Power generation equipment

Abstract

This power generation device comprises a coil, a magnet, and a vibrating plate. The magnet is provided at a position separated from the coil, and is disposed such that pole faces thereof are oriented to the direction of the coil. The vibrating plate vibrates upon reception of sound waves, and has disposed thereon either the coil or the magnet. The vibrating plate changes, by vibration thereof, the relative position of the coil and the magnet and causes a change in magnetic field of the coil, to thereby cause the coil to generate electromotive force, whereby electric power is generated.

Description

[Technical field]

[0001] The present invention relates to a power generation device that generates electricity from sound. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a power generating device that generates power by changing the magnetic flux of a coil by changing the relative position between a permanent magnet and a coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-32732 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional technology has focused on generating electricity from mechanical movements such as rotational motion, and there is room for improvement in terms of efficiently generating electricity from sound.

[0005] The present invention has been made in consideration of the above, and has an object to provide a power generation device that can efficiently generate power from voice. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the object, the power generating device according to the present invention includes a coil, a magnet, and a diaphragm. The magnet is provided at a position separated from the coil, and is arranged with its magnetic pole surface facing the direction of the coil. The diaphragm is a diaphragm that vibrates in response to sound waves, and either the coil or the magnet is installed on the diaphragm. The diaphragm generates power by generating an electromotive force in the coil due to a change in the magnetic field of the coil caused by a change in the relative positions of the coil and the magnet due to vibration. Effect of the Invention

[0007] According to the present invention, power can be generated efficiently from voice. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 1A is a diagram illustrating an example of the overall configuration of a power generating device according to an embodiment. [Figure 1B] FIG. 1B is a diagram illustrating an example of the overall configuration of a power generating device according to an embodiment. [Diagram 2] FIG. 2 is an explanatory diagram for explaining the power generation principle of the power generation device. [Diagram 3] FIG. 3 is an explanatory diagram for explaining the power generation principle of the power generation device. [Figure 4] FIG. 4 is a diagram showing a configuration example of a power generating device according to a modified example. [Diagram 5] FIG. 5 is a diagram showing a configuration example of a power generating device according to a modified example. [Figure 6] FIG. 6 is a diagram showing an example of the configuration of a power generating device according to a modified example. [Figure 7] FIG. 7 is a diagram showing a configuration example of a power generating device according to a modified example. [Figure 8] FIG. 8 is a diagram showing an example of the configuration of a power generating device according to a modified example. [Figure 9] FIG. 9 is a diagram showing a configuration example of a power generating device according to a modified example. [Figure 10] FIG. 10 is a diagram showing an example of the configuration of a magnet according to a modified example. [Figure 11] FIG. 11 is a diagram showing an example of the configuration of a magnet according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the power generating device disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiment described below.

[0010] First, an example of the overall configuration of a power generating device according to an embodiment will be described with reference to Fig. 1A and Fig. 1B. Fig. 1A and Fig. 1B are diagrams showing an example of the overall configuration of a power generating device according to an embodiment. Fig. 1A shows a side view of the power generating device 1, and Fig. 1B shows an exploded perspective view of the power generating device 1.

[0011] 1A and 1B, the power generating device 1 according to the embodiment includes a first diaphragm 2a, a second diaphragm 2b, a first coil 3a, a second coil 3b, a magnet 4, a fixed plate 5, and a chassis 10. In the following description, the first diaphragm 2a and the second diaphragm 2b may be collectively referred to as diaphragm 2, and the first coil 3a and the second coil 3b may be collectively referred to as coil 3.

[0012] The diaphragm 2 is a vibrating member that vibrates upon receiving sound waves, and in the present disclosure is configured in a thin, substantially square shape. In addition, both ends of the outer periphery of the diaphragm 2 are fixed to the side wall 50 of the chassis 10 by a fixing member such as an adhesive. Specifically, the diaphragm 2 is fixed so as to be in a flat state (the state shown in FIG. 1A) when it is not receiving sound waves. The diaphragm 2 is formed, for example, from a thin plate (film) such as paper or resin having appropriate rigidity and elasticity properties.

[0013] 1A, the diaphragm 2 is arranged such that the first diaphragm 2a and the second diaphragm 2b face each other. An internal space SP surrounded by the first diaphragm 2a, the second diaphragm 2b, and the sidewall 50 is sealed. That is, a sealed space is formed by the first diaphragm 2a and the second diaphragm 2b.

[0014] 1A shows an example in which the first diaphragm 2a and the second diaphragm 2b are arranged facing each other with the magnet 4 in between, but only one of the first diaphragm 2a and the second diaphragm 2b may be arranged as long as the internal space is an enclosed space. In other words, the diaphragm 2 may be composed of two diaphragms or one diaphragm.

[0015] The coils 3 are provided on each diaphragm 2 and are formed, for example, by embedding a metal conductor such as copper in the diaphragm 2, or by printing a conductive material on the diaphragm 2. Specifically, the coils 3 are arranged such that the first coil 3a is disposed in the center of the first diaphragm 2a, and the second coil 3b is disposed in the center of the second diaphragm 2b.

[0016] The magnet 4 is, for example, a permanent magnet such as a neodymium magnet. The magnet 4 is provided at a position spaced apart from the coil 3 in the vibration direction of the diaphragm 2, with the magnetic pole face facing the direction of the coil 3. The magnet 4 is also disposed at a position where the distance from the first coil 3a and the distance from the second coil 3b are equal. Both ends of the outer circumferential end of the magnet 4 are fixed to the fixing plate 5 by a fixing member made of adhesive. Both ends of the outer circumferential end of the magnet 4 may be fitted and fixed to the fixing plate 5.

[0017] The positional relationship between the coil 3 and the magnet 4 may be reversed. That is, the magnet 4 may be provided on each diaphragm 2, and the coil 3 may be fixed to the fixed plate 5. In this case, the polarities of the magnets 4 may be either with the same polarity facing each other or with opposite polarity facing each other, but considering that it is better for the magnetic flux change in the coil 3 to be large when the diaphragm 2 vibrates, it is preferable to install the magnets 4 on each diaphragm 2 with the same polarity facing each other.

[0018] The fixed plate 5 is a plate-like member to which the magnet 4 is fixed, and is disposed at a position spaced apart from the coil 3 in the vibration direction of the diaphragm 2. As shown in Fig. 1A, the fixed plate 5 is disposed between the first diaphragm 2a and the second diaphragm 2b, facing each of the diaphragms 2.

[0019] For example, both ends of the outer circumferential end of the fixed plate 5 are fixed to the side walls 50. The fixed plate 5 is made of a rigid material such as a resin material. The fixed plate 5 also has holes 51. In FIG. 1B, the fixed plate 5 has four holes 51 formed therein so as to be point symmetrical with respect to the magnet 4.

[0020] Specifically, the fixed plate 5 has a hole 51 that makes the internal space SP, which is a sealed space, an integrated space that is in contact with both the first diaphragm 2a and the second diaphragm 2b.

[0021] The chassis 10 is a fixing member that fixes the diaphragm 2 and the fixed plate 5 to the side wall 50. The chassis 10 is made of a rigid material such as resin or non-(low-)magnetic metal. In the present disclosure, the chassis 10 is formed by stacking an upper chassis 10a and a lower chassis 10b.

[0022] The inner periphery of the upper chassis 10a to which the first diaphragm 2a is fixed is recessed by the thickness of the first diaphragm 2a, forming a stepped shape. The first diaphragm 2a is bonded and fixed in place in a state where it fits into this stepped shape.

[0023] The lower chassis 10b has an inner periphery to which the fixing plate 5 is fixed, which is recessed by the thickness of the fixing plate 5, and is thus formed in a stepped shape. The fixing plate 5 is adhesively fixed in a state where it fits into this stepped shape. In other words, the fixing plate 5 is fixed to a side wall 50 of the lower chassis 10b. The lower chassis 10b has an inner periphery to which the second diaphragm 2b is fixed, which is recessed by the thickness of the second diaphragm 2b, and is thus formed in a stepped shape. The second diaphragm 2b is adhesively fixed in a state where it fits into this stepped shape.

[0024] Furthermore, the opposing surfaces of the upper chassis 10a and the lower chassis 10b are provided with either a positioning protrusion 52 or a positioning hole 53. This allows the upper chassis 10a and the lower chassis 10b to be easily positioned by fitting the protrusion 52 into the positioning hole 53 during manufacturing.

[0025] In this disclosure, an example in which the chassis 10 is composed of two members, the upper chassis 10a and the lower chassis 10b, has been shown, but the chassis 10 may be composed of one member. In such a case, this can be realized by providing a stepped shape for fixing the first diaphragm 2a and the second diaphragm 2b at both ends of the chassis 10, and a recess for fixing the fixing plate 5 at the center inside the side wall.

[0026] Here, the power generation principle of the power generation device 1 according to the embodiment will be described with reference to Fig. 2 and Fig. 3. Fig. 2 and Fig. 3 are explanatory diagrams for explaining the power generation principle of the power generation device 1. Note that various sound generating objects are assumed as the sound source shown in Fig. 2. For example, when installing the power generation device 1 in a vehicle, it is preferable to set an object sound source that constantly generates sound in the vehicle, such as an engine, and install the power generation device 1 in an appropriate position (position with good power generation efficiency) and in an appropriate state (state (direction, etc.) with good power generation efficiency) relative to the object sound source.

[0027] As shown in Fig. 2, first, the diaphragm 2 vibrates upon receiving sound waves from a sound source. In Fig. 2, sound waves from the sound source, i.e., air pressure fluctuations (air density changes), are propagated to the first diaphragm 2a, causing the air pressure on the sound source side of the first diaphragm 2a to fluctuate. Then, the first diaphragm 2a vibrates due to the air pressure fluctuations on the sound source side of the first diaphragm 2a.

[0028] Thereafter, the vibration of the first diaphragm 2a generates an air pressure fluctuation on the side of the first diaphragm 2a opposite to the sound source, and the air pressure fluctuation passes through the internal space SP of the power generating device 1, that is, through the hole 51 of the fixed plate 5, and is propagated to the second diaphragm 2b. The air pressure fluctuation propagated to the second diaphragm 2b causes the air pressure on the sound source side of the second diaphragm 2b to fluctuate, causing the second diaphragm 2b to vibrate. Note that the internal space SP does not need to be completely sealed, and it is sufficient that the air pressure fluctuation is sufficiently sealed to be propagated to the second diaphragm 2b.

[0029] That is, as shown in Fig. 2, when the first diaphragm 2a is curved to be convex toward the sound source side, the second diaphragm 2b is also curved to be convex toward the sound source side. Also, when the first diaphragm 2a is curved to be concave toward the sound source side, the second diaphragm 2b is also curved to be concave toward the sound source side.

[0030] As a result, the sound waves from the sound source vibrate the first diaphragm 2a, changing the relative position between the first coil 3a and the magnet 4. This causes a change in magnetic flux in the area of ​​the first coil 3a, which generates an electromotive force in the first coil 3a, generating electricity. The air pressure fluctuation caused by the vibration of the first diaphragm 2a is propagated to the second diaphragm 2b, which vibrates and changes the relative position between the second coil 3b and the magnet 4. This causes a change in magnetic flux in the area of ​​the second coil 3b, which generates an electromotive force in the second coil 3b, generating electricity.

[0031] Therefore, according to the power generation device 1 of this embodiment, power is generated in the first coil 3a and the second coil 3b by sound waves from the sound source, and power can be generated efficiently from sound.

[0032] Next, the principle of doubling the generated voltage by generating the voltage in the first coil 3a and the voltage in the second coil 3b in the same phase will be described with reference to FIG. 1B. As shown in FIG. 1B, the first coil 3a and the second coil 3b are wound clockwise from the outside to the inside as viewed from above. The first coil 3a and the second coil 3b are connected to the terminals 21a and 21b on the left side of the figure, and the terminals 20a and 20b on the right side of the figure are connected to the power output terminals 22a and 22b, respectively. The output terminals 22a and 22b are connected to a device (such as a storage battery) to which the power is output. The magnet 4 is installed with the north pole on the upper side of the figure and the south pole on the lower side.

[0033] In this case, when the first diaphragm 2a is curved and concave toward the sound source side, the upward magnetic field lines are strengthened as the first coil 3a approaches the magnet 4. When the second diaphragm 2b is curved and concave toward the sound source side, the second coil 3b moves away from the magnet 4, and the upward magnetic field lines are weakened.

[0034] As a result, in the first coil 3a, a current flows in the direction in which the downward magnetic lines of force are generated. That is, an electromotive force is generated so that the current flows from the terminal 21a of the first coil 3a to the terminal 20a of the first coil 3a. In addition, in the second coil 3b, a current flows in the direction in which the upward magnetic lines of force are generated. That is, an electromotive force is generated so that the current flows from the terminal 20b of the second coil 3b to the terminal 21b of the second coil 3b. Therefore, between the output terminal 22a and the output terminal 22b, there are two coils (the first coil 3a and the second coil 3b) connected in series that generate electromotive forces of the same polarity, and the sum of the voltages of the electromotive forces of both coils is generated between the output terminal 22a and the output terminal 22b. In this case, the output terminal 22a has a positive polarity, and the output terminal 22b has a negative polarity.

[0035] Furthermore, when the first diaphragm 2a is curved and convex toward the sound source side, the upward magnetic field lines are weakened as the first coil 3a moves away from the magnet 4. When the second diaphragm 2b is curved and convex toward the sound source side, the second coil 3b moves closer to the magnet 4, and the upward magnetic field lines are strengthened.

[0036] As a result, in the first coil 3a, a current flows in the direction in which the upward magnetic field lines are generated. That is, an electromotive force is generated so that the current flows from the terminal 20a of the first coil 3a to the terminal 21a of the first coil. In addition, in the second coil 3b, a current flows in the direction in which the downward magnetic field lines are generated. That is, an electromotive force is generated so that the current flows from the terminal 21b of the second coil 3b to the terminal 20b of the second coil. Therefore, between the output terminal 22a and the output terminal 22b, there are two coils (the first coil 3a and the second coil 3b) connected in series and generating electromotive forces of the same polarity, and the sum of the voltages of the electromotive forces of both coils is generated between the output terminal 22a and the output terminal 22b. In this case, the output terminal 22a has a negative polarity, and the output terminal 22b has a positive polarity.

[0037] In other words, by setting the winding direction of the first coil 3a and the second coil 3b and the connection relationship between the terminals of the first coil 3a and the second coil 3b so that the currents generated in the first coil 3a and the second coil 3b are in the same direction when the diaphragm vibrates, the sum of the electromotive forces in the first coil 3a and the second coil 3b can be made the output voltage, and as a result, the power generation efficiency can be improved.

[0038] In the above-described embodiment, as shown in Fig. 1A, the coil 3 and the magnet 4 are arranged in parallel with their respective central axes C aligned, but the coil 3 and the magnet 4 may be arranged in a positional relationship in which their respective central axes C are not aligned. This point will be described with reference to Figs. 4 to 6.

[0039] It should be noted that central axis C is the central axis in terms of magnetic characteristics (for example, in the case of a magnet, the central axis of magnetic flux). In the example of FIG. 1A, since coil 3 is toric, its central axis C is a straight line extending perpendicular to the plane of the ring that passes through the center of the ring, and since magnet 4 is cylindrical, its central axis C is the axis of the cylinder.

[0040] 4 to 6 are diagrams showing configuration examples of the power generating device 1 according to the modified example. In addition, in Fig. 4 to Fig. 6, a case where a magnet 4 is provided on a diaphragm 2 and a coil 3 is fixed to a fixed plate 5 is taken as an example.

[0041] In Figures 4 to 6, the diaphragm 2 and magnet 4 are shown by solid lines when the diaphragm 2 is in a reference state (a state in which no sound waves are applied), and the diaphragm 2 and magnet 4 are shown by dashed lines after movement from the reference state (a state in which sound waves are applied).

[0042] First, FIG. 4 shows an example in which magnet 4 is fixed to diaphragm 2 in a state inclined with respect to coil 3. In FIG.

[0043] 4, magnet 4 is fixed to an inclined surface (inclined with respect to diaphragm 2) of spacer 6 fixed to diaphragm 2. In other words, spacer 6 has a structure in which the fixed surface with magnet 4 is inclined with respect to the fixed surface with diaphragm 2. Specifically, spacer 6 has a shape obtained by cutting a cylinder with the same diameter as magnet 4 obliquely, and magnet 4 is fixed to a surface of spacer 6 other than the cut surface, and the cut surface of spacer 6 is fixed to diaphragm 2.

[0044] Furthermore, the inclination angle of the spacer 6 (the inclination angle of the magnet 4) is set so that the axis of the central axis of the magnet 4 passes through the center of gravity P of the coil 3 when the diaphragm 2 is in the reference state. This makes it possible to make the diaphragm 2 symmetrical with respect to its movement in both the up and down directions.

[0045] As a result, the central axis C of the magnet 4 is misaligned with the vibration direction of the diaphragm 2. In other words, the orientation of the central axis C of the magnet 4 differs from the vibration direction of the diaphragm 2.

[0046] In other words, the coil 3 and the magnet 4 are in a positional relationship in which their respective central axes are not aligned. When the diaphragm 2 vibrates, the magnet 4 changes position in the vibration direction while being tilted. As a result, the central axis of the magnetic flux of the coil 3 is misaligned with the central axis of the coil 3.

[0047] 4, the coil 3 is displaced by Δr from the central axis in the planar direction of the magnet 4 in accordance with the vibration of the diaphragm 2. As a result, a change in magnetic flux Δφr occurs due to the displacement of Δr.

[0048] 4, the distance between magnet 4 and coil 3 changes by Δd in accordance with the vibration of diaphragm 2. As a result, a change in Δd generates a change in magnetic flux Δφd.

[0049] In this way, changes in Δφr and Δφd occur in the magnetic flux passing through the coil 3, and the generated voltage can be increased by increasing the change in magnetic flux, thereby improving the power generation efficiency.

[0050] 5 shows an example in which the coil 3 and magnet 4 are fixed in a tilted state with respect to the diaphragm 2. Specifically, the magnet 4 is fixed to a tilted surface of the spacer 6 with respect to the diaphragm 2. In other words, the spacer 6 has a structure in which the fixing surface with the magnet 4 is tilted with respect to the fixing surface with the diaphragm 2. Specifically, the spacer 6 has a shape obtained by cutting a cylinder with the same diameter as the magnet 4 obliquely, and the magnet 4 is fixed to a surface of the spacer 6 other than the cut surface, and the cut surface of the spacer 6 is fixed to the diaphragm 2.

[0051] Moreover, the coil 3 is fixed to an inclined mounting hole 71 of a spacer 7 relative to the fixed plate 5 (i.e., the diaphragm 2).

[0052] Specifically, the spacer 7 has a fixing hole 71 into which the coil 3 is inserted and fixed, and the fixing hole 71 is a hole that is inclined with respect to the thickness direction of the fixing plate 5. Therefore, by fixing the spacer 7 so that its planar direction is aligned with the fixing plate 5, and inserting and fixing the coil 3 into the fixing hole 71 of the spacer 7, the coil 3 is fixed with respect to the diaphragm 2 such that the coil plane and the diaphragm plane are inclined.

[0053] Furthermore, the spacer 7 (fixing hole 71) is formed so that the coil 3 is approximately parallel to the magnetic pole surface of the magnet 4. Furthermore, the coil 3 and the magnet 4 are arranged so that their central axes are aligned when the diaphragm 2 is in the reference state. In other words, when the diaphragm 2 is in the reference state, the magnet 4 is arranged so that the central axis C passes through the center of gravity P of the coil 3.

[0054] As a result, the central axes of the coil 3 and the magnet 4 are misaligned with respect to the vibration direction of the diaphragm 2, and the central axes of the coil 3 and the magnet 4 are oriented in the same direction.

[0055] When the diaphragm 2 vibrates, the magnet 4 changes position in the vibration direction while remaining tilted. As a result, the positional relationship between the coil 3 and the magnet 4 changes while maintaining a parallel relationship about their respective central axes. Specifically, a Δr change (positional displacement) occurs in the magnet 4 in the planar direction of the magnetic pole face as the diaphragm 2 vibrates.

[0056] As a result, a change in magnetic flux Δφr occurs due to the deviation of Δr.

[0057] As shown in Fig. 5, the distance between the magnet 4 and the coil 3 changes by Δd as the diaphragm 2 vibrates. As a result, a change in magnetic flux Δφd occurs due to the change in Δd. In this way, the magnetic flux passing through the coil 3 changes by Δφr and Δφd, and the increased change in magnetic flux increases the generated voltage. In other words, the power generation efficiency can be increased.

[0058] Next, FIG. 6 shows an example in which one end of the diaphragm 2 is fixed. Specifically, one end of the diaphragm 2 is fixed by being sandwiched by a reinforcing plate 9. The reinforcing plate 9 is, for example, a plate-shaped member made of a resin material or a metal material having rigidity. In this case, when the diaphragm 2 receives sound waves, the other end of the diaphragm 2 vibrates in the rotation direction (vibration direction) with the fixed end as an axis. That is, the other end of the diaphragm 2 swings. As a result, the end of the magnet 4 located on the other end side of the diaphragm 2 changes position in the rotation direction due to vibration. That is, the magnet 4 also swings with respect to the vibration of the diaphragm 2. In addition, the coil 3 and the magnet 4 are arranged so that their central axes are aligned when the diaphragm 2 is in the reference state. In other words, when the diaphragm 2 is in the reference state, the magnet 4 is arranged so that the central axis C of the magnet 4 passes through the center of gravity P of the coil 3.

[0059] Then, the central axis C of the magnet 4 is shifted from the central axis of the coil 3 by the rotation (oscillation) angle associated with the vibration. Specifically, when the diaphragm 2 oscillates by Δθ, the central axis C of the magnet 4 is shifted from the central axis of the coil 3 by Δθ.

[0060] As a result, a change in magnetic flux Δφθ occurs due to the deviation of Δθ.

[0061] As shown in Fig. 6, the distance between the magnet 4 and the coil 3 changes by Δd as the diaphragm 2 vibrates. As a result, a change in magnetic flux Δφd occurs due to the change in Δd. In this way, the magnetic flux passing through the coil 3 changes by Δφr and Δφd, and the increased change in magnetic flux increases the generated voltage. In other words, the power generation efficiency can be increased.

[0062] Next, as another modified example, a configuration example in which power generation efficiency is improved by utilizing the characteristics of the magnetic flux density distribution of magnet 4 will be described with reference to Fig. 7 to Fig. 9. Fig. 7 to Fig. 9 are diagrams showing a configuration example of power generation device 1 according to a modified example.

[0063] First, the magnetic flux density distribution of magnet 4 will be described with reference to Fig. 7. In Fig. 7, the top surface of magnet 4 is the N pole and the bottom surface is the S pole, and for ease of understanding, the top half of magnet 4 is depicted as the N pole 41 and the bottom half as the S pole 42 (an example of the second polarity).

[0064] As shown in Fig. 7, the magnetic flux density distribution 100a on the main surface side of the N pole 41 is generally a bimodal distribution. Specifically, the magnetic flux density distribution 100a has a distribution shape in which the density is high near both ends in the width direction (perpendicular to the thickness direction) of the magnet 4 and the density change is also large. In other words, the magnet 4 has a distribution characteristic in which the magnetic flux density is higher near both ends in the width direction than in the center, and the change is also large. The magnetic flux density distribution on the main surface side of the S pole 42 has the same characteristics as the magnetic flux density distribution 100a on the main surface side of the N pole 41.

[0065] Therefore, the power generating device 1 of the modified example shown in Figs. 8 and 9 focuses on this distribution characteristic and is configured so that the coil 3 moves by passing near both ends in the width direction of the magnet 4 where the magnetic flux density is high.

[0066] First, the configuration of the power generating device 1 shown in Fig. 8 will be described. As shown in Fig. 8, the first coil 3a is fixed to the center of the first side wall 50a of the chassis 10 of the power generating device 1, and the second coil 3b is fixed to the center of the second side wall 50b facing the first side wall 50a of the chassis 10, by an adhesive or the like.

[0067] The first coil 3a is fixed to the first side wall 50a so that the normal to its opening is in the same direction as the normal to the plane of the first side wall 50a, and the second coil 3b is fixed to the first side wall 50a so that the normal to its opening is in the same direction as the normal to the plane of the second side wall 50b.

[0068] The chassis 10 is a rectangular tube with a square cross section, and the outer peripheral edges of the first diaphragm 2a and the second diaphragm 2b are attached to both openings with an adhesive or the like, so that the chassis 10 is in a substantially sealed state. The first diaphragm 2a and the second diaphragm 2b are made of thin plates such as paper or resin that have appropriate rigidity, elasticity, and sealing properties suitable for vibration.

[0069] The magnet 4 is fixed to the first diaphragm 2a and the second diaphragm 2b so that the normal of its magnetic pole face (the main face of the N pole 41 and the main face of the S pole 42) is in the same direction as the normal of the opening faces of the first coil 3a and the second coil 3b (and also in the same direction as the normal of the second coil 3b). In other words, the magnet 4 is fixed to the first diaphragm 2a and the second diaphragm 2b so that the magnetic pole face faces in a direction perpendicular to the vibration direction of the diaphragm 2. The first coil 3a and the second coil 3b are also placed in positions facing the magnetic pole faces of the magnet 4.

[0070] In addition, the magnet 4 is fixed so that the center of the magnet 4 is located on a straight line passing through the center of the opening surface of the first coil 3a and the second coil 3b when the first diaphragm 2a and the second diaphragm 2b are in the reference state (when sound waves are not applied to the first diaphragm 2a and the second diaphragm 2b). Furthermore, the size (and shape) of the magnet 4 is determined so that the outer periphery of the opening surface of the first coil 3a and the second coil 3b faces the vicinity of the outer periphery of the magnet 4 when the first diaphragm 2a and the second diaphragm 2b are in the reference state. In other words, the position, size, and shape of the magnet 4 are determined, and the positions of the first coil 3a and the second coil 3b are determined so that the conductor parts of the first coil 3a and the second coil 3b are located in an area where the magnetic flux density by the magnet 4 is high and the change in magnetic flux density (the change in magnetic flux density relative to the change in position) is large when the first diaphragm 2a and the second diaphragm 2b are in the reference state.

[0071] A specific fixing structure of the magnet 4 is a structure in which the side of the magnet 4 is fixed with an adhesive or the like to a first spacer 6a fixed with an adhesive or the like to the first diaphragm 2a and a second spacer 6b fixed with an adhesive or the like to the second diaphragm 2b. The first spacer 6a and the second spacer 6b are formed into a shape that supports the magnet 4 so as to achieve the positional relationship of the coil 3, the magnet 4, etc. described above. The first spacer 6a and the second spacer 6b are formed from resin or the like.

[0072] When sound is applied to the power generating device 1 having such a structure (from above in the figure), the sound causes a change in air pressure on the external space side of the first diaphragm 2a, causing the first diaphragm 2a to vibrate in the vertical direction in the figure. When the first diaphragm 2a vibrates, the first diaphragm 2a causes a change in air pressure on the internal space side, and the change in air pressure is transmitted through the internal space of the chassis 10 to the second diaphragm 2b. As a result, the second diaphragm 2b also vibrates.

[0073] The second diaphragm 2b moves when a force is applied so that the air pressure in the internal space and external space of the chassis 10 becomes the same, and since the distance between the first diaphragm 2a and the second diaphragm 2b is sufficiently short compared to the speed of sound (air pressure propagation speed), the second diaphragm 2b vibrates so as to move in the same direction as the first diaphragm 2a.

[0074] Therefore, the magnet 4 vibrates in accordance with the vibration of the first diaphragm 2a (the displacement direction and amount are the same at the same time), that is, in synchronization.

[0075] And with the above-mentioned structure, the magnet 4 vibrates around the point where the area where the magnetic flux density is high and where its fluctuation (the amount of change in magnetic flux density with respect to position change) is large is the position of the conductor wires of the first coil 3a and the second coil 3b.

[0076] Therefore, in the first coil 3a and the second coil 3b, when sound is applied to the first diaphragm 2a, the magnetic flux moves through a region where the magnetic flux density is high and the fluctuation is large, so that power is generated efficiently.

[0077] Next, the configuration of the power generating device 1 shown in Fig. 9 will be described. In Fig. 9, differences from the configuration in Fig. 8 will be described, and a description of the same configuration as in Fig. 8 will be omitted. As shown in Fig. 9, one end of the outer circumferential end of the first magnet 4a is fixed to the first diaphragm 2a.

[0078] Specifically, the first magnet 4a is fixed to the first diaphragm 2a with an adhesive or the like so that the normal to the magnetic pole face is in the same direction as the normal to the opening faces of the first coil 3a and the second coil 3b. In other words, the first coil 3a and the second coil 3b are installed at positions on both sides facing the magnetic pole face of the first magnet 4a.

[0079] Moreover, the first magnet 4a is disposed close to the second coil 3b. Specifically, the first magnet 4a is disposed close to the second coil 3b so that the magnetic pole face of the N pole 41a (polarity on the side farther from the second coil 3b) is located in the center between the first coil 3a and the second coil 3b.

[0080] In addition, the first magnet 4a is fixed to the first diaphragm 2a so that, when the first diaphragm 2a and the second diaphragm 2b are in the reference state, the end of the magnetic pole face of the first magnet 4a faces the outer periphery of the opening face of the second coil 3b.

[0081] That is, when the first diaphragm 2a and the second diaphragm 2b are in a reference state, the conductor portion of the second coil 3b is located in a region where the magnetic flux density caused by the first magnet 4a is high and where the amount of change in the magnetic flux density is large.

[0082] Moreover, one end of the outer circumferential end of the second magnet 4b is fixed to the second diaphragm 2b. Specifically, the second magnet 4b is fixed to the second diaphragm 2b with an adhesive or the like so that the normal to the magnetic pole face is in the same direction as the normal to the opening faces of the first coil 3a and the second coil 3b. In other words, the first coil 3a and the second coil 3b are respectively installed at positions on both sides facing the magnetic pole face of the second magnet 4b.

[0083] The second magnet 4b is disposed closer to the first coil 3a. Specifically, the second magnet 4b is disposed closer to the first coil 3a so that the magnetic pole face of the N pole 41b (polarity on the side farther from the first coil 3a) is located in the center between the first coil 3a and the second coil 3b.

[0084] In addition, the second magnet 4b is fixed to the second diaphragm 2b so that, when the first diaphragm 2a and the second diaphragm 2b are in the reference state, the end of the magnetic pole face of the second magnet 4a faces the outer periphery of the opening face of the first coil 3a.

[0085] That is, when first diaphragm 2a and second diaphragm 2b are in a reference state, the conductor portion of first coil 3a is located in a region where the magnetic flux density caused by second magnet 4b is high and where the amount of change in magnetic flux density is large.

[0086] When sound is applied to the power generating device 1 having such a structure (from above in the figure), the sound causes a change in air pressure on the external space side of the first diaphragm 2a, causing the first diaphragm 2a to vibrate in the vertical direction in the figure. When the first diaphragm 2a vibrates, the first diaphragm 2a causes a change in air pressure on the internal space side, and the change in air pressure is transmitted through the internal space of the chassis 10 to the second diaphragm 2b. As a result, the second diaphragm 2b also vibrates.

[0087] The second diaphragm 2b moves when a force is applied so that the air pressure in the internal space and external space of the chassis 10 becomes the same, and since the distance between the first diaphragm 2a and the second diaphragm 2b is sufficiently short compared to the speed of sound (air pressure propagation speed), the second diaphragm 2b vibrates so as to move in the same direction as the first diaphragm 2a.

[0088] Therefore, the first magnet 4a vibrates in accordance with the vibration of the first diaphragm 2a (the same displacement direction and amount at the same time), and the second magnet 4b vibrates in accordance with the vibration of the second diaphragm 2b. In other words, the first magnet 4a and the second magnet 4b vibrate in synchronization with each other.

[0089] With the above-described structure, the first magnet 4a vibrates around the point where the region where the magnetic flux density is high and where the fluctuation (the amount of change in magnetic flux density relative to a change in position) is large is located, which is the position of the conductor of the second coil 3b.

[0090] Also, the second magnet 4b vibrates around a point where the magnetic flux density is high and the fluctuation (amount of change in magnetic flux density relative to position change) is large, which is the position of the conductor of the first coil 3a.

[0091] Therefore, in the first coil 3a and the second coil 3b, when sound is applied to the first diaphragm 2a, the magnetic flux moves through a region where the magnetic flux density is high and the fluctuation is large, so that power is generated efficiently.

[0092] Furthermore, if the first magnet 4a and the second magnet 4b are made into a circular ring shape so as to face the wire loops of the first coil 3a and the second coil 3b, the entire conductor of each coil will be located within an area where the magnetic flux density is high and its fluctuations are large, so it is also a preferable structure to give the first magnet 4a and the second magnet 4b such a shape and arrange them in such a way.

[0093] Next, modified examples of magnets suitable for increasing power generation efficiency will be described. Figures 10 and 11 are diagrams showing configuration examples of magnets 4 according to modified examples. As shown in Figure 10, magnets 4 have a cylindrical first magnet 4a (cylindrical magnet) and an annular second magnet 4b (annular magnet), with the first magnet 4a inserted into the inner diameter hole (circular hole) of the second magnet 4b.

[0094] The magnetic poles of the first magnet 4a are on both flat surfaces of a cylinder, and the magnetic poles of the second magnet 4b are on both flat surfaces of a ring. The first magnet 4a and the second magnet 4b are inserted and integrated so that their magnetic poles have opposite polarities.

[0095] The first magnet 4a and the second magnet 4b are bonded with an adhesive, which creates a small gap between them. A non-magnetic material such as resin of an appropriate thickness may be interposed between the first magnet 4a and the second magnet 4b.

[0096] FIG. 11 is a diagram showing the magnetic flux density distribution in the upper part of the pole face of magnet 4 shown in FIG.

[0097] Since the first magnet 4a and the second magnet 4b have opposite magnetic poles on the top surface of the magnet shown in the figure, many of the magnetic field lines take a route between the top surface of the first magnet 4a and the top surface of the second magnet 4b. For example, in the structure of the magnet 4 shown in the lower part of Fig. 11, many of the magnetic field lines flow from the upper N pole surface 41a of the first magnet 4a through the upper space to the upper S pole surface of the second magnet 4b. For this reason, the magnetic flux density above the boundary surface between the first magnet 4a and the second magnet 4b becomes high, and the amount of change (change with respect to position change) also becomes large.

[0098] A similar phenomenon occurs, and the number of magnetic field lines that run between the lower surface of the first magnet 4a and the lower surface of the second magnet 4b increases.

[0099] Therefore, the coils 3 and magnets 4 of the power generating device 1 are arranged so that the conductor of the coil 3 is positioned in a region where the magnetic flux density is high above the boundary surface between the first magnet 4a and the second magnet 4b and where the amount of change in the magnetic flux density is also large.

[0100] With this configuration, when sound is applied, the change in magnetic flux passing through the power generating coil 3 in the power generating device 1 becomes large, so that the power generating device 1 can generate power efficiently.

[0101] As described above, the power generating device 1 according to the embodiment includes the coil 3, the magnet 4, and the diaphragm 2. The magnet 4 is provided at a position separated from the coil 3, and is disposed with its magnetic pole surface facing the direction of the coil 3. The diaphragm 2 is a diaphragm 2 that vibrates upon receiving sound waves, and either the coil 3 or the magnet 4 is provided on the diaphragm 2. The diaphragm 2 generates an electromotive force in the coil 3 due to a change in the magnetic field of the coil 3 caused by a change in the relative position of the coil 3 and the magnet 4 due to vibration, thereby generating power. This allows for efficient power generation.

[0102] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0103] 1. Power generation equipment 2 diaphragm 2a 1st diaphragm 2b 2nd diaphragm 3 Coil 3a First coil 3b Second coil 4. Magnets 4a First magnet 4b Second magnet 5 Fixed plate 6 Spacer 6a First spacer 6b Second spacer 7 Spacer 8 Holder 9 Reinforcement plate 10 Chassis 50 side wall 51 Hole SP interior space

Claims

1. A coil and a magnet provided at a position spaced apart from the coil, the magnet having a magnetic pole surface facing the coil; a diaphragm that vibrates upon receiving sound waves, the diaphragm having either the coil or the magnet disposed thereon; Equipped with The coil and the magnet are They are installed so that their central axes are not aligned. The diaphragm is The relative positions of the coil and the magnet are changed by vibration, which causes a change in the magnetic field of the coil to generate an electromotive force in the coil, thereby generating electricity. Power generation equipment.

2. At least one of the coil and the magnet is The direction of the central axis is different from the vibration direction of the diaphragm. The power generating device according to claim 1 .

3. The diaphragm is The first diaphragm and the second diaphragm are disposed opposite each other, The first diaphragm and the second diaphragm are Either the coil or the magnet is disposed, The other of the coil and the magnet is fixed to a fixed plate disposed between the first diaphragm and the second diaphragm The power generating device according to claim 1 or 2.

4. The first diaphragm and the second diaphragm form an enclosed space. The power generating device according to claim 3 .

5. The fixing plate is The sealed space has a hole that is in contact with both the first diaphragm and the second diaphragm and is integrated with the first diaphragm. The power generating device according to claim 4.

6. A coil and a magnet provided at a position spaced apart from the coil, the magnet having a magnetic pole surface facing the coil; a diaphragm that vibrates upon receiving sound waves, the diaphragm having either the coil or the magnet disposed thereon; Equipped with The magnet is a ring-shaped toric magnet; a cylindrical magnet inserted into the circular hole of the annular magnet; The polarity of the magnetic pole faces of the annular magnet and the cylindrical magnet facing in the same direction is opposite, The diaphragm is The relative positions of the coil and the magnet are changed by vibration, which causes a change in the magnetic field of the coil to generate an electromotive force in the coil, thereby generating electricity. Power generation equipment.

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