CN110758355B

CN110758355B - Accelerator anti-misstep brake auxiliary device

Info

Publication number: CN110758355B
Application number: CN201911216796.3A
Authority: CN
Inventors: 庞宇帆; 程冠达; 闫忠; 刘子平; 丁冬平
Original assignee: Dalian Jiaotong University
Current assignee: Dalian Jiaotong University
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2022-02-25
Anticipated expiration: 2039-12-03
Also published as: CN110758355A

Abstract

The invention relates to the technical field of vehicle manufacturing, and particularly discloses an accelerator mistaken-stepping prevention braking auxiliary device which comprises a base, a flexible top plate and non-Newtonian fluid, wherein the base is a shell with an opening at the upper part, the flexible top plate is connected to the opening at the upper part of the base in a sealing mode and encloses a sealed cavity with the base, the flexible top plate is made of flexible materials and is used for being in contact fit with the lower side of a vehicle accelerator pedal, and the non-Newtonian fluid is filled in the sealed cavity. The invention can effectively avoid traffic accidents caused by mistakenly stepping on the accelerator by a driver based on the solid-liquid phase morphological properties and the rheological relation of the non-Newtonian fluid, has strong practicability and low cost, has simpler process, longer service life and flexible and convenient assembly and disassembly compared with other braking safety auxiliary devices, and does not influence the driving performance and the driving feeling of the original vehicle.

Description

Accelerator anti-misstep brake auxiliary device

Technical Field

The invention relates to the technical field of vehicle manufacturing, in particular to an accelerator mistaken-stepping prevention braking auxiliary device based on non-Newtonian fluid.

Background

Many scholars and automobile researchers at home and abroad have conducted investigation and research, and the improvement and design schemes are provided for the throttle and brake mechanisms of the existing automobiles, and the overall scheme can be divided into two categories, namely a pure mechanical type and an electromechanical combined type.

The main working principle of the pure mechanical brake auxiliary device is that whether the accelerator is stepped by mistake is judged according to the stress or the angular velocity of the accelerator pedal, and the automatic braking of the vehicle is realized by utilizing a mechanical linkage device. Such as: an automobile accelerator mistaken stepping prevention device realizes that when a driver steps on an accelerator mistakenly, an accelerator pedal drives an accelerator rotating shaft to enable another linkage shaft to rotate quickly, when the rotating speed of the accelerator pedal rises to a preset value, a clutch on the rotating shaft enables a connecting block to be fixedly connected with the rotating shaft to drive a brake pull rod to rotate together, and the brake pull rod pulls an automobile brake pull wire and an emergency flameout pull wire to flameout and stop the automobile; the utility model provides an accelerator and brake pedal linkage remedy device, utilizes when the driver steps on the accelerator by mistake, the angular velocity of accelerator is too big, triggers linkage device's interior box vertical guide rail and slides downwards, makes interior outer box nested each other, drives outer box linkage traction brake pedal, has played the effect of emergency braking after stepping on the accelerator by mistake.

The electromechanical combined brake auxiliary device is mainly based on a control engineering technology, judges whether the accelerator is stepped by mistake or not by monitoring and analyzing the running state of the automobile in real time, and realizes the automatic braking of the automobile by using the electromechanical control device. Such as: a system collects the speed and route of a vehicle and the running data of surrounding vehicles through related sensors, and then analyzes the collected data to perform corresponding actions. If the driver steps on the accelerator by mistake, the system can automatically judge that the vehicle is in a dangerous state and correct the error instruction of the driver, so that the vehicle is braked automatically and the vehicle body is stabilized; the technology is to monitor the environment around an automobile by a panoramic monitoring system equipped for a daily-produced automobile model and cameras distributed around the automobile, and when a driver steps on the accelerator by mistake, the system automatically inhibits the acceleration of the automobile and brakes to avoid accidents.

Although the auxiliary device of pure mechanical type can realize comparatively effectively, reliable throttle mistake is stepped on and is prevented and the auxiliary brake effect, this type of design is to the lack of consideration of space structure in the car, it is great to the original braking of car and fuel feed system's structural modification, habit and impression when having influenced the driver and having accelerated with the braking, be difficult to popularize in the vehicle, in addition, because there is the hysteresis quality in this type of device, can only step on the consequence that produces to the throttle mistake and play the remedial action, can't follow the root and stop this phenomenon, the practicality is relatively lower. Although the electromechanical auxiliary system can efficiently and reliably eliminate serious consequences caused by mistaken stepping on the accelerator, the software and hardware cost of the system and the requirements on the hardware of the automobile are high, the system is easy to damage under the frequent action of a driver, and the later maintenance and repair cost is high, so that the system is difficult to popularize and apply.

Disclosure of Invention

The invention aims to provide a vehicle braking device based on non-Newtonian fluid, which solves the problem that the braking auxiliary device in the prior art cannot give consideration to the cost and the practicability of the braking auxiliary device, and effectively avoids the phenomenon of traffic accidents caused by the driver stepping on the accelerator by mistake.

In order to solve the technical problem, the invention provides an accelerator mistaken-stepping prevention braking auxiliary device which comprises a base, a flexible top plate and non-Newtonian fluid, wherein the base is a shell with an opening at the upper part, the flexible top plate is connected to the opening at the upper part of the base in a sealing mode and encloses a closed cavity with the base, the flexible top plate is made of flexible materials and is used for being in contact fit with the lower side of an accelerator pedal of a vehicle, and the non-Newtonian fluid is filled in the closed cavity.

Preferably, the base comprises a bottom plate and two rigid side plates, the shape of the bottom plate corresponds to that of a floor below a vehicle accelerator, the lower sides of the two rigid side plates are respectively connected with the left side and the right side of the bottom plate in a sealing mode, the rigid side plates are made of rigid materials, the two rigid side plates are parallel to each other and perpendicular to the bottom plate, and the flexible top plate is of an upward-protruding cambered surface structure.

Preferably, the non-Newtonian fluid is prepared by mixing one or more of corn starch, cassava starch, sweet potato starch and potato starch with water.

Preferably, a pigment is added to the non-newtonian fluid.

Preferably, in a non-working state, the non-Newtonian fluid occupies 89% -92% of the internal space of the closed cavity.

Preferably, a flexible protective layer is arranged on the inner wall of the closed cavity, and the non-Newtonian fluid is arranged in the flexible protective layer.

Preferably, a plurality of layers of perforated partition plates which are parallel to each other are arranged in the closed cavity.

Preferably, the perforated partition boards are provided with a plurality of round holes, and the round holes on the two adjacent perforated partition boards are not coaxial.

Preferably, the non-Newtonian fluid flow sensor further comprises a viscous sensor, and the viscous sensor is arranged in the closed cavity and used for detecting the viscosity coefficient of the non-Newtonian fluid.

Preferably, the vehicle safety system further comprises a data analysis module and an execution module, wherein the data analysis module is used for analyzing the data collected by the viscous sensor and then sending out corresponding control signals, and the execution module is used for receiving the control signals sent by the single chip microcomputer and then starting a corresponding safety system of the vehicle.

The accelerator mis-stepping prevention braking auxiliary device can effectively avoid traffic accidents caused by the fact that a driver mis-steps on the accelerator based on the solid-liquid phase morphological properties and rheological relations of the non-Newtonian fluid, is high in practicability and low in cost, is simpler in process, longer in service life, flexible and convenient to disassemble and assemble and free of influence on the driving performance and the driving feeling of an original vehicle compared with other braking safety auxiliary devices, adopts the non-Newtonian fluid as an internal working medium, belongs to a novel material, is not applied to large-scale industrialization at present, is low in price, various in formula and wide in applicability, has high application value, does not pollute the environment, is easy to degrade, does not consume energy during working, and does not need energy input. From the perspective of preventing the wrong driving behavior, the design can not only radically reduce the traffic accident rate caused by mistakenly stepping on the accelerator, but also help the driver to develop good driving habits and correct the wrong behavior, which is realized in the design of all previous similar devices and cannot be realized, so that the design has extremely high innovation and practicability. Therefore, the auxiliary device for preventing the accelerator from being stepped on by mistake has the advantages of reliable function, simple structure, simple installation, low manufacturing cost and the like, initiatively adopts energy-saving and environment-friendly non-Newtonian fluid and a control system taking a high-speed single chip microcomputer as a core, can realize quick response under emergency conditions, prevent a driver from stepping on the accelerator pedal by mistake due to tension, quickly perform auxiliary control on braking, body stability and the like of a vehicle, greatly improve the driving safety coefficient, reduce the device cost of the same type design and be very beneficial to large-scale popularization and application.

Drawings

FIG. 1 is a sectional view of an accelerator mis-stepping prevention braking assisting device according to an embodiment of the present invention;

fig. 2 is a perspective view of the accelerator mis-stepping prevention braking auxiliary device according to the embodiment of the invention.

In the figure, 1: an accelerator pedal; 2: a flexible top plate; 3: a flexible protective layer; 4: a base plate; 5: a non-Newtonian fluid; 6: a perforated partition plate; 7: a rigid side panel.

Detailed Description

The embodiments of the present invention will be described in further detail with reference to the drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

As shown in fig. 1 and 2, the accelerator mis-stepping prevention brake assisting device of the present embodiment includes: the automobile accelerator pedal comprises a base, a flexible top plate 2 and non-Newtonian fluid 5, wherein the base is a shell with an upper opening, the flexible top plate 2 is connected to the upper opening of the base in a sealing mode and surrounds the base to form a closed cavity, the flexible top plate 2 is made of flexible materials and is used for being in contact fit with the lower side of an automobile accelerator pedal 1, and the non-Newtonian fluid 5 is filled in the closed cavity.

The base includes a bottom plate 4 and two rigidity curb plates 7, the appearance of bottom plate 4 is corresponding with the appearance on vehicle accelerator below floor, 4 laminating bottom of the car body curves of bottom plate can improve device overall stability, can be according to the vehicle body curve laminating vehicle bottom of different motorcycle types, the lower level of two rigidity curb plates 7 respectively with bottom plate 4 about both sides sealing connection, rigidity curb plate 7 is made by rigid material, two rigidity curb plates 7 are parallel to each other and equal perpendicular to bottom plate 4, flexible roof 2 is the bellied cambered surface structure that makes progress, airtight cavity is whole to be the rectangular shape cavity that corresponds with vehicle accelerator pedal 1. The upper surface of the flexible top plate 2 is tangent to the contact surface of the accelerator pedal 1 in a non-working state and is used for protecting the non-Newtonian fluid 5 in the device from flowing out due to extrusion of an external force. In addition, in the normal process of stepping on the accelerator pedal 1, the flexible top plate 3 can deform along with the force applied by the accelerator pedal 1, and the normal work of the accelerator pedal 1 cannot be influenced.

The non-Newtonian fluid 5 may be one or more of corn starch, tapioca starch, sweet potato starch and potato starch mixed with water. A pigment may be added to the non-newtonian fluid 5. The non-newtonian fluid 5 is doped with a dye so that once the cavity is punctured causing the non-newtonian fluid 5 to flow out, one will quickly detect the failure and thus quickly stop using the broken device for replacement. In the non-operating state, the non-Newtonian fluid 5 typically occupies between 89% and 92%, such as 90%, of the internal volume of the closed chamber. And the cavity is extruded in the normal stepping process of the accelerator pedal 1, so that the occupied space of the non-Newtonian fluid 5 is increased, the occupied space of the non-Newtonian fluid occupies 96% of the internal space, and the good working environment of the non-Newtonian fluid 5 is ensured.

The inner wall of the closed cavity is provided with a flexible protective layer 3, and the non-Newtonian fluid 5 is arranged in the flexible protective layer 3. The flexible protective layer 3 is used for protecting the non-Newtonian fluid from flowing out, the temperature in the cavity can be kept from being changed too much, so that the property of the non-Newtonian fluid 5 in the cavity is changed, and the rubber surface is flexible and cannot influence the normal stepping of the accelerator pedal.

A plurality of layers of perforated partition boards 6 which are parallel to each other are arranged in the closed cavity. All be equipped with a plurality of round holes on foraminiferous baffle 6, and each round hole disalignment on two adjacent foraminiferous baffles 6. The perforated partition boards 6 are arranged in parallel, a plurality of circular holes with proper sizes are formed in the perforated partition boards 6, and the holes in the two adjacent partition boards are not coaxial, namely, the projection of the holes in the two side boards on any partition board is not coincident with the holes. Through setting up foraminiferous baffle 6, non-Newtonian fluid 5 in the intracavity can enough normally flow under the extrusion of accelerator pedal 1 normal operation, also can be when accelerator pedal 1 is stepped on by mistake, provide sufficient rigidity power to non-Newtonian fluid 5 in the cavity, make it viscosity increase suddenly, the transition is the solid phase, prevent accelerator pedal by being stepped on, when the driver realizes that current pedal can't be by normal when being stepped on will realize oneself the accelerator pedal 1 of stepping on by mistake, and make timely reaction, fundamentally has prevented the accelerator and has stepped on the serious accident that causes by mistake.

The auxiliary device for preventing the accelerator from being stepped on by mistake in the embodiment further comprises a viscous sensor, wherein the viscous sensor is arranged in the closed cavity and used for detecting the viscosity coefficient of the non-Newtonian fluid 5. The vehicle safety system further comprises a data analysis module and an execution module, wherein the data analysis module is used for analyzing data collected by the viscous sensor and then sending out corresponding control signals, and the execution module is used for receiving the control signals sent by the single chip microcomputer and then starting the corresponding safety system of the vehicle.

The control system of the auxiliary device for preventing the accelerator from being stepped on by mistake in the embodiment can take a single chip microcomputer as a core and mainly comprises four modules of data acquisition, data analysis, execution, self-checking and emergency execution.

(1) A data acquisition module: and data acquisition and transmission are carried out through corresponding sensors.

A pressure sensor I: the grip of the driver on the steering wheel is large.

And a pressure sensor II: the rigid impact on the accelerator pedal is large.

A speed sensor: the magnitude of the angular velocity of the accelerator pedal.

An acceleration sensor: magnitude of angular acceleration of the accelerator pedal.

A viscous sensor: the viscosity coefficient of the non-Newtonian fluid in the device is controlled by the accelerator misstep.

(2) A data analysis module: and analyzing the data collected by the sensor, and sending out corresponding control and display signals.

A single chip microcomputer: and comparing the acquired information with a reference value, immediately transmitting a control signal to an execution mechanism once corresponding conditions are met, and displaying a comparison result of data on the LED I in real time.

(3) An execution module: after receiving the control signal transmitted by the singlechip, the ABS braking anti-lock system and the ESP vehicle body electronic stabilizing system are immediately started, and the anti-collision equipment such as an air bag and the like is started when necessary, so that the safety of drivers and passengers is protected.

(4) Self-checking and emergency processing module: and the system is responsible for self-checking of software and hardware during startup, alarming faults and automatic processing.

Self-checking: before starting up, the states and corresponding parameters of each sensor, the single chip microcomputer and the execution module are firstly checked, a group of analog data is automatically input by the single chip microcomputer to check whether the system works normally, and the corresponding system state parameters are displayed on the LED II.

Emergency treatment: once the fault of the single chip microcomputer occurs during the running process, the microcomputer starts a standby circuit to directly communicate the sensor and the actuator as a redundant setting.

A voice prompt module can be added to provide voice prompt under the condition of mistaken stepping.

The non-Newtonian fluid is a fluid which does not satisfy the Newtonian viscosity experiment law, namely the fluid of which the shear stress and the shear strain rate are not in a linear relation, such as petroleum, slurry, coal water slurry, ceramic slurry, paper pulp, paint, printing ink, toothpaste, silk regeneration solution and the like. The impact force is applied to the non-Newtonian fluid, the short and instant impact force can enable the viscosity of the non-Newtonian fluid to be greatly improved at the moment of stress, even to be solid, and the non-Newtonian fluid can continuously keep flowing under the continuous and soft acting force. The non-Newtonian fluid adopts a rheological property material of which the internal viscosity is enhanced along with the increase of the shearing rate, and in consideration of the acquisition simplicity and the cost of the material, the main material of the non-Newtonian fluid in the auxiliary device for preventing the accelerator from being stepped on by the mistake is obtained by mixing one or more of corn starch, cassava starch, sweet potato starch or potato starch with water. The non-Newtonian fluid comprises 50-100% of amylopectin by mass in the main material. A small amount of pigment may also be added to the non-Newtonian fluid material to ensure that the device can be discovered and replaced in a timely manner in the event of a failure. In this embodiment, the non-Newtonian fluid can change the critical value of the phase change of the non-Newtonian fluid by changing the material according to the habit of the driver, and is more suitable for the habit of the user

The accelerator mistaken-stepping-prevention braking auxiliary device is a semi-rigid closed container filled with non-Newtonian fluid, is additionally arranged below an accelerator pedal of a vehicle, and prevents the accelerator from being mistakenly stepped by utilizing the characteristic that the hardness of the non-Newtonian fluid suddenly rises under certain rigid pressure, so that the accident prevention effect is effectively achieved. In addition, the single chip microcomputer is additionally arranged, the viscosity of the non-Newtonian fluid and the angular acceleration of an accelerator pedal and the like are monitored in real time by using the corresponding sensors, once the viscosity exceeds a threshold value, a control signal is immediately sent to enable the brake system to work, an ABS (anti-lock braking system), an ESP (electronic stability program) vehicle body electronic stabilizing system and the like are started to actively stabilize the vehicle body, and an anti-collision device such as an air bag is started when necessary to protect the safety of drivers and passengers.

The working process of the accelerator mistaken-stepping prevention braking auxiliary device of the embodiment is as follows: in the normal running process of the vehicle, the non-Newtonian fluid in the closed cavity is soft due to the force and does not reach the critical value of the phase change of the non-Newtonian fluid continuously, the accelerator pedal can be normally stepped, the non-Newtonian fluid keeps the liquid property, and the partition plate is provided with holes, so that the non-Newtonian fluid can normally flow in the device. When a driver needs to step on a brake emergently to step on an accelerator mistakenly, the force of stepping on the accelerator pedal is large and quick, the non-Newtonian flow is subjected to the impact force and exceeds the critical value of the phase change of the non-Newtonian flow, the non-Newtonian flow is changed from a liquid state to a solid state, the purpose of preventing the accelerator pedal from being continuously stepped on is achieved by means of the constraint of the partition plate with the holes, after the driver finds that the accelerator pedal cannot be continuously stepped on, the driver realizes that the subsequent safety protection behaviors can be carried out by stepping on the accelerator pedal mistakenly, the accelerator pedal is continuously accelerated due to the fact that the accelerator pedal is not continuously stepped on, and the safety effect of protecting the driver is better achieved. The serious accident caused by mistaken stepping on the accelerator is fundamentally prevented.

The auxiliary device for preventing the accelerator from being stepped on by mistake can be connected with the original safety system of the automobile, a single chip microcomputer is used as a core to detect the viscosity of non-Newtonian fluid through a viscosity sensor arranged in the device, a pressure sensor and an acceleration sensor which are arranged on the surface of a pedal respectively detect the rigid impact force applied to the pedal and the angular acceleration of the pedal, the pressure sensor arranged on a steering wheel detects the grip force of the steering wheel, the data are analyzed and compared through the single chip microcomputer, once a critical condition is reached, a control signal is transmitted to the automobile safety system to start an ABS braking anti-lock system and an ESP automobile body electronic stabilizing system, an anti-collision device such as a safety airbag is started when necessary, and the safety of drivers and passengers is protected.

The concrete advantages also include: the non-Newtonian fluid has simple raw materials, the whole device has low cost, and once the device is produced in large scale, the price is lower, compared with the high price of the accelerator anti-misstep device in the existing market, the device is beneficial to large-scale popularization and has good market value; the device is externally attached to the existing vehicle, is convenient to assemble and disassemble, does not conflict with the original safety system of the vehicle, and is only improved on the basis of the original safety system of the vehicle; the inherent properties of the non-Newtonian fluid are utilized, the properties of the non-Newtonian fluid are not easy to change, the safety is good, and the service life is long; the possible consequence after the mistaken stepping behavior is prevented, but the mistaken stepping behavior is not allowed to continue from the source, so that the mistaken stepping behavior is prevented.

If the accelerator mistaken-stepping prevention braking auxiliary device is put into production and applied in loading, good driving habits of novice drivers can be promoted, the driving safety coefficient of the novice drivers can be improved, the drivers can be assisted to make correct emergency response to emergency situations met by the novice drivers, particularly for driving scholars who are prone to making mistakes, the driving behavior error rate can be greatly reduced, unnecessary accidents can be reduced and avoided, and even major life and property losses can be recovered. In addition, compared with other braking safety auxiliary devices of the same type, the braking safety auxiliary device is more energy-saving and environment-friendly, the single chip microcomputer is low in power and low in energy consumption, pure energy electric energy is adopted, the non-Newtonian fluid working medium does not need other energy sources for working, and the braking safety auxiliary device is pollution-free, easy to degrade and higher in environment friendliness. Therefore, the invention also has higher energy efficiency ratio and excellent environmental protection property.

In conclusion, the design has the advantages of safety, reliability, convenience, economy, environmental friendliness and the like, and can effectively prevent and correct the wrong behavior of mistakenly stepping on the accelerator by a driver from the source of accidents, so that the design has good practical value and market application prospect.

The embodiments of the present invention have been presented for purposes of illustration and description, and are not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. The auxiliary device for preventing the accelerator from being stepped on by mistake is characterized by comprising a base, a flexible top plate and non-Newtonian fluid, wherein the base is a shell with an opening at the upper part, the base comprises a bottom plate and two rigid side plates, the appearance of the bottom plate corresponds to the appearance of a floor below a vehicle accelerator, the lower edges of the two rigid side plates are respectively in sealing connection with the left side and the right side of the bottom plate, the rigid side plates are made of rigid materials, the two rigid side plates are parallel to each other and are perpendicular to the bottom plate, the flexible top plate is of an upward-protruding cambered surface structure, the flexible top plate is in sealing connection with the opening at the upper part of the base and encloses a closed cavity with the base, the flexible top plate is made of flexible materials and is used for being in contact fit with the lower side of the vehicle accelerator pedal, and the non-Newtonian fluid is filled in the closed cavity, the non-Newtonian fluid viscosity coefficient detection device is characterized in that a plurality of layers of mutually parallel perforated partition plates are arranged in the closed cavity, a plurality of round holes are formed in each perforated partition plate, each round hole in each two adjacent perforated partition plates is not coaxial, the non-Newtonian fluid viscosity coefficient detection device further comprises a viscous sensor arranged in the closed cavity and used for detecting the viscosity coefficient of the non-Newtonian fluid, the non-Newtonian fluid viscosity coefficient detection device further comprises a data analysis module and an execution module, the data analysis module is used for analyzing data collected by the viscous sensor and then sending out corresponding control signals, and the execution module is used for receiving control signals transmitted by a single chip microcomputer and then starting a corresponding safety system of a vehicle.

2. The auxiliary device for preventing accelerator from being stepped on by mistake is characterized in that the non-Newtonian fluid is prepared by mixing one or more of corn starch, cassava starch, sweet potato starch and potato starch with water.

3. The accelerator false-stepping brake assisting device according to claim 1, wherein a pigment is added to the non-newtonian fluid.

4. The auxiliary device for preventing accelerator from being stepped on by mistake as claimed in claim 1, wherein the non-Newtonian fluid occupies 89-92% of the inner space of the closed cavity in the non-working state.

5. The auxiliary device for preventing accelerator from being stepped on by mistake as claimed in claim 1, wherein a flexible protective layer is arranged on the inner wall of the closed cavity, and the non-Newtonian fluid is arranged in the flexible protective layer.