WO2020235415A1 - Power source for tire monitoring system, tire monitoring system, and tire assembly - Google Patents

Abstract

A power source for a tire monitoring system disclosed in the present application comprises a power storage device and a power generation device that can supply generated electric power to the power storage device, wherein: the power generation device includes a sheet-shaped power generation element; the sheet-shaped power generation element includes a power generating body sheet that utilizes deformation for power generation; the sheet-shaped power generation element is attached to a tire and can generate electric power by being deformed by the rotation of the tire; and the power generating body sheet satisfies A/B ≤0.16 where A (mm) is the length of the tire in a rotation direction and B (mm) is the outer diameter of the tire.

Description

Power supply for tire monitoring system, tire monitoring system and tire assembly

The present application relates to a power source for a tire monitoring system capable of detecting tire information such as tire pressure, temperature, and acceleration, a tire monitoring system equipped with the power source, and a tire assembly provided with the tire monitoring system.

In recent years, as the traffic volume of vehicles has increased, serious accidents caused by tire defects have been scattered while the vehicle is running. Therefore, it has been pointed out that it is important to prevent the occurrence of serious accidents by maintaining the proper condition of the tires while driving.

Under such circumstances, in the United States, there are legal regulations regarding tire safety in order to ensure safety while the vehicle is running. In such countries, new vehicles are required to be equipped with a tire monitoring system that monitors tire pressure and the like. In addition to the United States, some countries such as Europe and South Korea have already established legal regulations on tire safety, and it is expected that legal regulations will be started in China and India.

Since the above-mentioned tire monitoring system is located inside the tire, it requires a power source for driving. As this power source, a primary battery such as a coin-type lithium primary battery is generally used. However, if a primary battery is used as the power source for the tire monitoring system, the battery may be exhausted and the battery may need to be replaced when the operating time of the system is extended.

On the other hand, in order to eliminate the need for battery replacement, for example, as shown in Patent Document 1, a tire that generates electricity by a piezoelectric element, stores the electric power obtained by the power generation in a secondary battery or the like, and uses it as a power source. Surveillance systems are known.

Further, Patent Document 2 proposes to use a triboelectric power generator that generates electricity by contact-charging resins with each other as a power generation element of the tire monitoring system.

Special Table 2005-525265 Japanese Unexamined Patent Publication No. 2016-88473

Here, when a power generator such as a piezoelectric element is used as the power generation source of the tire monitoring system, the power generation amount of the power generator is limited, so that the power consumption for detecting the tire information and transmitting the tire information is large. In that case, it is assumed that the driving power of the tire monitoring system is insufficient and the tire monitoring system does not work. Therefore, as a countermeasure, it is conceivable to increase the amount of power generation by increasing the size of the power generator.

However, when a power generator that generates electricity by utilizing the deformation of the tire during rotation, such as a piezoelectric element, is attached to the tire, the amount of power generation does not necessarily increase even if the element is made larger, and the tire is It was found that the amount of power generation would rather decrease depending on how the tires were installed.

This application solves the above-mentioned conventional problems, and when a sheet-shaped power generator that generates power by utilizing deformation during rotation of a tire is used as a power generation source of a tire monitoring system, the amount of power generation is large and stable. A power source for a tire monitoring system capable of operating the system and a tire monitoring system using the power source are provided.

The power source for the tire monitoring system of the present application includes a power storage device and a power generation device capable of supplying the generated power to the power storage device. The power generation device includes a sheet-shaped power generation element, and the sheet-shaped power generation element includes a sheet-shaped power generation element. A generator sheet that utilizes deformation for power generation is provided, and the sheet-shaped power generation element is attached to a tire and can be deformed by rotation of the tire to generate power. The generator sheet has a length in the rotation direction of the tire. A (mm) satisfies A / B ≦ 0.16 with respect to the outer diameter B (mm) of the tire.

Further, the tire monitoring system of the present application includes a tire information detection device, an information transmission device, and a power source capable of supplying power to the tire information detection device and the information transmission device, and the information transmission device includes the tire information. It is characterized in that the tire information detected by the detection device is transmitted, and the power source for the tire monitoring system of the present application is provided as the power source.

Further, the tire assembly of the present application is characterized by including the tire monitoring system of the present application and a tire.

According to the present application, even if a sheet-shaped power generation element that uses deformation due to rotation of the tire for power generation is used as the power generation source, the amount of power that can be extracted is large, and therefore the power supply that can stably function the tire monitoring system. , Can provide a tire monitoring system with that power source.

FIG. 1 is a block diagram showing a schematic configuration of the tire monitoring system of the embodiment. FIG. 2 is a schematic plan view showing an example of a sheet-shaped power generation element used in the embodiment. FIG. 3 is a schematic cross-sectional view taken along the line II of FIG. FIG. 4 is a schematic plan view showing another example of the sheet-shaped power generation element used in the embodiment. FIG. 5 is a schematic cross-sectional view of the tire assembly of the embodiment. FIG. 6 is a schematic perspective sectional view of a state in which the tire assembly of the embodiment is mounted on a wheel. FIG. 7 is a schematic cross-sectional view showing the tire assembly (A) of the embodiment and the ground contact state (B) of the tire assembly. FIG. 8 is a schematic cross-sectional view showing an example of a deformed state of the sheet-shaped power generation element. FIG. 9 is a schematic cross-sectional view showing another example of the deformed state of the sheet-shaped power generation element.

(Implementation of tire monitoring system and its power supply)
An embodiment of the tire monitoring system disclosed in the present application includes a tire information detection device, an information transmission device, and a power source capable of supplying power to the tire information detection device and the information transmission device. It has a function of transmitting the tire information detected by the tire information detection device.

Further, the tire monitoring system of the present embodiment includes, as the power source, a power source including a power storage device and a power generation device capable of supplying the generated power to the power storage device, and the power generation device includes a sheet-shaped power generation element. The sheet-shaped power generation element includes a power generator sheet that utilizes deformation for power generation, and the sheet-shaped power generation element is attached to a tire and can be deformed by rotation of the tire to generate power. The length A (mm) in the rotation direction of the tire is designed to satisfy A / B ≦ 0.16 with respect to the outer diameter B (mm) of the tire. Therefore, the power generation efficiency is improved and the amount of electric power that can be taken out is increased, so that the tire monitoring system of the present embodiment can function stably.

Hereinafter, the tire monitoring system of this embodiment will be described based on the drawings. In the following drawings, the same parts in the drawings may be designated by the same reference numerals and duplicate description may be omitted.

<Overall configuration>
FIG. 1 is a block diagram showing a schematic configuration of the tire monitoring system of the present embodiment. In FIG. 1, the solid arrow indicates the power supply direction, and the broken line arrow indicates the signal transfer direction.

In FIG. 1, the tire monitoring system 1 of the present embodiment includes a tire information detection device 10, an information transmission device 40, and a power source 50 capable of supplying electric power to the tire information detection device 10 and the information transmission device 40. Reference numeral 50 denotes a power storage device 20 and a power generation device 30 capable of supplying the generated electric power to the power storage device 20, and is mounted on a tire (not shown).

In the tire monitoring system 1 of the present embodiment, the tire information detection device 10, the power storage device 20, and the information transmission device 40 are housed in the same container (not shown), and the container is above the power generation device 30 provided with a sheet-shaped power generation element. It is located in. Here, a part of the tire information detection device 10, the power storage device 20, and the information transmission device 40 may be housed in another container. The tire monitoring system 1 of the present embodiment may substantially constitute a tire monitoring device as a whole.

The tire information detection device 10 detects tire information such as tire pressure, temperature, and acceleration, but the tire information is not limited to these. The tire information detection device 10 includes a sensor unit 11 and a calculation unit 12. The sensor unit 11 is composed of, for example, a pressure sensor capable of measuring air pressure, a temperature sensor capable of measuring temperature, an acceleration sensor capable of measuring acceleration, and the like. The sensor unit 11 outputs measurement data of tire information in the tire as a detection signal at all times or at regular intervals. The calculation unit 12 obtains the air pressure, temperature, acceleration, etc. in the tire based on the detection signal output from the sensor unit 11.

The information transmission device 40 includes a communication unit 41 and an antenna unit 42, and various measurement data obtained by the calculation unit 12 are wirelessly transmitted to a control device (not shown) of the vehicle via the communication unit 41 and the antenna unit 42. Will be sent. The wireless communication method by the information transmitting device 40 is not particularly limited, and a communication method using radio waves, sound waves, light waves, or the like can be adopted.

The power source 50 includes a power storage device 20 and a power generation device 30 capable of supplying the generated power to the power storage device 20, and can supply power to the tire information detection device 10 and the information transmission device 40. More specifically, the power storage device 20 supplies electric power to the sensor unit 11 and the calculation unit 12 of the tire information detection device 10, and the communication unit 41 of the information transmission device 40. The power storage device 20 is not particularly limited as long as it can store the power generated by the power generation device 30 described later, and for example, a secondary battery, a capacitor, or the like can be used. The electric power generated by the power generation device 30 is supplied to the power storage device 20 through a rectifier circuit such as a bridge circuit.

As the above secondary battery, for example, a lithium ion secondary battery or the like can be used, but a lithium ion secondary battery having excellent heat resistance using a lithium alloy as the negative electrode active material is particularly preferable. As the capacitor, for example, an electrolytic capacitor, a non-electrolytic capacitor, a super capacitor and the like can be used.

The power generation device 30 supplies the generated electric power to the power storage device 20, and the power generation device 30 includes a sheet-shaped power generation element including a power generation body sheet (not shown) that can be deformed to generate power. Power is generated by mounting it in a position that deforms due to the rotation of. The details of the power generation device 30 will be described below by exemplifying a case where the power generation sheet of the sheet-shaped power generation element is a piezoelectric sheet made of a piezoelectric material.

<Power generation device>
FIG. 2 is a schematic plan view showing an example of a sheet-shaped power generation element used in the power generation device constituting the tire monitoring system of the present embodiment, and FIG. 3 is a schematic cross-sectional view taken along the line II of FIG. In FIG. 2, the sheet-shaped power generation element 30a includes a terminal 32a, a piezoelectric sheet 33a made of a piezoelectric material, and a resin layer 35a. Further, in FIG. 3, the sheet-shaped power generation element 30a is provided with metal layers 34a for collecting electricity on both sides of the piezoelectric sheet 33a, and a protective resin layer is provided on the outer periphery of the piezoelectric sheet 33a and the outer surface of the metal layer 34a, respectively. It is equipped with 35a.

In FIG. 3, the piezoelectric material constituting the piezoelectric sheet 33a is not particularly limited, and for example, quartz, barium titanate, cadmium sulfide, lead zirconate titanate, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC). Etc. can be used. Among these, PVDF and PVC that easily impart flexibility to the piezoelectric sheet 33a are preferable, and more specifically, it is preferable to cut a PVDF sheet, a PVC sheet, or the like into a rectangular shape and use it.

In FIG. 3, the metal material constituting the metal layer 34a is not particularly limited, and for example, Al, Ni, Cu, or the like can be used. The metal layer 34a can be formed by a metal vapor deposition method, a crimping method of a metal sheet, or the like.

In FIG. 3, the resin material constituting the resin layer 35a is not particularly limited as long as it has heat resistance. For example, polyethylene terephthalate, polyamide, fluororesin, polyphenylene ether, polysulphon, polyarylate, polyethersulphon, polyphenylene sulfide, Heat-resistant resins such as polyetheretherketone can be used. The resin layer 35a can be formed by a coating method using a resin solution, a laminating method using a resin sheet, or the like. In order to protect the piezoelectric sheet 33a, it is desirable that the size of the resin layer 35a is larger than that of the piezoelectric sheet 33a and the periphery of the piezoelectric sheet 33a is covered with the resin layer 35a.

FIG. 4 is a schematic plan view showing another example of the sheet-shaped power generation element used in the power generation device constituting the tire monitoring system of the present embodiment. In FIG. 4, the sheet-shaped power generation element 30b includes a terminal 32b, a piezoelectric sheet 33b made of a piezoelectric material, and a resin layer 35b. Further, the sheet-shaped power generation element 30b shown in FIG. 4 has the same configuration as the sheet-shaped power generation element 30a shown in FIGS. 2 and 3 except that the outer shape of the main body is circular.

The sheet-shaped power generation elements 30a and 30b and the piezoelectric sheets 33a and 33b are formed in a rectangular shape and a circular shape, but are not limited to these, and can be formed in, for example, a polygonal shape and an elliptical shape. Further, the shapes of the sheet-shaped power generation element and the piezoelectric sheet may be different. Then, the sheet-shaped power generation elements 30a and 30b are attached to tires (not shown). The sheet-shaped power generation elements 30a and 30b are attached, for example, by aligning their longitudinal directions with the rotation direction of the tire. The sheet-shaped power generation elements 30a and 30b generate power when the piezoelectric sheets 33a and 33b are deformed by the rotation of the tire.

In FIGS. 2 and 4, the lengths of the piezoelectric sheets 33a and 33b in the sheet-shaped power generation elements 30a and 30b mounted on the tire in the tire rotation direction are L, and the length in the tire rotation axis direction is W. Then, by setting the length L of the piezoelectric sheet so that the value of the ratio of L to the outer diameter of the tire is 0.16 or less, the amount of power generated by the power generation element can be increased.

Here, it is considered that when the tire rotates, the portion that touches the road surface (particularly, the portion that starts and ends the ground contact) is deformed, which is transmitted to the piezoelectric sheet of the power generation element to generate power. Therefore, in the piezoelectric sheet of one power generation element, what actually contributes to power generation is a region located near the ground contact portion of the tire, particularly near the portion where the ground contact starts and the portion where the ground contact ends, and the road surface. It is considered that power generation is not performed in the area where the tire is not in contact with the ground.

Therefore, as the length of the piezoelectric sheet in the tire rotation direction becomes longer than the length of the tire in contact with the ground, even if the tire rotates and the power generation element is located on the road surface side, the piezoelectric sheet Among them, the proportion of areas that do not contribute to power generation increases.

In such a power generation element, the generated power cannot be taken out as it is, and a part of the piezoelectric sheet that does not contribute to power generation is consumed, and only the attenuated power can be taken out.

Therefore, in order to efficiently extract electric power from the power generation element mounted on the tire, the size of one power generation element is such that the entire piezoelectric sheet fits on the ground contact surface of the tire as much as possible when the tire rotates (tire). It is necessary to make the length in the direction of rotation of.

That is, assuming that the length of the contact patch of the tire in the rotation direction of the tire is proportional to the outer diameter of the tire, the length A (mm) of the piezoelectric sheet in the rotation direction of the tire is the outer diameter B of the tire. If the size satisfies A / B ≦ 0.16 with respect to (mm), when the tire rotates and the region where the power generation element is mounted touches the ground, most of the region of the piezoelectric sheet is almost simultaneously. It will generate electromotive force, and it is considered that a large amount of power generation can be efficiently extracted.

On the other hand, as the length A (mm) of the piezoelectric sheet in the rotation direction of the tire becomes shorter, the total amount of power generation decreases. Therefore, in order to obtain a certain amount of power generation or more, the value of A / B is set to 0. It is preferably 04 or more, more preferably 0.07 or more, and most preferably 0.1 or more.

Similarly, the area of the piezoelectric sheet is preferably 1500 mm ² or more, more preferably 1800 mm ² or more, and most preferably 2500 mm ² or more.

Further, when the area of the tire on which the power generation element is mounted touches the ground, the amount of power generation increases as the deformation of the piezoelectric sheet increases. Therefore, if the shape is the same, the entire power generation element is attached to the tire and fixed. Rather, it is desirable to mount the power generation element so that at least a part of the power generation element where the piezoelectric sheet is present is not fixed to the tire and can be deformed away from the tire. ..

For example, it is conceivable to attach only the outer peripheral portion of the power generation element to the tire, and attach the inner side (center side) to the tire in a deformable state away from the tire.

Of the part where the piezoelectric sheet of the power generation element exists, the area of the part that is not fixed to the tire is 10% of the total area of the piezoelectric sheet in order to increase the deformation of the piezoelectric sheet and increase the amount of power generation. It is preferably more than that, more preferably 30% or more, particularly preferably 50% or more, and most preferably not fixing the entire portion where the piezoelectric sheet is present to the tire.

On the other hand, in order to prevent the power generation element from peeling off from the tire during traveling, the area fixed to the tire by adhesion or the like is preferably 10% or more, and 20% or more of the total area of the power generation element. Is more preferable, and 30% or more is most preferable.

Although the embodiment of the power generation device 30 has been described above using the piezoelectric sheet made of a piezoelectric material as the generator sheet that uses the deformation for power generation, other generators that can be deformed to generate power have been described. A sheet made of a material may be used. For example, a triboelectric generator sheet having a pair of charging sheets, which can generate electricity by contacting each other and charging, can also be used.

The charging sheet is made of materials such as nylon, polyurethane, polyester, polyimide, fluororesin, polymethylmethacrylate, polyacrylonitrile, polydiphenol carbonate, natural rubber, polychloroprene, polyvinyl butyral, perfluoropolyether, and diamond-like carbon, respectively. It is configured so that one charged sheet is positively charged and the other charged sheet is negatively charged, combined and arranged to face each other.

Even when a triboelectric generator sheet is used, the shape and dimensions of the generator sheet may be the same as in the case of the piezoelectric sheet described above.

(Embodiment of tire assembly)
An embodiment of a tire assembly disclosed in the present application includes the tire monitoring system of the above-described embodiment and a tire. Since the tire assembly of the present embodiment includes the tire monitoring system of the above-described embodiment, electric power can be efficiently extracted from the sheet-shaped power generation element, and tire information can be stably monitored.

The sheet-shaped power generation element included in the tire monitoring system is usually mounted on the inner peripheral surface of the tire. The attachment to the inner peripheral surface can be easily performed by adhering the tire and the sheet-shaped power generation element with a tire direct adhesive. Further, the sheet-shaped power generation element may be embedded in the tire and arranged.

Hereinafter, the tire assembly of the present embodiment will be described based on the drawings. In the following drawings, the same parts in the drawings may be designated by the same reference numerals and duplicate description may be omitted.

FIG. 5 is a schematic cross-sectional view of the tire assembly of the present embodiment. In FIG. 5, the tire assembly 100 of the present embodiment includes the tire 101 and the tire monitoring system 1 of the above-described embodiment. The tire monitoring system 1 includes a container 60 containing a tire information detection device, a power storage device, and an information transmission device (not shown), and a sheet-shaped power generation element 30a. The sheet-shaped power generation element 30a includes each device in the container 60 and a container 60. It is electrically connected by wiring (not shown).

FIG. 6 is a schematic perspective sectional view of the tire assembly of the present embodiment mounted on the wheel. In FIG. 6, the tire assembly 100 of this embodiment is mounted on the wheel 102.

In FIGS. 5 and 6, the tire 101 and the sheet-shaped power generation element 30a are adhered to each other by a tire direct adhesive. As the tire direct adhesive, for example, "CB 2250" (trade name) manufactured by Cyberbond Co., Ltd. can be used.

FIG. 7 is a schematic cross-sectional view showing the tire assembly of the present embodiment and the ground contact state of the tire assembly. However, the hatching showing the cross section in FIG. 7 is omitted. FIG. 7A shows the tire assembly 100 before touchdown, FIG. 7B shows the contact state of the tire assembly 100, and the arrows in the figure indicate the direction of rotation of the tire.

As shown in FIG. 7B, the tire assembly 100 is deformed by rotating in a grounded state, and the piezoelectric sheet (not shown) of the sheet-shaped power generation element 30a is also deformed accordingly to generate power. The power generation mechanism will be briefly described below.

FIG. 8 is a schematic cross-sectional view showing an example of the deformed state of the sheet-shaped power generation element, and FIG. 9 is a schematic cross-sectional view showing another example of the deformed state of the sheet-shaped power generation element. However, the hatching showing the cross section in FIGS. 8 and 9 is omitted. In FIG. 8, the piezoelectric sheet (not shown) of the sheet-shaped power generation element 30a is deformed when the tire 101 touches the ground, stress is generated in the direction of the arrow in FIG. 8, and the shaded portion of FIG. 8 is pressed by the stress. Power is generated in the vicinity. As the tire 101 rotates, the shaded portion continuously moves in the piezoelectric sheet (not shown) of the sheet-shaped power generation element 30a, so that the sheet-shaped power generation element 30a can continuously generate power.

Further, as shown in FIG. 9, even when the tire 101 rides on some obstacle, the piezoelectric sheet (not shown) of the sheet-shaped power generation element 30a is deformed, and stress is generated in the direction of the arrow in FIG. 9, and the stress is generated. The power is generated intermittently in or near the shaded area of FIG. 9 pulled by.

Even when the sheet-shaped power generation element is configured by using a power generation body of another type such as a triboelectric power generation body sheet, the tires are similar to the case of the piezoelectric sheet, although the mode of power generation is different. Power can be generated by the deformation when rotating.

Hereinafter, the power supply for the tire monitoring system disclosed in the present application will be described based on the examples. However, the power source for the tire monitoring system disclosed in the present application is not limited to the following examples.

(Example 1)
<Manufacturing of sheet-shaped power generation element>
A sheet-shaped power generation element having the form shown in FIG. 4 was manufactured as follows. First, as a piezoelectric sheet, a circular PVDF sheet having a diameter of 50 mm and a thickness of 220 μm (KF piezo sensor “KFP-40AS” (model number) manufactured by Kureha Corporation) was prepared. Next, Al was vapor-deposited on both sides of the PVDF sheet. Subsequently, terminals made of Ni were attached to both sides of the Al-deposited layer, and then the outer surface of the Al-deposited layer was coated with PET to form a resin layer. Further, a sheet-shaped power generation element having a diameter of 60 mm was produced by forming a resin layer having a width of 5 mm around the PVDF sheet in a plan view.

<Manufacturing power supply for tire monitoring system>
After connecting the sheet-shaped power generation element to a power storage device having a bridge circuit and a power storage capacitor, the sheet-shaped power generation element and the power storage device are attached and fixed on the inner peripheral surface of the tire with an adhesive to fix the tire monitoring system. I made a power supply for.

The entire surface of the sheet-shaped power generation element was fixed to the tire with an adhesive. Further, the tire used has an outer diameter of 634 mm mounted on the 17-inch wheel, and the ratio of the length A (50 mm) of the piezoelectric sheet of the sheet-shaped power generation element in the rotation direction of the tire to the outer diameter B of the tire. The A / B was 0.079.

(Example 2)
A power source for a tire monitoring system in the same manner as in Example 1 except that only a portion of the sheet-shaped power generation element having a width of 5 mm on the outer periphery where the piezoelectric sheet does not exist in a plan view is fixed to the tire with an adhesive. Was produced. In the above power generation element, the entire part where the piezoelectric sheet exists in a plan view is not fixed to the tire, and the ratio of the area of the part fixed to the tire with the adhesive is 31% of the total area of the power generation element. there were.

(Comparative Example 1)
Similar to the first embodiment, a PVDF sheet having a length L in the long side direction of 400 mm and a length W in the short side direction of 50 mm was provided, and a resin layer having a width of 5 mm was formed around the PVDF sheet. A sheet-shaped power generation element having the form shown in FIG. 3 was produced. Further, the entire surface of the sheet-shaped power generation element is fixed to the tire with an adhesive so that the long side direction coincides with the rotation direction of the tire, and the power supply for the tire monitoring system is manufactured in the same manner as in the first embodiment. did.

The ratio A / B of the length A (400 mm) of the piezoelectric sheet of the sheet-shaped power generation element in the direction of rotation of the tire to the outer diameter B of the tire was 0.63.

<Evaluation of power generation capacity of power supply for tire monitoring system>
Information including an AD converter that digitally converts the voltage value of a power storage capacitor and a circuit that transmits the information at regular intervals to the power supply for the tire monitoring system of Example 1, Example 2, and Comparative Example 1. By connecting the transmitter and attaching and fixing the information transmitter on the inner peripheral surface of the tire, a measuring device for evaluating the power generation capacity of the power source for the tire monitoring system was constructed.

Next, as shown in Fig. 6, each tire was mounted on a wheel and a running test was conducted. The traveling speed was set to 30 km / h, the voltage value of the storage capacitor transmitted from the information transmission device was monitored, and the power generation capacity of the sheet-shaped power generation element of each power source was evaluated.

Table 1 shows the voltage values of each storage capacitor 3 minutes after the start of running.

Based on the above results, Examples 1 and the embodiment in which the ratio A / B of the length A of the piezoelectric sheet in the sheet-shaped power generation element to the outer diameter B of the tire in the rotation direction of the tire is in the range of 0.16 or less. The power source for the tire monitoring system of Example 2 can significantly improve the power generation capacity as compared with the power source of Comparative Example 1 in which the value of the above ratio is larger than 0.16, and makes the tire monitoring system function stably. It turned out that it is a power source that can be used.

In particular, the power source of Example 2 in which the portion of the sheet-shaped power generation element in which the piezoelectric sheet is present is not fixed to the tire is superior to the power source of Example 1 in which the entire sheet-shaped power generation element is fixed to the tire. It had a power generation capacity.

The present application can be implemented in a form other than the above as long as the purpose is not deviated. The embodiments disclosed in the present application are examples, and the present invention is not limited thereto. The scope of the present application shall be construed in preference to the description of the appended claims over the description of the specification described above, and all changes within the scope of the claims shall be included in the scope of the claims. It is something that can be done.

The power supply for the tire monitoring system disclosed in the present application is reliable because the amount of power that can be generated and extracted is large even if a sheet-shaped power generation element that can be deformed to generate power is used, and the system can function stably. It is possible to provide a highly reliable tire monitoring system.

1 Tire monitoring system 10 Tire information detection device 11 Sensor unit 12 Calculation unit 20 Power storage device 30 Power generation device 30a, 30b Sheet-type power generation element 32a, 32b Terminal 33a, 33b Piezoelectric sheet 34a Metal layer 35a, 35b Resin layer 40 Information transmission device 41 Communication unit 42 Antenna unit 50 Power generation 60 Container 100 Tire assembly 101 Tire 102 Wheel

Claims (13)

1. A power source for a tire monitoring system including a power storage device and a power generation device capable of supplying the generated electric power to the power storage device.
   The power generation device includes a sheet-shaped power generation element.
   The sheet-shaped power generation element includes a power generation body sheet that utilizes deformation for power generation.
   The sheet-shaped power generation element is attached to a tire and can be deformed by the rotation of the tire to generate power.
   The power generator sheet is a power source for a tire monitoring system, wherein the length A (mm) in the rotation direction of the tire satisfies A / B ≦ 0.16 with respect to the outer diameter B (mm) of the tire. ..
2. The power source for the tire monitoring system according to claim 1, wherein the generator sheet satisfies 0.04 ≤ A / B.
3. The power supply for the tire monitoring system according to claim 1 or 2, wherein at least a part of the portion of the sheet-shaped power generation element in which the generator sheet exists is not fixed to the tire.
4. The power source for the tire monitoring system according to claim 3, wherein in the sheet-shaped power generation element, 10% or more of the area of the portion where the power generator sheet exists is not fixed to the tire.
5. The power source for the tire monitoring system according to claim 3, wherein the entire portion of the sheet-shaped power generation element in which the generator sheet exists is not fixed to the tire.
6. The power supply for a tire monitoring system according to any one of claims 3 to 5, wherein the area of the sheet-shaped power generation element fixed to the tire is 10% or more of the total area of the power generation element.
7. The power source for the tire monitoring system according to any one of claims 1 to 6, wherein the generator sheet is a piezoelectric sheet containing a piezoelectric material.
8. A tire monitoring system including a tire information detection device, an information transmission device, and a power source capable of supplying power to the tire information detection device and the information transmission device.
   The information transmitting device transmits tire information detected by the tire information detecting device, and the information transmitting device transmits the tire information.
   A tire monitoring system comprising a power source for the tire monitoring system according to any one of claims 1 to 7 as the power source.
9. The tire monitoring system according to claim 8, wherein the tire information detection device includes a sensor unit and a calculation unit.
10. The tire monitoring system according to claim 8 or 9, wherein the tire information detection device detects at least one tire information selected from air pressure, temperature, and acceleration.
11. The tire monitoring system according to any one of claims 8 to 10, wherein the information transmission device includes a communication unit and an antenna unit.
12. A tire assembly comprising the tire monitoring system according to any one of claims 8 to 11.
13. The tire assembly according to claim 12, wherein the sheet-shaped power generation element included in the tire monitoring system is embedded in the tire and arranged.

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