Pump cavity layer structure of ceramic chip, ceramic chip and nitrogen-oxygen sensor

Abstract

The utility model discloses a pump chamber layer structure of a ceramic chip, the ceramic chip and a nitrogen oxygen sensor, and relates to the technical field of sensors, the pump chamber layer structure comprises a gas inlet buffer chamber, a main pump chamber, an auxiliary pump chamber and a measuring pump chamber are sequentially arranged at the rear end of the gas inlet buffer chamber, and the gas inlet buffer chamber is of an arc-shaped structure; the ceramic chip comprises the pump chamber layer structure. The nitrogen-oxygen sensor comprises the ceramic chip. A gas inlet buffer chamber in the pump chamber layer structure is arranged to be of an arc-shaped structure, the phenomenon of turbulent flow after tail gas enters the ceramic chip can be effectively avoided, the stability of the tail gas after the tail gas enters the ceramic chip is improved, and then the testing precision of the ceramic chip is improved. The outer surface of the ceramic chip containing the pump cavity layer structure is in an arc-shaped outline, and the main pump cavity, the auxiliary pump cavity, the measuring cavity and the motor are all in arc-shaped outline design, so that stress concentration during normal work can be eliminated and reduced, and the service life of the ceramic chip is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, specifically to a pump chamber layer structure of a ceramic chip, a ceramic chip, and a nitrogen and oxygen sensor. Background Technology

[0002] In a vehicle's exhaust system, a ceramic chip in a nitrogen oxide sensor probe detects the concentration of nitrogen oxides in the exhaust. The ceramic chip is the core component of the entire sensor, and exhaust gases enter the chamber within the ceramic chip through diffusion channels.

[0003] The internal structure of the elongated ceramic chip is complex, and each chamber is rectangular. In addition, its external structure is designed with sharp edges and corners. When subjected to temperature shock, local heat concentration is likely to occur, resulting in thermal stress concentration, which can cause the chip to crack, be damaged and fail.

[0004] Meanwhile, because the internal chambers of the ceramic chip are rectangular, when the exhaust gas passes through the buffer chamber and the diffusion slit into the main pump, auxiliary pump and measuring pump chambers for exhaust gas composition testing, flow separation and vortex phenomena will occur in the right-angle area of ​​the rectangular buffer chamber due to the fluidity of the gas, affecting the stability of the test exhaust gas flow. Utility Model Content

[0005] The technical problem this invention aims to solve is that current ceramic chips are prone to localized heat concentration and thermal stress concentration when subjected to temperature shock, leading to chip cracking, damage, and failure. Furthermore, current ceramic chips can also affect the stability of the test exhaust gas flow. Based on this, a pump chamber layer structure for a ceramic chip, a ceramic chip, and a nitrogen-oxygen sensor are proposed. The pump chamber structure of this ceramic chip is designed in an arc shape, which reduces the number of right angles inside the ceramic chip, reduces abrupt changes in cross-section, improves stress distribution, and enhances the temperature shock resistance of the ceramic chip.

[0006] This utility model is achieved through the following technical solution:

[0007] In a first aspect, this application provides a pump chamber layer structure for a ceramic chip, including a gas inlet buffer chamber, wherein a main pump chamber, an auxiliary pump chamber, and a measuring pump chamber are sequentially arranged at the rear end of the gas inlet buffer chamber, and the gas inlet buffer chamber has an arc-shaped structure.

[0008] Furthermore, the main pump chamber, auxiliary pump chamber, and measuring pump chamber all have an arc-shaped profile.

[0009] Furthermore, it also includes a reference chamber located at the head of the ceramic chip.

[0010] Furthermore, the outline of the reference chamber is also arc-shaped.

[0011] Secondly, this application provides a ceramic chip including the aforementioned pump chamber layer.

[0012] Furthermore, the structure of the ceramic chip, from top to bottom, consists of an outer electrode layer, an upper ceramic sheet, a pump electrode layer, a pump chamber layer, a middle ceramic sheet, a heating layer, and a lower ceramic sheet.

[0013] Furthermore, the four corners of the outer surface of the ceramic chip have an arc-shaped structure.

[0014] Furthermore, both the outer electrode layer and the lower ceramic sheet are connected to contact pins.

[0015] Furthermore, the pump electrode layer includes a main pump electrode, an auxiliary pump electrode, and a measuring pump electrode; a reference pump electrode is installed between the pump chamber layer and the middle ceramic plate.

[0016] Thirdly, this application provides a nitrogen and oxygen sensor, including the aforementioned ceramic chip.

[0017] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0018] (1) The gas inlet buffer chamber in the pump chamber layer structure of this utility model is set as an arc-shaped structure. Compared with the edge design of the long strip chip chamber, the pump chamber layer structure can effectively avoid the phenomenon of turbulence after the exhaust gas enters the ceramic chip, improve the stability after the exhaust gas enters the ceramic chip, and thus improve the testing accuracy of the ceramic chip.

[0019] (2) The reference chamber in this utility model is arc-shaped and located in the functional area of ​​the ceramic chip head. When the ceramic chip head is heated and the stress is concentrated, a new stress concentration point is formed at the top of the arc of the reference chamber, which distributes the excessively concentrated thermal stress of the chip head, reduces and avoids cracking, damage and failure caused by the excessively concentrated thermal stress, and improves the service life of the ceramic chip.

[0020] (3) The ceramic chip in this utility model has the mechanical strength characteristics of hard and brittle ceramic materials. The arc-shaped contour of the outer surface of the ceramic chip can reduce the phenomenon of mechanical stress concentration caused by mechanical impact during testing and packaging, which leads to cracking, damage and failure of the ceramic chip, and improves the pass rate of the ceramic chip.

[0021] (4) The outer surface of the ceramic chip in this utility model is arc-shaped. The main pump chamber, auxiliary pump chamber, measuring chamber and motor are all arc-shaped. Compared with the edge design of the long strip chip chamber, it is beneficial to eliminate and reduce stress concentration during normal operation and improve the service life of the ceramic chip. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0023] Figure 1 This is a schematic diagram of the structure of the pump chamber layer of a ceramic chip in this utility model;

[0024] Figure 2 This is a schematic diagram of the structure of a ceramic chip before packaging according to this utility model;

[0025] Figure 3 This is a schematic diagram of the structure of a ceramic chip after packaging according to the present invention.

[0026] The attached diagram shows the markings and corresponding component names:

[0027] 10-Outer electrode layer, 20-Upper ceramic sheet, 30-Pump electrode layer, 40-Pump chamber layer, 50-Middle ceramic sheet, 60-Heating layer, 70-Lower ceramic sheet, 31-Main pump electrode, 32-Auxiliary pump electrode, 33-Measuring pump electrode, 34-Reference pump electrode, 41-Gas inlet buffer chamber, 42-Main pump chamber, 43-Auxiliary pump chamber, 44-Measuring pump chamber, 45-Reference chamber, 11-First contact pin, 71-Second contact pin. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description of this utility model is provided in conjunction with the embodiments. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0029] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to implement the present invention. In other embodiments, well-known materials or methods have not been specifically described in order to avoid obscuring the present invention.

[0030] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples.

[0031] In this application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and other terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to describe the relative positional relationship between the components or parts and do not specifically limit the specific installation orientation of each component or part.

[0032] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0033] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0034] Furthermore, the structures, proportions, sizes, etc., drawn in the accompanying drawings of this application are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0035] Example 1

[0036] like Figures 1-3 As shown, this embodiment provides a pump chamber layer 40 for a ceramic chip, including a gas inlet buffer chamber 41. A main pump chamber 42, an auxiliary pump chamber 43, and a measurement pump chamber 44 are sequentially arranged at the rear end of the gas inlet buffer chamber 41. The gas inlet buffer chamber 41 has an arc-shaped structure. The main pump chamber 42, the auxiliary pump chamber 43, and the measurement pump chamber 44 also have arc-shaped contour structures. It also includes a reference chamber 45 located at the head of the ceramic chip. The reference chamber 45 is correspondingly connected to a reference pump electrode 34. The contour of the reference chamber 45 is also arc-shaped.

[0037] Working Principle: The ceramic chip of the nitrogen-oxygen sensor is heated during operation, with a significant temperature gradient. The temperature of the functional area at the chip head can reach over 800℃, while the temperature at the tail is generally around 50℃. When the functional area is heated, the different chambers expand and contract unevenly due to temperature differences, material inconsistencies, and structural differences, generating internal forces. Compared to a right-angle design, the internal forces acting on the arcs of each chamber significantly reduce stress concentration. Simultaneously, the reference chamber 45, located at the chip head, acts as a "stress relief groove," transferring the internal forces to the reference chamber 45, further reducing stress concentration at the chip head.

[0038] Compared to a right-angle design, when exhaust gas enters the arc-shaped buffer chamber, localized flow separation and vortex phenomena do not occur, thus affecting the freely diffused exhaust gas composition as it diffuses into the main pump chamber 42, auxiliary pump chamber 43, and measurement pump chamber 44, consequently impacting exhaust gas composition testing. The pump chamber layer 40 structure in this embodiment effectively prevents turbulence after exhaust gas enters the ceramic chip, improving its stability and thus enhancing the testing accuracy. The reference chamber 45 is arc-shaped and located in the functional area of ​​the ceramic chip head. When thermal stress concentrates at the ceramic chip head, the arc-shaped top of the reference chamber 45 forms a new stress concentration point, distributing the excessively concentrated thermal stress at the chip head, reducing and avoiding cracking, damage, and failure caused by the previously excessively concentrated thermal stress, and improving the lifespan of the ceramic chip.

[0039] Example 2

[0040] Based on Example 1, such as Figures 1-3 As shown, this embodiment provides a ceramic chip that reduces the right-angle design inside the ceramic chip, reduces abrupt changes in cross-section, improves stress distribution, and enhances the ceramic chip's resistance to temperature shock. The structure of the ceramic chip includes the pump chamber layer 40 in Embodiment 1.

[0041] In addition, the four corners of the outer surface of the ceramic chip are rounded. The structure of the ceramic chip from top to bottom consists of an outer electrode layer 10, an upper ceramic sheet 20, a pump electrode layer 30, a pump chamber layer 40, a middle ceramic sheet 50, a heating layer 60, and a lower ceramic sheet 70. Contact pins are connected to both the outer electrode layer 10 and the lower ceramic sheet 70. The pump electrode layer 30 includes a main pump electrode 31, an auxiliary pump electrode 32, and a measurement pump electrode 33; a reference pump electrode 34 is installed between the pump chamber layer 40 and the middle ceramic sheet 50.

[0042] The outer electrode layer of the ceramic chip is connected to a first contact pin 11, and the lower ceramic sheet 70 is connected to a second contact pin 71.

[0043] The four corners of the outer surface of the ceramic chip are die-cut into an arc shape, which can reduce the mechanical stress concentration that may occur during testing and packaging, and improve the yield of ceramic chips.

[0044] In the actual installation of the ceramic chip, the functional layers such as heating wire electrode, pump electrode and pump chamber are printed on the corresponding ceramic sheet according to the pre-designed printing pattern. Then, the different ceramic sheets are stacked in sequence, isostatically pressed and formed, then die-cut and sintered to obtain the nitrogen and oxygen sensor ceramic chip.

[0045] Measuring NO in exhaust gas x At a certain concentration, the ceramic chip raises the temperature to 800℃ through the heating layer 60. The exhaust gas enters the buffer chamber through the inlet, and after passing through the first diffusion barrier, enters the main pump chamber 42. The main pump electrode 31 and the common external electrode 10 pump most of the oxygen out of the main pump chamber 42 through the zirconia substrate 20. The remaining exhaust gas enters the auxiliary pump chamber 43 through the second diffusion. The auxiliary pump electrode 32 and the common external electrode 10 pump the remaining oxygen out of the auxiliary pump chamber 43 through the zirconia substrate 20, thus reducing the NO concentration in the exhaust gas. x The exhaust gas, containing only NO, enters the measuring chamber, where it is catalytically decomposed into N2 and O2. The measuring pump electrode 33 and the common external electrode 10 pump the O2 out of the measuring chamber through the zirconia substrate 20. The microcurrent in the measuring circuit then yields the NO content in the exhaust gas. x Concentration. The reference pump electrode 34 forms a Nernst electromotive force with the main pump electrode 31, auxiliary pump electrode 32 and measuring pump electrode 33 through the zirconia substrate 40. The Nernst electromotive force is detected to adjust the pumping voltage of each chamber.

[0046] The ceramic chip in this embodiment possesses the mechanical strength characteristics of ceramic materials—hardness and brittleness. The arc-shaped contour of the ceramic chip's outer surface reduces stress concentration during testing and packaging, preventing cracking, damage, and failure, thus improving the chip's yield. The arc-shaped contour of the main pump chamber 42, auxiliary pump chamber 43, measuring pump chamber 44, and electrodes, compared to the edge design of elongated chip chambers, helps eliminate and reduce stress concentration during normal operation, extending the lifespan of the ceramic chip.

[0047] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A ceramic chip pump chamber layer structure, characterized by, The gas inlet buffer chamber (41) is sequentially provided with a main pump chamber (42), an auxiliary pump chamber (43) and a measurement pump chamber (44) at the rear end, and is in an arc structure.

2. A ceramic chip pump chamber layer structure according to claim 1, characterized in that The main pump chamber (42), the auxiliary pump chamber (43) and the measurement pump chamber (44) are all in an arc profile.

3. The ceramic chip pump chamber layer structure of claim 1, wherein, A reference chamber (45) is further arranged at the head of the ceramic chip.

4. A ceramic chip pump chamber layer structure according to claim 3, wherein The reference chamber (45) is also in an arc structure.

5. A ceramic chip, characterized by The pump chamber layer (40) of any one of claims 1-4 is included.

6. A ceramic chip according to claim 5, wherein The ceramic chip is sequentially provided with an outer electrode layer (10), an upper ceramic sheet (20), a pump electrode layer (30), a pump chamber layer (40), a middle ceramic sheet (50), a heating layer (60) and a lower ceramic sheet (70) from top to bottom.

7. The ceramic chip of claim 5 wherein, The four corners of the outer surface of the ceramic chip are in an arc structure.

8. The ceramic chip of claim 6 wherein, The outer electrode layer (10) and the lower ceramic sheet (70) are both connected with contact pins.

9. The ceramic chip of claim 6 wherein, The pump electrode layer (30) includes a main pump electrode (31), an auxiliary pump electrode (32) and a measurement pump electrode (33); and a reference pump electrode (34) is arranged between the pump chamber layer (40) and the middle ceramic sheet (50).

10. A nitrogen oxide sensor, characterized by The ceramic chip of any one of claims 5-9 is included.

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