JPS6361225B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an anti-theft device for an automobile.

(Prior Art) As a conventional anti-theft device for automobiles, for example, as disclosed in Japanese Patent Application Laid-Open No. 55-83641,
It is known that an ignition key switch is short-circuited without using the key so that an alarm sounds when the engine is started. Furthermore, as seen in Japanese Utility Model Publication No. 50-38921, there is a known engine which is equipped with an ignition prevention mechanism, and the engine can only be started after the ignition prevention mechanism is unlocked. More specifically, the ignition prevention mechanism is unlocked on the condition that the hazard switch, light switch, wiper switch, radio switch, and heater switch are closed in a predetermined order within a predetermined period of time. Therefore, the engine cannot be started unless the user knows the necessary operations to unlock the ignition blocking mechanism.

However, in the case of the former, which generates an alarm sound, even if the alarm sounds, the engine itself can be started by short-circuiting the ignition key switch, so it is effective in preventing car theft. is not necessarily sufficient. On the other hand, in the latter case, even if the ignition key switch is short-circuited, the engine cannot be started unless the ignition prevention mechanism is unlocked, so it is effective in preventing car theft. However, the normal engine starting operation, that is, inserting the key into the key switch for starting the engine, turning the key to turn the ignition key switch "ON",
Next, in addition to a series of starting key operations such as turning the starter switch "ON," it is necessary to unlock the ignition prevention mechanism, which is complicated and impractical in daily use of a car.

(Object of the Invention) Therefore, an object of the present invention is to prevent theft of an automobile without impairing the usability of the automobile on a daily basis.

(Structure and operation of the invention) The present invention focuses on the order of operation of key switches for starting the engine, and makes it possible to supply power to the starter motor on the condition that each switch is turned "ON" in sequence in the normal order of operation. It's meant to be.

More specifically, a key switch for starting an engine has at least an ignition key switch position that is operated by using a key to turn on and off power supply to the ignition; and insertion of a key into the key switch; key detection means for detecting non-insertion; ignition key position detection means for detecting that the key is located at the ignition key switch position; the key detection means and the ignition key position detection means; An output is input, and based on the output, key operations are performed in the normal operation sequence corresponding to a normal starting key operation in which the key switch position moves to the ignition key switch position after the key is inserted into the key switch. a key operation determining means for determining whether or not the key operation has been performed; and on/off control is performed based on the output from the key operation determining means, and on condition that the key operations are performed in the normal operation order, the key operation is performed to the starter motor. The device is configured to include an anti-theft switching means that enables power supply.

With this configuration, even if the ignition key switch is short-circuited without using the key, the starter motor will Power supply to is prohibited. As a result, it becomes impossible to start the engine.

On the other hand, in daily use, the engine can be started by a very common key operation, and no additional operation is required for this starting operation.

(Example) An example of the anti-theft device for an automobile according to the present invention will be described below based on the drawings.

In FIG. 1, 1 is a battery, and its positive side is connected to a key switch 3 via a fuse 2.
It is also connected to a relay 5 via a fuse 4, and the negative side of the battery 1 is connected to ground. The relay 5 has a function of supplying power to a horn 6 for generating an alarm sound, and the relay 5 is roughly composed of a coil 7, a fixed contact 8, and a movable contact 9. One end of the coil 7 is connected to the fuse 4. The other end of the coil 7 is connected to the ground via a manual switch 10, which is a push button type and is installed in the driver's seat. When this manual switch 10 is closed,
The coil 7 is energized in the direction of arrow A, the movable contact 9 is closed, power is supplied from the battery 1 to the horn 6, and the horn 6 generates an alarm sound. Here, two horns 6 are provided, one of which is designed to generate a low tone, and the other is configured to generate a high tone.

The key switch 3 has a plurality of key switch positions, 11 is a keyless switch position, 12 is an accessory switch position, 13 is an ignition switch position,
14 is the starter switch position. The keyless switch position 11 has a fixed contact 15 and a movable contact 16, and the accessory switch position 12 has a fixed contact 17 and a movable contact 1.
8, the ignition switch position 13 has a fixed contact 19 and a movable contact 20, and the starter switch position 14 has a fixed contact 19 and a movable contact 20.
has a fixed contact 21 and a movable contact 22. In the keyless switch position 11, when a key (not shown) is inserted into the key switch 3,
The movable contact 16 is closed, and has a function of activating the horn 6 to generate an alarm sound when the user forgets to remove the key. The accessory switch position 12 has the function of closing the movable contact 18 and supplying battery voltage to accessory parts such as a radio when the key is placed in that position. has the function of supplying battery voltage to the ignition coil by closing the movable contact 20 when the key is placed in that position.
has a function of closing the movable contact 22 when the key is placed in that position and supplying power to the starter motor 24 via the relay 23.

The output from the key switch 3 is input to the key operation determining means 25.
has a function of determining whether key operations have been performed in a predetermined operation order based on the output from the key switch 3. This key operation determination means 25
has flip-flops 26 to 28 and a reset circuit 29, and the output from the keyless switch position 11 is connected to the D of the flip-flop 26.
The output from the accessory switch position 12 is input to the CP terminal of the flip-flop 26, the output from the ignition switch position 13 is input to the CP terminal of the flip-flop 27, The output from starter switch position 14 is input to the CP terminal of flip-flop 28.
When the input to its CP terminal and the input to its D terminal are both high, the flip-flop 26
The output to the Q terminal is high, and the output from the Q terminal of the flip-flop 26 is input to the D terminal of the flip-flop 27. When the input to the CP terminal and the input to the D terminal of the flip-flop 27 are both high, the output of the Q terminal of the flip-flop 27 becomes high. It is input to the D terminal of 28. Flip-flop 28 outputs its Q when the input to its CP terminal and the input to its D terminal are both high.
The output of each Q terminal of flip-flops 26 to 28 is changed from low to high in response to a key operation. These flip-flops 26 to 28 are
The reset circuit 29 is configured such that when the key is removed from the key switch 3, the movable contact 16 of the reset circuit 29 is opened and outputs a reset signal. , the output of each Q terminal is set to low based on this reset signal.

The output of the key operation determining means 25 is input to the anti-theft switching means 30, and the anti-theft switching means 30 turns on and off based on the output of the key operation determining means 25.
It is supposed to be turned off. The anti-theft switching means 30 is roughly composed of AND circuits 31 and 32 and switching transistors 33 and 34, and the AND circuit 31 and the switching transistor 33 have the function of controlling the opening and closing of the relay 23. The AND circuit 32 and the switching transistor 34 have a function of controlling the opening and closing of the relay 5. The relay 23 is connected to the coil 3
5, a fixed contact 36, and a movable contact 37.
is connected to the starter magnet 38 of the starter motor 24 via a movable contact 37, one end of the coil 35 is connected to the positive side of the battery 1 via the fuse 4, and the other end of the coil 35 is connected to the switch. The emitter of the switching transistor 33 is connected to the ground via a resistor, and the base of the switching transistor 33 is connected to the output terminal of the AND circuit 31 via a resistor. The output of the Q terminal of the flip-flop 28 is input to one input terminal of the AND circuit 31, and the output from the starter position is input to the other input terminal of the AND circuit 31. When the inputs to both input terminals are high, the output of the output terminal becomes high, and the switching transistor 33 is turned on when the output of the AND circuit 31 is high, Electricity is applied in the direction of arrow B, and the switching transistor 33 is turned on, so that the coil 35 is energized, and the movable contact 37 of the relay 23 is closed, and the relay 23 is transferred from the starter switch position 14 to the starter motor 24. This makes it possible to supply power.

The AND circuit 32 has one input terminal inputted with the output from the starter switch position 14, and the other input terminal inputted with the output of the Q terminal of the flip-flop 28 via the inverter element 39. 32 is AND circuit 3
When the output of 1 is high, its output is low,
When the switch (between the fixed contacts 21 and 21) of the starter position 14 is short-circuited by theft and the input to one input terminal is high and the output of the Q terminal of the flip-flop 28 is low, The output of the AND circuit 32 is input to the base of the switching transistor 34 via a resistor, and the collector of the switching transistor 34 is connected to the other end of the coil 7. The emitter of the switching transistor 34 is connected to ground through a resistor, and the switching transistor 34 is turned on when the output of the AND circuit 32 is high, causing the coil 7 to flow in the direction of arrow C. Electricity is applied, movable contact 9 is closed, and power is supplied to horn 6 from battery 1.

Next, the effect will be explained.

When the key is inserted into the key switch 3, the movable contact 16 of the keyless switch position 11 is closed, and the flip-flop 2 is opened as shown in FIG.
The high output from the keyless switch position 11 is input to the D terminal of the keyless switch 6 and the reset circuit 29. When the key is inserted into the key switch 3 and moved to the accessory switch position 12, the movable contact 18 is closed and the high output from the accessory switch position 12 is transferred to the flip-flop 26 as shown in FIG. Input to CP terminal. Then, the output of the Q terminal of the flip-flop 26 changes from low to high. When the key is moved from the accessory switch position 12 to the ignition switch position 13, the movable contact 18 is closed, the movable contact 20 is closed, and the ignition switch position is moved as shown in FIG. 13
The high output from the flip-flop 27 is input to the CP terminal of the flip-flop 27. Then, flip-flop 27
The output of the Q terminal of the flip-flop 26 is high because the output of the Q terminal of the flip-flop 26 is high. When the key is moved from the ignition switch position 13 to the starter switch position 14, the movable contact 13 is opened and the movable contact 22 is closed.
As shown in FIG.
Input to CP terminal. Then, the output of the Q terminal of the flip-flop 28 becomes the output of the flip-flop 27.
Since the output of the Q terminal of the flip-flop 27 is high, the output of the Q terminal of the flip-flop 27 becomes high, and as shown in FIG.
1 becomes high, and the switching transistor 33 is turned on. Then, the coil 35 is energized, the movable contact 37 is closed, and power can be supplied from the starter switch position 14 to the starter motor 24. If the key is moved to a key switch position other than the starter switch position 14, the movable contact 22 is opened and power is not supplied to the starter motor 24, but the flip-flops 26 to 28
The output of each Q terminal of
28 will remain in the high state unless reset, so the closed state of the movable contact 37 will be maintained and the state in which power can be supplied will continue. When the key is removed from the key switch, each flip-flop 26-28 is reset by the reset circuit 29, the output of the Q terminal of each flip-flop 26-28 becomes low, the output of the AND circuit 31 becomes low, and the switching transistor 33 becomes low. The coil 35 is de-energized and the movable contact 37 is turned off.
is opened, and power cannot be supplied from the starter switch position 14 to the starter motor.

Inserting the key and transferring the key to accessory switch position 12, transferring the key from accessory switch position 12 to ignition switch position 13, and transferring the key from ignition switch position 13 to starter position 14 If the switches of the starter switch position 14 are short-circuited without using a key in an attempt to start the starter motor 24 without going through the predetermined key operation sequence, the key operation determination means 25
Since the output of the Q terminal of the flip-flop 28 remains low, the output of the AND circuit 31 remains low, the switching transistor 33 remains off, and the movable contact 37 is not closed.
The state in which power cannot be supplied from the starter switch position 14 to the starter motor 24 continues, and the output of the AND circuit 32 becomes high because both of its inputs become high, and the switching transistor 34 becomes high. When the relay is turned on, the coil 7 of the relay 5 is energized and its movable contact 9 is closed, and power is supplied from the battery 1 to the horn 6 to operate the horn 6 and generate an alarm sound.

(Effects of the Invention) As explained above, in the present invention, when a key is inserted into a key switch and the keys are not operated in a predetermined order of operation, power cannot be supplied to the starter magnet. It is possible to provide a practical theft prevention device that can prevent theft of a car without impairing the ease of use of the car.

[Brief explanation of drawings]

FIG. 1 is a circuit configuration diagram of an automobile anti-theft device according to the present invention. FIG. 2 is a timing chart of the automobile theft prevention device according to the present invention. 1...Battery, 3...Key switch, 5...
Relay, 6... Horn, 11... Keyless switch position, 12... Accessory switch position, 13... Ignition switch position, 14... Starter switch position, 2
3... Relay, 24... Starter motor, 25...
... Key operation determination means, 26 to 28 ... Flip-flop, 29 ... Reset circuit, 30 ... Anti-theft switching means, 31, 32 ... AND circuit, 33, 34 ... Switching transistor.

Claims (1)

[Scope of Claims] 1. A key switch for starting an engine, which has at least an ignition key switch position that is operated by using a key to turn on and off power supply to the ignition; and insertion of a key into the key switch. , a key detecting means for detecting non-insertion, an ignition key position detecting means for detecting that the key is located at the ignition key switch position, the key detecting means, and the ignition key position detecting means. Based on the output, the keys are operated in the normal sequence of operations corresponding to normal starting key operations in which the key switch position moves to the ignition key switch position after the key is inserted into the key switch. a key operation determining means for determining whether or not a key operation has been performed, and an on/off control is performed based on an output from the key operation determining means, and a starter is activated on the condition that the key operations are performed in the normal operation order. An anti-theft device for an automobile, comprising: anti-theft switching means that enables power to be supplied to a motor; 2. In the automobile anti-theft device according to claim 1, the anti-theft switching means operates a horn for generating an alarm sound when key operations are not performed in the normal order of operation. An automobile theft prevention device characterized by: