JP2595509Y2 - Moving magnet type actuator - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to control devices, electronic devices,
The present invention relates to a movable magnet type actuator for converting electric energy into reciprocating kinetic energy or the like by electromagnetic action in a machine tool or the like.

[0002]

2. Description of the Related Art Conventionally, as a movable magnet type reciprocating device, there are a device having a structure of a first conventional example shown in FIG. 7 and a device having a structure of a second conventional example shown in FIG.

In the first conventional example shown in FIG. 7, reference numeral 10 denotes a magnet movable body made of a rod-shaped permanent magnet magnetized in the axial direction.
It has magnetic poles on both end faces. The coils 11A and 11B are
The magnet movable body 10 is wound around the outer periphery of the end portion in an annular manner, and the same polarity is generated in adjacent portions. Although not shown, the coil 11
A and 11B are usually mounted on a guide cylinder for guiding the magnet movable body 10 movably in the axial direction. The magnetic flux from each end face of the magnet movable body 10 is
A and 11B are linked.

In the second conventional example shown in FIG.
Reference numeral 5 denotes two rod-shaped permanent magnets 16A and 16B which are arranged in the same pole opposition.
And a bar-shaped soft magnetic body 17 fixed between the permanent magnets 16A and 16B. The coil 18 is wound around the outer periphery of the intermediate portion of the magnet movable body 15 in an annular manner. Has been turned. Although not shown, the coil 18 is usually mounted on a guide cylinder for guiding the magnet movable body 15 movably in the axial direction. The magnetic flux from the end face of the permanent magnet facing the same pole of the magnet movable body 15 is linked with the coil 18.

In the first and second conventional examples, the thrust generated in the movable magnets 10 and 15 basically conforms to the thrust given based on Fleming's left-hand rule (Fleming). Is applied to the coil, but here the coil is fixed, so
A thrust as a reaction force of the force acting on the coil is generated in the magnet movable body. ). Therefore, what contributes to the thrust is the vertical component (the component orthogonal to the axial direction of the permanent magnet) of the magnetic flux of the permanent magnet that the movable magnet has.

[0006] Then, in the case of one permanent magnet or two permanent magnets of the same polarity opposing arrangement, the vertical component of the magnetic flux was analyzed.

FIG. 9 shows a result of a magnetic field analysis of a vertical component of a surface magnetic flux density along a longitudinal side surface of a single permanent magnet.
However, the permanent magnet is a rare earth permanent magnet and has a diameter of 2.5 m.
m, length 6mm, 0.25 ~ 0.45mm from the surface of permanent magnet
The distance was measured.

FIG. 10 shows the results of a magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side surfaces of the two permanent magnets when two permanent magnets are arranged in the same polarity and are directly joined. . However, each permanent magnet was a rare earth permanent magnet, having a diameter of 2.5 mm and a length of 3 mm (6 mm for two pieces), and measured at a position 0.25 to 0.45 mm away from the surface of the permanent magnet.

FIG. 11 shows a magnetic field analysis of a vertical component of a surface magnetic flux density along a longitudinal side surface of two permanent magnets when two permanent magnets are arranged at the same pole opposition and the opposing interval is 1 mm. The results are shown. However, each permanent magnet was a rare earth permanent magnet, having a diameter of 2.5 mm and a length of 3 mm, and was measured at a position 0.25 to 0.45 mm away from the surface of the permanent magnet.

FIG. 12 shows a vertical magnetic field analysis of the surface magnetic flux density along the longitudinal side surfaces of two permanent magnets when two permanent magnets are arranged at the same pole opposition and the opposing interval is 2 mm. The results are shown. However, each permanent magnet was a rare earth permanent magnet, having a diameter of 2.5 mm and a length of 3 mm, and was measured at a position 0.25 to 0.45 mm away from the surface of the permanent magnet.

FIG. 13 shows a magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side surfaces of two permanent magnets when two permanent magnets are arranged in the same pole opposition and the opposing interval is 3 mm. The results are shown. However, each permanent magnet was a rare earth permanent magnet, having a diameter of 2.5 mm and a length of 3 mm, and was measured at a position 0.25 to 0.45 mm away from the surface of the permanent magnet.

FIG. 14 shows a case where two permanent magnets are arranged in the same polarity and opposed to each other, and a soft magnetic material having a length of 1 mm is arranged between the two permanent magnets. The result of the magnetic field analysis of the vertical component of the density is shown. However, each permanent magnet was a rare earth permanent magnet, having a diameter of 2.5 mm and a length of 3 mm, and was measured at a position 0.25 to 0.45 mm away from the surface of the permanent magnet.

FIG. 15 shows two permanent magnets having the same polarity facing each other, a soft magnetic body having a length of 1 mm disposed between the two permanent magnets, and further facing the outer periphery of the two permanent magnets. The result of performing a magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side surfaces of the two permanent magnets when the yoke is provided is shown. However, each permanent magnet is a rare earth permanent magnet, having a diameter of 2.5 mm and a length of 3 mm, a yoke having a cylindrical shape surrounding the permanent magnet, a thickness of 0.5 mm, a length of 10 mm and a distance of 1.25 mm from the outer periphery of the permanent magnet. The vertical component of the surface magnetic flux density was measured at a position 0.25 to 0.45 mm away from the surface of the permanent magnet.

[0014]

[Problems to be Solved by the Invention] As described above, the thrust generated in the magnet movable body basically conforms to the thrust given based on Fleming's left-hand rule.
Although it is desired that the vertical component of the magnetic flux of the permanent magnet interlinking with the coil (the component orthogonal to the axial direction of the permanent magnet) is large, the vertical component of the surface magnetic flux density in the first conventional example of FIG. As a result, it has been found that the vertical component is smaller as compared with the case where the two permanent magnets of FIGS. For this reason, in the configuration of the first conventional example shown in FIG. 7, there is a limit in improving the thrust. For example, the magnet movable body 10 is composed of a rare-earth permanent magnet having a diameter of 2.5 mm and a length of 6 mm, and each coil 11A, 11B has a current of 40 mA so that the same polarity is generated in an adjacent portion of the two coils 11A, 11B. The thrust F1 generated when a current was applied was 4.7 (gf).

On the other hand, the second conventional example shown in FIG. 8 uses a magnet movable body 15 in which a soft magnetic material is arranged between two permanent magnets of the same polarity facing each other, and the vertical component of the magnetic flux density is shown in FIG. Thus, the magnetic flux emitted from the magnetic poles of the permanent magnets 16A and 16B opposed to each other with the same polarity is larger than that in the case of one permanent magnet (see FIG. 9) or in the case of only two permanent magnets (see FIGS. 10 to 13). However, there is only one coil surrounding the intermediate portion of the movable magnet 15, and there is a dislike that the magnetic flux generated by the magnetic poles on both end surfaces of the movable magnet 15 is not effectively used. For this reason, FIG.
Also in the case of the conventional example, it was difficult to improve the thrust. For example, FIG.
In the second conventional example, the magnet movable body 15 has a diameter of 2.5 m.
FIG. 7 shows an example in which two rare-earth permanent magnets having a length of 3 mm and a length of 3 mm are used (the performance of the rare-earth permanent magnets is assumed to be the same as that of the first conventional example), and a soft magnetic material having a length of 1 mm is arranged between them. First
Coil 18 created to have the same power consumption as the conventional example
And a thrust F2 generated when the same power consumption as that of the first conventional example was applied was 5.6 (gf).

When a magnet movable body is formed by combining a plurality of permanent magnets, it is necessary to surely integrate the permanent magnets, and it is necessary to consider this point.

According to the present invention, at least two
The use of a magnet movable body in which two permanent magnets are arranged in the same pole opposition and are surely integrated, and the magnetic flux generated by the magnetic poles of the permanent magnets are effectively used to improve reliability, thrust and efficiency. It is an object to provide a movable magnet type actuator.

[0018]

In order to achieve the above object, a movable magnet type actuator according to the present invention has a magnetic body disposed between at least two permanent magnets of the same polarity, and these permanent magnets and A magnetic body is fixed in a non-magnetic cylindrical holder to form a magnet movable body, the magnet movable body is slidably provided inside a guide cylinder, and wound around an outer peripheral side of the magnet movable body. At least three coils are mounted on the guide cylinder and disposed inside the magnetic yoke, and at least three of the at least three coils are located at end portions.
The permanent magnet is wider than that of the permanent magnet and intersects with the magnetic flux from the same-polarity opposite end of the permanent magnet, and the end position is interposed with the magnetic flux from the end magnetic pole of the permanent magnet. so
The coils are connected so that currents flow in different directions across magnetic poles of the permanent magnets.

The permanent magnet and the magnetic body may be fixed in the cylindrical holder by caulking an end of the cylindrical holder.

Further, a structure may be employed in which a pinned member for taking out output is fixed at the end of the cylindrical holder.

[0021]

The principle of operation of the movable magnet type actuator according to the present invention will be described with reference to the schematic diagram of FIG. In FIG. 5, the magnet movable body 3 is composed of two columnar permanent magnets 5 arranged in the same pole opposition.
A and 5B and a columnar soft magnetic body 6 fixed between these permanent magnets 5A and 5B are integrated using a non-magnetic cylindrical holder 7, and as shown in FIG. The structure has a large number of vertical components of the density (components perpendicular to the axial direction of the permanent magnet). The three coils 2A, 2B, 2C
The left end of the permanent magnet 5A, which is wound around the outer periphery of the magnet movable body 3 and constitutes the magnet movable body 3, the permanent magnets 5A,
The permanent magnet 5B is arranged so as to interlink with the magnetic flux from the same pole facing end and the magnetic flux from the rightmost magnetic pole of the permanent magnet 5B. These coils 2A, 2B, 2C are connected so that currents flow in different directions with the boundary between the magnetic poles of the permanent magnets 5A, 5B (if the boundary between the magnetic poles is between the magnetic poles, it is not necessarily the middle of the magnetic poles). It does not have to be in position.) Although not shown, the coils 2A, 2B, 2C are usually mounted on a guide cylinder for guiding the magnet movable body 3 so as to be movable in the axial direction. The positional relationship between the coils 2A, 2B, 2C and the magnet movable body 3 is such that in most of the movable positions of the magnet movable body 3 including at rest, currents flowing through the respective coils with respect to the permanent magnet magnetic poles are mutually reciprocal. Set in the opposite direction.

In the structure of the magnet movable body 3 in FIG. 5, when the nonmagnetic cylindrical holder 7 is omitted, as shown in FIG. It is arranged. In FIG. 14, the vertical component of the surface magnetic flux density in the region Q corresponding to the position of the soft magnetic material is superior to FIGS. 10 to 13 without the soft magnetic material (the width of the peak having a magnetic flux density of 0.3 T or more). Is wide and the peak is high.).

As described above, the magnet movable body 3 in which the two permanent magnets 5A and 5B are opposed to each other with the same polarity and the soft magnetic body 6 is provided between the permanent magnets can contribute to the thrust based on Fleming's left-hand rule. The magnetic flux component perpendicular to the longitudinal direction of the movable body 3 can be increased, and the three coils 2A, 2B, 2C are effectively linked to the magnetic flux of all the magnetic poles of the permanent magnet, so that the three coils 2A, 2B, 2C By passing a current in a direction that generates a magnetic field of the opposite polarity alternately, a large thrust that cannot be reached in the conventional example can be generated. When the current of each coil is reversed, the direction of the thrust of the magnet movable body 3 is also reversed. When an alternating current is passed, it works as a vibrator that repeats oscillation at a constant cycle. At this time, the magnet movable body 3 is one in which the two permanent magnets 5A, 5B and the soft magnetic body 6 are housed and fixed in the cylindrical holder 7, and their assembly accuracy is good and integration is reliable. The danger of the permanent magnets 5A, 5B and the soft magnetic material 6 being separated from each other due to the repulsive force between the permanent magnets 5A, 5B to eliminate defective products can be eliminated, and reliability can be maintained.

In the case of FIG. 5 according to the present invention, for example, two rare earth permanent magnets having a diameter of 2.5 mm and a length of 3 mm are used as the magnet movable body 3 (the performance of the rare earth permanent magnet is the same as that of the first conventional example). ) And three coils 2A, 2B made of a soft magnetic material having a length of 1 mm disposed therebetween so as to have the same power consumption as the first and second conventional examples of FIGS. , 2
The thrust F3 generated when a current of 40 mA was passed through C and the power consumption was the same was 6.7 (gf). This is about 1.42 times the thrust of the first conventional example with the same power consumption, and about 1.2 times the thrust of the second conventional example.
Also, it is found that it is much better than the second conventional example.

The curve (a) in FIG. 6 shows the relationship between the axial displacement of the magnet movable body 3 and the thrust (gf) in the case of FIG. 5 (without yoke). However, the dimensions and characteristics of the permanent magnet are as shown in FIG. 14, and the displacement amount is zero when the middle point of the magnet movable body 3 is located at the middle point of the center coil 2B.
The current of each coil was 40 mA. Also, the same coil
Under the flow conditions, the curve (b) in FIG.
Between the axial displacement of the magnet movable body 3 and the thrust (gf)
Magnet moving body in a direction away from the zero displacement point
The curve (c) is close to the point where the displacement is zero.
It shows when it operates in the direction of sticking. Yes if there is a yoke
The thrust can be further improved.

As described above, the movable magnet type actuator according to the present invention has a structure in which permanent magnets of the same polarity are incorporated in the non-magnetic cylindrical holder to constitute the magnet movable body, and the magnetizing direction of the permanent magnets. The magnetic flux density component perpendicular to (axial direction) can be made sufficiently large, and the magnetic flux generated by all the magnetic poles of the permanent magnet can be used effectively . It also circulates around the magnet movable body.
Of the at least three coils, the middle one
The width of the permanent magnet is wider than that of the permanent magnet.
Left hand method of framing between the current flowing through each coil
The thrust based on the law can be made sufficiently large. That is, the intermediate
The coil at the position is wide and the magnet on the same pole opposite side of the permanent magnet is
Flux distribution (more than the magnetic flux at the end,
Wide) and the end coil is narrow
And the current density increases, and the magnetic flux distribution (magnetic
Effectively generates thrust between the area where the bundle is large and the width is narrow)
it can. Further, the magnetic yoke is connected to the at least three
Thrust can also be improved by arranging it outside the coil.
Wear. As a result, a large thrust can be obtained with a small size and a small current, and since the permanent magnet and the soft magnetic material are housed and fixed in the non-magnetic cylindrical holder, the structure of the magnet movable body is made firm and the reliability is improved. obtain.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a movable magnet type actuator according to the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of the present invention. In these figures, reference numeral 1 denotes a cylindrical yoke made of a soft magnetic material, and a triple coil 2A,
2B and 2C are arranged and fixed to the cylindrical yoke 1 with an insulating member such as an insulating resin constituting a guide cylinder 4 for slidably guiding the magnet movable body 3. Magnet movable body 3
Are two columnar rare earth permanent magnets 5A,
5B, a cylindrical soft magnetic body 6 disposed between the permanent magnets 5A and 5B, and a non-magnetic cylindrical holder 7. The permanent magnets 5A and 5B and the soft magnetic body 6 It is housed inside and fixed with an adhesive or the like. The three coils 2A, 2B, 2C are connected so that currents flow in different directions from the magnetic poles of the permanent magnets 5A, 5B. That is, the center coil 2B surrounds the ends including the N poles of the soft magnetic body 6 and the permanent magnets 5A and 5B, and the coils 2A and 2C on both sides surround the ends including the S poles of the permanent magnets 5A and 5B, respectively. And the direction of the current flowing through the center coil 2B and the directions of the coils 2 on both sides.
The directions of the currents A and 2C are opposite to each other (see N and S attached to each coil in FIG. 1).

In the first embodiment, each of the coils 2A, 2A
Since the cylindrical yoke 1 made of a soft magnetic material is provided on the outer peripheral side of B and 2C, the vertical component of the surface magnetic flux density of the magnet movable body 3 further increases as shown in FIG. For this reason, the magnetic flux component perpendicular to the longitudinal direction of the magnet movable body 3 that can contribute to the thrust based on Fleming's left-hand rule can be increased, and the triple coils 2A and 2 wound around the magnet movable body 3 in an annular shape.
A larger thrust can be generated by supplying a current in a direction in which magnetic fields of opposite polarities are alternately generated in B and 2C. For example, the magnet movable body 3 has a diameter of 2.5 m.
FIG. 7 shows an example in which two rare earth permanent magnets having a length of 3 mm and a length of 3 mm are used (the performance of the rare earth permanent magnets is assumed to be the same as that of the first conventional example), and a soft magnetic material having a length of 1 mm is arranged between them. ,
The thrust F4 generated when a current of 40 mA flows through the triple coils 2A, 2B, and 2C created to have the same power consumption as the first and second conventional examples in FIG. 0 (gf). The direction of the thrust F4 is a direction in which the magnet movable body 3 moves to the right in the polarity of FIG.
When the current of each coil is reversed, the direction of the thrust of the magnet movable body 3 is also reversed. When an alternating current is passed, it works as a vibrator that repeats vibration at a constant cycle and can be incorporated in a pager or the like. The center coil 2B is located at the end.
It is configured wider than the coils 2A and 2C of the section,
The magnetic flux distribution on the opposite side of the permanent magnets 5A and 5B (the magnetic flux at the ends)
More than the bundle and the width of the area with much magnetic flux is wider)
I am trying to do it. The coils 2A and 2C at the ends are
As the width is smaller, the current density increases and the permanent magnets 5A and 5B
Flux distribution on the end side (the width of the area with much magnetic flux is narrow)
And thrust can be generated effectively.

The curve (b) in FIG. 6 shows the axial displacement of the magnet movable body 3 in the case of the first embodiment (however, the dimensions and arrangement of the permanent magnet and the yoke and the characteristics of the permanent magnet are as shown in FIG. 15). This shows the relationship with the thrust (gf) when the magnet movable body moves in a direction away from the zero displacement point. The curve (c)
Shows the relationship between the axial displacement of the magnet movable body 3 and the thrust (gf) in the case of the first embodiment (with yoke), and shows the case where the magnet moves in a direction approaching the point of zero displacement. However, when the intermediate point of the magnet movable body 3 was located at the intermediate point of the center coil 2B, the displacement amount was set to zero, and the current of each coil was set to 40 mA. As described above, the thrust differs depending on whether the magnet movable body 3 approaches or moves away from the point where the displacement amount is zero, because the magnet movable body 3 is displaced between the magnetic pole of the permanent magnet of the magnet movable body 3 and the yoke 1. This is because the magnetic attractive force for returning to the quantity zero point is working.

Further, in the case of the first embodiment, the permanent magnets 5A and 5B and the soft magnetic body 6 are housed and fixed in the non-magnetic cylindrical holder 7, so that the permanent magnets are disjointed by the same repulsive force of the permanent magnets. The structure of the magnet movable body 3 can be made firm, and the permanent magnet can be prevented from being chipped or worn to improve reliability. In addition, assembling accuracy can be improved.

FIG. 3 shows a second embodiment of the present invention. In this case, the magnet movable body 3A is composed of two columnar rare-earth permanent magnets 5A and 5B arranged in the same pole opposition, and these permanent magnets 5A and 5B.
B, a cylindrical soft magnetic body 6, a non-magnetic pinned member 9 and a non-magnetic cylindrical holder 7A disposed on the outer end face of each permanent magnet, and these permanent magnets 5A, 5A.
B, the disk-shaped bases of the soft magnetic body 6 and the member 9 with pins are housed in a cylindrical holder 7A and fixed with an adhesive or the like. Further, soft magnetic attraction plates 8A and 8B are fitted and fixed to both ends of the cylindrical yoke 1 and the guide cylinder 4 made of a soft magnetic material. Then, a member 9 with pins fixed to the outer end surfaces of the permanent magnets 5A, 5B through holes formed in the attraction plates 8A, 8B.
Pins protrude for taking out output. The pin portion of the member 9 with pins is slidable with respect to the holes of the suction plates 8A and 8B, and the other structure is the same as that of the first embodiment.

In the case of the second embodiment, the magnet movable body 3A is attracted to one of the soft magnetic attraction plates 8A and 8B when the coils 2A, 2B and 2C are not energized.
Now, when the magnet movable body 3A is in the state shown in the drawing, if the coils 2A, 2B, 2C are energized alternately to generate a magnetic field of opposite polarity to generate a thrust in the direction of arrow R, the magnet movable body 3A 3A detaches from the suction plate 8A, moves in the direction of the arrow R, stops on the suction plate 8B. In addition, each coil 2
If the currents of A, 2B, and 2C are reversed to generate a thrust in the direction opposite to the arrow R, the magnet movable body 3A separates from the attraction plate 8B, moves toward the attraction plate 8A, attracts and stops. . By providing the suction plates 8A and 8B in this manner, the movement range of the magnet movable body 3A can be accurately regulated, and the movement of the magnet movable body 3A can be transmitted to the outside via the pinned member 9.

FIG. 4 shows a modification of the movable magnet body usable in the first embodiment. In this case, the magnet movable body 3B is composed of two columnar rare earth permanent magnets 5A, 5B arranged in the same pole opposition.
And a cylindrical soft magnetic body 6 disposed between these permanent magnets 5A and 5B, and a non-magnetic cylindrical holder 7B. The permanent magnets 5A and 5B and the soft magnetic body 6 are
B, and is fixed and integrated by caulking the end of the cylindrical holder 7B. According to this structure, the productivity of the magnet movable body can be increased.

Also in the second embodiment, the disk-shaped bases of the permanent magnets 5A and 5B, the soft magnetic body 6 and the member 9 with pins are housed in a cylindrical holder, and the ends of the cylindrical holder are closed. By caulking, a fixed and integrated magnet movable body can be used.

In each of the above embodiments, two permanent magnets having the same polarity and a soft magnetic material between the two permanent magnets are housed and fixed in a cylindrical holder to form a magnet movable body. The permanent magnet opposing the same pole and the soft magnetic material between the two permanent magnets may be housed and fixed in a cylindrical holder to form a magnet movable body, and the number of coils may be four or more in accordance with this. it can.

In the second embodiment, soft magnetic attraction plates 8A and 8B are provided on both sides of the cylindrical yoke 1 and the guide cylinder 4, respectively.
Pinned members 9 are provided on the outer end surfaces of both permanent magnets 5A and 5B.
However, a structure in which the suction plate and the member with the pin are provided on only one of them may be adopted.

Further, in each of the embodiments, the cylindrical yoke 1 and the guide cylinder 4 are used, but a yoke and a guide cylinder such as a rectangular cylinder or an elliptical cylinder are employed, and a prismatic or cylindrical magnet movable body is used. An elliptical cylinder may be employed (in this case, the cylindrical holder has a rectangular cylinder or an elliptical cylinder, and the permanent magnet and the soft magnetic material have a prism or an elliptical cylinder). In these cases as well, each coil may be wound around the outer periphery of the movable magnet.

[0039]

As described above, according to the movable magnet type actuator of the present invention, a magnetic body is arranged between at least two permanent magnets of the same polarity and these are fixed in a non-magnetic cylindrical holder. As a result, the magnet movable body has a strong structure to improve wear resistance, and a magnetic flux component perpendicular to the longitudinal direction of the magnet movable body (permanent magnet magnetization direction). Can be large enough . At least three coils surrounding the magnet movable body
(Middle position is wider than end position)
And provided to the magnetic yoke inside, since the magnetic poles of the magnet moving body was effectively possible linkage with magnetic flux generated, Fleming's left-hand rule between the current flowing in the perpendicular magnetic flux component and the coil , The thrust given on the basis of the pressure can be sufficiently increased. Therefore, a highly reliable, small-sized, small-current, large-thrust movable magnet actuator can be realized.

[Brief description of the drawings]

FIG. 1 is a first view of a movable magnet type actuator according to the present invention.
It is a front sectional view showing an example.

FIG. 2 is a side view of the same.

FIG. 3 is a front sectional view showing a second embodiment of the present invention.

FIG. 4 is a front sectional view showing a modification of the magnet movable body that can be used in the first embodiment.

FIG. 5 is a schematic configuration diagram showing a basic configuration of the present invention.

FIG. 6 is a graph showing a relationship between a displacement amount of a magnet movable body and a thrust in the movable magnet type actuator of FIGS. 1 and 5;

FIG. 7 is a schematic configuration diagram showing a first conventional example.

FIG. 8 is a schematic configuration diagram showing a second conventional example.

FIG. 9 is a graph showing a vertical component (a component perpendicular to the longitudinal side surface) of the surface magnetic flux density on a longitudinal side surface (a surface parallel to the magnetization direction of the permanent magnet) of a single permanent magnet.

FIG. 10 is a graph showing a vertical component of a surface magnetic flux density on a longitudinal side surface when two permanent magnets of the same polarity facing each other are directly in contact with each other.

FIG. 11 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side surface when two permanent magnets are placed in the same-pole opposing state via an air gap of 1 mm.

FIG. 12 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side surface when two permanent magnets are placed in the same pole opposing state via an air gap of 2 mm.

FIG. 13 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side surface when two permanent magnets are placed in the same pole opposing state via an air gap of 3 mm.

FIG. 14 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side surface when two permanent magnets are placed in the same pole opposing state via a soft magnetic material.

FIG. 15 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side surface when two permanent magnets are placed in the same pole opposing state via a soft magnetic material and a soft magnetic yoke is arranged.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical yoke 2A, 2B, 2C Coil 3, 3A, 3B Magnet movable body 4 Guide cylinder 5 Cylindrical permanent magnet 6 Cylindrical soft magnetic body 7, 7A, 7B Cylindrical holder 8A, 8B Attraction plate

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shigeo Saito 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (56) Reference European Patent Application Publication 457389 (EP, A1) (58) Survey Field (Int.Cl. ⁶ , DB name) H02K 33/16

Claims (3)

(57) [Scope of request for utility model registration] A magnet movable body is provided by disposing a magnetic body between at least two permanent magnets of the same polarity and fixing the permanent magnet and the magnetic body in a non-magnetic cylindrical holder.
The magnet movable body is slidably provided inside the guide cylinder, and at least three coils wound around the outer periphery of the magnet movable body are attached to the guide cylinder, and the magnetic body is mounted on the guide cylinder.
And the middle one of the at least three coils is wider than the one at the end, and interlinks with the magnetic flux from the same pole opposite end of the permanent magnet. In an arrangement
The end positions are arranged so as to interlink with the magnetic flux from the end magnetic poles of the permanent magnet , and each coil is connected such that current flows in a different direction with a boundary between the magnetic poles of each permanent magnet. The movable magnet type actuator characterized by being performed. 2. The movable magnet type actuator according to claim 1, wherein the magnet movable body fixes the permanent magnet and the magnetic body by caulking an end of the cylindrical holder. 3. The movable magnet type actuator according to claim 1, wherein said magnet movable body is formed by fixing a member with a pin for taking out output at an end of said cylindrical holder.