Composite self-sensing and self-regulating intelligent rubber material as well as preparation method and sensing and regulating method thereof

Abstract

The invention discloses a composite self-sensing and self-regulating intelligent rubber material as well as a preparation method and a sensing and regulating method thereof. The intelligent rubber material comprises a first component rubber layer and a second component rubber layer, the first component rubber layer is filled with a hard magnetic material, and a conductive material is added into the second component rubber layer. The intelligent rubber material is obtained by cutting a first component rubber layer and a second component rubber layer of a thin-passing sheet into a proper size, laminating, putting into a mold, vulcanizing and combining in a vulcanizing machine, and magnetizing. According to the prepared composite self-sensing and self-regulating intelligent rubber material, pressure and friction signals in the service process of the rubber material can be sensed and analyzed through the double-layer structural design, and then real-time regulation of friction force and pressure is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of rubber materials, and particularly relates to a composite self-sensing and self-regulating intelligent rubber material and a preparation method and sensing and regulating method thereof. BACKGROUND

[0002] Intelligent rubber materials have shown wide application prospects in the field of modern science and technology, especially in flexible electronic devices, intelligent sensors, bionic systems, and wearable devices. Magnetorheological rubber is a kind of intelligent material that can change its mechanical properties under the action of a magnetic field. By adjusting the strength of the applied magnetic field, magnetorheological rubber can real-time regulate its hardness and elastic modulus, thus having important application potential in vibration control, active damping, and precision driving systems. However, existing magnetorheological rubber materials mainly focus on the regulation of damping performance, and relatively little research has been done on the intelligent regulation of friction characteristics. Friction is a key factor affecting the performance of many mechanical systems, especially in high-precision motion control, flexible sensors, and adaptive surface technology, and accurate control of friction is crucial.

[0003] Rubber sealing elements have a large number of applications in reciprocating dynamic seals and rotary dynamic seals. In dynamic sealing, a layer of lubricating oil film is formed between the rubber and the metal friction pair. When the oil film thickness is too small, the friction between the rubber and the friction pair will be increased, accelerating the wear of the rubber. When the oil film thickness is too large, the sealing effect will be reduced, causing leakage. Therefore, ensuring the appropriate size of the oil film thickness has an important influence on the performance of the rubber sealing element, and appropriate oil film pressure can ensure the appropriate size of the oil film. Traditional rubber seals mainly provide positive pressure through interference fit and pre-tightening force of other workpieces to achieve sealing. However, during the long-term service of the equipment, the rubber material will inevitably age and relax, causing the pre-tightening force to gradually decrease. The decrease in pre-tightening force directly affects the sealing effect, especially under the action of friction and wear, the gap between the rubber and the friction pair will continuously increase, eventually leading to sealing failure, which may cause leakage accidents and safety hazards. In addition, traditional rubber can only achieve passive friction and cannot sense the pressure and friction signals during service. In production operations, this situation forces maintenance personnel to ensure the normal operation of the equipment only through regular maintenance and shutdown maintenance. However, this not only reduces the working efficiency of the equipment, but also significantly increases the maintenance cost.

[0004] In view of the above problems, the magnetorheological rubber material with intelligent control of friction provides a new idea for the improvement of the sealing system. Unlike traditional seals, this intelligent rubber material can real-time sense its working state and adjust the friction force as needed. SUMMARY

[0005] In order to solve the above problems, the application provides a composite self-sensing and self-regulating intelligent rubber material, a preparation method thereof and a sensing and regulating method, which solve the technical problems that the existing rubber material cannot sense and regulate pressure and friction signals in the service process.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the application is: In one aspect, the application provides a composite self-sensing and self-regulating intelligent rubber material, which comprises a first component rubber layer and a second component rubber layer bonded together by molding, the types and vulcanization systems of the rubbers in the first component rubber layer and the second component rubber layer are the same, but the components are different, the first component rubber layer is filled with hard magnetic material, and the second component rubber layer is added with conductive material, the intelligent rubber material can sense and analyze the pressure and friction signals in the service process of the rubber material through the double-layer structure design, and then realize real-time regulation of the friction and pressure.

[0007] Further, the hard magnetic material is one of ferrite permanent magnetic material, metal alloy permanent magnetic material and rare earth permanent magnetic material, and preferably neodymium iron boron magnetic powder; the conductive material is carbon nanotube.

[0008] Further, the thickness of the first component rubber layer is 1-1.5 mm, and the thickness of the second component rubber layer is 1.5-2 mm.

[0009] In another aspect, the application provides a preparation method of the composite self-sensing and self-regulating intelligent rubber material as described above, which comprises the following steps: S1: the hard magnetic material and the carbon nanotube are modified with a silane coupling agent respectively to enhance the bonding strength of the surfaces of the two materials and the rubber; S2: the contents of the component raw materials are as follows: raw rubber 100 parts, acid absorbent 5-10 parts, hard magnetic material 30-100 parts, carbon black 0-30 parts, and vulcanizing agent 5 parts, which are uniformly mixed by mixing on an open mill, and then the first component rubber layer is obtained by thin passing and sheeting; S3: the contents of the component raw materials are as follows: raw rubber 100 parts, acid absorbent 5-10 parts, carbon nanotube 3-9 parts, carbon black 0-30 parts, and vulcanizing agent 5 parts, which are uniformly mixed by mixing on an open mill, and then the second component rubber layer is obtained by thin passing and sheeting; S4: the mixing rubber sheets of the first component rubber layer and the second component rubber layer are cut to a suitable size, stacked and placed in a mold, and then vulcanized in a vulcanizing machine to combine the two component rubber layers to obtain vulcanized rubber; S5: the vulcanized rubber obtained in step S4 is placed in a magnetizing machine for magnetizing treatment to obtain a laminated magnetic and conductive integrated rubber material, i.e. the composite self-sensing and self-regulating intelligent rubber material.

[0010] Further, the step S1 is specifically: soaking and stirring the hard magnetic material and the carbon nanotube in a silane coupling agent solution for 10-20 min, and then drying in a vacuum drying oven at 75-85 DEG C for 1-2 h.

[0011] Further, in the steps S2 and S3, the raw rubber is binary fluororubber raw rubber FKM-26; the acid absorbent is Ca(OH)2 and MgO, which is used for neutralizing hydrogen fluoride (HF) generated in the vulcanization process, preventing rubber chain degradation and improving vulcanization efficiency; and the vulcanizing agent is bisphenol AF, which reacts with FKM segments to form an aromatic nucleophilic substitution reaction and a thermally stable crosslinking network. Further, 0.7-0.8 parts of an accelerator, benzyl triphenyl phosphonium chloride (BPP), is added to the components in the steps S2 and S3, which promotes rapid crosslinking of the bisphenol AF system, shortens the vulcanization time and improves the vulcanization density.

[0012] Further, the mixing temperature of the open mill in the steps S2 and S3 is 85-90 DEG C, and the mixing time is 10-15 min; in the step S4, the vulcanization process parameters are set as follows: the vulcanization temperature is 170-180 DEG C, the pressure in the mold is 10-20 MPa, the pressure maintaining time is 10-20 min, the exhaust frequency is twice, the mold is cooled by water cooling, and the cooling time is 2.5-5 min.

[0013] Further, the particle size of the hard magnetic material is 8-10 μm in diameter; and the length of the carbon nanotube is 18-20 μm, and the purity is 95%.

[0014] In a third aspect, the application further provides a sensing and regulating method for the composite self-sensing and self-regulating intelligent rubber material, which is implemented by a sensing and regulating device, the sensing and regulating device comprising an intelligent rubber material, an electromagnet, a metal friction pair, a positioning mechanism, an excitation power supply, a digital resistance meter and a PC control system, the electromagnet being connected with the excitation power supply and arranged outside a first component rubber layer of the intelligent rubber material, the intelligent rubber material being arranged in the positioning mechanism, the first component rubber layer outside being in interaction with the metal friction pair, the digital resistance meter being connected with a second component rubber layer of the intelligent rubber material through wires, and the excitation power supply and the digital resistance meter being connected with the PC control system through wires. The sensing and regulating method comprises the following processes: The first component rubber layer of the intelligent rubber material has magnetic sensitivity, and the friction force can be adjusted by an external magnetic field; the layer is connected to an electromagnet through an excitation power supply, and the external magnetic field generated by the electromagnet acts on the magnetic powder in the first component rubber layer, thereby realizing the regulation of the friction force and the oil film thickness. If the pressure is too large or too small, it indicates that the thickness of the oil film has a large deviation, and the current direction and the magnetic field strength of the electromagnet are adjusted through the PC terminal control system, thereby affecting the magnetic field attraction or repulsion effect of the upper layer of intelligent rubber, and then controlling the friction force and the oil film thickness between the intelligent rubber and the outer wall, thereby ensuring the effective sealing of the rubber element. The second component rubber layer of the intelligent rubber material is filled with carbon nanotubes to form a conductive network in the rubber. When the intelligent rubber material is subjected to pressure, the conductive network of the carbon nanotubes changes in resistance based on the piezoresistive effect. The digital resistance meter detects the change in resistance within the rubber to obtain real-time pressure change information. The PC control system senses the stress on the rubber based on the mapping relationship between the resistance and the pressure, and monitors and feeds back the stress, senses the pressure change based on the piezoresistive effect, and thus realizes the monitoring and intelligent regulation of the pressure of the rubber material in service.

[0015] In summary, the present application provides a composite self-sensing and self-regulating intelligent rubber material, which is a laminated sensing and regulating friction intelligent rubber material. The entire rubber material can be divided into a first component rubber layer and a second component rubber layer in a top and bottom structure, and the two layers are combined together through vulcanization molding. The first component rubber layer is filled with hard magnetic material (such as neodymium iron boron magnetic powder) and then magnetized. The second component rubber layer is filled with carbon nanotubes to form a conductive network in the rubber. The first component rubber layer can attract and repel magnetic fields after being magnetized. The second component rubber layer can form a conductive network and change in resistance based on the piezoelectric effect when subjected to pressure, thereby establishing a mapping relationship between pressure and resistance to sense the change in pressure experienced by the rubber sealing element during service. At the same time, the magnetized magnetorheological rubber is regulated by an external magnetic field, and the actual pressure detected by the sensing rubber is compared with the designed pressure of the seal. The repulsion or attraction of the magnetized rubber adjusts the pressure between the rubber and the sealing surface to the appropriate size. The composite self-sensing and self-regulating intelligent rubber material of the present application is used as a rubber sealing element. Through the monitoring and active regulation of the pressure of the rubber sealing element during service, the reliability of effective sealing is ensured, the service life of the rubber sealing element is prolonged, and the risk of accidental leakage is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The flowchart for preparing the composite self-sensing and self-regulating intelligent rubber material of the present application embodiment 1.

[0017] Figure 2 The schematic diagram of the device for sensing and regulating the composite self-sensing and self-regulating intelligent rubber material of the application.

[0018] Figure 3 The schematic diagram of the rubber piezoresistive effect working principle.

[0019] Figure 4 The mapping diagram of the rubber service pressure and resistance relationship.

[0020] Figure 5 The schematic diagram of the comparison of the rubber sample surface microstructure before and after applying a magnetic field. Figure 6 The comparison diagram of the extrusion stress and relative resistance relationship of the intelligent rubber material prepared by the layered composite preparation method of Example 1 and the mixing integrated preparation method of the comparative example.

[0021] Figure 7 The physical diagram of the rubber performance test after cutting. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the application clearer, the technical scheme of the application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of the application. Example 1

[0023] The preparation method of the composite self-sensing and self-regulating intelligent rubber material of the embodiment is as shown in Figure 1 Specifically as follows: Step 1: The neodymium iron boron magnetic powder and carbon nanotubes are respectively modified with silane coupling agent, and the neodymium iron boron magnetic powder and carbon nanotubes are respectively soaked and stirred in the silane coupling agent solution for 10 min, and then placed in a vacuum drying oven and dried at 75℃ for 1h to enhance the bonding strength of the surfaces of the two materials and the rubber. At the same time, it should be noted that the selected magnetic powder particles and the physical form of carbon nanotubes will affect the strength and elastic deformation capacity of the composite rubber, etc. When selecting the diameter of the magnetic powder particles and the length and purity of the carbon nanotubes, the mechanical properties of the rubber, the sensitivity of the electric resistance change and the controllability of the magnetic field force should be considered comprehensively. Here, the diameter of the neodymium iron boron magnetic powder particles is 8μm, and the length of the carbon nanotubes is 20μm, and the purity is 95%.

[0024] Step 2: The ingredient content of each component is as follows: 100 parts of raw binary fluorine rubber, 5 parts of each of acid absorbent Ca(OH)2 and MgO, 100 parts of neodymium-iron-boron magnetic powder, 5 parts of carbon black, and 5 parts of vulcanizing agent bisphenol AF are mixed on an open mill, wherein the mixing temperature is set to 85 DEG C, and after uniform mixing, the A component rubber is obtained by thinning and sheeting. In order to increase the strength and hardness of the rubber, carbon black is added. In order to prevent the rubber from scorching and premature vulcanization during mixing, the mixing time is reasonably controlled to be no more than 15 min, the mixing operation temperature is reduced, the storage environment is improved, the storage time is shortened, and an appropriate amount of anti-scorching accelerator is added to the rubber compound, and in this embodiment, 0.7 parts of accelerator BPP is recommended.

[0025] Step 3: The ingredient content of each component is as follows: 100 parts of raw binary fluorine rubber, 5 parts of each of acid absorbent Ca(OH)2 and MgO, 5 parts of carbon nanotubes, and 5 parts of vulcanizing agent bisphenol AF are mixed on an open mill, and after uniform mixing, the B component rubber is obtained by thinning and sheeting. In this step, 0.7 parts of anti-scorching accelerator is also added to the rubber compound.

[0026] Step 4: The mixed rubber sheets of the above A and B components are cut to an appropriate size, stacked in a mold, and placed in a vulcanizing machine, wherein the parameter settings of the vulcanizing machine are as follows: preheating time is 3 min, pre-pressing time is 2 s, vulcanizing time is 10 min, vulcanizing pressure is 50T, and exhaust frequency is 2 times. The two-component rubber is bonded together through vulcanization to form a layered composite multifunctional rubber.

[0027] Step 5: The vulcanized rubber is placed in a magnetizing machine for magnetizing treatment to obtain a layered magnetic and conductive integrated rubber material.

[0028] Please refer to Figure 2 The application also provides a method for sensing the service pressure of a rubber element and regulating rubber friction, which is performed by a set of sensing and regulating devices.

[0029] The device mainly comprises intelligent rubber material, electromagnets, metal friction pairs, positioning mechanisms, excitation power sources, digital resistance meters, and a PC control system. The device realizes intelligent regulation and real-time monitoring of friction through the combined action of the piezoresistive effect of the intelligent rubber and the external electromagnetic field.

[0030] Firstly, the intelligent rubber is composed of two layers, and the lower layer is filled with carbon nanotubes to form a conductive network in the rubber. When the intelligent rubber is subjected to pressure, the conductive network of the carbon nanotubes changes in resistance based on the piezoresistive effect. The digital resistance meter detects the resistance change in the rubber to obtain real-time pressure change information. The PC control system senses the stress condition of the rubber according to the mapping relationship between the resistance and the pressure, and monitors and feeds back the stress condition. The relevant principle diagram is as shown in Figure 3 andFigure 4 As shown. Figure 3 When a composite material is subjected to tensile force, its electrical resistance shows a continuous upward trend. For example... Figure 4 The fluororubber filled with carbon nanotubes forms a three-dimensional conductive network composed of carbon nanotubes. Due to the inherent resistance of the carbon nanotubes and the contact resistance between them, the composite material has a certain initial resistance. When an external tensile force is applied, the distance between the carbon nanotubes increases, and the contact between some nanotubes decreases, causing the current path to become discontinuous or broken, thus increasing the resistance. When an external pressure is applied, the carbon nanotubes are compressed, increasing the contact area between them and forming more conductive pathways. The current conductivity increases, and the resistance decreases, manifested as a decrease in resistance. Therefore, with changes in external force, the composite material will produce corresponding strain, and the resistance value will change accordingly, thus enabling pressure monitoring.

[0031] The upper layer of intelligent rubber is composed of fluororubber filled with neodymium iron boron magnetic powder. This layer is connected to an electromagnet via an excitation power supply. The external magnetic field generated by the electromagnet acts on the magnetic powder in the upper layer of rubber, thereby controlling the friction and oil film thickness. Excessive or insufficient pressure indicates a significant deviation in the oil film thickness. Here, pressure refers to the sealing pressure of the sealing ring, which directly affects the thickness of the dynamic pressure oil film formed between the sealing ring surface and the mating surface. The optimal oil film thickness is 1-3 μm, providing both lubrication and sealing. An excessively thick oil film can lead to fluid leakage; an excessively thin film will fail to provide effective lubrication, resulting in lip wear. The current direction and magnetic field strength of the electromagnet are adjusted via a PC-based control system, influencing the magnetic attraction or repulsion effect of the upper intelligent rubber layer, thus controlling the friction and oil film thickness between the intelligent rubber and the outer wall, ensuring effective sealing of the rubber component. Furthermore, applying a magnetic field can also adjust the microstructure of the sealing ring surface, such as… Figure 5 As shown, the maximum profile height S of the rubber sample surface after applying a magnetic field of 400 mT is... z and surface arithmetic height S a All of these are reduced. Under the influence of a magnetic field, the surface profile of magnetorheological rubber will move slightly along the direction of the magnetic field. The surface profile has an overall downward trend and weakens the higher micro-protrusions, forming a filling effect. This leads to a decrease in the surface roughness of the rubber, reduces the temperature rise caused by friction, improves the wear resistance of the rubber material, and extends the service life of the rubber seal.

[0032] It can be seen that the upper layer of the composite rubber material has magnetic sensitivity characteristics, and the friction force can be adjusted by an external magnetic field; the lower layer of rubber forms a conductive network, which senses pressure changes based on the piezoresistive effect, thereby achieving intelligent regulation of the service state of the rubber material. This process not only improves the bonding strength of the rubber and functional fillers, but also achieves friction regulation and pressure sensing through a layered structure, making it suitable for seals or dynamic friction pairs that require high performance, wear resistance, and long service life. Example 2

[0033] The preparation method of the composite self-sensing and self-regulating intelligent rubber material in this embodiment is as follows: first, the neodymium iron boron magnetic powder and carbon nanotubes are modified by silane coupling agent to enhance the bonding force with the rubber matrix. The neodymium iron boron magnetic powder and carbon nanotubes are immersed in the coupling agent solution and stirred for 10 minutes, then dried in a vacuum drying oven at 75°C for 1 hour. The physical properties of these substances, including the diameter of the neodymium iron boron particles and the length and purity of the carbon nanotubes, all have an impact on the strength, elasticity, and electrical conductivity of the composite material. In this embodiment, neodymium iron boron powder with a diameter of 8 μm and carbon nanotubes with a length of 20 μm and a purity of 95% are selected. The mechanical properties, magnetic field response, and electrical conductivity sensitivity of the material all need to be considered comprehensively. The raw materials are added to the mixer in proportion, where the A component includes 100 parts of raw fluorine rubber, 5 parts of acid absorbent Ca(OH)2 and MgO each, 100 parts of neodymium iron boron magnetic powder, 6 parts of carbon black, and 5 parts of vulcanizing agent bisphenol AF, with a mixing temperature of 85°C. To avoid premature vulcanization, the mixing time should not exceed 15 minutes, and 0.8 parts of accelerator BPP are added to prevent scorching. After uniform mixing, the rubber is sheeted by thin passage method. The B component is 100 parts of raw fluorine rubber, 5 parts of acid absorbent Ca(OH)2 and MgO each, 3 parts of carbon black, 4 parts of carbon nanotubes, 5 parts of vulcanizing agent bisphenol AF, and 0.8 parts of accelerator BPP, which are also mixed and sheeted. The A and B sheets are stacked and vulcanized in a vulcanizing machine, with the parameters set as preheating time 3 minutes, pre-pressing time 2 seconds, vulcanization time 10 minutes, vulcanization pressure 50 tons, and exhaust twice, finally forming a layered composite rubber. After vulcanization, the material is magnetized to obtain a composite rubber with magnetic sensitivity and electrical conductivity. This method of processing and preparing intelligent rubber has significant advantages. First, by modifying the neodymium iron boron magnetic powder and carbon nanotubes, the bonding force between the fillers and the rubber matrix is enhanced, significantly improving the mechanical properties of the material. Second, the layered structure design achieves the multifunctionality of the material, with the upper layer of magnetic sensitive rubber adjusting the friction force according to the external magnetic field, and the lower layer of conductive network achieving precise pressure monitoring. This intelligent regulation capability greatly extends the service life of the material and enhances the wear resistance of the seal, making it suitable for high-performance applications and having wide industrial prospects. Comparative Example

[0034] To better demonstrate the advantages of the layered composite structure of the present application, two different structures of composite materials are compared in the comparative example. In the comparative example, neodymium iron boron magnetic powder and carbon nanotubes are first modified by silane coupling agent respectively. The specific method is to immerse the neodymium iron boron magnetic powder with a diameter of 8 μm and the carbon nanotubes with a length of 20 μm and a purity of 95% into the coupling agent solution respectively, stir for 10 minutes, and then dry in a vacuum drying oven at 75°C for 2 hours. The treated magnetic powder and carbon nanotubes are not treated separately, but are directly mixed and filled into the rubber matrix as the same component. Then, the rubber compound is prepared using the following formulation: 100 parts of raw rubber of binary fluorine rubber, 5 parts of acid absorbent Ca(OH) 2, 10 parts of acid absorbent MgO, 100 parts of modified neodymium iron boron magnetic powder, 4 parts of modified carbon nanotubes, 6 parts of carbon black, 5 parts of vulcanizing agent bisphenol AF, and 0.8 parts of accelerator BPP. All the ingredients are mixed at 85°C for 15 minutes, and processed into rubber sheet by thin pass method. Finally, the sheet is vulcanized in a flat vulcanizing machine, and the vulcanization temperature and pressure are controlled as follows: preheating for 3 minutes, pre-pressing for 2 seconds, vulcanizing for 10 minutes, and vulcanization pressure of 50 tons.

[0035] The layered composite structure is adopted in the present application to overcome the problem of strength reduction of the matrix caused by mixing neodymium iron boron magnetic powder and carbon nanotubes into the rubber matrix at the same time. In the mixed integrated structure, due to the variety of two fillers and the mutual interference of their distribution, stress concentration points are easily formed in the rubber matrix, which can cause crack propagation or overall failure during stress process. After adopting the layered composite structure, the component ratio of each layer of material is optimized, which can not only ensure the mechanical properties and interface bonding strength of each layer of rubber matrix, but also effectively prevent the occurrence of stress concentration phenomenon, thereby ensuring the mechanical property stability and reliability of the overall composite material. In addition, since the magnetic powder and the carbon nanotubes are arranged in different layers, their functions are independent and each performs its own function, which can avoid the performance degradation caused by uneven distribution or mutual obstruction in the same matrix, so that the magnetic response ability of the magnetic powder and the electrically conductive sensitivity of the carbon nanotubes can be maximized, further improving the functional efficiency and service life of the composite material.

[0036] As shown in Figure 6 , the conductive layer of the layered composite rubber is designed separately, and the carbon nanotubes form a more uniform conductive network in the rubber, which can respond more sensitively to external pressure changes. Compared with the mixed integrated rubber, the piezoresistive effect is more significant, which is suitable for high-precision pressure monitoring.

[0037] Figure 7 The physical map after cutting for performance test of the rubber of the present application is shown. The samples shown include dumbbell-shaped samples for mechanical tensile test ( Figure 7 , left figure in the middle), circular samples for compression test ( Figure 7 , middle figure in the middle), and long strip-shaped samples for electrical performance test ( Figure 7middle right graph).

[0038] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A composite self-sensing and self-regulating intelligent rubber material, characterized in that, The material comprises a first component rubber layer and a second component rubber layer bonded together by molding. The types of rubber and the vulcanization system in the first and second component rubber layers are the same. The first component rubber layer is filled with a hard magnetic material, and the second component rubber layer is filled with a conductive material. The smart rubber material, through its dual-layer structure design, can sense and analyze pressure and friction signals during service, thereby achieving real-time control of friction and pressure.

2. The composite self-sensing and self-regulating intelligent rubber material according to claim 1, characterized in that, The hard magnetic material is one of ferrite permanent magnet material, metal alloy permanent magnet material, and rare earth permanent magnet material, preferably neodymium iron boron magnetic powder; the conductive material is carbon nanotube.

3. The composite self-sensing and self-regulating intelligent rubber material according to claim 2, characterized in that, The thickness of the first component rubber layer is 1-1.5 mm; the thickness of the second component rubber layer is 1.5-2 mm.

4. The preparation method of the composite self-sensing and self-regulating intelligent rubber material as described in any one of claims 2-3, characterized in that, Includes the following steps: S1: Hard magnetic materials and carbon nanotubes are modified with silane coupling agents to enhance the bonding strength between the surfaces of the two materials and rubber. S2: Mix the raw materials of each component in the following proportions: 100 parts raw rubber, 5-10 parts acid absorber, 30-100 parts hard magnetic material, 0-30 parts carbon black, and 5 parts vulcanizing agent on a two-roll mill until they are evenly mixed, and then sheet them out in thin sheets to obtain the first component rubber layer. S3: Mix the raw materials of each component according to the following proportions: 100 parts raw rubber, 5-10 parts acid absorber, 3-9 parts carbon nanotubes, 0-30 parts carbon black, and 5 parts vulcanizing agent on a two-roll mill until they are evenly mixed, and then sheet them out to obtain the second component rubber layer. S4: Cut the mixed rubber sheets of the first and second component rubber layers to a suitable size, stack them in a mold, and vulcanize them in a vulcanizing machine to combine the two component rubber layers together to obtain vulcanized rubber. S5: The vulcanized rubber obtained in step S4 is placed into a magnetizer for magnetization treatment to obtain a layered magnetically sensitive and conductive integrated rubber material, that is, the composite self-sensing and self-regulating intelligent rubber material.

5. The method for preparing a composite self-sensing and self-regulating intelligent rubber material according to claim 4, characterized in that, Step S1 specifically involves immersing and stirring the hard magnetic material and carbon nanotubes in a silane coupling agent solution for 10-20 minutes, and then drying them in a vacuum drying oven at 75-85°C for 1-2 hours.

6. The method for preparing a composite self-sensing and self-regulating intelligent rubber material according to claim 4, characterized in that, In steps S2 and S3, the raw rubber is binary fluororubber raw rubber FKM-26; the acid absorber is Ca(OH)2 and MgO; and the vulcanizing agent is bisphenol AF.

7. The method for preparing a composite self-sensing and self-regulating intelligent rubber material according to claim 6, characterized in that, In steps S2 and S3, 0.7-0.8 parts of an accelerator, namely benzyltriphenylphosphine chloride (BPP), are also added to the components.

8. The method for preparing a composite self-sensing and self-regulating intelligent rubber material according to claim 4, characterized in that, In steps S2 and S3, the mixing temperature of the open mill is 85-90℃ and the mixing time is 10-15min. In step S4, the vulcanization process parameters are set as follows: vulcanization temperature is 170-180℃, mold pressure is 10-20MPa, holding time is 10-20min, venting is performed twice, and the mold is cooled by water for 2.5-5min.

9. The method for preparing a composite self-sensing and self-regulating intelligent rubber material according to claim 4, characterized in that, The hard magnetic material has a particle size of 8-10 μm in diameter; the carbon nanotubes have a length of 18-20 μm and a purity of 95%.

10. The sensing and control method for the composite self-sensing and self-regulating intelligent rubber material as described in any one of claims 2-3, characterized in that, This is implemented through a sensing and control device, which includes a smart rubber material, an electromagnet, a metal friction pair, a positioning mechanism, an excitation power supply, a digital resistor, and a PC control system. The electromagnet is connected to the excitation power supply and is disposed on the outside of the first component rubber layer of the smart rubber material. The smart rubber material is disposed in the positioning mechanism. The outer first component rubber layer interacts with the metal friction pair. The digital resistor is connected to the second component rubber layer of the smart rubber material via a wire. Both the excitation power supply and the digital resistor are connected to the PC control system via wires. The sensing and control method includes the following processes: The first component rubber layer of the intelligent rubber material possesses magnetic sensitivity, allowing for adjustment of friction through an external magnetic field. This layer is connected to an electromagnet via an excitation power supply. The external magnetic field generated by the electromagnet acts on the magnetic powder in the first component rubber layer, thereby controlling the friction and oil film thickness. If the pressure is too high or too low, it indicates a significant deviation in the oil film thickness. The current direction and magnetic field strength of the electromagnet are adjusted via a PC-based control system, influencing the magnetic attraction or repulsion effect of the upper intelligent rubber layer. This, in turn, controls the friction and oil film thickness between the intelligent rubber and the outer wall, ensuring effective sealing of the rubber component. The second component of the smart rubber material, the rubber layer, is filled with carbon nanotubes, forming a conductive network within the rubber. When the smart rubber material is subjected to pressure, the conductive network of carbon nanotubes undergoes a change in resistance based on the piezoresistive effect. A digital resistance meter detects this change in resistance within the rubber to obtain pressure change information in real time. The PC control system senses the stress on the rubber based on the mapping relationship between resistance and pressure, and monitors and provides feedback on it. By sensing pressure changes based on the piezoresistive effect, the system achieves monitoring and intelligent control of the pressure under service conditions of the rubber material.

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