WO2018055939A1 - Piezoelectric power generation device, piezoelectric power generation module, and transmitter - Google Patents

Abstract

A piezoelectric power generation device (100) is equipped with piezoelectric elements (120a) having a rectangular shape when seen from a planar view, a case body (110), and a lever (130). The piezoelectric elements (120a) are flexible, and generate power by deforming in the thickness direction. The case body (110) supports the piezoelectric elements (120a) in a flexurally deformable manner. The lever (130) is rotatably supported by the case body (110), and causes flexural deformation of the piezoelectric elements (120a) by displacing when an external force is applied thereto. The rotational axis (1000) of the lever (130) is positioned in parallel with two opposing sides of the piezoelectric elements (120a) when seen from a planar view, and the case body (110) has a contact part (115a) provided along the side among said two sides which is farther from the rotational axis (1000). The lever (130) contacts the contact part (115a), thus restricting rotation of the lever (130).

Description

Piezoelectric generator, piezoelectric generator module and transmitter

The present invention relates to a piezoelectric power generation device that generates power using a piezoelectric element, a piezoelectric power generation module including the piezoelectric power generation device, and a transmitter including the piezoelectric power generation module.

Piezo-electric element generates electric power according to the amount of deformation by being deformed by receiving external force. Therefore, conventionally, various piezoelectric power generation devices using piezoelectric elements have been proposed.

For example, Japanese Patent Laying-Open No. 2006-262575 (Patent Document 1) discloses a piezoelectric power generation apparatus incorporated in a portable electronic device having a key. The piezoelectric power generation device includes a piezoelectric element that is supported by a support member so as to be able to bend and deform. When the piezoelectric power generation device is arranged behind the key, the piezoelectric element is pushed down by the key to bend and deform. It is configured as follows.

However, since the piezoelectric element is a relatively fragile member, there is a problem that it is damaged when an excessive external force is applied. Therefore, when designing the piezoelectric power generation apparatus, it is important to configure so that an excessive external force is not applied to the piezoelectric element.

Here, Japanese Patent Laid-Open No. 2001-307592 (Patent Document 2) discloses a portable electronic device in which a key is prevented from being excessively pressed although a piezoelectric power generation device is not incorporated. ing. In the portable electronic device, a wiring board provided with a switch is disposed behind a front panel on which a key is assembled, and a flange that restricts movement of the key toward the wiring board on the front panel In this configuration, an excessive external force is not applied to the wiring board when the key is in contact with the stopper portion.

JP 2006-262575 A Japanese Patent Laid-Open No. 2001-307592

However, even if the configuration disclosed in the above Japanese Patent Application Laid-Open No. 2001-307575 is applied to the configuration disclosed in the above Japanese Patent Application Laid-Open No. 2006-262575, if an excessive external force is applied to the key, the stopper portion is As long as it is provided in the case, the front case is deformed, the piezoelectric element cannot be sufficiently protected, and the piezoelectric element may be damaged.

Accordingly, the present invention has been made to solve the above-described problem, and a piezoelectric power generation device that can reliably prevent an excessive external force from being applied to the piezoelectric element, and a piezoelectric power generation module and a transmitter including the same. The purpose is to provide.

The piezoelectric power generation device according to the present invention includes at least one or more piezoelectric elements, a support member, and a lever. The piezoelectric element has flexibility and generates power by being deformed in the thickness direction. The support member supports the piezoelectric element so that it can be bent and deformed. The lever is rotatably supported by the support member so as to face the piezoelectric element, and is displaced in a direction substantially along the thickness direction of the piezoelectric element by receiving an external force, thereby the piezoelectric element. This causes bending deformation of the element. The rotation axis of the lever is arranged so as to be parallel to two opposite sides of the piezoelectric element when viewed along the thickness direction of the piezoelectric element. The support member has an abutting portion provided along one of the two sides of the piezoelectric element that is farther from the rotation axis. The piezoelectric power generation device according to the present invention is configured such that the rotation of the lever toward the piezoelectric element side is restricted when a part of the lever comes into contact with the abutting portion. Yes.

In the piezoelectric power generation device according to the present invention, the support member may have a box-like shape that accommodates the piezoelectric element, and in that case, the abutting portion is formed on the piezoelectric element. It is preferable to be configured by an upper surface of a side wall portion provided along one side farther from the rotation axis of the two sides.

In the piezoelectric power generation device according to the present invention, the lever preferably has an elongated rectangular shape in a plan view. In this case, the long side direction of the lever is the rotation axis of the rotation shaft. It is preferable to be parallel to the extending direction.

The piezoelectric power generation device according to the present invention may further include an external force transmission unit that transmits the external force received by the lever to the piezoelectric element. In that case, it is preferable that the external force transmission unit includes a reversing spring. In that case, the reversing spring is preferably disposed between the piezoelectric element and the lever.

In the piezoelectric power generation device according to the present invention, the external force transmission unit may further include an auxiliary spring connected in parallel to the reversing spring. It is preferable to arrange between the element and the lever.

In the piezoelectric power generation device according to the present invention, the piezoelectric element may include a metal plate and a plate-like piezoelectric body provided on one main surface of the metal plate.

The piezoelectric power generation device according to the present invention may include a plurality of the piezoelectric elements, and in that case, the plurality of piezoelectric elements are preferably stacked in the thickness direction.

In the piezoelectric power generation device according to the present invention, the support member preferably has a box-like shape including a bottom plate portion and side wall portions erected from four sides of the bottom plate portion.

A piezoelectric power generation module according to the present invention includes the piezoelectric power generation apparatus according to the present invention and a power supply circuit for supplying the power generated by the piezoelectric element to a load.

The transmitter based on this invention is equipped with the piezoelectric power generation module based on the said invention, and the transmission part which transmits a radio signal using the said electric power supplied from the said piezoelectric power generation module as said load. .

According to the present invention, a piezoelectric power generation device that can reliably prevent an excessive external force from being applied to the piezoelectric element, a piezoelectric power generation module including the piezoelectric power generation device, and a transmitter can be provided.

It is a circuit block diagram which shows roughly the structure of the transmitter in embodiment of this invention. It is a figure which shows the logic circuit of the signal output part shown in FIG. FIG. 3 is a Venn diagram corresponding to the logic circuit shown in FIG. 2. 1 is a perspective view of a piezoelectric power generator in an embodiment of the present invention. FIG. 5 is a sectional view taken along line VV shown in FIG. 4. FIG. 5 is a cross-sectional view taken along the line VI-VI shown in FIG. 4. It is a disassembled perspective view of the piezoelectric power generator shown in FIG. FIG. 8 is an exploded perspective view of the piezoelectric element shown in FIG. 7. It is sectional drawing in the state in which the external force was provided to the piezoelectric power generator shown in FIG. It is a time chart for demonstrating an example of operation | movement of the transmitter shown in FIG. It is a conceptual diagram which shows the schematic structure of the piezoelectric generator according to embodiment of this invention, and the connection structure of a lever and a case body. It is a conceptual diagram which shows the schematic structure of the piezoelectric power generator which concerns on a comparative example, and the connection structure of a lever and a case body. It is a conceptual diagram which shows the connection structure of the lever and case body of the piezoelectric generator in embodiment of this invention. It is a graph which shows the relationship between the operation amount of an inversion spring, and operation force. It is the graph which showed the result of the verification test. It is sectional drawing which shows schematic structure of the piezoelectric electric power generating apparatus which concerns on the 1st modification based on embodiment of this invention. It is sectional drawing which shows schematic structure of the piezoelectric electric power generating apparatus which concerns on the 2nd modification based on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below exemplifies a case where the present invention is applied to a transmitter, a piezoelectric power generation module provided in the transmitter, and a piezoelectric power generation device provided in the piezoelectric power generation module. In the following embodiments, the same or common parts are denoted by the same reference numerals in the drawings, and description thereof will not be repeated.

FIG. 1 is a circuit block diagram schematically showing a configuration of a transmitter according to an embodiment of the present invention. 2 is a diagram showing a logic circuit of the signal output unit shown in FIG. 1, and FIG. 3 is a Venn diagram corresponding to the logic circuit shown in FIG. First, with reference to these FIG. 1 thru | or FIG. 3, the structure of the transmitter 1 in this Embodiment and the structure and operation | movement of the signal output part 13 are demonstrated.

The transmitter 1 in the present embodiment is configured as a so-called remote controller, and generates power using an external force that is applied to the operation button when the operation button is pressed down, and uses the generated power. Thus, the transmission unit is configured to operate. Therefore, transmitter 1 in the present embodiment does not require replacement of a power source such as a dry battery.

As shown in FIG. 1, the transmitter 1 includes a piezoelectric power generation module 10 and a transmission unit 20. The piezoelectric power generation module 10 includes a piezoelectric power generation apparatus 100 (see FIGS. 4 to 6 and the like), which will be described later, and supplies generated power to the transmission unit 20. The transmission unit 20 corresponds to a load that operates with electric power supplied from the piezoelectric power generation module 10.

The transmission unit 20 includes an RF (Radio Frequency) antenna 21 and an RF circuit 22. The transmission unit 20 transmits an RF signal to a receiver (not shown) provided at a position away from the transmitter 1 using the electric power supplied from the piezoelectric power generation module 10. This RF signal may be a signal indicating a control command to the receiver, or a signal for transmitting various types of information to the receiver.

The piezoelectric power generation module 10 includes a piezoelectric power generator 120, a full-wave rectifier circuit 11, a capacitor C, a DC / DC converter 12, a signal output unit 13, a control circuit 14, a discharge switch 15, and a first switch 141A. 141B and the second switch 142 are mainly provided.

The piezoelectric power generator 120 includes an output terminal T1 and an output terminal T2, and includes a plurality of piezoelectric elements 120a (see FIG. 4 to FIG. 6 and the like) that generate power by being deformed. Here, the potential of the output terminal T1 with respect to the potential of the output terminal T2 is defined as “output voltage V”.

The full-wave rectifier circuit 11 is electrically connected between the piezoelectric power generator 120 and the DC / DC converter 12, and performs full-wave rectification on the output voltage V of the piezoelectric power generator 120. As the full-wave rectifier circuit 11, for example, a general full-wave rectifier circuit including a diode bridge (not shown) can be used.

The full-wave rectifier circuit 11 includes nodes N1 and N2. The node N1 is electrically connected to the DC / DC converter 12 by the power line PL, and outputs a full-wave rectified voltage (rectified voltage) Vc to the DC / DC converter 12. Node N2 is electrically connected to power line GL having reference potential GND.

The capacitor C is electrically connected between the power line PL and the power line GL, and smoothes the rectified voltage Vc.

The DC / DC converter 12 converts the smoothed rectified voltage Vc into a predetermined voltage, and includes an input terminal Vin, an output terminal Vout, and an enable terminal EN. The input terminal Vin is electrically connected to the node N1 of the full-wave rectifier circuit 11, and the output terminal Vout is electrically connected to the RF circuit 22. The enable terminal EN is electrically connected to the output node OUT of the signal output unit 13.

The first switches 141A and 141B are switched from a non-conduction state (off) to a conduction state (on) when a user operation is accepted, and each has a pair of contacts. As will be described later, the first switches 141A and 141B are arranged on the side opposite to the side where the piezoelectric power generation body 120 is located when viewed from the lever 130 of the piezoelectric power generation apparatus 100 (see FIGS. 4 to 7, etc.).

The first switches 141A and 141B are configured to be operated independently by the user, and only one of the switches or both switches can be operated simultaneously. In the present embodiment, as will be described later, the first switches 141A and 141B are both constituted by membrane switches, but other types of switches can also be used.

One of the pair of contacts of the first switch 141A is electrically connected to the power line PL, and the other is electrically connected to the input node IN1A of the signal output unit 13. Thereby, the first switch 141A outputs the signal S1A to the signal output unit 13 in the ON state.

One of the pair of contacts of the first switch 141B is electrically connected to the power line PL, and the other is electrically connected to the input node IN1B of the signal output unit 13. Thereby, the first switch 141B outputs the signal S1B to the signal output unit 13 in the ON state.

The second switch 142 switches from a non-conductive state (off) to a conductive state (on) when a user operation is accepted, and has a pair of contacts. As will be described later, the second switch 142 is disposed on the side where the piezoelectric power generation body 120 is located when viewed from the lever 130 of the piezoelectric power generation apparatus 100 (see FIGS. 5 to 7 and the like). The second switch 142 differs from the above-described first switches 141A and 141B in on / off at different timings in the user's button operation, and details thereof will be described later.

As will be described later, one of the pair of contacts of the second switch 142 is constituted by a reversing spring 160, and the other is a wiring board (second flexible wiring board 150 ( 5 to 7 etc.))).

One of the pair of contacts of the second switch 142 is electrically connected to the power line PL, and the other is electrically connected to the input node IN2 of the signal output unit 13. Thereby, the second switch 142 outputs the signal S2 to the signal output unit 13 in the ON state.

The signal output unit 13 includes switching elements Q including diodes D1 to D4, resistors R1 to R4, and NMOS (n-type Metal Oxide-Semiconductor) transistors in addition to the input nodes IN1A, IN1B, IN2 and the output node OUT. Including.

The input node IN1A is electrically connected to the gate of the switching element Q via the diode D1. The anode of the diode D1 is electrically connected to the power line GL via the resistor R1. Similarly, the input node IN1B is electrically connected to the gate of the switching element Q via the diode D2. The anode of the diode D2 is electrically connected to the power line GL via the resistor R2.

The drain of the switching element Q is electrically connected to the power line PL via the resistor R3. The source of the switching element Q is electrically connected to the power line GL.

The anode of the diode D3 is electrically connected to a connection node between the resistor R3 and the drain of the switching element Q. The cathode of the diode D3 is electrically connected to the output node OUT. Further, the cathode of the diode D3 is electrically connected to the power line GL via the resistor R4.

The input node IN2 is electrically connected to the anode of the diode D4. The cathode of the diode D4 is electrically connected to the cathode of the diode D3.

Here, the output node OUT of the signal output unit 13 is electrically connected to the enable terminal EN of the DC / DC converter 12. Thus, the enable terminal EN receives the switching signal SW output from the output node OUT as an enable signal for the DC / DC converter 12.

The logic circuit of the signal output unit 13 having the above circuit configuration is as shown in FIG. That is, as shown in FIG. 2, the signal output unit 13 includes an input node IN1A that receives the signal S1A, an input node IN1B that receives the signal S1B, an input node IN2 that receives the signal S2, and an output node that outputs the switching signal SW. It includes OUT, a NOR circuit (negative OR circuit) 13a, and an OR circuit (OR circuit) 13b.

The NOR circuit 13a outputs to the OR circuit 13b a signal indicating the operation result of the negative logical sum of the signal S1A and the signal S1B. The OR circuit 13b outputs a signal indicating the logical sum of the signal from the NOR circuit 13a and the signal S2 to the output node OUT.

As shown in FIG. 3, the signal output unit 13 configured as described above is H (high) when the first switches 141A, 141B and the second switch 142 are all off, as shown in the region K1. A level switching signal SW is output.

As shown in regions K2 and K3, when one of the first switches 141A and 141B is on, the other is off, and the second switch 142 is off, the signal output unit 13 Outputs an L (low) level switching signal SW. Further, as shown in the region K4, the signal output unit 13 outputs the L level switching signal SW even when both the first switches 141A and 141B are on and the second switch 142 is off. .

On the other hand, as shown in the regions K5 to K8, when the second switch 142 is on, the signal output unit 13 outputs an H level switching signal SW. Note that, as is apparent from the configuration of the piezoelectric power generation device 100 described later, in the present embodiment, the state in which the second switch 142 is on (even though both the first switches 141A and 141B are off) ( The area K8) does not actually occur.

As described above, the signal output unit 13 sends the H level or L level switching signal SW to the enable terminal EN of the DC / DC converter 12 based on the combination of the on state or the off state of the first switches 141A, 141B and the second switch 142. Output to.

As shown in FIG. 1, the control circuit 14 is connected between the power line PL and the power line GL. The control circuit 14 is a part that controls the operation of the transmission unit 20, and a detailed description thereof is omitted here. However, the control circuit 14 is configured to receive signals S1A and S1B separately. In response, an operation command is output to the transmitter 20. Further, the control circuit 14 outputs a discharge command to the discharge switch 15.

The discharge switch 15 is connected between the output terminal T1 and the output terminal T2 of the piezoelectric power generator 120, and is used to discharge the electric charge stored in the piezoelectric power generator 120. More specifically, the discharge switch 15 is switched from a non-conductive state (off) to a conductive state (on) in response to a discharge command from the control circuit 14.

Thereby, when the discharge switch 15 is turned on, the output terminal T1 and the output terminal T2 are short-circuited, and the electric charge stored in the piezoelectric power generator 120 is discharged. As the discharge switch 15, for example, an IC (Integrated Circuit) such as an analog switch or a FET (Field Effect Transistor) can be used.

In the transmitter 1 described above, the DC / DC converter 12 switches the H level from the signal output unit 13 to the enable terminal EN based on the on state or the off state of the first switches 141A and 141B and the second switch 142. When receiving the input of the signal SW, the power is supplied to the transmitting unit 20, and when receiving the input of the L level switching signal SW from the signal output unit 13 to the enable terminal EN, the power to the transmitting unit 20 is supplied. Will not be supplied.

With this configuration, in the transmitter 1 according to the present embodiment, electric power is generated by the piezoelectric power generator 120 based on the combination of the on state or the off state of the first switches 141A and 141B and the second switch 142. By supplying power to the transmission unit 20 at a predetermined timing, efficient power generation and necessary transmission operation are realized. Details of the operation of the transmitter 1 will be described later, and The piezoelectric power generation apparatus 100 provided in the above-described piezoelectric power generation module 10 will be described in detail.

FIG. 4 is a perspective view of the piezoelectric power generation apparatus according to the present embodiment, and FIGS. 5 and 6 are cross-sectional views taken along lines VV and VI-VI shown in FIG. 4, respectively. 7 is an exploded perspective view of the piezoelectric power generation device shown in FIG. 4, and FIG. 8 is an exploded perspective view of the piezoelectric element shown in FIG. First, with reference to these FIG. 4 thru | or FIG. 8, the structure of the piezoelectric generator 100 in this Embodiment is demonstrated.

4 to 7, the piezoelectric power generation apparatus 100 includes a case body 110 as a support member, a piezoelectric power generation body 120 in which a plurality of piezoelectric elements 120a are stacked, a lever 130 as a movable portion, A flexible wiring board 140, a second flexible wiring board 150, a reversing spring 160 and an auxiliary spring 170 as external force transmission units, and a screw 180 are provided.

The piezoelectric power generator 100 is disposed behind an operation button (not shown). Specifically, the operation buttons are installed on the main surface of the piezoelectric power generation apparatus 100 on the side where the first flexible wiring board 140 is located. In this embodiment, two operation buttons that can be operated independently are installed at the positions of arrows AR1 and AR2 shown in FIGS. 4 to 6, and the operation buttons are operated by the user. Then, external forces are applied to the piezoelectric power generation apparatus 100 in the directions of the arrows AR1 and AR2, respectively.

The case body 110 has a box shape including a bottom plate portion 111 having a substantially rectangular shape in plan view and side wall portions 112 to 115 erected from four sides of the bottom plate portion 111. The case body 110 is a member that serves as a base for supporting other parts constituting the piezoelectric power generation apparatus 100. The other parts constituting the piezoelectric power generation apparatus 100 are surrounded by the bottom plate portion 111 and the side wall portions 112 to 115. Mainly housed in the open space.

The side wall portions 112 and 115 are erected from two opposite sides of the bottom plate portion 111 so as to face each other, and the side wall portions 113 and 114 are different from the above-described two sides of the bottom plate portion 111 so as to face each other. It is erected from the other two sides. At the four corners of the bottom plate portion 111, there are formed portions where the side wall portions 112 to 115 are not provided so that the side wall portions 112 to 115 are discontinuous with each other.

At the four corners of the bottom plate portion 111, support portions 111a are provided so as to protrude from the inner bottom surface of the bottom plate portion 111, respectively. These support portions 111a are portions for supporting the piezoelectric power generator 120 so as to be able to bend and deform.

The shaft support holes 113a and 114a are provided at predetermined positions near the side wall 112 of the side walls 113 and 114 so as to face each other (see FIGS. 5 and 7). The shaft support holes 113a and 114a are portions for supporting the lever 130 so as to be rotatable.

The side wall portion 115 is configured to be slightly lower than the other side wall portions 112 to 114, and has an abutting surface 115a as an abutting portion for restricting the rotation of the lever 130 on its upper surface.

The case body 110 having the above-described configuration is preferably formed by pressing a metal plate-like member having a predetermined thickness. With this configuration, the case body 110 is provided with high rigidity. can do. In particular, the strength of the case body 110 can be kept high by erecting the side wall portions 112 to 115 from the four sides of the bottom plate portion 111 by bending as shown in the figure. Specifically, the case body 110 is configured by, for example, a press-formed product of a stainless steel plate member having a thickness of 0.25 [mm].

The case body 110 is positioned with respect to the case body 110 only by disposing the piezoelectric power generation body 120 in a space surrounded by the bottom plate portion 111 and the side wall portions 112 to 115. Furthermore, it is preferable that the size is slightly larger than the size of the piezoelectric power generator 120 described later.

The piezoelectric power generator 120 is formed by laminating a plurality of plate-like piezoelectric elements 120a having a rectangular shape in plan view, and has a plate-like shape as a whole. The individual piezoelectric elements 120a generate power by being deformed in the thickness direction, and the plurality of piezoelectric elements 120a are stacked so that the thickness directions thereof match each other. As the piezoelectric element 120a, any of a unimorph type, a bimorph type, and a multimorph type may be used. However, in the present embodiment, a piezoelectric body in which six layers of piezoelectric films described later are laminated is provided. A multimorph type piezoelectric element 120a is used.

As shown in FIG. 8, the piezoelectric element 120 a mainly includes a metal plate 121 and a plate-like piezoelectric body 122 provided on one main surface of the metal plate 121. The metal plate 121 and the piezoelectric body 122 are bonded together by an adhesive layer 124 made of, for example, an epoxy adhesive. In this manner, by sticking the metal plate 121 to one main surface of the piezoelectric body 122, it is possible to obtain a piezoelectric element having excellent durability that is not easily damaged even by repeated bending deformation.

The piezoelectric element 120a has a pair of terminals 123 for external connection. The pair of terminals 123 are bonded to a pair of external electrodes provided on the front surface of the piezoelectric body 122 using a conductive adhesive 125. The pair of terminals 123 is made of a sheet-like flexible metal member, and a part of the terminals 123 is drawn toward a region outside the piezoelectric body 122. In addition, a through hole 123 a is provided at a predetermined position at the tip of each of the pair of terminals 123.

The piezoelectric body 122 is formed by laminating a plurality of piezoelectric films made of, for example, lead zirconate titanate-based ceramics, and has the above-described pair of external electrodes on its front surface. A plurality of internal electrodes are provided inside the piezoelectric body 122, and each of these internal electrodes is connected to one of a pair of external electrodes provided on the front surface of the piezoelectric body 122. As the piezoelectric body 122, lead-free piezoelectric ceramics (potassium sodium niobate ceramics, alkali niobic ceramics, etc.) may be used.

A protective film 126 is provided on the front surface of the piezoelectric body 122 so as to cover the entire surface. The protective film 126 protects the piezoelectric body 122, the terminal 123, and the like. For example, a polyimide sheet that can be attached to the piezoelectric body 122 can be used as the protective film 126.

Here, the size of the piezoelectric element 120a is not particularly limited, but the piezoelectric element 120a in the present embodiment has a size of 14 [mm] × 14 [mm] excluding the pair of terminals 123. × 0.08 [mm] is used.

As shown in FIGS. 4 to 7, the plurality of piezoelectric elements 120 a are arranged such that the front surface of the piezoelectric body 122 included in each of the piezoelectric elements 120 a faces the bottom plate portion 111 side of the case body 110 (that is, the piezoelectric body 122 is made of metal. The layers are stacked and placed on the case body 110 so as to be positioned closer to the bottom plate portion 111 than the plate 121. Thereby, the piezoelectric power generating body 120 comes into contact with the support portions 111a provided on the bottom plate portion 111 of the case body 110 at the four corners of the lower surface, and most of the piezoelectric power generation body 120 is located at a distance from the bottom plate portion 111. The body 110 is supported so as to be able to bend and deform. In the present embodiment, a total of four piezoelectric elements 120a are stacked.

Here, the plurality of piezoelectric elements 120a are preferably laminated so that all or part of them are in contact with each other. By configuring in this way, the piezoelectric elements 120a located on the bottom plate portion 111 side are further reached. Deformation due to the application of external force can be generated. In particular, when a part of the plurality of piezoelectric elements 120a is brought into contact with each other, the four corners and the center of each of the plurality of piezoelectric elements 120a can be brought into contact with each other by providing irregularities or the like on the exposed surface side of the metal plate. preferable.

The lever 130 includes a base portion 131 having a substantially rectangular shape in plan view and standing wall portions 133 and 134 erected from two opposite sides of the base portion 131 so as to face each other. The base portion 131 is disposed so as to face the piezoelectric power generator 120, and the standing wall portions 133, 134 are disposed so as to face the side wall portions 113, 114 of the case body 110, respectively.

A pair of screw holes 131 a are provided at predetermined positions of the base 131. The screw hole 131a is a part for fixing the second flexible wiring board 150 and the auxiliary spring 170 to the lever 130, and a screw 180 is attached to each of the screw holes 131a.

Shaft portions 133a and 134a are provided at predetermined positions on the outer surfaces of the standing wall portions 133 and 134 and near the side wall portion 112 of the case body 110 so as to protrude outward (see FIGS. 5 and 7). ). The shaft portions 133a and 134a are pivotally supported by the shaft support holes 113a and 114a by being inserted into the shaft support holes 113a and 114a provided in the case body 110, respectively. Thus, the lever 130 is rotatably supported by the case body 110 with the axis connecting the shaft portions 133a and 134a serving as the rotation shaft 1000 (see FIGS. 5 and 6).

When the lever 130 is rotatably supported by the case body 110 and an external force is applied to the base 131 of the lever 130, the lever 130 is in a direction substantially along the thickness direction of the piezoelectric power generator 120. It is displaced to. Along with the displacement of the lever 130, the external force received by the lever 130 is transmitted to the piezoelectric power generator 120 via a reversing spring 160 and an auxiliary spring 170 as an external force transmitting portion, which will be described later, and thereby to each piezoelectric element 120a. A bending deformation will occur.

Here, the tip portion 135 of the base portion 131 that is the portion farthest from the above-described rotating shaft 1000 in the lever 130 is disposed at a position on the side wall portion 115 side of the case body 110, and the tip portion 135 is a lever. When 130 is rotated to the piezoelectric power generation body 120 side, it is comprised so that it may contact | abut to the contact surface 115a provided in the side wall part 115 of the case body 110 (refer FIG. 9).

More specifically, the rotating shaft 1000 of the lever 130 has two opposite sides of the piezoelectric power generator 120 when viewed along the thickness direction of the piezoelectric power generator 120 (that is, two sides provided with the side walls 112 and 115). The abutting surface 115a described above is provided along one of the two sides far from the rotation axis 1000 (that is, the side wall 115).

With this configuration, the rotation range of the lever 130 toward the piezoelectric power generator 120 is limited. Therefore, an excessive external force can be applied to the piezoelectric power generator 120 by appropriately setting the position where the abutting surface 115a is provided according to the installation position of the piezoelectric power generator 120, the arrangement position and shape of the lever 130, and the like. As a result, it is possible to prevent the piezoelectric power generator 120 from being damaged.

The lever 130 having the above-described configuration is preferably formed by pressing a metal plate-like member having a predetermined thickness. With this configuration, the lever 130 is provided with high rigidity. Can do. In particular, as shown in the drawing, the standing wall portions 133 and 134 are erected from the two opposite sides of the base portion 131 by bending, and lightly bent to the two opposite sides of the base portion 131 on the side where the standing wall portions 133 and 134 are not located. By applying the processing, the strength of the lever 130 can be kept high, and damage when an excessive external force is applied can be prevented. Specifically, the lever 130 is configured by a press-formed product of a stainless steel plate-like member having a thickness of 0.6 [mm], for example.

In the present embodiment, the rotating shaft 1000 of the lever 130 is the main surface on the side where the lever 130 of the piezoelectric power generator 120 is located, and the side wall 112 of the case body 110 rather than the central portion of the piezoelectric power generator 120. It is arranged at the side position. With this configuration, the lever 130 can be configured by a plate-like member having an elongated shape in plan view, and the long side direction of the lever 130 is the rotation axis 1000 of the lever 130. The lever 130 can be arranged so as to be parallel to the extending direction. Here, the term “parallel to the extending direction of the rotating shaft 1000” includes the case of being approximately parallel with a shift of about ± 5 [°].

Therefore, by adopting this configuration, the distance from the rotation shaft 1000 to the side wall 115 provided with the abutting surface 115a can be shortened, and the rotation radius of the tip portion 135 of the lever 130 can be reduced. The bending deformation generated in the lever 130 when the operation button is pressed down can be greatly suppressed, and the piezoelectric power generator 120 can be more reliably prevented from being damaged.

The first flexible wiring board 140 is provided on the main surface on the side where the piezoelectric power generator 120 is not located, of the pair of main surfaces of the base 131 of the lever 130. The first flexible wiring board 140 is formed by forming various conductive patterns on the surface of a multi-layer base material, and the two membrane switches constituting the first switches 141A and 141B described above are provided at predetermined positions. Have.

The two membrane switches constituting the first switches 141A and 141B are provided so as to be aligned along a direction parallel to the extending direction of the rotating shaft 1000 of the lever 130. Thus, the two membrane switches are positioned to face the two operation buttons (not shown) described above.

The two membrane switches constituting the first switches 141A and 141B are preferably switched from the off state to the on state with a low load of 2 [N] or less. It is possible to quickly detect that the button is depressed. The two membrane switches do not need to convey a click feeling to the user.

The first flexible wiring board 140 has a connection portion 143 at a predetermined position. The connection part 143 is a part that is electrically connected to the second flexible wiring board 150.

The first flexible wiring board 140 is preferably fixed to the lever 130 with a double-sided tape or the like (not shown). By configuring as such, the position of the membrane switch relative to the operation button (not shown) or the lever 130 is shifted. Can be prevented.

The second flexible wiring board 150 is provided on the main surface of the pair 131 main surfaces of the lever 130 on the side where the piezoelectric power generator 120 is located. The second flexible wiring board 150 is formed by forming various conductive patterns on the surface of a single-layer or multilayer substrate, and has two connection portions 153 and 154.

The connection unit 153 is a part that is electrically connected to the first flexible wiring board 140, and the connection unit 154 connects the piezoelectric power generation apparatus 100 to an external power management circuit (that is, the piezoelectric power generation module 10 illustrated in FIG. 1). A power supply circuit excluding a circuit portion constituted by the piezoelectric power generation apparatus 100 from the circuit block corresponds to this).

As shown in FIGS. 5 to 7, a reversing spring 160 as an external force transmission unit and an auxiliary force are provided between the piezoelectric power generation body 120 and the second flexible wiring board 150 disposed on one main surface of the lever 130. A spring 170 is arranged. The reversal spring 160 and the auxiliary spring 170 as the external force transmission unit are for transmitting the external force received by the lever 130 to the piezoelectric power generator 120.

The reversing spring 160 is mounted on a portion of the second flexible wiring board 150 that is located on the main surface of the base 131 of the lever 130 and that faces the central portion of the piezoelectric power generator 120.

The reversing spring 160 is buckled so that its concavo-convex shape is reversed when an external force is applied and a predetermined load is applied. When the external force is released, the buckling is eliminated and the original shape is restored. For example, a metal member having a dome shape or a laminated structure thereof.

The reversing spring 160 constitutes one of the pair of contacts of the second switch 142 described above, and has a posture that protrudes downward so that a space is formed between the reversing spring 160 and the second flexible wiring board 150. That is, it is fixed to the second flexible wiring board 150 (that is, the top of the dome-shaped reversal spring 160 is positioned on the piezoelectric power generator 120 side).

On the other hand, the other of the pair of contacts of the second switch 142 described above is provided as a conductive terminal in a portion of the second flexible wiring board 150 covered with the reversing spring 160 described above.

With this configuration, the pair of contacts of the second switch 142 can be turned on when the reversing spring 160 is reversed, and the second switch 142 can be turned on when the reversing spring 160 is not reversed. The pair of contacts can be turned off (off).

By using the reversing spring 160, when the user pushes down the operation button, the above-described buckling phenomenon occurs when a predetermined load is applied, and the spring constant of the reversing spring 160 is instantaneous. Will fall. Thereby, the user can get a click feeling by applying the impact, and the operability when operating the operation buttons can be ensured.

On the other hand, the auxiliary spring 170 has an elongated plate-like shape that is substantially V-shaped when viewed from the side, and has a posture that protrudes downward to accept the reversing spring 160 (that is, an auxiliary that is substantially V-shaped when viewed from the side. The spring 170 is attached to the second flexible wiring board 150 so that the top of the spring 170 is located on the piezoelectric power generator 120 side. The auxiliary spring 170 is constituted by, for example, a single metal leaf spring or a laminated structure thereof.

More specifically, a through hole 170a (see FIGS. 5 and 7) is provided at both ends of the auxiliary spring 170, and the second flexible wiring board 150 corresponding to the through hole 170a also has a through hole 150a. (See FIGS. 5 and 7). These through holes 150a and 170a are provided so as to match the screw holes 131a provided in the base 131 of the lever 130 described above, and the screws 180 are inserted into the screw holes 131 so as to be inserted through the through holes 150a and 170a. The second flexible wiring board 150 and the auxiliary spring 170 are fixed to the lever 130 by being screwed to 131a. In addition, as a result, the reversal spring 160 is sandwiched between the second flexible wiring board 150 and the auxiliary spring 170, thereby fixing the reversal spring 160 to the second flexible wiring board 150.

The auxiliary spring 170 adjusts the spring constant of the entire external force transmission unit that transmits the external force received by the lever 130 to the piezoelectric power generator 120. By providing the auxiliary spring 170, the click feeling of the reversing spring 160 is reduced. The degree (refer to the click rate described later) can be adjusted and the balance of the force applied to the piezoelectric power generator 120 and the reversing spring 160 can be corrected. The details will be described later.

Further, the auxiliary spring 170 corresponding to the top of the reversing spring 160 is provided with a protrusion 171 that contacts the top of the reversing spring 160. Thereby, when the user operates the operation button, the buckling phenomenon of the reversing spring 160 occurs surely.

As shown in the figure, in the present embodiment, the reversing spring 160 is constituted by a laminated structure in which four thin metal members having a dome shape are laminated, and the auxiliary spring 170 is made of one metal. It consists of a leaf spring. This is a result of adjusting the degree of the click feeling described above and correcting the balance of the force applied to the piezoelectric power generator 120 and the reversing spring 160. Of course, when the specifications of the piezoelectric power generator 100 are different, These can be changed as appropriate.

As shown in FIG. 4, the above-described piezoelectric power generation apparatus 100 is fixed to a casing or the like of the transmitter 1 (not shown) using press-fit pins 190. Specifically, the press-fit pin 190 penetrates the through hole 123a provided in the terminal 123 of each piezoelectric element 120a included in the piezoelectric power generator 120 and the second flexible wiring board 150 provided so as to overlap therewith. The tip is inserted into the hole 150b (see FIG. 7) and fixed by being press-fitted into a press-fitting hole provided in the casing of the transmitter 1 or the like.

Here, the terminal 123 of the piezoelectric power generation body 120 and the second flexible wiring board 150 are press-contacted by the press-fit pins 190, so that electrical connection between the piezoelectric power generation body 120 and the second flexible wiring board 150 is ensured. It will be. If a metal pin is used as the press-fit pin 190, the electrical connection between the piezoelectric power generator 120 and the second flexible wiring board 150 can be made more reliable.

FIG. 9 is a cross-sectional view of the piezoelectric power generation device shown in FIG. 4 with an external force applied thereto. Next, a state where an external force is applied to the piezoelectric power generation apparatus 100 according to the present embodiment will be described with reference to FIG.

In the state shown in FIG. 4, for example, in a state where the user pushes down an operation button (not shown) corresponding to the first switch 141A in the direction of the arrow AR1 shown in the figure, the operation button is moved to move the first. The lever 130 receives an external force through the flexible wiring board 140. As a result, as shown in FIG. 9, the lever 130 rotates about the rotation shaft 1000 in the direction of the arrow DR in the figure, and as a result, the lever 130 is displaced so as to tilt toward the piezoelectric power generator 120 side.

When the lever 130 is displaced, the reversing spring 160 and the auxiliary spring 170 as external force transmitting portions arranged between the piezoelectric power generator 120 and the lever 130 are compressed by these, and receive the reaction force. Thus, the individual piezoelectric elements 120a included in the piezoelectric power generator 120 are also deformed by bending.

When bending deformation occurs in the piezoelectric element 120a, polarization occurs in the piezoelectric body 122 in the deformation process. Along with the polarization, one of the pair of external electrodes provided on the piezoelectric element 120a is negatively charged and the other is positively charged. Therefore, electric power is generated in the piezoelectric power generator 120.

Here, the reversing spring 160 is preferably set so as to be reversed (that is, buckled) at a predetermined pressing stroke that is equal to or greater than the pressing stroke necessary for power generation in the piezoelectric power generator 120. With this configuration, the reversing spring 160 is reversed when the amount of power to be generated is generated in the piezoelectric power generator 120 or thereafter, so that an operation amount (that is, a push amount) for the operation button of the user is ensured. It is possible to complete the power generation operation with certainty.

The first switch 141A is switched from the off state to the on state at an initial stage when the user starts to push down the operation button. On the other hand, the second switch 142 configured to include the reversing spring 160 is switched from the off state to the on state at the time when or after the amount of electric power to be generated is accumulated in the piezoelectric power generator 120. For this reason, the second switch 142 is switched to the ON state with a delay from the first switch 141A.

Referring to FIG. 9, in the piezoelectric power generation apparatus 100 according to the present embodiment, as described above, the lever 130 is rotated by a predetermined amount so that an excessive external force is not applied to the piezoelectric power generation body 120. When moved, the distal end portion 135 of the lever 130 is configured to come into contact with the abutting surface 115 a of the case body 110.

Here, the amount of rotation of the lever 130 where the distal end portion 135 of the lever 130 abuts against the abutting surface 115a of the case body 110 is set so that the reversing spring 160 reverses within a range in which excessive external force is not applied to the piezoelectric power generator 120. By setting it to be larger than the amount of movement, it is possible to achieve both efficient power generation by the piezoelectric power generator 120 and prevention of breakage thereof.

On the other hand, when the user releases the operation of the operation button (not shown) corresponding to the first switch 141A from the state shown in FIG. 9, the external force applied to the piezoelectric power generation apparatus 100 is removed. . As a result, the piezoelectric generator 120, the reversing spring 160, and the auxiliary spring 170 are restored to their original states based on the elastic force, and the lever 130 is also displaced again (that is, shown in FIG. 9). Return to the original position (displaced in the direction opposite to the arrow DR direction). As a result, the piezoelectric power generating apparatus 100 returns to the state shown in FIG. At this time, the buckling generated in the reversing spring 160 is also eliminated.

Polarization occurs in the piezoelectric body 122 even in the process in which the piezoelectric element 120a that has undergone bending deformation returns to its original shape. Along with the polarization, one of the pair of external electrodes provided on the piezoelectric element 120a is positively charged and the other is negatively charged. Therefore, electric power having a polarity opposite to that of the deformation process described above is generated in the piezoelectric power generator 120. In the present embodiment, this reverse polarity power is also used, but the details will be described later.

Here, the second switch 142 including the reversing spring 160 is switched from the on state to the off state at an initial stage when the user starts to release the depression of the operation button. On the other hand, the first switch 141 </ b> A is switched from the on state to the off state at the time when or after the amount of electric power to be generated is accumulated in the piezoelectric power generator 120. Therefore, the first switch 141A is switched to the off state with a delay later than the second switch 142.

Although explanation thereof is omitted here, when the user operates an operation button (not shown) corresponding to the first switch 141B, and the user simultaneously operates the operation button corresponding to the first switch 141A, 141B. In some cases, the state is in accordance with the above description.

FIG. 10 is a time chart for explaining an example of the operation of the transmitter shown in FIG. Next, with reference to FIG. 10, as an example of the operation of the transmitter 1 described above, a case where the user performs an operation of depressing the operation button corresponding to the first switch 141A will be described. In FIG. 10, the horizontal axis indicates the elapsed time, and the vertical axis indicates the load on / off, the output voltage of the piezoelectric power generator, the first switch 141A on / off, and the first switch 141B in order from the top. ON / OFF, second switch 142 ON / OFF, and piezoelectric generator reset operation ON / OFF.

As shown in FIG. 10, until the time t1, the first switches 141A and 141B and the second switch 142 are all off, so that the switching signal SW of the signal output unit 13 is at the H level. However, since power generation is not yet performed in the piezoelectric power generator 120, power supply from the piezoelectric power generation module 10 to the transmission unit 20 is not performed.

When the application of external force is started at time t1, the load applied to the piezoelectric power generation apparatus 100 starts to increase.

After that, when the first switch 141A is turned on at time t2, the switching signal SW of the signal output unit 13 becomes L level. Accordingly, power supply from the piezoelectric power generation module 10 to the transmission unit 20 is not performed.

Almost simultaneously with the time t2, the piezoelectric power generator 120 begins to bend and deform as the load applied to the piezoelectric power generator 100 increases. Along with this deformation, the piezoelectric power generator 120 generates power, and the generated power is stored in the piezoelectric power generator 120 without being supplied to the transmitter 20.

At time t3, the reversing spring 160 starts reversing. When reversing of the reversing spring 160 is completed at time t4, the second switch 142 is turned on at time t4. Thereby, the switching signal SW of the signal output unit 13 becomes H level. Accordingly, the electric power stored in the piezoelectric power generator 120 is supplied from the piezoelectric power generation module 10 to the transmission unit 20, and the transmission operation is started in the transmission unit 20.

Here, from time t3 to time t4, a click operation occurs, and the user feels a click feeling. In addition, after time t4, power is supplied from the piezoelectric power generation module 10 to the transmission unit 20, so that the output voltage of the piezoelectric power generation body 120 decreases.

When the transmission operation is completed, the reset operation of the piezoelectric power generator 120 is started at time t5, whereby the electrodes of the piezoelectric power generator 120 are short-circuited, thereby resetting the output voltage of the piezoelectric power generator 120 to 0 [V]. Is done. Thereafter, the reset operation of the piezoelectric power generator 120 is stopped at time t6.

When the application of external force starts to be released at time t7, the reversing spring 160 starts reversing again (reversing to return to the original shape), and the second switch 142 is turned off at the time t7. Thereby, the switching signal SW of the signal output unit 13 becomes L level. Accordingly, power supply from the piezoelectric power generation module 10 to the transmission unit 20 is not performed.

Almost simultaneously with the time t7, the bending deformation of the piezoelectric power generation body 120 starts to be eliminated as the load applied to the piezoelectric power generation apparatus 100 decreases. Along with this deformation, the piezoelectric power generator 120 generates power, and the generated power is stored in the piezoelectric power generator 120 without being supplied to the transmitter 20.

Note that a click operation occurs from time t7 until the reversal of the reversal spring 160 is completed at time t8, and the user feels a click feeling.

When the first switch 141A is turned off at time t9, the switching signal SW of the signal output unit 13 becomes H level. Accordingly, the electric power stored in the piezoelectric power generator 120 is supplied from the piezoelectric power generation module 10 to the transmission unit 20, and the transmission operation is started in the transmission unit 20.

Thereafter, the application of the external force ends at time t10. In addition, after time t9, power is supplied from the piezoelectric power generation module 10 to the transmission unit 20, so that the output voltage of the piezoelectric power generation body 120 decreases.

When the transmission operation is completed, the reset operation of the piezoelectric power generator 120 is started at time t11, so that the electrodes of the piezoelectric power generator are short-circuited, thereby resetting the output voltage of the piezoelectric power generator 120 to 0 [V]. Is done. Thereafter, the reset operation of the piezoelectric power generator 120 is stopped at time t12.

As described above, the transmitter 1 according to the present embodiment includes the piezoelectric power generation module 10 including the piezoelectric power generation apparatus 100 having the above-described configuration. Therefore, during the operation of the operation button by the user once, The transmission operation can be performed twice. Therefore, the time when the operation button is operated can be determined by detecting the time interval between the two receptions on the receiver side.

Although explanation thereof is omitted here, when the user operates an operation button (not shown) corresponding to the first switch 141B, and the user simultaneously operates the operation button corresponding to the first switch 141A, 141B. Even in this case, the transmission operation according to the above description is performed.

FIG. 11 and FIG. 12 are conceptual diagrams showing a schematic configuration of a piezoelectric power generating device according to the present embodiment and a piezoelectric power generating device according to a comparative example, and a connection structure between a lever and a case body, respectively. Hereinafter, with reference to these FIG. 11 and FIG. 12, the effect obtained by disposing the reversal spring 160 between the lever 130 and the piezoelectric power generator 120 will be described in detail.

As shown in FIG. 11A, the piezoelectric power generation apparatus 100 ′ according to the present embodiment is not provided with the auxiliary spring 170 when compared with the piezoelectric power generation apparatus 100 according to the present embodiment described above. The configuration is different only in that the reversing spring 160 and the piezoelectric power generator 120 are in direct contact.

In the piezoelectric power generating apparatus 100 ′ configured as described above, the piezoelectric power generating body 120 is supported by the case body 110 with a point P0 shown in the drawing as a fulcrum, and the lever 130 has a point P1 shown in the drawing. As a fulcrum, the case body 110 is rotatably supported.

Further, in this piezoelectric power generation device 100 ′, an external force is applied to the lever 130 with the point P2 shown in the figure as a power point, and on the other hand, when the lever 130 rotates, a point P3 shown in the figure is obtained. A force is applied to the reversing spring 160 with the action point as the point of action.

As described above, in the piezoelectric power generation apparatus 100 ′, the reversing spring 160 and the piezoelectric power generation body 120 are in direct contact, and thus the connection structure between the lever 130 and the case body 110 in the piezoelectric power generation apparatus 100 ′ is conceptual. Is as shown in FIG.

That is, as shown in FIG. 11B, in the piezoelectric power generating apparatus 100 ′, the lever 130 and the case body 110 are connected by the reversing spring 160 and the piezoelectric power generating body 120 connected in series therebetween. Will be.

On the other hand, as shown in FIG. 12A, the piezoelectric power generation device 100X according to the comparative example is not provided with the auxiliary spring 170 when compared with the piezoelectric power generation device 100 in the present embodiment described above. The configuration is different in that the reversing spring 160 is disposed between the piezoelectric power generation body 120 and the case body 110.

In the piezoelectric power generating apparatus 100X configured as described above, the piezoelectric power generating body 120 is formed by the case body 110 with the point P0 shown in the figure as a fulcrum, similarly to the piezoelectric power generating apparatus 100 ′ according to the above-described embodiment. The lever 130 is supported by the case body 110 so as to be rotatable about a point P1 shown in the drawing.

On the other hand, in the piezoelectric power generation device 100X, an external force is applied to the lever 130 with the point P2 shown in the figure as a power point, and on the other hand, when the lever 130 rotates, a point P3 shown in the figure is obtained. A force is applied to the piezoelectric power generator 120 with the action point as a point of action.

As described above, in the piezoelectric power generation device 100X, since the reversing spring 160 is disposed between the piezoelectric power generation body 120 and the case body 110, the connection structure between the lever 130 and the case body 110 in the piezoelectric power generation device 100X. Is shown conceptually as shown in FIG.

That is, as shown in FIG. 12B, in the piezoelectric power generation device 100X, the lever 130 and the case body 110 are connected by the reversing spring 160 and the piezoelectric power generation body 120 connected in parallel between them. It will be.

Here, when an external force is applied to the lever 130 in the connection structure shown in FIG. 12B, the piezoelectric power generator 120 is used as a pressing load for generating a pressing stroke necessary for power generation in the piezoelectric power generator 120. Not only a pressing load for deforming but also a pressing load for deforming the reversing spring 160 is required. For this reason, the click feeling obtained by providing the reversing spring 160 is extremely reduced according to the spring constant of the piezoelectric power generator 120, and a pressing stroke necessary for power generation in the piezoelectric power generator 120 is generated. The pressing load for making it increase will also increase significantly.

On the other hand, when an external force is applied to the lever 130 in the connection structure shown in FIG. 11B, according to the law of action and reaction, depending on the ratio of the spring constant of the reversal spring 160 and the spring constant of the piezoelectric power generator 120. Since the pressing load is applied to the reversing spring 160 and the piezoelectric power generation body 120, respectively, a pressing load more than the load necessary for power generation in the piezoelectric power generation body 120 is not necessary. Therefore, the click feeling obtained by providing the reversing spring 160 is maintained as it is regardless of the spring constant of the piezoelectric power generator 120, and the pressing load for generating a pressing stroke necessary for power generation in the piezoelectric power generator 120 is maintained. The increase can also be suppressed.

Accordingly, by disposing the reversing spring 160 between the lever 130 and the piezoelectric power generation body 120 as in the piezoelectric power generation apparatus 100 in the present embodiment described above or the piezoelectric power generation apparatus 100 ′ equivalent thereto, the piezoelectric power generation body. It becomes possible to obtain a high click feeling while keeping the pressing load necessary for power generation at 120 low.

FIG. 13 is a conceptual diagram showing a connection structure between the lever and the case body of the piezoelectric power generation apparatus in the present embodiment described above. Next, with reference to FIG. 13, effects obtained by disposing the auxiliary spring 170 in addition to the reversing spring 160 between the lever 130 and the piezoelectric power generator 120 will be described in detail.

FIG. 13 conceptually shows the connection structure between the lever 130 and the case body 110 of the piezoelectric power generation apparatus 100 in the present embodiment described above. That is, as shown in FIG. 13, in the piezoelectric power generating apparatus 100, the lever 130 and the case body 110 are in series with the reversing spring 160 and auxiliary spring 170 connected in parallel with each other, and with the reversing spring 160 and auxiliary spring 170. And the piezoelectric power generator 120 connected to.

By providing the auxiliary spring 170 so as to be connected in parallel only to the reversing spring 160 in this way, as described above, adjustment of the degree of click feeling by the reversing spring 160 and the force applied to the piezoelectric power generator 120 and the reversing spring 160 are performed. The balance can be corrected.

Specifically, when the reversing spring 160 is reversed with a pressing load smaller than the pressing load necessary for power generation in the piezoelectric power generator 120, the power is supplied to the power management circuit before the necessary power is obtained. It will be supplied and will cause malfunction. Therefore, by connecting the auxiliary spring 170 in parallel with the reversing spring 160, a load that causes the reversing phenomenon of the reversing spring 160 (hereinafter referred to as a reversing load) and a pressing load that is added by providing the auxiliary spring 160 By setting the sum to be approximately equal to the pressing load required for power generation in the piezoelectric power generator 120, the operation amount (ie, the pushing amount) for the operation button of the user can be ensured, and the power generation operation is more reliably performed. It can be completed.

Here, in the piezoelectric power generation apparatus 100 according to the present embodiment described above, as shown in FIGS. 5 and 6 and the like, the reversing spring 160 is formed of a laminated structure in which four thin metal members having a dome shape are laminated. In addition, by configuring the auxiliary spring 170 with a single leaf spring, an appropriate click feeling can be obtained.

That is, in the piezoelectric power generation device 100 in the present embodiment, the power generation amount to be generated using the piezoelectric power generation body 120 is set to approximately 15 [N]. Therefore, it is preferable that a click feeling is obtained when the pressing load is about 15 [N] (more preferably 15 [N] or more). However, the reversal load per dome-shaped thin metal member is usually about 2 [N] to 3 [N], and a click feeling can be obtained with an appropriate pressing load by using only one of these. I can't.

Therefore, as described above, the reversing spring 160 is constituted by a laminated structure in which four thin metal members having a dome shape are laminated, and the auxiliary spring 170 is constituted by one leaf spring, while the auxiliary spring 170 is constituted. By optimizing the spring constant of the spring 170, a click feeling is obtained in about 15 [N].

If a stronger click feeling is required, the arrangement of the auxiliary spring 170 may be eliminated to provide a configuration like the piezoelectric power generation apparatus 100 ′ according to the above-described embodiment.

In the following, a verification test that confirms changes in the click rate and reverse load when the configuration of the reverse spring is changed while using a predetermined auxiliary spring will be described. FIG. 14 is a graph showing the relationship between the amount of operation of the reversing spring and the operating force, and FIG. 15 is a graph showing the results of the verification test.

As shown in FIG. 14, with the increase in operating force (load), the reversing spring momentarily decreases when the predetermined operating amount (displacement) is reached, and then increases again. As a result, the amount of operation continues to increase.

Here, the degree of click feeling described above is generally defined as a click rate, and the operation forces Fa and Fb shown in FIG. 14 (where Fa is the operation force at the moment when the operation force starts to decrease instantaneously). , Fb is an operation force at the time when the operation force starts to recover thereafter, and is expressed as 100 × (Fa−Fb) / Fa [%].

In the verification test, a reversing spring is formed by a laminated structure in which five thin metal members having a dome shape are stacked, and a plurality of samples in which auxiliary springs having different configurations are connected in parallel to the sample are manufactured. The click rate and reversal load in each sample were measured. Here, with respect to the auxiliary spring, a plurality of leaf springs having the same shape and the same spring constant are prepared, and the configuration is changed by changing the number of connections for each sample.

As can be understood from FIG. 14, as a result of the verification test, in the sample in which the auxiliary spring is not connected, the click rate was 51 [%] in the actual measurement value, but in the sample in which one auxiliary spring was connected in parallel. It is confirmed that the actual measured value decreases to 38 [%], and that the actual measured value decreases to 25 [%], 15 [%], and 7 [%] in order by increasing the number of auxiliary springs connected. It was.

On the other hand, the reversal load was 11.0 [N] in the measured value in the sample not connected to the auxiliary spring, but about 12.5 [measured in the sample in which one auxiliary spring was connected in parallel. It is confirmed that by increasing the number of connected auxiliary springs to 1N [N], 14.5 [N], and 16.0 [N] in order by increasing the number of auxiliary springs connected It was done.

In addition, in FIG. 14, in addition to the measured value of the click rate, the calculated value calculated based on the model shown in FIG. 13 is also shown. It was also confirmed that the click rate can be designed based on the model because the measured value and the calculated value of the click rate are generally matched.

As is clear from the results of the verification test described above, the piezoelectric power generation apparatus 100 according to the present embodiment described above or the piezoelectric power generation apparatus 100 ′ according to the above-described embodiment can reduce the pressing load necessary for power generation in the piezoelectric power generation body 120. It can be said that it was confirmed experimentally that a high click feeling can be obtained while keeping it low.

As described above, in the piezoelectric power generation device 100 according to the present embodiment, the case body 110 is provided with the abutting surface 115a as the abutting portion that comes into contact with the distal end portion 135 of the lever 130, whereby the lever 130 has the piezoelectric power generator 120 side. The rotation range toward is limited so that an excessive external force can be prevented from being applied to the piezoelectric power generator 120. Such a configuration can be effectively applied to a piezoelectric power generation device having a configuration different from that of the piezoelectric power generation device 100 described above. Hereinafter, some of the configuration examples will be exemplified as piezoelectric power generation devices according to modifications based on the above-described embodiment.

16 and 17 are cross-sectional views showing a schematic configuration of the piezoelectric power generation apparatus according to the first and second modifications based on the present embodiment.

As shown in FIG. 16, the piezoelectric power generation device 100A according to the first modification has a connection structure between the lever 130 and the case body 110 similar to the piezoelectric power generation device 100X according to the comparative example described above. The difference is that an abutting surface 115 a as an abutting portion is provided on the side wall 115 of the body 110.

Even in such a configuration, it is possible to prevent excessive external force from being applied to the piezoelectric power generator 120, as in the case of the above-described embodiment of the present invention.

As shown in FIG. 17, the piezoelectric power generating apparatus 100B according to the second modified example is different from the piezoelectric power generating apparatus 100A according to the first modified example described above in that the installation position of the reversing spring 160 is different. A lever member 200 is disposed between one of the support portions 111a provided in the case body 110 and the piezoelectric power generator 120, and the lever member 200 is supported by the one support portion 111a and the reversing spring 160 described above. In that respect, the configuration is different.

Even in such a configuration, it is possible to prevent excessive external force from being applied to the piezoelectric power generator 120, as in the case of the above-described embodiment of the present invention.

In addition to the first and second modified examples, the present invention is applied to piezoelectric power generation devices having various configurations such as a configuration in which a reversing spring or an auxiliary spring is removed from the configuration described in the embodiment of the present invention. Is possible.

In the embodiment of the present invention described above, the case where the reversal spring is used as a switch has been described as an example. However, it is not always necessary to configure the switch using the reversal spring, and an alternative switch is separately provided. If a switch is not necessary between the movable part and the piezoelectric element, only a reversing spring may be provided between them.

Moreover, the configuration of the power management circuit of the piezoelectric power generation module shown in the above-described embodiment of the present invention is merely an example, and it is naturally possible to adopt a different circuit configuration.

Furthermore, in the above-described embodiment of the present invention, the case where the present invention is applied to the transmitter and the piezoelectric power generation module included in the transmitter has been described by way of example. However, the scope of the present invention is limited thereto. Of course, the present invention is not limited, and the present invention can be applied to other electronic devices and piezoelectric power generation modules included in the electronic devices.

Thus, the above-described embodiment disclosed herein is illustrative in all respects and is not restrictive. The technical scope of the present invention is defined by the scope of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 transmitter, 10 piezoelectric generator module, 11 full-wave rectifier circuit, 12 DC / DC converter, 13 signal output unit, 13a NOR circuit, 13b OR circuit, 14 control circuit, 15 discharge switch, 20 transmitter unit, 21 RF antenna, 22 RF circuit, 100 piezoelectric generator, 110 case body, 111 bottom plate part, 111a support part, 112-115 side wall part, 113a, 114a shaft support hole, 115a abutting surface, 120 piezoelectric generator, 120a piezoelectric element, 121 metal plate , 122 piezoelectric body, 123 terminal, 123a through hole, 124 adhesive layer, 125 conductive adhesive, 126 protective film, 130 lever, 131 base, 131a screw hole, 133, 134 standing wall, 133a, 134a shaft, 135 Tip, 140 1st Rexible wiring board, 141A, 141B first switch, 142, second switch, 143 connection, 150 second flexible wiring board, 150a, 150b through-hole, 153,154 connection, 160 reversing spring, 170 auxiliary spring, 170a through-hole , 171 protrusion, 180 screw, 190 press-fit pin, 200 lever member, 1000 rotating shaft, C capacitor, D1-D4 diode, EN enable terminal, GL power line, IN1A, IN1B, IN2 input node, N1, N2 node, OUT output Node, PL power line, Q switching element, R1 to R4 resistors, T1, T2 output terminals, Vin input terminal, Vout output terminal.

Claims (10)

1. At least one plate-like piezoelectric element having a rectangular shape in plan view, which has flexibility and generates power by being deformed in the thickness direction;
   A support member that supports the piezoelectric element so as to be able to bend and deform;
   The piezoelectric element is rotatably supported by the support member so as to face the piezoelectric element, and is deformed in a direction substantially along the thickness direction of the piezoelectric element by receiving an external force, thereby causing the piezoelectric element to bend and deform. And a lever to
   The rotation axis of the lever is arranged to be parallel to two opposite sides of the piezoelectric element when viewed along the thickness direction of the piezoelectric element,
   The support member has an abutting portion provided along one side far from the rotation axis of the two sides of the piezoelectric element,
   The piezoelectric power generation device is configured such that rotation of the lever toward the piezoelectric element side is restricted when a part of the lever comes into contact with the abutting portion.
2. The support member has a box-like shape for accommodating the piezoelectric element;
   2. The piezoelectric power generation device according to claim 1, wherein the abutting portion is configured by an upper surface of a side wall portion provided along one side far from the rotation axis among the two sides of the piezoelectric element.
3. The lever has an elongated rectangular shape in plan view,
   The piezoelectric power generator according to claim 1 or 2, wherein a long side direction of the lever is parallel to an extending direction of the rotation shaft.
4. An external force transmission unit that transmits the external force received by the lever to the piezoelectric element;
   The external force transmission portion includes a reversing spring;
   4. The piezoelectric power generation device according to claim 1, wherein the reversing spring is disposed between the piezoelectric element and the lever. 5.
5. The external force transmission unit further includes an auxiliary spring connected in parallel to the reversing spring,
   The piezoelectric power generator according to claim 4, wherein the auxiliary spring is disposed between the piezoelectric element and the lever.
6. The piezoelectric generator according to claim 1, wherein the piezoelectric element includes a metal plate and a plate-like piezoelectric body provided on one main surface of the metal plate.
7. A plurality of the piezoelectric elements;
   The piezoelectric power generation device according to claim 1, wherein the plurality of piezoelectric elements are stacked in each thickness direction.
8. The piezoelectric power generator according to any one of claims 1 to 7, wherein the support member has a box-like shape including a bottom plate portion and side wall portions erected from four sides of the bottom plate portion.
9. A piezoelectric power generation device according to any one of claims 1 to 8,
   A piezoelectric power generation module comprising: a power supply circuit for supplying power generated by the piezoelectric element to a load.
10. The piezoelectric power generation module according to claim 9,
    A transmitter comprising: a transmitter that transmits a radio signal using the electric power supplied from the piezoelectric power generation module as the load.

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