JPS61211150A - Theft alarm device for car - Google Patents

Abstract

PURPOSE:To accurately prevent the theft of a tire and the like even at parking on a slope by setting the tilt angle of a car body at the operation start as an initial value and actuating an alarming means when the car body is tilted from this initial value exceeding a preset angle. CONSTITUTION:A fan-shaped sensing plate 11 is swingably supported on a rotary axis 13 whose fan-shaped central part is fixed to a car body and the swing angle of this sensing plate 11 following the tilting of the car body is sensed by a photointerruptor 14 provided corresponding to a number of slits 12 that are formed along the arched circumferential section of the sensing plate 11. After the output signals of this photointerruptor 14 are shaped into rectangular waves by a waveform shaping circuit 23, the leading and trailing edges of the signals are sensed by an edge sensing circuit 24. Then, while pulses are being output from the first time limiting circuit 41 according to the output of the edge sensing circuit 24, alarm signals are output to an alarm circuit 60 from a counter circuit 43 when a preset number of edge sensing pulses are input.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a vehicle theft alarm device, and more particularly to a device that issues an alarm when a tire of a vehicle is about to be stolen.

[Background Art] Conventional vehicle theft alarm devices have been known to detect the tilting of the vehicle body that occurs when a part of the vehicle body is lifted up, such as by lifting a part of the vehicle body in an attempt to steal a tire, and to issue an alarm. In detecting the inclination of
There are some that use a mercury switch, such as the one disclosed in Japanese Patent No. 64504. However, in this conventional example, the horizontal position or the tilt is detected, so even on a slope! v. When driving a car, a warning may be issued just by activating the device, and there is a problem that it cannot be used on slopes.

[Objective of the Invention 1 The present invention has been made in view of the above-mentioned points, and its main purpose is to provide a theft alarm device for a vehicle that can be used even when the vehicle is parked on a slope. be.

[Disclosure of the Invention] The present invention includes a tilt angle detection means for detecting the tilt angle of the vehicle body, an initial tilt angle setting means for setting the tilt angle of the vehicle body at the start of operation as an initial value, and a tilt angle setting means for setting the tilt angle of the vehicle body at the start of operation as an initial value. By comprising a determination means that outputs a warning signal when the vehicle is tilted at a predetermined angle or more, and an alarm means that issues an alarm when the warning signal is input, the vehicle can be parked regardless of whether the vehicle is parked on a flat or sloped site. Disclosed is a theft alarm device for a vehicle that is configured to issue an alarm when a tire is tilted by a predetermined angle or more from a tilted state to prevent theft of a tire.

(Embodiment 1) In Embodiment 1, a rotary encoder is disclosed as the inclination angle detection means. Generally, optical and magnetic rotary encoders are available. In the optical type, a disk-shaped detection plate with many slits locally formed at equal intervals as detection segments is rotatably arranged, and a light-emitting element and a light-receiving element are arranged facing each other. The rotation angle of the detection plate can be detected by inserting a local part of the detection plate in between and counting the number of slits that pass between the light emitting element and the light receiving element as the detection plate rotates. There is. In addition, in the magnetic type, a disk-shaped detection plate with a large number of SM and N poles alternately magnetized around the periphery is rotatably arranged as a detection segment, and a hole is placed close to the periphery of the detection plate. The detection plate is equipped with a magnetoelectric transducer such as an element, and counts the number of times a small magnetic field formed between adjacent south and north poles crosses the magnetoelectric transducer as the detection plate rotates. The rotation angle can be detected. By the way, if you try to steal a vehicle's tires or tires, the vehicle body will tilt at least 2 degrees or more. Therefore, if you try to use a rotary encoder as a tilt angle detection means, the minimum detection angle of the rotary encoder will be 2 degrees or less. is required. If we use a rotary encoder with a minimum detection angle of 2 degrees, 1 rotation will result in 1 rotation.
A resolution of 80 pulses is required, and in order to obtain this resolution with a small rotary encoder, high dimensional accuracy is required for the shape of the slits and magnetized parts formed on the detection plate, so rotary encoders are used. The problem is that it is very expensive. On the other hand, for the purpose of preventing vehicle tire theft, even when parking on a slope, it is sufficient to be able to detect the angle of inclination within a range of approximately ±20 degrees, and in that case, it is not necessary to use a circular detection plate. In both cases, a fan-shaped detection plate with a central angle of about 40 degrees can sufficiently detect the inclination angle of the vehicle. In this way, in the case of a fan shape with a central angle of about 40 degrees, compared to the case where detection segments are provided around the entire circumference of a circle, the effort of dimension management is reduced, and the detection plate can be produced at a relatively low cost.

As shown in FIG. 2, the detection plate 11 is formed into a fan shape, and the rotation shaft 1 is fixed to the vehicle body at the center of the fan shape.
If the detection plate 11 is made swingable by being pivotally supported on the vehicle body, the straight line connecting the center of gravity of the detection plate 11 will be tilted with respect to the vehicle body as the vehicle body tilts. This allows the angle of inclination to be detected. Here, in order to facilitate rotation of the detection plate 11, the rotating shaft 13 may be supported by a bearing 15, as shown in FIG.

A large number of slits 12 are formed at equal intervals on the detection plate 11 as detection segments along the arc-shaped local part, and the detection plate 11
The inclination angle of is detected by a photointerrupter 14 disposed at a position corresponding to the slit 12. As shown in FIG. 1, the photointerrupter 14 is composed of a light emitting element 21 such as a light emitting diode and a light receiving element 22 such as a 7-channel transistor facing each other. By interposing the peripheral part of the detection plate 11 in the slit 12, when the slit 12 is located at the opening between the light emitting element 21 and the light receiving element 22, the light from the light emitting element 21 is received by the light receiving element 22, and the light from the adjacent light emitting element 21 is received by the light receiving element 22. When the pair of slits 12 are located, light is blocked. Therefore, as the detection plate 11 rotates, a pulse-like signal is output from the light receiving cable 22. By counting these pulsed signals, the tilt of the vehicle body can be detected. In this way, when the detection plate 11 is tilted, the
Since the inclination angle of the vehicle body is detected by detecting the number of slits 12 passing through the automatic interrupter 14, the interval between a pair of adjacent slits 12 should be set so that the center angle thereof is 2 degrees or less. Of course. Here, since the detection plate 11 is fan-shaped with a central angle of approximately 40 degrees, if the size of the device is the same as a rotary encoder using a circular detection plate 11, the length corresponding to the diameter of the circle is It can be made into a fan-shaped radius, and as a result, the length of the portion forming the slit 12 can be doubled, making it easier to form the slit 12. Although this embodiment shows an optical encoder in which a slit 12 is provided in the detection plate 11, as shown in Figure NIJ6, S and N poles are arranged alternately on the arc-shaped circumference of the detection plate 11. Even if the number of passages of a small magnetic field formed between the adjacent S and N poles is detected by the Hall element 16 instead of the 7-oto-interrupter 14, the same effect as in the case of the optical method can be obtained. It's a big deal to handle.

Now, if the vehicle body is tilted due to a jerk or the like, the above-mentioned detection plate 11 will be tilted and the output of the light receiving element 22 will alternately repeat L level and H level. However, when the road vibrates or the unit is shaken, A similar signal will be output.

However, when the car body is tilted due to jacking, etc., the output of the light receiving element 22 changes over a longer period of time (the rate of change is smaller) than when the car body is vibrating, so if this difference can be determined, it can be determined that the car body is vibrating. You can tell by the fact that it is tilted due to jacking or something like that.

FIG. 1 is a block diagram of a circuit that processes the output signal of the light-receiving probe 22, and the specific circuit is shown in FIG.
FIG. 5 shows the signals of each part in FIG. 4. The output signal of the light receiving element 22 is a signal as shown in FIG. 5(a), and is shaped by the waveform shaping circuit 23 to become a rectangular wave as shown in FIG. 5(b). The waveform shaping circuit 23 is a circuit that converts the analog signal output from the light receiving element 22 into a digital signal corresponding to its output level.

The output of the waveform shaping circuit 23 is input to an edge detection circuit 24. The edge detection circuit 24 detects the rise and fall of the output signal of the waveform shaping circuit 23, and outputs edge detection pulses as shown in FIG. 5(c) in response to these. It has become. The rise of the signal is detected by the rise detection circuit 24&, and the rise detection circuit 24a is connected to the inverter 2.
The rising edge of the input signal is detected by obtaining the logical product of the signal passed through the delay circuit 5a and the delay circuit 26a and the original signal by the AND circuit 27a. Further, the falling edge of the signal is detected by the falling edge detection circuit 24b, and in the falling edge detection circuit 24b, the logical product of the signal passed through the delay circuit 26b and the signal passed through the inverter 25b is obtained by an AND circuit 27b. Therefore, during the pulse of the 6-edge detection pulse that detects the falling edge of the input signal, the outputs of the 0-edge detection circuits 24a and 24b determined by the time constants of the delay circuits 26g and 26b are passed through the OR circuit 28, and It is output as the output of the m-arithm or edge detection circuit 24. The output of the edge detection circuit 24 is input to the determination means.

The determination means is composed of a pair of time limit circuits 41, 42 and a counter circuit 43, and each time limit circuit 41, 42 is set to a different time constant.

The counter circuit 43 outputs an alarm signal for driving an alarm circuit when a predetermined number of edge detection pulses are input. That is, when the vehicle body is tilted by a predetermined angle or more, a plurality of two-foot detection pulses are sent out, and an alarm signal is output depending on the number of the two-foot detection pulses. The number set by the counter circuit 43 is set to a different value depending on the interval between the slits 12 formed in the detection plate 11. The first time limit circuit 41 is operated for a time sufficiently longer than the time required to tilt the vehicle body with the glossy pulse Ta, that is, a time sufficiently longer than the time required to detect a predetermined number of edge detection pulses set by the counter circuit 43. It is set to output a pulse having a width Ta, and the counter circuit 43 is reset F when the output pulse falls. The second time limit circuit 42 generates the next edge detection pulse during a time Tb that is shorter than the time from when one edge detection pulse falls until the next two edge detection pulses are output when the vehicle body is tilted by jacking. When inputted, the counter circuit 43 is reset. Therefore, if a predetermined number of edge detection pulses set in the counter circuit 43 are input while one edge detection pulse is input and a pulse is output from the first time limit circuit 41, the counter circuit 43 outputs an alarm signal. On the other hand, the time Ta set in the time limit circuit 41 of pIIJl after one edge detection pulse is input
When a predetermined number of edge detection pulses are not input within the specified number of days, or when the next edge detection pulse is input within the time Tb set in the second eye time 11842 after one nick detection pulse is input, The counter circuit 43 is determined to be noise and not an edge detection pulse, and the counter circuit 43 is reset so as not to output an alarm signal.

In the circuit shown in FIG. 4, the set number of counter circuits 43 is 3.
It is said that The first time limit circuit 41 is triggered at the rising edge of the edge detection pulse, and the retrieval is a one-shot at the rising edge of the output signal of the monostable multipipe rake (hereinafter abbreviated as monostable multi) 51 and monostable multipipe rake 51. It consists of a one-shot generation circuit 52 that generates pulses, and is shown in FIGS. 5(c), (d), and (e).
As shown in FIG. 2, when the edge detection pulse rises, the negative logic output terminal Q of the monostable multi 51 becomes L for a predetermined time Ta'.
level. At this time, the time-opening Ta' is set to the time-opening value obtained by dividing the time-opening Tn to be set in the first time limit circuit 41 by the value obtained by subtracting 1 from the number set in the counter circuit 43.

That is, it is set to be longer than the time from when one edge detection pulse is output until the next edge detection pulse is output when the unit is tilted by a jack. When the next edge detection pulse is input within this time Ta', the trigger is applied again and the pulse is further extended by the time Ta'. At this time, the next edge detection pulse is input within Ta'. If not, one-shot generation circuit 5
One-shot pulses are output from 2 onwards.

The second time limit circuit 42 includes a monostable multi 53 which is triggered at the rising edge of the edge detection pulse, and an edge detection pulse is output a predetermined time after the positive logic output jIQ of the monostable multi 53 becomes H level. and a delay circuit 54 whose output is set to H level, and the monostable multi 53 outputs one edge detection pulse and then outputs the next edge detection pulse when tilting the car body using a jack. The normal time required for this, that is, the above time Tb
The time constant is set to output a pulse of . Further, the time constant of the delay circuit 54 is set to be slightly larger than that during the edge detection pulse. Therefore, the fifth
As shown in the diagrams (cHf) and (gHh), the time period from when one edge detection pulse is input until the next edge detection pulse is input is the time T set in the monostable multi 53.
When it is shorter than b, the delay circuit 54 outputs a pulse.

The counter circuit 43 includes a delay circuit 55 that delays edge detection pulses, a shift register 56 that outputs an alarm signal when a predetermined number of edge detection pulses are input, and a three-way OR circuit connected to a reset terminal of the shift register 56. It consists of 57. Therefore, the two-edge detection pulse is input to the shift register 56 after being delayed by the time set by the capacitor C and the resistor R of the delay circuit 55, and when three edge detection pulses are input, the shift register 56
The third output terminal Q becomes H level and an alarm signal is output. Each input terminal of the off circuit 57 has a first
The output end of the side timer circuit 41, the second timer circuit 42, and the ignition switch SW are connected, and the side timer circuit 4
The shift register 56 is reset when either one of the outputs of 1.42 becomes H level or when the ignition switch SW is opened.

E in the figure is a car battery. Therefore, the time from when one edge detection pulse is input to the shift register 56 until the next edge detection pulse is manually input is longer than the time-open Ta' set in the first time limit circuit 41, or If the time is less than the time Tb set in the second time limit circuit 42, the third output terminal Q of the shift register 56 does not go to the H level, and these edge detection pulses are determined to be noise, and an alarm signal is generated. It is not output.

As described above, the counter circuit 43 is reset when the ignition switch SW is turned off, and the number of edge detection pulses is counted based on that point. It is possible to issue an alarm when the state is tilted by a predetermined angle from a reference value, and has the advantage that it can be used regardless of whether the ground is flat or the slope is a value.

(Embodiment 2) In Embodiment 2, as shown in FIG. , mercury switch 31
has three contacts 32,33. The mercury switch 31 is configured so that when the mercury switch 31 is in a horizontal state, the mercury 34 contacts only the center contact 32, and when the detection 1! There is.

The contacts 33 at both ends are connected outside the mercury switch 31. A solenoid 37 having a plant spring 36 biased toward the back surface of the detection plate 11 by a spring 35 is disposed on the back surface of the detection plate 11. When the coil 38 is not energized, the solenoid 37 shown in FIG. ), the tip of the planter 35 presses the detection plate 11 due to the pressing force of the spring 35, and the detection plate 1
1 is fixed to the solenoid 37.

Thus, the lead wire p from the center contact 32 of the mercury switch 31 and the lead wires q from the contacts 33 at both ends are connected to determination means as shown in FIG. 9. The determination means includes a resistor R1 whose one end is connected to the off gA contact of the ignition switch SW, a capacitor C5 whose one end is grounded, and a resistor R2 inserted between the other end of the resistor R1 and the other end of the capacitor C5. consists of resistor R2 and capacitor C8
The connection α is connected to the input end of the alarm circuit 60, and the connection point of both resistors R, , R2 is grounded via the mercury switch 31. Therefore, the ignition switch SW
When the contact 32.33i1i of the mercury switch 31 is open, the input terminal of the alarm circuit 60 becomes H level, and the contact 32.33 of the mercury switch 31 is closed. Then, the input terminal of the alarm circuit 60 becomes L level. The alarm circuit 60 is set to issue an alarm when the input terminal becomes L level, and an alarm is issued when the detection plate 11 is tilted 2 degrees.

The on-side contact of the ignition switch SW is connected to the coil 38 of the coil 37 through the switching transistor Q.
When the ignition switch SW is closed to the on side, the coil 38 of the plunger 37 is energized, and the tip of the plunger 35 is separated from the detection plate 11 as shown in FIG. The detection plate 11 is in a state where it can swing around the rotating shaft 136. That is, when the vehicle is running, the detection plate 11 is able to swing freely, and the mercury switch/chip 31 is kept in a substantially horizontal state due to the action of gravity. When the ignition switch SW is turned off when parking, the detection plate 11 is fixed in position by the plunger 35, and when the vehicle body is tilted at a predetermined angle with a shovel or the like, the mercury 34 moves and the mercury switch 3 is closed. The W report is then broadcast. This configuration has the advantage of low power consumption because the solenoid 37 is not energized when the alarm circuit 60 is activated.

(Embodiment 3) In Embodiment 3, the inclination angle detection means includes a pISl pendulum 61 and a second pendulum 62 which are swingably attached to the rotating shaft 13 via a bearing 15, and a second pendulum 62.
It consists of a fan-shaped stopper 65 provided at the upper i part and a plunger 37 that can be brought into contact with and removed from it, and a spherical contact 63, 64 is provided at the lower end of each pendulum 61, 62, respectively. It is being Each pendulum 61.62
are each entirely composed of a conductor, and the bearing 15
Drawer in parts #! Gl and Q are connected. Rotating shaft 13
is an insulator, and both pendulums 61 and 62 are spherical contacts 63.
．． Conductivity is possible only through 64. As in the second embodiment, the solenoid 37 has a plunger 36 urged toward a stopper 65 by a spring 35, and a filter 38.
The lead wires p and q drawn out from the pendulums 61 and 62, which are designed to cause the tip of the plunger 36 to move away from the stopper 65 when energized, are connected to a circuit having a v4 hole similar to that in Example 2. . However, the alarm circuit 60 is configured to issue an alarm when the input terminal reaches the I4 level.

As in the second embodiment, when the ignition switch SW is in the on state, the coil 38 of the solenoid 37 is energized, so both pendulums 61 and 62 can swing freely, and the spherical contacts The contact state of 63.64 is maintained. On the other hand, when the ignition switch SW is turned off when parking, the plunger 3
6 presses the stopper 65, and the second pendulum 62 is fixed at a fixed position. If the car body tilts here,
Since the first pendulum 61 rotates around the rotating shaft 13, the spherical contacts 63 and 64 are separated, and the two pendulums 61 and 62 are opened. Therefore, the input terminal of the seed circuit 60 becomes H level, and an alarm is issued.

(Embodiment 4) Embodiment 4 has the same configuration as Embodiment 3, but shows a device with further improved operation. That is, in Embodiment 3, both pendulums 61 and 62 are designed to swing freely, so both pendulums 61 and 62 vibrate violently while the vehicle is running, and when the vehicle is parked and the ignition switch is When the SW is turned off, the pendulum 62 of IpJ2 may not necessarily be oriented in the vertical direction. Further, even though the vehicle body is not tilted by a 7-way angle, the first pendulum 61 may separate from the second pendulum 62 due to vibration from the outside, causing a false alarm.

In order to improve these points, in the fourth embodiment, a braking means is connected to the upper end of each pendulum 61, 62. As shown in FIG. 13, the braking means includes a speed increasing gear train 67 that meshes with a partial gear 66 provided at the upper end of each pendulum 61, 62 to increase its rotation speed, and a last stage of the speed increasing wheel train 67. When the pendulums 61 and 62 swing, the impeller 68 rotates and the pendulum 61 and 68 rotate due to air resistance.
．． It is designed to brake the movement of 62. In other words, the apparent inertia of the pendulum 61.62 is increased, and when the vibration period of the car body is short, the pendulum 61.62
The pendulums 61 and 62 do not vibrate, and the pendulums 61 and 62 swing when the car body slowly shakes. Therefore, when the vehicle body is shaken, the vibrations are not detected, but when the vehicle body is tilted slowly due to jacking, the tilt of the vehicle body is detected. Note that the impeller 68 uses air resistance, but if the impeller 68 is rotated in highly viscous oil, the number of stages in the speed increasing gear train 67 can be reduced or the impeller 68 can be made smaller. This leads to miniaturization.

(Example 5) In Example 5, a mercury switch 71 is used as the tilt angle detection means. As shown in FIG. 14, this mercury switch 71 has mercury particles 73 housed in a curved hollow tube 72, and the vehicle body is adjusted so that the center of curvature is located vertically above the hollow tube 72. Fixed in position. Further, the hollow tube 72 is arranged so that the longitudinal direction of the hollow tube 72 is in the left-right direction of the vehicle so that the mercury particles 73 move within the hollow tube 72 due to the inclination of the vehicle body. A large number of contacts 74a are provided at the lower end of the inner peripheral surface of the hollow tube 72 at approximately equal intervals in the longitudinal direction of the hollow tube 72. Further, at the lower end of the inner circumferential surface of the hollow tube 72, a common contact 74b is provided which runs over substantially the entire length of the hollow tube 72 in the longitudinal direction.
Is there a common contact point? 4b is grounded.

The mercury grains 73 are stored in an amount sufficient to span the plurality of contacts 74a, and some of the contacts 74a and the common contact 74b are electrically connected via the mercury grains 73. The tilt of the car body is like a grain of mercury 7
This is done by detecting the movement of 3, and the circuits shown in FIGS. 15 and 16 are used for this detection.

That is, the terminal signal change detection circuit 75 detects the movement of the mercury particles 73 within the hollow tube 72, and this circuit includes a plurality of inverters 7 whose input terminals are connected to each contact 74a.
6, a plurality of differentiating circuits connected to the output end of each inverter 76, respectively, and the output of all differentiating circuits 77! ! ′
It is composed of an unpowered AND circuit 78 that outputs a logical result, and seven two-man powered NOR circuits that output an alarm signal when the ignition switch SW is turned off and movement of the mercury droplet 73 is detected. A pull amplifier resistor R3 is connected to the input terminal of each inverter 76, and a differentiator circuit 77
One end of the resistor R4 constituting the differential circuit 77 is connected to the power supply V, and is set so that when the input to the differential circuit 77 does not change, the output of the differential circuit 77 becomes H level.

Therefore, when the ignition switch SW is turned off, one input terminal of the two-person circuit 79 becomes L level, so the AND circuit 7 connected to the other input terminal
When the output terminal of NOR circuit 79 becomes L level, the output terminal of NOR circuit 79 becomes H level and an alarm signal is output. As described above, the output of the differentiating circuit 77 is at the H level when the input to the differentiating circuit 77 does not change, so the output terminal of the AND circuit 78 is at the H level.

By the way, as mentioned above, each contact 74 of the mercury switch 71
Since the differential circuit 77 is connected to a through the inverter 76, when the mercury switch 71 is tilted and the mercury drop 73 moves, the contact 74 that was in contact with the mercury drop 73 until then is
al: The input terminal of the connected inverter 76 changes from the L level to the H level, and the output of the inverter 76 falls, so the output of the differentiating circuit 77 becomes L with a time width corresponding to the time constant set in the differentiating circuit 77. During this period, the output of the AND circuit 78 becomes L level. therefore,
A pulse with a time width corresponding to the time constant of the differentiating circuit 77 is output from the NOR circuit 79, and if this pulse is input as an alarm signal to the alarm circuit 60, an alarm is issued. That is, if the vehicle is tilted in an attempt to steal a tire, the mercury particles 73 of the mercury switch 71 move and an alarm is issued.

(Example 6) In Example 6, as shown in FIG. 17, a magnetic fluid 82 is stored in a curved hollow tube 81 made of a non-magnetic material, and the hollow tube 81 is inserted into a hollow coil 83. An inclination angle detection means is used. The coil 83 is provided integrally with the hollow tube 81, and the coil 83 is arranged offset from the center in the longitudinal direction of the hollow tube 81. The hollow tube 81 is arranged so that the center of curvature of the hollow W81 is located vertically above the hollow tube 81, and is fixed to the vehicle body so that the longitudinal direction of the hollow tube 81 coincides with the left-right direction of the vehicle body. Ru. Therefore, when the unit is tilted, the amount of magnetic fluid 82 located within the coil 83 changes, and the inductance of the coil 83 changes. By detecting this change in inductance, the tilt of the vehicle body can be detected.

As a circuit for detecting a change in the inductance of the coil 83, a circuit as shown in FIG. 19 is used. This circuit includes an oscillation circuit 84 using a coil 83 and a capacitor (not shown) as a tuning circuit, a counter circuit 85 that detects the output frequency of the oscillation circuit 84, and outputs an alarm signal when the frequency changes. The zero frequency change detection circuit 86, which is composed of a frequency change detection circuit 86 and an alarm circuit 87 that notifies an alarm by an alarm signal, detects when a change occurs in the output frequency of the oscillation circuit 84 after the ignition switch SW is turned off. It outputs an alarm signal, and the output frequency of the oscillation circuit 84 at the time when the ignition switch SW is turned off is stored and used as an initial value. Therefore, even when the vehicle is parked on a slope, the oscillation frequency at that time is set as the initial value, so the slope from that state can be detected, and the vehicle can be used even on slopes.

As the inclination angle detection means, an example is shown in which only the magnetic fluid 82 is housed in the curved hollow WB2, but as shown in FIG. 88, magnetic fluid 82 and non-magnetic fluid 88
A movable separation plate 89 may be provided at the boundary between the magnetic fluid 82 and the normal fluid 88 so that the two do not mix.If the magnetic fluid 82 and the normal fluid 88 do not mix at all, a separation plate 89 may be provided. It is not necessary. The hollow tube 81 is a U-shaped tube in which the cross-sectional area of the central portion is smaller than that of both ends, and the boundary between the magnetic fluid 82 and the non-magnetic fluid 88 is formed when the hollow tube 81 is disposed approximately horizontally. The magnetic fluid 82 and the non-magnetic fluid 88 are selected so that their portions are located approximately at the center of the hollow W81, and the coil 83 is also disposed at the center of the hollow W81. Also in this inclination angle detection means, the inductance of the coil 83 changes when the hollow W81 inclines.
By detecting the change in inductance using the above-mentioned circuit, a warning can be issued regarding the tilt of the vehicle body.

[Effect of the Invention 1] As described above, the present invention includes a tilt angle detection means for detecting the tilt angle of the vehicle body, an initial tilt angle setting means for setting the tilt angle of the vehicle body at the start of operation as an initial value, and the above-mentioned initial value. The device is composed of a determination means that outputs a warning signal when the vehicle is tilted at a predetermined angle or more, and an alarm means that issues an alarm when the warning signal is input. This system issues an alarm when the parking lot is tilted by a predetermined angle or more from the initial state, and has the advantage that it can be used in the same way regardless of whether the parking lot is flat or sloped.

[Brief explanation of the drawing]

Figure MS1 is a block diagram showing Embodiment 1 of the present invention, Figures 2 (a) and (b) are front and side views respectively showing an example of the inclination angle detection means used in the above, and Figure 3 is used in the same. FIG. 4 is a circuit diagram of the same as above, fIS5 is an operation explanatory diagram showing the signal of the container part in FIG. 4, and FIG. 6 is a tilt angle used in the above. FIG. 7 is a front view showing still another example of the detection means, FIG. 7 is a front view showing the inclination angle detection means used in the second embodiment of the present invention, FIGS. 10 is a side view showing the inclination angle detection means used in the third embodiment of the present invention, FIG. 11 is an explanatory diagram of the operation of the same, and FIG. 12 is a front view showing the pendulum used in the above. 13(aHb) are a front view and a sectional view of a main part showing the inclination angle detection means used in Example 4 of the present invention, respectively, and FIGS. 14(a) and 14(b) are respectively an embodiment of the present invention. A plan view and a side view showing the inclination angle detection means used in Example 5, FIG. 15 is a block diagram of the same as above, fJS16
17 is an operation explanatory diagram showing an example of the tilt angle detection means used in the sixth embodiment of the present invention, and FIG. 18 is an operation diagram showing another example of the tilt angle detection means used in the same example. The explanatory diagram, FIG. 19, is a block diagram of the same as above. 11 is a detection plate, 12 is a slit, 13 is a rotating shaft, 14 is a photointerrupter, 16 is a Hall element, 23 is a waveform shaping circuit, 24 is an Esso detection circuit, 31 is a mercury switch,
32 and 33 are contacts, 38 is a solenoid, 41 is a first time limit circuit, 42 is a second time limit circuit, 43 is a counter circuit,
60 is a twi circuit, 61.62 is a pendulum, 63.64 is a spherical contact, 65 is a stopper, 67 is a speed increasing gear train, 68 is an impeller, 71 is a mercury switch, 72 is a hollow tube, 73 is mercury, 74a is a contact, 74b is a common rear 7α, 75 is a terminal signal change detection circuit, 81 is a hollow tube, 82 is a magnetic fluid, 83 is a coil, 84 is an oscillation circuit, 85 is a counter circuit, and 86 is a frequency change detection circuit. . Agent Patent Attorney Ishi 1) Chief 7 Figure 4 Figure 6 Figure 7 Figure 8 (a) (b) Figure 9 n~0. 0 Figure 16 Figure 19 Figure 17 (b) Drawing (b)

Claims (6)

[Claims] (1) Inclination angle detection means for detecting the inclination angle of the vehicle body;
initial inclination angle setting means for setting the inclination angle of the vehicle body at the start of operation as an initial value; and determination means for outputting a warning signal when the vehicle body inclines by a predetermined angle or more from the initial value;
1. A vehicle theft alarm device comprising an alarm means for notifying an alarm when an alarm signal is input. (2) The tilt angle detection means is formed in a fan shape, and the center of the fan shape is pivotally supported by a rotating shaft fixed to the vehicle body, and a large number of detection segments are formed at equal intervals along the periphery of the curved part. and a detection section that is arranged in a fixed position on the vehicle body in correspondence with the detection segments and detects the inclination angle of the detection plate based on the number of passing detection segments. The vehicle theft alarm device according to scope 1. (3) The tilt angle detection means includes a pendulum that can swing freely around a rotating shaft fixed at a fixed position on the vehicle body, and a mercury switch that is attached to the tip of the pendulum and closes the contact when the pendulum is tilted at a predetermined angle. 2. The vehicle theft alarm system according to claim 1, wherein the initial inclination angle setting means is a locking device that fixes the pendulum in a fixed position when the pendulum is parked. (4) The inclination angle detection means is a pair of pendulums that have contacts at their tips and the contacts touch each other, and the initial inclination angle setting means is a locking device that fixes one of the pendulums in a fixed position during parking. A vehicle theft alarm device according to claim 1, characterized in that: (5) The tilt angle detection means is a mercury switch,
A mercury switch has a large number of contacts formed in a hollow tube at approximately equal intervals in the longitudinal direction, and a common contact running along the longitudinal direction in the hollow tube. 2. The vehicle theft alarm device according to claim 1, wherein the mercury particles moving in the hollow tube are placed inside the hollow tube. (6) The above-mentioned inclination angle detection means is composed of a hollow tube made of a non-magnetic material fixed at a fixed position on the vehicle body and filled with magnetic fluid, and a cylindrical coil through which the hollow tube is inserted. 2. The vehicle theft alarm system according to claim 1, wherein the inclination angle is detected by a change in the inductance of the coil when the magnetic fluid moves within the hollow tube.