JPS5820402Y2 - Sharintounankeihousouchi - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a wheel theft alarm device that issues an alarm when a wheel of an automobile or the like is stolen.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG.
, a transmitting section (2), and a receiving alarm section (2).The transmitting section (2) and the receiving/alarm section (2) are fixed to a vehicle body such as an automobile, and the transmitting section (2) is attached to a wheel.

In FIG. 1, 1 is an oscillation circuit that generates an AC signal, 2
As shown in Fig. 2, is a transmitter coil made of a U-shaped magnetic material wound with a wire, and the above-mentioned oscillation circuit 1 and transmitter coil 2 constitute a transmitter section I, and the oscillation output of the oscillation circuit is used as the above-mentioned transmitter. When applied to the coil 2, the transmitting coil 2 emits electromagnetic waves.

Reference numeral 3 denotes a wheel portion of a wheel constituting the transmission portion (2).

FIG. 3 shows a cross section of the wheel. In FIG. 3, 3 is a wheel portion made of a magnetic material, 7 is a tire, and the transmitting coil 2 is provided close to the wheel portion 3.

Reference numeral 4 denotes a receiving coil having a similar structure to the transmitting coil 2 shown in FIG. 2, and this receiving coil 4 is also provided close to the wheel portion 3.

Note that the transmitting coil 2 and the receiving coil 4 are desirably arranged on a concentric circle, and are arranged at a certain interval to prevent the magnetic flux emitted from the transmitting coil 2 from directly entering the receiving coil 4. .

5 is an amplifier circuit, and 6 is an alarm device driven by the output of the amplifier circuit 5.

Next, the operation of the above embodiment will be explained.

When the wheels are properly attached to the vehicle body, the magnetic flux oscillated from the +-3 transmitting coil 2 is transmitted to the receiving coil 4 using the wheel portion 3 as a magnetic path.

The voltage induced in the receiving coil 4 is amplified by the amplifier circuit 5.

When the wheel is stolen, the magnetic flux transmitted from the transmitting coil 2 is not transmitted to the receiving coil 4 because there is no wheel section 3 serving as a transmitting section, and the signal level of the receiving coil 4 decreases.

Fig. 4 shows the relationship between the relative short distance between the receiving coil, the oscillating coil, and the wheel section 3 and the induced voltage V induced in the receiving coil 4. A voltage vl is induced in the receiving coil 4, and when the wheel is stolen, the induced voltage decreases to 2.

As described above, a change in the signal level of the receiving coil 4 is detected and an alarm is issued.

In the above embodiment, an example was explained in which the vehicle is used for anti-theft purposes, but in addition to preventing theft, it is also possible to detect whether the bottle tightening the wheels loosens while the vehicle is running and the wheels become loose.

Furthermore, although the above embodiment uses a wheel portion made of a magnetic material, if the wheel portion is made of a non-magnetic material, magnetic powder may be applied to the portion of the wheel portion facing the transmitting coil and the receiving coil. It can be applied in a circular manner.

The device of the present invention has the above-mentioned structure, and has a simple structure.
Theft of wheels and poor tightening of wheels can be detected regardless of whether the vehicle, such as an automobile, is running or stopped.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a wheel theft alarm device according to an embodiment of the present invention, Fig. 2 is a perspective view of an oscillation coil used in the device, Fig. 3 is a sectional view of a wheel of the device, and Fig. 4 is a transmitter. FIG. 6 is a diagram showing the relationship between the coil, the relative distance between the receiving coil and the wheel portion, and the voltage induced in the receiving coil. 1... Baking plate circuit, 2... Shinshin coil, 3...
...Wheel part (magnetic material), 4...Reception coil.

Claims (1)

[Scope of utility model registration request] The wheel includes a magnetic body provided in an annular shape, a transmitting coil and a receiving coil arranged opposite to the magnetic body, and an oscillation circuit that applies an alternating current signal to the transmitting coil, and the magnetic body is used as a magnetic path. A wheel theft alarm device characterized by detecting a signal level induced in a transmitting coil.