JPH0732142U - Key device - Google Patents

Abstract

(57) [Summary] [Purpose] Minimize the time required for one frequency sweep. [Structure] By changing the frequency by sweeping the frequency, which is started by inserting the key into the lock, the sweep time is shortened and the output of the engine drive permission signal is accelerated.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a key device suitable for preventing theft of a vehicle or the like.

[0002]

[Prior art]

 As a conventional key device, there is, for example, one shown in Japanese Patent Publication No. 4-15141, which will be described with reference to FIGS. 3 to 6. In the figure, a key insertion hole 12 is formed in the lock 10, and an annular rotor case 14 is fixed to the entrance side of the key insertion hole 12 of the lock 10. A cylindrical rotor 16 is rotatably mounted inside the rotor case 14. The rotor 16 has a key insertion hole 18 communicating with the key insertion hole 12. Further, as shown in FIG. 4, an annular core 22 having a tapered surface on the outer inner surface is arranged on the outer periphery of the rotor 16. One end 22A of the annular core 22 is formed in a taper shape and is exposed at the entrance end of the key insertion hole 18. The rotor coils 24 and 26 are wound around the annular core 22 in the same direction.

The rotor coils 24 and 26 are connected to a variable frequency oscillator 30 via a resistor 28, as shown in FIG. The variable frequency oscillator 30 supplies a signal for information detection to the rotor coils 24 and 26 in response to a command from the microcomputer 32. The rotor coils 24 and 26 are connected to the microcomputers 24 and 26 via an amplifier 34, a diode 36, a capacitor 37, and an A / D converter 38. Then, information on the current flowing through the rotor coils 24 and 26 is detected as a voltage drop of the resistor 28, and the detected output is supplied to the microcomputer 32 via the amplifier 34, the diode 36 and the A / D converter 38. .

Then, the microcomputer 32 as a control unit controls the operation of the engine drive unit based on the information from the A / D converter 38. That is, the information based on the signal from the A / D converter 38 is compared with the determination information previously stored in the ROM 39, and the engine drive permission signal is output to the engine drive unit only when the contents of both are matched. It has become.

Further, the tip side 20 C of the grip portion 20 B of the key 20 is formed in a tapered shape that can engage with the tapered surface of the annular core 22. A shaft-shaped core 40 is mounted in the middle of the tip side 20C so as to connect the pair of tapered surfaces. This axial core 40 has a key coil 42 wound in one direction, which is magnetically coupled to the rotor coils 24 and 26 when the key 20 is inserted into the key insertion hole 12. The key coil 42 is connected to a coil L1 and a capacitor C1 that form a resonance circuit, and also forms a resonance circuit, and is connected in parallel to the coil L2 and the capacitor C2 to the resonance circuit. Note that the capacitances of the coils L1 and L2 and the capacitors C1 and C2 are set so that the resonance frequencies of the resonance circuits are different from each other.

Then, a signal for information detection is supplied from the variable frequency oscillator 30 to the rotor coils 24 and 26, and when the frequency of this signal changes from the lower side to the higher side as shown in FIG. A current flows through the rotor coils 24 and 26 according to the change of The current I1 in FIG. 6 shows the current value due to the resonance of the coil L1 and the capacitor C1, and the current I2 shows the current value due to the resonance of the coil L2 and the capacitor C2.

When the currents shown in FIG. 6 are supplied to the microcomputer 32 via the amplifier 34, the diode 36, and the A / D converter 38, respectively, these pieces of information are sequentially read by the microcomputer 32, If this judgment signal is compared with information stored in advance in the ROM 39 as judgment information and the engine drive permission signal is output only when this signal matches the judgment information, the key 20 is inserted. The engine can be driven only when it is inserted into the hole 18. This prevents the vehicle from being stolen due to unauthorized unlocking.

[0008]

[Problems to be solved by the device]

 However, in such a key device, the frequency output from the variable frequency oscillator has a configuration in which the frequency is continuously swept from the lowest frequency to the highest frequency within a predetermined range. It took a lot of time. Therefore, the engine is not driven even if it is a legitimate key until the driver inserts the key into the lock and the verification ends, and the engine drive permission signal is generated and output, waiting for the driver. There was a problem that I had to do it.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to reduce the time required for one sweep of the frequency as much as possible.

[0010]

[Means for Solving the Problems]

 A key device according to the present invention detects a rotor core arranged around a key insertion hole of a lock, a signal generating means for supplying an information detection signal to a rotor coil provided in the core, and a signal transmitted to the rotor coil. The signal detection means and the output signal of the signal detection means are fetched, the information based on the signal is compared with the stored judgment information, and the engine drive permission signal is issued only when the information contents of the two match. And a key formed so that it can be inserted into the key insertion hole of the lock, and the key is a shaft that forms a magnetic circuit close to the rotor core at two positions when the key is inserted. -Shaped core, a key coil wound around an axial core and magnetically coupled with a rotor coil when a key is inserted, and a signal containing specific information in response to a signal induced in the key coil. And an information generating means for generating Le, the frequency of the information detection signal is to change discontinuously for each frequency, including the estimated values.

[0011]

[Action]

 According to this invention, the sweep time is shortened by discontinuously changing the frequency caused by the insertion of the key into the lock, thereby speeding up the output of the engine drive enable signal.

[0012]

【Example】

 Hereinafter, an embodiment according to the present invention will be described in detail with reference to FIGS. 1 and 2. In FIG. 1, the same or equivalent components as those of the conventional example shown in FIGS. 3 to 6 are designated by the same reference numerals, detailed description thereof will be omitted, and only different portions will be described.

That is, in FIG. 1, 50 is a resonance detection circuit, the input terminal of which is connected to the connection point between the resistor 28 and the rotor coil 26, and the resonance frequency is detected and detected every time the resonance frequency is detected from the voltage change at that point. A reading instruction signal is output to a frequency reading circuit 51 described later. The frequency reading circuit 51 is constantly input to monitor the frequency of the information reading signal supplied from the variable frequency oscillator 54 to the rotor coils 24 and 26, and when receiving the reading instruction signal from the resonance detecting circuit 50, At that time, the frequency of the information detection signal output from the variable frequency oscillator 54 is supplied to the microcomputer 52. Reference numeral 54 denotes a frequency variable oscillator, which is structurally the same as the frequency variable oscillator 30 in FIG. 3, except that the frequency of the information detection signal output according to the signal supplied from the microcomputer 52 is discontinuously changed. different. The microcomputer 52 has almost the same function as the microcomputer 32 in FIG. 3, but the different points will be described below.

That is, the microcomputer 52 detects the number of resonance frequencies supplied from the frequency reading circuit 51, and has, for example, 7 resonance points, and the pattern stored in the ROM 53 at 7 resonance frequencies. If it is determined that a predetermined resonance point of the same pattern as any of them appears, the comparison work is stopped by comparing the pattern of the resonance frequency and the resonance frequency stored in the ROM 53, and the engine drive permission signal is not generated, and the comparison is performed. If the result is good and it is determined that the key is the proper key 20, the engine drive permission signal is output.

Further, the microcomputer 52 reads the resonance frequency combination table stored in the ROM 53 each time the resonance frequency is supplied from the frequency reading circuit 51, and reads the combination of the resonance frequencies supplied up to the previous time. The next resonance frequency is predicted from the pattern, and the frequency of the information detection signal output from the variable frequency oscillator 54 is changed based on the prediction result.

Next, the operation of the above configuration will be described based on the flowchart shown in FIG. When the key 20 is inserted into the lock 10, the microcomputer 52 detects it and proceeds to the start step 100 to initialize the inside of the microcomputer 52. In the next initial frequency setting step 101, a signal for setting the start frequency (minimum frequency) for sweeping the frequency output from the variable frequency oscillator 54 is output from the microcomputer 53 to the variable frequency oscillator 54 (this Therefore, the frequency variable oscillator 54 discontinuously raises the output frequency according to the instruction of the microcomputer 52). In the resonance frequency reading step 102, the microcomputer 52 reads the resonance frequency supplied from the frequency reading circuit 51.

In the resonance frequency pattern comparison step 103, the combination pattern of the resonance frequencies stored in the ROM 53 is compared with the read resonance frequency pattern. As a result of the comparison and comparison, when it is determined that the predetermined number of resonance frequencies are not yet obtained, the process proceeds to the resonance frequency estimation step 104, and the next resonance frequency is predicted from the combination of the resonance frequencies obtained so far. Then, in the oscillation frequency output step 105, the microcomputer 52 outputs a signal for instructing the frequency of the next information read signal to the frequency variable oscillator 54.

When it is determined that both patterns are the same in the resonance frequency pattern step 103, the process proceeds to an engine drive permission signal creating step 106, and the microcomputer 52 drives the engine drive system (not shown) to drive the engine. A permission signal is output, and in the next end step 107, the collation work according to the above flow chart is ended.

[0019]

[Effect of device]

 As described above, according to this invention, the key code can be verified in a short time, and the vehicle can be started quickly.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a key device according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the configuration of FIG.

FIG. 3 is an overall explanatory view of a key device showing a conventional example.

FIG. 4 is an explanatory diagram of a rotor core and a rotor coil wound around it in FIG.

5 is a circuit block diagram connected to the key device shown in FIG. 3. FIG.

FIG. 6 is a diagram for explaining the operation of the conventional example.

[Explanation of symbols]

 20 key 50 resonance detection circuit 51 frequency reading circuit 52 microcomputer 53 ROM 54 frequency variable oscillator

Claims (1)

[Scope of utility model registration request] 1. A signal generating means for supplying an information detection signal to a rotor core (22) arranged around a key insertion hole (12) of a lock (10) and a rotor coil (24, 26) provided in the core. (30) and rotor coil (24, 26)
Signal detecting means (28, 3) for detecting a signal transmitted to
4, 36, 38) and the output signal of the signal detecting means, the information based on the signal is compared with the stored determination information, and the engine drive permission signal is sent to the engine only when the information contents of the two match. Control means for outputting to the drive unit (3
2) and a key (20) formed to be inserted into the key insertion hole (12) of the lock (10), and the key (20) is provided with the rotor core (22) and the rotor core (22) when the key is inserted.
Axial cores (40) closely forming a magnetic circuit at one place
And a rotor coil (2
4, 26), and a key coil (42) magnetically coupled to the key coil (42), and information generating means (42, L1, L2) for generating a signal containing specific information from the key coil (42) in response to a signal induced in the key coil. , C1, C2), and the frequency of the information detection signal changes discontinuously for each frequency including the estimated value.