JP2005300199A - Tilt angle sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilt angle sensor capable of finely detecting continuous angle value of a vehicle and the like. <P>SOLUTION: The fulcrum of a metal pendulum 13 is supported swingably in a case 11. In the vicinity of the pendulum 13, a magnetic force output coil 21 as a magnetic force output part whose magnetic force is arranged in a direction perpendicular to the swinging direction of the pendulum 13 outputs periodically varying magnetic force. The tilt sensor is constituted so that the magnetic force having varied through the pendulum 13 swinging corresponding to the angle value is output as an electromagnetic induction voltage by a magnetic force detection coil 22 arranged facing the magnetic force output coil 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tilt angle sensor that detects a tilt angle of a vehicle or the like.

  In recent years, with the advancement of advanced functions of vehicles, the tilt angle is detected for controlling the vehicle according to the tilt angle, such as detecting the tilt angle of the vehicle and issuing an alarm when the predetermined tilt angle is reached. Sensors are regarded as important.

  Such a conventional tilt angle sensor will be described with reference to FIGS.

  FIG. 7 is a front view of a conventional tilt angle sensor, and FIG. 8 is a front view of the tilt angle sensor. In FIG. 7, reference numeral 1 denotes a housing, and slopes 5A and 5B are provided on the bottom surface.

  Further, contacts 2A and 2B for constituting a switch are formed on the bottom surface, and contacts 4A and 4B are formed on the side surface.

  Reference numeral 3 denotes a metal spherical movable contact. The movable contact 3 is movably accommodated in the housing 1 to constitute an inclination angle sensor.

  The inclination angle sensor is mounted on the vehicle, and the contacts 2A, 2B, 4A, and 4B are connected to an electronic circuit (not shown) on the vehicle side.

  In the above configuration, when the vehicle is not tilted, the movable contact 3 comes into contact with 2A and the contact 2B, and the electronic circuit on the vehicle side detects that the vehicle is not tilted by the conduction between the contact 2A and the contact 2B.

  For example, when the vehicle tilts to the left and the tilt angle becomes greater than 5A, the movable contact 3 moves to the left as shown in FIG. 8, and the movable contact 3 contacts the contacts 2A and 4A. Then, the electrical circuit on the vehicle side detects that the vehicle is tilted to the left by the conduction between the contact 2A and the contact 4A.

  Conversely, when the vehicle tilts to the right and the tilt angle becomes greater than 5B, the movable contact 3 moves to the right, the movable contact 3 contacts the contact 2B and the contact 4B, and the contact 2B and the contact By the conduction of 4B, the vehicle-side electronic circuit is configured to detect that the vehicle has tilted to the right.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2001-174256 A

  However, in the above conventional tilt angle sensor, since the vehicle tilt angle can only detect an extreme tilt to the left or right of the tilt 5A, 5B or more, for example, gradually to the left or right at an angle less than the tilt 5A, 5B. There has been a problem that it is difficult to detect continuous and detailed tilt angles that change.

  The present invention solves such a conventional problem, and an object of the present invention is to provide an inclination angle sensor capable of detecting continuous and detailed inclination angles.

  In order to achieve the above object, the present invention has the following configuration.

  According to the first aspect of the present invention, a fulcrum portion of a metal pendulum is swingably supported in a housing, and a magnetic force is disposed in the vicinity of the pendulum in a direction perpendicular to the swinging direction of the pendulum. The magnetic force output coil outputs a periodically changing magnetic force, and the magnetic force detection coil arranged opposite to the magnetic force output part generates electromagnetic induction induced by the pendulum that swings according to the inclination angle. The tilt angle sensor is configured to output as a voltage, and the magnitude of the eddy current generated in the pendulum is reduced by the change in the overlapping area of the pendulum and the magnetic force output unit corresponding to the tilt angle of the tilt angle sensor. Since the magnetic force detection coil outputs an electromagnetic induced electromotive voltage value that changes according to the magnetic force that changes according to the magnitude of the eddy current, a tilt angle sensor capable of detecting a continuous detailed tilt angle is obtained. The effect of being able to A.

  The invention according to claim 2 is the tilt angle sensor according to claim 1, wherein the magnetic force output part is constituted by a magnetic force output coil, and the magnetic force output part has a simple structure, and can be easily manufactured. It has the effect | action that can be obtained.

  The invention according to claim 3 is the invention according to claim 1, wherein the pendulum is made of a non-magnetic metal, and a magnet is disposed in the vicinity of the pendulum in a direction in which the magnetic force of the magnet is orthogonal to the pendulum. When the pendulum suddenly swings in the direction perpendicular to the magnetic force of the magnet, the faster this movement of the pendulum, the larger the eddy current is generated in the pendulum by the magnet corresponding to this, and the direction of movement of the pendulum is Since it receives a force in the opposite direction, it has the effect of preventing erroneous detection of the angle due to a sudden movement of the pendulum during vehicle vibration or acceleration.

  The invention according to claim 4 is the invention according to claim 1, wherein a plurality of sets of magnetic force output portions and magnetic force detection coils are arranged symmetrically with respect to the swing center of the pendulum. By arranging a plurality of coils with respect to the swing center of the pendulum, the range of the area where the pendulum and the magnetic force output unit face each other can be taken at a wide angle, so that the range of the tilt angle that can be detected can be widened. .

  According to a fifth aspect of the present invention, in the first aspect of the invention, a plurality of pendulums are provided, the pendulums are fixed at a predetermined interval, and a magnetic force output unit and a magnetic force detection coil are disposed between the pendulums. While the magnetic force output part and the magnetic force detection coil are fixed to the housing, there is a gap between the swinging pendulum and the housing, so there is a force in the direction perpendicular to the swinging direction. When the pendulum is added, the distance between the pendulum and the magnetic force output part or magnetic force detection coil changes, resulting in a change in magnetic force. However, by fixing multiple pendulums at a predetermined interval, one pendulum and the magnetic force output part or magnetic force detection coil Even if the distance between the two is reduced, the distance from the other pendulum is increased, so that the change in magnetic force is canceled out, and stable tilt angle detection can be performed even when a force perpendicular to the swinging direction is applied. Work that can Having.

  The invention according to claim 6 is the invention according to claim 2, wherein a capacitor is connected to the magnetic force detection coil to constitute an LC resonance circuit, and the frequency of the alternating current flowing through the magnetic force output coil is made the same as this LC resonance frequency. Since a small change in magnetic force can be detected as a large voltage, it has the effect that highly sensitive detection can be performed.

  As described above, according to the present invention, it is possible to obtain an advantageous effect that it is possible to obtain an inclination angle sensor capable of detecting continuous and detailed inclination angles.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

(Embodiment)
FIG. 1 is a front view of an inclination angle sensor according to an embodiment of the present invention, FIG. 2 is a side view thereof, in which 11 is a casing, 16 is a bearing fixed to the casing 11, and 15 is A shaft 13 is supported by the bearing 16 so as to be swingable. A pendulum 13 is a substantially fan-shaped pendulum made of non-magnetic metal such as aluminum or copper fixed to the shaft 15 and swings with the center of the shaft 15 as a fulcrum. Supported as possible.

  In the vicinity of the rear of the pendulum 13, a substantially arc-shaped magnetic force detection coil 22 having one end slightly overlapped with both ends of the pendulum 13 and the other end extending upward is made of paper phenol or glass epoxy board made of copper alloy or the like. Is formed in a substantially spiral shape from the substantially arc-shaped outer periphery to the inside by a wiring pattern (not shown) such as a copper alloy so that the magnetic force is orthogonal to the swing direction of the pendulum 13. In addition, two sets are formed symmetrically with respect to the swing center of the pendulum 13.

  Similarly, two sets of magnetic force output coils 21 as magnetic force output portions are formed at positions facing the back surface of the magnetic force detection coil 22 via the wiring board 12.

  Reference numeral 14 denotes a magnet, which is arranged in a direction in which the magnetic force of the magnet 14 is orthogonal to the pendulum 13, similarly to the magnetic output coil 21 and the magnetic detection coil 22.

  Further, as shown in the block circuit diagram of FIG. 3, one of the magnetic force output coils 21 is connected to a ground terminal, and the other terminal is connected to an oscillation circuit 25 formed by an oscillation element or the like via a resistor 24.

  The magnetic force detection coil 22 constitutes a parallel resonance circuit with a capacitor 23 formed of ceramic or the like. An earth terminal is connected to one side of the parallel resonance circuit, and an output terminal 26 that generates an electromagnetic induction voltage on the other side. Are provided to constitute an inclination angle sensor.

  The tilt angle sensor is mounted on the vehicle, and two sets of output terminals 26 on the left and right sides are connected to an electronic circuit (not shown) on the vehicle side.

  In the above configuration, when the oscillation circuit 25 generates a square wave voltage that periodically changes as shown in FIG. 5A, the magnetic force output coil 21 has a square value obtained by dividing the square wave voltage by the resistor 24. Although a wave current flows, because of the electrical characteristics of the coil, a voltage is generated only at the change point of the current, so that a spire-like voltage is generated only at the change point of the current as shown in FIG.

  When the current flowing through the magnetic output coil 21 changes in this way, an alternating magnetic field in which the direction of the magnetic field periodically changes is generated from the magnetic output coil 21, and an electromagnetic induction electromotive voltage is generated in the magnetic detection coil 22 by this alternating magnetic field. Is generated, and a sinusoidal electromagnetic induction electromotive voltage as shown in FIG. 5C is generated.

  At this time, by setting the resonance frequency of the LC resonance circuit including the magnetic force detection coil 22 and the capacitor 23 to be the same as the oscillation frequency of the oscillation circuit 25, the electromagnetic induction voltage can be further increased.

  The electromagnetic induction voltage is generated in proportion to the magnitude of the alternating magnetic field according to the law of electromagnetic induction. The larger the area where the pendulum 13 overlaps the magnetic output coil 21, the more the loss due to the eddy current generated in the pendulum 13 is. Since the magnitude of the alternating magnetic field decreases, the electromagnetic induction voltage generated in the magnetic force detection coil 22 decreases as shown in FIG.

  In the state of FIG. 1 where the vehicle is not tilted, the facing area of the pendulum 13 and the left magnetic output coil 21 and the facing area of the right magnetic output coil 21 are the same, so the left and right magnetic detection coils 22 are the same. The electromagnetic induction electromotive force values output from the vehicle are the same, and these values are decoded by the vehicle-side electronic circuit so that the vehicle-side electronic circuit detects that the vehicle is not tilted.

  Also, as shown in FIG. 4, when the vehicle is tilted to the left, as the tilt increases, the facing area between the pendulum 13 and the left magnetic output coil 21 increases, and the loss of the alternating magnetic field on the left increases. The electromagnetic induction voltage value of the left magnetic detection coil 22 decreases.

  Conversely, when the vehicle leans to the right, the area where the pendulum 13 and the right magnetic output coil 21 face each other increases, and the electromagnetic induction voltage of the right magnetic detection coil 22 decreases.

  Then, the changes in the electromagnetic induction electromotive force values of the left and right magnetic force detection coils 22 and these values are decoded by the vehicle-side electronic circuit, so that the vehicle-side electronic circuit can determine the vehicle tilt direction and the tilt direction. Detects continuous detailed tilt angles that gradually change.

  As described above, according to the present embodiment, the fulcrum portion of the metal pendulum 13 is swingably supported in the housing 11, and the magnetic force is orthogonal to the swing direction of the pendulum 13 in the vicinity of the pendulum 13. The magnetic force output coil 21 as a magnetic force output unit arranged in the direction outputs a magnetic force that periodically changes, and the magnetic force changed through the pendulum 13 that swings in accordance with the tilt angle is opposed to the magnetic force output coil 21. By configuring the tilt angle sensor so that the magnetic force detection coil 22 arranged in this manner outputs an electromagnetic induction electromotive force, the pendulum 13 and the magnetic force output coil 21 face each other according to the tilt angle of the tilt angle sensor. Since the magnetic force detection coil 22 outputs the electromagnetic induction electromotive force value that changes according to the change in the area, it is possible to obtain a tilt angle sensor capable of detecting a continuous detailed tilt angle.

  In addition, by configuring the magnetic force output portion with the magnetic force output coil 21, the magnetic force output portion can have a simple configuration, and an inclination angle sensor that can be easily manufactured can be obtained.

  Then, the pendulum 13 is made of a non-magnetic metal and is placed close to the pendulum 13 so that the magnet 14 is disposed in a direction in which the magnetic force is orthogonal to the pendulum 13, whereby the pendulum 13 is orthogonal to the magnetic force of the magnet 14. When the pendulum 13 is swung rapidly, the faster the movement of the pendulum 13, the larger the eddy current is generated in the pendulum 13 by the magnet 14, and the pendulum 13 receives a force in the direction opposite to the direction of movement. It is possible to prevent erroneous detection of an angle due to sudden movement of the pendulum 13 during acceleration due to vehicle vibration.

  The magnet 14 may not be provided. In this case, the pendulum 13 may be made of a metal having magnetism such as iron.

  Further, by arranging a plurality of sets of the magnetic force output coil 21 and the magnetic force detection coil 22 as the magnetic force output unit with respect to the swing center of the pendulum 13, the range of the area where the pendulum 13 and the magnetic force output coil 21 face each other at a wide angle. Therefore, the range of inclination angles that can be detected can be expanded.

  Then, a capacitor 23 is connected to the magnetic force detection coil 22 to form an LC resonance circuit, and the frequency at which the magnetic force of the magnetic force output coil 21 changes is the same as this LC resonance frequency, so that a small change in magnetic force can be achieved. Since it can be detected as a large voltage, highly sensitive detection can be performed.

  In the above description, a single pendulum 13 is provided, and a magnetic force output coil 21 and a magnetic force detection coil 22 as a magnetic force output unit are disposed in the vicinity of the pendulum 13, but as shown in FIG. A plurality of pendulums 33A and 33B are provided, and these pendulums 33A and 33B are fixed to the casing 31 at a predetermined interval, and a magnetic output coil 21 and a magnetic detection coil as a magnetic output unit are provided between the pendulums 33A and 33B. The present invention can also be implemented as a configuration in which 22 is arranged.

  With this configuration, the magnetic force output coil 21 and the magnetic force detection coil 22 are fixed to the casing 31, whereas there is a gap between the swinging pendulums 33 </ b> A and 33 </ b> B and the casing 31. Therefore, when a force is applied in a direction orthogonal to the swinging direction, the distance between the pendulums 33A and 33B and the magnetic force output coil 21 or the magnetic force detection coil 22 changes to cause a change in magnetic force. Even if the distance between the coil 21 and the magnetic force detection coil 22 is reduced, the distance from the other pendulum 33A is increased, so that the change in magnetic force is canceled out and stable even if a force in the direction orthogonal to the swinging direction is applied. The detected inclination angle can be detected.

  In the above description, the magnetic force output unit is described as being configured by the magnetic output coil 21. However, the magnetic force may be periodically changed by rotating a magnet.

  The pendulums 33A and 33B are made of metal, but the surface of the pendulum made of resin may be plated with metal such as copper or aluminum.

  Further, the magnetic force output coil 21 and the magnetic force detection coil 22 as the two sets of magnetic force output portions are described as being symmetrically arranged with respect to the swing center of the pendulum 13, but the range of the inclination angle that can be detected is reduced to 1 It is good also as a structure which arrange | positions a magnetic output part and magnetic detection coil of a group.

  The magnetic force detection coil 22 is disposed in the vicinity of the back of the pendulum 13 and the magnetic force output coil 21 is disposed at a position facing the back surface of the pendulum 13 with the wiring board 12 interposed therebetween. 21 may be arranged at a position facing the magnetic force detection coil 22 in the vicinity of the front of the pendulum 13, or the positions of the magnetic force detection coil 22 and the magnetic force output coil 21 may be interchanged.

  The tilt angle sensor according to the present invention has an advantageous effect of being able to obtain a tilt angle sensor capable of detecting a continuous detailed tilt angle, and is useful for a tilt angle sensor that detects a tilt angle of a vehicle or the like. is there.

The front view of the inclination-angle sensor by one embodiment of this invention Side view Same block circuit diagram Front view when tilted to the left Same timing waveform diagram Side view of a tilt angle sensor according to another embodiment Front view of conventional tilt angle sensor Front view when tilted

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 31 Case 12 Wiring board 13, 33A, 33B Pendulum 14 Magnet 15 Shaft 16 Bearing 21 Magnetic output coil 22 Magnetic detection coil 23 Capacitor 24 Resistance 25 Oscillation circuit 26 Output terminal

Claims (6)

A housing, a metal pendulum with a fulcrum supported in a swingable manner in the housing, and a magnetic force disposed in the direction perpendicular to the swinging direction of the pendulum in the vicinity of the pendulum in the housing The magnetic force detection coil includes an output unit and a magnetic force detection coil. The magnetic force output unit outputs a magnetic force that periodically changes, and the magnetic force detection coil electromagnetically changes the magnetic force changed through the pendulum that swings according to an inclination angle. Tilt angle sensor that outputs as an induced electromotive voltage. The tilt angle sensor according to claim 1, wherein the magnetic force output portion is a magnetic force output coil. The tilt angle sensor according to claim 1, wherein the pendulum is made of a non-magnetic metal, and a magnet is disposed in the vicinity of the pendulum in a direction in which the magnetic force of the magnet is orthogonal to the pendulum. 2. The tilt angle sensor according to claim 1, wherein a plurality of sets of magnetic force output portions and magnetic force detection coils are arranged symmetrically with respect to the swing center of the pendulum. The inclination angle sensor according to claim 1, wherein a plurality of pendulums are provided, the pendulums are fixed at a predetermined interval, and a magnetic force output unit and a magnetic force detection coil are disposed between the pendulums. 3. The tilt angle sensor according to claim 2, wherein an LC resonance circuit is configured by connecting a capacitor to the magnetic force detection coil, and the frequency of the alternating current flowing through the magnetic force output coil is the same as the LC resonance frequency.

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