JPS6124809B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) This invention is directed to magnetic shielding in fasteners using permanent magnets, that is, destruction of magnetic recording parts of cash cards, magnetic tapes, etc. due to lines of magnetic force. The present invention relates to the disclosure of an extremely novel engagement tool that is designed to prevent such problems and to focus lines of magnetic force as much as possible to significantly improve its magnetic adhesion.

(Prior Art) Many ideas have been devised as means for promoting magnetic shielding and magnetic attraction in this type of engagement tool.

(Problems to be Solved by the Invention) However, none of the conventional devices has a sufficient structure, and in devices that aim for complete magnetic shielding, the magnetic force is significantly reduced, and the magnetic force is not sufficient. When it manifests, it causes a lot of leakage magnetism.

(Means for Solving the Problems) The present invention aims to harmonize the magnetic shielding and magnetic force in such conventional engagement tools, and at the same time achieves effective magnetic shielding and at the same time, reduces the magnetic capacity of the permanent magnet used as much as possible. In order to solve the above problems by creating a field of magnetic attraction that never occurs, a permanent magnet 1 having a hole 1a extending from one magnetic pole surface a to the other magnetic pole surface b, and a magnetic pole surface b of the permanent magnet 1 are used. A ferromagnetic plate 2 to be attached and a shield plate 3 having a hole 3a communicating with the hole 1a and attached to the magnetic pole face a are fitted in a cylindrical non-magnetic case 4. A flange portion 4b bent inward is provided on one opening edge of the case 4, and the flange portion 4b is engaged with the peripheral step portion 3a provided on the peripheral edge of the shield plate 3, and the case 4 is provided with a flange portion 4b bent inwardly. 4
one stopper A in which a plurality of claws 4a provided on the other opening edge are folded onto the ferromagnetic plate 2;
a male tool B consisting of a shallow dish-shaped ferromagnetic plate 5 which is attracted onto the shield plate 3 and has a rising edge 5b on the circumferential side; The provided ferromagnetic protrusions 2a, 5
The engaging tool is configured such that the ferromagnetic plates 2 and 5 are removably attracted to each other or to the other ferromagnetic plates 2 and 5 within the hole 1a of the permanent magnet 1.

(Example) The details of the present invention will be described below with reference to a typical example shown in the drawings. 1 is a permanent magnet having a hole 1a, and the hole 1a is opened when the magnet 1 is manufactured. In other words, there are cases where an arbitrary plurality of magnets are assembled and the assembly gap is formed.

A ferromagnetic plate 2 is provided on one magnetic pole surface b of such permanent magnet 1, and a hole 3 communicating with the hole 1a is provided on the other magnetic pole surface a.
A ferromagnetic shield plate 3 having a ferromagnetic shield plate 3 is attached, and a flange 4b bent inward is provided at one opening edge of the non-magnetic case 4 fitted on the peripheral surface of the permanent magnet 1. is engaged with the circumferential step portion 3a provided on the circumferential edge of the shield plate 3, and a plurality of claws 4a provided on the other opening edge of the case 4 are engaged with the ferromagnetic plate 2.
By folding upward, the shield plate 3 and the ferromagnetic plate 2 are integrally fixed to the permanent magnet 1, thereby forming the female tool A.

Next, prepare a ferromagnetic plate 5 that is removably magnetically attached to the surface of the shield plate 3 attached to the magnetic pole surface a, and use this as a male tool B. The ferromagnetic plate 2 in the permanent magnet 1 is connected to the hole 1a,
The two ferromagnetic plates 2 and 5 are brought into contact with each other in a removably magnetic manner via the ferromagnetic plates 3a, and various structures can be used to bring the two ferromagnetic plates 2 and 5 into contact with each other.

One of them has ferromagnetic protrusions 2a and 5a protruding from the ferromagnetic plates 2 and 5, and each ferromagnetic protrusion 2
In the case where the ends a and 5a are in contact with each other, in the other case, a ferromagnetic protrusion 5a' with a length extending from the ferromagnetic plate 5 to the end surface of the ferromagnetic plate 2 is provided to protrude from the ferromagnetic plate 5. In the case where the magnetic protrusion 5a' and the ferromagnetic plate 2 are in direct contact with each other, the three ferromagnetic protrusions are arranged so that the ferromagnetic plate 2 has a length that coincides with the upper surface of the shield plate 3 or is exposed from the upper surface. It is planned that the protrusions 2a' are provided in a protruding manner so that the ferromagnetic protrusions 2a' and the ferromagnetic plate 5 are in direct contact with each other. is caulked,
It is attached by brazing, spot welding, etc.

In addition, various mounting structures are planned for the means for attaching the male tool B and the female tool A to a handbag, etc., but the illustrated example is a typical example of a mounting plate having leg pieces 6a to 6a. The structure is shown in which the mounting washer 7 having the leg pieces 7a to 7a is fixed together with the ferromagnetic plate 2 by the bent edge 4a of the case 4. It is something.

The shield plate 3 mentioned above is basically a ferromagnetic plate 5.
Although the desired shielding effect was achieved both necessary and sufficiently by completely closing the top of the magnetic pole tip surface a in contact with Hole 3b
By bending the end inside the hole 1a of the magnet 1 to form the engaging edge flange 3c, leakage of magnetic lines of force from the magnetic pole end surface a is more reliably prevented, and such structural characteristics are The lines of magnetic force are focused on the edge of this edge flange 3b, and the magnetic force of the magnet 1 can be made stronger. Of course, this edge flange 3b also has the effect of securely fixing the ferromagnetic plate 3 in terms of structure.

Next, the ferromagnetic plate 5 has a peripheral edge flange 5b whose peripheral edge is engaged with the circumferential side of the magnet 1, which reliably prevents the magnetically attached surface of the ferromagnetic plate 5 from shifting, and also reduces the strength during engagement. This is designed to reduce leakage of lines of magnetic force from the ends of the magnetic plate 5.

In addition, the ferromagnetic protrusions 2a, 5a, 2 in the above
Both a' and 5a' are provided with a magnetic gap 8 corresponding to the holes 1a and 3a, and due to the presence of the magnetic gap 8, a magnetic closed circuit between the ferromagnetic plates 2 and 5 is formed. are these ferromagnetic protrusions 2a, 5a, 2a', 5
It is focused only on the a' portion, and its magnetic force is significantly enhanced.

Incidentally, this magnetic force is amplified by the hole 3b of the shield plate 3.
This is also ensured by making the edge of the magnet hole 1a face the edge of the magnet hole 1a and maintaining a required magnetic gap between this edge and the ferromagnetic protrusions 5a, 2a', 5a'.

The present invention has the characteristic structure described above, in particular, the shield plate 3 and the ferromagnetic plate 2 for attachment are fixed to the permanent magnet 1 using the cover 4, and the shield plate 3 and the ferromagnetic plate 2 for attachment are fixed to the permanent magnet 1 on the surface of the magnet circumferential surface with relatively few lines of magnetic force. , a magnetic gap corresponding to the thickness of this cover 4 was created, and the respective magnetic pole end faces were completely shielded by the ferromagnetic plate 2 and the shield plate 3, and the engagement of the ferromagnetic plates 2 and 5 was made through the hole 1a. ,3a
The ferromagnetic plate 5 is directly attracted to the ferromagnetic shield plate 3 by the ferromagnetic protrusions 2a, 5a, 2a', 5a' provided through the required magnetic gap 8, and the magnetic gap Due to the absence of this material, specific effects of the above-mentioned characteristics can be expected.

Thus, according to the present invention, the lines of magnetic force are connected to the shield plate 3.
By placing the ferromagnetic protrusions 2a, 5a, 2a', and 5a' within the lines of magnetic force, the magnetic force is extremely strong, and magnetic leakage is also relatively small. This has made it possible to reliably prevent damage caused by destruction of the magnetic recording parts of tickets, cash cards, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a typical embodiment of the present invention, and FIGS. 2 to 4 are sectional views showing other embodiments. In the figure, 1... magnet, 2... ferromagnetic plate, 3...
Shield plate, 4... Case, 5... Ferromagnetic plate, 6
...Mounting plate, 7...Mounting washer, 8...Magnetic gap.

Claims (1)

[Scope of Claims] 1. A permanent magnet 1 having a hole 1a extending from one magnetic pole surface a to the other magnetic pole surface b, a ferromagnetic plate 2 attached to the magnetic pole surface b of the permanent magnet 1, and the hole 1a. A shield plate 3 having a hole 3a communicating with the magnetic pole face 1a and attached to the magnetic pole face a is fitted in a cylindrical non-magnetic case 4, and a shield plate 3 is fitted in a cylindrical non-magnetic case 4, and is folded inwardly at one opening edge of the case 4. A bent flange 4b is provided, and the flange 4b is engaged with a peripheral step 3a provided on the peripheral edge of the shield plate 3, and a plurality of bent flange portions 4b are provided on the other opening edge of the case 4. A female tool A having a claw 4a folded onto the ferromagnetic plate 2, and a male tool B consisting of a shallow dish-shaped ferromagnetic plate 5 which is attracted onto the shield plate 3 and has a rising edge 5b on the circumferential side. The ferromagnetic protrusions 2a, 5a protruding from both or one of the ferromagnetic plates 2, 5 are connected to each other or the other ferromagnetic plate 2, 5a within the hole 1a of the permanent magnet 1.
5. An engagement tool characterized in that it is removably adsorbed on the holder.