JP2009273201A - Electric power generating apparatus using electroactive polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain an electric power generating apparatus which is not provided separately with an initial voltage supply means, such as, a secondary battery or a capacitor but uses an electroactive polymer, and can be utilized in various fields under various conditions, by attaining optimization of timing for supplying initial electric energy and taking out output electric energy by a simple arrangement. <P>SOLUTION: An electric power generating apparatus has an electric power generating unit 10 which converts movement of a piston shaft 11 in the axial direction into a force for deforming an electroactive polymer 12, and performs switching between initial electrical energy supply to the electroactive polymer 12 and delivery of output electrical energy from the polymer 12 according to the deformation state of the electroactive polymer 12, wherein a piezoelectric element 17 that generates initial electric energy is arranged in the electric power generating unit 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric field responsive polymer (electroactive polymer) made of a dielectric elastomer, and more particularly to a power generation apparatus using an electric field responsive polymer.

  Over the past decade, most researches on electric field responsive polymers made of dielectric elastomers have focused on use as actuators. When the electric field responsive polymer is placed in a strong electric field, the electric field responsive polymer contracts in the direction of the electric field and expands in a direction perpendicular to the electric field by Coulomb force. Therefore, a kind of variable capacitor having elasticity like rubber is formed by fixing carbon powder or aluminum powder serving as electrodes on both surfaces of the electric field responsive polymer. When a voltage is applied to this, a positive charge is stored in one electrode and a negative charge is stored in the other electrode. As a result, an attractive force is generated between the electrodes, and the electric field responsive polymer is crushed by this force and expands in the surface direction. The use of this change as an actuator for a robot or the like has attracted attention (see, for example, Patent Documents 1 and 2).

Furthermore, in recent years, global warming has become a serious social problem, there is no problem of CO ₂ emissions, and it is difficult to achieve with existing power generation methods such as generators (for example, required for wave power generation) Development of a power generation device that converts kinetic energy of 0.3 Hz) or non-constant frequency vibration (vibration with an undefined period) into electrical energy is required.
US Pat. No. 6,781,284 U.S. Pat. No. 6,882,086

  However, it is hardly known that electric field responsive polymers have remarkable performance in power generation, and although there are proposals for application to power generation, practical power generators have not been realized. . As one of the causes, in order to use the electric field responsive polymer as a power generation element, it is necessary to apply initial electric energy at an early stage of power generation, that is, in a state where the electric field responsive polymer is stretched, with good timing. In addition, it is necessary to provide an initial electric energy supply means such as a secondary battery or a capacitor for storing electric power generated by the electric field responsive polymer itself and using it as initial electric energy. Furthermore, it is necessary to switch the supply of the initial electric energy and the extraction of the output electric energy from the electric field responsive polymer with good timing according to the deformation state of the electric field responsive polymer. It was an obstacle when used as an element.

  Therefore, the technical problem to be solved by the present invention, that is, the object of the present invention is to realize a power generator using an electric field responsive polymer without providing a separate initial voltage supply means such as a secondary battery or a capacitor. In addition, it is an object of the present invention to provide a power generator that can be used in various conditions and in various fields by optimizing the timing of supply of initial electric energy and extraction of output electric energy with a simple mechanism.

  First, the invention according to claim 1 converts the axial movement of the piston shaft into a force that deforms the electric field responsive polymer, and the electric field responsive polymer according to the deformation state of the electric field responsive polymer. A power generation unit that switches between the supply of initial electric energy to the output of the electric field responsive polymer and the output of electric energy from the electric field responsive polymer; boosts the initial electric energy supplied to the electric field responsive polymer; An electric field responsive polymer comprising: a voltage conversion unit for stepping down output electric energy output from a polymer; and a power storage unit for storing output electric energy stepped down by the power conversion unit and discharging to an external load. In the power generation device used, the piezoelectric element that generates the initial electrical energy is disposed in the power generation unit portion, thereby solving the problem.

The main material of the piezoelectric element in the present invention is not particularly limited as long as it generates a sufficient electromotive force by pressing. For example, polyvinylidene fluoride (PVDF), lead zirconate titanate ( PZT) and barium titanate (BaTiO ₃ ) can be used.

  The invention according to claim 2 further solves the problem in the power generation device using the electric field responsive polymer according to claim 1, wherein the piezoelectric element is polyvinylidene fluoride. .

  The invention according to claim 3 is the power generation device using the electric field responsive polymer according to claim 1 or 2, wherein the electric field responsive polymer is arranged such that the negative electrode is disposed outside. The above-mentioned problem is further solved by laminating two sheets integrally.

  The electric field responsive polymer in the present invention is a new material developed by SRI International based in California, USA, and is an elastic thin polymer (such as acrylic resin or silicone resin) ( It has a structure in which a dielectric elastomer) is sandwiched between flexible electrodes that can be expanded and contracted, and is commercially available under the trade name EPAM (Electroactive Polymer Artificial Muscle).

  Here, an outline of the principle of power generation by the electric field responsive polymer will be described with reference to FIGS.

  The electric field responsive polymer 1 is composed of a polymer film 1a such as an acrylic resin or a silicone resin sandwiched between two flexible electrodes 1b and 1c. In the actuation (driving) mode that has been widely used in the past, when a potential difference is applied between the electrodes as shown in FIG. 1, the polymer film 1a contracts in the thickness direction due to electrostatic force, and as a result, the electric field response is high. Molecule 1 extends in the plane direction.

  On the other hand, in the power generation mode, as shown in FIG. 2, the movement opposite to that of the actuation (drive) mode, that is, the electric field responsive polymer 1 is subjected to external pressure such as wave force, wind force, hydraulic power and human action, and extension force. To generate electric power by stretching the electric field responsive polymer 1.

  In these modes, the electric field responsive polymer 1 is considered to function like a variable capacitor. When the electric field responsive polymer 1 is stretched by some force, the electric field responsive polymer 1 is given a small amount of electric charge as a source of power generation. This charge appears on the surface of the polymer film 1 a of the electric field responsive polymer 1. When the film relaxes, the elastic force of the electric field responsive polymer 1 works against the electric field pressure, and as a result, electric energy increases. Microscopically, charges are pushed toward the electrodes 1b and 1c by the elastic force of the polymer film 1a (the thickness of the polymer film 1a increases in the contracted state), and between the charges on the electrodes 1b and 1c. The distance becomes shorter (the plane area decreases in the contracted state).

  Such a change in charge increases the voltage difference. As a result, the amount of electrostatic energy is increased, and electric energy can be supplied to an external load, and the electric field responsive polymer functions as a power generation element.

  According to the power generation device using the electric field responsive polymer of the present invention, the axial movement of the piston shaft is converted into a force that deforms the electric field responsive polymer, and the electric field responsive polymer according to the deformation state of the electric field responsive polymer. A power generation unit that switches between supply of initial electric energy to the electric field responsive polymer and output of electric electric energy from the electric field responsive polymer, and boosts the initial electric energy supplied to the electric field responsive polymer And a voltage conversion unit for stepping down the output electric energy output from the electric field responsive polymer, and a power storage unit for storing the output electric energy stepped down by the power conversion unit and discharging to an external load. Therefore, the kinetic energy applied to the electric field responsive polymer can be efficiently converted into electric energy, and the initial electric energy can be reduced. Optimization of the timing of supply and extraction of output electric energy can be achieved with a simple mechanism, so that motion in the low frequency band (for example, 0.3 Hz required for wave power generation), irregular vibrations and one-time It is possible to realize a power generation device that can be used in various conditions and fields such as non-low-frequency motion, and in addition, has the following special effects corresponding to the configuration specific to each claim: it can.

  That is, according to the power generation device using the electric field responsive polymer according to the first aspect, since the piezoelectric element that generates initial electric energy is arranged in the power generation unit portion, the piezoelectric element is Since the initial electric energy is generated in response to the deformation of the conductive polymer, a power generation device using an electric field responsive polymer is realized without providing an initial electric energy supply means using a secondary battery or a capacitor. can do.

  According to the power generation device using the electric field responsive polymer according to claim 2, in the electric power generation device using the electric field responsive polymer according to claim 1, the piezoelectric element is polyvinylidene fluoride. Since polyvinylidene fluoride has excellent piezoelectric properties and elasticity close to that of an electric field responsive polymer, initial electrical energy can be generated efficiently.

  According to the invention of claim 3, in the power generation device using the electric field responsive polymer according to claim 1 or 2, the electric field responsive polymer is arranged such that the negative electrode is arranged outside. Since the two sheets are laminated together, the both sides of the electric field responsive polymer become negative electrode films, so there is a high electric field between the electric shock and the electric field responsive polymer and the housing of the power generation unit. The occurrence of (discharge) is avoided and the safety of the power generation device using the electric field responsive polymer is dramatically improved.

  Moreover, since the two electric field responsive polymers are connected in parallel, the output electric energy can be increased.

  The power generation device using the electric field responsive polymer of the present invention converts the axial movement of the piston shaft into a force that deforms the electric field responsive polymer, and changes the electric field according to the deformation state of the electric field responsive polymer. A power generation unit for switching between supply of initial electric energy to the responsive polymer and output of electric energy from the electric field responsive polymer; and boosting the initial electric energy supplied to the electric field responsive polymer A voltage conversion unit for stepping down output electric energy output from the electric field responsive polymer; and a power storage unit for storing output electric energy stepped down by the power conversion unit and discharging to an external load, Since the piezoelectric element that generates initial electrical energy is disposed in the power generation unit, an initial voltage supply unit such as a secondary battery or a capacitor is separately provided. A power generator using an electric field responsive polymer is realized, and the timing of initial electric energy supply and output electric energy extraction is optimized with a simple mechanism and used in various conditions and fields. As long as it is possible, any specific embodiment may be used.

  Hereinafter, a power generator using an electric field responsive polymer (hereinafter referred to as EPAM) according to an embodiment of the present invention will be described with reference to FIGS.

  Here, FIG. 3 is an overall configuration diagram of the power generation apparatus using the EPAM that is Embodiment 1 of the present invention, and FIG. 4 is an enlarged cross-sectional view of the power generation unit portion indicated by reference numeral 10 in FIG. 5 is an enlarged cross-sectional view of the EPAM cartridge, which is a main component of the power generation unit shown in FIG. 4, and FIG. 6 shows a specific example of the power generation apparatus using the EPAM shown in FIG. It is an example of a simple circuit configuration diagram. 4 shows that the EPAM shown in FIG. 3 is in a relaxed state while the EPAM shown in FIG. 4 is in a relaxed state for convenience of explanation. Yes.

  First, the power generator using the EPAM according to the first embodiment of the present invention converts the axial movement of the piston shaft 11 into a force for extending or relaxing the EPAM 12 as shown in FIGS. At the same time, according to the deformation state of the EPAM 12, that is, in a state where the EPAM 12 is expanded, the charging terminal 13 and the EPAM plus terminal 16a are contacted to supply the initial electrical energy to the EPAM 12, and the EPAM 12 is discharged in a relaxed state. The power generation unit 10 has a switching function in which the terminal 14 and the EPAM plus terminal 16a are in contact with each other and output electric energy from the EPAM 12 is output.

  When the axial force F is applied to the piston shaft 11, the EPAM 12 is expanded, and the charging terminal 13 is insulated from the bottom plate 10 a of the power generation unit 10 and the charging terminal 13 made of a copper plate or the like. As a result, the generated initial electrical energy is boosted by the boosting circuit 22 of the voltage conversion unit 20 and supplied to the EPAM 12 in the expanded state via the charging terminal 13.

  On the other hand, when the force F applied to the piston shaft 11 is eliminated and the EPAM 12 is in a relaxed state, the EPAM 12 is in a small area due to its own elastic force. As a result, as shown in FIG. 4, the discharge terminal 14 fixed to the top plate 10 b of the power generation unit 10 and the EPAM plus terminal 16 a come into contact with each other, and the output electric energy generated by the EPAM 12 is converted into the voltage down converter of the voltage converter 20. The voltage is stepped down by 24, stored in the power storage unit 30, and discharged to an external load as necessary.

  A push plate 15 is vertically joined to the piston shaft 11, and by applying or eliminating force F to the push plate 15, the piston shaft 11 moves in the axial direction to extend the EPAM 12. To relax.

  Here, based on FIG.4 and FIG.5, the structure of the electric power generation unit part 10 is demonstrated in more detail. The power generation unit 10 is supported by a peripheral support member 16c in which a polymer film 12a of an EPAM 12 having a substantially circular shape, and a flexible EPAM plus electrode film 12b and an EPAM minus electrode film 12c bonded thereto are integrated. An EPAM cartridge 16 is provided. At this time, the EPAM plus electrode film 12b and the EPAM minus electrode film 12c are eccentrically joined to the polymer film 12a. An EPAM plus electrode 16d that conducts to the EPAM plus electrode film 12b and an EPAM minus electrode 16e that conducts to the EPAM minus electrode film 12c are provided at positions facing each other across the center of the peripheral support member 16c, that is, a position on one diameter. It has been.

  The EPAM 12 is sandwiched by a central support member 16b made of an insulating material such as a resin at the center thereof, and sandwiched by EPAM plus terminals 16a made of a conductive material such as copper on both outer sides thereof, and by through bolts 16f made of a conductive material. The EPAM plus terminal 16a, the central support member 16b, and the EPAM 12 are fastened together. Furthermore, the EPAM plus electrode 16d and the EPAM plus terminal 16a are connected by a conducting wire 16g, and the two EPAM plus terminals 16a provided so as to sandwich the EPAM 12 are, as described above, through-bolts made of a conductive material. Since the connection is made by 16f, EPAM plus terminals 16a that are connected to the EPAM plus electrode film 12b are arranged on both sides of the center of the EPAM cartridge 16. When the EPAM plus terminal 16a is in contact with the charging terminal 13 or the discharging terminal 14 of the power generation unit section 10, supply of initial electric energy to the EPAM 12 corresponding to the deformation state of the EPAM 12 and output of output electric energy from the EPAM 12 Are switched.

  As the step-up circuit 22 and step-down circuit 24 constituting the first embodiment, commercially available general-purpose step-up circuits and step-down circuits can be used, and FIG. 3 shows an example of a specific circuit configuration thereof. It is described in correspondence with the overall configuration diagram. Therefore, the components corresponding to those shown in FIG. That is, the block denoted by reference numeral 10 in FIG. 6 is a power generation unit section. SW1 corresponds to the EPAM plus terminal 16a and the charging terminal 13 in FIG. 3, and is turned ON when the piston shaft 11 is pushed and the EPAM 12 is in the extended state (that is, the state shown in FIG. 3). It turns OFF when the force applied to the shaft 11 is released.

  On the other hand, SW2 corresponds to the EPAM plus terminal 16a and the discharge terminal 14 in FIG. 3, and when the force applied to the piston shaft 11 is released and the EPAM 12 is completely contracted by its own elasticity (that is, When the force is applied to the piston shaft 11, it is turned OFF. As described above, the power generation unit 10 of the present invention has an extremely simple configuration in which the EPAM plus terminal 16a and the charging terminal 13 or the discharging terminal 14 are brought into a contact state or a non-contact state by utilizing the elasticity of the EPAM 12. The timing of initial electric energy supply and output electric energy extraction is optimized.

  The block denoted by reference numeral 22 in FIG. 6 is a booster circuit for boosting the low-voltage electrical energy obtained from the piezoelectric element 17 and supplying it to the EPAM 12 as initial electrical energy. In the example shown in FIG. 6, the primary voltage is boosted by an inverter circuit composed of a transistor, a capacitor, a coil, a transformer, etc., and then the output voltage of the inverter circuit is quadrupled by a multistage voltage doubler rectifier circuit composed of a capacitor and a diode. To the power generation unit section 10. Specifically, the voltage of about 3.5 V obtained from the piezoelectric element 17 is increased to 700 to 800 V by an inverter circuit, and further boosted to 2800 to 3200 V, which is four times that by a multistage voltage doubler rectifier circuit. Supply.

  The block denoted by reference numeral 24 is a step-down circuit for stepping down the high-voltage output electrical energy output from the power generation unit unit 10 to a low voltage suitable for charging a storage battery or the like of the power storage unit 30. It is. Here, the voltage is stepped down by a step-down circuit including a pulse generator, a MOSFET, a transformer, and the like. In this embodiment, one piezoelectric element 17 is used as a source of initial electrical energy. However, by using a plurality of piezoelectric elements stacked in series, the electromotive force is increased, thereby boosting the voltage. It is also possible to simplify the circuit configuration.

  Next, Example 2 which is another embodiment of the present invention will be described with reference to FIG. The power generator using the EPAM according to the second embodiment is different only in the structure of the EPAM cartridge of the power generator using the EPAM described in the first embodiment, and the basic configuration is the same as that of the first embodiment. Therefore, only the structure of the EPAM cartridge is described, and the description of the other configuration is omitted. Further, since the EPAM cartridge shown in FIG. 7 is different from the EPAM cartridge 16 shown in FIG. 5 only in that two EPAMs are laminated, the corresponding members are denoted by the same reference numerals, and detailed description thereof will be made. Is omitted. The EPAM cartridge 16 is disposed so that the two EPAM plus electrode films 12b are in close contact with each other. For this reason, the exposed electrode films of the EPAM cartridge 16 are the negative electrode films 12c and 12c on both sides, so that an electric shock or dielectric breakdown (discharge) due to a high electric field occurs between the EPAM 12 and the housing of the power generation unit section 10. In addition, since the two EPAMs 12 are connected in parallel, the output electrical energy can be increased.

  The power generation device using the electric field responsive polymer of the present invention is not separately provided with an initial voltage supply means such as a secondary battery or a capacitor, has a simple configuration, requires almost no maintenance, and has various conditions and fields. Power generation devices that can be used in the field, including power generation by gentle movements of wave power, hydropower, wind power, etc., for example, using power devices for tire pressure sensors, shaking of tree trunks and branches Power generation, power generation using gas pressure such as exhaust gas, power generation using water pressure such as drainage, power generation due to vibration and impact generated when the vehicle travels, power generation by human power as an emergency power source, pressure generated in a narrow space such as in a tunnel Its industrial applicability, such as power generation by change, is extremely high.

The figure explaining the operation principle of the drive mode of the electric field responsive polymer used for this invention. The figure explaining the operation | movement principle of the electric power generation mode of the electric field responsive polymer used for this invention. 1 is an overall configuration diagram of Embodiment 1 of the present invention. The expanded sectional view of the electric power generation unit part shown in FIG. FIG. 5 is an enlarged cross-sectional view of the EPAM cartridge shown in FIG. FIG. 3 is a specific circuit configuration diagram of the first embodiment. FIG. 4 is an enlarged cross-sectional view of an EPAM cartridge of Example 2.

Explanation of symbols

1 ... Electric field responsive polymer (EPAM)
1a: polymer film 1b (of electric field responsive polymer), 1c: electrode (of electric field responsive polymer)
DESCRIPTION OF SYMBOLS 10 ... Power generation unit part 10a ... Bottom plate 10b (of power generation unit part) ... Top plate 11 (of power generation unit part) ... Piston shaft 12 ... Electric field responsive polymer (EPAM)
12a ... Polymer film 12b ... EPAM plus electrode film 12c ... EPAM minus electrode film 13 ... Charging terminal 14 ... Discharge terminal 15 ... Push plate 16 ... EPAM cartridge 16a ... EPAM plus terminal 16b (for EPAM cartridge) Central support member 16c (for EPAM cartridge) Peripheral support member 16d (for EPAM cartridge) EPAM plus electrode 16e (for EPAM cartridge) EPAM negative electrode 16f (of the EPAM cartridge) ... through bolt 16g (of the EPAM cartridge) ... conductive wire 17 (of the EPAM cartridge) ... piezoelectric element 20 ... voltage converter 22 ... boost circuit 24 ...・ Step-down circuit 30 ・ ・ ・ Power storage unit

Claims (3)

The axial motion of the piston shaft is converted into a force that deforms the electric field responsive polymer, and the initial electric energy is supplied to the electric field responsive polymer and the electric field responsiveness according to the deformation state of the electric field responsive polymer. A power generation unit that switches between output of electrical energy from the polymer, and
A voltage converter that steps up the initial electrical energy supplied to the electric field responsive polymer and lowers the output electric energy output from the electric field responsive polymer;
A power generation device using an electric field responsive polymer comprising a storage unit for storing output electric energy stepped down by the power conversion unit and a storage unit for discharging to an external load,
A power generation apparatus using an electric field responsive polymer, wherein the piezoelectric element that generates the initial electric energy is disposed in the power generation unit section.   The power generation apparatus using an electric field responsive polymer according to claim 1, wherein the piezoelectric element is polyvinylidene fluoride.   3. The power generation device using the electric field responsive polymer according to claim 1, wherein the electric field responsive polymer is laminated in one piece so that the negative electrode is disposed outside. .

Images