Gas sensor, gas monitoring device and vehicle

Abstract

The utility model relates to a gas sensor, a gas monitoring device and a vehicle, the gas sensor comprises a detection unit and a heating unit, and the heating unit is located on the surface of the detection unit and comprises a heating electrode. The heating electrode extends in the first direction and comprises a heating part, a buffering part and a lead part which are arranged in the first direction, the buffering part is located between the heating part and the lead part, and the resistance of the buffering part is smaller than that of the heating part and larger than that of the lead part. The buffer part is additionally arranged between the heating part and the lead part, and the total resistance of the buffer part is larger than that of the lead part and smaller than that of the heating part, so that the heat generated by the buffer part is larger than that generated by the lead part and smaller than that generated by the heating part; the temperature of the buffer part is larger than that of the lead part and smaller than that of the heating part, so that the temperature gradient between the heating part and the lead part can be reduced, and the failure rate of a product is reduced.

Description

Technical Field

[0001] The present application relates to the field of electronic technologies, and particularly to a gas sensor, a gas monitoring device, and a vehicle. Background Art

[0002] The oxygen sensor is an important part of the engine air-fuel ratio adjustment system and is directly related to whether the vehicle emissions meet the standards. The main material of the oxygen sensor is zirconia solid electrolyte, and this material needs to work at a high temperature above 350°C. In order to enable the oxygen sensor to quickly enter the working state after the vehicle is ignited, a heater (or heating unit) is usually provided inside the oxygen sensor. After the oxygen sensor is powered on, the heater can raise the temperature of the oxygen sensor to 700°C - 800°C within a very short time (about 10s).

[0003] After the heater generates heat, the heat quickly concentrates at a high level in the heating part, resulting in a large temperature gradient in the Y direction, and then generating thermal stress. After long-term operation, the oxygen sensor is prone to cracks in the area where the thermal stress is concentrated, causing component failure. Summary of the Utility Model

[0004] Embodiments of the present application provide a gas sensor, a gas monitoring device, and a vehicle, aiming to reduce the temperature gradient between the heating part and the lead part in the heating unit.

[0005] To achieve the above object, according to the first aspect of the present application, there is provided a gas sensor, including:

[0006] A detection unit;

[0007] A heating unit, located on the surface of the detection unit, and including a heating electrode, the heating electrode extends along a first direction, and includes a heating part, a buffer part, and a lead part arranged along the first direction, the buffer part is located between the heating part and the lead part, and the total resistance of the buffer part is less than the total resistance of the heating part and greater than the total resistance of the lead part.

[0008] In some embodiments, the total resistance of the heating part is 55% - 65% of the total resistance of the heating electrode, the total resistance of the buffer part is 15% - 30% of the total resistance of the heating electrode, and the total resistance of the lead part is 15% - 30% of the total resistance of the heating electrode.

[0009] In some embodiments, the temperature of the heating part is 400°C - 800°C, the temperature of the buffer part is 200°C - 800°C, and the temperature of the lead part is less than 200°C.

[0010] In some embodiments, the lead portion includes a first sub-lead portion and a second sub-lead portion that are oppositely disposed in a second direction, the second direction is perpendicular to the first direction and parallel to the surface of the detection unit;

[0011] The buffer portion includes a first sub-buffer portion connected to the first sub-lead portion and a second sub-buffer portion connected to the second sub-lead portion;

[0012] The heating portion includes a first end connected to the first sub-buffer portion and a second end connected to the second sub-buffer portion;

[0013] Wherein, the dimension of the first sub-buffer portion in the second direction gradually increases in the direction from the first end to the first sub-lead portion, and the dimension of the second sub-buffer portion in the second direction gradually increases in the direction from the second end to the second sub-lead portion.

[0014] In some embodiments, the minimum dimension of the first sub-buffer portion in the second direction is greater than or equal to the dimension of the first end in the second direction;

[0015] The maximum dimension of the first sub-buffer portion in the second direction is less than or equal to the dimension of the first sub-lead portion in the second direction.

[0016] In some embodiments, the heating electrode further includes a transition portion, the transition portion includes a first sub-transition portion connected between the first sub-buffer portion and the first sub-lead portion, and a second sub-transition portion connected between the second sub-buffer portion and the second sub-lead portion;

[0017] Wherein, the dimension of the first sub-transition portion in the second direction gradually increases in the direction from the first sub-buffer portion to the first sub-lead portion, and the dimension of the second sub-transition portion in the second direction gradually increases in the direction from the second sub-buffer portion to the second sub-lead portion.

[0018] In some embodiments, the dimension of the lead portion in the first direction is greater than the dimension of the heating portion in the first direction, and the dimension of the lead portion in the first direction is greater than the dimension of the buffer portion in the first direction.

[0019] In some embodiments, the resistivity of the buffer portion is greater than the resistivity of the lead portion.

[0020] In some embodiments, the heating portion further includes a plurality of sub-heating portions disposed along the first direction, and the plurality of sub-heating portions are connected in series end to end;

[0021] The dimension of the heating portion in the first direction is greater than or equal to the dimension of the buffer portion in the first direction.

[0022] In some embodiments, the resistivity of the buffer portion is less than or equal to the resistivity of the heating portion.

[0023] In some embodiments, the resistivity of the heating portion is 35 μΩ·cm to 50 μΩ·cm, and the resistivity of the buffer portion is 10 μΩ·cm to 25 μΩ·cm.

[0024] In some embodiments, the dimension of the buffer portion along the first direction is 50% to 100% of the dimension of the heating portion along the first direction.

[0025] In some embodiments, the heating electrode has a symmetry axis extending along the first direction, and the first sub-buffer portion and the second sub-buffer portion are symmetric about the symmetry axis;

[0026] The first sub-buffer portion has a first outer side surface away from the second sub-buffer portion, the heating portion has a second outer side surface connected to the first outer side surface, and the first outer side surface and the second outer side surface extend in the first direction, or the first outer side surface is located on one side of the second outer side surface close to the second sub-buffer portion.

[0027] In some embodiments, the first sub-buffer portion has an inner side surface close to the second sub-buffer portion, and the inner side surface is a flat surface or a stepped surface.

[0028] In some embodiments, the detection unit includes a first electrolyte layer, a first electrode, a second electrode, and a standard gas channel. The first electrode and the second electrode are located on both sides of the first electrolyte layer along the third direction. The standard gas channel is located on one side of the first electrolyte layer close to the heating unit and is connected to the second electrode. The third direction is perpendicular to the surface of the detection unit.

[0029] In some embodiments, a pump unit is further included. The pump unit includes a second electrolyte layer, a third electrode, and a fourth electrode. The third electrode is located on one side of the second electrolyte layer away from the first electrode, and the fourth electrode is located on one side of the second electrolyte layer close to the first electrode;

[0030] The orthographic projections of the first electrode, the second electrode, the third electrode, and the fourth electrode on the first electrolyte layer are all within the range of the orthographic projection of the heating portion on the first electrolyte layer.

[0031] According to a second aspect of the present application, a gas monitoring device is provided, including the gas sensor in any of the above embodiments.

[0032] According to a third aspect of the present application, a vehicle is provided, including the above gas monitoring device.

[0033] The present application provides a gas sensor, a gas monitoring device and a vehicle. The gas sensor includes a detection unit and a heating unit. The heating unit is located on the surface of the detection unit and includes a heating electrode. The heating electrode extends in a first direction and includes a heating portion, a buffer portion and a lead portion arranged along the first direction. The buffer portion is located between the heating portion and the lead portion, and the resistance of the buffer portion is less than that of the heating portion and greater than that of the lead portion. By adding a buffer portion between the heating portion and the lead portion in the present application, and the total resistance of the buffer portion is greater than that of the lead portion and less than that of the heating portion, the heat generated by the buffer portion is greater than that generated by the lead portion and less than that generated by the heating portion. Therefore, the temperature of the buffer portion is greater than that of the lead portion and less than that of the heating portion, which can reduce the temperature gradient between the heating portion and the lead portion, thereby reducing the product failure rate. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0035] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, where the same reference numerals in the following description represent the same parts.

[0036] Figure 1 is a three-dimensional structural diagram of a gas sensor provided by some embodiments of the present application;

[0037] Figure 2 is provided by some embodiments of the present application Figure 1 The cross-sectional view of the gas sensor along the YZ direction;

[0038] Figure 3 is a top view structural schematic diagram of a heating electrode provided by some embodiments of the present application;

[0039] Figure 4 is a top view structural schematic diagram of a heating electrode provided by some embodiments of the present application;

[0040] Figure 5 is a top view structural schematic diagram of a heating electrode provided by some embodiments of the present application. Detailed Embodiments

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the protection scope of the present application.

[0042] In this article, directions are represented in Cartesian coordinates, where the "Y" represents the first direction; the "X" represents the second direction; the "Z" represents the third direction. The first direction, the second direction, and the third direction intersect each other, that is, X, Y, and Z intersect each other, for example, they can be perpendicular to each other or form a certain angle.

[0043] Please refer to Figure 1 、 Figure 2 and Figure 3 , Figure 1 which are the three-dimensional structure diagrams of the gas sensor provided by some embodiments of the present application, Figure 2 and Figure 1 is the sectional view of the gas sensor in Figure 3 along the YZ direction provided by some embodiments of the present application, and

[0044]

[0045] The gas sensor 100 includes a detection unit 10 and a heating unit 20. The heating unit 20 is located on the surface of the detection unit 10 and includes a heating electrode 21. The heating electrode 21 extends along the first direction (Y) and includes a heating portion 211, a buffer portion 212, and a lead portion 213 arranged along the first direction Y. The buffer portion 212 is located between the heating portion 211 and the lead portion 213, and the resistance of the buffer portion 212 is less than the resistance of the heating portion 211 and greater than the resistance of the lead portion 213. By adding a buffer portion 212 between the heating portion 211 and the lead portion 213 in the present application, and the resistance of the buffer portion 212 is greater than the total resistance of the lead portion 213 and less than the total resistance of the heating portion 211, the heat generated by the buffer portion 212 is greater than the heat generated by the lead portion 213 and less than the heat generated by the heating portion 211. Therefore, the temperature of the buffer portion 212 is greater than the temperature of the lead portion 213 and less than the temperature of the heating portion 211, so that the temperature gradient between the heating portion 211 and the lead portion 213 can be reduced, thereby reducing the product failure rate. Among them, the surface of the detection unit 10 is the surface formed by the first direction Y and the second direction X.

[0046] As Figure 1 shown, the dimensions of the gas sensor 100 in three dimensions are: 0.9 mm to 1.1 mm in the Z direction, 4.1 mm to 4.5 mm in the X direction, and 35 mm to 40 mm in the Y direction.

[0047] In some embodiments, the total resistance of the heating part 211 is 55% - 65% of the total resistance of the heating electrode 21, the total resistance of the buffer part 212 is 15% - 30% of the total resistance of the heating electrode 21, and the total resistance of the lead part 213 is 15% - 30% of the total resistance of the heating electrode 21. Thus, the temperature of the heating part 211 can be 400°C - 800°C, the temperature of the buffer part 212 can be 200°C - 800°C, and the temperature of the lead part 213 is less than 200°C. In some embodiments, as Figure 2 shown, the detection unit 10 may include a first electrolyte layer 11, a first electrode 12, a second electrode 13, and a standard gas channel 14. The first electrode 12 and the second electrode 13 are located on both sides of the first electrolyte layer 11 along the third direction Y. The standard gas channel 14 is located on one side of the first electrolyte layer 11 close to the heating unit 20 and is connected to the second electrode 13. The third direction Y is perpendicular to the surface of the detection unit 10. That is to say, the second electrode 13 is located on one side of the first electrolyte layer 11 close to the heating unit 20, and the first electrode 12 is located on one side of the first electrolyte layer 11 far from the heating unit 20.

[0048] The gas sensor 100 may further include a pump unit 30. The pump unit 30 includes a second electrolyte layer 31, a third electrode 32, and a fourth electrode 33. The third electrode 32 is located on one side of the second electrolyte layer 31 far from the first electrode 12, and the fourth electrode 33 is located on one side of the second electrolyte layer 31 close to the first electrode 12.

[0049] In some embodiments, the orthographic projections of the first electrode 12, the second electrode 13, the third electrode 32, and the fourth electrode 33 on the first electrolyte layer 11 are all within the range of the orthographic projection of the heating part 211 on the first electrolyte layer 11, so that the electrodes above the heating part 211 can be heated evenly.

[0050] In some embodiments, the detection unit 10 may further include a third electrolyte layer 34 and a gas channel 35. The third electrolyte layer 34 is located between the first electrolyte layer 11 and the second electrolyte layer 31. A diffusion barrier structure 341 and a detection cavity 342 are connected to each other in the third electrolyte layer 34, and the first electrode 12 is connected to the detection cavity 342. The gas channel 35 connects the external environment and the diffusion barrier structure 341, and the gas channel 35 can penetrate through the second electrolyte layer 31 and the third electrolyte layer 34 along the third direction Y.

[0051] The materials of the first electrolyte layer 11, the second electrolyte layer 31, and the third electrolyte layer 34 may all include zirconia and additives, and the additives include yttrium oxide or scandium oxide.

[0052] In some embodiments, the diffusion barrier structure 341 may be disposed around the gas passage 35, the fourth electrode 33, the first electrode 12, and the detection chamber 342 may all be disposed around the diffusion barrier structure 341, and the orthographic projections of the fourth electrode 33, the first electrode 12, and the detection chamber 342 on the first electrolyte layer 11 coincide.

[0053] The automobile exhaust gas sequentially passes through the gas passage 35 and the diffusion barrier structure 341 and enters the detection chamber 342, is detected by the first electrode 12, and is compared with the second electrode 13 for detecting the standard gas. If it does not meet the critical value requirement, the control element of the engine will apply a pump current through the third electrode 32 and the fourth electrode 33. Since the second electrolyte layer 31 is an ion conductor, a current path is formed by the first electrode 12, the second electrolyte layer 31, and the fourth electrode 33, so that oxygen can be pumped into or out of the detection chamber 342 to make the engine operate at the best air-fuel ratio state.

[0054] The heating unit 20 may further include an insulating layer 22 surrounding the heating electrode 21 and a fourth electrolyte layer 23 surrounding the insulating layer 22. The material of the insulating layer 22 may include alumina or aluminum nitride.

[0055] In some embodiments, as Figure 3 shown, the lead portion 213 mainly functions as a conductor. The dimension of the lead portion 213 along the first direction Y is greater than the dimension of the heating portion 211 along the first direction Y, and the dimension of the lead portion 213 along the first direction Y is greater than the dimension of the buffer portion 212 along the first direction Y.

[0056] In some embodiments, the resistivity of the lead portion 213 is relatively low and it only functions as a conductor, hardly generating heat. Such a design can save power consumption and also protect the external connector at the tail of the heating electrode 21. The external connector connects the external power supply to the heating electrode 21. The metal spring piece in the connector is usually made of copper and has a plastic protective shell outside. Therefore, the temperature at the tail of the heating electrode 21 needs to be at a relatively low level to prevent the connector from being ablated and damaged.

[0057] In some embodiments, the resistivity of the buffer portion 212 may be set to be greater than the resistivity of the lead portion 213, so that the buffer portion 212 has a greater resistance than the lead portion 213 under the condition of a smaller length (dimension along the first direction).

[0058] The heating part 211 may further include a plurality of sub - heating parts 211 arranged along the first direction Y, and the plurality of sub - heating parts 211 are connected in series end to end. Among them, the opposite ends of two adjacent sub - heating parts 211 are connected by bending parts. This meandering shape can increase the overall length of the heating part 211 to increase the resistance of the heating part 211 and make the thermal field uniform within the heating range where the heating part 211 is located.

[0059] In some embodiments, the dimension of the heating part 211 along the first direction Y is greater than or equal to the dimension of the buffer part 212 along the first direction Y. Therefore, the actual length of the heating part 211 is greater than the actual length of the buffer part 212. So, the resistivity of the buffer part 212 can be set to be less than or equal to the resistivity of the heating part 211, so that the resistance of the heating part 211 is greater than the resistance of the buffer part 212. Herein, the "actual length" refers to the length along the current flow direction after being connected in series.

[0060] In some embodiments, the dimension of the buffer part 212 along the first direction Y is 50% - 100% of the dimension of the heating part 211 along the first direction Y. It can be understood that the dimension range of the buffer part 212 along the first direction can be set according to the required proportion of the total resistance of the buffer part 212 in the total resistance of the heating electrode.

[0061] Specifically, the dimension of the heating part along the first direction and the dimension of the buffer part along the first direction are both equal to 4 mm.

[0062] In some embodiments, since the actual length of the buffer part 212 is less than the actual length of the heating part 211, the resistivity of the buffer part 212 can be set to be less than or equal to the resistivity of the heating part 211 to control the total resistance of the buffer part 212 to be less than the total resistance of the heating part 211.

[0063] In one embodiment, the resistivity of the buffer part 212 is less than the resistivity of the heating part 211. The resistivity of the heating part 211 is 35 μΩ·cm - 50 μΩ·cm, and the resistivity of the buffer part 212 is 10 μΩ·cm - 25 μΩ·cm. It can be understood that the respective resistivity can be set according to the required total resistance of the two.

[0064] In one embodiment, the resistivity of the buffer part 212 can be set to be equal to the resistivity of the heating part 211. In this way, the buffer part 212 and the heating part 211 can use the same material, so the manufacturing process and cost can be reduced.

[0065] Such as Figure 3As shown, the lead portion 213 may include a first sub-lead portion 2131 and a second sub-lead portion 2132 that are oppositely arranged in the second direction X, where the second direction X is perpendicular to the first direction Y and parallel to the surface of the detection unit 10. The buffer portion 212 includes a first sub-buffer portion 2121 connected to the first sub-lead portion 2131 and a second sub-buffer portion 2122 connected to the second sub-lead portion 2132. The heating portion 211 includes a first end 2111 connected to the first sub-buffer portion 2121 and a second end 2112 connected to the second sub-buffer portion 2122. In this way, the first sub-lead portion 2131, the first sub-buffer portion 2121, the first end 2111, the second end 2112, the second sub-buffer portion 2122, and the second sub-lead portion 2132 can be connected in series in sequence to achieve the heating function.

[0066] Among them, the size of the first sub-buffer portion 2121 in the second direction X gradually increases in the direction from the first end 2111 to the first sub-lead portion 2131 (the illustrated direction is from left to right), and the size of the second sub-buffer portion 2122 in the second direction X gradually increases in the direction from the second end 2112 to the second sub-lead portion 2132 (the illustrated direction is from left to right). In this way, the resistance of the buffer portion 212 is different at different positions, and the resistance gradually decreases from left to right, so the temperature gradually decreases from left to right, which can make the temperature in the buffer portion 212 gradually transition, facilitating the alleviation of the concentration of thermal stress.

[0067] Through experimental fitting, the temperature change at each position in the buffer portion 212 is shown by the following formula:

[0068]

[0069] Among them, T1 is the temperature at the junction of the buffer portion 212 and the heating portion 211, T2 is the temperature at a position where the distance from the buffer portion 212 to the junction of the buffer portion 212 and the heating portion 211 is L, a is a constant, and the value range of a is 0.5 - 5. It can be seen that the farther the position in the buffer portion 212 is from the heating portion 211, the lower the temperature.

[0070] In some embodiments, the sizes of the first sub-lead portion 2131 and the second sub-lead portion 2132 in the second direction X are uniform, and the sizes of the first sub-lead portion 2131 and the second sub-lead portion 2132 in the second direction X may be the same.

[0071] The minimum dimension W1 (left end dimension) of the first sub-buffer portion 2121 along the second direction X is equal to the dimension W1 of the first end 2111 along the second direction X, and the maximum dimension W2 (right end) of the first sub-buffer portion 2121 along the second direction X is equal to the dimension W2 of the first sub-lead portion 2131 along the second direction X. That is, the first sub-buffer portion 2121 is directly connected to the first sub-lead portion 2131 and the first end 2111.

[0072] The heating electrode 21 has a symmetry axis extending along the first direction Y, and the first sub-buffer portion 2121 and the second sub-buffer portion 2122 are symmetric about the symmetry axis. Therefore, the minimum dimension W1 (left end dimension) of the second sub-buffer portion 2122 along the second direction X is equal to the dimension of the second end 2112 along the second direction X, and the maximum dimension W2 (right end) of the second sub-buffer portion 2122 along the second direction X is equal to the dimension of the second sub-lead portion 2132 along the second direction X.

[0073] In some embodiments, the first sub-buffer portion 2121 has a first outer side surface 2121O away from the second sub-buffer portion 2122, and the heating portion 211 has a second outer side surface 2111O connected to the first outer side surface 2121O.

[0074] In one embodiment, as Figure 3 shown, the first outer side surface 2121O and the second outer side surface 2111O extend in the first direction Y, that is, the first outer side surface 2121O and the second outer side surface 2111O are in one plane.

[0075] In another embodiment, the first outer side surface 2121O is located on the side of the second outer side surface 2111O close to the second sub-buffer portion 2122.

[0076] In some embodiments, the first sub-buffer portion 2121 has an inner side surface 2121I close to the second sub-buffer portion 2122, and the inner side surface 2121I is a flat surface.

[0077] Please refer to Figure 4 , Figure 4 is a top view structural schematic diagram of the heating electrode provided by some embodiments of the present application. For the sake of easy understanding and brief description, the same structures in this embodiment and the above embodiments continue to use the same reference numerals, and the same structures will not be described in detail. This embodiment only describes the different structures in detail.

[0078] This embodiment and Figure 3The difference between the embodiments is that the maximum dimension W2 (right end) of the first sub-buffer portion 2121 along the second direction X is smaller than the dimension W3 of the first sub-lead portion 2131 along the second direction X, and the maximum dimension (right end) of the second sub-buffer portion 2122 along the second direction X is smaller than the dimension of the second sub-lead portion 2132 along the second direction X. Therefore, a transition portion can be provided to transition the dimensional change between the first sub-buffer portion 2121 and the first sub-lead portion 2131, and to transition the dimensional change between the second sub-buffer portion 2122 and the second sub-lead portion 2132.

[0079] In some embodiments, the heating electrode 21 further includes a transition portion 214. The transition portion 214 includes a first sub-transition portion connected between the first sub-buffer portion 2121 and the first sub-lead portion 2131, and a second sub-transition portion connected between the second sub-buffer portion 2122 and the second sub-lead portion 2132. Among them, the dimension of the first sub-transition portion along the second direction X gradually increases in the direction from the first sub-buffer portion 2121 to the first sub-lead portion 2131 (the illustrated direction is from left to right), and the dimension of the second sub-transition portion along the second direction X gradually increases in the direction from the second sub-buffer portion 2122 to the second sub-lead portion 2132 (the illustrated direction is from left to right).

[0080] It can be understood that the minimum dimension (left end dimension) of the first sub-buffer portion 2121 along the second direction X can also be greater than the dimension of the first end 2111 along the second direction X. Specifically, as an example, a transition portion can be provided between the first sub-buffer portion 2121 and the first end 2111.

[0081] Please refer to Figure 5 , Figure 5 is a top view structural schematic diagram of a heating electrode provided by some embodiments of the present application. For the convenience of understanding and brief description, the same structures in this embodiment as those in the above embodiments continue to use the same reference numerals, and the same structures will not be described in detail. This embodiment only describes the different structures in detail.

[0082] This embodiment and Figure 4 The difference between the embodiments is that the first sub-buffer portion 2121 has an inner side surface 2121I close to the second sub-buffer portion 2122. The inner side surface 2121I is a stepped surface, and the resistance of the first sub-buffer portion 2121 is different at each step.

[0083] The gas sensor provided by the embodiment of the present application includes a detection unit 10 and a heating unit 20. The heating unit 20 is located on the surface of the detection unit 10 and includes a heating electrode 21. The heating electrode 21 extends along a first direction Y and includes a heating portion 211, a buffer portion 212, and a lead portion 213 arranged along the first direction Y. The buffer portion 212 is located between the heating portion 211 and the lead portion 213, and the total resistance of the buffer portion 212 is less than the total resistance of the heating portion 211 and greater than the total resistance of the lead portion 213. By adding a buffer portion 212 between the heating portion 211 and the lead portion 213 in the present application, and the total resistance of the buffer portion 212 is greater than the total resistance of the lead portion 213 and less than the total resistance of the heating portion 211. Therefore, the heat generated by the buffer portion 212 is greater than the heat generated by the lead portion 213 and less than the heat generated by the heating portion 211. So the temperature of the buffer portion 212 is greater than the temperature of the lead portion 213 and less than the temperature of the heating portion 211. In this way, the temperature gradient between the heating portion 211 and the lead portion 213 can be reduced, thereby reducing the product failure rate.

[0084] The following Examples 1 to 5 and Comparative Example 1 are provided in the present application to illustrate the advantages of the products in the present application.

[0085] Example 1

[0086] The product adopts the heating electrode structure shown in Figure 3 wherein, the size of the heating portion along the first direction and the size of the buffer portion along the first direction are both equal to 4 mm.

[0087] Example 2

[0088] The product adopts the heating electrode structure shown in Figure 4 wherein, the size of the heating portion along the first direction and the size of the buffer portion along the first direction are both equal to 4 mm.

[0089] Example 3

[0090] In this example, except for the size of the buffer portion, other features of the product are the same as those in Example 1 (for example, the size of the heating portion along the first direction is 4 mm), wherein the size of the buffer portion along the first direction is 3 mm.

[0091] Example 4

[0092] In this example, except for the size of the buffer portion, other features of the product are the same as those in Example 1 (for example, the size of the heating portion along the first direction is 4 mm), wherein the size of the buffer portion along the first direction is 2 mm.

[0093] Example 5

[0094] In this embodiment, except for the size of the buffer part, other features of the product are the same as those in Embodiment 1 (for example, the size of the heating part along the first direction is 4 mm), and the size of the buffer part along the first direction is 1 mm.

[0095] Comparative Example 1

[0096] Except for the absence of a buffer part, other features of the product are the same as those in Embodiment 1.

[0097] Perform a thermal shock resistance test on the products provided in the above embodiments and comparative examples: Pass 12V direct current into the heater of the product to quickly heat up the product. After maintaining for 1 minute, cut off the power supply, and the product cools naturally for 1 minute. This is 1 heating and cooling cycle, and 1 cycle is recorded once.

[0098] After the thermal shock resistance test, measure the internal resistance of the oxygen sensor. If the internal resistance exceeds a 5% change range, it is determined that cracks have occurred in the solid electrolyte body of the oxygen sensor, and record the number of power on and off times when the cracks occur, which is the effective number of thermal shock resistance of the oxygen sensor. The results are shown in Table 1 below.

[0099] From the results in Table 1, it can be seen that setting a buffer part can increase the effective number of thermal shock resistance of the product, and when the difference in the size of the buffer part along the first direction and the size of the heating part along the first direction is large, the effective number of thermal shock resistance of the product decreases; when the difference in the size of the buffer part along the first direction and the size of the heating part along the first direction is smaller, the effective number of thermal shock resistance of the product is larger.

[0100] Table 1

[0101] Effective number of thermal shock resistance / times Example 1 ＞5000 Example 2 ＞5000 Example 3 ＞5000 Example 4 ＞4500 Example 5 ＜4000 Comparative Example 1 ＜3000

[0102] This application provides a gas monitoring device, which includes the above gas sensor. This gas monitoring device has all the beneficial effects of the above gas sensor, and will not be elaborated here in this application.

[0103] This application provides a vehicle, which includes the above gas monitoring device. This vehicle has all the beneficial effects of the above gas monitoring device, and will not be elaborated here in this application. This gas monitoring device can be applied to the exhaust gas monitoring of vehicles.

[0104] This vehicle can be a fuel vehicle, a plug-in hybrid vehicle, a new energy vehicle, etc., and this disclosure does not make specific limitations thereto.

[0105] In the description of the present application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality of" means two or more unless otherwise specifically defined.

[0106] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0107] The embodiments, implementation manners and related technical features of the present application can be combined and replaced with each other without conflict.

[0108] The above are only the preferred embodiments of the present application and do not impose any formal limitations on the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of the technical solution of the present application.

Claims

1. A gas sensor, characterized in that, including: a detection unit; a heating unit, located on the surface of the detection unit, and including a heating electrode, the heating electrode extending along a first direction, and including a heating portion, a buffer portion, and a lead portion arranged along the first direction, the buffer portion being located between the heating portion and the lead portion, and the total resistance of the buffer portion being less than the total resistance of the heating portion and greater than the total resistance of the lead portion.

2. The gas sensor according to claim 1, characterized in that, The total resistance of the heating portion is 55% - 65% of the total resistance of the heating electrode, the total resistance of the buffer portion is 15% - 30% of the total resistance of the heating electrode, and the total resistance of the lead portion is 15% - 30% of the total resistance of the heating electrode.

3. The gas sensor according to claim 1, characterized in that, The temperature of the heating portion is 400°C - 800°C, the temperature of the buffer portion is 200°C - 800°C, and the temperature of the lead portion is less than 200°C.

4. The gas sensor according to claim 1, characterized in that, The lead portion includes a first sub-lead portion and a second sub-lead portion oppositely arranged in a second direction, the second direction being perpendicular to the first direction and parallel to the surface of the detection unit; The buffer portion includes a first sub-buffer portion connected to the first sub-lead portion and a second sub-buffer portion connected to the second sub-lead portion; The heating portion includes a first end connected to the first sub-buffer portion and a second end connected to the second sub-buffer portion; wherein, the dimension of the first sub-buffer portion in the second direction gradually increases from the first end to the direction of the first sub-lead portion, and the dimension of the second sub-buffer portion in the second direction gradually increases from the second end to the direction of the second sub-lead portion.

5. The gas sensor according to claim 4, characterized in that, The minimum dimension of the first sub-buffer portion in the second direction is greater than or equal to the dimension of the first end in the second direction; The maximum dimension of the first sub-buffer portion in the second direction is less than or equal to the dimension of the first sub-lead portion in the second direction.

6. The gas sensor according to claim 4, characterized in that, The heating electrode further includes a transition portion, the transition portion including a first sub-transition portion connected between the first sub-buffer portion and the first sub-lead portion, and a second sub-transition portion connected between the second sub-buffer portion and the second sub-lead portion; wherein, the dimension of the first sub-transition portion in the second direction gradually increases from the first sub-buffer portion to the direction of the first sub-lead portion, and the dimension of the second sub-transition portion in the second direction gradually increases from the second sub-buffer portion to the direction of the second sub-lead portion.

7. The gas sensor according to claim 1, characterized in that, The dimension of the lead portion in the first direction is greater than the dimension of the heating portion in the first direction, and the dimension of the lead portion in the first direction is greater than the dimension of the buffer portion in the first direction.

8. The gas sensor according to claim 7, characterized in that, The resistivity of the buffer portion is greater than the resistivity of the lead portion.

9. The gas sensor according to claim 7, characterized in that, The heating portion further includes a plurality of sub-heating portions arranged along the first direction, and the plurality of sub-heating portions are connected in series end to end; The dimension of the heating portion in the first direction is greater than or equal to the dimension of the buffer portion in the first direction.

10. The gas sensor according to claim 9, characterized in that, The resistivity of the buffer portion is less than or equal to the resistivity of the heating portion.

11. The gas sensor according to claim 10, wherein, The resistivity of the heating portion is 35 μΩ·cm - 50 μΩ·cm, and the resistivity of the buffer portion is 10 μΩ·cm - 25 μΩ·cm.

12. The gas sensor according to claim 9, wherein, The dimension of the buffer portion along the first direction is 50% to 100% of the dimension of the heating portion along the first direction.

13. The gas sensor according to claim 4, characterized in that, The heating electrode has a symmetry axis extending along the first direction, and the first sub-buffer portion and the second sub-buffer portion are symmetric about the symmetry axis; The first sub-buffer portion has a first outer side surface away from the second sub-buffer portion, the heating portion has a second outer side surface connected to the first outer side surface, and the first outer side surface and the second outer side surface extend in the first direction, or the first outer side surface is located on the side of the second outer side surface close to the second sub-buffer portion.

14. The gas sensor according to claim 13, characterized in that, The first sub-buffer portion has an inner side surface close to the second sub-buffer portion, and the inner side surface is a flat surface or a stepped surface.

15. The gas sensor according to claim 1, characterized in that, The detection unit includes a first electrolyte layer, a first electrode, a second electrode, and a standard gas channel. The first electrode and the second electrode are located on both sides of the first electrolyte layer along the third direction. The standard gas channel is located on the side of the first electrolyte layer close to the heating unit and is connected to the second electrode. The third direction is perpendicular to the surface of the detection unit.

16. The gas sensor according to claim 15, characterized in that, It further includes a pump unit. The pump unit includes a second electrolyte layer, a third electrode, and a fourth electrode. The third electrode is located on the side of the second electrolyte layer away from the first electrode, and the fourth electrode is located on the side of the second electrolyte layer close to the first electrode; The orthographic projections of the first electrode, the second electrode, the third electrode, and the fourth electrode on the first electrolyte layer are all within the range of the orthographic projection of the heating portion on the first electrolyte layer.

17. A gas monitoring device, characterized in that, It includes the gas sensor according to any one of claims 1 to 16.

18. A vehicle, characterized in that, It includes the gas monitoring device according to claim 17.

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