JP3000857U - Magnetic detachable device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a structure for a magnetic attachment / detachment device for detachably attaching an accessory to a bag or the like, the structure not easily coming off even when an external force or an impact is applied. [Structure] An adsorption unit 8 mounted on the surface of a bag and an attachment / detachment unit 2 to which the accessory 1 is connected. The attraction unit 8 is a short-tube permanent magnet 10, a yoke plate 11, and a thin plate cover 12.
The thin plate cover 12 has a small elliptical hole 13 formed therein. On the other hand, in the detachable unit 2, the small oval first contact plate portion 3, the short column portion 5, and the second contact plate portion 4 are integrally formed of a ferromagnetic material. By inserting the first contact plate portion 3 of the detachable unit 2 into the hole 13 of the suction unit 8 and rotating it by 90 °, both units 2 and 8 are magnetically attached. The detachable unit (2) does not drop out due to the engagement relationship between the first contact plate portion (3) and the thin plate cover (12) even if it is separated from the magnetically attached state and immediately returns to the original magnetically attached state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention relates to a magnetic attachment / detachment device, and is applied to a portion where various simple attachment / detachment functions are required, and in particular, various types of surfaces such as bags such as handbags and shoes such as boots or leather clothes The invention relates to a device making it possible to attach accessories.

[0002]

[Prior art]

 Traditionally, bags and other items such as handbags are often provided with decorations made of metal, resin, etc. on their surfaces, and of course, decorations have important meaning as part of the design. The accessory is fixedly attached to a handbag or the like by screwing, crimping, or adhering.

[0003] When a consumer purchases a handbag or the like, he or she looks at the entire design including the accessory and selects one that suits his or her taste, and the accessory is fixed as described above. It is generally impossible to change because it is implemented by.

On the other hand, recently, the tastes of consumers have diversified, and various designs such as handbags have been sold, but basic designs such as shapes and colors are liked. However, it is often the case that the accessory that is worn gives an unpleasant impression. I bought a handbag that suits my taste, but sometimes I want to change the accessory according to the so-called TPO or costume while keeping the basic design.

[0005] In particular, the sales of handbags for young people tend to be remarkably different depending on how the accessory is used. In other words, as if the owner freely exchanges the accessory and owns a large number of handbags. It is thought that there is a potential demand to show it. Further, as described above, the problem that the taste is greatly influenced by the accessory and the demand for changing the accessory are not limited to bags such as handbags, but shoes such as boots and leather clothes. The same applies to the above.

Therefore, there is a demand for a device that allows the accessory to be attached and detached and replaced by a simple operation, but it is conceivable to use a magnet type hooking device that is used for an opening / closing portion of a handbag or the like. A variety of attachment / detachment devices of that kind have been proposed for a long time. For example, in the device of Japanese Utility Model Publication No. 56-27781, "a magnetic plate having a protrusion having no hollow portion on its surface and a pair of upper and lower magnetic poles are provided. A permanent magnet in the form of a cylinder having a through hole formed therethrough, the magnet being formed by inserting the protrusion into the through hole and magnetically abutting the magnetic plate on a magnetic pole surface below the magnet. Various improvements and expansion techniques have been proposed for "stoppers", as well as in British Patent No. 1519246 and Japanese Patent Publication No. 60-27169.However, these devices use an adsorption device that holds a short-cylindrical permanent magnet. Inside the hollow hole of the permanent magnet in the unit, attach / detach to / from the magnetically adhering surface on the adsorption unit side. The feature is that it secures power.

[0007]

[Problems to be solved by the device]

 By the way, when the attaching / detaching device is used as the attaching device for the accessory, the attaching / detaching unit side can attach the attaching / detaching unit side to which the ornament is connected with a large adsorption force, but it is still large for the ornament. It is possible that the detachable unit may come off when an external force or impact is applied. In that case, when it is used for the opening / closing part of the handbag, the opening / closing part is not normally closed and no harm is usually caused.However, if it is used for the accessory attaching device, the accessory may be lost. is there.

On the contrary, when the accessory is replaced, the detachable unit is naturally removed from the suction unit. However, since the attach / detach device has a considerably large attracting force, the accessory is pulled. When attempting to remove it, the connecting portion between the detachable unit and the accessory may be cut and separated, or the accessory itself may be damaged. In particular, relatively thin chains are often used for accessories, and the possibility is extremely high.

Therefore, the present invention was created for the purpose of improving so that when the magnet type attaching / detaching device is used as a device for attaching the accessory, the above-mentioned problems and cutting / damage of the accessory do not occur. It was

[0010]

[Means for Solving the Problems]

 According to a first aspect of the present invention, a short-cylindrical permanent magnet having both end faces as magnetic poles, a short column portion which is internally fitted to an intermediate position in a hollow hole of the permanent magnet, and the short column portion are internally fitted to the permanent magnet. A ferromagnetic yoke plate consisting of a flat plate portion that is joined to the rear end face of the permanent magnet in a state, and a ferromagnetic yoke plate that is hooked on the flat plate portion of the yoke plate and covers the side peripheral surface and the front end face of the permanent magnet. And a suction unit composed of a ferromagnetic thin plate cover with a non-circular hole formed at a position facing the short column portion of the yoke plate, and a hole for the thin plate cover on the suction unit side. A first contact plate part having a non-circular shape that fits in and a thickness smaller than the facing distance between the thin plate cover and the end face of the short column part on the suction unit side and a plane shape larger than the first contact plate part. The second contact plate part and the respective contact plate parts that are A short column part that is connected to face the first contact plate part in contact with the end face of the short column part on the suction unit side, and the second contact plate part on the thin plate cover on the suction unit side. The present invention relates to a magnetic attachment / detachment device including a ferromagnetic attachment / detachment unit configured to be in contact with each other.

A second invention is a short-cylindrical permanent magnet having both end faces as magnetic poles, and a region which is internally fitted to an intermediate position in the hollow hole of the permanent magnet and which opposes a hole in a thin plate cover described later on the end face. On the back side end surface of the permanent magnet in a state where the projecting portion having a sloping inclined surface in the circumferential direction is formed with the outer part of the A ferromagnetic yoke plate composed of a flat plate portion to be joined, and a yoke plate which is hooked on the flat plate portion of the yoke plate to cover the side peripheral surface and the front end surface of the permanent magnet, and the short length of the yoke plate. An adsorption unit composed of a ferromagnetic thin plate cover in which a non-circular hole is formed at a position facing the column portion, and a non-circular shape that fits through the hole in the thin plate cover on the adsorption unit side. Together with the suction unit side Of the thin plate cover and the apex of the end face of the short column part, the first contact plate part having a thickness smaller than the facing distance, the second contact plate part having a planar shape larger than the first contact plate part, and each contact plate thereof. The second contact plate in a state in which the first contact plate part is in contact with a region other than the projecting portion of the end face of the short column part on the adsorption unit side The present invention relates to a magnetic attachment / detachment device including a ferromagnetic attachment / detachment unit configured so that its portion contacts the thin plate cover on the suction unit side.

[0012]

[Action]

 Regarding the first invention; The detachable unit is mounted by inserting the first contact plate portion into the hole on the suction unit side and rotating the entire unit relative to the suction unit. In that case, the first contact plate part contacts the end face of the short column part on the adsorption unit side, and the second contact plate part contacts the thin plate cover on the adsorption unit side. The magnetic circuit is efficiently constructed and a strong attraction force is obtained.

Since the first contact plate portion on the detachable unit side and the suction hole on the suction unit side are each formed in a non-circular shape, when the detachable unit is rotated, the first contact plate portion is sucked. Even if the detachable unit is detached from the end face of the short column portion, there is an engaging relationship with the thin plate cover, and the detachable unit can be prevented from falling off from the suction unit side. Further, even in the detached state as described above, since the distance between the first contact plate portion and the end face of the short column portion is small, the original suction state can be easily restored.

Regarding the second device; The procedure for attaching the detachable unit is the same as that of the first device. However, in this invention, since the protruding portion is formed on the end surface of the short column portion on the suction unit side, the suction force is extremely weak when the first contact plate is inserted into the suction hole on the suction unit side. By the rotation of the detachable unit, the first contact plate portion is strongly magnetically attached at the stage of contacting with the area other than the projecting portion on the end face of the short column portion.

This invention can prevent the detachable unit from coming off from the suction unit side by the engagement relationship between the first contact plate portion and the thin plate cover as in the first invention, but at the same time when removing the detachable unit. It is characterized by its simplicity. That is, when the detachable unit is rotated from the suction state and the first contact plate part is rotated to the angle corresponding to the hole on the suction unit side, the first contact plate part is formed on the end face of the short column part. It will be lifted while touching the inclined surface of the protruding part, and when it reaches the top of the protruding part (the first contact plate part and the suction hole on the suction unit side correspond in plan), the short column part Since the contact area with the end face is extremely small, the detachable unit can be pulled out with a very small force. In addition, since the projecting part is composed of a gently sloping surface in the circumferential direction, it is sufficient even if the rotating torque applied to the detachable unit is small.

In the first and second inventions, the “non-circular shape” includes shapes other than a circle, such as an ellipse, a triangle, a polygon, and a star.

[0017]

【Example】

 Hereinafter, an embodiment of the "magnetic attachment / detachment device" of the present invention (an example applied as a device for attaching accessory) will be described in detail with reference to the drawings. Embodiment 1 First, FIG. 1 shows a plan view (A), a front view (B) and a side view (C) of a detachable unit 2 to which an accessory 1 is attached. In the figure, the detachable unit 2 is a ferromagnetic body composed of a first contact plate portion 3 having a small elliptical shape, a second contact plate portion 4 having a circular shape, and a short column portion 5, and the short column portion 5 is the first contact portion. The central portions of the plate portion 3 and the second contact plate portion 4 are connected so that the contact plate portions 4 and 5 are parallel to each other. A triangular connecting piece 6 is integrally formed in the second contact plate portion 4 in the plane direction, and the accessory 1 is connected to the connecting piece 6 using a hole 6a formed in the connecting piece 6. ing. In the present embodiment, it is assumed that the accessory 1 including the connecting portion and the tuft as shown in the drawing is attached to the second contact plate portion 4.

Next, FIG. 2 shows a side view (A) and a front view (B) in a state where the suction unit 8 is attached to the opening / closing plate portion 7 of the handbag. As shown in FIG. 2 (A), the suction unit 8 has a short cylindrical shape, and the two washer plates 9a and 9b attached to the back surface of the suction unit 8 are passed through the holes provided in the opening / closing plate section 7. The front end side is bent and attached to the opening / closing plate part 7.

The specific structure thereof will be described with reference to FIG. 3 which is a sectional view taken along the line YY in FIG. 2B and FIG. 4 which is a sectional view taken along the line XX. In each cross-sectional view, 10 is a short cylinder, and a permanent magnet magnetized so that each end face thereof becomes a magnetic pole, 11 is a ferromagnetic yoke plate, and 12 is a ferromagnetic thin plate cover.

Here, the yoke plate 11 has a shape in which a short column portion 11a and a flat plate portion 11b are integrally formed, and in a state where the short column portion 11a is internally fitted to an intermediate position in the hollow hole of the permanent magnet 10. The flat plate portion 11b is bonded to the back surface side of the permanent magnet 10. Further, the thin plate cover 12 is formed in a cup shape so as to hold the permanent magnet 10 and the yoke plate 11, and the permanent magnet 10 is formed by bending the claw portion on the back side of the yoke plate 11. And the yoke plate 11 is fixed inside. Further, a small elliptical hole 13 into which the first contact plate portion 3 of the attraction unit 8 is inserted is formed in the center of the surface plate portion of the thin plate cover 12 that is joined to the permanent magnet 10.

Therefore, the hole 13 and the end surface 14 of the short column portion 11a face each other through the space formed inside the thin plate cover 12, and in this embodiment, the small elliptical hole 13 has a long axis direction. Corresponds to the inner diameter of the permanent magnet 10 (≈outer diameter of the short column portion 11a), and the region in the short axis direction is located at the center of the hollow hole (end face of the short column portion 11a) of the permanent magnet 10. . Further, the facing distance h between the end surface 14 of the short column portion 11a and the inner surface of the thin plate cover 12 is larger than the thickness t1 (see FIG. 1) of the first contact plate portion 3 of the detachable unit 2, and the facing distance is h : h and the thickness: s of the thin plate cover 12 (s + s) corresponds to the distance: t2 (see FIG. 1) between the surface of the first contact plate 3 and the surface of the second contact plate 4 of the detachable unit 2. It is sized. There is. The washers 9a and 9b are attached to the rear surface of the yoke plate 11 by means of caulking or the like.

In the above-mentioned configuration, the accessory 1 is attached to the handbag side by attaching the detachable unit 2 to the suction unit 8. The attaching procedure and the attaching state are shown in FIG. First, as shown in FIG. 5 (A), the first contact plate portion 3 of the detachable unit 2 is inserted into the hole 13 of the suction unit 8 with the long and short axis directions aligned. In this case, the extraction hole 13 of the suction unit 8 has its major axis horizontal as shown in FIG. 2 (B), and the first contact plate portion 3 of the detachable unit 2 is as shown in FIG. 1 (B). Since the major axis is vertical, the first contact plate portion 3 of the detachable unit 2 is fitted and inserted with the accessory 1 horizontal. When the first contact plate portion 3 of the detachable unit 2 comes into contact with the end surface 14 of the short column portion 11a of the suction unit 8 by the insertion, the second contact plate portion 4 is simultaneously covered by the thin plate cover based on the above dimensional relationship. It comes into contact with the surface of 12, and at that time the detachable unit 2 is strongly adsorbed to the adsorption unit 8 side. That is, permanent magnet 10 → thin plate cover 12 → second contact plate part 4 → short column part 5 → first contact plate part 3 → yoke plate 11 (short column part 11a → flat plate part 11b) → path of permanent magnet 10 The magnetic path has extremely low magnetic resistance, and the adsorption unit 8 magnetically attaches the detachable unit 2 with a strong force.

Next, the detachable unit 2 is rotated by 90 ° from the above state, so that the accessory 1 hangs down as shown in FIG. 5 (B). At this time, the attachment / detachment unit 2 rotates in sliding contact while being attracted, but naturally the major axis of the first contact plate portion 3 is in the vertical direction and is magnetically attached in that direction. That is, as shown in FIG. 5 (C), when the first contact plate portion 3 is rotated by 90 °, the major axis direction thereof substantially coincides with the minor axis direction of the extraction hole 13 on the suction unit 8 side. Become.

By the way, when a strong external force or impact is applied to the accessory 1 or the detachable unit 2 in the suction state of FIG. 5 (B), the first contact plate portion 3 and the second contact plate portion 4 are moved to the suction unit 8 side. It may separate from the end face 14 and the surface of the thin plate cover 12. However, according to the present embodiment, the major axis of the first contact plate portion 3 is in the vertical direction and is in the relationship of always engaging with the thin plate cover 12, and the first contact plate portion 3 is disengaged from the punch hole 13. Therefore, it is possible to prevent the detachable unit 2 and the accessory 1 from falling off from the suction unit 8 side (handbag side). Further, even if the first contact plate portion 3 and the second contact plate portion 4 separate as described above, the separation distance of the first contact plate portion 3 is limited to an extremely small distance in the thin plate cover 12, Immediately returns to the original magnetic state.

When removing the accessory 1 from the handbag to replace it, the detachable unit 2 and the accessory 1 are rotated by 90 ° in the reverse order of the above procedure, and the thin hole 13 of the thin plate cover 12 is removed. If the detachable unit 2 is pulled toward the front against the suction force in the state where the major axis directions of the first contact plate portion 3 are aligned, the suction state can be released and the first contact plate portion 3 can be pulled out.

Embodiment 2 In Embodiment 1 described above, since the adsorption unit 8 magnetically attaches the detachable unit 2 with a considerably strong adsorption force, a considerable force is required when detaching the detachable unit 2. When the accessory 1 is pulled to attempt to remove it, the force may cut the link part of the accessory 1 or damage the connection part with the connecting piece 6. Therefore, in this embodiment, when the detachable unit 2 is detached from the adsorption unit 8, the adsorption force becomes extremely small when the detachable unit 2 is rotated to the position at the time of attachment.

First, the attachment / detachment unit and the suction unit of the present embodiment have the same basic configurations as those of the first embodiment. As shown in FIG. 6, the feature of this embodiment is that two protruding portions 20a, 20b are formed on the end surface 14 of the short column portion 11a of the yoke plate 11 in the suction unit 8. More specifically, each of the protruding portions 20a, 20b is formed in the annular region of the end face 14 near the outer periphery in a symmetrical relationship with respect to the minor axis direction of the small elliptical hole 13. The position corresponding to the long-axis direction of is the apex and has a gently sloping surface in the circumferential direction. In addition, in the flat area formed between the protrusions 20a and 20b on the end surface 14, the first contact plate portion 3 of the detachable unit 2 has a sufficient width for contacting with its major axis in the vertical direction. ing.

Here, as shown in FIG. 6A, the height of the apex of each protruding portion 20a, 20b is p, and the facing distance between the flat surface of the end face 14 and the thin plate cover 12 is the same as in the first embodiment. Similarly, when h is set, the distance between the apexes of the protrusions 20a and 20b and the thin plate cover 12 is (hp). Therefore, in the first embodiment, the thickness t1 (see FIG. 1) of the first contact plate portion 3 of the detachable unit 2 is set to be smaller than h (see FIGS. 3 and 4). Thickness of plate part 3: t1 is set smaller than (hp). The distance t2 (see FIG. 1) between the surface of the first contact plate portion 3 and the surface of the second contact plate portion 4 of the detachable unit 2 is (h + s), which is the same as in the first embodiment.

Next, a procedure for attaching / detaching the attaching / detaching unit 2 to / from the suction unit 8 according to the present embodiment will be described. First, when attaching the detachable unit 2, the first contact plate portion 3 is inserted into the removal hole 13 of the suction unit 8 as in the first embodiment. By the insertion, the first contact plate portion 3 contacts the respective protrusion portions 20a, 20b on the suction unit 8 side, but the planar relationship between each protrusion portion 20a, 20b and the first contact plate portion 3 in the contact state. 7 (A), the first contact plate portion 3 is only in contact with the apexes of the protrusions 20a and 20b, and the second contact plate portion 4 and the thin plate cover 12 have a space p. Because of the existence of, only a slight adsorption force acts.

Here, when the detachable unit 2 is rotated by 90 ° as in the case of the first embodiment, the planar relationship between the protruding portions 20a, 20b and the first contact plate portion 3 is shown in FIG. 7 (B). As a result, the first contact plate portion 3 contacts the flat area formed between the protrusions 20a and 20b, and at that stage, the second contact plate portion 4 and the thin plate cover 12 are also contacted. Since they are in contact with each other, they are magnetically attracted with a strong attractive force. Then, in the attached state, as in the case of the first embodiment, the longitudinal direction of the first contact plate portion 3 and the longitudinal direction of the punched hole 13 of the thin plate cover 12 are in a vertical relationship, so that the detachable unit 2 is attached. Even if the first contact plate 3 and the second contact plate 4 are separated from the end face 14 of the suction unit 8 side and the surface of the thin plate cover 12 due to a strong external force or impact, the first contact plate 3 and the second contact plate 3 are pulled out. It is possible to prevent the detachable unit 2 from falling off the suction unit 8 due to the engagement relationship of the holes 13.

On the other hand, when detaching the detachable unit 2 from the mounted state, the detachable unit 2 is rotated 90 ° and the first contact plate portion 3 is pulled out as in the case of the first embodiment. By the way, in the case of the first embodiment, both the detachable unit 2 is magnetically attached to the suction unit 8 side by a strong suction force in the states of (A) and (B) of FIG. In this embodiment, when the detachable unit 2 is rotated by 90 ° for removal, the planar relationship between the respective protruding portions 20a, 20b and the first contact plate portion 3 is as shown in FIG. 7 (A). Since only a slight suction force is applied, as in the case of the insertion and insertion, the detachable unit 2 can be removed with an extremely light pulling force. Further, since each of the protrusions 20a, 20b has a gently sloping surface in the circumferential direction, it is sufficient to give an extremely light rotational torque when rotating the attachment / detachment unit 2.

As described above, the first and second embodiments provide a structure in which the accessory 1 is detachably attached to the handbag by a simple operation and is not easily removed, and the second embodiment removes it with a slight force. I can do it. FIG. 8 shows a state in which the accessory 1 is attached to the handbag 30 by using the magnetic attachment / detachment device of each embodiment. Then, as shown in FIG. 9, if the three attachment / detachment parts 3 are attached to the handbag 30, as shown in FIGS. 9A to 9C, the handbag is designed by devising the design of the accessory. The design of the whole 30 can be changed into various modes having different tastes.

[0033]

[Effect of device]

 The "magnetic attachment / detachment device" of the present invention has the following effects by having the above-mentioned configuration. The invention of claim 1 is an apparatus for magnetically attaching a detachable unit to an adsorption unit by a magnetic force, wherein the detachable unit is attached to the detachable unit side even if a large external force or impact acts on the detachable unit side to detach the magnetically attached surface. It provides a structure that immediately returns to the original magnetic state without coming off the unit, and prevents the detachable unit and the accessory connected to it from being lost. The invention according to claim 2 provides a structure in which the detachable unit can be released from the magnetically attached state and removed by simply applying a slight torque and pulling-out force, and prevents the accessory or the like connected to the detachable unit from being damaged. .

[Brief description of drawings]

FIG. 1 is a plan view of a detachable unit according to first and second embodiments.
It is (A), a front view (B), and a side view (C).

FIG. 2 is a side view (A) and a front view (B) showing a mounting state of the suction unit according to the first embodiment.

FIG. 3 is a sectional view of the suction unit according to the first embodiment [FIG.
FIG. 7B is a sectional view taken along line YY of FIG.

FIG. 4 is a sectional view of the suction unit according to the first embodiment [FIG.
FIG. 7B is a cross-sectional view taken along line XX of FIG.

FIG. 5 is a cross-sectional view [(A), (B)] showing a mounting procedure for mounting the detachable unit 2 to the suction unit and a mounting mode.
It is a plan view (C) showing (planar relationship between the first contact plate portion and the punched hole of the thin plate cover).

6A and 6B are a cross-sectional view (A) and a plan view (B) of an end face of a short column portion of an adsorption unit according to a second embodiment.

FIG. 7 is a plan view relationship between each protrusion and the first contact plate portion in the second embodiment [(A) is a state of fitting / removing, (B) is a magnetic state].

FIG. 8 is a front view of the handbag to which the accessory is attached.

FIG. 9 is a view showing a front side design of the handbag main body when various accessories are attached to the handbag.

[Explanation of symbols]

1 ... accessory, 2 ... detachable unit, 3 ... first contact plate part, 4 ... second contact plate part, 5 ... short column part, 6 ... connecting piece, 6a ... hole, 7 ... handbag opening / closing plate part, 8 … Suction unit, 9a, 9b… Washer plate, 10
... Permanent magnets, 11 ... Yoke plate, 11a ... Short column part, 11b ... Flat plate part, 12 ... Thin plate cover, 13 ... Holes, 20a, 20b ... Projection part, 30 ... Handbag, t1 ... Thickness of first contact plate part , T2 ...
The distance between the surface of the first contact plate portion and the surface of the second contact plate portion, h ... The facing distance between the end face of the short column portion of the yoke plate and the thin plate cover, s ...
Thickness of thin plate cover, p ... Height of apex of protruding part.

Claims (2)

[Scope of utility model registration request] 1. A short-cylindrical permanent magnet having both end faces as magnetic poles, a short column portion internally fitted to an intermediate position in a hollow hole of the permanent magnet, and a state in which the short column portion is internally fitted to the permanent magnet. A ferromagnetic yoke plate composed of a flat plate portion joined to the back end surface of the permanent magnet, and is attached to the flat plate portion of the yoke plate so as to cover the side peripheral surface and the front end surface of the permanent magnet. At the same time, the adsorption unit constituted by a ferromagnetic thin plate cover in which a non-circular hole is formed at a position facing the short column portion of the yoke plate, and the hole of the thin plate cover on the side of the adsorption unit are fitted. A first contact plate portion having a non-circular shape and a thickness smaller than the facing distance between the thin plate cover and the end face of the short column portion on the suction unit side, and a second contact having a planar shape larger than the first contact plate portion. The plates and their respective contact plates are made to face each other substantially in parallel. And the second contact plate portion is in contact with the thin plate cover on the suction unit side in a state where the first contact plate portion is in contact with the end face of the short column portion on the suction unit side. Magnetic attachment / detachment device consisting of a ferromagnetic attachment / detachment unit configured as described above. 2. A short-cylindrical permanent magnet having both end faces as magnetic poles, and an inner portion of the permanent magnet which is internally fitted to an intermediate position in a hollow hole and which has an outer side portion of a region facing a punched hole of a later-described thin plate cover. A short column portion having a protruding portion having a gently inclined surface in the circumferential direction as an apex, and a flat plate portion joined to the back end surface of the permanent magnet in a state where the short column portion is fitted in the permanent magnet. A ferromagnetic yoke plate consisting of a yoke plate and a flat plate part of the yoke plate so as to cover the side peripheral surface and the front side end surface of the permanent magnet, and at a position facing the short column part of the yoke plate. An adsorption unit composed of a ferromagnetic thin plate cover in which a non-circular hole is formed,
And a first contact plate that has a non-circular shape that fits through a hole in the suction unit side thin plate cover and that has a thickness smaller than the facing distance between the suction unit side thin plate cover and the apex of the short column end face. Part and a second contact plate part having a larger planar shape than the first contact plate part, and a short column part connecting and connecting each contact plate part thereof in substantially parallel, the first contact plate part Magnetic force comprising a ferromagnetic detachable unit configured such that the second contact plate portion is in contact with the thin plate cover on the adsorption unit side in a state of being in contact with a region other than the projecting portion on the end surface of the short column portion on the adsorption unit side. Detachable device.