Pressure sensitive assembly of single-core differential pressure sensor

Abstract

The invention belongs to the field of pressure sensors, and particularly relates to a pressure sensitive assembly of a single-core differential pressure sensor. The structural scheme of a pressure sensitive assembly of a single-core differential pressure sensor is complex, and the technological feasibility of the welding process is low. According to the pressure sensitive assembly of the single-core differential pressure sensor, a cover plate is welded to the upper end of a sleeve in a sealed mode, a filler neck is welded to the outer edge of the lower end of the sleeve in a sealed mode, an annular body structure is arranged in the sleeve, the upper end and the lower end of a differential pressure core are welded to the annular body structure in a sealed mode, and the annular body structure is further provided with a plurality of drainage holes communicating cavities in the upper side and the lower side; the cup body part at the upper end of the flow guide pipe is hermetically welded with the lower end of the annular body structure; the filler neck is provided with a first air inlet communicated with the stepped hole; miniaturization, structure stabilization and process convenience of the differential pressure sensor are achieved, feasibility and convenience of the process are met, and the differential pressure sensor has high practical application value.

Description

Technical Field

[0001] The present invention belongs to the field of pressure sensors, and in particular relates to a pressure sensitive component of a single-core pressure differential sensor, which improves the structural stability, process feasibility and miniaturization of the single-core pressure differential sensor. Background Art

[0002] In the application field of pressure sensors, the pressure difference between two points needs to be accurately measured and converted into a readable electrical signal for further processing and application.

[0003] Traditional differential pressure sensors are mostly made of dual cores, which have poor structural space optimization and low stability. For sensors on aircraft, miniaturization is the general trend of development. The corresponding pressure sensors must meet customer needs in terms of structural stability and external dimensions while ensuring that the performance meets the requirements. The pressure sensitive components of single-core differential pressure sensors have a more complex structural solution, with many welds, high coaxiality requirements during welding, low process feasibility, and an overall center of gravity layout offset, which affects durability requirements. Its structure is as follows: Figure 1 As shown, there is an additional air duct connecting the upper and lower cavities on the outside of the product shell. Summary of the invention

[0004] The purpose of the present invention is to provide a pressure sensitive component of a single-core differential pressure sensor, which not only meets the conventional pressure measurement function of the differential pressure sensor, but also meets the customer's demand for miniaturization of the sensor and improves its process feasibility and structural stability.

[0005] The technical solution of the present invention is: a pressure sensitive component of a single-core pressure difference sensor, the component includes a cover plate, a pressure difference core, a sleeve, a guide tube and a pipe nozzle, the cover plate is seal-welded at the upper end of the sleeve, the pipe nozzle is seal-welded at the outer edge of the lower end of the sleeve, an annular body structure is provided inside the sleeve, the upper and lower ends of the pressure difference core are seal-welded on the annular body structure, the annular body structure also has a plurality of drainage holes connecting the upper and lower side cavities; the cup body part at the upper end of the guide tube accommodates the lower end of the pressure difference core and is seal-welded with the lower end of the annular body structure, the lower end of the guide tube penetrates into the stepped hole of the pipe nozzle and is seal-welded at the lower end face; the pipe nozzle has a first air inlet connected to the stepped hole, and the lower end of the guide tube is a second air inlet.

[0006] Advantageously, the annular structure has a stepped hole at the upper end, and the upper side of the pressure difference core is placed on the stepped hole for sealing welding.

[0007] Advantageously, the lower end of the annular body structure and the upper end of the guide tube form a nested structure, and the two are tightly inserted and sealed and welded.

[0008] Advantageously, the cover plate is seal-welded in the stepped hole at the upper end of the sleeve.

[0009] Advantageously, the lower end of the guide pipe is flush with the lower end of the filler nozzle or slightly protrudes from the filler nozzle.

[0010] Advantageously, the sleeve further has a process hole penetrating the inside and the outside.

[0011] Advantageously, the stepped hole comprises a large diameter portion, a middle diameter portion and a small diameter portion, the cup portion is located in the large diameter portion, the first air inlet is located in the middle diameter portion, and the lower end of the guide tube is clearance-matched with the small diameter portion.

[0012] Advantageously, the space on the upper side of the annular structure is the upper pressure-sensing chamber I, the space inside the cup body is the lower pressure-sensing chamber III, and the space outside the cup body is the transition chamber II.

[0013] In order to improve the structural stability and process feasibility of the sensor, the pressure sensitive component has been optimized in the following aspects.

[0014] 1. The sleeve structure adopts a symmetrical design. The core body only needs to be placed from the upper end of the sleeve and matched with the wire outlet hole before welding, without the need for additional clamps for auxiliary fixing.

[0015] 2. The drainage holes inside the sleeve can be adjusted according to the changes in the medium and sensor weight requirements, achieving adaptability to different media and weight requirements.

[0016] 3. The overall center of gravity of the guide device is in the middle of the entire sensor, which improves the stability and durability of the overall structure.

[0017] 4. The overall welding and installation of the guide device does not require unnecessary and complicated positioning.

[0018] The beneficial effects of the present invention are as follows: the present invention realizes the miniaturization, structural stabilization and process convenience of the differential pressure sensor, meets the feasibility and convenience of the process, and has great practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the pressure sensitive component of a conventional single-core differential pressure sensor;

[0020] Figure 2 An exploded view of a pressure sensitive component of a single-core differential pressure sensor of the present invention;

[0021] Figure 3 It is a cross-sectional view of a pressure sensitive component of a single-core differential pressure sensor of the present invention;

[0022] Figure 4 Schematic diagram of air flow direction in working state.

[0023] 1. Cover plate, 2. Pressure difference core, 3. Sleeve, 4. Flow guide tube, 5. Take-over nozzle, 6. Ring structure, 7. First air inlet, 8. Step hole, 9. Process hole, 10. Second air inlet, 11. Drainage hole DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0025] See also Figure 2-3 In the illustrated embodiment, the pressure sensitive component of the single-core pressure difference sensor mainly includes a cover plate 1 , a pressure difference core 2 , a sleeve 3 , a flow guide tube 4 and a nozzle 5 .

[0026] The sleeve 3 is made of stainless steel, and is mainly responsible for fixing the pressure differential core 2 and guiding the side pressure of the nozzle 5, and leaving space for the outlet of the pressure differential core 2. The inner side of the sleeve 3 has an annular structure 6, and the pressure differential core 2 is sealed and installed in the axial hole of the annular structure 6. In this embodiment, the pressure sensing ends on both sides of the axial hole are realized by laser welding. The annular structure 6 also has a plurality of axial drainage holes 11 arranged symmetrically. The drainage holes 11 are mainly used to guide the medium pressure in the transition chamber II to the upper end pressure sensing chamber I. The outer edge of the lower end of the sleeve 3 is laser welded with the nozzle 5 to achieve a sealed installation, and the inner edge of the lower end of the annular structure 6 is laser welded with the guide tube 4 to achieve a sealed installation. The outlet hole of the sleeve 3 does not affect the pressure drainage while ensuring the outlet. The pressure differential core 2 is located at the center of the sleeve 3, and the pressure differential core 3 can be placed in the axial hole of the annular structure 6 for laser welding without the need for additional welding fixtures.

[0027] The nozzle 5 is an annular structure, and the axial hole inside it is a stepped hole 8. The nozzle 5 has a radial first air inlet 7 in the middle diameter area of ​​the stepped hole 8. The guide tube 4 is inserted into the stepped hole 8. The cup body part at the upper end of the guide tube 4 is located in the large diameter area of ​​the stepped hole 8, and the upper end face of the cup body part is welded to the inner edge of the lower end of the annular structure 7. The lower end of the guide tube 4 passes through the small diameter area of ​​the stepped hole 8 and is welded to the nozzle 5 at the end face. A transition chamber II is formed between the lower side of the cup body part and the stepped hole 8. The opening at the lower end of the guide tube 4 is a second air inlet 10, through which the medium pressure is guided to the pressure sensing chamber III at the lower end of the cup body part.

[0028] The cover plate 1 is made of stainless steel and is mainly responsible for encapsulating the opening at the upper end of the sleeve 3 and sealing the upper end pressure sensing cavity.

[0029] During installation, the annular structure of the sleeve 3 and the pressure difference core 2 are sealed and fixed by laser welding through the weld B at the upper end and the weld C at the lower end, and the sleeve 3 and the guide tube 4 are sealed and fixed by laser welding through the weld D. The guide tube 4 is inserted into the axial hole of the nozzle 5, and the sleeve 3 is sealed by laser welding to the upper end of the nozzle 5 through the weld E, and the lower end of the nozzle 5 is sealed by laser welding to the guide tube 4 through the weld F, and the upper end of the sleeve 3 and the cover plate 1 are sealed and fixed by laser welding through the weld A.

[0030] Thus, the medium pressure at the lower end of the sensor is led from the second air inlet 10 of the guide tube 4 to the lower pressure-sensitive diaphragm of the pressure differential core 2, and this area is the lower pressure-sensitive cavity III. The medium pressure is led from the first air inlet 7 on the side of the nozzle 5 to the upper pressure-sensitive diaphragm of the sleeve 3, and this area is the upper pressure-sensitive cavity I. The pressure at both ends is separated, and outlet holes are opened at both ends of the sleeve 3. The pressure at the lower end of the sensor is stably guided to the upper part of the core while ensuring the outlet space of the pressure differential core.

[0031] The outer diameter of the pressure sensitive component is small, which can reach Φ23mm, and the size of the pressure sensitive component can be further reduced according to the size of the pressure differential core. The process feasibility is high, with only 6 welds, and no additional installation fixtures are required. The production efficiency of workers is improved. The structure is highly stable and can adapt to the requirements of the sensor for environmental adaptability, and can meet the assessment of vibration, impact and other tests, and the requirements of different pressure media.

Claims

1. A pressure sensitive component of a single-core differential pressure sensor, characterized in that: The assembly comprises a cover plate (1), a pressure difference core (2), a sleeve (3), a guide tube (4) and a take-off nozzle (5); the cover plate (1) is seal-welded at the upper end of the sleeve (3); the take-off nozzle (5) is seal-welded at the outer edge of the lower end of the sleeve (3); an annular structure (6) is provided inside the sleeve (3); the upper and lower ends of the pressure difference core (2) are seal-welded to the annular structure; the annular structure (6) also has a plurality of drainage holes (11) connecting the upper and lower cavities; the cup body portion at the upper end of the guide tube (4) accommodates the lower end of the pressure difference core (2) and is seal-welded to the lower end of the annular structure (6); the lower end of the guide tube (4) penetrates into the stepped hole (8) of the take-off nozzle (5) and is seal-welded at the lower end surface; the take-off nozzle (5) has a first air inlet (7) connected to the stepped hole (8); the lower end of the guide tube (4) is a second air inlet (10).

2. The pressure sensitive component of the single-core pressure differential sensor according to claim 1, characterized in that: The annular structure (6) has a stepped hole at the upper end, and the upper side of the pressure difference core (2) is placed on the stepped hole for sealing welding.

3. The pressure sensitive component of the single-core differential pressure sensor according to claim 1, characterized in that: The lower end of the annular structure (6) and the upper end of the flow guide tube (4) form a nested structure, and the two are tightly inserted and sealed and welded.

4. The pressure sensitive component of the single-core differential pressure sensor according to claim 1, characterized in that: The cover plate (1) is seal-welded in the stepped hole at the upper end of the sleeve (3).

5. The pressure sensitive component of the single-core differential pressure sensor according to claim 1, characterized in that: The lower end of the flow guide pipe (4) is flush with the lower end of the filling nozzle (5) or slightly protrudes from the filling nozzle (5).

6. The pressure sensitive component of the single-core differential pressure sensor according to claim 1, characterized in that: The sleeve (3) also has a process hole (9) that penetrates the inside and outside.

7. The pressure sensitive component of the single-core differential pressure sensor according to claim 1, characterized in that: The stepped hole (8) comprises a large diameter portion, a middle diameter portion and a small diameter portion, the cup body portion is located in the large diameter portion, the first air inlet (7) is located in the middle diameter portion, and the lower end of the guide tube (4) is clearance-matched with the small diameter portion.

8. The pressure sensitive component of the single-core differential pressure sensor according to any one of claims 1 to 7, characterized in that: The space on the upper side of the annular structure (6) is the upper pressure-sensing chamber I, the space inside the cup body is the lower pressure-sensing chamber III, and the space outside the cup body is the transition chamber II.

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