A gas detection device

Abstract

This application relates to the field of detection technology, specifically to a gas detection device that can improve the accuracy of detection results. Through a cantilever section located within the housing and capable of energized vibration, driving gas enters the housing through an inlet and exits through an outlet. The outlet is positioned at least partially facing the circuit board, allowing the fluid flowing from the outlet to act on the circuit board, thereby reducing the temperature of the circuit board and electrical components. This reduces the influence of the electrical components on the temperature of the thermistor, thus improving the accuracy of the gas detection results.

Description

Technical Field

[0001] This application relates to the field of detection technology, specifically to a gas detection device for detecting gases such as refrigerants. Background Technology

[0002] Air conditioning systems use environmentally friendly refrigerants, but these refrigerants are flammable compared to traditional refrigerants, posing certain safety hazards. Therefore, sensors are installed to detect the gas concentration to determine if there is a refrigerant leak, so that the control system can shut down and issue an alarm in time, reducing the safety hazards caused by environmentally friendly refrigerants.

[0003] The sensor includes a housing containing a circuit board. A sensing component is mounted on the circuit board, and the sensing component has two chambers. One chamber contains a thermistor. An air inlet is located at the top of the chamber. When gas enters the chamber through the inlet, the thermal conductivity of the gas changes. Thermal conductivity affects the heat dissipation of the thermistor; if the gas has high thermal conductivity, heat is more easily dissipated from the thermistor, resulting in a change in resistance. This change in resistance is then converted into an electrical signal by a signal conditioning and conversion circuit, thereby enabling the measurement of gas concentration.

[0004] However, the circuit board contains several electrical components that generate heat when they are in operation. This heat affects the temperature of the thermistor, thus affecting the sensor's detection accuracy. Summary of the Invention

[0005] The purpose of this application is to provide a gas detection device that can improve the accuracy of the detection results.

[0006] The gas detection device provided in this application includes:

[0007] The sensing component includes a detection unit capable of detecting gases;

[0008] The circuit board and at least one electrical component, the sensing assembly and the electrical component are all electrically connected to the circuit board;

[0009] At least one gas-driven mechanism, the gas-driven mechanism including a mechanism housing and a cantilever portion located within the mechanism housing and capable of being electrically vibrated, the mechanism housing having an air inlet and an air outlet, the air outlet and the air inlet being located on opposite sides in the thickness direction of the cantilever, and the air outlet being disposed toward at least a portion of the circuit board.

[0010] The gas detection device of this application uses a cantilever section located inside the housing that is energized and vibrates to drive gas into the housing through an inlet and out through an outlet. The outlet is positioned so that at least a portion faces the circuit board, allowing the fluid flowing out of the outlet to act on the circuit board, thereby reducing the temperature of the circuit board and electrical components. This reduces the influence of the electrical components on the temperature of the thermistor, thus improving the accuracy of the gas detection results. Attached Figure Description

[0011] Figure 1 This is an explosion diagram of a gas detection device in one embodiment of this application;

[0012] Figure 2 for Figure 1 A schematic diagram of the circuit board assembly inside the gas detection device.

[0013] Figure 3 for Figure 2 Enlarged diagram of part A in the middle;

[0014] Figure 4 for Figure 3 Schematic sectional view along the BB direction;

[0015] Figure 5 for Figure 4 A magnified view of part C in the middle;

[0016] Figure 6 for Figure 4 A schematic diagram of the gas-driven mechanism;

[0017] Figure 7 for Figure 4 A schematic diagram of a circuit board with through-holes;

[0018] Figure 8 This is a schematic diagram of the circuit board assembly of the gas detection device in another embodiment of this application;

[0019] Figure 9 This is a schematic diagram of the circuit board assembly in a gas detection device according to another embodiment of this application;

[0020] Figure 10 for Figure 9 Bottom view of the circuit board assembly;

[0021] Figure 11 for Figure 9 Top view of the circuit board assembly;

[0022] Figure 12 for Figure 11 A sectional view along the DD direction;

[0023] Figure 13 for Figure 11 A sectional view along the EE direction;

[0024] Figure 14 This is a schematic cross-sectional view of the circuit board assembly and the lower shell fitting together in a gas detection device according to one embodiment of this application;

[0025] Figure 15 This is a schematic cross-sectional view of the circuit board assembly and the lower housing in a gas detection device according to another embodiment of this application.

[0026] The annotations in the attached figures are explained as follows:

[0027] 100 - Gas detection device;

[0028] 1001 - Circuit board assembly;

[0029] 10-Gas-driven mechanism; 101-Mechanism housing; 1011-Top wall of housing; 1012-Bottom wall of housing; 1013-Side wall of housing; 102-Base; 103-Cantilever; 1031-First cantilever; 1032-Second cantilever; 101a-Air inlet; 101b-Air outlet; 101c-First chamber; 101d-Second chamber;

[0030] 20 - Sensing component; 201 - First detection unit; 2011 - First housing; 202 - Second detection unit; 2021 - Second housing;

[0031] 30 - Electrical component; 301 - First electrical component; 302 - Second electrical component; 30a - Relay; 30b - Surface mount resistor;

[0032] 40 - Circuit board; 40a - Through hole; 40b - Ventilation hole;

[0033] 50 - Outer shell; 5011 - Top wall of outer shell; 501 - Upper shell; 501a - First vent structure; 502 - Lower shell; 5021 - Side wall of outer shell; 5022 - Bottom wall of outer shell; 502a - Second vent structure;

[0034] 60 - Waterproof and breathable structure;

[0035] 70-Support frame. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. In the embodiments of this application, the terms "first," "second," etc., are only used to distinguish the same or similar structural features, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0037] Please refer to Figure 1 and Figure 2 , Figure 1 This is an explosion diagram of a gas detection device 100 in one embodiment of this application; Figure 2 for Figure 1 A schematic diagram of the internal circuit board assembly 1001 of the gas detection device 100.

[0038] This embodiment provides a gas detection device 100, which includes a housing 50 and a circuit board assembly 1001 located inside the housing 50. The circuit board assembly 1001 includes a sensing component 20 and a circuit board 40, which are electrically connected so that the signal detected by the sensing component 20 can be converted and transmitted to the outside. Figure 2 The circuit board assembly 1001 shown in the diagram also includes multiple electrical components 30 disposed on the circuit board 40. These electrical components 30 may be, for example, relays 30a or surface-mount resistors 30b. The housing 50 covers the circuit board 40, the sensing assembly 20, and the multiple electrical components 30 for protection. Figure 1 The outer casing 50 shown in the diagram specifically includes an upper casing 501 and a lower casing 502, which are connected together. In this embodiment, the gas detection device 100 is used for gas detection. The outer casing 50 has a first vent structure 501a to allow gas to enter the interior of the outer casing 50 of the gas detection device 100. The first vent structure 501a is specifically located on the upper casing 501. After the gas enters the interior of the outer casing 50, it is detected by the sensing component 20. A waterproof and breathable structure 60 is provided at the location of the first vent structure 501a, and a support frame 70 can be provided to position the waterproof and breathable structure 60. The waterproof and breathable structure 60 allows external gas to enter and provides waterproof and dustproof protection for the interior circuit board assembly 1001.

[0039] This gas detection device 100 is used, for example, to detect the refrigerant in an air conditioning system. The gas detection device 100 can be installed outdoors, near the outdoor unit of the air conditioning system. If the refrigerant leaks into the air outside the outdoor unit, the air mixed with the refrigerant will enter the casing 50 and be detected by the gas detection device 100.

[0040] like Figure 2As shown, the sensing component 20 includes a detection unit for detecting gas. In this embodiment, the detection unit includes a first detection unit 201 and a second detection unit 202. Specifically, the first detection unit 201 includes a first housing 2011 and a first detection element (not shown in the figure). The first detection element is located inside the first housing 2011 and is used to detect gas. The first detection element is, for example, a thermistor, and more specifically, a thermistor resistor. When gas enters the first housing 2011, its thermal conductivity affects the heat dissipation of the thermistor. If the thermal conductivity of the gas is high, heat will dissipate more easily from the thermistor, resulting in a decrease in the resistance of the thermistor. The second detection unit 202 includes a second housing 2021 and a second detection element (not shown in the figure). The second detection element is located inside the second housing 2021 and can also be a thermistor.

[0041] Based on the Wheatstone bridge principle, under the combined action of the first and second detection elements, the change in resistance caused by the gas to be detected can be converted into an electrical signal through signal conditioning and conversion circuits, thereby realizing the measurement of gas concentration. The gas detection device 100 is, for example, a MEMS (Micro Electromechanical System) sensor. The principle of gas concentration detection by the sensing component 20 is known technology and will not be discussed further. As described above, during detection, the gas to be detected needs to enter the first housing 2011, thus allowing communication with the outside, while the second housing 2021 is not connected to the outside, and its inner cavity is a closed cavity.

[0042] Please refer to Figures 3 to 5 , Figure 3 for Figure 2 Enlarged diagram of part A in the middle; Figure 4 for Figure 3 Schematic sectional view along the BB direction; Figure 5 for Figure 4 A magnified view of part C in the middle; Figure 6 for Figure 4 A schematic diagram of the gas-driven mechanism 10.

[0043] The gas detection device 100 in this embodiment also includes a gas driving mechanism 10, which is also mounted on and electrically connected to the circuit board 40. The circuit board 40 can supply power to the gas driving mechanism 10 and transmit signals via lines. Please see... Figure 6The gas-driven mechanism 10 includes a housing 101 and a base 102. A portion of the base 102 is located inside the housing 101, and another portion is located outside the housing 101. The portion of the base 102 outside the housing 101 can be connected to a circuit board 40. A gap exists between the housing 101 and the circuit board 40, meaning they are spaced apart in a direction perpendicular to the circuit board 40. The gas-driven mechanism 10 also includes a cantilever 103 connected to the base 102. At least a portion of the cantilever 103 is suspended within the housing 101 and above the base 102. The cantilever 103 is electrically connected to the circuit board 40, specifically through the base 102. Figure 6 The diagram illustrates two cantilever sections 103, namely a first cantilever section 1031 and a second cantilever section 1032, which are suspended from the base 102 in opposite directions. The first cantilever section 1031 and the second cantilever section 1032 can be an integral structure, with their connection point supported on the base 102. The base 102 may include a base body and a conductive layer attached to the outer surface of the base body. The conductive layer is used for electrical connection with the cantilever section 103, thereby indirectly realizing the electrical connection between the cantilever section 103 and the circuit board 40. Of course, the electrical connection method between the cantilever section 103 and the circuit board 40 is not limited to this; for example, the base 102 may have a built-in wire harness to connect the cantilever section 103 and the circuit board 40, etc., which will not be listed here.

[0044] The side of the housing 101 closest to the circuit board 40 is defined as the bottom wall portion 1012, the side opposite to the bottom wall portion 1012 is defined as the top wall portion 1011, and the portion between the bottom wall portion 1012 and the top wall portion 1011 is defined as the side wall portion 1013. A portion of the inner cavity of the housing 101, located between the cantilever portion 103 and the top wall portion 1011, is designated as the first cavity 101c, and another portion of the inner cavity, located between the cantilever portion 103 and the bottom wall portion 1012, is designated as the second cavity 101d. The circuit board 40 can be defined as having a first side and a second side distributed along its thickness direction, wherein the side facing the first vent structure 501a is its first side, and the other side is its second side. Figure 6 From the perspective of the first side facing upwards and the second side facing downwards, the first cavity 101c and the second cavity 101d are distributed vertically, and the first cavity 101c and the second cavity 101d are connected.

[0045] In this embodiment, the housing 101 is further provided with an air inlet 101a and an air outlet 101b. The air inlet 101a can be located on the top wall portion 1011 of the housing 101, and the air outlet 101b can be located on the bottom wall portion 1012 of the housing 101, corresponding to the two cantilever portions 103. The bottom wall portion 1012 is provided with at least two air outlets 101b, and the projections of the corresponding wall portions of the at least two air outlets 101b are respectively located within the projections of the first cantilever portion 1031 and the second cantilever portion 1032. The projection of the corresponding wall portion of the air inlet 101a is located within the projection of the base 102. Specifically, this embodiment provides two air outlets 101b, one opposite to the first cantilever portion 1031 and the other opposite to the second cantilever portion 1032. Specifically, the air inlet 101a of the gas drive mechanism 10 connects the first cavity 101c and the inner cavity of the outer shell 50, and the air outlet 101b connects the second cavity 101d and the inner cavity of the outer shell 50.

[0046] In this embodiment, the cantilever portion 103 of the gas-driven mechanism 10 can vibrate when energized, for example, by being driven by a piezoelectric element. The cantilever portion 103 may include a cantilever body and a piezoelectric element (not shown in the figure). The cantilever body may include stainless steel, nickel alloy, Hastelloy, Al (e.g., aluminum alloy), and / or Ti (e.g., Ti6Al-4V titanium alloy), etc. The piezoelectric element may be a ceramic piezoelectric sheet, or other piezoelectric crystal structures. When energized, the piezoelectric element in this type of cantilever portion 103 deforms. If a changing electric field is applied, the piezoelectric element will continuously deform in different directions, and the cantilever body connected to the piezoelectric element will continuously move in different directions, thereby generating vibration. That is, the first cantilever portion 1031 and the second cantilever portion 1032 will vibrate. Specifically... Figure 6 In the middle, the two cantilever sections 103 can be along the thickness direction ( Figure 6 The two cantilever sections 103 can vibrate in the same phase or out of phase, meaning that the gas drive mechanism 10 uses the inverse piezoelectric effect to achieve the vibration of the cantilever section 103. The inverse piezoelectric effect is existing technology and will not be discussed further.

[0047] As can be seen, in this embodiment, the first cantilever portion 1031 and the second cantilever portion 1032 of the gas drive mechanism 10 can be electrically vibrated, thereby creating a pressure difference between the first cavity 101c and the second cavity 101d on both sides of the thickness direction of the cantilever portion 103, which in turn causes the fluid to enter from the air inlet 101a on one side of the gas drive mechanism 10 and flow out from the air outlet 101b on the other side, so as to generate a relatively high-speed fluid.

[0048] In this embodiment, the gas-driven mechanism 10 is mounted on the circuit board 40, which can dissipate heat from the electrical components 30 on the circuit board 40, such as relays 30a and surface-mount resistors 30b, which have high power and generate a lot of heat during operation. Furthermore, the circuit board 40 itself is a heat-generating element, and the gas-driven mechanism 10 can also dissipate heat from it. In particular, the air outlet 101b of the mechanism housing 101 is located on the side facing the circuit board 40, allowing the high-velocity fluid to flow directly onto the surface of the circuit board 40 and quickly remove heat. Thus, the heat from the circuit board 40 and the electrical components 30 on it has a reduced impact on the temperature sensing of the sensing component 20, thereby improving the accuracy of the gas detection device 100's detection results. In addition, the gas-driven mechanism 10 can also accelerate the airflow into the housing 50 of the gas detection device 100, thereby facilitating the detection by the sensing component 20.

[0049] Furthermore, the minimum distance between the gas drive mechanism 10 and at least one electrical component 30 in the plane of the circuit board 40 is less than the minimum distance between the gas drive mechanism 10 and the sensing component 20 in the plane of the circuit board 40. That is, the gas drive mechanism 10 is positioned closer to one or more electrical components 30 that need heat dissipation, while being as far away from the sensing component 20 as possible. As can be seen from the above description, in this embodiment, the gas drive mechanism 10 generates a pressure difference by vibrating the first cantilever portion 1031 and the second cantilever portion 1032 to accelerate airflow for heat dissipation. Compared to the electrical component 30 that needs heat dissipation, setting the gas drive mechanism 10 to be farther away from the sensing component 20 can reduce or avoid the impact of the cooling and heat dissipation of the gas drive mechanism 10 on the temperature detection of the sensing component 20.

[0050] Please refer to Figure 7 , Figure 7 for Figure 4 A schematic diagram of the structure of the circuit board 40 with through hole 40a.

[0051] The circuit board 40 may also be provided with a through hole 40a, the hole of which extends through the thickness direction of the circuit board 40. Firstly, in the planar direction of the circuit board, the minimum distance between the gas drive mechanism 10 and the corresponding wall of the through hole 40a is less than the distance between the gas drive mechanism 10 and the sensing component 20. Secondly, the minimum distance between the gas drive mechanism 10 and at least one electrical component 30 used for cooling and heat dissipation is less than the minimum distance between the gas drive mechanism 10 and the corresponding wall of the through hole 40a. Thus, as... Figure 7 The airflow shown passes through the flow path of the gas drive mechanism 10. After the airflow from the gas drive mechanism 10 comes into contact with and dissipates heat from the nearby electrical components 30, it can first pass through the position of the hole in the through hole 40a and flow from the hole in the through hole 40a to the other side of the circuit board 40, thereby reducing or even avoiding the impact on the temperature detection of the sensing component 20.

[0052] You can continue to refer to this. Figure 8 understand, Figure 8 This is a schematic diagram of the circuit board assembly 1001 of the gas detection device 100 in another embodiment of this application.

[0053] This embodiment has a structure basically the same as the gas detection device 100 in the above embodiment, except for the arrangement of the electrical components 30 and the gas driving mechanism 10. Specifically, in the height direction perpendicular to the circuit board 40, at least one electrical component 30 is a first electrical component 301. The height of the first electrical component 301 is not less than the height of the gas driving mechanism 10, and the first electrical component 301 is positioned between the sensing component 20 and the gas driving mechanism 10. For example, the relay 30a is generally taller and can be selected as the first electrical component 301. The taller first electrical component 301 can block the space between the sensing component 20 and the gas driving mechanism 10. In this way, the first electrical component 301 acts as a shield between the sensing component 20 and the gas driving mechanism 10, thereby greatly reducing or even avoiding the influence of the gas driving mechanism 10 on the temperature detection of the sensing component 20. Moreover, the gas driving mechanism 10 can be relatively close to the first electrical component 301 to better cool and dissipate heat from the first electrical component 301.

[0054] Specifically, such as Figure 8 As shown, in this embodiment, three relays 30a are arranged on the circuit board 40. Two cylindrical relays 30a are arranged in a row, serving as the first electrical component 301. The other is a square relay 30a. The gas drive mechanism 10 is positioned between the row of cylindrical and square relays 30a. In this case, the two cylindrical relays 30a in the row act as a barrier between the sensing component 20 and the gas drive mechanism 10. Furthermore, the gas drive mechanism 10 can simultaneously dissipate heat from multiple relays 30a. However, this arrangement is not limited to this. For example, only one cylindrical relay 30a can be positioned between the gas drive mechanism 10 and the sensing component 20, or the square relay 30a can be arranged between the gas drive mechanism 10 and the sensing component 20, using the square relay 30a as the first electrical component 301 as a barrier.

[0055] One outlet 101b of the gas drive mechanism 10 can be connected to one side of the sensing component 20, and the other outlet 101b can be connected to the other side of the sensing component 20. The sensing component 20, the two connecting lines, and the gas drive mechanism 10 enclose the main flow area W after the gas flows out of the outlet 101b. Of course, if the gas drive mechanism 10 is only provided with one outlet 101b, the outlet 101b can be connected to both sides of the sensing component 20 to determine the area W. In this embodiment, the first electrical component 301 is located between the sensing component 20 and the gas drive mechanism 10, which means that it is projected along a direction perpendicular to the circuit board 40. At least a portion of the first electrical component 301 is located in the area W to block the gas flowing out of the gas drive mechanism 10.

[0056] Let's look again. Figure 8 At least one electrical component 30 may also be a second electrical component 302, such as a Figure 8 The surface mount resistor shown is 30B. (Example:) Figure 5 As shown, there is a gap between the wall corresponding to the air outlet 101b of the gas drive mechanism 10 and the circuit board 40, which can be defined as the third gap a. The distance of the third gap a perpendicular to the circuit board 40 is d1. The height of the second electrical component 302 can be no greater than the height of the third gap c. The second electrical component 302 can be disposed on the side of the gas drive mechanism 10 and can be relatively close to the gas drive mechanism 10, for example, by projecting along a direction perpendicular to the circuit board 40. The distance between the projection of the second electrical component 302 and the projection of the air outlet 101b can be set within 5mm. This facilitates the airflow from the air outlet 101b to the third gap c, which allows it to quickly contact the second electrical component 302, thereby providing timely heat dissipation for the second electrical component 302.

[0057] There can be multiple second electrical components 302. In this case, multiple second electrical components 302 can be arranged close to the gas drive mechanism 10, for example, multiple second electrical components 302 can be arranged around the gas drive mechanism 10, or... Figure 8 As shown, the gas drive mechanism 10 is located between two cylindrical relays 30a and a square relay 30a. The gas drive mechanism 10 has two sides that are arranged opposite to each other. One side is arranged opposite to the cylindrical relays 30a, and the other side is arranged opposite to the square relays 30a. The other two sides of the gas drive mechanism 10 are arranged opposite to a plurality of second electrical components 302. In this way, the gas drive mechanism 10 can be used to better dissipate heat and cool the electrical components 30 that need heat dissipation.

[0058] The above embodiment uses a gas drive mechanism 10 as an example. It can be seen that the number of gas drive mechanisms 10 in this embodiment is not limited and can be determined by comprehensive consideration based on the available layout area of ​​the circuit board 40, the number of electrical components 30 that need heat dissipation, etc.

[0059] Please continue to refer to this. Figures 9 to 13 understand, Figure 9 This is a schematic diagram of the circuit board assembly 1001 in the gas detection device 100 in another embodiment of this application; Figure 10 for Figure 9 Bottom view of the middle circuit board assembly 1001; Figure 11 for Figure 9 Top view of the middle circuit board assembly 1001; Figure 12 for Figure 11 A sectional view along the DD direction; Figure 13 for Figure 11 A cross-sectional view along the EE direction.

[0060] This embodiment has a structure that is basically the same as the gas detection device 100 in the above embodiment, except that the gas driving mechanism 10 and the sensing component 20 in the above embodiment are located on the same side of the circuit board 40, while... Figure 9-13 In the illustrated embodiment, the gas driving mechanism 10 and the sensing component 20 are located on different sides of the circuit board 40. As previously stated, the circuit board 40 has a first side and a second side distributed along its thickness direction. The sensing component 20 is disposed on the first side of the circuit board 40, and the gas driving mechanism 10 is disposed on the second side of the circuit board 40. Figure 12 , 13 In this configuration, the first side is the upper side, and the second side is the lower side. This arrangement allows the high-velocity gas flowing from the gas-driven mechanism 10 to dissipate heat from the electrical components 30 on the back side, while also keeping them far from the sensing component 20, minimizing interference with its detection. The circuit board 40 can then be a double-sided circuit board 40, meaning that electrical components 30 are arranged on both sides. Positioning the gas-driven mechanism 10 on the second side of the circuit board 40 also provides more space for its arrangement, allowing for the installation of a larger number of gas-driven mechanisms 10, for example… Figure 10 The diagram shows two gas-driven mechanisms 10.

[0061] In some embodiments, the projection of the gas drive mechanism 10 along the thickness direction of the circuit board 40 can at least partially coincide with the projection of at least one electrical component 30. This allows the gas drive mechanism 10 to be positioned as close as possible to the electrical component 30 that requires heat dissipation, for example, directly below the electrical component 30. Figure 12 , 13In the circuit board 40, a gas drive mechanism 10 is provided on the second side directly below the two cylindrical relays 30a and the square relay 30a. With this arrangement, the air outlet 101b of the gas drive mechanism 10 faces the circuit board 40, and the outflowing air can directly flow to the surface of the circuit board 40 to dissipate heat, thereby indirectly dissipating heat from the electrical components 30 located above, thus ensuring the heat dissipation effect.

[0062] The housing 50 of the gas detection device 100 has a housing side wall portion 5021 and a housing bottom wall portion 5022. Figure 14 The outer shell sidewall portion 5021 is only the sidewall of the lower shell 502. The outer shell sidewall portion 5021 of the outer shell 50 also includes the sidewall of the upper shell 501. Of course, the structural form of the outer shell 50 is not limited to the upper shell 501 and the lower shell 502 being joined together. Here, the outer shell sidewall portion 5021 is the part located between the outer shell top wall portion 5011 and the outer shell bottom wall portion 5022 of the outer shell 50. The space between the circuit board 40 and the outer shell top wall portion 5011 is defined as the first cavity, and the space between the outer shell bottom wall portion 5022 and the circuit board 40 is defined as the second cavity. The airflow entering from the first vent structure 501a enters the first cavity to provide airflow to the sensing component 20. The first cavity and the second cavity can be configured to be interconnected. In this way, the airflow can also flow from the first cavity into the second cavity to provide airflow to the gas drive mechanism 10 located on a different side from the sensing component 20. Specifically, the circuit board 40 may be provided with a ventilation hole 40b extending along its thickness direction, which connects the first cavity and the second cavity.

[0063] like Figures 9-11 As shown, the circuit board 40 is provided with two ventilation holes 40b, namely a first ventilation hole 40b1 and a second ventilation hole 40b2, each ventilation hole 40b being close to a gas driving mechanism 10. As described above, the housing 50 of the gas detection device 100 is provided with a first vent structure 501a, located above the housing 50. Gas enters from above the housing 50, closer to the first side of the circuit board 40, while the gas driving mechanism 10 is located on the second side of the circuit board 40. The ventilation holes 40b on the circuit board 40 facilitate the introduction of some gas to the second side of the circuit board 40, making it easier for the gas to enter the gas driving mechanism 10 to form a high-velocity heat dissipation gas. In this embodiment, each gas driving mechanism 10 on the circuit board 40 is provided with a ventilation hole 40b, which can be... Figure 10 The elongated hole structure shown in the diagram can be, where space permits, shaped like a straight line, an L-shape, a U-shape, etc., and can be located on one side of the gas drive mechanism 10 or surround at least both sides of the gas drive mechanism 10.

[0064] Of course, in order to introduce airflow to the gas drive mechanism 10, it is not limited to providing ventilation holes 40b on the circuit board 40. For example... Figure 14 As shown, Figure 14 This is a schematic cross-sectional view of the circuit board assembly 1001 and the lower shell 502 in a gas detection device 100 according to one embodiment of this application.

[0065] In this embodiment, the outer periphery of the circuit board 40 and the side wall portion 5021 of the housing are disposed opposite to each other, and at least a portion of the outer periphery of the circuit board 40 and the side wall portion 5021 of the housing 50 have a gap, which can be defined as a first gap b. The first gap b serves as an air intake channel and connects the first cavity and the second cavity. At this time, the bottom wall portion 5022 of the housing 50 and the second side of the circuit board 40 are spaced apart to leave space for accommodating the gas drive mechanism 10 on the second side of the circuit board 40 and other electrical components that can be disposed on the second side. The wall portion corresponding to the air inlet 101a of the gas drive mechanism 10 and the bottom wall portion 5021 of the housing have a gap, which can be defined as a second gap c. In this way, the airflow entering from the first vent structure 501a can also enter from the first gap b between the outer periphery of the circuit board 40 and the outer shell side wall 5021 of the outer shell 50, into the second gap c between the circuit board 40 and the outer shell bottom wall 5022 of the outer shell 50, and then flow to the air inlet 101a of the gas drive mechanism 10. In this way, the circuit board 40 does not need to be provided with a vent 40b.

[0066] In the above embodiments, the housing 50 of the gas detection device 100 is provided with a first vent structure 501a. The airflow enters the housing 50 through the first vent structure 501a. For the airflow to enter the second side of the circuit board 40, a ventilation hole 40b needs to be provided on the circuit board 40 or the first gap b between the circuit board 40 and the side wall portion 5021 of the housing needs to flow downwards to the circuit board 40. However, it is known that when the gas driving mechanism 10 is provided on the second side of the circuit board 40, in some embodiments, the airflow can also be delivered to the gas driving mechanism 10 in other ways.

[0067] like Figure 15 As shown, Figure 15 This is a schematic cross-sectional view of the circuit board assembly 1001 and the lower shell 502 in the gas detection device 100 in another embodiment of this application.

[0068] In this embodiment, an additional airflow hole is provided on the outer casing 50, namely, a second vent structure 502a is provided. For example, the second vent structure 502a can be directly provided on the bottom wall portion 5022 of the outer casing 50, and the second vent structure 502a is connected to the air inlet 101a. It can be directly connected, or the corresponding wall portions of the bottom wall portion 5022 and the air inlet 101a can have a gap, so that the second vent structure 502a and the air inlet 101a are indirectly connected through the gap. In this way, the airflow entering from the first vent structure 501a enters the first side of the circuit board 40 and flows towards the sensing component 20, and the airflow entering from the second vent structure 502a of the bottom wall portion 5022 of the outer casing 50 can enter the second side of the circuit board 40 and flow towards the gas drive mechanism 10, so that the airflows do not interfere with each other. The number of second vent structures 502a is not limited; there can be one or more. This embodiment does not impose specific restrictions. The second vent structure 502 can be set close to the gas drive mechanism 10 to facilitate the delivery of airflow to the gas drive mechanism 10.

[0069] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A gas detection device, characterized by, include: The sensing component (20) includes a detection unit capable of detecting gases; A circuit board (40) and at least one electrical component (30), wherein the sensing assembly (20) and the electrical component (30) are both electrically connected to the circuit board (40); At least one gas-driven mechanism (10) includes a housing (101) and a cantilever (103) located within the housing (101) and capable of vibrating electrically. The housing (101) has an air inlet (101a) and an air outlet (101b). The air outlet (101b) and the air inlet (101a) are located on opposite sides of the thickness direction of the cantilever (103), and the air outlet (101b) is disposed facing at least a portion of the circuit board (40).

2. The gas detection device of claim 1, wherein, The cantilever (103) includes a cantilever body and a piezoelectric part connected to the cantilever body. The piezoelectric part is electrically connected to the circuit board (40). The gas drive mechanism (10) includes a base (102). The base (102) is at least partially located within the housing (101). The cantilever (103) is connected to a portion of the base (102) located within the housing (101). A portion of the cantilever (103) is suspended from the base (102) within the housing (101).

3. The gas detection device of claim 2, wherein, The cantilever portion (103) includes a first cantilever portion (1031) and a second cantilever portion (1032). The first cantilever portion (1031) and the second cantilever portion (1032) are suspended from the base (102) in opposite directions. The number of air outlets (101b) is at least two. The projections of the at least two air outlets (101b) corresponding to the wall portions are respectively located within the projection of the first cantilever portion (1031) and the projection of the second cantilever portion (1032). The projection of the air inlet (101a) corresponding to the wall portion is located within the projection of the base (102).

4. The gas detection device of claim 3, wherein, The side of the housing (101) closest to the circuit board (40) is the bottom wall (1012). The housing (101) also includes a top wall (1011) opposite to the bottom wall (1012). The inner cavity of the housing (101) includes a first cavity (101c) and a second cavity (102d). The first cavity (101c) is located between the cantilever (103) and the top wall (1011), and the second cavity (101d) is located between the cantilever (103) and the bottom wall (1012). The gas detection device (100) includes a housing (50), the sensing component (20), the circuit board (40), and the gas driving mechanism (10) are all located in the inner cavity of the housing (50), the air inlet (101a) connects the first cavity (101c) and the inner cavity of the housing (50), and the air outlet (101b) connects the second cavity (101d) and the inner cavity of the housing (50).

5. The gas detection device according to any one of claims 1 to 4, characterized in that, The gas drive mechanism (10) and the sensing component (20) are located on the same side of the circuit board (40).

6. The gas detection device of claim 5, wherein, At least one of the electrical components (30) is a first electrical component (301), and the height of the first electrical component (301) in the direction perpendicular to the circuit board (40) is greater than the height of the gas drive mechanism (10) in the direction perpendicular to the circuit board (40); At least one of the first electrical components (301) is located between the sensing assembly (20) and at least one of the gas drive mechanisms (10).

7. The gas detection device according to any one of claims 1 to 4, wherein The sensing component (20) and the gas driving mechanism (10) are located on different sides of the circuit board (40).

8. The gas detection device according to claim 7, characterized in that, Projecting along the thickness direction of the circuit board (40), the projection of the gas drive mechanism (10) and the projection of at least one of the electrical components (30) at least partially overlap.

9. The gas detection device according to claim 7, characterized in that, The gas detection device includes a housing (50), and the circuit board (40) is located inside the housing (50); the housing (50) has a bottom wall portion (5022) and a top wall portion (5011) disposed opposite to each other, and a side wall portion (5021) located between the bottom wall portion (5022) and the top wall portion (5011). The bottom wall portion (5022) of the outer casing and the gas drive mechanism (10) are located on the same side of the circuit board (40), and the top wall portion (5011) of the outer casing is located on the other side of the circuit board (40); the first cavity between the top wall portion (5011) of the outer casing and the circuit board (40) is connected to the second cavity between the circuit board (40) and the bottom wall portion (5022) of the outer casing.

10. The gas detection device according to claim 9, characterized in that, The circuit board (40) is provided with a ventilation hole (40b) extending through its thickness direction, and the ventilation hole (40b) connects the first cavity and the second cavity; Alternatively, the top wall portion (5011) of the outer casing is provided with a first vent structure (501a), the outer periphery of the circuit board (40) and the side wall portion (5021) of the outer casing are disposed opposite to each other, and at least a portion of the outer periphery of the circuit board (40) and the side wall portion (5021) of the outer casing have a first gap (b), the first gap (b) connecting the first cavity and the second cavity.

11. The gas detection device according to claim 7, characterized in that, The gas detection device includes a housing (50), and the circuit board (40) is located inside the housing (50); the housing (50) has a bottom wall portion (5022) and a top wall portion (5011) disposed opposite to each other, the bottom wall portion (5022) and the gas driving mechanism (10) are located on the same side of the circuit board (40), and the top wall portion (5011) is located on the other side of the circuit board (40); The top wall portion (5011) of the outer casing is provided with a first vent structure (501a), and the bottom wall portion (5022) of the outer casing is provided with a second vent structure (502a). The second vent structure (502a) is connected to the air inlet (101b).

12. The gas detection device according to any one of claims 1 to 4, characterized in that, There is a third gap (a) between the wall where the air outlet (101b) is located and the circuit board (40). At least one of the electrical components (30) is a second electrical component (302). In the direction perpendicular to the circuit board (40), the height of the second electrical component (302) is not greater than the height of the third gap (a). In the extension direction of the surface of the circuit board (40), the second electrical component (302) is distributed on at least one side of the gas drive mechanism (10).

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