JPH07225242A - Acceleration sensor, acceleration sensor system, vehicle equipped with acceleration sensor system, and other devices - Google Patents

Abstract

PURPOSE:To detect acceleration in only a desired direction without being affected by accelerations excluding that in the desired direction by setting the acceleration detecting direction so that the output caused by the acceleration crossing the acceleration detecting direction at a right angle may become the minimum. CONSTITUTION:An axial direction X for detecting acceleration is set to cross vertically a plane L including a rocking center M of the center of gravity M and the center of gravity G in a mass part 4. Therefore, when an acceleration in the direction X is applied thereto, the part 4 is displaced due to elastic deformation of a beam 3, and the gap amount of a movable electrode 5 and fixed electrode 7 is changed according to the displacement, so that the acceleration change in the direction X may be detected based on the change in electrostatic capacity between the both electrodes. In case of axial direction Y, since an inertia force applied to the center of gravity G at this acceleration passes through the center M, no bending moment is generated in the beam 3 and detection sensitivity for acceleration becomes about zero. In addition, in case of widthwise direction, since the part 4 is supported by a plurality of beams 3 placed in the widthwise direction, the part 4 is hardly changed and the detection sensitivity becomes zero. Therefore, the accelerations in only the direction X can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration sensor, an acceleration sensor device, and a vehicle and other equipment mounted with the acceleration sensor device. Specifically, the present invention relates to a technique for minimizing the sensitivity of an acceleration sensor or an acceleration sensor device to acceleration other than the intended acceleration detection direction.

[0002]

2. Description of the Related Art Conventionally, as a semiconductor acceleration sensor using a semiconductor manufacturing process, a mass portion is supported by a frame (supporting member) in a cantilever manner by an elastic beam (elastically deforming portion), and at least one of the frames is supported. There is a cover attached to the surface. FIG. 1A is a perspective view of a conventional acceleration sensor 1a, and FIG. 1B is a sectional view thereof. Reference numeral 2 is a frame, 3 is a plurality of beams, and 4 is a mass portion. The frame 2, the beam 3, and the mass portion 4 are integrally formed by subjecting a silicon wafer (silicon substrate) 8 to an electrochemical etching method, and the entire mass portion 4 has conductivity. Is a movable electrode 5. A cover 6 made of glass is attached to the lower surface of the frame 2 by an anodic bonding method, and a fixed electrode 7 is formed on the inner surface of the cover 6 with a small gap from the movable electrode 5. In this acceleration sensor 1a, as shown in FIG. 1B, the mounting surface 9 of the acceleration sensor 1a and the silicon wafer 8 are
The acceleration detection axis direction X is set or designed in a direction perpendicular to the main surface 8a of the above, and the acceleration detection axis direction X is arranged and used so as to be aligned with the intended acceleration detection direction to be measured. Was becoming. That is, in the conventional acceleration sensor 1a, the direction perpendicular to the mounting surface 9 defined on the lower surface of the acceleration sensor 1a is matched with the intended acceleration detection direction.

Further, as used in the acceleration sensor device A of FIG. 2, a glass cover 6 is joined to the upper surface of the frame 2 which supports the mass portion 4 by the beam 3 so that the mass portion 4 is joined. There is an acceleration sensor 1b in which a fixed electrode 7 is also provided on the inner surface of the upper cover 6 with a small gap from the movable electrode 5 on the upper surface. Also in this acceleration sensor 1b, similarly to the acceleration sensor 1a in FIG. 1, the acceleration detection axis direction X is set or designed in a direction perpendicular to the mounting surface 9 of the lower surface of the lower cover 6 and the main surface 8a of the silicon wafer 8. In this case, the acceleration detection axis direction X is arranged and used so as to match the intended acceleration detection direction.

These acceleration sensors 1a and 1b are shown in FIG.
Like the acceleration sensor 1b shown in FIG. 1, the mounting surface 9 is placed on the mounting board 21 and mounted horizontally, and then the mounting board 2 is mounted.
1 is supported horizontally by a shock absorbing support member 22, and is housed in a case body 23 made of metal, for example. The case body 23 is covered with a cover 24.
3 and the cover 24 are further housed in a resin case 25,
It is covered with a resin cover 26. The acceleration sensor device A configured as described above maintains a straight posture (that is, the mounting surface 9 of the acceleration sensor 1 is kept horizontal when detecting acceleration in the vertical direction, for example). Is attached to the vehicle body of a vehicle such as an automobile by an attachment member 27. Reference numeral 28 in the figure denotes a feedthrough capacitor, which is used to prevent radio wave interference from the acceleration sensor device A to the outside or to the acceleration sensor device A from the outside
This is to prevent radio wave interference that occurs in the.

FIG. 3 shows another conventional acceleration sensor device B, specifically, a sectional view of an acceleration sensor built-in type electronic control unit for a vehicle. The acceleration sensor 1b (or the acceleration sensor 1a) is the mounting board 2
After being mounted on No. 1, it is supported by the shock absorbing support member 22, is housed in the case body 23, and is covered with the cover 24. An electronic control circuit (not shown) is provided on the mounting board 21 to control the vehicle suspension device from sensor signals from the acceleration sensor 1 and vehicle speed sensors and steering angle sensors attached to the vehicle. This acceleration sensor device B
Also, for example, when detecting acceleration in the vertical direction, the acceleration sensor 1 is attached to the vehicle body or the like by the attachment member 27 in a straight posture so that the acceleration detection axis direction X of the acceleration sensor 1 faces the vertical direction.

However, when acceleration is applied to the acceleration sensors 1a and 1b mounted on a vehicle such as an automobile, the mass portion 4 is displaced by the elastic deformation of the beam 3, and the movable electrode 5 is moved according to the displacement amount of the mass portion 4. The gap amount between the fixed electrode 7 and the fixed electrode 7 changes. When the gap amount changes, the electrostatic capacitance between the movable electrode 5 and the fixed electrode 7 changes, and therefore, the change in the acceleration can be detected by outputting the change in the electrostatic capacitance as an electric signal.

[0007]

As described above, in the acceleration sensor (semiconductor acceleration sensor) in which the beam 3 and the mass portion 4 are manufactured by applying the semiconductor manufacturing technique to the semiconductor substrate such as the single crystal silicon substrate, the beam 3 or An electrochemical etching method is used to efficiently manufacture the mass portion 4.
That is, according to the electrochemical etching method, productivity can be improved as compared with a method in which the semiconductor substrate is chemically etched from both upper and lower surfaces and the etching depths on the upper and lower surfaces are made equal by controlling the time. However, in the electrochemical etching method, the semiconductor substrate cannot be equally etched from both sides, and only one side can be etched.

Therefore, these conventional acceleration sensors 1
1B, the center of gravity G of the mass portion 4 passes through the swing center (instantaneous rotation center) M of the center of gravity G of the mass portion 4 and the main surface of the silicon wafer 8 is a. 8a and beam 3
(Strictly speaking, it is not located on a plane L ′ parallel to the neutral plane of the beam 3 in terms of material mechanics), and is not in the target acceleration detection direction (that is, the acceleration detection axis direction X). There is a problem that the influence of the sensitivity on the directional acceleration becomes large. That is, since the center of gravity G of the mass portion 4 is not located on the plane L ′ that passes through the center of gravity G of the mass portion 4 and is parallel to the beam 3, the direction of the other axis shown in FIG. When the acceleration in the direction Y orthogonal to the acceleration detection axis direction X acts on the mass portion 4, a bending moment is generated in the beam 3 so that the mass portion 4 rotates around the swing center M. Displace in direction X. In this way, since the mass portion 4 is displaced by the acceleration in the other axis direction Y,
The acceleration in the other axis direction Y is detected as the acceleration in the acceleration detection axis direction X (that is, it has sensitivity in the other axis direction Y), and an error is added to the measured value of the acceleration in the target detection direction. It was happening.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object of the present invention is to minimize the detection sensitivity of acceleration other than the intended detection direction. It is to reduce the measurement error of the acceleration in the detection direction.

[0010]

In a first acceleration sensor according to the present invention, a mass portion is swingably supported by a supporting member by an elastically deformable portion, and the center of gravity of the mass portion passes through the swing center of the center of gravity. The acceleration sensor is not located in the plane parallel to the elastically deformable portion, and the acceleration detection axis direction is set so that the output due to the acceleration in the direction orthogonal to the acceleration detection axis direction is minimized.

A second acceleration sensor according to the present invention is an acceleration sensor in which an elastically deformable portion and a mass portion are formed by an electrochemical etching method, and the elastically deformable portion swingably supports the mass portion on a support member. The acceleration detection axis direction is set so that the output due to the acceleration in the direction orthogonal to the acceleration detection axis direction is minimized.

In the third acceleration sensor according to the present invention, the support member, the elastically deforming portion and the mass portion are formed by processing the substrate, and the elastically deforming portion allows the mass portion to swing on the supporting member. An acceleration sensor which is supported and whose direction connecting the center of gravity of the mass portion and the center of swing of the center of gravity is not parallel to the main surface of the substrate, and which has a minimum output due to acceleration in a direction orthogonal to the acceleration detection axis direction. The acceleration detection axis direction is set so that

Further, in the fourth acceleration sensor according to the present invention, the support member, the elastically deforming portion and the mass portion are formed by processing the substrate, and the elastically deforming portion allows the mass portion to swing on the supporting member. An acceleration sensor which is supported and whose length direction of the elastically deformable portion is not parallel to the main surface of the substrate, and which is set so as to minimize the output due to the acceleration in the direction orthogonal to the acceleration detection axis direction. It is set.

In these acceleration sensors, it is preferable that the direction in which the output due to acceleration is minimized is in the plane parallel to the plane for mounting. It is also preferable that the direction in which the output due to acceleration is minimized is perpendicular to the surface for attachment.

An acceleration sensor device according to the present invention is an acceleration sensor device provided with the above acceleration sensor, wherein the acceleration sensor is arranged in a posture that minimizes the acceleration detection sensitivity in a direction orthogonal to the intended acceleration detection direction. It is characterized by having been set up.

For this purpose, the mounting member such as the mounting board or the package may be mounted on the mounting member with a predetermined inclination angle. Alternatively,
The acceleration sensor may be housed in the case with a predetermined inclination angle with respect to the case. Alternatively, the acceleration sensor may be housed in a case installed with a predetermined inclination angle. Alternatively, these methods may be combined. That is, a method of mounting the acceleration sensor on a mounting member such as a mounting board or a package with an inclination angle, a method of mounting the acceleration sensor in a case with an inclination angle, and a case installed with an inclination angle. The acceleration sensor may be arranged in a predetermined posture by combining at least two or more of the methods stored therein.

Further, as the acceleration sensor device, a fixed electrode is provided so as to face a movable electrode formed on a mass portion of the acceleration sensor, and a capacitance change between the movable electrode and the fixed electrode is detected as an acceleration change. The electrostatic capacitance type may be used. Further, a strain detection system in which a strain detection element is provided in the beam portion of the acceleration sensor may be used.

The acceleration sensor device of the present invention can be used for vehicles. In this case, the vertical direction of the vehicle can be set as the target acceleration detection direction. Moreover,
The target acceleration detection direction is the vertical direction of the vehicle, and the direction with the minimum acceleration detection sensitivity can be oriented in the front-back direction of the vehicle. Alternatively, the front-back direction of the vehicle may be set as the target acceleration detection direction. Furthermore, the acceleration detection direction may be the front-rear direction of the vehicle, and the direction with the minimum acceleration detection sensitivity may be directed in the vertical direction of the vehicle. Alternatively, the left-right direction of the vehicle may be the target acceleration detection direction. Furthermore, the acceleration detection direction may be the left-right direction of the vehicle, and the direction with the smallest acceleration detection sensitivity may be oriented in the vertical direction of the vehicle.

A vehicle according to the present invention is characterized by including the above acceleration sensor device.

The present position display system for displaying the present position on a map according to the present invention is characterized by including the acceleration sensor device.

A vibration detecting device according to the present invention is characterized by including the above acceleration sensor device.

An earthquake detecting device according to the present invention is characterized by including the above acceleration sensor device.

A pedometer according to the present invention is characterized by including the above acceleration sensor device.

[0024]

According to the acceleration sensor of the present invention, the acceleration detection axis direction is set so that the output due to the acceleration in the direction orthogonal to the acceleration detection axis direction is set to the minimum. By arranging the direction so that it coincides with the target acceleration detection direction, it is possible to detect the acceleration only in the target detection direction without being affected by the acceleration other than the target detection direction. Therefore, even in the case of an acceleration sensor in which the center of gravity of the mass part does not lie on a plane that passes through the center of swing of the mass part and is parallel to the beam or the main surface of the substrate, the measurement error of the acceleration in the target detection direction Can be reduced. That is, it is possible to improve the accuracy of detecting the acceleration in the target detection direction.

Further, in these acceleration sensors, the direction in which the output due to acceleration is minimized is directed to a plane parallel to the mounting surface or a direction perpendicular to the mounting surface. By doing so, it is possible to control the installation direction in which the output due to acceleration is the minimum, and by using the same direction as the direction in which the detection sensitivity is desired to be the minimum, the sensitivity of other axes can be made smaller. can do.

Further, according to the acceleration sensor device of the present invention, since the acceleration sensor device is arranged in a posture in which the acceleration detection sensitivity in the direction orthogonal to the intended acceleration detection direction is minimized, the acceleration in a direction other than the intended detection direction is accelerated. It is possible to detect the acceleration only in the target detection direction without being affected by. Therefore, even in the case of an acceleration sensor device in which the center of gravity of the mass portion does not lie on the plane that passes through the swing center of the mass portion and is parallel to the beam or the main surface of the substrate, the measurement error of the acceleration in the target detection direction Can be reduced. Therefore, according to the acceleration sensor device of the present invention, it is possible to improve the accuracy of detecting the acceleration in the target detection direction.

In the case of this acceleration sensor device, by mounting the acceleration sensor on the mounting member with a predetermined inclination angle with respect to the mounting member, the acceleration detection sensitivity in the direction orthogonal to the intended acceleration detection direction is minimized. The acceleration sensor can be arranged so that That is, for example, by installing the acceleration sensor device with the mounting member as a reference so that the mounting member is perpendicular to the target acceleration detecting direction, the acceleration detection sensitivity in the direction orthogonal to the target acceleration detecting direction can be easily obtained. Can be minimized.
Further, by accommodating the acceleration sensor in the case with a predetermined inclination angle with respect to the case, the acceleration sensor is arranged so that the acceleration detection sensitivity in the direction orthogonal to the intended acceleration detection direction is minimized. Can be
For example, by installing the acceleration sensor device with the case as a reference so that the case is straight with respect to the intended acceleration detection direction, the acceleration detection sensitivity in the direction orthogonal to the intended acceleration detection direction can be easily minimized. Can be. Alternatively, the acceleration sensor is housed in a case installed with a predetermined inclination angle, and when the case is installed at a predetermined inclination angle, the acceleration detection sensitivity in the direction orthogonal to the intended acceleration detection direction is the minimum. May be Of course, by combining these methods, the acceleration detection sensitivity in the direction orthogonal to the intended acceleration detection direction may be minimized.

When this acceleration sensor device is used in a vehicle, if the vertical direction of the vehicle is used as the target acceleration detection direction, it will not be affected by the movement or vibration of the vehicle in the left-right direction or the front-rear direction, for example. It is possible to accurately detect only the vertical vibration of the vehicle due to the unevenness of the road surface or the like. In this case, in particular, since the vehicle has greater motion and vibration in the front-rear direction than in the left-right direction, if the direction with the minimum acceleration detection sensitivity (preferably the direction with zero acceleration detection sensitivity) is oriented in the front-rear direction of the vehicle, detection is performed. The influence of vibrations in directions other than the direction can be reduced. Similarly, if the target acceleration detection direction is the front-rear direction of the vehicle, only the front-rear vibration or movement of the vehicle can be accurately detected without being affected by the left-right or up-down movement or vibration of the vehicle. can do. In particular,
Since the vibration of the vehicle is larger in the vertical direction than in the horizontal direction,
If the direction in which the acceleration detection sensitivity is the minimum is oriented in the vertical direction of the vehicle, the influence of vibrations in directions other than the detection direction can be reduced. Similarly, if the target acceleration detection direction is the left-right direction of the vehicle, only the left-right vibration or movement of the vehicle can be accurately detected without being affected by the front-rear direction or up-down movement or vibration of the vehicle. can do. In particular, the vibration of the vehicle is larger in the vertical direction than in the front-rear direction. Therefore, if the direction with the minimum acceleration detection sensitivity is directed to the vertical direction of the vehicle, the influence of vibrations in directions other than the detection direction can be reduced. Therefore, by providing the acceleration sensor device in each of the up, down, left, right, and front directions of the vehicle, it is possible to accurately detect vibrations and movements in these directions with high resolution. Therefore, automatic control of the vehicle speed and vibration control can be reliably performed, and accurate information necessary for comfortable driving control can be obtained.

Further, in the present position display system using the acceleration sensor device of the present invention, since the accurate acceleration can be known, the traveling distance and the traveling direction can be calculated from the acceleration to find out in what situation. However, the current position can be surely grasped, and the current position with less error can be known.

Further, in the vibration detecting device, the seismic detecting device and the pedometer of the present invention, since it is possible to measure only accurate vibration and acceleration in the respective intended directions, it is possible to detect abnormal vibrations. In addition, it is possible to accurately judge an earthquake and to measure an accurate number of steps.

[0031]

FIG. 4 is a sectional view showing an acceleration sensor 10 according to an embodiment of the present invention. In the acceleration sensor 10, a mass portion 4 is arranged in the center of an opening portion of a frame (support member) 2 having a rectangular frame shape, and the mass portion 4 has a plurality of elastic beams (two in the drawing) of a beam 3. Is supported by the frame 2 in a cantilever manner, and the mass portion 4 is swung around its swing center M due to the elastic deformation of the beam 3 and can be freely displaced in the thickness direction of the mass portion 4. There is. The frame 2, the beam 3, and the mass portion 4 are integrally formed from the single crystal silicon wafer 8 by a semiconductor manufacturing process, the entire mass portion 4 has conductivity, and the lower surface of the mass portion 4 functions as the movable electrode 5. have. Further, since the beam 3 and the mass portion 4 are formed by etching from the lower surface side by the electrochemical etching method, the mass portion 4 is formed by the beam 3 and the mass portion 4.
Located on the lower side, the plurality of beams 3 extend parallel to the main surface (wafer surface) 8a of the silicon wafer 8,
The center of gravity G of the mass portion 4 passes through the swing center M thereof and is deviated from the plane L ′ parallel to the beam 3 (or the main surface 8a) to the lower surface side.

A glass cover 6 having a uniform thickness is laid on the lower surface of the frame 2 (the lower main surface 8a of the silicon wafer 8), and the peripheral portion of the cover 6 is framed by the anodic bonding method.
Is joined to. A fixed electrode 7 is formed on the inner surface of the cover 6 with a small gap from the movable electrode 5 of the mass portion 4. The lower surface of the cover 6 serves as a mounting surface 9 for mounting on a mounting board or for directly mounting on various devices.

In this acceleration sensor 10, a plane L including the center of swing M of the center of gravity G of the mass portion 4 and the center of gravity G of the mass portion.
(Because it is a plane parallel to the width direction of the acceleration sensor 10,
The acceleration detection axis direction X is set or designed in a direction perpendicular to the plane perpendicular to the paper surface of FIG. Therefore, in this embodiment, the acceleration detection axis direction X is neither perpendicular nor parallel to the mounting surface 9, but when the acceleration sensor 10 is used,
It is mounted or mounted in a posture in which the acceleration detection axis direction X coincides with the intended acceleration detection direction.

When the acceleration detection axis direction X of the acceleration sensor 10 is made to coincide with the intended acceleration detection direction in this way, when acceleration in the acceleration detection axis direction X is applied to the acceleration sensor 10, the beam 3 is elastically deformed. The mass portion 4 is displaced, the gap amount between the movable electrode 5 and the fixed electrode 7 is displaced according to the displacement amount of the mass portion 4, and the movable electrode 5 and the fixed electrode 7 are displaced.
The change in the acceleration in the acceleration detection axis direction X is detected from the change in the capacitance during the period. On the other hand, when acceleration in the other axis direction Y (direction orthogonal to the acceleration detection axis direction X and the width direction) acts on the acceleration sensor 10, the inertial force acting on the center of gravity G of the mass portion 4 by the acceleration in the other axis direction Y. Is on the plane L and passes through the swing center M of the mass portion 4, so that no bending moment is generated in the beam 3 unlike the conventional example, and the mass portion 4 is not displaced. Therefore, the acceleration detection sensitivity with respect to the acceleration in the other axis direction Y is almost zero. Also, considering the width direction, which is one of the other axial directions, the mass portion 4 is supported by the plurality of beams 3 arranged in the width direction, and therefore the mass portion 4 cannot be displaced in the width direction. The acceleration detection sensitivity with respect to the directional acceleration is zero. Therefore, in such an acceleration sensor 10, only the acceleration in the acceleration detection axis direction X can be detected, and there is no influence of the acceleration in other axis directions other than this, and the acceleration detection axis direction is not affected. The X acceleration can be measured accurately and with high resolution.

However, if the acceleration detection axis direction X is the same as that of the acceleration sensor 10 shown in FIG. 4, it is troublesome to attach the acceleration sensor 10 so that it coincides with the intended acceleration detection direction. In each of the following embodiments, it is easy to mount or mount it in accordance with the target acceleration detection direction.

FIGS. 5A and 5B show an acceleration sensor 11 according to another embodiment of the present invention, which is shown in FIG.
Is a perspective view of the acceleration sensor 11, and FIG. 4B is a sectional view thereof. This acceleration sensor 11 has a structure similar to that of the acceleration sensor 10 shown in FIG.
The point is that an inclined surface 31 is provided on the lower surface of the cover 6. This inclined surface 31 is a swing center M of the center of gravity G of the mass portion 4.
Is parallel to the plane L including the center of gravity G of the mass portion, that is, perpendicular to the acceleration detection axis X. And this inclined surface 31
Is the mounting surface 9 of the acceleration sensor 11. Therefore, in this acceleration sensor 11, the acceleration detection axis direction X can be matched with the intended acceleration detection direction with reference to the mounting surface 9 (the inclined surface 31). If the inclined surface 31 is attached so as to be aligned with a surface perpendicular to the intended acceleration detection direction, the acceleration detection axis direction X and the intended acceleration detection direction can be easily matched. The inclined surface 31 can be provided by dicing a glass substrate, which is the material of the cover 6, and the inclination angle of the inclined surface 31 is calculated by the size of the mass portion 4 or the like.

The acceleration sensor 11 shown in FIG.
In the inclined posture as shown in (a), the mounting is performed such that the inclined surface 31 is brought into contact with a mounting member such as the mounting substrate 21 and the sensor mounting surface, and the inclined surface 31 (hence the plane L) is mounted on the mounting substrate 21 and the sensor. It is mounted so as to be parallel to a mounting member such as a mounting surface. At this time, when acceleration in the acceleration detection axis direction X is applied to the acceleration sensor 11, the mass portion 4 is displaced by the elastic deformation of the beam 3, and the gap amount between the movable electrode 5 and the fixed electrode 7 is changed according to the displacement amount of the mass portion 4. Is displaced, and a change in acceleration in the acceleration detection axis direction X is detected from a change in capacitance between the movable electrode 5 and the fixed electrode 7. On the other hand, it has no detection sensitivity for acceleration in the direction parallel to the inclined surface 31 (mounting surface 9).

FIG. 6 is a sectional view showing an acceleration sensor 12 according to still another embodiment of the present invention. In the acceleration sensor 12, a strain detecting element 32 such as a piezoresistive element or a strain gauge is formed on the upper surface of the beam 3. As described above, even in the acceleration sensor 12 in which the strain detection element 32 is provided on the beam 3, if the inclined surface 31 that is perpendicular to the acceleration detection axis direction X is formed on the cover 6, it is easily mounted in a predetermined inclined posture. Therefore, it can be used in a posture in which the detection sensitivity in the acceleration direction other than the target acceleration detection direction is minimized, and only the acceleration in the target acceleration detection direction can be detected.

FIGS. 7 (a) and 7 (b) show an acceleration sensor 13 according to still another embodiment of the present invention. FIG. 6 (a) is a perspective view of the acceleration sensor 13, and FIG. Is a sectional view thereof. A step 33 is provided on the lower surface of the cover 6 of the acceleration sensor 13 over the entire width of the cover 6. The step 33 allows the acceleration sensor 13 to be mounted in an inclined posture, and the tangent plane H of the lower surface of the cover 6 is parallel to the plane L including the swing center M of the center of gravity G of the mass part 4 and the center of gravity G of the mass part 4 (hence, , The step 33 is formed so as to be perpendicular to the acceleration detection axis direction X). The step 33 can be produced, for example, by etching a glass substrate, and the size of the step 33 can be determined by calculation depending on the size of the mass portion 4 or the like. Further, as shown by the step 33 shown by the imaginary line (two-dot chain line) in FIG.
It is also possible to have three stages. If the step 33 is provided and the tangential plane H (or the end of the step 33 and the cover 6 in contact with the tangent plane H) is used as the mounting surface 9 of the acceleration sensor 13, the tangent plane H is the object. By mounting the acceleration sensor 13 in a tilted posture so as to be aligned with a plane perpendicular to the acceleration detection direction, the acceleration detection axis direction X can be easily matched with the target acceleration detection direction.
Further, in this embodiment, since the bottom surface and the corners of the step 33 need only be cut, fine adjustment of the inclination angle becomes easier than in the case where the inclined surface 31 is provided.

FIGS. 8A and 8B show a state (acceleration sensor device) in which the acceleration sensor 13 is mounted on the mounting substrate 21, and FIG. 8A is an external view thereof and FIG. 8B. Is a sectional view thereof. The acceleration sensor 13 is arranged on the mounting substrate 21 with the end 6a of the cover 6 and the end 33a of the step 33 in contact with each other. As described above, in the acceleration sensor 13, the contact point perpendicular to the acceleration detection axis direction X, which is oriented in the direction perpendicular to the plane L including the center of swing M of the center of gravity of the mass portion 4 and the center of gravity G of the mass portion 4. Since the step 33 is formed so as to have the plane H, the end portion 6 a of the cover 6 is mounted on the mounting substrate 21.
In the state in which the acceleration sensor 13 is mounted on the end 33a of the step 33, the acceleration detection axis direction X of the acceleration sensor 13 is oriented in the direction perpendicular to the mounting substrate 21. Therefore, by mounting the mounting board 21 so as to be perpendicular to the intended acceleration detection direction, the sensitivity of the other axis can be minimized. For example, when it is mounted on the horizontal mounting board 21, only the vertical acceleration can be accurately detected without detecting the horizontal acceleration. It should be noted that the mounting board 21 and the acceleration detection axis direction X may be made vertical by providing an inclined pedestal between the acceleration sensor 10 having the structure as shown in FIG. 4 and the mounting board 21. Is the acceleration sensor 1
As 0 becomes smaller, the pedestal becomes more difficult to manufacture, and the mounting accuracy of the acceleration sensor 10 becomes insufficient. On the other hand, according to the acceleration sensor 13 of this embodiment, the pedestal does not need to be manufactured and the mounting can be easily performed. Therefore, even when the acceleration sensor 13 is miniaturized, the disadvantage does not occur.

FIG. 9A is a perspective view showing an acceleration sensor 14 according to still another embodiment of the present invention, and FIG. 9B is a sectional view thereof. In this embodiment, the leg portion 34 is provided on the lower surface of the cover 6 over the entire width of the cover 6. The leg portion 34 can be formed by etching a glass substrate, which is the material of the cover 6, similarly to the step 33, for example. Further, it is not necessary to provide the leg portion 34 over the entire width of the cover 6, and the swing center M of the center of gravity G of the mass portion 4
The columnar leg portions 34 may be provided on both side ends of the cover 6 so that the plane L including the center of gravity G of the mass portion 4 and the tangential plane H are parallel to each other. The size of the leg portions 34 and the position where the leg portions 34 are provided can be determined by calculation depending on the size of the mass portion 4 and the like. In addition, the leg portion 3 indicated by a chain double-dashed line in FIG.
As shown in FIG. 4, the leg portions 34 may be provided at two or more places so as to be in contact with the same tangent plane H. Even when the leg portions 34 are provided in this way, fine adjustment of the inclination angle is easier than when the inclined surface 31 is provided. Also in this embodiment, the tangential plane H parallel to the plane L (or the end of the cover 6 and the leg 34 in contact with the tangent plane H) is mounted on the mounting board or the like as the mounting surface 9 of the acceleration sensor 14. .

FIG. 10A is a perspective view showing an acceleration sensor 15 according to still another embodiment of the present invention, and FIG. 10B is a sectional view thereof. The acceleration sensor 15 includes a frame 2 in which a mass portion 4 is supported in a cantilever manner by a plurality of beams 3.
An inclined surface 31 is provided on the lower surface of the so as to be parallel to the swing center M of the center of gravity G of the mass portion 4 and the plane L including the center of gravity G of the mass portion 4 (that is, perpendicular to the acceleration detection axis direction X). The cover 6 is bonded to the upper surface of the frame 2 and the silicon wafer 8
With respect to the lower cover 6, another cover 35 having a shape symmetrical to the lower cover 6 is joined. By joining the covers 6 and 35 having plane symmetry to the upper and lower sides of the frame 2 in this way, distortion at the joining surface due to the difference in the coefficient of thermal expansion between glass and silicon can be minimized. Therefore, the temperature characteristics of the acceleration sensor 15 can be improved, and the acceleration can be detected accurately in a wide temperature range.

The acceleration sensors 10, 13, 14, 15
However, like the acceleration sensor 12, a strain detecting element 32 such as a piezoresistive element or a strain gauge may be formed on the beam 3.

11A and 11B are a sectional view and an external perspective view showing an acceleration sensor 16 according to still another embodiment of the present invention. In this acceleration sensor 16, an inclined surface 31a is formed on the inner surface of the lower cover 6, and a frame in which a mass portion 4 is swingably supported by a plurality of beams 3 on the inclined surface 31a. Two are joined. Also,
A cover 35 having substantially the same shape as the lower cover 6 is placed on the upper surface of the frame 2 in a 180-degree inverted state, and the upper surface of the frame 2 and the inclined surface 31a of the inner surface of the cover 35 are joined. The outer shape of the acceleration sensor 16 is symmetrical with respect to the front and back sides, and the outer surfaces of the upper and lower covers 6 and 35 are both mounting surfaces 9. There is. In addition, in each of the inclined surfaces 31a of the covers 6 and 35, the swing center M of the center of gravity G of the mass portion 4 and the plane L including the center of gravity G of the mass portion 4 are parallel to both mounting surfaces 9 (that is, the acceleration detection axis). Perpendicular to direction X)
It is formed so that. Therefore, no matter which mounting surface 9 is attached to the mounting substrate or the like, the mounting is performed so that the acceleration detection axis direction X is perpendicular to the mounting substrate or the like.

Therefore, this acceleration sensor 16 is shown in FIG.
As shown in (b), the direction perpendicular to the mounting surface 9 is the acceleration detection axis direction X, and the two minimum sensitivity directions Y and Z.
Are parallel to the mounting surface 9 and are oriented parallel to the width direction and the length direction, respectively. Incidentally, the acceleration sensors 11, 12, 13, 14, other than the acceleration sensor 16,
Also in 15, the acceleration detection axis direction X faces the direction perpendicular to the mounting surface 9 with the mounting surface 9 as a reference, and the two minimum sensitivity directions Y and Z are parallel to the mounting surface 9 and are in the width direction and the length direction, respectively. 11B is the same as FIG. 11B.

FIG. 12 shows an acceleration sensor 17 according to still another embodiment of the present invention. FIG. 12 (a) is a plan view showing an intermediate silicon wafer 8 and FIG. 12 (b) is an external perspective view. is there. The acceleration sensor 17 has glass covers 6 and 6 anodically bonded to both upper and lower surfaces of a silicon wafer 8 and has an outer shape of a rectangular parallelepiped. The frame 2, the beam 3 and the mass portion 4 are made of an insulating silicon wafer 8
Is formed by performing etching on the mass portion 4.
Are formed. A plane L including the swing center M of the center of gravity G of the mass portion 4 and the center of gravity G of the mass portion 4 is parallel to the side surface 17a of the acceleration sensor 17, and the acceleration detection axis direction X is a direction perpendicular to the plane L. It is set. Therefore, in the acceleration sensor 17, the acceleration detection axis direction X is perpendicular to the side surface 17a of the acceleration sensor 17. The surface of one cover 6 of the acceleration sensor 17 is a mounting surface 9 for mounting and the like, and the surface of the other cover 6 has the acceleration detection axis direction X as shown in FIG. 12B. You may give the mark 17c shown. Also, the acceleration sensor 1
The mass portion 4 is not displaced by the acceleration in the other axis direction Y which is perpendicular to the other side surface 17b of 7, and this direction is the minimum sensitivity direction. Further, the beam 3 has a width (Z direction) compared to the thickness.
Is increased to minimize the sensitivity of the other axis in this direction. Therefore, this acceleration sensor 17
Then, the acceleration detection axis direction X is parallel to the mounting surface 9, the other axis direction Z having the minimum sensitivity is oriented in the direction perpendicular to the mounting surface 9, and the other axis direction Y having the minimum sensitivity is parallel to the mounting surface 9 and the acceleration is performed. The direction is perpendicular to the detection axis direction X.

If the mounting surface 9 is changed in the acceleration sensors 11, 12, 13, 14, 15, 16 other than the acceleration sensor 17 and the mounting surface 9 is set on the side surface of each acceleration sensor, for example, FIG. As shown in (b), the acceleration detection axis direction X may be parallel to the mounting surface 9 and the direction perpendicular to the mounting surface 9 may be the other axis direction with the minimum sensitivity.

13 and 14 are sectional views showing acceleration sensors 18 and 19 according to still another embodiment of the present invention. In the acceleration sensors 18 and 19, when the silicon wafer 8 is electrochemically etched to form the beam 3 and the mass portion 4, a beam portion having a large thickness is formed, and the upper and lower surfaces of the beam portion having a large thickness are formed. V-grooves 3a and 3b are formed by etching in a V-groove shape by an appropriate etching method, respectively, thereby forming a beam 3 having a small thickness and inclined in an oblique direction.

Of these, the acceleration sensor 18 shown in FIG.
Is a main surface 8 of the silicon wafer 8 (frame 2) where the plane L including the center of gravity M of the center of gravity G of the mass part 4 and the center of gravity G of the mass part 4 is
The beam 3 is formed so as to be parallel to a.
The acceleration detection axis direction X is a direction perpendicular to the main surface 8a. According to this method, the mounting surface 9 on the lower surface of the cover 6 and the acceleration detection axis direction X can be made perpendicular without forming an inclined surface on the cover 6.

Further, in the acceleration sensor 19 shown in FIG. 14, the center of gravity M of the center of gravity G of the mass part 4 and the center of gravity G of the mass part 4 are measured.
The beam 3 is formed so that the plane L including the line and the neutral plane of the beam 3 coincide with each other. In this embodiment, since the acceleration in the other axis direction Y applied to the center of gravity G of the mass portion 4 passes through the beam 3, the buckling strength of the beam 3 is improved.

Next, when the acceleration sensor itself does not have an external form indicating the set acceleration detection axis direction X as in the acceleration sensor 10 shown in FIG. 4, the acceleration detection axis direction X of the acceleration sensor is set. A method of mounting the device in accordance with the target acceleration direction will be described.

FIG. 15 is a perspective view showing an acceleration sensor device C according to an embodiment of the present invention. The acceleration sensor device C includes the acceleration sensor 10 and the mounting adjustment unit 36 shown in FIG.
And a mounting substrate 21 having In this acceleration sensor device C, the mounting adjustment portion 36 having a convex shape with an inclination is integrally formed with the mounting substrate 21, and the mounting surface 9 of the acceleration sensor 10 is mounted on the mounting adjustment portion 36. Has been done. As a result, the mounting adjustment unit 36 is mounted so that the acceleration detection axis direction X faces the direction perpendicular to the mounting substrate 21. If the target acceleration detection direction is used so as to face the direction perpendicular to the mounting substrate 21, when the acceleration in the target detection direction is applied to the acceleration sensor device C, the mass acceleration causes the mass portion 4 to move. It is displaced and the acceleration in the target detection direction is detected. On the other hand, since the acceleration in the other axis direction has the minimum acceleration detection sensitivity, the acceleration in the direction orthogonal to the target detection direction, that is, the acceleration in the direction parallel to the mounting board 21 is not detected. Therefore, only the acceleration in the target detection direction can be accurately detected without being affected by the acceleration in other directions.

FIG. 16 is a perspective view showing an acceleration sensor device D according to still another embodiment of the present invention,
The resin package 37 is provided with a large number of lead frames 38, and the mounting surface of the resin package 37 is formed with a mounting adjustment portion 36. The acceleration sensor 1 is attached to the resin package 37 provided with the lead frame 38.
0, the lead frame 38 and the lead-out pad 38 (not shown) for the sensor signal, which is configured in the acceleration sensor 10.
If the and are connected by a bonding wire or the like, connection with the sensor signal processing circuit or mounting on a circuit board or the like equipped with the sensor signal processing circuit can be facilitated.

FIG. 17 is a sectional view of an acceleration sensor device E according to another embodiment of the present invention. Acceleration sensor 10
After being mounted on the mounting substrate 21, the product is supported by the shock absorbing support member 22 and is housed in a case body 23 such as a metal case or a resin case. The case body 23 is covered with a cover 24, and the case body 23 and the cover 24 are further housed in a resin case 25 and covered with a resin cover 26. Shock absorbing support member 22
Is formed of an elastic material such as rubber or soft resin capable of absorbing shock. The mounting substrate 21 has four corners fitted in the notches 22a of the shock absorbing member 22, and is supported in a state separated from the case body 23. It is designed to be able to absorb impacts such as drop impacts.

The acceleration sensor 10 is mounted on the mounting substrate 21 at an angle that minimizes the acceleration detection sensitivity of the other axis with respect to the target acceleration detection axis, and specifically, the center of gravity G of the mass portion 4 swings. It is mounted so that a plane L including the center of motion M and the center of gravity G of the mass portion 4 is parallel to the mounting board 21, that is, the acceleration detection axis direction X is perpendicular to the mounting board 21. For this purpose, the mounting substrate 21 integrally formed with the mounting adjustment part 36 like the acceleration sensor device C may be used, or the resin package 37 provided with the lead frame 38 may be used.

Although not shown in the drawing, the acceleration sensor 11 of the embodiment of the present invention, to which the cover 6 having the inclined surface 31, the step 33, etc., is joined, is mounted in the case body as shown in FIG. You can also

FIG. 18 is a sectional view of an acceleration sensor device F according to another embodiment of the present invention. In the acceleration sensor device F, after the acceleration sensor 10 is horizontally mounted on the mounting substrate 21 (hence, the acceleration sensor 10
The acceleration detection axis direction X is not perpendicular to the mounting substrate 21), and the acceleration detection is set in a direction perpendicular to the swing center M of the center of gravity G of the mass portion 4 and the plane L including the center of gravity G of the mass portion 4. For shock absorption by inclining the mounting substrate 21 by a predetermined inclination angle θ (equal to the angle between the vertical direction of the acceleration sensor 10 and the acceleration detection axis direction X) so that the axial direction X faces the vertical direction of the case body 23. It is held by the support member 22 and is housed in the case body 23. Further, the mounting member 27 provided in the acceleration sensor device F is the acceleration sensor device F.
Is provided in a direction parallel to the vertical direction of. In this acceleration sensor device F, the acceleration detection axis direction X of the acceleration sensor 10 is oriented in the vertical direction of the acceleration sensor device F, and the other axis direction Y is oriented in the horizontal direction of the acceleration sensor device F. When 27 is attached to a part parallel to the intended acceleration detection direction, the acceleration detection axis direction X
Can be made to match the desired acceleration detection direction,
There is no sensitivity in the direction orthogonal to the target acceleration detection direction, and only the acceleration in the target detection direction can be accurately detected.

At this time, as shown in FIG. 19, if the acceleration sensor 10 is previously packaged in a small metal package 39 or the like and the sensor signal of the acceleration sensor 10 is extracted from the connection terminal 40, the mounting substrate 21 will be described.
It can be easily connected to the detection circuit above. or,
As shown in FIG. 20, it may be fixed on a small fixed substrate 42 and then packaged in a small insulating plastic case 41 or the like. As described above, the acceleration sensor 10 is packaged in the metal package 39, the plastic case 41, or the like, so that the mounting on the mounting substrate 21 can be facilitated.

FIG. 21 is a sectional view showing an acceleration sensor device I according to still another embodiment of the present invention.
The acceleration sensor 10 is horizontally mounted on the mounting board 21, and the mounting board 21 is horizontally housed in the case body 23. Therefore, in this state, the acceleration detection axis direction X of the acceleration sensor 10 is inclined by θ from the vertical direction of the case body 23. In this acceleration sensor device I, the mounting member 27 provided in the case body 23 is not parallel to the vertical direction of the case body 23 but is inclined by θ, and the acceleration detection axis direction X of the acceleration sensor 10 is set in the mounting member 27.
It is parallel to. Therefore, if the mounting member 27 is fixed to a portion parallel to the intended acceleration detection direction,
The acceleration detection axis direction X of the acceleration sensor 10 can be matched with the target acceleration detection direction. Therefore, the detection sensitivity to the acceleration in the direction orthogonal to the target detection direction can be minimized, and only the acceleration in the target detection direction can be accurately detected.

FIG. 22 is a sectional view showing an acceleration sensor device J according to another embodiment of the present invention.
The acceleration sensor 10 is horizontally mounted on the mounting board 21, and the mounting board 21 is horizontally housed in the case body 23. Further, the mounting member 27 provided on the case body 23 is parallel to the vertical direction of the case body 23. Therefore, in this acceleration sensor device J, the acceleration detection axis direction X of the acceleration sensor 10 is neither parallel to the vertical direction of the case body 23 nor to the mounting member 27, and is inclined by θ with respect to the mounting member 27. Looking at However, even in the case of this acceleration sensor device J,
If the portion 46 for mounting the mounting member 27 is tilted by θ, the acceleration sensor device J is set in a vehicle or the like so that the acceleration detection axis direction X of the acceleration sensor 10 is parallel to the target acceleration detection direction. Appropriate attachment site 4
6 can be mounted. Therefore, also in the case of this acceleration sensor device J, the detection sensitivity to the acceleration in the direction orthogonal to the target detection direction can be minimized, and only the acceleration in the target detection direction can be accurately detected.

Although not shown, the method of the present invention
By combining two or more, for example, the acceleration sensor device E in which the acceleration sensor 10 is mounted on the mounting board 21 provided with the mounting adjustment unit 36 is provided with an appropriate angle on the arm 27a of the mounting member 27, the acceleration detection axis direction It is also possible for X to point in the desired direction within the acceleration sensor device. As described above, if the acceleration sensor device E having the acceleration sensor 10 mounted on the mounting substrate 21 is tilted and mounted on a vehicle or the like, it can be easily applied even when the mounting position is restricted. Further, a large number of acceleration sensor devices E having different mounting angles of the acceleration sensor 10 are manufactured, and the mounting member 27 is installed at the time of installation.
It can be easily mounted by adjusting the inclination angle of the arm 27a or adjusting the inclination angle of the attachment portion 46 of the vehicle body or the like. Of course, the acceleration sensor device I in which the arm portion 27a of the attachment member 27 has an angle may be attached to the attachment portion 46 of the vehicle body that is inclined at an appropriate angle.

Next, an application example in which an acceleration sensor is mounted by the mounting method of the present invention, particularly an application example using an acceleration sensor device will be described. The following description will be made mainly using the acceleration sensor 10 of FIG.
Acceleration sensor 11 of the present invention in which a step 32 and the like are formed
Similarly, the acceleration sensor 13 and the like can be used. First, FIG. 23 shows three acceleration sensor devices 51a, 51b,
It is a schematic block diagram of the motor vehicle K with which 51c was mounted. 52
Is a vehicle body, 53 is a tire, and 54 is a shock absorber that prevents vibration of the tire 53 and the like from being transmitted to the vehicle body 52. Three acceleration sensor devices 51a, 51b,
Reference numerals 51c denote attachment portions 46 located at three locations near the center of the left and right front wheels and the left and right rear wheels by the attachment members 27, respectively.
And the detected acceleration signal is output to the electronic control unit 56 by the control line 55.
The acceleration sensor devices 51a, 51b, 51c are mounted so that the acceleration sensitivity in the direction orthogonal to the assigned acceleration detection direction is minimized. Specifically, the acceleration sensor device 51a is installed as shown in FIG. Is installed so that the acceleration detection axis direction X of the acceleration sensor 10 is aligned with the vertical direction of the automobile K, and the width direction of the acceleration sensor 10 is aligned with the front-back direction (forward / backward direction) of the automobile K. The device 51b is the acceleration sensor 10
The acceleration detection axis direction X is aligned with the front-back direction (forward / backward direction) of the vehicle K, and the width direction of the acceleration sensor 10 is installed so as to match the up-down direction of the vehicle K. The remaining acceleration sensor device 51c is an acceleration sensor. The acceleration detection axis direction X of the vehicle 10 is installed so as to match the lateral direction of the vehicle K, and the width direction of the acceleration sensor 10 is installed so as to match the vertical direction of the vehicle K. Further, a steering angle sensor 58 is attached to the handle shaft 57, and a handle 59
Is detected, and the detected steering angle signal is output to the electronic control unit 56 together with the vehicle speed signal from the vehicle speed sensor 60.

These three acceleration sensor devices 51a, 5a
1b and 51c are vertical accelerations of the automobile K,
The acceleration in the front-rear direction and the acceleration in the left-right direction can be measured without being affected by the acceleration in the other axis direction, and the resolution in the acceleration detection direction is high. Further, in the acceleration sensor 10 and the like, since the mass portion 4 is supported by the plurality of beams 3, the mass portion 4 is unlikely to be displaced due to the acceleration in the width direction, and has the highest sensitivity in other axial directions. Poor, the sensitivity is almost zero. Therefore, the acceleration sensor device 51 in which the acceleration detection axis direction X matches the vertical direction of the automobile K
In a, if the width direction of the acceleration sensor 10 is made to coincide with the front-back direction in which a larger acceleration is generated than in the left-right direction, the other axis sensitivity can be suppressed more effectively. Further, the durability of the beam 3 of the acceleration sensor 10 is also improved. Further, in the acceleration sensor device 51b in which the acceleration detection axis direction X coincides with the front-rear direction of the vehicle K, if the width direction of the acceleration sensor 10 coincides with the vertical direction in which a larger acceleration is generated than the left-right direction, The sensitivity of the other axis can be suppressed more effectively, and the durability of the beam 3 is also improved. Further, in the acceleration sensor device 51c in which the acceleration detection axis direction X is aligned with the left-right direction of the automobile K, the width direction of the acceleration sensor 10 is
By matching the vertical direction where a larger acceleration is generated than the front-back direction, the sensitivity of the other axis can be suppressed more effectively, and the durability of the beam 3 is also improved.

The electronic control unit 56 analyzes the acceleration signal, the steering angle signal and the vehicle speed signal input from the three acceleration sensor devices 51a, 51b and 51c and performs signal processing, and the vehicle such as the actuator 61 in the shock absorber 54. It is possible to control the suspension device and automatically control the vibration of the automobile K to provide a comfortable ride.

FIG. 25 is a schematic configuration diagram of another automobile U provided with the acceleration sensor device 51, in which the acceleration sensor 10 is mounted in the electronic control unit 56. The acceleration sensor 10 is mounted so that the acceleration detection sensitivity in the direction orthogonal to the determined acceleration detection direction is minimized. As a structure therefor, for example, the electronic control unit N shown in FIG. 26 is mounted. The acceleration sensor 10 is mounted on the mounting board 21 on which the adjusting unit 36 is provided.
Or mounting a predetermined angle θ between the mounting member 27 mounted on the vehicle body 52 and the unit support portion 27b supporting the electronic control unit 56 as in the electronic control unit O shown in FIG. be able to. Further, as shown in FIG. 28, the attachment member 27 provided straight on the electronic control unit P may be attached to the attachment portion 46 of the vehicle body 52 provided by being inclined by a predetermined angle θ. At this time, for example, as shown in FIG. 29, the acceleration detection axis direction X of the acceleration sensor 10 is matched with the vertical direction of the vehicle U, and the width direction of the acceleration sensor 10 is matched with the front-back direction of the vehicle U in which a large acceleration is generated. Thus, it is possible to measure only the acceleration in the vertical direction without being affected by the acceleration in the front-back direction and the width direction.

FIG. 30 is a block diagram of a current position display system Q which is a so-called navigation system in which the current position of an automobile or the like is displayed on a map displayed on the display. The current position display system Q analyzes an antenna 72 that receives a GPS signal transmitted from artificial hygiene at a predetermined position on the earth, the received GPS signal, the acceleration signal from the acceleration sensor 71, and the gyro signal from the gyroscope 73. Position detecting means 74 for calculating the current position information of the vehicle, map storing means 75 such as a CD-ROM or semiconductor ROM storing road map information, and the current position information and map storage calculated by the position detecting means 74. The output means 76 outputs an output signal to a display means 78 such as a CRT or a liquid crystal display based on the road map information stored in the means 74.
The acceleration sensor 71 is housed in the GPS controller 79 together with the gyroscope 73, the position detection means 74, the output means 76, and the like. This current position display system Q
When a GPS signal is received, the current position of the automobile or the like can be shown on the map displayed on the display means 78 such as a cathode ray tube or a liquid crystal panel based on the GPS signal. However, as if you were passing through a tunnel, GP
If the S signal cannot be received, the current position cannot be displayed. For this reason, the position detecting means 74 uses the acceleration sensor 7
The acceleration is obtained based on the acceleration signal from 1, and the obtained acceleration is integrated once or twice to calculate the velocity and the moving distance, and the gyroscope 7
The gyro signal from 3 is used to determine the moving direction and the current position information is calculated.

Since the acceleration sensor 71 provided in the present position display system Q can accurately determine the acceleration of the automobile, especially the acceleration in the front-rear direction,
Even if the S signal cannot be received, the current position can be shown on the map displayed on the display unit 78 without error. Even when the GPS signal is received, the current position is corrected more accurately by correcting the current position from the acceleration signal from the acceleration sensor 71 and the gyro signal from the gyroscope 73. You can also

The present position display system Q is not limited to this embodiment, and various embodiments can be considered. For example, without providing the gyroscope 73,
An acceleration sensor 71 may be provided in front of and behind the vehicle body of the automobile, and the moving direction of the automobile may be calculated from the difference in acceleration obtained from the two acceleration sensors 71.
The current position information may be calculated based on the acceleration signal from the acceleration sensor 71 and the gyro signal from the gyroscope 73 without depending on the GPS signal.

FIG. 31 is a block diagram showing a vibration detecting device R according to the present invention. The vibration detecting device R is for diagnosing an abnormality around a shaft of a motor driving a motor driving device. is there. The motor drive machine 81 is composed of a motor 82 and a gear train 83 connected to a rotation shaft 84 thereof. For example, as shown in FIG. 32, an acceleration sensor (or acceleration sensor device) 85 is attached to a mounting jig 9.
It is attached to the upper part of the motor 82 via the No. 3. Then, from the motor drive machine 81 side to the vibration detection unit 86 side,
A signal indicating the vibration of the motor 82 detected by the acceleration sensor 85, that is, a time-series vibration signal is output.
The vibration detector 86 includes an amplifier 87 and a frequency filter 88.
A Fourier transform unit (FFT) 89, two feature extraction units 90 and 91, and a classification diagnosis unit 92. The time-series vibration signal transmitted from the acceleration sensor 85 is amplified by the amplifier 87, and then the signal in the frequency range required by the frequency filter 88, that is, the motor drive machine 81,
Only the signal in the frequency region of the motor rotation speed and the abnormal vibration is allowed to pass. Then, the signal after passing through the frequency filter 88 is directly input to the feature extraction unit 91 on the one hand, and the signal in the frequency space on the other hand by the Fourier transform unit 89. After being subjected to the fast Fourier transform, the data is input to the feature extraction unit 90.

In the feature extraction unit 91, the motor 82 is analyzed by analyzing a large number of signals appearing in the time series vibration signal.
The characteristics of the basic vibration signal at the same number of revolutions as the number of revolutions and the abnormal vibration signal due to scratches on the gear and scratches on the bearing inner ring, bearing outer ring, etc. are extracted. Further, the feature extraction unit 90 extracts features of the fundamental vibration signal and the abnormal vibration signal by analyzing a large number of signals represented by the Fourier transform signal. When the feature extraction is performed, the classification / diagnosis unit 92 classifies the position of occurrence of an abnormality such as a scratch or foreign matter and its type, and outputs a diagnosis result (diagnosis output).

In the vibration detecting device R as described above, the acceleration sensor 85 is unlikely to be affected by the acceleration other than the intended acceleration detecting direction, so that the vibration generated from the motor 82 can be accurately captured, and The abnormality of the drive machine 81 can be accurately determined. In particular, when the motor drive machine 81 is driven while being moved, the time-series vibration signal is output in a state in which the acceleration component generated due to the movement is removed, so that the subsequent analysis of the signal is simplified. can do.

FIG. 33 is a block diagram of the earthquake detecting apparatus S of the present invention, which is to judge whether the detected vibration is an earthquake or not to issue an alarm or the like. The earthquake detector S is
From the vibration detection unit 101, in which the three acceleration sensors 103a, 103b, and 103c are installed, to the vibration determination unit 102,
Two sensor signals are being output. As shown in FIG. 34, each of the three acceleration sensors 103a, 103b, and 103c of the vibration detecting unit 101 matches each acceleration detection axis direction X with one of the U axis, the V axis, and the W axis, and the other axis. It is mounted on the mounting substrate 110 so as to minimize the acceleration detection sensitivity in the direction. For example, the acceleration sensor 10
3a is mounted on the mounting adjustment unit 111 integrally formed on the mounting substrate 110 via the fixed substrate 109, and is not affected by the acceleration in the V-axis direction or the W-axis direction, which is the other axis direction, and is accelerated. Only the acceleration in the U-axis direction that coincides with the detection axis direction X can be measured. Further, in the acceleration sensor 103b, the acceleration detection axis direction X coincides with the V axis direction, and the direction in which the acceleration detection sensitivity becomes minimum coincides with the U axis direction and the W axis direction. It is mounted upright on the mounting substrate 110 in a posture inclined by a certain angle, and only the acceleration in the V-axis direction can be measured.
Further, in the acceleration sensor 103c, the acceleration detection axis direction X coincides with the W axis direction, and the direction in which the acceleration detection sensitivity becomes the minimum coincides with the U axis direction and the V axis direction. It is mounted upright on the mounting substrate 110 in a posture inclined by a certain angle, and only the acceleration in the W-axis direction can be measured.

The vibration discriminating unit 102 includes three amplifiers 104.
An A / D conversion circuit 105, a feature amount calculation unit 106,
The determination unit 107 and the output unit 108 are included.
The sensor signals output from the three acceleration sensors 103a, 103b, and 103c are respectively amplified by the amplifier 104, converted into pulse-shaped waveform signals by the A / D conversion circuit 105, and input to the feature amount calculation unit 106. It
The characteristic amount calculation unit 106 analyzes the input waveform signal to obtain the vibration acceleration, the vibration cycle, and the total energy amount that exceeds the detection level within a predetermined time (specifically, calculated from the area of the acceleration waveform). It is possible to determine the total amount of energy within a predetermined time. The determination unit 107 determines whether the vibration applied to the earthquake detection device S is an earthquake from the obtained feature amount, and when it is determined that the vibration is an earthquake, the output unit 108 issues an alarm or the like. Even in this earthquake detector S, each acceleration sensor 1
03a, 103b, 103c are mounted so that the influence of accelerations other than the respective acceleration detection axis directions X aligned with the U-axis, V-axis, and W-axis is minimized, so that the earthquake detection accuracy is high. False alarms can be reduced.

FIG. 35 shows a pedometer T according to the present invention.
FIG. 37 is a schematic perspective view in which a part of FIG. The pedometer T is an acceleration sensor (or acceleration sensor device) 122, a signal processing device 123 that analyzes and processes sensor signals from the acceleration sensor 122, and a display device that displays the analysis and processing results of the signal processing device 123. The pedometer T is mounted on a person's waist or the like, and detects the acceleration generated when a person walks or runs to display the number of steps walked or the distance traveled on the display 124. Can be displayed. The signal processing device 123 includes an amplifier 125 and a filter circuit 126.
And a level comparison circuit 127, a counter 129, and an arithmetic circuit 130. Acceleration sensor 1
A sensor signal indicating the acceleration generated by walking is output from the signal processing device 123 to the signal processing device 123. The output sensor signal is amplified by the amplifier 125, and then only a signal of a predetermined frequency is output by the filter circuit 126. Be passed through. The passed signal is converted into a voltage in the level comparison circuit 127 and then compared with the reference voltage 128, and only the signal higher than the reference voltage 128 is counted by the counter 129, and then the arithmetic circuit 130 determines the count value of the counter 129. It can be displayed on the display device 124 as it is, or can be displayed on the display device 124 after converting the count value into a distance or the like. The pedometer T can prevent the step count from being measured due to vertical vibration, and can accurately measure the step count.

[0075]

According to the present invention, in the acceleration sensor, the acceleration detection axis direction is set so that the output due to the acceleration in the direction orthogonal to the acceleration detection axis direction is set to the minimum, and the acceleration sensor device has an object. Since the acceleration sensor is arranged in a posture that minimizes the acceleration detection sensitivity in the direction orthogonal to the acceleration detection direction, the target is not affected by the acceleration in the direction other than the intended detection direction. It is possible to accurately detect only the acceleration in the detection direction, and it is possible to reduce the measurement error of the acceleration sensor device.

Therefore, in the vehicle and equipment in which the acceleration sensor device of the present invention is mounted, the acceleration and vibration can be accurately measured in each direction, so that a high-performance vehicle and equipment are provided. be able to.

[Brief description of drawings]

FIG. 1A is a perspective view of a conventional acceleration sensor,
(B) is the sectional view.

FIG. 2 is a cross-sectional view of a conventional acceleration sensor device.

FIG. 3 is a cross-sectional view of another conventional acceleration sensor device.

FIG. 4 is a sectional view showing an acceleration sensor according to an embodiment of the present invention.

5A is a perspective view of an acceleration sensor according to another embodiment of the present invention, and FIG. 5B is a sectional view thereof.

FIG. 6 is a sectional view of an acceleration sensor according to another embodiment of the present invention.

7A is a perspective view of an acceleration sensor according to still another embodiment of the present invention, and FIG. 7B is a sectional view thereof.

FIG. 8A is a perspective view showing a state in which the acceleration sensor of the above is mounted on a mounting board, and FIG. 8B is a sectional view thereof.

9A is a perspective view of an acceleration sensor according to still another embodiment of the present invention, and FIG. 9B is a sectional view thereof.

10A is a perspective view of an acceleration sensor according to still another embodiment of the present invention, and FIG. 10B is a sectional view thereof.

11A is a sectional view of an acceleration sensor according to still another embodiment of the present invention, and FIG. 11B is an external perspective view thereof.

FIG. 12 is an acceleration sensor according to still another embodiment of the present invention, (a) is a plan view showing a portion of the silicon wafer, and (b) is an external perspective view of the acceleration sensor.

FIG. 13 is a sectional view showing an acceleration sensor according to still another embodiment of the present invention.

FIG. 14 is a sectional view showing an acceleration sensor according to still another embodiment of the present invention.

FIG. 15 is a perspective view of an acceleration sensor device according to another embodiment of the present invention.

FIG. 16 is a perspective view of an acceleration sensor device according to another embodiment of the present invention.

FIG. 17 is a sectional view showing an acceleration sensor device according to still another embodiment of the present invention.

FIG. 18 is a sectional view of an acceleration sensor device according to another embodiment of the present invention.

FIG. 19 is a cross-sectional view showing an acceleration sensor filled in a metal package used in the above acceleration sensor device.

FIG. 20 is a cross-sectional view showing an acceleration sensor filled in a plastic case used in the above acceleration sensor device.

FIG. 21 is a sectional view of an acceleration sensor device according to another embodiment of the present invention.

FIG. 22 is a sectional view of an acceleration sensor device according to another embodiment of the present invention.

FIG. 23 is a schematic configuration diagram of a vehicle according to the present invention.

FIG. 24 is a partially cutaway plan view of the acceleration sensor device mounted on the above vehicle.

FIG. 25 is a schematic configuration diagram of another vehicle according to the present invention.

FIG. 26 is a sectional view of an acceleration sensor device mounted on the above vehicle.

FIG. 27 is a cross-sectional view of another acceleration sensor device mounted on the above vehicle.

FIG. 28 is a cross-sectional view of still another acceleration sensor device mounted on the above vehicle.

FIG. 29 is a partially cutaway plan view of the acceleration sensor device mounted on the above vehicle.

FIG. 30 is a block diagram showing a configuration of a current position display system according to the present invention.

FIG. 31 is a block diagram showing a configuration of a vibration detection device according to the present invention.

FIG. 32 is a perspective view showing a part of the vibration detection device of the above.

FIG. 33 is a block diagram showing a configuration of an earthquake detection device according to the present invention.

FIG. 34 is a schematic perspective view showing a vibration detection unit of the above-mentioned earthquake detection device.

FIG. 35 is a partially cutaway schematic perspective view showing a pedometer according to the present invention.

FIG. 36 is a block diagram showing a configuration of the pedometer of the above.

[Explanation of symbols]

1 Conventional acceleration sensor 10, 11, 12, 13, 14, 15 Acceleration sensor of the present invention 3 Beam 4 Mass part 6 Cover 22 Impact absorbing support member 23 Case body 25 Resin case 27 Mounting member 31 Inclined surface 32 Step 33 Leg Part 36 Mounting adjustment part 38 Lead frame 46 Attachment part for vehicles 56 Electronic control unit 61 Actuator G Mass center of mass part M Mass center of gravity swing center X Acceleration detection axis direction L Mass center of gravity and its swing center Plane containing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masatoshi Oba 10 Okaron Dodocho, Hanazono, Ukyo-ku, Kyoto Prefecture Kyoto Omron Corporation

Claims (24)

[Claims] 1. An acceleration sensor in which a mass portion is swingably supported by a support member by an elastically deformable portion, and a center of gravity of the mass portion does not lie in a plane passing through a swing center of the center of gravity and parallel to the elastically deformable portion. An acceleration sensor in which the acceleration detection axis direction is set so that the output due to the acceleration in the direction orthogonal to the acceleration detection axis direction is minimized. 2. An acceleration sensor in which an elastically deformable portion and a mass portion are formed by an electrochemical etching method, and the mass portion is swingably supported by a supporting member by the elastically deformable portion, the acceleration sensor being orthogonal to the acceleration detection axis direction. An acceleration sensor in which the acceleration detection axis direction is set so that the output due to the acceleration in the direction is minimized. 3. A support member, an elastically deformable portion, and a mass portion are formed by processing the substrate, and the elastically deformable portion swingably supports the mass portion on the support member. An acceleration sensor in which the direction connecting the center of swing is not parallel to the main surface of the substrate, and the acceleration detection axis direction is set so that the output due to the acceleration in the direction orthogonal to the acceleration detection axis direction is minimized. Acceleration sensor. 4. A support member, an elastically deformable portion, and a mass portion are formed by processing a substrate, and the elastically deformable portion swingably supports the mass portion on the support member. An acceleration sensor which is not parallel to the main surface of the substrate and whose acceleration detection axis direction is set so as to minimize the output due to acceleration in the direction orthogonal to the acceleration detection axis direction. 5. The acceleration sensor according to claim 1, wherein the direction in which the output due to the acceleration is minimized is in a plane parallel to the plane for mounting. 6. The acceleration according to claim 1, 2, 3 or 4, wherein the direction in which the output due to the acceleration is minimized is a direction perpendicular to a surface for mounting. Sensor. 7. An acceleration sensor device comprising the acceleration sensor according to claim 1, 2, 3, 4, 5 or 6, wherein a posture for minimizing acceleration detection sensitivity in a direction orthogonal to a target acceleration detection direction. The acceleration sensor device is characterized in that the acceleration sensor is provided. 8. The acceleration sensor device according to claim 7, wherein the acceleration sensor is mounted on the mounting member such as a mounting board or a package with a predetermined inclination angle. 9. The acceleration sensor device according to claim 7, wherein the acceleration sensor is housed in the case with a predetermined inclination angle with respect to the case. 10. The acceleration sensor device according to claim 7, wherein the acceleration sensor is housed in a case installed with a predetermined inclination angle. 11. A method of mounting the acceleration sensor on a mounting member such as a mounting board or a package with an inclination angle, a method of mounting the acceleration sensor in a case with an inclination angle, and an installation with an inclination angle. The acceleration sensor device according to claim 7, wherein the acceleration sensor is arranged in a predetermined posture by combining at least two methods out of the methods to be stored in the case. 12. The fixed electrode is provided so as to face the movable electrode formed on the mass portion of the acceleration sensor, and a change in capacitance between the movable electrode and the fixed electrode is detected as a change in acceleration. The acceleration sensor device according to 8, 9, 10 or 11. 13. The acceleration sensor device according to claim 7, wherein a strain detection element is provided in a beam portion of the acceleration sensor. 14. An acceleration sensor device for a vehicle, comprising:
14. The acceleration sensor device according to claim 7, 8, 9, 10, 11, 12 or 13, wherein the acceleration detection direction is intended to be the vertical direction of the vehicle. 15. The direction in which the acceleration detection sensitivity is the minimum,
The acceleration sensor device according to claim 14, which is oriented in the front-rear direction of the vehicle. 16. An acceleration sensor device for a vehicle, comprising:
The acceleration sensor device according to claim 7, 8, 9, 10, 11, 12 or 13, wherein the acceleration direction is intended to be the front-back direction of the vehicle. 17. The direction in which the acceleration detection sensitivity is the minimum,
The acceleration sensor device according to claim 16, which is oriented in the vertical direction of the vehicle. 18. An acceleration sensor device for a vehicle, comprising:
The acceleration sensor device according to claim 7, 8, 9, 10, 11, 12, or 13, wherein the acceleration detection direction is intended to be the left-right direction of the vehicle. 19. A direction in which the acceleration detection sensitivity is minimum,
The acceleration sensor device according to claim 18, which is oriented in the vertical direction of the vehicle. 20. Claims 14, 15, 16, 17, 18
A vehicle including the acceleration sensor device according to Item 19. 21. A current position display system for displaying the current position on a map, the current position display system comprising the acceleration sensor device according to claim 7, 8, 9, 10, 11, 12 or 13. 22. Claims 7, 8, 9, 10, 11, 12
A vibration detection device including the acceleration sensor device according to item 13. 23. Claims 7, 8, 9, 10, 11, 12
Or an earthquake detection device including the acceleration sensor device according to 13. 24. Claims 7, 8, 9, 10, 11, 12
Or a pedometer provided with the acceleration sensor device according to 13.