JP3673987B2 - Tilt sensor - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a tilt sensor that detects a tilt state of a vehicle.
[0002]
[Prior art]
In general, the tilt sensor is used to take various safety measures such as detecting that the two-wheeled vehicle has fallen or the four-wheeled vehicle has been rolled over and stopping the engine in an emergency.
[0003]
Conventionally, as this kind of tilt sensor, when the balance weight that rotates according to the tilting state of the vehicle rotates more than a predetermined value, the reed switch works to detect the tilting state of the vehicle exceeding the predetermined value. Exists. The balance weight is immersed in oil having a relatively high viscosity so as to have an oil damper function so as not to be erroneously detected due to momentary rotation caused by vibration during vehicle travel.
[0004]
[Problems to be solved by the invention]
The problem to be solved is that in the conventional tilt sensor, the case has to be sealed with oil, which increases the number of parts and man-hours, and takes time to manufacture. In addition, since the oil damper function is provided, the response time for detecting the tilted state changes depending on the oil viscosity due to the use environment temperature.
[0005]
Also, when the vehicle tilts more than a predetermined level, it is difficult to adjust the reed switch to turn on according to the rotation state of the balance weight at that time, and detection according to the tilt angle for each product There is a tendency for the accuracy to vary.
[0006]
[Means for Solving the Problems]
The tilt sensor according to the present invention does not have any damper function, so that the tilt state of the vehicle can be detected with good responsiveness without complicated adjustments. And a notch portion is formed in the upper portion with a predetermined opening angle so as to be symmetric with respect to a perpendicular passing through the center of the circle, and the rotation state of the magnetized movement at a predetermined angle or more is predetermined. A switch when the movement is rotated more than a predetermined angle so that the Hall element provided at the position on the perpendicular above the movement faces the S pole of the movement so that it can be detected with high sensitivity and accuracy. by on-and such Rukoto, in terms of its predetermined angle further rotation is to be detected, the cut portion with a small opening angle to both end portions N pole is respectively formed of So that magnetizing the movement with that pattern.
[0007]
In particular, in the present invention, for example, even when the motorcycle is tilted and then comes up to a normal state, safety measures such as fuel cut and engine ignition system power cut-off are continuously performed. Therefore, the detection signal of the tilted state is output in the detection circuit that outputs the detection signal of the tilted state when the Hall element detects the rotation state of the movement more than a predetermined angle and is switched on. A holding circuit for holding the output is provided.
[0008]
【Example】
In the tilt sensor according to the present invention, as shown in FIGS. 1 and 2, a magnetized pendulum type movement 2 is pivotally supported within a case 1 so as to be rotatable on a rotation shaft 3. ing.
[0009]
The case 1 has a waterproof structure by fitting the upper portion of the lower case 11 to which the movement 2 is attached to the upper case 12 via the sealing O-ring 4 and hooking the fitting portions at a plurality of locations. It is formed to become. In the figure, reference numeral 14 denotes a hook engaging portion.
[0010]
A detection circuit is mounted in the upper case 12 so that the Hall IC 5 detects a rotation state of the movement 2 at a predetermined angle or more and outputs a detection signal when the movement IC is switched on. A circuit board 6 is attached. In the figure, reference numeral 7 denotes a mounting screw.
[0011]
Further, as shown in FIG. 3, the upper case 12 is integrally formed with a socket portion 8 from which the terminals of the power supply Vcc, the ground GND, and the detection output OUT from the circuit board 6 are drawn out.
[0012]
Further, the upper case 12 is provided with a mounting seat 10 for attaching it to the vehicle body side through a rubber bush 9 for absorbing vibration.
[0013]
As shown in FIGS. 4 and 5, the movement 2 is provided with a horizontal rotation shaft 3 at the center of the circle. The upper portion of the movement 2 is provided with a notch 21 having a predetermined opening angle α (for example, 70 °) so as to be symmetric with respect to a rotation reference position O that is a perpendicular line passing through the center of the circle . A weight portion 22 for balancing the reference position O in the vertical direction is provided at the lower portion thereof.
[0014]
The Hall IC 5 attached to the circuit board 6 is arranged on the reference position O of the movement 2 and is switched on when the movement 2 rotates and the S poles face each other. .
[0015]
Therefore, since the notch 21 is provided at the upper part of the movement 2 and the weight part 22 is provided at the lower part, the weight distribution is sufficiently heavy below the rotating shaft 3, A large moment is required to rotate the movement 2, and the movement 2 is difficult to rotate due to vibration during vehicle travel.
[0016]
The upper portion of the movement 2 is provided with a notch 21 with a relatively large opening angle α so that the reference position O of rotation is at the center. The Hall IC 5 does not respond even if it swings within the range of the opening angle α. Therefore, the Hall IC 5 is switched on only when the vehicle is tilted more than a predetermined angle without being erroneously detected by vibration during vehicle travel.
[0017]
Further, as shown in FIGS. 4 and 6, the movement 2 is magnetized so as to have a different polarity and multiple poles with the illustrated polarity so as to be symmetric with respect to the reference position O. That is, the N pole part has a minute opening angle β (for example, 8 °) at both ends on the notch 21 side, and the minute opening angle γ centered on the reference position O at the lower part.
N pole portions are respectively formed (for example, 10 °), and S pole portions are formed between the N poles with a predetermined opening angle δ (for example, 132 °).
[0018]
Thus, by adopting such a different pitch multipolar structure, the change of the magnetic flux at the boundary between the N pole part and the S pole part can be made steep, and the movement 2 rotates more than a predetermined angle. Positioning when the switch is turned on when the S pole part faces the Hall IC 5 can be set with high accuracy.
[0019]
FIG. 7 shows an example of a detection circuit for detecting the tilted state of the vehicle according to the switching state of the Hall IC 5.
[0020]
Here, the Hall IC 5 is configured to output a high-level detection signal when a movement state of the movement 2 of a predetermined angle or more is detected and the switch 2 is turned on. Is provided with a time constant circuit comprising capacitors C1 and C2 and a resistor R4 so as not to respond to instantaneous switch-on of the Hall IC 5 within a time determined by the time constant.
[0021]
That is, at the normal time when the Hall IC 5 is switched off, the capacitors C1 and C2 are charged, the output transistor Q4 is turned on, and the voltage at the output terminal OUT is at a low level. When the vehicle tilts and the Hall IC 5 is switched on, a discharge circuit for the capacitors C1 and C2 is formed. After a predetermined time, the output transistor Q4 is turned off and the voltage at the output terminal OUT is switched to a high level. Change.
[0022]
Therefore, when the movement 2 is instantaneously rotated more than a predetermined angle by the traveling vibration of the vehicle, the tilted state is not erroneously detected.
[0023]
At this time, if the movement 2 is pivoted so much that the S pole portion faces the Hall IC 5 over a time set by the time constants of the capacitors C1, C2 and the resistor R4, the tilted state is erroneously detected. Therefore, as shown in FIG. 4 and FIG. 6, the magnetic pole is divided by providing an N pole portion (which may be a non-magnetized portion) in the middle, so that the S pole portion can be maintained over a set time. It does not face the Hall IC 5.
[0024]
In addition, the detection circuit is provided with a constant current circuit that supplies a constant current to the collector of the control transistor Q2, and the voltage of the battery power supply (Vcc) changes depending on the rated specification change, the charging state, the temperature environment, and the like. Even so, the timing of detecting the tilted state does not fluctuate.
[0025]
Here, as a constant current circuit, a Zener diode ZD is provided to make the battery power supply (Vcc) power supply constant so that the collector current is always supplied through the resistor R7 when the control transistor Q2 is turned on. Yes.
[0026]
That is, when the constant current circuit by the Zener diode ZD and the resistor R7 is not provided, if the voltage of the battery power supply (Vcc) varies, the control transistor Q2 collector current changes accordingly and the switching timing changes. Therefore, the tilt detection timing determined by the condensers C1 and C2 and the resistor R4 varies.
[0027]
In such a detection circuit, in the present invention, in particular, a tilt state detection holding circuit 13 including resistors R5 and R6, a capacitor C3 and a transistor Q1 is provided in the detection circuit.
[0028]
In the tilt state detection holding circuit 13, when the tilt state of the vehicle is detected and the output transistor Q4 is turned off and the voltage at the output terminal OUT becomes high level, the transistor Q1 is turned on, whereby the output transistor Q4. Is kept off.
[0029]
The holding state is released by turning off the ignition switch of the vehicle and cutting off the battery power supply (Vcc).
[0030]
Therefore, for example, even if the motorcycle is tilted and then comes up to a normal state, safety measures such as fuel cut will continue until the vehicle's ignition switch is turned off. It will be.
[0031]
【The invention's effect】
As described above, according to the present invention, a notch is formed in the upper portion with a predetermined opening angle so as to be symmetric with respect to a perpendicular passing through the center of the circle and having a rotation axis at the center of the circle, and movement is rotated beyond a predetermined angle that is, the Hall element provided at a position on the vertical line of the upper movement is by switching on and such Rukoto when facing the S pole of the movement, of the predetermined Since the rotation more than the angle is detected, the movement is magnetized with a pattern in which N poles are formed at both end portions on the notch portion side with a minute opening angle. The change in the magnetic flux density at both end portions becomes steep, so that the state in which the vehicle is tilted more than a predetermined angle can be detected with a predetermined sensitivity with high accuracy. A holding circuit for holding the output of the tilt detection signal is provided in the detection circuit that outputs a tilt detection signal when the Hall element detects a rotation state of a predetermined angle or more of the movement. For example, even if the motorcycle gets up to its normal state after being tilted, safety measures such as fuel cut will be taken until the self-holding state is reset by the driver's intention. Has the advantage of being able to continue.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a tilt sensor according to the present invention.
FIG. 2 is a side sectional view of a tilt sensor in the same embodiment.
FIG. 3 is a bottom view of the socket terminal portion of the tilt sensor in the same embodiment.
FIG. 4 is a front view showing the movement of the tilt sensor in the same embodiment.
FIG. 5 is a side view of the movement.
FIG. 6 is a development view showing a magnetization pattern in the movement.
FIG. 7 is an electric circuit diagram showing a detection circuit for detecting the tilted state of the vehicle.
[Explanation of symbols]
1 Case 11 Lower Case 12 Upper Case 2 Movement 3 Axis 4 O-ring 5 Hall IC
6 Circuit board 13 Holding circuit

Claims (1)

A notch is formed in the upper part with a predetermined opening angle so that it has a rotation axis at the center of the circle and is symmetric with respect to a perpendicular passing through the center of the circle, and the magnetized movement can be rotated with the case and axially supported, the movement is rotated to a predetermined angle or more, the switch-on and a Rukoto when the Hall element provided at a position on the vertical line of the upper movement is opposed to the S pole of the movement The tilt sensor is configured to detect the rotation more than the predetermined angle, and magnetizes the movement with a pattern in which N poles are respectively formed with a small opening angle at both end portions on the notch portion side. In the detection circuit that outputs the detection signal of the tilted state when the Hall element detects the rotation state of the movement more than a predetermined angle, the detection signal of the tilted state is output. Tilting sensor, characterized in that a holding circuit for lifting.

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