A sensing device

Abstract

This application provides a sensing device, including a first housing, a second housing, a first sensing element, a second sensing element, and a circuit board. The first housing forms a first receiving cavity, and the second housing forms a second receiving cavity. The first housing has a communication port, through which the first receiving cavity communicates directly or indirectly with the outside of the sensing device. The second receiving cavity is a closed cavity. The first sensing element is located inside the first receiving cavity and includes a first thermistor. The second sensing element is located inside the second receiving cavity and includes a second thermistor. The first and second receiving cavities are located on opposite sides of the circuit board along its thickness direction. On a plane perpendicular to the thickness direction of the circuit board, the orthographic projections of the first and second receiving cavities at least partially overlap. This sensing device has high detection accuracy.

Description

Technical Field

[0001] This application relates to the field of gas detection technology, particularly to refrigerant leak detection, and specifically to a sensing device. Background Technology

[0002] Some air conditioning systems use refrigerants that are flammable, and leaks can pose safety hazards. Therefore, it is necessary to install sensors to detect refrigerant leaks in order to eliminate safety hazards in a timely manner.

[0003] The sensing device detects refrigerant leakage based on the Wheatstone bridge principle. It includes two sets of thermistors, which act as the two arms of the Wheatstone bridge: a control group and a detection group. The detection group is located in an open cavity, connected to the area where refrigerant may leak. The control group is located in a closed cavity, isolated from the area where refrigerant may leak. When refrigerant leaks, the change in resistance in the detection group differs from that in the control group, disrupting the balance of the Wheatstone bridge and generating a differential signal, which is used to determine that a refrigerant leak has occurred.

[0004] In related technologies, the sensing devices where the open cavity containing the detection group and the closed cavity containing the control group are located on the same side of the circuit board's thickness direction and arranged side by side have low detection accuracy. The inventors analyzed and found that the reason for the low detection accuracy of previous sensing devices is that the circuit board inevitably generates heat when energized. When the open cavity containing the detection group and the closed cavity containing the control group are located on the same side of the circuit board's thickness direction and arranged side by side, the open cavity and the closed cavity correspond to different areas of the circuit board. Since the heat generated in different areas of the circuit board varies significantly, the resistance changes of the detection group in the open cavity and the control group in the closed cavity due to the heat generated by the circuit board differ significantly. This causes the Wheatstone bridge balance to be disrupted even without refrigerant leakage, resulting in differential signal output and misjudgment.

[0005] Therefore, how to improve the detection accuracy of sensing devices is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] One objective of this application is to improve the detection accuracy of sensing devices. To achieve this objective, this application provides a sensing device comprising a first housing, a second housing, a first sensing unit, a second sensing unit, and a circuit board. The first housing has a first receiving cavity, and the second housing has a second receiving cavity. The first housing has a communication port, and the first receiving cavity is directly or indirectly connected to the outside of the sensing device through the communication port. The second receiving cavity is a closed cavity. The first sensing unit is located in the first receiving cavity, and the second sensing unit is located in the second receiving cavity. The first sensing unit includes a first thermistor, and the second sensing unit includes a second thermistor. The first housing and the second housing are located on opposite sides in the thickness direction of the circuit board, and on a plane perpendicular to the thickness direction of the circuit board, the orthographic projections of the first housing and the second housing at least partially overlap.

[0007] The sensing device provided in this application has a first housing and a second housing located on opposite sides of the circuit board in the thickness direction. The orthographic projections of the first housing and the second housing overlap at least partially on a plane perpendicular to the thickness direction of the circuit board. Therefore, the first housing and the second housing correspond at least partially to the same area of ​​the circuit board. As a result, the resistance changes of the first thermistor and the second thermistor due to the heat of the circuit board are similar or the same, thus improving the detection accuracy. Attached Figure Description

[0008] Figure 1 A top view of one embodiment of the sensing device provided in this application;

[0009] Figure 2 for Figure 1 Sectional view along axis AA;

[0010] Figure 3 for Figure 2 A magnified view of the area inside the center circle;

[0011] Figure 4 A top view of another embodiment of the sensing device provided in this application;

[0012] Figure 5 for Figure 4 Sectional view along axis AA;

[0013] Figure 6 for Figure 5 A three-dimensional view of the circuit board, heat conduction frame, and first housing;

[0014] Figure 7 for Figure 6 Top view;

[0015] Figure 8 for Figure 7BB-direction sectional view;

[0016] Figure 9 for Figure 8 A 3D view of a single heat-conducting frame.

[0017] The annotations in the attached figures are explained as follows:

[0018] 10 First shell, 101 First shell body, 102 First shell base, F Connecting port;

[0019] 20 Second shell, 201 Second shell body, 202 Second shell base;

[0020] 30 First sensing unit; 301 First thermistor;

[0021] 40 Second sensing unit; 401 Second thermistor;

[0022] 50 Circuit board, C1 is the first through hole, C2 is the second through hole;

[0023] 60 Heat-conducting part, 601 First heat-conducting cover, 602 Second heat-conducting cover, X1 First fixing hole, X2 Second fixing hole, Y1 First abutting surface, Y2 Second abutting surface, 603 Heat-conducting frame, 6031 Pressing part, D Snap-fit ​​hole, E Connecting hole, 6032 Snap-fit ​​post;

[0024] 70 First outer casing, 701 Air inlet, 702 Insertion interface; 80 Second outer casing; 90 Air inlet cover, G Through hole; 100 Sealing ring;

[0025] A1 is the first receiving cavity, A2 is the second receiving cavity, A3 is the third receiving cavity, A4 is the fourth receiving cavity, and A5 is the fifth receiving cavity. Detailed Implementation

[0026] This application provides a sensing device. To enable those skilled in the art to better understand the technical solution of this application, the following description is provided in conjunction with the appendix. Figure 1-9 The technical solutions of this application will be further described in detail below with reference to specific embodiments.

[0027] The sensing device provided in this application includes a first housing 10, a second housing 20, a first sensing unit 30, a second sensing unit 40, and a circuit board 50.

[0028] The first housing 10 has a first receiving cavity A1, and the second housing 20 has a second receiving cavity A2. In the illustrated embodiment, the first housing 10 includes a first housing body 101 and a first housing base 102, one end of the first housing body 101 ( Figure 2The lower end of the first shell body 101 is an open end, and the first shell base 102 is sealed to the open end of the first shell body 101. The second shell 20 includes a second shell body 201 and a second shell base 202. One end of the second shell body 201 ( Figure 2 The upper end of the second shell body 201 is an open end, and the second shell base 202 is sealed to the open end of the second shell body 201.

[0029] The first housing 10 is provided with a communication port F, and the first receiving cavity A1 is directly or indirectly connected to the outside of the sensing device through the communication port F, making the first receiving cavity A1 an open cavity. In the illustrated embodiment, the communication port F is located at the end of the first housing body 101 opposite to the open end ( Figure 2 The first housing body 101 (upper end) is connected to the outside of the sensing device via a connecting port F. Specifically, the first housing A1 is connected to the fifth housing A5 via the connecting port F, and the fifth housing A5 is connected to the outside of the sensing device via an air inlet. The second housing A2 is a closed cavity.

[0030] The first housing 10 and the second housing 20 are located on opposite sides of the circuit board 50 in the thickness direction. On a plane perpendicular to the thickness direction of the circuit board 50, the orthographic projections of the first housing 10 and the second housing 20 partially or completely overlap.

[0031] The first sensing unit 30 is located inside the first receiving cavity A1, and the second sensing unit 40 is located inside the second receiving cavity A2. The first sensing unit 30 includes a first thermistor 301, and the second sensing unit 40 includes a second thermistor 401. Specifically, the circuit board 50 includes a detection circuit, which includes a Wheatstone bridge. The first thermistor 301 and the second thermistor 401 are electrically connected to the detection circuit, and the first thermistor 301 and the second thermistor 401 serve as two arms of the Wheatstone bridge.

[0032] When the refrigerant in the air conditioning system leaks, the refrigerant enters the first containment cavity A1 through the connection port F, causing a change in the thermal conductivity of the first containment cavity A1. This, in turn, causes a change in the resistance of the first thermistor 301 in the first containment cavity A1. However, the refrigerant does not enter the second containment cavity A2. Therefore, the change in the resistance of the second thermistor 401 in the second containment cavity A2 is less than the change in the resistance of the first thermistor 301, which breaks the balance of the Wheatstone bridge and outputs a differential signal. Based on this differential signal, it can be determined that there is a refrigerant leak and the amount of refrigerant leaked can be calculated.

[0033] It should be noted that the sensing device provided in this application can also be used for the detection of other gases, and is not limited to detecting refrigerant leaks.

[0034] When the sensing device is working, the circuit board 50 is energized. The energized circuit board 50 will inevitably generate heat. The heat generated by the circuit board 50 will be conducted to the interior of the first receiving cavity A1 and the second receiving cavity A2, causing changes in the resistance values ​​of the first thermistor 301 and the second thermistor 401. The heat generated in different areas of the circuit board 50 varies greatly. Therefore, when the first housing 10 and the second housing 20 correspond to different areas of the circuit board 50, the amount of resistance change of the first thermistor 301 affected by the heat of the circuit board 50 is significantly different from the amount of resistance change of the second thermistor 401 affected by the heat of the circuit board 50. This may cause the balance of the Wheatstone bridge to be broken, resulting in the output of a differential signal even when there is no refrigerant leakage. Therefore, the detection accuracy is low and misjudgment is prone to occur.

[0035] The sensing device provided in this application has the following advantages: the first housing 10 and the second housing 20 are located on opposite sides of the circuit board 50 in the thickness direction, and the orthographic projections of the first housing 10 and the second housing 20 at least partially overlap on a plane perpendicular to the thickness direction of the circuit board 50. This makes the first housing 10 and the second housing 20 at least partially correspond to the same area of ​​the circuit board 50. Therefore, the resistance change of the first thermistor 301 caused by the heat of the circuit board 50 is similar to or the same as the resistance change of the second thermistor 401. Thus, the detection accuracy can be improved, thereby reducing the probability of misjudgment.

[0036] In some embodiments, such as Figure 2 or Figure 5 As shown, on a plane perpendicular to the thickness direction of the circuit board 50, the orthographic projections of the first housing 10 and the second housing 20 completely overlap, and the first housing 10 and the second housing 20 are arranged along the same center line. In this way, the first housing 10 and the second housing 20 all correspond to the same area of ​​the circuit board 50, which is more conducive to reducing the difference between the resistance change of the first thermistor 301 and the resistance change of the second thermistor 401 caused by the heat of the circuit board 50. Therefore, it is more conducive to improving detection accuracy and thus reducing the probability of false positives.

[0037] In some embodiments, the sensing device includes a heat-conducting part 60. The first housing 10 and the second housing 20 are relatively fixed to the circuit board 50 through the heat-conducting part 60. The heat-conducting part 60 is in contact with the first housing 10 and the second housing 20, allowing heat conduction between the first housing 10 and the second housing 20. When refrigerant leaks, in addition to the change in thermal conductivity inside the first receiving cavity A1 caused by the refrigerant, which will cause a change in the resistance of the first thermistor 301, the temperature of the circuit board 50 and the temperature of the leaking refrigerant itself will also cause changes in the resistance of the first thermistor 301 and the second thermistor 401. If the difference in the amount of change in the resistance of the first thermistor 301 and the second thermistor 401 caused by temperature is large, it will not only lead to misjudgment, but also reduce the accuracy of the detected amount of refrigerant leakage. By allowing the first housing 10 and the second housing 20 to conduct heat through the heat-conducting part 60, the temperature difference between the outer shells of the first housing 10 and the second housing 20 can be reduced. This makes the influence of the first housing 10 on the internal temperature of the first receiving cavity A1 and the influence of the second housing 20 on the internal temperature of the second receiving cavity A2 tend to be the same or remain the same. As a result, the influence of the first housing 10 on the first thermistor 301 and the influence of the second housing 20 on the second thermistor 401 can be similar or the same, thus further improving the detection accuracy and reducing the probability of false judgment.

[0038] Figures 1-3 The structure of the heat-conducting part 60 in the illustrated embodiment is similar to... Figures 4-9 The structure of the heat-conducting part 60 in the illustrated embodiment is different.

[0039] Specifically, Figures 1-3 In the embodiment shown, the heat-conducting part 60 has a third receiving cavity A3. The heat-conducting part 60 is provided with a first fixing hole X1 and a second fixing hole X2. The circuit board 50 is located in the third receiving cavity A3. The first housing 10 is at least partially inserted into the first fixing hole X1 and is tightly fitted with the hole sidewall corresponding to the first fixing hole X1. The second housing 20 is at least partially inserted into the second fixing hole X2 and is tightly fitted with the hole sidewall corresponding to the second fixing hole X2.

[0040] More specifically, such as Figure 2 As shown, the heat-conducting part 60 includes a first heat-conducting shield 601 and a second heat-conducting shield 602, one end of the first heat-conducting shield 601 ( Figure 2 The lower end of the first heat-conducting shield 601) and one end of the second heat-conducting shield 602 ( Figure 2 The upper end of the second heat-conducting cover 602 is an open end, and the open ends of the first heat-conducting cover 601 and the second heat-conducting cover 602 are connected. A first fixing hole X1 is located at the end of the first heat-conducting cover 601 opposite to the open end. Figure 2 The second fixing hole X2 is located at the upper end of the first heat-conducting cover 601, and is located at the end of the second heat-conducting cover 602 opposite to the open end. Figure 2 The lower end of the second heat-conducting cover 602). The third receiving cavity A3 is located inside the first heat-conducting cover 601 and the second heat-conducting cover 602. The circuit board 50 is at least partially located between the first heat-conducting cover 601 and the second heat-conducting cover 602. The circuit board 50, the first heat-conducting cover 601, and the second heat-conducting cover 602 are fixed or limited. In the illustrated embodiment, the inner side of the first heat-conducting cover 601 is provided with a first abutment surface Y1, and the inner side of the second heat-conducting cover 602 is provided with a second abutment surface Y2. The first abutment surface Y1 and the second abutment surface Y2 abut against the opposite sides of the circuit board 50 in the thickness direction, thereby clamping the circuit board 50.

[0041] Specifically, Figures 4-9 In the illustrated embodiment, the heat-conducting part 60 includes two heat-conducting frames 603. The two heat-conducting frames 603 have essentially the same structure. Each heat-conducting frame 603 includes a pressing part 6031 and a snap-fit ​​post 6032. One end of the snap-fit ​​post 6032 is fixed to or integrally formed with the pressing part 6031, and the other end of the snap-fit ​​post 6032 has a snap-fit ​​protrusion. The two heat-conducting frames 603 are respectively the first heat-conducting frame and the second heat-conducting frame. The pressing part 6031 of the first heat-conducting frame abuts against the first housing 10, and the pressing part 6031 of the second heat-conducting frame abuts against the second housing 20. The circuit board 50 is provided with a first through hole C1 and a second through hole C2. The first heat-conducting frame's snap-fit ​​post 6032 passes through the first through hole C1 on the circuit board 50 and snaps into the second heat-conducting frame's pressing part 6031. The second heat-conducting frame's snap-fit ​​post 6032 passes through the second through hole C2 on the circuit board 50 and snaps into the first heat-conducting frame's pressing part 6031, so that the first heat-conducting frame presses the first housing 10 against one side of the circuit board 50 and the second heat-conducting frame presses the second housing 20 against the other side of the circuit board 50.

[0042] More specifically, such as Figure 8 and Figure 9As shown, the first heat-conducting frame is located above the second heat-conducting frame. The pressing part 6031 of the first heat-conducting frame is provided with a snap-fit ​​hole D. The snap-fit ​​post 6032 of the second heat-conducting frame has a snap-fit ​​protrusion at one end, which extends from the lower side of the pressing part 6031 of the first heat-conducting frame through the snap-fit ​​hole D to the upper side of the pressing part 6031 of the first heat-conducting frame. The snap-fit ​​protrusion of the second heat-conducting frame abuts against the upper side of the pressing part 6031 of the first heat-conducting frame, thereby realizing the snap-fit ​​between the snap-fit ​​post 6032 of the second heat-conducting frame and the pressing part 6031 of the first heat-conducting frame. The pressing part 6031 of the second heat-conducting frame is provided with a snap-fit ​​hole D. The first heat-conducting frame's snap-fit ​​post 6032, with a snap-fit ​​protrusion at one end, extends from the upper side of the second heat-conducting frame's pressing part 6031 through the snap-fit ​​hole D to the lower side of the second heat-conducting frame's pressing part 6031. The snap-fit ​​protrusion of the first heat-conducting frame abuts against the lower side of the second heat-conducting frame's pressing part 6031, thereby achieving snap-fit ​​between the first heat-conducting frame's snap-fit ​​post 6032 and the second heat-conducting frame's pressing part 6031. The first heat-conducting frame's snap-fit ​​post 6032 and the second heat-conducting frame's snap-fit ​​post 6032 are arranged approximately at 180 degrees about the center lines of the first housing 10 and the second housing 20.

[0043] More specifically, such as Figure 8 and Figure 9 As shown, the pressing portions 6031 of both heat-conducting frames 603 are provided with connecting holes E. The first housing 10 is at least partially located within the connecting hole E of the first heat-conducting frame, and the sidewall of the hole corresponding to the connecting hole E of the first heat-conducting frame is at least partially in contact with the first housing 10. The second housing is at least partially located within the connecting hole E of the second heat-conducting frame, and the sidewall of the hole corresponding to the connecting hole E of the second heat-conducting frame is at least partially in contact with the second housing 20. This design ensures a large contact area between the first housing 10, the second housing 20, and the two heat-conducting frames 603, allowing the first housing 10 and the second housing 20 to better conduct heat through the two heat-conducting frames 603.

[0044] More specifically, such as Figure 9As shown, the two heat conduction frames 603 have a protrusion (pointed to by E1 in the figure) that protrudes towards the center of the connection hole E and a recess (pointed to by E2 in the figure) that is recessed away from the center of the connection hole E on the side wall of the hole corresponding to the connection hole E. The protrusion of the first heat conduction frame contacts the first housing 10, and there is a gap between the recess of the first heat conduction frame and the first housing 10. The protrusion of the second heat conduction frame contacts the second housing 20, and there is a gap between the recess of the second heat conduction frame and the second housing 10. This design ensures a large contact area between the first housing 10, the second housing 20, and the two heat-conducting frames 603. It also ensures that leaked refrigerant can flow from the side where the first housing 10 is located through the gap and the through hole on the circuit board 50 to the side where the second housing 20 is located. This allows the temperature of the leaked refrigerant to be conducted relatively evenly to the first housing 10 and the second housing 20, avoiding a large temperature difference between the first housing 10 and the second housing 20 that could lead to misjudgment or inaccurate detection. Furthermore, it ensures that the first housing 10, the second housing 20, and the heat-conducting frame 603 are easy to assemble.

[0045] In some embodiments, such as Figure 2 or Figure 5 As shown, the sensing device includes a first housing 70 and a second housing 80. One end of the first housing 70 and the second housing 80 is an open end, and the open ends of the first housing 70 and the second housing 80 are joined together. The sensing device has a cavity located inside the first housing 70 and the second housing 80. In the illustrated embodiment, a sealing ring 100 is provided between the first housing 70 and the second housing 80. A plug-in interface 702 is formed on one side of the joint area of ​​the first housing 70 and the second housing 80 (e.g., Figure 4 (As shown in the figure). The heat-conducting part 60, circuit board 50, first housing 10 and second housing 20 are all located inside the housing cavity. An air inlet 701 is provided on the end wall of the first housing 70 away from the second housing 80 (on the upper end wall of the first housing 70 in the figure).

[0046] In some embodiments, such as Figure 5As shown, the sensing device includes an air intake shroud 90 located within the housing cavity, dividing the housing cavity into a fourth receiving cavity A4 and a fifth receiving cavity A5. All air intake holes 701 communicate with the fifth receiving cavity A5; that is, the orthographic projection of the fifth receiving cavity A5 onto the end wall of the first housing 70 where the air intake holes 701 are located covers all the air intake holes 701. The air intake shroud 90 has a connecting hole G, and the first housing 10 is at least partially inserted into the connecting hole G, thus the air intake shroud 90 can limit the movement of the first housing 10. The connecting port F of the first housing 10 is located within the fifth receiving cavity A5 or within the connecting hole G. There is a gap between the first housing 10 and the side wall of the connecting hole G, through which the connecting hole G connects the interior of the fifth receiving cavity A5 and the interior of the fourth receiving cavity A4. When the refrigerant leaks, it enters the fifth receiving cavity A5 through the air inlet 701, and then splits into two paths. One path enters the first receiving cavity A1 through the connecting port F, and the other path enters the fourth receiving cavity A4 through the gap and flows around or through the circuit board 50 from the side where the first housing 10 is located to the side where the second housing 20 is located. In this way, the temperature of the leaking refrigerant can be conducted to the first housing 10 and the second housing 20 relatively evenly, avoiding a large temperature difference between the first housing 10 and the second housing 20 caused by the temperature of the leaking refrigerant, which could lead to misjudgment or inaccurate detection.

[0047] In some embodiments, the sum of the total conductive areas of all air inlets 701 is greater than the conductive areas of all the connecting ports F. When there are multiple air inlets 701, the total conductive area of ​​all air inlets 701 refers to the sum of the conductive areas of each air inlet 701. When there are multiple connecting ports F, the conductive area of ​​all connecting ports F refers to the sum of the conductive areas of each connecting port F.

[0048] The above examples illustrate the principles and implementation methods of this application. The descriptions of the embodiments are merely for the purpose of helping to understand the methods and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A sensing device, characterized in that, The sensing device includes a first housing (10), a second housing (20), a first sensing part (30), a second sensing part (40), and a circuit board (50). The first housing (10) has a first receiving cavity (A1), and the second housing (20) has a second receiving cavity (A2). The first housing (10) is provided with a connecting port (F). The first receiving cavity (A1) is directly or indirectly connected to the outside of the sensing device through the connecting port (F). The second receiving cavity (A2) is a closed cavity. The first sensing part (30) is located in the first receiving cavity (A1), and the second sensing part (40) is located in the second receiving cavity (A2). The first sensing part (30) includes a first thermistor (301), and the second sensing part (40) includes a second thermistor (401). The first housing (10) and the second housing (20) are located on opposite sides of the thickness direction of the circuit board (50). On a plane perpendicular to the thickness direction of the circuit board (50), the orthographic projection of the first housing (10) and the orthographic projection of the second housing (20) at least partially overlap.

2. The sensing device according to claim 1, characterized in that, On a plane perpendicular to the thickness direction of the circuit board (50), the orthographic projection of the first housing (10) and the orthographic projection of the second housing (20) completely overlap, and the first housing (10) and the second housing (20) are arranged along the same center line.

3. The sensing device according to claim 1 or 2, characterized in that, The sensing device includes a heat-conducting part (60) that contacts the first housing (10) and the second housing (20).

4. The sensing device according to claim 3, characterized in that, The heat-conducting part (60) has a third receiving cavity (A3). The heat-conducting part (60) is provided with a first fixing hole (X1) and a second fixing hole (X2). The circuit board (50) is fixed in the third receiving cavity (A3). The first housing (10) is at least partially located in the first fixing hole (X1) and is tightly fitted with the hole sidewall corresponding to the first fixing hole (X1). The second housing (20) is at least partially located in the second fixing hole (X2) and is tightly fitted with the hole sidewall corresponding to the second fixing hole (X2).

5. The sensing device according to claim 4, characterized in that, The heat-conducting part (60) includes a first heat-conducting cover (601) and a second heat-conducting cover (602). One end of the first heat-conducting cover (601) and the second heat-conducting cover (602) is an open end. The third receiving cavity (A3) is located inside the first heat-conducting cover and the second heat-conducting cover. The circuit board (50) is at least partially located between the first heat-conducting cover (601) and the second heat-conducting cover (602). The circuit board (50), the first heat-conducting cover (601), and the second heat-conducting cover (602) are fixed or limited. The first fixing hole (X1) is provided at the end of the first heat-conducting cover (601) opposite to the open end. The second fixing hole (X2) is provided at the end of the second heat-conducting cover (602) opposite to the open end.

6. The sensing device according to claim 3, characterized in that, The heat-conducting part (60) includes two heat-conducting frames (603), each of which includes a pressing part (6031) and a snap-fit ​​post (6032). The two heat-conducting frames (603) are respectively the first heat-conducting frame and the second heat-conducting frame. The pressing part (6031) of the first heat-conducting frame abuts against the first housing (10), and the pressing part (6031) of the second heat-conducting frame abuts against the second housing (20). The circuit board (50) is provided with a first through hole (C1) and a second through hole (C2). The snap-fit ​​post (6032) of the first heat-conducting frame passes through the... The first through hole (C1) on the circuit board (50) is engaged with the pressing part (6031) of the second heat conduction frame. The locking post (6032) of the second heat conduction frame passes through the second through hole (C2) on the circuit board (50) and engages with the pressing part (6031) of the first heat conduction frame, so that the pressing part (6031) of the first heat conduction frame presses the first housing (10) against one side of the circuit board (50) and the pressing part (6031) of the second heat conduction frame presses the second housing (20) against the other side of the circuit board (50).

7. The sensing device according to claim 6, characterized in that, Both heat-conducting frames (603) have a connecting hole (E) in their pressing part (6031); the first housing (10) is at least partially located in the connecting hole (E) of the first heat-conducting frame, and the sidewall of the hole corresponding to the connecting hole (E) of the first heat-conducting frame is at least partially in contact with the first housing (10); the second housing (20) is at least partially located in the connecting hole (E) of the second heat-conducting frame, and the sidewall of the hole corresponding to the connecting hole (E) of the second heat-conducting frame is at least partially in contact with the second housing (20).

8. The sensing device according to claim 7, characterized in that, The two heat-conducting brackets (603) have a protrusion that protrudes towards the center of the connection hole (E) and a recess that is recessed away from the center of the connection hole (E) on the sidewall of the corresponding hole. The protrusion of the first heat-conducting bracket is in contact with the first housing (10), and there is a gap between the recess of the first heat-conducting bracket and the first housing (10). The protrusion of the second heat-conducting bracket is in contact with the second housing (20), and there is a gap between the recess of the second heat-conducting bracket and the second housing (10).

9. The sensing device according to claim 3, characterized in that, The sensing device includes a first housing (70) and a second housing (80). One end of the first housing (70) and one end of the second housing (80) are open ends. The sensing device has a cavity located inside the first housing (70) and the second housing (80). The first housing (70) and the second housing (80) are connected. The heat-conducting part (60), the circuit board (50), the first housing (10) and the second housing (20) are all located inside the cavity. An air inlet (701) is provided on the end wall of the first housing (70) away from the second housing (80).

10. The sensing device according to claim 9, characterized in that, The sensing device includes an air intake shroud (90) located inside the housing cavity and dividing the housing cavity into a fourth receiving cavity (A4) and a fifth receiving cavity (A5). All the air intake holes (701) communicate with the fifth receiving cavity (A5). The air intake shroud (90) is provided with a connecting hole (G). At least a portion of the first housing (10) is located within the connecting hole (G). There is a gap between the first housing (10) and the corresponding sidewall of the connecting hole (G), and the gap communicates the fifth receiving cavity (A5) and the fourth receiving cavity (A4); and / or, The total conductive area of ​​all the air inlets (701) is greater than the total conductive area of ​​all the connecting ports (F).

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