Lead-free oxygen sensor

Abstract

The utility model relates to a lead-free oxygen sensor. The sensor comprises a shell and an upper cover, an air inlet is formed in the upper cover, a communicating hole is formed in the shell, an electrochemical reaction layer and a partition plate are sequentially arranged in the shell from top to bottom, and a liquid injection opening is formed in the shell. A mounting groove for mounting the electrochemical reaction layer is formed in the upper end of the partition plate, an annular groove is coaxially formed in the peripheral surface of the partition plate, and the liquid injection opening is formed in the side wall of the shell and is opposite to the annular groove; an electrolyte channel is arranged on the partition plate and / or between the partition plate and the shell so that electrolyte in the annular groove can enter the electrochemical reaction layer in the mounting groove. And an air outlet is formed in the groove bottom of the mounting groove. The lead-free oxygen sensor with the structure not only solves the technical problem that the electrolyte is difficult to inject into the shell, but also can reduce the volume of the sensor in the vertical direction, and facilitates the miniaturization design of the lead-free oxygen sensor.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of electrochemical gas sensor, concretely relates to a leadless oxygen sensor. BACKGROUND

[0002] In the field of electrochemical gas sensor, the application range of oxygen sensor is extremely wide, and its market demand is almost equal to the sum of all other types of gas sensors. However, the traditional leaded oxygen sensor has many defects, such as the consumption of lead block generates PbO, which leads to the performance degradation of the sensor; the expansion of lead block can cause internal stress release, and then lead to electrolyte leakage, corrosion of the sensor shell and pins, and even pollution and damage to the PCB of the instrument, which seriously affects the service life of the sensor, and even may cause environmental pollution and personal safety problems. In addition, due to the high oxygen content in the air, the leaded oxygen sensor is exposed to the air for a long time, and the continuous reaction of oxygen and catalyst accelerates the service life attenuation of the sensor.

[0003] To solve the above problems, the industry has launched a long-life leadless oxygen sensor. At present, most of the leadless oxygen sensors are composed of a shell, a waterproof and breathable film, a working electrode, a reference electrode, a counter electrode, an electrolyte, a metal conductive wire and a pin, each pin is connected with the corresponding electrode by welding the metal conductive wire, and the shell is provided with an air inlet, an electrolyte injection port and an air outlet. With the continuous development of sensing technology, sensors are moving towards miniaturization. Miniature sensors have small size, light weight and low power consumption, and can be widely used in aerospace, medical treatment, environmental protection and other fields, and can also meet the needs of small devices and intelligent systems. After the volume of the leadless oxygen sensor becomes super miniaturized, it is still necessary to ensure that the performance of the sensor is consistent with that of the conventional market sensor, which makes the structural design of the super miniaturized sensor very important. The existing leadless oxygen sensor has the following shortcomings: the pin is not easy to spot weld the platinum wire, and the pin is also easy to be corroded by the electrolyte; 2: the electrolyte is not easy to inject; 3, the unreasonable structure design leads to large volume. Therefore, the purpose of the utility model is to optimize the internal structure layout, reduce the volume of the sensor, and the electrolyte is easy to inject and the pin is not easy to be corroded by the electrolyte. CONTENT OF THE UTILITY MODEL

[0004] The utility model aims to provide a leadless oxygen sensor to solve the technical problems of electrolyte not easy to inject and large volume in the prior art.

[0005] In order to achieve the above object, the utility model discloses a kind of leadless oxygen sensors using following technical solutions: a kind of leadless oxygen sensor, including shell and upper cover, upper cover is provided with air inlet hole, shell is provided with communication hole, shell is sequentially provided with electrochemical reaction layer and baffle from top to bottom in it, shell is provided with liquid injection port, the upper end of baffle is provided with the installation groove for the installation of electrochemical reaction layer, coaxial annular groove is provided on the outer circumferential surface of baffle, liquid injection port is arranged on the side wall of shell and is opposite to annular groove, electrolyte channel is provided on baffle and / or between baffle and shell to make electrolyte in annular groove enter electrochemical reaction layer in installation groove;Gas outlet is provided on the groove bottom of installation groove.

[0006] The upper groove wall of the annular groove is provided with a liquid passage that communicates the annular groove and the installation groove, and the liquid passage forms the electrolyte channel.

[0007] The upper end of the baffle has a first gap with the upper cover, and the outer circumferential surface of the baffle has a second gap with the shell, the second gap communicates with the annular groove, and the first gap and the second gap communicate and form the electrolyte channel.

[0008] The groove bottom of the installation groove is provided with a groove, and the gas outlet is arranged on the groove bottom of the groove. A waterproof and breathable membrane is arranged above the gas outlet in the groove.

[0009] The bottom plate of the inner cavity of the shell is provided with a positioning protrusion protruding upward, the communication hole penetrates the positioning protrusion from top to bottom, and the lower side of the baffle is provided with a positioning installation groove for positioning installation with the positioning protrusion.

[0010] The bottom plate of the inner cavity of the shell is provided with a needle, and the lower side of the baffle is provided with a containing groove for covering and accommodating the outer part of the upper end of each needle. The lower side of the baffle and the bottom plate of the inner cavity of the shell are sealingly arranged to avoid contact between the electrolyte and the needle.

[0011] The utility model has the advantages that the electrolyte is injected into the shell through the liquid injection port, directly enters the annular groove of the baffle, and then enters the electrochemical reaction layer in the installation groove through the electrolyte channel, thereby solving the technical problem of difficult injection of electrolyte into the shell. At the same time, the installation groove is arranged at the upper end of the baffle, and the electrochemical reaction layer is installed in the installation groove. This design can reduce the volume of the sensor in the up-down direction, which is beneficial to the miniaturization design of the leadless oxygen sensor. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a structure schematic diagram of an embodiment of the leadless oxygen sensor of the utility model;

[0013] Figure 2 It is Figure 1 It is a structure schematic diagram under another angle.

[0014] Figure 3 is Figure 1 the internal structure diagram of a lead-free oxygen sensor in

[0015] Figure 4 is the structure diagram of the partition plate in the figure;

[0016] Figure 5 is Figure 4 the structure diagram in another angle. DETAILED DESCRIPTION

[0017] In order to facilitate the understanding of the present application, the present application will be described in more detail below in conjunction with the drawings and specific embodiments. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms and is not limited to the embodiments described in the specification. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0018] It should be noted that, unless otherwise defined, the technical and scientific terms used in the specification are the same as the meanings commonly understood by those skilled in the art of the technology to which the present application belongs. The technical and scientific terms used in the specification are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0019] An embodiment of a lead-free oxygen sensor of the present application, as shown in Figures 1-4 , comprises a shell 1 and an upper cover 2, the upper cover 2 is provided with an air inlet hole 3, and the bottom of the shell is provided with a communication hole 6 communicating with the outside. The shell has an inner cavity, and the inner cavity of the shell is sequentially provided from top to bottom with an electrochemical reaction layer 8 and a partition plate 9. The electrochemical reaction layer 8 is the electrochemical reaction in this part, which includes a working electrode, a reference electrode, a counter electrode, a liquid absorbing cotton and a gas impermeable diaphragm, the liquid absorbing cotton is used to absorb the electrolyte, and the gas impermeable diaphragm is used to isolate the gas. The electrochemical reaction layer belongs to the prior art, and its specific structure and working principle will not be described in detail in this embodiment, and the mounting relationship between the working electrode, the reference electrode, the counter electrode, the liquid absorbing cotton and the gas impermeable diaphragm can be referred to the contents disclosed in CN 117147648A and CN 221405514 U.

[0020] In this embodiment, the structure of the partition plate is as shown in Figures 3-5As shown, the upper end of the partition 9 is provided with an installation groove 14, which is used for installing the electrochemical reaction layer 8. A vent 10 is provided on the bottom of the installation groove 14, connecting the electrochemical reaction layer 8 and the connecting hole 6, allowing gas generated in the counter electrode to pass through and be discharged from the housing through the connecting hole. A groove 15 is provided on the bottom of the installation groove 14, and the vent 10 is located on the bottom of the groove 15. A waterproof and breathable membrane (not shown in the figure) is provided in the groove above the vent to prevent electrolyte leakage. An annular groove 11 is coaxially provided on the outer circumferential surface of the partition 9, and a liquid injection port 4 is provided on the vertical sidewall of the housing. The liquid injection port 4 is positioned opposite to the annular groove 11, allowing liquid injected from the liquid injection port to directly enter the annular groove. In this embodiment, an electrolyte channel is provided on the partition and between the partition and the housing to allow the electrolyte in the annular groove to enter the electrochemical reaction layer in the installation groove. Specifically, the electrolyte channel has two parts. One part is a liquid passage 16 on the upper wall of the annular groove on the partition plate, which connects the annular groove and the mounting groove. The other part is that there is a first gap 12 between the upper end of the partition plate and the upper cover, and a second gap 13 between the outer peripheral surface of the partition plate and the shell. The second gap 13 is connected to the annular groove 11, and the first gap 12 and the second gap 13 are connected.

[0021] The bottom plate of the inner cavity of the housing has an upwardly protruding positioning protrusion 7, and a connecting hole 6 passes through the positioning protrusion vertically. The lower side of the partition has a positioning mounting groove 17 that mates with the positioning protrusion for easy installation of the partition in the inner cavity of the housing. The bottom plate of the inner cavity of the housing has pins 5. In this embodiment, there are 3 pins, and each pin is connected to a corresponding electrode by welding a metal conductive wire (not shown in the figure). In this embodiment, the pins and the housing are integrally formed together during the injection molding process. The lower side of the partition has a receiving groove 18 for covering and accommodating the upper part of each pin, and the lower side of the partition is sealed to the bottom plate of the inner cavity of the housing to prevent the electrolyte from contacting the pins and to protect the pins from corrosion by the electrolyte.

[0022] This utility model discloses a lead-free oxygen sensor. By optimizing the internal structural layout and reducing the sensor size, it achieves stable performance and is suitable for portable small devices or space-constrained applications. A partition is installed at the bottom of the housing. This partition allows gas generated by the counter electrode to pass through while simultaneously allowing a heat-fused waterproof and breathable membrane to prevent electrolyte leakage from the connecting holes. The annular groove on the partition is positioned opposite the liquid injection port on the side of the housing. Combined with the liquid passage, the first gap between the partition and the top cover, and the second gap between the partition and the interior of the housing, these elements form an electrolyte flow channel, thus solving the problem of difficult electrolyte injection into the housing. In this embodiment, a metal conductive wire is spot-welded to the pin at the bottom of the housing before the partition and electrochemical reaction layer are placed inside. The partition is connected to the bottom shell with epoxy adhesive. The inclusion of the receiving groove further protects the pin and significantly reduces the possibility of electrolyte corrosion.

[0023] In the above description of the present specification, unless otherwise explicitly specified and limited, the terms "fixed", "mounted", "connected" or "linked" and the like should be understood in a broad sense. For example, as to the term "connected", it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through an intermediate medium, or it can be internal communication of two elements or interaction relationship between two elements. Therefore, unless otherwise explicitly limited in the present specification, the above terms can be understood in the specific meaning in the present application by the person skilled in the art according to the specific circumstances.

[0024] According to the above description of the present specification, the person skilled in the art can also understand that the terms used, such as "upper", "lower", "front", "rear", "left", "right", "length", "width", "thickness", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", "center", "longitudinal", "transverse", "clockwise" or "counterclockwise" and the like indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings of the present specification, which is only for the purpose of facilitating the description of the present application and simplifying the description, and is not explicitly or implicitly indicated that the device or element involved must have the specific orientation, be constructed and operated in the specific orientation, therefore the above orientation or positional relationship terms cannot be understood or interpreted as a limitation on the present application.

[0025] In addition, the terms "first" or "second" and the like used in the present specification are terms used to refer to numbers or ordinal numbers only for the purpose of description, and cannot be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" or "second" can explicitly or implicitly include at least one of the features. In the description of the present specification, the meaning of "plurality" is at least two, for example, two, three or more, etc., unless otherwise explicitly specified and limited.

[0026] In other embodiments of the present application, the liquid passage can also be provided only on the partition plate; or the liquid passage can not be provided, and the electrolyte enters the electrochemical reaction layer in the mounting groove from the annular groove through the second gap and the first gap.

Claims

1. A lead-free oxygen sensor, comprising a housing and a top cover, wherein the top cover is provided with an air inlet, the housing is provided with a connecting hole, an electrochemical reaction layer and a partition are arranged sequentially from top to bottom inside the housing, and a liquid injection port is provided on the housing, characterized in that: The upper end of the partition is provided with an installation groove for installing the electrochemical reaction layer. An annular groove is coaxially provided on the outer circumferential surface of the partition. The liquid injection port is provided on the side wall of the shell and is opposite to the annular groove. An electrolyte channel is provided on the partition and / or between the partition and the shell to allow the electrolyte in the annular groove to enter the electrochemical reaction layer in the installation groove. A vent hole is provided on the bottom of the installation groove.

2. The lead-free oxygen sensor according to claim 1, characterized in that: The partition plate has a liquid passage on the upper wall of the annular groove that connects the annular groove and the mounting groove, and the liquid passage forms the electrolyte channel.

3. The lead-free oxygen sensor according to claim 1 or 2, characterized in that: There is a first gap between the upper end of the partition and the upper cover, and a second gap between the outer peripheral surface of the partition and the shell. The second gap is connected to the annular groove, and the first gap and the second gap are connected to form the electrolyte channel.

4. The lead-free oxygen sensor according to claim 1, characterized in that: The mounting groove has a groove at the bottom, an air outlet is located at the bottom of the groove, and a waterproof and breathable membrane is provided in the groove above the air outlet.

5. The lead-free oxygen sensor according to claim 1, characterized in that: The bottom plate of the inner cavity of the housing is provided with an upwardly protruding positioning protrusion, and the connecting hole passes through the positioning protrusion from top to bottom. The lower side of the partition is provided with a positioning mounting groove that cooperates with the positioning protrusion for positioning and installation.

6. The lead-free oxygen sensor according to claim 1, characterized in that: The bottom plate of the inner cavity of the housing is provided with pins, and the lower side of the partition is provided with a receiving groove for covering and accommodating the upper end of each pin. The lower side of the partition is sealed with the bottom plate of the inner cavity of the housing to prevent the electrolyte from contacting the pins.

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