Dustproof sealing structure for gas sensor

Abstract

The gas sensor comprises a shell and a chip, the chip is covered with jelly glue, the dustproof sealing structure is arranged at an opening in the upper end of the shell, the dustproof sealing structure comprises a body and a plurality of ribs, the upper end of the body is closed, the lower end of the body is open, and the ribs are arranged in the shell. The lower edge of the open end of the body is lower than the upper edge of the shell, the ribs are arranged on the inner side face of the body, the body is arranged on the outer side of the upper end of the shell in a sleeved mode through the ribs in an interference fit mode, and a gap of a labyrinth body structure is formed. According to the utility model, the dustproof sealing structure with one closed end is sleeved on the shell of the gas sensor in an interference fit manner, so that the chip can be effectively protected, and the mechanical damage of gold threads in the chip is prevented; the gap cavity structure formed between the ribs and the gas sensor shell is used for filtering solid particles in the gas, and the situation that the measurement precision is not accurate due to the fact that a chip or pressure guiding adhesive in the gas sensor is polluted by particle pollutants in the gas to be measured is prevented.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas sensor protection, and particularly relates to a dust-proof sealing structure for a gas sensor. Background Art

[0002] In the fields of industrial and environmental monitoring, gas sensors play a crucial role. Gas sensors include gas pressure sensors and gas temperature sensors. The gas pressure sensor is used to measure the pressure of the gas, and the gas temperature sensor is used to detect the temperature of the gas. These gas sensors are widely used in many fields such as air quality monitoring, medical equipment, and safety monitoring, and play an irreplaceable role in ensuring the safety of human life and industrial production.

[0003] The core component of a gas sensor is the chip inside its housing. Taking the gas pressure sensor as an example, it usually uses a steel cylinder as the housing, and a precision MEMS (Microelectro Mechanical Systems) pressure gas sensor chip and an ASIC (Application-Specific Integrated Circuit) conditioning chip are provided inside the housing. The manufacturing process of the chip involves die bonding and wire bonding processes. The chip is adhered to the circuit board through the die bonding process, and in the wire bonding process, gold wires are used to connect and conduct between chips and between the chip and the circuit board pin pads. Finally, a layer of jelly glue with a thickness of 1-2 mm is coated on the chip inside the housing. This design helps to protect the gold wires from corrosion and external damage, and improves the sensitivity and response speed of the gas sensor.

[0004] However, in actual applications, the current structure of the gas sensor also causes the gas sensor chip to encounter the following several damage situations: First, during the assembly, welding, or die bonding process of the gas sensor, the chip inside the housing is directly exposed, and when touched by a hard object, the gold wires inside the chip may be physically damaged; Second, the gas sensor may be affected by pollutants during use. If the gas to be detected contains solid particles, such as large dust particles and / or small dust particles, these pollutants may enter the gas sensor housing and adhere to the jelly glue, resulting in a change in the properties of the jelly glue and affecting the measurement accuracy of the gas sensor. Taking the gas pressure sensor as an example, generally, jelly glue is used as the pressure guiding glue. When the pressure guiding glue adheres to dust particle pollutants, the pressure guiding ability of the pressure guiding glue becomes poor, and the pressure value will deflect and distort, resulting in inaccurate measurement accuracy.

[0005] Upon retrieval, a Chinese utility model document with the existing publication number CN219551556 discloses a protection device for an environmental temperature gas sensor, "including: a cylindrical filter screen; a fixing bracket, on which a bolt is rotatably connected through a bearing, a sensor is fixedly connected to the middle of the fixing bracket, an installation groove is provided on the fixing bracket, a limiting hole is provided in the installation groove, and a number of first magnets are arranged equidistantly at the bottom of the fixing bracket; an installation component, the installation component includes an annular plate fixedly connected above the cylindrical filter screen, and an installation block is fixedly connected to the annular plate." In this utility model, a certain degree of protection is provided by setting the cylindrical filter screen. At the same time, the installation and disassembly of the cylindrical filter screen are realized by setting the installation component.

[0006] However, the structural design of this cylindrical filter screen still has certain limitations. For example, assume that in an industrial environment, the gas sensor needs to be exposed to air containing a large amount of dust particles for a long time. The cylindrical filter screen of this utility model may be quickly blocked by these particles, resulting in the gas sensor probe being unable to fully contact the air in the environment, restricting the ventilation effect of the gas sensor probe, thereby reducing the accuracy of the detection data and affecting its measurement accuracy; in addition, if the cylindrical filter screen needs to be installed and uninstalled during maintenance, it may be time-consuming and prone to causing additional damage to the gas sensor chip due to its fixed setting, and it is impossible to avoid leaving the gas sensor chip partially unprotected during the installation and uninstallation process. Utility Model Content

[0007] To solve the problems existing in the above-mentioned prior art, the purpose of the present utility model is to provide a dust-proof and sealing structure for a gas sensor, which protects the gas sensor chip and improves its durability while filtering particulate pollutants in the gas to be measured, thereby ensuring the measurement accuracy.

[0008] To achieve the above purpose and other related purposes, the present utility model adopts the following technical solutions:

[0009] The present utility model provides a dust-proof and sealing structure for a gas sensor. The gas sensor includes a housing and a chip, and a jelly glue is covered on the chip. It is characterized in that a dust-proof and sealing structure is provided at the upper opening of the housing. The dust-proof and sealing structure includes a body and a number of ribs. The upper end of the body is closed and the lower end is open. The height of the lower edge of the open end of the body is lower than the height of the upper edge of the housing. Each rib is arranged on the inner side surface of the body. The body is sleeved on the outer side of the upper end of the housing by interference fit through the ribs. The inner side surface of each rib is attached to the outer side surface of the housing, and a gap for gas to pass through is formed between the gas sensor housing and the body of the dust-proof and sealing structure. The gap has a labyrinth structure.

[0010] As a preferred technical solution, the rib includes a radial rib and an axial rib. A radial gap is formed between the radial rib and the gas sensor housing, and an axial gap is formed between the axial rib and the gas sensor housing. The radial gap and the axial gap communicate with each other to form a labyrinth structure.

[0011] As a preferred technical solution, the radial rib is disposed on the inner top surface of the dust-proof sealing structure and radiates from the radial direction of the body to the center of the body.

[0012] As a preferred technical solution, the axial rib is axially disposed along the central axis of the body on the inner top surface of the dust-proof sealing structure.

[0013] As a preferred technical solution, a chamfer is provided on the body. The chamfer on the body is an arc that slopes from the inner edge at the lower end of the body towards the inner center.

[0014] Further, a rib chamfer is provided on the lower end surface of the axial rib. The rib chamfer is a bevel surface, and the rib chamfer is connected to the chamfer on the body.

[0015] As a preferred technical solution, the outer side surface of the closed end of the body is a planar structure.

[0016] As described above, the present utility model has the following beneficial effects:

[0017] (1) For the dust-proof sealing structure for a gas sensor of the present utility model, by fitting the dust-proof sealing structure with one end closed over the gas sensor housing with an interference fit, the chip can be effectively protected and mechanical damage to the gold wires inside the chip can be prevented.

[0018] (2) For the dust-proof sealing structure for a gas sensor of the present utility model, the gap cavity structure formed between the rib and the gas sensor housing is used to filter solid particles in the gas, preventing particulate contaminants inside the gas to be measured from contaminating the chip or the pressure guiding glue inside the gas sensor, thereby causing the measurement accuracy to be inaccurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a three-dimensional structural schematic diagram of the gas sensor in Embodiment 1 of the present utility model.

[0020] Figure 2 is a three-dimensional structural schematic diagram of a dust-proof sealing structure for a gas sensor of the present utility model.

[0021] Figure 3 is a three-dimensional structural schematic diagram when the dust-proof sealing structure of the present utility model is installed on the gas sensor.

[0022] Figure 4It is the front view of the dust-proof and sealing structure of the present utility model when installed on a gas sensor.

[0023] Among them, the specific descriptions of the reference numerals are as follows: 1. Housing; 2. Body; 21. Body chamfer; 22. Planar structure; 3. Rib; 31. Radial rib; 32. Axial rib; 33. Rib chamfer. Detailed implementation manners

[0024] In order to better understand the purpose, structure and function of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0025] In the description of the present utility model, it should be noted that the positional relationships indicated by terms such as "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. cited in this specification are based on the positional relationships shown in the accompanying drawings. It is only for the convenience of describing the embodiments of the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific direction. Therefore, it should not be construed as a limitation to the present utility model.

[0026] Embodiment

[0027] As Figures 1 to 4 shown, this embodiment provides a dust-proof and sealing structure for a gas sensor. The gas sensor includes a housing 1, a chip is provided at the inner bottom of the housing 1, and a jelly glue is covered on the chip. In this embodiment, taking a gas pressure sensor as an example, the jelly glue uses Wacker 927f as the pressure-conducting colloid. A dust-proof and sealing structure is provided at the upper opening of the housing 1, which is applicable to a gas pressure sensor and a gas temperature sensor. The dust-proof and sealing structure includes a body 2 and a plurality of ribs 3.

[0028] The upper end of the body 2 is closed and the lower end of the opposite side is open. The outer side surface of the closed end of the body 2 is a non-porous planar structure 22. The visual recognition system can be combined to use a suction cup to align and adsorb the center position of the planar structure 22 of the body 2, so as to realize the automatic assembly of directly grasping the dust-proof and sealing structure and positioning and assembling it on the gas sensor. The height of the lower edge of the open end of the body 2 is lower than the height of the upper edge of the housing 1 of the gas sensor, thereby providing an air flow channel for gas to enter and exit.

[0029] The ribs 3 are uniformly arranged on the inner side surface of the dust-proof and sealing structure. The dust-proof and sealing structure is sleeved on the outer side of the upper end of the gas sensor housing 1 through interference fit of the ribs 3, which can ensure the tight fixation between the dust-proof and sealing structure and the housing 1, and avoid the risk of the dust-proof and sealing structure falling off during use. During operation, during the process of pressing the dust-proof and sealing structure body 2 into the top end of the gas sensor housing 1 for interference fit fixation, the ribs 3 play a role of guiding and positioning. After fixation, the inner side surface of the ribs 3 fits with the outer side surface of the gas sensor housing 1, and a gap for gas passage is formed between the gas sensor housing 1 and the dust-proof and sealing structure body 2. The shape of the gap matches the shape of the gas sensor housing 1. As Figure 1 shown, in this embodiment, the shape of the gas sensor housing 1 is a cylinder. Therefore, the structure of the body 2 also adopts a cylindrical shape, and the gap of the air flow channel formed between the body 2 and the housing 1 is annular.

[0030] The ribs 3 include radial ribs 31 and axial ribs 32. The radial ribs 31 are arranged on the inner top surface of the dust-proof and sealing structure and radiate towards the center of the body 2 along the radial direction of the body 2, ensuring the radial gap between the dust-proof and sealing structure and the gas sensor housing 1. The axial ribs 32 are arranged on the inner top surface of the dust-proof and sealing structure along the axis 32 of the body 2, ensuring the axial gap between the dust-proof and sealing structure and the gas sensor housing 1. The radial gap and the axial gap are connected to form a labyrinth structure. Relying on the support of the radial ribs 31 and axial ribs 32 inside the body 2, a stable and reliable air flow passage can be ensured, which can filter both large dust particles and small dust particles at the same time, and prevent dust particle pollutants in the air from entering the position of the internal chip of the gas sensor.

[0031] The body 2 is provided with a body chamfer 21. The body chamfer 21 is an arc inclined from the inner edge of the lower end of the body 2 towards the inner center. A rib chamfer 33 is arranged on the lower end surface of the axial rib 32. The rib chamfer 33 is a bevel surface, and the rib chamfer 33 is connected to the body chamfer 21, which is convenient for the assembly and positioning of the dust-proof and sealing structure and the housing 1 of the gas sensor, allows more gas flow to enter, and at the same time realizes the protection function of avoiding hard objects from damaging the gas sensor chip and the dust-proof function of avoiding pollutants in the gas to be measured from contacting the jelly glue.

[0032] Taking the gas pressure sensor in this embodiment as an example, the working principle of the present utility model is as follows: A cavity is formed between the rib 3 and the gas sensor housing 1 through the dust-proof sealing structure. When the air flow of the gas to be measured enters through the chamfer 33, large dust particles in the gas are blocked outside the axial gap, thereby achieving preliminary filtration. Small dust particles are filtered when passing through the labyrinth structure formed by the connection of the axial gap and the radial gap. Therefore, through the labyrinth structure formed between the dust-proof sealing structure of the present utility model and the gas sensor housing 1, it is possible to effectively block and prevent particulate contaminants in the gas from entering the interior of the housing 1. Moreover, when the filtered gas finally converges in the cavity, the gas flow forms a uniform pressure and contacts the jelly glue on the chip of the gas sensor, thereby improving the durability and measurement accuracy of the gas sensor.

[0033] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any changes or equivalent replacements of these features and embodiments can be made by those skilled in the art without departing from the spirit and scope of the present utility model. Additionally, under the teaching of the present utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present utility model.

Claims

1. A dustproof sealing structure for a gas sensor, the gas sensor comprising a housing (1) and a chip, the chip being covered with jelly glue, characterized in that: A dustproof sealing structure is provided at the opening of the upper end of the shell (1), and the dustproof sealing structure comprises a body (2) and a plurality of ribs (3). The upper end of the body (2) is closed and the lower end is open, and the lower edge height of the open end of the body (2) is lower than the upper edge height of the shell (1). Each rib (3) is arranged on the inner side surface of the body (2). The body (2) is sleeved on the outer side of the upper end of the shell (1) through the interference fit of the ribs (3), and the inner side surface of each rib (3) is in contact with the outer side surface of the shell (1). A gap for gas to pass through is formed between the gas sensor shell (1) and the dustproof sealing structure body (2), and the gap is in a labyrinth structure.

2. A dustproof sealing structure for a gas sensor according to claim 1, characterized in that: The ribs (3) comprise radial ribs (31) and axial ribs (32); a radial gap is formed between the radial ribs (31) and the gas sensor housing (1); an axial gap is formed between the axial ribs (32) and the gas sensor housing (1); the radial gap and the axial gap are connected to form a labyrinth structure.

3. A dustproof sealing structure for a gas sensor according to claim 2, characterized in that: The radial ribs (31) are arranged on the inner top surface of the dustproof sealing structure and radiate radially toward the center of the main body (2) along the main body (2).

4. A dustproof sealing structure for a gas sensor according to claim 2, characterized in that: The axial rib (32) is axially arranged on the inner top surface of the dustproof sealing structure along the central axis of the body (2).

5. The dustproof sealing structure for a gas sensor according to claim 1, characterized in that: The body (2) is provided with a body chamfer (21), and the body chamfer (21) is an arc-shaped arc inclined from the inner edge of the lower end of the body (2) toward the inner center.

6. A dustproof sealing structure for a gas sensor according to claim 5, characterized in that: A rib chamfer (33) is arranged on the lower end surface of the axial rib (32), the rib chamfer (33) is an inclined surface, and the rib chamfer (33) is connected with the body chamfer (21).

7. A dustproof sealing structure for a gas sensor according to claim 1, characterized in that: The outer side surface of the closed end of the body (2) is a plane structure (22).

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