JPH0460074A - Key ridge detector - Google Patents

Abstract

PURPOSE:To surely prevent illegal unlocking by providing a key made of a magnetic material, a magnetic substance member provided around the key hole of a key barrel, and a means detecting the magnetic characteristic of a magnetic circuit changed in response to the key ridge shape of the key. CONSTITUTION:When a key 1 is inserted into the key hole 2a of a key barrel 2, a magnetic circuit is formed via a gap between the key 1 and a magnetic substance 3. When the key 1 is inserted into the key hole 2a in sequence, the magnetic circuit is changed in response to the change of the shapes of key ridges 1a, 1b. The inductance of an electric coil 4 is measured by an electric circuit, and electrical signals in response to the key ridges 1a, 1b are inputted to a judging circuit. The judging circuit compares these electrical signals with the previously stored normal electrical signals corresponding to the inductance of the key 1, it operates an unlocking system if they coincide, and the key barrel 2 is rotated together with the key 1 for unlocking.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a key pile detector for a key of a key device configured by combining mechanical and electrical key information, and particularly relates to a key pile detector for a key made of a magnetic material. The present invention relates to a key pile detector suitable for detecting key pile information through magnetic coupling with a magnetic member on the key barrel side to prevent unauthorized unlocking.

[Conventional technology]

Key devices are widely used, for example, in doors of houses and automobiles, and in various devices. In recent years, instead of the mechanical keys that have been used for a long time, electric or electronic keys that detect magnetic codes or optical codes are being used as key devices.
Alternatively, highly reliable keys can be created by using both together. For example, as shown in FIG. 7, a so-called barcode in a striped black and white pattern is provided on the side surface of a key 1 having locks 1a and lb on both sides, and this barcode is read by a light emitting element 3 and a light receiving element 4, The key structure is such that the lock can be unlocked if it matches the registered pattern and the key pile 1a1b also matches.

[Problem to be solved by the invention]

In the optical key device of the above-mentioned type, barcode patterns are easily read, duplicate keys are easily made, and it is also susceptible to dirt and the like. Furthermore, the optical system for reading the pattern requires precision, and a sophisticated discrimination circuit is also required, making it relatively expensive.

An object of the present invention is to provide a highly reliable key pile detector for a key device that can prevent unauthorized unlocking with a simple and inexpensive structure.

[Means to solve the problem]

In order to achieve the above object, the key peak detector of the present invention is made of a magnetic material and has a key peak formed therein. - a key, a key barrel having a keyhole, a magnetic member provided around the keyhole of the key barrel and forming a magnetic circuit when the key approaches, and a magnetic circuit that changes depending on the shape of the front key thread. and means for detecting the magnetic properties of the magnetic field.

[For production]

When a regular key is inserted into the keyhole of the #I cylinder, a magnetic circuit is formed in the magnetic material provided around the keyhole. The magnetic properties of this magnetic circuit are determined by the cross-sectional area of the key, and this cross-sectional area varies depending on the position of the key. Therefore, since the magnetic characteristics unique to the key are obtained by the shape of the key, this magnetic characteristic is detected by the detection means, and when the magnetic characteristics match the magnetic characteristics of the regular key, the lock can be unlocked.

〔Example〕 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows the structure of a key peak detector that detects the magnetic resistance that changes between the key and the U-shaped magnetic body when the key is inserted. The key 1 is formed into a plate shape using a magnetic material t4 such as iron, and has a plurality of key locks 1a on each of two opposing sides.
1b is formed.

Further, a keyhole 2a is provided in the front end face of a key barrel 2 provided in a key device (not shown). A U-shaped magnetic body 3 is attached around the inside of the keyhole 2a, and an electric coil 4 is wound around a part of the magnetic body 3. smart electric coil 4
As shown in FIG. 2, an electric circuit 5 is connected to measure the inductance of the electric coil 4, and the shapes of the key ridges 1a and lb of the key 1 are electrically detected by this electric circuit 5. A discrimination circuit I@6 is connected to the electric circuit 5, which compares this electric signal with an electric signal based on a regular keychain shape and determines whether they match or not, and the discrimination circuit 6 determines whether the two signals match. When this occurs, the unlocking mechanism 7 is operated to enable unlocking.

Next, the operation of this embodiment will be explained. m 1 in the second keyhole 2a
In the process of inserting the key 1, the key 1 enters inside the U-shaped magnetic body 3, and a magnetic circuit is formed between the key 1 and the magnetic body 3 through a gap. The magnetic resistance of this magnetic circuit changes depending on the insertion position of #11.

In other words, the magnetic path length of the magnetic circuit carried by the key 1 is the thickness t of the key 1.
The cross-sectional area is constant at each key peak 1a, 1
It varies depending on the position of b and is proportional to the width of the key 1. For example, the width of the tip of ml is a, and the width of the adjacent key thread is b, and b>a, so the magnetic resistance of the magnetic circuit is smaller at the key thread than at the tip. By sequentially inserting the keys 1 into the keyholes 2a in this way, the locks 1a.

The magnetic circuit formed by the key 1 and the magnetic body 3 changes according to the change in the shape of the key 1b.

On the other hand, an electric coil 4 is wound around the magnetic body 3, and the inductance of this electric coil 4 changes according to changes in the magnetic resistance of the magnetic circuit. The relationship between magnetic resistance and inductance is inversely proportional; as magnetic resistance increases, inductance decreases. Therefore, by measuring the inductance of the electric coil 4 using the electric circuit 5, an electric signal corresponding to the locks 1a, lb of the key 1 can be obtained.

Judging this electrical signal 11th time! r 6 and compare it with the electrical signal for the inductance of the regular key 1 stored in advance. If they match, the unlocking mechanism 7 can be activated to electrically unlock the key, and the key 1 and Rotate the key barrel 2 together to unlock.

According to this embodiment, by combining with a conventional mechanical unlocking device, it becomes a double key device, and unauthorized unlocking can be reliably prevented. Furthermore, since the key threads 1a and 1b are detected non-contact by magnetic means, there are no moving parts and reliability can be improved. Furthermore, even if the position of the key 1 is slightly shifted vertically or horizontally within the keyhole 2a, the change in magnetic resistance is not significantly affected and the lock can be unlocked easily.

Other embodiments of the present invention will be described below. Note that parts that are the same as or equivalent to those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and their explanations will be omitted.

FIG. 3 shows a key pile detector having a structure in which an electric coil is provided on the middle side of a mouth-shaped magnetic body 3. Mouth-shaped magnetic material 3
The intermediate side thereof is arranged parallel to the longitudinal direction of the keyhole 2a, and the electric coil 4 is wound around this intermediate side.

The magnetic path length of the magnetic circuit carried by the key 1 is the width II (for example, a and b shown in FIG. 1), and differs depending on the position of each key thread Ia and Ib. On the other hand, the cross-sectional area of the magnetic circuit is constant and does not change. Therefore, in this case as well, by inserting #11 into the key hole 2a, the magnetic path length changes in each key thread 1a, 1b, and the value of magnetic resistance changes. For example, there is a relationship baa between the width a of the tip of the key 1 and the width of the adjacent key thread part, and the magnetic path length carried by the key 1 is longer in the key thread part, but on the other hand, the air gap is shorter. As a result, the overall magnetic resistance is smaller at the key crest. This is because the magnetic resistance of the air gap is greater than that of the magnetic material. As the key 1 is inserted in this way, the magnetic resistance changes depending on each key thread, and as in the first embodiment, the key threads 1a, 1a,
1b can be detected electrically.

FIG. 4 shows a key peak detector using a Hall element. The mouth-shaped magnetic body 3 is a quadrangular prism-shaped permanent magnet 6 which is parallel to the longitudinal direction of the keyhole 2a and is opposed to the square prism-shaped magnetic bodies 3a and 3b.
are connected. A magnetically sensitive element 5 such as a Hall element or a magnetoresistive element that detects magnetism and converts it into an electric signal is provided at one of the connecting parts. The permanent magnet 6 is magnetized in the longitudinal direction.

When the key 1 is inserted into the keyhole 2a, a magnetic circuit is formed between the magnetic bodies 3a, 3b having the permanent magnet 6 and the key 1, and within this magnetic circuit, the magnetism generated by the permanent magnet 6 forms a closed loop. The magnetically sensitive element 5 detects the magnetic flux density within this closed loop.

Incidentally, as in the first embodiment, the magnetic resistance of the magnetic circuit differs depending on the position of the key crest of the key 1. On the other hand, since the magnetic flux density in the magnetic circuit is inversely proportional to the magnetic resistance, the locks 1 a and 1 b of the key 1 can be detected by the magnetic density detected by the magnetically sensitive element 5, that is, by the electric signal emitted from the magnetically sensitive element 5. I can do it.

FIG. 5 shows another embodiment using a Hall element, and shows a key peak detector constructed of an electric coil 7 instead of the permanent magnet 6. An electric coil 7 is wound around the rectangular columnar magnetic body 3C, and magnetism is generated by passing a current through the electric coil 7.

The operation of this embodiment is almost the same as that of the third embodiment, but
The generated magnetism can be electrically controlled and stable magnetism can be supplied.

FIG. 6 shows a key pile detector using two electric coils 4. The mouth-shaped magnetic body 3 has a first electric coil 4a.
and a second electric coil 4b are wound. Note that these two electric coils 4a.

4b may be wound in an overlapping manner at the same position.

In this embodiment, as in the first embodiment, changes in the magnetic resistance of the magnetic circuit formed by the key 1 and the magnetic body 3 can be electrically detected. That is, the first electric coil 4a and the second
It is magnetically coupled to the electric coil 4b by a magnetic circuit, and the mutual conductance between the two is inversely proportional to the magnetic resistance of the magnetic circuit. Therefore, when a constant alternating current is passed through the first electric coil 4a, a voltage that is inversely proportional to the magnetic resistance of the magnetic circuit is generated at both ends of the second electric coil 4b. can be detected.

〔Effect of the invention〕

As mentioned above, according to the present invention, the distance is 1 m! By combining it with a mechanical unlocking device, it becomes a double key device and can reliably prevent unauthorized unlocking.

Moreover, since the key pile is detected non-contact by magnetic means,
The structure is simple and there are no moving parts, so the reliability of key pile detection can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of the first embodiment of the present invention, FIG. 2 is a block diagram for processing key information, FIGS. 3 and 4,
5 and 6 are the second, third, and fourth embodiments of the present invention, respectively.
FIG. 7 is a perspective view showing the configuration of a fifth embodiment, and FIG. 7 is a basic configuration diagram of a conventional optical key device. 1... Key, 1 a 1 b, Key stock, Key barrel a, Key hole, Magnetic material, 4° electric coil, ... Magnetic sensing element, - Permanent magnet (magnetism generating means).

Claims (1)

[Claims] (1) A key made of a magnetic material and having a lock formed thereon, a key barrel having a keyhole, a magnetic member provided around the keyhole of the key barrel and forming a magnetic circuit when the key approaches; A key pile detector comprising means for detecting magnetic characteristics of a magnetic circuit that change depending on the shape of the key pile.