JP2014108772A - Storage circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the use number of diodes used in a rectifying circuit to reduce cost.SOLUTION: A storage circuit is provided with: n pieces of power generation means generating the electric power at both electrodes by deformation; n diode pairs for rectification; and a capacitor pair for power storage. One electrode of each power generation means is connected to an intermediate point Dm between the diodes of each diode pair, and the other electrode of each power generation means is short-circuited with each other and is connected to an intermediate point Cm between the capacitors of each capacitor pair. The cathode-side electrodes of each diode pair are short-circuited mutually and are connected to one electrode of the capacitor pair, and the anode-side electrodes of each diode pair are mutually short-circuited and are connected to the other electrode of the capacitor pair.

Description

  The present invention relates to a power storage circuit that can significantly reduce the number of diodes used in a rectifier circuit and can reduce costs.

  In recent years, a tire pressure monitoring system (hereinafter abbreviated as TPMS) has been developed to measure the tire pressure and temperature and send the information wirelessly to the vehicle body to inform the driver in order to increase vehicle safety. ing. In such a TPMS, a power source is required for a tire pressure sensor, a transmitter, and the like, and a power generation device using, for example, a piezoelectric element as the power source has been proposed.

  However, in the power generation device, since the generated power of the piezoelectric element alone is very small, it is necessary to connect a plurality of piezoelectric elements in order to obtain larger power.

  On the other hand, an alternating voltage is induced in the piezoelectric element. Therefore, when a plurality of piezoelectric elements are connected in parallel, there is a problem that voltages induced for each element cancel each other out depending on their polarities. Therefore, in order to store electric energy from a plurality of piezoelectric elements, as shown in FIG. 11, a rectifier circuit b is connected to each piezoelectric element a to convert an AC voltage into a DC voltage, and these are converted into a capacitor c or the like. (See, for example, FIG. 6 of Patent Document 1).

  However, as shown in the figure, the rectifier circuit b requires four diodes b1 and b1 for one piezoelectric element a. Therefore, in the case of the power storage circuit A or the power generation apparatus using the plurality of piezoelectric elements a, the number of diodes b1 used is increased, resulting in a problem that the cost is increased and the circuit is complicated.

Special table 2009-542169 gazette

  In view of the above, an object of the present invention is to provide a power storage circuit that can significantly reduce the number of diodes used in a rectifier circuit and can suppress an increase in cost and circuit complexity.

In order to solve the above-mentioned problem, the invention of claim 1 of the present application is such that n (a plurality of) power generating means that are attached to an attachment and generate electric power at both poles by deformation, and n pieces of diodes connected in series with a pair of diodes. A power storage circuit comprising a rectifying diode pair and one power storage capacitor pair in which a pair of capacitors are connected in series,
One electrode of each of the power generation means is connected to an intermediate point Dm between the diodes of each of the diode pairs,
And the other electrode of each of the power generating means is short-circuited to each other and connected to an intermediate point Cm between the capacitors of the capacitor pair,
The cathode side electrodes of each of the diode pairs are short-circuited to each other and connected to one electrode of the capacitor pair,
The anode-side electrodes of each diode pair are short-circuited to each other and connected to the other electrode of the capacitor pair.

  According to a second aspect of the present invention, the attached object is a tire.

  According to a third aspect of the present invention, each of the power generation means includes a plurality of power generation elements connected in parallel, and the plurality of power generation elements forming one power generation means are spaced apart from each other by an interval longer than the length of the ground contact area in the tire circumferential direction. It is characterized by being separated from each other.

  According to a fourth aspect of the present invention, each of the power generation means includes one power generation element.

Further, according to the fifth aspect, n (plurality) power generating means that are attached to the tire and generate electric power in both poles by deformation, one rectifying diode pair in which a pair of diodes are connected in series, and a pair of capacitors are connected in series. A storage circuit comprising a single connected capacitor pair for storage,
Each of the power generation means is composed of one power generation element, and each of the power generation means is separated from each other with an interval longer than the contact area length in the tire circumferential direction,
One electrode of each of the power generation means is short-circuited to each other and connected to an intermediate point Dm between the diodes of the diode pair,
The other electrodes of the power generation means are short-circuited to each other and connected to an intermediate point Cm between the capacitors of the capacitor pair,
The cathode side electrode of the diode pair is connected to one electrode of the capacitor pair,
The anode side electrode of the diode pair is connected to the other electrode of the capacitor pair,
Between the other electrode of each of the power generation means and the intermediate point Cm of the capacitor pair, or between one electrode of each of the power generation means and the intermediate point Dm of the diode pair, within a grounding region during tire rotation. It is characterized in that switching means for connecting only the power generation means located with the intermediate point Cm or the intermediate point Dm is provided.

  The power storage circuit of the first invention uses a plurality of power generation means by using two diodes for one power generation means (power generation element, etc.) as described in the section “DETAILED DESCRIPTION OF THE INVENTION” below. Can be stored in the capacitor after being converted into a DC voltage. Therefore, the number of diodes used can be halved, and an increase in cost and circuit complexity can be suppressed in the power storage circuit.

  In the power storage circuit of the second invention, a plurality of power generation means are used by using two diodes for a plurality of power generation means (power generation elements, etc.) attached to the tire with a circumferential interval longer than the length of the ground contact area of the tire. Can be stored in the capacitor after being converted into a DC voltage. Accordingly, although switching means is required, only two diodes are used, and it is possible to suppress an increase in cost and circuit complexity in the power storage circuit.

It is a perspective view which shows one Example at the time of being used for the electric power generating apparatus of the tire of the electrical storage circuit of this invention. (A) is a circumferential cross-sectional view conceptually showing the power generator, and (B) is a partially enlarged cross-sectional view in the tire axial direction. It is sectional drawing which shows an example of a piezoelectric element notionally. It is a circuit diagram of a 1st embodiment in a power storage circuit of the 1st invention. (A), (B) is a circuit diagram which shows the flow of electricity in an electrical storage circuit. It is a circuit diagram of 2nd Embodiment in the electrical storage circuit of 1st invention. It is a schematic sectional drawing explaining grouping of the electric power generation element in 2nd Embodiment. It is a circuit diagram of the electrical storage circuit of 2nd invention. It is a conceptual diagram which shows arrangement | positioning of the electric power generation element and acceleration sensor in 2nd invention. It is a graph explaining the recognition method of the earthing | grounding area | region by the output curve of an acceleration sensor. It is a circuit diagram which shows the conventional electrical storage circuit.

  Hereinafter, embodiments of the present invention will be described in detail. 1 and 2 are perspective views illustrating an embodiment of a tire power generation device 11 in which the power storage circuit 1 of the present invention is employed. The power storage circuit 1 will be described below together with the power generation device 11.

  The power generation apparatus 11 of this example is attached to the tire lumen surface 12S of the pneumatic tire 12 that is the attachment T, and generates power by tire deformation at the time of ground contact. Specifically, the power generation device 11 includes a resin-made annular band 14 disposed along the tire lumen surface 12S, the power storage circuit 1 formed on the inner peripheral surface of the annular band 14, An insulating sheet 15 (shown in FIG. 2) covering the power storage circuit 1 is included.

  The annular belt 14 is made of an insulating resin material, and in this example, has an outer diameter substantially equal to the diameter of the tire lumen surface 12S. As a result, the annular band 14 can be in close contact with the tire lumen surface 12S, and the ground deformation of the pneumatic tire 12 can be reliably transmitted to the power generation means 2 of the power storage circuit 1. The resin material for forming the annular band 14 is not particularly limited, but is preferably made of fiber reinforced plastic because it deforms following the ground deformation of the pneumatic tire 12, and its thickness is 0.4-0. .6 mm is preferred.

  Further, the power generation device 11 of this example includes a misalignment prevention means 16 for preventing misalignment with the pneumatic tire 12. The displacement prevention means 16 includes a recess 16A formed on one of the tire lumen surface 12S or the outer peripheral surface of the annular band 14, and the other of the tire lumen surface 12S or the outer peripheral surface of the annular band 14. Convex part 16B formed in this. Then, the recesses 16A and the protrusions 16B are fitted to each other, so that the displacement, particularly the circumferential displacement due to tire rotation is prevented.

  The concave portions 16A and the convex portions 16B are formed in at least one, preferably a plurality, for example, about six. When a plurality of tires are formed, they are spaced at equal intervals in the tire circumferential direction. The cross-sectional shapes of the concave portions 16A and the convex portions 16B are preferably rectangular in cross section (including a square shape) from the viewpoint of preventing displacement. The size of the concave portion 16A and the convex portion 16B is not particularly restricted, but from the viewpoint of preventing displacement and ground deformation, the depth (or height) is in the range of 10 to 20 mm, and the tire axial length is 80 to 80. The range of 100 mm and the tire circumferential width are preferably 10 to 30 mm.

  The convex portion 16B is preferably formed of a rubber elastic body from the viewpoint of ground deformation, and particularly preferably formed of a rubber elastic body having substantially the same hardness as the tire rubber forming the tire lumen surface 12S. The “substantially the same hardness” means a difference in rubber hardness of 10 ° or less, and the rubber hardness is a durometer A hardness measured in a 23 ° C. environment using a durometer type A based on JIS-K6253. means.

  Next, as shown in FIG. 4, the power storage circuit 1 of the first invention is connected to n (plurality) of power generation means 2 that generates power in both poles 2 a and 2 b by deformation, and to each power generation means 2. A total of n rectifying diode pairs 3 and a total of one capacitor pair 4 for storing electrical energy from each power generation means 2 are provided. The n (plurality) of power generation means 2 are attached to the inner circumferential surface of the annular band 14 with a gap.

  In the power storage circuit 1 according to the first embodiment of the first invention, each of the power generation means 2 is formed of one power generation element 5. In particular, in this example, two power generation element arrays 5R (shown in FIGS. 1 and 2) are formed on both sides in the tire axial direction, and each power generation element array 5R is arranged at equal intervals in the tire circumferential direction. For example, a case where 24 power generating elements 5 are formed is shown. Therefore, in this example, a total of 48 (n = 48) power generation means 2 (power generation elements 5) are attached to the pneumatic tire 12 (corresponding to the attachment T) via the annular belt body 14.

  As the power generation element 5, a piezoelectric element is preferably employed in this example. As conceptually shown in FIG. 3, the piezoelectric element is composed of, for example, a piezoelectric ceramic plate 5 a and a metal plate 5 b bonded thereto, as is well known. Then, the piezoelectric element (power generation element 5) bends according to the tire deformation through the annular band 14, so that an alternating voltage is generated between the electrode 2a on the piezoelectric ceramic plate 5a side and the electrode 2b on the metal plate 5b side. Occur.

  And in order to store the alternating voltage from the electric power generation means 2 which is the said electric power generation element 5, as shown in the said FIG. 4, the said electrical storage circuit 1 is the n rectifier diode pairs 3 connected to each electric power generation means 2. And one capacitor pair 4.

  Each diode pair 3 is formed of a pair of diodes 3A and 3B connected in series. The capacitor pair 4 is formed of a pair of capacitors 4A and 4B connected in series.

  One electrode 2a of each power generation means 2 is connected to an intermediate point Dm between the diodes 3A and 3B in each diode pair 3. The other electrode 2b of each power generation means 2 is short-circuited to each other and connected to an intermediate point Cm between the capacitors 4A and 4B in the capacitor pair 4. The cathode-side electrodes 3 a of each diode pair 3 are short-circuited with each other and connected to one electrode 4 a of the capacitor pair 4. The anode-side electrodes 3b of each diode pair 3 are short-circuited with each other and connected to the other electrode 4b of the capacitor pair 4.

  In such a storage circuit 1, as shown in FIG. 5A, when a positive induced voltage is generated in the power generation means 2, for example, the positive electrode 2a of the power generation means 2 → the intermediate point Dm → the diode 3A. → Capacitor 4A → Intermediate point Cm → Electricity flows through the path (shown by the solid line arrow) of the negative electrode 2b of the power generation means 2, and electricity is stored in the capacitor 4A. On the contrary, when a negative induced voltage is generated in the power generating means 2, for example, as shown in FIG. 5B, the negative electrode 2b of the power generating means 2 → the intermediate point Cm → the capacitor 4B → the diode 3B → the intermediate. Electricity flows along the path of the point Dm → the positive electrode 2a of the power generation means 2 (indicated by a broken arrow), and electricity is stored in the capacitor 4B.

  That is, in the power storage circuit 1, regardless of the power generation means 2, the positive induced voltage generated in each power generation means 2 is stored in the capacitor 4A, and the negative induced voltage is stored in the capacitor 4B. Moreover, no current flows between the power generation means 2 and 2 because there is no path for current to flow between the power generation means 2 and 2 even if a voltage is induced in either the positive side or the negative side. In addition, since the positive and negative voltages induced in the power generation means 2 are stored in the capacitors 4A and 4B connected in series, electric energy can be stored in the capacitor pair 4 without canceling out the voltages. it can.

  Therefore, in the power storage circuit 1, the number of rectifying diodes used can be halved as compared with the conventional power storage circuit, and the cost can be reduced and the circuit can be simplified.

  Next, FIGS. 6 and 7 show a power storage circuit 1 according to a second embodiment of the first invention. In the power storage circuit 1 of the second embodiment, each of the power generation means 2 is formed from a plurality of power generation elements 5 connected in parallel. The plurality of power generation elements 5 constituting one power generation means 2 are spaced apart from each other with an interval longer than the ground contact region length L in the tire circumferential direction.

  Specifically, as shown in FIG. 7, in this example, for example, 24 power generating elements 5 are arranged at intervals in the circumferential direction. The 24 power generating elements 5 are divided into a plurality (four in this example) of groups Ga to Gd (referred to collectively as group G), and each group G forms one power generating means 2. To do. The power generating elements 5 belonging to the same group G are separated from each other with an interval longer than the grounding region length L.

  The power generating elements 5 belonging to the same group G are connected in parallel to each other. As in the first embodiment, one electrode 2a of each power generating means 2 is connected to the intermediate point Dm of each diode pair 3, and the other electrode 2b of each power generating means 2 is short-circuited to each other. The cathode-side electrodes 3a of the diode pairs 3 are short-circuited to each other and connected to one electrode 4a of the capacitor pair 4, and connected to the intermediate point Cm of the capacitor pair 4. 3 anode side electrodes 3b are short-circuited to each other and connected to the other electrode 4b of the capacitor pair 4.

  In the case of the second embodiment, in one group G, two or more power generating elements 5 are not grounded at the same time. Therefore, even when the power generation elements 5 belonging to the same group G are connected in parallel, their outputs do not interfere with each other. Therefore, even when one diode pair 3 is connected to one group G, electric energy can be stored in the capacitor pair 4. In this case, the number of diodes used can be further reduced.

  Here, when the outer peripheral contact position in the tire circumferential direction that contacts the ground when a normal load is applied to the tire that is assembled with the normal rim and filled with the normal internal pressure is E, the tire radius that passes through each outer contact outer position E A region between the direction lines Xe and Xe is referred to as a ground region Y. The circumferential length of the ground contact area Y measured on the mounting surface (the tire lumen surface 12S in this example) to which the power generating element 5 is attached is referred to as the ground contact area length L. The distance between the power generation elements 5 and 5 means a circumferential distance measured on the mounting surface.

  The “regular rim” is a rim determined for each tire in the standard system including the standard on which the tire is based, for example, a standard rim for JATMA, “Design Rim” for TRA, or ETRTO means "Measuring Rim". The “regular internal pressure” is the air pressure defined by the standard for each tire. The maximum air pressure for JATMA, the maximum value described in the table “TIRE LOAD LIMITS AT VARIOUS COLD INFLATIONPRESSURES” for TR A, ETRTO Means "INFLATION PRESSURE", but in the case of passenger car tires, it is 180 kPa. The “regular load” is the load specified by the standard for each tire. The maximum load capacity shown in the table “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” is the maximum load capacity for JATMA and TRA for TRA If it is ETRTO, it is "LOAD CAPACITY".

  Next, FIGS. 8 to 10 show a power storage circuit 1 according to the second invention. The power storage circuit 1 of the second invention comprises a plurality of power generation means 2, one rectifying diode pair 3, one power storage capacitor pair 4, and switching means 7. Each of the power generation means 2 includes one power generation element 5, and each of the power generation means 2 is spaced in the circumferential direction with an interval longer than the grounding region length L.

  One electrode 2 a of each power generation means 2 is short-circuited to each other and connected to the intermediate point Dm of the diode pair 3. The other electrodes 2 b of the power generation means 2 are short-circuited with each other and connected to the intermediate point Cm of the capacitor pair 4. The cathode side electrode 3 a of the diode pair 3 is connected to one electrode 4 a of the capacitor pair 4. The anode side electrode 3 b of the diode pair 3 is connected to the other electrode 4 b of the capacitor pair 4.

  Further, switching is performed between the other electrode 2b of each power generation means 2 and the intermediate point Cm of the capacitor pair 4 or between one electrode 2a of each power generation means 2 and the intermediate point Dm of the diode pair 3. Means 7 are interposed. This switching means 7 connects only the power generation means 2 located in the ground contact area Y during tire rotation to the intermediate point Cm or the intermediate point Dm.

  Specifically, as shown in FIG. 9, first, the tire 12 is equally divided into a plurality of circumferential regions J having a circumferential length larger than the ground contact region length L. The power generation means 2 (consisting of one power generation element 5) is disposed at the circumferential center position of each circumferential region J. Therefore, the power generation means 2 is arranged in the circumferential direction with an interval longer than the ground contact region length L.

  In this example, the switching means 7 is interposed between the other electrode 2b of each power generation means 2 and the intermediate point Cm of the capacitor pair 4, and the electrode 2b of the power generation means 2 located in the ground region Y. Only the intermediate point Cm.

  By using the switching means 7, the number of diodes used can be reduced to two. Here, the reason for disconnecting the power generation means 2 outside the grounding area by the switching means 7 is that various vibrations are generated in the tire 12 during traveling, and some induced voltage is also generated in the power generation means 2 outside the grounding area. It is to do. Therefore, by canceling the connection of the power generation means 2 outside the ground area, it becomes possible to prevent the electric energy from being canceled by the power generation means 2 outside the ground area.

  Although not particularly restricted as the switching means 7, this example includes, for example, two acceleration sensors 8A and 8B, a recognition means 9 for recognizing the power generation means 2 in the grounding region Y by its output signal, and a switch 10. Composed.

  As shown in FIG. 9, in this example, a case where four power generation means 2 are arranged is illustrated. Specifically, the tire 12 is equally divided into four circumferential regions J1 to J4, and the power generation means 2 is arranged at the circumferential center position of each circumferential region J1 to J4.

  The two acceleration sensors 8A and 8B are attached at two positions separated by an angle of 90 degrees in the circumferential direction. In this example, the acceleration sensor 8A is attached to the boundary position between the circumferential regions J1 and J2, and the acceleration sensor 8B is attached to the boundary position between the circumferential regions J1 and J4. As shown in FIG. 10, each acceleration sensor 8A, 8B outputs the acceleration at the time of tire rotation as a sine curve. However, since the mounting positions of the acceleration sensors 8A, 8B are shifted by 90 degrees, the output signals (sine curves) ) FA and FB are also 90 ° out of phase in the circumferential direction.

  In this example, the direction of the gain is set so that one of the acceleration sensors 8A has an output of 0 at the 3 o'clock and 9 o'clock rotational positions and a maximum (max) output at the 12 o'clock rotational position. ing. The direction of the gain of the other acceleration sensor 8B is set so that the output is 0 when the rotation position is 3 o'clock and 9 o'clock and the output is maximum (max) when the rotation position is 6 o'clock.

Therefore, it is possible to determine which of the circumferential regions J1 to J4 is grounded by combining + and − of the outputs of the acceleration sensors 8A and 8B.
That is, as shown in FIG.
The circumferential region J3 is grounded when the acceleration sensor 8A is + and the acceleration sensor 8B is-
The circumferential region J4 is grounded when the acceleration sensor 8A is + and the acceleration sensor 8B is +
The circumferential region J1 is grounded when the acceleration sensor 8A is-and the acceleration sensor 8B is +
The circumferential direction region J2 is grounded when the acceleration sensor 8A is-and the acceleration sensor 8B is-.

  That is, the power generation means 2 in the grounding area Y can be recognized. The determination of the grounding of the circumferential regions J1 to J4 based on the sensor output is performed by the recognition means 9, and the switch 10 turns on / off the circuit by the recognition means 9. The switching means 7 can be attached to the annular band 14, and the power of the switching means 7 can also be supplied from the power storage circuit 1. As a method for recognizing the power generation means 2 located in the ground contact area Y, a rotation position detector such as an encoder for detecting the tire rotation position is attached to the tire, wheel, axle, etc., and each power generation means 2 during tire rotation is attached. Various methods can be employed, such as being able to be performed by constantly recognizing the position of the.

  The power storage circuit 1 may be used in a power generation device 11 for tires, for example, a power generation system that generates power using floor bending or vibration when a person walks, for example, a road or a bridge by passing an automobile or the like. The present invention can be applied to various power generation systems such as a power generation system that generates power using the vibration of the structure, for example, a power generation system that generates power using vibration of a machine in a factory. In addition to the piezoelectric element, various elements such as a magnetostrictive element, such as a change in the lines of magnetic force obtained from vibration or the like, may be used as the power generation element 5 by using a coil or the like.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

DESCRIPTION OF SYMBOLS 1 Power storage circuit 2 Electric power generation means 2a, 2b Electrode 3 Diode pair 3A, 3B Diode 3a Cathode side electrode 3b Anode side electrode 4 Capacitor pair 4A, 4B Electrode 4a, 4b Electrode 5 Electric power generation element 7 Switching means 12 Tire L Grounding area length T Attachment

Claims (5)

N power generators that are attached to an attachment and generate electric power in both poles by deformation, n rectifying diode pairs in which a pair of diodes are connected in series, and one in which a pair of capacitors are connected in series A power storage circuit comprising a pair of capacitors for power storage,
One electrode of each of the power generation means is connected to an intermediate point Dm between the diodes of each of the diode pairs,
And the other electrode of each of the power generating means is short-circuited to each other and connected to an intermediate point Cm between the capacitors of the capacitor pair,
The cathode side electrodes of each of the diode pairs are short-circuited to each other and connected to one electrode of the capacitor pair,
An anode side electrode of each diode pair is short-circuited to each other and connected to the other electrode of the capacitor pair.   The power storage circuit according to claim 1, wherein the attachment object is a tire.   Each of the power generation means is composed of a plurality of power generation elements connected in parallel, and the plurality of power generation elements forming one power generation means are separated from each other with an interval longer than the length of the ground contact area in the tire circumferential direction. The power storage circuit according to claim 2, wherein:   3. The power storage circuit according to claim 1, wherein each of the power generation means includes one power generation element. N (several) power generating means attached to the tire and generating electric power in both poles by deformation, one rectifying diode pair in which a pair of diodes are connected in series, and one power storage in which a pair of capacitors are connected in series A storage circuit comprising a capacitor pair for
Each of the power generation means is composed of one power generation element, and each of the power generation means is separated from each other with an interval longer than the contact area length in the tire circumferential direction,
One electrode of each of the power generation means is short-circuited to each other and connected to an intermediate point Dm between the diodes of the diode pair,
The other electrodes of the power generation means are short-circuited to each other and connected to an intermediate point Cm between the capacitors of the capacitor pair,
The cathode side electrode of the diode pair is connected to one electrode of the capacitor pair,
The anode side electrode of the diode pair is connected to the other electrode of the capacitor pair,
Between the other electrode of each of the power generation means and the intermediate point Cm of the capacitor pair, or between one electrode of each of the power generation means and the intermediate point Dm of the diode pair, within a grounding region during tire rotation. A power storage circuit comprising switching means for connecting only the power generation means positioned to the intermediate point Cm or the intermediate point Dm.

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