Power generating device

Abstract

A power-generating device comprises a coil, a magnet, and a diaphragm. The magnet is positioned away from the coil and has magnetic pole faces oriented towards the coil. The diaphragm vibrates when it receives sound waves, and either the coil or the magnet is mounted on it. The diaphragm generates electricity by producing an electromotive force in the coil through a change in the coil's magnetic field caused by the diaphragm's vibration and the resulting change in the relative position of the coil and magnet.

Description

Field of invention

[0001] The present invention relates to a power generation device that generates electricity from sound. General state of the art

[0002] A power generating device that generates electricity by changing the magnetic flux of a coil due to a change in the relative position of a permanent magnet and the coil is conventionally known. List of literature on patent literature

[0003] Patent literature example 1: Japanese patent publication no. 2000-32732 Brief description of the invention: Technical problem

[0004] However, conventional technologies have focused on generating electricity from a mechanical movement such as a rotary motion, which is why there is potential for improvement with regard to enabling high-performance electricity generation from sound.

[0005] The present invention was made in view of the circumstances described above, and its object is to provide a power generation device capable of generating efficient power from sound. Solution to the problem

[0006] A power-generating device comprises a coil, a magnet, and a diaphragm. The magnet is positioned away from the coil and has magnetic pole faces oriented in one direction toward the coil. The diaphragm vibrates when it receives sound waves, and either the coil or the magnet is mounted on it. The diaphragm generates electricity by producing an electromotive force in the coil through a change in the coil's magnetic field caused by the vibration of the diaphragm. Advantageous effects of the invention

[0007] According to the present invention, efficient power generation from sound is made possible. Brief description of the drawings Fig. Figure 1A is a diagram showing an example of a complete setup of a power generating device according to one embodiment. Fig. Figure 1B is a diagram showing an example of the complete setup of the power generation device according to the embodiment. Fig. Figure 2 is an explanatory diagram describing the principle of power generation by the power generating device. Fig. Figure 3 is an explanatory diagram describing the principle of electricity generation by the electricity generating device. Fig. Figure 4 is a diagram showing an example of the construction of a power generation device according to a modified example. Fig. Figure 5 is a diagram showing an example of the construction of a power generation device according to a modified example. Fig. Figure 6 is a diagram showing an example of the construction of a power generation device according to a modified example. Fig. Figure 7 is a diagram showing an example of the construction of a power generation device according to a modified example. Fig. Figure 8 is a diagram showing an example of the construction of a power generation device according to a modified example. Fig. Figure 9 is a diagram showing an example of the construction of a power generation device according to a modified example. Fig. Figure 10 is a diagram showing an example of the construction of a magnet according to a modified example. Fig. Figure 11 is a diagram showing the example of the construction of the magnet according to the modification example. Description of embodiments

[0008] An embodiment of a power generating device disclosed in this application will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited by the following embodiment.

[0009] First, with reference to Fig. 1A and Fig. 1B An example of the entire setup of the power generation device according to the embodiment is described. Fig. 1A and Fig. Figure 1B shows diagrams illustrating an example of the complete setup of the power generation device according to the embodiment. Fig. Figure 1A shows a side view of a power generating device 1 and Fig. Figure 1B shows a stretched perspective view of the power generating device 1.

[0010] As in Fig. 1A and Fig. As shown in Figure 1B, the power generating device 1 according to the embodiment comprises a first diaphragm 2a, a second diaphragm 2b, a first coil 3a, a second coil 3b, a magnet 4, a fixing plate 5, and a frame 10. In the following description, the first diaphragm 2a and the second diaphragm 2b may be referred to collectively as diaphragm 2, and the first coil 3a and the second coil 3b may be referred to collectively as coil 3.

[0011] The membrane 2 is a vibrating element that oscillates when exposed to sound waves and, in the present embodiment, is formed in a thin, plate-like, and essentially square shape. Furthermore, both ends of the outer circumferential edges of the membrane 2 are fixed to side walls 50 of the frame 10 by a fixing element such as an adhesive or the like. In particular, the membrane 2 is fixed such that it remains flat in a flat state (the one described in the diagram). Fig. (state shown in 1A) when it receives no sound waves. Membrane 2, for example, is formed from a thin sheet (film) of paper, resin, or the like with moderate rigidity specifications and elastic properties.

[0012] Furthermore, the first membrane 2a and the second membrane 2b of membrane 2 are as in Fig. 1A is shown arranged so that they face each other. This creates a tightly sealed interior SP, which is surrounded by the first membrane 2a, the second membrane 2b and the side walls 50. That is, a tightly sealed space is formed by the first membrane 2a and the second membrane 2b.

[0013] Although Fig. Figure 1A shows an example where the first membrane 2a and the second membrane 2b are arranged facing each other as membrane 2 via the magnet inserted between them. It is also possible to arrange only one membrane 2a and one membrane 2b, provided the interior space is designed as a tightly sealed chamber. That is, membrane 2 can be formed by two membranes or by a single membrane.

[0014] The coil 3 is arranged on each of the membranes 2 and is formed, for example, by embedding a metallic conductor such as copper in the membrane 2 or by printing a conductive material onto the membrane 2. In particular, for the coil 3, the first coil 3a is arranged in the center of the first membrane 2a and the second coil 3b is arranged in the center of the second membrane 2b.

[0015] Magnet 4 is, for example, a permanent magnet such as a neodymium magnet. Magnet 4 is positioned at a distance from coil 3 in the direction of oscillation of the diaphragm 2, with its magnetic poles facing the direction of coil 3. Magnet 4 is also positioned equidistant from both the first coil 3a and the second coil 3b. Both ends of the outer circumferential edges of magnet 4 are fixed to the mounting plate 5 by a fixing element such as an adhesive. It should be noted that both ends of the outer circumferential edges of magnet 4 can be fixed to the mounting plate 5 by a fitting.

[0016] The positional relationship of the coil 3 and the magnet 4 can be reversed. That is, a magnet 4 can be provided at each of the diaphragms 2, and the coil 3 can be fixed to the mounting plate 5. In this case, with regard to the polarity of each of the magnets 4, like polarities can face each other, or opposite polarities can face each other. However, considering that a greater change in the magnetic flux in the coil 3 during the oscillation of the diaphragm 2 is preferable, the magnets 4 are preferably arranged at the respective diaphragms 2 such that like polarities face each other.

[0017] The fixing plate 5 is a plate-like element to which the magnet 4 is fixed and is arranged in a position that is away from the coil 3 in the direction of oscillation of the diaphragm 2. As in Fig. As shown in Figure 1A, the fixing plate 5 is arranged between the first membrane 2a and the second membrane 2b, while facing each of the membranes 2.

[0018] For example, both ends of the outer circumferential edges of the fixing plate 5 are fixed to the side walls 50. The fixing plate 5 is made, for example, of a rigid material such as a resin material or the like. Furthermore, the fixing plate 5 has a perforated area 51. Fig. 1B the fixing plate 5 has four hole areas 51 which are formed such that they are point-symmetric with respect to the magnet 4.

[0019] In particular, the fixing plate 5 has the hole areas 51 to allow the interior SP, which is a tightly sealed space, to be closed off and to come into contact with both the first membrane 2a and the second membrane 2b.

[0020] The frame 10 is a fixing element that secures the membrane 2 and the fixing plate 5 to the side walls 50. The frame 10 is, for example, made of a rigid material such as a resin or a non- / weakly magnetic metal. In the present disclosure, the frame 10 is formed by stacking an upper frame 10a and a lower frame 10b.

[0021] The upper frame 10a has a stepped shape in which the inner circumferential area, where the first membrane 2a is fixed, is recessed by the thickness of the first membrane 2a. The first membrane 2a is fixed in a state that fits into the stepped shape by gluing.

[0022] Furthermore, the lower frame 10b has a stepped shape where the inner circumferential area, to which the fixing plate 5 is attached, is recessed by the thickness of the fixing plate 5. The fixing plate 5 is fixed in a position that fits into the stepped shape by gluing. That is, the fixing plate 5 is fixed to the side walls 50 of the lower frame 10b. In addition, the lower frame 10b has a stepped shape where the inner circumferential area, to which the second membrane 2b is attached, is recessed by the thickness of the second membrane 2b. The second membrane 2b is fixed in a position that fits into the stepped shape by gluing.

[0023] Furthermore, positioning projections 52 or positioning openings 53 are provided on the surfaces of the upper frame 10a and the lower frame 10b that face each other. This allows for easy alignment of the positions of the upper frame 10a and the lower frame 10b during manufacturing by aligning the projections 52 and the positioning openings 53.

[0024] Although the present disclosure shows an example in which the frame 10 is formed by two elements, namely the upper frame 10a and the lower frame 10b, the frame 10 can also be formed by a single element. Such a case can be implemented by providing a stepped form at both ends of the frame 10 for fixing the first membrane 2a and the second membrane 2b, and by providing a recess in the middle on the inside of the side walls for fixing the fixing plate 5.

[0025] Now, with reference to Fig. 2 and Fig. 3 the principle of electricity generation of the electricity generating device 1 according to the embodiment will be described. Fig. 2 and Fig. Figure 3 are explanatory diagrams describing the principle of electricity generation by the electricity generating device 1. It should be noted that for the sound source, which is in Fig. As shown in Figure 2, a variety of sound-generating sources are conceivable. If, for example, the power-generating device 1 is installed in a vehicle, it is advantageous to use the engine or the like, which continuously generates sound in the vehicle, as the target sound source and to position the power-generating device 1 in a suitable position (a position with good power-generating efficiency) and in a suitable state (a state (of a direction or the like) with good power-generating efficiency) relative to the target sound source.

[0026] As in Fig. As shown in Figure 2, the membrane 2 vibrates when it receives sound waves from the sound source. Fig. 2. Sound waves propagate from the sound source, i.e., air pressure fluctuations (changes in air pressure), to the first diaphragm 2a, causing a fluctuation in air pressure on the sound source side of the first diaphragm 2a. The first diaphragm 2a then vibrates due to the air pressure fluctuations on the sound source side.

[0027] Subsequently, the vibration of the first diaphragm 2a generates pressure fluctuations on the side of the first diaphragm 2a opposite the sound source. These pressure fluctuations propagate through the interior SP of the power-generating device 1, that is, through the perforated areas 51 of the fixing plate 5, to the second diaphragm 2b. The air pressure fluctuations that have propagated to the second diaphragm 2b cause a fluctuation in air pressure on the sound-source side of the second diaphragm 2b, which in turn causes the second diaphragm 2b to vibrate. It should be noted that the interior SP does not need to be completely sealed, but only sufficiently sealed to allow the pressure fluctuations to propagate adequately to the second diaphragm 2b.

[0028] That is, if the first membrane 2a is as in Fig. If the first diaphragm 2a assumes a convex arc shape with respect to the sound source side, then the second diaphragm 2b also assumes a convex arc shape with respect to the sound source side. And if the first diaphragm 2a assumes a concave arc shape with respect to the sound source side, then the second diaphragm 2b also assumes a concave arc shape with respect to the sound source side.

[0029] As a result, the sound waves from the sound source cause the first diaphragm 2a to vibrate, which changes the relative position of the first coil 3a and the magnet 4. The resulting change in magnetic flux in the region of the first coil 3a then generates an electromotive force in the first coil 3a, enabling current generation. Furthermore, the air pressure fluctuations generated by the vibration of the first diaphragm 2a propagate to the second diaphragm 2b, causing the second diaphragm 2b to vibrate and changing the relative position of the second coil 3b and the magnet 4. The resulting change in magnetic flux in the region of the second coil 3b then generates an electromotive force in the second coil 3b, enabling current generation.

[0030] Thus, in the power generation device 1 according to the embodiment, current is generated by the sound waves from the sound source in the first coil 3a and the second coil 3b, thereby enabling efficient power generation from sound.

[0031] Next will Fig. Figure 3 is used to describe the principle of doubling the generated voltage by generating the voltage produced by the first coil 3a and the voltage produced by the second coil 3b with the same phase. It should be noted that the first coil 3a and the second coil 3b are connected as shown in Fig. The coils 1B, shown in the drawing viewed from above, are wound clockwise from the outside in. Furthermore, on the first coil 3a and the second coil 3b, terminals 21a and 21b are connected on the left side of the drawing, and terminals 20a and 20b are connected on the right side of the drawing, respectively, to output terminals 22a and 22b for the current. A current output device (a storage battery or the like) is connected to output terminals 22a and 22b. It is also assumed that magnet 4 is positioned such that its N-pole is on the top side and its S-pole is on the bottom side of the drawing.

[0032] If, in such a case, the first diaphragm 2a assumes a concave arc shape relative to the sound source side, the first coil 3a moves closer to the magnet 4, which strengthens the upward-directed magnetic field lines. Conversely, if the second diaphragm 2b assumes a concave arc shape relative to the sound source side, the second coil 3b moves away from the magnet 4, which weakens the upward-directed magnetic field lines.

[0033] As a result, an electric current flows in the first coil 3a in the direction in which the downward-pointing magnetic field lines are generated. That is, an electromotive force is generated such that an electric current flows from terminal 21a to terminal 20a of the first coil 3a. Furthermore, an electric current flows in the second coil 3b in the direction in which the upward-pointing magnetic field lines are generated. That is, an electromotive force is generated such that an electric current flows from terminal 20b to 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, generating an electromotive force of the same polarity. The sum of the voltages resulting from the electromotive forces of the two coils is generated between the output terminal 22a and the output terminal 22b.In this case, output terminal 22a has a positive polarity and output terminal 22b has a negative polarity.

[0034] When the first diaphragm 2a assumes a convex arc shape relative to the sound source side, the first coil 3a moves away from the magnet 4, which weakens the upward-directed magnetic field lines. When the second diaphragm 2b assumes a convex arc shape relative to the sound source side, the second coil moves closer to the magnet 4, which strengthens the upward-directed magnetic field lines.

[0035] As a result, an electric current flows in the first coil 3a in the direction in which the upward-directed magnetic field lines are generated. That is, an electromotive force is generated such that an electric current flows from terminal 20a to terminal 21a of the first coil 3a. Furthermore, an electric current flows in the second coil 3b in the direction in which the downward-directed magnetic field lines are generated. That is, an electromotive force is generated such that an electric current flows from terminal 21b to terminal 21a 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, generating an electromotive force of the same polarity. The sum of the voltages resulting from the electromotive forces of the two coils is generated between the output terminal 22a and the output terminal 22b.In this case, output terminal 22a has a negative polarity and output terminal 22b has a positive polarity.

[0036] This means that by specifying 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, such that the electrical currents generated during the oscillation of the diaphragms in the first coil 3a and the second coil 3b have the same direction, it is possible to obtain the sum of the respective electromagnetic forces in the first coil 3a and the second coil 3b as the output voltage. As a result, the power generation efficiency can be increased.

[0037] In the embodiment described above, an example was described in which the coil 3 and the magnet 4 are as shown in Fig. 1A shows coil 3 and magnet 4 arranged in parallel in a positional relationship in which their respective central axes C are aligned. However, coil 3 and magnet 4 can be in a positional relationship in which their respective central axes C are not aligned. This point is addressed with reference to Fig. 4 to Fig. 6 will be described.

[0038] The central axis C is the central axis with respect to the magnetic force properties (for example, in the case of a magnet, the center-of-mass axis of the magnetic flux). Since coil 3 in the example of Fig. 1A has a ring shape, its central axis C is a straight line extending orthogonally to the plane of the ring passing through the center of the ring shape, and since the magnet 4 has a cylindrical shape, its central axis C is the axis line of the cylinder.

[0039] Fig. 4 to Fig. Figure 6 shows diagrams illustrating examples of the construction of the power generation device 1 according to modified examples. Fig. 4 to Fig. Figure 6 shows examples of a case in which the magnet 4 is arranged on the membrane 2 and the coil 3 is fixed to the fixing plate 5.

[0040] In Fig. 4 to Fig. Figure 6 shows the membrane 2 and the magnet 4 with solid lines when the membrane 2 is in a reference state (a state in which no sound waves are exerted), and the membrane 2 and the magnet after a displacement from the reference state (in a state in which sound waves are exerted) are shown with dashed lines.

[0041] First, it shows Fig. 4 is an example in which the magnet 4 is fixed obliquely to the diaphragm 2 in relation to the coil 3.

[0042] As in Fig. As shown in Figure 4, the magnet 4 is fixed to an inclined surface (inclined with respect to the membrane 2) of a spacer 6 fixed to the membrane 2. In other words, the spacer 6 is designed such that a fixing surface for the magnet 4 is inclined with respect to a fixing surface on the membrane 2. In particular, the spacer 6 has a shape that is an obliquely truncated form of a cylinder with the same diameter as that of the magnet 4. The magnet 4 is fixed to a surface of the spacer 6 that is not the cut surface, and the cut surface of the spacer 6 is fixed to the membrane 2.

[0043] The inclination angle of the spacer 6 (the inclination angle of the magnet 4) is set such that the axis of the central axis of the magnet 4 passes through a center of mass P of the coil when the diaphragm 2 is in the reference state. This makes it possible to establish a symmetrical state with respect to the movement of the diaphragm 2 in both the upward and downward directions.

[0044] This causes the central axis C of magnet 4 to be shifted relative to the direction of vibration of membrane 2. That is, the direction in which the central axis C of magnet 4 points differs from the direction of vibration of membrane 2.

[0045] In other words, coil 3 and magnet 4 are in a positional relationship where their central axes are not aligned. Then, when diaphragm 2 vibrates, magnet 4 changes its position in the direction of vibration, becoming tilted. As a result, the central axis of the magnetic flux of coil 3 is displaced relative to the central axis of coil 3.

[0046] In particular, coil 3 is used as shown in Fig. Figure 4 shows that due to the vibration of the membrane 2 in the plane direction of the magnet 4, it is displaced by Δr from the central axis. As a result, the magnetic flux changes Δφr due to the displacement by Δr.

[0047] As in Fig. As shown in Figure 4, the distance between the magnet 4 and the coil 3 changes by Δd in conjunction with the vibration of the membrane 2. As a result, the magnetic flux changes by Δφd due to the change in Δd.

[0048] In this way, the generated voltage can be increased by changing Δφr and Δφd in the magnetic flux passing through the coil and by increasing the rate of change of the magnetic flux. That is, the power generation efficiency can be increased.

[0049] Next, show Fig. Figure 5 is an example in which the coil 3 and the magnet 4 are fixed while being inclined with respect to the diaphragm 2. In particular, the magnet 4 is fixed to the surface of the spacer 6 that is inclined with respect to the diaphragm 2. In other words, the spacer 6 is designed such that a fixing surface for the magnet 4 is inclined with respect to a fixing surface on the diaphragm 2. In particular, the spacer 6 has a shape that is an obliquely truncated form of a cylinder with the same diameter as that of the magnet 4. The magnet 4 is fixed to a surface of the spacer 6 that is not the cut surface, and the cut surface of the spacer 6 is fixed to the diaphragm 2.

[0050] Furthermore, the coil 3 is fixed in relation to the fixing plate 5 (i.e., the diaphragm 2) 3 in an inclined mounting opening 71 of a spacer 7.

[0051] In particular, the spacer 7 has the fixing opening 71, in which the coil 3 is inserted and fixed, the fixing opening 71 being an opening inclined with respect to the thickness direction of the fixing plate 5. Therefore, the coil 3 is fixed by fixing the spacer 7 in a form in which the plane direction is aligned with the fixing plate 5, and by inserting and fixing the coil 3 in the fixing opening 71 of the spacer 7 in a state with respect to the diaphragm 2 in which the plane of the coil and the plane of the diaphragm are inclined.

[0052] Furthermore, the spacer 7 (the fixing opening 71l) is designed such that the coil 3 lies substantially parallel to the magnetic pole faces of the magnet 4. Moreover, the coil 3 and the magnet 4 are arranged such that their central axes are aligned with each other when the diaphragm 2 is in the reference state. In other words, they are arranged such that the central axis C of the magnet 4 passes through the center of gravity P of the coil 3 when the diaphragm 2 is in the reference state.

[0053] This shifts the central axes of coil 3 and magnet 4 with respect to the direction of vibration of diaphragm 2, and makes the directions in which the central axes of coil 3 and magnet 4 are aligned the same.

[0054] Then, when the diaphragm 2 vibrates, the magnet 4 changes its position in an inclined state in the direction of vibration. As a result, the positional relationship between the coil 3 and the magnet 4 changes, while maintaining their parallel relationship about their respective central axes. In particular, the magnet undergoes a change (misalignment) Δr in the plane direction of the magnetic pole surfaces due to the vibration of the diaphragm 2.

[0055] As a result, the magnetic flux changes due to the displacement by Δr, resulting in a change of Δφr.

[0056] Furthermore, how does it change in Fig. Figure 5 shows the distance between magnet 4 and coil 3 in conjunction with the oscillation of diaphragm 2 by Δd. As a result of the change in magnetic flux by Δd, Δφd changes. In this way, the generated voltage can be increased by causing changes in Δφr and Δφd in the magnetic flux passing through the coil and by increasing the rate of change of the magnetic flux. That is, the power generation efficiency can be increased.

[0057] Next, show Fig. Figure 6 shows an example where one end of the diaphragm 2 is fixed. Specifically, one end of the diaphragm 2 is fixed by being clamped by a reinforcing plate 9. The reinforcing plate 9 is a plate-shaped element made, for example, of a rigid resin or metal material. When the diaphragm 2 receives sound waves in such a case, the other end of the diaphragm 2 vibrates with the fixed end as its axis in a direction of rotation (the direction of vibration). That is, the other end of the diaphragm 2 oscillates. As a result, the end of the magnet 4, which is located at the other end of the diaphragm 2, changes its position due to the vibrations in the direction of rotation. That is, the magnet 4 also oscillates in response to the vibration of the diaphragm 2. Moreover, the coil 3 and the magnet 4 are arranged such that their central axes are aligned with each other when the diaphragm 2 is in the reference state.In other words, they are arranged such that the central axis C of the magnet 4 passes through the center of gravity P of the coil 3 when the diaphragm 2 is in the reference state.

[0058] Then the central axis C of magnet 4 is displaced from the central axis of coil 3 by the angle of rotation (oscillation angle) associated with the oscillation. In particular, when the diaphragm 2 oscillates by Δθ, the central axis C of magnet 4 is displaced by Δθ from the central axis of coil 3.

[0059] As a result, the magnetic flux changes due to the displacement by Δθ, resulting in a change of Δφθ.

[0060] Furthermore, how does it change in Fig. Figure 6 shows the distance between magnet 4 and coil 3 in conjunction with the oscillation of diaphragm 2 by Δd. As a result of the change in magnetic flux by Δd, Δcpd changes. As described, the generated voltage can be increased by changing Δφr and Δφd in the magnetic flux passing through coil 3 and by increasing the rate of change of the magnetic flux. That is, the power generation efficiency can be increased.

[0061] Next, other examples of variations will be given with reference to Fig. 7 to Fig. Nine examples of a setup are described that use the distribution characteristic of the magnetic flux density of magnet 4 to increase the power generation efficiency. Fig. 7 to Fig. Figure 9 are diagrams showing examples of the construction of the power generation device 1 according to modified examples.

[0062] First, with reference to Fig. 7. The distribution of the magnetic flux density of magnet 4 is described. Fig. 7 is the upper surface of the magnet 4 in the drawing the N-pole and the lower surface the S-pole and for clarity the upper half-layer of the magnet 4 is schematically represented as N-pole 41 and the lower half-layer as S-pole 42 (an example of the second polarity).

[0063] As in Fig. As shown in Figure 7, the distribution of the magnetic flux density 100a on the main surface of the N-pole 41 is generally a bimodal distribution. Specifically, the distribution of the magnetic flux density 100a exhibits a distribution pattern in which the area around both ends of the magnet 4 has a higher density in the lateral direction (perpendicular to the thickness direction), and the density variation therein is also greater. That is, the magnet 4 has a distribution characteristic in which the magnetic flux density in the area around both ends is higher in the lateral direction than in the center, and its variation is also greater. It should be noted that the distribution of the magnetic flux density on the main surface of the S-pole 42 also exhibits the same characteristic as the distribution of the magnetic flux density 100a on the main surface of the N-pole 41.

[0064] Therefore, the power generating device 1 focuses on the modification examples given in Fig. 8 and Fig. Figure 9 shows the distribution characteristic, and it is designed such that the coil 3 moves by passing through the environment of both ends of the magnet 4 in the lateral direction, where the magnetic flux density is high.

[0065] First, the structure of the in Fig. The power generating device 1 shown in section 8 is described. As in Fig. As shown in Figure 8, the first coil 3a is fixed to the central region of a first side wall 50a of the frame 10 of the power generating device 1 and the second coil 3b is fixed to the central region of a second side wall 50b, which is opposite the first side wall 50a of the frame 10, using an adhesive or the like for fixing.

[0066] It should be noted that the first coil 3a is fixed to the first side wall 50a such that the normal to its opening surface points in the same direction as the normal to the plane of the first side wall 50a. Furthermore, the second coil 3b is fixed to the first side wall 50a such that the normal to its opening surface points in the same direction as the normal to the plane of the second side wall 50b.

[0067] Furthermore, the frame 10 is a square tube with a square cross-section, and the outer circumferential edges of the first membrane 2a and the second membrane 2b are fixed at its two openings by an adhesive or the like. Therefore, the frame 10 is in a substantially tightly sealed state. The first membrane 2a and the second membrane 2b are made of thin sheets of paper, resin, or the like, possessing moderate rigidity, elasticity, and sealing properties suitable for vibration.

[0068] Magnet 4 is fixed to the first diaphragm 2a and the second diaphragm 2b such that the normal to the magnetic pole faces (the main face of the N pole 41 and the main face of the S pole 42) runs in the same direction as the normal to the opening faces of the first coil 3a and the second coil 3b (and also the normal to the second coil 3b). That is, magnet 4 is fixed to the first diaphragm 2a and the second diaphragm 2b such that the magnetic pole faces are oriented perpendicular to the direction of oscillation of diaphragm 2. Furthermore, the first coil 3a and the second coil 3b are positioned opposite the magnetic pole faces of magnet 4.

[0069] Magnet 4 is fixed such that its central region lies on a straight line passing through the central region of the openings of the first coil 3a and the second coil 3b when the first diaphragm 2a and the second diaphragm 3b are in the reference state (the state in which no sound waves are applied to the first diaphragm 2a and the second diaphragm 2b). Furthermore, the size of magnet 4 is determined such that the outer circumference of the openings of the first coil 3a and the second coil 3b is opposite the surrounding area of ​​the outer circumference of magnet 4 when the first diaphragm 2a and the second diaphragm 2b are in the reference state.That is, the position, size and shape of the magnet 4 as well as the position of the first coil 3a and the second coil 3b are determined such that the conductor sections of the first coil 3a and the second coil 3b are positioned in a region where the magnetic flux density generated by the magnet 4 is high and the magnitude of the change in magnetic flux density (the magnitude of the change in magnetic flux density in relation to the magnitude of the change in position) is large when the first diaphragm 2a and the second diaphragm 2b are in the reference state.

[0070] Regarding the specific mounting structure of the magnet 4, the side surfaces of the magnet 4 are fixed by an adhesive or the like to a first spacer 6a, which is fixed by an adhesive or the like to the first membrane 2, and to a second spacer 6b, which is fixed by an adhesive or the like to the second membrane 2b. Furthermore, the first spacer 6a and the second spacer 6b are shaped such that they support the magnet 4 in such a way that the coil 3, the magnet 4, and the like are in the positional relationship described above. The first spacer 6a and the second spacer 6b are formed from a resin or the like.

[0071] When sound is applied to the power generating device 1 with this setup (from above in the drawing), the first diaphragm 2a vibrates in the perpendicular direction in the drawing due to the air pressure fluctuations on the outer side of the diaphragm 2a caused by the sound. As the first diaphragm 2a vibrates, it causes air pressure fluctuations on its inner side, and these air pressure fluctuations are transmitted through the interior of the frame 10 to the second diaphragm 2b. Therefore, the second diaphragm 2b also vibrates.

[0072] The second diaphragm 2b moves due to a force exerted such that the air pressures inside and outside the housing 10 become equal. Since the distance between the first diaphragm 2a and the second diaphragm 2b is sufficiently small with respect to the speed of sound (the speed of propagation of air pressure), the second diaphragm 2b oscillates in the same direction as the first diaphragm 2a.

[0073] Therefore, the magnet 4 oscillates in accordance with the oscillation of the first membrane 2a (at the same time in the same direction of displacement and with the same degree of displacement), that is, synchronously.

[0074] Due to the setup described above, the area of ​​magnet 4 where the magnetic flux density is high and the fluctuation (the extent of the change in magnetic flux density with respect to the change in position) oscillates around the points that represent the positions of the conductors of the first coil 3a and the second coil 3b.

[0075] Therefore, the area with high magnetic flux density and large fluctuation, in conjunction with the application of sound to the first diaphragm 2a, moves to the first coil 3a and the second coil 3b, thereby achieving powerful current generation.

[0076] Next, the construction of the power generating device 1, which is located in Fig. As shown in 9, it will be described. With reference to Fig. 9 will be points that differ from the structure in Fig. 8 distinguish, are described, while an explanation of those points that contribute to the structure in Fig. 8 corresponds, is omitted. As in Fig. As shown in Figure 9, one end of the outer circumferential edge of a first magnet 4a is fixed to the first membrane 2a.

[0077] In particular, the first magnet 4a is fixed to the first membrane 2a by an adhesive or the like such that the normal to the magnetic pole faces points in the same direction as the normal to the opening faces of the first coil 3a and the second coil 3b. That is, the first coil 3a and the second coil 3b are each arranged at positions in both directions opposite the magnetic pole faces of the first magnet 4a.

[0078] Furthermore, the first magnet 4a is arranged closer to the side of the second coil 3b. In particular, the first magnet 4a is arranged closer to the side of the second coil 3b such that the magnetic pole face of an N-pole 41a (the polarity on the side furthest from the second coil 3b) is located midway between the first coil 3a and the second coil 3b.

[0079] Moreover, the first magnet 4a is fixed to the first diaphragm 3a in such a way that the end region of the magnetic pole surface of the first magnet 4a is directed towards the region of the outer circumference of the opening surface of the second coil 3b when the first diaphragm 2a and the second diaphragm 2b are in the reference state.

[0080] This means that when the first membrane 2a and the second membrane 2b are in the reference state, the conductor section of the second coil 3b is positioned in a region where the magnetic flux density of the first magnet 4a is high and the magnitude of the change in magnetic flux density is large.

[0081] Furthermore, one end of the outer circumferential edge of a second magnet 4b is fixed to the second membrane 2b. Specifically, the second magnet 4b is fixed by an adhesive or the like such that the normal to the magnetic pole face points in the same direction as the normal to the opening faces of the first coil 3a and the second coil 3b. That is, the first coil 3a and the second coil 3b are each arranged at positions in both directions opposite the magnetic pole faces of the second magnet 4b.

[0082] Furthermore, the second magnet 4b is arranged closer to the side of the first coil 3a. In particular, the second magnet 4b is arranged closer to the side of the first coil 3a such that the magnetic pole face of an N-pole 41b (the polarity on the side furthest from the first coil 3a) is located midway between the first coil 3a and the second coil 3b.

[0083] Moreover, the second magnet 4b is fixed to the second diaphragm 2b in such a way that the end region of the magnetic pole surface of the second magnet 4a is directed towards the region of the outer circumference of the opening surface of the first coil 3a when the first diaphragm 2a and the second diaphragm 2b are in the reference state.

[0084] This means that when the first membrane 2a and the second membrane 2b are in the reference state, the conductor section of the first coil 3a is positioned in an area where the magnetic flux density generated by the second magnet 4b is high and the magnitude of the change in magnetic flux density is large.

[0085] When sound is applied to the power generating device 1 with this setup (from above in the drawing), the first diaphragm 2a vibrates in the perpendicular direction in the drawing due to the air pressure fluctuations on the outer side of the diaphragm 2a caused by the sound. As the first diaphragm 2a vibrates, it causes air pressure fluctuations on its inner side, and these air pressure fluctuations are transmitted through the interior of the frame 10 to the second diaphragm 2b. Therefore, the second diaphragm 2b also vibrates.

[0086] The second diaphragm 2b moves due to a force exerted such that the air pressures inside and outside the housing 10 become equal. Since the distance between the first diaphragm 2a and the second diaphragm 2b is sufficiently small with respect to the speed of sound (the propagation speed of air pressure), the second diaphragm 2b oscillates in the same direction as the first diaphragm 2a.

[0087] Therefore, the first magnet 4a oscillates in accordance with the oscillation of the first diaphragm 2a (at the same time, in the same direction of displacement, and with the same degree of displacement), and the second magnet 4b oscillates in accordance with the oscillation of the second diaphragm 2b. That is to say, the first magnet 4a and the second magnet 4b oscillate synchronously.

[0088] Due to the setup described above, the area of ​​the first magnet 4a where the magnetic flux density is high and the fluctuation (the extent of the change in magnetic flux density with respect to the change in position) oscillates around the point that represents the position of the conductor of the second coil 3b.

[0089] Furthermore, in the second magnet 4b, the area where the magnetic flux density is high and the fluctuation (the extent of the change in magnetic flux density with respect to the change in position) oscillates around the point that represents the position of the conductor of the first coil 3a.

[0090] Therefore, the area with high magnetic flux density and large fluctuation, in conjunction with the application of sound to the first diaphragm 2a, moves to the first coil 3a and the second coil 3b, thereby achieving powerful current generation.

[0091] If the first magnet 4a and the second magnet 4b are formed in a ring shape so that they are opposite the conduction rings of the first coil 3a and the second coil 3b, the entire conductors of each coil will lie in the region where the magnetic flux density is high and its fluctuation is high. Therefore, such a design and arrangement of the first magnet 4a and the second magnet 4b also results in an advantageous configuration.

[0092] Next, a modified example of the magnet, suitable for increasing the efficiency of power generation, will be described. Fig. 10 and Fig. Figure 11 shows an example of the construction of magnet 4 according to the modified example. As in Fig. As shown in Figure 10, the magnet 4 has a structure comprising a cylindrical first magnet 4a (a cylindrical magnet) and a ring-shaped second magnet 4b (a ring magnet), wherein the first magnet 4a is inserted into the opening on the inner diameter (the round opening) of the second magnet 4b.

[0093] It should be noted that the magnetic poles of the first magnet 4a are the two planes of the cylinder, and the magnetic poles of the second magnet 4b are the two planes of the ring. Furthermore, the first magnet 4a and the second magnet 4b are assembled in such a way that the polarities of their magnetic poles are opposite.

[0094] The first magnet 4a and the second magnet 4b are glued together, creating a small gap between them. It should be noted that a non-magnetic material, such as a resin of suitable thickness, can be inserted between the first magnet 4a and the second magnet 4b.

[0095] Fig. Figure 11 is a diagram showing the distribution of magnetic flux density at the top of the magnetic pole face of the [unclear text]. Fig. 10 shows magnet 4.

[0096] Since the polarities of the magnetic poles of the first magnet 4a and the second magnet 4b are opposite at the upper surfaces of the magnets shown in the drawing, there are more magnetic field lines running along the paths between the upper surface of the first magnet 4a and the upper surface of the second magnet 4b. For example, in the setup of magnet 4, which is in Fig.As shown in Figure 11 below, there are more magnetic flux lines flowing through the upper space from an upper N-pole surface 41a of the first magnet 4a to an upper S-pole surface of the second magnet 4b. Therefore, the magnetic flux density across the interface of the first magnet 4a and the second magnet 4b becomes higher, and its magnitude of change (the fluctuation with respect to the change in position) is also greater.

[0097] Due to the same phenomenon, there are also more magnetic field lines that run through the paths between the lower surface of the first magnet 4a and the lower surface of the second magnet 4b.

[0098] Therefore, the coil 3 and the magnet 4 of the power generating device 1 are each arranged such that the conductor of the coil 3 is located in the area where the magnetic flux density over the interface between the first magnet 4a and the second magnet 4b becomes higher and its magnitude of change also increases.

[0099] Such a setup results in a large change in the magnetic flux passing through coil 3 to generate current for the power generating device 1 when sound is applied, enabling the power generating device 1 to generate current efficiently.

[0100] As described above, the power-generating device 1, according to the embodiment, comprises the coil 3, the magnet 4, and the diaphragm 2. The magnet 4 is positioned remotely from the coil 3 and has magnetic pole faces oriented towards the coil 3. The diaphragm 2 is a vibrating plate that oscillates when it receives sound waves, and either the coil 3 or the magnet 4 is mounted on it. The diaphragm 2 generates electricity by producing an electromotive force in the coil 3 through the change in its magnetic field caused by the change in the relative positions of the coil 3 and the magnet 4 due to the oscillation. This enables efficient power generation from sound.

[0101] Experts can easily deduce further effects and examples of modifications. Therefore, the more general aspects of the present invention are not limited to the specific details and representative embodiment presented and described above. Thus, various modifications are possible without departing from the spirit or scope of the general concept of the present invention as defined by the accompanying claims and their equivalents. Reference symbol list 1 Power generating device 2 Membran 2a first membrane 2b second membrane 3 coil 3a first coil 3b second coil 4 Magnet 4a first magnet 4b second magnet 5 Fixing plate 6 spacer 6a first spacer 6b second spacer 7 spacers 8 holders 9 Reinforcement plate 10 frames 50 side wall 51-hole area SP Interior

Claims

[1] Power generating device comprising a coil; a magnet provided at a position remote from the coil and having magnetic pole faces facing in a direction of the coil; and a membrane that vibrates when it receives sound waves and on which either the coil or the magnet is arranged, where the membrane generates current by generating an electromotive force in the coil through a change in a magnetic field of the coil, which is caused by changing a relative position of the coil and the magnet due to the vibration. [2] Power generation device according to claim 1, wherein the membrane comprises a first membrane and a second membrane arranged facing each other, one of the coil and the magnet is arranged on the first membrane and the second membrane, and the other of the coil and the magnet is arranged between the first membrane and the second membrane. [3] The power generation device according to claim 2, wherein a tightly sealed space is formed by the first membrane and the second membrane. [4] Power generation device according to claim 3, wherein the magnet is fixed to a fixing plate arranged between the first membrane and the second membrane, and the fixing plate has a hole portion that allows the sealed space to be a contiguous space that comes into contact with both the first membrane and the second membrane. [5] A power generating device according to any one of claims 1 to 4, wherein the coil and the magnet are arranged to be in a positional relationship in which the respective center axes are not aligned. [6] The power generating device according to claim 5, wherein a direction in which the central axis of at least one of the coil and the magnet faces is different from a vibration direction of the diaphragm. [7] A power generating device according to any one of claims 1 to 4, wherein the magnet is oscillatory fixed to the diaphragm and oscillates in conjunction with the oscillation of the diaphragm. [8] Power generation device according to claim 2, wherein the magnet is fixed to the first membrane and the second membrane such that the magnetic pole faces face in a direction perpendicular to a direction of vibration of the membrane, and the coil is arranged at a position opposite the magnetic pole faces of the magnet. [9] A power generating device according to claim 8, wherein the coil is arranged at each of positions in both directions opposite to the magnetic pole faces of the magnet. [10] The power generating device according to claim 8 or 9, wherein the coil and the magnet are arranged at positions where an outer peripheral portion of an opening surface of the coil is opposed to a vicinity of an outer peripheral portion of the magnetic pole surface of the magnet. [11] Power generation device according to claim 9, wherein the magnet is formed such that a first magnet is arranged on one of the membranes and a second magnet is arranged on the other of the membranes, the first magnet is fixed to the first membrane such that an end region of the magnetic pole face of the first magnet is opposite an end region of the magnetic pole face of one of the coils, and the second magnet is fixed to the second diaphragm such that one end portion of the magnetic pole face of the second magnet is opposite to an outer peripheral portion of the opening face of the other of the coils. [12] Power generating device according to one of claims 1 to 11, wherein the magnet a ring-shaped magnet; and a cylindrical magnet inserted into a round opening of the ring-shaped magnet, and the polarities at the magnetic pole face of the ring-shaped magnet and the magnetic pole face of the cylindrical magnet, which face in an identical direction, are opposite.

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