Gauge pressure sensor and assembling method

Abstract

The invention discloses a gauge pressure sensor, which comprises a shell defining a mounting cavity, the shell comprises an upper cover and a main shell which are bonded and combined together through a sealant, the upper cover comprises a ventilation part, and the ventilation part defines a ventilation hole; the dustproof cover is fixed outside the ventilation part, a ventilation gap communicated with the outer end of the ventilation hole is defined between the dustproof cover and the upper cover, and the dustproof cover is provided with at least one buckle clamped in the ventilation hole; and the pressure measuring assembly is arranged in the mounting cavity and is configured to measure the pressure difference between the pressure of the medium to be measured introduced through a pressure introduction channel on the shell and the environment pressure introduced through the ventilation gap and the ventilation hole in sequence. The invention further discloses an assembling method of the gauge pressure sensor. When the gauge pressure sensor is assembled, the size matching precision of the dustproof cover and the upper cover is relatively reduced, and the working procedures can be saved at the same time.

Description

Technical Field

[0001] The present application relates to the technical field of pressure sensors, and particularly relates to a gauge pressure sensor and an assembly method thereof. Background Art

[0002] As Figure 1 shown, a known gauge pressure sensor includes a housing formed by combining a main housing 01 and an upper cover 02. The upper cover 02 includes an upper cover main body 021 and a sealing flange 023 formed by the downward extension of the edge of the upper cover main body 021. An opening is formed at the upper end of the upper cover 02, and a sealing groove 01a is provided outside the opening. After the sealing flange 023 is assembled into the sealing groove 01a, a sealed connection is formed by filling with a sealant 06. The upper cover 02 has a ventilation part 022, and a dust-proof cover 04 is fixed on the ventilation part 022. A ventilation gap including an axial groove 040 is formed between the dust-proof cover 04 and the upper cover 02. A waterproof and breathable film 05 is adhesively bonded to the upper end surface of the ventilation part 022. A pressure measurement component 03 is provided inside the housing. The pressure measurement component 03 has a pressure sensitive element 030. The lower side of the pressure sensitive element 030 introduces a medium to be measured through a pressure introduction channel 010 on the housing, and the upper side thereof is communicated to the environment through a ventilation hole 022a, the waterproof and breathable film 05, and the ventilation gap in sequence, so as to use the ambient pressure as a reference pressure.

[0003] Among them, since the vast majority of sealants need to be cured at high temperature for a long time, and leak detection is required after curing to ensure that a qualified sealed connection has been formed between the upper cover 02 and the main housing 01 through the sealant 06. During leak detection, leak detection gas is usually introduced through the ventilation part 022. After the leak detection is qualified, the dust-proof cover 04 is buckled outside the ventilation part 022.

[0004] The defects of the above gauge pressure sensor are as follows: First, due to the existence of the axial groove 040, it is difficult to seal between the nozzle for providing leak detection gas and the ventilation part 022 when they are plugged. Second, since the dust-proof cover is small and thin, the matching accuracy requirement between it and the ventilation part 022 is high. And when the dust-proof cover 04 is buckled to the ventilation part 022, if the buckling force is too large, it is very likely to damage the sensor housing. Therefore, usually, the dust-proof cover 04 needs to be preheated to reduce the buckling force and accuracy requirement, but this increases the process complexity.

[0005] The information disclosed in the background part of the present invention is only used to enhance the understanding of the general background of the present invention, and should not be regarded as an admission or any form of implication that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present application provides a gauge pressure sensor to solve at least one of the above defects.

[0007] To achieve the above object, the present application provides the following technical solutions: A gauge pressure sensor, which includes:

[0008] A housing that encloses an installation cavity, including an upper cover and a main housing bonded together by a sealant. The upper cover includes a ventilation part that defines a ventilation hole;

[0009] A dust-proof cover fixed to the outside of the ventilation part, which forms a ventilation gap communicating with the outer end of the ventilation hole between it and the upper cover, and has at least one buckle clamped in the ventilation hole;

[0010] And a pressure measurement component disposed in the installation cavity, which is configured to measure the pressure difference between the pressure of the medium to be measured introduced through a pressure introduction channel on the housing and the ambient pressure introduced sequentially through the ventilation gap and the ventilation hole.

[0011] Preferably, the buckle includes an elastic arm that extends substantially vertically downward from the dust-proof cover and an anti-disengagement part formed by the elastic arm extending radially outward; the lower part of the ventilation hole expands radially outward to form an enlarged part for accommodating the anti-disengagement part.

[0012] Preferably, the upper end of the ventilation hole forms a flared guiding surface.

[0013] Preferably, the dust-proof cover includes a top and a side part whose upper edge is integrally connected to the peripheral edge of the top; at least one support rib plate is formed on the top with gaps formed at intervals in the circumferential direction; the lower end of the support rib plate is blocked by the upper end face of the ventilation part.

[0014] Preferably, the dust-proof cover further includes a side part whose upper end peripheral edge is integrally connected to the top, and the support rib plate is integrally connected to the side part radially outward.

[0015] Preferably, the support rib plate is integrally connected to the buckle radially inward.

[0016] Preferably, the root of the buckle extends in the circumferential direction to form a cylindrical part, and the support rib plate is integrally connected to the outer wall of the cylindrical part radially inward.

[0017] Preferably, a waterproof and breathable membrane is provided on the end face of the inner end of the ventilation hole.

[0018] An assembly method, which is applicable to the above-mentioned gauge pressure sensor, and includes the steps:

[0019] Install the pressure measurement component into the main housing;

[0020] Combine the upper cover to the main housing;

[0021] Apply a sealant at the junction of the main housing and the upper cover, and then cure the combination of the main housing and the upper cover under heating conditions for a period of time;

[0022] Take out the combination of the main housing and the upper cover while it is hot, and insert the buckle of the dust cover downward into and snap it into the vent hole.

[0023] Preferably, the above assembly method further includes: before combining the upper cover to the main housing, bond a waterproof and breathable membrane to the end face at the inner end of the vent hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a known gauge pressure sensor;

[0025] Figure 2 is a schematic structural diagram of the gauge pressure sensor of the first embodiment;

[0026] Figure 3 is a partial structural schematic diagram of the gauge pressure sensor of the first embodiment;

[0027] Figure 4 is a perspective view of the dust cover of the first embodiment;

[0028] Figure 5 is a partial structural schematic diagram of the gauge pressure sensor of the second embodiment;

[0029] In the figure: 10, pressure introduction channel; 11d, pressure joint; 12, electrical connector; 1a, sealing groove; 1, main housing; 21a, end face; 21, upper cover body; 22a, vent hole; 22b, enlarged portion; 22c, guiding surface; 22d, stopping portion; 22e, tapered surface; 22, vent portion; 23, sealing flange; 2, upper cover; 30, pressure sensitive element; 31, substrate; 32, processing circuit; 33, frame; 34, protective gel; 35, pin; 36, lead; 37, protective material; 38, lead; 3, pressure measurement assembly; 41, top; 42, side; 431, elastic arm; 432, anti - detachment portion; 43, buckle; 44, support rib plate; 45, cylindrical portion; 4a, gap; 4b, gap; 4c, gap; 4, dust cover; 5, waterproof and breathable membrane; 6, sealant; 7, sealing sleeve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain the present application, and should not be construed as a limitation of the present application. In the following description, the same reference numerals are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0031] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present application. In addition, the prefixes "first", "second", "third", etc. are only used for the purpose of distinguishing the objects to be modified, and should not be construed as indicating or implying relative importance.

[0032] In addition, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0033] It should be further understood that the term "and / or" used in the specification and corresponding claims of the present application refers to any combination and all possible combinations of one or more of the listed items.

[0034] As Figure 2 、 Figure 3 shown. The gauge pressure sensor of the first embodiment includes a housing. Among them, the housing includes an upper cover 2 and a main housing 1 bonded together by a sealant 6. The upper cover 2 and the main housing 1 enclose an installation cavity, and a pressure measurement component 3 is arranged in the installation cavity. A pressure joint 11d for connecting with the container of the medium to be measured is arranged at the lower end of the main housing 1, and a pressure introduction channel 1 is arranged in the pressure joint 11d to convey the pressure of the medium to be measured to the pressure measurement component 3. The upper cover 2 includes a ventilation part 22. The ventilation part 22 defines a ventilation hole 22a that penetrates the upper cover 2 up and down, and it can be substantially columnar. A dust-proof cover 4 is fixed to the outside of the ventilation part 22, and a ventilation gap (not marked) communicating with the outer end of the ventilation hole 22a is formed between it and the upper cover 2. The dust-proof cover 4 has three buckles 43 clamped in the ventilation hole 22a.

[0035] Among them, the pressure measurement component 3 is configured to measure the pressure difference between the pressure of the medium to be measured and the ambient pressure. The pressure of the medium to be measured is introduced into the pressure-sensitive element 30 through a pressure introduction channel 10 on the housing, and the ambient pressure is introduced into the pressure-sensitive element 30 through the ventilation gap and the ventilation hole 22a in sequence. The pressure measurement component 3 includes a pressure-sensitive element 30. The type of the pressure-sensitive element 30 does not need to be particularly limited, but it is preferably a piezoresistive semiconductor pressure chip, or a capacitive semiconductor pressure chip, a metal thick film pressure-sensitive element, or other suitable pressure-sensitive elements.

[0036] Only by way of example, the pressure measurement component 3 may include a substrate 31 and a processing circuit 32 disposed on the upper side of the substrate 31. The substrate 31 is hermetically fixed to the inner end of the pressure introduction channel 10. The pressure-sensitive element 30 may be mounted on the upper side surface away from the pressure introduction channel 10 of a pressure hole (not marked) opened on the pressure-sensitive element 30. The processing circuit 32 is electrically connected to the pressure-sensitive element 30 through a lead 38. A frame 3 may also be fixed on the upper side surface of the substrate 31. The frame 33 surrounds the outside of the pressure-sensitive element 30 and the lead 38, and a protective gel 34 covering the pressure-sensitive element 30 and the lead 38 is filled inside it. In order to transmit the signal processed by the processing circuit to an external device, a pin 35 may be embedded in the main housing 1. The outer end of the pin 35 extends outward into an electrical connection portion 12 formed on the main housing 1, and its inner end extends into the installation cavity and is electrically connected to the processing circuit 32 through a lead 36. A protective material 37 may be covered on the lead 36. A sealing sleeve 7 may be sleeved outside the pressure joint 11d to form a seal with the container of the medium to be measured.

[0037] Specifically, the main housing 1 may have an upper end opening (not marked), and a sealing groove 1a is provided around its upper end opening. The upper cover 2 may include an upper cover main body 21 extending substantially horizontally and a sealing flange 23 extending downward from the periphery of the upper cover main body 21. After the sealing flange 23 extends into the sealing groove 1a, the upper end opening of the main housing 1 is sealed by filling a sealant 6 in the sealing groove 1a.

[0038] When assembling the above-mentioned gauge pressure sensor, the following steps can be carried out:

[0039] (1) Install the pressure measurement component 3 on the main housing 1;

[0040] (2) Combine the upper cover 2 with the main housing 1;

[0041] (3) Apply the sealant 6 at the joint of the main housing 1 and the upper cover 2; then cure the combined body of the main housing 1 and the upper cover 2 in a curing furnace under heating conditions for a period of time;

[0042] (4) Take out the combination of the main housing 1 and the upper cover 2 while it is still hot, and insert the buckle 43 of the dust cover 4 downward into and snap it into the vent hole 22a.

[0043] Since the combination of the main housing 1 and the upper cover 2 is still warm when taken out, the inner diameter of its vent hole 22a is larger than that at normal temperature. Therefore, when inserting and snapping the buckle 43 into the vent hole 22a, it can be more convenient, and thus the dust cover 4 can be snapped onto the vent part 22 with relatively less pressure. In addition, since the buckle 43 is snapped into the vent hole 22a from the inside instead of the outside of the vent part 22, an axial groove can be left on the outer wall of the vent part 22, so that the nozzle for detecting gas can more easily form a sealed connection with the vent part 22.

[0044] Specifically, the buckle 43 may include an elastic arm 431 that extends substantially vertically downward from the dust cover 4 and an anti - detachment part 432 that extends radially outward from the elastic arm 431. The lower part of the vent hole 22a may expand radially outward to form an enlarged part 22b for accommodating the anti - detachment part 432, and a stop part 22d for stopping the anti - detachment part 432 downward is correspondingly formed in the vent hole 22a. Preferably, a flared guiding surface 22c is formed at the upper end of the vent hole 22a, which can facilitate the insertion of the buckle 43 into the vent hole 22a.

[0045] In order to form the above - mentioned vent gap between the dust cover 4 and the upper cover 2, the dust cover 4 may include a top 41 and a side part 42 whose upper edge is integrally connected to the periphery of the top 41. The lower end of the side part 42 is inclined radially outward relative to the upper end, that is, the combination of the top 41 and the side part 42 arches upward in the middle as a whole to form a substantially inverted bowl - like shape, which can improve the pressure - resistant strength of the dust cover 4. At least one support rib 44 with gaps 4c formed at intervals in the circumferential direction is formed on the top 41. The lower end of the support rib 44 is stopped at the upper end face of the vent part 22. The dust cover 4 may further include a side part 42 whose upper end periphery is integrally connected to the top 41. The vent gap includes, from the inside to the outside, a gap 4a provided between the lower end of the side part 42 and the upper cover body 21, a gap 4b provided between the inner wall of the side part 42 and the vent part 22, and the gap 4c. Preferably, the upper end of the vent part 22 may be relatively contracted to form a conical surface 22e, so that the gap 4b has an appropriate thickness.

[0046] Preferably, the support rib 44 is integrally connected to the side part 42 radially outward, and / or the support rib 44 is integrally connected to the root (i.e., the upper part) of the buckle 43 radially inward.

[0047] Among them, in order to further enhance the strength of the dust cover 4, the root of the buckle 43 may extend circumferentially to form a cylindrical part 45. The support rib 44 may be integrally connected to the outer wall of the cylindrical part 45 radially inward.

[0048] Please refer to Figure 5 Differing from the first embodiment, in the second embodiment, the lower end of the side portion 42 may extend downward and be completely perpendicular to the top portion 41.

[0049] In each of the above embodiments, a waterproof and breathable film 5 is provided on the end face 21a at the inner end of the vent hole 22a. The waterproof and breathable film 5 can be adhered to the end face 21a at the inner end of the vent hole 22a before the upper cover 2 is assembled to the main housing 1.

[0050] The scope of the present 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 construed as being included in the present disclosure.

Claims

1. A gauge pressure sensor, characterized in that, Comprising: A housing defining an installation cavity, including an upper cover (2) and a main housing (1) bonded together by a sealant (6), the upper cover (2) including a ventilation portion (22), and the ventilation portion (22) defining a ventilation hole (22a); A dust-proof cover (4) fixed to the outside of the ventilation portion (22), defining a ventilation gap communicating with the outer end of the ventilation hole (22a) between it and the upper cover (2), and having at least one buckle (43) snapped into the ventilation hole (22a); And a pressure measurement assembly (3) disposed in the installation cavity, configured to measure the pressure difference between the pressure of the medium to be measured introduced through a pressure introduction channel (10) on the housing and the ambient pressure introduced sequentially through the ventilation gap and the ventilation hole (22a).

2. The differential pressure sensor according to claim 1, characterized in that, The buckle (43) includes an elastic arm (431) extending substantially vertically downward from the dust-proof cover (4) and an anti-disengagement portion (432) formed by the elastic arm (431) extending radially outward; a lower portion of the ventilation hole (22a) expands radially outward to form an enlarged portion (22b) for accommodating the anti-disengagement portion (432).

3. The manometric pressure sensor according to claim 2, wherein, An upper end of the ventilation hole (22a) forms a flared guiding surface (22c).

4. The manometer sensor according to claim 1, characterized in that The dust-proof cover (4) includes a top (41) and a side portion (42) with an upper edge integrally connected to the periphery of the top (41); at least one support rib plate (44) is formed on the top (41) with gaps (4c) formed at intervals in the circumferential direction; a lower end of the support rib plate (44) is blocked by the upper end face of the ventilation portion (22).

5. The differential pressure sensor according to claim 4, wherein, The dust-proof cover (4) further includes a side portion (42) with an upper end periphery integrally connected to the top (41), and the support rib plate (44) is integrally connected to the side portion (42) radially outward.

6. The manometer sensor according to claim 4, wherein The support rib plate (44) is integrally connected to the buckle (43) radially inward.

7. The manometer sensor according to claim 6, characterized in that A root portion of the buckle (43) extends in the circumferential direction to form a cylindrical portion (45), and the support rib plate (44) is integrally connected to an outer wall of the cylindrical portion (45) radially inward.

8. The differential pressure sensor according to any one of claims 1 to 7, characterized in that, A waterproof and breathable membrane (5) is provided on an end face of an inner end of the ventilation hole (22a).

9. An assembly method, applicable to the gauge pressure sensor according to any one of claims 1 to 7, characterized in that, Including steps: Installing the pressure measurement assembly (3) onto the main housing (1); Combining the upper cover (2) with the main housing (1); Applying a sealant (6) at the joint of the main housing (1) and the upper cover (2), and then curing the combination of the main housing (1) and the upper cover (2) under heating conditions for a period of time; Taking out the combination of the main housing (1) and the upper cover (2) while it is hot, and inserting the buckle (43) of the dust-proof cover (4) downward and snapping it into the ventilation hole (22a).

10. The assembly method according to claim 9, characterized in that, Further including: Before combining the upper cover (2) with the main housing (1), bonding a waterproof and breathable membrane (5) on an end face of an inner end of the ventilation hole (22a).

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