JP2771780B2 - electromagnet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet mechanically operated by energizing a coil, for example, an electromagnet for driving an electromagnetic relay, an electromagnetic valve, an electromagnetic vibration device, an electromagnetic operating mechanism, or the like.

[0002]

2. Description of the Related Art A conventional electromagnet is provided between a stator and a movable core by energizing a coil wound on the stator and disposing a movable core disposed on a magnetic pole surface of the stator with an operation gap therebetween. It has a configuration and a function of returning the operating gap between the stator and the movable iron core using the biasing force of the spring by stopping the coil and stopping the energization by sucking the spring against the biasing force of the spring.

FIG. 21 shows such a planar magnetic pole type plunger electromagnet, in which a fixed core 51 is provided with a coil 52, and a movable core 53 is urged by a spring 54 in a direction separating the fixed core and the movable core. When the coil 52 is energized, the movable core 53 is attracted to the fixed core 51. Such an electromagnet exhibits characteristics as shown in FIG. A penetrating plunger type electromagnet as shown in FIG. 23 is also known. Such a penetrating plunger type electromagnet is shown in FIG.
The characteristics as shown in FIG.

A self-holding solenoid having a self-holding permanent magnet 55 as shown in FIG.
It is disclosed in -170513. The technology is
The coil 52 and the permanent magnet 55 are connected coaxially, the movable iron core 53 is made sufficiently long, and the stopper 57 is connected to the yoke 58. The permanent magnet 55 is in contact with the yoke 58 and has a pole piece 56 at the other end, and is provided near the movable iron core 53. The permanent magnet 55 holds the movable iron core 53 and the stopper 57 in the attracted state.

[0005]

The above-mentioned prior art electromagnet has the following problems. (1) High sensitivity performance for operating a movable iron core with a small current is poor. (2) The effective suction force of the movable iron core is reduced by an amount corresponding to the urging force of the spring. (3) The planar magnetic pole plunger type electromagnet and the self-holding type solenoid have a problem that an impact force and an impact sound are generated at the end of the suction operation. For example, in an electromagnetic relay or the like, a cause of chattering of an electric contact or the like may be induced to impair the reliability of operation and the life of the device. In addition, a sharp impact sound is generated due to the collision of the magnetic pole surfaces of the fixed iron core and the movable iron core, and the sound often damages the environment.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an electromagnet having a high sensitivity operation characteristic operated by a minute electric input and having a noiseless and excellent attractive force characteristic. is there.

[0007]

SUMMARY OF THE INVENTION The present invention provides a magnetic member having a plurality of magnetic pole surfaces in which a coil and a permanent magnet are coaxially juxtaposed and arranged at intervals along the axial direction. An electromagnet comprising a movable iron core having a counter electrode surface facing each magnetic pole surface of the member in a non-equilibrium manner.

[0008] The magnetic member may be one in which the magnetization directions of the coil and the permanent magnet are arranged in the same or opposite directions and the magnetic pole faces are provided at both ends in the axial direction and at three places between the coil and the permanent magnet. Alternatively, the coils and the permanent magnets may be arranged so that their magnetization directions are orthogonal to each other, and the magnetic pole faces are provided at both ends in the axial direction. Further, it is preferable that a stable holding piece made of a magnetic material and in contact with the end face of the movable core is attached to the opposite end of the permanent magnet opposite the coil side of the pole piece on the opposite side of the coil, so that the movable iron core is stably held when the coil is not energized.

In the present invention, the fact that the movable iron core faces each magnetic pole face of the magnetic member non-equilibrium means that the movable iron core is formed so as not to uniformly face the magnetic pole face of the opposite magnetic pole face of the movable iron core. When the movable iron core faces the one pole face, the counter pole face facing the other pole face is omitted. For example, the movable iron core is formed by shortening at least one of the magnetic pole surfaces at both ends of the magnetic member with respect to at least the entire length of the magnetic member, or has a magnetic resistance at a portion to be the other counter surface. One provided with a non-magnetic member can be used. Further, the movable core may have a non-magnetic portion formed at a portion facing a magnetic pole surface provided between the coil and the permanent magnet.

[0010] It should be noted that the coil and the permanent magnet may be plural, and the movable iron core may operate stepwise. An electromagnet in which the magnetic pole surface of the magnetic body member faces inward and the movable iron core is provided inside thereof, that is, a plunger penetrating type may be used. It may be a mover type. In these cases, in the plunger penetrating type, the magnetic pole surface has a cylindrical inner diameter, and the movable iron core has a cylindrical shape, and in the external mover type, the magnetic pole surface has a cylindrical outer diameter. It may be a typical shape that is a cylindrical shape that fits outside, but the magnetic pole surface may be any shape inward or outward,
The movable core may have any shape facing the movable core.

The plurality of magnetic pole surfaces arranged at intervals may be magnetic pole surfaces arranged in a circumferential direction, and the movable core may be a rotating movable core whose movable direction is a rotation direction.

[0012]

FIG. 1 is a schematic structural view of one embodiment of the present invention, and FIG. 2 is an explanatory view of its operation.
This will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of an electromagnet according to an embodiment of the present invention, in which the upper side of the center line has the movable core facing the right end of the stroke, and the lower side of the center line has the movable core facing the left end of the stroke. . The specific configuration of the present invention is as follows: (a) a coil 2 in which an electric wire is wound around a hollow cylindrical bobbin 1 (b) a coaxial opening (a cylindrical inner magnetic pole) which surrounds the coil 2 and is provided at both ends of the hollow hole of the bobbin. (C) A permanent magnet 5 (a) in which one magnetic pole is fixed to the yoke 3 and a magnetic pole piece 4 having an opening (cylinder inner magnetic pole 8) coaxial with the bobbin is fixed to the other magnetic pole. D) The yoke 3 is inserted through the hollow hole of the bobbin 1, the opening of the yoke 3 (the magnetic pole surfaces 6 and 7), and the opening of the pole piece 4 (the magnetic pole surface 8) so as to slide in the axial direction. A circumferential surface facing only two of the three magnetic pole surfaces 6, 7, 8 of the inner circumferential surface of the opening (magnetic pole surfaces 6, 7) and the inner circumferential surface (magnetic pole surface 8) of the pole piece 4 of the permanent magnet ( A plunger penetrating electromagnet comprising a movable iron core 9 having a counter electrode surface.

The operation of the present invention will be described with reference to FIG.
You. Now, if the coil 2 is in a non-energized state, a permanent magnet
Magnetic flux by magnetomotive force of 5, Φ _a , Φ_b , Φ_m By the action of
The movable core 9 is positioned above the center line in FIG.
That is, the movable iron core 9 faces the magnetic pole faces 7 and 8 and
It is stable in a state that is not suitable. That is, the movable iron core 9
The position is magnetically set by the permanent magnet 5 in the upper half of FIG.
Is in a state of being restrained.

When the coil 2 is energized to induce a magnetic flux Φ _i as shown in FIG.
An electromagnetic attraction force is generated in the axial left direction proportional to the magnetic flux (Φ _a + Φ _i ) ² with respect to the movable iron core. The magnetic flux (Φ _b + Φ _i ) ² in the gap between the pole faces 7, the magnetic flux (Φ
_Although an electromagnetic attraction force proportional to _m ² = (Φ _a + Φ _b ) ² is generated, the electromagnetic attraction force does not act in the axial direction of the movable iron core 9. Therefore, between the movable core 9 and the stator, only a large electromagnetic attraction force of magnetic flux (Φ _a + Φ _i ) ² acts in the axial left direction of the movable core 9, and the movable core 9 is displaced in the axial left direction. Then, as the movable iron core 9 moves to the left, the magnetic pole face 8
In the gap, the rightward acting force of the electromagnetic attraction force proportional to the magnetic flux Φ _m ² increases, and the leftward electromagnetic attraction force on the movable iron core 9 is reduced. As a result, the movable iron core 9 stops at a position where the electromagnetic attraction force in the left-right direction is balanced.

Therefore, the driven mechanism is arranged at the required stroke position to generate the maximum thrust at the beginning of driving of the movable core 9, and at the end of driving, the required movable core 9 smaller than the maximum thrust.
Of the movable iron core 9 can be realized without impact. When the energization of the coil 2 is stopped in a state where the movable iron core 9 is attracted, the magnetic flux Φ _a is applied to the gap between the magnetic pole faces 6 and the magnetic flux Φ is applied to the gap between the magnetic pole faces 7.
_b and the gap between the pole faces 8 generate a magnetic attractive force proportional to the square of the magnetic flux Φ _m = Φ _a + Φ _b . However, in this case, the suction force acting in the axial direction of the movable core is
In the gap between the pole faces 6 and 7, the sum of the axial component forces is zero,
The movable core starts moving to the right only by the acting force in the axial right direction that is proportional to the magnetic flux Φ _m ² in the gap between the pole faces 8. As the movable iron core moves to the right, the leftward acting force of the magnetic attraction force proportional to the magnetic flux Φ _a ² in the gap between the magnetic pole faces 6 increases, canceling the rightward acting force on the movable iron core. , And returns to its initial position, which is the equilibrium position, and stands still.

The operation of the present invention is specifically shown by the suction force characteristic curve shown in FIG. 20 for the embodiment shown in FIG. An electromagnet of an example having a shape and dimensions in which dimension lines and dimensions (unit: mm) are entered in FIG. 19 was manufactured, and an experiment was performed. The movable iron core 9 was loosely fitted in a cylindrical stator in which the coil 2 and the permanent magnet 5 were coaxially arranged and covered with the yoke 3. The movable core 9 is shorter (1 mm) in axial direction length than the stator by the axial length of one magnetic pole surface. A current of 5 V and 0.4 A was supplied to the coil 2. FIG. 20 shows the results of experiments in which the types of permanent magnets were variously changed. The left end (YY ′) of the cross section shown in FIG. 19 was set to zero, and the suction amount was set to be positive when acting toward the left and negative when acting toward the right. When the coil was not energized, the suction force was measured when the coil was energized. The reference numerals in FIG. 20 are as follows.

Curve A: using a rare earth permanent magnet B curve: using a ferrite permanent magnet C curve: using no permanent magnet D curve: using a ferrite permanent magnet E curve: using a rare earth permanent magnet As a result, in the electromagnet having the illustrated structure and dimensions, It can be seen that even if the current supplied to the coils is the same (0.4 A) depending on the presence or absence of the magnet and the strength of the magnetomotive force of the permanent magnet, a difference of several times in the attraction force occurs.

[0018]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 shows its operation. One of the magnetic poles is fixed to the yoke 3 having the coil 2 and the cylindrical inner magnetic pole surfaces 6, 7;
A magnetic member 5 in which a magnetic body 4 having a cylindrical inner magnetic pole surface 8 is fixed to the other magnetic pole, and a circumferential surface (a counter electrode surface) facing only two of the three magnetic pole surfaces 6, 7, 8 are provided. And a movable iron core 9. When the coil 2 is not energized, the movable iron core 9 is stable in a state where it faces the magnetic pole faces 7 and 8 but does not face the magnetic pole face 6 due to the action of the magnetic flux by the magnetomotive force of the permanent magnet 5.

When the coil 2 is energized, the movable core 9
Is displaced to the left of the axis. When the movable iron core 9 moves to the left, the movable iron core 9 stops at a position where the electromagnetic attraction in the left and right directions is balanced. FIG. 3 is a longitudinal sectional view illustrating a schematic structure of another embodiment in which the magnetic pole arrangement of the movable iron core is different. When the nonmagnetic groove 10 is arranged on the peripheral surface of the movable iron core and the coil 2 is de-energized, The magnetic pole surface of the movable core 9 is opposed to the magnetic poles on the inner surfaces of the pair of openings of the yoke 3 by being displaced in opposite directions to the movable core axis direction, and the magnetic pole surface 8 of the cylindrical inner surface of the magnetic body 4 is aligned. It is to let.

The operation of the electromagnet having the structure shown in FIG. 3 will be described.
First, when the coil 2 is not energized, the movable core is stationary at the position shown in the upper half of FIG. That is, as shown in FIG. 5, the magnetic fluxes Φ _a , Φ _b , and Φ _m by the permanent magnet 5
Is stationary and restrained by the action of Here, when the coil 2 is energized to generate a magnetic flux Φ _i in the illustrated direction, an electromagnetic attractive force proportional to the magnetic flux (Φ _i + Φ _b ) ² acts on the gap between the magnetic pole faces 7 of the movable iron core, As shown in the lower half of the center line in FIG. 3, the movable iron core moves leftward in the axial direction. When the direction of the magnetic flux Φ _i is reversed by setting the magnetism of the coil to the reverse direction, an electromagnetic force proportional to the magnetic flux (Φ _i + Φ _a ) ² is generated in the gap between the magnetic pole surfaces 6 of the movable iron core, The movable iron core moves rightward in the axial direction as shown in FIG. That is, the electromagnet having the configuration of FIG.
The movable iron core 9 that is stabilized at the position shown in the upper half of FIG. 3 in the state where the coil is not energized is displaced in the left or right axis direction (FIG. 4) by selecting the polarity of the energization of the coil 2 to switch the energization. By stopping, the operation of the tristable operation of returning to the stable position of the movable core illustrated in the upper half of FIG. 3 can be performed.

FIG. 6 shows a modification of the embodiment shown in FIG.
A stable holding piece 14 made of a magnetic material and brought into contact with the end face of the movable iron core against the end of the permanent magnet 4 opposite the coil on the side opposite the coil.
Is installed. The stable holding piece 14 stably holds the movable iron core when the coil is not energized. FIG. 7 is a modification of the embodiment of FIG. 3 having a stable holding piece 14 similar to FIG.

FIGS. 8 and 9 show a comparison with the embodiment shown in FIG.
The shape of the nonmagnetic groove on the peripheral surface of the movable iron core and the arrangement position thereof are different. The cross-sectional shape of the nonmagnetic groove 10 in FIG.
By selecting the inclination angle of the trapezoid, it is possible to provide a means for adjusting the effective suction force characteristics. The electromagnet shown in FIG. 8 and FIG. 9 has the movable iron core arranged such that the opposite pole face of the movable iron core faces the magnetic pole face 8 of the magnetic body 4 even when the operation of the movable iron core is completed. Even if the energization of the coil 2 is stopped after the operation of the movable core 9 is completed,
Can be held by the magnetomotive force of the permanent magnet 5, and the self-holding operation characteristic is exhibited.

In the embodiment shown in FIG. 10, the inner movable core 9 of the embodiment shown in FIG.
FIG. The pole faces 6, 7 of FIG.
8 corresponds to the pole faces 26, 27 and 28, respectively. FIG.
The outer movable core 29 of 0 can be designed to have a smaller magnetic resistance in the gap of the magnetic path due to its structural characteristics than the inner movable core 9 of FIG. 1, and more favorable operating characteristics can be expected.

FIG. 11 shows an embodiment in which the magnetization direction of the permanent magnet 5 is set in the radial direction of the movable iron core. In this case, the pole face 7 between the coil 2 and the permanent magnet 5 is omitted. FIG. 12 shows an embodiment in which a plurality of electromagnets of the embodiment shown in FIG. 1 are connected in the axial direction, have a multiple stroke, and have a function of stepping. In this embodiment, the operation of selecting and switching the polarity of the current flowing through the coil is shown in FIGS.
As described above, the movable iron core can be moved with a multiple stroke in multiple times.

In the above embodiment, the movable iron core has been described as having a cylindrical or cylindrical shape. However, the present invention is not limited to this, and may be, for example, a square rod, a plate, or any other cross section. Further, the present invention is not limited to a circular permanent magnet or a circular polar surface, but may be a rectangular parallelepiped permanent magnet or a bar-shaped yoke. FIG. 14 is a longitudinal sectional view of another embodiment of the present invention, in which a plurality of magnetic pole surfaces are formed as magnetic pole surfaces separated in a circumferential direction, and a movable core is a rotatable movable core. Reference numerals 1 to 9 are the same as those in FIG. The magnetic pole surface 7 is formed by a tongue piece 12 which has entered the circumference from the yoke 3. FIG.
(A), (b) and (c) are AA and B in FIG.
-B and CC sectional views taken along arrows CC. The rotating movable iron core 9 is a rotating body including two arc surfaces forming a counter electrode surface and a peripheral surface having a clearance so as not to form a counter electrode surface. FIG. 15 shows the movable core 9 held in a rotating position by a permanent magnet in a state where the coil is not energized, and FIG. 16 shows the rotating position of the movable core 9 when the coil is energized. In this electromagnet, the movable core rotates between the positions shown in FIGS. 15 and 16 depending on whether or not the coil is energized.

FIGS. 17 (a), 17 (b) and 17 (c) are cross-sectional views taken along arrows AA, BB and CC, respectively, in a state where the coil of another type shown in FIG. 14 is not energized. Is shown. FIG. 18 shows a state in which the coil of the embodiment of FIG. 17 is energized with a predetermined polarity. By adopting a configuration of appropriate selection and combination in each of the above-described embodiments, it becomes easy to provide an electromagnet that meets application conditions according to various requests. In addition, it is easy to apply means for modifying the attraction force operating characteristics of the movable core by applying a spring resistance in the axial direction of the movable core of the electromagnet of each of the above embodiments.

[0027]

The electromagnet of the present invention exhibits the following excellent effects. (1) High sensitivity operation performance can be obtained. In contrast to a conventional electromagnet limited to an attractive force proportional to Φ _i ² due to a magnetic flux Φ induced by energization of a coil, the electromagnet of the present invention has a shunt magnetic flux due to _a permanent magnet as Φa,
(Φ _a + Φ _i) to generate a high suction force proportional to ^the. In addition, it is essential for conventional electromagnets to apply a spring resistance to the movable core for returning the movable core after the operation of the movable core. However, since the electromagnet of the present invention can effectively utilize the magnetic attraction force of the permanent magnet for returning the movable iron core, the initial attraction force of the electromagnet is not impaired. Therefore, the device of the present invention enables high-sensitivity operation to generate a high attraction force several times higher than that of the conventional technology by using minute electric energy, and enables an electromagnetic device that can be driven by a small-capacity power source such as a dry battery. Can be provided. (2) The shock during operation is quiet and does not generate an impact sound.

Since the fixed iron core has no collision mechanism with the movable iron core, the apparatus of the present invention does not generate an environmentally damaging impact sound. Further, it is easy to adjust the impact force of the electromagnet to the driven device, and by performing quiet driving, it is possible to prevent chattering of electric contacts such as electromagnetic relays. (3) It is possible to reduce the size and weight.

If the required attraction force is equal, the same mechanical work can be performed with a smaller and lighter device as compared with a conventional electromagnet. In particular, with the recent development of high-performance magnetic materials, further miniaturization can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment.

FIG. 2 is an explanatory diagram of the principle of the present invention.

FIG. 3 is a longitudinal sectional view of another embodiment.

FIG. 4 is a longitudinal sectional view of another embodiment.

FIG. 5 is an operation explanatory view of another embodiment.

FIG. 6 is a longitudinal sectional view of another embodiment.

FIG. 7 is a longitudinal sectional view of another embodiment.

FIG. 8 is a longitudinal sectional view of another embodiment.

FIG. 9 is a longitudinal sectional view of another embodiment.

FIG. 10 is a longitudinal sectional view of another embodiment.

FIG. 11 is a longitudinal sectional view of another embodiment.

FIG. 12 is a longitudinal sectional view of another embodiment.

FIG. 13 is a longitudinal sectional view of another embodiment.

FIG. 14 is a longitudinal sectional view of another embodiment.

FIG. 15 is a cross-sectional view of the embodiment.

FIG. 16 is a cross-sectional view of the embodiment.

FIG. 17 is a cross-sectional view of the embodiment.

FIG. 18 is a cross-sectional view of the embodiment.

FIG. 19 is a longitudinal sectional view of the embodiment.

20 is a graph showing the characteristics of FIG.

FIG. 21 is a longitudinal sectional view of a conventional electromagnet.

FIG. 22 is a graph showing characteristics of a conventional electromagnet.

FIG. 23 is a longitudinal sectional view of a conventional electromagnet.

FIG. 24 is a graph showing characteristics of a conventional electromagnet.

FIG. 25 is a longitudinal sectional view of a conventional electromagnet.

[Explanation of symbols]

 Reference Signs List 1 bobbin 2 coil 3 yoke 4 magnetic material 5 permanent magnet 6, 7, 8 magnetic pole surface 9 movable iron core 10 groove 11, 12 non-magnetic material 13 tongue piece 14 stable holding piece 26, 27, 28 magnetic pole surface 29 movable iron core 51 fixed iron core 52 Coil 53 Moving iron core 54 Spring 55 Permanent magnet 56 Magnetic pole piece 57 Stopper 58 Yoke

Claims (10)

(57) [Claims] 1. A magnetic member having a plurality of magnetic pole surfaces in which a coil and a permanent magnet are juxtaposed coaxially and spaced from each other in an axial direction, and a magnetic member having a plurality of magnetic pole surfaces is provided. An electromagnet, comprising: a movable core having a counter electrode surface facing non-equilibrium. 2. The magnetic member is characterized in that the magnetization directions of the coil and the permanent magnet are arranged in the same or opposite directions, and the magnetic pole surfaces are provided at both ends in the axial direction and between the coil and the permanent magnet. The electromagnet according to claim 1. 3. The electromagnet according to claim 1, wherein the magnetic members are arranged side by side with the magnetization directions of the coil and the permanent magnet orthogonal to each other, and magnetic pole faces are provided at both ends in the axial direction. 4. The magnetic material member is characterized in that a stable holding piece made of a magnetic material is provided at the opposite end of the permanent magnet from the opposite coil side of the opposite coil side magnetic pole piece to the end face of the movable core. The electromagnet according to claim 1. 5. The electromagnet according to claim 2, wherein the movable iron core is shorter than at least one of the pole faces at both ends from the entire length of the magnetic member. 6. The electromagnet according to claim 2, wherein the movable core has a non-magnetic portion formed at a portion facing a magnetic pole surface provided between the coil and the permanent magnet. 7. The electromagnet according to claim 1, wherein the coil and the permanent magnet are plural. 8. The electromagnet according to claim 1, wherein the electromagnet is a plunger penetrating type. 9. The electromagnet according to claim 1, wherein the electromagnet is an external mover type. 10. The electromagnet according to claim 1, wherein the plurality of magnetic pole faces arranged at intervals are magnetic pole faces arranged in a circumferential direction, and the movable core is a rotating movable core. .