Heat conduction type gas sensor

Abstract

The utility model discloses a heat conduction type gas sensor, which comprises a main board, a probe assembly and a heat conduction reducing structure, the probe assembly is electrically connected with the main board, and the heat conduction reducing structure is arranged in at least one direction around the probe assembly and can be used for reducing heat transfer in at least one direction around the probe assembly. According to the heat conduction type gas sensor, a good heat insulation effect is achieved through the reasonable structural design, and the influence of temperature changes around the probe assembly on the measurement accuracy and the response speed is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to gas sensor technical field, especially a kind of thermal conductivity gas sensor. BACKGROUND

[0002] Thermal conductivity gas sensor can convert the information related to gas species and concentration into electrical signal, so that detection, monitoring, analysis and alarm can be carried out, for example, it can be applied to air conditioning product to detect refrigerant gas leakage. The working principle of thermal conductivity gas sensor is to measure the change of gas thermal conductivity to realize the analysis of measured gas, so the change of temperature around probe assembly has certain influence on measurement accuracy and response time, in order to improve the measurement accuracy and response speed of thermal conductivity gas sensor, measures need to be taken to reduce the influence of temperature change around probe assembly. SUMMARY

[0003] Therefore, the purpose of the utility model is to provide a kind of thermal conductivity gas sensor, and better heat insulation effect is realized by reasonable structure design, and the influence of temperature change around probe assembly on measurement accuracy and response speed is reduced.

[0004] In order to achieve the above purpose, the utility model provides the following technical scheme:

[0005] A kind of thermal conductivity gas sensor, comprising:

[0006] Mainboard;

[0007] Probe assembly, electrically connected with the mainboard;

[0008] Reducing heat conduction structure, the reducing heat conduction structure is arranged in at least one direction around the probe assembly, and can be used to reduce heat transfer in at least one direction around the probe assembly.

[0009] The thermal conductivity gas sensor provided by the utility model has the following beneficial effects:

[0010] Since the reducing heat conduction structure is arranged in at least one direction around the probe assembly, heat transfer in at least one direction around the probe assembly can be reduced, so that heat generated by the heat source around the probe assembly, such as mainboard, is more difficult to transfer to the probe assembly, thereby reducing the influence of temperature change on the operation of the probe assembly, and improving the measurement accuracy and response speed of the thermal conductivity gas sensor. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0012] Figure 1 is the appearance structure schematic diagram of the thermal conductivity type gas sensor provided by the embodiment of the present application;

[0013] Figure 2 is the internal structure schematic diagram of the thermal conductivity type gas sensor after the shell is removed provided by the embodiment of the present application;

[0014] Figure 3 is Figure 2 schematic diagram after the cover is removed;

[0015] Figure 4 is the schematic diagram of the structure in another view; Figure 3

[0016] Figure 5 is the schematic diagram of various structure forms of the slot of the main board;

[0017] Figure 6 is the internal structure schematic diagram of the thermal conductivity type gas sensor provided by another embodiment of the present application;

[0018] Figure 7 is the connection structure schematic diagram of the first support and the first printed circuit board in Figure 6

[0019] Figure 8 is the schematic diagram of one connection structure of the first support and the probe assembly;

[0020] Figure 9 is the schematic diagram of another connection structure of the first support and the probe assembly.

[0021] In the figure, the mark is:

[0022] 1, shell; 2, main board; 21, slot; 22, insertion slot; 3, cover; 4, temperature and humidity sensing element; 5, probe assembly; 51, connecting block; 6, third support; 7, heat blocking piece; 71, connecting foot; 8, second printed circuit board; 91, first support; 911, metal pin; 912, support shell; 92, second support; 10, first printed circuit board. DETAILED DESCRIPTION

[0023] ​​The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0024] Referring to Figures 1-9 The utility model embodiment provides a kind of thermal conductivity gas sensor, including mainboard 2, probe assembly 5 and reduce heat conduction structure, wherein, probe assembly 5 is electrically connected with mainboard 2, reduce heat conduction structure is arranged in at least one direction around probe assembly 5, can be used to reduce heat transfer in at least one direction around probe assembly 5.

[0025] The form of reduce heat conduction structure can have multiple choices, in some embodiments, reduce heat conduction structure can include cover 3, cover 3 is fixedly connected with mainboard 2, cover 3 is covered in probe assembly 5, to make probe assembly 5 be located in the accommodating space formed by cover 3 and mainboard 2. Figure 1 And Figure 3 As shown in the drawings, the shell 1 of thermal conductivity gas sensor is provided with opening (not marked in the drawing), and the measured gas can enter the inside of thermal conductivity gas sensor through the opening on the shell 1, so as to be detected by probe assembly 5 located inside. The mainboard 2 and other components inside thermal conductivity gas sensor generate heat when working, since probe assembly 5 and these components are located in shell 1, so the heat generated by these components is easy to affect probe assembly 5, that is, when too much heat is transferred to probe assembly 5, the measurement accuracy and response speed of probe assembly 5 can be poor. Figure 2 And Figure 3 As shown in the drawings, cover 3 is located in the inside of thermal conductivity gas sensor, and is covered in probe assembly 5, so that probe assembly 5 is located in the accommodating space formed by cover 3 and mainboard 2, it should be understood that the accommodating space is not closed space, so the measured gas can continue to enter the accommodating space formed by cover 3 and mainboard 2 after entering the inside of thermal conductivity gas sensor from the opening on shell 1, however, cover 3 plays the role of space division, separates the space inside shell 1 into the above-mentioned accommodating space where probe assembly 5 is located and other space outside cover 3, cover 3 partially forms barrier at the boundary between the above-mentioned accommodating space and other space, plays the role of space heat insulation, so as to reduce the influence of ambient temperature change on the work of probe assembly 5, and be conducive to improving the measurement accuracy and response speed of thermal conductivity gas sensor.

[0026] As Figure 1 And Figure 2As shown, in some embodiments, the cover 3 can be configured to have a barrier at least at a position facing the opening of the housing 1. This can reduce the impact of temperature changes outside the housing 1 on the operation of the probe assembly 5. The shape of the cover 3 can be flexibly configured as needed, for example, cylindrical, hemispherical, rectangular, cube, etc. The cover 3 should be made of a material with low thermal conductivity, such as plastic.

[0027] like Figures 2-4 As shown, in some embodiments, the structure for reducing heat conduction can include grooves 21 provided on the mainboard 2 near the periphery of the probe assembly 5 to reduce heat conduction. The grooves 21 serve to locally reduce the thickness of the mainboard 2 (if the grooves 21 extend through both the upper and lower surfaces of the mainboard 2, the thickness is considered to be zero). This makes it difficult for heat to be transferred from the mainboard 2 to the probe assembly 5. In other words, the grooves 21 reduce heat conduction through the mainboard, thereby reducing the impact of ambient temperature changes on the operation of the probe assembly 5.

[0028] The shape of the cutting groove 21 can be selected in various forms, such as Figure 5 As shown, the shape of the groove 21 can be set to be an arc, a straight line, a right angle, an obtuse angle, or an acute angle. It is easy to understand that in order to reduce the impact on the arrangement of components in other areas of the mainboard 2, the groove 21 should be set as close to the structural edge of the probe assembly 5 as possible. The number of grooves 21 can be more than two, and the depth of a single groove 21 can be equal to the thickness of the mainboard 2 or less than the thickness of the mainboard 2. That is, the groove 21 can pass through the upper and lower surfaces of the mainboard 2 or not pass through the upper and lower surfaces of the mainboard 2. In other words, the thickness of the groove 21 is between zero and the thickness of the mainboard 2. The groove width of the groove 21 is generally set to 1 mm to 2 mm, for example, 1.5 mm.

[0029] It should be noted that when providing a structure to reduce heat conduction, the cover 3 and the slot 21 can be provided separately or simultaneously. For example, in one embodiment, the mainboard 2 of the thermal conductivity gas sensor is provided with the cover 3 but without the slot 21. In another embodiment, the mainboard 2 of the thermal conductivity gas sensor is provided with the slot 21 but without the cover 3. In yet another embodiment, the mainboard 2 of the thermal conductivity gas sensor is provided with both the slot 21 and the cover 3. The thermal insulation effects of the above different embodiments vary slightly, but all serve to reduce heat transfer in at least one direction around the probe assembly 5. In embodiments in which both the cover 3 and the slot 21 are provided, the slot 21 can be provided near the periphery of the cover 3, preferably along the structural edge of the cover 3. This achieves better thermal insulation while minimizing the impact on component placement in other areas of the mainboard 2.

[0030] In some embodiments, the heat conduction reduction structure may include a first support member 91. At least a portion of the first support member 91 is positioned vertically between the probe assembly 5 and the mainboard 2, maintaining a predetermined distance between the probe assembly 5 and the mainboard 2. The vertical direction refers to a direction perpendicular to the surface of the mainboard 2. Because the probe assembly 5 is positioned at a predetermined distance from the mainboard 2, the probe assembly 5 is elevated and away from the mainboard 2, thereby reducing the impact of heat from the mainboard 2 on the operation of the probe assembly 5. The predetermined distance between the probe assembly 5 and the mainboard 2 can be 2 mm to 10 mm, for example, 5 mm.

[0031] The first support member 91 can be used to raise the position of the probe assembly 5 in various structural forms, such as Figure 8 As shown, in one structural form, there are at least two first support members 91 located between the main board 2 and the probe assembly 5. The first support members 91 are in the form of legs, one end of which is connected to the main board 2 and the other end of which is connected to the probe assembly 5. The at least two legs are distributed along the circumference of the probe assembly. When the first support members 91 are in the form of legs, in order to achieve connection with the first support members 91 in the form of legs, the main board 2 is provided with a slot 22 (see FIG. 2 ) that is plugged into the legs. Figure 6 ).like Figure 9 As shown, in another structural form, the heat conduction reduction structure includes a connecting block 51 and a first support member 91. The connecting block 51 is fixedly connected to the outer wall of the probe assembly 5. One end of the first support member 91 is fixedly connected to the connecting block 51, and the other end of the first support member 91 is fixedly connected to the mainboard 2. In this structure, the first support member 91 is fixedly connected to the probe assembly 5 via the connecting block 51 on the outer wall of the probe assembly 5. This facilitates connection operations. For example, the first support member 91 and the connecting block 51 are connected by welding. Since the operating space outside the side wall of the probe assembly 5 is relatively large, this facilitates welding operations.

[0032] In addition, the first support member 91 can also work with other components to raise the position of the probe assembly 5, for example, to lower the heat conduction structure including the first printed circuit board 10 and the first support member 91, one end of the first support member 91 is electrically connected to the main board 2, the first printed circuit board 10 is electrically connected to the other end of the first support member 91, and the probe assembly 5 is electrically connected to the side of the first printed circuit board 10 facing away from the main board. Figure 6 As shown, the heat conduction reduction structure may include a first printed circuit board 10 parallel to the main board 2, the first printed circuit board 10 and the main board 2 are connected via a first support member 91 perpendicular to the main board 2, and are electrically connected via a plug-in, a wiring harness or a flexible circuit board. The probe assembly 5 is installed on the side of the first printed circuit board 10 facing away from the main board 2 and is electrically connected to the first printed circuit board 10. Figure 7As shown, the first support 91 can include a support shell 912 and a metal pin 911, the metal pin 911 is at least partially arranged in the support shell 912, one end of the metal pin 911 is welded with the first printed circuit board 10, the other end of the metal pin 911 is welded with the main board 2, one end of the support shell 912 is fixedly connected with the first printed circuit board 10, the other end of the support shell 912 is fixedly connected with the main board 2.

[0033] On the basis that the probe assembly 5 is away from the main board 2 by a preset distance, a heat blocking member 7 can also be arranged between the probe assembly 5 and the main board 2, the heat conductivity of the heat blocking member 7 is less than that of the main board 2, for example, the heat blocking member 7 is arranged as a plastic member, the heat blocking member 7 can further reduce the influence of the heat on the main board 2 on the working of the probe assembly 5.

[0034] As shown, Figure 6 On the basis that the first printed circuit board 10 is arranged, the heat conduction structure can include a second printed circuit board 8 parallel to the first printed circuit board 10, the second printed circuit board 8 is located on the side of the first printed circuit board 10 away from the main board 2, is connected with the first printed circuit board 10 through a second support 92 perpendicular to the first printed circuit board 10, and is electrically connected with the main board 2 through a plug-in, a wire harness or a flexible circuit board. Some sensing elements also have the need to be arranged away from the main board 2 can be installed on the second printed circuit board 8, for example, the temperature and humidity sensing element 4 is installed on the side of the second printed circuit board 8 away from the first printed circuit board 10. The temperature and humidity sensing element 4 is used for detecting temperature and humidity, the temperature and humidity sensing element 4 is away from the main board 2 with large heat, which reduces the influence of the heat on the main board 2 on the working of the temperature and humidity sensing element 4.

[0035] As shown, Figure 6 By arranging three printed circuit boards (i.e. the main board 2, the first printed circuit board 10 and the second printed circuit board 8), it becomes more difficult for the heat on the main board 2 to be transmitted to the probe assembly 5 and the temperature and humidity sensing element 4, thereby achieving the purpose of heat insulation. Further, in order to make the overall structure more compact and avoid space waste, the second printed circuit board 8 can be provided with a relief hole (not marked in the figure) for avoiding the probe assembly 5, the probe assembly 5 extends from the relief hole to the side of the second printed circuit board 8 away from the first printed circuit board 10, that is, the second printed circuit board 8 is sleeved on the probe assembly 5.

[0036] Of course, in other embodiments, the above-mentioned structure of arranging three printed circuit boards can be changed to as Figure 3The structure of the two printed circuit boards shown, that is, the heat conduction structure can be reduced, can include a second printed circuit board 8 parallel to the main board 2, the second printed circuit board 8 is connected with the main board 2 through a third support 6 perpendicular to the main board 2, and is electrically connected with the main board 2 through a plug-in, a wire harness or a flexible circuit board. In the embodiment of the two printed circuit boards of the main board 2 and the second printed circuit board 8, some sensing elements also have the demand of being arranged away from the main board 2, for example, the second printed circuit board 8 can be provided with a temperature and humidity sensing element 4 on the side away from the main board 2. The temperature and humidity sensing element 4 is used for detecting temperature and humidity, and the temperature and humidity sensing element 4 is away from the main board 2 with large heat, so that the influence of the heat on the main board 2 on the working of the temperature and humidity sensing element 4 is reduced. On this basis, in order to make the overall structure more compact and avoid space waste, the second printed circuit board 8 can be provided with a avoiding hole (not marked in the figure) for avoiding the probe assembly 5, and the probe assembly 5 extends to the side of the second printed circuit board 8 away from the main board 2. One end of the third support 6 is electrically connected with the main board 2, and one end of the second printed circuit board 8 away from the main board 2 is electrically connected with the third support 6. The heat blocking piece 7 is located between the main board 2 and the second printed circuit board 8, the heat blocking piece 7 has a mounting space, the probe assembly 5 is arranged in the mounting space, the area of the heat blocking piece 7 is not less than the area of the probe assembly 5, that is, the area of the orthographic projection of the heat blocking piece 7 to the main board 2 is not less than the area of the orthographic projection of the probe assembly 5 to the main board 2, and one end of the heat blocking piece 7 away from the second printed circuit board 8 is provided with a connecting leg 71, and the connecting leg 71 is fixedly connected with the main board 2.

[0037] It should be noted that in the case of the first printed circuit board 10 and / or the second printed circuit board 8, if the cover 3 is also provided, the first printed circuit board 10 and / or the second printed circuit board 8 can be arranged in the accommodating space formed by the cover 3 and the main board 2, so as to complete the arrangement of the cover 3 and better play the heat insulation role of the cover 3.

[0038] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0039] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A thermal conductivity gas sensor, characterized in that: include: Motherboard; A probe assembly is electrically connected to the main board; A heat conduction reduction structure is arranged in at least one direction around the probe assembly and can be used to reduce heat transfer in at least one direction around the probe assembly. The heat conduction reduction structure includes a cover fixedly connected to the mainboard, and the cover covers the probe assembly so that the probe assembly is located in the accommodation space formed by the cover and the mainboard.

2. The thermal conductivity gas sensor according to claim 1, wherein: The structure for reducing heat conduction includes a groove provided on the main board near the periphery of the probe assembly for reducing heat conduction, and the thickness of the groove is between zero and the thickness of the main board.

3. The thermal conductivity gas sensor according to claim 2, wherein: There are at least two cutting grooves, and at least one of the cutting grooves is configured to be in the shape of an arc, a straight line, a right angle, an obtuse angle, or an acute angle. The groove width of the cutting groove is 1 mm to 2 mm.

4. The thermal conductivity gas sensor according to claim 1, wherein: The heat conduction reduction structure includes a first support member, at least a portion of which is located between the probe assembly and the main board in a height direction, so that the probe assembly is at a preset distance from the main board.

5. The thermal conductivity gas sensor according to claim 4, characterized in that: The first support member is located between the main board and the probe assembly and there are at least two of them. The first support member is in the form of a support foot, one end of the support foot is connected to the main board, and the other end of the support foot is connected to the probe assembly. At least two of the support feet are distributed circumferentially along the probe assembly.

6. The thermal conductivity gas sensor according to claim 4, characterized in that The heat conduction reduction structure includes a connecting block and the first support member, the connecting block is fixedly connected to the outer wall of the probe assembly, one end of the first support member is fixedly connected to the connecting block, and the other end of the first support member is fixedly connected to the mainboard.

7. The thermal conductivity gas sensor according to claim 4, characterized in that: The heat conduction reduction structure includes a first printed circuit board and the first support member, one end of the first support member is electrically connected to the mainboard, the first printed circuit board is electrically connected to the other end of the first support member, and the probe assembly is electrically connected to a side of the first printed circuit board facing away from the mainboard.

8. The thermal conductivity gas sensor according to claim 7, characterized in that: The first support member includes a support shell and a metal pin, wherein the metal pin is at least partially disposed in the support shell, one end of the metal pin is welded to the first printed circuit board, and the other end of the metal pin is welded to the mainboard, one end of the support shell is fixedly connected to the first printed circuit board, and the other end of the support shell is fixedly connected to the mainboard.

9. The thermal conductivity gas sensor according to claim 1, wherein: The thermal conductivity gas sensor also includes a second printed circuit board and a third support member, the second printed circuit board is sleeved on the probe assembly, one end of the third support member is electrically connected to the main board, the second printed circuit board is electrically connected to the end of the third support member facing away from the main board, a temperature and humidity sensor element is installed on the side of the second printed circuit board facing away from the main board, the heat conduction reducing structure includes a heat shield, the heat shield is located between the main board and the second printed circuit board, the heat shield has an installation space, the probe assembly is arranged in the installation space, the area of ​​the heat shield is not less than the area of ​​the probe assembly, and the end of the heat shield facing away from the second printed circuit board is provided with a connecting pin, and the connecting pin is fixedly connected to the main board.

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