Direct insertion type differential pressure sensor

Abstract

The invention discloses a direct insertion type differential pressure sensor, and relates to the technical field of differential pressure measurement, the direct insertion type differential pressure sensor comprises a sensor sintering seat, a pressure base and a differential pressure diaphragm capsule, the differential pressure diaphragm capsule comprises a cylindrical diaphragm capsule body, the cylindrical diaphragm capsule body is arranged in a circular cavity, corrugated diaphragms are arranged at two ends of the cylindrical diaphragm capsule body, a central diaphragm is arranged in the cylindrical diaphragm capsule body, and the central diaphragm is arranged in the cylindrical diaphragm capsule body. The top wall of the circular cavity is provided with vertical holes communicated with the two through holes, and the two vertical holes are communicated with the positive pressure end and the negative pressure end respectively. Through the arrangement of the circular cavity and the differential pressure diaphragm capsule, a high-temperature medium can only reach the positive pressure cavity and the negative pressure cavity of the circular cavity, the high-temperature medium is separated from silicone oil, and the high-temperature medium is prevented from damaging a sensor chip, so that the differential pressure of a high-temperature fluid medium can be measured; the sensor chip is prevented from being damaged due to the fact that pressure borne by the corrugated diaphragm is too large, the sensor can be used in a high-static-pressure state, and the overload capacity of the sensor is improved.

Description

Technical Field

[0001] The invention relates to the technical field of differential pressure measurement, and in particular to a direct insertion differential pressure sensor. Background Art

[0002] In the prior art, when measuring the operating conditions of the filter element at the oil supply end in aircraft engines, heavy-duty loading vehicle engines, and hydraulic systems, the differential pressure between the filter element inlet and outlet is measured to determine the filter element life and engine life. When the filter element is clogged, the inlet pressure is much greater than the outlet pressure, forming a certain differential pressure value. Due to the structure and volume limitations of the filter element, a direct-insertion differential pressure sensor is generally used for differential pressure measurement. In some occasions (such as aircraft engine oil filtration systems), the surface temperature of the medium and equipment is extremely high, with the highest temperature reaching above 200°C, and has a very high static pressure, with a static pressure value of up to 25MPa, which will damage the differential pressure sensor to a certain extent.

[0003] Some of the existing ground equipment also uses plug-in differential pressure sensors, which are all mechanical structures and use the spring piston principle for measurement. They only have simple switching signals and large accuracy errors. The differential pressure sensors used in some aircraft engines are dual pressure sensors for difference measurement. Although this method can meet the requirements of accurate measurement and local heat dissipation and high temperature resistance, it is not suitable for use in high temperature and high static pressure conditions. The high static pressure far exceeds its overload capacity.

[0004] In view of this, the present invention is proposed to solve the above technical problems. Summary of the invention

[0005] The present invention aims to provide a direct-insertion differential pressure sensor to solve the technical problem that the existing direct-insertion differential pressure sensor is not capable of being used under high temperature and high static pressure conditions.

[0006] The technical solution of the present invention is: a direct insertion differential pressure sensor, comprising: A sensor sintering seat, a sensor chip is arranged at the bottom of the sensor sintering seat, the bottom of the sensor chip has a positive pressure end and a negative pressure end, and a brazed oil-filled pipe is arranged on the sensor sintering seat; A pressure base, a sensor sintering base is arranged on the pressure base, a circular cavity is opened in the pressure base, the circular cavity is arranged horizontally, and a positive pressure pipeline and a negative pressure pipeline that are connected to each other are opened at the bottom of the circular cavity; The differential pressure diaphragm box comprises a cylindrical diaphragm box body, which is arranged in a circular cavity. Corrugated diaphragms are arranged at both ends of the cylindrical diaphragm box body, and a central diaphragm is arranged in the cylindrical diaphragm box body. Two through holes are opened on the outer circumferential wall of the cylindrical diaphragm box body, and the brazed oil-filled pipe is connected with the through holes. A vertical hole connected with the two through holes is opened on the top wall of the circular cavity, and the two vertical holes are respectively connected with the positive pressure end and the negative pressure end.

[0007] Furthermore, the sensor sintering seat is fixedly arranged on the pressure base through an external fixing seat.

[0008] Furthermore, a sensor outer shell is also arranged on the upper end of the pressure base, and the sensor sintering seat is located in the sensor outer shell.

[0009] Furthermore, a plurality of diaphragm box sealing rings are evenly arranged on the outer peripheral wall of the cylindrical diaphragm box body, and gaps are left between the two corrugated diaphragms and the inner walls at both ends of the circular cavity to form a negative pressure cavity and a positive pressure cavity. The plurality of diaphragm box sealing rings are used to isolate the negative pressure cavity from the positive pressure cavity.

[0010] Furthermore, a membrane box end cover is fixedly provided on the end surface of the circular cavity to seal the end of the positive pressure cavity.

[0011] Furthermore, a signal conditioning circuit board is arranged on the sensor sintering seat, and the signal conditioning circuit board is connected with the sensor chip electrical signal.

[0012] Furthermore, an M12 aviation plug is provided on the top of the sensor housing, the lower end of the M12 aviation plug passes through the sensor housing, and the M12 aviation plug is electrically connected to the signal conditioning circuit board through a silicone wire.

[0013] Furthermore, a negative pressure end sealing ring and a positive pressure end sealing ring are sequentially arranged at the lower end of the pressure base from top to bottom for sealing the filter element.

[0014] Furthermore, negative pressure sealing steel balls are provided at the lower end and the negative pressure end of the negative pressure pipeline.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects: By setting up a circular cavity and a differential pressure diaphragm box, double-layer isolation is adopted so that the high-temperature medium can only reach the positive pressure cavity and the negative pressure cavity of the circular cavity, so that the high-temperature medium is isolated from the silicone oil, and the high-temperature medium is prevented from damaging the sensor chip through the vertical hole. Silicone oil, as a pressure transmission medium with excellent temperature stability, can effectively transmit pressure changes to the sensor chip without direct contact with the high-temperature fluid, so that the differential pressure of the high-temperature fluid medium can be measured, which prolongs the service life of the sensor and ensures the accuracy of the measurement. At the same time, through the central diaphragm set in the cylindrical diaphragm box body, the central diaphragm not only has high elasticity and toughness, but also can automatically adjust the state under high static pressure, disperse and absorb excess pressure, and avoid the pressure peak directly impacting the sensor chip, which greatly improves the overload protection ability of the sensor and prevents the corrugated diaphragm from being damaged by excessive pressure. The sensor chip can be used under high temperature and high static pressure conditions, which improves the overload capacity of the sensor and realizes accurate differential pressure measurement in high temperature and high static pressure environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are part of this application and are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings: Figure 1 This is a schematic diagram of the structure of the direct-insertion differential pressure sensor provided in this embodiment of the present application; Figure 2 A cross-sectional view of the direct insertion differential pressure sensor provided in this embodiment of the present application; Figure 3 A schematic diagram of the structure of the pressure base of the direct-insertion differential pressure sensor provided in this embodiment of the present application; Figure 4 This is a schematic structural diagram of the differential pressure membrane box of the direct-insertion differential pressure sensor provided in this embodiment of the present application.

[0017] Figure numerals: 1. sensor sintering seat; 2. pressure base; 3. sensor outer shell; 4. differential pressure diaphragm box; 5. external fixing seat; 6. sensor chip; 7. M12 aviation plug; 8. diaphragm box end cover; 9. signal conditioning circuit board; 10. center diaphragm; 11. negative pressure sealing steel ball; 12. brazed oil-filled pipe; 13. negative pressure end sealing ring; 14. positive pressure end sealing ring; 21. negative pressure pipeline; 22. circular cavity; 23. positive pressure pipeline; 41. cylindrical diaphragm box body; 42. corrugated diaphragm; 43. diaphragm box sealing ring; 44. through hole.

[0018] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0019] The specific implementation modes of the present invention are further described in detail with reference to the accompanying drawings.

[0020] See also Figures 1 to 4As shown, the embodiment of the present application provides a direct-insertion differential pressure sensor, including: a sensor sintering seat 1, a pressure base 2 and a differential pressure membrane box 4, a sensor chip 6 is arranged at the bottom of the sensor sintering seat 1, and the bottom of the sensor chip 6 has a positive pressure end and a negative pressure end, a brazed oil-filled pipe 12 is arranged on the sensor sintering seat 1, the sensor sintering seat 1 is welded on the pressure base 2, a circular cavity 22 is opened in the pressure base 2, the circular cavity 22 is arranged horizontally, and a positive pressure pipeline 23 and a negative pressure pipeline 21 that are connected to each other are opened at the bottom of the circular cavity 22, and the differential pressure membrane box 4 includes a cylindrical membrane box body 41, and the cylindrical membrane box body 41 is arranged in the circular cavity 22. Both ends of the cylindrical diaphragm box body 41 are provided with corrugated diaphragms 42, which together with the cylindrical diaphragm box body 41 can dissipate heat for the high-temperature medium. A central diaphragm 10 is provided inside the cylindrical diaphragm box body 41, which divides the cylindrical diaphragm box body 41 to reduce the maximum unidirectional pressure. The two corrugated diaphragms 42 respectively form a positive pressure cavity and a negative pressure cavity between the two ends of the circular cavity 22. The outer circumferential wall of the cylindrical diaphragm box body 41 is provided with two through holes 44, and the top wall of the circular cavity 22 is provided with a vertical hole connected with the two through holes 44. The two vertical holes are respectively connected with the positive pressure end and the negative pressure end, and the brazed oil-filled pipe 12 is connected with the through hole 44.

[0021] It should be noted that the brazed oil-filling tube 12 can be filled with silicone oil under vacuum, and the silicone oil enters the cylindrical diaphragm box body 41 through the internal oil circuit, vertical holes and through holes 44 of the sensor. After the silicone oil is filled, the brazed oil-filling tube 12 is welded and sealed, and the internal oil circuit of the sensor is sealed. When the differential pressure of the sensor chip 6 is monitored, the medium in the filter element is transmitted to the circular cavity 22 through the positive pressure pipeline 23 and the negative pressure pipeline 21 in the pressure base 2, and acts on the two corrugated diaphragms 42. The corrugated diaphragm 42 is deformed under pressure, pushing the silicone oil in the cylindrical diaphragm box body 41 to compress, and the silicone oil transmits the pressure to the sensor chip 6. The sensor chip 6 converts the pressure signal into an electrical signal for precise output. When the filter element is detected to be blocked, the positive pressure in the circular cavity 22 is much greater than the negative pressure.

[0022] When the positive pressure or negative pressure exceeds the unidirectional pressure of the differential pressure diaphragm box 4, the differential pressure diaphragm box 4 is attached to the central diaphragm 10 through the corrugated diaphragm 42 to prevent the sensor chip 6 from being damaged by excessive pressure. When the pressure is released, the corrugated diaphragm 42 rebounds due to elasticity, and the sensor returns to normal measurement state.

[0023] In the above scheme, the sensor chip 6 is located on the pressure base 2. Through the circular cavity 22 and the differential pressure diaphragm box 4, the high-temperature medium can only reach the positive pressure cavity and the negative pressure cavity of the circular cavity 22, so that the high-temperature medium is isolated from the silicone oil, and the high-temperature medium is prevented from damaging the sensor chip 6 through the vertical hole. Silicone oil, as a pressure transmission medium with excellent temperature stability, can effectively transmit pressure changes to the sensor chip 6 without direct contact with the high-temperature fluid, so that the differential pressure of the high-temperature fluid medium can be measured, which prolongs the service life of the sensor and ensures the accuracy of the measurement. At the same time, through the central diaphragm 10 set in the cylindrical diaphragm box body 41, the central diaphragm 10 not only has high elasticity and toughness, but also can automatically adjust the state under high static pressure, disperse and absorb excess pressure, and avoid the pressure peak directly impacting the sensor chip 6, which greatly improves the overload protection ability of the sensor, prevents the corrugated diaphragm 42 from being subjected to excessive pressure and damaging the sensor chip 6, and can be used under high temperature and high static pressure conditions, improves the overload capacity of the sensor, and realizes accurate differential pressure measurement under high temperature and high static pressure environment.

[0024] The sensor sintered seat 1 is welded to the pressure base 2 via an outer fixing seat 5 .

[0025] In some possible implementations, see Figure 1 and Figure 2 As shown, a sensor housing 3 is also welded to the upper end of the pressure base 2, the sensor sintering seat 1 is located in the sensor housing 3, the sensor chip 6 and the circuit are arranged on the upper end of the pressure base 2, and the differential pressure diaphragm box 4 is located in the pressure base 2, and a distance isolation is performed to prevent the high-temperature medium in the cylindrical diaphragm box body 41 from damaging the sensor chip 6 and the circuit. The sensor housing 3 plays a certain protective role on the sensor chip 6 and the circuit.

[0026] In some possible implementations, see Figure 2 and Figure 4 As shown, a plurality of diaphragm box sealing rings 43 are evenly arranged on the outer peripheral wall of the cylindrical diaphragm box body 41, and two corrugated diaphragms 42 leave gaps with the inner walls at both ends of the circular cavity 22 to form a negative pressure cavity and a positive pressure cavity. The plurality of diaphragm box sealing rings 43 are used to isolate the negative pressure cavity from the positive pressure cavity.

[0027] A membrane box end cover 8 is fixedly provided on the end surface of the circular cavity 22 for sealing the end of the positive pressure cavity.

[0028] In some possible implementations, see Figure 2 As shown, a signal conditioning circuit board 9 is disposed on the sensor sintering seat 1 , and the signal conditioning circuit board 9 is electrically connected to the sensor chip 6 .

[0029] In the above scheme, the signal conditioning circuit board 9 is used to convert the sensor signal into a digital signal to facilitate data acquisition, control process, execution of calculation display readout; it is also used to amplify and buffer weak signals, enhance the amplitude of the signal, and make it more suitable for subsequent processing and transmission; before digitization, the signal conditioning circuit board 9 can also remove noise from the signal to ensure the purity of the signal.

[0030] In some possible implementations, see Figure 1 and Figure 2 As shown, an M12 aviation plug 7 is provided on the top of the sensor housing 3, the lower end of the M12 aviation plug 7 passes through the sensor housing 3, and the M12 aviation plug 7 is electrically connected to the signal conditioning circuit board 9 through a silicone wire.

[0031] In the above solution, the M12 aviation plug 7 includes a plurality of contact pins with various shapes, such as needle type or hole type, to meet different connection requirements and ensure stability and reliability in harsh environments.

[0032] In some possible implementations, see Figure 2 As shown, the lower end of the pressure base 2 is provided with a negative pressure end sealing ring 13 and a positive pressure end sealing ring 14 from top to bottom, which are used to seal the filter element. The negative pressure end sealing ring 13 isolates the negative pressure, and the positive pressure end sealing ring 14 isolates the positive pressure to avoid leakage of the filter element pressure.

[0033] In some possible implementations, see Figure 2 As shown, negative pressure sealing steel balls 11 are provided at the lower end and the negative pressure end of the negative pressure pipeline 21. The negative pressure sealing steel balls 11 can form a negative pressure environment, which can effectively enhance the sealing effect and prevent the fluid medium from leaking between the sealing surfaces.

[0034] Working principle: The lower end of the pressure base 2 of the differential pressure sensor provided in the embodiment of the present application is assembled with the filter element, and after insertion, the pressure is transmitted through the negative pressure pipeline 21 and the positive pressure pipeline 23. When the fluid medium enters the negative pressure chamber and the positive pressure chamber through the negative pressure pipeline 21 and the positive pressure pipeline 23, the two corrugated diaphragms 42 are deformed after being compressed, pushing the silicone oil in the cylindrical diaphragm box body 41 to compress. The silicone oil passes through the two through holes 44 to make the sensor chip 6 feel the pressure. The sensor chip 6 converts the pressure signal into a high-precision electrical signal and transmits it to the signal conditioning circuit board 9, and finally displays the differential pressure value.

[0035] The sensor chip 6 is located on the pressure base 2. Through the circular cavity 22 and the differential pressure diaphragm box 4, the high-temperature medium can only reach the positive pressure cavity and the negative pressure cavity of the circular cavity 22, so that the high-temperature medium is isolated from the silicone oil, and the high-temperature medium is prevented from damaging the sensor chip 6 through the vertical hole. Silicone oil, as a pressure transmission medium with excellent temperature stability, can effectively transmit pressure changes to the sensor chip 6 without direct contact with the high-temperature fluid, so that the differential pressure of the high-temperature fluid medium can be measured, which prolongs the service life of the sensor and ensures the accuracy of the measurement. At the same time, through the central diaphragm 10 set in the cylindrical diaphragm box body 41, the central diaphragm 10 not only has high elasticity and toughness, but also can automatically adjust the state under high static pressure, disperse and absorb excess pressure, and avoid the pressure peak directly impacting the sensor chip 6, which greatly improves the overload protection ability of the sensor, prevents the corrugated diaphragm 42 from being subjected to excessive pressure and damaging the sensor chip 6, and can be used under high temperature and high static pressure conditions, improves the overload capacity of the sensor, and realizes accurate differential pressure measurement in high temperature and high static pressure environments.

[0036] This specific embodiment is merely an explanation of the invention and is not a limitation of the invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as they are within the scope of protection of the invention, they are protected by patent law.

Claims

1. A direct insertion differential pressure sensor, characterized in that: include: A sensor sintering seat (1), wherein a sensor chip (6) is arranged at the bottom of the sensor sintering seat (1), the bottom of the sensor chip (6) has a positive pressure end and a negative pressure end, and a brazed oil-filled tube (12) is arranged on the sensor sintering seat (1); A pressure base (2), the sensor sintering base (1) being arranged on the pressure base (2), a circular cavity (22) being provided in the pressure base (2), the circular cavity (22) being arranged transversely, and a positive pressure pipeline (23) and a negative pressure pipeline (21) being interlinked with each other being provided at the bottom of the circular cavity (22); A differential pressure diaphragm box (4), the differential pressure diaphragm box (4) comprising a cylindrical diaphragm box body (41), the cylindrical diaphragm box body (41) being arranged in the circular cavity (22), corrugated diaphragms (42) being arranged at both ends of the cylindrical diaphragm box body (41), a central diaphragm (10) being arranged in the cylindrical diaphragm box body (41), two through holes (44) being arranged on the outer circumferential wall of the cylindrical diaphragm box body (41), the brazed oil filling pipe (12) being connected to the through holes (44), a vertical hole being arranged on the top wall of the circular cavity (22) being connected to the two through holes (44), and the two vertical holes being respectively connected to the positive pressure end and the negative pressure end.

2. The direct insertion differential pressure sensor according to claim 1, characterized in that: The sensor sintering seat (1) is fixedly arranged on the pressure base (2) via an external fixing seat (5).

3. The direct insertion differential pressure sensor according to claim 2, characterized in that: A sensor outer shell (3) is also provided at the upper end of the pressure base (2), and the sensor sintering seat (1) is located inside the sensor outer shell (3).

4. The direct insertion differential pressure sensor according to claim 1, characterized in that: The outer peripheral wall of the cylindrical diaphragm box body (41) is evenly provided with a plurality of diaphragm box sealing rings (43), and the two corrugated diaphragms (42) respectively leave gaps with the inner walls at both ends of the circular cavity (22) to form a negative pressure cavity and a positive pressure cavity. The plurality of diaphragm box sealing rings (43) are used to isolate the negative pressure cavity from the positive pressure cavity.

5. The direct insertion differential pressure sensor according to claim 4, characterized in that: A membrane box end cover (8) is fixedly provided on the end surface of the circular cavity (22) and is used to seal the end of the positive pressure cavity.

6. The direct insertion differential pressure sensor according to claim 3, characterized in that: A signal conditioning circuit board (9) is arranged on the sensor sintering seat (1), and the signal conditioning circuit board (9) is electrically signal-connected to the sensor chip (6).

7. The direct insertion differential pressure sensor according to claim 6, characterized in that: An M12 aviation plug (7) is arranged on the top of the sensor outer shell (3), the lower end of the M12 aviation plug (7) passes through the sensor outer shell (3), and the M12 aviation plug (7) is electrically connected to the signal conditioning circuit board (9) via a silicone wire.

8. The direct insertion differential pressure sensor according to claim 7, characterized in that: The lower end of the pressure base (2) is provided with a negative pressure end sealing ring (13) and a positive pressure end sealing ring (14) in sequence from top to bottom, which are used to seal the filter element.

9. The direct insertion differential pressure sensor according to claim 8, characterized in that: Negative pressure sealing steel balls (11) are provided at the lower end of the negative pressure pipeline (21) and the negative pressure end.

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