JP2020122176A - Method for manufacturing oscillation power generation device and method for manufacturing magneto-striction component - Google Patents

Abstract

To provide a method for manufacturing an oscillation power generation device which improves productivity of a magneto-striction component having a large magnetostriction constant.SOLUTION: An oscillation power generation device 1 includes a body 2 to be oscillated that is propagated by receiving oscillation from an oscillation source 3, magnetic field action means 4 acting a magnetic field on at least a part of the body 2 to be oscillated, a magneto-striction component 5 which is provided in an action region of a magnetic field by the magnetic field action means 4 in the body 2 to be oscillated and includes a magneto-striction material, and a coil 6 which is wound around the magneto-striction component 5 and carries out electromagnetic induction depending on distortion of the magneto-striction material of the magneto-striction component 5. When the oscillation power generation device 1 is manufactured, the magneto-striction component 5 is manufactured through a molding step 11 of filling a predetermined magneto-striction component-shaped die (molding die 12) with a powdery magneto-striction crystal material M1, and performing molding, and a discharge plasma sintering step 14 of carrying out discharge plasma sintering on a magneto-striction molding 13 containing the magneto-striction crystal material molded in the molding step 11, and obtaining a magneto-striction sintered body 16.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vibration power generation device that generates power by vibration from a vibration source such as a motor, a bridge, or a person's movement, and particularly to a method for manufacturing a vibration power generation device using a magnetostrictive component made of a magnetostrictive material and a method for manufacturing the magnetostrictive component. Regarding

As a conventional vibration power generation technology, a technology that uses a piezoelectric element (a technology that deforms a piezoelectric element to generate electricity by applying an external force to the piezoelectric element in some way) or a technology that uses a magnetostrictive element (magnetostrictive element) In addition, a power generation technique utilizing the inverse magnetostriction effect using a magnet or a coil is already known.
Examples of this type of vibration power generation device include those described in Patent Documents 1 to 3.
Patent Literature 1 describes a sound power generation device that uses a piezoelectric element to generate power by utilizing pressure fluctuations of air due to sound, and a vibration power generation device that uses pressure variation due to vibration to generate power using a piezoelectric element. .. This is a system in which vibration of a human voice is deformed by a piezoelectric ceramic to obtain electric power. Although μW level electric power for producing sound from a speaker can be obtained, mW level electric power required for IOT communication cannot be obtained.
Further, in Patent Document 2, as a vibration power generator using a magnetostrictive element, a magnetostrictive rod having a fixed magnetostrictive material has a cantilever structure, and bending stress is applied to the magnetostrictive rod to bend and deform the magnetostrictive material. It is disclosed that an inverse magnetostrictive effect changes a magnetic flux passing through a coil wound around a magnetostrictive material to generate an induced voltage in the coil.
Further, in Patent Document 3, after obtaining an amorphous Fe-Dy-Tb-based powder having an Fe-Dy-Tb-based component composition, and then solidifying the amorphous Fe-Dy-Tb-based powder, Fe- A method of manufacturing a giant magnetostrictive element for obtaining an amorphous giant magnetostrictive element having a Dy-Tb system component composition is disclosed.

Japanese Unexamined Patent Publication No. 2006-166694 (best mode for carrying out the invention, FIG. 10) Japanese Patent No. 4905820 (Mode for carrying out the invention, FIG. 4A) Japanese Patent Laid-Open No. 11-189853 (Example, FIGS. 1 and 2)

In the vibration force power generator using the piezoelectric element described in Patent Document 1, the piezoelectric material forming the piezoelectric element is a brittle material and is a material that is weak against bending and impact. Therefore, there is a problem that an excessive load cannot be applied, and it becomes difficult to apply a large bending or impact to increase the amount of power generation. Further, the piezoelectric element has a high impedance at a low frequency, and when a load having an impedance lower than that of the piezoelectric element is connected, the voltage generated in the load becomes small, so that the power generated by the power generation becomes small and the power generation efficiency is low. There is also a problem.
On the other hand, in the power generation element using the magnetostrictive material described in Patent Document 2, the magnetostrictive material is a ductile material and is more resistant to bending and impact than the piezoelectric material. Therefore, the amount of power generation can be increased by applying large bending or impact. It is possible to increase. Further, since the impedance of the power generation element is lower than that of the piezoelectric material, the power generation efficiency is less likely to decrease due to the connection of the load having low impedance, and the above-mentioned problems of the piezoelectric material can be solved.
However, the vibration power generation device described in Patent Document 2 includes a magnet for applying a bias magnetic field to the magnetostrictive rod, and generates a large amount of vibration from the vibration source in order to generate spring deformation of the magnetostrictive rod while vibrating. Vibration force is required, and there is a concern that the absorption of vibration energy will be worse. Further, since a frame such as an iron system is used for the frame (coupling yoke) that supports the magnetostrictive rod, rust and metal fatigue easily occur, and an adhesive or solder is used for joining the frame and the magnetostrictive rod. Therefore, there was a problem in long-term reliability.

Further, in order to manufacture a magnetostrictive rod made of a magnetostrictive material, since the crystal made of the magnetostrictive material has an ingot shape, it is necessary to process this into a plate shape to form a magnetostrictive rod. At this time, it is conceivable to use a method such as slicing, electric discharge machining, and wire saw for ingot-shaped crystals, but if this kind of processing method is adopted, a machining cutting margin will occur and most of the ingot-shaped crystals will be produced. May be discarded and wasted. Further, since the crystal is brittle and easily cracked, there is a concern that the processing cost will be very high. This type of processing method is generally difficult to adopt because of the high crystal cost including the processing cost.
Furthermore, for crystal growth, the Czochralski method (CZ method: Czochralski method, crystal pulling method), the vertical Bridgman method (VB method: Vertical Bridgman method), or the floating zone method (Floating zone method) However, it takes time to grow the crystal, which is another factor that increases the manufacturing cost of the crystal. Further, in Patent Document 3, Fe-Dy-Tb, which is a magnetostrictive material forming a magnetostrictive element, is a very hard and brittle material, and it is very difficult to process a thin plate. Further, there is also a demand that a material using a rare earth is expensive and it is not necessary to leave a wasteful part in processing.
Under these circumstances, when manufacturing a magnetostrictive component containing a magnetostrictive material, there is a strong demand for a manufacturing method effective for manufacturing a high quality magnetostrictive component.

A technical problem to be solved by the present invention is to provide a method of manufacturing a vibration power generation device in which the productivity of a magnetostrictive component having a large magnetostriction constant is improved.

A first technical feature of the present invention is to provide a vibrating body that receives and propagates vibrations from a vibration source, a magnetic field acting unit that causes a magnetic field to act on at least a part of the vibrating body, and the vibrating body. Provided in the magnetic field acting area by the magnetic field acting means, a magnetostrictive component including a magnetostrictive crystal material, and a coil wound around the magnetostrictive component, and electromagnetic induction depending on the strain of the magnetostrictive crystal material of the magnetostrictive component, When manufacturing a vibration power generation device comprising, the magnetostrictive component, a molding step of filling a powder-shaped magnetostrictive crystal material into a mold of a predetermined magnetostrictive component shape, and molding, the molding step. And a discharge plasma sintering step in which a magnetostrictive molded body containing the magnetostrictive crystal material is formed into a magnetostrictive sintered body by discharge plasma sintering.

A second technical feature of the present invention is the method for manufacturing an oscillating power generation device having the first technical feature, wherein the magnetostrictive crystal material is Fe-Ga or Fe-Co. This is a device manufacturing method.
A third technical feature of the present invention is a method of manufacturing a vibration power generation device having the first or second technical feature,
The molding step is a method of manufacturing a vibration power generation device, characterized in that the magnetostrictive molded body is molded by adding any one of copper, aluminum, boron, and carbon in addition to the magnetostrictive crystal material.
A fourth technical feature of the present invention is the method for manufacturing a vibration power generation device having any of the first to third technical features, wherein the magnetostrictive crystal material is pulverized to have an average particle diameter of 40 to 100 nm. In addition, the present invention provides a method of manufacturing a vibration power generation device, which is characterized in that it is in powder form.
A fifth technical feature of the present invention is the method for manufacturing an oscillating power generation device having any one of the first to fourth technical features, wherein the molding step is performed on the magnetostrictive crystal material filled in the mold. A method of manufacturing a vibration power generation device, characterized in that pressure is applied in one direction at 20 to 100 MPa.
A sixth technical feature of the present invention is the method for manufacturing a vibration power generation device having any one of the first to fifth technical features, wherein the spark plasma sintering step has a sintering environmental temperature of 800° C. or higher. And a temperature lower than the melting temperature of the magnetostrictive crystal material is maintained.
A seventh technical feature of the present invention is the method for manufacturing a vibration power generation device having any one of the first to sixth technical features, wherein in the discharge plasma sintering step, the mold used in the molding step is used. It is a method for manufacturing a vibration power generation device, which is also used as a sintering mold.
An eighth technical feature of the present invention is a method for manufacturing a vibration power generation device having any one of the first to seventh technical features, wherein the magnetostrictive sintered body is a polycrystalline body. It is a manufacturing method of a vibration power generation device.

A ninth technical feature of the present invention is, in manufacturing a magnetostrictive component used for a vibration power generation device, a molding step of filling a powdery magnetostrictive crystal material into a predetermined mold of the magnetostrictive component shape, and molding. And a discharge plasma sintering step of forming a magnetostrictive molded body containing the magnetostrictive crystal material molded in the molding step into a magnetostrictive sintered body by discharge plasma sintering, the magnetostrictive component being manufactured. Is a manufacturing method.

According to the first technical feature of the present invention, it is possible to provide a vibration power generation device with improved productivity of a magnetostrictive component having a large magnetostriction constant.
According to the second technical feature of the present invention, it is possible to provide a vibration power generation device including a magnetostrictive component which has a high magnetostriction constant, is inexpensive, and has good workability.
According to the third technical feature of the present invention, it is possible to provide a magnetostrictive component having improved magnetostrictive characteristics as compared with the case where no additive other than the magnetostrictive crystal material is contained.
According to the fourth technical feature of the present invention, it is possible to provide a vibration power generation device including a magnetostrictive component having a high sintering density as compared with the case of using a magnetostrictive crystal material having an average particle diameter of more than 100 nm.
According to a fifth technical feature of the present invention, there is provided a vibration power generation device including a magnetostrictive component capable of further increasing a packing density of a magnetostrictive crystal material, as compared with a case of molding without pressure in a molding process. can do.
According to the sixth technical feature of the present invention, it is possible to provide a vibration power generation device including a magnetostrictive component made of a magnetostrictive sintered body in which the crystallinity of a magnetostrictive crystal material is improved.
According to the seventh technical feature of the present invention, in manufacturing the magnetostrictive component of the vibration power generation device, the mold used in the molding step and the spark plasma sintering step can be shared.
According to the eighth technical feature of the present invention, it is possible to provide a vibration power generation device that maintains the crystallinity of a magnetostrictive crystal material and that includes a magnetic component made of a magnetostrictive sintered body that is inexpensive and highly prone to increase in productivity. ..
According to the ninth technical feature of the present invention, the productivity of the magnetostrictive component having a large magnetostriction constant can be improved.

(A) is an explanatory view showing an outline of an embodiment of a vibration power generation device to which the present invention is applied, (b) is an explanatory view showing a structural example of a magnetostrictive component used in the vibration power generation device shown in (a), FIG. 3C is an explanatory diagram showing a method for manufacturing a magnetostrictive component used in this embodiment. (A) is explanatory drawing which shows the structural example of the vibration power generation device which concerns on Embodiment 1, (b) is explanatory drawing which shows the structural example of the magnetostrictive component used by (a), and the example of attachment to a support frame. (A)-(c) is explanatory drawing explaining the manufacturing method of the magnetostrictive component used by Embodiment 1, (a) is a shaping|molding which shape|molds a powdery magnetostrictive crystal material into a magnetostrictive compact. For example, (b) is an example of a molding die used in the molding step of (a), (c) is a discharge for performing a discharge plasma sintering step of forming a magnetostrictive molded body into a magnetostrictive sintered body by spark plasma sintering. It is explanatory drawing which shows an example of a plasma sintering apparatus, respectively. FIG. 6 is an explanatory diagram showing a configuration example of a vibration power generation device according to a second embodiment. FIG. 9 is an explanatory diagram showing a configuration example of a vibration power generation device according to a third embodiment, and FIG. 9B is an explanatory diagram showing an example of mounting a magnetostrictive component on a support frame. (A) is explanatory drawing which shows the structural example of the vibration power generation device which concerns on Embodiment 4, (b) is explanatory drawing which shows the principal part of the modification 4-1 of the vibration power generation device which concerns on Embodiment 4. FIG. ..

◎Outline of Embodiment FIG. 1A shows a configuration example of a vibration power generation device to which the present invention is applied.
In the figure, the vibration power generation device 1 includes a vibrated body 2 that receives and propagates vibrations from a vibration source 3, a magnetic field acting unit 4 that applies a magnetic field to at least a part of the vibrated body 2, and a vibrated body 2. Among them, a magnetostrictive component 5 including a magnetostrictive material is provided in a magnetic field acting area by the magnetic field acting means 4, and a coil 6 wound around the magnetostrictive component 5 and electromagnetically induced depending on the strain of the magnetostrictive material of the magnetostrictive component 5. And,.
When manufacturing this type of vibration power generation device 1, as shown in FIGS. 1B and 1C, the magnetostrictive component 5 is formed by molding a powdery magnetostrictive crystal material M1 into a predetermined magnetostrictive component shape mold (molding die). 12) Filling and molding in 12), and discharge plasma firing to make the magnetostrictive molded body 13 containing the magnetostrictive crystal material molded in the molding step 11 into a magnetostrictive sintered body 16 by spark plasma sintering (SPS). It is manufactured through the bonding step 14. In FIG. 1(c), reference numeral 15 is a discharge plasma sintering apparatus for generating discharge plasma SP and sintering the magnetostrictive molded body 13.

In such a technical means, the vibrating body 2 may be made of any material as long as it can receive and propagate vibration. As the magnetic field acting means 4, a permanent magnet is typically mentioned, but a wide range of means for applying a magnetic field to the vibrated body 2 is included. Further, as shown in FIG. 1B, the magnetostrictive component 5 only needs to include at least the magnetostrictive crystal material M1, and the additive material M2 made of a material other than the magnetostrictive crystal material M1 (copper, aluminum, etc.) is added. Aspect is also included. The “magnetostrictive crystal material M1” here means a magnetostrictive material having crystallinity.
In addition, it is preferable to add a biasing force by a weight or a spring material in order to adjust the resonance frequency of the vibrated body 2.
Further, in the manufacturing method of the magnetostrictive component 5, when the discharge plasma sintering method is adopted, it is necessary to mold the powdery magnetostrictive crystal material M1 into a predetermined shape. Therefore, the discharge plasma sintering step is performed through the molding step. It is necessary to carry out.
In this example, the molding process is typically pressure molding, but includes no pressure. Further, it is necessary to appropriately select the usage conditions of the spark plasma sintering (SPS: Spark Plasma Sintering) in consideration of the magnetostrictive crystal material M1 and the additive material M2 to be sintered.

Next, a representative aspect or a preferable aspect of the method for manufacturing the vibration power generation device according to the present embodiment will be described.
First, as a preferable example of the magnetostrictive crystal material M1, Fe-Ga or Fe-Co can be cited. This example illustrates a material having a high magnetostriction constant among the magnetostrictive crystal materials M1.
In addition, as a preferable mode of the molding step 11, a mode in which the magnetostrictive molded body 13 is molded by adding any one of copper, aluminum, boron, and carbon as the additive material M2 in addition to the magnetostrictive crystal material M1. This example is an embodiment in which a small amount of a material (Cu, Al, B, C) having an improved magnetostriction characteristic is added in addition to the magnetic crystal material M1. Improving the magnetostrictive property here means increasing the magnetostriction constant.
Furthermore, as a preferable example of the magnetostrictive crystal material M1, there is an aspect in which the magnetostrictive crystal material M1 is in the form of powder pulverized to have an average particle diameter of 40 to 100 nm. In this example, 100 nm or less is preferable for increasing the sintering density, but if it is less than 40 nm, the crushing cost may increase.
Further, as a preferable mode of the molding step 11, there is a mode in which the magnetostrictive crystal material M1 filled in the molding die 12 is pressed from 20 to 100 MPa from one direction. In this example, if it is 20 MPa or more, the packing density (or sintering density) of the magnetostrictive crystal material M1 can be sufficiently increased, but if it exceeds 100 MPa, the volume of the magnetostrictive molded body 13 is unnecessarily reduced. I have a concern.

Further, as a preferable mode of the spark plasma sintering step 14, a mode in which the sintering environment temperature is kept at 800° C. or higher and lower than the melting temperature of the magnetostrictive crystal material M1 can be mentioned. This example shows preferable temperature conditions for improving the crystallinity of the magnetostrictive crystal material M1.
Further, as another preferable aspect of the spark plasma sintering step 14, there is an aspect in which the forming die 12 used in the forming step 11 is also used as a sintering die. In this example, the mold used in the molding step 11 is used in the spark plasma sintering step 14.
Furthermore, as a preferable aspect of the magnetostrictive sintered body 16, an aspect in which it is a polycrystalline body can be mentioned. Although the manufacturing cost of the single crystal is high, in this example, the magnetostrictive sintered body 16 is made of a polycrystal, which suppresses the manufacturing cost of the single crystal and is slightly lower than that of the single crystal. The orientation is obtained as having excellent crystallinity.

Further, in the present embodiment, the method of manufacturing the vibration power generation device 1 has been described, but it can be understood as a method of manufacturing the magnetostrictive component 5 used in the vibration power generation device 1.
Specifically, when manufacturing the magnetostrictive component 5 used in the vibration power generation device 1, a molding step 11 in which the powdery magnetostrictive crystal material M1 is filled into a molding die 12 having a predetermined magnetostrictive component shape and molded. It is manufactured through a discharge plasma sintering step 14 in which a magnetostrictive molded body 13 containing the magnetostrictive crystal material M1 molded in the molding step 11 is converted into a magnetostrictive sintered body 16 by discharge plasma sintering. Good.
This example is effective in consideration of the tradeability of the magnetostrictive component 5 alone, in the stage before being incorporated into the vibration power generation device 1, that is, in the manufacturing stage of the magnetostrictive component 5, and in exerting the effect of the right on the manufactured magnetostrictive component. is there.

Hereinafter, the present invention will be described in more detail based on the embodiments shown in the accompanying drawings.
◎ Embodiment 1
FIG. 2A is an explanatory diagram showing the overall configuration of the vibration power generation device according to the first embodiment.
− Overall configuration of vibration power generation device −
In the figure, a vibration power generation device 1 includes a support frame 20 as a vibrating body that receives and propagates vibrations from a vibration source 3, and a magnet 30 as a magnetic field acting means that applies a magnetic field to at least a part of the support frame 20. And the magnetostrictive component 5 including the magnetostrictive material, which is provided in the region of the support frame 20 where the magnetic field is applied by the magnet 30, and is wound around the magnetostrictive component 5, and the electromagnetic induction depends on the strain of the magnetostrictive material of the magnetostrictive component 5. And a coil 6 to operate.

<Support frame>
In this example, the support frame 20 is composed of an elastic plate member 21 made of a magnetic material such as SUS having a substantially U-shaped cross section, and one arm part 22 of the elastic plate member 21 is fixed as a fixing part 20A to an installation location (not shown). In addition, the other arm portion 23 extending from the one arm portion 22 via the bending portion 24 is made to function as the movable portion 20B capable of vibrating. Further, in this example, the other arm portion 23 that is the movable portion 20B has the extension portion 25 on the side opposite to the bending portion 24 as compared with the one arm portion 22 that is the fixed portion. There is a positional relationship in which the vibration from the vibration source 3 is applied to the tip of the.

<Magnet>
Further, in this example, the magnet 30 is installed on the one arm portion 22 of the support frame 20, and the magnet 30 is a permanent magnet (for example, a neodymium magnet) having upper and lower magnetic poles N and S. An action region of the magnetic field G by the magnet 30 is formed in a portion of the other arm portion 23 of the armature 20 which is located almost directly above the magnet 30 in the one arm portion 22 via the curved portion 24. ..
<magnetostrictive parts>
Further, in this example, the elongated rectangular plate-shaped magnetostrictive component 5 manufactured by the manufacturing method described later is installed in the magnetic field G acting region of the other arm 23 of the support frame 20 by the magnet 30. In particular, in this example, as shown in FIGS. 2A and 2B, the other arm 23 is provided with a recess 40 capable of accommodating the magnetostrictive component 5, and the recess 40 is provided with a recess 40 of the magnetostrictive component 5. A step portion 41 that supports both end portions in the longitudinal direction is formed, and the magnetostrictive component 5 is fixedly installed on the step portion 41.
<coil>
In addition, in this example, the coil 6 is evenly wound around the magnetostrictive component 5, and a part of the coil 6 wound around the magnetostrictive component 5 is accommodated in the recess 40 together with the magnetostrictive component 5, and the coil 6 The part is arranged outside the recess 40.

<weight>
Further, in this example, a resonance frequency adjusting weight 50 is provided on the extension portion 25 of the other arm portion 23 of the support frame 20. The weight may be fixed by its own magnetic force by using a magnet, for example, or may be fixed by a separate fastener such as a screw. Further, the weight of the weight 50 can be appropriately adjusted, and the installation position of the weight 50 may be variably set as necessary.
<Power generation take-out structure>
Further, in the present example, the electrode 60 is provided in the vicinity of the coil 6 in the other arm portion 23 of the support frame 20, the wiring 61 from both ends of the coil 6 is drawn to the outside via the electrode 60, and the magnetostrictive component 5 is formed. The AC induction voltage from the coil 6 which electromagnetically induces depending on the strain of the magnetostrictive material is connected to a rectification booster circuit 62 which is boosted to a predetermined level after rectification, and the rectification booster circuit 62 outputs a power generation output E of a predetermined level. Is obtained.

-Manufacturing method of magnetostrictive component-
In this example, the magnetostrictive component 5 is manufactured by the following manufacturing method.
As the material of the magnetostrictive component 5 of this example, as shown in FIG. 2B, a mixed material of the magnetostrictive crystal material M1 and the additive material M2 other than the magnetostrictive crystal material M1 is used.
<Magnetic strain crystal material>
In this example, Fe-Ga or Fe-Co having a high magnetostriction constant is used as the magnetostrictive crystal material M1. Here, Fe-Dy, Fe-Tb, and Fe-Dy-Tb are materials having a higher magnetostriction constant than Fe-Ga. However, since it is hard and brittle, and contains a large amount of rare earth (40% level), it becomes an expensive material. In this respect, Fe-Ga and Fe-Co contain about 80% of Fe and have good workability and may be inexpensive.
Further, regarding these magnetostrictive crystal materials M1, it is necessary to pulverize them into a powder form. However, the smaller the particle size of the powder used in this example, the higher the sintering density and the cost. After crushing, the micron powder is crushed again into nano powder and sintered without binder. As an example, in order to produce an Fe-Ga or Fe-Co alloy in a powder form, a powder-like material made of powder obtained by pulverizing a powder having a particle diameter of 2 to 3 μm with a ball mill to an average particle diameter of 40 to 100 nm is used. You can do this.
Further, if a trace amount of copper, aluminum, etc. is added to the alloy component, the magnetostrictive characteristic is improved.
<Additive material>
As the additive material M2, a material useful for improving the magnetostrictive characteristics of the magnetostrictive crystal material M1 is used, and is pulverized into powder like the magnetic crystal material M1 for use.
Specifically, there are copper (Cu), aluminum (Al), boron (B), carbon (C), and the like, and the content ratios thereof vary depending on the material. For example, Al is 4 to 7 at% (atomic percent) and B is 1 Around 6 at% and C is around 1.4 at %.

<Molding process>
In this step, the powdery magnetostrictive crystal material M1 (containing a predetermined additive material M2 in this example) is filled in a predetermined mold 12 of the magnetostrictive component 5 for molding.
In this example, since the magnetostrictive component 5 has a plate-like shape that can be mounted on the support frame 20, the molding die 12 has a plurality of magnetostrictive components 5 as shown in FIGS. So as to be manufactured at the same time, a plurality of (in this example, an array of 2×7) rectangular recesses 12a are provided, and the powdery magnetostrictive crystal material M1 is filled in the recesses 12a. Good.
Then, the molding die 12 covers the magnetostrictive crystal material M1 in the recess 12a with a covering die 12b, and pressurizes it with no pressure or with a predetermined pressure (20 MPa to 100 MPa). Here, if it is 20 MPa or more, the packing density of the magnetostrictive crystal material M1 can be sufficiently increased, and the larger the pressing force is, the higher the packing density becomes, which is preferable. However, it is of course possible to pressurize with a pressing force exceeding 100 MPa, but there is a concern that the volume of the magnetostrictive molded body after molding will be unnecessarily reduced.
Here, the molding die 12 may be made of graphite, a die type, a superhard type, or a ceramic, as long as it has a strength capable of withstanding a unidirectional pressing force of about 20 to 100 MPa.

<Discharge plasma sintering process>
The spark plasma sintering process is performed using the spark plasma sintering device 15 shown in FIG.
In this example, the discharge plasma sintering apparatus 15 uses the forming die 12 used in the forming process as it is as a sintering die, and arranges electrode pressing shafts 151 and 152 above and below in a vacuum chamber 150, respectively. A DC pulse sintering power source 153 is connected to the pressure shafts 151 and 152, and a molding die (also serving as a sintering die) 12 is sandwiched between the electrode pressure shafts 151 and 152 via punches 154 and 155. Further, the punches 154, 155 and the molding die 12 are pressed by a die 156 from the side.
A temperature sensor 157 including, for example, a thermocouple is provided in the die 156 to detect the discharge plasma sintering temperature for the magnetostrictive crystal material M1. The temperature information detected by the temperature sensor 157 is a controller. The controller 158 controls the output of the DC pulse sintering power source 153 based on the temperature information from the temperature sensor 157.

The spark plasma sintering device 15 is a device that embodies spark plasma sintering SPS (Spark Plasma Sintering), and has the following features as the features of the spark plasma sintering method SPS.
• Rapid sintering is possible (sintering time is 1/20 to 1/100 compared to conventional HIP (Hot Isostatic Pressing) and hot pressing methods).
・Controlled sintering of fine structure is possible.
-Easy to control grain growth and solidify nano powder with nano structure.
-Temperature gradient sintering is possible and solid phase sintering is possible.
-High-temperature sintering of high-temperature ceramics such as SiC and WC is possible without sintering aid, and low-temperature sintering is possible.
・Amorphous materials and sintering below the Curie point are possible.
・Reactive sintering in gas or electromagnetic field is possible.

<Implementation of molding process using spark plasma sintering equipment>
Particularly, in the present example, the discharge plasma sintering apparatus 15 takes a step of pressurizing the molding die 12 before performing the discharge plasma sintering, so that the above-described molding process sets the molding die 12 in the discharge plasma sintering apparatus 15. It will be carried out at the stage where it was done.
Incidentally, it goes without saying that the molding process may be performed separately from the molding process by the discharge plasma sintering device 15.

<Discharge plasma sintering procedure>
After the molding die 12 (also serving as a sintering die) of the spark plasma sintering device 15 is set and pressure-molded, the temperature in the vacuum chamber 150 is raised. At this time, a temperature rising rate of 20 to 200 K/min is used, and rapid temperature rising of 500 to 1000 K/min is also possible. In this example, for example, when the sample piece is small and has a diameter of 20 to 30 mm, it is appropriate to raise the temperature for several minutes to about 20 minutes. The temperature raising time may be selected accordingly.
Further, as the temperature condition in the vacuum chamber 150, the holding temperature maintained after the temperature rise is 800 to 2100°C. This also changes depending on the material, and in the Fe alloy, the holding temperature is optimally lower than the melting temperature, for example, 1000°C. Maintaining this temperature improves the crystallinity of the Fe alloy.
Furthermore, the sintering temperature of the SPS process is lower than the internal temperature by about 100 to 200K. This type of SPS treatment is based on the fact that the surface diffusion phenomenon between substance particles is dominant and the reactive rest temperature raising effect and the electric field diffusion effect contribute. A longer holding temperature is effective in that a uniform high density sintered body can be obtained. Here, the holding time is suitably 5 to 30 minutes, and 10 minutes is optimal for the Fe alloy.

The voltage and current for SPS are major factors for improving the sinterability, but they vary depending on the material. Ceramic powder has a high current value, and metal powder has a lower current value. The DC pulse sintering power supply 153 applies a DC voltage of about 4 to 20 V and an ON-OFF pulsed current of 500 to 40,000 A to the powder for sintering. 800 to 1200 A is suitable for the electric current to be applied to an Fe-based material having a relatively low melting point, which changes depending on the material.
A DC voltage of 4V, which is low in the Fe system, is suitable. Depending on the material, it is appropriate that the discharge time is about 1 to 2 hours for the ceramic type, but 5 to 20 minutes that does not dissolve in the metal is appropriate.
As described above, the DC pulse sintering power source 153 is repeatedly turned on and off to apply a voltage and a current, whereby the magnetostrictive molded body 13 (see FIG. 1) in the molding die 12 has a discharge point and a Joule heating point (locally). The high temperature generation field) moves, is dispersed in the entire magnetostrictive compact 13 and the phenomenon and effect in the ON state are uniformly repeated in the magnetostrictive compact 13, resulting in low power consumption and efficient sintering. Done.
Through such a process, the magnetostrictive molded body 13 molded by the molding die 12 is sintered into the magnetostrictive sintered body 16 (see FIG. 1) by spark plasma sintering.

-Method of manufacturing vibration power generation device and operation example-
After the magnetostrictive component 5 is manufactured by the manufacturing method described above, the magnet 30 and the weight 50 are installed on the support frame 20, the coil 6 having a predetermined number of turns is wound around the magnetostrictive component 5, and the magnetostrictive component 5 with the coil 6 is supported on the support frame. It may be installed in the recess 40 of 20.
As described above, if the magnetostrictive component 5 having a large magnetostriction constant is mounted on the vibration power generation device 1, the vibration from the vibration source 3 is propagated to the support frame 20, and thus the magnetostrictive component 5 mounted on the support frame 20. When the magnetostrictive crystal material (1) is distorted with a regular orientation, a large induction voltage is generated in the coil 6 due to electromagnetic induction depending on the distortion. Therefore, a high power generation output E from the rectification booster circuit 62 can be obtained.

◎ Embodiment 2
FIG. 4 shows a main part of the vibration power generation device according to the second embodiment.
In the figure, the vibration power generation device 1 includes a support frame 20, a magnet 30, a magnetostrictive component 5 (manufactured by the manufacturing method of the first embodiment), and a coil 6, as in the first embodiment. Unlike the first embodiment, the slide switch 100 is provided on the flexible rod 101 near the tip of one arm 22 of the support frame 20, and the tip position of the other arm 23 is set to the tip position of the one arm 22. It is arranged closer to the curved portion 24 than the curved portion 24, and the tip of the other arm portion 23 of the support frame 20 is pressed from above by the slide switch 100 described above, and the other arm portion is provided on one arm portion 22 of the support frame 20. A biasing spring 102 that biases 23 upward is provided. The same components as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the detailed description thereof is omitted here.
According to the present embodiment, when slide switch 100 is moved away from the other arm portion 23, the pressing of the tip of the other arm portion 23 by slide switch 100 is released accordingly. Then, the other arm portion 23 of the support frame 20 is biased upward by the biasing spring 102, so that the movable portion 20B (the other arm portion 23+the bending portion 24) of the support frame 20 vibrates greatly. As a result, a large vibration is propagated to the magnetostrictive component 5 mounted on the support frame 20, and the strain of the magnetostrictive material of the magnetostrictive component 5 increases correspondingly, and the induced voltage from the coil 6 due to electromagnetic induction is increased. The vibration power generation device 1 can obtain a large power generation output.
In this example, the slide switch 100 supporting the flexible rod 101 and the biasing spring 102 are used as the vibration source. However, instead of the slide switch 100 supporting the flexible rod 101, the slide switch 100 supporting the flexible rod 101 is supported by a coil spring. It is also possible to apply a large vibration to the movable portion 20B of the support frame 20 by pressing the tip of the other arm portion 23 of the support frame 20 with the pushed push button and pushing down the push button to release it.

◎ Embodiment 3
FIG. 5A shows a main part of the vibration power generation device according to the third embodiment.
In the figure, the basic configuration of the vibration power generation device 1 includes a support frame 20, a magnetostrictive component 5 and a coil 6 as in the first embodiment, but unlike the first embodiment, the support frame 20 and the The configuration of the magnetic field acting means is different from that of the first embodiment. The same components as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the detailed description thereof is omitted here.
In this example, the support frame 20 has a substantially U-shaped elastically deformable frame body 121 made of resin. Here, as the resin material 122, polyethylene, which is rich in corrosion resistance, heat resistance, mechanical strength and flexibility, olefin resin such as polypropylene, polyamide resin made of nylon 12, nylon 6 or the like, polyphenylene sulfide (PPS). ) Resin is used.
Further, magnetic powder 123 is dispersed in the frame body 121. As the magnetic powder 123, ferrite-based, neodymium-based, samarium-cobalt-based, samarium-iron-nitrogen-based particles having a particle size of about 1 to 10 μm are used. The magnetic powder 123 is uniformly mixed with the resin material 122 before injection-molding the support frame 20, and then uniformly dispersed in the resin by injection molding.
Further, in this example, since the magnetic powder 123 is dispersed in the support frame 20 as the magnetic field acting means, the magnetostriction in the other arm portion 23 of the pair of arm portions 22 and 23 of the support frame 20. N-pole and S-pole magnetized portions 124 and 125 are formed in a region sandwiching the installation location of the component 5, and a magnetic field G is formed at the installation location of the magnetostrictive component 5 between the magnetization portions 124 and 125. It has become.
Furthermore, in this example, as shown in FIG. 5B, the other arm portion 23 of the support frame 20 is provided with a recess 40 in which the magnetostrictive component 5 is accommodated. 5 are accommodated. Then, in the present example, unlike the first embodiment, the coil 6 is wound around the other arm portion 23 of the support frame 20 and the magnetostrictive component 5 by a predetermined number, and depends on the strain of the magnetostrictive material of the magnetostrictive component 5. The coil 6 is electromagnetically induced.
As described above, in the present embodiment, the support frame 20 has the resin frame main body 121 in which the magnetic powder 123 is dispersed, and further, the external magnet (the magnet 30 of the first and second embodiments) is used as the magnetic field acting means. By adopting the magnetizing portions 124 and 125 without using a magnetizing portion), it is possible to reduce the weight of the vibration power generation device 1 and to reduce the size because a magnet installation space is not required. It is possible.

◎ Embodiment 4
FIG. 6A shows a main part of the vibration power generation device according to the fourth embodiment.
In the figure, the basic configuration of the vibration power generation device 1 includes a support frame 20 having a resin frame body 121 in which magnetic powder 123 is dispersed, a magnetostrictive component 5, and a coil 6, as in the third embodiment. However, unlike the third embodiment, as magnetic field acting means, instead of the magnetizing portions 124 and 125, small magnets 131 and 132 having N and S poles are embedded in the frame body 121. The magnetic field G is made to act on the installation location of 5.
Therefore, also in the present embodiment, similarly to the third embodiment, the support frame 20 has the resin frame main body 121 in which the magnetic powder 123 is dispersed, and moreover, the external magnet ( Since the embedded small magnets 131 and 132 are adopted without using (corresponding to the magnet 30 of the first and second embodiments), the vibration power generation device 1 can be reduced in weight, and the installation space of the magnet, etc. Since it is unnecessary, the size can be reduced.
In the present embodiment, the support frame 20 has the resin frame body 121 in which the magnetic powder 123 is dispersed, but the present invention is not limited to this. For example, as shown in FIG. A resin frame body 121 ′ containing no magnetic powder 123 is adopted as the support frame 20, and the small magnets 131 and 132 are embedded in the frame body 121 ′, whereby the magnetic field G is placed at the installation location of the magnetostrictive component 5. It is also possible to make it act.

◎Example 1
As the magnetostrictive crystal material, Fe and Ga having a particle diameter of 2 to 3 μm and a purity of 3N manufactured by Kojundo Chemical Co., Ltd. were mixed at a ratio of 75:25 wt %.
Here, the ideal composition is 82:18, but since Ga easily volatilizes, it is set to 75:25.
In addition, a molding die (rectangular groove width 4.5, length 12.7, depth 0.7 mm) made of a superhard material having 14 grooves (corresponding to recesses) was filled with the above material and added. The pressure was increased to 30 MPa.
SPS was performed by setting the above-mentioned molding die in LABOX-600 manufactured by Sinterland Co., Ltd. as a spark plasma sintering apparatus.
SPS sintering conditions:
-SPS temperature rising rate 373 K/min It was kept at a temperature of 1000°C for 10 minutes-Maximum pulse current of 1000 A was applied for 5 minutes The physical properties of the sintered Fe-Ga magnetostrictive sintered body (magnetostrictive component) were measured.
・Viccus hardness 15.6 GPa
・Maximum room temperature bending strength 420MPa
Moreover, when XRD measurement was performed, it was a polycrystalline body in which orientation indices (100) and (111) were observed.
The size of the magnetostrictive sintered body was 4.1, the length was 12.5, and the thickness was 0.65 mm.
This magnetostrictive sintered body is set on the support frame of FIG. 2, 1800 copper wires as a coil are wound, and one neodymium magnet for magnetic field application 2×3×1 (unit: mm) size is set on the support frame, An Fe—Ga magnetostrictive sintered body was sandwiched and fixed in the recess of the support frame shown in FIG. A copper wire as a coil having a diameter of 0.33 mm was wound 2000 times from above.
The magnetostrictive constant of the magnetostrictive crystal material used at this time was 96 ppm. The weight was adjusted so that the maximum voltage could be obtained (resonance frequency) with 1 g of resin containing magnetic powder at the tip. As a result of applying a vibration with a frequency of 100 Hz and an acceleration of 0.1 G using this vibration power generation device, a peak voltage of 0.18 V (corresponding to the power generation output in FIG. 2) was generated.

◎Example 2
A magnetostrictive molded body and a magnetostrictive sintered body were produced by using the same molding die and discharge plasma sintering apparatus as in Example 1. The magnetostrictive crystal material is the same as in Example 1 except that Fe-Co powder is used. Further, a vibration power generation device was constructed in the same manner as in Example 1, and its characteristics were measured. The magnetostrictive constant of the magnetostrictive crystal material used at this time was 80 ppm. Further, as a result of applying a vibration with a frequency of 100 Hz and an acceleration of 0.1 G using the vibration power generation device, a peak voltage of 0.11 V (corresponding to the power generation output in FIG. 2) was generated.

◎Comparative example 1
When the Fe—Ga crystal was grown by the CZ method, it took 2 days to grow the diameter of 1 inch and the length of 3 cm. This crystal price is expensive, and it is easily scratched and cracked, so it is difficult to machine, and when it was cut into small pieces by electrical discharge machining to form strips, the processing cost was as high as ¥1,500. Therefore, it is understood that it is unsuitable as a power supply for IoT (Internet of Things) that requires low price.

Since the vibration power generation device according to the present invention is equipped with a magnetostriction component having a high magnetostriction constant with improved productivity, the price of the magnetostriction component can be reduced, and the price of the vibration power generation device can be reduced accordingly. be able to. Therefore, it can be effectively used for a sensor of a communication module for IoT and a power supply for communication which are required to be low in price.

DESCRIPTION OF SYMBOLS 1 Vibration power generation device 2 Vibrated body 3 Vibration source 4 Magnetic field acting means 5 Magnetostrictive component 6 Coil 11 Molding process 12 Molding die 13 Magnetostrictive compacting body 14 Discharge plasma sintering process 15 Discharge plasma sintering apparatus 16 Magnetostrictive sintered body M1 Magnetostrictive crystal Material M2 Additive material E Power generation output G Magnetic field 20 Support frame 20A Fixed part 20B Movable part 21 Elastic plate material 22 One arm part 23 The other arm part 24 Curved part 25 Extension part 30 Magnet 40 Recess 41 Step part 50 Weight 60 Electrode 61 Wiring 62 rectification booster circuit 100 slide switch 101 rod 102 urging spring 121 frame body 122 resin material 123 magnetic powder 124 magnetizing part 125 magnetizing part 131 small magnet 132 small magnet 150 vacuum chamber 151 electrode pressing shaft 152 electrode pressing shaft 153 DC pulse sintering power supply 154 Punch 155 Punch 156 Die 157 Temperature sensor 158 Controller

Claims (9)

A vibrating body that receives and propagates vibrations from a vibration source,
Magnetic field acting means for acting a magnetic field on at least a part of the vibrated body,
A magnetostrictive component provided in a magnetic field acting area of the vibrating body by the magnetic field acting means and including a magnetostrictive crystal material,
A coil wound around the magnetostrictive component, and a coil for electromagnetic induction depending on the strain of the magnetostrictive crystal material of the magnetostrictive component, and in producing a vibration power generation device,
The magnetostrictive component is
A molding step in which a powdery magnetostrictive crystal material is filled into a predetermined mold of the magnetostrictive component shape and molded,
A discharge plasma sintering step in which a magnetostrictive molded body containing the magnetostrictive crystal material molded in the molding step is a magnetostrictive sintered body by discharge plasma sintering,
A method for manufacturing a vibration power generation device, comprising: The method for manufacturing the vibration power generation device according to claim 1,
The method of manufacturing a vibration power generation device, wherein the magnetostrictive crystal material is Fe-Ga or Fe-Co. The method for manufacturing a vibration power generation device according to claim 1 or 2,
In the molding step, the magnetostrictive molded body is molded by adding any one of copper, aluminum, boron, and carbon in addition to the magnetostrictive crystal material. The method for manufacturing a vibration power generation device according to claim 1,
The method for manufacturing a vibration power generation device, wherein the magnetostrictive crystal material is in the form of powder pulverized to have an average particle size of 40 to 100 nm. The method for manufacturing a vibration power generation device according to any one of claims 1 to 4,
The method of manufacturing a vibration power generation device, wherein the molding step presses the magnetostrictive crystal material filled in the mold from 20 to 100 MPa in one direction. The method for manufacturing a vibration power generation device according to claim 1,
The method of manufacturing a vibration power generation device, wherein the spark plasma sintering step is performed at a sintering environment temperature of 800° C. or higher and a temperature lower than the melting temperature of the magnetostrictive crystal material. The method for manufacturing a vibration power generation device according to claim 1,
The method of manufacturing a vibration power generation device, wherein the spark plasma sintering step is performed by using the mold used in the molding step also as a sintering mold. The method for manufacturing a vibration power generation device according to claim 1,
The method for manufacturing a vibration power generation device, wherein the magnetostrictive sintered body is a polycrystalline body. When manufacturing magnetostrictive components used in vibration power generation devices,
A molding step in which a powdery magnetostrictive crystal material is filled into a predetermined mold of the magnetostrictive component shape and molded,
A discharge plasma sintering step in which a magnetostrictive molded body containing the magnetostrictive crystal material molded in the molding step is a magnetostrictive sintered body by discharge plasma sintering,
A method for manufacturing a magnetostrictive component, which is manufactured through

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