Composite sensor for monitoring acceleration and pressure and working method thereof

Abstract

The invention relates to a composite sensor for acceleration and pressure monitoring and a working method thereof, and belongs to the field of sensors, the composite sensor comprises an upper shell, a middle shell and a lower shell, the upper end of the upper shell is provided with an M6 mounting thread, the lower end of the upper shell is a hexagonal base, and a groove space is reserved in the inner side of the lower end of the hexagonal base; the appearance of the middle shell is a hexagonal base, and M5 mouthpiece installation holes are formed in the left side and the right side of the middle shell. A double-end beam sheet is arranged in the middle of the inner side of the middle shell and is of a sheet-shaped structure, and the two ends of the double-end beam sheet are fixedly connected with the front inner wall and the rear inner wall of the middle shell or integrally formed. The center of the double-end beam sheet is provided with an integrally connected cylindrical screw rod, and the cylindrical screw rod is provided with an acceleration sensor core body structure; the appearance of the lower shell is a hexagonal base, and a mounting groove is formed in the bottom of the lower shell and used for mounting a pressure sensor core structure; the upper shell, the middle shell and the lower shell are connected in a welded mode. The device is simple in structure, can realize synchronous monitoring of acceleration and pressure without mutual interference, and can realize multi-scene application at the same time.

Description

Technical Field

[0001] The invention relates to a composite sensor for monitoring acceleration and pressure and a working method thereof, belonging to the technical field of sensors. Background Art

[0002] Piezoelectric accelerometers and piezoelectric pressure sensors use piezoelectric materials as sensitive elements. Under the action of external force, accelerometers are sensors that can measure acceleration. They are usually composed of mass blocks, elastic elements, sensitive elements, etc. During the acceleration process, the sensor measures the inertial force on the mass block and uses Newton's second law to obtain the acceleration value. Pressure sensors are devices or devices that can sense pressure signals and convert pressure signals into usable output electrical signals according to certain rules. Both sensors are involved in many industries such as water conservancy and hydropower, railway transportation, intelligent buildings, production automation, aerospace, military industry, petrochemicals, oil wells, electricity, ships, machine tools, pipelines, etc. Traditional sensors are often used in a single occasion, cannot achieve simultaneous measurement of acceleration and pressure, and cannot have multi-scenario application functions; traditional accelerometers have small vibration output magnitude and poor measurement sensitivity; therefore, the structure of such sensors also needs to be further improved. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a composite sensor for acceleration and pressure monitoring and a working method thereof, which has a simple structure, can realize synchronous monitoring of acceleration and pressure without interfering with each other, and can realize multi-scenario application.

[0004] The present invention adopts the following technical solutions:

[0005] On the one hand, the present invention provides a composite sensor for monitoring acceleration and pressure, comprising an upper shell, a middle shell and a lower shell, wherein the upper end of the upper shell is an M6 mounting thread, the lower end is a hexagonal base, and a groove space is reserved inside the lower end of the hexagonal base for vibration of the acceleration sensor core structure;

[0006] The middle shell has a hexagonal base shape, and M5 nozzle mounting holes are provided on the left and right sides for installing the nozzle; a double-end beam piece connected to the shell is provided at the middle position of the inner side of the middle shell, and the double-end beam piece is a sheet-like structure, and both ends are fixedly connected or integrally formed with the front and rear inner walls of the middle shell; an integrally connected cylindrical screw is provided at the center of the double-end beam piece, and the cylindrical screw is used as a screw of the acceleration sensor structure, and the acceleration sensor core structure is installed on the cylindrical screw;

[0007] The lower shell has a hexagonal base shape, and a mounting groove is provided at the bottom for mounting the pressure sensor core structure; the upper shell, the middle shell and the lower shell are welded together.

[0008] Preferably, the acceleration sensor core structure includes an electrode sheet, a mass block, a fastening nut and two large piezoelectric ceramics, wherein the first large piezoelectric ceramic, the electrode sheet, the second large piezoelectric ceramic and the mass block are sequentially arranged on the cylindrical screw of the double-end beam sheet, and the top of the cylindrical screw is provided with an M2 mounting thread, which is tightened by the fastening nut. In the acceleration sensor core structure, the first large piezoelectric ceramic, the electrode sheet, the second large piezoelectric ceramic and the mass block are concentrically processed during the assembly process, and no insulating sleeve is required to avoid short circuit.

[0009] Preferably, the electrode sheet is a thin-sheet circular ring structure with a convex surface on one side for wire welding and fixation. The wire connection nozzle is used for signal output. The nozzle is a conventional cylindrical structure with an M5 thread for testing needs. The large piezoelectric ceramic and the mass block are both circular ring structures with a through hole in the middle.

[0010] Preferably, the thickness of the double-ended beam is 0.5 mm. The signal output magnification based on the double-ended beam structure is related to the thickness of the double-ended beam. The specific magnification needs to be recorded during calibration with the standard sensor, and the acceleration and charge signal output calculation can be performed based on the actual magnification.

[0011] Preferably, the pressure sensor core structure comprises an insulating ring, a lower mounting threaded column, a pre-tightening screw, two small piezoelectric ceramics and two electrode blocks, the insulating ring is placed in the mounting groove of the lower shell, the first small piezoelectric ceramic is arranged on the inner side of the insulating ring and fits the top surface of the mounting groove; the first electrode block, the second small piezoelectric ceramic and the second electrode block are arranged in sequence under the first small piezoelectric ceramic in the insulating ring;

[0012] The top of the lower mounting threaded column is fitted with the second electrode block, and the lower mounting threaded column is butted against the lower shell body and then welded to be connected; a pre-tightening screw is arranged inside the lower mounting threaded column.

[0013] Preferably, the insulating ring is a circular ring structure, the small piezoelectric ceramic is a circular ring structure with a through hole in the middle; the electrode block is a solid disc structure, used for outputting electrical signals of the small piezoelectric ceramic and providing support; a wire is welded at the center of the first electrode block, and the wire is connected to the nozzle through the through hole of the first small piezoelectric ceramic for signal transmission;

[0014] A φ0.5 wire through hole is provided in the center of the lower shell for wire output; the lower mounting threaded column is a cylindrical structure with a hole in the middle, a thin sheet is provided at the top of the lower mounting threaded column, and the thin sheet and the lower mounting threaded column are integrally formed and used as a deformation diaphragm of the pressure sensor; the lower mounting threaded column is provided with an M6 thread on the outside for sensor installation, and an M4 internal thread on the inside for tightening the pre-tightening screw;

[0015] The pre-tightening screw is a cylindrical structure, with an external thread on the outer side of the middle and lower ends for cooperating with the M4 internal thread inside the lower mounting threaded column. A φ1.5 through hole is provided in the middle of the pre-tightening screw for circulation and transmission of fluid media. The upper end surface of the pre-tightening screw is flat and the surface area is similar to that of the small piezoelectric ceramic, and is used for compressive support of the small piezoelectric ceramic after tightening.

[0016] Preferably, a "M"-shaped groove is provided at the bottom of the pre-tightening screw. The groove can not only concentrate the pressure in the screw through hole, but also serve as a pre-tightening debugging groove, which can be tightened with a "one" or "cross" screwdriver. By controlling the tightening force, the diaphragm is deformed, thereby controlling the pre-tightening force of the pressure sensor structure. When the tightening force is small, the sensor test range increases, and when the tightening force is large, the sensor test range decreases, and at the same time the linear performance is getting better and better, so that it can be applied to a variety of different application scenarios.

[0017] Preferably, the sheet thickness of the lower mounting threaded column is 0.2 mm.

[0018] Preferably, the assembly process is as follows:

[0019] (1) Place the insulating ring into the mounting groove at the lower end of the lower shell, and place the first small piezoelectric ceramic into the inner side of the insulating ring, so that the first small piezoelectric ceramic fits the top surface of the mounting groove;

[0020] (2) Weld the wire to the center of the first electrode block, so that the top surface of the first electrode block is in contact with the first small piezoelectric ceramic, and the wire passes through the through hole of the first small piezoelectric ceramic and the wire through hole of the φ0.5 of the lower shell in sequence;

[0021] (3) Place the second small piezoelectric ceramic inside the insulating ring and fit it to the first electrode block; Place the second electrode block inside the insulating ring and fit the top to the second small piezoelectric ceramic;

[0022] (4) Butt the upper end of the lower mounting threaded column with the lower end of the lower shell, pre-press and then weld;

[0023] (5) Screw the preload screw into the M4 internal thread inside the lower mounting threaded column;

[0024] (6) Sleeve the first large piezoelectric ceramic onto the cylindrical screw of the double-end beam until it fits with the surface of the double-end beam;

[0025] (7) Sleeve the electrode sheet onto the cylindrical screw until it fits with the first large piezoelectric ceramic, and weld a wire on the convex surface of one side of the electrode sheet for signal transmission;

[0026] (8) Sleeve the second large piezoelectric ceramic onto the cylindrical screw until it fits with the electrode sheet; Sleeve the mass block onto the cylindrical screw until it fits with the second large piezoelectric ceramic;

[0027] (9) Tighten the fastening nut onto the cylindrical screw;

[0028] (10) butting the upper shell, the middle shell, and the lower shell together and welding the contact surfaces;

[0029] (11) Lead out the two wires from the M5 nozzle mounting holes at both ends of the middle shell, and weld them to the central output point of the nozzle;

[0030] (12) Connect the nozzle to the M5 nozzle mounting hole of the middle shell and fix it by welding on the contact surface.

[0031] The upper shell, middle shell, lower shell, lower mounting threaded column, pre-tightening screw, electrode block, electrode sheet and fastening nut in the present invention are all made of 17-4 stainless steel, and the whole is sealed and welded, which has high strength.

[0032] On the other hand, the present invention provides a working method based on the above-mentioned composite sensor for acceleration and pressure monitoring, wherein the composite sensor adopts an upper installation method or a lower installation method, and can realize multi-scenario application;

[0033] When the composite sensor has no pressure monitoring requirements, it is installed on the pipe through the M6 ​​mounting thread on the upper end of the upper shell. At this time, only the acceleration sensor works.

[0034] When the composite sensor needs to monitor both pressure and acceleration, a lower installation method is adopted, and the lower installation threaded column of the lower shell is used to install it on the pipeline. At this time, the acceleration sensor and the pressure sensor work at the same time; when the fluid medium in the pipeline passes through to generate a pressure source, the fluid medium passes through the through hole in the middle of the pre-tightening screw, and squeezes the thin sheet at the top of the lower installation threaded column. The pressure is transmitted to the electrode block through the thin sheet, and further transmitted to the small piezoelectric ceramic. After being squeezed, the small piezoelectric ceramic outputs a signal based on the piezoelectric effect, thereby realizing the pressure monitoring in the pipeline; if the pipeline surface vibrates, the sensor body generates a small vibration, and the vibration is amplified by the double-end beam, causing the mass block on the acceleration sensor core structure to squeeze the large piezoelectric ceramic due to inertia when moving up and down, and output a charge signal based on the piezoelectric effect, thereby realizing the vibration monitoring of the pipeline surface.

[0035] Where the present invention is not exhaustive, prior art may be used.

[0036] The beneficial effects of the present invention are:

[0037] 1. The overall design of the sensor of the present invention is a symmetrical structure, the overall design of the housing is a hexagonal structure, there are M6 threads on both the upper and lower ends, and the output nozzles are located on both sides, which reduces interference in use and greatly enhances the applicability of use and installation.

[0038] 2. The present invention adopts a composite structure of an acceleration sensor and a pressure sensor, with the lower end being a pressure sensor structure and the middle end being an acceleration sensor structure. It can not only monitor the vibration of conventional objects, but also monitor pressure signals. When there is no need for pressure monitoring, the sensor can be installed from above, and when there is a need for pressure monitoring, it can be installed from below, which can realize multi-scenario applications and greatly improve performance.

[0039] 3. Based on the conventional compression and bending piezoelectric acceleration sensor structure, the present invention designs a double-end beam sheet structure similar to the cantilever beam of the bending acceleration sensor, and an integrated cylindrical screw is provided at the center of the double-end beam sheet structure, which can be installed with the compression acceleration sensor core structure. Among them, the two ends of the double-end beam sheet are an integrated structure with the sensor housing, and the thickness of the double-end beam sheet is about 0.5mm. When the sensor is monitoring and running, the sensor structure is subjected to external forces (such as inertial forces caused by acceleration changes), and the mass block will generate corresponding acceleration due to inertia. This acceleration causes the mass block to drive the double-end beam sheet to bend, thereby further stretching or compressing the large piezoelectric ceramic, and then generating charge output. The magnitude of the charge is proportional to the magnitude of the acceleration, so the magnitude of the acceleration can be inferred by measuring the charge. This structure not only avoids the shortcomings of large size and inconvenience of use of the bending piezoelectric acceleration sensor, but also has the characteristics of low resonance frequency and high sensitivity of the conventional bending piezoelectric acceleration sensor, so it can be often used for low-frequency measurement.

[0040] In addition, the double-end beam of the present invention is also based on the principle of installing the acceleration sensor on the cantilever beam for testing, so that it can amplify the sensor output signal during small vibrations. However, compared with the conventional cantilever beam test structure, the two ends of this structure are fixed, which helps to ensure that the core is constrained to vibrate up and down during vibration, avoiding lateral signal interference under the conventional cantilever beam vibration structure. Therefore, the present invention can be used for micro-vibration measurement of large buildings such as earthquake foundation vibration, dam power stations, and detection of low-frequency vibration signals such as pipeline leakage, and the test performance is greatly improved.

[0041] 4. The deformable diaphragm (thin sheet) of the pressure sensor structure of the present invention is located between the lower mounting threaded column and the electrode block, and the deformable diaphragm and the lower mounting threaded column are an integrated structure, about 0.2 mm thick, and have strong strain. In addition, an internal thread is provided on the inner side of the hole of the lower mounting threaded column, and a pre-tightening screw is adapted to tighten the pre-tightening screw to the inner side of the hole of the lower mounting threaded column. A "M"-shaped groove is provided at the bottom of the pre-tightening screw, which can not only concentrate the pressure in the through hole of the pre-tightening screw, but also serve as a pre-tightening debugging groove, thereby controlling the pre-tightening force of the pressure sensor structure. In addition, a through hole of φ1.5 is provided at the bottom of the pre-tightening screw, and the deformable diaphragm is exposed on the inner side of the through hole and contacts the fluid medium. When pressure is generated, the core structure of the pressure sensor can be directly pressurized, thereby causing a small piezoelectric ceramic to deform and generate a charge signal output.

[0042] 5. The upper shell, double-end beam and middle shell of the present invention are an integral structure with high rigidity and are not easy to be damaged. A vibration space is left at the upper end of the upper shell to avoid output interference. The pressure sensor structure design of the present invention is simple, and due to the double-end beam structure on the acceleration sensor, the distance between the two is large, resulting in no interference between the two when they are running synchronously. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the overall structure of the composite sensor for acceleration and pressure monitoring of the present invention;

[0044] Figure 2 It is a cross-sectional view of a composite sensor for acceleration and pressure monitoring of the present invention;

[0045] Figure 3 The anatomical stereogram of the composite sensor for acceleration and pressure monitoring of the present invention;

[0046] Figure 4 Schematic diagram of the three-dimensional structure of the upper shell of the present invention, (a) is angle 1, (b) is angle 2;

[0047] Figure 5 Schematic diagram of the middle shell structure of the present invention, (a) is a three-dimensional view, (b) is a top view, and (c) is a left side view;

[0048] Figure 6 Schematic diagram of the three-dimensional structure of the lower shell of the present invention, (a) is angle 1, (b) is angle 2;

[0049] Figure 7 Schematic diagram of the three-dimensional structure of the lower mounting threaded column of the present invention, (a) is angle 1, (b) is angle 2;

[0050] Figure 8 Schematic diagram of the three-dimensional structure of the pre-tightening screw of the present invention, (a) is angle 1, (b) is angle 2, and (c) is angle 3;

[0051] Fig. 9 Schematic diagram of the three-dimensional structure of the fastening nut of the present invention, (a) is angle 1, (b) is angle 2;

[0052] Fig.10 It is a schematic diagram of the three-dimensional structure of the mass block of the present invention;

[0053] Fig.11 It is a schematic diagram of the three-dimensional structure of the large piezoelectric ceramic of the present invention;

[0054] Fig.12 It is a schematic diagram of the three-dimensional structure of the electrode sheet of the present invention;

[0055] Fig.13 It is a schematic diagram of the three-dimensional structure of the insulating ring of the present invention;

[0056] Fig.14 It is a schematic diagram of the three-dimensional structure of the electrode block of the present invention;

[0057] Fig.15 It is a schematic diagram of the lower installation method of the sensor of the present invention;

[0058] In the figure, 1-upper shell, 2-middle shell, 3-nozzle, 4-lower shell, 5-insulating ring, 6-lower mounting threaded column, 7-pre-tightening screw, 8-electrode block, 9-small piezoelectric ceramic, 10-electrode sheet, 11-large piezoelectric ceramic, 12-mass block, 13-fastening nut, 14-double-end beam sheet, 15-cylindrical screw, 16-thin sheet. DETAILED DESCRIPTION

[0059] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, they will be described in detail with reference to the accompanying drawings and specific embodiments, but are not limited to these. Anything not fully described in the present invention shall be based on conventional techniques in the art.

[0060] In the description of the present invention, it should be noted that the terms "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0061] Example 1

[0062] A composite sensor for acceleration and pressure monitoring, such as Figure 1 to Figure 14 As shown, it includes an upper shell 1, a middle shell 2 and a lower shell 4. The upper end of the upper shell 1 is an M6 mounting thread, and the lower end is a hexagonal base. A groove space is left inside the lower end of the hexagonal base for vibration of the acceleration sensor core structure;

[0063] The middle shell 2 has a hexagonal base shape, and M5 nozzle mounting holes are provided on the left and right sides for mounting the nozzle 3; a double-end beam piece 14 connected to the shell is provided at the middle position of the inner side of the middle shell, and the double-end beam piece is a sheet-like structure, and both ends are fixedly connected or integrally formed with the front and rear inner walls of the middle shell; an integrally connected cylindrical screw 15 is provided at the center of the double-end beam piece 14, and the cylindrical screw 15 is used as a screw of the acceleration sensor structure, and the acceleration sensor core structure is installed on the cylindrical screw 15;

[0064] The lower shell 4 has a hexagonal base shape, and a mounting groove is provided at the bottom for mounting the pressure sensor core structure; the upper shell 1, the middle shell 2 and the lower shell 4 are welded together.

[0065] Example 2

[0066] A composite sensor for monitoring acceleration and pressure, as described in Example 1, except that the acceleration sensor core structure includes an electrode sheet 10, a mass block 12, a fastening nut 13 and two large piezoelectric ceramics 11, wherein the first large piezoelectric ceramic 11, the electrode sheet 10, the second large piezoelectric ceramic 11, and the mass block 12 are sequentially arranged on a cylindrical screw 15 of a double-end beam sheet, and an M2 mounting thread is arranged at the top of the cylindrical screw 15, and the M2 mounting thread is tightened by the fastening nut 13.

[0067] The electrode sheet 10 is a thin-sheet circular ring structure with a convex surface on one side for wire welding and fixing. The wire connection nozzle is used for signal output. The nozzle is a conventional cylindrical structure with an M5 thread for testing needs. The large piezoelectric ceramic and the mass block are both circular ring structures with a through hole in the middle.

[0068] The thickness of the double-end beam piece 14 is 0.5 mm. The signal output magnification factor based on the double-end beam piece structure is related to the thickness of the double-end beam piece. The specific magnification factor needs to be recorded during calibration with the standard sensor, and the acceleration and charge signal output calculation can be performed based on the actual magnification factor.

[0069] Example 3

[0070] A composite sensor for monitoring acceleration and pressure, as described in Example 2, except that the pressure sensor core structure includes an insulating ring 5, a lower mounting threaded column 6, a pre-tightening screw 7, two small piezoelectric ceramics 9 and two electrode blocks 8, the insulating ring 5 is placed in the mounting groove of the lower shell 4, the first small piezoelectric ceramic 9 is arranged on the inner side of the insulating ring 5 and fits the top surface of the mounting groove; the first electrode block 8, the second small piezoelectric ceramic 9 and the second electrode block 8 are arranged in sequence under the first small piezoelectric ceramic in the insulating ring 5;

[0071] The top of the lower mounting threaded column 6 is fitted with the second electrode block 8, and the lower mounting threaded column 6 is connected to the lower shell 4 by welding after being butted against each other; a pre-tightening screw 7 is arranged inside the lower mounting threaded column.

[0072] The insulating ring 5 is a circular ring structure, and the small piezoelectric ceramic 9 is a circular ring structure with a through hole in the middle; the electrode block 8 is a solid disc structure, which is used for outputting electrical signals of the small piezoelectric ceramic and providing support; a wire is welded at the center of the first electrode block 8, and the wire is connected to the nozzle 3 through the through hole of the first small piezoelectric ceramic 9 for signal transmission;

[0073] A φ0.5 wire through hole is provided at the center of the lower housing 4 for wire output; the lower mounting threaded column 6 is a cylindrical structure with a hole in the middle, and a thin sheet 16 is provided at the top of the lower mounting threaded column 6. The thin sheet 16 and the lower mounting threaded column are integrally formed and used as a deformation diaphragm of the pressure sensor; the lower mounting threaded column 6 is provided with an M6 thread on the outside for sensor installation, and an M4 internal thread on the inside for tightening the pre-tightening screw 7;

[0074] The pre-tightening screw 7 is a cylindrical structure with an external thread on the outer side of the middle and lower ends for cooperating with the M4 internal thread inside the lower mounting threaded column. A φ1.5 through hole is provided in the middle of the pre-tightening screw 7 for circulation and transmission of fluid medium. The upper end surface of the pre-tightening screw is flat and the surface area is similar to that of the small piezoelectric ceramic, and is used for compressive support of the small piezoelectric ceramic after tightening.

[0075] A "M"-shaped groove is provided at the bottom of the pre-tightening screw 7. This groove can not only concentrate the pressure in the screw through hole, but also serve as a pre-tightening debugging groove. It can be tightened with a "one" or "cross" screwdriver. By controlling the tightening force, the diaphragm is deformed, thereby controlling the pre-tightening force of the pressure sensor structure. When the tightening force is small, the sensor test range increases, and when the tightening force is large, the sensor test range decreases, and at the same time the linear performance is getting better and better, so it can be applied to a variety of different application scenarios.

[0076] The thickness of the sheet 16 for mounting the lower threaded column is 0.2 mm.

[0077] Example 4

[0078] A composite sensor for monitoring acceleration and pressure, as described in Example 3, except that the assembly process is as follows:

[0079] (1) Place the insulating ring 5 into the mounting groove at the lower end of the lower housing 4, and place the first small piezoelectric ceramic 9 into the inner side of the insulating ring, so that the first small piezoelectric ceramic 9 is in contact with the top surface of the mounting groove;

[0080] (2) Weld the wire to the center of the first electrode block 8, so that the top surface of the first electrode block 8 is in contact with the first small piezoelectric ceramic 9, and the wire passes through the through hole of the first small piezoelectric ceramic and the wire through hole of the φ0.5 of the lower shell in sequence;

[0081] (3) Place the second small piezoelectric ceramic 9 inside the insulating ring 5 and fit it to the first electrode block 8; Place the second electrode block 8 inside the insulating ring 5 and fit the top to the second small piezoelectric ceramic 9;

[0082] (4) Butt the upper end of the lower mounting threaded column 6 with the lower end of the lower shell 4, pre-press and then weld;

[0083] (5) Screw the preload screw 7 into the M4 internal thread inside the lower mounting threaded column 6;

[0084] (6) Sleeve the first large piezoelectric ceramic 11 onto the cylindrical screw 15 of the double-end beam 14 until it fits with the surface of the double-end beam 14;

[0085] (7) The electrode sheet 10 is placed on the cylindrical screw 15 until it fits with the first large piezoelectric ceramic 11, and a wire is welded on the convex surface of one side of the electrode sheet 10 for signal transmission;

[0086] (8) Sleeve the second large piezoelectric ceramic 11 onto the cylindrical screw 15 until it fits with the electrode sheet 10; Sleeve the mass block 12 onto the cylindrical screw 15 until it fits with the second large piezoelectric ceramic 11;

[0087] (9) Tighten the fastening nut 13 onto the cylindrical screw 15;

[0088] (10) butting the upper shell 1, the middle shell 2 and the lower shell 4 together and then welding the contact surfaces;

[0089] (11) Lead out the two wires from the M5 nozzle mounting holes at both ends of the middle shell, and weld them to the central output point of nozzle 3;

[0090] (12) Connect the nozzle 3 to the M5 nozzle mounting hole of the middle housing 2 and fix it by welding on the contact surface.

[0091] The metal materials in the present invention are all made of 17-4 stainless steel, and the whole is sealed and welded, so it has high strength.

[0092] Example 5

[0093] A working method of a composite sensor for monitoring acceleration and pressure, wherein the composite sensor is installed from top to bottom and can be applied in multiple scenarios;

[0094] When the composite sensor has no pressure monitoring requirement, it is installed on the pipe through the M6 ​​mounting thread on the upper end of the upper shell 1. At this time, only the acceleration sensor works.

[0095] When the composite sensor needs to monitor both pressure and acceleration, the bottom installation method is adopted, such as Fig.15As shown, the lower mounting threaded column 6 of the lower shell 4 is installed on the pipeline. At this time, the acceleration sensor and the pressure sensor work simultaneously; when the fluid medium in the pipeline passes through a pressure source, the fluid medium passes through the through hole in the middle of the pre-tightening screw 7, and squeezes the thin sheet 16 at the top of the lower mounting threaded column 6. The pressure is transmitted to the electrode block 8 through the thin sheet 16, and further transmitted to the small piezoelectric ceramic. After being squeezed, the small piezoelectric ceramic outputs a signal based on the piezoelectric effect, thereby realizing the pressure monitoring in the pipeline; if the pipeline surface vibrates, the sensor body generates a small vibration, and the vibration is amplified by the double-end beam 14, resulting in the mass block 12 on the acceleration sensor core structure squeezing the large piezoelectric ceramic due to inertia when moving up and down, and outputting a charge signal based on the piezoelectric effect, thereby realizing the vibration monitoring of the pipeline surface.

[0096] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composite sensor for acceleration and pressure monitoring, characterized in that: It includes an upper shell, a middle shell and a lower shell. The upper end of the upper shell is an M6 mounting thread, and the lower end is a hexagonal base. A groove space is left inside the lower end of the hexagonal base for vibration of the acceleration sensor core structure. The middle shell has a hexagonal base shape, and M5 nozzle mounting holes are provided on the left and right sides for installing the nozzle; a double-end beam piece is provided at the middle position of the inner side of the middle shell, and the double-end beam piece is a sheet-like structure, and the two ends are fixedly connected or integrally formed with the front and rear inner walls of the middle shell; an integrally connected cylindrical screw is provided at the center of the double-end beam piece, and the acceleration sensor core structure is installed on the cylindrical screw; The lower shell has a hexagonal base shape, and a mounting groove is provided at the bottom for mounting the pressure sensor core structure; the upper shell, the middle shell and the lower shell are welded together.

2. The composite sensor for acceleration and pressure monitoring according to claim 1, characterized in that: The acceleration sensor core structure includes an electrode sheet, a mass block, a fastening nut and two large piezoelectric ceramics, wherein the first large piezoelectric ceramic, the electrode sheet, the second large piezoelectric ceramic and the mass block are sequentially arranged on a cylindrical screw of a double-end beam sheet, and an M2 mounting thread is arranged at the top end of the cylindrical screw, and the M2 mounting thread is tightened by a fastening nut.

3. The composite sensor for monitoring acceleration and pressure according to claim 2, characterized in that: The electrode sheet is a thin circular ring structure with a convex surface on one side for wire welding and fixing, and the wire is connected to the nozzle for signal output; the large piezoelectric ceramic and the mass block are both circular ring structures with a through hole in the middle.

4. The composite sensor for monitoring acceleration and pressure according to claim 3, characterized in that: The thickness of the double-end beam piece is 0.5 mm.

5. The composite sensor for monitoring acceleration and pressure according to claim 4, characterized in that: The pressure sensor core structure includes an insulating ring, a lower mounting threaded column, a pre-tightening screw, two small piezoelectric ceramics and two electrode blocks. The insulating ring is placed in the mounting groove of the lower shell, and the first small piezoelectric ceramic is arranged on the inner side of the insulating ring and fits the top surface of the mounting groove; the first electrode block, the second small piezoelectric ceramic and the second electrode block are arranged in sequence under the first small piezoelectric ceramic in the insulating ring; The top of the lower mounting threaded column is fitted with the second electrode block, and the lower mounting threaded column is butted against the lower shell body and then welded to be connected; a pre-tightening screw is arranged inside the lower mounting threaded column.

6. The composite sensor for monitoring acceleration and pressure according to claim 5, characterized in that: The insulating ring is a circular ring structure, and the small piezoelectric ceramic is a circular ring structure with a through hole in the middle; the electrode block is a solid disc structure, which is used for outputting electrical signals of the small piezoelectric ceramic and providing support; a wire is welded at the center of the first electrode block, and the wire is connected to the nozzle through the through hole of the first small piezoelectric ceramic for signal transmission; A wire through hole is provided in the center of the lower shell for wire output; the lower mounting threaded column is a cylindrical structure with a hole in the middle, a thin sheet is provided at the top of the lower mounting threaded column, and the thin sheet and the lower mounting threaded column are integrally formed and used as a deformation diaphragm of the pressure sensor; the lower mounting threaded column is provided with an M6 thread on the outside for sensor installation, and an M4 internal thread on the inside for tightening the pre-tightening screw; The pre-tightening screw is a cylindrical structure, with an external thread on the outer side of the middle and lower end for matching with the M4 internal thread inside the lower mounting threaded column, and a through hole in the middle of the pre-tightening screw for circulation and transmission of fluid media.

7. The composite sensor for monitoring acceleration and pressure according to claim 6, characterized in that: A "M"-shaped groove is arranged at the bottom of the pre-tightening screw.

8. The composite sensor for monitoring acceleration and pressure according to claim 7, characterized in that: The thickness of the sheet of the lower mounting threaded column is 0.2 mm.

9. The composite sensor for monitoring acceleration and pressure according to claim 8, characterized in that: The assembly process is as follows: (1) Place the insulating ring into the mounting groove at the lower end of the lower shell, and place the first small piezoelectric ceramic into the inner side of the insulating ring, so that the first small piezoelectric ceramic fits the top surface of the mounting groove; (2) welding the wire to the center of the first electrode block, so that the top surface of the first electrode block is in contact with the first small piezoelectric ceramic, and the wire passes through the through hole of the first small piezoelectric ceramic and the wire through hole of the lower shell in sequence; (3) Place the second small piezoelectric ceramic inside the insulating ring and fit it to the first electrode block; Place the second electrode block inside the insulating ring and fit the top to the second small piezoelectric ceramic; (4) Butt the upper end of the lower mounting threaded column with the lower end of the lower shell, pre-press and then weld; (5) Screw the preload screw into the M4 internal thread inside the lower mounting threaded column; (6) Sleeve the first large piezoelectric ceramic onto the cylindrical screw of the double-end beam until it fits with the surface of the double-end beam; (7) Sleeve the electrode sheet onto the cylindrical screw until it fits with the first large piezoelectric ceramic, and weld a wire on the convex surface of one side of the electrode sheet for signal transmission; (8) Sleeve the second large piezoelectric ceramic onto the cylindrical screw until it fits with the electrode sheet; Sleeve the mass block onto the cylindrical screw until it fits with the second large piezoelectric ceramic; (9) Tighten the fastening nut onto the cylindrical screw; (10) butting the upper shell, the middle shell, and the lower shell together and welding the contact surfaces; (11) Lead out the two wires from the M5 nozzle mounting holes at both ends of the middle shell, and weld them to the central output point of the nozzle; (12) Connect the nozzle to the M5 nozzle mounting hole of the middle shell and fix it by welding on the contact surface.

10. A working method of the composite sensor for acceleration and pressure monitoring according to claim 9, characterized in that: The composite sensor can be installed from top to bottom or from bottom to bottom, which can be used in multiple scenarios. When the composite sensor has no pressure monitoring requirements, it is installed on the pipe through the M6 ​​mounting thread on the upper end of the upper shell. At this time, only the acceleration sensor works. When the composite sensor needs to monitor both pressure and acceleration, a lower installation method is adopted, and the lower installation threaded column of the lower shell is installed on the pipeline. At this time, the acceleration sensor and the pressure sensor work at the same time; when the fluid medium in the pipeline passes through a pressure source, the fluid medium passes through the through hole in the middle of the pre-tightening screw, and squeezes the thin sheet at the top of the lower installation threaded column. The pressure is transmitted to the electrode block through the thin sheet, and further transmitted to the small piezoelectric ceramic. After being squeezed, the small piezoelectric ceramic outputs a signal based on the piezoelectric effect, thereby realizing pressure monitoring in the pipeline; if the pipeline surface vibrates, the sensor body vibrates, and the vibration is amplified by the double-end beam, causing the mass block on the acceleration sensor core structure to squeeze the large piezoelectric ceramic due to inertia when moving up and down, and output a charge signal based on the piezoelectric effect, thereby realizing vibration monitoring of the pipeline surface.

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