JP2015084618A - Energy conversion system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the combined value of reaction forces which a drive section receives from individual cams.SOLUTION: An energy conversion system 100 includes piezoelectric elements 11, 21, cam mechanisms 15, 25 which apply the load periodically to the piezoelectric elements 11, 21 by rotating cams 16, 26, and a drive section for rotating the cams 16, 26 by moving relatively to the cams 16, 26. When the drive section rotates the cams 16, 26 by moving relatively, a reaction force caused by the rotation of the cams acts periodically on the drive section. The reaction force received by the drive section, while the drive section moving relatively by a predetermined distance, due to rotation of the cams 16, 26, has the same period and different phases.

Description

  The present invention relates to an energy conversion system, and more particularly to an energy conversion system that converts mechanical energy into electrical energy using a cam and a piezoelectric element.

  International Publication No. 2013/069516 (Patent Document 1) discloses a piezoelectric power generation element including a cam, a piezoelectric element, and a slide member. As the slide member moves, the slide member rotates the cam. A load is periodically applied to the piezoelectric element by the rotation of the cam, and electric power is generated by the piezoelectric effect of the piezoelectric element.

International Publication No. 2013/069516

  When the cam is rotated using a slide member or the like, a load is applied to the piezoelectric element as the cam rotates. On the other hand, the reaction force of the load acts on the drive unit. The reaction force received by the drive unit from the cam may act to be a resistance to the operation of the drive unit. When a plurality of piezoelectric elements and a plurality of cams are used, reaction forces received by the drive unit from the plurality of cams act on the drive unit in a combined state. It is preferable that the combined value of the reaction forces that the driving unit receives from the individual cams is small.

  An object of the present invention is to provide an energy conversion system capable of reducing a combined value of reaction forces received by a drive unit from individual cams when a plurality of piezoelectric elements and a plurality of cams are used.

  An energy conversion system according to the present invention has a plurality of piezoelectric elements that generate electric power when a load is applied, and a plurality of cams provided corresponding to each of the plurality of piezoelectric elements, and each of the cams rotates. By doing so, the cams of the plurality of cam mechanisms are moved relative to the cams of the plurality of cam mechanisms that periodically apply loads to the corresponding piezoelectric elements, and the cams of the plurality of cam mechanisms. And when the drive unit rotates the cam by relative movement of the drive unit, a reaction force generated by the rotation of the cam periodically acts on the drive unit. The reaction force received by the rotation of the cams of the plurality of cam mechanisms during the relative movement of the drive unit by a predetermined distance has the same cycle and different phases.

  Preferably, the cams of the plurality of cam mechanisms have the same shape. Preferably, the cam of the cam mechanism has a shape deformed so that four corners of a square are rounded.

  Preferably, the drive unit performs reciprocal movement. Preferably, the driving unit performs rotational movement. Preferably, a speed change mechanism for changing the rotational speed of the cam is further provided.

  ADVANTAGE OF THE INVENTION According to this invention, when using a some piezoelectric element and a some cam, the energy conversion system which can make small the synthetic value of the reaction force which a drive member receives from each cam can be provided.

1 is a plan view showing an energy conversion system in Embodiment 1. FIG. 2 is a plan view showing a power generation unit provided in the energy conversion system in Embodiment 1. FIG. It is a perspective view which shows the state which the electric power generation part with which the energy conversion system in Embodiment 1 is equipped disassembled. 5 is a plan view for explaining the operation of the energy conversion system in Embodiment 1. FIG. FIG. 6 is a diagram illustrating the relationship between the magnitude (load) of the force received by the drive member as the first cam rotates and the position of the drive member with respect to the first embodiment. FIG. 6 is a diagram illustrating the relationship between the magnitude (load) of the force received by the drive member as the second cam rotates and the position of the drive member with respect to the first embodiment. FIG. 6 is a diagram illustrating the relationship between the magnitude (load) of the force received by the driving member as the first cam and the second cam rotate and the position of the driving member in the first embodiment. It is a top view which shows the energy conversion system in a comparative example. It is a figure which shows the relationship between the magnitude | size (load) of the force which a drive member receives with rotation of a 1st cam and a 2nd cam, and the position of a drive member regarding a comparative example. 6 is a plan view showing an energy conversion system in a second embodiment. FIG. FIG. 6 is a plan view showing an energy conversion system in a third embodiment. It is a top view which shows the model of the cam used in the experiment example. It is a figure which shows the verification result of an experiment example. FIG. 10 is a plan view showing an energy conversion system in a fourth embodiment. FIG. 10 is a plan view showing an energy conversion system in a fifth embodiment. FIG. 10 is a plan view showing an energy conversion system in a sixth embodiment.

  Embodiments based on the present invention will be described below with reference to the drawings. When referring to the number, amount, etc., the scope of the present invention is not necessarily limited to the number, amount, etc., unless otherwise specified. The same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated.

[Embodiment 1]
(Energy conversion system 100)
FIG. 1 is a diagram showing an energy conversion system 100 according to the first embodiment. The energy conversion system 100 includes power generation units 10 and 20 and a drive member 50.

  The power generation units 10 and 20 and the drive member 50 can move relative to each other. For example, the power generation units 10 and 20 are attached to a door frame, and the drive member 50 is attached to a door. When the drive member 50 moves along the direction of the arrow AR as the door moves, the power generation units 10 and 20 generate power (details will be described later). By driving a wireless communication unit (not shown) or the like by power generation, the open / closed state of the door can be detected at a remote place.

(Power generation unit 10)
FIG. 2 is a plan view showing the power generation unit 10. FIG. 3 is a perspective view showing an exploded state of the power generation unit 10. The power generation unit 10 will be described with reference to FIGS. For convenience of illustration, in FIG. 2 and FIG. 3, the drive member 50 is partially illustrated and the rack tooth 51 side is illustrated, but the rack tooth 52 (see FIG. 1) side is illustrated. Not listed.

  As shown in FIGS. 1 to 3, the power generation unit 10 includes a piezoelectric element 11, a support 12, and a cam mechanism 15. The piezoelectric element 11 has a quadrangular prism-shaped piezoelectric body and a pair of electrodes, and surfaces 11A and 11B are formed at both ends in the longitudinal direction. The piezoelectric body of the piezoelectric element 11 is made of, for example, lead zirconate titanate (PZT).

  The support 12 includes a stopper 13 and a lever 14, which are integrally formed. The stopper 13 has a contact portion 13A. The contact portion 13 </ b> A is in contact with the surface 11 </ b> A of the piezoelectric element 11. A cam 16 and a gear 17 of the cam mechanism 15 are rotatably attached to the stopper 13.

  The lever 14 includes a connecting portion 14A, a contact portion 14B, and a displacement portion 14C. The lever 14 is formed of a highly rigid metal or ceramic. The connection portion 14A connects the contact portion 14B and the displacement portion 14C. The contact portion 14B has a contact portion 14D. The contact portion 14 </ b> D is in contact with the surface 11 </ b> B of the piezoelectric element 11.

  The cam mechanism 15 includes a cam 16 (also referred to as a first cam), a gear 17 and a protrusion 18. The planar shape of the cam 16 is non-circular. In plan view, the cam 16 of the present embodiment has a shape (substantially square shape) deformed so that four corners of a square are rounded. The cam 16 is integrated with the gear 17, and the cam 16 and the gear 17 rotate integrally.

  The gear 17 is disposed so as to mesh with the rack teeth 51 (drive unit) of the drive member 50. The protrusion 18 has a cylindrical shape and is fixed to the displacement portion 14 </ b> C of the lever 14. The cam 16 and the protrusion 18 are disposed so as to contact each other. From the viewpoint of suppressing deformation and improving wear resistance, the cam 16 and the protrusion 18 may be formed of POM, metal, or the like, and the surface thereof may be processed to improve slidability.

  When the drive member 50 reciprocates in the direction of the arrow AR (FIG. 1), the rack teeth 51 move relative to the gear 17. The gear 17 and the cam 16 rotate integrally. As the gear 17 and the cam 16 rotate, the distance between the central axis of the cam 16 and the protrusion 18 periodically changes, and the displacement portion 14C swings.

  When the displacement portion 14 </ b> C swings, the lever 14 swings in the rotation direction around the rotation shaft 19 positioned in the vicinity of the connection portion between the stopper 13 and the lever 14. The contact portion 14D of the contact portion 14B is displaced relative to the contact portion 13A in the longitudinal direction of the piezoelectric element 11. The contact portion 14D presses the surface 11B of the piezoelectric element 11, and the piezoelectric element 11 is repeatedly compressed.

  As a result, a load is applied to the piezoelectric element 11, and the piezoelectric element 11 generates electricity due to the piezoelectric effect. A load is periodically applied to the piezoelectric element 11 by an amount corresponding to the amount of movement of the driving member 50, and the electric power generated in the piezoelectric element 11 is stored in a capacitor or the like (not shown).

(Power generation unit 20)
Referring again to FIG. 1, the power generation unit 20 includes a piezoelectric element 21, a support body 22, and a cam mechanism 25. The power generation unit 20 has substantially the same configuration as the power generation unit 10, and the piezoelectric element 21, the support 22, and the cam mechanism 25 correspond to the piezoelectric element 11, the support 12, and the cam mechanism 15 of the power generation unit 10, respectively. doing.

  The cam mechanism 25 includes a cam 26 (also referred to as a second cam), a gear 27, and a protrusion 28. The planar shape of the cam 26 is non-circular. In plan view, the cam 26 has a shape (substantially square shape) deformed so that four corners of a square are rounded. The cam 16 of the power generation unit 10 and the cam 26 of the power generation unit 20 have the same shape.

  When the drive member 50 reciprocates, the rack teeth 52 (drive unit) move relative to the gear 27. The gear 27 and the cam 26 rotate integrally. As the gear 27 and the cam 26 rotate, the distance between the central axis of the cam 26 and the projection 28 changes, and the piezoelectric element 21 is repeatedly compressed. As a result, a load is applied to the piezoelectric element 21, and the piezoelectric element 21 generates power due to the piezoelectric effect. A load is periodically applied to the piezoelectric element 21 by an amount corresponding to the amount of movement of the driving member 50, and the electric power generated in the piezoelectric element 21 is stored in a capacitor or the like (not shown).

  In the present embodiment, two cams 16 and 26 are provided to correspond to the two piezoelectric elements 11 and 21, respectively. The drive portions (rack teeth 51, 52) of the drive member 50 move relative to the cams 16, 26, whereby the cams 16, 26 rotate. As the cams 16 and 26 rotate, a periodic load is applied to the piezoelectric elements 11 and 21. On the other hand, the reaction force of the load acts on the driving member 50 periodically. In the present embodiment, the reaction force received by the rotation of the cams 16 and 26 while the drive member 50 is relatively moved by a predetermined distance is configured to have the same period and different phases. Yes.

  The configuration will be described more specifically with reference to FIGS. FIG. 4 is a plan view showing the state of the energy conversion system 100 at a certain point in time when the drive member 50 is moving in the direction of the arrow AR1. FIG. 4 schematically shows the gears 17 and 27.

  When the drive member 50 moves in the direction of the arrow AR1, the cam 16 rotates in the direction of the arrow DR1, and the cam 26 rotates in the direction of the arrow DR2. The cams 16 and 26 are configured such that the lower point (bottom dead center) of the cam 26 contacts the protrusion 28 when the apex (top dead center) of the cam 16 contacts the protrusion 18. . Therefore, at the time shown in FIG. 4, the protrusion 18 is in sliding contact with the circumferential surface of the cam 16 so as to go from the apex of the cam 16 to the lower point, while the cam 26 is below the cam 26. The projecting portion 28 is in sliding contact with the peripheral surface of the cam 26 so as to go from the point to the apex.

  With respect to the cam 16, the projection 18 is slidably contacted with the peripheral surface of the cam 16 from the apex to the lower point, so the direction of the force that the cam 16 receives from the projection 18 is the direction indicated by the arrow DR3. . The direction of the arrow DR3 is the same as the direction in which the cam 16 rotates by the movement of the drive member 50 in the direction of the arrow AR1, that is, the direction of the arrow DR1. The force shown in the direction of the arrow DR3 is transmitted as a load to the driving member 50 through the gear 17 and acts in the same direction as the direction in which the driving member 50 moves.

  With respect to the cam 26, since the protrusion 28 is in sliding contact with the peripheral surface of the cam 26 from the lower point toward the apex, the direction of the force in the rotational direction that the cam 26 receives from the protrusion 28 is the direction indicated by the arrow DR4. . The arrow DR4 direction is opposite to the direction in which the cam 26 is rotated by the movement of the drive member 50 in the arrow AR1 direction, that is, the arrow DR2 direction. The force shown in the direction of the arrow DR4 is transmitted as a load to the driving member 50 through the gear 27, and acts in a direction opposite to the direction in which the driving member 50 moves.

  In the cams 16 and 26, an operation opposite to the above is performed at another timing. That is, when the drive member 50 moves, the cams 16 and 26 rotate synchronously (rotate while maintaining the cycle and phase). The force that the driving member 50 receives from the cams 16 and 26 when the driving member 50 moves includes a force acting in the moving direction of the driving member 50 and a force acting in the direction opposite to the moving direction of the driving member 50. include. These are described as graphs as follows.

  5 and 6 show the magnitude (load) of the force received by the drive member 50 as the cam 16 (first cam) and the cam 26 (second cam) rotate, and the position of the drive member 50, respectively. It is a figure which shows a relationship. 5 and 6, the force acting in the radial direction of the cams 16 and 26 and the force acting in the rotation direction of the cams 16 and 26 are separately shown. The radial direction of the cams 16 and 26 is a direction on a line passing through the centers of the rotation axes of the cams 16 and 26 and the centers of the protrusions 18 and 28 in FIG. The rotation direction of the cams 16 and 26 is a direction perpendicular to the radial direction of the cams 16 and 26 in FIG. In the figure, the force applied in the rotation direction is positive when the projection moves in the direction of climbing the ridge of the cam, and when the projection moves in the direction of descending the ridge of the cam. The generated force is-. The force acting in the rotation direction of the cams 16 and 26 is a force indicated by arrows DR3 and DR4 in FIG.

  As shown in FIGS. 5 and 6, the reaction force that the driving member 50 receives by the rotation of the cams 16 and 26 while the driving member 50 moves by a predetermined distance has the same period and a different phase. This is common for both radial and rotational forces. Here, the phase is different from the timing at which the apex (top dead center) of the cam 16 contacts the projection 18 and the timing at which the apex (top dead center) of the cam 26 contacts the projection 28. Means not. The force acting in the radial direction with the rotation of the cams 16 and 26 has little influence on the movement of the drive member 50, and therefore details thereof will not be described.

  FIG. 7 is a diagram showing the relationship between the magnitude (load) of the force received by the drive member 50 as the cam 16 (first cam) and the cam 26 (second cam) rotate and the position of the drive member 50. is there. FIG. 7 shows the force acting in the rotational direction of the cams 16 and 26 and the force received by the drive member 50 acting as a combined force of these forces.

  As shown in FIG. 7, the force received by the drive member 50 with the rotation of the cam 16 (first cam) and the force received by the drive member 50 with the rotation of the cam 26 (second cam) cancel each other. There is a relationship. Therefore, the maximum value of the load acting on the driving member 50 as the combined force is smaller than the maximum value of the load received by the driving member 50 from the individual cams 16 and 26. Since the peak-to-peak of the force for driving the drive member 50 can be reduced, the power generation amount per input force can be increased. In other words, the power generation efficiency per piezoelectric element can be improved.

  When the peak-to-peak interval is 360 °, the force received by the drive member 50 as the cam 16 rotates and the force received by the drive member 50 as the cam 26 rotates from 90 °. It is preferable that a large deviation of less than 270 ° is provided, more preferably a deviation of 180 ° is provided. The shape of the circumferential surface of the cam can increase the effect of canceling the forces by making the waveform of the force applied in the rotation direction as close as possible to the sine waveform.

  In the present embodiment, the mechanical energy stored when the power generation unit 10 compresses the piezoelectric element 11 is utilized when the power generation unit 20 compresses the piezoelectric element 21. In other words, when applying a load to the piezoelectric element 11, the energy while applying the load to the piezoelectric element 21 is used, and when applying a load to the piezoelectric element 21, the load is applied to the piezoelectric element 11. Energy is used efficiently because it uses the energy that was spent.

  Therefore, energy for applying a load to the piezoelectric elements 11 and 21 can be reduced. In order to drive the drive member 50, the energy consumed when the piezoelectric elements 11 and 21 convert energy, the energy consumed when the piezoelectric elements 11 and 21 are deformed, and the cams 16 and 26 It is only necessary to apply a drive having a necessary minimum drive amount such as replenishment by the amount of energy consumed when friction or heat between the projections 18 and 28 is generated.

  In the present embodiment, the power generation units 10 and 20 (cams 16 and 26) are arranged to face each other with the drive member 50 interposed therebetween, but the power generation units 10 and 20 (cams 16 and 26) are arranged on the drive member 50. You may arrange | position so that it may shift | deviate to a moving direction, and two may be arrange | positioned along with the rack tooth | gear 51 side. Even with these arrangements, the same operations and effects as described above can be obtained.

[Comparative example]
FIG. 8 is a plan view showing the energy conversion system 101 in the comparative example. FIG. 8 shows a state of the energy conversion system 101 at a certain point in time when the driving member 50 is moving in the direction of the arrow AR1.

  In the energy conversion system 101, when the drive member 50 moves in the arrow AR1 direction, the cam 16 rotates in the arrow DR1 direction, and the cam 26 rotates in the arrow DR2 direction. The cams 16 and 26 are configured such that the apex (top dead center) of the cam 26 contacts the projection 28 when the apex (top dead center) of the cam 16 contacts the projection 18. As for the cam 16, the protrusion 18 is slidably contacted with the peripheral surface of the cam 16 so as to go from the apex of the cam 16 to the lower point, and the protrusion 28 of the cam 26 also cams so as to go from the apex of the cam 26 to the lower point 26 in sliding contact with the peripheral surface.

  The directions of the forces in the rotational direction that the cams 16 and 26 receive from the projections 18 and 28 are directions indicated by arrows DR3 and DR4, respectively. The directions of the arrows DR3 and DR4 are the same as the direction in which the cam 16 is rotated by the movement of the drive member 50 in the direction of the arrow AR1, that is, the direction of the arrow DR1. The force that the driving member 50 receives from the cams 16 and 26 includes a force that acts in the moving direction of the driving member 50 and a force that acts in the direction opposite to the moving direction of the driving member 50.

  However, while the cam 16 generates a force that acts in the direction of movement of the drive member 50, the cam 26 also generates a force that acts in the direction of movement of the drive member 50. The same applies to the reverse case, and while the cam 16 generates a force acting in the direction opposite to the moving direction of the drive member 50, the cam 26 also generates a force acting in the direction opposite to the moving direction of the drive member 50. ing. These are described as graphs as follows.

  FIG. 9 is a diagram illustrating the relationship between the magnitude (load) of the force received by the drive member 50 as the cam 16 (first cam) and the cam 26 (second cam) rotate and the position of the drive member 50. is there. In FIG. 9, the force acting in the rotation direction of the cams 16 and 26 and the force received by the drive member 50 acting as a combined force of these forces are shown.

  As shown in FIG. 9, the reaction force that the driving member 50 receives by the rotation of the cams 16 and 26 has the same period and the same phase. The force received by the drive member 50 along with the rotation of the cam 16 (first cam) and the force received by the drive member 50 along with the rotation of the cam 26 (second cam) are in a mutually reinforcing relationship.

  Therefore, the maximum value of the load acting on the driving member 50 as a combined force is larger than the maximum value of the load received by the driving member 50 from the individual cams 16 and 26. In the configuration of the energy conversion system 101, the peak-to-peak of the force for driving the drive member 50 cannot be reduced. The amount of power generation per input power cannot be increased, and the energy use efficiency is low.

  On the other hand, in the first embodiment described above, the reaction force received by the rotation of the cams 16 and 26 while the drive member 50 moves by a predetermined distance has the same period and a different phase. . Since the peak-to-peak of the force for driving the drive member 50 can be reduced, the power generation amount per input force can be increased.

[Embodiment 2]
With reference to FIG. 10, the energy conversion system 102 in Embodiment 2 is demonstrated. In the above-described first embodiment (see FIG. 1), the power generation units 10 and 20 are arranged so as to extend along the moving direction of the driving member 50 with respect to the driving member 50 that reciprocates.

  As in the energy conversion system 102, the power generation units 10 and 20 may be arranged so as to extend in a direction orthogonal to the moving direction of the driving member 50 with respect to the driving member 50 that reciprocates. Also with this configuration, the same operations and effects as described above can be obtained. The power generation units 10 and 20 may be arranged so as to be inclined with respect to the moving direction of the drive member 50 according to the arrangement relationship of the devices around the power generation units 10 and 20 and the drive member 50.

[Embodiment 3]
With reference to FIG. 11, the energy conversion system 103 in Embodiment 3 is demonstrated. In the above-described first embodiment (see FIG. 1), the drive member 50 reciprocates. In contrast, in the energy conversion system 103 of the present embodiment, the drive member 50A supported by the central shaft 55 rotates. The drive member 50A has a gear 56 (drive unit) on the outer periphery, and is configured to rotate in conjunction with, for example, a rotating door knob.

  When the gear 56 of the drive member 50A rotates in the arrow AR2 direction, the cam 16 rotates in the arrow DR1 direction, and the cam 26 rotates in the arrow DR2 direction. The cams 16 and 26 are configured such that the lower point (bottom dead center) of the cam 26 contacts the protrusion 28 when the apex (top dead center) of the cam 16 contacts the protrusion 18. .

  At the time shown in FIG. 11, the protrusion 18 is in sliding contact with the peripheral surface of the cam 16 so as to go from the apex of the cam 16 toward the lower point, while the cam 26 starts from the lower point of the cam 26. The projecting portion 28 is in sliding contact with the peripheral surface of the cam 26 so as to reach the apex.

  Regarding the cam 16, the direction of the force in the rotational direction that the cam 16 receives from the protrusion 18 is the direction indicated by the arrow DR3. The direction of the arrow DR3 is the same as the direction in which the cam 16 is rotated by the rotational movement of the drive member 50A in the direction of the arrow AR2, that is, the direction of the arrow DR1. The force shown in the direction of the arrow DR3 is transmitted as a load to the driving member 50A through the gear 17 and acts in the same direction as the direction in which the driving member 50A moves.

  Regarding the cam 26, the direction of the force in the rotational direction that the cam 26 receives from the protrusion 28 is the direction indicated by the arrow DR4. The arrow DR4 direction is opposite to the direction in which the cam 26 rotates due to the rotational movement of the drive member 50A in the arrow AR2 direction, that is, the arrow DR2 direction. The force shown in the direction of the arrow DR4 is transmitted as a load to the driving member 50A through the gear 27 and acts in a direction opposite to the direction in which the driving member 50A moves.

  In the cams 16 and 26, an operation opposite to the above is performed at another timing. That is, when the drive member 50A rotates, the cams 16 and 26 rotate synchronously (rotate while maintaining the cycle and phase). The reaction forces received by the rotation of the cams 16 and 26 while the gear 56 (drive unit) of the drive member 50A rotates by a predetermined distance have the same period and different phases.

  The force received by the drive member 50 </ b> A as the cam 16 rotates and the force received by the drive member 50 </ b> A as the cam 26 rotates are in a mutually canceling relationship. Therefore, the maximum value of the load acting on the driving member 50A as a combined force is smaller than the maximum value of the load received by the driving member 50A from the individual cams 16 and 26. Since the peak-to-peak of the force for driving the drive member 50A can be reduced, the power generation amount per input force can be increased. In other words, when a plurality of piezoelectric elements are used, the power generation efficiency per piezoelectric element can be improved.

[Experimental example]
With reference to FIG. 12, an experimental example performed on each of the above-described embodiments will be described. As shown in FIG. 12, two types of cams having shapes (substantially square shapes) deformed so that four corners of a square are rounded are prepared, and act on the drive member when these cams rotate. The magnitude of the load was verified.

  In FIG. 12, the distance L1 between the lower points of the cams facing each other is 4.0 mm, and the distance L2 between the vertices of the cams facing each other is 4.3 mm. The values of the intervals L1 and L2 are common to the two types of cams. On the other hand, the radius R of the arc portion formed at the top is 1.0 mm for one cam and 0.8 mm for the other cam, and different values are adopted for the two types of cams. One cam is provided with four vertices having R1.0, and the other cam is provided with four vertices having R0.8.

  Referring to FIG. 13, as a result of verifying the magnitude of the load acting on the drive member when these cams rotate, the case where the cam having the vertex of R1.0 is used has the vertex of R0.8. The maximum load was smaller than when using a cam with this.

  Furthermore, the case of using two cams having the top of R1.0 and the case of using two cams having the top of R0.8 are as in the first embodiment (see FIG. 1). As a result of assembling as an energy conversion system and verifying the synthesis force, it was found that the case of R1.0 can be reduced by about 60% compared to the case of R0.8. Therefore, from the viewpoint of reducing the combined value of the reaction forces received by the driving members from the individual cams, it has been found that better results can be obtained with R1.0 than with R0.8.

[Embodiment 4]
With reference to FIG. 14, the energy conversion system 104 in Embodiment 4 is demonstrated. The energy conversion system 104 includes three power generation units 10, 20, 30, and three piezoelectric elements 11, 21, 31 and three cam mechanisms 15, 25, 35 are used. The power generation units 10, 20, and 30 (cam mechanisms 15, 25, and 35) have substantially the same configuration.

  When the drive member 50 moves in the direction of the arrow AR1, the gears 17, 27, and 37 of the cam mechanisms 15, 25, and 35 rotate, the cam 16 of the cam mechanism 15 rotates in the direction of the arrow DR1, and the cam of the cam mechanism 25 26 rotates in the direction of the arrow DR2, and the cam 36 of the cam mechanism 35 rotates in the direction of the arrow DR5. The reaction force that the driving member 50 receives by the rotation of the three cams 16, 26, 36 while the driving member 50 moves by a predetermined distance is configured to have the same period and different phases.

  At the time shown in FIG. 14, the direction of the rotational force that the cam 16 receives from the protrusion 18 is the direction indicated by the arrow DR3, and is opposite to the moving direction indicated by the arrow AR1 of the drive member 50. The direction of the rotational force that the cam 26 receives from the protrusion 28 is the direction indicated by the arrow DR4, and is the same direction as the movement direction indicated by the arrow AR1 of the drive member 50. The direction of the rotational force that the cam 36 receives from the protrusion 38 is the direction indicated by the arrow DR6 and is opposite to the moving direction indicated by the arrow AR1 of the drive member 50.

  These three forces are in a mutually canceling relationship. Therefore, the maximum value of the load acting on the driving member 50 as a combined force is smaller than the maximum value of the load received by the driving member 50 from the individual cams 16, 26, 36. When the peak-to-peak interval is 360 °, there is a 120 ° deviation between the forces received by the drive member 50 as the cams 16, 26, 36 of the cam mechanisms 15, 25, 35 rotate. It is preferable. The effect of canceling forces can be increased.

  In the present embodiment, three cams 16, 26, and 36 and three piezoelectric elements 11, 21, and 31 are used. However, even when four or more of these are used, the driving member 50 rotates the cam. The same action and effect can be obtained by configuring the reaction force received by the step 1 so that the period is the same and the phase is different. When four cams are used, it is preferable that a 90 ° shift is provided between the forces received by the drive member 50 as the four cams rotate. When five cams are used, it is preferable that a shift of 72 ° is provided between the forces received by the drive member 50 as the five cams rotate.

[Embodiment 5]
With reference to FIG. 15, the energy conversion system 105 in Embodiment 5 is demonstrated. The energy conversion system 105 includes three power generation units 10, 20, and 30, and the drive member 50 </ b> A is used as in the case of the third embodiment described above.

  When the gear 56 of the drive member 50A rotates in the direction of the arrow AR2, the gears 17, 27, 37 of the cam mechanisms 15, 25, and 35 rotate, respectively, and the cam 16 of the cam mechanism 15 rotates in the direction of the arrow DR1. The cam 26 of the mechanism 25 rotates in the arrow DR2 direction, and the cam 36 of the cam mechanism 35 rotates in the arrow DR5 direction. The reaction force received by the driving member 50A by the rotation of the three cams 16, 26, 36 while the gear 56 of the driving member 50A rotates by a predetermined distance is configured to have the same period and different phases. .

  At the time shown in FIG. 15, the direction of the rotational force that the cam 16 receives from the protrusion 18 is the direction indicated by the arrow DR3, and is the direction along the rotational direction indicated by the arrow AR2 of the drive member 50A. The direction of the rotational force that the cam 26 receives from the protrusion 28 is the direction indicated by the arrow DR4, and is the direction along the rotational direction indicated by the arrow AR2 of the drive member 50A. The direction of the rotational force that the cam 36 receives from the protrusion 38 is the direction indicated by the arrow DR6, and is opposite to the direction of the force along the rotational direction indicated by the arrow AR2 of the drive member 50A.

  These three forces are in a mutually canceling relationship. Therefore, the maximum value of the load acting on the driving member 50A as the combined force is smaller than the maximum value of the load received by the driving member 50A from the individual cams 16, 26, 36. When the peak-to-peak interval is 360 °, there is a 120 ° deviation between the forces received by the drive member 50A as the cams 16, 26, 36 of the cam mechanisms 15, 25, 35 rotate. It is preferable. The effect of canceling forces can be increased.

  In the present embodiment, three cams 16, 26, and 36 and three piezoelectric elements 11, 21, and 31 are used. However, even when four or more of these are used, the driving member 50A rotates the cam. The same action and effect can be obtained by configuring the reaction force received by the step 1 so that the period is the same and the phase is different.

[Embodiment 6]
With reference to FIG. 16, the energy conversion system 106 in Embodiment 6 is demonstrated. In each of the above-described embodiments, a plurality of cams having the same shape is used. In the energy conversion system 106 of the present embodiment, cams 16 and 26 having different shapes and a transmission mechanism 40 that changes the rotational speed of the cam 16 are used.

  The cam 16 is formed in an elliptical shape in plan view and has two vertices. The cam 26 is formed in a substantially square shape in plan view and has four apexes. The speed change mechanism 40 is configured by a gear. The speed change mechanism 40 changes the rotational speed of the cam 16 with respect to the moving speed of the drive member 50, that is, the reduction ratio. By providing the speed change mechanism 40, it is possible to adjust the cycle and phase of the reaction force acting on the drive member 50.

  In the present embodiment, the rotational speed of the cam 16 is changed by the speed change mechanism 40, and the cam 16 rotates twice while the cam 26 rotates once. As a result, the reaction force received by the drive member 50 due to the rotation of the cams 16 and 26 is configured to have the same period and different phases, and obtain the same operations and effects as in the above embodiments. Is possible.

  When a plurality of cams having different numbers of vertices are used in combination, it is preferable that the rotational forces of the plurality of cams are matched by using the speed change mechanism 40 (close to the same value). The rotational force referred to here is a value (torque) necessary for the protrusion to get over the top of the cam, and this rotational force is shown by arrows F1 and F2 in the figure relative to the drive member 50. Works. In order to match the rotational forces of a plurality of cams, for example, a relationship of (number of ridges of cam 16) / (number of ridges of cam 26) = (radius R13 of cam 16) / (radius R23 of cam 26) is established. You can do it. According to this configuration, it is possible to further reduce the combined value of the reaction forces that the driving member 50 receives by the rotation of the cams 16 and 26.

  Further, the rotational force required for the protrusion to get over the top of the cam can be freely designed by the top radius of the cam. When the amplitudes of the two cams (the dimensional difference between the apex and the lower point) are the same, the combined value of the reaction forces that the driving member 50 receives due to the rotation of the cams 16 and 26 can be made smaller. Become. In the case of the configuration shown in FIG. 16, for each of the cams 16 and 26, (vertex height R11−lower point height R12) = (vertex height R21−lower point height R22) and R11 = R12 / 2. If is established, the rotational forces of the plurality of cams can be canceled out more.

  As mentioned above, although each embodiment, modification, and Example based on this invention were described, the content disclosed above is an illustration and restrictive at no points. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10, 20, 30 Power generation part, 11, 21, 31 Piezoelectric element, 12, 22 Support body, 13 Stopper, 13A, 14B, 14D Contact part, 14 Lever, 14A Connection part, 14C Displacement part, 15, 25, 35 Cam mechanism, 16, 26, 36 Cam, 17, 27, 37 Gear, 18, 28, 38 Protruding part, 19 Rotating shaft, 40 Speed change mechanism, 50, 50A Drive member, 51, 52 Rack tooth (drive part), 55 Central shaft, 56 gears (drive unit), 100, 101, 102, 103, 104, 105, 106 Energy conversion system.

Claims (6)

A plurality of piezoelectric elements that generate electricity by applying a load;
A plurality of cam mechanisms provided corresponding to each of the plurality of piezoelectric elements, and a plurality of cam mechanisms for periodically applying a load to the corresponding piezoelectric elements by rotation of the respective cams;
A drive unit configured to rotate the cams of the plurality of cam mechanisms by moving relative to the cams of the plurality of cam mechanisms;
When the drive unit rotates the cam by the relative movement of the drive unit, the reaction force generated along with the rotation of the cam is periodically acting on the drive unit,
The reaction force received by the rotation of the cams of the plurality of cam mechanisms during the relative movement of the drive unit by a predetermined distance has the same period and different phases.
Energy conversion system. The cams of the plurality of cam mechanisms have the same shape,
The energy conversion system according to claim 1. The cam of the cam mechanism has a shape deformed so that four corners of a square are rounded.
The energy conversion system according to claim 1 or 2. The drive unit performs reciprocal movement;
The energy conversion system of any one of Claim 1 to 3. The drive unit performs rotational movement.
The energy conversion system of any one of Claim 1 to 3. A transmission mechanism for changing the rotational speed of the cam;
The energy conversion system according to any one of claims 1 to 5.

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