Oxygen sensor and wire harness structure thereof

Abstract

The invention discloses an oxygen sensor and a wire harness structure thereof, the wire harness structure comprises an upper shield, an electrode porcelain seat, a terminal, a spring seat, a sealing plug and a wire, the upper shield is a cylindrical piece and comprises a first cylinder and a second cylinder, the diameter of the first cylinder is greater than that of the second cylinder, and a step for supporting the spring seat is formed at the joint of the first cylinder and the second cylinder; the upper end of the first cylinder is connected with an upper fastening cylinder body of a shell of a probe subassembly of the oxygen sensor in a tight fit manner, and the upper end of the electrode porcelain seat is propped against a riveted ceramic piece of the probe subassembly of the oxygen sensor; the spring seat comprises an annular elastic piece, a center hole and a plurality of vertical elastic pieces, an elastic support of the electrode ceramic seat is formed, the vertical elastic pieces extend in the same direction from the inner ring edge of the annular elastic piece and are perpendicular, and the outer ring edge of the annular elastic piece is supported on the step of the upper protective cover. The structure is simplified, the stress of the zirconium element is transferred to the upper shield, the overall robustness is improved, and the internal leakage of the oxygen sensor is effectively controlled.

Description

Technical Field

[0001] The invention relates to the field of automobile parts production and manufacturing, and in particular to an oxygen sensor. Background Art

[0002] Oxygen sensors are essential auto parts in the vehicle manufacturing industry. They are used to detect the oxygen content in the exhaust gas in the exhaust pipe of the automobile engine to determine the real-time air-fuel ratio of the engine. According to the different oxygen concentrations, the sensor will output different voltage signals to the engine electronic control module (ECM), which serves as an important basis for the closed-loop fuel correction and compensation control of the system. Due to the application of oxygen sensors, the engine can operate in an ideal air-fuel ratio state under most working conditions, thereby obtaining good emission characteristics and fuel economy.

[0003] The oxygen sensor uses a flat multilayer ceramic element as the basic element, in which the zirconium oxide layer is the core element. The working principle of the zirconium oxide element is equivalent to a simple solid primary battery. According to the principle of electrochemistry, there will be a potential difference between the electrodes on both sides due to the difference in oxygen ion concentration. Since the outer electrode is exposed to the exhaust gas, the oxygen ion concentration will change according to the actual working conditions, while the inner electrode is the reference air, and the oxygen ion concentration is constant. When the engine air-fuel ratio is lean, the oxygen ion concentration in the exhaust gas is relatively high, and the difference in oxygen ion concentration between the inner and outer electrodes is small, that is, the potential difference is small, and the output voltage signal of the oxygen sensor is close to 0V; conversely, when the air-fuel ratio is rich, the oxygen ion concentration in the exhaust gas is also relatively low, and the difference in oxygen ion concentration between the inner and outer electrodes is large, that is, the potential difference is large, and the output voltage of the sensor is close to 1V.

[0004] The current oxygen sensor, switch oxygen and line oxygen, the wiring harness structure adopts the method of fixing the electrode ceramic and the retaining frame, and riveting the upper shield to form a fixed structure for easy automated assembly. However, the disadvantage is that the zirconium element is easy to break and the production cost of the wiring harness is relatively high. Summary of the invention

[0005] The object of the present invention is to provide a wiring harness structure and an oxygen sensor using the wiring harness structure, so as to simplify the structure and make the zirconium element less likely to break, effectively control the internal leakage of the oxygen sensor, and improve the sealing performance.

[0006] To achieve the above-mentioned object, the present invention provides a wiring harness structure for an oxygen sensor, characterized in that it includes an upper shield and an electrode porcelain seat, a terminal, a spring seat, a sealing plug and a wire contained in the upper shield, wherein the terminal is mounted on the electrode porcelain seat, the electrode porcelain seat is supported on the spring seat, the spring seat is supported in the upper shield, the wire connects the terminal and passes through the sealing plug located at the lower end of the upper shield, wherein the upper shield is a cylindrical member, including a first cylinder and a second cylinder, the diameter of the first cylinder is larger than that of the second cylinder, so that the connection between the first cylinder and the second cylinder is A step for supporting the spring seat is formed at the spring seat; the upper end of the first cylinder is connected to the upper fastening cylinder of the shell of the probe subassembly of the oxygen sensor in a tight fit, and the upper end of the electrode porcelain seat abuts against the riveted ceramic part of the probe subassembly of the oxygen sensor; the spring seat includes an annular elastic sheet, a center hole and a plurality of vertical elastic sheets, forming an elastic support for accommodating and supporting the electrode porcelain seat, the plurality of vertical elastic sheets extend from the inner ring edge of the annular elastic sheet in the same direction and are perpendicular to the annular elastic sheet, and the outer ring edge of the annular elastic sheet is supported on the step of the upper shield.

[0007] As a preferred embodiment, the number of the plurality of vertical elastic sheets is 4 and they are evenly distributed along the inner ring edge of the spring seat.

[0008] As a preferred embodiment, the sealing plug is made of fluororubber.

[0009] As a preferred embodiment, the number of the terminals is four, one end of the terminal is a spring seat with a contact, and the other end is used to fix the wire, and the four terminals are respectively connected to the four wires; the terminals are opposite to each other in pairs to clamp and fully contact the zirconium element; two of the four wires are used to heat the zirconium element, and the other two wires are used to transmit signals.

[0010] As a preferred embodiment, the electrode porcelain seat has a through hole for accommodating the terminal and the wire, and the step of the through hole cooperates with the protrusion of the terminal to support and position the terminal.

[0011] On the other hand, the present invention further provides an oxygen sensor, which includes the aforementioned wiring harness structure and a probe subassembly.

[0012] As a preferred embodiment, the probe subassembly includes a zirconium element, a shell, a ceramic part, a sealing material and a lower shield, wherein the zirconium element is a long strip with a rectangular cross-section, arranged to pass through the shell and the ceramic part and the sealing material located in the shell along the central axis of the shell; the shell is a U-shaped cylindrical shell, including an upper opening, a shell bottom, and a cylindrical hollow portion extending from the upper opening to the shell bottom, and the outer surface of the shell starts from the upper opening and includes an upper opening edge, an upper fastening cylinder, a shoulder, a lower connecting threaded cylinder, and a lower shield connecting flange connected in sequence along the central axis, wherein the shell bottom has a shell bottom plane, the lower shield connecting flange extending vertically along the edge of the shell bottom plane, and a rectangular cross-section. a through hole located at the central axis of the shell for the zirconium element to pass through; the upper fastening cylinder is used to connect the upper shield of the oxygen sensor by a tight fit; the lower shield connecting flange is used to connect the lower shield; the outer surface of the lower connecting threaded cylinder has threads for connecting the interface threads of the vehicle exhaust pipe; the sealing material fills the lower part of the cylindrical hollow part and is in close contact with the surface of the zirconium element and the cylindrical hollow part; the sealing material includes 30% to 50% talcum powder, 30% to 50% glass powder and 10% to 15% magnesium stearate; the ceramic part is located at the upper part of the cylindrical hollow part, pressed on the sealing material, and fixed by riveting the upper opening edge.

[0013] As a preferred embodiment, the lower shield has an outer tube and an inner tube, the outer tube has a flange, the lower shield connecting flange is riveted onto the flange of the outer tube, and when the lower shield connecting flange is riveted onto the flange, the top end of the inner tube rests on the bottom plane of the shell.

[0014] As a preferred method, the preparation of the sealing material includes the following process: weigh the components of the sealing material according to the ratio, put them into a stirrer, add appropriate amount of pure water to stir evenly, put them into an oven for drying, keep the moisture content at 5% after drying, and granulate them with an 80-mesh or 100-mesh sieve.

[0015] As a preferred method, the assembly process of the probe subassembly is: take the zirconium element; place the zirconium element into the shell; inject an appropriate amount of the granulated sealing material; press-fit the ceramic part: press-fit the ceramic part into a fixed position, and rivet the upper opening edge to encapsulate it; sinter and solidify: put the pressed probe subassembly into a high-temperature furnace, heat it to 650°C~700°C, keep it warm for 20-60 minutes, and cool it down with the furnace.

[0016] The oxygen sensor for detecting oxygen content in the automobile exhaust system of the present invention detects oxygen concentration and feeds it back to the vehicle ECU for closed-loop control to correct the fuel injection amount, so as to achieve optimal emission.

[0017] On the one hand, the wiring harness structure of the oxygen sensor in the prior art is to fix the electrode ceramic and the retaining frame, and rivet and press with the upper shield to form a fixed structure, which is convenient for automated assembly. However, the problem with this structure is that the stress point is on the zirconium element itself rather than the upper shield, which makes the zirconium element prone to breakage due to uneven stress. In addition, the wiring harness structure of the prior art is complex and the material production cost is high. Moreover, the retaining frame is riveted, the process is complex and the production cost is high. The focus of the present invention is to first change the design, that is, to simplify the structure and process to reduce the cost of wiring harness production, and improve the force distribution of zirconium element assembly.

[0018] Compared with the prior art, the wiring harness structure of the present invention has the following changes: 1. The structure has been fundamentally improved, the retaining frame has been eliminated and replaced with a new spring seat, which simplifies the structure and reduces material costs; 2. The structure has been changed, the retaining frame riveting has been eliminated, the manufacturing process has been reduced, and the process cost has been reduced; 3. The structure has been fundamentally improved, so that the force of the zirconium element is transferred to the upper shield, and the unbalanced force buffer of the zirconium element is increased to increase the overall robustness.

[0019] On the other hand, the oxygen sensors of the prior art, whether heated or non-heated, switch type or wide-range type, generally use talcum powder and ceramic insulators to seal by one or more press-fitting. The quality of the seal determines the accuracy of the sensor signal. The current problem is that internal leakage is difficult to control, and the structure is complex and the cost is high. The focus of the present invention is to change the design, that is, to reduce the cost and solve the sealing problem at the same time.

[0020] Compared with the prior art, the oxygen sensor of the present invention can effectively control the internal leakage of the oxygen sensor, has high sealing performance, is not easy to fall off powder, and avoids pollution; and its structure is simple and the cost is low, which is extremely beneficial to product production and market promotion.

[0021] Therefore, the present invention has the following advantages:

[0022] 1. The structure of the product is greatly simplified compared with the existing technology, which reduces the material cost.

[0023] 2. Brand-new sealing materials and brand-new curing structure have greatly improved the stability of sealing control and effectively prolonged the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a cross-sectional schematic diagram of an embodiment of the wiring harness structure of an oxygen sensor of the present invention.

[0025] Figure 2 It is an exploded view of an embodiment of the wiring harness structure of an oxygen sensor of the present invention.

[0026] Figure 3 It is a cross-sectional schematic diagram of an oxygen sensor embodiment of the present invention.

[0027] Figure 4 The figure is a cross-sectional schematic diagram of an upper protective cover of an embodiment of a wiring harness structure of an oxygen sensor of the present invention.

[0028] Figure 5 This is a perspective view of a terminal of an embodiment of a wiring harness structure of an oxygen sensor according to the present invention.

[0029] Figure 6 The present invention is a stereoscopic view of an electrode porcelain seat of an oxygen sensor wiring harness structure embodiment of the present invention.

[0030] Figure 7 It is a stereoscopic view of a sealing plug of an embodiment of a wiring harness structure of an oxygen sensor of the present invention.

[0031] Figure 8 The present invention is a perspective view of a spring seat of an embodiment of a wiring harness structure of an oxygen sensor.

[0032] Fig. 9 It is a front view of a spring seat of an embodiment of a wiring harness structure of an oxygen sensor of the present invention.

[0033] Fig.10 It is a cross-sectional schematic diagram of an embodiment of a probe subassembly of an oxygen sensor of the present invention.

[0034] Fig.11 It is a schematic perspective structural diagram of a part of an embodiment of a probe subassembly of an oxygen sensor of the present invention, without showing a lower shield and a zirconium element.

[0035] Fig.12 It is a schematic cross-sectional view of the shell of the probe subassembly embodiment of the present invention. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of an oxygen sensor of the present invention will be described with reference to the accompanying drawings.

[0037] The embodiments described herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention, are illustrative and exemplary, and should not be interpreted as limiting the embodiments of the present invention and the scope of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the claims and the contents disclosed in the specification of this application, including any obvious replacement and modification of the embodiments described herein.

[0038] The drawings in this specification are schematic diagrams, which assist in explaining the concept of the present invention and schematically show the shapes of various parts and their mutual relationships.

[0039] Figure 1 It is a cross-sectional schematic diagram of an embodiment of the wiring harness structure of an oxygen sensor of the present invention. Figure 2It is an exploded view of an embodiment of the wiring harness structure of an oxygen sensor of the present invention. Figure 3 It is a cross-sectional schematic diagram of an oxygen sensor embodiment of the present invention. Figure 4-9 The parts drawings of the upper shield, terminal, electrode porcelain seat, sealing plug and spring seat are shown respectively.

[0040] like Figure 3 As shown, the oxygen sensor of the present invention includes a probe subassembly and a wiring harness structure.

[0041] Referring to 1 and 2 again, the wiring harness structure of the oxygen sensor of the present invention includes an upper shield 5 and an electrode porcelain seat 1, a terminal 2, a spring seat 3, a sealing plug 4 and a wire 6 accommodated in the upper shield 5.

[0042] The terminal 2 is installed on the electrode porcelain seat 1, the electrode porcelain seat 1 is supported on the spring seat 3, the spring seat 3 is supported in the upper protective cover 5, and the wire 6 is connected to the terminal 2 and passes through the sealing plug 4 located at the lower end of the upper protective cover 5.

[0043] The upper shield 5 is a cylindrical member, including a first cylinder and a second cylinder. The diameter of the first cylinder is larger than that of the second cylinder, so that a step for supporting the spring seat 3 is formed at the connection between the first cylinder and the second cylinder.

[0044] The upper end of the first cylinder is connected to the upper fastening cylinder of the shell of the probe sub-assembly in a tight fit, and the upper end of the electrode porcelain seat 1 abuts against the riveted ceramic part of the probe sub-assembly of the oxygen sensor.

[0045] The spring seat 3 includes an annular elastic sheet, a center hole and four vertical elastic sheets, forming an elastic support for accommodating and supporting the electrode porcelain seat 1. The four vertical elastic sheets extend from the inner ring edge of the annular elastic sheet in the same direction and are perpendicular to the annular elastic sheet. The outer ring edge of the annular elastic sheet is supported on the step of the upper shield 5.

[0046] The number of the four vertical elastic pieces is evenly distributed along the inner ring edge of the spring seat 3. Although the embodiment shows four vertical elastic pieces, those skilled in the art will appreciate that the number of the vertical elastic pieces can be set as required, for example, 2, 3, 6, 8, etc.

[0047] The sealing plug 4 is made of fluororubber or silicone rubber to resist high temperature, preferably fluororubber. The sealing plug 4 has through holes for passing the wire 6, and the number of through holes is 4 in this embodiment.

[0048] There are four terminals 2, one end of which is a spring seat with a contact, and the other end is used to fix the wire 6. The four terminals 2 are respectively connected to four wires 6. The terminals 2 are opposite to each other to clamp and fully contact the zirconium element. The clamping force of the terminal 2 clamping the zirconium element is about 20N, for example.

[0049] Two of the four wires 6 are used to heat the zirconium element, and the other two are used to transmit signals. The zirconium element has two sides, one is a heating layer with positive and negative poles, and the other is a signal layer with two electrode pins, namely a signal terminal and a ground terminal.

[0050] The electrode porcelain base 1 has a through hole for accommodating the terminal 2 and the wire 6, and the step of the through hole cooperates with the protrusion of the terminal 2 to support and position the terminal 2.

[0051] The wiring harness structure of the present invention adopts a new spring seat, which simplifies the structure and reduces material costs; the riveting of the retaining frame is eliminated, the manufacturing process is reduced, and the process cost is reduced; in addition, the structure is fundamentally improved, so that the force of the zirconium element is transferred to the upper shield, and the unbalanced force buffer of the zirconium element is increased, thereby increasing the overall robustness.

[0052] Fig.10 It is a cross-sectional schematic diagram of an embodiment of a probe subassembly of an oxygen sensor of the present invention. Fig.11 It is a schematic perspective structural diagram of a part of an embodiment of a probe subassembly of an oxygen sensor of the present invention, without showing a lower shield and a zirconium element. Fig.12 It is a schematic cross-sectional view of the shell of the probe subassembly embodiment of the present invention.

[0053] like Fig.10 , 11 As shown in FIG. 12 , the probe subassembly embodiment of the oxygen sensor of the present invention includes a housing 7, a sealing material 8, a ceramic member 9, a zirconium element 10 and a lower shield 13. The probe subassembly is as shown in FIG. Fig.12 Shown with a central axis.

[0054] The zirconium element 10 is a long strip with a rectangular cross section, and is arranged to pass through the housing 7 and the ceramic member 9 and the sealing material 8 located in the housing 7 along the central axis of the housing 7. A heating circuit is printed on the surface of the zirconium element 10, and the heating circuit includes a heating resistor for heating the zirconium element 10.

[0055] The shell 7 is a U-shaped cylindrical shell, including an upper opening 16, a shell bottom, and a cylindrical hollow portion extending from the upper opening 16 to the shell bottom. The outer surface of the shell 7 includes an upper opening edge, an upper fastening cylinder, a shaft shoulder 11, a lower connecting threaded cylinder, and a lower shield connecting flange 141 along the central axis starting from the upper opening 16. Please note that these parts of the outer surface of the shell 7 are connected in sequence without any gaps.

[0056] The shell bottom has a shell bottom plane 14, a lower shield connection flange 141 and a through hole 17. The lower shield connection flange 141 extends vertically along the edge of the shell bottom.

[0057] The through hole 17 is located at the central axis of the housing 7 and has a rectangular cross section for the zirconium element 10 to pass through. The maximum value of the gap between the four surfaces of the rectangular through hole 17 and the corresponding four surfaces of the zirconium element 10 is 0.1 mm.

[0058] See also Figure 3 The lower shield 13 has an outer tube 13-1 and an inner tube 13-2, and the outer tube 13-1 has a flange. The lower shield connection flange 141 is used to connect the lower shield 13. The lower shield 13 and the shell 7 are connected by riveting the lower shield connection flange 141 on the flange of the outer tube 13-1. When the lower shield connection flange 141 is riveted to the flange of the outer tube 13-1, the top of the inner tube 13-2 abuts against the shell bottom plane 14. It is preferred to rivet the entire lower shield connection flange 141 on the flange of the outer tube 13-1, so that firstly, it is ensured that the gas enters from the opening of the lower shield instead of leaking in from the gap; secondly, it makes the fixation more tight.

[0059] See also Figure 4 The upper fastening cylinder is used to connect the upper shield 5 of the oxygen sensor through a tight fit.

[0060] The outer surface of the lower connecting threaded barrel has threads for connecting the interface threads of the vehicle exhaust pipe. In this embodiment, the outer surface threads of the lower connecting threaded barrel extend along the entire length of the lower connecting threaded barrel and have a back cutter groove.

[0061] The sealing material 8 fills up the lower part of the cylindrical hollow portion, and is in close contact with the zirconium element 10 and the surface of the cylindrical hollow portion.

[0062] The ceramic part 9 is located at the upper part of the cylindrical hollow part, and is pressed on the sealing material 8. The ceramic part 9 is fixed by riveting the upper opening edge. It is preferred to rivet the entire upper opening edge on the ceramic part 9 to secure the parts. If distributed riveting points are used, the parts may be easily loosened.

[0063] The cylindrical hollow part is filled with the ceramic part 9 and the sealing material 8, except for the margin of the upper opening edge for pressing the ceramic part 9. The sealing material 8 occupies most of the space of the cylindrical hollow part, and the ceramic part 9 only occupies a small part of the space of the cylindrical hollow part. The height of the sealing material 8 occupies, for example, five-sixths, four-fifths, etc. of the height of the cylindrical hollow part, and the height of the ceramic part 9 occupies, for example, one-sixth, one-fifth, etc. of the height of the cylindrical hollow part.

[0064] In this embodiment, the shoulder 11 is hexagonal. The shoulder 11 is used to install and rotate the probe sub-assembly, and can also be quadrilateral or pentagonal, or circular, or have a knurled surface.

[0065] The sealing material 8 is formed at the lower portion of the cylindrical hollow portion by sintering.

[0066] The proportion of the sealing material 8 is as follows:

[0067] 1. 30% to 50% talcum powder, the main component of talcum powder is magnesium silicate, which is used as the main material of the sealing material 8;

[0068] 2.30% to 50% glass powder, the softening temperature of glass powder is 600-700℃, and talcum powder is blended together to improve air tightness.

[0069] 3.10% to 15% magnesium stearate. Magnesium stearate is used as a lubricant to facilitate powder flow and granulation during the powder production process.

[0070] The preparation process of the sealing material 8 is as follows:

[0071] Talc powder, glass powder and magnesium stearate are weighed according to the determined ratio, the powder mixture is put into a blender, and an appropriate amount of purified water is added and stirred evenly. After that, the stirred evenly mixed mixture is put into an oven for drying. After drying, the sealing material 8 is kept to contain 5% of water, and granulated with an 80-mesh or 100-mesh screen.

[0072] The probe subassembly assembly of the present invention comprises the following steps:

[0073] First, take the zirconium element 10;

[0074] Secondly, the zirconium element 10 is placed in the housing 7;

[0075] Afterwards, inject an appropriate amount of granulated sealing material 8;

[0076] Next, press-fit the ceramic part 9: press-fit the ceramic part 9 to a fixed position and rivet and seal it, that is, rivet and press the edge of the opening 16 of the central cylindrical cavity of the housing 7 to fix the ceramic part 9;

[0077] Finally, sintering and curing: put the pressed oxygen sensor probe subassembly into a high-temperature furnace, heat it to 650℃~700℃, keep it warm for 20-60min, and cool it down with the furnace. Please note that the sintering and holding time can be preferably 20min, 30min, 40min, but should not be less than 20min, because production is generally batch production, and there is a heat radiation process during sintering. The minimum time is guaranteed to heat through a batch of sintered parts.

[0078] A leakage comparison test was conducted between the oxygen sensor of the present invention and the oxygen sensor of the prior art, and the steps are as follows:

[0079] 1. Take the oxygen sensor probe subassembly pressed by the existing talc block as a comparison part, measure the leakage value and record it;

[0080] 2. Take the prepared sealing material 8, install the zirconium element 10 into the housing 7, fill the sealing material 8 and compact it, install the ceramic part 9 into the housing 7, press and rivet, measure the leakage value and record it;

[0081] 3. Assemble the oxygen sensor of the existing technology, measure the leakage value and record it;

[0082] 4. Place the assembled comparison parts and test parts in a high-temperature furnace and keep them at 650℃ for 30 minutes (high temperature and insulation to simulate the high temperature of actual vehicle testing). After the furnace cools down to room temperature, test the leakage values ​​of the comparison parts and test parts respectively and record them.

[0083] The results of the comparative test are as follows:

[0084]

[0085]

[0086] It can be seen from the test results that the leakage value of the talc block of the oxygen sensor of the prior art increased by 0.07-0.08cc after high-temperature sintering, an increase of about 40%. However, the sealing structure and sealing material 8 of the oxygen sensor of the present invention reduced the leakage value by 0.05-0.06cc after high-temperature sintering, which is about 25% lower than that of the prior art; therefore, the oxygen sensor of the present invention has a positive effect on improving the leakage rate.

[0087] At the same time, the oxygen sensor of the present invention improves the sealing structure, effectively reduces the number of parts and components, and greatly reduces the production cost.

[0088] The oxygen sensor of the present invention can effectively control the internal leakage of the oxygen sensor, has high sealing performance, is not easy to fall off powder, and avoids pollution; and the oxygen sensor of the present invention has a simple structure and low cost, which is extremely beneficial to product production and market promotion.

[0089] The present invention has the following advantages over the prior art:

[0090] 1. The structure of the product is greatly simplified compared with the existing technology, which reduces the material cost.

[0091] 2. The new sealing material 8 and the new curing structure greatly improve the stability of sealing control and effectively extend the service life of the product.

[0092] The above description of the embodiments of the oxygen sensor of the present invention is intended to explain the spirit of the present invention. Please note that those skilled in the art can modify and combine the features of the above embodiments without departing from the spirit of the present invention. Therefore, the present invention is not limited to the above embodiments. The specific features of the oxygen sensor, such as shape, size and position, can be specifically designed based on the effects of the features disclosed above, and these designs can be implemented by those skilled in the art. Moreover, the technical features disclosed above are not limited to the combination with other features disclosed. Those skilled in the art can also make other combinations between the technical features according to the purpose of the invention, so as to achieve the purpose of the present invention.

Claims

1. A wiring harness structure for an oxygen sensor, characterized in that: It includes an upper shield and an electrode porcelain seat, a terminal, a spring seat, a sealing plug and a wire contained in the upper shield. The terminal is mounted on the electrode porcelain seat, the electrode porcelain seat is supported on the spring seat, the spring seat is supported in the upper shield, the wire is connected to the terminal and passes through the sealing plug at the lower end of the upper shield, wherein: The upper shield is a cylindrical member, comprising a first cylinder and a second cylinder, wherein the diameter of the first cylinder is larger than that of the second cylinder, so that a step for supporting the spring seat is formed at the connection between the first cylinder and the second cylinder; The upper end of the first cylinder is connected to the upper fastening cylinder of the shell of the probe subassembly of the oxygen sensor in a tight fit, and the upper end of the electrode porcelain seat abuts against the riveted ceramic part of the probe subassembly of the oxygen sensor; The spring seat includes an annular elastic sheet, a center hole and a plurality of vertical elastic sheets, forming an elastic support for accommodating and supporting the electrode porcelain seat. The plurality of vertical elastic sheets extend in the same direction from the inner ring edge of the annular elastic sheet and are perpendicular to the annular elastic sheet. The outer ring edge of the annular elastic sheet is supported on the step of the upper shield.

2. The wiring harness structure according to claim 1, characterized in that: The number of the plurality of vertical elastic sheets is 4 and they are evenly distributed along the inner ring edge of the spring seat.

3. The wiring harness structure according to claim 1, characterized in that: The sealing plug is made of fluororubber.

4. The wiring harness structure according to claim 1, characterized in that: There are four terminals, one end of each terminal is a spring seat with a contact, and the other end is used to fix the wire, and the four terminals are respectively connected to four wires; The terminals are opposite to each other in pairs to clamp and fully contact the zirconium element; and Two of the four wires are used for heating the zirconium element, and the other two wires are used for transmitting signals.

5. The wiring harness structure according to claim 1, characterized in that: The electrode porcelain seat has a through hole for accommodating the terminal and the wire, and the step of the through hole cooperates with the protrusion of the terminal to support and position the terminal.

6. An oxygen sensor, characterized in that: It comprises a wiring harness structure as described in any one of claims 1 to 5, and a probe sub-assembly.

7. The probe subassembly according to claim 6, characterized in that: The probe subassembly includes a zirconium element, a housing, a ceramic component, a sealing material and a lower shield, wherein: The zirconium element is a long strip with a rectangular cross section, and is arranged to pass through the shell and the ceramic member and the sealing material located in the shell along the central axis of the shell; The shell is a U-shaped cylindrical shell, including an upper opening, a shell bottom, and a cylindrical hollow portion extending from the upper opening to the shell bottom. The outer surface of the shell includes an upper opening edge, an upper fastening cylinder, a shaft shoulder, a lower connecting threaded cylinder, and a lower shield connecting flange connected in sequence along the central axis from the upper opening, wherein: The shell bottom has a shell bottom plane, a lower shield connecting flange extending vertically along the edge of the shell bottom plane, and a through hole with a rectangular cross section, the through hole is located at the central axis of the shell and is used for the zirconium element to pass through; The upper fastening cylinder is used to connect the upper shield of the oxygen sensor through a tight fit; The lower shield connecting flange is used to connect the lower shield; The outer surface of the lower connecting threaded cylinder has threads for connecting to the interface threads of the vehicle exhaust pipe; The sealing material fills the lower part of the cylindrical hollow part and is in close contact with the zirconium element and the surface of the cylindrical hollow part; the sealing material comprises 30% to 50% talc powder, 30% to 50% glass powder and 10% to 15% magnesium stearate; The ceramic piece is located at the upper part of the cylindrical hollow part and is pressed onto the sealing material. The ceramic piece is fixed by riveting the upper opening edge.

8. The probe subassembly according to claim 6, characterized in that: The lower shield has an outer tube and an inner tube, the outer tube has a flange, the lower shield connection flange is riveted on the flange of the outer tube, and when the lower shield connection flange is riveted on the flange, the top end of the inner tube abuts against the shell bottom plane.

9. The probe subassembly according to claim 6, characterized in that: The preparation of the sealing material includes the following process: weigh the components of the sealing material according to the ratio, put them into a stirrer, add appropriate amount of pure water to stir them evenly, put them into an oven for drying, keep the moisture content at 5% after drying, and granulate them with an 80-mesh or 100-mesh screen.

10. The probe subassembly according to claim 6, characterized in that: The assembly process of the probe subassembly is as follows: Taking the zirconium element; placing the zirconium element into a housing; injecting an appropriate amount of the granulated sealing material; Press-fitting the ceramic piece: press-fitting the ceramic piece to a fixed position, and riveting the upper opening edge to seal it; Sintering and curing: Place the pressed probe subassembly into a high-temperature furnace, heat it to 650℃~700℃, keep it warm for 20-60min, and then cool it down with the furnace.

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