JP2004112937A - Magnetic actuator and tactile display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dissolve the nonconformity of a conventional actuator referring to such a problem that it causes the leakage of a magnetic field from the side and a problem that it can not operate stably in the whole movable range. <P>SOLUTION: This magnetic actuator is equipped with a first magnet array where magnets 10a to 10d are arranged side by side with their different magnetic poles directed alternately and plane coils 12a and 12d which are installed astride the two or more magnetic poles of the first magnet array, and this gets driving force by letting a current flow to the plane coils 12a to 12d. The problems are solved by using this magnetic actuator where magnets 24a and 24d are arranged at a specified interval from the first magnet array, thereby forming a second magnet array, and the second magnet array is constituted by juxtaposing the magnets 24a to 24d with mutually different magnetic poles facing the magnetic poles of the magnets 10a to 10d of the first magnet array. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic actuator and a tactile sensation presentation device that reduce magnetic flux leakage to the outside of the device and enable stable operation.
[0002]
[Prior art]
In recent years, magnetic actuators utilizing electromagnetic interaction as driving force have been widely used. For example, with the development of information transmission devices, means for transmitting information via tactile sensation in addition to vision and hearing are required, and a small magnetic actuator is incorporated into a pointing device such as a mouse to apply vibration to a fingertip. A tactile presentation device that can be provided has been realized.
[0003]
Japanese Patent Application Laid-Open No. 2000-330688 discloses a tactile sense presentation device incorporating a magnetic actuator. As shown in FIG. 8A, a magnetic actuator is provided in the pointing device 100, and a transmission unit 18 connected to the magnetic actuator is provided. At the time of use, as shown in FIG. 8B, by touching the transmitting portion 18 with a fingertip, vibration from the magnetic actuator can be transmitted to the fingertip.
[0004]
9 and 10 show a side view and a developed perspective view of a main part of a magnetic actuator incorporated in the tactile sense presentation device, respectively.
[0005]
As shown in FIG. 9, the magnetic actuator includes a magnet array 10, a planar coil 12, yoke plates 14a and 14b, a stud 16, a transmitting unit 18, a sliding unit 20, and a connecting unit 22. As shown in FIG. 10, the magnet array 10 includes magnets 10a to 10d, and the planar coil 12 includes planar coils 12a to 12d.
[0006]
The magnets 10a to 10d are juxtaposed on the yoke plate 14a alternately with different polarities. The planar coils 12a to 12d are separated from the magnets 10a to 10d by a predetermined gap, and are installed so as to straddle a plurality of magnets. A yoke plate 14b is provided so as to cover the planar coil 12. The studs 16 support the yoke plates 14a and 14b at a constant interval.
[0007]
As shown in FIG. 9, the transmission unit 18 is commonly connected to the planar coils 12 a to 12 d via the connection unit 22. On the other hand, the transmission section 18 is slidably connected to the outer member 26 by the sliding section 20.
[0008]
A magnetic field is generated between the yoke plates 14a and 14b by the magnets 10a to 10d. In this magnetic field, by passing a current through the planar coils 12a to 12d, an electromagnetic force is generated on the planar coils 12a to 12d, and the transmission unit 18 is driven. For example, as shown in FIG. 10, when the N and S poles of the magnets 10a to 10d are arranged in the Z-axis direction and the plane coil 12 is installed in the XY plane, A driving force can be generated.
[0009]
The magnetic actuator incorporated in such a pointing device or the like needs to be as small as possible, and on the other hand, there is a demand to increase the movable range as much as possible. In addition, in order to obtain a driving force as large as possible with respect to the size, it is necessary to prevent the leakage magnetic flux to the outside and to increase the interaction between the magnetic field and the coil current. Further, in order to avoid an influence on external devices (for example, a display or a magnetic card), it is necessary to sufficiently reduce a leakage magnetic field from a magnet in the magnetic actuator to the outside.
[0010]
[Patent Document 1]
JP 2000-330688 A
[Problems to be solved by the invention]
However, the above-mentioned conventional magnetic actuator has the following problems.
[0012]
(A) Since the magnetic field is blocked by the yoke plates 14a and 14b at the upper and lower portions of the magnetic actuator, the magnetic field leaking to the outside is suppressed. However, a yoke cannot be provided on the side of the magnetic actuator in order to avoid interference between the members when the planar coil 12 moves, and the magnetic field leaking from the side to the outside is smaller than that of the upper and lower parts. growing. Therefore, there is a problem that the magnetic field effective for generating the driving force is reduced, and the influence on external devices is increased. Further, as the planar coil 12 moves away from the center of the magnetic actuator, it becomes more susceptible to the decrease in the magnetic field due to the leakage magnetic flux from the side, and a problem arises in that a sufficient driving force cannot be obtained.
[0013]
(B) When a yoke is provided on the side of the magnetic actuator to avoid the above-mentioned problem (A), the magnetic actuator itself needs to be enlarged in order to obtain the same movable range as that of the related art, The demand for weight reduction and weight reduction cannot be satisfied.
[0014]
(C) In the magnetic actuator, when the planar coil 12 is moved to near the end of the magnet 10 as shown in FIG. 11, one side of the planar coil 12 approaches the vicinity of the boundary between the two magnets. In the vicinity of the boundary between adjacent magnets, since the N pole and the S pole are close to each other, a horizontal magnetic field is generated from the N pole to the S pole. This magnetic field generates a driving force in a direction deviating from the originally required driving force in the in-plane direction of the planar coil 12, as shown in FIG.
[0015]
Therefore, when approaching the vicinity of the boundary between the magnets, there is a problem that the planar coil 12 is inclined or the planar coil 12 is caught by another member. In particular, when the plane coil 12 moves to the ends in the X direction and the Y direction, a problem occurs in that a driving force in a substantially vertical direction is generated for all the plane coils 12.
[0016]
In view of the above-mentioned problems of the prior art, the present invention reduces the leakage magnetic field from the side while maintaining the size and weight as before without providing a new member on the side, and is stable over the entire movable range. It is an object to provide a magnetic actuator and a tactile sensation providing device that operate.
[0017]
[Means for Solving the Problems]
By adopting the following configuration, the above problem was successfully solved.
[0018]
The present invention for solving the above problems includes a magnet arranged with magnetic poles different from each other facing each other, and a coil having at least a part inserted between the magnetic poles, and a magnetic field generated by the magnet. , A driving force for the coil is obtained by passing a current through the coil.
[0019]
Further, in the above magnetic actuator, the magnets are a first magnet array magnetized alternately with different magnetic poles, and a second magnet array arranged to face the first magnet array, It is preferable that each magnetic pole of the first magnet array includes a second magnet array magnetized such that different magnetic poles face each other.
[0020]
Further, in the above magnetic actuator, it is preferable that a distance between the opposed magnetic poles is equal to or less than １ ／ of a square root of an area of the opposed magnetic poles.
[0021]
According to another aspect of the present invention, there is provided a tactile sensation providing device that stimulates the tactile sensation of an animal by vibrating, wherein at least one magnet is disposed with different magnetic poles facing each other. And a magnetic actuator characterized in that a driving force for the coil is obtained by passing a current through the coil in a magnetic field generated by the magnet. And
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a magnetic actuator according to an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 show a side view and a developed perspective view of a main part of a magnetic actuator according to the present embodiment, respectively.
[0023]
As shown in FIG. 1, the magnetic actuator according to the present embodiment basically includes magnet arrays 10 and 24, a planar coil 12, yoke plates 14a and 14b, a stud 16, a transmission unit 18, a sliding unit 20, and a connecting unit 22. Be composed. The magnet arrays 10 and 24 include four magnets 10a to 10d and magnets 24a to 24d, respectively, as shown in FIG. The planar coil 12 includes four planar coils 12a to 12d. In the magnetic actuator of the present embodiment, in addition to the magnets 10a to 10d being arranged on the lower yoke plate 14a, the magnets 24a to 24d are newly provided on the upper yoke plate 14b. It is characteristic.
[0024]
The magnets 10a to 10d are juxtaposed on the lower yoke plate 14a so that different magnetic poles are alternately directed in the Z-axis direction. For example, as shown in FIG. 2, when the N pole of the magnet 10a is installed facing the inside of the magnetic actuator, the S pole of the magnet 10b, the S pole of the magnet 10c, and the N pole of the magnet 10d face the inside of the magnetic actuator. Install. In the present embodiment, separate permanent magnets are used as the magnets 10a to 10d, however, one magnet may be magnetized so that different magnetic poles face partially and alternately.
[0025]
As shown in FIG. 1, the planar coils 12a to 12d are installed on the magnets 10a to 10d with a predetermined gap in parallel with the magnets 10a to 10d. The planar coils 12a to 12d are installed so as to be relatively movable with respect to the magnets 10a to 10d.
[0026]
Further, the planar coils 12a to 12d are arranged so as to straddle any two of the magnets 10a to 10d. For example, the planar coil 12a is disposed so as to straddle the magnets 10a and 10b in the X direction. Similarly, the planar coil 12b is arranged so that the magnets 10c and 10d extend in the X direction, the planar coil 12c extends across the magnets 10a and 10c in the Y direction, and the planar coil 12d extends across the magnets 10b and 10d in the Y direction.
[0027]
The planar coils 12a and 12b are connected to each other so that a common current flows in a figure 8 as shown in FIG. The planar coils 12c and 12d are also connected to each other as shown in FIG. The effects of these coil currents will be described later in detail.
[0028]
Copper wires are generally used for the windings of the planar coils 12a to 12d, but it is also preferable to use a material such as copper-clad aluminum to reduce the weight of the magnetic actuator.
[0029]
As shown in FIG. 2, the magnets 24a to 24d are fixed to the upper yoke plate 14b, and are installed with a predetermined gap from the planar coils 12a to 12d so as to face the magnets 10a to 10d, respectively. The magnets 24a to 24d and the magnets 10a to 10d are arranged such that their mutually facing magnetic poles are different. For example, when the north pole of the magnet 10a is arranged toward the inside of the magnetic actuator, the south pole of the magnet 24a is arranged toward the inside of the magnetic actuator. Similarly, the magnet 10b and the magnet 24b, the magnet 10c and the magnet 24c, and the magnet 10d and the magnet 24d are installed so that different magnetic poles face each other. The gap between the magnet array 24 and the magnet array 10 is set to a predetermined distance, and is fixedly supported by the stud 16 connecting the upper yoke plate 14b and the lower yoke plate 14a.
[0030]
The distance between the magnet array 10 and the magnet array 24 is preferably equal to or less than の of the width of each magnet. Further, it is more preferable that the width is not more than 1/5 of the width of each magnet. Further, when the facing surface of each magnet is not rectangular but circular or the like, the distance between the magnet array 10 and the magnet array 24 may be １ ／ or less of the square root of the area of the facing surface. It is suitable. Further, it is preferable that the width be equal to or less than 1/5 of the square root of the area of the facing surfaces.
[0031]
Permanent magnets can be used for the magnets 10a to 10d and 24a to 24d. The permanent magnet may be a general ferrite magnet, but it is preferable to use a rare earth magnet such as a neodymium magnet having a stronger magnetic force. When the weight of the magnetic actuator is not a problem, the same effect as that of the present embodiment can be obtained by a configuration in which the electromagnet is formed by a coil.
[0032]
As shown in FIG. 1, the transmission unit 18 is commonly fixed to all of the planar coils 12 a to 12 d via the connection unit 22. In addition, the transmission unit 18 is coupled to the outer member 26 by the sliding unit 20 so as to be relatively movable. That is, in the XY plane, the magnets 10a to 10d and the magnets 24a to 24d fixed to the yoke plates 14a and 14b are movably coupled to each other. For the sliding portion 20, for example, it is preferable to use an elastic body such as rubber or a spring, a ball bearing, or the like.
[0033]
Hereinafter, the operation and action of the magnetic actuator according to the present embodiment will be described in detail with reference to FIG. For the sake of simplicity, FIG. 3 shows only the arrangement of the magnets 10a to 10b and the planar coils 12a to 12d arranged on the lower yoke plate 14a.
[0034]
Before driving, as shown in FIG. 3A, no current flows through any of the planar coils 12a to 12d, and the center point of the planar coils 12a to 12d is Is held near the center of
[0035]
At the time of driving, as shown in FIG. 3B, a current is applied to the planar coils 12a and 12b from an external power supply (not shown) so as to draw a figure of eight. A driving force in the X direction is generated by an electromagnetic interaction between the magnetic field and the coil current by the magnets 10a to 10d and the magnets 24a to 24d (not shown). At this time, the transmission unit 18 (not shown) fixed in common with the planar coils 12a to 12d is driven in the X direction together with the planar coils 12a to 12d.
[0036]
Similarly, as shown in FIG. 3 (c), when an electric current is caused to flow from the external power supply in a figure 8 to the planar coils 12c and 12d, a driving force in the Y direction is generated by electromagnetic interaction. Therefore, the transmission unit 18 (not shown) is driven in the Y direction together with the planar coils 12a to 12d.
[0037]
Further, when currents are simultaneously supplied to the planar coils 12a and 12b and the planar coils 12c and 12d as shown in FIG. 3D, the planar coils are changed according to the magnitude of the current for each combination of the planar coils. It moves simultaneously in the X and Y directions.
[0038]
At this time, in the present embodiment, in addition to the magnets 10a to 10d, the magnets 24a to 24d are further provided, so that the entire inside of the magnetic actuator is perpendicular to the XY plane as shown in FIG. A magnetic field (dotted arrow) can be generated. Therefore, even when the planar coil 12 is driven to near the ends of the magnets 10a to 10d and 24a to 24d, generation of a force in the vertical direction (Z direction) on the planar coil 12 can be significantly reduced. Further, the magnetic actuator can be driven stably.
[0039]
Further, by reducing the magnetic field in the horizontal direction, the strength of the magnetic field in the vertical direction can be increased at the same time. As a result, the driving force in the direction parallel to the plane coil 12 (X or Y direction) can be increased.
[0040]
Further, since the magnetic field is directed in the vertical direction also at the magnet end, the leakage magnetic field from the side surface of the magnetic actuator is reduced. As a result, the influence of the magnetic field on the external device can be significantly reduced.
[0041]
At this time, by reducing the thickness of the magnets 10a to 10d by the thickness of the newly provided magnets 24a to 24d, it is possible to maintain the size and weight of the magnetic actuator at least as high as those of the related art. Furthermore, since the magnetic field generated from the magnet can be effectively used in the vertical direction, the size and weight of the magnetic actuator can be reduced.
[0042]
In the present embodiment, the magnet array 10 and the magnet array 24 are configured by four magnets 10a to 10d and magnets 24a to 24d, respectively, but the number of magnets is not limited to this. For example, in the case of driving only in one of the X direction and the Y direction, the magnet array 10 and the magnet array 24 may each be constituted by two magnets, and one planar coil may be provided in a gap between the magnets.
[0043]
As shown in FIG. 8, the tactile sense presentation device can be configured by incorporating the magnetic actuator according to the present embodiment into a pointing device. Since the leakage magnetic flux can be reduced, the influence of the magnetic field on other devices such as a display can be reduced. In addition, since the driving force can be efficiently obtained, the tactile sensation providing device can be downsized.
[0044]
【Example】
(Comparative example)
Hereinafter, a comparative example along the form of the related art shown in FIGS. 9 and 10 will be described.
[0045]
The yoke plates 14a and 14b were made of iron and rectangular in shape, and the length of each side was appropriately set according to the size of the magnet. The yoke plates 14a and 14b are provided with openings due to the configuration.
[0046]
Neodymium magnets were used for the magnets 10a to 10d. The thickness is a predetermined level from a level of 1 to 10 mm, and the length of each side is a predetermined level from a level of 5 to 50 mm, and a portion where the stud 16 is provided is cut out in an arc shape. Was used.
[0047]
The magnets 10a to 10d were placed in close contact with the lower yoke plate 14a such that the magnetic poles faced alternately. At this time, a part of the yoke plate 14a was cut out and installed in accordance with the opening.
[0048]
Each of the planar coils 12a to 12d has a conductive wire wound around a substantially rectangular shape with a predetermined number of turns in a level of 50 to 300 turns, and has a thickness of a level of 1 to 5 mm and a predetermined thickness. A copper wire was used as the conductive wire.
[0049]
Studs 16 were installed at the four corners of the yoke plate to keep the yoke plates 14a and 14b substantially parallel at a predetermined gap.
[0050]
The planar coils 12a to 12d are maintained with a gap that does not contact the magnets 10a to 10d.
[0051]
(Example)
Hereinafter, an example according to the above-described embodiment shown in FIGS. 1 and 2 will be described.
[0052]
The yoke plates 14a and 14b were made of iron, and had the same thickness and length as those of the comparative example. Each of the yoke plates 14a and 14b has a rectangular opening due to its configuration.
[0053]
Neodymium magnets were used for the magnets 10a to 10d and the magnets 24a to 24d. The thickness was set to half the thickness of the comparative example, the length of each side was the same as that of the comparative example, and the portion where the stud 16 was provided was cut out in an arc shape.
[0054]
The magnets 10a to 10d and the magnets 24a to 24d were installed in close contact with the lower yoke plate 14a and the upper yoke plate 14b, respectively, such that the magnetic poles faced alternately. At this time, a part of the yoke plates 14a and 14b was cut out and installed in accordance with the openings.
[0055]
The planar coils 12a to 12d used under the same conditions as those of the comparative example.
[0056]
Studs 16 were installed at the four corners of the yoke plates 14a and 14b to keep them substantially parallel with a predetermined gap.
[0057]
The planar coils 12a to 12d are inserted between the magnets 10a to 10d and the magnets 24a to 24d, and are maintained while maintaining a gap that does not contact each other.
[0058]
(Measurement of external leakage flux)
With respect to the comparative example and the example, the magnetic flux leakage to the outside of the magnetic actuator was measured. As shown in FIG. 5, the measurement was performed at a position separated by 5 mm from the upper yoke plate 14b of the magnetic actuator (broken line a in FIG. 5) and at a position separated by 5 mm from the lower yoke plate 14a (broken line b in FIG. 5). , And at a position 5 mm away from the side of the magnetic actuator (broken line c in FIG. 5), the maximum leakage flux was measured.
[0059]
FIG. 12 shows the measurement results of the magnetic flux leakage at each location. In the vicinity of the upper yoke plate 14b (dashed line a in FIG. 5) and the lower yoke plate 14a (dashed line b in FIG. 5), the maximum leakage flux in the comparative example is about 40% of the maximum leakage magnetic flux in the comparative example. Decreased to. In the vicinity of the side (broken line c in FIG. 5), the maximum leakage magnetic flux in the comparative example was reduced to about 10 to 20% in the example, and the effect was verified.
[0060]
(Measurement of driving force)
Also, the results of measuring the driving force when the same current is applied to the planar coils 12a and 12b in Comparative Examples and Examples are shown.
[0061]
As shown in FIG. 6, the driving force in the direction parallel to the plane coil (X direction) was increased in the example compared to the comparative example. On the other hand, the driving force in the vertical direction (Z direction) with respect to the planar coil was significantly reduced in the example as compared with the comparative example, as shown in FIG.
[0062]
Further, the results of measuring the driving force when the same current is applied to the planar coils 12a and 12b and the planar coils 12c and 12d in Comparative Examples and Examples are shown.
[0063]
As shown in FIG. 7, the driving force in the horizontal direction (X-Y direction) with respect to the planar coil was increased in the example compared to the comparative example. On the other hand, the driving force in the vertical direction (Z direction) with respect to the planar coil was significantly reduced in the example as compared with the comparative example, as shown in FIG.
[0064]
【The invention's effect】
According to the present invention, it is possible to generate a magnetic field in a direction perpendicular to a plane coil in the entire inside of a magnetic actuator. As a result, the generation of a force in the direction perpendicular to the plane coil (Z direction) can be greatly reduced, and at the same time, the driving force in the direction parallel to the plane coil (X or Y direction) can be increased. Therefore, the magnetic actuator can be operated stably.
[0065]
Further, according to the present invention, since the magnetic field is directed in the vertical direction even at the magnet end, the leakage magnetic flux from the side surface of the magnetic actuator can be reduced. As a result, the influence of the magnetic field on the external device can be significantly reduced.
[0066]
Further, according to the present invention, the above-described effects can be obtained while maintaining the size and weight of the magnetic actuator as in the related art.
[Brief description of the drawings]
FIG. 1 is a side view showing a configuration of a magnetic actuator according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a main part of the magnetic actuator according to the embodiment of the present invention.
FIG. 3 is a diagram illustrating a relationship between a current of a planar coil of the magnetic actuator and a driving direction according to the embodiment of the present invention.
FIG. 4 is an explanatory diagram of a driving force generated in a planar coil of the magnetic actuator according to the embodiment of the present invention.
FIG. 5 is a diagram showing locations where external leakage magnetic flux is measured in a comparative example and an example of the present invention.
FIG. 6 is a diagram showing a measurement result of a driving force generated in a coil in a comparative example and an example of the present invention.
FIG. 7 is a diagram showing a measurement result of a driving force generated in a coil in a comparative example and an example of the present invention.
FIG. 8 is a diagram showing the appearance and usage of a tactile sensation providing device incorporating a magnetic actuator.
FIG. 9 is a side view showing a configuration of a conventional magnetic actuator.
FIG. 10 is an exploded perspective view of a main part of a conventional magnetic actuator.
FIG. 11 is a diagram illustrating a driving force generated in a planar coil of a conventional magnetic actuator.
FIG. 12 is a diagram showing measurement results of external leakage magnetic flux in a comparative example and an example of the present invention.
[Explanation of symbols]
10, 24 magnet array, 10a, 10b, 10c, 10d, 24a, 24b, 24c, 24d magnet, 12, 12a, 12b, 12d plane coil, 14a, 14b yoke plate, 16 stud, 18 transmitting unit, 20 sliding unit , 22 connecting portion, 26 outer member, 100 pointing device (tactile presentation device).

Claims (4)

A magnet arranged with different magnetic poles facing each other,
A coil having at least a part inserted between the magnetic poles,
A magnetic actuator, wherein a driving force for the coil is obtained by passing a current through the coil in a magnetic field generated by the magnet. The magnetic actuator according to claim 1,
The magnet is
A first magnet array alternately magnetized to different magnetic poles;
A second magnet array disposed to face the first magnet array, wherein the second magnet is magnetized such that different magnetic poles face each other with respect to each magnetic pole of the first magnet array. An array,
A magnetic actuator, comprising: The magnetic actuator according to claim 1, wherein
The magnetic actuator according to claim 1, wherein a distance between the facing magnetic poles is equal to or less than a half of a square root of an area of the facing magnetic poles. A tactile sensation providing device that stimulates the tactile sensation of an animal by vibration,
The magnet includes a magnet arranged with magnetic poles facing each other facing each other, and a coil having at least a part inserted between the magnetic poles, and in a magnetic field generated by the magnet, a current is applied to the coil to cause the coil to flow. A tactile sensation providing device, comprising: a magnetic actuator characterized by obtaining a driving force for the tactile sense.

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