JPS61200048A - Theft preventing apparatus for car - Google Patents

Abstract

PURPOSE:To certainly prevent theft by interposing the pressure sensors connected to an alarm means between a key body and the outer plate of a door and arranging said pressure sensors so as to nip a plurality of key bodies. CONSTITUTION:A pair of pressure sensors A and B are interposed between the outer plate 5a of a door 5 and a key body 11. Said pressure sensors A and B are installed at the front part of a chassis so as to nip the key body 11. When, on the basis of the output signals transmitted form the pressure sensors A and B, it is judged that a driver, etc. is unreasonably inserted into a key hole and the door is forced to be opened, an alarm means is operated to transmit alarm sounds.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an anti-theft device for automobiles that can more reliably prevent theft of automobiles.

(Prior Art) Since automobiles are often parked outdoors when not in use, there is a risk that the automobile itself or items left in the cabin may be stolen.

Therefore, it has been proposed to prevent the theft by interlocking with the operation of the starting operation system of the automobile (for example, Japanese Utility Model Publication No. 50-48335).

(Problem to be Solved by the Invention) Incidentally, it is thought that theft is often committed by a person attempting to steal by forcing open a locked door and entering the vehicle compartment. With this configuration, it is not possible to prevent a would-be thief from opening the door or stealing something left in the passenger compartment.

(Purpose of the Invention) This invention was made with attention to the above-mentioned circumstances, and is intended to more reliably prevent theft by stopping this act as early as possible when there is an attempt to steal a car. However, in this case, the purpose is to correctly detect that the act is an attempt to steal, and to prevent a theft prevention warning from being erroneously issued.

(Structure of the Invention) A feature of the present invention for achieving the above object is that a pressure sensor connected to a warning means is interposed between the key body and the outer panel of the door, and a plurality of pressure sensors are provided. Another feature is that these pressure sensors are arranged so as to sandwich the key body in the direction along the door outer panel.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, l is an automobile, and a door opening 3 is formed on the side surface of the vehicle body 2. A door 5 is provided which allows the door opening 3 to be opened and closed.

The door 5 is pivotally supported at the front edge of the door opening 3 via a hinge 6 so as to rotate in the vehicle width direction.

Further, a locking mechanism 7 is provided that allows the door 5 to be locked when the door opening 3 is closed. This locking mechanism 7 includes a striker provided on the vehicle body side (not shown),
The latch is provided at the pivot end of the door 5 and engages with the striker.

Further, a key means 8 for locking or unlocking the lock mechanism 7 is provided.

3 to 5, the key means 8 is a key lO
and the locking mechanism 7. The key body 11 is interlocked with the key body 11 and locks or unlocks the lock mechanism 7 by operating the key 10, and a retainer 12 supports the key body 11 on the outer panel 5a of the door 5.

The key body 11 includes a disc-shaped head 14 and a disc-shaped head 14.
It has a main body case 15 projecting from the main body case 15, and the protruding end side of the main body case 15 is fitted into a through hole 16 formed in the outer plate 5a of the door 5.

The head 14 is exposed to the outside of the vehicle body 2.

A rubber ring 17 is inserted between the head 14 and the opening edge of the through hole 16.

Furthermore, notches 19 are formed on the outer peripheral surface of the main body case 15 at symmetrical positions in the radial direction, and a portion of the retainer 12 is fitted into each of the notches 19 . This retainer 12 is formed of an elastic member, and urges the key body 11 toward the inside of the vehicle so as to resist the elastic force of the rubber ring 17.

A keyhole 20 is formed in the end face of the head 14, and the key 10 is inserted into and removed from the keyhole 20. Further, a key shaft 21 is provided protruding from the main body case 15, and although not shown, this key shaft 21 is interlocked and connected to the latch of the locking mechanism 7. Then, the key shaft 21 is rotated by inserting and rotating the key lO into the key hole 20, and in conjunction with the key shirt 21, the locking mechanism 7 is locked or unlocked.

A pair of pressure sensors A and B are interposed between the outer panel 5a of the door 5 and the key body 11. That is.

These pressure sensors A and B are provided in the front and back direction of the vehicle body 2 so as to sandwich the key body 11 between the head 14 and the opening edge of the through hole 16.
It is located in 7.

In this case, the repressure sensors A and B may be provided above and below so that the key body 11 is sandwiched therebetween.

The pressure sensors A and B mentioned above may be made of, for example, piezoelectric ceramics that generate an electromotive force when pressurized and strained, or flexible switches that change resistance when compressed by mixing metal powder into rubber, or their low capacitance changes. It is said to be a type touch switch.

6 to 8 are diagrams showing the output states of the pressure sensors A and H when an external force is applied to the key body 11. FIG.

That is, FIG. 6 shows the case where the key 1O is inserted into the key hole 20, and since the force acting on the key body 11 during this operation is small, the pressure sensor A is used.

The output voltage of B can be kept relatively low. Further, FIG. 7 shows a case where a foreign object such as a screwdriver is forcibly inserted into the key hole 20. In this case, the force acting on the key body 11 is large, so the output voltages of the pressure sensors A and B become large. FIG. 8 also shows the output signal of pressure sensor A (shown by the solid line in the figure) and the output signal of pressure sensor B (shown by the chain double-dashed line in the figure) when the screwdriver inserted into the keyhole 20 is pushed forward and backward of the vehicle body 2. This shows that when one pressure sensor A outputs a positive voltage (for example, part a in the figure), the other pressure sensor B outputs a negative voltage (see the figure). For example, part b).

Referring to FIG. 1, a series circuit including an adder circuit 23, a low-pass filter 24, a comparator circuit 25, and a differential amplifier 27. A series circuit including a low-pass filter 25 and a comparison circuit 29 is connected in parallel to each pressure sensor A, H, and each comparison circuit 25, 29 is connected to a warning means 31 such as a buzzer.

Then, the output signals of the repressure sensors A and B are added by an adder circuit 23 and inputted to a comparator circuit 25 through a low-pass filter 24.

In this case, the low-pass filter 24 inputs only those signals having a frequency of several Hz or less among the signals added by the adder circuit 23 to the comparator circuit 25 . That is, the vibration frequency of the outer panel 5a when a foreign object such as a screwdriver is inserted into the key hole 20 is generally several Hz or less, while the vibration frequency of the outer panel 5a when the outer panel 5a of the door 5 is hit is generally less than a few Hz. 500Hz~5K
Hz, and use the above low-pass filter to distinguish between the two? 4 is provided. If the output of the low-pass filter 24 is larger than the set value in the comparison circuit 25, it is determined that a foreign object such as a screwdriver has been forcibly inserted into the keyhole 20, as shown in FIG. 25 outputs a signal to warning means 31.

On the other hand, the difference between the outputs of the repressure sensors A and B is determined by the differential amplifier 27.
If the output of the differential amplifier 27 passed through the low-pass filter 28 is larger than the set value in the comparison circuit 29, the keyhole 20 has been damaged by a foreign object such as a screwdriver, as shown in FIG. This comparison circuit 29 outputs a signal to the warning means 31.

Then, when a signal is output from the dual ratio rotational circuits 25 and 29 to the warning means 31, the warning means 31 is activated and a warning sound is emitted.

(Effects of the Invention) According to the present invention, a pressure sensor connected to the warning means is interposed between the key body and the outer panel of the door, a plurality of pressure sensors are provided, and these pressure sensors are connected to the outer panel of the door. Because the key body is placed so that it is sandwiched in the direction along the differentially outputs a signal to accurately detect this movement, which generates a warning.

Therefore, the attempted theft can be stopped at an early stage before it reaches the passenger compartment, and theft can be more reliably prevented.

Moreover, the act of repeatedly breaking the key body as described above is a characteristic act when attempting to steal, and is therefore accurately distinguished from other normal acts.
It is possible to prevent theft prevention warning from being erroneously issued.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which Fig. 1 is an electrical block diagram, Fig. 2 is an overall side view of the automobile, Fig. 3 is a partially enlarged view of Fig. 2, and Fig. 4 is IV-IV of Fig. ξ. FIG. 5 is a view taken along the IT line, FIG. 5 is a view taken along the v-v line in the same figure, and FIGS. be. 1ms car, 5 fist/door, 5aφ/outer plate, 7...lock mechanism, 8...key means, tte fist key body, 31φ-
Warning means, A...pressure sensor, B...pressure sensor.

Claims (1)

[Claims] 1. A door device for an automobile, comprising a locking mechanism capable of locking a vehicle door in a closed state, and a key body attached to the outer panel of the door, which is interlocked with the locking mechanism and locks or unlocks the locking mechanism by key operation. A pressure sensor connected to a warning means is interposed between the key body and the outer panel of the door, a plurality of pressure sensors are provided, and the key body is sandwiched between the pressure sensors in a direction along the outer panel of the door. An anti-theft device for an automobile, characterized in that it is arranged as follows.