Sensing device

Abstract

The invention provides a sensing device which comprises a detection assembly and a shell, the detection assembly comprises a first thermistor, a first conductive part and a first base, the first conductive part is connected with the first base, and the first thermistor is electrically connected with the first conductive part; the shell comprises a first pipe cap, the first pipe cap is provided with a first inner cavity and a first through hole, and the first thermistor is located in the first inner cavity; a plane perpendicular to the height direction of the sensing device is defined as a first surface, the first surface intersects with the first thermistor, the plane where the first surface is located is a first plane, the first plane and the first pipe cap have an intersection line, the distance between two points farthest from each other on the intersection line is d1, b1 / (d1 / 2) is larger than 0.70, and d2 / d1 / d2 is larger than 0.70. The heat generated when the first thermistor works can be dissipated to the first pipe cap, so that the external temperature of the first pipe cap is increased, the phenomenon that water vapor is condensed when encountering cold is reduced, and the detection precision is improved.

Description

Technical Field

[0001] The present application relates to the field of measurement technology, and in particular to a sensor device. Background Art

[0002] The sensing device includes a first thermistor, a first tube cap and a first inner cavity, wherein the first thermistor is located in the first inner cavity, and the first inner cavity is connected to the external gas. When the temperature around the sensing device is high, water vapor in the environment is easily affected by the ambient temperature and condenses on the surface of the first tube cap, thereby affecting the detection accuracy of the sensing device. Summary of the invention

[0003] The inventors have found that the above technical problem can be well solved by adjusting the position of the first thermistor in the first inner cavity. To this end, the present application provides a high-precision sensing device.

[0004] The sensor device provided in the present application includes a detection component and a housing, the detection component includes a first thermistor, a first conductive part and a first base, the first conductive part is connected to the first base, and the first thermistor is electrically connected to the first conductive part;

[0005] The housing comprises a first tube cap, the first tube cap has a first inner cavity and a first through hole, the first through hole is in communication with the first inner cavity, the first through hole is in communication with the outside of the sensor device, and the first thermistor is located in the first inner cavity;

[0006] The first tube cap constitutes at least a portion of the wall of the first inner cavity, and the first base constitutes at least a portion of the wall of the first inner cavity.

[0007] In a plane perpendicular to the height direction of the sensor device, the first thermistor is defined to have a first surface, the plane where the first surface is located is defined as a first plane, the first plane and the first tube cap have two intersection points, and the maximum distance between the two intersection points is d1,

[0008] The distance between the first thermistor and the first conductive portion is b1, wherein b1 / (d1 / 2) is greater than 0.70.

[0009] In the sensing device of the present application, when b1 / (d1 / 2) is greater than 0.70, the heat generated by the first thermistor during operation can be dissipated to the first tube cap, causing the external temperature of the first tube cap to increase, thereby reducing the condensation of water vapor when cooled, thereby improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic diagram of a first tube cap and a second tube cap provided in one embodiment of the present application;

[0011] Figure 2 A cross-sectional schematic diagram of a sensor device provided in one embodiment of the present application;

[0012] Figure 3 A cross-sectional schematic diagram of a sensor device provided in one embodiment of the present application;

[0013] Figure 4 An explosion diagram of a sensor device provided in one embodiment of the present application;

[0014] Figure 5 A cross-sectional schematic diagram of a sensor device provided in one embodiment of the present application;

[0015] Figure 6 An exploded schematic diagram of a partial structure of a sensor device provided in one embodiment of the present application;

[0016] Figure 7 A cross-sectional schematic diagram of a sensor device provided in one embodiment of the present application;

[0017] Figure 8 A schematic diagram of a sensing device provided in one embodiment of the present application;

[0018] Fig. 9 for Figure 8 A cross-sectional schematic diagram of a sensing device is provided. DETAILED DESCRIPTION

[0019] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0020] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0021] At present, the relevant sensor device includes a detection component 2 and a housing 3, wherein the detection component 2 includes a first thermistor 21a, the housing 3 includes a first tube cap 31, the first tube cap 31 has a first inner cavity 311 and a first through hole 312, the first through hole 312 is connected to the first inner cavity 311, the first through hole 312 is connected to the outside of the sensor device 1, and the first thermistor 21a is located in the first inner cavity 311. When the gas to be detected enters the first inner cavity 311 through the first through hole 312, the first thermistor 21a senses the change in gas temperature and its resistance value will change accordingly. The change in resistance value will be accompanied by the change in electrical signals. The processing unit of the sensor device will process the electrical signals, so that the sensor device and the air conditioning system will take corresponding countermeasures, such as issuing an alarm prompt, to ensure the safety of the air conditioning system. When the equipment is cooling, the temperature around the sensor device will drop, and the water vapor in the environment is easily affected by the surrounding temperature and condenses, thereby affecting the detection accuracy.

[0022] In order to improve the detection accuracy of the sensor device 1, Figure 2 and Figure 5 As shown, the sensor device 1 of the present application includes a detection component 2 including a first conductive portion 22a and a first base 23a, the first conductive portion 22a is connected to the first base 23a, and the first thermistor 21a is electrically connected to the first conductive portion 22a; the first tube cap 31 includes a first top wall 313, and the first through hole 312 is arranged on the first top wall 313; the sensor device 1 has a height direction H, along the height direction H of the sensor device 1, the first top wall 313 and the first base 23a are respectively located on both sides of the first inner cavity 311, and the first tube cap 31 constitutes the first At least a part of the wall of the inner cavity 311, the first base 23a constitutes at least a part of the wall of the first inner cavity 311, and the plane perpendicular to the height direction of the sensor device 1 is defined as the first surface 4, the first surface 4 intersects with the first thermistor 21a, the plane where the first surface 4 is located is the first plane 41, the first plane 41 and the first tube cap 31 have an intersection line, the distance between the two farthest points on the intersection line is d1, the distance between the first thermistor 21a and the first conductive part 22a is b1, wherein b1 / (d1 / 2) is greater than 0.70. The first thermistor 21a is close to the first tube cap 31, and the temperature of the outer surface of the first tube cap 31 increases, thereby increasing the detection environment temperature, reducing the phenomenon of water vapor condensation when it encounters cold, and thus improving the detection accuracy of the sensor device 1.

[0023] At the same time, b1 / (d1 / 2) is greater than 0.70, which reduces the inner diameter of the first tube cap 31, reduces the air volume in the first inner cavity 311, and increases the temperature in the first inner cavity 311. The temperature of the first thermistor 21a also increases. When the ambient temperature changes, the first thermistor 21a is less affected by the ambient temperature due to its high temperature, thereby improving the detection accuracy of the sensor device 1.

[0024] In one embodiment, if Figure 5 As shown, b1 / (d1 / 2) is less than 0.96. This can prevent the inner diameter of the first tube cap 31 from being too small, causing the first conductive portion 22a to contact the first tube cap 31, resulting in the failure of the insulation between the first conductive portion 22a and the first tube cap 31, and thus the sensor device 1 cannot detect. Further, in one embodiment, b1 / (d1 / 2) ranges from 0.838 to 0.915.

[0025] In one embodiment, if Figure 1 and Figure 5 As shown, the first tube cap 31 may be a columnar body, and d1 is the inner diameter of the columnar body.

[0026] Further, in one embodiment, if Figure 5 As shown, the first thermistor 21a has a center, which is the centroid of the first thermistor 21a; that is, the distance between the first thermistor 21a and the first top wall 313 is the distance between the center of the first thermistor 21a and the first top wall 313; the distance between the first thermistor 21a and the first conductive portion 22a is the distance between the center of the first thermistor 21a and the first conductive portion 22a. The distance between the first thermistor 21a and the first top wall 313 or the distance between the first thermistor 21a and the first conductive portion 22a is further limited, and a more accurate distance can better improve the detection accuracy of the sensor device 1. In another embodiment, the first plane 41 passes through the center of the first thermistor 21a.

[0027] Meanwhile, in one embodiment, if Figure 3 As shown, the first tube cap 31 includes an outer wall surface 3131 and an inner wall surface 3132, and the inner wall surface 3132 is closer to the first thermistor 21a relative to the outer wall surface 3131; the intersection is located on the inner wall surface 3132, which improves the accuracy of b1 and further improves the detection accuracy of the sensor device 1.

[0028] Along the height direction H of the sensor device 1, the first conductive portion 22a has a terminal end 221, and the terminal end 221 is close to the first top wall 313 relative to the first base 23a. In the related art, the first thermistor 21a of the sensor device 1 is close to the first top wall 313 relative to the terminal end 221. When the sensor device 1 is manufactured, the first tube cap 31 is easy to hit the first thermistor 21a, thereby affecting the detection accuracy. Therefore, in order to improve the detection accuracy of the sensor device 1, in one embodiment, as shown in FIG. Figure 2 and Figure 3 and Figure 4 As shown, along the height direction H of the sensor device 1 , the first thermistor 21 a is not higher than the end 221 of the first conductive portion 22 a .

[0029] The detection component 2 includes a first lead 24a, the first thermistor 21a is electrically connected to the first lead 24a, and the first lead 24a is electrically connected to the first conductive portion 22a. Figure 6 and Figure 7 As shown, the first lead 24a is not higher than the end 221 of the first conductive portion 22a, which can reduce the deformation of the first lead 24a under the action of external force. In addition, the overall height of the detection component 2 can be reduced, which is conducive to the miniaturization of the detection component 2. Further, along the height direction H, the first lead 24a is located on the same side of the end 221.

[0030] In one embodiment, if Figure 3 As shown, in order to further reduce the deformation of the first lead 24 a under the action of external force, the first lead 24 a is fixedly connected to the end 221 .

[0031] In order to improve the sensitivity of the sensor device 1 in transmitting electrical signals, in some embodiments, Figure 6 As shown, the first lead 24a includes at least one pair of electrodes 241, 242, and the electrodes 241, 242 are electrically connected to the first thermistor 21a; at least one pair of electrodes 241, 242 are axially symmetrically arranged, or at least one pair of electrodes 241, 242 are centrally symmetrically arranged.

[0032] In some embodiments, the material of the first connection portion 24a1 is tin or a tin alloy. The thermal conductivity of tin is 67W / m·K, the melting point is 232°C, and the resistivity at 25°C is 0.126μΩ·m. Although the resistivity of tin is greater than that of precious metals such as gold, silver, and copper, the thermal conductivity of tin is much smaller than that of precious metals such as gold, silver, and copper. When tin or a tin alloy is used as the first connection portion 24a1, the negative impact of its larger resistivity on the detection accuracy compared to precious metals such as gold, silver, and copper can be completely offset by the positive impact of the small thermal conductivity on the detection accuracy, thereby improving the detection sensitivity and detection accuracy of the thermal conductivity sensor device 1. That is to say, the resistivity of tin or tin alloy is greater than that of precious metals such as gold, silver, and copper, which may reduce the detection accuracy of the sensor device 1; however, the thermal conductivity of tin or tin alloy is smaller than that of precious metals such as gold, silver, and copper, which can improve the detection accuracy of the sensor device 1. For the thermal conductivity sensor device 1, the improvement of detection accuracy due to the small thermal conductivity of tin or tin alloy is greater than the reduction of detection accuracy due to its large resistivity. Therefore, in general, using tin or tin alloy as the main component of the first connecting portion 24a1 can improve the detection accuracy of the sensor device 1.

[0033] In addition, since tin and tin alloys have a low melting point, they can be electrically connected to the lead-out portion with low-energy welding, reducing damage to the detection portion during the welding process. Moreover, compared with precious metals, tin or tin alloys as the connection portion can also reduce the manufacturing cost of the sensor device 1.

[0034] In some embodiments, the tin alloy is a tin-lead alloy, a tin-bismuth alloy, a tin-bismuth-silver alloy, a tin-cadmium alloy, or a tin-indium alloy. 92.5 Sn5Ag 2.5 SnBi 58 SnBi 35 Ag1. Different tin alloys have their own thermal conductivity, melting point and resistivity. Different tin alloys can be selected according to the detection needs, on the premise of meeting the above-mentioned thermal conductivity and melting point requirements. For example, a metal with low thermal conductivity, low resistivity and low melting point can be selected to form an alloy with tin, so that the thermal conductivity of the alloy is within the range specified in this application, and at least one of the resistivity and melting point is also within the range specified in this application.

[0035] In order to further enable the first thermistor 21a to sense the gas change more quickly and make a rapid detection, in one embodiment, as Figure 2 As shown, at least a portion of the first thermistor 21a is disposed in alignment with the first through hole 312. For ease of arrangement, the first through hole 312 is preferably in the shape of a regular polygon or a circle.

[0036] In order to improve the detection accuracy of the sensor device 1, in one embodiment, Figure 7 As shown, the housing 3 includes a second cap 32, the second cap 32 has a second inner cavity 322, and the second inner cavity 322 is a closed cavity; the detection component 2 includes a second thermistor 21b, the second thermistor 21b is located in the second inner cavity 322, and the second thermistor 21b is used as a reference resistor in the second inner cavity 322. When the first thermistor 21a and the second thermistor 21b reach a certain resistance difference, the sensor device 1 will sound an alarm. Further, in one embodiment, the first thermistor 21a and the second thermistor 21b are both NTC thermistor chips, so as to facilitate component selection.

[0037] In order to prevent the ambient air temperature from affecting the second thermistor 21b and thus affecting the detection accuracy of the sensor device 1, in one embodiment, Figure 8 As shown, there is a gap between the first tube cap 31 and the second tube cap 32. Alternatively, in one embodiment, as shown in FIG. Figure 8As shown, the first tube cap 31 and the second tube cap 32 are an integral part, the housing 3 includes a connecting wall 30, the first tube cap 31 and the second tube cap 32 are both connected to the connecting wall 30, and further, a spacing groove 33 is provided between the first tube cap 21 and the second tube cap 32; along the height direction H, the connecting wall 30 is away from the first top wall 313 relative to the spacing groove 33, and the size of the spacing groove 33 in the height direction H is larger than the size of the connecting wall 30 in the height direction H, so that the spacing groove 33 isolates the heat conduction between the shared spacing wall of the first tube cap 31 and the second tube cap 32, thereby further improving the detection accuracy of the sensor device 1.

[0038] In order to enhance the connection firmness between the first lead 24a and the first conductive portion 22a, the first lead 24a is provided with a first connecting portion 24a1, and the first connecting portion 24a1 is at least partially electrically connected to the first conductive portion 22a, and the first connecting portion 24a1 is linear or planar. When the first connecting portion 24a1 is linear, the connection between the first lead 24a and the first conductive portion 22a is a linear connection, and when the first connecting portion 24a1 is planar, the connection between the first lead 24a and the first conductive portion 22a is a planar connection. In one embodiment, as Figure 6 As shown, surface connection is preferred.

[0039] The detection component 2 includes a second conductive portion 22b, a second lead 24b and a second connecting portion 24b1, the second conductive portion 22b is electrically connected to the second lead 24b, and the second lead 24b is electrically connected to the second thermistor 21b. In order to further facilitate the selection of components, in some embodiments, the selection and connection method of the second lead 24b and the second connecting portion 24b1 are the same as those of the first lead 24a and the second connecting portion 24a1.

[0040] In one embodiment, if Figure 4 As shown, the first tube cap 31 includes a first flange portion 314, and the first flange portion 314 is close to the first base 23a relative to the first through hole 312. The second tube cap 32 includes a second top wall 321 and a second flange portion 323. The detection component 2 includes a second base 23b. Along the height direction H of the sensor device 1, the second top wall 321 and the second base 23b are respectively located on both sides of the second inner cavity 322; along the height direction H, the second flange portion 323 is close to the second base 23b relative to the second top wall 321.

[0041] The first base 23a includes a first step 23a1, which is protruded from the first base 23a toward the first top wall 313, and the second base 23b includes a second step 23b1, which is protruded from the second base 23b toward the second top wall 321. The first base 23a is provided with a first end face 23a2, which is away from the first top wall 313 relative to the first step 23a1, and the first end face 23a2 is connected to the first step 23a1; the second base 23b is provided with a second end face 23b2, which is away from the second top wall 321 relative to the second step 23b1, and the second end face 23b2 is connected to the second step 23b1. In order to better seal the installation, the first flange portion 314 is sealed and connected to the first end face 23a2, and the second flange portion 323 is sealed and connected to the second end face 23b2, wherein the sealing connection method includes welding or sealing adhesive connection or connection through a sealing ring.

[0042] In one embodiment, if Fig. 9 As shown, the size of the spacing groove 33 in the height direction H of the sensor device 1 is L1, and the size of the connecting wall 30 in the height direction H of the sensor device 1 is L2, where L1 and L2 satisfy the following relationship: 2≤L1 / L2≤4. When the size of the spacing groove 33 in the height direction H is more than twice and less than four times the size of the connecting wall 30 in the height direction H, the heat transfer between the first inner cavity 311 and the second inner cavity 322 is further reduced, thereby further improving the detection accuracy of the sensor device 1, while taking into account the connection strength of the spacing groove 33. Preferably, L1 / L2=3, which can reduce the heat transfer between the first inner cavity 311 and the second inner cavity 322, and the connection strength between the first tube cap 31 and the second tube cap 32 is strong enough.

[0043] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A sensor device, comprising a detection component and a housing, characterized in that: The detection assembly includes a first thermistor, a first conductive portion and a first base, the first conductive portion is connected to the first base, and the first thermistor is electrically connected to the first conductive portion; The housing comprises a first tube cap, the first tube cap has a first inner cavity and a first through hole, the first through hole is in communication with the first inner cavity, the first through hole is in communication with the outside of the sensor device, and the first thermistor is located in the first inner cavity; The first tube cap constitutes at least a portion of the wall of the first inner cavity, and the first base constitutes at least a portion of the wall of the first inner cavity. A plane perpendicular to the height direction of the sensor device is defined as a first plane, the first plane intersects with the first thermistor, the plane where the first plane is located is defined as a first plane, the first plane and the first tube cap have an intersection line, and the distance between the two farthest points on the intersection line is d1, The distance between the first thermistor and the first conductive portion is b1, wherein b1 / (d1 / 2) is greater than 0.

70.

2. The sensor device according to claim 1, characterized in that: The b1 / (d1 / 2) is less than 0.

96.

3. The sensor device according to claim 2, characterized in that: The b1 / (d1 / 2) ranges from 0.838 to 0.

915.

4. The sensor device according to claim 1, characterized in that: The first thermistor has a center, the center being the centroid of the first thermistor; The distance between the first thermistor and the first conductive portion is the distance between the center of the first thermistor and the first conductive portion.

5. The sensor device according to claim 4, characterized in that: The first tube cap comprises an outer wall surface and an inner wall surface, wherein the inner wall surface is closer to the first thermistor than the outer wall surface; The first plane passes through the center of the first thermistor; The intersection line is located on the inner wall surface.

6. The sensor device according to claim 1, characterized in that: Along the height direction of the sensing device, the first conductive part has an end, the first tube cap includes a first top wall, along the height direction of the sensing device, the first top wall and the first base are respectively located on both sides of the first inner cavity, the end is close to the first top wall relative to the first base, and the first thermistor is not higher than the end of the first conductive part.

7. The sensor device according to claim 1, characterized in that: The detection component includes a first lead, the first thermistor is electrically connected to the first lead, the first lead is provided with a first connecting portion, the first connecting portion is at least partially electrically connected to the first conductive portion, the first connecting portion is linear or planar, and the material of the first connecting portion includes tin or tin alloy; along the height direction, the first lead is located on the same side of the end.

8. The sensor device according to claim 7, characterized in that: The first lead includes at least one pair of electrodes, and the electrodes are electrically connected to the first thermistor; The at least one pair of electrodes is arranged axially symmetrically, or the at least one pair of electrodes is arranged centrally symmetrically.

9. The sensor device according to claim 1, characterized in that: The first through hole is at least partially aligned with the first thermistor; The first thermistor is an NTC thermistor.

10. The sensor device according to claim 1, characterized in that: The housing includes a second tube cap, the second tube cap has a second inner cavity, and the second inner cavity is a closed cavity; the detection component includes a second thermistor, and the second thermistor is located in the second inner cavity; There is a distance between the first tube cap and the second tube cap; or, the first tube cap and the second tube cap are an integral piece, the shell comprises a connecting wall, and the first tube cap and the second tube cap are both connected to the connecting wall.

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