JPH0241637B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic key,
In particular, the present invention relates to a method for manufacturing a magnetic key that is simple with fewer steps and that can produce a magnetic key without the risk of the magnet falling off.

As shown in Fig. 1, a plurality of magnetic keys (the one shown is 10
It has permanent magnets 2, 2 embedded therein, and is used for unlocking a so-called magnetic tumbler lock (not shown). That is, as is well known, a magnetic tumbler lock has a plurality of so-called magnetic tumblers equipped with permanent magnets movably arranged therein, and when a magnetic key is inserted into a keyhole formed in the inner cylinder of the magnetic tumbler lock, , permanent magnet 2 of the magnetic key,
The magnetic tumbler is moved using the magnetic attractive force and/or magnetic repulsive force that acts between the permanent magnet of the corresponding magnetic tumbler, and the inner cylinder can be rotated by aligning the end face of each magnetic tumbler on the shear line. do.

The functions and effects of such a magnetic key in a magnetic tumbler lock are not the gist of the present invention, and are described in, for example, Japanese Patent Publication No. 56-23031, so a detailed explanation will be omitted.

It should be noted that each permanent magnet (hereinafter simply referred to as a magnet) 2 of the magnetic key shown in the first figure is magnetized in the direction of the page or in the width direction of the main body 1, and is disposed so as to extend flatly on the side surface of the main body 1. However, there are also magnetic keys in which the magnet 2 is embedded in the side edge of the main body 1, depending on the type of the corresponding magnetic tumbler lock.

[Conventional technology and problems]

One of the methods for manufacturing the above-mentioned magnetic key is to form a recess (not shown) into which the magnet 2 fits into the main body 1 (see FIG. 1), for example, by die-casting. The magnet is fixed by interposing an adhesive in the gap between the magnet 2 and the inner surface and/or bottom surface. However, the method of fixing the magnet with adhesive has the disadvantage that, for example, due to aging or impact caused by falling of the magnetic key, the adhesive may peel off or be sheared, causing the magnet to fall off from the main body. .

Another manufacturing method is to cover the keyhole insertion portion of the main body 1 together with the magnets 2, 2 with a thin sheath 3 made of a non-magnetic material, as shown in FIG. 2, for example. However, the manufacturing method for this magnetic key involves a step of manufacturing a sheath body 3 having the same cross-sectional shape as the main body 1 by molding a thin tube, and after fitting the sheath body 3 onto the main body 1, the former is brought into close contact with the latter. In order to tighten the entire surface of the sheath body 3 and to prevent the sheath body 3 from shifting in the length direction of the body 1, the end edge of the body 1 is crimped with a punch, for example. This has the disadvantage of requiring complicated manufacturing processes and manufacturing equipment, such as a process of crimping from the outside.
Furthermore, since the distance between the magnet 2 and the magnet of the magnetic tumbler is increased by at least the thickness of the sheath body 3, the force driving the magnetic tumbler is correspondingly weakened.

Furthermore, the opening edge of the recess containing the magnet 2 is plastically deformed by hitting with a thin punch or pressing with a press tool so that the inner surface of the recess protrudes toward the magnet. A method of fixing the magnet by strongly holding the magnet between the inner surfaces of the part is also considered.

However, the former method is not only troublesome because each magnet must be fixed one by one, but also unevenness occurs around the magnet due to punch marks and burrs (not shown). Relatively strong pressure is required to press all the edges of the opening at the same time, and the required plastic deformation force varies greatly depending on the clearance between the magnet 2 and the inner surface of the recess, so it is difficult to set it, and it is difficult to tighten it sufficiently. However, there are disadvantages in that the magnets may fall off or, in some cases, may crack due to excessive plastic deformation.

[Purpose of the invention]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a magnetic key that is simple in process and easy to implement, and that can produce a magnetic key in which there is no risk of the magnet falling off from the main body.

[Means for solving problems]

In order to achieve the above object, the present invention forms a plurality of recesses for accommodating magnets at predetermined locations of a magnetic key made of a non-magnetic material, and at least one small recess near the opening edge of each recess. A main body molding process in which protrusions are provided, a magnet filling process in which magnets are filled into each concave portion with the magnetization direction directed in a predetermined direction according to the different keys of the corresponding magnetic tumbler lock, and a small A magnet fixing step in which the inner surface of the recess is plastically deformed so as to curve and protrude toward the magnet by crimping the protrusion, and the magnet is thereby firmly pressed against the inner surface of the recess and clamped to be fixed. It is characterized by

Embodiments of the present invention will be described below with reference to FIGS. 3 to 11.

Example 1 The first step of the method of the present invention is to mold a non-magnetic metal such as a zinc alloy by die casting, and as shown in FIGS. This is a main body forming step in which a plurality of recesses 4, 4 for housing magnets are formed, and at least one small protrusion 5 is integrally formed in the vicinity of the opening edge of each recess. In the illustrated embodiment, the small protrusions 5 are protrusions formed along the opening edges of the recessed portions 4, and are formed along a pair of opening edges facing each other in the length direction of the main body 1 of each recessed portion 4. Two pieces are formed.

The cross-sectional shape of the small protrusion 5 is, for example, a sawtooth shape as shown in FIG. 4, and the side surface facing the recess 4 is an extension of the inner surface of the recess 4.

Further, in the illustrated embodiment, the shape of the magnet 2 is a rectangular parallelepiped or a cube, so the shape of the opening of the concave portion 4 is rectangular. However, if the magnet 2 is a cylinder, the opening will be circular. Of course. In this case, the entire small protrusion 5 is formed in an arc shape along the opening edge of the recess (not shown).

Note that the small protrusions 5, 5 can be formed by slightly modifying the mold of a conventional main body casting machine,
After all, this body molding process can be easily carried out using conventional production equipment.

Next, as shown in FIGS. 5 and 6, depending on the different keys of the corresponding magnetic tumbler locks, that is, the combination of the magnetization directions of the magnets of the magnetic tumblers inside the tumbler locks that are to be unlocked by this magnetic key, Each concave portion 4 is filled with magnets 2 such that the magnets 2 are magnetized in a predetermined direction.

That is, depending on the designated magnetization direction of the magnet 2 filled in each concave part 4, the magnet 2 may be directed so that, for example, the N pole of the magnet 2 faces the bottom surface of the concave part 4, or it appears in the opening. or toward one side edge of the main body 1. At this time, when the dimensions of the magnet 2 and the depth of the recess 4 are appropriately set and the magnet 2 is filled into the recess 4, as shown in FIG. It is desirable to make it sink slightly from the top. However, in Figure 6, for clarity,
The amount of sinking of the magnet 2 from the surface of the main body is exaggerated.

Next, as shown in FIGS. 7 and 8, the small convex projections 5, 5 protruding from the opening edge of the concave portion 4 filled with the magnet 2 are crimped to fix the magnet 2. This caulking may be performed, for example, by tapping the openings of the recesses 4 one by one with a small hammer, or by tightening all the sides of the keyhole insertion part of the main body 1, that is, all the recesses 4, 4. At the same time, all the small protrusions 5, 5 may be crimped simultaneously by pressing a crimping tool with a flat bottom surface using a press machine.

By tightening the small protrusions 5, 5, as shown in FIG.
are plastically deformed to curve and protrude toward the magnet 2 side, forming protruding curved surfaces 42, 42. At the same time, a part of the plastically deformed small protrusion 5 is connected to the magnet 2 and the concave part 4.
Fill the gap d between the magnet 2 and the inner surface of the magnet 2.
plastically deforms so as to cover part of the upper surface (see Figure 7). That is, the substantial part of each small protrusion 5 is the eighth
It is plastically deformed so as to fill regions A and B shown in the figure. In addition, in FIG. 8, the upper part of the protruding curved surface 42 indicated by the two-dot chain line is a virtual part and is not actually formed.

As a result, each magnet 2 has a shape engagement with the concave portion 4, a frictional engagement caused by being strongly pressed and clamped to the protruding curved surfaces 42, 42 formed by plastic deformation of the small protrusions 5, 5, and It is firmly fixed to the main body 1 by engaging with a part of the small protrusion 5 which has been plastically deformed, and thus the magnetic key is completed.

It is clear that magnetic keys manufactured as described above perform the same function as those manufactured using other manufacturing methods. Plastically deformed small protrusion 5,
Even if the small protrusions 5 cover a part of the magnet 2, the small protrusions 5 are integral with the main body 1 and are made of the same non-magnetic material, so they do not block the magnetic flux of the magnet 2.

In addition, in FIG. 8, the caulked small protrusions 5, 5 are drawn as rising from the surface of the main body 1, but this is only for clarity of the drawing, and the cross-sectional area of the small protrusions 5 is If is set appropriately, this raised amount h can be made smaller than, for example, the thickness of one hair (approximately 0.05 to 0.1 mm). Therefore, when the keyhole is inserted into the keyhole, the plastically deformed small protrusion 5 does not get caught in the keyhole, and the keyhole can be inserted smoothly like a conventional magnetic key.

Embodiment 2 FIGS. 9 and 10 show another embodiment of the present invention, in which a pair of small protrusions forming a part of a spherical surface, for example, are provided near the opening edge of the recessed portion 4 that accommodates the magnet. 5, 5 are formed, and after filling the recessed portion 4 with the magnet 2, the small protrusions 5, 5 are crimped.

In this way, when the small protrusions 5, 5 are crimped, the inner surface of the concave portion 4 is plastically deformed so as to curve and protrude toward the magnet 2, as shown in FIG. 42, and the magnet 2, which is tightly pressed and clamped by these protruding curved surfaces 42, 42, is firmly fixed to the main body 1. Although the one shown in FIG. 11 does not have a locking claw that engages with the upper surface of the magnet 2, the fixing strength is still more than sufficient, and there is no fear that the magnet will fall off.

〔effect〕

As is clear from the above description, the present invention forms at least one small protrusion near the opening edge of the recess formed in the main body, and by tightening this small protrusion, the inner surface of the recess is curved toward the magnet. The magnet is plastically deformed so that it protrudes, and the magnet is firmly held by the protrusion.This, together with the shape engagement between the concave part and the magnet, makes it possible to fix the magnet with adhesive, for example. It is possible to obtain a magnetic key that does not have the risk of the magnet falling off.

Moreover, since only the small protrusion is crimped instead of crimping the entire opening edge of the recessed part, stress is concentrated in this area, and the required amount of plastic deformation can be obtained with a small crimping force.

Furthermore, after the small protrusion is plastically deformed, the tightening force is distributed over the entire area of the opening edge of the recess, and the tightening force required for further plastic deformation increases step by step. It can be used as a tightening force setting mechanism). That is,
If the size of the small protrusion is appropriately set depending on the material of the main body or the amount of gap between the magnet and the inner surface of the recess, the constant amount of force necessary to fix the magnet can be achieved without having to particularly adjust the tightening force. The amount of plastic deformation can be stably obtained. In other words, the clamping force of the magnet can be adjusted by adjusting the size of the small protrusions.

In addition, small protrusions can be easily formed by slightly modifying the mold of a conventional main body casting machine, and the magnet can be fixed to the main body by simply crimping them, making the process not only simple but also easy to implement. Moreover, when fixing magnets with adhesive, it is difficult to confirm whether the adhesive has spread to the entire adhesive surface or not, which leaves some concerns.However, according to the method of the present invention, deformation of small protrusions can be visually confirmed. By doing so, it is possible to confirm whether the magnet is securely fixed, thereby facilitating inspection, and various other effects are achieved.

[Modification example]

Note that the present invention is not limited to the illustrated embodiment, and can be implemented with various modifications.

For example, in the illustrated embodiment, two small protrusions are formed for each recess, and there is no limit to the number of these small protrusions and their relative positions in the opening of the recess. When the opening of the recess is rectangular, the fixing strength of the magnet is further increased by providing four small protrusions to surround it.

Further, the recessed portion housing the magnet does not have to have a closed bottom surface as in the illustrated embodiment, and may be partially open.

Furthermore, in the above explanation, the small protrusions are crimped after filling all the recesses with magnets, but filling the magnets and crimping the small protrusions may be alternately repeated for each recess. Of course it's a good thing.

Furthermore, in the above-mentioned embodiment, the small protrusion is formed integrally with the main body, but this means, for example, that a small hole is opened near the opening edge of the recessed part, and the head is fitted into the small hole and the head is formed on the main body surface. It is also possible to tighten a pin slightly protruding from the top. That is, the small protrusions may be separate from the main body.

[Brief explanation of drawings]

Fig. 1 is a plan view of a magnetic key manufactured by a conventional magnetic key manufacturing method, and Fig. 2 is an enlarged cross-sectional view of the keyhole insertion portion of a magnetic key manufactured by another conventional manufacturing method. , 3rd
The figure is a plan view of the main body after the main body molding process, FIG. 4 is an enlarged sectional view taken along the line of FIG.
The figures are an enlarged cross-sectional view taken along the lines in FIG. 5, FIG. 7 is a plan view of a magnetic key manufactured by the method of the present invention, and FIG. 8 is an enlarged cross-sectional view taken along the lines shown in FIG. 7, showing the gap between the magnet and the inner surface of the recess. is exaggerated,
FIG. 9 is a partially enlarged plan view of the surface of the main body according to another embodiment of the present invention, FIG. 10 is a sectional view taken along the line of FIG. 9, and FIG. 11 is similar to FIG. FIG. 3 is a partially enlarged plan view. 1...Main body, 2...Magnet, 4...Concave portion, 5...
...Small protrusion, 42...Protruding curved surface.

Claims (1)

[Scope of Claims] 1. A plurality of recesses for storing magnets are formed at predetermined locations of a magnetic key made of a non-magnetic material, and at least one small protrusion is provided protruding near the opening edge of each recess. The main body forming process, the magnet filling process of filling each recess with a magnet with the magnetization direction directed in a predetermined direction according to the different keys of the corresponding magnetic tumbler lock, and crimping the small protrusions of each recess. A magnet fixing step of plastically deforming the inner surface of the concave portion so as to curve and protrude toward the magnet side, and thereby firmly pressing and clamping the magnet to the inner surface of the concave portion and fixing the magnet. How to manufacture magnetic keys. 2. The magnetic key according to claim 1, wherein the small protrusion forms a protrusion having a sawtooth cross section along the opening edge of the recess, and the side surface facing the recess is an extension of the inner surface of the recess. manufacturing method.