Nitrogen oxide sensor ceramic chip, nitrogen oxide sensor and vehicle

Abstract

The utility model provides a nitrogen oxide sensor ceramic chip, a nitrogen oxide sensor and a vehicle, belongs to the field of vehicle tail gas measurement, and solves the problem that gas is not further buffered when entering a third cavity from a second cavity, so that the measurement precision is reduced. The nitrogen oxide sensor ceramic chip comprises a chip body, a main pump oxygen electrode, an auxiliary pump oxygen electrode and a measuring electrode, a first cavity, a second cavity and a third cavity are formed in the chip body, the first cavity and the second cavity are arranged in a spaced mode in the first direction, the second cavity and the third cavity are arranged in a spaced mode in the second direction, and the first direction is perpendicular to the second direction; one end of the first cavity is communicated with the inlet of the chip body, and the other end is communicated with the second cavity; in the second direction, the second cavity is communicated with the third cavity, the main pump oxygen electrode is arranged in the first cavity, the auxiliary pump oxygen electrode is arranged in the second cavity, and the measuring electrode is arranged in the third cavity. To-be-measured gas entering the third cavity can be buffered, and the measurement precision is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of vehicle exhaust measurement, in particular to a nitrogen oxide sensor ceramic chip, a nitrogen oxide sensor and a vehicle. Background Art

[0002] like Figure 2 As shown, the chamber of the ceramic chip of the nitrogen oxide sensor is generally a three-chamber structure. The first chamber is the main pump chamber, which pumps the oxygen in the exhaust gas entering the chip out of the chip, and controls the oxygen content in the first chamber at the PPM level; the second chamber is the auxiliary pump chamber, which continues to pump out the small amount of oxygen entering from the first chamber and decomposes the nitrogen dioxide in the exhaust gas into nitric oxide and oxygen, and also pumps out the decomposed oxygen, and controls the oxygen content in the second chamber at the PPB level; the third chamber is the measurement chamber, which further decomposes the nitric oxide entering from the second chamber into nitrogen and oxygen. At this time, the current measured in the third chamber represents the oxygen content in the exhaust gas. However, in the existing nitrogen oxide sensor ceramic chip, the first chamber, the second chamber and the third chamber are arranged in sequence in the horizontal direction. The gas is not further buffered when entering the third chamber from the second chamber. The amount of gas to be measured entering the third chamber is difficult to control, resulting in a large measurement current of the chip in the air. The greater the current at this time, the greater the deviation of the measurement system, which will affect the measurement accuracy, causing the nitrogen oxide sensor to have a large deviation when measuring low-concentration exhaust gas. Moreover, when the exhaust gas flow rate suddenly increases, the gas entering the third chamber also increases rapidly, causing the measurement system to become unstable in a short period of time. Although it can return to a normal measurement state within a few seconds, the measurement accuracy has decreased in a few seconds during complex driving processes. Utility Model Content

[0003] In view of this, in order to solve the problem that in the existing nitrogen oxide sensor ceramic chip, the first chamber, the second chamber and the third chamber are arranged in sequence in the horizontal direction, the gas is not further buffered when entering the third chamber from the second chamber, and the measurement accuracy is reduced, the utility model proposes a nitrogen oxide sensor ceramic chip, a nitrogen oxide sensor and a vehicle.

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

[0005] A nitrogen oxide sensor ceramic chip, comprising:

[0006] The chip body includes a first cavity, a second cavity, and a third cavity. The first cavity and the second cavity are spaced apart along a first direction, and the second cavity and the third cavity are spaced apart along a second direction. The first direction is perpendicular to the second direction. Along the first direction, one end of the first cavity is connected to the inlet of the chip body, and the other end is connected to the second cavity; along the second direction, the second cavity is connected to the third cavity.

[0007] A main pump oxygen electrode is arranged in the first cavity;

[0008] An auxiliary pump oxygen electrode is arranged in the second cavity;

[0009] The measuring electrode is arranged in the third cavity.

[0010] As a preferred solution of the above-mentioned nitrogen oxide sensor ceramic chip, the number of the third cavities is two, the number of the measuring electrodes is two, the two measuring electrodes are respectively arranged in the two third cavities, and the second cavity is located between the two third cavities.

[0011] As a preferred solution of the above-mentioned nitrogen oxide sensor ceramic chip, the second cavity is connected to the third cavity through a connecting port, and the inner diameter of the connecting port is smaller than the inner diameter of the third cavity.

[0012] As a preferred solution of the above-mentioned nitrogen oxide sensor ceramic chip, the nitrogen oxide sensor ceramic chip also includes a common electrode and a ventilation structure. The common electrode and the ventilation structure are fixedly arranged inside the chip body. The ventilation structure is in contact with the common electrode. One end of the ventilation structure is located at the edge of the chip body and is connected to the outside world.

[0013] As a preferred solution of the above-mentioned nitrogen oxide sensor ceramic chip, the ventilation structure is a porous alumina structure.

[0014] As a preferred solution of the above-mentioned ceramic chip for the nitrogen oxide sensor, the chip body is made of zirconium oxide material.

[0015] As a preferred solution of the above-mentioned nitrogen oxide sensor ceramic chip, the number of the main pump oxygen electrode and the auxiliary pump oxygen electrode are both two, the two main pump oxygen electrodes are respectively arranged at the two ends of the first cavity along the second direction, and the two auxiliary pump oxygen electrodes are respectively arranged at the two ends of the second cavity along the second direction.

[0016] As a preferred solution of the above-mentioned nitrogen oxide sensor ceramic chip, the nitrogen oxide sensor ceramic chip further includes a reference electrode and a heating electrode, and the reference electrode and the heating electrode are fixedly arranged on the chip body.

[0017] The utility model also provides a nitrogen oxide sensor, comprising the above-mentioned nitrogen oxide sensor ceramic chip.

[0018] The utility model also provides a vehicle, comprising the above-mentioned nitrogen oxide sensor.

[0019] Compared with the prior art, the beneficial effects of the nitrogen oxide sensor ceramic chip, nitrogen oxide sensor and vehicle provided by the present invention are:

[0020] 1. The utility model provides a nitrogen oxide sensor ceramic chip, a nitrogen oxide sensor and a vehicle. In the nitrogen oxide sensor ceramic chip, the first cavity and the second cavity are spaced apart along the first direction, and the second cavity and the third cavity are spaced apart along the second direction. The first direction is perpendicular to the second direction. Along the first direction, one end of the first cavity is connected to the inlet of the chip body, and the other end is connected to the second cavity; along the second direction, the second cavity is connected to the third cavity. When used, the exhaust gas passes through the inlet, the first cavity and the second cavity in sequence along the first direction, and collides on the inner wall of the second cavity before entering the third cavity along the second direction. The gas to be measured entering the third cavity can be buffered, and a more uniform flow can be achieved when the gas to be measured enters the third cavity, thereby improving measurement accuracy. In addition, when a large amount of airflow flows in instantaneously, there is also a better buffering effect, so that the gas to be measured entering the third cavity is more stable, thereby achieving more accurate transient measurement.

[0021] 2. The utility model provides a nitrogen oxide sensor ceramic chip, a nitrogen oxide sensor and a vehicle. In the nitrogen oxide sensor ceramic chip, two measuring electrodes are respectively arranged in two third cavities, and the second cavity is located between the two third cavities. In actual application, the two third cavities are separately arranged, and the two measuring electrodes can be controlled separately. When the measuring electrode of one third cavity fails during measurement, the measuring electrode in the other third cavity can continue to work, so as not to affect the normal driving of the vehicle, and the fault will be reported to the user. The user can replace the nitrogen oxide sensor in time, so that the monitoring data that needs to be reported to the Ministry of Environmental Protection will not be interrupted. Moreover, the measurement values ​​measured by the two measuring electrodes respectively located in the two separately set third cavities are calculated by the controller to obtain an average value, and the average value is used as the measurement result, which can improve the measurement accuracy.

[0022] 3. The present invention provides a nitrogen oxide sensor ceramic chip, a nitrogen oxide sensor, and a vehicle. In the nitrogen oxide sensor ceramic chip, a common electrode is disposed inside the chip body. Since the common electrode needs to discharge oxygen ions attached to the surface of the common electrode into the air, the surface of the common electrode contacts a porous alumina structure. One end of the porous alumina structure is located at the edge of the chip body and communicates with the outside world. The porous alumina structure is used to achieve the ventilation requirements of the common electrode. Placing the common electrode inside the chip body is equivalent to changing the protective layer from the original 20μm aluminum oxide material to a 125μm zirconium oxide material chip body. First, the thickness of the protective layer is increased, and second, after sintering, the toughness and strength of zirconium oxide are better than those of aluminum oxide, so it can better protect the common electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the structure of the ceramic chip of the nitrogen oxide sensor provided by a specific embodiment of the utility model;

[0025] Figure 2 It is a schematic diagram of the structure of a ceramic chip of a nitrogen oxide sensor in the prior art.

[0026] In the picture:

[0027] 1. Chip body; 2. First cavity; 3. Second cavity; 4. Third cavity; 5. Main pump oxygen electrode; 6. Auxiliary pump oxygen electrode; 7. Measuring electrode; 8. Common electrode; 9. Porous alumina structure; 10. Reference electrode; 11. Heating electrode;

[0028] 100, first chamber; 200, second chamber; 300, third chamber. DETAILED DESCRIPTION

[0029] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other in the absence of conflict, and the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0030] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0031] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0032] In the description of this embodiment, terms such as "upper," "lower," and "right" are used to refer to positions or locations based on the positions or locations shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0033] See also Figure 1 Description of this embodiment: The utility model provides a nitrogen oxide sensor ceramic chip, a nitrogen oxide sensor and a vehicle. The nitrogen oxide sensor ceramic chip includes: a chip body 1, a main pump oxygen electrode 5, an auxiliary pump oxygen electrode 6 and a measuring electrode 7. A first cavity 2, a second cavity 3 and a third cavity 4 are provided in the chip body 1. The first cavity 2 and the second cavity 3 are spaced apart along the first direction, and the second cavity 3 and the third cavity 4 are spaced apart along the second direction. The first direction is perpendicular to the second direction. Along the first direction, one end of the first cavity 2 is connected to the inlet of the chip body 1, and the other end is connected to the second cavity 3; along the second direction, the second cavity 3 is connected to the third cavity 4. The main pump oxygen electrode 5 is arranged in the first cavity 2, the auxiliary pump oxygen electrode 6 is arranged in the second cavity 3, and the measuring electrode 7 is arranged in the third cavity 4.

[0034] In this embodiment, the first direction is a horizontal direction, and the second direction is a vertical direction.

[0035] In this nitrogen oxide sensor ceramic chip, exhaust gas passes through the inlet, the first cavity 2, and the second cavity 3 in sequence in the horizontal direction, and only enters the third cavity 4 in the vertical direction after colliding with the inner wall of the second cavity 3. This can buffer the gas to be measured entering the third cavity 4, and the gas to be measured can achieve a more uniform flow when entering the third cavity 4, thereby improving measurement accuracy. In addition, it also has a better buffering effect when a large amount of airflow flows in instantaneously, making the gas to be measured entering the third cavity 4 more stable and achieving more accurate transient measurement.

[0036] In the prior art, such as Figure 2 As shown, there is only one measurement chamber and one measuring electrode. The measured data is unique, but there may be some deviation between the measured value and the actual value. Furthermore, due to the extremely harsh operating environment, if the measurement accuracy of the measuring electrode deviates during use, and the deviation exceeds the allowable range of the vehicle control system, the vehicle will issue a fault alarm and stop recording NOx monitoring data, affecting normal driving. In principle, the vehicle cannot continue to drive at this time. During the annual vehicle inspection, all NOx data must be read via OBD (On-Board Diagnostics). If the data is interrupted, the vehicle may fail the inspection. At the same time, the vehicle control system will reduce the power due to the loss of NOx monitoring, also affecting normal driving.

[0037] In this embodiment, Figure 1 As shown, there are two third cavities 4 and two measuring electrodes 7 . The two measuring electrodes 7 are respectively arranged in the two third cavities 4 , and the second cavity 3 is located between the two third cavities 4 .

[0038] The two third chambers 4 are separately provided, enabling independent control of the two measuring electrodes 7. If a measuring electrode 7 in one third chamber 4 malfunctions during measurement, the measuring electrode 7 in the other third chamber 4 continues to function, without affecting normal vehicle operation. Furthermore, the fault is reported to the user, allowing the user to promptly replace the NOx sensor, thereby maintaining monitoring data required for reporting to the Ministry of Environmental Protection. Controlling the measuring electrodes 7 is conventional technology and will not be further elaborated here.

[0039] Furthermore, the controller calculates the average value of the measurement values ​​measured by the two measurement electrodes 7 located in the two separately arranged third cavities 4, and uses the average value as the measurement result, thereby improving the measurement accuracy.

[0040] In this embodiment, the two measuring electrodes 7 have the same size, performance and function.

[0041] Optionally, the second chamber 3 is connected to the third chamber 4 via a connecting port, and the inner diameter of the connecting port is smaller than the inner diameter of the third chamber 4, so as to further buffer the gas to be measured entering the third chamber 4.

[0042] It is understandable that the third cavity 4 and the measuring electrode 7 are manufactured by punching holes in the membrane and printing the electrodes.

[0043] Optionally, the chip body 1 is made of zirconia. Zirconia has a phase transformation toughening mechanism. When subjected to external force, its tetragonal phase transforms into a monoclinic phase, expanding in volume, thereby absorbing energy and preventing crack propagation, making the zirconia material have high toughness and fracture resistance.

[0044] like Figure 2 As shown, in existing technologies, common electrodes are designed directly on the top surface of ceramic chips. Although there is a protective layer of aluminum oxide, the thinness of this layer limits its protective effect. Ceramic chips are installed in vehicle exhaust pipes, a harsh operating environment, and prolonged exposure to exhaust gases can easily damage the common electrodes. Research has shown that common electrodes currently have the highest failure rate among all ceramic chip failure modes.

[0045] In this embodiment, Figure 1 As shown, the nitrogen oxide sensor ceramic chip also includes a common electrode 8 and a vent structure. Both the common electrode 8 and the vent structure are fixedly disposed within the chip body 1. The vent structure contacts the common electrode 8. One end of the vent structure is located at the edge of the chip body 1 and communicates with the outside world. Optionally, the vent structure is a porous alumina structure 9.

[0046] The common electrode 8 is arranged inside the chip body 1. Since the common electrode 8 needs to discharge the oxygen ions attached to the surface of the common electrode 8 into the air, the surface of the common electrode 8 is in contact with the porous alumina structure 9. One end of the porous alumina structure 9 is located at the edge of the chip body 1 and is connected to the outside world. The ventilation requirements of the common electrode 8 are achieved through the porous alumina structure 9.

[0047] Placing common electrode 8 inside chip body 1 is equivalent to changing the protective layer from the original 20μm alumina material to 125μm zirconia material. This increases the thickness of the protective layer and, after sintering, zirconia exhibits greater toughness and strength than alumina, thus providing better protection for common electrode 8. Zirconia's flexural strength can reach 800 MPa to 1200 MPa, or even higher, while alumina's flexural strength is generally between 300 MPa and 500 MPa.

[0048] Optionally, there are two main pump oxygen electrodes 5 and two auxiliary pump oxygen electrodes 6, the two main pump oxygen electrodes 5 are respectively arranged at both ends of the first cavity 2 along the second direction, and the two auxiliary pump oxygen electrodes 6 are respectively arranged at both ends of the second cavity 3 along the second direction.

[0049] Optionally, the nitrogen oxide sensor ceramic chip further includes a reference electrode 10 , which is fixedly disposed on the chip body 1 .

[0050] Optionally, the nitrogen oxide sensor ceramic chip further includes a heating electrode 11 , which is fixedly disposed on the chip body 1 .

[0051] The utility model also provides a nitrogen oxide sensor, comprising the above-mentioned nitrogen oxide sensor ceramic chip.

[0052] The utility model also provides a vehicle, comprising the above-mentioned nitrogen oxide sensor.

[0053] Obviously, the embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Numerous modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. An exhaustive list of all possible embodiments is unnecessary and impossible.

Claims

1. A nitrogen oxide sensor ceramic chip, characterized in that: include: A chip body (1) is provided with a first cavity (2), a second cavity (3) and a third cavity (4), the first cavity (2) and the second cavity (3) are spaced apart along a first direction, the second cavity (3) and the third cavity (4) are spaced apart along a second direction, the first direction is perpendicular to the second direction, and along the first direction, one end of the first cavity (2) is communicated with an inlet of the chip body (1), and the other end is communicated with the second cavity (3); along the second direction, the second cavity (3) is communicated with the third cavity (4); A main pump oxygen electrode (5), the main pump oxygen electrode (5) is arranged in the first cavity (2); An auxiliary pump oxygen electrode (6), the auxiliary pump oxygen electrode (6) is arranged in the second cavity (3); A measuring electrode (7) is arranged in the third cavity (4).

2. The nitrogen oxide sensor ceramic chip according to claim 1, characterized in that: The number of the third cavities (4) is two, the number of the measuring electrodes (7) is two, the two measuring electrodes (7) are respectively arranged in the two third cavities (4), and the second cavity (3) is located between the two third cavities (4).

3. The nitrogen oxide sensor ceramic chip according to claim 1, characterized in that: The second cavity (3) is connected to the third cavity (4) via a connecting port, and the inner diameter of the connecting port is smaller than the inner diameter of the third cavity (4).

4. The nitrogen oxide sensor ceramic chip according to claim 1, characterized in that: It also includes a common electrode (8) and a ventilation structure, both of which are fixedly arranged inside the chip body (1), the ventilation structure is in contact with the common electrode (8), and one end of the ventilation structure is located at the edge of the chip body (1) and is connected to the outside world.

5. The nitrogen oxide sensor ceramic chip according to claim 4, characterized in that: The ventilation structure is a porous alumina structure (9).

6. The nitrogen oxide sensor ceramic chip according to claim 1, characterized in that: The chip body (1) is made of zirconium oxide material.

7. The nitrogen oxide sensor ceramic chip according to claim 1, characterized in that: The number of the main pump oxygen electrode (5) and the auxiliary pump oxygen electrode (6) is two, the two main pump oxygen electrodes (5) are respectively arranged at the two ends of the first cavity (2) along the second direction, and the two auxiliary pump oxygen electrodes (6) are respectively arranged at the two ends of the second cavity (3) along the second direction.

8. The nitrogen oxide sensor ceramic chip according to claim 1, characterized in that: It also includes a reference electrode (10) and a heating electrode (11), and both the reference electrode (10) and the heating electrode (11) are fixedly arranged on the chip body (1).

9. A nitrogen oxide sensor, characterized in that: The nitrogen oxide sensor ceramic chip comprises the nitrogen oxide sensor ceramic chip according to any one of claims 1 to 8.

10. A vehicle, characterized in that: The nitrogen oxide sensor according to claim 9 is included.

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