A coaxial pressure sensor

Abstract

The present invention discloses a coaxial pressure sensor, comprising a pressure-inducing module, wherein a mounting portion for connecting to an external pressure source is provided below the pressure-inducing module, and a signal processing module is installed above the pressure-inducing module. Two pressure-inducing channels and two pressure-taking chambers are provided in the pressure-inducing module, and the pressure-taking chambers are horizontal thin-layer cavities. The two thin-layer cavities are distributed up and down and are parallel to each other. The two ends of the pressure-inducing channel are respectively a pressure-inducing inlet and a pressure-inducing outlet, wherein the two pressure-inducing inlets correspond one-to-one to the two pressure-taking chambers, and the pressure-inducing inlets face the corresponding pressure-taking chambers. The two pressure-inducing inlets are respectively sealed and covered with an isolation diaphragm to separate the pressure-taking chamber from the pressure-inducing inlet. The pressure-inducing module is provided with two external pressure channels for introducing an external pressure source, and the inner ends of the two external pressure channels are respectively connected to the two pressure-taking chambers. Compared with the existing conventional left and right pressure-inducing structures, the pressure-inducing module of the present invention has a compact structure, which is conducive to reducing the size of the entire sensor.

Description

Technical Field

[0001] The invention relates to a pressure measuring device, in particular to a coaxial pressure sensor. Background Art

[0002] Pressure sensors are widely used to measure fluid pressure. They rely on a pressure-sensitive element to sense external pressure. The pressure-sensitive element then converts the pressure signal into an electrical signal, which is then transmitted to a signal processing unit to obtain the pressure value. Existing pressure sensors can be divided into various types based on the pressure-sensitive element. Common ones include resistive pressure sensors, piezoelectric quartz crystal pressure sensors, and capacitive pressure sensors. The core detection element of capacitive pressure sensors is a diaphragm-type differential pressure sensor. A diaphragm-type differential pressure sensor consists of two disc-shaped diaphragm seats with a measuring diaphragm positioned between them. The two diaphragm seats are butt-welded to clamp the measuring diaphragms. A sensing cavity for silicone oil is located between the measuring diaphragm and the two diaphragm seats. Each sensing cavity is connected to a pressure-inducing tube that introduces the external pressure to be measured to either side of the measuring diaphragm. Due to the different pressures on both sides, the measuring diaphragm deforms toward the side with lower pressure, and the amount of deformation is reflected as a change in the capacitance signal. Existing capacitive pressure sensors are relatively complex due to the connection to an external pressure source and the transmission of static pressure. Summary of the Invention

[0003] In view of this, the present invention provides a coaxial pressure sensor.

[0004] The technical solution is as follows:

[0005] A coaxial pressure sensor includes a pressure-inducing module. The key feature is that a mounting portion for connecting to an external pressure source is provided below the pressure-inducing module, and a signal processing module is installed above the pressure-inducing module.

[0006] The pressure-inducing module is provided with two pressure-inducing channels and two pressure-taking cavities, wherein the pressure-taking cavities are horizontal thin-layer cavities, and the two thin-layer cavities are distributed vertically and parallel to each other;

[0007] The two ends of the pressure-introducing channel are respectively a pressure-introducing inlet and a pressure-introducing outlet, wherein the two pressure-introducing inlets correspond one to one with the two pressure-taking cavities, and the pressure-introducing inlets face the corresponding pressure-taking cavities;

[0008] The two pressure inlets are respectively sealed and covered with an isolation diaphragm to separate the pressure taking cavity from the pressure inlet;

[0009] The pressure-introducing module is provided with two external pressure channels for introducing an external pressure source, and the inner ends of the two external pressure channels are respectively communicated with the two pressure-taking chambers.

[0010] As a preferred technical solution, the two pressure-taking cavities are respectively a first thin-layer cavity and a second thin-layer cavity;

[0011] The pressure-inducing module includes a cylindrical pressure-inducing seat, a mounting blind hole is provided on the bottom surface of the pressure-inducing seat, a measuring pressure-inducing block is fixedly provided in the mounting blind hole, and the measuring pressure-inducing block and the bottom of the mounting blind hole are sealed to form the first thin-layer cavity;

[0012] A lower end cover is buckled on the bottom surface of the pressure-inducing seat, and the lower end cover and the lower surface of the measuring pressure-inducing block are sealed to form the second thin layer cavity.

[0013] As an optimal technical solution, the above-mentioned mounting blind hole is a multi-step step hole, the measuring pressure block is cylindrical, the side wall of the measuring pressure block cooperates with the step of the mounting blind hole, and the outer wall circumferential surface of the measuring pressure block is sealed and welded with the inner wall circumferential surface of the mounting blind hole.

[0014] As a preferred technical solution, the two pressure-inducing channels are respectively an atmospheric pressure-inducing channel and a measuring pressure-inducing channel, wherein the pressure-taking cavity corresponding to the atmospheric pressure-inducing channel is an atmospheric pressure-taking cavity, and the pressure-taking cavity corresponding to the measuring pressure-inducing channel is a measuring pressure-taking cavity;

[0015] The pressure inlets of the two pressure-introducing channels are respectively connected to bell mouths, the openings of the two bell mouths face the corresponding pressure-taking chambers, and the two bell mouths are respectively sealed and covered with the isolation diaphragms;

[0016] Wherein, a bell mouth is provided on the bottom of the installation blind hole, and the bell mouth is communicated with the pressure inlet of the atmospheric pressure channel;

[0017] Another bell mouth is provided on the lower surface of the pressure measuring block, and the bell mouth is communicated with the pressure inlet of the pressure measuring channel.

[0018] As a preferred technical solution, a first expansion groove is provided on the upper end surface of the pressure measuring block, the first expansion groove is directly opposite to the isolation diaphragm at the pressure inlet of the atmospheric pressure channel, and the first expansion groove is connected to the atmospheric pressure taking cavity;

[0019] A second expansion groove is formed on the inner wall of the lower end cover. The second expansion groove faces the isolation diaphragm at the pressure inlet of the pressure measuring channel and is communicated with the pressure measuring chamber.

[0020] As a preferred technical solution, the two external pressure channels are respectively a pressure channel and an atmospheric channel;

[0021] The atmospheric channel is radially opened on the pressure-inducing seat corresponding to the side wall of the atmospheric pressure-taking chamber;

[0022] A columnar pressure-taking joint is integrally formed at the center of the lower surface of the lower end cover, and the pressure-taking channel is passed through the pressure-taking joint and the center of the lower end cover.

[0023] Compared with the prior art, the present invention has the following beneficial effects: compared with the existing conventional left and right pressure-inducing structures, the pressure-inducing module of the present invention has a compact structure, which is conducive to reducing the size of the entire sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic structural diagram of the first perspective of the present invention;

[0025] Figure 2 A schematic structural diagram of the second perspective of the present invention;

[0026] Figure 3 for Figure 2 Middle AA section view;

[0027] Figure 4 It is a structural diagram of the differential pressure sensor module. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0029] like Figures 1 to 3 As shown, a coaxial pressure sensor includes a pressure module. A mounting portion for connecting to an external pressure source is provided below the pressure module, and a signal processing module is mounted above the pressure module. A differential pressure sensor module 100 is provided above the pressure module. The differential pressure sensor module 100 is provided with two pressure tubes 160. The two pressure tubes 160 are connected to two pressure channels provided on the pressure module. The pressure channels have a pressure inlet and a pressure outlet at either end. The two pressure outlets are provided on the surface of the pressure module and correspond to and connect to the two pressure tubes 160. Both pressure inlets open into the pressure module. Pressure chambers are provided within the pressure module corresponding to the two pressure inlets. Each pressure inlet is sealed with an isolation diaphragm 230 to separate the pressure chamber from the pressure inlet. The pressure channels are filled with a liquid pressure transmission medium, such as silicone oil, to transmit external pressure to the differential pressure sensor module 100.

[0030] The pressure-taking chambers are thin, horizontal cavities, with two parallel, vertically spaced cavities. A thin cavity is defined as one whose thickness does not exceed one-third of its width. The pressure-introduction module includes two external pressure channels for introducing an external pressure source. The inner ends of these channels communicate with the two pressure-taking chambers, respectively.

[0031] The pressure sensing sensor of this embodiment is used to measure gauge pressure, and therefore has two external pressure channels: a pressure channel 310 and an atmospheric channel 250. The inner end of the atmospheric channel 250 communicates with one of the pressure-taking cavities, while the outer end opens onto the surface of the pressure-introducing module. The inner end of the pressure-introducing channel 310 communicates with the other pressure-introducing cavity. The pressure-introducing module is provided with a pressure-introducing connector 300, and the outer end of the pressure-introducing channel 310 extends through the pressure-introducing connector 300. The pressure-introducing channel 310 is used to introduce external fluid into the corresponding pressure-introducing cavity.

[0032] Specifically, if Figure 3 As shown, the pressure-inducing module includes a cylindrical pressure-inducing seat 200, above which the differential pressure sensor module 100 is disposed. Two pressure-inducing outlets are respectively provided on the upper surface of the pressure-inducing seat 200, and pressure-inducing tube sockets are respectively provided at the pressure-inducing outlets. A mounting groove is provided on the upper surface of the pressure-inducing seat 200, within which the differential pressure sensor module 100 is disposed. The two pressure-inducing tubes 160 of the differential pressure sensor module 100 are respectively sealed and inserted into the corresponding pressure-inducing tube 160 sockets. The differential pressure sensor module 100 does not contact the inner wall of the mounting groove and is suspended, supported only by the two pressure-inducing tubes 160. This design is intended to prevent the differential pressure sensor module 100 from being fixedly assembled with the pressure-inducing seat 200, thereby preventing deformation of the differential pressure sensor module 100 due to assembly stress, thereby preventing deformation of the sensitive element within the differential pressure sensor module 100, namely the diaphragm 120, due to assembly. The area above the pressure-inducing seat 200 is also used to mount the signal processing module and the meter.

[0033] The pressure-taking connector 300 is provided at the lower end of the pressure-taking seat 200, and the connecting end of the pressure-taking connector 300 faces downward. The pressure-taking channel 310 is opened along the axial direction of the pressure-taking connector 300, and the upper end of the pressure-taking channel 310 is opposite to the pressure-taking cavity connected thereto.

[0034] When in use, the pressure tapping connector 300 is directly connected to the pressure source to be measured, so that the meter reading can be directly observed.

[0035] like Figure 3 As shown, the two pressure-introducing channels are respectively an atmospheric pressure-introducing channel 220 and a measuring pressure-introducing channel 210, wherein the pressure-taking chamber corresponding to the atmospheric pressure-introducing channel 220 is the atmospheric pressure-taking chamber 240, and the pressure-taking chamber corresponding to the measuring pressure-introducing channel 210 is the measuring pressure-taking chamber 260. The pressure-introducing inlets of the two pressure-introducing channels are respectively connected to bell mouths, the openings of the two bell mouths facing the corresponding pressure-taking chambers, and the two bell mouths are respectively sealed and covered with the isolation diaphragms 230. The atmospheric pressure-introducing channel 220 is used to introduce the ambient air pressure into the atmospheric pressure-taking chamber 240, and the measuring pressure-introducing channel 210 introduces the fluid to be measured into the measuring pressure-taking chamber 260. In this way, the differential pressure sensor module 100 measures gauge pressure.

[0036] The specific structure of the pressure-inducing seat 200 is as follows: a mounting blind hole is defined on the bottom surface of the mounting blind hole, and a bell mouth is defined at the bottom of the mounting blind hole. This bell mouth communicates with the pressure-inducing inlet of the atmospheric pressure-inducing channel 220. A pressure-inducing measuring block is fixedly installed within the mounting blind hole. The measuring pressure-inducing block and the bottom of the mounting blind hole are sealed to form a first thin cavity, which forms the atmospheric pressure-taking chamber 240.

[0037] The atmospheric pressure channel 220 includes two first vertical sections opened on the pressure seat 200, and the two first vertical sections are separated up and down. The upper end of the first vertical section located above forms the pressure outlet of the atmospheric pressure channel 220, and a first horizontal section is connected between the lower end of the first vertical section located above and the upper end of the first vertical section located below, and the lower end of the first vertical section located below forms the pressure inlet of the atmospheric pressure channel 220.

[0038] A first expansion groove is provided on the upper end surface of the measuring pressure block, which is opposite to the isolation diaphragm 230 at the pressure inlet of the atmospheric pressure channel 220. The first expansion groove is connected to the atmospheric pressure taking chamber 240 to increase the volume of the atmospheric pressure taking chamber 240, so that the atmospheric pressure acts more sensitively on the corresponding isolation diaphragm 230.

[0039] The atmospheric passage 250 is radially opened on the pressure-drawing seat 200 corresponding to the side wall of the atmospheric pressure-drawing cavity 240 .

[0040] The lower surface of the pressure measuring block is provided with a bell mouth, which communicates with the pressure inlet of the pressure measuring channel 210. The pressure measuring channel 210 is provided on the pressure measuring block and the pressure measuring seat 200. A lower end cover 301 is fastened to the lower end surface of the pressure measuring seat 200. The lower end cover 301 and the lower surface of the pressure measuring block form a sealed second thin layer cavity, which forms the pressure measuring chamber 260.

[0041] The pressure measurement channel 210 includes a second vertical section located above the pressure-inducing seat 200 and a second vertical section located below the pressure measurement block. The upper end of the second vertical section forms the pressure-inducing outlet of the pressure measurement channel 210, while the lower end of the second vertical section forms the pressure-inducing inlet of the pressure measurement channel 210. The pressure measurement block has a connecting cavity 270 that connects the lower end of the second vertical section located above with the lower second vertical section.

[0042] To facilitate the formation of a pressure channel and a pressure-taking cavity in the pressure seat 200: the mounting blind hole is a multi-stepped hole, and the measuring pressure block includes a cylindrical upper block 201 and a lower block 202. The diameter of the lower block 202 is larger than the diameter of the upper block 201. The upper block 201 and the upper section of the mounting blind hole are positioned by steps and the circumferential surfaces are welded and sealed. The lower block 202 and the lower section of the mounting blind hole are also positioned by steps and the circumferential surfaces are welded and sealed. The lower surface of the upper block 201 and the upper surface of the lower block 202 are separated, thereby forming the connecting cavity 270 with the inner wall of the mounting blind hole. The second vertical section located below is opened at the center of the lower block 202. The upper end of the second vertical section located below is connected to the connecting cavity 270, and the lower end is connected to the corresponding bell mouth.

[0043] A second expansion groove is provided on the inner wall of the lower end cover 301, which is opposite to the isolation diaphragm 230 at the pressure inlet of the pressure measuring channel 210. The second expansion groove is connected to the pressure measuring chamber 260 to expand the volume of the pressure measuring chamber 260, so as to facilitate the external fluid pressure to be measured to act more sensitively on the corresponding isolation diaphragm 230.

[0044] The lower end cap 301 is threadedly sealed to the lower sidewall of the pressure-drawing seat 200. A cylindrical pressure tap 300 is integrally formed in the center of the lower surface of the lower end cap 301. A pressure channel 310 extends through the center of the pressure tap 300 and the lower end cap 301. Connecting threads 320 are machined on the outer wall of the lower end of the pressure tap 300 to facilitate direct threaded connection to an external pressure source. The upper end of the pressure tap 300 has an external hexagonal outer wall 330 for easy twisting.

[0045] The pressure-inducing structure of the pressure detection sensor is simple and compact, and is very convenient to connect to an external pressure source during use, making it easy to use.

[0046] In order to improve the measurement accuracy of the capacitive differential pressure sensor and thus improve the detection accuracy of the pressure detection sensor, the differential pressure sensor module 100 is structurally improved compared to the traditional capacitive differential pressure sensor.

[0047] like Figure 4 The differential pressure sensor module 100 is provided with two sealed sensing chambers 130 separated by a diaphragm 120, and each sensing chamber 130 is connected to a pressure-inducing pipe 160. The differential pressure sensor module 100 is provided with a static pressure compensation structure corresponding to each sensing chamber 130.

[0048] The differential pressure sensor module 100 includes two disc-shaped first membrane seats 110, a metal diaphragm 120 is sandwiched between the two first membrane seats 110, the edges of the two first membrane seats 110 are butt-welded to fix the diaphragm 120, and a sealed sensing cavity 130 is formed between each first membrane seat 110 and the diaphragm 120, and each sensing cavity 130 is respectively connected to the pressure lead pipe 160.

[0049] The static pressure compensation structure is used to prevent the first diaphragm seat 110 from deforming outward under the high pressure of the liquid in the sensing chamber 130. The static pressure compensation structure includes a second diaphragm seat 140 disposed outside each first diaphragm seat 110. The second diaphragm seat 140 is sealed and fixedly connected to the outer edge of the corresponding first diaphragm seat 110. The second diaphragm seat 140 and the corresponding first diaphragm seat 110 enclose a pressure-stabilizing chamber 150, which is connected to the sensing chamber 130 located on the same side as the diaphragm 120.

[0050] The second membrane holder 140 has the same structure as the first membrane holder 110. The first membrane holder 110 has a groove on the side facing the diaphragm 120, and the groove on the second membrane holder 140 faces the corresponding outer side of the first membrane holder 110. The pressure-inducing tube 160 connected to each sensing cavity 130 is sealed outwardly through the first and second membrane holders 110, 140, and opens into the corresponding pressure-stabilizing cavity 150.

[0051] Each first membrane holder 110 has a coating electrode disposed on its inner side. The coating electrode on the inner side of each first membrane holder 110 and the corresponding side of the membrane 120 facing it form a first capacitor, i.e., a measuring capacitor. Each coating electrode on the first membrane holder 110 is connected to a first signal lead 170, which extends through the first membrane holder 110 in a sealed manner.

[0052] The inner side of the second membrane holder 140 is also provided with a coating electrode. The outer side of each first membrane holder 110 is a metal surface. The coating electrode of the second membrane holder 140 forms a second capacitor, i.e., a compensation capacitor, with the outer side of the first membrane holder 110. The coating electrode of each second membrane holder 140 is connected to a second signal lead 180, which is sealed and extends through the second membrane holder 140.

[0053] In this embodiment, the structure of the second membrane holder 140 is identical to that of the first membrane holder 110. The first membrane holder 110 comprises an inner glass disc 111 and an outer metal disc 112. A groove is defined on the inner side of the inner disc 111. The inner disc 111 and the outer disc 112 are sintered together, and the outer side and edge of the inner disc 111 are covered by the outer disc 112. The edges of the outer discs 112 of the two first membrane holders 110 clamp the diaphragm 120 and are welded together. The grooves on the second membrane holder 140 face the outer side of the corresponding first membrane holder 110.

[0054] A plated electrode is processed on the bottom surface of the groove inside the inner disk 111.

[0055] The inner disk 111 partially extends outward from the outer circumference of the outer disk 112, forming an extension block 113. The first signal lead 170 is led outward from the inner disk 111 through the extension block 113, thereby isolating the first signal lead 170 and the plated electrode from the outer disk 112. This structure is primarily for process reasons. During the manufacture of the first membrane holder 110, the first signal lead 170 is embedded within the inner disk 111 and integrally formed. The second signal lead 180 is mounted on the second membrane holder 140 in the same manner as the first signal lead 170.

[0056] The connection point between the first signal lead 170 or the second signal lead 180 and the corresponding plated electrode is close to the edge of the corresponding groove to facilitate processing.

[0057] After the sensor is assembled, all metal outer disks 112 are welded to the diaphragm 120 to form a single conductor. All outer disks 112 and diaphragm 120 are connected to the same capacitor lead. This capacitor lead and the first signal lead 170 form the two leads for the measurement capacitor, and this capacitor lead and the second signal lead 180 form the two leads for the compensation capacitor. All first signal leads 170, second signal leads 180, and capacitor leads are connected to an external signal processing circuit.

[0058] When a pressure differential exists, diaphragm 120 deforms toward the side with less pressure, causing the capacitance of the two first capacitors to change. The resulting capacitance change signals are transmitted via first signal leads 170 to external signal processing circuitry for pressure calculation. For each first diaphragm holder 110, since the hydraulic pressure within the pressure-stabilizing chamber 150 and the sensing chamber 130 on either side of it is always consistent, outward deformation of the first diaphragm holder 110 under high pressure is suppressed, thereby improving measurement accuracy. This improves measurement accuracy from a mechanical perspective.

[0059] Since silicone oil is the medium between the two plates of the second capacitor, the dielectric constant will change when its temperature changes, thereby changing the capacitance of the second capacitor. At the same time, although the outward deformation of the first membrane seat 110 is suppressed, the liquid pressure exerted on the first membrane seat 110 is transmitted to the second membrane seat 140 on the same side of the diaphragm 120, so that the second membrane seat 140 undergoes a slight outward deformation, which also changes the capacitance of the second capacitor. The capacitance change signal formed is transmitted from the second signal lead 180 to the external signal processing circuit. This signal can be used to detect parameters such as silicone oil temperature and static pressure, and can also be substituted into the calculation of pressure values ​​to correct the differential pressure value measured based on the first capacitor, further improving the measurement accuracy of the sensor from an electrical point of view.

[0060] A specific structure of the pressure-inducing pipe 160 is as follows: the pressure-inducing pipe 160 includes a straight pipe 161 and a curved pipe 162. The straight pipe 161 is disposed in the center of the first membrane seat 110, with its ends opening into the bottom surface of the groove of the inner disc 111 and the outer surface of the outer disc 112, respectively. The wall of the straight pipe 161 is sealed against the inner disc 111 and the outer disc 112.

[0061] The curved tube 162 is passed through the center of the second membrane seat 140, and the inner end of the curved tube 162 opens to the bottom surface of the groove of the second membrane seat 140. The inner end of the curved tube 162 is opposite to the outer end of the straight tube 161, and the outer end of the curved tube 162 passes out of the second membrane seat 140, and the outer wall of the curved tube 162 is sealed with the second membrane seat 140.

[0062] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention. Such changes fall within the scope of protection of the present invention.

Claims

1. A coaxial pressure sensor, comprising a pressure-drawing module, characterized in that: A mounting portion for connecting to an external pressure source is provided below the pressure-inducing module, and a signal processing module is installed above the pressure-inducing module; The pressure-inducing module is provided with two pressure-inducing channels and two pressure-taking cavities, wherein the pressure-taking cavities are horizontal thin-layer cavities, and the two thin-layer cavities are distributed vertically and parallel to each other; The two ends of the pressure-introducing channel are respectively a pressure-introducing inlet and a pressure-introducing outlet, wherein the two pressure-introducing inlets correspond one to one with the two pressure-taking cavities, and the pressure-introducing inlets face the corresponding pressure-taking cavities; The two pressure inlets are respectively sealed and covered with an isolation diaphragm (230) to separate the pressure taking cavity from the pressure inlet; The pressure-introducing module is provided with two external pressure channels for introducing an external pressure source, and the inner ends of the two external pressure channels are respectively connected to the two pressure-taking chambers; The two external pressure channels are a pressure channel (310) and an atmospheric channel (250), the inner end of the atmospheric channel (250) is connected to one of the pressure-taking cavities, and the outer end opens to the surface of the pressure-leading module; the inner end of the pressure channel (310) is connected to the other pressure-taking cavity, and the pressure-leading module is provided with a pressure-leading connector (300), the outer end of the pressure channel (310) passes through the pressure-leading connector (300), and the pressure channel (310) is used to introduce external fluid into the corresponding pressure-leading cavity.

2. The coaxial pressure sensor according to claim 1, characterized in that: The two pressure-taking cavities are respectively a first thin-layer cavity and a second thin-layer cavity; The pressure-inducing module comprises a cylindrical pressure-inducing seat (200), a mounting blind hole being provided on the bottom surface of the pressure-inducing seat (200), a measuring pressure-inducing block being fixedly provided in the mounting blind hole, and the measuring pressure-inducing block and the bottom of the mounting blind hole being sealed to form the first thin-layer cavity; A lower end cover (301) is buckled on the bottom surface of the pressure-inducing seat (200), and the lower end cover (301) and the lower surface of the measuring pressure-inducing block are sealed to form the second thin layer cavity.

3. The coaxial pressure sensor according to claim 2, characterized in that: The mounting blind hole is a multi-step hole, the measuring pressure block is cylindrical, the side wall of the measuring pressure block cooperates with the steps of the mounting blind hole, and the outer wall circumference of the measuring pressure block is sealed and welded with the inner wall circumference of the mounting blind hole.

4. The coaxial pressure sensor according to claim 3, characterized in that: The two pressure-inducing channels are respectively an atmospheric pressure-inducing channel (220) and a measuring pressure-inducing channel (210), wherein the pressure-taking cavity corresponding to the atmospheric pressure-inducing channel (220) is an atmospheric pressure-taking cavity (240), and the pressure-taking cavity corresponding to the measuring pressure-inducing channel (210) is a measuring pressure-taking cavity (260); The pressure inlets of the two pressure-introducing channels are respectively connected to bell mouths, the openings of the two bell mouths face the corresponding pressure-taking chambers, and the two bell mouths are respectively sealed and covered with the isolation diaphragms (230); A bell mouth is provided on the bottom of the blind hole, and the bell mouth is connected to the pressure inlet of the atmospheric pressure channel (220); Another bell mouth is provided on the lower surface of the pressure measuring block, and the bell mouth is communicated with the pressure inlet of the pressure measuring channel (210).

5. The coaxial pressure sensor according to claim 4, characterized in that: A first expansion groove is provided on the upper end surface of the pressure measuring block, the first expansion groove being directly opposite to the isolation diaphragm (230) at the pressure inlet of the atmospheric pressure channel (220), and the first expansion groove being in communication with the atmospheric pressure taking cavity (240); A second expansion groove is provided on the inner wall of the lower end cover (301), the second expansion groove being directly opposite to the isolation diaphragm (230) at the pressure inlet of the pressure measuring channel (210), and the second expansion groove being in communication with the pressure measuring chamber (260).

6. The coaxial pressure sensor according to claim 4, characterized in that: The atmospheric pressure channel (250) is radially opened on the pressure-inducing seat (200) corresponding to the side wall of the atmospheric pressure-taking cavity (240); A columnar pressure-taking joint (300) is integrally formed at the center of the lower surface of the lower end cover (301), and the pressure-taking passage (310) passes through the pressure-taking joint (300) and the center of the lower end cover (301).

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