JPS61137509A - Clamp using permanent magnet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention relates to a stop using a permanent magnet held in a non-magnetic metal case, which is used for a stop for a bag lid, a button, a stop for a furniture door, etc. The present invention relates to the disclosure of a fastener that increases the strength of the case and strengthens the suction force.

(Prior art) Conventional fasteners of this type generally encapsulate a permanent magnet in a non-magnetic metal case and attach it to the mounting surface; The ferromagnetic plate that is attached and detached is attracted and locked through a non-magnetic metal case, and the case has a uniform thickness when molded.

(Problem to be solved by the invention) From this point of view, if the thickness of the non-magnetic metal case is increased in order to increase the strength of the non-magnetic metal case in order to ensure secure attachment, the magnetic surface of the permanent magnet and the ferromagnetism attracted by this The problem is that as the distance from the plate increases, the adsorption force decreases in inverse proportion to the square of the distance.

(Means for Solving the Problems) This invention was specifically proposed to solve the problems in the conventional fasteners using permanent magnets, and it is The bottom surface, which is the annular contact surface with the member, is made into a thin wall part compressed by press working to increase the hardness, and it is made to protrude to the circumferential side and the periphery of the hole to form the inside of the intestine, and it is placed between the permanent magnet and the ferromagnetic member. In addition to providing strength to the intervening metal case surface, the distance between the two magnetically attached surfaces is shortened to obtain effective adsorption force, and at the same time, the adhesion of the plating is improved, and the bulge portion allows the magnetic recording card,
It also has a magnetic shielding effect when it comes into contact with tapes, etc.

(Embodiments) Hereinafter, embodiments of the fastener according to the present invention shown in the drawings will be described in detail.

Figures 1 and 2 show a non-magnetic metal case (4) made of brass or the like used as a stopper, and a hole (1) a of a permanent magnet (1) held in the metal case (4). Communicating hole (4)a
The bottom surface (4)b, which is the contact surface of the ferromagnetic plate (3) of the other engaging tool, has an annular shape and is pressed into a thin part by press working, and the circumferential surface of the bottom surface (4)b Side part (4)'b and hole (4)a Peripheral part (4)'a is the inside of the protruding intestine, and Figure 1 shows the peripheral part (4)' of the bottom surface (4)b. b shows the inside of the intestine that bulges out in the direction of the circumferential side of the cylinder, and Fig. 2 shows the inside of the intestine that bulges upward at the circumferential side part (4)'b of the bottom surface (4)b. Show what you did.

(4) C is a tongue piece that is bent to hold the magnet (1) etc. inside the metal case (0).

Figures w43 to 11 show a metal case (4) containing a sintered magnet such as ferrite A-plane, a bar tlII magnet, a plastic magnet, or a rare earth magnet when a special attraction force is required, and a disc-shaped one-sided magnet. A ferromagnetic plate (1) is brought into contact with the permanent magnet (1) and one of the magnetic pole surfaces a, with the permanent magnet (1) having a hole (1) a facing from the magnetic pole surface a of the magnetic pole surface toward the other magnetic pole surface a on the inside. 2) is integrally held by the tongue piece (4)c, and one stopper A has a leg piece (5)a which is inserted into the base plate and bent and attached, and the permanent magnet (1) of the stopper A. ) is made of a ferromagnetic plate (3) that is attracted to the other magnetic pole face of the
Fig. 3 shows the metal case (4) of the stop A and the other stop B having the same leg piece (6) a.
Peripheral part (4)' b and hole (4) a Peripheral part (4)' a of the bottom surface (4) b of the ferromagnetic plate (2), hole (1) of the permanent magnet (1) in the ferromagnetic plate (2) A ferromagnetic part (7) with a length reaching the middle of the hole (1) a on the a side is integrally fixed to the ferromagnetic plate (2) by a caulking method, so that the first ferromagnetic part (7) The permanent magnet (1) is erected with particular consideration so as not to come into contact with the inner circumferential wall surface of the hole (1) a. In addition to the caulking described above, various indigenous methods such as brazing, welding, press-fitting, and screwing are used. Also, the leg piece (5) a has a washer (5
), and the washer (5) is caulked at the same time as the ferromagnetic part (7) is fixed to the ferromagnetic plate (2). Stop B has a ferromagnetic part (8) in the center of the ferromagnetic plate (3).
) of the permanent magnet (1) in the ttJLA.
It is erected with a length that reaches the middle, and is fixed together with a washer (6) having a leg piece (6) a using the same method as stopper A. Stoppers A and B are ferromagnetic. The plate (3) is attracted to one magnetic pole face of the permanent magnet (1) and the metal case (4)
The ferromagnetic part (?), (8) comes into contact with the bottom surface (4) b of the
are engaged with each other by suction so that their tips abut each other within the hole (1) a.

In addition to the above-mentioned leg pieces, the fasteners A and B can be fastened to the base plate, etc. by caulking, sewing, screwing with adhesive screws, or other methods. Fig. 4 shows that stop A does not have a ferromagnetic part (8) and the ferromagnetic part (8) of stop B has the same length as the hole (1) a of the permanent magnet (1). ) with the same diameter as the permanent magnet (1) and fixed to the metal case (4), the leg piece (5
) a is provided.

Note that the leg piece (5) a and the washer (5) are integrally formed or made integral by various methods such as brazing and welding. In Fig. 5, contrary to Fig. 4, the ferromagnetic part (8) of the stopper B is not provided, and the length of the ferromagnetic part (7) of the stopper A is set to the hole (1) of the permanent magnet (1).
) The length of a is shown.

Figures 6 to 12 show the metal case (4) in the stop AA.
The peripheral side (4)'b of the bottom surface (4)b is shown as the inside of the intestine bulging upward, and Figures 9 to 11 show one magnetic pole face of the permanent magnet (1). magnetic shield plate (9
) is attached and held in the metal case (4), and the lengths of the ferromagnetic rods (7) and (8) are changed in the same manner as in FIGS. 3 to 5 above. This figure shows an example in which this was done.

Moreover, FIG. 12 shows the case where the stopper A comes into contact with the magnetic card (10), and the magnetic card (10) is attached to the metal case (
The circumferential side part (4)'b formed inside the intestine of 4) prevents the surface (10) a from coming into contact with the annular contact surface.

(Effects) With the above-described characteristic configuration, this invention enhances the strength of the metal case that holds the permanent magnet of the stopper, obtains an effective adsorption force, and also provides a magnetic shielding effect. This is what I did.

That is, the annular bottom surface (4) which is the contact surface of the metal case (4)
)b by pressing the peripheral side part (
4)'b and the periphery of the hole (4)a (4)'A is formed with an intestine inside, and the chain part has rounded corners to improve the strength of the case, while the bottom surface (4) Although b is thinner, it has increased hardness and is less likely to be scratched, and also has improved plating adhesion and no peeling and is durable.

Also, by making the bottom surface (4) b thinner, the ferromagnetic member (
The distance between 3) and one magnetic pole surface a of the permanent magnet (1) is shortened, and due to the property that the magnetic attraction force is inversely proportional to the square of the distance, the attraction force is strengthened and effective locking is achieved.

Furthermore, by making the peripheral side of the annular contact surface of the metal case (4) into an inner portion that protrudes above the contact surface, magnetic recording cards, tapes, etc. do not come into direct contact with the contact surface, and the magnetic recording is prevented from being damaged. It rarely happens. Furthermore, by attaching a magnetic shield plate (9) to the magnetic pole face of the permanent magnet (1), the magnetic shielding effect is further enhanced and magnetic damage to the magnetic recording card, etc. can be completely prevented.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of a metal case used in a fastener according to the present invention, and FIG. 2 is a cross-sectional view of the same embodiment.
3 to 11 are cross-sectional views showing various embodiments of the tool,
FIG. 12 is a sectional view showing the state of contact between the stopper and the magnetic recording card. 1... Permanent magnet, 2.3... Ferromagnetic plate, 4... Metal case, 5.6... Washer, 7.8... Ferromagnetic rod,
9...Magnetic shield plate. Figure 3

Claims (1)

[Claims] Hole (1) a from one magnetic pole surface a to the other magnetic pole surface b
The ferromagnetic member (2) provided on one magnetic pole surface a of the permanent magnet (1) having The hole (1) a of the permanent magnet (1) is
The permanent magnet (1) and the ferromagnetic member (2) are held inside a flat cylindrical non-magnetic metal case (4) with a bottom and a hole (4) a communicating with the permanent magnet (1). In the integrally held stop, the annular contact surface of the stop with the ferromagnetic member (3) in the metal case (4) is a pressed thin part, and the circumferential side of the annular contact surface and a stopper using a permanent magnet, characterized in that the peripheral edge of the hole (4) a is a protruding, enlarged portion.