KR101944278B1 - Electrochemical gas sensor with flat plate type case - Google Patents

Abstract

The present invention relates to an electrochemical gas sensor having a metal electrode structure which is stably fixed to a case and is easy to assemble, including a case including an empty accommodation space therein and configured such that a detection target gas can be introduced into the accommodation space; an electrolyte disposed in the accommodation space; a soft material-based electrode portion including acting, counter, and reference electrodes, installed in the accommodation space, performing electrolysis in contact with the electrolyte, and capable of detecting a change in current generated in accordance with the concentration at which the detection target gas is dissolved in the electrolyte; and a fixing portion configured to include three metal electrodes electrically connecting each of the electrodes of the electrode portion to the outside, the end of the metal electrode positioned in the case being bent at 90 degrees on a two-dimensional plane parallel to the bottom. In the structure of the present invention, the fixing portion for fixing the metal electrode in the case is bent at 90 degrees to the left or right on a two-dimensional plane parallel to the bottom, and thus the case can be manufactured and assembled with ease as compared with an existing structure based on double upward bending and coupling. In addition, the fixed state can be stably maintained. Further, it is possible to configure a very small, low-power, and long-life electrochemical gas sensor having a plate-like outer shape with a low height.

Description

[0001] ELECTROCHEMICAL GAS SENSOR WITH FLAT PLATE TYPE CASE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a metal electrode that electrically connects a gas sensor to the outside, and more particularly to an electrochemical gas sensor having a specific metal electrode structure.

Generally, a gas sensor for detecting a gas present in the atmosphere includes a semiconductor gas sensor in which a catalyst is added to a metal oxide semiconductor material such as tin oxide, a solid electrolyte gas sensor in which zirconia is the main material, An optical gas sensor that detects the wavelength of the ultraviolet light emission, and an electrochemical gas sensor that measures the current intensity generated by the electrode reaction in the redox reaction in the electrolyte of the gas.

Among these, the electrochemical gas sensor is capable of detecting a large number of gases such as combustible gas, toxic gas and environmental gas, and has a characteristic of being able to measure even a low concentration of several ppm (ppm). Therefore, Research is also actively proceeding.

The electrochemical gas sensor includes three electrodes and an electrolyte, which are divided into a working electrode, a counter electrode, and a reference electrode. The electrolytic gas sensor includes an electrolytic solution having a constant potential between a working electrode and a reference electrode, And the magnitude of the electrolytic current generated between the working electrode and the counter electrode is detected to detect the presence or absence of the gas and its concentration. At this time, it is possible to quantitatively detect the specific gas by advancing the oxidation and reduction reaction selectively by changing the specific potential according to the type of gas to be detected.

A metal electrode for electrically connecting the three electrodes included in the electrochemical gas sensor to the outside is connected to each electrode. The metal electrode is fixed to the case of the electrochemical gas sensor. One end of the metal electrode is inserted into the case and contacts one of the working electrode, the counter electrode and the reference electrode. The other end is connected to an external electric circuit from outside the case. Japanese Patent No. 4204292 discloses a structure in which a metal electrode is stably fixed to a case of an electrochemical gas sensor so as to be in contact with an electrode, and Japanese Patent No. 4204292 discloses a structure in which a first bent portion bent upward in the case, And a second bent portion bent in the horizontal direction.

However, due to the structure in which the metal electrode is bent twice inside the case, it is difficult to install the metal electrode after first fabricating the case, so that it is difficult to process the case in which the metal electrode is injected in the injection process of the case Furthermore, since the metal electrode is bent in the upward direction, the height of the electrochemical gas sensor is increased, which is not suitable for miniaturization of the sensor.

Japanese Patent No. 4204292

It is an object of the present invention to provide an electrochemical gas sensor having a metal electrode structure which is stably fixed in a case of an electrochemical gas sensor and easy to assemble.

According to an aspect of the present invention, there is provided an electrochemical gas sensor having a flat plate-like external shape and having a low height and including a hollow accommodation space therein, the case being configured to allow a detection target gas to flow into the accommodation space; An electrolyte disposed in the accommodation space; A counter electrode and a reference electrode provided in the accommodation space and capable of detecting a change in current generated in contact with the electrolyte to perform electrolysis and a concentration of the detection target gas dissolved in the electrolyte, An electrode part made of a flexible material; And three metal electrodes electrically connecting each of the electrodes of the electrode unit to the outside, wherein the metal electrode includes a fixing unit having an end located inside the case and bent at 90 degrees on a two-dimensional plane parallel to the bottom .

The present invention is characterized by a structure of a metal electrode for electrically connecting a working electrode to a counter electrode and a reference electrode in an electrochemical gas sensor. More specifically, the present invention provides a two-dimensional A 90 ° bent structure is applied to the left or right side of the plane. With this structure, it is possible to easily assemble the case and the metal electrode, to maintain a mechanically stable structure, to increase the contact area with the electrode, and to reduce the height of the electrochemical gas sensor, There are advantages.

At this time, a supporting structure corresponding to the shape of the fixing portion is formed in the case, and the metal electrode is stably fixed by being inserted and positioned in the supporting structure. The case is preferably formed of a lower case having a receiving space and an upper case covering the receiving space, and the supporting structure is formed in the lower case and the metal electrode is installed in the lower case. It is preferable that the supporting structure has a structure having a height and shape such that the upper surface of the metal electrode can be exposed to the electrode of the electrode part.

Meanwhile, it is preferable that the metal electrode has a structure in which the middle portion thereof is bent at an angle of 90 deg. So that the end portion exposed to the outside of the case, that is, the side opposite to the fixed portion faces downward. The end of the metal electrode is directed downward and is directly connected to an external terminal, so that the electrochemical gas sensor can be installed in a state in which it is kept horizontal.

It is preferable that the surface of the metal electrode contacting the case is subjected to a knurling treatment so that the metal electrode is more stably fixed.

The material of the metal electrode is not limited as long as it is an electrically connectable material, but it is preferably made of a material containing one of tantalum (Ta), titanium (Ti) and nickel (Ni).

The present invention constructed as described above has a structure in which the fixing portion for fixing the metal electrode in the case is formed by being bent at 90 degrees to the left or right on a two-dimensional plane parallel to the floor, It is possible to manufacture and assemble the case easily.

In addition, a support structure corresponding to the fixed portion of the metal electrode is formed in the case, thereby stably maintaining the fixed state.

In addition, the area of contact with the electrode of the electrode portion is increased through the structure bent on the two-dimensional plane, and the height of the electrochemical gas sensor is reduced, thereby producing a micro electrochemical gas sensor of a flat plate-like outer shape.

Further, the electrochemical gas sensor to which the structure of the present invention is applied has the effect of reducing the electric power used and increasing the service life.

1 is an exploded perspective view illustrating a structure of a metal electrode of an electrochemical gas sensor according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanying drawings, embodiments of the present invention will be described in detail.

The electrochemical gas sensor of the present invention comprises a case, an electrolyte disposed in the accommodation space inside the case, and an electrode unit provided in the accommodation space.

The case is a body constituting the electrochemical gas sensor. A housing space is formed in the housing, and a ventilation hole is formed so that air containing the gas to be detected can be introduced into the housing space. A filter is provided in the ventilation hole to block the inflow of moisture or dust from the outside, and the configuration of the ventilation hole for the inflow of gas and the filter can be applied without limitation to the general gas sensor technology without impairing the characteristics of the present invention , And a detailed description thereof will be omitted.

The electrolyte is electrolyzed by the current applied between the working electrode and the reference electrode while the detection target gas introduced through the vent of the case dissolves and the current between the working electrode and the counter electrode changes, Since it has the same function as the electrolyte of the sensor, its detailed description is omitted.

The electrode unit includes a working electrode, a reference electrode for electrolyzing the working electrode and the electrolyte, and a counter electrode for measuring an electrolytic current generated between the working electrode and the working electrode. The electrode unit of the conventional electrochemical gas sensor can be applied to all of them, and thus a detailed description thereof will be omitted.

The metal electrode has a structure for electrically connecting the electrodes included in the electrode portion to the outside. The metal electrode is in contact with the electrodes of the electrode portion inside the case at one end and exposed to the outside of the case at the other end, Lt; / RTI > The material of the metal electrode may be any material used in conventional electrochemical gas sensors such as tantalum (Ta), titanium (Ti), and nickel (Ni).

The present invention includes the general construction of the electrochemical gas sensor described above, but differs from the conventional technology in the specific structure of the metal electrode.

Hereinafter, the specific structure of the metal electrode, which is a characteristic part of the present invention, will be described.

1 is an exploded perspective view illustrating a structure of a metal electrode of an electrochemical gas sensor according to an embodiment of the present invention.

In the electrochemical gas sensor of this embodiment, three metallic electrodes 210, 220 and 230 are provided in the case 100.

Although not shown, the case 100 may have a housing space, and may be divided into an upper case and a lower case. In this embodiment, a metal case is provided in the lower case, but the present invention is not limited thereto.

Each of the three metal electrodes 210, 220, and 230 installed in the lower case contacts one of the working electrode, the counter electrode, and the reference electrode. Specifically, the electrode unit is positioned on the upper side of the metal electrodes 210, 220, and 230, and the electrodes formed on the electrode units are disposed to contact the upper surfaces of the metal electrodes 210, 220, and 230.

The three metal electrodes 210, 220, and 230, which are in contact with the working electrode, the counter electrode, and the reference electrode, respectively, are the same in structure. Therefore, one metal electrode 210 will be described as a representative structure.

The metal electrode 210 of the present embodiment includes a body 212, a fixing portion 214 at both ends, and an external connection portion 215.

The body 212 has a straight line structure that is located between the outside and the inside of the case 100.

The fixing part 214 is a part connected to the end of the body 212 inside the case 100 and has a structure bent to the left or right on a two-dimensional plane. A supporting structure 110 is formed in the case 100 in a shape corresponding to the bent shape of the fixing portion 214. The fixing portion 214 is inserted into the supporting structure 110 to be positioned on the metal electrode 210, The metal electrode 210 can be prevented from moving inside the case 100. [0050] In addition,

At this time, the body 212 connected to the fixing portion 214 and the fixing portion 214 must be exposed to the supporting structure 110 without being completely covered with the electrode formed on the electrode portion, The height should also be such that the electrode can contact.

In addition, the rear portion of the support structure may be formed of the isolation wall 150, which is a wall for isolation, so that the electrolyte in the accommodation space can be prevented from passing over the space where the metal electrode is installed. The waste of space is reduced as compared with the case where the isolation wall is formed separately from the supporting structure and the space for accommodating space can be secured when fabricating the micro electro chemical gas sensor.

In contrast, the metal electrode 210 of the present embodiment has a configuration in which the end portion of the case side includes the fixing portion 214 which is bent horizontally. Therefore, compared with the case where the end portion of the metal electrode is simply linear, The contact area can be relatively widened. Also, there is an advantage that the contact state can be maintained even if the position of a portion formed to contact the metal electrode 210 at the electrode of the electrode portion is slightly deviated. This increase in contact area reduces the number of failures and increases the lifetime of the sensor.

The case 100 and the metal electrode 210 are separately manufactured and then the metal electrode 210 is attached to the case 100 in the assembling process, unlike the case where the metal electrode is formed by bending the case upward twice inside the case Can be installed. This is advantageous in that the manufacturing process is much simpler than the injection molding in which the metal electrode is positioned in the case manufacturing process. In addition, since the upper space of the metal electrode is not used in addition to the case where the electrode is bent upward twice inside the case, a low-height electrolytic chemical gas sensor can be manufactured, and finally, There is an advantage to be able to do.

The external connection portion 215 is a portion that extends from the outside of the case 100 to the end of the body 212 and is bent downward by 90 degrees. Since the electrochemical gas sensor is installed in an external circuit or the like in a state in which the electrochemical gas sensor is maintained in a horizontal position, terminals for electrical connection are mostly formed on the bottom. Conventionally, . However, since the metal electrode 210 of the present embodiment is formed by forming the external connection portion 215 by bending the end portion exposed to the outside of the case 100 downward by 90 degrees, the metal electrode 210 can be connected to the terminal formed on the bottom by itself have.

Since the external connection part 215 is bent downward from the outside of the case 100, there is no problem in the process of installing the metal electrode 210 in the case 100. [

The metal electrode 210 of the present embodiment performs a knurling process on a surface of a portion of the body 212 located outside and inside the case 100 in contact with the case 100 to form a nulling portion 216 ).

The nulling portion 216 is engaged with the upper case and the lower case to prevent the metal electrode 210 from moving when the sensor is finally assembled. At this time, the knurling portion 216 is formed only at a portion where the knurling portion 216 makes contact with the case 100, and is formed so as not to be seen from outside after assembling.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Those skilled in the art will understand. Therefore, the scope of protection of the present invention should be construed not only in the specific embodiments but also in the scope of claims, and all technical ideas within the scope of the same shall be construed as being included in the scope of the present invention.

100: Case
110, 120, 130: support structure
150: isolation wall
210, 220, 230: metal electrode
212: Body
214:
215: External connection
216: null ring

Claims (8)

A case including an empty accommodation space inside and configured to allow detection target gas to flow into the accommodation space;
An electrolyte disposed in the accommodation space;
A counter electrode and a reference electrode provided in the accommodation space and capable of detecting a change in current generated in contact with the electrolyte to perform electrolysis and a concentration of the detection target gas dissolved in the electrolyte, An electrode part made of a flexible material; And
And three metal electrodes electrically connecting the electrodes of the electrode unit to the outside,
Wherein the metal electrode includes a fixed portion which is bent at an angle of 90 degrees on a two-dimensional plane where an end portion located inside the case is parallel to the bottom,
Wherein the case has a supporting structure corresponding to the shape of the fixing part, and the fixing part is inserted and positioned in the supporting structure.
delete The method according to claim 1,
The case includes a lower case having a receiving space and an upper case covering the receiving space,
Wherein the support structure is formed in the lower case.
The method of claim 3,
Wherein the support structure has a structure in which an upper surface of the metal electrode is exposed to be in contact with an electrode of the electrode unit.
The method according to claim 1,
Wherein the metal electrode has a structure in which an intermediate portion of the metal electrode is bent at an angle of 90 DEG with an end portion exposed to the outside of the case facing downward.
The method according to claim 1,
Wherein the metal electrode is knurled on a surface in contact with the case.
The method according to claim 1,
Wherein the metal electrode is made of one of tantalum (Ta), titanium (Ti), and nickel (Ni).
The method according to claim 1,
Wherein the case is provided with an isolating wall in contact with the fixing portion.

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