JPH0576194U - High Magnetostrictive Rare Earth Alloy Protection Mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent bending and chipping of a magnetostrictive rod formed using a high magnetostrictive rare earth alloy. [Structure] A pair of or a plurality of pairs of bearings 20 are provided on a vibrating body 15 provided on both end surfaces of a magnetostrictive rod 10.
A shaft 21 for protecting the magnetostrictive rod is slidably inserted into the shaft, one end of the shaft 21 is slidably supported, and the other end is fixed to the diaphragm 15. As a result, the bending stress and shearing force acting as external force are absorbed by the bearing 20 and the shaft 21 and are not transmitted to the magnetostrictive rod 10.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a protection mechanism for a high magnetostrictive rare earth alloy, which protects the high magnetostrictive rare earth alloy from destruction in various drive devices such as a submersible wave transmitter using the high magnetostrictive rare earth alloy.

[0002]

[Prior Art]

 Conventionally, as a technique in such a field, there has been one described in the following documents, for example. Reference: UDT CONFERENCE (1991) (France) Fclaeyssen D, Boucher, “DESIGN OF LANTHANIDE MAGNETOSTRICTIVE SONAR PROJECTO RS” P. 1059-1065 FIG. 2 is a schematic sectional view of a conventional underwater transmitter using the high magnetostrictive rare earth alloy described in the above-mentioned document.

This wave transmitter has a plurality of magnetostrictive rods 1 formed of a high magnetostrictive rare earth alloy, and a coil 2 for magnetic bias or AC magnetic field generation is wound around the magnetostrictive rods 1. There is. Disc-shaped vibrators 4 are attached to both end surfaces of the magnetostrictive rod 1 via magnetic couplers 3, respectively. The vibrating body 4 attached to both end surfaces of the magnetostrictive rod 1 is fixed with bolts 5 for applying prestress, and prestress is applied to the magnetostrictive rod 1 in its axial direction. A forced cooling device 6 is attached to the outside of the coil 2 so that the heat generated in the coil 2 is radiated to the outside.

In this type of underwater transmitter, after being appropriately waterproofed, it is placed in water and an alternating current is passed through the coil 2, whereby an alternating magnetic field causes the magnetostrictive rod 1 to move in the axial direction ( It expands and contracts in the length direction) and generates a driving force in the axial direction. This driving force is transmitted to the vibrating body 4 and vibrates the vibrating body 4, and a sound wave (ultrasonic wave or the like) is generated and the sound wave is radiated into water.

[0005]

[Problems to be solved by the device]

 However, the device having the above configuration has the following problems. Since the magnetostrictive rod 1 formed of a high magnetostrictive rare earth alloy has a weak strength against lateral load, there is a problem that it is broken by mechanical force due to twisting or bending when it is attached to the vibrating body 4 or the like. It was Also, when prestressing the magnetostrictive rod 1 with the bolt 5, it is difficult to keep the joint surfaces of the vibrating body 4 and the magnetostrictive rod 1 in parallel, and since it is not possible to keep them in parallel, There is a problem that force is concentrated on a part of the joint surface of the rod 1 with the magnetic coupler 3 to cause chipping, and it is difficult to sufficiently protect it against the magnetostrictive rod 1. Met.

The present invention provides a protection mechanism for a high magnetostrictive rare earth alloy, which has been solved as a problem that the above-mentioned prior art has, such as breaking or chipping of a magnetostrictive rod formed using a high magnetostrictive rare earth alloy. Is provided.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention provides a magnetostrictive rod which is formed by using a high magnetostrictive rare earth alloy and which expands and contracts in the axial direction according to the magnitude of an alternating magnetic field acting from the outside, and is attached to the end face of the magnetostrictive rod. In a driving device such as an actuator or a transducer including a vibrating body that vibrates due to strain of the magnetostrictive rod and a prestress applying unit that applies a prestress to the magnetostrictive rod in the axial direction, the following means are provided. Are taking.

That is, in the present invention, a pair of bearings or a plurality of pairs are provided on the vibrating body, and the bearing has a bearing surface in a direction parallel to the magnetostrictive rod, and a shaft is slidable in parallel with the magnetostrictive rod. It is equipped with a supported shaft to protect high magnetostrictive rare earth alloys.

[0009]

[Action]

 According to the present invention, since the protection mechanism of the high magnetostrictive rare earth alloy is configured as described above, the bearing mounted on the vibrating body having the bearing surface in the direction parallel to the magnetostrictive rod has the shaft inserted therein. It works so that it can slide freely (slide itself) with a small clearance. Therefore, transmission of force is restricted only in the driving direction (axial direction) of the magnetostrictive rod, transmission of force from other directions is excluded, and bending stress and shearing force acting as external forces are not transmitted to the magnetostrictive rod. This can solve problems such as cutting and chipping of the magnetostrictive rod.

[0010]

【Example】

 1 (a) and 1 (b) are schematic structural views of an underwater transmitter showing an embodiment of the present invention. FIG. 1 (a) is a plan view and FIG. 1 (b) is a sectional view. is there. This wave transmitter has a magnetostrictive rod 10 formed of a giant magnetostrictive rare earth alloy such as terbium / dysprosium / iron (TbDyFe). The magnetostrictive rod 10 is used from one to a plurality depending on the purpose of use, but FIG. 1 shows the case where one rod is used. A cylindrical bobbin 11 is arranged on the outer circumference of the magnetostrictive rod 10, and a solenoid coil 12 for driving the magnetostrictive rod is wound around the bobbin 11.

A disk-shaped vibrating body 15 made of brass or the like is attached to both end surfaces of the magnetostrictive rod 10 via a magnetic coupler 13 for applying a magnetic bias to the magnetostrictive rod 10 and a permanent magnet 14. There is. The vibrating plates 15 on both sides are connected to each other by a plurality of shafts 16 which are prestress applying means, and the magnetostrictive rods 1 are provided by coil springs 17 provided at both ends of each shaft 16 and provided in the vibrating plates 15. The prestress is applied in parallel to 0 in the axial direction. The shaft 16 for applying the stress and the coil spring 17 are provided in two to five directions with respect to one magnetostrictive rod 10. In FIG. 1, it is provided in three directions.

A slide bearing 20 having a bearing surface in a direction parallel to the magnetostrictive rod 10 is embedded in each of the diaphragms 15 on both sides, and a shaft 21 for protecting the magnetostrictive rod is inserted into a hole of each slide bearing 20. Thus, the driving force is transmitted only to the axial direction of the magnetostrictive rod 10. That is, the shaft 21 is fixed to only one of the vibrating bodies 16 by using the bolt 22, and the other end of the magnetostrictive rod 10 is left in a free state (sliding state) so as to be stiff to the axial drive. It does not work as (stiffness; fixed state), and is in a state including resistance due to friction. This shaft 21 is also provided in the 2 to 5 directions with respect to one magnetostrictive rod 10 as in the prestress system. In FIG. 1, it is provided in three directions. Further, the clearance between the bearing surface of the sliding shaft system 20 and the shaft 21 is set to about 10 μm to 0.5 mm as a region that has low friction and satisfies the conditions of axial regulation.

In this type of underwater wave transmitter, it is put in water after being subjected to appropriate waterproofing treatment. Since a magnetic bias is applied to the magnetostrictive rod 10 by the magnetic coupler 13 and the permanent magnet 14, when an alternating current is superposed on the solenoid coil 12, an alternating magnetic field is generated by the solenoid coil 12 so that the magnetostrictive rod 10 has its axis. It causes the vibration of expansion and contraction in the direction. Then, due to this vibration, the vibrating bodies 15 on both sides vibrate, and a sound wave (ultrasonic wave or the like) is generated and radiated into water.

In the protection mechanism for a high magnetostrictive rare earth alloy in this underwater transmitter, each vibration body 15 is provided with a slide bearing 20, and one end of a shaft 21 is slidably inserted into the slide bearing 20 with a small clearance. The other end of the shaft 21 is fixed to the one vibrating body 15. Therefore, the other vibrating body 15 can slide with respect to the shaft 21 only in one axial direction parallel to the magnetostrictive rod 10. Therefore, when a mechanical force such as a twist or a bending is applied to the magnetostrictive rod 10 when the magnetostrictive rod 10 is attached to the vibrating body 15, the mechanical force is absorbed by the slide bearing 20 and the shaft 21. And is not applied to the magnetostrictive rod 10. Therefore, it is possible to accurately prevent the magnetostrictive rod 10 from being broken by a mechanical force. Further, when prestressing the magnetostrictive rod 10 by the shaft 16 and the coil spring 17, the sliding bearing 20 and the shaft 21 can keep the joint surfaces of the vibrating body 15 and the magnetostrictive rod 10 parallel to each other. The chipping that occurs in 10 can be accurately prevented.

The present invention is not limited to the above embodiment, and various modifications can be made. (A) In FIG. 1, the slide bearing 20 is used as the bearing, but the use of other bearings such as oilless bearings (rolling bearings) can also obtain the same operation and effect as the above-mentioned embodiment. (B) Although one end of the protective shaft 21 is fixed to the vibrating body 15 by using the bolt 22, it may be fixed by another method using an adhesive or the like. (C) In FIG. 1, the permanent magnet 14 is used to apply the magnetic bias to the magnetostrictive rod 10, but the magnetic bias may be applied by another method.

(D) In the above-described embodiment, the shaft 16 and the coil spring 17 are used to constitute the prestress applying means, but the prestress applying means may be constituted by another structure using an elastic body or the like. .. (E) In the above embodiments, the underwater wave transmitter has been described. However, if the drive device uses the vibration power of the magnetostrictive rod, the magnetostrictive rod protection mechanism may be applied to various devices such as actuators. It is possible. The protection mechanism may be changed to another shape or structure depending on the structure or shape of the drive device.

[0017]

[Effect of the device]

 As described in detail above, according to the present invention, in a drive device using a high magnetostrictive rare earth alloy, a bearing is provided on a vibrating body to regulate vibration in a uniaxial direction, and the shaft is slidably supported by the bearing. Since it is supported, the force is smoothly transmitted only in one axial direction, and bending stress and shearing force acting as external forces are absorbed by the bearing and the shaft and are not transmitted to the magnetostrictive rod. Therefore, it is possible to accurately prevent the magnetostrictive rod from chipping or breaking with a simple structure. Therefore, it can be applied to various drive devices such as an underwater transmitter.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram of an underwater transmitter showing an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a conventional underwater transmitter.

[Explanation of symbols]

 10 Magnetostrictive Rod 12 Solenoid Coil 13 Magnetic Coupler 14 Permanent Magnet 15 Vibrating Body 16 Prestressing Shaft 17 Coil Spring 20 Sliding Bearing 21 Magnetostrictive Rod Protection Shaft

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Takashi Yoshikawa 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Nobuhiro Tani 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Yasutaka Amitani 2-15, Natsushima-cho, Yokosuka City, Kanagawa Prefecture Marine Science and Technology Center (72) Toshio Tsuchiya 2-15, Natsushima-cho, Yokosuka City, Kanagawa Prefecture Marine Science and Technology In the center (72) Inventor Katsuhiko Murakami 1-2 1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (72) Innovator Nobuo Yamagami 1-2 1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A magnetostrictive rod formed of a high magnetostrictive rare earth alloy, which expands and contracts in the axial direction according to the magnitude of an alternating magnetic field acting from the outside, and is attached to an end face of the magnetostrictive rod and vibrates by the strain of the magnetostrictive rod. In a drive device comprising a vibrating body and a prestress applying means for applying a prestress to the magnetostrictive rod in the axial direction thereof, a pair or a plurality of pairs are provided on the vibrating body and bearings are provided in a direction parallel to the magnetostrictive rod. A protective mechanism for a high magnetostrictive rare earth alloy, comprising: a bearing having a surface; and a shaft axially supported by the bearing surface so as to be slidable in parallel with the magnetostrictive rod.