JP3814908B2 - Key insertion detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a key insertion detection device that detects whether or not a key is inserted into a key cylinder.
[0002]
[Prior art]
Conventionally, as a key insertion detection device that detects whether a key has been inserted into the key cylinder in order to activate the key-forgetting key warning / key lock-in prevention function, room lighting timer, etc., when a key is inserted into the key cylinder itself, There is a built-in mechanical key insertion detection switch that turns on and turns off when the key is removed (or vice versa), and turns on the interior lighting when the door switch detects that the door has been opened When the key insertion detection switch detects key insertion, the interior lighting is turned off. When the key insertion detection switch detects key insertion, the door switch signal is detected to be opened. An alarm is issued when it is determined that the key has been forgotten.
[0003]
[Problems to be solved by the invention]
However, in such a conventional key insertion detection device, since the mechanical key insertion detection switch is incorporated in the key cylinder, the structure of the key cylinder is complicated, the size is increased, the weight is increased, and the cost is increased. It was a factor of deterioration.
[0004]
The present invention has been made in view of such a conventional problem. By determining key insertion detection based on a combination of signals from an existing immobilizer and a door switch used as a vehicle antitheft system, An object of the present invention is to provide a key insertion detecting device capable of correctly detecting key insertion without adding mechanical elements to the equipment.
[0008]
[Means for Solving the Problems]
The key insertion detecting device according to the first aspect of the present invention includes a key incorporating a transponder that transmits an ID code registered in response to a magnetic field, and a main body of the key cylinder or near the key cylinder. An immobilizer that receives an ID code signal from the transponder, collates the ID code, determines that it is a genuine key when the collation is established, and starts communication regarding engine start with the engine control unit; And a key presence detection means for generating a magnetic field in the immobilizer when the engine is turned off by the key and executing the key ID code verification, and outputting a key detection signal when the ID code verification is established. It is a thing.
[0009]
In the key insertion detecting device according to the second aspect of the present invention, when the key presence detecting means performs an engine-off operation by the key, the immobilizer generates a magnetic field to execute the key ID code verification, and the ID code verification is established. Key detection signal is output.
[0010]
As a result, the combination of the existing vehicle anti-theft equipment and door switch signal detects that the door has been opened while the key is still inserted into the key cylinder, and forgets to remove the key and prevents the key from being locked. The key cylinder does not require a mechanical key insertion detection switch to be incorporated into the key cylinder. The structure of the key cylinder, which has been a problem in the past, becomes complicated, and the size increases, resulting in an increase in weight and cost. In addition, it is possible to prevent deterioration in vehicle mountability.
[0012]
【The invention's effect】
According to the first aspect of the present invention, it is detected that the door is opened while the key is inserted into the key cylinder by the combination of the signal of the door switch and the existing vehicle theft prevention equipment, and the key is removed. The necessary signal for the forgetting alarm / key lock-in prevention function can be taken out, and it is not necessary to incorporate a mechanical key insertion detection switch in the key cylinder. The structure of the existing key cylinder is complicated, and the structure can be increased to prevent weight increase, cost increase, and vehicle mountability.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a circuit configuration of one embodiment of the present invention. A key 1 is incorporated with a transponder 2 that is excited under a weak magnetic field and transmits a unique ID code signal registered in advance. Yes. The key cylinder 3 on the vehicle side incorporates an antenna 4 that transmits and receives signals to and from the transponder 2 and an amplifier (AMP) 5 that amplifies the signal. An immobilizer (IMMC / U) 6 is connected to the amplifier 5, and the immobilizer 6 is connected to an engine control unit (ECM) 7. A signal from the door switch 8 is input to the immobilizer 6 and a key insertion detection signal KS is output based on a determination function described later.
[0014]
FIG. 2 shows the functional configuration of the immobilizer 6. An electric field generator 6 a that has been conventionally provided as a vehicle antitheft function, a key ID receiver 6 b that receives a key ID code signal, and a key ID code registered in advance. A key ID collating unit 6c that collates with the ID code of the authentic key that has been set, and when this key ID collating unit 6c determines that the collation has been established, communicates with the engine control unit 7 side to collate the engine start permission ID code. The collation unit 6d has an engine start ID registration unit 6e that determines and registers the next engine start permission ID code with the engine control unit 7 when the engine is off, and a key state determination unit 6f that determines whether the engine is on / off from the key position. I have.
[0015]
In addition to these, the immobilizer 6 of the present invention further outputs a door switch signal input unit 6g for inputting an on / off signal of the door switch 8 by opening and closing the door, and a key ID code verification establishment determination signal of the key ID verification unit 6c. The key insertion determination unit 6h that determines that the key 1 has been inserted into the key cylinder 3 is received, and when the key insertion determination unit 6h determines that the key is inserted, the determination signal KS is used as an alarm for forgetting to remove the key and a key confinement prevention circuit. A key insertion determination signal output unit 6j that outputs to the outside for use in an indoor lighting timer circuit or the like is provided.
[0016]
Next, the operation of the key insertion detection device having the above configuration will be described. FIG. 3 shows a flowchart of the key insertion detection operation in the immobilizer 6 particularly when the user who has the genuine key opens the driver's seat door and gets in, and inserts the key into the key cylinder. This process flow is started by inputting a door opening signal from the door switch 8 (step S1), and the immobilizer 6 excites the antenna 4 in the electric field generator 6a (step S2).
[0017]
When the user inserts the key 1 into the key cylinder 3 (step S3), the transponder 2 of the key 1 responds under the weak magnetic field generated by the antenna 4 and transmits a key ID code signal. Receive it. This key ID code signal is amplified by the amplifier 5 and input to the immobilizer 6, analyzed by the key ID receiving unit 6b, and verified by the key ID collating unit 6c with the ID code of the authentic key registered in advance. Then, it is determined as a genuine key (step S4).
[0018]
If the verification of the key ID code is established, the immobilizer 6 exhibits the vehicle anti-theft function as before, and the engine start ID verification unit 6d communicates with the engine control unit 7 to perform verification of the engine start permission ID code. If the verification of the engine start permission ID is established, fuel supply to the engine is permitted and the engine can be started. At the same time, when the verification of the key ID code is established, the key insertion determination unit 6h determines that the key has been inserted, and causes the key insertion detection signal output unit 6j to output the key insertion detection signal KS to the outside (step S5).
[0019]
If the door switch signal input unit 6g determines from the signal of the door switch 8 that the door is closed (step S6), the electric field generation unit 6a receives this and stops the excitation of the antenna 4 (step S7), and inserts the key. The output of the detection signal is stopped, and the key insertion detection process is terminated (step S8).
[0020]
The immobilizer 6 performs a key insertion determination process shown in FIG. That is, the key state determination unit 6f detects that the accessory switch has changed from on to off and starts the process of this flowchart (step S11). The electric field generation unit 6a excites the antenna 4 to generate a weak magnetic field. (Step S12). Under the weak magnetic field generated by the antenna 4, the transponder 2 of the key 1 responds and transmits a key ID code signal, and the key ID receiving unit 6b receives it via the antenna 4 (step S13). If the key ID collating unit 6c collates with the ID code of the authentic key and the collation is established, the key insertion detection signal output unit 6j outputs the key insertion detection signal KS to the outside (step S14).
[0021]
Subsequently, when the key insertion determination unit 6h determines that the key has been pulled out because the key ID reception unit 6b of the immobilizer 6 stops receiving the key ID code signal (step S15), the electric field generation unit does not forget to remove the key. 6a stops the excitation of the antenna 4 and ends the key insertion detection process (step S16).
[0022]
However, while the key 1 remains inserted in the key cylinder 3 after the engine is turned off, the determination in step S15 branches to NO, and the door switch signal input unit 6g receives a door open signal from the door switch 8. If the door is not opened, the process from step S12 is repeated. If the door is opened, the process proceeds to step S1 in the flowchart of FIG. 3 (step S17). Therefore, in this key insertion detection device, after the engine is turned off, the key detection signal KS is continuously output until the key 1 is removed from the key cylinder 3.
[0023]
This key insertion detection signal KS is used in a key removal forgotten alarm / key confinement prevention circuit. That is, when the door opening signal is received from the door switch 8 while receiving the key insertion detection signal KS from the immobilizer 6, it is determined that the door is opened while the key 1 is inserted into the key cylinder 3, and the key is forgotten to be removed. Is to emit.
[0024]
In this way, according to the embodiment of the present invention, by incorporating some determination functions into the existing functions of the key and immobilizer built in the transponder that have been conventionally used as a vehicle antitheft device, Thus, key insertion detection can be performed accurately without incorporating a mechanical key insertion detection switch into the key cylinder, and the key cylinder can be made smaller and lighter. Complicated and large in size can prevent weight increase, cost increase, and vehicle mountability deterioration.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of one embodiment of the present invention.
FIG. 2 is a block diagram showing a functional configuration of an immobilizer in the embodiment.
FIG. 3 is a flowchart of a key insertion detection operation when entering the vehicle according to the embodiment.
FIG. 4 is a flowchart of a key insertion detection operation when the engine is stopped according to the embodiment.
[Explanation of symbols]
1 Key 2 Transponder 3 Key cylinder 4 Antenna 5 Amplifier 6 Immobilizer 7 Engine control unit 8 Door switch

Claims (1)

A key with a built-in transponder that responds to a magnetic field and transmits an ID code registered in itself;
The key cylinder main body is installed near the key cylinder, generates the magnetic field, receives the ID code signal from the transponder, collates the ID code, and determines that the key is authentic when the collation is established, An immobilizer for starting communication regarding engine start with the control unit;
Key presence detection means for generating a magnetic field in the immobilizer when the engine is turned off by the key and executing the key ID code verification, and outputting a key detection signal when the ID code verification is established. A key insertion detection device.

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