阅读说明：本技术 柔性摩擦纳米发电机、轮胎的垂向力感应装置及估算方法 (Flexible friction nano generator, vertical force sensing device of tire and estimation method ) 是由 徐婷 张不扬 于 2020-04-19 设计创作，主要内容包括：本发明涉及纳米新能源技术领域,尤其涉及一种柔性摩擦纳米发电机、轮胎的垂向力感应装置及估算方法。本发明的柔性摩擦纳米发电机包括柔性封装腔、分别固定设置在柔性封装腔两相对内壁上电性连接的两导电层,以及分别固定设置在两导电层上的两摩擦层以及固定安装在两摩擦层之间边角处的绝缘支撑层；当以上结构在两导电层的相对方向上受压时,两摩擦层的中间区域能够接触,当所受压力减小时两摩擦层脱离接触,过程中产生交流电；以上结构简单、耐潮、稳定性和柔性优良。本发明的轮胎的垂向力感应装置能够感应轮胎所受的垂向力,本发明的轮胎的垂向力估算系统及估算方法,能够估算得到轮胎所受垂向力的大小。(The invention relates to the technical field of nano new energy, in particular to a vertical force sensing device of a flexible friction nano generator and a tire and an estimation method. The flexible friction nano generator comprises a flexible packaging cavity, two conductive layers which are respectively and fixedly arranged on two inner walls of the flexible packaging cavity and are electrically connected, two friction layers which are respectively and fixedly arranged on the two conductive layers and an insulating support layer which is fixedly arranged at the corner between the two friction layers; when the structure is pressed in the opposite direction of the two conductive layers, the middle areas of the two friction layers can be contacted, and when the pressure is reduced, the two friction layers are separated from contact, so that alternating current is generated in the process; the structure is simple, and the moisture resistance, the stability and the flexibility are excellent. The vertical force sensing device of the tire can sense the vertical force applied to the tire, and the vertical force estimation system and the vertical force estimation method of the tire can estimate and obtain the magnitude of the vertical force applied to the tire.)

1. A flexible triboelectric nanogenerator, comprising: the flexible packaging cavity comprises a flexible packaging cavity, a first conducting layer, a second conducting layer, an insulating supporting layer, a first friction layer and a second friction layer, wherein the first conducting layer, the second conducting layer, the insulating supporting layer, the first friction layer and the second friction layer are arranged in the flexible packaging cavity;

the first conducting layer and the second conducting layer electrically connected with the first conducting layer are respectively and fixedly arranged on a group of opposite inner walls of the flexible packaging cavity, the first friction layer is fixedly arranged on one surface, facing the second conducting layer, of the first conducting layer, and the second friction layer is fixedly arranged on one surface, facing the first conducting layer, of the second conducting layer; the insulating support layer is fixedly arranged between the first friction layer and the second friction layer and is distributed at the corner;

when the flexible packaging cavity is pressed and deformed in the opposite directions of the first conductive layer and the second conductive layer, the middle area of the first friction layer and the middle area of the second friction layer can be close to and contact with each other; when the pressure applied to the flexible packaging cavity is reduced, the contact areas of the first friction layer and the second friction layer can be separated from contact and are far away from each other.

2. The flexible triboelectric nanogenerator of claim 1, wherein: the insulating support layer includes a spring and/or an elastic polymer.

3. The flexible triboelectric nanogenerator of claim 1, wherein:

the first conductive layer comprises a first flexible substrate layer and a first electrode layer, the first flexible substrate layer is fixedly arranged on the inner wall of the flexible packaging cavity, and the first electrode layer is fixedly arranged on the surface, close to the first friction layer, of the first flexible substrate layer;

and/or the second conducting layer comprises a second flexible substrate layer and a second electrode layer, the second flexible substrate layer is fixedly arranged on the inner wall of the flexible packaging cavity, and the second electrode layer is fixedly arranged on the surface, close to the second friction layer, of the second flexible substrate layer.

4. The flexible triboelectric nanogenerator of claim 3, wherein: the first flexible substrate layer and/or the second flexible substrate layer and the flexible packaging cavity are of an integrated insulating structure made of the same material.

5. The flexible triboelectric nanogenerator according to claim 3 or 4, wherein: the first friction layer and the first electrode layer are of an integral conductive structure made of the same materials or the second friction layer and the second electrode layer are of an integral conductive structure made of the same materials.

6. The flexible triboelectric nanogenerator of claim 1, wherein: the first conductive layer and/or the second conductive layer include a flexible substrate and a conductive medium mixed with the flexible substrate to form a flexible conductive film layer.

7. A vertical force sensing device of tire for sensing the magnitude of the vertical force that the tire receives, comprising: the device comprises an energy module, an induction module and a signal output module which are arranged in the tire, wherein the signal output module is respectively and electrically connected with the energy module and the induction module;

the induction module comprises at least one flexible friction nano-generator according to any one of claims 1 to 6, fixedly mounted as an induction unit on a circumferential centerline of the inner tread surface of the tire; when the induction unit passes through a ground contact footprint area of the tire, the induction unit is pressed to generate alternating current, and the electric signal characteristic of the alternating current is specifically related to the magnitude of vertical force applied to the tire;

the signal output module can output the electric signal characteristics obtained from the induction module under the energy supply of the energy module.

8. A vertical force sensing apparatus for a tire according to claim 7, wherein: the energy module comprises at least one flexible friction nano-generator according to any one of claims 1 to 6, which is fixedly mounted on the inner surface of the tread and/or the inner surface of the sidewall of the tire as a power generating unit; the power generation unit is pressed to generate alternating current when passing through the grounding print area and can supply the alternating current to the signal output module;

the vertical force sensing device of the tire further comprises an energy management module, the energy management module and the signal output module are sequentially connected in series, and the energy management module can convert alternating current generated by the energy module into direct current to be supplied to the signal output module.

9. A vertical force sensing apparatus for a tire according to claim 8, wherein: a plurality of flexible friction nano generators fixedly arranged on the inner surface of the tread are distributed on the circumferential central line of the inner surface of the tread at equal intervals;

and/or the flexible friction nano generators fixedly arranged on the inner surface of the sidewall are symmetrically distributed on the inner surface of the sidewall on two sides of the inner surface of the tire tread, and the flexible friction nano generators on the same side are distributed on a circumferential ring line of the inner surface of the sidewall parallel to the circumferential central line at equal intervals.

10. A vertical force estimation system for a tire for estimating the magnitude of a vertical force experienced by the tire, comprising: the vertical force sensing device of any one of claims 7 to 9, further comprising an estimation module disposed in the vehicle and electrically connected to the vehicle-mounted power supply of the vehicle, wherein the estimation module is in signal connection with the signal output module, and can estimate the vertical force applied to the tire by using the characteristics of the electrical signal transmitted by the signal output module.

11. The vertical force estimation system of a tire of claim 10, wherein: the system for estimating the vertical force of the tire further comprises a vehicle-mounted electric control system, and when the magnitude of the vertical force applied to the tire estimated by the estimation module exceeds a set range, the vehicle-mounted electric control system can adjust the running state of the automobile.

12. A method for estimating a vertical force exerted on a tire, comprising:

constructing the flexible friction nano generator as claimed in any one of claims 1 to 6 as an induction unit through simulation or test means, wherein specific correlation exists between the characteristics of an electric signal and vertical force applied to a tire;

under the actual working condition of automobile running, the electric signal characteristics of the sensing unit are measured, and the vertical force applied to the tire is calculated according to the specific correlation between the electric signal characteristics and the vertical force applied to the tire.

13. The method of estimating vertical force of a tire according to claim 12, wherein:

measuring open-circuit voltage peak value data of the sensing unit under different tire pressures and vertical force data borne by the tire at corresponding moments through tire finite element simulation or tire indoor bench test;

constructing a first relation model of open-circuit voltage peak data and vertical force data under different tire pressures;

and under the actual working condition of automobile running, measuring the tire pressure and the open-circuit voltage peak value of the induction unit, and calculating according to the first relation model to obtain the vertical force applied to the tire.

14. The method of estimating vertical force of a tire according to claim 12, wherein:

by means of finite element simulation of the tire or bench test in the tire chamber,

measuring the open circuit voltage period T from grounding to ground of the induction unit under different tire pressures₁And the open circuit voltage period T of the two adjacent earthed induction units₂Or measuring the short-circuit current period T from the ground to the ground of the induction unit under different tire pressures₁And the short-circuit current period T of the two adjacent earthed induction units₂；

According to a ═ 2k · Rsin (pi T)₁/T₂) Calculating to obtain the length a of the grounding footprint, wherein k is a proportional coefficient obtained through experiments or experiences, and R is the radius of the tire;

then according toWherein P is tire pressure, a is calculated length of the grounding trace, a₁、a₂、a₃Calculating the tire load for the identifiable parameterVertical force F of_z。

Technical Field

The invention belongs to the technical field of nano new energy, and particularly relates to a vertical force sensing device and an estimation method for a flexible friction nano generator and a tire.

Background

The power generation principle of the friction nanometer generator is that when two different materials are contacted under the action of mechanical force, the surfaces of the two different materials can generate positive and negative static charges under the action of contact electricity; when the two materials are separated, positive and negative charges generated by contact electrification are separated, and then an induced potential difference is generated between the electrodes of the two materials and electrons are induced; if a load is connected between the electrodes of the two materials or the two materials are in a short circuit state, the induced potential difference drives the induced electrons to flow between the two electrodes through an external circuit so as to form alternating current.

The existing friction nanometer generator is always under the continuous action of mechanical force in order to ensure that the generator can generate electricity continuously, the stability and the reliability of the structure of the generator are poor, and the mechanical property of the installation position of the generator under stress can be seriously influenced; meanwhile, the friction material or the electrode in the friction nano generator is exposed to moisture for a long time, and the electric output performance and the energy conversion efficiency of the friction nano generator are adversely affected.

Disclosure of Invention

The invention mainly aims to provide a flexible friction nano generator which is simple in structure, good in stability and flexibility and reliable in moisture resistance.

The invention also provides a vertical force sensing device of the tire, which is used for sensing the vertical force applied to the tire through the flexible friction nano generator.

The invention also provides a vertical force estimation system of the tire, which is used for estimating the magnitude of the vertical force applied to the tire.

Meanwhile, the invention also provides a tire vertical force estimation method, which can estimate the magnitude of the vertical force applied to the tire.

The invention relates to a flexible friction nano generator, which comprises: the flexible packaging cavity comprises a flexible packaging cavity, a first conducting layer, a second conducting layer, an insulating supporting layer, a first friction layer and a second friction layer, wherein the first conducting layer, the second conducting layer, the insulating supporting layer, the first friction layer and the second friction layer are arranged in the flexible packaging cavity;

the first conducting layer and the second conducting layer electrically connected with the first conducting layer are respectively and fixedly arranged on a group of opposite inner walls of the flexible packaging cavity, the first friction layer is fixedly arranged on one surface, facing the second conducting layer, of the first conducting layer, and the second friction layer is fixedly arranged on one surface, facing the first conducting layer, of the second conducting layer; the insulating support layer is fixedly arranged between the first friction layer and the second friction layer and is distributed at the corner;

when the flexible packaging cavity is pressed and deformed in the opposite directions of the first conductive layer and the second conductive layer, the middle area of the first friction layer and the middle area of the second friction layer can be close to and contact with each other; when the pressure applied to the flexible packaging cavity is reduced, the contact areas of the first friction layer and the second friction layer can be separated from contact and are far away from each other.

Optionally, the insulating support layer comprises a spring and/or an elastic polymer.

Optionally, the first conductive layer includes a first flexible substrate layer and a first electrode layer, the first flexible substrate layer is fixedly mounted on the inner wall of the flexible packaging cavity, and the first electrode layer is fixedly mounted on a surface of the first flexible substrate layer close to the first friction layer;

and/or the second conducting layer comprises a second flexible substrate layer and a second electrode layer, the second flexible substrate layer is fixedly arranged on the inner wall of the flexible packaging cavity, and the second electrode layer is fixedly arranged on the surface, close to the second friction layer, of the second flexible substrate layer.

Optionally, the first flexible substrate layer and/or the second flexible substrate layer and the flexible encapsulation cavity are of an integrated insulating structure made of the same material.

Optionally, the first friction layer and the first electrode layer are an integral conductive structure made of the same material, or the second friction layer and the second electrode layer are an integral conductive structure made of the same material.

Optionally, the first conductive layer and/or the second conductive layer comprise a flexible substrate and a conductive medium mixed with the flexible substrate to form a flexible conductive film layer.

A vertical force sensing device for a tire for sensing the magnitude of a vertical force applied to the tire, comprising: the device comprises an energy module, an induction module and a signal output module which are arranged in the tire, wherein the signal output module is respectively and electrically connected with the energy module and the induction module;

the induction module comprises at least one flexible friction nano generator, and the flexible friction nano generator is fixedly arranged on a circumferential central line of the inner surface of the tire tread of the tire when serving as an induction unit; when the induction unit passes through a ground contact footprint area of the tire, the induction unit is pressed to generate alternating current, and the electric signal characteristic of the alternating current is specifically related to the magnitude of vertical force applied to the tire;

the signal output module can output the electric signal characteristics obtained from the induction module under the energy supply of the energy module.

Optionally, the energy module comprises at least one flexible friction nano-generator as described in any one of the above, which is fixedly mounted on the inner surface of the tread and/or inner surface of the sidewall of the tire when serving as a power generation unit; the power generation unit is pressed to generate alternating current when passing through the grounding print area and can supply the alternating current to the signal output module;

the vertical force sensing device of the tire further comprises an energy management module, the energy management module and the signal output module are sequentially connected in series, and the energy management module can convert alternating current generated by the energy module into direct current to be supplied to the signal output module.

Optionally, a plurality of the flexible friction nano-generators fixedly mounted on the inner surface of the tread are distributed at equal intervals on the circumferential center line of the inner surface of the tread;

and/or the flexible friction nano generators fixedly arranged on the inner surface of the sidewall are symmetrically distributed on the inner surface of the sidewall on two sides of the inner surface of the tire tread, and the flexible friction nano generators on the same side are distributed on a circumferential ring line of the inner surface of the sidewall parallel to the circumferential central line at equal intervals.

The vertical force estimation system of the tire is used for estimating the magnitude of the vertical force applied to the tire, and further comprises an estimation module which is arranged in a vehicle and electrically connected with a vehicle-mounted power supply of the vehicle, wherein the estimation module is in signal connection with the signal output module, and can estimate the magnitude of the vertical force applied to the tire by utilizing the characteristics of an electric signal sent by the signal output module.

Optionally, the system for estimating the vertical force of the tire further comprises a vehicle-mounted electronic control system, and when the magnitude of the vertical force applied to the tire estimated by the estimation module exceeds a set range, the vehicle-mounted electronic control system can adjust the running state of the automobile.

A method for estimating the vertical force of a tyre, for estimating the magnitude of the vertical force to which the tyre is subjected:

when the flexible friction nano generator is constructed as an induction unit through simulation or test means, specific correlation exists between the characteristics of an electric signal and the vertical force borne by a tire;

under the actual working condition of automobile running, the electric signal characteristics of the sensing unit are measured, and the vertical force applied to the tire is calculated according to the specific correlation between the electric signal characteristics and the vertical force applied to the tire.

Optionally, through tire finite element simulation or tire indoor bench test, measuring open-circuit voltage peak data of the sensing unit under different tire pressures and vertical force data borne by the tire at corresponding moments;

constructing a first relation model of open-circuit voltage peak data and vertical force data under different tire pressures;

and under the actual working condition of automobile running, measuring the tire pressure and the open-circuit voltage peak value of the induction unit, and calculating according to the first relation model to obtain the vertical force applied to the tire.

Alternatively, the tire is tested by tire finite element simulation or tire indoor bench test,

measuring the open circuit voltage period T from grounding to ground of the induction unit under different tire pressures₁And the open circuit voltage period T of the two adjacent earthed induction units₂Or measuring the short-circuit current period T from the ground to the ground of the induction unit under different tire pressures₁And the short-circuit current period T of the two adjacent earthed induction units₂；

According to a ═ 2k · Rsin (pi T)₁/T₂) Calculating to obtain the length a of the grounding footprint, wherein k is a proportional coefficient obtained through experiments or experiences, and R is the radius of the tire;

then according toWherein P is tire pressure, a is calculated length of the grounding trace, a₁、a₂、a₃For the purpose of obtaining identification parameters by test, calculating to obtain the vertical force F borne by the tire_z。

The invention has the beneficial effects that:

the invention discloses a flexible friction nano generator which comprises a flexible packaging cavity, a first conducting layer, a second conducting layer, a first friction layer, a second friction layer and an insulating support layer, wherein the first conducting layer and the second conducting layer are fixedly arranged in the flexible packaging cavity respectively and are electrically connected with each other on two inner walls; when the structure is pressed in the opposite direction of the two conductive layers, the middle areas of the two friction layers can be close to each other and contact with each other to generate positive and negative static charges, when the pressure is reduced, the contact areas of the two friction layers can be separated from contact with each other and far away from each other, and electrons flow between the two conductive layers to form alternating current. The flexible friction nano generator has the advantages of simple structure, moisture resistance, and excellent stability and flexibility.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a cross-sectional view of one embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 2 is a cross-sectional view of a second embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 3 is a cross-sectional view of a third embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 4 is a cross-sectional view of a fourth embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 5 is a schematic diagram of one embodiment of a vertical force sensing device for a tire of the present invention;

FIG. 6 is a schematic structural diagram of one embodiment of the flexible friction nano-generator of the present invention as an induction unit fixedly mounted on the inner surface of a tread;

FIG. 7 is a schematic structural view of an embodiment of the flexible friction nano-generator of the present invention as a power generation unit fixedly mounted on the inner surface of a sidewall;

FIG. 8 is a schematic diagram of an embodiment of a vertical force estimation system for a tire of the present invention, showing an onboard power source of an automobile.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

In the description of the present application, it is to be understood that the terms "length", "inner", "outer", "axial", "radial", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected or detachably connected or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The invention provides a flexible friction nano-generator, a first embodiment of which is shown in fig. 1 and comprises:

the flexible packaging cavity comprises a flexible packaging cavity 1, a first conducting layer 2, a second conducting layer 3, a first friction layer 4, a second friction layer 5 and an insulating support layer 6, wherein the first friction layer 4 and the second friction layer 5 are made of different materials.

As shown in fig. 1, a first embodiment of the flexible friction nanogenerator of the invention is characterized in that a first conductive layer 2 and a second conductive layer 3 are respectively and fixedly arranged on a group of opposite inner walls of a flexible packaging cavity 1, a first friction layer 4 is fixedly arranged on one surface of the first conductive layer 2 facing the second conductive layer 3, and a second friction layer 5 is fixedly arranged on one surface of the second conductive layer 3 facing the first conductive layer 2; the first conducting layer 2 is electrically connected with the second conducting layer 3, and the insulating support layer 6 is fixedly arranged between the first friction layer 4 and the second friction layer 5 and distributed at the corners of the two friction layers, so that the spacing distance between the two friction layers is ensured.

When the structure is pressed and deformed in the direction of the first conductive layer 2 and the second conductive layer 3, the insulating support layer 6 is not arranged between the middle area of the first friction layer 4 and the middle area of the second friction layer 5, so that the two friction layers can be close to each other to be contacted, and positive and negative static charges can be generated due to extrusion friction when the two friction layers are contacted; when the pressure applied to the structure is reduced, the first friction layer 4 and the second friction layer 5 can be separated from contact and away from each other, and an induced potential difference is generated between the two conductive layers, and the induced potential difference drives electrons to flow through an electric connection circuit between the first conductive layer 2 and the second conductive layer 3 to form alternating current.

The flexible friction nano generator has a simple structure, the flexible packaging cavity can buffer the pressure applied to the flexible friction nano generator, the conductive layer and the friction layer in the flexible friction nano generator are protected, a relatively clean and dry closed environment is provided for the internal structure, the stability and the reliability of the whole structure of the flexible friction nano generator are improved, the service life of the flexible friction nano generator is prolonged, and the electrical output performance and the energy conversion efficiency are optimized. Meanwhile, the flexible friction nano generator has excellent flexibility, and the mechanical property of the installation position of the flexible friction nano generator under stress cannot be influenced excessively.

In this embodiment, further, the material of the first friction layer 4 and the material of the second friction layer 5 may be different, and not adjacent to each other in the triboelectric series, and the sequence in the triboelectric series is as far as possible, so that the first friction layer 4 and the second friction layer 5 can generate more charges when contacting each other, which is more beneficial for the flexible friction nano-generator of the present invention to generate electricity. Further, the first friction layer 4 and the second friction layer 5 are provided as flexible film layers (i.e., flexible materials with small thickness), which can improve the flexibility of the structure.

Here, the material of the first friction layer 4 may be one of polytetrafluoroethylene, polydimethylsiloxane, polyimide, polyvinylidene fluoride, polyethylene terephthalate, carbon nanotube, elastic silicone, epoxy resin, brominated butyl rubber, and nylon, and the material of the second friction layer 5 may be one of the above materials, as long as it is different from the material of the first friction layer 4.

In this embodiment, further, the flexible packaging cavity 1 may be made of an insulating material including at least one of rubber, silica gel, elastic resin, and polyimide, so as to meet the flexibility requirement of the flexible packaging cavity.

In this embodiment, further, the insulating support layer 6 is provided with a spring and/or an elastic polymer, and at this time, the insulating support layer 6 not only can ensure that a certain interval is always kept between the two friction layers in the initial natural state, but also can provide restoring force for the two friction layers to enable the two friction layers to be quickly restored to the initial position when the pressure applied to the flexible packaging cavity 1 is reduced.

In the second embodiment of the present invention, on the basis of the structure of the first embodiment, the first conductive layer 2 is provided to include a first flexible substrate layer 201 and a first electrode layer 202; the first flexible substrate layer 201 is fixedly installed on the inner wall of the flexible packaging cavity 1, and the first electrode layer 202 is fixedly installed on the surface, close to the first friction layer 4, of the first flexible substrate layer 201;

alternatively, the first and second electrodes may be,

providing a second conductive layer 3 comprising a second flexible substrate layer 301 and a second electrode layer 302; the second flexible substrate layer 301 is fixedly installed on the inner wall of the flexible packaging cavity 1, and the second electrode layer 302 is fixedly installed on the surface, close to the second friction layer 5, of the second flexible substrate layer 301;

still alternatively, the first and second substrates may be,

as shown in fig. 2, the first conductive layer 2 comprises a first flexible substrate layer 201 and a first electrode layer 202, while the second conductive layer 3 comprises a second flexible substrate layer 301 and a second electrode layer 302.

In the above structure, due to the arrangement of the first flexible substrate layer 201 and the second flexible substrate layer 301, the first conductive layer 2 and the second conductive layer 3 have flexibility, so that the flexibility of the overall structure of the flexible friction nano-generator is improved; in addition, the flexibility of the first flexible substrate layer 201 and the second flexible substrate layer 301 can be larger than the flexibility of the installation position of the flexible friction nano-generator, so that the mechanical property of the installation position of the flexible friction nano-generator under stress cannot be excessively influenced when the flexible friction nano-generator is installed.

The third embodiment of the invention is based on the structure of the second embodiment:

arranging a first flexible substrate layer 201 and a flexible packaging cavity 1 to be of an integrated insulation structure with the same material; or, the second flexible substrate layer 301 and the flexible packaging cavity 1 are arranged to be of an integrated insulation structure with the same material; or, as shown in fig. 3, the first flexible substrate layer, the second flexible substrate layer and the flexible packaging cavity are an integrated insulating structure made of the same material.

Here, it can also be understood that, when the materials of the first flexible substrate layer 201 and the second flexible substrate layer 301 are simultaneously suitable for being made into the material of the flexible packaging cavity 1, the inner wall of the flexible packaging cavity 1 can be used as the substrate of the first electrode layer 202 and the second electrode layer 302 while enclosing to form a closed cavity, so as to simplify the structure; when the materials of the first flexible substrate layer 201 and the second flexible substrate layer 301 are not suitable for the material of the flexible packaging cavity 1, the flexible substrate layers and the flexible packaging cavity 1 need to be arranged independently.

The fourth embodiment of the present invention is based on the structures of the second and third embodiments of the present invention:

the first friction layer 4 and the first electrode layer 202 are integrally formed of the same material, or the second friction layer 5 and the second electrode layer 302 are integrally formed of the same material.

As shown in fig. 4, in addition to the structure of the embodiment shown in fig. 3 of the present invention, the second friction layer 5 and the second electrode layer 302 are provided with the integral conductive structure 7 made of the same material, so that the structure of the flexible friction nano-generator of the present invention is simplified on the premise of ensuring normal power generation.

In the present invention, the following design can also be adopted for the structures of the first conductive layer 2 and the second conductive layer 3:

the first conductive layer 2 and/or the second conductive layer 3 comprise a flexible substrate and a conductive medium mixed with the flexible substrate to form a flexible conductive film layer. For example, the flexible substrate can be a silica gel substrate with good flexibility, even a silica gel substrate subjected to vulcanization treatment, and the conductive medium can be silver-plated glass powder, or carbon nanotubes and carbon black. Of course, there is no particular limitation on the materials selected for the flexible substrate and the conductive medium, as long as the two can be mixed to form the flexible conductive film layer. At this time, the flexibility of the structures of the first conductive layer 2 and the second conductive layer 3 is improved, and the structural integrity is improved by the mixed composition mode of the flexible substrate and the conductive medium, so that the flexible substrate is more stable and reliable.

On the basis of the structure of any one of the above embodiments, there may be provided:

one surface of the first friction layer 4 facing the second friction layer 5 and/or one surface of the second friction layer 5 facing the first friction layer 4 are/is provided with a micro-nano structure. The surface of the friction layer is provided with a micro-nano structure, so that the structure period density of the surface of the friction layer and the charge density which can be generated can be improved, and the micro-nano structure can be a patterned micro-nano structure, and/or a nano composite structure, and/or a high-density grid structure.

The present invention also provides a vertical force sensing device for a tire, as shown in fig. 5 and 6, including:

the energy module 8, the induction module 9 and the signal output module 10 are arranged inside the tire, wherein the signal output module 10 is electrically connected with the energy module 8 and the induction module 9 respectively.

If the tire on which the vertical force sensor of the present invention is mounted is denoted as a, then,

the induction module 9 comprises at least one flexible friction nano generator of the invention, and when the flexible friction nano generator is used as an induction unit B, the flexible friction nano generator is fixedly arranged on the circumferential central line of the inner surface of the tread of the tire A; when the sensing unit B passes through the grounding imprinting area of the tire A, alternating current is generated by pressing, and the electrical signal characteristics of the alternating current are specifically related to the vertical force applied to the tire A;

at this time, the signal output module 10 can output the electric signal characteristics obtained from the sensing unit B under the power of the power module 8.

Further, the signal output module 10 includes an RF transmitter 101 and an MCU micro-control unit 102 electrically connected to each other. The RF radio frequency transmitter 101 is capable of sending out the electrical signal modulation received from the induction module 9 in the form of high frequency filtering; MCU 102 can provide in-depth control of signal output module 10 from receiving data to transmitting signals.

In the above structure, the principle that the characteristics of the electric signal generated by the sensing unit B in the alternating current and the vertical force applied to the tire a are specifically related lies in that: the tire A is periodically grounded when rolling, and the sensing unit B arranged on the circumferential center line of the inner surface of the tread of the tire A also periodically passes through the grounding footprint area of the tire A; when the sensing unit B does not enter the grounding trace area, the two friction layers are initially in a mutually separated state, when the sensing unit B enters the grounding trace area, the inner surface of the tire tread in the grounding trace area vertically deforms under the action of a vertical force, so that the sensing unit B in the grounding trace area is pressed to deform, the two friction layers are mutually close to each other to be in contact, then the sensing unit B leaves the grounding trace area, the two friction layers are mutually far away, the sensing unit B generates alternating current based on friction electrification and electrostatic induction, when the structure and the material of the sensing unit B are determined, the open-circuit voltage of the alternating current is specifically associated with the vertical deformation of the inner surface of the tire tread, namely, the vertical force causing the vertical deformation of the inner surface of the tire tread. In addition, the period of the open-circuit voltage and the period of the short-circuit current of the alternating current of the sensing unit B are specifically related to the length of the grounding trace, namely, the vertical force causing the change of the length of the grounding trace.

Based on the above principle, the vertical force sensing device of the above tire can sense the vertical force applied to the tire.

Here, it is equivalent to that the sensing unit B monitors the periodic deformation of the inner surface of the tread, and the periodic deformation of the inner surface of the tread has the characteristics of low frequency and high amplitude, so the strength of the insulating support layer 6 in the sensing unit B needs to be optimally designed, for example, when a relationship between the open circuit voltage of the alternating current and the vertical force needs to be established, the open circuit voltage peak value of the sensing unit B needs to be basically linearly increased along with the increase of the vertical force without saturation, the sensitivity and the range of the sensing unit B when the vertical force is indirectly sensed are ensured, in addition, the parameter design needs to be performed on the sensing unit B, so as to avoid the natural frequency of the sensing unit B from further resonating within the deformation frequency range of the inner surface of the tread, and the range of the sensing unit B is.

A second embodiment of the vertical force sensing device of the tire according to the present invention is based on the structure of the first embodiment, and the energy module 8 is provided with at least one flexible friction nano-generator according to the present invention as described in any one of the above embodiments, as shown in fig. 7, where the flexible friction nano-generator is fixedly mounted on the inner surface of the tread and/or the inner surface of the sidewall of the tire a as a power generation unit C; the power generation unit C generates an alternating current under pressure when passing through the footprint area of the tire a and supplies the alternating current to the signal output module 10.

That is, the vertical force sensing device of the tire according to the present invention can perform a passive operation without additional access to other power sources.

The process of generating the alternating current by the power generation unit C here is:

the tire A has a contact patch when rolling;

when the power generation unit C mounted on the inner surface of the tread and/or the inner surface of the sidewall of the tire a does not enter the footprint area, the two friction layers inside the power generation unit C are in a state of a spaced distance;

when the power generation unit C arranged on the inner surface of the tread and/or the inner surface of the sidewall of the tire A gradually enters the grounding imprint area, the power generation unit C is pressed, two friction layers in the power generation unit C gradually approach to a contact state, and the power generation unit C and the two friction layers are in contact electrification;

when the power generation unit C installed on the inner surface of the tread and/or the inner surface of the sidewall of the tire A gradually leaves the grounding imprint area, the pressure borne by the power generation unit C is reduced, two friction layers in the power generation unit C are gradually far away from each other to be separated from contact, and at the moment, electrostatic induction is generated between two conductive layers in the power generation unit C to further form induction current;

since the power generation unit C mounted on the inner surface of the tread and/or the inner surface of the sidewall of the tire a periodically passes through the footprint area when the tire a rolls, an induced current is periodically generated to generate an alternating current.

In the above embodiment, the size of the selected power generation unit C is based on the fact that the mechanical property of the tire is not affected, the installation position of the selected power generation unit C is preferably based on the fact that the mass balance and the dynamic balance of the tire are not affected, and the number of the selected power generation units C, the electrical connection relationship (series connection and/or series-parallel connection) of the plurality of power generation units C, the area of the friction layer in each power generation unit C, and the interval between the two friction layers need to be designed comprehensively, so that the whole energy module 8 can meet the electric power required by the induction module 9 as necessary.

Meanwhile, the present embodiment further includes an energy management module 11, the energy module 8, the energy management module 11 and the signal output module 10 are sequentially connected in series, and the energy management module 11 can convert the alternating current generated by the energy module 8 into a direct current to be supplied to the signal output module 10.

Further, as shown in fig. 5, the energy management module 11 includes a switch 111, a transformer 112, a rectifier bridge 113, and a capacitor 114, which are electrically connected. The switch 111 can solve the impedance mismatch problem of electric energy and improve the transfer efficiency of the electric energy; the transformer 112 can increase the output current and increase the charging speed of the capacitor 114; the ac power output from the transformer 112 is converted into dc power by the rectifier bridge 113, and then stored in the capacitor 114 to supply power to the subsequent signal output module 10.

A third embodiment of the vertical force sensing apparatus for a tire according to the present invention is based on the structure of the second embodiment:

setting a plurality of flexible friction nano generators (including an induction unit B and also including a power generation unit C) fixedly installed on the inner surface of the tread to be distributed at equal intervals on the circumferential central line of the inner surface of the tread; and/or a plurality of flexible friction nano-generators (power generation units C) fixedly arranged on the inner surface of the tire side are symmetrically distributed on the inner surface of the tire side at two sides of the inner surface of the tire tread, and the flexible friction nano-generators positioned at the same side are distributed on a circumferential ring line of the inner surface of the tire side parallel to the circumferential center line of the inner surface of the tire tread at equal intervals.

The distribution scheme of the flexible friction nano generator can ensure the mass balance of the tire A as far as possible, and further ensure the dynamic balance of the tire A during rotation.

The invention also discloses a vertical force estimation system of the tire, which is used for estimating the vertical force borne by the tire A, and as shown in fig. 8, the vertical force estimation system of the tire comprises the sensing device of the tire of the invention in any embodiment, and further comprises an estimation module 12 in signal connection with the signal output module 10 in the sensing device of the tire of the invention, wherein the estimation module 12 is arranged in the vehicle and is electrically connected with the vehicle-mounted power supply D of the vehicle, and the vertical force borne by the tire can be estimated by utilizing the characteristics of the electric signal sent by the signal output module 10 under the energy supply of the vehicle-mounted power supply D.

Further, the estimation module 12 of the present invention further includes an RF receiver 121, a vehicle-mounted control unit 122, and an LED display screen 123 electrically connected to each other. The RF receiver 121 receives the high-frequency filter transmitted by the RF transmitter 101, modulates the high-frequency filter into an electrical signal, analyzes and processes the electrical signal by the vehicle-mounted control unit 122 (a micro control unit may be selected), and displays the electrical signal on the LED display screen 123 in a data form for the vehicle interior personnel, particularly the driver to view.

Further, the system for estimating the vertical force of the tire further comprises a vehicle-mounted electronic control system 13, and when the vertical force applied to the tire estimated by the estimation module 12 exceeds a preset range (a tire stress range ensuring the safety of the running of the vehicle), the vehicle-mounted electronic control system 13 can adjust the running state of the vehicle.

The invention also provides a tire vertical force estimation method, which is used for estimating the magnitude of the vertical force borne by the tire:

the specific correlation between the electric signal characteristics of the flexible friction nano-generator serving as the induction unit B and the vertical force borne by the tire is established by a simulation or test means;

under the actual working condition of automobile running, the electric signal characteristics of the sensing unit B are measured, and the vertical force applied to the tire is calculated according to the specific correlation between the electric signal characteristics and the vertical force applied to the tire.

In particular, it can be set up such that,

measuring open-circuit voltage peak data of the sensing unit B under different tire pressures and vertical force data borne by the tire at corresponding moments through tire finite element simulation or tire indoor bench test;

constructing a first relation model of open-circuit voltage peak data and vertical force data under different tire pressures;

under the actual working condition of automobile running, the tire pressure and the open-circuit voltage peak value of the sensing unit B are measured, and the vertical force applied to the tire is calculated according to the first relation model.

Still alternatively, it may be set as:

by means of finite element simulation of the tire or bench test in the tire chamber,

measuring the open circuit voltage period T from grounding to grounding of the sensing unit B under different tire pressures₁And the open circuit voltage period T of the two adjacent earthed induction units B₂，

Meanwhile, according to a first formula: a 2k Rsin (pi T)₁/T₂)，

Wherein k is a proportional coefficient obtained through experiments or experiences and generally takes the value of 1.1, R is the radius of the tire, and the length a of the grounding trace is obtained through calculation;

and then according to an empirical formula of the length a of the grounding trace:

wherein P is tire pressure, a is calculated length of the grounding trace, a₁、a₂、a₃Is a distinguishable parameter (a here)₁、a₂、a₃Also obtained through finite element simulation of the tire or indoor bench test of the tire and based on the formula identification), and the vertical force F borne by the tire is obtained through calculation_z。

When the length of the length a of the grounding trace is calculated according to the first formula, the short-circuit current period T from grounding to grounding of the sensing unit B under different tire pressures can be measured₁And a short-circuit current period T of two adjacent earthed induction units B₂。

In the above scheme, induction is obtainedOpen circuit voltage period T from ground to ground for cell B₁And the open circuit voltage period T of the two adjacent earthed induction units B₂Before, or after, obtaining a short-circuit current period T from ground to ground of the induction unit B₁And a short-circuit current period T of two adjacent earthed induction units B₂Before, the waveform of the short-circuit current or the open-circuit voltage may be filtered to remove interference waves caused by environmental noise, structural interference, resonance, and other factors.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.