JP6426931B2 - Generator - Google Patents

Description

  The present invention relates to a generator, and more particularly to a generator in which a coreless coil is linearly driven between fixed magnets to generate electric power.

  A thermoacoustic engine is an engine that generates sonic vibration by giving a temperature difference to both ends of a heat storage unit, and converts (generates) this sonic vibration energy into electric power to use the exhaust heat from a factory etc. as electrical energy. It can be played back. A linear generator is positioned as the purpose of this power generation. In linear generators, the magnitude of the amplitude of the reciprocation is variable. For example, the sound wave vibration by the thermoacoustic engine has an amplitude of about ± 1 to ± 200 mm, and a vibration frequency of about 10 to about 1000 Hz.

  On the other hand, vibration power generation using the piezoelectric effect, magnetostrictive effect, etc. is a minute vibration source having a small amplitude of about 1 mm and a small power generation amount. Also, while wave power generation has a large amplitude, the frequency is on the order of Hz, and the propeller is often turned by wave power. As described above, in vibration power generation and wave power generation, the specifications of energy sources are different from power generation by vibration energy from thermoacoustics. Therefore, at present, there is no efficient linear generator suitable for a thermoacoustic engine, for example.

  In a linear generator, power can be generated by changing a magnetic field crossing a coil. The linear generator is classified into a movable core type, a movable magnet type, a movable coil type, and the like according to a member that moves to change a magnetic field. As the prior art related to a moving coil type generator that generates electric power by moving a coil, and a motor or actuator in which a coil moves by an electric current supplied to the coil, for example, techniques described in Patent Documents 1 to 5 are known.

  The permanent magnet generator described in Patent Document 1 is a rotary generator provided with a coreless coil (coreless coil) and a permanent magnet, and a disk-shaped coil sandwiched between two magnets rotates. To generate electricity.

In Patent Document 2, the inner peripheral surface of a permanent magnet faces the outer peripheral surface of a stator coil (air core coil) via an air gap, and the outer rotor type in which the permanent magnet is rotated by supplying a current to the coil Coreless motors are described. The coreless motor described in Patent Document 2 is configured to be reversibly applicable to power generation by rotating a coil.
The conventional moving coil type generator is generally a rotary type composed of a rotor and a stator as in Patent Documents 1 and 2, and a linear generator that converts reciprocating motion into electricity as it is can be seen almost I can not.

  The oscillating actuator described in Patent Document 3 is an actuator in which an arm having a coil attached thereto is disposed on a magnetic circuit of a permanent magnet, and the arm is rotated at a constant angle corresponding to the direction of current flowing through the coil.

The linear motor described in Patent Document 4 continuously arranges a plurality of permanent magnets, moves the electromagnet along the permanent magnet while changing the polarity of the electromagnet along the side surface. Here, the electromagnet is obtained by winding a coil around a nonmagnetic coil frame, and forms a kind of movable coil.
Both Patent Documents 3 and 4 aim to move the moving body linearly, and although it is theoretically possible to generate electricity in the coil by moving the coil support, it is possible to It is unsuitable for the use of the electric power generation using the vibration whose amplitude is about 20 mm.

  The voice coil type linear motor described in Patent Document 5 has a rectangular cross section as viewed from one side in the coil driving direction (axial direction of the coil), the coil is wound around a rectangular central axis, and the rectangular cross section is It has a structure in which it is sandwiched by two magnets and the lower cross section is sandwiched by two magnets. And the side yoke is each distribute | arranged to the both ends of an axial direction. In this voice coil linear motor, a sun-shaped closed magnetic circuit is constituted by a pair of outer yokes provided parallel to the inner yoke and a pair of side yokes connecting the outer yoke and the inner yoke.

The voice coil linear motor vibrates the coil by supplying a current to the coil. The voice coil type linear motor can be reversibly applied to power generation by applying vibrational energy from the outside to linearly drive the coil.
For example, the speaker is also a kind of moving coil type linear motor. The speaker comprises a magnetic circuit with a magnet and a yoke, and is provided with a back yoke on one side in the direction (the axial direction of the coil) in which the coil is driven, and a diaphragm on the other side.

Patent 472303 gazette Patent No. 2646319 Japanese Patent Application Laid-Open No. 7-143721 Patent 3220666 Japanese Patent Application Laid-Open No. 8-214530

As a generator, it is required to be suitable for linear motion, to be light in weight, to have high power generation efficiency, not to be complicated in structure, and to be good in heat dissipation.
The moving coil type is different from the moving iron core type and the moving magnet type, and it is a coil that causes reciprocation. When the coil, which is a mover, is light, movement can be performed at a higher frequency as compared with the case where the mover is a magnet or an iron core. In addition, the moving coil type is free from iron loss and cogging because the magnetic circuit does not change.

  However, the voice coil type linear motor described in Patent Document 5 has a problem that a magnetic field is formed in the yoke by the coil current, and iron loss occurs as the current changes, and side yokes (back yokes) are formed at both ends in the axial direction. There is a problem that the cooling effect is small because it is not open.

  Moreover, since the voice coil type linear motor described in Patent Document 5 has a structure in which the upper side of the rectangular cross section is sandwiched by two magnets and the lower side cross section is sandwiched by two magnets, it is formed of a magnet, an inner yoke, and a back yoke. The magnetic circuit to be formed is formed only in the vertical direction, and when the generator is configured, the output can not be large. In addition, since the speaker has a structure in which a magnet is placed around the outside of the coil and one magnetic circuit is formed by the magnet, the inner yoke, and the back yoke, a large output can not be obtained when the generator is configured.

  The present invention has been made in view of the above problems, and a generator suitable for linear power generation of coggingless, iron loss free, light weight, high efficiency, high heat dissipation without complicating the structure The task is to provide.

In order to solve the above problems, the generator according to the present invention generates electricity by linearly driving the coil so that at least a part of the coil is linked to a magnetic field generated within the movable range of the coreless coil. A plurality of electrically connected coils, a coil support made of a nonmagnetic material for supporting the plurality of coils at a distance, and the coils are disposed on the inner and outer sides in the circumferential direction of the respective coils. And the coil support supports the plurality of coils in the axial direction of the coil, and for each of the coils, a region of the coil is directed inward from the outer side in the circumferential direction of the coil. A magnetic field in the direction of interlinking with the magnetic field, and a magnetic field in the direction of interlinking with the other region of the coil, directed from the inside to the outside in the circumferential direction of the coil, within the movable range of the coil The The direction of the magnetic field generated in the predetermined area of one coil is opposite to the direction of the magnetic field generated in the predetermined area of the other coil facing the predetermined area of the one coil. The magnetic field is stationary, and a plurality of looped magnetic circuits are formed by magnetic fields in which the directions of the adjacent magnetic fields alternate, and the yoke is formed in the circumferential direction of each of the coils. And an outer yoke formed in a tubular shape so as to surround the axial yoke in the circumferential direction and disposed on the outer side in the circumferential direction of each of the coils; Both ends in the axial direction are open, and the coils supported by the coil support generate power by driving in the magnetic field in the axial direction of the coil.
In the generator according to the present invention, power may be generated at a frequency equivalent to the vibration frequency of the coil.
In the generator according to the present invention, as means for generating a magnetic field within the movable range of the coil, an outer magnet respectively arranged outside the coils and an inner magnet respectively arranged inside the coils , And the inner magnet is fixed to the axial yoke so as to face the outer magnet, and the outer magnet is disposed to face the inner magnet to the outer yoke. The two outer magnets adjacent to each other in the axial direction are arranged such that the polarities of the adjacent ones are opposite to each other, and the outer magnets move the coils in the circumferential direction. It may be arranged so as to surround it.

According to such a configuration, since the generator is disposed so that the outer magnet surrounds the coil in the circumferential direction, the inner magnet facing the outer magnet surrounds the axial yoke in the circumferential direction, and the outer magnet is fixed. The outer yoke is disposed to surround the shaft yoke in the circumferential direction.
Further, in the generator, since a pair of magnets by the outer magnet and the opposing inner magnet and a pair of similar magnets are adjacent in the axial direction of the coil, between the two pairs of adjacent magnets, A stationary magnetic circuit closed in the axial direction of the coil can be configured. Thus, the generator can generate a stable electromotive force in response to the movement of the coil. Further, in the generator, since a plurality of magnetic circuits formed in a loop shape in the axial direction of the coil are formed in the circumferential direction of the coil, the output can be increased. Further, in the generator, since the mover is a lightweight coil, it can be moved at a higher frequency as compared with the case where the mover is a magnet or an iron core. Moreover, in the generator, in the yoke to which the magnet was fixed, the axial both ends of the coil are open | released and heat dissipation is favorable.

  Further, in the generator according to the present invention, the outer yoke is formed in a tubular shape so as to surround the shaft yoke in the circumferential direction, and the outer magnet is formed by circumferentially extending the inner circumferential surface of the outer yoke. 1 is formed of a predetermined number of magnets surrounding at a predetermined interval, and the inner magnet is formed of the same number as the predetermined number of magnets surrounding the outer peripheral surface of the axial yoke at a second predetermined interval in the circumferential direction Is preferred.

  In this case, the coil support includes, for example, a plurality of axial supports, which are claw-shaped members extending in the axial direction of the coil and sandwiching the plurality of coils from the outer side and the inner side in the radial direction; An annular plate member having an opening passing therethrough, and a plurality of support plates respectively fixing the plurality of axial supports at predetermined positions in the axial direction, the plurality of axial supports being It is possible to use one which is fitted in the gap between the plurality of magnets forming the inner magnet and the gap between the plurality of magnets forming the outer magnet.

  In the generator according to the present invention, the wire usage rate is 50% or more, which is a ratio of the length of a portion interlinked with the magnetic field for one turn to the entire length for one turn in the coil. preferable.

  Further, in the generator according to the present invention, the outer yoke is formed in a tubular shape so as to surround the axial yoke in the circumferential direction, and the outer magnet surrounds the entire inner circumferential surface of the outer yoke. It may be formed of a magnet, and the inner magnet may be formed of a magnet surrounding the entire circumference of the outer peripheral surface of the axial yoke. By doing this, the magnetic flux density becomes high, and the power generation output can be made high.

Further, the generator according to the present invention, the distance between two of said magnetic field between the direction of the magnetic field What if the opposite directions to each other adjacent in the axial direction of the coil as a desired length L (L> 0), and, if determining the half amplitude of the vibration of the coils as l, and the width W of the magnetic field in the axial direction of the coil, wherein the width w of the axial direction of the coil, the following formula (1) It is preferable to be configured to satisfy the relationship.
L l l + w / 2-W / 2 Formula (1)

According to this configuration, in the generator, it is possible to prevent the mover from moving too much and entering the reverse magnetic flux, and the operation can be stabilized.
The generator according to the present invention is a generator that generates electric power by linearly driving the coil such that at least a part of the coil is linked to a magnetic field generated within the movable range of the coreless coil. And a coil support made of a nonmagnetic material for supporting the plurality of coils apart from each other, the coil support supporting the plurality of coils in the axial direction of the coil A magnetic field directed from the outside to the inside of the circumferential direction of the coil and linking with one region of the coil, and the other from the inside to the outside of the circumferential direction of the coil. A magnetic field in the direction of interlinking with the area is generated within the movable range of the coil, and the direction of the magnetic field generated in the predetermined area of one of the two opposing coils, and the predetermined area of the one coil The direction is opposite to the direction of the magnetic field generated in the predetermined area of the other opposing coil, and the plurality of the magnetic fields are stationary, and the adjacent magnetic fields alternate in the direction of the magnetic field to form a loop. A plurality of magnetic circuits are formed, and each of the coils supported by the coil support generates electric power by driving in the axial direction of the coil in the magnetic field, and within the movable range of the coils As means for generating a magnetic field, an outer magnet respectively disposed outside each of the coils, and an inner magnet respectively disposed inside each of the coils are provided, and the inner magnet is opposed to the outer magnet A columnar axial yoke fixed so as to be positioned, and an external yoke fixed so that those facing each other at the position where the outer magnet faces the inner magnet have different polarities. The two outer magnets axially adjacent to each other are arranged with their polarities reversed from each other, the outer magnets are arranged to surround the coil in the circumferential direction, and the outer yoke is the axial yoke The outer magnet is formed of a predetermined number of magnets surrounding the inner circumferential surface of the outer yoke at a first predetermined interval in the circumferential direction, The magnet may be formed of the same number of magnets as the predetermined number surrounding the outer peripheral surface of the axial yoke at a second predetermined interval in the circumferential direction.

  Further, in the generator according to the present invention, a unit configuration including the coil, the outer magnet disposed outside the coil, and the inner magnet disposed inside the coil is an axis of the coil. It is also possible to arrange two or more in the direction. By doing this, the power generation output can be increased.

According to the present invention, it is possible to provide a generator suitable for linear power generation of coggingless, iron loss free, light weight, high efficiency and high heat dissipation without complicating the structure.
The generator according to the present invention does not require yokes on both sides in the coil drive direction, so the power generation output can be increased by arranging a plurality of coils in the axial direction, increasing the number of turns, or increasing the coil winding width. can do. Further, in the generator of the present invention, since both axial ends of the coil are open, the coil can be stably supported on the axis of the coil, and the coil and the magnetic circuit can be naturally cooled.

It is a perspective view showing typically the appearance of the generator concerning the embodiment of the present invention. It is the right view which looked at the generator of FIG. 1 from the right. It is a perspective view including the AA line section of Drawing 1 in part. It is an AA line cross section arrow line view of FIG. It is a perspective view of the coil support body which supports the coil of FIG. It is explanatory drawing of the displacement amount of the coil moved in the generator of FIG. 1, Comprising: (a) is negative maximum displacement, (b) has shown the center position of displacement, (c) has shown positive maximum displacement. It is a figure which shows the simulation result of the magnetic field analysis of the generator of FIG. It is explanatory drawing of the transient response analysis of the generator of FIG. 1, Comprising: (a) is a circuit diagram which shows the connection of each coil and load resistance, The figure which showed the generator of (a) by an equivalent circuit. It is. It is a graph which shows the simulation result of the transient response analysis of the generator of FIG. It is a schematic diagram of the generator which concerns on the modification of this invention.

  The form for carrying out the generator of the present invention will be described in detail with reference to FIGS. 1 to 6 as appropriate. Note that the size, positional relationship, and the like of members and the like shown in the drawings may be exaggerated for the sake of clarity.

In the generator 1, the coreless coil 10 is linearly driven between the fixed magnets 20 and 30 to generate electric power.
The generator 1 includes a plurality of coils 10 electrically connected to each other, an outer magnet 20 disposed outside each coil 10, an inner magnet 30 disposed inside each coil 10, and an inner magnet 30. external yoke but a shaft yoke 40 fixed so as to position facing the outer magnet 20, the same Judges that faces at a position outside the magnet 20 faces the inner magnet 30 is fixed so as to be different polarities 50 and a coil support 60 (see FIG. 5).
As shown in FIGS. 3 and 4, in the generator 1, the two coils 10 a and 10 b are separated and supported on an axis in the left-right direction which is the moving direction. In addition, the coil support body is abbreviate | omitted in drawings other than FIG. 5 on account of description. Further, the explanation of the symbols representing the dimensions in FIG. 3 will be described later. The axial yoke 40 is illustrated as being clogged up to the inside of the shaft, but may be a cylindrical shape in which the central portion is hollow in the axial direction.

Hereinafter, the plurality of coils 10 and the coil support 60 are collectively referred to as a mover.
The inner magnet 30 and the axial yoke 40 to which the inner magnet 30 is fixed are collectively referred to as an inner stator. Further, the outer magnet 20 and the outer yoke 50 to which the outer magnet 20 is fixed are collectively referred to as an outer stator. When the inner stator and the outer stator are not distinguished, they are simply referred to as a stator.

<Coil>
A plurality of (two) coils 10a and 10b are disposed in the axial direction of the coil (the left and right direction in FIG. 4). The coil material may be any conductor, and examples thereof include copper, silver, aluminum and the like. Copper insulation (of the type referred to as magnet wire) is preferred.

The motion direction of the coil 10 is the axial direction (left and right direction in FIG. 4).
If the amplitude range of the coil is, for example, in the range of ± 1 mm to ± 200 mm, it is possible to use the principle of the present invention.

<Magnet>
Outer magnet 20, as shown in FIGS. 3 and 4, the Judges that faces are arranged such that different polarities at positions opposing the inner magnet 30. That is, if the side of the surface facing the inner magnet 30 of the outer magnet 20 is the S pole, the side of the surface facing the outer magnet 20 of the inner magnet 30 is the N pole.
Further, as shown in FIGS. 3 and 4, the two outer magnets 20 adjacent to each other in the axial direction is arranged to reverse the polarity of Tonarido workers.
Furthermore, as shown in FIGS. 1 and 2, the outer magnet 20 is disposed so as to surround the coils 10 a and 10 b in the circumferential direction.
The axial length of the coil for the outer magnet 20 is predetermined, and hereinafter also referred to as the magnet width W (see FIGS. 3 and 6).
The distance between the two outer magnets 20 axially adjacent to the coil is predetermined. Hereinafter, this distance is also referred to as axial magnet distance L (see FIGS. 3 and 6).

The inner magnets 30 are respectively disposed at positions facing the outer magnets 20 as shown in FIGS. 3 and 4.
The axial length (width of the magnet) of the coil for the inner magnet 30 is predetermined and is preferably the same as the width W of the magnet of the outer magnet 20.
The thickness T5 of the inner magnet 30 and the thickness T2 of the outer magnet 20 may be any size and shape in which magnetic saturation does not easily occur, and may not necessarily have the same thickness.
The distance between the two inner magnets 30 axially adjacent to the coil is predetermined and is preferably the same as the distance L between the outer magnets 20 in the axial direction.
The distance between the inner magnet 30 and the outer magnet 20 is predetermined so as to secure a space in which the coil 10 can vibrate. Hereinafter, this distance is also referred to as a radial direction magnet-to-magnet distance T3 (see FIG. 3).

  As a magnet material, a general thing, for example, a permanent magnet, an electromagnet, a superconducting magnet etc. can be used. In the case of a permanent magnet, for example, neodymium, samarium cobalt, ferrite or the like is preferably used, and neodymium is particularly preferable.

<Yoke>
As shown in FIGS. 1 to 4, the axial yoke 40 has a cylindrical shape. In the generator 1 shown in FIG. 1, as an example, the cross section has a circular cylindrical shape.
As shown in FIGS. 1 to 4, the outer yoke 50 is formed in a tubular shape so as to surround the axial yoke 40 in the circumferential direction. In the generator 1 shown in FIG. 1, as an example, the cylindrical outer yoke 50 has an annular cross section.

  The yoke material may be any material that can form a magnetic flux circuit, and for example, iron (pure iron), a permanent magnet, a magnetic steel sheet, etc. can be used. Pure iron is particularly preferred because a high saturation magnetic flux density is required.

  The generator 1 does not have to provide yokes on both sides in the coil driving direction (left and right direction in FIG. 1) by forming the shaft yoke 40 and the external yoke 50 in the above-described shape. In the yoke 1 provided with a magnet, both ends in the axial direction of the generator 1 are open and do not have a back yoke.

<Arrangement of magnets and coils>
In the present embodiment, as shown in FIG. 2, the outer magnet 20 is formed of a plurality of magnets 20 surrounding the inner circumferential surface of the outer yoke 50 at a first predetermined interval in the circumferential direction.
Similarly, the inner magnet 30 is formed of the same number of magnets as the predetermined number surrounding the outer peripheral surface of the axial yoke 40 at a second predetermined interval in the circumferential direction.

  Here, the angle in the circumferential direction of the surface (inner circumferential surface) facing the inner magnet 30 in the outer magnet 20 is the same as the angle in the circumferential direction of the surface (outer circumferential surface) facing the outer magnet 20 in the inner magnet 30 The first predetermined interval and the second predetermined interval are determined so that In another viewpoint, the distance between the magnets 20 (first predetermined distance) and the distance between the magnets 30 (second predetermined distance) correspond to the angular range θ in which the magnets are disposed in FIG.

  Specifically, as shown in FIG. 2, the outer magnet 20 is formed of four magnets 20 which are disposed 90 ° apart so as to surround the coil 10 for each coil 10, similarly, The magnet 30 is formed of four magnets 30 for each coil 10. In FIG. 2, the angular range θ in which the magnets are disposed is 60 °, and the angle corresponding to the gap between the magnets in the circumferential direction is 30 °. As shown in FIG. 2, there are four gaps between the magnets disposed in the circumferential direction of the stator before the coil 10 is disposed between the outer stator and the inner stator as shown in FIG. This is because the coil support 60 having the configuration shown as an example in 5 is incorporated in this portion. In addition, in FIG. 2, since the state after arrange | positioning the coil 10 between the outer side stator and the inner side stator is shown in figure, the clearance gap is vacant in eight places.

Assuming that the entire length is C [m] and the length of a portion interlinked with the magnetic field is x [m] in one turn of the coil 10 in which the conductor of a predetermined number of turns is wound, the conductor usage rate η [%] Is expressed by equation (2). In the example shown in FIG. 2, η is 67%.
η = x / C × 100 ... Formula (2)

  In the structure including the yoke formed in the shape of the day character as described in Patent Document 5, the portion interlinked with the magnetic field in one turn of the coil corresponds to the four sides of the coil viewed from the axial direction. It is only in the vertical direction. That is, the part contributing to power generation is the upper and lower two coil sides, and the two coil sides on the left and right do not contribute to the power generation, and the usage rate of the conducting wire is reduced to about 50%.

  As shown in FIG. 4, the generator 1 arranges the polarities of the two magnets 30, 20 sandwiching the left coil 10a with SN, SN from the side of the shaft yoke 40, and sandwiches the right coil 10b. The polarities of the magnets 30 and 20 are arranged as SN and SN from the side of the outer yoke 50. That is, the magnets are arranged such that a magnetic circuit is formed by magnetic flux lines in the direction indicated by thick arrows passing through the two coils 10a and 10b.

  Between the magnet 20 and the magnet 30, there is an air gap for the coil 10 to reciprocate. By being excited, the left coil 10a and the right coil 10b move in the same direction. On the other hand, the direction of the magnetic flux produced by the stator at the portion where the left coil 10a is disposed is opposite to the direction of the magnetic flux produced by the stator at the portion where the right coil 10b is disposed. Therefore, according to the direction of the current flowing in each coil 10a and 10b when moving in the same direction, the winding direction of the lead of the coil 10a on the left side is opposite to the winding direction of the lead of the coil 10b on the right There is.

  FIG. 4 is a sectional view of the generator of FIG. 2 taken along a vertical plane (e.g.,) = 0 °), for example, at a plane of a predetermined angle in the range of −30 ° ≦ ° ≦ 30 °. The same drawing is obtained in the case of cutting, and a magnetic circuit is similarly formed. In addition, the same drawing is obtained when the generator of FIG. 2 is cut along a horizontal plane (for example, Ψ = 90 °) or a plane having a predetermined angle within a range of 60 ° ≦ Ψ ≦ 120 °, for example. A circuit is formed. That is, in the generator 1, magnetic circuits are formed in many directions in the upper and lower, front and back directions in FIG. 2. In the structure including the yoke formed in the shape of a Japanese character as described in Patent Document 5, the magnetic circuit is formed only in one direction.

<Coil support>
The coil support 60 (see FIG. 5) supports the plurality of coils 10a and 10b spaced apart on the same axis. The coil support 60 vibrates with the coil. The coil support 60 is made of nonmagnetic material.
Examples of the nonmagnetic material include plastics, ceramics, nonmagnetic metals and the like.

  The coil support 60, an example of which is shown in FIG. 5, includes a plurality of (for example, four) axial supports 61, 62, 63, 64 and a plurality of (for example, two) support plates 65, 66. .

  The axial supports 61, 62, 63, 64 are claws extended in the axial direction of the coil, and sandwich the plurality of coils 10a, 10b from the outside and the inside in the radial direction. The axial supports 61, 62, 63, 64 are fitted in the gaps between the plurality of magnets forming the inner magnet 30 and the gaps between the plurality of magnets forming the outer magnet 20.

The support plates 65, 66 are annular plate members having openings 65a, 66a through which the shaft yoke 40 passes, and fix a plurality of axial support members 61, 62, 63, 64 at predetermined positions in the axial direction. It is In the illustrated example, the support plate 65 fixes the axial supports 61, 62, 63, 64 at the left end of the coil support 60, and the support plate 66 supports the axial support 61 at the right end of the coil support 60, Fix 62, 63, 64.
The support plates 65 and 66 have a plurality of (e.g., eight) holes in which the claw members of the axial supports 61, 62, 63 and 64 are fitted.

  In this case, the mover (coil 10 and coil support 60) is incorporated into the stator, for example, as follows. The coil support 60 is disposed with the spacers 67 and 67 in close contact with each other in the left and right direction of each coil 10, and is held by the axial supports 61, 62, 63 and 64 from the inside and the outside of each coil 10 It is assembled integrally with the coil 10. Here, the spacers 67, 67 are nonmagnetic materials that fill the gap between the two claws, for example, in order to prevent the coil 10 from shifting from the axial support 61. Then, the four axial supports 61, 62, 63, 64 assembled integrally with the respective coils 10 are respectively fitted in four gaps arranged 90.degree. Apart in the stator shown in FIG. Then, the left end and the right end of the axial supports 61, 62, 63, 64 are fitted in the holes of the two support plates 65, 66 from both sides in the axial direction (left and right direction) where the yoke of the stator is not disposed. Fix it.

  In the example shown in FIG. 5, in order to prevent breakage of the lead wire due to vibration, a braided wire is used at the contact portion between the coil 10 and an external circuit (not shown). That is, the left end of the conducting wire of the coil 10a is connected to the external circuit through a braided wire not shown, and the right end of the conducting wire of the coil 10a is connected to the left end of the conducting wire of the coil 10b. Further, the right end portion of the conductive wire of the coil 10b is connected to an external circuit through a braided wire not shown. Here, in order to connect two coils 10a and 10b in series, one coil may form two coils 10a and 10b.

<Operation>
The coil support 60 of the generator 1 is supported from both axial sides of the coil 10 by a support mechanism (not shown). Among them, one (for example, the left) support mechanism is provided with a drive shaft for reciprocating the coil support 60, and the other (for example, the right) support mechanism facilitates the reciprocation of the coil support 60. Bearings are provided. For example, when connected to a thermoacoustic engine, the drive shaft of one of the support mechanisms described above is a vibration unit constituted by a sound wave vibration output end of the thermoacoustic engine, that is, a piston provided in the vicinity of the tip of the resonance pipe. Directly connected to Here, the vibration unit is a member that reciprocates within the resonance tube when sonic vibration energy is applied.
Then, in the generator 1, the movable element reciprocates by vibrational energy, and as shown in FIGS. 4 and 6, the coils 10a and 10b move perpendicular to the magnetic field direction, according to Fleming's right-hand rule An electromotive force is generated at the linkage point, and power can be extracted from the coils 10a and 10b. The moving direction of the mover is the left and right direction in FIG. FIG. 4 illustrates the direction of the current when the coils 10a and 10b move leftward.

[Design Example of Generator Components]
As shown in FIG. 3, the inner diameter of the coil 10 is represented by the sum of the diameter φ1 of the axial yoke 40, the length twice the thickness T5 of the magnet 30, and the air gap. Here, the air gap is defined as a length obtained by subtracting the thickness of the coil from the distance between radial magnets T3. That is, assuming that the thickness of the coil is T4, the air gap G is expressed by the following equation (3).
G = T3-T4 ... Formula (3)
The inner diameter of the coil 10 is proportional to the wire length of one turn. When the inner diameter of the coil 10 is increased, the magnetic flux crossing the coil 10 is increased and the amount of power generation is increased. When the inter-magnet distance T3 is maintained at a predetermined value, the outer diameter of the outer stator is similarly increased when the inner diameter of the coil 10 is increased.

  When a flat wire is used as the conductive wire used for the coil 10, the space factor is improved as compared with the round wire. In a coil in which round wires are used for the windings (conductors), a gap is generated between the conductors, and the number of turns per volume becomes worse. On the other hand, the flat wire can be closely aligned, and there is no gap between the conducting wires, and the reduction in the number of turns can be suppressed. Moreover, since the unevenness | corrugation on the surface of a coil at the time of completion | finish of winding is lose | eliminated, an air gap can be shrink | contracted and it can install.

  When an aluminum wire is used as the wire used for the coil 10, the weight reduction is improved compared to a copper wire. The resistivity of an aluminum wire is about 1.6 times larger than that of a copper wire, but the specific gravity is as small as 30%, so the weight of the coil can be reduced to about half.

  The radial direction inter-magnet distance T3 was adjusted to a distance at which a desired magnetic flux density (for example, about 0.8 T or more) can be obtained between the radial direction magnets 20 and 30. The thickness T4 of the coil 10 and the air gap G were determined so as to satisfy the radial direction inter-magnet distance T3.

Furthermore, in the present embodiment, the width W of the magnet and the axial width (coil width w) of the coil are selected in order to prevent the mover from entering the reverse magnetic flux due to excessive movement. ing. That is, when the axial direction inter-magnet distance L and the one-sided amplitude l of the vibration of the coil are determined, the generator 1 is such that the width W of the magnet and the coil width w satisfy the relationship of the following formula (1) It is configured.
L l l + w / 2-W / 2 Formula (1)

  This holds true even if the width W of the magnet is equal to or less than the coil width w. However, when the width W of the magnet is smaller than the coil width w, part of the coil is out of the magnetic field before the mover starts to move. Also, if the width W of the magnet is the same as the coil width w, when the mover starts to move, a part of the coil starts to lose the magnetic field, and when the move distance of the mover reaches (W + w) / 2, the coil It does not interact with the magnetic field. If the magnetic field linked to the coil is small relative to the moving area, no electromotive force is generated because there is no magnetic field even if the speed at which power can be generated is high. The average power is low because the output occurs only when the coil reaches the magnetic field region.

Therefore, in order to increase the output, here, the width W of the magnet is made larger than the width w of the coil as shown in the drawing. In order to make the output a sinusoidal waveform, a magnetic field may be generated widely within the movable range. In order to generate a magnetic field widely in the movable range, the width W of the magnet was made wider than the half amplitude l of the vibration of the coil. The movable range is represented by the sum of the coil width w and the length (full amplitude) twice as large as the one-sided amplitude l of the coil vibration.
Table 1 shows an example of each parameter of the component of the generator and its value. The parameter values shown in Table 1 were used as set values in the simulation described later. The symbols representing the corresponding parameters are as shown in FIG. 2, FIG. 3 and FIG.

FIG. 6 is a view similar to FIG. 4, but hatching indicating a cross section is omitted to explain the displacement of the coil. FIG. 6 (b) is a diagram showing the case where the positions of the coils 10a and 10b are central positions of displacement. 6 (a) is a view showing a left end position displaced to the left (minus direction) by a displacement amount l (one amplitude l) from the coil position shown in FIG. 6 (b), and FIG. 6 (c) is a view It is a figure which shows the right end position displaced only the displacement amount 1 (one amplitude l) from the coil position shown to 6 (b) right (plus direction).
In the setting shown in Table 1, the width W of the magnet is set so as to be the sum of the coil width w and the length twice the half amplitude l (full amplitude). As a result, the output can be increased by preventing the situation where the coil 10 does not interlink with the magnetic field without the coil 10 losing the magnetic field during the reciprocating movement of the mover.

In the setting shown in Table 1, the material of the axial yoke 40 and the outer yoke 50 is iron.
In a general motor or generator, when the coil is wound around an iron core (core), the current direction or the magnetic flux direction of the coil crosses. In this case, iron loss (eddy current loss, hysteresis loss) occurs. Therefore, silicon steel plates (magnetic steel plates) are often used in motors and generators.
On the other hand, in the generator 1 of the present embodiment, the direction and strength of the magnetic flux of the stator (magnet and yoke) outside the coil 10 are always in a constant state without changing. That is, it can be said that the magnetic circuit is hard to change, and the magnetic field of the magnetic circuit is direct current. As described above, in the generator 1, no cross-over magnetic field is generated, so that the cost can be suppressed by using normal iron without using expensive silicon steel plates as in the setting shown in Table 1.

[simulation]
In order to confirm the performance of the generator 1 of the present embodiment, simulations of magnetic field analysis and transient response analysis were performed using electromagnetic field analysis software (JMAG (registered trademark): manufactured by JSOL Co., Ltd.).

<1. Magnetic field analysis>
A vector diagram of magnetic flux is shown in FIG. 7 based on the result of magnetic field analysis. 7 corresponds to the area of the upper half of the cross-sectional view of the generator 1 shown in FIG. 4, and the left-right direction of FIG. 7 corresponds to the left-right direction shown in FIG. The positions of the coils 10a and 10b are central positions of displacement as in FIG. 6 (b).

  In FIG. 7, a vector plot of magnetic flux density (small multiple arrows) indicates the strength of magnetic flux density by the size and color of the arrow, and indicates the direction of magnetic flux in the direction of the arrow. In this vector plot, the sizes of the arrows are, for example, red (1.5 T), orange (1.3 T), yellow (1.2 T), green (0.9 T), light blue (0.5 T), blue (0 .3 T), and then decreasing in the order of navy blue (0.1 T).

  In the vector plot, the direction of the magnetic field linked to the coil is perpendicular (up and down) to the direction of movement (left and right direction) from the direction of the arrow, and it passes through two coils 10 to form one magnetic It can be confirmed that a circuit is formed.

In the vector plot, it was found that the maximum value of the magnetic flux density is 2.1 T and the minimum value is 0.0076 T.
Among them, the magnetic flux density at the middle portion in the left and right direction of the inner stator was 1.5 T (red) on average, and it was confirmed that the magnetic saturation was able to be adjusted. Similarly, even in the outer stator, the magnetic flux density is as high as 1.5 T at high torque, and no saturation phenomenon occurs.
The magnetic flux density at the center point between the opposing outer magnet 20 and the inner magnet 30 was about 0.9 T (green).

Although illustration is omitted, when the position of the coils 10a and 10b is the left end position of the displacement as in FIG. 6A, the maximum value of the magnetic flux density is 2.0T and the minimum value is 0.014T.
Although not shown, when the positions of the coils 10a and 10b are at the right end position of the displacement as in FIG. 6C, the maximum value of the magnetic flux density is 2.1 T and the minimum value is 0.0087 T. . It was confirmed that the same magnetic circuit was formed regardless of the position of the coil 10 in any case.

<2. Transient response analysis>
The mover was reciprocated sinusoidally on the simulation. As the conditions at this time, the operating frequency is 60 Hz, and the one-sided amplitude l of the vibration of the coil is 12 mm.
Then, as shown in the circuit diagram of FIG. 8A, an external load is connected to both ends of the entire coil consisting of two coils 10a and 10b connected in series in the generator 1, and an ammeter and a voltmeter are Connection was made, and the output was calculated from the current flowing at this time. The two coils 10a and 10b have different winding directions. The generator 1 shown by a broken line in FIG. 8A can be represented by an electromotive force E and an internal resistance (resistance value r) in the equivalent circuit shown in FIG. 8B. As shown in Table 1, the resistance value r was 0.585 Ω.

The characteristics when load resistances of resistance value R _L = 0.585 Ω, 2.34 Ω and 5.265 Ω were respectively connected as external loads were calculated from transient response analysis. The results are shown in FIG.

When a load resistance of resistance value R _L = 0.585Ω is connected, the resistance value is the same as the resistance value r of the internal resistance, so the maximum output is obtained, and the position of the coil 10 is the center position of displacement (FIG. 6 (b) When it is reference), the amplitude of the output waveform became maximum, and when it was this maximum value, it became 1730 W. Since the operating frequency is 60 Hz in this example, the period is about 0.017 seconds. Therefore, for example, when the position of the coil 10 is at the left end position of the displacement when the output 0 W is about 0.013 seconds (see FIG. 6A), then the output 0 W is about 0.022 seconds. The position of the coil 10 is the right end position of the displacement (see FIG. 6C), and the position of the coil 10 is returned to the left end position of the displacement at about 0.03 seconds when the output is 0 W next. It will be.
When a load resistance of resistance value R _L = 2.34 Ω was connected, the maximum value was 1230 W at the maximum value.
When the load resistance of resistance value R _L = 5.265 Ω was connected, it became 700 W at the maximum amplitude value.

  As shown in Table 1, the weight of the two coils is 170 g, and even the mover including the coil support 60 is lightweight, so that it vibrates at an operating frequency of 60 Hz or more in the thermoacoustic engine as well. Can.

  As described above, in the generator 1 according to the embodiment of the present invention, since both ends in the axial direction of the coil 10 are opened without providing a yoke or the like, heat generation of the coil and the magnetic circuit can be dissipated by natural cooling. In addition, since the generator 1 does not require the yoke at both axial ends of the coil 10, the entire device is also lighter than in the past. The generator 1 is free from iron loss in the magnetic circuit and free from cogging.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to this. For example, although four magnets 20 and 30 are disposed for each coil 10 and shifted by 90 ° so as to surround the coil 10 in the circumferential direction, the number of magnets disposed surrounding the coil 10 is It is sufficient if it is two or more. When a coil support as shown in FIG. 5 is used, three or more are preferable in consideration of balance. Further, the angular range θ in which the magnet is disposed may be determined so that the wire usage rate η is at least 50% or more.

Further, the angular range θ in which the magnet is disposed may be 360 °. That is, for each coil 10, one annular magnet 20, 30 may be used so as to surround the entire circumference of the coil 10. This annular shape increases cost as compared with the case of the angular range θ <360 °, but increases the volume of the magnet, so that the magnetic flux increases and the power generation output can be increased.
Also, in the case of the angular range θ = 360 °, the coil support is not the structure shown in FIG. 5, but instead is, for example, a cylindrical nonmagnetic body, and a plurality of coils 10 are separated by a predetermined width Bobbins that can be fixed to

Also, the coil support is not limited to that shown in FIG. The coil support may be formed of a nonmagnetic material and has a degree of axial movement, so long as the coil 10 can be fixed in the space. For example, the entire coil 10 is made of a heat-resistant resin You may form by solidifying in a cylindrical shape.
Further, in the coil support, an air-cooling splash may be provided at at least one end in the coil driving direction to enhance the cooling function.

Further, as long as the coil 10a and the coil 10b can be joined together, they may be connected not only in series but also in parallel.
Moreover, although the generator 1 used two sets of coils 10a and 10b as the several coil 10, you may use three sets of coils and a coil of four or more sets. When the coil 10 is thus connected in multiples of three or more, the magnets 20 and 30 may be increased in the axial direction according to the number of coils. In FIG. 10, the generator 1B using 4 series coil 10a, 10b, 10c, 10d as an example was shown. FIG. 10 is a drawing corresponding to FIG. In the generator 1B, a unit structure including a coil 10, a magnet 20 disposed on the outer side of the coil 10, and a magnet 30 disposed on the inner side of the coil 10 extends in the axial direction of the coil. It is arranged in four rows. A magnetic circuit similar to the magnetic circuit shown in FIG. 4 is formed by the two unit configurations adjacent in the axial direction of the coil. For example, in the unit configuration including the coil 10c and the unit configuration including the coil 10d, a loop in the same direction as the magnetic circuit shown in FIG. 4 is formed, and in the unit configuration including the coil 10b and the unit configuration including the coil 10c, FIG. A loop is formed in the opposite direction to the illustrated magnetic circuit. When the coil 10 is connected in multiples of three or more in this way, the weight of the mover increases as compared with the case where two or more coils 10 are used, but the output is increased by the amount by which the coil is increased. be able to.

  Moreover, the cross-sectional shape of the axial yoke 40 is not limited to the illustrated circular shape, and may be an elliptical shape or a polygonal shape. Similarly, the cross-sectional shape of the outer yoke 50 is not limited to the illustrated annular ring, and may be an annular shape based on an oval or a polygon. When the cross-sectional shape of the outer yoke 50 is such a shape, the shape of the coil 10 is based on an oval or a polygon as in the cross-sectional shape of the outer yoke 50 instead of the shape of the annular ring shown in FIG. It does not matter if it has an annular shape.

  Also, the vibration source (vibration source) of the generator is not limited to the thermoacoustic engine. A generator may, for example, be incorporated into the suspension of the vehicle volume to generate electricity by its vibration. For example, the generator may be floated on the sea to generate electric power by wave power or the like. A generator may be installed, for example, on a bridge girder to generate power by vibration of the bridge girder.

1 generator 10, 10a, 10b coil 20 outer magnet 30 inner magnet 40 axial yoke 50 outer yoke 60 coil support 61, 62, 63, 64 axial support 65, 66 support disc 65a, 66a opening 67 spacer

Claims (6)

A generator wherein the coil is linearly driven to generate electric power so that at least a part of the coil interlinks with a magnetic field generated within a movable range of the coreless coil,
A plurality of coils connected electrically,
A coil support made of nonmagnetic material for supporting the plurality of coils apart from each other;
And yokes respectively disposed on the inner side and the outer side in the circumferential direction of each of the coils .
The coil support supports the plurality of coils in the axial direction of the coil,
For each of the coils, a magnetic field directed inward from the outer side of the circumferential direction of the coil in a direction intersecting with one region of the coil, and from the inner side to the outer direction of the coil in the circumferential direction Generating an alternating magnetic field within the movable range of the coil,
In the two opposing coils, the direction of the magnetic field generated in the predetermined area of one coil and the direction of the magnetic field generated in the predetermined area of the other coil opposed to the predetermined area of the one coil are opposite to each other And
The plurality of magnetic fields are stationary, and a plurality of looped magnetic circuits are formed by magnetic fields in which the directions of the adjacent magnetic fields alternate with each other,
The yoke is
Column-shaped axial yokes disposed on the inner side in the circumferential direction of the respective coils,
An outer yoke formed in a cylindrical shape so as to surround the axial yoke in the circumferential direction and disposed outside the circumferential direction of each coil, and the axial ends of the coil are open;
A generator characterized in that each of the coils supported by the coil support drives power in the magnetic field in the axial direction of the coil.   The generator according to claim 1, wherein power is generated at a frequency equivalent to the vibration frequency of the coil. As a means for generating a magnetic field within the movable range of the coil,
An outer magnet disposed on the outside of each of the coils;
And an inner magnet respectively disposed inside the coils.
The inner magnet is fixed to the axial yoke so as to face the outer magnet ,
Wherein the outer yoke, between which the outer magnet is opposed at a position opposed to the inner magnet is fixed so as to be different polarities,
The two axially adjacent outer magnets are arranged such that their polarities are opposite to each other,
The generator according to claim 1, wherein the outer magnet is disposed to surround the coil in a circumferential direction. The outer yoke is formed in a tubular shape so as to surround the axial yoke in the circumferential direction,
The outer magnet is formed of a predetermined number of magnets surrounding the inner circumferential surface of the outer yoke at a first predetermined interval in the circumferential direction,
4. The generator according to claim 3, wherein the inner magnet is formed of the same number of magnets as the predetermined number surrounding the outer peripheral surface of the axial yoke at a second predetermined interval in the circumferential direction. The distance between two magnetic fields adjacent to each other in the axial direction of the coil and in which the direction of the magnetic field is opposite to each other is a desired length L (L> 0), and the amplitude of the vibration of each coil is When it is determined as l, the width W of the magnetic field in the axial direction of the coil and the width w in the axial direction of each coil satisfy the relationship of the following formula (1): The generator according to any one of claims 1 to 4, wherein the generator is characterized.
L l l + w / 2-W / 2 Formula (1) A generator wherein the coil is linearly driven to generate electric power so that at least a part of the coil interlinks with a magnetic field generated within a movable range of the coreless coil,
A plurality of coils connected electrically,
A coil support made of a nonmagnetic material for supporting the plurality of coils apart from each other;
The coil support supports the plurality of coils in the axial direction of the coil,
For each of the coils, a magnetic field directed inward from the outer side of the circumferential direction of the coil in a direction intersecting with one region of the coil, and from the inner side to the outer direction of the coil in the circumferential direction Generating an alternating magnetic field within the movable range of the coil,
In the two opposing coils, the direction of the magnetic field generated in the predetermined area of one coil and the direction of the magnetic field generated in the predetermined area of the other coil opposed to the predetermined area of the one coil are opposite to each other And
The plurality of magnetic fields are stationary, and a plurality of looped magnetic circuits are formed by magnetic fields in which the directions of the adjacent magnetic fields alternate with each other,
Each of the coils supported by the coil support generates power by driving in the magnetic field in the axial direction of the coil,
  As a means for generating a magnetic field within the movable range of the coil,
  An outer magnet disposed on the outside of each of the coils;
And an inner magnet respectively disposed inside the coils.
A columnar axial yoke fixed so that the inner magnet faces the outer magnet;
And an outer yoke fixed such that the opposite magnets face each other at the position where the outer magnet faces the inner magnet.
The two axially adjacent outer magnets are arranged such that their polarities are opposite to each other,
The outer magnet is disposed so as to circumferentially surround the coil.
The outer yoke is formed in a tubular shape so as to surround the axial yoke in the circumferential direction,
The outer magnet is formed of a predetermined number of magnets surrounding the inner circumferential surface of the outer yoke at a first predetermined interval in the circumferential direction,
The generator according to claim 1, wherein the inner magnet is formed of the same number of magnets as the predetermined number surrounding the outer peripheral surface of the axial yoke at a second predetermined interval in the circumferential direction.