JP4122412B2 - Immobilizer - Google Patents

Description

  The present invention relates to an immobilizer capable of preventing theft of a vehicle or the like by enabling the engine to be started when an ID code received by transmitting and receiving a unique ID code is a preset proper one. Is.

  Along with the increase in theft of vehicles in recent years, in addition to mechanical engine start by the ignition key (engine start by the same shape of key shape and key hole shape), it is embedded in the grip part of the ignition key and has a unique ID A transponder capable of transmitting a code, an antenna disposed near the keyhole and capable of receiving an ID code from the transponder, and determining whether or not the ID code received by the antenna is preset. Is provided with an immobilizer provided with a control circuit capable of transmitting a start permission signal to an ECU (engine control device).

  According to such an immobilizer, mechanical engine start by an ignition key and electronic engine start permission by transmission / reception of an ID code can be performed together, and the antitheft effect can be improved. However, the immobilizer is a so-called retrofit (optional) because it transmits a start permission signal to the ECU when it is determined that the received ID code is authentic, so that the engine can be started. When applied to the above, the ECU program must be changed, which increases the installation cost.

Therefore, conventionally, a normally open relay is provided in the middle of the engine starting circuit, and the engine is started by closing the switch only when it is determined that the ID code received by the antenna is normal. In addition, it has been proposed to prevent theft by leaving the switch open when it is determined that the received ID code is not legitimate and making it impossible to start the engine. In addition, since the prior art regarding such a conventional post-attachment immobilizer does not relate to the known literature invention, there is no prior art document information to be described.
JP-A-10-81203

  However, although the above-described conventional immobilizer can cope with a so-called retrofit type, it has a normally open relay and the engine can be started by closing the relay. When an immobilizer is attached later to a vehicle provided with an engine starter or a turbo timer, there is a problem that the installation becomes difficult. In addition, after starting the engine, it is necessary to stop the relay to reduce the power consumption of the immobilizer. Therefore, a circuit and wiring for detecting that the engine has started is necessary, and there is a problem that costs increase.

  The present invention has been made in view of such circumstances, and is easily applied to what is called a retrofit, and is provided with a separate device that functions while the ID code is not transmitted and received. An object of the present invention is to provide an immobilizer that can be made easy.

  According to the first aspect of the present invention, a transmission means for transmitting a unique ID code that can be carried by the driver, a reception means for receiving an ID code transmitted from the transmission means, and a reception means for receiving the ID code. A determination unit that determines whether or not the ID code is a preset normal one, and the engine is started when the determination unit determines that the ID code received by the reception unit is a normal one. And an immobilizer having an engine start permission means for making it impossible to start the engine when it is determined that the received ID code is not legitimate, wherein the engine start permission means Based on the detection signal of the key detection means that consists of a normally closed relay arranged in the middle of the circuit and that detects that the ignition key has been inserted into the key hole The ID code received by the receiving means by the judging means after the key detecting means is opened when the key detecting means detects the ignition key and the engine starting circuit is made non-conductive, is authentic. When it is determined that the engine start circuit is closed again, the engine start circuit is turned on to enable the engine to start.

  According to a second aspect of the present invention, in the immobilizer according to the first aspect, the transmitting means includes a transponder capable of transmitting an ID code and is formed separately from the ignition key.

  According to the first aspect of the present invention, the engine start permission means comprises a normally closed relay disposed in the middle of the engine start circuit, and the key detection means detects that the ignition key has been inserted into the key hole. Since it can be opened and closed based on the signal, it can be easily applied to a so-called immobilizer, and can be easily provided with a separate device that functions while the ID code is not transmitted and received. In addition, the circuit configuration and wiring of the immobilizer can be simplified.

  According to the second aspect of the present invention, the transmission means includes a transponder capable of transmitting an ID code and is formed separately from the ignition key. For example, as compared with the case where the transponder is embedded in the ignition key holding portion. Furthermore, it is suitable for a retrofit type immobilizer.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The immobilizer according to the present embodiment is attached to the driver's seat side of an automobile as a so-called retrofit type (optional), and is connected to the immobilizer main body 1 and the immobilizer main body 1 via the wiring C1 as shown in FIG. The antenna unit 2 and the transmitting means 10 as shown in FIG.

  The transmission means 10 can be carried by the driver, and, as shown in FIG. 5, is configured by embedding a transponder 10b capable of transmitting a unique ID code, and is separate from an ignition key (not shown). It has been done. More specifically, as shown in FIG. 4, the transmitting means 10 is formed of a substantially stick-like shape as a whole, a ring hole 10 a provided on the proximal end side thereof, a distal end surface 10 c, It is mainly composed of a gripping portion 10d provided on the proximal side surface.

  Then, for example, a metal ring (not shown) is inserted into the ring hole 10a, and an ignition key gripping part (not shown) is also inserted through the metal ring, thereby connecting the transmitting means 10 and the ignition key. And can be carried around. Further, in order to authenticate the ID code, the grip portion 10d is gripped and brought close to or in contact with the tip surface 10c facing the surface of the antenna portion 2.

  The antenna unit 2 is fixed by sticking or the like in the vicinity of the key hole through which the ignition key of the automobile is inserted. As shown in FIG. 3, the antenna unit 2 is connected to the coil so that the ID code transmitted from the transmitting means 10 can be received. The antenna 2a (receiving means) and a substrate (RF module) 2b electrically connected to the antenna 2a are included. However, the ID code received by the antenna 2a is transmitted to the CPU 4a of the control unit 4 via the code C1.

  The immobilizer body 1 is installed and fixed at a predetermined position on the driver's seat side of the automobile, and as shown in FIG. 2, a control unit 4, a normally closed relay 5 and a speaker 3 are disposed therein, and the control unit 4 The normally closed relay 5 and the speaker 3 are electrically connected to each other. Further, from the immobilizer body 1, in addition to the wiring C1 extending to the antenna unit 2, a wiring C2 extending from the normally closed relay 5, a wiring C3 extending to a key detection switch 8 described later, and a wiring C4 to be grounded extend. It is installed. A connector C having an RL / IN terminal, an RL / OUT terminal, and an OUT terminal is formed at the tip of the wiring C2, as shown in FIG.

  As shown in FIG. 6, the control unit 4 includes a CPU 4 a serving as a determination unit and a transistor 4 b for monitoring a voltage to detect an electrical failure of the immobilizer and perform self-diagnosis. . The CPU 4a determines whether or not the ID code transmitted from the antenna unit 2 is a preset regular one. In addition to the antenna unit 2, the key detection switch 8 ( Key detection means), normally closed relay 5, and speaker control unit 6 for controlling guidance sounds emitted from the speaker 3 and the like.

  The key detection switch 8 is normally opened, and is closed when the ignition key is inserted into the key hole, so that the ignition key detection signal can be sent to the CPU 4a. The speaker control unit 6 includes a memory 6a, a sound IC 6b, and an amplifier 6c, and can perform desired guidance or the like from the speaker 3 by using voice or the like previously stored in the memory 6a. Yes.

  Further, the normally closed relay 5 as an engine start permission means is mainly composed of a normally closed switch 5a and a coil 5b as an electromagnet, and allows or interrupts the flow of current to the coil 5b based on control by the CPU 4a. By doing so, the normally closed switch 5a can be opened and closed. On the other hand, the wiring L1 connected to the battery with the start switch 7 and the wiring L2 grounded with the cell starter 9 form an engine starting circuit disposed on the vehicle side. The normally-closed relay 5 is arranged via the wiring C2. The start switch 7 is closed by rotating the ignition key inserted into the key hole from the off position to the on position.

  As a result, when the normally closed relay 5 is closed (that is, the normally closed switch 5a is closed), power is supplied to the cell starter 9 by closing the start switch 7, and the engine can be started. If the normally closed relay 5 is open (ie, the normally closed switch 5a is open), even if the start switch 7 is closed, no power is supplied to the cell starter 9 and the engine does not start. It becomes possible.

Next, the operation of the immobilizer with the above configuration will be described with reference to FIG.
When the automobile engine is stopped and the ignition key is not inserted into the key hole, the start switch 7 and the key detection switch 8 are opened and the normally closed relay 5 is closed as shown in FIG. . When the driver inserts an ignition key into the key hole to start the engine, the key detection switch 8 is closed and a detection signal is transmitted to the CPU 4a.

  The CPU 4a that has received such a detection signal allows the current flow to the coil 5b to open the normally closed switch 5a (that is, to open the normally closed relay 5) and to turn off the engine starting circuit. The engine cannot be started even when the start switch 7 is closed. After that, when the driver receives the ID code emitted from the transponder 10b by bringing the tip surface 10c of the transmitting means 10 close to or in contact with the antenna unit 2, the ID code is transmitted to the CPU 4a and set in advance. A determination is made as to whether it is a regular one.

  When it is determined that the ID code received by the antenna 2a is authentic, the CPU 4a cuts off the flow of current to the coil 5b, and again closes the normally closed switch 5a (that is, normally closes the normally closed relay 5). When the start switch 7 is closed, the engine start circuit becomes conductive and the engine can be started. If it is determined that the ID code received by the antenna 2a is not legitimate, the CPU 4a continues to allow current flow to the coil 5b and keeps the normally closed switch 5a open, thereby starting the engine. Impossible.

  That is, the normally closed relay 5 is determined to be closed until the ignition key is inserted (engine startable state), and when inserted, the normally closed relay 5 is determined to be open, and the received ID code is valid. Then, the closed state (engine startable state) is again established.

  Further, since the engine start circuit can be opened and closed by the opening and closing operation of the normally closed relay 5 and the engine start can be selectively enabled or disabled, the ECU can be compared with the one that transmits an engine start permission signal to the ECU. Therefore, it is not necessary to rewrite the program, and it is easy to apply to a so-called retrofit program. Furthermore, since the transmission means is formed separately from the ignition key, it is not necessary to change the existing ignition key, and it is suitable for a retrofit type immobilizer.

  It is preferable that the immobilizer state is notified by voice or the like at the speaker 6, and when the abnormal voltage is detected by the self-diagnosis by the transistor 4 b, the abnormality is notified by the speaker 6. Is preferred. Such notification may be a predetermined sound (such as a buzzer sound) in addition to the voice. Further, a plurality of sounds (including voice) may be stored in advance in the memory 6a so that the driver can arbitrarily select a sound emitted from the speaker 3 at the time of notification.

  Although the immobilizer according to the present embodiment has been described above, the present invention is not limited to this. For example, the means for detecting the insertion of the ignition key into the key hole and the antenna for receiving the ID code from the transmission means 10 are different from the above. The transistor 4b that monitors the voltage, or the speaker 3 or the speaker control unit 6 that controls the transistor 4b may be omitted. Furthermore, in the present embodiment, it is applied as an anti-theft device for automobiles, but it is applied to various four-wheeled vehicles, two-wheeled vehicles, ATVs, PWCs, snowmobiles, outboard motors, construction machines, and the like. May be.

  Further, the installation location of the antenna unit 2A is not limited to the vicinity of the keyhole, and the user can install it at an arbitrary position, and the installation location of the immobilizer body 1 is not limited to the driver seat side, for example, on the passenger seat side. Can be installed. Furthermore, in the present embodiment, the ID code is authenticated after the ignition key is inserted into the key hole. However, the ignition key may be inserted into the key hole after the ID code is authenticated. Good. In this case, it is desirable to limit the time from the authentication of the ID code to the insertion of the ignition key into the key hole to a certain time (for example, within one minute).

  After the ignition key is inserted into the key hole and opened, a normally closed relay that is closed when it is determined that the received ID code is genuine is provided in the middle of the engine start circuit. If it exists, it can be applied to various immobilizers such as an external shape and other functions added.

The external view which shows the immobilizer main body and antenna part in the immobilizer which concerns on embodiment of this invention II-II sectional view in FIG. Side view showing the antenna part of the immobilizer Front view, top view and side view showing transmission means of the immobilizer VV line sectional view in FIG. The immobilizer main body of the same immobilizer, the antenna part, the key detection switch which the vehicle side comprises, and the schematic diagram which shows the wiring state in an engine starting circuit

Explanation of symbols

1 Immobilizer body 2 Antenna part 2a Antenna (receiving means)
3 Speaker 4 Control Unit 5 Normally Closed Relay 6 Speaker Control Unit 7 Start Switch 8 Key Detection Switch (Key Detection Means)
9 Cell Starter 10 Transmitting Means 10b Transponder L1, L2 Wiring Constructing Engine Start Circuit C Connector C1-C4 Wiring

Claims (2)

A transmission means that the driver can carry and transmits a unique ID code;
Receiving means capable of receiving the ID code transmitted from the transmitting means;
Determining means for determining whether or not the ID code received by the receiving means is a preset regular one;
When the determination means determines that the ID code received by the receiving means is authentic, the engine can be started, and when the received ID code is determined not to be authentic, the engine An engine start permission means for making the start impossible,
An immobilizer having
The engine start permission means comprises a normally closed relay disposed in the middle of the engine start circuit, and can be opened and closed based on a detection signal of a key detection means for detecting that the ignition key is inserted into the key hole. When the key detection means detects the ignition key and enters the open state to place the engine start circuit in a non-conductive state, and then the determination means determines that the ID code received by the reception means is authentic. An immobilizer characterized in that when the engine is closed again, the engine start circuit is turned on to enable the engine to start.   2. The immobilizer according to claim 1, wherein the transmitting means includes a transponder capable of transmitting an ID code and is separate from the ignition key.

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