JP3233796B2 - Linear drive actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear drive actuator applied to a drive mechanism of a structure vibration control device, a traverse drive device of a container crane, a machine tool or a transfer device.

[0002]

2. Description of the Related Art FIG. 20 illustrates a configuration diagram of a conventional driving device. AA and B- in FIG.
Cross-sectional views along B are shown in FIGS. 21 and 22, respectively.

In the conventional device shown in FIG. 20, a plurality of exciting coils 3 made of a good conductor are arranged inside a magnetic circuit 4 made of a ferromagnetic material such as steel. A DC current is applied to these exciting coils 3, and the DC magnetic field formed in the magnetic circuit 4 is converted into a yoke 1 ′ (hereinafter referred to as a convex part) made of a ferromagnetic material which is a part of the magnetic circuit 4. , Which is referred to as a fixed yoke).

Here, in the above-described conventional apparatus, the excitation magnetic field concentrated by the fixed yoke 1 ′ is supplied in a direction orthogonal to the drive coil 2. The so-called Lorentz (Lorentz) is the interaction force between this exciting magnetic field and the drive current.
z) A force acts between the stationary yoke 1 ′ as the stationary side and the drive coil 2. As a result, assuming that the magnetic circuit 4 is a stator, the drive coil 2 moves in the direction of the movable range (stroke range) 10 by this Lorentz force. Further, by further reversing the polarity of the current of the drive coil 2, the Lorentz force acts in the opposite direction. As a result, the drive coil 2 is a device capable of moving in the direction of the movable range 10 'opposite to the above. The driving coil 2
For example, a ball bearing 21 as shown is provided as a bearing in order to support the movable portion in accordance with the above-described movement. (However, a bearing portion corresponding to a ball bearing is not shown in other drawings.) Note that a DC magnetic field generated inside the magnetic circuit 4 by the exciting coil 3 is fixed from the periphery of the magnetic circuit 4 to the fixed yoke. 1 '
And through the drive coil 2 to the center of the magnetic circuit 4.

[0005]

In the conventional apparatus as shown in FIG. 20, due to the following problems, the movable range of the stroke is limited to a maximum of about 50 mm. Naturally, there were restrictions on the expansion.

(1) When the movable range, that is, the stroke is lengthened, the length of the device is the sum of the stroke, the drive coil length, the winding thickness of the exciting coil, the yoke width of the magnetic circuit, etc. Since the size of the device itself increases, the installation area naturally increases.

(2) When the conventional device is made longer, it is necessary to lengthen the driving coil inevitably due to its structure. Interference between the AC magnetic field generated by the driving coil and the DC magnetic field generated by the exciting coil is required. Since it becomes large, it adversely affects the linearity of the generated thrust. That is, the proportional relationship between the drive current and the generated thrust is impaired. In normal operation, since the generated thrust is controlled by the magnitude of the drive current, it is difficult to control the generated thrust.

(3) When the conventional device is lengthened, the magnetic circuit needs to be lengthened, resulting in an increase in magnetic flux leakage,
The magnetic flux density at the portion where the fixed yoke and the drive coil are orthogonal to each other, which contributes to the generated thrust, is reduced, and the generated thrust proportional to the magnetic flux density is also reduced.

(4) When the length of the drive coil is increased, the inductance of the drive coil increases. However, in order to obtain a drive current for generating a necessary thrust, a power supply voltage corresponding to the increase in the drive coil inductance is required. Since the increase is required, the power loss is large. In addition, the responsiveness of the actuator also decreases.

(5) In order to increase the magnetic flux density applied to the drive coil as much as possible, the radial thickness of the drive coil is preferably small. However, during operation of the apparatus, a reaction force of Lorentz force is applied to the drive coil. Therefore, in an apparatus utilizing a large thrust, the thickness of the drive coil must be increased in terms of strength. Further, the exciting power for securing the same magnetic flux density also increases. As described above, there were many problems to be solved.

[0011] Accordingly, an object of the present invention is to keep the size of the entire device relatively small even if the drive coil constituting the device is lengthened in order to expand the movable range in accordance with the application. Rather, it is more compact than it is,
It is an object of the present invention to provide a linear drive actuator that maintains a proportional relationship between a drive current and a generated thrust even during operation, and has low power loss and good responsiveness.

[0012]

In order to solve the above-mentioned problems of the prior art and achieve the above object, the present invention employs the following means. That is, a magnetic circuit made of a magnetic material in which an exciting coil to which a DC current is applied is wound inside, and a DC magnetic field generated in a gap provided in a part of the circuit and the gap are orthogonal to the magnetic field. (1) A yoke for supplying a DC magnetic field in a concentrated manner to the drive coil is independent of a magnetic circuit for excitation. Then, relative movement is enabled through a predetermined gap, and the drive coil is fixed to the magnetic circuit main body.

(2) The shape of the cross section orthogonal to the movable direction of the magnetic circuit is rectangular, and only one direction is the direction in which the acting force acts, and the other direction is relatively different between the movable side and the stationary side. It is formed in a structure that allows a shift.

(3) An exciting coil is provided on the yoke separated from the exciting magnetic circuit main body. (4) A conductive brush mechanism which is fixed to a yoke at a portion of the drive coil fixed to the magnetic circuit, and which conducts a current while sliding on the drive coil by a length of the drive coil substantially equal to the width of the yoke. Is further provided.

That is, in the present invention, as shown in FIG. 1, the yoke 1 which is a part of the magnetic circuit 4 arranged to concentrate and supply the magnetic field to the drive coil 2 is separated from the magnetic circuit main body 4 ( The yoke 1 separated from the magnetic circuit main body receives the reaction force of the Lorentz force, which is the interaction force between the excitation magnetic field and the drive current, by fixing the drive coil 2 to the magnetic circuit main body. The structure to gain is implemented. By fixing the drive coil 2 to the center of the magnetic circuit 4, there is no need for reinforcement measures for maintaining the coil shape.

In the structure in which the yoke 1 is movable, a conductive brush mechanism is provided on the movable yoke 1, and a portion (width) opposed to the movable yoke, which has conventionally been always energized to the entire drive coil, is used. ) To suppress the interference of the magnetic field and maintain the proportional relationship between the thrust and the drive current. In addition, the drive coil inductance has been reduced, so that it has become possible to reduce the power supply cost associated with the lengthening and to reduce the power consumption.

FIG. 12 shows the problem that the magnetic flux leaks from the peripheral portion of the magnetic circuit to the central portion of the magnetic circuit as the length of the magnetic circuit increases, and the magnetic flux density in the thrust generating portion decreases. As shown, it is also possible to provide a driving device that can efficiently supply magnetic flux to the driving coil 2 that is a thrust generating unit by disposing the exciting coil 3 around the movable yoke 1 that requires the highest concentration of magnetic flux. is there.

However, by separating the yoke 1 from the magnetic circuit 4 and making it movable, it is necessary to provide an air gap (gap) on both the excitation yoke side (outer circumference) and the drive coil side (inner circumference). However, this air gap may be small, and is an amount that does not cause a problem compared to the gap amount provided by the above-mentioned problem (5).

[0019]

By taking such measures, the device of the present invention has the following effects. As shown in the first embodiment of the device of the present invention, a movable yoke provided for concentrating the DC magnetic field generated by the exciting coil on the drive coil is separated from the magnetic circuit, and the drive coil which has been conventionally free is separated from the magnetic circuit. By fixing the movable yoke freely in the X-axis direction while being fixed to the center of the circuit, it is possible to reduce the overall length of the device body, which required twice or more the movable stroke in the conventional device. Become.

Further, depending on the application of the device to be actually used, the movable yoke side can be fixed and the magnetic circuit side can be reciprocated linearly. FIG. 18 shows a comparison between the size of the conventional device and the size of the device of the present invention in comparison of how much the total length can be reduced.
It is clear from FIG. That is, the total length L of the conventional device
_{0 (= l y + l 1} + l 2 + L 1 + L 2 + 2
· In _{l f + 2 · l t)} , L 1 + L 2 is a stroke range. In contrast, the total length L _N (=
Comparison with _{l y + L 1 + L 2} + 2 · l f +2 · l t), as compared with the conventional apparatus, it is possible to reduce only l ₁ + l _2. Here, when the drive coil 2 is in the center of the stroke range in the conventional device (that is, L ₁
= L ₂ , l ₁ = l ₂ ), the portion l ₁ + l _{2 of} the drive coil not facing the fixed yoke and the stroke range L
₁ + L ₂ are in a relationship of _{l 1 + l 2 ≦ L 1} + L 2. Therefore, when the conventional apparatus and the apparatus of the present invention are compared from the above, the longer the stroke L ₁ + L ₂ becomes, the longer the length l ₁ + l ₂ that can be reduced becomes. become.

As shown in the second embodiment, the strength of the AC magnetic field generated by the drive coil is reduced by arranging the conductive brush mechanism for making the exciting portion of the drive coil only the width facing the movable yoke. It is possible to suppress the interference with the DC magnetic field generated by the exciting coil. At the same time, the inductance of the driving coil can be reduced, the power supply cost associated with the elongation of the device can be suppressed, and the power consumption associated with operation can be reduced.

From the above, the generated thrust and the driving current at the place where the conventional apparatus was lengthened were graphed (FIG. 17).
It is possible to maintain a proportional relationship as shown in FIG. Further, by increasing the length, the magnetic flux leakage from the peripheral portion of the magnetic circuit to the central portion of the magnetic circuit increases, and the magnetic flux density between the yoke of the thrust generating portion and the drive coil (for example, reference numeral 11 in FIG. 11). And the generated thrust decreases. To prevent this problem, the peripheral part (outer peripheral part) and the central part (central shaft part) of the magnetic circuit should be separated from each other, and the magnetic resistance between them should be increased to reduce magnetic leakage. There is also a way to do it. However, this method increases the size of the magnetic circuit (for example,
(Increase in diameter). Therefore, in the present invention, the cylindrical structure, which was a conventional shape feature, is improved to a rectangular structure, and the exciting coil is wound around the movable yoke.
The magnetic flux generated by the exciting coil can be directly and efficiently supplied from the movable yoke to the drive coil. In this case, if the magnetic circuit side is assumed to be a movable side and the yoke is used as a fixed portion, the excitation and drive current supply sides are all fixed sides. It also has the secondary advantage of being easier.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plurality of embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a plan view showing a configuration of a linear drive actuator according to a first embodiment of the present invention. 2 is a cross-sectional view along AA of FIG. 1, FIG. 3 is a cross-sectional view along B-B of FIG. 1, and FIG. 4 is a cross-section along CC of FIG. The plan views are respectively illustrated.

As is apparent from FIGS. 1 to 4, a plurality of exciting coils 3 are wound and attached to both ends of the magnetic circuit body 4 made of a magnetic material, which are symmetrical with respect to the center. DC power supply (DC) outside this magnetic circuit main body 4
5 generates a DC magnetic field in the vicinity of the movable yoke 1 by applying a DC current to these exciting coils 3 wired in series. A drive coil 2 is fixedly wound in the longitudinal direction of the main body between the movable yoke 1 and the center of the magnetic circuit 4 in order to generate a thrust for linear drive. An AC current is supplied to the drive coil 2 from an AC power supply (AC) 6 located outside the magnetic circuit main body 4. A movable yoke 1 for concentrating and supplying a DC magnetic field to the drive coil 2
Is disposed movably and independently of the magnetic circuit 4 for excitation and in a state capable of relative movement through a predetermined gap, and has a movable direction having a predetermined length in the longitudinal direction of the main body. The driving coil 2 is arranged so as to have a positional relationship orthogonal to the above-described DC magnetic field. That is, a linear drive actuator that performs a reciprocating linear motion using a Lorentz force (described later) that is an interaction force between the magnetic field and the DC current applied to the drive coil 2 is configured.

That is, in the configuration of the present embodiment, the movable yoke 1 installed for concentrating the DC magnetic field generated by the exciting coil 3 on the drive coil 2 is separated from the magnetic circuit 4, so that the drive which has conventionally been free is provided. A configuration is implemented in which the coil 2 is fixed to the center of the magnetic circuit, and the movable yoke 1 is freely movable in the X-axis direction. As a result, it is possible to reduce the overall length of the apparatus main body, which required twice or more the movable stroke in the conventional apparatus.

Depending on the actual application, it is also possible to carry out modifications such as fixing the movable yoke side and linearly reciprocating the magnetic circuit side. Here, FIG. 11 shows the operation principle of the large displacement type electromagnetic actuator according to the present invention. That is, an exciting current 13 (a direct current) is applied to the exciting coil 3 in the direction shown in FIG.
Supply intensively. By the supplied static magnetic field 7 and the driving current 12 (alternating current) applied from the alternating-current power supply 6 (not shown), a Lorentz force acts on the driving coil 2 in a direction according to the “Fleming's left-hand rule”. Further, since the drive coil 2 has a structure fixed to the magnetic circuit main body 4, the generated thrust acts on the movable yoke 1 as a reaction force thereof. That is, the direction of this reaction force is indicated by arrow 1 in the figure.
It can be seen that the orientation is 5.

(Second Embodiment) FIG. 5 is a schematic diagram of an actual apparatus used as a device according to a second embodiment of the present invention, which is used for a driving mechanism of a structural vibration damping device using a pendulum mechanism described later. It is shown. As is clear from this configuration diagram,
Structurally, the components of the first embodiment shown in FIG. 1 are similar in the operation principle. That is,
A DC magnetic field is generated between the magnetic circuit body 4 and the movable yoke 1 by applying a current to the exciting coil 3 wound around both ends of the central portion of the magnetic circuit body 4 by a DC power supply (not shown). A drive coil 2 for generating a thrust is provided between the central portions of the circuit 4. Similarly, a power supply (not shown) is provided outside the main body to supply a predetermined current. However, the feature of the second embodiment is that FIG.
In addition to the shape improvement of the cross-sectional structure described later as shown in FIG.
The point is that two conductive brush mechanisms 7 and a jig 8 are provided.

FIG. 6 is a side view of the apparatus of the present invention shown in FIG. 5, and it can be seen that two conductive brush mechanisms 7 and two jigs 8 are provided on the upper and lower sides of the main body, respectively. The detailed structure of the conductive brush mechanism 7 is shown in an enlarged sectional view of FIG.

In the configuration of the second embodiment, FIGS.
The exciting portion of the drive coil 2 shown in FIG.
There is further provided a conductive brush mechanism 7 for making only the width opposite to. This drive coil 2 which becomes a thrust generator
Generates a thrust only in a portion to which a static magnetic field is supplied by the exciting coil 3, so that the movable yoke 1 has a conductive brush mechanism 7 for supplying a predetermined current to the drive coil 2.
Are arranged as shown in FIG. As shown in the enlarged cross-sectional view, the conductive brush mechanism 7 applies a predetermined current to only the drive coil 2 that moves relative to the movable yoke 1 to which the conductive brush mechanism 7 is attached while keeping the end of the brush in contact. Do.

FIG. 8 is a cross-sectional view taken along the line AA in FIG. Air gap 9 in FIG. 8 representing the air gap
Is a gap portion for freely moving the pendulum mechanism peculiar to the vibration damping device in the vertical direction, but since this portion does not contribute to the generated thrust at all, it is sufficient for the vertical motion. It is possible to have a degree of freedom.

The cross-sectional structure of the magnetic circuit may be formed not in a circular shape but in a rectangular shape as shown in the cross-sectional shape of FIG. Jig 8 for supporting 1 (however, non-magnetic material)
Are also arranged. In the structure damping device, since the large displacement type actuator according to the present invention is used as a part of the pendulum, the movable yoke 1 is set as a stator, and the magnetic circuit main body 4 is set as a mover. Is done.

FIG. 9 exemplifies an explanatory diagram showing the relationship between the two conductive brush mechanisms 7 and the drive coil 2 of the device of the present invention. As shown in the drawing, two conductive brush mechanisms 7 arranged at an interval of a brush width 20 are in contact with the outer periphery of the drive coil 2 stacked in a single winding, and a predetermined current is applied to the drive coil 2. ing. Both ends of the drive coil 2 have an open structure.

FIG. 10 is a partially enlarged view of the drive coil of the device of the present invention. The illustrated single-turn drive coil 2 is formed from a good conductor (for example, copper) steel plate. Further, insulating paper or the like for insulation is sandwiched and laminated between adjacent steel plates to form a drive coil 2 having an integral structure as shown in the figure.

By providing the conductive brush mechanism 7 as described above, the intensity of the AC magnetic field generated by the drive coil 2 can be reduced, and interference with the DC magnetic field generated by the exciting coil 3 can be suppressed. . At the same time, the inductance of the drive coil 2 is reduced, so that the power supply cost due to the elongation of the device itself can be suppressed, and the power consumption due to actual operation can be reduced. Further, an increase in the inductance of the drive coil 2 due to the lengthening is suppressed, and the efficiency of the drive power supply and power consumption is improved. Further, by suppressing the generation of an AC magnetic field by the drive coil and suppressing the influence of the excitation coil on the DC magnetic field, which is a problem of the conventional device, the proportional relationship between the thrust and the drive current is maintained.

The DC magnetic field supplied to the drive coil 2 by the excitation coils 3 arranged at both ends of the center of the magnetic circuit main body requires a longer magnetic circuit as the length becomes longer. Magnetic flux leakage from the peripheral portion of the magnetic circuit to the central portion of the magnetic circuit may increase, which may cause a decrease in magnetic flux density in a thrust generating portion where the movable yoke 1 and the drive coil 2 face each other.

(Third Embodiment) FIG. 12 shows an actually manufactured device configuration as a third embodiment of the device of the present invention improved as a measure against the above-mentioned problems. That is, this improvement addresses the above-described problem by winding the exciting coil 3 of the second embodiment around both ends of the movable yoke 1. As a result, even if a magnetic flux leaks, a constant magnetic flux can always be supplied to the thrust generating portion of the drive coil 2 facing the movable yoke 1.

FIG. 13 is a sectional view taken along the line A--A of the apparatus of the present invention in FIG. 12, and FIG.
A cross-sectional view along BB of the device of the present invention is shown in detail as an actual configuration example. That is, as shown in these cross-sectional views, it can be seen that the exciting coil 3 is wound around both ends of the movable yoke 1 and arranged very close to each other.

FIG. 15 is a side view of the vibration damping device incorporating the linear drive actuator of the present invention as viewed from the side, and FIG. 16 is a front view of the vibration damping device also viewed from the vertical direction. It is shown.

In these figures, the magnetic circuit 4 of the linear drive electromagnetic actuator includes a first
And a second arm 18 connected via a gear 16 connected to the first arm 17, constitutes a "pendulum mechanism" having a pendulum shape, and drives this linear drive electromagnetic actuator. By doing so, the so-called “active mass damper (
AMD) ". The feature of such a mechanism is that the magnetic circuit 4 is used as a mass, and the arm of the pendulum is composed of the gear 16, the first arm 17, and the second arm 18. It is in a point. Further, by adjusting the lengths of the arms of the first arm 17 and the second arm 18 and the gear ratio of the gear 16,
Another feature is that the oscillation period of the pendulum can be lengthened.

FIG. 17 is a line graph showing the results of a thrust change test when the drive current is fixed. As can be seen from the measured test results, the curve of the graph after the installation has a tendency to approximate horizontally, which indicates that the generated thrust at each yoke position is almost constant, compared to before the installation of the conductive brush mechanism. is there. That is, since the conductive brush mechanism is provided, the generated thrust is stabilized regardless of the yoke position in the relationship between the drive current and the generated thrust.

FIG. 18 shows an example of the dimensions of the device of the present invention as a third embodiment of the present invention. That is, the total length L _N of the _{device, L N = l y + L} 1 + L 2 +
Represented by _{2 · l f + 2 · l} t. Therefore, it is clear from the comparison with FIG. 14 showing the dimensions of the conventional device how much the present device can be reduced in overall length as compared with the total length of the conventional device. That is, the total length L ₀ of the conventional _{apparatus, L 0 = l y + l} 1 + l 2 +
Represented by _{L 1 + L 2 + 2 ·} l f + 2 · l t.
Incidentally, the stroke range is L ₁ + L _2.

Thus, it can be seen that the present apparatus is configured such that its total length is shorter by l ₁ + l ₂ than the conventional apparatus.
That is, the total length can be reduced by l ₁ + l ₂ . Here, when the driving coil 2 is located at the center of the stroke range in the conventional device of FIG. 19 (that is, L ₁ = L ₂ , l _1).
= L ₂ ), the portion of the drive coil 2 not facing the fixed yoke 1 ', l ₁ + l _2, and the stroke range L ₁
+ L ₂ has a relationship of l ₁ + l ₂ ≦ L ₁ + L ₂ . Therefore, comparing the device of the conventional apparatus and the present invention from above, the longer the stroke range L ₁ + L _2, the length l ₁ + l ₂ also it can be seen that the longer that can be reduced.

Further, in the basic structure of the device of the present invention, the stator is on the movable yoke 1 side, but as a result of adopting the conductive brush mechanism 7 and improving the arrangement of the exciting coil 3 as described above, the movable On the side, there is also an advantage in wiring connection that a cable for power supply or the like does not need to be wired.

(Modified Embodiment) In each of the above embodiments, the yoke is configured to be movable (movable yoke 1). However, depending on the use of the apparatus, the movable yoke 1 side is fixed and the magnetic yoke 1 is fixed. Of course, it is also possible to configure the circuit 4 side to be capable of reciprocating linear movement. In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0045]

The following performance can be confirmed as an example showing the effect of the present invention. In other words, a test drive with a magnetic flux density of 1.4 T, a peak value thrust of 280 kgf, and a stroke length of ± 0.1 m at the thrust generating section was produced. Was done.

In consideration of the fact that the overall length of the above-mentioned drive device is within 0.66 m and the stroke range is 0.2 m, it can be said that this type of device is compact in size. Regarding the dimension of the entire length, the entire length of the driving device may be formed to be longer by an amount corresponding to the length in order to secure a necessary stroke length. As a result, the longer the stroke width, the smaller the ratio of the overall length of the driving device to the stroke length is.

According to a comparison between the dimensions of the conventional apparatus (FIG. 19) and the dimensions of the apparatus of the present invention (FIG. 18), it is possible to reduce the overall length by l ₁ + l ₂ , that is, to make the apparatus compact, as compared with the conventional apparatus. It is possible. This is because the total length L of the conventional device
_{0, L 0 = l y + l} 1 + l 2 + L 1 + L 2
+ Represented by _{2 · l f + 2 · l} t, the total length L _N of the present invention _{apparatus, L N = l y + L} 1 + L 2 + 2 · l f
It is because the + represented by 2 · l _t. (However, L ₁ + L
₂ is the stroke range).

Further, in the device of the present invention, a circular structure, which was a characteristic feature of the cross section of the conventional device, is formed into a rectangular structure, and the exciting coil 3 is wound around the movable yoke 1 so that the magnetic flux generated by this exciting coil is obtained. From the movable yoke 1 to the drive coil 2 efficiently. In the case of this structure, if the magnetic circuit side is a movable part and the yoke side is a fixed part,
Since the excitation and drive current supply sides are all fixed, it is easy to hold the energizing cable. The supply of the drive current to the drive coil 2 is easily performed by the conductive brush mechanism 7.

As is clear from the graph of FIG. 17, the graph curve of the device of the present invention having the conductive brush mechanism is approximated horizontally as compared with the device without the conductive brush mechanism. The thrust generated at the yoke position is almost constant. This phenomenon proves that, in the relationship between the driving current and the generated thrust, the effect that the thrust is stably generated regardless of the difference in the yoke position can be sufficiently exhibited.

[Brief description of the drawings]

FIG. 1 is a configuration diagram according to a first embodiment of the device of the present invention.

FIG. 2 is a cross-sectional view of the apparatus taken along line AA in FIG.

FIG. 3 is a cross-sectional view of the apparatus taken along line BB in FIG.

FIG. 4 is a cross-sectional view of the apparatus taken along the line CC in FIG.

FIG. 5 is a configuration diagram according to a second embodiment of the device of the present invention.

FIG. 6 is a side view of the apparatus of FIG. 5;

FIG. 7 is an enlarged vertical sectional view of a conductive brush mechanism portion along XX in FIG. 5;

FIG. 8 is a cross-sectional view of the apparatus taken along line AA in FIG.

FIG. 9 is a perspective view showing an outline of a conductive brush mechanism and a drive coil of the device of the present invention.

FIG. 10 is a partially enlarged view of the drive coil of FIG. 9;

FIG. 11 is an explanatory diagram illustrating the operation principle of an electromagnetic actuator.

FIG. 12 is a configuration diagram according to a third embodiment of the device of the present invention.

FIG. 13 is a cross-sectional view of the device of the present invention in FIG. 12 along AA.

FIG. 14 is a cross-sectional view of the device of the present invention shown in FIG. 12 along the line BB.

FIG. 15 is a side view of a vibration damping device incorporating the linear drive actuator of the present invention.

FIG. 16 is a front view of a vibration damping device incorporating the linear drive actuator of the present invention.

FIG. 17 is a graph showing a measurement result of a generated thrust with respect to a yoke position with and without a conductive brush mechanism.

FIG. 18 is an explanatory diagram relating to dimensions of each part of the third embodiment of the present invention.

FIG. 19 is an explanatory diagram relating to dimensions of each part of the conventional device.

FIG. 20 is a configuration diagram showing a configuration of a conventional driving device.

21 is a cross-sectional view of the conventional device shown in FIG. 20, taken along line AA.

FIG. 22 is a cross-sectional view of the conventional device shown in FIG. 20 along the line BB.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Moving yoke, 2 ... Drive coil, 3 ... Exciting coil, 4 ... Magnetic circuit, 5 ... DC power supply, 6 ... AC power supply, 7 ... Conductive brush mechanism, 8 ... Jig, 9 ... Vertical gap, 10 ... Stroke Range, 11: air gap of thrust generating part, 12: drive current, 13: excitation current,
14: DC magnetic field, 15: Generated thrust, 1
6: gear, 17: first arm, 18: second arm, 19: pedestal, 20: brush width,
21 ... Ball bearing.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Tonaka 4-22, Kannonshinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory (72) Inventor Hiroshi Kondo Kannon-Shimmachi 4 in Nishi-ku, Hiroshima-shi, Hiroshima No. 6-22, Mitsubishi Heavy Industries, Ltd.Hiroshima Works (72) Inventor Kenji Imada 4-6-2-2 Kanon Shinmachi, Nishi-ku, Hiroshima, Hiroshima Prefecture, Mitsubishi Heavy Industries, Ltd.Hiroshima Works (72) Inventor Takeshi Hachioji, Tokyo 806-1 Utsugicho, Shinken Co., Ltd. (56) References JP-A-1-308160 (JP, A) JP-A-2-32749 (JP, A) JP-A-2-10782 (JP, U) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 33/18 H02K 35/00 E04H 9/02

Claims (4)

(57) [Claims] A magnetic circuit made of a magnetic material, an exciting coil wound around the inside of the magnetic circuit and supplied with a direct current, and a predetermined magnetic field inside the magnetic circuit where the exciting coil generates a DC magnetic field. A driving coil disposed in a direction orthogonal to the DC magnetic field along a longitudinal direction of the gap and having a gap having a length and a width, the driving coil being applied to the DC magnetic field and the driving coil; In a linear drive actuator that performs a reciprocating linear motion using a Lorentz force that is an interaction force with an alternating current, a yoke portion that concentrates and supplies the DC magnetic field to the drive coil, wherein the yoke portion is The drive coil is disposed independently of the magnetic circuit, has a predetermined movable direction capable of relatively moving with the magnetic circuit through a predetermined gap, and the drive coil is fixedly disposed on the magnetic circuit main body. Linear drive actuator according to claim Rukoto. 2. A shape of a cross section of the magnetic circuit orthogonal to the movable direction is rectangular, and an acting force is applied only in a first direction which is one of the movable directions in accordance with a direction of the supplied current. The second direction, which is opposite to the first direction, is allowed to relatively displace in the movable direction on the movable side and the stationary side in the relative movement. 2. The linear drive actuator according to 1. 3. The linear drive actuator according to claim 2, wherein the yoke portion separated from the magnetic circuit main body at a predetermined interval is provided with a DC excitation coil. . 4. A predetermined portion of the drive coil fixedly disposed in the magnetic circuit for excitation has a length equal to a length of the drive coil fixed to the yoke portion and approximate to the length of the yoke portion. 4. The apparatus according to claim 1, further comprising: a conductive brush mechanism for applying an alternating current to the drive coil while sliding the drive coil only.
The linear drive actuator according to the paragraph.