Triboelectric hemispherical composite film pressure sensing device and control method thereof

Abstract

The application relates to the technical field of fluid pressure sensing, in particular to a triboelectric hemispherical composite film pressure sensing device and a control method thereof. The device comprises a shell, a top gland and a sensing unit in the shell. The sensing unit comprises, from bottom to top, an insulating cover plate, a composite film, an insulating ring cover, a transmission buffer block, a ring-shaped end cover and a hemispherical composite film. The composite film directly contacts hydraulic oil, is deformed under pressure and generates a first electric signal in cooperation with the copper foil on the lower side of the transmission buffer block. When the pressure increases, the transmission buffer block is pushed upwards, so that the upper side of the spherical copper foil cooperates with the hemispherical composite film to generate a second electric signal. The application realizes self-power supply by using the triboelectric nanogenerator principle, realizes wide-range monitoring through a double-layer sensing structure, cooperates with the spherical contact design and a multiple sealing structure, and has the advantages of high sensitivity, good sealing performance, adaptation to complex hydraulic working conditions and the like.

Description

Technical Field

[0001] This invention relates to the field of fluid pressure sensing technology, and in particular to a triboelectric hemispherical composite thin film pressure sensing device and its control method. Background Technology

[0002] Hydraulic systems are widely used in industrial machinery, construction machinery, aerospace, and other fields. Real-time monitoring of their pressure parameters is crucial to ensuring the safe and stable operation of the system. Current industry monitoring solutions suffer from several problems, such as reliance on external power sources and additional wiring. In scenarios involving mobile hydraulic equipment or enclosed cavities, the wiring is complex and prone to damage due to vibration and aging, leading to inconvenience in installation and maintenance, as well as the risk of signal interference. Furthermore, hydraulic systems often experience complex operating conditions such as pressure pulsation and high-pressure impacts, making the sensitive elements of traditional sensors susceptible to wear or fatigue damage, resulting in decreased monitoring accuracy and shortened lifespan.

[0003] Triboelectric nanogenerator technology offers a solution for self-powered systems, but current products have yet to overcome industrialization bottlenecks. Based on the principles of triboelectric generation and electrostatic induction, triboelectric nanogenerator technology can directly convert mechanical energy into electrical energy. It boasts advantages such as simple structure, low cost, and strong self-powering capability, providing a new approach to solving the power supply problem of traditional sensors. However, existing triboelectric nanogenerator-based sensors generally suffer from poor compatibility with hydraulic oil, low signal transmission efficiency, and insufficient structural sealing when used in hydraulic environments, making them unsuitable for the high-pressure, high-pulsation conditions of hydraulic systems.

[0004] To address the aforementioned pain points, this invention proposes a self-powered hydraulic pressure sensor based on triboelectric nanogenerators through structural innovation and material optimization. This solves the problems of power supply dependence and operating condition adaptability of traditional sensors, and makes up for the shortcomings of existing triboelectric sensors in terms of compatibility, signal efficiency, and integration, thereby achieving efficient and stable monitoring of hydraulic pressure. Summary of the Invention

[0005] To address the core problems of existing hydraulic pressure sensors and triboelectric sensors in industrial applications, such as power supply dependence, poor sealing, low signal acquisition efficiency, and insufficient adaptability to operating conditions, this invention provides a triboelectric hemispherical composite thin film pressure sensing device and its control method.

[0006] To achieve the above objectives, the present invention provides a triboelectric hemispherical composite thin film pressure sensing device for use in a hydraulic system, comprising: a housing having an inner cavity inside and a liquid flow channel communicating with the inner cavity at the bottom; a top cover installed at the top opening of the housing; and a sensing unit disposed within the inner cavity of the housing and axially pressed by the top cover.

[0007] The sensing unit includes an insulating cover plate, a composite film, an insulating ring cover, a transmission buffer block, an annular end cover, and a hemispherical composite film arranged sequentially from bottom to top along the axial direction.

[0008] The insulating cover plate and the insulating ring cover cooperate to clamp the edge of the composite film, and the lower surface of the composite film faces the liquid flow channel;

[0009] The transfer buffer block is movably disposed in the inner cavity of the insulating ring cover. The lower surface of the transfer buffer block is provided with a lower copper foil, and the upper surface is provided with an upper spherical copper foil.

[0010] The annular end cap and the insulating annular end cap cooperate to clamp the edge of the hemispherical composite film, and the hemispherical composite film is located above the transfer buffer block;

[0011] The composite film is configured to deform under liquid pressure and rub against the lower copper foil to generate a first electrical signal; the transmission buffer block is configured to move upward under the deformation of the composite film, so that the upper spherical copper foil rubs against the hemispherical composite film to generate a second electrical signal.

[0012] Furthermore, the lower surface of the insulating cover is provided with an annular groove for accommodating an O-ring, and the O-ring abuts against the bottom wall of the inner cavity of the outer shell.

[0013] Furthermore, the insulating ring cover has a first wiring groove on its side wall, the transmission buffer block has a second wiring groove on its side wall, and the annular end cover has a third wiring groove on its side wall; the first wiring groove, the second wiring groove, and the third wiring groove are interconnected to form a wire channel; the top cover has a through wiring hole, which is connected to the wire channel to lead out the wire.

[0014] Furthermore, the composite film has a three-layer structure, including a lower polydimethylsiloxane film, a middle conductive ink layer, and an upper polydimethylsiloxane film; the hemispherical composite film has a three-layer structure, including a lower hemispherical polydimethylsiloxane film, a middle conductive ink layer, and an upper hemispherical polydimethylsiloxane film.

[0015] Furthermore, the upper surface of the transfer buffer block is a convex spherical surface, and the bottom inner side of the annular end cap is provided with a concave spherical surface. The curvature of the convex spherical surface of the transfer buffer block is adapted to the curvature of the hemispherical composite film and the inner spherical surface of the top cover.

[0016] The present invention also provides a control method for the above-mentioned device, comprising: according to the liquid pressure entering the liquid channel, causing the composite film in the first layer pressure sensing part to contact the lower copper foil to generate a first electrical signal; when the pressure increases and pushes the transmission buffer block to move, causing the upper spherical copper foil in the second layer pressure sensing part to contact the hemispherical composite film to generate a second electrical signal; and a signal processor determining the current liquid pressure according to the changes in the first and second electrical signals.

[0017] The beneficial effects of this invention are:

[0018] Employing a dual-layer sensing structure, the bottom composite diaphragm operates under low pressure, while the top hemispherical diaphragm works in conjunction with the bottom composite diaphragm via a transmission buffer block under high pressure. This not only achieves self-powered monitoring without an external power source but also significantly expands the pressure monitoring range. A multi-layer sealing structure is formed through the threaded connection at the bottom of the housing, the internal O-ring seal, and the threaded encapsulation of the top cap, effectively preventing high-pressure hydraulic oil leakage. The composite diaphragm directly contacts the hydraulic oil, enabling rapid response to pressure pulsations; the spherical design increases the effective contact area, improving signal output strength and stability. The interconnected wiring channels on each component solve the internal wiring problem, resulting in a smaller sensor size and easier integration. Attached Figure Description

[0019] Figure 1 This is an exploded structural diagram of the hydraulic pressure sensing device of the present invention;

[0020] Figure 2 This is a cross-sectional structural diagram of the sensing unit of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the insulating cover plate of the present invention;

[0022] Figure 4 This is a schematic diagram of the transfer buffer block of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of the annular end cap of the present invention;

[0024] Figure 6 This is a schematic diagram of the layered structure of the composite film of the present invention;

[0025] Figure 7 This is a schematic diagram of the layered structure of the hemispherical composite film of the present invention;

[0026] Figure 8 This is a cross-sectional structural diagram of the outer casing of the present invention;

[0027] Figure 9 This is a schematic cross-sectional view of the top cap of the present invention;

[0028] Figure 10 This is a schematic diagram illustrating the working principle of the sensing device of the present invention;

[0029] Figure 11 This is a flowchart illustrating the control method for the sensing device of the present invention.

[0030] In the picture,

[0031] 1-Sensing unit; 11-O-ring seal; 12-Insulating cover plate; 121-Annular groove; 13-Composite film; 131-Lower polydimethylsiloxane film; 132-First intermediate conductive ink layer; 133-Upper polydimethylsiloxane film; 14-Insulating ring cover; 141-First wiring groove; 15-Transfer buffer block; 151-Second wiring groove; 152-Lower copper foil; 153-Upper spherical copper foil; 16-Annular end cap; 161-Third wiring groove; 162-Screw countersunk hole; 163-Concave spherical surface; 17-Hemispherical composite film; 171-Lower hemispherical polydimethylsiloxane film; 172-Second intermediate conductive ink layer; 173-Upper hemispherical polydimethylsiloxane film;

[0032] 2-Outer shell; 21-Inner cavity of outer shell; 22-External thread; 23-Liquid flow channel;

[0033] 3-Top cap; 31-External hexagonal post; 32-Cable routing hole. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0036] Figures 1-11 This is a specific embodiment of the present invention, which is a triboelectric hemispherical composite thin film pressure sensing device and its control method.

[0037] like Figure 1 As shown, the present invention provides a triboelectric hemispherical composite thin film pressure sensing device for use in hydraulic systems, which mainly consists of a sensing unit 1, a housing 2 and a top cover 3.

[0038] Outer shell 2 (e.g.) Figure 8 (As shown) is made of 316 stainless steel, with external threads 22 at the bottom for connection to the hydraulic valve body, and a liquid flow channel 23 in the center. The inner cavity 21 of the outer shell has internal threads for connection to the top cover 3. The top cover 3 (as shown) Figure 9 As shown, the upper part has an external hexagonal post 31 for easy installation, and a wiring hole 32 in the center. Its inner side is designed as a spherical surface for pressing and fitting internal components.

[0039] Sensing unit 1 is placed in the inner cavity 21 of the outer casing, and its specific structural hierarchy is as follows:

[0040] The bottom layer is an insulating cover plate 12 (such as...) Figure 3 As shown), its lower surface has an annular groove 121, in which an O-ring 11 (e.g., made of fluororubber) is embedded to achieve a static seal with the bottom of the housing. Above the insulating cover 12 is a composite film 13. (As shown...) Figure 6 As shown, the composite film 13 has a three-layer structure: a lower polydimethylsiloxane film 131, a first intermediate conductive ink layer 132, and an upper polydimethylsiloxane film 133. The lower polydimethylsiloxane film 131 faces the liquid flow channel 23 and directly bears the liquid pressure. The edges of the composite film 13 are pressed together by an insulating cover plate 12 and an upper insulating ring cover 14.

[0041] The insulating ring cover 14 contains a transfer buffer block 15 (such as...) Figure 4 (As shown). The transfer buffer block 15 can be made of polytetrafluoroethylene (PTFE) material, with a lower copper foil 152 attached to its lower surface and an upper spherical copper foil 153 attached to its upper surface.

[0042] To facilitate internal wiring, the side wall of the insulating ring cover 14 is provided with a first wiring groove 141, the side wall of the transfer buffer block 15 is provided with a second wiring groove 151, and the side wall of the annular end cover 16 is provided with a third wiring groove 161. These three wiring grooves are interconnected after assembly to form a complete wire channel for guiding the wires of the internal electrodes to the wiring hole 32 of the top cover 3.

[0043] Above the buffer block 15 is a hemispherical composite film 17. For example... Figure 7 As shown, it also has a three-layer structure, including a lower hemispherical polydimethylsiloxane film 171, a second intermediate conductive ink layer 172, and an upper hemispherical polydimethylsiloxane film 173. The shape of the lower hemispherical polydimethylsiloxane film 171 is adapted to the spherical shape of the top of the transfer buffer block 15.

[0044] The topmost part is the annular end cap 16 (e.g.) Figure 5 As shown), it has a concave spherical surface 163 for pressing the edge of the hemispherical composite film 17, and fixes each layer of the entire sensing unit by screws passing through the countersunk screw holes 162.

[0045] like Figure 10 As shown, this device operates using the principle of triboelectric nanogenerators.

[0046] When hydraulic oil enters through the liquid flow channel 23, the pressure acts on the lower surface of the composite film 13, causing it to deform upward.

[0047] Phase 1 (Low-pressure monitoring): The composite film 13 deforms, and its upper polydimethylsiloxane film 133 comes into contact with and separates from the lower copper foil 152 at the bottom of the transfer buffer block 15, generating a first triboelectric signal. This signal is led out through a wire to reflect the pressure change in the low-pressure section.

[0048] Second stage (high-pressure monitoring): As the pressure increases, the deformation of the composite film 13 increases, and the mechanical thrust pushes the entire transmission buffer block 15 upward within the insulating ring cover 14. At this time, the upper spherical copper foil 153 on the top of the transmission buffer block 15 comes into close contact with the lower hemispherical polydimethylsiloxane film 171 of the hemispherical composite film 17. Since both are spherical in design and supported by the spherical top cover 3, the contact area is large and uniform, generating a second triboelectric signal.

[0049] Control methods such as Figure 11 As shown:

[0050] 1. Signal acquisition: The first and second electrical signals are acquired separately or in combination through the wires led out through the wiring hole 32.

[0051] 2. Signal Processing: The signal processor receives electrical signals. When the pressure is low, it mainly judges the pressure based on the signal amplitude and frequency of the first-layer sensing part; when the pressure is high and triggers the second-layer sensing part, it combines the two sets of signals for comprehensive analysis.

[0052] 3. Fault diagnosis: The system can extract features such as waveform distortion rate of electrical signals and compare them with preset thresholds to determine whether there are faults such as leakage, wear or seal failure in the hydraulic system, and then feed back to control the hydraulic valve body.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A triboelectric hemispherical composite thin film pressure sensing device, comprising a housing (2), a sensing unit (1), and a top cover (3), characterized in that: The outer shell (2) has an inner cavity (21) inside, and a liquid flow channel (23) communicating with the inner cavity (21) is provided at the bottom; the top cover (3) is installed at the top opening of the outer shell (2); the sensing unit (1) is disposed in the inner cavity (21) and is axially pressed by the top cover (3); The sensing unit (1) includes an insulating cover plate (12), a composite film (13), an insulating ring cover (14), a transmission buffer block (15), an annular end cover (16), and a hemispherical composite film (17) arranged sequentially from bottom to top along the axial direction. The insulating cover plate (12) and the insulating ring cover (14) cooperate to clamp the edge of the composite film (13), and the lower surface of the composite film (13) faces the liquid flow channel (23). The transfer buffer block (15) is movably disposed in the inner cavity of the insulating ring cover (14). The lower surface of the transfer buffer block (15) is provided with a lower copper foil (152), and the upper surface is provided with an upper spherical copper foil (153). The annular end cap (16) and the insulating annular cap (14) cooperate to clamp the edge of the hemispherical composite film (17), and the hemispherical composite film (17) is located above the transfer buffer block (15); The composite film (13) is configured to deform under liquid pressure and rub against the lower copper foil (152) to generate a first electrical signal; the transmission buffer block (15) is configured to move upward under the deformation of the composite film (13) so that the upper spherical copper foil (153) rubs against the hemispherical composite film (17) to generate a second electrical signal.

2. The triboelectric hemispherical composite thin film pressure sensing device according to claim 1, characterized in that: The lower surface of the insulating cover plate (12) is provided with an annular groove (121) for accommodating the O-ring (11), and the O-ring (11) abuts against the bottom wall of the inner cavity (21) of the outer shell.

3. The triboelectric hemispherical composite thin film pressure sensing device according to claim 1, characterized in that: The insulating ring cover (14) has a first wiring groove (141) on its side wall, the transmission buffer block (15) has a second wiring groove (151) on its side wall, and the annular end cover (16) has a third wiring groove (161) on its side wall. The first wiring groove (141), the second wiring groove (151) and the third wiring groove (161) are interconnected to form a wire channel; The top cover (3) is provided with a through wiring hole (32), which is connected to the wire channel to lead out the wire.

4. The triboelectric hemispherical composite thin film pressure sensing device according to claim 1, characterized in that: The composite film (13) has a three-layer structure, including a lower polydimethylsiloxane film (131), a first intermediate conductive ink layer (132), and an upper polydimethylsiloxane film (133); the first intermediate conductive ink layer (132) is connected to lead wires.

5. The triboelectric hemispherical composite thin film pressure sensing device according to claim 1, characterized in that: The hemispherical composite film (17) has a three-layer structure, including a lower hemispherical polydimethylsiloxane film (171), a second intermediate conductive ink layer (172), and an upper hemispherical polydimethylsiloxane film (173); the second intermediate conductive ink layer (172) is connected to lead wires.

6. The triboelectric hemispherical composite thin film pressure sensing device according to claim 1, characterized in that: The upper surface of the transfer buffer block (15) is a convex spherical surface, the bottom inner side of the annular end cap (16) is provided with a concave spherical surface (163), and the inner side of the top pressure cap (3) is provided with a concave spherical surface; the curvature of the convex spherical surface of the transfer buffer block (15) is adapted to the curvature of the hemispherical composite film (17) and the inner spherical surface of the top pressure cap (3).

7. The triboelectric hemispherical composite thin film pressure sensing device according to claim 1, characterized in that: The outer peripheral surface of the bottom of the outer casing (2) is provided with an external thread (22) for connecting with the hydraulic pipeline; the inner wall of the inner cavity (21) of the outer casing is provided with an internal thread, and the outer peripheral surface of the top cover (3) is provided with an external thread that mates with the internal thread.

8. The triboelectric hemispherical composite thin film pressure sensing device according to claim 3, characterized in that: The upper surface of the top cover (3) is integrally formed with an external hexagonal column (31), and the wiring hole (32) passes through the center of the external hexagonal column (31).

9. A control method for a triboelectric hemispherical composite thin film pressure sensing device, based on the triboelectric hemispherical composite thin film pressure sensing device according to any one of claims 1-8, characterized in that, Includes the following steps: Collect the first electrical signal generated by the contact separation between the composite film (13) and the lower copper foil (152); Collect the second electrical signal generated by the contact separation between the hemispherical composite film (17) and the upper spherical copper foil (153); When the detected pressure is low, the current liquid pressure is calculated based on the amplitude change of the first electrical signal; When the detected pressure increases to the point that the composite film (13) pushes the transmission buffer block (15) into contact with the hemispherical composite film (17), the current liquid pressure is calculated by combining the changes in the first and second electrical signals.

10. The control method of the triboelectric hemispherical composite thin film pressure sensing device according to claim 9, characterized in that, Also includes: Extract the amplitude, frequency, and waveform distortion rate of the first or second electrical signal; The extracted feature values ​​are compared with preset thresholds to determine whether there are fault conditions such as leakage, component wear, blockage, or seal failure in the hydraulic circuit.

Images