JP2001110631A - Meta-magnetostrictive actuator and active damping device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a large output/great displacement by elongating/contracting a large meta-magnetostrictive rod with a small driving current and to surely suppress vibrations, even when a large-sized object is vibrated. SOLUTION: Respective members 5, 6 and 7 of a yoke Y, arranged with a supermagnetostrictive rod 3 as a center are formed from a ferromagnetic materials, a closed magnetic circuit is composed of the yoke Y and the supermagnetostrictive rod 3, and respective members 10, 12 and 13 of a pressure frame F, with which the yoke Y is assembled in the inside, and a push rod 9 provided at a free end 3b of the supermagnetostrictive rod 3 are formed from nonmagnetic materials. Since magnetic flux leaking from the yoke Y and the supermagnetostrictive rod 3 hardly occurs, the supermagnetostrictive rod 3 can be elongated/contracted while, effectively utilizing a magnetic force generated by a magnetic field coil 2 without waste, and a large output/great displacement can be provided with only little power consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a giant magnetostrictive actuator which expands and contracts a giant magnetostrictive rod according to the magnitude of a magnetic force generated by a magnetic field coil and transmits the movement of its free end to the outside. The present invention relates to an active vibration damping device that suppresses vibration of a vibration generator using the same.

[0002]

2. Description of the Related Art In recent years, attention has been paid to a cogeneration system that supplies heat simultaneously with power generation. This cogeneration system includes gasoline, heavy oil, light oil, kerosene,
Power is generated by turning a generator with an engine such as a gas turbine.
Next, steam is extracted from the heat of the exhaust gas, and hot water is further extracted from the remaining heat, and the energy of the fuel is thoroughly used.

[0003] Therefore, it has a remarkable energy saving effect and excellent thermal efficiency, and is used in hotels, factories, hospitals, office buildings and the like. In addition, the obtained steam is not only used as it is as various heat sources for heating and production,
Since the cold water can be taken out by an absorption refrigerator and used for cooling, its use value is very high.

[0004] The equipment is composed of an engine, a generator, a boiler, a heat exchanger, etc., and has an output of 300 to 500 kW.
This device has a weight of about 2t, and when the engine is driven, the entire device having a weight of 2t vibrates and becomes a vibration source. Therefore, it is necessary to take measures against vibration and sound. In particular, when a cogeneration system installed adjacent to a living space is operated at midnight, anti-vibration measures and sound-proof measures are important issues. For this reason, conventionally, the entire apparatus is supported by anti-vibration rubber or the like. In addition, the vibration is to be absorbed.

[0005]

However, the vibration-proof rubber, although somewhat relieved of vibration, is still insufficient, so that when installed adjacent to a living space, the vibration is damped to such an extent that it can be operated at midnight. It is not possible. For this reason, the present inventors prototyped a vibration damping device using a giant magnetostrictive actuator, but in order to reduce the vibration of a vibration source having a weight of 2t, a large number of giant magnetostrictive actuators must be used. Did not.

For example, a commercially available giant magnetostrictive actuator using a giant magnetostrictive rod having a diameter of about 12 mm and a length of about 100 mm has a maximum dynamic force of about 880 N (90 kgf) when the driving current is 5 A, so that it is calculated to be at least 2,000 N. As many as / 90 @ 23 giant magnetostrictive actuators must be used.

However, if the entire device is supported by as many as 23 points, the behavior at each fulcrum is different. Therefore, it is not possible to control all of these actuators in a synchronized manner to control the vibration, which makes the control extremely complicated. Not only
The total amount of drive current flowing through each actuator is 5 × 2
3 = 115 A, and there is a problem that the power consumption is too large.

Further, a giant magnetostrictive actuator using a large giant magnetostrictive rod has been prototyped so that the entire apparatus can be supported by a small number of giant magnetostrictive actuators. However, a drive current for driving each actuator is increased. Therefore, the total amount of current could not be reduced.

Accordingly, the present invention provides a giant magnetostrictive actuator capable of outputting a large displacement with a small driving current even when a large giant magnetostrictive rod is used.
It is a technical object to provide a vibration damping device using such a giant magnetostrictive actuator.

[0010]

In order to solve this problem, a giant magnetostrictive actuator according to the present invention has a giant magnetostrictive rod around which a magnetic field coil is wound, which is arranged at the center of a yoke, and the yoke is a preload frame. A yoke, wherein the yoke slidably supports a fixed support member engaging and supporting one end serving as a fixed end of the giant magnetostrictive rod and another end serving as a free end. It consists of a sliding support member and a connecting member for connecting these support members,
At the free end of the giant magnetostrictive rod, a push rod for transmitting the displacement to the outside is directly or indirectly abutted, and is formed so as to protrude from the sliding support member.
A pedestal for engaging and supporting the fixed support member, a preload member for slidably penetrating the push rod and applying a compressive force by a spring to the giant magnetostrictive rod via the push rod, and the pedestal and the preload member The yoke and the giant magnetostrictive rod form a closed magnetic circuit, and the yoke and the giant magnetostrictive rod form a closed magnetic circuit, and the push rod and the preload frame. Is formed of a non-magnetic material.

According to the present invention, since a closed magnetic circuit is formed by the yoke and the giant magnetostrictive rod, when a current is supplied to the magnetic field coil, the generated lines of magnetic force pass through the giant magnetostrictive rod and the yoke.

At this time, since the push rod for transmitting the displacement of the free end of the giant magnetostrictive rod to the outside is formed of a non-magnetic material, when the drive current is supplied to the magnetic field coil,
Almost no magnetic flux leaks from the free end of the giant magnetostrictive rod to the outside through the push rod. Also, since the preload frame to which the yoke is assembled is all formed of a non-magnetic material, almost no magnetic flux leaks from the yoke constituting the closed magnetic circuit to the preload frame. Therefore, the giant magnetostrictive rod can be expanded and contracted by effectively using the magnetic force generated by the magnetic field coil without waste, and a large output and a large displacement can be obtained with small power consumption.

[0013]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1 is an exploded view showing a giant magnetostrictive actuator according to the present invention, FIG. 2 is a sectional view thereof, FIG. 3 is a schematic explanatory view showing an active damping device according to the present invention, and FIG. It is a graph which shows a change.

In the giant magnetostrictive actuator 1 shown in FIGS. 1 and 2, a giant magnetostrictive rod 3 around which a magnetic field coil 2 is wound is disposed at the center of a yoke Y, and the yoke Y is assembled in a preload frame F. I have.

The magnetic field coil 2 includes, for example, two conductors 4a,
4b, a bias coil 2a for applying a magnetic bias to the giant magnetostrictive rod 3 is formed by one conductive wire 4a, and a drive coil 2b for expanding and contracting the giant magnetostrictive rod 3 is formed by the other conductive wire 4b. . In this example, the giant magnetostrictive rod 3 is ETREAMA TERENOL.
-D (trade name of Etrimer) is used.

The yoke Y is a fixed end 3a of the giant magnetostrictive rod 3.
A fixed support plate (fixed support member) 5 that engages and supports one end side, a slide support plate (slide support member) 6 that slidably supports the other end side that is the free end 3b, Panel 5,
6 is composed of three connecting rods (connecting members) 7 for connecting 6 and a cap 8 which is put on the free end 3 b of the giant magnetostrictive rod 3.

A recess 5a is formed at the center of the fixed support plate 5 so as to be engaged with the fixed end 3a of the giant magnetostrictive rod 3.
An engagement hole 5b into which the lower end of the connecting rod 7 is inserted is formed around the periphery, and an engagement protrusion 5c that engages with a preload frame F described later is formed on the bottom surface side. In the center of the sliding support plate 6, a through hole 6a is formed at the center thereof so as to slidably support the free end 3b of the giant magnetostrictive rod 3, and around the engaging hole 6b into which the upper end of the connecting rod 7 is inserted. Are formed.

The free end 3b of the giant magnetostrictive rod 3 is selected so that its free end 3b does not protrude from the sliding support plate 6 in the state of being disposed at the center of the yoke Y. To cover the through hole 6a and move up and down with the expansion and contraction of the giant magnetostrictive rod 3.

The members 5 to 8 constituting the yoke Y
Are made of a soft magnetic material such as iron, nickel, cobalt, or alloys containing them, preferably 45Ni permalloy or supermalloy, and are generated by the magnetic field coil 2 together with the giant magnetostrictive rod 3 disposed at the center thereof. A closed magnetic circuit for confining magnetic flux is formed.

The free end 3b of the giant magnetostrictive rod 3 has
A push rod 9 for transmitting the displacement to the outside is abutted via the cap 8 and is formed so as to protrude from the sliding support board 6.

The preload frame F to which the yoke Y is assembled is
A pedestal 10 that engages and supports the fixed support plate 5, and a preload plate that slidably penetrates the push rod 9 and applies a compressive force by a spring 11 to the giant magnetostrictive rod 3 via the push rod 9 ( A preloading member) 12 and a tightening bolt (connecting member) 13 which is passed through the base 10 and the preloading plate 12 and fastened by a nut 14.

The pedestal 10 has a fixed support plate 5 at its center.
An engaging recess 10a to be engaged with the engaging convex portion 5c is formed, and a bolt hole 10b of the tightening bolt 13 is formed around the engaging recess 10a. The preloading plate 12 has a through hole 12a at the center thereof through which the push rod 9 is inserted, and a bolt hole 12b of a tightening bolt 13 formed therearound.

A flange 9f is formed at the lower end of the push rod 9, and a spring 11 having a disc spring overlapped between the flange 9f and the preloading plate 12 is disposed.
Therefore, the fastening bolt 13 is attached to the base 10 and the preloading plate 12.
Through the nut 14 and tighten the spring 1
The push rod 9 is pressed down by the elastic force of 1 and a compressive force can be applied to the giant magnetostrictive rod 3 as prestress.

The push rod 9 and at least the pedestal 10 and the preloading plate 1 among the members forming the preload frame F
2. The tightening bolt 13 is a yoke Y forming a closed magnetic circuit.
Aluminum, titanium, SUS304, etc., so as not to generate a leakage magnetic flux even if it is placed in contact with or near the magnetostrictive rod 3.
And the like.

The above is an example of the configuration of the giant magnetostrictive actuator according to the present invention. Next, the operation thereof will be described. The assembling sequence of the giant magnetostrictive actuator 1 will be described. First, the fixed support board 5 is placed on the pedestal 10 through which the tightening bolt 13 is passed, and the engaging concave portion 10a and the engaging convex portion 5 are formed.
c is engaged. Then, the giant magnetostrictive rod 3 is set up in the concave portion 5a formed at the center of the fixed support board 5, the connecting rod 7 is set up in the engaging hole 5b formed therearound, and the magnetic field coil 2 is covered with the giant magnetostrictive rod 3. Then, the sliding support plate 6 is put on the disk. At this time, the free end 3b of the giant magnetostrictive rod 3 is inserted into the through hole 6a, and the upper end of the connecting rod 7 is engaged with the engaging hole 6b.

Next, the through holes 6a
The cap 8 is put on the free end 3b of the giant magnetostrictive rod 3 so as to close the rod, and the push rod 9 is set up on the cap 8. Then, the spring 1 is attached to the push rod 9.
1, and the preloading plate 12 is mounted thereon. At this time, the push rod 9 is inserted into the through hole 12a, and the tightening bolt 13 is inserted into the bolt hole 12b. And
By tightening the tightening bolt 13 with the nut 14,
The assembly of the giant magnetostrictive actuator 1 is completed.

Here, the bias coil 2 of the magnetic field coil 2
When a predetermined alternating current is supplied to the drive coil 2b while a predetermined bias current is supplied to the drive coil 2a to generate a bias magnetic field, an alternating magnetic field is generated, whereby the giant magnetostrictive rod 3 expands and contracts, and the push rod 9 moves up and down. Go to

At this time, since the bias coil 2a is wound around the entire length of the giant magnetostrictive rod 3,
The bias magnetic field generated thereby penetrates the giant magnetostrictive rod 3 having a relatively high magnetoresistance and acts substantially uniformly in the longitudinal direction. Therefore, when the drive current is passed through the drive coil 2b to expand and contract the giant magnetostrictive rod 3, the linearity of the deformation amount with respect to the magnetic field strength is excellent.

A yoke Y made of a ferromagnetic material
Form a closed magnetic circuit together with the giant magnetostrictive rod 3 and confine the leakage magnetic flux from the closed magnetic circuit with the preload frame F and the push rod 9 made of a non-magnetic material. Can be effectively applied to the giant magnetostrictive rod 3 without waste. Since the giant magnetostrictive rod 3 can be expanded and contracted by using this magnetic force, a large output and a large displacement can be obtained with small power consumption, and heat generation can be suppressed. Further, the fixed support plate 5 of the yoke Y
And the sliding support board 6 are connected by the connecting rod 7, and the pedestal 10 of the preload frame F and the preload board 12 are connected by the tightening bolt 14, so that the magnetic field coil 2 is exposed to the outside air, and the air permeability is improved. It has a structure that is hard to trap heat inside.

According to our experiments, the diameter is 20 mm,
When a giant magnetostrictive rod 3 having a length of 120 mm is used, a maximum displacement of 140 μm and a maximum dynamic force of 4400 N (about 450 kgf) are obtained with a driving current of 5 A at maximum.
Compared with the conventional product using a giant magnetostrictive rod of approximately the same size, a value about 5 times as large as the maximum dynamic force was obtained. Therefore, when supporting a thing with a weight of 2t,
It is enough if there are six giant magnetostrictive actuators 1.

Also, a larger diameter of 40 mm and a length of 15 mm
When a giant magnetostrictive rod 3 of 0 mm is used, a maximum displacement of 180 μm and a maximum dynamic force of 17700 N (about 1800 kgf) can be obtained with a driving current of 5 A at maximum. Aside from the problem described above, two giant magnetostrictive actuators 1 are sufficient, and three giant magnetostrictive actuators 1 are required in consideration of stability.
Is enough.

FIG. 3 shows an active vibration damping device 21 using the above-described giant magnetostrictive actuator 1, wherein a heavy object having a weight of about 2 t, such as mechanical equipment used in a cogeneration system, is used as a vibration generator 22. In such a case, the vibration is suppressed and sound and vibration are prevented.

In this vibration damping device 21, the tips of the push rods 9 of the four giant magnetostrictive actuators 1 mounted on the base B are mounted on the bottom of the vibration generator 22, and the vibration displacement of the vibration generator 22 is controlled. 23 to the magnetic field coil 2 of each giant magnetostrictive actuator 1 so that the giant magnetostrictive rod 3 expands and contracts in the opposite phase to the vibration displacement detected by the sensor 23 directly or indirectly. It has a controller 24 for supplying current.

As the sensor 23, for example, an acceleration sensor using a piezoelectric element is used. The controller 24 calculates the vibration displacement of the vibration generator 22 and its frequency by integrating the detection signal twice. ing.

The giant magnetostrictive rod 3 expands due to a magnetic field generated when a positive current is supplied to the drive coil 2b, and contracts due to a magnetic field generated when a reverse current is supplied to the drive coil 2b. On the basis of the displacement and the frequency, the AC driving currents having the same frequency and opposite phases are arranged such that the giant magnetostrictive rod 3 expands when the vibration generator 22 is displaced downward, and contracts when the vibration generator 22 is displaced upward. Supply.

FIG. 4 is a graph showing the displacement and the drive current of the vibration generator 22 before and after damping, and shows the vibration displacement X before damping.
_When a drive current (2 A alternating current) of the same phase and a drive current D having the same frequency as that of ₁ is supplied and vibration is damped, the vibration displacement X ₂ after vibration damping has an amplitude of about 1/3 of that before vibration damping. It can be seen that it has attenuated up to. As described above, when active damping of a heavy object was performed using the giant magnetostrictive actuator 1 according to the present invention, it was confirmed that the active mass could be reliably damped with low electric power.

In the above description, the case where two coils, the bias coil 2a and the drive coil 2b, are formed as the magnetic field coil 2, but one coil may be used for both. In this case, with a constant bias current supplied, an alternating current may be supplied with reference to the bias current. For example, in the case where an alternating current of ± 2 A is supplied as a driving current when the bias current is 1 A DC, the current value may be changed between -1 A and +3 A.

Also, the case where the bias coil 2a is wound around the giant magnetostrictive rod 3 as the magnetism generating means for applying a magnetic bias to the giant magnetostrictive rod 3 has been described. However, the present invention is not limited to this. A permanent magnet or an electromagnet may be incorporated in the yoke Y to be formed. In this case, the bias coil is wound around the connecting rod 7 or the connecting rod 7
May be formed entirely or partially with permanent magnets, or permanent magnets may be provided at both ends of the giant magnetostrictive rod 3.

Further, the case where the bias coil 2a is wound around the giant magnetostrictive rod 3 and the case where the yoke Y incorporates a permanent magnet or an electromagnet may be used in combination. In this case, there is an advantage that a more uniform magnetic bias can be applied to the giant magnetostrictive rod 3. That is, the magnetism generating means in which the bias coil 2a is wound around the giant magnetostrictive rod 3 can apply a uniform magnetic bias to the central part of the giant magnetostrictive rod 3, but the magnetic field tends to decrease at both ends, If the yoke Y is provided with a magnetic generating means,
A magnetic bias can be applied to both ends of the giant magnetostrictive rod 3, but it does not reach the center. Therefore, by applying a composite magnetic bias using them in combination, the disadvantages can be complemented by each other. A uniform magnetic bias can be applied.

Although the magnetic bias by the electromagnet and the magnetic bias by the permanent magnet have substantially the same effect, the use of an electromagnet allows the magnetic force to be adjusted by controlling the current. When a bias coil is wound around the connecting rod 7, if the material of the connecting rod 7 serving as a core is made of a soft magnetic material such as 45Ni permalloy, it can be magnetically biased with an extremely small current, and a small amount of power can be obtained. Thus, a magnetic bias whose magnetic force can be adjusted is obtained.

[0041]

As described above, according to the present invention, the giant magnetostrictive rod can be expanded and contracted by effectively using the magnetic force generated by the magnetic field coil without waste. Rank, and therefore
Even if the vibration generator is heavy, there is an excellent effect that the vibration can be reliably damped by supporting it and expanding and contracting the giant magnetostrictive rod in a phase opposite to the vibration displacement.

[Brief description of the drawings]

FIG. 1 is an exploded view showing a giant magnetostrictive actuator according to the present invention.

FIG. 2 is a sectional view thereof.

FIG. 3 is a schematic explanatory view showing an active vibration damping device according to the present invention.

FIG. 4 is a graph showing changes in vibration displacement before and after vibration suppression.

[Explanation of symbols]

 1 ... giant magnetostrictive actuator 2 ... magnetic field coil 2a ... bias coil 2b ... drive coil 3 ... giant magnetostrictive rod 3a ... fixed end 3b ... free end Y ... yoke F ... preload Frame 5: fixed support board (fixed support member) 6: sliding support board (sliding support member) 7: connecting rod (connecting member) 8: cap 9: push rod 10 ... Pedestal 11... Spring 12... Preloading plate (preloading member) 13... Tightening bolt (connecting member) 21... Active vibration damping device 22... Vibration generator 23. ………controller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takaaki Makino 1-3-3 Azamino Minami, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Inside Moritex Yokohama Technical Center (72) Inventor Masayoshi Tatsumi Aoba, Yokohama-shi, Kanagawa 1-3-3, Azaminominami, Ward F-term in the Moritex Yokohama Technical Center (reference) 3J048 AB08 AC08 AD03 EA38 5E048 AA02 AA08 AD02

Claims (5)

[Claims] A giant magnetostrictive rod (3) having a magnetic field coil (2) wound therearound is disposed at the center of a yoke (Y), and the yoke (Y) is assembled in a preload frame (F). A magnetostrictive actuator, wherein the yoke (Y) is a fixed end (3) of a giant magnetostrictive rod (3).
a) A fixed support member (5) that engages and supports one end side as described above.
A sliding support member (6) for slidably supporting the other end, which is a free end (3b); and a connecting member (7) for connecting these support members (5, 6), A free end (3b) of the magnetostrictive rod (3) is directly or indirectly abutted on a push rod (9) for transmitting the displacement to the outside, and is formed to protrude from the sliding support member (6). A pedestal (10) for engaging and supporting the fixed support member (5) with a preload frame (F);
And a spring (11) is attached to the giant magnetostrictive rod (3) via the push rod (9).
Each of the members (5, 6, 6) comprising a preloading member (12) for applying a compressive force by the above and a connecting member (13) for connecting the pedestal (10) and the preloading member (12). 7) is formed of a ferromagnetic material, a closed magnetic circuit is formed by the yoke (Y) and the giant magnetostrictive rod (3), and the members () constituting the push rod (9) and the preload frame (F) are formed. A giant magnetostrictive actuator characterized in that (10, 12, 13) is formed of a non-magnetic material. 2. A bias coil (2) for applying a magnetic bias to a giant magnetostrictive rod (3).
2. A giant magnetostrictive actuator according to claim 1, comprising: a) and a drive coil (2b) for generating a magnetic field for expanding and contracting the giant magnetostrictive rod (3). 3. The giant magnetostrictive actuator according to claim 1, wherein magnetism generating means for applying a magnetic bias to the giant magnetostrictive rod is formed on a yoke forming the closed magnetic circuit. 4. The connecting member of the yoke (Y) is formed at both upper and lower ends thereof by a connecting rod (7) engaged with a fixed supporting member (5) and a sliding supporting member (6). Tightening bolt (13) which is passed through the pedestal (10) and the preloading member (12) and fastened with the nut (14)
3. The giant magnetostrictive actuator according to claim 1, wherein the giant magnetostrictive actuator is formed of: A giant magnetostrictive rod (3) having a magnetic field coil (2) wound therearound is arranged at the center of a yoke (Y), and the yoke (Y) is assembled in a preload frame (F). The vibration generator (22) is supported by the giant magnetostrictive actuator (1), and a sensor (23) for directly or indirectly detecting the vibration displacement of the vibration generator (22); A controller (24) for supplying an alternating current to the magnetic field coil (2) of each of the giant magnetostrictive actuators (1) so that the giant magnetostrictive rod (3) expands and contracts in the opposite phase with respect to the vibration displacement detected in (23). An active vibration damping device comprising: a yoke (Y) of each giant magnetostrictive actuator (1);
A fixed support member (5) for engaging and supporting one end serving as a fixed end (3a) of the giant magnetostrictive rod (3), and a sliding support member for slidably supporting the other end serving as a free end (3b). (6) and a connecting member (7) for connecting these support members (5, 6), and a push rod (3) for transmitting the displacement to the free end (3b) of the giant magnetostrictive rod (3) to the outside. 9) abuts directly or indirectly to protrude from the slide support member (6), and the preload frame (F) engages and supports the fixed support member (5). And the push rod (9)
And a spring (11) is attached to the giant magnetostrictive rod (3) via the push rod (9).
Each of the members (5, 6, 6) comprising a preloading member (12) for applying a compressive force due to the above, and a connecting member (13) connecting the pedestal (10) and the preloading member (12). 7) is formed of a ferromagnetic material, a closed magnetic circuit is formed by the yoke (Y) and the giant magnetostrictive rod (3), and the members () constituting the push rod (9) and the preload frame (F) are formed. An active vibration damper characterized in that (10, 12, 13) is formed of a non-magnetic material.