An axial lead differential pressure sensor

Abstract

The present invention discloses a direct plug-in differential pressure sensor, which relates to the technical field of differential pressure measurement. It includes a sensor sintering base, a pressure base, and a differential pressure diaphragm box. The differential pressure diaphragm box includes a cylindrical diaphragm box body, which is arranged in a circular cavity. Corrugated diaphragms are provided at both ends of the cylindrical diaphragm box body. A central diaphragm is arranged inside the cylindrical diaphragm box body. A vertical hole communicating with two through holes is opened on the top wall of the circular cavity, and the two vertical holes are respectively communicated with the positive pressure end and the negative pressure end. By providing the circular cavity and the differential pressure diaphragm box, the high-temperature medium can only reach the positive pressure chamber and the negative pressure chamber of the circular cavity, isolating the high-temperature medium from the silicone oil, avoiding damage to the sensor chip caused by the high-temperature medium, so that the differential pressure of the high-temperature fluid medium can be measured. By providing the central diaphragm inside the cylindrical diaphragm box body, it is prevented that the pressure received by the corrugated diaphragm is too large and damages the sensor chip, and it can be used under high static pressure conditions, improving the overload capacity of the sensor.

Description

Technical Field

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

[0002] In the prior art, when measuring the operating conditions of the fuel filter element at the fuel supply end in an aeroengine, a heavy-duty loading vehicle engine, or a hydraulic system, the differential pressure between the inlet and outlet of the filter element is measured to determine the life of the filter element and the engine life. When the filter element is blocked, the inlet pressure is much greater than the outlet pressure, forming a certain differential pressure value. Due to the structural and volume limitations of the filter element, a direct insertion type differential pressure sensor is generally used for differential pressure measurement. In some cases (such as the oil filtering system of an aeroengine), the temperature of the medium and the surface of the equipment is extremely high, with the maximum temperature reaching over 200 °C, and there is a very high static pressure, with the static pressure value reaching 25 MPa, which will damage the differential pressure sensor to a certain extent.

[0003] In existing ground equipment, there are also some that use insertion type differential pressure sensors, all of which are mechanical structures and use the spring piston principle for measurement. They only have simple switch signals and large accuracy errors; some aeroengines use differential pressure sensors that perform subtraction using two pressure sensors. Although this usage can meet accurate measurement and local heat dissipation and high temperature resistance, it still cannot be used under high temperature and high static pressure conditions, and the high static pressure far exceeds its overload capacity.

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

[0005] The purpose of the present invention is to provide a direct insertion type differential pressure sensor to solve the technical problem that the existing direct insertion type differential pressure sensors cannot be used under high temperature and high static pressure conditions.

[0006] The technical solution of the present invention is: a direct insertion type differential pressure sensor, comprising:

[0007] A sensor sintering base, a sensor chip is arranged at the bottom of the sensor sintering base, the bottom of the sensor chip has a positive pressure end and a negative pressure end, a brazing filling oil pipe is arranged on the sensor sintering base, a signal conditioning circuit board is arranged on the sensor sintering base, and the signal conditioning circuit board is electrically connected to the sensor chip;

[0008] A pressure base, the sensor sintering base is arranged on the pressure base, a circular cavity is opened in the pressure base, the circular cavity is arranged horizontally, a positive pressure pipeline and a negative pressure pipeline that communicate with each other are opened at the bottom of the circular cavity, a sensor housing is further arranged at the upper end of the pressure base, the sensor sintering base is located inside the sensor housing, an M12 aviation plug is arranged at the top of the sensor housing, the lower end of the M12 aviation plug penetrates through the sensor housing, and the M12 aviation plug is electrically connected to the signal conditioning circuit board through a silica gel wire;

[0009] Differential pressure diaphragm box, the differential pressure diaphragm box includes a cylindrical diaphragm box body, the cylindrical diaphragm box body is arranged in a circular cavity, corrugated diaphragms are arranged at both ends of the cylindrical diaphragm box body, a central diaphragm is arranged inside the cylindrical diaphragm box body, two through holes are opened on the outer circumferential wall of the cylindrical diaphragm box body, a brazed filling oil pipe is communicated with the through holes, vertical holes communicated with the two through holes are opened on the top wall of the circular cavity, and the two vertical holes are respectively communicated with the positive pressure end and the negative pressure end.

[0010] Further, the sensor sintering seat is fixedly arranged on the pressure base through an outer fixing seat.

[0011] Further, a plurality of diaphragm box sealing rings are uniformly arranged on the outer peripheral wall of the cylindrical diaphragm box body, 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, and the plurality of diaphragm box sealing rings are used to isolate the negative pressure cavity from the positive pressure cavity.

[0012] Further, a diaphragm box end cover is fixedly arranged on the end face of the circular cavity for sealing the end of the positive pressure cavity.

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

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

[0015] By adopting the above technical solutions, the present invention has the following beneficial effects:

[0016] By arranging the circular cavity and the differential pressure diaphragm box and adopting double-layer isolation, 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, avoiding damage to the sensor chip by the high-temperature medium passing through the vertical hole. The silicone oil, as a pressure transmission medium with excellent temperature stability, can effectively transmit the pressure change to the sensor chip without directly contacting the high-temperature fluid, so that the differential pressure of the high-temperature fluid medium can be measured, the service life of the sensor is prolonged and the measurement accuracy is ensured. At the same time, through the central diaphragm arranged inside the cylindrical diaphragm box body, the central diaphragm not only has high elasticity and toughness, but also can automatically adjust its state under high static pressure conditions, disperse and absorb the excess pressure, avoiding the direct impact of the pressure peak on the sensor chip, greatly improving the overload protection ability of the sensor, preventing the pressure on the corrugated diaphragm from being too large and damaging the sensor chip, and can be used under high-temperature and high-static pressure conditions, improving the overload capacity of the sensor, and realizing accurate differential pressure measurement in high-temperature and high-static pressure environments. Description of the Drawings

[0017] The accompanying drawings, as part of this application, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation to the present invention. Obviously, the accompanying drawings in the following description are only some embodiments. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. In the drawings:

[0018] Figure 1 is a schematic structural diagram of the direct insertion differential pressure sensor provided in this embodiment of the present application;

[0019] Figure 2 is a cross-sectional view of the direct insertion differential pressure sensor provided in this embodiment of the present application;

[0020] Figure 3 is a schematic structural diagram of the pressure base of the direct insertion differential pressure sensor provided in this embodiment of the present application;

[0021] Figure 4 is a schematic structural diagram of the differential pressure diaphragm box of the direct insertion differential pressure sensor provided in this embodiment of the present application.

[0022] Reference numerals: 1, sensor sintering base; 2, pressure base; 3, sensor housing; 4, differential pressure diaphragm box; 5, outer fixing base; 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, brazing filling oil 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.

[0023] It should be noted that these drawings and text descriptions are not intended to limit the scope of the concept of the present invention in any way, but to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Description of the Specific Embodiments

[0024] The specific embodiments of the present invention will be further described in detail in conjunction with the accompanying drawings.

[0025] See Figures 1 to 4As shown in the figure, an embodiment of the present application provides a direct plug-in differential pressure sensor, including: a sensor sintering base 1, a pressure base 2, and a differential pressure diaphragm box 4. A sensor chip 6 is provided at the bottom of the sensor sintering base 1. The bottom of the sensor chip 6 has a positive pressure end and a negative pressure end. A brazing filling oil pipe 12 is provided on the sensor sintering base 1. A signal conditioning circuit board 9 is provided on the sensor sintering base 1. The signal conditioning circuit board 9 is electrically connected to the sensor chip 6. The signal conditioning circuit board 9 is used to convert the signal of the sensor into a digital signal for easy data acquisition, control process, and execution of calculation and display reading; it is also used for amplifying and buffering weak signals to 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 denoise the signal to ensure the purity of the signal. The sensor sintering base 1 is welded to the pressure base 2. A circular cavity 22 is provided in the pressure base 2. The circular cavity 22 is horizontally arranged. A positive pressure pipeline 23 and a negative pressure pipeline 21 that communicate with each other are provided at the bottom of the circular cavity 22. A sensor housing 3 is also welded to the upper end of the pressure base 2. The sensor sintering base 1 is located inside the sensor housing 3. The sensor chip 6 and the circuit are arranged at the upper end of the pressure base 2. The differential pressure diaphragm box 4 is located inside the pressure base 2 for distance isolation 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 for the sensor chip 6 and the circuit. An M12 aviation plug 7 is provided at the top of the sensor housing 3. The lower end of the M12 aviation plug 7 penetrates the sensor housing 3, and the M12 aviation plug 7 is electrically connected to the signal conditioning circuit board 9 through a silica gel wire. The M12 aviation plug 7 includes a plurality of contact pins with various shapes, such as pin type or hole type, to adapt to different connection requirements and ensure stability and reliability in harsh environments. The differential pressure diaphragm box 4 includes a cylindrical diaphragm box body 41. The cylindrical diaphragm box body 41 is arranged in the circular cavity 22. Corrugated diaphragms 42 are provided at both ends of the cylindrical diaphragm box body 41. The corrugated diaphragms 42 and the cylindrical diaphragm box body 41 can play a role in dissipating heat from the high-temperature medium. A center diaphragm 10 is provided inside the cylindrical diaphragm box body 41. The center diaphragm 10 divides the cylindrical diaphragm box body 41 to reduce the one-way maximum pressure. A positive pressure chamber and a negative pressure chamber are respectively formed between the two corrugated diaphragms 42 and both ends of the circular cavity 22. Two through holes 44 are provided on the outer circumferential wall of the cylindrical diaphragm box body 41. Vertical holes communicating with the two through holes 44 are provided on the top wall of the circular cavity 22. The two vertical holes are respectively communicated with the positive pressure end and the negative pressure end. The brazing filling oil pipe 12 is communicated with the through hole 44.

[0026] It should be noted that the brazed filling oil pipe 12 can be filled with silicone oil under vacuum. The silicone oil enters the cylindrical diaphragm box body 41 through the internal oil circuit of the sensor, the vertical holes and the through holes 44. After the silicone oil filling is completed, the brazed filling oil pipe 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 diaphragms 42 are deformed under pressure, pushing the silicone oil in the cylindrical diaphragm box body 41 to be compressed. The silicone oil transmits the pressure to the sensor chip 6, and the sensor chip 6 converts the pressure signal into an electrical signal for accurate output. When it is monitored that the filter element is blocked, the positive pressure in the circular cavity 22 is much greater than the negative pressure.

[0027] When the positive pressure or negative pressure exceeds the one-way pressure of the differential pressure diaphragm box 4, the differential pressure diaphragm box 4 adheres to the central diaphragm 10 through the corrugated diaphragm 42 to prevent the sensor chip 6 from being damaged due to excessive pressure. When relieving pressure, the corrugated diaphragm 42 rebounds due to elasticity, and the sensor returns to the normal measurement state.

[0028] In the above solution, the sensor chip 6 is located on the pressure base 2. By setting the circular cavity 22 and the differential pressure diaphragm box 4, the high-temperature medium can only reach the positive pressure chamber and the negative pressure chamber of the circular cavity 22, separating the high-temperature medium from the silicone oil, and preventing the high-temperature medium from damaging the sensor chip 6 through the vertical holes. As a pressure transmission medium with excellent temperature stability, the silicone oil can effectively transmit the pressure change to the sensor chip 6 without directly contacting the high-temperature fluid, so that the differential pressure of the high-temperature fluid medium can be measured, extending the service life of the sensor and ensuring the measurement accuracy. At the same time, by setting the central diaphragm 10 in the cylindrical diaphragm box body 41, the central diaphragm 10 not only has high elasticity and toughness, but also can automatically adjust its state under high static pressure conditions, dispersing and absorbing the excess pressure, avoiding the direct impact of the pressure peak on the sensor chip 6, greatly enhancing the overload protection ability of the sensor, preventing the corrugated diaphragm 42 from being damaged due to excessive pressure on the sensor chip 6, and can be used under high-temperature and high-static pressure conditions, improving the overload capacity of the sensor, and realizing accurate differential pressure measurement in high-temperature and high-static pressure environments.

[0029] The sensor sintering seat 1 is welded to the pressure base 2 through the outer fixing seat 5.

[0030] In some possible implementation schemes, as shown in Figure 2 and Figure 4 A plurality of diaphragm box sealing rings 43 are uniformly arranged on the outer peripheral wall of the cylindrical diaphragm box body 41. There are gaps between the two corrugated diaphragms 42 and the inner walls at both ends of the circular cavity 22, forming a negative pressure chamber and a positive pressure chamber. The plurality of diaphragm box sealing rings 43 are used to isolate the negative pressure chamber and the positive pressure chamber.

[0031] A diaphragm cell end cover 8 is fixedly arranged at the end face of the circular cavity 22 for sealing the end of the positive pressure chamber.

[0032] In some possible embodiments, as shown in Figure 2 As shown, a negative pressure end sealing ring 13 and a positive pressure end sealing ring 14 are sequentially arranged from top to bottom at the lower end of the pressure base 2 for sealing 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, avoiding the leakage of the filter element pressure.

[0033] In some possible embodiments, as shown in Figure 2 As shown, negative pressure sealing steel balls 11 are arranged at the lower end of the negative pressure pipeline 21 and the negative pressure end. The negative pressure sealing steel balls 11 can form a negative pressure environment, effectively enhancing the sealing effect and preventing fluid media from leaking between the sealing surfaces.

[0034] Working principle:

[0035] 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. After insertion, 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 under pressure, pushing the silicone oil in the cylindrical diaphragm cell body 41 to be compressed. The silicone oil enables the sensor chip 6 to sense the pressure through the two through holes 44. 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 the differential pressure value is displayed.

[0036] The sensor chip 6 is located on the pressure base 2. By providing the circular cavity 22 and the differential pressure diaphragm cell 4, the high-temperature medium can only reach the positive pressure chamber and the negative pressure chamber of the circular cavity 22, isolating the high-temperature medium from the silicone oil and avoiding damage to the sensor chip 6 by the high-temperature medium through the vertical holes. The silicone oil, as a pressure transmission medium with excellent temperature stability, can effectively transmit the pressure change to the sensor chip 6 without directly contacting the high-temperature fluid, so that the differential pressure of the high-temperature fluid medium can be measured, extending the service life of the sensor and ensuring the measurement accuracy. At the same time, by providing the central diaphragm 10 in the cylindrical diaphragm cell body 41, the central diaphragm 10 not only has high elasticity and toughness, but also can automatically adjust its state under high static pressure conditions, dispersing and absorbing the excess pressure, avoiding the direct impact of the pressure peak on the sensor chip 6, greatly enhancing the overload protection ability of the sensor, preventing the corrugated diaphragm 42 from being damaged due to excessive pressure on the sensor chip 6, enabling it to be used under high-temperature and high-static pressure conditions, improving the overload capacity of the sensor, and achieving accurate differential pressure measurement in high-temperature and high-static pressure environments.

[0037] This specific embodiment is only an interpretation of the invention and not a limitation thereof. After reading this specification, those skilled in the art may make modifications to this embodiment that do not contribute creatively as needed, but as long as they are within the protection scope of the present invention, they are protected by the patent law.

Claims

1. A direct-insert differential pressure sensor, characterized in that, Comprising: A sensor sintering base (1), a sensor chip (6) is arranged at the bottom of the sensor sintering base (1), the bottom of the sensor chip (6) has a positive pressure end and a negative pressure end, a brazing filling oil pipe (12) is arranged on the sensor sintering base (1), a signal conditioning circuit board (9) is arranged on the sensor sintering base (1), and the signal conditioning circuit board (9) is electrically connected to the sensor chip (6); A pressure base (2), the sensor sintering base (1) is arranged on the pressure base (2), a circular cavity (22) is formed in the pressure base (2), the circular cavity (22) is horizontally arranged, a positive pressure pipeline (23) and a negative pressure pipeline (21) which are communicated with each other are arranged at the bottom of the circular cavity (22), a sensor outer housing (3) is further arranged at the upper end of the pressure base (2), the sensor sintering base (1) is located inside the sensor outer housing (3), an M12 aviation plug (7) is arranged at the top of the sensor outer housing (3), the lower end of the M12 aviation plug (7) penetrates through the sensor outer housing (3), and the M12 aviation plug (7) is electrically connected to the signal conditioning circuit board (9) through a silica gel wire; A differential pressure diaphragm box (4), the differential pressure diaphragm box (4) comprises a cylindrical diaphragm box body (41), the cylindrical diaphragm box body (41) is arranged in the circular cavity (22), corrugated diaphragms (42) are arranged at both ends of the cylindrical diaphragm box body (41), a center diaphragm (10) is arranged inside the cylindrical diaphragm box body (41), two through holes (44) are formed in the outer circumferential wall of the cylindrical diaphragm box body (41), the brazing filling oil pipe (12) is communicated with the through holes (44), vertical holes communicated with the two through holes (44) are formed in the top wall of the circular cavity (22), and the two vertical holes are respectively communicated with the positive pressure end and the negative pressure end.

2. The direct-insert differential pressure sensor according to claim 1, wherein The sensor sintering base (1) is fixedly arranged on the pressure base (2) through an outer fixing base (5).

3. The direct-insert differential pressure sensor according to claim 2, wherein A plurality of diaphragm box sealing rings (43) are uniformly arranged on the outer peripheral wall of the cylindrical diaphragm box body (41), gaps are left between the two corrugated diaphragms (42) and the inner walls at both ends of the circular cavity (22) to form a negative pressure cavity and a positive pressure cavity, and the plurality of diaphragm box sealing rings (43) are used for isolating the negative pressure cavity from the positive pressure cavity.

4. The plug-in differential pressure sensor according to claim 3, wherein, A diaphragm box end cover (8) is fixedly arranged at the end face of the circular cavity (22) for sealing the end of the positive pressure cavity.

5. The direct plug-in differential pressure sensor according to claim 2, wherein A negative pressure end sealing ring (13) and a positive pressure end sealing ring (14) are sequentially arranged from top to bottom at the lower end of the pressure base (2) for sealing the filter element.

6. The plug-in differential pressure sensor according to claim 1, wherein Negative pressure sealing steel balls (11) are arranged at the lower end of the negative pressure pipeline (21) and the negative pressure end.

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