A gauge pressure sensor

Abstract

A gauge pressure sensor includes: a housing having an interior forming a mounting cavity, the housing having an inner end connected to the mounting cavity for introducing a medium to be measured; a plunger made of an elastic material sealingly passing through the housing, having a longitudinally extending through-hole that at least partially defines a reference pressure channel for introducing an ambient medium; a pressure measuring assembly enclosed at the inner end of the pressure introducing channel, including a pressure chip receiving the pressure of the medium to be measured and the pressure of the ambient medium, a frame surrounding the pressure chip, and a soft gel filling the frame and at least covering the pressure chip; and a sealing skirt integrally extending from the plunger around the through-hole, the skirt sealingly and elastically pressing against an axial end of the frame. The aforementioned gauge pressure sensor ensures that the ambient reference pressure is directly and sealingly connected to the substrate while reducing the risk of seal failure under vibration conditions.

Description

Technical Field

[0001] This application relates to the field of pressure sensor technology, specifically to a gauge pressure sensor. Background Technology

[0002] Technical Background: To protect pressure-sensitive elements from corrosion by moisture or other corrosive components in the environment, pressure sensors, especially gauge pressure sensors, require a frame to enclose the pressure-sensitive element and infuse it with protective gel. On the other hand, to prevent corrosion of other electronic components besides the pressure-sensitive element, the cavity can be partitioned to further protect these components. For example, US6993976B2 uses a straight rib formed on the inside of the top cover to seal the circuit board with sealant. However, this method makes it difficult to achieve a proper seal between the circuit board and the pressure inlet channel, or the seal is easily damaged during use due to vibration or other factors. To address this, CN118999880A discloses a gauge pressure sensor that uses a ring of tubing integrally connected to the top cover and axially sealed to the substrate to directly and securely connect the ambient reference pressure to the substrate, thereby preventing moisture in the ambient pressure from corroding other electronic components. However, during use, it has been found that under vibration conditions, the tubing may detach from the substrate, leading to seal failure. Furthermore, the engagement between the dust cover and the outer wall of the hollow column protruding outwards requires high tolerance precision to ensure a correct fit and that the dust cover can be smoothly fitted onto the outside of the hollow column. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this application provides a gauge pressure sensor that ensures direct and sealed communication of the environmental reference pressure to the substrate while reducing the risk of seal failure under vibration conditions.

[0004] A gauge pressure sensor, comprising: The outer casing has an interior cavity that is surrounded by a pressure introduction channel with one end of its inner side connected to the cavity for introducing the medium to be measured. A plunger made of elastic material that passes through the housing in a sealed manner has a longitudinally extending through-hole that at least partially defines a reference pressure channel for introducing ambient media. A pressure measuring component enclosed at one end of the pressure inlet channel includes a pressure chip that receives the pressure of the medium to be measured and the pressure of the ambient medium, a frame surrounding the pressure chip, and a soft gel that fills the frame and at least covers the pressure chip. A sealing skirt integrally extends from the plunger around the through hole, which presses inwardly and elastically against one axial end of the frame.

[0005] Preferably, the sealing skirt includes at least a lateral extension, one end of which is integrally connected to the inner end of the plunger, and the outer portion of which is sealed against the axial end of the frame.

[0006] Preferably, a sealing groove is formed on the outer side of the sealing skirt to partially receive one axial end of the frame.

[0007] Preferably, the outer end of the sealing skirt has a side surface that defines the outer cladding portion of the outer inner wall of the sealing groove.

[0008] Preferably, the outer part is attached to the outer wall of the frame.

[0009] Preferably, the reference pressure channel is provided with a waterproof and breathable membrane for filtering environmental media.

[0010] Preferably, it further includes a dust cover that forms a dustproof gap between the outside of the housing and the outer wall of the housing, the inner wall of the dust cover at least partially defining the middle portion of the reference pressure channel, the outer end of the middle portion communicating with the dustproof gap.

[0011] Preferably, the dust cover includes a main body portion facing inwardly at an interval opposite to the plunger and a wall portion extending from the outer periphery of the main body portion toward the outer casing; a dustproof gap is provided between a corresponding end of the wall portion and the outer wall of the outer casing.

[0012] Preferably, the middle part of the main body extends longitudinally toward the outer shell to form a cylindrical part that is sealed and inserted into the through hole. The inner cavity of the cylindrical part is axially connected to the through hole, and its side wall outside the through hole is provided with a connecting port that communicates outward to the middle part; the waterproof and breathable membrane is fixedly covered on the outer end of the connecting port.

[0013] Preferably, the axial outer end face of the plunger is recessed inward to form a cavity, and the waterproof and breathable membrane is located at least partially within the cavity. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the gauge pressure sensor in the first embodiment.

[0015] Figure 2 This is a partial structural schematic diagram of the gauge pressure sensor in the first embodiment.

[0016] Figure 3 This is a schematic diagram of a corresponding part of the structure of the gauge pressure sensor in the second embodiment.

[0017] Explanation of reference numerals in the attached drawings: 1. Housing; 10. Mounting cavity; 100. Gauge pressure sensor; 11. Main housing; 12. Top cover; 12a. Outer surface; 12b. Hole; 13. Pressure interface tube; 130. Pressure inlet channel; 14. Electrical connector; 141. Terminal; 2. Pressure measuring assembly; 20. Pressure chip; 21. Substrate; 21a. Pressure hole; 22. Lead wire; 23. Frame; 24. Soft gel; 26. Processing circuit; 3. Waterproof and breathable structure; 30. Reference pressure channel; 30a. Dustproof gap; 30b. Top gap 31. Gap; 31. Dust cover; 311. Main body; 312. Wall; 313. Cylindrical part; 313a. Inner cavity; 313b. Connecting port; 3131. Positioning protrusion; 314. Anti-detachment part; 32. Piston; 32a. Through hole; 32b. Longitudinal groove; 32d. Concave cavity; 32f. Positioning groove; 321. Radial protrusion; 322. Neck; 323. Radial protrusion; 33. Sealing skirt; 33a. Sealing groove; 331. Lateral extension; 332. Outer wrapping; 34. Waterproof and breathable membrane; 91. Seal; 92. Lead wire. Detailed Implementation

[0018] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the following description, the same reference numerals are used to denote the same or equivalent elements, and repeated descriptions are omitted.

[0019] In the description of this application, it should be understood that the terms "upper," "lower," "inner," "outer," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the prepositions "first," "second," and "third," etc., are only used for the purpose of distinguishing the modified objects, and should not be construed as indicating or implying relative importance.

[0020] Furthermore, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0021] It should also be further understood that the term "and / or" as used in this application specification and the corresponding claims refers to any combination of one or more of the listed items and all possible combinations.

[0022] like Figure 1 , Figure 2 As shown. In a first embodiment of the invention, the gauge pressure sensor 100 includes a housing 1 and a pressure measuring assembly 2. The housing 1 internally forms a mounting cavity 10, which has an inner end communicating with the mounting cavity 10 for introducing a medium to be measured. For manufacturability purposes, the housing 1 preferably includes a main housing 11 and a top cover 12. The pressure introducing channel 130 may be at least partially defined by the inner cavity of a pressure interface tube 13 integrally connected to the main housing 11. A seal 91 may be provided on the outer wall of the pressure interface tube 13 to provide a seal when connected to a container of the medium to be measured.

[0023] The interior of the mounting cavity 10 is connected to the external environment (usually the atmosphere) of the outer shell 1 through a waterproof and breathable structure 3 provided on the upper cover 12, so that the pressure inside the mounting cavity 10 is equal to that of the environment, that is, the environmental pressure is used as a reference pressure. The waterproof and breathable structure 3 includes at least a plunger 32 made of elastic material, which passes through the upper cover 12 in a sealing manner. For example, the upper cover 12 is provided with a hole 12b. The plunger 32 includes, from the inside to the outside, a radial protrusion 323, a neck 322 and a radial protrusion 321 located in the mounting cavity 10. The neck 322 is coaxially located inside the hole 12b. The radial protrusions 323 and 321 both protrude radially from the axial ends of the neck 322 and are preferably sealed to the inner and outer end faces of the hole 12b respectively.

[0024] The plunger 32 has a through hole 32a extending longitudinally through both the inner and outer end faces of the plunger 32. The corresponding part of the upper cover 12 preferably extends laterally, that is, the thickness direction of the part corresponding to the hole 12b is also longitudinally arranged. The through hole 32a of the plunger 32 allows the ambient medium to pass inward and enter the interior of the mounting cavity 10, which defines a reference pressure channel 30 for introducing the ambient medium.

[0025] The pressure measuring component 2 is enclosed at one end inside the pressure inlet channel 130 and receives the pressure of the medium to be measured and the reference pressure within the mounting cavity 10, and measures the relative pressure of the medium to be measured with respect to the reference pressure within the mounting cavity 10. For example, the pressure measuring component 2 may include a pressure chip 20 to receive the pressure of the medium to be measured and the pressure of the ambient medium, and a frame 23 surrounding the pressure chip 20. The pressure measuring component 2 also includes a substrate 21, preferably laterally extending. The pressure chip 20 is mechanically fixed to the surface of the substrate 21 away from the substrate 21, i.e. Figure 1 , Figure 2The upper surface of the frame 23 is electrically connected to the processing circuit 26 disposed on the upper surface of the substrate 21 via a lead 22, and is also connected to the pressure introduction channel 130 via a downward-facing pressure hole 21a disposed on the substrate 21. One axial end, i.e., the lower end, of the frame 23 can be bonded to the upper surface of the substrate 21 with a sealant. The frame 23 can be filled with a soft gel 24 to cover the pressure chip 20. An electrical connector 14 can also be disposed on the main housing 11, and a plurality of terminals 141 extend from the cavity of the electrical connector 14 into the mounting cavity 10 and are electrically connected to the processing circuit 26 via a lead 92.

[0026] The gauge pressure sensor 100 also includes a sealing skirt 33 integrally extending from the plunger 32 around the through hole 32a. The sealing skirt 33 is sealed and elastically pressed against one axial end of the frame 23, i.e., the upper end of the frame 23, inward.

[0027] The gauge pressure sensor 100 of this embodiment forms a through hole 32a for introducing ambient reference pressure through a plunger 32 made of elastic material disposed on the housing 1. At the same time, it is elastically sealed to the frame 23 by an integrally connected sealing skirt 33. This not only ensures that the ambient reference pressure is directly and sealed to the substrate, but also reduces the risk of the seal failing under vibration conditions.

[0028] Preferably, the sealing skirt 33 may include at least a lateral extension 331 to ensure sufficient elasticity, with one inner end integrally connected to the inner end of the plunger 32, and its outer portion sealingly pressing against one axial end of the frame 23. More preferably, a sealing groove 33a is formed on the outer portion of the sealing skirt 33 to partially receive the corresponding axial end of the frame 23. Even more preferably, the outer end of the sealing skirt 33 may have an outer covering 332, one side surface of which defines the outer inner wall of the sealing groove 33a. The outer covering 332 also preferably conforms to the outer wall of the frame 23.

[0029] Preferably, a waterproof and breathable membrane 34 for filtering environmental media is provided on the reference pressure channel 30. For example, the wall portion 312 can be fixed to the outer wall of the plunger 32, and the waterproof and breathable membrane 34 is fixedly covered on the longitudinal outer end face of the through hole 32a.

[0030] Preferably, the gauge pressure sensor 100 may further include a dust cover 31, which is fixed to the upper cover 12 and forms a dustproof gap 30a between the outside of the housing 1 and the outer surface 12a of the housing 1 to filter particulate matter such as dust in the environmental medium. As an example only, the dust cover 31 may include a main body portion 311 facing inwardly at a distance from the plunger 32 and a wall portion 312 extending from the outer periphery of the main body portion 311 toward the housing 1. A dustproof gap 30a is left between a corresponding end of the wall portion 312 and the outer wall of the housing 1. The inner wall of the wall portion 312 is tightly fitted onto the outer wall of the radial protrusion 321, and the axial outer end of the radial protrusion 321 may extend radially outward to form a radial protrusion (not marked), and the lower part of the wall portion 312 may extend radially inward to form an anti-detachment portion 314, which abuts against the radial protrusion longitudinally outward to prevent the dust cover 31 from falling off the radial protrusion 321. The inner wall of the dust cover 31 at least partially defines the middle portion of the reference pressure channel, and the outer end of the middle portion communicates with the dust gap 30a. For example, the middle portion includes a longitudinal groove 32b longitudinally provided on the outer wall of the radial protrusion 321, and a top gap 30b left between the inner wall of the main body 311 and the outer end face of the radial protrusion 321, and a protrusion 315 that can extend downward on the inner wall of the main body 311 to define the thickness of the top gap 30b.

[0031] Please refer to the following: Figure 3 Compared to the first embodiment, in the pressure sensor 100 of the second embodiment, the middle portion of the main body 311 extends downward toward the outer casing 1 to form a cylindrical portion 313. The cylindrical portion 313 is sealed into the through hole 32a, and its inner cavity 313a is axially connected to the through hole 32a. The cylindrical portion 313 is located on the side wall outside the through hole 32a and has a connecting port 313b that communicates outward to the middle portion. A waterproof and breathable membrane 34 is fixedly covered on the outer end of the connecting port 313b.

[0032] At this time, the axial outer end face of the plunger 32 can be recessed inward to form a cavity 32d, and 34 is at least partially located within the cavity 32d. The middle portion of the reference pressure channel 30 also includes the cavity 32d, the connecting port 313b, and the inner cavity 313a of the cylindrical portion 313. The longitudinal groove 32b is also replaced by the annular space between the outer wall of the radial protrusion 321 and the inner wall of the wall portion 312. Correspondingly, the radial protrusion of the radial protrusion 321 and the anti-detachment portion 314 can be omitted. In this way, the cross-sectional area of ​​the longitudinal portion of the reference pressure channel 30 is increased accordingly, and the ventilation capacity is improved.

[0033] Preferably, one inner end of the cylindrical portion 313 protrudes radially outward to form a positioning protrusion 3131, and a corresponding positioning groove 32f is provided on the through hole 32a to accommodate the positioning protrusion 3131, thereby creating a longitudinal positioning between the dust cover 31 and the plunger 32 and preventing the dust cover 31 from falling off. In this case, the protrusion 315 can also be omitted accordingly.

[0034] The scope of this disclosure is not limited by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be included in this disclosure.

Claims

1. A gauge pressure sensor (100), characterized in that, include: The outer shell (1) has an interior cavity (10) that is connected to the cavity (10) for introducing the medium to be measured. A plunger (32) made of elastic material that is sealed through the housing (1) has a longitudinally extending through-hole (32a) that at least partially defines a reference pressure channel (30) for introducing an ambient medium. The pressure measurement component (2) enclosed at one end of the pressure introduction channel (130) includes a pressure chip (20) that receives the pressure of the medium to be measured and the pressure of the ambient medium, a frame (23) surrounding the pressure chip (20), and a soft gel (24) filled in the frame (23) and at least covering the pressure chip (20). A sealing skirt (33) integrally extends from the plunger (32) around the through hole (32a), which presses against one axial end of the frame (23) in a sealing manner and elastically toward the inside.

2. The gauge pressure sensor (100) according to claim 1, characterized in that, The sealing skirt (33) includes at least a lateral extension (331), one end of which is integrally connected to the inner end of the plunger (32), and the outer portion of which is sealed against the axial end of the frame (23).

3. The gauge pressure sensor (100) according to claim 2, characterized in that, A sealing groove (33a) is formed on the outer portion of the sealing skirt (33) to partially receive the corresponding axial end of the frame (23).

4. The gauge pressure sensor (100) according to claim 3, characterized in that, The outer end of the sealing skirt (33) has a side surface that defines the outer cladding (332) of the outer inner wall of the sealing groove (33a).

5. The gauge pressure sensor (100) according to claim 4, characterized in that, The outer part (332) is attached to the outer wall of the frame (23).

6. The gauge pressure sensor (100) according to any one of claims 1 to 5, characterized in that, The reference pressure channel (30) is provided with a waterproof and breathable membrane (34) for filtering environmental media.

7. The gauge pressure sensor (100) according to claim 6, characterized in that, It also includes a dust cover (31) that forms a dustproof gap (30a) between the outside of the housing (1) and the outer wall of the housing (1), the inner wall of the dust cover (31) at least partially defining the middle portion of the reference pressure channel, the outer end of the middle portion communicating with the dustproof gap (30a).

8. The gauge pressure sensor (100) according to claim 7, characterized in that, The dust cover (31) includes a main body (311) facing the plunger (32) inwardly and spaced apart, and a wall (312) extending from the outer periphery of the main body (311) toward the outer shell (1); a dust gap (30a) is provided between a corresponding end of the wall (312) and the outer wall of the outer shell (1).

9. The gauge pressure sensor (100) according to claim 8, characterized in that, The middle part of the main body (311) extends longitudinally toward the outer shell (1) to form a cylindrical part (313) that is sealed and inserted into the through hole (32a). The inner cavity (313a) of the cylindrical part (313) is axially connected to the through hole (32a), and a connecting port (313b) is provided on the side wall outside the through hole (32a) that connects outward to the middle part. The waterproof and breathable membrane (34) is fixedly covered on the outer end of the connecting port (313b).

10. The gauge pressure sensor (100) according to claim 9, characterized in that, The axial outer end face of the plunger (32) is recessed inward to form a cavity (32d), and the waterproof and breathable membrane (34) is located at least partially within the cavity (32d).

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