WO2015023015A1 - Piezoelectric harvesting system using compression force - Google Patents
Piezoelectric harvesting system using compression force Download PDFInfo
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- WO2015023015A1 WO2015023015A1 PCT/KR2013/007393 KR2013007393W WO2015023015A1 WO 2015023015 A1 WO2015023015 A1 WO 2015023015A1 KR 2013007393 W KR2013007393 W KR 2013007393W WO 2015023015 A1 WO2015023015 A1 WO 2015023015A1
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/30—Piezoelectric or electrostrictive devices with mechanical input and electrical output, e.g. functioning as generators or sensors
- H10N30/304—Beam type
- H10N30/306—Cantilevers
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- a piezoelectric harvesting system using a compressive force is disclosed. More specifically, a piezoelectric harvesting system using a compressive force capable of significantly increasing the amount of power generated by applying a sufficient compressive force to the piezoelectric body while preventing damage to the piezoelectric body using mainly external force applied to the piezoelectric body as a compressive force is disclosed.
- piezoelectric energy harvesting which can be used as renewable energy at relatively fine energy among recent renewable energy, has been studied, and much attention has been drawn to industrialization.
- a piezoelectric system has a relatively low toughness of the piezoelectric body (a material having low toughness is very weak against tensile stress).
- a piezoelectric system using a blow or vibration used so far i.e., a system in which tensile stress is applied to the piezoelectric body, is relatively low. Not only are they damaged in a short time of use, but there is a disadvantage that sufficient power generation cannot be obtained because the tensile stress applied to the piezoelectric body is small.
- An object according to an embodiment of the present invention is to provide a piezoelectric harvesting system that can take the compressive force of the external force generated by the load and the strike and generate electrical energy using the same.
- another object according to an embodiment of the present invention is to provide a piezoelectric harvesting system capable of preventing damage to the piezoelectric body by mainly applying a compressive force to the piezoelectric material having a weak property to the tensile force.
- another object according to the embodiment of the present invention by applying a compressive force to the piezoelectric can use the high compressive stress characteristics of the piezoelectric, through which high compressive force can be applied to the piezoelectric itself, high repulsive force that takes a large force on the piezoelectric crystal It is to provide a piezoelectric harvesting system that can generate a high load capacity and, as a result, obtain a high generation amount from the piezoelectric body.
- the piezoelectric material is provided with a piezoelectric material; And a fixture to which the piezoelectric body is attached; It includes, the piezoelectric body is attached to one surface on which the fixture is compressed, when a compressive force is applied to the fixture may be applied to the piezoelectric force to generate electrical energy.
- the fixture further includes a fixing support to be mounted in a cantilever type, it is possible to apply a compressive force to the fixture by hitting an area of the fixture with the piezoelectric body is not attached.
- it may further include a tension preventing member attached to the other surface of the fixture to prevent the fixture from being tensioned in the process of being restored after receiving the compressive force.
- the coating on one surface of the piezoelectric may further include a coating to prevent the piezoelectric peeling off.
- the position of the neutral axis (neutral axis) can be adjusted, as a result, the conventional piezoelectric harvesting that the compressive stress can mainly act on the piezoelectric, which is a tensile stress
- the piezoelectric damage can be reduced as compared to the casting system, and high compressive stress is applied, thereby greatly increasing the amount of power generated.
- the fixture may be manufactured in a plate type using stainless steel (stainless steel).
- it may further include a crack which is mounted on the opposite side of one surface of the piezoelectric body attached to the fixed body to withstand the compressive force applied to the piezoelectric body.
- the piezoelectric harvesting system according to an embodiment of the present invention, a fixed body, a piezoelectric material attached to one surface of the fixed body and provided with a piezoelectric material and a striking member hitting the other surface of the fixed body is not attached to the piezoelectric body.
- the fixture may be bent toward the striking direction.
- the apparatus may further include a tension preventing member attached to the other surface of the fixing body to reduce the degree of bending of the piezoelectric body in a direction opposite to the hitting direction.
- the compressive force is applied among the external forces generated by the load and the hitting, and electric energy can be generated using the same.
- a compressive force to the piezoelectric can use the high compressive stress characteristics of the piezoelectric, through which a high compressive force can be applied to the piezoelectric itself, thereby providing a high repulsive force and a high strength that takes a large force on the piezoelectric crystal It is possible to generate high power from the piezoelectric body.
- the load on the fixing body is reduced to prevent deformation and damage of the fixing body.
- the elastic force of the piezoelectric body itself is used, so that the burden on the fixing body is reduced, so that the thickness of the fixing body can be made thinner than before, thereby reducing the material cost and weight of the fixing body.
- FIG. 1 is a view schematically showing a piezoelectric harvesting system using a compressive force according to an embodiment of the present invention.
- FIG. 2 is a view schematically illustrating a coupling structure of the fixture and the piezoelectric body shown in FIG. 1.
- FIG. 3 is a view for explaining the structure in which the piezoelectric body shown in FIG. 2 is coated with a coating agent.
- FIG. 4 is a diagram illustrating a state in which a piezoelectric body is compressed when a force acts in one direction.
- FIG. 5 is a diagram illustrating a state in which a piezoelectric body is compressed when a force in a direction opposite to that of FIG. 4 is applied.
- FIG. 7 is a graph showing a change in power generation amount according to the number of revolutions when alternating tension and compression are applied with one piezoelectric body.
- FIG. 1 is a view schematically showing a piezoelectric harvesting system using a compressive force according to an embodiment of the present invention
- FIG. 2 is a view schematically showing a coupling structure of a fixture and a piezoelectric body shown in FIG. 3 is a view for explaining a structure in which the piezoelectric body shown in FIG. 2 is coated with a coating agent
- FIG. 4 is a view illustrating a state in which the piezoelectric body is compressed when a force acts in one direction
- FIG. The piezoelectric element is compressed when the force in the opposite direction to the force action direction is applied.
- the piezoelectric harvesting system 100 using a compressive force includes a fixture 102, a piezoelectric member 103 attached to one surface of the fixture 102, and a piezoelectric harvesting system 100.
- the fixing support 107 is fixed to one side of the fixing body 102 so that the fixing body 102 becomes a cantilever type, and it is mounted on the other surface of the fixing body 102 so that a tension force is generated in the fixing body 102. It may include a tension preventing member 105 to block.
- the coating agent 104 may be coated on one surface of the piezoelectric material 103.
- Fixing body 102 of the present embodiment is provided in a flat plate (plate) type can be mounted on the fixed support cantilever type, one side of the fixing body 102, in the present embodiment the piezoelectric material 103 is attached to the lower surface Can be.
- the piezoelectric material 103 of the present embodiment is basically a ceramic piezoelectric element having a high generation amount, and has excellent physical flexibility, such that a polymer or a hybrid piezoelectric element in which a polymer and a ceramic are mixed may be used. Therefore, it is durable due to its excellent physical flexibility and is therefore easy to develop.
- PVDF is basic, and may include barium titanate, PZT crystal, or PZT fiber.
- Lead-free piezoelectric materials such as NKN, BZT-BCT, BNT, BSNN, and BNBN, PLZT, P (VDF-TrFE), quartz, tourmaline, Rochelle salt, barium titanate, dihydrogen phosphate Ammonium, ethylene tartarate, etc. can be used.
- the type and material of the piezoelectric material 103 are not limited thereto, and it is natural that other materials may be used as long as sufficient power generation can be generated by external force.
- the piezoelectric material 103 may be attached to one surface to be compressed when an external force is applied on both sides of the fixture 102, and when the external force is applied to the fixture 102 to deform the fixture 102, That is, when one surface of the fixture 102 is bent inward, the piezoelectric body 102 may also be compressed.
- the fixture 102 may be made of a metal material, for example, stainless steel. Due to such a material, when a hit is applied to the fixing body 102, the fixing body 102 may be deformed in the compression direction, and when the external force is lost, the fixing body 102 may be returned to its original state. In addition, the durability can be minimized to minimize the occurrence of deformation.
- the material of the fixing body 102 is not limited thereto.
- the width of the fixture 102 of the present embodiment is formed to be wider than the width of the piezoelectric material 103, through which the deformation on the piezoelectric material 103 by the impact applied to one surface of the fixture 102, as well as to the external force It can maximize the hit area by
- a coating agent 104 may be coated on the piezoelectric material 103 of the present embodiment to prevent the piezoelectric material 103 from peeling off.
- the coating agent 104 of the present embodiment is made of a coating material that is ductile and can be coated as thin as possible. This is because, when the ductility of the coating agent 104 is poor, the coating agent 104 absorbs the compressive stress that must act on the piezoelectric member 103, so that a small force is applied to the piezoelectric member 103, and thus the amount of power generation can be reduced. In addition, when the coating agent 104 is thickly used, a tensile force rather than a compressive force is applied to the piezoelectric material 103, thereby reducing power generation as well as durability.
- the piezoelectric harvesting system 100 may further include a striking member (not shown) that strikes the other surface of the fixture 102 to which the piezoelectric member 103 is not attached, and the fixture 102 may be bent toward the striking direction. have.
- the piezoelectric member 103 is formed so that the compressive force mainly acts. This may be implemented by adjusting the thickness of the fixture 102 and the piezoelectric member 103, and adjusting the position of the neutral axes A1, A2, and neutral axes.
- the compressive force may mainly act on the piezoelectric member 103, thereby reducing the damage of the piezoelectric member 103, and taking a high compressive stress, thereby reducing the amount of power generated by the conventional piezoelectric harvesting system in which tensile force is mainly applied. Can be increased.
- the neutral axes A1 and A2 may be set to be the top or bottom of the piezoelectric member 103 according to the direction of the force F acting on the piezoelectric member 103.
- the neutral shafts A1 and A2 are moved according to the state of the piezoelectric harvesting system of FIG. 4 and the magnitude of the force F applied to the piezoelectric harvesting system of FIG. 5, the thickness of the piezoelectric member 103 according to the respective situation. And the neutral shafts A1 and A2 are brought into place by adjusting the thickness of the fixture 102. At this time, when the direction of the force F is directed downward (see Fig. 4), the neutral axis (top) is placed on the top of the piezoelectric member 103 when the direction of the force F is directed upward (see Fig. 5). A1, A2) can be set to come.
- the thinner the thickness of the fixture 102 the lower the movement of the system due to the movement in the negative direction. Since the piezoelectric material 103 may be cracked, the thickness of the fixture 102 may be set so that such a fear does not occur.
- cracks may be formed on the other surface of the piezoelectric member 103 positioned on the opposite side of the surface of the fixed body 102 and the piezoelectric member 103 attached thereto.
- the crack may be formed in a direction perpendicular to the compressive force applied to the piezoelectric material 103.
- Such a crack may function to make the piezoelectric member 103 better withstand the compressive force.
- the piezoelectric member 103 according to the present embodiment is compressively deformed, so that a high generation amount can be obtained even if there is a crack.
- the tension preventing member 105 may be attached to one surface of the fixture 102 facing the piezoelectric member 103 of the present embodiment.
- the tension preventing member 105 may prevent the piezoelectric body 103 from being deformed.
- the piezoelectric member 103 when the piezoelectric member 103 is pressurized in the compression direction (strike direction), it may be bent upward while being bent, at which time the piezoelectric member 103 and the fixing body 102 are prevented from bending.
- the 105 it is possible to prevent the tensile force from being applied to the piezoelectric member 103 due to the deformation.
- the external force generated by the load and hitting the compressive force is applied and can be used to generate electrical energy, by applying a compressive force mainly to the piezoelectric material (103) of weak properties to the tensile force Damage to the piezoelectric member 103 can be prevented, and by applying a compressive force to the piezoelectric member 103, a high compressive stress characteristic of the piezoelectric member 103 can be used, and thus high compressive force can be applied to the piezoelectric member 103 itself. It is possible to create a high repulsion force and proof strength that takes a large force in the piezoelectric crystal, and as a result there is an advantage that can obtain a high power generation amount in the piezoelectric material (103).
- the elastic force of the piezoelectric body 103 itself is sufficiently used to reduce the load on the fixing body 102 to prevent deformation and damage of the fixing body 102, and furthermore, the piezoelectric body 103 itself. Because of the use of the elastic force of the load on the fixture 102 is reduced, there is also an advantage that can reduce the material cost and weight of the fixture 102 by making the thickness of the fixture 102 thinner than conventional.
- FIG. 6 is a graph showing a change in power generation amount according to the number of revolutions when alternating tension and compression are applied with one piezoelectric body.
- the maximum amount of power generation is shown at 400 to 420 rpm in both the case where the tensile force is applied to the piezoelectric body and the compressive force is applied to the piezoelectric body.
- the average power using the tensile force is about 45mW
- the average power using the compressive force is about 65mW
- the power generation using the tensile force is stopped at 530rpm, the power generation using the compression force can be seen through Figure 6 that the power generation is gradually reduced while continuing to generate power even beyond 650rpm, so the piezoelectric harvesting system using the compressive force is a system using the tensile force It can be seen that it has more excellent durability.
- Figure 7 is a graph obtained by performing an optimization experiment of power generation using a compressive force with another piezoelectric body.
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Abstract
Description
압축력을 이용한 압전 하베스팅 시스템이 개시된다. 보다 상세하게는, 압전체에 걸리는 외력을 주로 압축력으로 사용하여 압전체의 손상을 방지하는 동시에 압전체에 충분한 압축력을 가함으로써 발전량을 비약적으로 증대시킬 수 있는 압축력을 이용한 압전 하베스팅 시스템이 개시된다.A piezoelectric harvesting system using a compressive force is disclosed. More specifically, a piezoelectric harvesting system using a compressive force capable of significantly increasing the amount of power generated by applying a sufficient compressive force to the piezoelectric body while preventing damage to the piezoelectric body using mainly external force applied to the piezoelectric body as a compressive force is disclosed.
최근 자연의 에너지 사용 비중이 꾸준히 늘어나고 있으며 발전량의 크기도 점점 대형화되고 있어 이를 위한 발전 시스템의 용량도 점점 늘어나고 있다. 일반적인 신재생의 에너지 발전, 태양광이나 풍력 발전의 경우 불규칙한 자연에너지로 인하여 발전량이 안정적이지 못하고 사람들로부터 멀리 떨어진 곳에 설치하여야 되는 문제가 있어 추가적인 발전 시스템이 고려되고 있다.Recently, the share of energy use in nature is steadily increasing, and the size of power generation is also getting bigger and larger, and the capacity of the power generation system is increasing. In the case of general renewable energy generation, photovoltaic or wind power generation, there is a problem that power generation is not stable due to irregular natural energy and needs to be installed far from people.
이러한 문제점을 해결하기 위해 여러 형태의 분산전원으로서 초전도 발전 시스템이 고려되고 있으나, 신재생 에너지의 발전 효율 등을 고려할 때, 압전 발전 시스템의 개발이 진행 중이다.In order to solve this problem, superconducting power generation systems have been considered as various types of distributed power sources. However, considering the generation efficiency of renewable energy, piezoelectric power generation systems are under development.
한편, 최근 신재생 에너지 중에서도 비교적 미세한 에너지에서 재생 에너지로 사용할 수 있는 압전 에너지 하베스팅이 연구되고, 또한 산업화에 많은 관심이 모아지고 있다.On the other hand, piezoelectric energy harvesting, which can be used as renewable energy at relatively fine energy among recent renewable energy, has been studied, and much attention has been drawn to industrialization.
일반적으로 압전체를 이용한 시스템은, 압전체 본체의 인성이 비교적 작기 때문에(인성이 낮은 물질은 인장 응력에 대해 매우 약함) 지금까지 사용한 타격 혹은 진동을 이용하는 압전 시스템, 즉 압전체에 인장 응력이 걸리는 시스템은 비교적 짧은 사용시간에 손상될 뿐만 아니라 압전체에 걸리는 인장 응력이 작기 때문에 충분한 발전량을 얻을 수 없다는 단점이 있었다. In general, a piezoelectric system has a relatively low toughness of the piezoelectric body (a material having low toughness is very weak against tensile stress). Thus, a piezoelectric system using a blow or vibration used so far, i.e., a system in which tensile stress is applied to the piezoelectric body, is relatively low. Not only are they damaged in a short time of use, but there is a disadvantage that sufficient power generation cannot be obtained because the tensile stress applied to the piezoelectric body is small.
본 발명의 실시예에 따른 목적은, 하중 및 타격에 의해 발생되는 외력 중 압축력이 걸리고 이를 이용하여 전기에너지를 생성할 수 있는 압전 하베스팅 시스템을 제공하는 것이다.An object according to an embodiment of the present invention is to provide a piezoelectric harvesting system that can take the compressive force of the external force generated by the load and the strike and generate electrical energy using the same.
또한 본 발명의 실시예에 따른 다른 목적은, 인장력에 약한 성질의 압전체에 주로 압축력을 가해줌으로써 압전체의 손상을 방지할 수 있는 압전 하베스팅 시스템을 제공하는 것이다.In addition, another object according to an embodiment of the present invention is to provide a piezoelectric harvesting system capable of preventing damage to the piezoelectric body by mainly applying a compressive force to the piezoelectric material having a weak property to the tensile force.
또한 본 발명의 실시예에 따른 다른 목적은, 압전체에 압축력을 걸어 줌으로써 압전체가 가지는 높은 압축 응력 특성을 이용할 수 있으며, 이를 통해 압전체 자체에 높은 압축력을 가할 수 있어 압전 결정에 큰 힘이 걸리는 높은 반발력과 내력을 창출할 수 있으며 그 결과 압전체에서 높은 발전량을 얻을 수 있는 압전 하베스팅 시스템을 제공하는 것이다.In addition, another object according to the embodiment of the present invention, by applying a compressive force to the piezoelectric can use the high compressive stress characteristics of the piezoelectric, through which high compressive force can be applied to the piezoelectric itself, high repulsive force that takes a large force on the piezoelectric crystal It is to provide a piezoelectric harvesting system that can generate a high load capacity and, as a result, obtain a high generation amount from the piezoelectric body.
본 발명의 실시예에 따른 압축력을 이용한 압전 하베스팅 시스템은, 압전 물질로 마련되는 압전체; 및 상기 압전체가 부착되는 고정체; 를 포함하며, 상기 압전체는 상기 고정체가 압축되는 일면에 부착되어 상기 고정체에 압축력이 가해지는 경우 상기 압전체에 압축력이 가해짐으로써 전기에너지를 생성할 수 있다.Piezoelectric harvesting system using a compressive force according to an embodiment of the present invention, the piezoelectric material is provided with a piezoelectric material; And a fixture to which the piezoelectric body is attached; It includes, the piezoelectric body is attached to one surface on which the fixture is compressed, when a compressive force is applied to the fixture may be applied to the piezoelectric force to generate electrical energy.
일측에 의하면, 상기 고정체가 외팔보 타입으로 장착되는 고정지지대를 더 포함하며, 상기 압전체가 미부착된 상기 고정체의 일 영역을 타격함으로써 상기 고정체에 압축력을 가할 수 있다.According to one side, the fixture further includes a fixing support to be mounted in a cantilever type, it is possible to apply a compressive force to the fixture by hitting an area of the fixture with the piezoelectric body is not attached.
일측에 의하면, 상기 고정체의 타면에 부착되어 상기 고정체가 압축력을 받은 후 복원되는 과정에서 인장되는 것을 방지하는 인장 방지체를 더 포함할 수 있다.According to one side, it may further include a tension preventing member attached to the other surface of the fixture to prevent the fixture from being tensioned in the process of being restored after receiving the compressive force.
일측에 의하면, 상기 압전체의 일면에 코팅 처리되어 상기 압전체가 벗겨지는 것을 방지하는 코팅제를 더 포함할 수 있다.According to one side, the coating on one surface of the piezoelectric may further include a coating to prevent the piezoelectric peeling off.
일측에 의하면, 고정체 및 압전체의 두께를 조절하여, 중립축(neutral axis)의 위치를 조정할 수 있으며, 그 결과, 압전체에 주로 압축 응력이 작용할 수 있으며, 이로 인해 인장 응력이 가해지는 종래의 압전 하베스팅 시스템에 비해 압전체 손상을 줄일 수 있고, 또한 높은 압축 응력이 걸림으로써 발전량을 비약적으로 증대시킬 수 있다.According to one side, by adjusting the thickness of the fixed body and the piezoelectric, the position of the neutral axis (neutral axis) can be adjusted, as a result, the conventional piezoelectric harvesting that the compressive stress can mainly act on the piezoelectric, which is a tensile stress The piezoelectric damage can be reduced as compared to the casting system, and high compressive stress is applied, thereby greatly increasing the amount of power generated.
일측에 의하면, 상기 고정체는 스테인리스 스틸(stainless steel)을 이용하여 플레이트(plate) 타입으로 제조될 수 있다.According to one side, the fixture may be manufactured in a plate type using stainless steel (stainless steel).
일측에 의하면, 상기 고정체와 부착되는 상기 압전체의 일면의 반대측에 장착되어 상기 압전체에 가해지는 압축력을 견디도록 하는 크랙을 더 포함할 수 있다.According to one side, it may further include a crack which is mounted on the opposite side of one surface of the piezoelectric body attached to the fixed body to withstand the compressive force applied to the piezoelectric body.
한편, 본 발명의 실시예에 따른 압전 하베스팅 시스템은, 고정체, 상기 고정체의 일면에 부착되며 압전 물질로 마련되는 압전체 및 상기 압전체가 미부착된 상기 고정체의 타면을 타격하는 타격부재를 포함하고, 상기 고정체는 상기 타격 방향 쪽으로 휘어질 수 있다. 또한, 상기 고정체의 타면에 부착되며, 상기 압전체가 상기 타격 방향의 반대 방향으로 휘어지는 정도를 감소시키기 위한 인장 방지체를 더 포함할 수 있다.On the other hand, the piezoelectric harvesting system according to an embodiment of the present invention, a fixed body, a piezoelectric material attached to one surface of the fixed body and provided with a piezoelectric material and a striking member hitting the other surface of the fixed body is not attached to the piezoelectric body. The fixture may be bent toward the striking direction. The apparatus may further include a tension preventing member attached to the other surface of the fixing body to reduce the degree of bending of the piezoelectric body in a direction opposite to the hitting direction.
본 발명의 실시예에 따르면, 하중 및 타격에 의해 발생되는 외력 중 압축력이 걸리고 이를 이용하여 전기에너지를 생성할 수 있다.According to the embodiment of the present invention, the compressive force is applied among the external forces generated by the load and the hitting, and electric energy can be generated using the same.
또한 본 발명의 실시예에 따르면, 인장력에 약한 성질의 압전체에 주로 압축력을 가해줌으로써 압전체의 손상을 방지할 수 있다.In addition, according to the embodiment of the present invention, it is possible to prevent damage to the piezoelectric body by mainly applying a compressive force to the piezoelectric material having a weak property to the tensile force.
또한 본 발명의 실시예에 따르면, 압전체에 압축력을 걸어 줌으로써 압전체가 가지는 높은 압축 응력 특성을 이용할 수 있으며, 이를 통해 압전체 자체에 높은 압축력을 가할 수 있어 압전 결정에 큰 힘이 걸리는 높은 반발력과 내력을 창출할 수 있으며 그 결과 압전체에서 높은 발전량을 얻을 수 있다.In addition, according to an embodiment of the present invention, by applying a compressive force to the piezoelectric can use the high compressive stress characteristics of the piezoelectric, through which a high compressive force can be applied to the piezoelectric itself, thereby providing a high repulsive force and a high strength that takes a large force on the piezoelectric crystal It is possible to generate high power from the piezoelectric body.
또한 본 발명의 실시예에 따르면, 압축 응력을 사용했을 때 압전체 자체의 탄성력을 충분히 사용하므로 고정체에 걸리는 부담이 감소하여 고정체의 변형과 손상을 막을 수 있다.In addition, according to an embodiment of the present invention, when the compressive stress is used, since the elastic force of the piezoelectric body is sufficiently used, the load on the fixing body is reduced to prevent deformation and damage of the fixing body.
또한, 본 발명의 실시예에 따르면, 압전체 자체의 탄성력을 이용하기 때문에 고정체에 걸리는 부담이 감소하여 고정체의 두께를 기존보다 얇게 하여 고정체의 재료비 및 무게를 줄일 수 있다.In addition, according to the embodiment of the present invention, since the elastic force of the piezoelectric body itself is used, the burden on the fixing body is reduced, so that the thickness of the fixing body can be made thinner than before, thereby reducing the material cost and weight of the fixing body.
도 1은 본 발명의 일 실시예에 따른 압축력을 이용한 압전 하베스팅 시스템을 개략적으로 도시한 도면이다.1 is a view schematically showing a piezoelectric harvesting system using a compressive force according to an embodiment of the present invention.
도 2는 도 1에 도시된 고정체 및 압전체의 결합 구조를 개략적으로 도시한 도면이다.FIG. 2 is a view schematically illustrating a coupling structure of the fixture and the piezoelectric body shown in FIG. 1.
도 3은 도 2에 도시된 압전체가 코팅제에 의해 코팅되는 구조를 설명하기 위한 도면이다.3 is a view for explaining the structure in which the piezoelectric body shown in FIG. 2 is coated with a coating agent.
도 4는 힘이 일 방향으로 작용하는 경우 압전체가 압축되는 상태를 도시한 도면이다.4 is a diagram illustrating a state in which a piezoelectric body is compressed when a force acts in one direction.
도 5는 도 4의 힘 작용 방향과 반대 방향의 힘이 작용하는 경우 압전체가 압축되는 상태를 도시한 도면이다.FIG. 5 is a diagram illustrating a state in which a piezoelectric body is compressed when a force in a direction opposite to that of FIG. 4 is applied.
도 7은 하나의 압전체를 가지고 인장과 압축을 교대로 가할 때 회전수에 따른 발전량의 변화를 나타낸 그래프이다.7 is a graph showing a change in power generation amount according to the number of revolutions when alternating tension and compression are applied with one piezoelectric body.
도 7은 다른 압전체를 가지고 압축력을 이용한 발전의 최적화 실험을 수행함으로써 획득된 그래프이다.7 is a graph obtained by performing an optimization experiment of power generation using compression force with another piezoelectric body.
이하, 첨부 도면을 참조하여 본 발명의 실시예에 따른 구성 및 적용에 관하여 상세히 설명한다. 이하의 설명은 특허 청구 가능한 본 발명의 여러 태양(aspects) 중 하나이며, 하기의 기술(description)은 본 발명에 대한 상세한 기술(detailed description)의 일부를 이룬다. Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the configuration and application according to an embodiment of the present invention. The following description is one of several aspects of the patentable invention and the following description forms part of the detailed description of the invention.
다만, 본 발명을 설명함에 있어서, 공지된 기능 혹은 구성에 관한 구체적인 설명은 본 발명의 요지를 명료하게 하기 위하여 생략하기로 한다.However, in describing the present invention, a detailed description of known functions or configurations will be omitted for clarity of the gist of the present invention.
도 1은 본 발명의 일 실시예에 따른 압축력을 이용한 압전 하베스팅 시스템을 개략적으로 도시한 도면이고, 도 2는 도 1에 도시된 고정체 및 압전체의 결합 구조를 개략적으로 도시한 도면이고, 도 3은 도 2에 도시된 압전체가 코팅제에 의해 코팅되는 구조를 설명하기 위한 도면이며, 도 4는 힘이 일 방향으로 작용하는 경우 압전체가 압축되는 상태를 도시한 도면이고, 도 5는 도 4의 힘 작용 방향과 반대 방향의 힘이 작용하는 경우 압전체가 압축되는 상태를 도시한 도면이다.1 is a view schematically showing a piezoelectric harvesting system using a compressive force according to an embodiment of the present invention, FIG. 2 is a view schematically showing a coupling structure of a fixture and a piezoelectric body shown in FIG. 3 is a view for explaining a structure in which the piezoelectric body shown in FIG. 2 is coated with a coating agent, FIG. 4 is a view illustrating a state in which the piezoelectric body is compressed when a force acts in one direction, and FIG. The piezoelectric element is compressed when the force in the opposite direction to the force action direction is applied.
도 1에 도시된 바와 같이, 본 발명의 일 실시예에 따른 압축력을 이용한 압전 하베스팅 시스템(100)은, 고정체(102)와, 고정체(102)의 일면에 부착되는 압전체(103)와, 고정체(102)의 일측을 고정시킴으로써 고정체(102)가 외팔보 타입이 되도록 하는 고정지지대(107)와, 고정체(102)의 타면에 장착되어 고정체(102)에 인장력이 발생되는 것을 저지하는 인장 방지체(105)를 포함할 수 있다. 여기서 압전체(103)의 일면에는 코팅제(104)가 코팅될 수 있다.As shown in FIG. 1, the
본 실시예의 고정체(102)는 평평한 플레이트(plate) 타입으로 마련되어 고정지지대에 외팔보 타입으로 장착될 수 있고, 이러한 고정체(102)의 일면, 본 실시예의 경우 하면에 압전체(103)가 부착될 수 있다.
본 실시예의 압전체(103)는 기본적으로 발전량이 우수한 세라믹(ceramic) 압전소자를 비롯하여 물리적 유연성이 뛰어나 폴리머(polymer)나 폴리머와 세라믹이 혼합된 하이브리드 압전소자가 사용될 수 있다. 따라서 뛰어난 물리적 유연성으로 인해 내구성을 가지며 이에 따라 발전에 용이하다.The
또한, 압전체(103)의 압전소자 종류로는 PVDF의 사용이 기본적이고, 바륨 티타네이트, PZT 결정 또는 PZT 섬유를 포함할 수 있다. 그 외에 NKN계, BZT-BCT계, BNT계, BSNN, BNBN계 등의 무연(Lead-free) 압전소재, PLZT, P(VDF-TrFE), 수정, 전기석, 로셸염, 티탄산바륨, 인산이수소암모늄, 타르타르산에틸렌디아민 등을 사용할 수 있다. In addition, as the type of piezoelectric element of the
다만, 압전체(103)의 종류 및 재질이 이에 한정되는 것은 아니며, 외력에 의해 충분한 발전량을 발생시킬 수 있다면 다른 재질 등이 사용될 수 있음은 당연하다.However, the type and material of the
이러한 압전체(103)는 고정체(102)의 양면 중 외력이 가해지는 경우 압축되는 일면에 부착될 수 있으며, 이를 통해 고정체(102)에 외력이 가해져서 고정체(102)가 변형되는 경우, 즉, 고정체(102)의 일면이 내측으로 벤딩되는 경우 압전체(102)도 함께 압축될 수 있다.The
여기서, 고정체(102)는 금속 재질, 예를 들면 스테인리스 스틸(stainless steel) 재질로 제작될 수 있다. 이러한 재질로 인해, 고정체(102)에 타격이 가해지는 경우 고정체(102)는 압축되는 방향으로 변형될 수 있으며, 외력이 없어지는 경우 다시 원래의 상태로 복귀할 수 있다. 또한 내구성이 강하여 변형 발생을 최소화할 수 있다. 다만, 고정체(102)의 재질이 이에 한정되는 것은 아니다.Here, the
본 실시예의 고정체(102)의 넓이는 압전체(103)의 넓이보다 넓게 형성되며, 이를 통해 고정체(102)의 일면에 가해지는 타격에 의해서 압전체(103)에 변형이 발생될 뿐만 아니라 외력에 의한 타격 면적을 더욱 극대화할 수 있다.The width of the
한편, 본 실시예의 압전체(103)에는, 도 3에 도시된 바와 같이, 압전체(103)의 벗겨짐을 방지하기 위하여 코팅제(104)가 코팅 처리될 수 있다. 본 실시예의 코팅제(104)는 연성이 좋고, 최대한 얇게 코팅될 수 있는 코팅 물질로 마련된다. 이는, 코팅제(104)의 연성이 나쁜 경우, 압전체(103)에 작용해야 하는 압축 응력을 코팅제(104)가 흡수하여 압전체(103)에 작은 힘이 걸리게 되고 따라서 발전량이 저하될 수 있기 때문이다. 또한 코팅제(104)가 두껍게 사용될 경우 압전체(103)에 압축력이 아닌 인장력이 작용되어 발전량 저하뿐만 아니라 내구성 또한 감소할 수 있기 때문이다.Meanwhile, as illustrated in FIG. 3, a
압전 하베스팅 시스템(100)은 압전체(103)가 미부착된 고정체(102)의 타면을 타격하는 타격부재(미도시)를 더 포함할 수 있고, 고정체(102)는 타격 방향 쪽으로 휘어질 수 있다.The
도 4 및 도 5를 참조하면, 본 실시예에서, 압전체(103)는 압축력이 주로 작용하도록 형성된다. 이는 고정체(102) 및 압전체(103)의 두께를 조절하여, 중립축(A1, A2, neutral axis)의 위치조정을 통해 구현될 수 있다. 4 and 5, in this embodiment, the
그 결과, 압전체(103)에 주로 압축력이 작용할 수 있으며, 이로 인해 인장력이 주로 가해지는 종래의 압전 하베스팅 시스템에 비해 압전체(103) 손상을 줄일 수 있고, 또한 높은 압축 응력이 걸림으로써 발전량을 비약적으로 증대시킬 수 있다.As a result, the compressive force may mainly act on the
도 4 및 도 5에 도시된 것처럼, 압전체(103)에 작용하는 힘(F)의 방향에 따라 중립축(A1, A2)은 압전체(103)의 상단 또는 하단이 되도록 설정될 수 있다.As shown in FIGS. 4 and 5, the neutral axes A1 and A2 may be set to be the top or bottom of the
즉, 도 4의 압전 하베스팅 시스템 상태 및 도 5의 압전 하베스팅 시스템에 각각 걸리는 힘(F)의 크기에 따라 중립축(A1, A2)이 이동하기 때문에 각각의 상황에 따라 압전체(103)의 두께 및 고정체(102)의 두께를 조절하여 제자리에 중립축(A1, A2)이 오게 할 수 있다. 이 때, 힘(F)의 방향이 하방을 향할 때(도 4 참조) 압전체(103) 하단에, 힘(F)의 방향이 상방을 향할 때(도 5 참조) 압전체(103) 상단에 중립축(A1, A2)이 오도록 설정할 수 있다.That is, since the neutral shafts A1 and A2 are moved according to the state of the piezoelectric harvesting system of FIG. 4 and the magnitude of the force F applied to the piezoelectric harvesting system of FIG. 5, the thickness of the
중립축(A1, A2)을 조정하기 위하여 고정체(102)의 두께 및 압전체(103)의 두께를 조절하는 경우, 고정체(102)의 두께를 얇게 할수록 해당 시스템이 진동 시 마이너스 방향의 운동에 의해 압전체(103)에 균열이 생길 우려가 있으므로, 이러한 우려가 발생되지 않도록 고정체(102)의 두께가 설정될 수 있다.When adjusting the thickness of the
또한, 각 중립축(A1, A2)과 고정체(102)와 압전체(103)가 만나는 부분의 차이를 작게 할수록, 고정체(102)로부터 압전체(103)로의 압축력 전달 효율을 향상시킬 수 있어 발전량을 크게 할 수 있다. 즉, 도 4 및 도 5에 도시된 것처럼, 고정체(102)와 압전체(103)가 만나는 접선 부분(B1, B2)과, 중립축(A1, A2) 사이의 델타(Δ) 값이 작아지도록 고정체(102)의 두께를 설정하고 압전체(103)를 고정체(102)에 부착함으로써 압전체(103)에 외력 발생 시 전기 발생량을 증대시킬 수 있다.In addition, the smaller the difference between the portions in which the neutral shafts A1 and A2 meet with the
또한, 도시하지는 않았지만, 고정체(102)와 부착된 압전체(103)의 일 면의 반대측에 위치하는 압전체(103)의 타 면에는 크랙이 형성될 수 있다. 구체적으로, 크랙은 압전체(103)에 가해지는 압축력에 수직한 방향으로 형성될 수 있다. 이러한 크랙은 압전체(103)가 압축력에 더욱 잘 견디도록 하는 기능을 할 수 있다. 인장력을 받는 경우와는 달리, 본 실시예에 따른 압전체(103)는 압축 변형되므로 크랙이 있더라도 높은 발전량을 얻을 수 있다.In addition, although not illustrated, cracks may be formed on the other surface of the
한편, 도 1을 참조하면, 본 실시예의 압전체(103)와 대향되는 고정체(102)의 일면에 인장 방지체(105)가 부착될 수 있다. 여기서 인장 방지체(105)는 압전체(103)가 변형되는 것을 방지할 수 있다. 예를 들면, 압전체(103)를 압축 방향(타격 방향)으로 가압하는 경우 펴지면서 위로 휘어질 수 있는데, 이 때 압축 방향과 반대 방향으로 압전체(103) 및 고정체(102)가 휘는 것을 방지체(105)가 방지함으로써 변형으로 인하여 압전체(103)에 인장력이 가해지는 것을 방지할 수 있다.Meanwhile, referring to FIG. 1, the
이와 같이, 본 발명의 일 실시예에 따르면, 하중 및 타격에 의해 발생되는 외력 중 압축력이 걸리고 이를 이용하여 전기에너지를 생성할 수 있고, 인장력에 약한 성질의 압전체(103)에 주로 압축력을 가해줌으로써 압전체(103)의 손상을 방지할 수 있으며, 압전체(103)에 압축력을 걸어 줌으로써 압전체(103)가 가지는 높은 압축 응력 특성을 이용할 수 있으며, 이를 통해 압전체(103) 자체에 높은 압축력을 가할 수 있어 압전 결정에 큰 힘이 걸리는 높은 반발력과 내력을 창출할 수 있으며 그 결과 압전체(103)에서 높은 발전량을 얻을 수 있는 장점이 있다.As such, according to one embodiment of the present invention, the external force generated by the load and hitting the compressive force is applied and can be used to generate electrical energy, by applying a compressive force mainly to the piezoelectric material (103) of weak properties to the tensile force Damage to the
또한, 압축력을 사용했을 때 압전체(103) 자체의 탄성력을 충분히 사용하므로 고정체(102)에 걸리는 부담이 감소하여 고정체(102)의 변형과 손상을 막을 수 있고, 또한, 압전체(103) 자체의 탄성력을 이용하기 때문에 고정체(102)에 걸리는 부담이 감소하여 고정체(102)의 두께를 기존보다 얇게 하여 고정체(102)의 재료비 및 무게를 줄일 수 있는 장점도 있다.In addition, when the compressive force is used, the elastic force of the
한편, 이하에서는 도 6 및 도 7을 참조하여, 본 실시예처럼 압전체에 압축력이 가해지는 경우와 종래의 경우처럼 인장력이 가해지는 경우 회전수에 따른 발전량을 비교하기로 한다.On the other hand, with reference to Figures 6 and 7, below, when the compressive force is applied to the piezoelectric body as in the present embodiment and when the tensile force is applied as in the conventional case will be compared with the amount of power generation according to the rotation speed.
도 6은 하나의 압전체를 가지고 인장과 압축을 교대로 가할 때 회전수에 따른 발전량의 변화를 나타낸 그래프이다.6 is a graph showing a change in power generation amount according to the number of revolutions when alternating tension and compression are applied with one piezoelectric body.
이에 도시된 것처럼, 인장력이 압전체에 가해지는 경우와 압축력이 압전체에 가해지는 경우 모두 400 내지 420 rpm에서 발전량이 최대로 나타남을 알 수 있다. 그런데, 인장력을 이용한 평균전력은 45mW 정도인 반면에, 압축력을 이용한 평균전력은 65mW 정도로 압축력을 이용한 본 실시예의 압전 하베스팅 시스템이 인장력을 이용한 시스템보다 더 높은 발전량을 얻을 수 있음을 알 수 있다.As shown in the figure, it can be seen that the maximum amount of power generation is shown at 400 to 420 rpm in both the case where the tensile force is applied to the piezoelectric body and the compressive force is applied to the piezoelectric body. However, the average power using the tensile force is about 45mW, while the average power using the compressive force is about 65mW it can be seen that the piezoelectric harvesting system of the present embodiment using the compressive force can obtain a higher power generation than the system using the tensile force.
또한, 인장력을 이용한 발전은 530rpm에서 멈추지만, 압축력을 이용한 발전은 650rpm이 넘어서도 계속 발전을 하면서 발전량이 점점 줄어듬을 도 6을 통해 알 수 있으며, 따라서 압축력을 이용한 압전 하베스팅 시스템이 인장력을 이용한 시스템보다 우수한 내구성을 구비함을 알 수 있다.In addition, the power generation using the tensile force is stopped at 530rpm, the power generation using the compression force can be seen through Figure 6 that the power generation is gradually reduced while continuing to generate power even beyond 650rpm, so the piezoelectric harvesting system using the compressive force is a system using the tensile force It can be seen that it has more excellent durability.
한편, 도 7은 다른 압전체를 가지고 압축력을 이용한 발전의 최적화 실험을 수행함으로써 획득된 그래프이다.On the other hand, Figure 7 is a graph obtained by performing an optimization experiment of power generation using a compressive force with another piezoelectric body.
이에 도시된 것처럼, 본 실험의 경우 300rpm으로부터 회전수를 늘려갔고, 피크 파워를 지나 다시 전력량이 줄어드는 시점까지 실험을 수행하였다. 실험 결과, 대략 410rpm에서 피크 파워가 나타났고, 410rpm에서 평균전력 88mW, 최대전력 102mW 값을 나타냈다. 이 경우 도 6의 실험보다 상대적으로 많은 발전량이 나온 이유는 임피던스 매칭(부하에 최대로 전력을 전달할 수 있는 임피던스 값을 찾는 실험)을 추가적으로 했기 때문이며 이로 인해 더 많은 발전량을 얻을 수 있었다.As shown in this figure, in the case of this experiment, the rotation speed was increased from 300rpm, and the experiment was performed until the amount of power was reduced again after passing the peak power. As a result of the experiment, peak power appeared at about 410rpm, and average power 88mW and maximum power 102mW at 410rpm. In this case, the reason why the amount of power generated is relatively higher than in the experiment of FIG. 6 is because an impedance matching (an experiment for finding an impedance value capable of delivering the maximum power to the load) is added, thereby generating more power.
한편, 본 발명은 기재된 실시예에 한정되는 것이 아니고, 본 발명의 사상 및 범위를 벗어나지 않고 다양하게 수정 및 변형할 수 있음은 이 기술의 분야에서 통상의 지식을 가진 자에게 자명하다. 따라서 그러한 수정예 또는 변형예들은 본 발명의 특허청구범위에 속한다 하여야 할 것이다.On the other hand, the present invention is not limited to the described embodiments, it is apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to be belong to the claims of the present invention.
Claims (9)
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| CN108448933A (en) * | 2018-04-18 | 2018-08-24 | 武汉珈鹰智能科技有限公司 | A kind of energy regenerating and conversion storage device based on piezoelectric material |
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