceleration sensor device 9 is mounted.

  The acceleration sensor device 9 detects the position of the high-permeability body block 3 that moves according to the acceleration of the space 1 based on a change in the inductance of the coiled conductor 2, and obtains the position of the high-permeability body block 3. The acceleration is calculated based on the stress acting from the elastic member 4.

  That is, according to the acceleration sensor device 9, when acceleration occurs in the space 1, the inertial force according to the acceleration and the elastic member 4 that repels the high permeability body block 3 that moves by the inertial force. Stress acts on the high permeability block 3. The high permeability block 3 is stationary with respect to the space 1 at a position where the inertial force and stress are balanced, and the inductance of the coiled conductor 2 is changed at this position.

  Therefore, by previously measuring the mass of the high permeability block 3 and the force required to deform the elastic member 4 (stress applied from the elastic member 4), the stationary position (the position of the corresponding coiled conductor 2) is measured. ) Can be detected, and the inertial force acting on the high permeability body block 3 can be detected, and the acceleration acting on the high permeability body block 3 is calculated from the inertial force and the mass of the high permeability body block 3. be able to.

For example, when the acceleration is a, the mass of the high-permeability body block 3 is m, and the inertial force corresponding to the acceleration is F ₁ , as is well known, F ₁ = m × a, and the elastic member 4 at the stationary position described above. stress from when the _{F 2 F 1 = F 2 =} m × a, a that is a _{= F} 2 / m. Therefore, by measuring the force F ₂ required to deform the mass m and the elastic member 4 in advance high permeability material block 3, it is possible to calculate the acceleration a which acts on high permeability material block 3 .

Actually, since resistance such as friction between the high permeability block 3 and the inner surface of the space 1 is added, it is preferable to correct that amount. For example, the frictional force the frictional force when the F _3, the original inertial force F ₁ generated according to the acceleration a, the inertial force F ₁₁ of apparent between the bottom surface of the bottom surface and the space 1 of the high permeability material block 3 The size is the sum of F ₃ (F ₁ = F ₁₁ + F ₃ ). Since the inertial force _{F 11} of the apparent stress _{F 2} is balanced _F 11 = _{F 2,} is that is _{F 1 = F 2 + F 3} , from the right acceleration _{a, a = F 1 / m,} a = F ₂ / m + F ₃ / m.

  Such an acceleration sensor device 9 has a simple structure, for example, a fine part such as a beam portion, because the high-permeability body block 3 is only accommodated in the space 1 in which the coiled conductor 2 surrounds the outside. The microfabrication for forming the movable part is not particularly necessary and is easy to manufacture. In addition, since there are no fine movable parts, mechanical destruction that hinders the function of the acceleration sensor device hardly occurs, and the reliability is high. Further, since the inertial force resulting from the acceleration can be detected as the stress acting from the elastic member 4 by using the change in the inductance of the coiled conductor 2, the accuracy of the acceleration detection is high. Therefore, according to the acceleration sensor device 9 of the present invention, it is possible to provide the acceleration sensor device 9 that is easy to manufacture with a simple structure and that has high reliability and high accuracy of acceleration detection.

  The space 1 is for accommodating the high magnetic permeability body block 3 and the elastic member 4, and the accommodated high magnetic permeability body block 3 is separated from the inertia force caused by the acceleration generated in the space 1 and the elastic member 4. It has a shape and dimensions that can move inside depending on the elastic force acting on it.

  In the example of this embodiment, the space 1 has a quadrangular prism shape, and a cross section (vertical cross section) in a direction orthogonal to the length direction is rectangular. The space 1 may have a square shape in the longitudinal section, a quadrangular prism shape in which corner portions are formed in an arc shape, a cylindrical shape, an elliptical column shape, or the like.

  The coiled conductor 2 is formed so as to surround the space 1 in order to effectively detect a change in magnetic permeability of the inner portion thereof as a change in inductance, and a plurality of the coiled conductors 2 are arranged in the length direction of the space 1. Yes. The change in the magnetic permeability is caused by the movement of the high magnetic permeability body block, thereby detecting the position of the high magnetic permeability body block 3 and acting on the space 1 based on the position. Acceleration can be detected.

  The coiled conductor 2 detects the movement of the high permeability body block 3 according to the magnitude of acceleration as a change in inductance, and thereby detects the magnitude of acceleration. A plurality are arranged in a row toward the part.

  That is, since the plurality of coiled conductors 2 are arranged in the length direction of the space 1, by detecting which coiled conductor 2 changes the inductance, the high permeability body block in the space 1 3 position can be detected easily and reliably. The change in inductance of the coiled conductor 2 can be measured by connecting the coiled conductor 2 to a measuring instrument capable of measuring inductance, such as an LCR measuring instrument, for example. The change in inductance can also be detected by applying a constant alternating current to each of the coiled conductors 2 and measuring the change in current with an ammeter or the like. Then, by measuring the inductance of each coiled conductor 2 and detecting the change thereof, the inertial force acting on the high permeability body 3 block, that is, the acceleration generated in the space 1 can be detected. .

  When the plurality of coiled conductors 2 can detect acceleration in both end directions of the space 1 in the same manner, they should be arranged in the same direction at both ends with the center portion interposed therebetween. (So-called left-right symmetry) is preferable.

  In addition, the coiled conductor 2 is arranged so that the elastic member 4 described later has the same adjacent spacing in a region (elastic region) in which the elastic member 4 described later is deformed at a constant rate according to a proportional constant such as a spring constant or Young's modulus. , Acceleration can be detected at a constant rate of change. In this case, for example, it is effective for an application where it is desired to detect the acceleration at a constant change rate, such as an application for managing the acceleration (deceleration) of an endless belt for conveyance that repeats stopping and starting. For example, when an object that has moved at a constant speed, such as this endless belt, decelerates, an inertial force is generated in the opposite direction to that during acceleration, and the deceleration rate (negative acceleration) is detected by this inertial force. be able to.

The number of coiled conductors 2 arranged from both ends of the space 1 to the center may be set according to the required acceleration measurement accuracy, measurement range, and the like. For example, in the example of this embodiment, two coil-shaped conductors 2 are arranged from both end portions of the space 1 toward the central portion, and one coil conductor 2 is disposed in the central portion of the space 1. The plurality of coiled conductors 2 are arranged in the length direction of the space 1 at substantially equal intervals. In this case, it is effective for linearly detecting the magnitude and change of the acceleration generated in the space 1 from 0 km / s ² to the maximum measurable value.

  The coiled conductors 2 are not necessarily arranged at regular intervals in the length direction of the space 1 and may be arranged in other ways. For example, when the coiled conductor 2 is arranged outside at one place between the center and both ends of the space 1 and the acceleration corresponding to this position occurs, the capacitance changes and a signal is transmitted. Such a structure may be used. In this case, for example, it is effective for a purpose of causing a device on which the acceleration sensor device 9 is mounted to perform an operation such as displaying a warning indicating that a predetermined acceleration has occurred or stopping the device.

  The high permeability body block 3 moves in the space 1 according to the acceleration generated in the space 1 and the elastic force applied from the elastic member 4, and the inductance of the coiled conductor 2 surrounding the space 1 by the moved portion. It is for enlarging.

  By measuring the inductance of the coiled conductor 2 in the space 1 in which the high permeability block 3 is accommodated and detecting the change in inductance, the position of the high permeability block 3, that is, inertial force and elasticity The position where the force is balanced can be detected. Then, by measuring the force required to deform the elastic member 4 to its position and the mass of the high permeability block 3 in advance, the inertial force can be detected and the acceleration can be calculated.

  In addition, when the acceleration is not generated or when the generated acceleration disappears, the high-permeability body block 3 is located in the central portion of the space 1 or returned, so that no acceleration is generated in the space 1. This can be easily detected. In order to detect that the high permeability block 3 is located in the center of the space 1, for example, the coiled conductor 2 may be disposed in the center of the space 1.

  The high-permeability body block 3 is formed in a shape and size that can move while deforming (compressing) the elastic member 4 in a direction in which an inertial force acts (a direction opposite to the direction where acceleration is applied). It is accommodated in the space 1. The movement of the high-permeability body block 3 in the space 1 is caused by sliding or rolling on the lower surface of the space 1 due to the inertial force acting due to the acceleration of the space 1.

  In order to facilitate such movement, the high-permeability body block 3 is formed in a polygonal columnar shape such as a triangular column shape or a quadrangular column shape (cuboid shape), a cylindrical shape, an elliptical column shape, a spherical shape, or the like. . In addition, the high magnetic permeability body block 3 may have these shapes and the upper and lower surfaces, the side surfaces, and the like are curved, or a portion in which an uneven portion is formed.

  Further, the high permeability block 3 moves to the inside of the coiled conductor 2 in the space 1 and changes the capacitance generated between the insides of the coiled conductor 2 to such an extent that it can be easily detected. The material and dimensions are such that

  The high-permeability material that forms such a high-permeability body block 3 may be any material that has a permeability higher than that of the moving space 1 as the high-permeability body, but with high sensitivity and accuracy. In order to detect the acceleration stably and satisfactorily, a material having as high a permeability as possible is preferable. In the acceleration sensor device 9 of the present invention, a material having a high relative permeability of, for example, about 150 or more, such as iron, iron-nickel alloy (so-called permalloy), ferrite, or the like can be used (relative permeability is , About 150 so-called 0.2 impurity iron containing about 0.2% by mass of impurities mainly composed of carbon, about 500 for silicon steel, about 5000 for pure iron, about 10000 for iron-nickel alloy (so-called 78 permalloy), Mn- It is about 2000 to 20000 for Zn-based ferrite and about 600 to 1000 for Ni—Zn-based ferrite (see “Metal Handbook” on pages 650 to 651). Other materials such as aluminum, copper, silver, palladium, lead, etc. have a relative permeability of about 1 and are almost the same as air, so that the inductance of the coiled conductor 2 can be effectively changed. Not appropriate.

  In order to effectively change the inductance of the coiled conductor 2 surrounding the space 1, the thickness and width of the high permeability block 3 (outer dimensions corresponding to the inner dimensions in the width direction of the space 1) are: As long as it can move smoothly in the space 1, it is preferable that it is thicker and wider so that it fits in the space 1. This is because the inductance of the coiled conductor 2 changes in proportion to the magnetic permeability of the inner portion of the coiled conductor 2, so that the permeability of the high permeability block 3 when entering and exiting the inner portion of the coiled conductor 2 is increased. This is to increase the change as much as possible. The higher the proportion of the high permeability block 3 in the inner part of the coiled conductor 2, the higher the permeability of that part (as compared to the case where the inner space 1 is filled with air having a relative permeability of about 1). ) Become high.

  In the example of the embodiment shown in FIGS. 1 and 2, the high magnetic permeability body block 3 is formed in a rectangular column shape which is slightly lower than the height and width of the square columnar space 1. The high permeability block 3 is disposed such that the bottom surface thereof is in contact with the lower surface of the space 1. If the shape, size, and arrangement of the high magnetic permeability body block 3 are set as described above, the high magnetic permeability body block 3 occupies most of the inner portion of the coiled conductor 2. The inductance can be changed effectively.

  For example, in the case of a quadrangular prism shape, the high magnetic permeability body block 3 is formed into a predetermined shape and size of the high magnetic permeability body block 3 by subjecting a plate-shaped iron material to processing such as cutting, grinding, and polishing. It can produce by doing.

  If the space 1 and the high magnetic permeability body block 3 are in the shape of a quadrangular prism as in this embodiment, for example, the space 1 has a quadrangular prism shape with a width and height of about 5 to 10 mm. The high-permeability body block 3 is formed in a rectangular column shape with a side length of about 4.5 to 9.5 mm, and the upper surface and side surfaces of the high-permeability body block 3 and the inner surface of the space 1 (inner side surface and upper surface). It is sufficient to ensure a distance of about 0.2 mm.

  The elastic member 4 has a function of applying stress (elastic force) to the high magnetic permeability body block 3. When acceleration occurs in the space 1, stress (elastic force) is applied in the opposite direction from the elastic member 4 to the high permeability body block 3 that attempts to move in the space 1 due to inertial force caused by the acceleration. The stress increases as the deformation (compression) of the elastic member 4 increases, and the high-permeability body block 3 is stationary with respect to the space 1 at a position where the inertial force and the elastic force are balanced. Further, when no acceleration is generated in the space 1 (when no inertial force is applied to the high permeability body block 3), the high permeability body block 3 is located in the center of the space 1 by the elastic force of the elastic member 4. (So-called return to origin).

  As such an elastic member 4, a spring made of a coil spring or an air spring, a resin material having a low elastic modulus (Young's modulus), or a member made of a rubber material such as rubber or sponge rubber can be used.

  If a spring is used as the elastic member 4, the range of elastic deformation (expansion / contraction) in proportion to the spring constant due to the inertial force is longer than the distance from the end (both ends) of the space 1 to the center. It is preferable to use one.

For example, when the length from the end portion of the space 1 to the central portion is set to 0.05 m (5 cm), the mass of the high permeability block 3 is 0.01 kg (10 g), and the maximum value of the assumed acceleration is about In the case of 10 m / s ² , the maximum value of inertial force is about 0.1N. As is well known, since F (force, unit: N) = k (spring constant, unit: N / m) × x (length to expand and contract, unit: m), the length x of the spring contracts is about 0.1 / k. In order to keep the length x below the length of the space 1, a spring such as a coil spring having a spring constant k of about 2 N / m or slightly larger (not easily contracted) than 0.1 / k <0.05. Is suitable.

  Moreover, as a resin material with a low Young's modulus, for example, a material having a Young's modulus of about 1 to 20 MPa, such as a polyurethane resin or a silicone resin, can be used. As the rubber, natural rubber, urethane rubber, butyl rubber, neoprene rubber, styrene butadiene rubber, or other rubber materials (Young's modulus is about 0.01 to 10 MPa) can be used. As the sponge rubber, a material made porous (so-called sponge-like) by adding a foaming agent such as sodium carbonate, sodium bicarbonate, ammonium carbonate to the above-described rubber material (particularly rubber material other than natural rubber) is used. be able to.

  When the elastic member 4 is made of a resin material, rubber, or sponge rubber, the elastic member 4 may be disposed so as to fill the space 1 from both ends to the vicinity of the center, and is formed into a columnar shape or a cylindrical shape. It may be arranged in the space 1 in a different form.

  The elastic member 4 made of resin material, rubber, or sponge rubber has a high permeability body block 3 in the space 1 when an inertial force corresponding to the upper limit of the acceleration range to be detected by the acceleration sensor device 9 is applied. It is preferable to have a Young's modulus and dimensions (area on which the length and stress act) that do not move to either end.

For example, if the mass of the high permeability block 3 is 0.05 kg (50 g) and the maximum value of acceleration assumed is about 10 m / s ² , the maximum value of inertial force is about 0.5 N and the stress Is set to 5 mm × 5 mm (25 × 10 ⁻⁶ m ² ), the stress per unit area σ = 0.5 (N) / 25 × 10 ⁻⁶ (m ² ) = 0.02 × 10 ⁶ N / m ² = 0.02 MPa.

  As is well known, since ε (strain) = σ (stress per unit area, unit: MPa) / E (Young's modulus, unit: MPa), for example, ε is set to 0.5 (the length of the elastic member 4 is about half). The Young's modulus E of the elastic member 4 becomes E = 0.02 / 0.5 = 0.04 from 0.5 = 0.02 / E. That is, in this case, a material having a Young's modulus of about 0.04 MPa is suitable for the elastic member 4. Further, when a larger acceleration is applied or when the length of the space 1 is shortened, a material having a higher Young's modulus (not easily deformed) is suitable for the elastic member 4, and a case where a smaller acceleration is applied or a space In the case where the length of 1 is increased, a material having a smaller Young's modulus (easily deformed) is suitable.

  In such an acceleration sensor device 9, as in the example of this embodiment, for example, when the space 1 is formed in the insulating container 5 and a plurality of coiled conductors 2 are arranged surrounding the space 1, It has the following effects.

  That is, the high magnetic permeability block 3 is enclosed in the space 1 in the insulating container 5 and each of the coiled conductors 2 is formed inside the insulating container 5 constituting the space 1. 3 can be reliably stored in a space 1 in which a plurality of coiled conductors 2 are arranged on the outside.

  Further, since a part of the insulating container 5 is interposed between the high magnetic permeability body block 3 and the coiled conductor 2, wear or chipping due to direct contact of the coiled conductor 2 with the high magnetic permeability body block 3, etc. Can be effectively prevented. In addition, a plurality of coiled conductors 2 can be formed in the insulating container 5 while ensuring good electrical insulation between adjacent ones. Therefore, in this case, the reliability and productivity of the acceleration sensor device 9 can be improved.

  In the example of this embodiment, the outer shape of the insulating container 5 is a rectangular parallelepiped, and a space 1 having a similar shape and a small size is formed therein, but at least the high permeability block 3 is accommodated therein. As long as the outer dimensions are such that the space 1 can be provided, a cylindrical shape or an elliptical column shape extending in the lateral direction may be used. For example, in consideration of workability when the acceleration sensor device 9 is mounted on a device or transported, suppression of breakage, and the like, an unevenness is provided on a part of the outer surface of the insulating container 5 or corners (ridges) are provided. A portion may be chamfered.

  The insulating container 5 includes an aluminum oxide sintered body (aluminum oxide ceramics), an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body, a silicon nitride sintered body, and a glass ceramic sintered body. Etc., a resin material such as an epoxy resin, a polyimide resin, and an acrylic resin, or an electrically insulating material such as a composite material of an inorganic material such as a ceramic material and a resin material.

  In the example of this embodiment, the insulating container 5 is formed by bonding a flat lid 5b to the upper surface of an insulating base 5a having a recess (no symbol) on the upper surface. A space 1 in which the high magnetic permeability body block 3 is accommodated is formed by the concave portion of the insulating base 5a and the lid 5b. The lid 5b may have a recess (not shown) that faces the recess of the insulating base 5a.

  Further, the surface of the insulating container 5 (5a) which is the lower surface of the space 1 is subjected to a polishing process (for example, a so-called mirror polishing process) in order to facilitate the sliding of the high permeability block 3. The smoothness may be increased. If the smoothness of the lower surface of the space 1 is increased, the correction of the frictional force as described above can be suppressed to a small level. In this case, if the insulating base 5a has a flat plate shape and the lid 5b has a recess (not shown) on the lower surface side, the upper surface of the insulating base 5a corresponding to the lower surface of the space 1 is polished. Can be done more easily. Therefore, the high-permeability body block 3 can be easily moved by sliding, and is effective in increasing the productivity of the acceleration sensor device 9 having high acceleration detection accuracy.

  If the insulating container 5 (5a, 5b) is made of, for example, an aluminum oxide sintered body, the raw material powder composed mainly of aluminum oxide powder and added with silicon oxide, calcium oxide, etc. A plurality of ceramic green sheets are produced by processing into a sheet shape together with a solvent and a binder, laminated, and then fired to produce the insulating base 5a and the lid 5b, and then the insulating base 5a and the lid 5b are brazed. It can be manufactured by bonding via a material or a resin adhesive.

  Further, if the insulating container 5 (5a, 5b) is made of a resin material such as an epoxy resin or a polyimide resin, an uncured material of these resin materials is used to form a predetermined insulating base 5a or lid using a mold. The insulating base 5a and the lid 5b can be produced by molding into the shape of the body 5b and curing, and these can be produced by joining them with a resin adhesive.

  The plurality of coiled conductors 2 are formed, for example, inside the insulating container 5 (5a, 5b) so as to surround the space 1. The coiled conductor 2 is formed of a metal material such as tungsten, molybdenum, manganese, copper, silver, palladium, gold, or platinum. Such a metal material is attached to the insulating base 5a and the lid 5b of the insulating container 5 (5a, 5b) in the form of a metallized layer, a plating layer, a metal foil, a vapor deposition layer, or the like.

  Each of the plurality of coiled conductors 2 is printed on a ceramic green sheet such that, for example, a tungsten metal paste is printed on a ceramic green sheet serving as the insulating base 5a or the lid 5b, and the printed metal paste is positioned inside. It can be formed by laminating sheets.

  The insulating container 5 (5a, 5b) has a wiring conductor (FIG. 5) as a conductive path for electrically connecting each coiled conductor 2 to an external electric circuit from the coiled conductor 2 to the upper surface and the lower surface. (Not shown) is preferably formed. By measuring the inductance of the coiled conductor 2 by connecting the exposed portion of the wiring conductor to an external electric circuit, the change of the inductance is detected to detect the position of the high permeability block 3, and as described above. Based on the position of the high permeability body block 3, the acceleration generated in the space 1, that is, the acceleration of the acceleration sensor device 9 can be detected.

  In this case, the external electric circuit is formed on a circuit board mounted on a device such as an automobile, a game machine, or a transport device such as an endless belt. When the acceleration sensor device 9 is mounted as a component, the acceleration generated in the device is detected, and in the case of an automobile, the speed is adjusted by a curve. In the case of a game machine, the acceleration is displayed on the screen depending on the magnitude of the acceleration. The size can be displayed.

  In addition, an electronic component (semiconductor integrated circuit element, capacitor element, inductor element, etc.) (not shown) that performs processing such as calculation of acceleration as described above and analysis and amplification of an electrical signal according to the calculated acceleration is provided. The insulating container 5 (5a, 5b) may be mounted on the surface or inside. In addition, an electric circuit (not shown) corresponding to a capacitor element or an inductor element may be formed inside or on the surface of the insulating container 5 (5a, 5b). These electric circuits can be formed by the same method using the same material as that for forming the coiled conductor 2.

  Further, in this acceleration sensor device 9, the interval between adjacent ones of the plurality of coiled conductors 2 is smaller than the outer dimension in the length direction of the space 1 of the high permeability block 3, and more than half of the outer dimension. Is larger, the acceleration sensor device 9 with higher detection accuracy can be obtained.

  That is, when the interval between the adjacent coil-shaped conductors 2 is smaller than the outer dimension in the length direction of the space 1 of the high-permeability body block 3, the high-permeability body moved according to the acceleration (inertial force). It is effectively prevented that the block 3 enters between the adjacent coiled conductors 2 and no change in inductance occurs in any of the coiled conductors 2. Moreover, when this space | interval is larger than the half of the external dimension of the high magnetic permeability body block 3, for example, the high magnetic permeability body block 3 may enter inside across three or more adjacent coiled conductors 2. Therefore, it is possible to effectively prevent the detection accuracy of the position of the high-permeability body block 3 from being lowered due to a large number of coil-shaped conductors 2 and the inductance being changed.

  Therefore, in spite of the acceleration occurring in the space 1, the inductance does not change in any of the coiled conductors 2, and it may be erroneously detected that no acceleration occurs, or the high permeability block 3. It is possible to effectively prevent the acceleration detection accuracy based on the position of the sensor from being lowered, and to obtain the acceleration sensor device 9 with higher detection accuracy.

  Further, in the acceleration sensor device 9, the plurality of coiled conductors 2 have different numbers of turns and, when connected in series, the plurality of coiled conductors 2 connected in series. By detecting the degree of change in the total inductance, it is possible to detect in which coil-like conductor 2 the inductance is changed, that is, in which position the high permeability block 3 is moved. The acceleration generated in the space 1 can be detected from the position of the high permeability block 3.

  That is, in this case, the inductance of each coil-shaped conductor 2 is proportional to the relative dielectric constant and cross-sectional area of the inner portion of the coil-shaped conductor 2, and is proportional to the square of the number of turns. The inductances of the conductors 2 are different from each other. Further, the amount of increase in inductance when the high permeability block 3 moves inside the coiled conductor 2 also varies in proportion to the square of the number of turns. The total inductance of the plurality of coiled conductors 2 is the sum of the inductances of the plurality of coiled conductors 2. Therefore, by detecting a change in the total inductance of the plurality of coiled conductors 2, which coiled conductor 2 has its inner permeability changed, that is, where the high permeability body block 3 exists. Can be detected.

  Therefore, in this case, it is not necessary to measure the inductance of each of the plurality of coiled conductors 2, and the acceleration sensor device can detect the acceleration more easily.

For example, in the acceleration sensor device 9 shown in FIG. 1, when the area inside the coiled conductor 2 (the area of the longitudinal section of the space 1) is 1 cm ² (1 × 10 ⁻⁴ m ² ), the number of turns is the smallest. For example, suppose that the number of turns of the coiled conductor 2 is c and the number of turns is increased in the order of 2 × c, 3 × c, 4 × c, and 5 × c and five coiled conductors 2 are arranged. , Where c is a positive integer.

First, assuming that the high permeability block 3 does not exist, the total inductance Lt of the five coiled conductors 2 is, as described above, the inductance L of each coiled conductor 2 = μ × n ² × S. In addition, since the total inductance of the plurality of coiled conductors 2 connected in series with each other is the sum of the inductances of the individual coiled conductors 2, Lt = (μ _a × c ² + μ _a × (2 × c ) ² + μ _a × (3 × c) ² × μ _a × (4 × c) ² + μ _a × (5 × c) ² ) × (1 × 10 ⁻⁴ ) = 55 × μ _a × c ² × 10 ^{− 4} becomes (H) (however, mu _a air permeability: about ^{1.26 × 10 -6 (N / a} 2)).

On the other hand, a high permeability block 3 having a relative permeability of about 1000 (permeability is about 1000 × μ _a (N / A ² )) is present inside the coiled conductor 2 having the number of turns c. Suppose that the total inductance Lt is Lt≈ (1000 × μ _a × c ² + μ _a × (2 × c) ² + μ _a × (3 × c) ² + μ _a × (4 × c) ² + μ _a × (5 × c) ² ) × (1 × 10 ⁻⁴ ) = 1054 × μ _a × c ² × 10 ⁻⁴ (H)

Further, if a high permeability block 3 having a relative permeability of about 1000 is present inside the coiled conductor 2 having 3 × c turns (having moved according to the acceleration), the total The inductance Lt is Lt≈ (μ _a × c ² + μ _a × (2 × c) ² + 1000 × μ _a × (3 × c) ² + μ _a × (4 × c) ² + μ _a × (5 × c) ² ) × (1 × 10 ⁻⁴ ) = 9046 × μ _a × c ² × 10 ⁻⁴ (H).

  That is, the change amount (increase amount) of the total inductance Lt is substantially proportional to the square of the number of turns of the coiled conductor 2 in which the high permeability block 3 exists. Therefore, by detecting the change in the total inductance Lt, it is possible to easily detect which coil-shaped conductor 2 is changing the inductance, that is, at which position the high permeability block 3 is present. .

  In this case, if c = 1, that is, if the number of turns is increased one by one in order, even if the coiled conductor 2 is formed by printing a metal paste as described above, for example, Since it is possible to reduce the trouble of printing the metal paste to be the shape conductor 2, the productivity as the acceleration sensor device 9 can be ensured satisfactorily.

  The arrangement of the coiled conductors 2 having different winding numbers is not particularly limited in measuring the total inductance and detecting the change, and may be in any order.

  However, for example, as shown in FIG. 3, the coiled conductor 2 (coiled conductor 21 having a winding number c to a coil having a winding number 5 × c so that the number of turns alternately increases across the center of the space 1. If the conductors 25) are arranged, the amount of change in inductance between the adjacent coil conductors 2 can be increased from the center of the space 1 toward one end. In this case, since the amount of change in the total inductance when the high magnetic permeability block 3 moves between the adjacent coiled conductors 2 can be increased, it is easier to detect the acceleration. FIG. 3 is a plan view schematically showing another example of the embodiment of the acceleration sensor device 9 of the present invention. In FIG. 3, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  The plurality of coiled conductors 2 are connected in series, for example, by forming a connecting conductor 6 on the insulating container 4 using the same metal material as that of the coiled conductor 2 so that adjacent coiled conductors 2 are connected in series. This can be done.

  Note that such an acceleration sensor device 9 includes, for example, the elastic member 4 and the high height formed in the recess of the insulating base 5a manufactured as described above according to the distance from the center to the end of the recess. It can be manufactured (assembled) by inserting the permeability block 3 and then joining the lid 5b to the upper surface of the insulating base 5a so as to close the recess.

  The elastic member 4 is externally connected to the insulating container 5 (5a, 5b) via, for example, bowl-shaped metal fittings (not shown) or the like attached to both ends of the insulating container 5 (5a, 5b) in advance. It can be attached so that the end part does not move. Moreover, you may make it adhere | attach the outer end part of the elastic member 4 to the insulating container 5 (5a, 5b) using an adhesive agent instead of a metal fitting. Moreover, you may use these metal fittings and resin adhesives together.

  Further, the lid 5b and the insulating base 5a can be bonded by, for example, bonding via a bonding material such as an organic resin adhesive, glass, brazing material, or the like. In this case, a metal layer (not shown) may be formed in advance on the joint surface between the two, and the metal layers may be joined with a brazing material. The metal layer can be formed by the same method using the same metal material as that of the coiled conductor 2.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, at least a part of the insulating container 5 (5a, 5b) is formed of a light-transmitting material such as glass, acrylic resin, methacrylic resin, etc., and the position of the high magnetic permeability body block 3 is visually recognized from the outside. You may be able to do it. In this case, it is possible to easily confirm whether or not the high-permeability body block 3 is moving normally according to the acceleration of the space 1, and the acceleration sensor device 9 is more accurate and easy to check. It can be.

  In addition, two such acceleration sensor devices 9 are mounted on an external device so as to be orthogonal to each other in the horizontal direction, and the acceleration components in the two orthogonal directions (so-called XY directions) are combined to generate a horizontal acceleration. It is also possible to detect the size of.

(A) is a top view (perspective view) which shows an example of embodiment of the acceleration sensor apparatus (1st structure) of this invention, (b) is sectional drawing in the AA line. FIG. 2 is a perspective view (perspective view) of the acceleration sensor device shown in FIG. 1. It is a top view which shows typically the other example of embodiment of the acceleration sensor apparatus of this invention.

Explanation of symbols

1 ... Space 2 ... Coiled conductor
21-25 ... Coiled conductor 3 ... High permeability block 4 ... Elastic member 5 ... Insulating container 5a ... Insulating substrate 5b ... Lid 6... Connection conductor 9... Acceleration sensor device

Claims (4)

A plurality of coiled conductors each arranged in the longitudinal direction outside the columnar space, each surrounding the space, an elastic member respectively disposed from both ends of the space toward the center, and the space An acceleration sensor device comprising: a high permeability block housed between the elastic members. The acceleration sensor device according to claim 1, wherein the space is formed in an insulating container. The interval between adjacent ones of the plurality of coiled conductors is smaller than the outer dimension in the length direction of the space of the high permeability block, and larger than half of the outer dimension. Item 2. The acceleration sensor device according to Item 1. The acceleration sensor device according to claim 1, wherein the plurality of coiled conductors have different numbers of turns and are connected in series to each other.

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