JPS6134903A - Magnetic circuit device - Google Patents

Abstract

PURPOSE:To enable to detect the mounting and dismounting condition of an armature piece by a method wherein a sub-permanent magnet, which will be attracted to or separated from the other end of a yoke piece corresponding to the mounting or dismounting of an armature piece, is provided. CONSTITUTION:A yoke piece 2 is fixed in a tightly contacted manner on both end faces of the main permanent magnet 1 whereon a magnetic pole is formed on both end faces. Also, an armature piece 4 is fixed on the opening- and closing member 5 such as a door, a cover and the like, and it is positioned on the tip face of the yoke piece 2 in a freely detachable manner. On the other hand, a sub-permanent magnet 6 is arranged opposing to the back end face of the yoke 2 in such a manner that the N-pole of the sub-permanent magnet 6 is opposing to the yoke piece located on the N-pole side of the main permanent magnet 1. When the magnetic flux density condition, wherein the sub- permanent magnet 6 is attracted to an separated from the back end of the yoke 2 corresponding to the attraction and separation of 1:1 for the tip of the yoke piece 2 of the armature piece 4, an ON-OFF operation can be performed on a movable contact 7 and fixed contacts 8A and 8B utilizing the movement of the sub-permanent magnet 6, thereby enabling to detect the opening and shutting condition of the opening-shutting member 5 such as a door, a cover and the like.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides a magnetic catch function for locking and holding doors, lids, etc. in the closed state, and a function for detecting the closed state of the doors, lids, etc. The present invention relates to a magnetic circuit device having the following features.

(Prior Art) Conventionally, as shown in FIG. 13, a general magnetic catch has a structure in which a permanent magnet 1 having magnetic poles on both end faces has yoke pieces 2 made of iron or the like disposed on each end face. This attracts and holds an armature piece (movable magnetic piece) 4 such as an iron piece attached to the side of the opening/closing member 5 such as a door or a lid.

(Problem to be Solved by the Invention) In this case, the magnetic catch only has the function of locking the opening/closing member 5 in the closed state, and for example, the magnetic catch only has the function of locking the opening/closing member 5 in the closed state. For detection, it was necessary to provide another detection means such as a limit switch, a microswitch, or a combination of a permanent magnet and a reed switch. For this reason, these switch parts are required in addition to the magnetic catch, which not only increases the cost, but also causes inconveniences such as the fact that installation of these switch parts requires separate space.

(Means for Solving the Problems) In view of the above points, the present invention provides a main permanent magnet having magnetic poles formed on both end faces, a pair of yoke pieces closely attached to the magnetic pole faces of the main permanent magnet, and the yoke. In addition to the conventional magnetic catch structure consisting of an armature piece (movable magnetic material piece) that is removably arranged at one end of the piece, there is also a yoke piece other than the yoke piece that corresponds to the attachment and detachment of the armature piece. It is an object of the present invention to provide a magnetic circuit device in which an auxiliary permanent magnet is provided at the end to attract and detach, and the state of attachment and detachment of the armature piece can be detected from the state of the auxiliary permanent magnet.

(Example) Hereinafter, an example of a magnetic circuit device according to the present invention will be described with reference to the drawings.

1 and 2 show a first embodiment of the present invention, FIG. 1 shows a state in which the auxiliary permanent magnet is detached, and FIG. 2 shows a state in which the auxiliary permanent magnet is attracted.

In these figures, yoke pieces 2 made of iron or the like are closely fixed to both end faces of a main permanent magnet 1 having magnetic poles formed on both end faces. Further, an armature piece (movable magnetic material piece) 4 made of iron or the like is fixed to an opening/closing member 5 such as a door or a lid. The armature piece 4 is removably located on the front end surfaces of the pair of yoke pieces 2. On the other hand, an auxiliary permanent magnet 6 is arranged opposite to the rear end surfaces of the pair of yoke pieces 2, and the auxiliary permanent magnet 6 has an N pole on the surface facing the yoke pieces 2.

Two south poles are formed. That is, main permanent magnet 1
The N pole of the sub permanent magnet 6 is set to face the N pole side yoke piece of the sub permanent magnet 6. Mechanically, the sub permanent magnet 6 is supported movably within a range from a state where it is attracted to the yoke piece 2 to a state where it is separated from the yoke piece 2 by a certain distance,
A movable contact 7 is connected to the sub permanent magnet 6. Further, fixed contacts 8A and 8B are arranged opposite to the movable contact 7.

Next, the operation of the magnetic circuit device shown in the first embodiment will be explained. First, as shown in Figure 3, amateur piece 4
If we ignore the existence of the secondary permanent magnet 6 and consider the magnetic flux density that only the main permanent magnet 1 exerts on the yoke piece 2, the magnetic flux density at the end of the yoke piece is Bd, and its direction is as shown by the arrow in the figure. be. Further, as shown in Fig. 4, if the existence of the main permanent magnet 1 and the armature piece 4 is ignored and the magnetic flux density that only the sub permanent magnet 6 gives to the yoke piece 2 is Bd2, the direction is as shown by the arrow in the figure. be. Furthermore, as shown in FIG. 5, ignoring the existence of the sub permanent magnet 6, the main permanent magnet 1
The magnetic flux density inside the yoke piece 2 in a state where the armature pieces 4 are attracted and held at the tips of the yoke pieces 2 on both sides is defined as Bd, and its direction is indicated by an arrow in the figure. In FIG. 5, the rear end of the yoke piece 2, that is, the side facing the sub-permanent magnet is indicated by X. , when the tip, that is, the armature-piece contact side position is Xa, the magnetic flux density Bdz increases in the Xa force direction as shown in FIG. In this case, when the saturation magnetic flux density of the yoke piece 2 is Bs, the setting is made so that the yoke piece 2 is not magnetically saturated even at the position Xa.

Now, as shown in FIG. 2, the opening/closing member 5 is brought into the closed state,
When the armature piece 4 is attracted and held on the end face of the yoke piece 2, the magnetic flux density in the yoke due to the main permanent magnet 1 is Bd3 in the direction of the arrow in the figure, as shown in FIG. As can be seen from FIG. 7, the magnetic flux density Bd2 also occurs in the same direction as Bc13, and as a result, an attractive force acts between the rear end of the yoke piece 2 and the magnetic pole of the auxiliary permanent magnet 6. is attracted to the rear end of the yoke piece corresponding to the attraction of the armature piece 4. When the auxiliary permanent magnet 6 is in the attracted state, the movable contact 7 moves to the left in conjunction with this position, so that the electrical connection between the fixed contacts 8A and 8B is turned off.

FIG. 8 shows the magnetic flux density from the X0 position to Xa in the yoke piece 2 when the armature piece is attracted.

In this way, the magnetic flux density in yoke piece 2 is Bd2+Bd
, but at the tip position Xa (・but the saturation magnetic flux density B
It is preferable to avoid reaching point s or to be in a state near point Bs.

If the yoke piece 2 becomes magnetically saturated and becomes ν, even if the armature piece 4 becomes attracted as shown in Fig. 2, the first
As shown in Fig. 0, there exists a magnetic flux density Bd toward the rear end of the yoke piece in the opposite direction to the magnetic flux density Bd3, and in this state) when B d4 > B d2, the armature piece 4 Even in the attracted state, a repulsive force is generated at the rear end of the yoke piece, and the auxiliary permanent magnet 6 is not attracted.

Next, when the opening/closing member 5 is opened from the state shown in FIG. 2 as shown in FIG. 1 and the 7-mesh piece 4 is separated from the tip surface of the yoke piece 2, the magnetic flux density B due to the main permanent magnet 1 is shown in FIG.
The direction of dl is opposite to the magnetic flux density Bd- due to the auxiliary permanent magnet 6, as shown by the arrow in FIG. As a result,
When the condition of Bdl>Bd2 is satisfied, Bd
,, Since the magnetic flux vectors of Bd2 are reversed, the sub permanent magnet 6 is separated from the attracted state shown in Fig. 2 as shown in Fig. 1 in response to the separation of the armature piece 4.

However, in the case of the condition Bd2>Bd, the sub permanent magnet 6
generates an attractive force against the yoke piece 2 (1 does not separate).Also, in the case of Bd2=Bd, it is inappropriate because no repulsive force is generated.

Therefore, as shown in Figures 1 and 2, amateur
When the armature piece 4 is in the detached state, the auxiliary permanent magnet 6 is detached, and the armature arm piece 4 is in the attracted state (1) The armature arm arm 4 and the auxiliary permanent magnet 6 are connected so that the auxiliary permanent magnet 6 is attracted. In order to correspond 1:1 with the movement, the condition Bdl>Bd2 and the magnetic flux density Bd directed toward the rear end if the yoke piece 2 is not magnetically saturated or even if there is magnetic saturation are required.
, <Bd2 must be satisfied.

According to the first embodiment, the sub permanent magnet 6 is attracted to and detached from the rear end of the yoke piece in 1:1 correspondence to the adsorption and detachment of the armature piece 4 to and from the tip of the yoke piece, and the sub permanent magnet 6 is attached to and detached from the rear end of the yoke piece. Using the movement of the magnet 6, the movable contact 7 and the fixed contact 8A,
8B can be turned on and off, thereby making it possible to reliably detect the closed state of the opening/closing member 5 such as a door or lid. It can also have a closed state detection function. Also, it is a combination of two permanent magnets,
The structure is simple and does not require a coil, allowing for miniaturization and cost reduction.

In the first embodiment shown in FIGS. 1 and 2, the sub permanent magnet 6
has a single-sided bipolar structure and can be closely attached to the rear end surface of the yoke piece 2. This structure is suitable when the main permanent magnet 1 and the auxiliary permanent magnet 6 are made of the same material, for example, both are ferrite magnets or both are rare earth magnets. It is not necessary to have a structure that allows close contact, and a predetermined interval may be provided.

FIG. 11 shows a second embodiment of the present invention, in which the sub permanent magnet 6
A magnet having magnetic poles formed on both end faces is used as A, and the N poles are arranged to face the inner surface of the N pole side yoke piece of the main permanent magnet 1 at predetermined intervals.

Note that the configuration in which the movable contact 7 is connected to the sub-permanent magnet 6 and the fixed contacts 8A and 8B are provided opposite thereto is the first one.
It may be similar to FIG. 2 and FIG.

The second embodiment shown in FIG. 11 is particularly effective when a strong magnet such as a rare earth magnet is used as the sub permanent magnet 6A. In other words, when a ferrite magnet is used as the main permanent magnet 1 and a rare earth magnet is used as the sub permanent magnet 6, if the sub permanent magnet is in close contact with the rear end surface of the yoke piece, Bd>Bd2 as explained in FIG. This is because there is a risk that the conditions may not be satisfied and the auxiliary permanent magnet will always be attracted to the rear end of the yoke piece. That is, in FIG. 11, the main permanent magnet 1 is made of ferrite, the sub permanent magnet 6A is also made of 7-elite, and the distance between the sub permanent magnet 6A and the yoke piece 2 is D.
In this case, regardless of the value of D, when armature piece 4 is in the detached state as shown in curve F1 in Figure 12, a repulsive force is generated on the sub permanent magnet side, and when armature piece 4 is in the attracted state as shown in curve F2, An attractive force is generated on the side of the auxiliary permanent magnet, but when a rare earth magnet is used as the auxiliary permanent magnet 6A, the attractive force when the armature piece 4 is attracted appears normally as shown by curve R2, but when the armature piece 4 is The repulsive force on the auxiliary permanent magnet side when separated is shown by curve R6, and D
It can be seen that when the auxiliary permanent magnet 6A becomes smaller than a certain level, the repulsive force changes to an attractive force, and it becomes impossible to separate the sub permanent magnet 6A by repulsion. Therefore, it may be necessary to provide appropriate spacing as shown in FIG. 11.

In each of the above embodiments, the switch is turned off when the sub permanent magnet is attracted, and the switch is turned on when the sub permanent magnet is removed.
Conversely, the switch may be turned on when the sub permanent magnet is attracted, and turned off when it is removed.

(Effects of the Invention) As explained above, according to the magnetic circuit device of the present invention,
In addition to its function as a magnetic catch, it can also be equipped with a function to detect the open/closed state of doors and lids, etc. Furthermore, by interlocking the switch mechanism with the secondary permanent magnet, it can be used as a general proximity switch consisting of an electric circuit. It is possible to configure a magnetic microswitch, a proximity switch, etc. using only different magnetic circuits.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a first embodiment of the magnetic circuit device according to the present invention, showing a state in which the armature is detached from the armature, FIG. An explanatory diagram showing the magnetic flux density and its direction in the yoke piece due to the permanent magnet, FIG. 4 is an explanatory diagram showing the magnetic flux density and its direction in the yoke piece due to the sub permanent magnet, and FIG.
An explanatory diagram showing the magnetic flux density and its direction in the yoke piece when one side is attracted. Fig. 6 is a graph showing the change in magnetic flux density Bd3 in the yoke piece A position. Fig. 7 is the rear end of the yoke piece when the sub permanent magnet is attracted. An explanatory diagram showing the magnetic flux density and its direction at the yoke part. Fig. 8 is a graph showing the state of change in the magnetic flux density Bd20Bd at the position of the yoke piece in that case. Fig. 9 shows the yoke piece in a state where the sub permanent magnet is detached. Explanatory diagram showing the magnetic flux density and its direction at the rear end portion, No. 10
The figure is an explanatory diagram showing the magnetic flux density and its direction when magnetic saturation occurs in the yoke piece, Fig. 11 is an explanatory diagram showing the second embodiment of the present invention, and Fig. 12 is an explanatory diagram showing the spacing of the second embodiment. Graph showing the relationship between and the repulsive force and attractive force of the sub permanent magnet, 1st
FIG. 3 is an explanatory diagram showing a conventional magnetic catch. 1... Main permanent magnet, 2 river yoke piece, 4... Amateur piece, 5... Opening/closing member, 6, 6A... Sub-permanent magnet, 7... Movable contact, 8A, 8B ...Fixed contact.

Claims (4)

[Claims] (1) A main permanent magnet with magnetic poles formed on both end faces, and a pair of yoke pieces respectively arranged on the magnetic pole faces of the main permanent magnet,
a movable magnetic piece detachably disposed on one end of the yoke piece; when the movable magnetic piece is attracted to the one end of the yoke piece, it is attracted to the other end of the yoke piece; A magnetic circuit device comprising: a sub-permanent magnet that repels and separates from the other end of the yoke piece when the movable magnetic piece is separated from the one end of the yoke piece. (2) The magnetic circuit according to claim 1, wherein the auxiliary permanent magnet has a single-sided bipolar structure and has an N pole facing an end face of the N-pole side yoke piece of the main permanent magnet. Device. (3) The auxiliary permanent magnet has a structure in which magnetic poles are formed on both end surfaces, and has an N pole facing the inner surface of the N-pole side yoke piece of the main permanent magnet. 2. Magnetic circuit device described in Section 1. (4) a main permanent magnet with magnetic poles formed on both end faces, and a pair of yoke pieces respectively arranged on the magnetic pole faces of the main permanent magnet;
a movable magnetic piece detachably disposed on one end of the yoke piece; when the movable magnetic piece is attracted to the one end of the yoke piece, it is attracted to the other end of the yoke piece; and a sub-permanent magnet that repels and separates from the other end of the yoke piece when the movable magnetic piece is separated from one end of the yoke piece, and a switch mechanism interlocked with the sub-permanent magnet. A magnetic circuit device characterized by: