JPH041496Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a cell structure of a gas detector that utilizes electrochemical action, and more specifically to an electrolyte holding member.

(Prior art) An electrochemical gas detector used in a portable gas measuring device is an electrode made of an electrode material such as platinum black, which is airtightly attached to one end of a cylindrical case, and a porous gas detector impregnated with an electrolyte. The other electrode is airtightly attached to the other end. According to such a structure, the electrolyte can be brought into contact with the electrode surface regardless of the orientation of the detector, but on the other hand, the porous material is pressed during assembly, exposing the electrolyte, and the electrolyte is not provided on the electrode surface. This has the disadvantage that it adheres to the gas-permeable membrane and the lead wires that take out the electrode potential to the outside, impairing reliability.

(Purpose) The present invention was made in view of the above problems, and its purpose is to provide an electrochemical gas detector that can minimize exposure of electrolyte during assembly. There is a particular thing.

(Structure) The details of the present invention will be described below based on illustrated embodiments.

Figures 1 and 2 show an embodiment of the present invention, in which reference numeral 1 is an electrolyte holding member, which is made by cutting out a water-absorbing material such as filter paper to match the inner shape of the cylindrical case 2. electrodes 6, 9 when housed in
In the base material 1a, which has a thickness that is in contact with the surface of the base material 1, holes penetrating through both sides are bored in a substantially uniform distribution to provide the missing parts 1b, 1b, 1b...
The electrolytic solution 13 is absorbed into the electrolytic solution 13. This electrode solution holding member 1 is housed in a cylindrical case 2 in which a fixing ring 3, a packing member 4, a gas permeable membrane 5, an electrode 6, and a filter paper 7 are assembled in this order from the outside at one end. , the filter paper 8, the electrode 9, the gas permeable membrane 10, and the packing member 11 are stacked in order on the top surface of this, and finally they are pressed together with the fixing ring 12 and fixed integrally to the case 2 to form an electrochemical gas detector. It is configured. The electrolytic solution 13 will be squeezed out from the electrode solution holding member 1 due to the pressure when the fixing ring 12 is attached, but the squeezed out electrolytic solution 13a will be transferred to the missing parts 1b, 1b, 1
It does not flow into the space b... and overflow outside the case (Figure 3 B).

According to this embodiment, the surfaces of the two electrodes 6 and 9 are in contact with the electrolyte holding member 1 and in contact with the electrolyte 13, and generate an electrolytic current proportional to the target gas concentration in the atmosphere.

On the other hand, if an external force is applied to the electrodes 6, 9 or the case 2, or if the internal pressure increases due to a rise in temperature, the electrolyte holding member 1 may no longer be able to hold the electrolyte 13, and the electrolyte 13 may drain from the holding member 1. Even if it seeps out, the electrolyte 13a will not flow into the missing parts 1b, 1b, 1b, . . . of the electrolyte holding member 1 and will not leak to the outside. Further, when the electrolyte in the holding member 1 decreases due to long-term use, the electrolyte 13a accommodated in the missing parts 1b, 1b, 1b, . . . is absorbed by the base material 1a, and the electrode 6, Since the liquid is supplied to the surface of the electrode 9, the electrodes 6 and 9 always maintain a constant state of contact with the liquid.

FIG. 4 shows a second embodiment of the electrolyte holding member, in which a cavity is formed in the center of a base material 20a made of a water-absorbing material formed to match the cross-sectional shape of the case. According to this embodiment, the surface of the electrolyte holding member can be brought into uniform contact with the electrode without using an auxiliary member such as a filter paper.

FIG. 5 shows a third embodiment of the electrolyte holding member, in which concentric or spiral grooves are formed on at least one surface of a base material 30a to provide missing portions 30b, 30b. According to this embodiment, the squeezed electrolyte can be quickly dispersed and leakage can be more reliably prevented.

FIG. 6 shows a fourth embodiment of the electrolyte holding member, in which a part of the base material 40a made of a water-absorbing material formed to match the cross-sectional shape of the case is cut out to provide a cutout portion 40b. It is something.

In this example, the case was explained using a case in which the electrodes were arranged at both ends of the cylindrical case, but it is also possible to form the case into a cylindrical shape with a bottom and arrange the electrodes at the open end side. It is clear that the same effect can be achieved even when applied to a type of device.

(Effects) As explained above, according to the present invention, an electrolytic solution is impregnated into an electrolytic solution holding member that can be housed in a case and has a missing part in the base material made of a water-absorbing material that is in contact with the electrode surface. Since the electrolyte is squeezed out from the electrolyte holding member during assembly and is placed in contact with the electrode, the electrolyte is stored in the missing part to prevent loss of electrolyte due to flowing out of the case or adhesion to other parts. This not only improves the reliability of the detector, but also allows the missing part to function as a reserve tank to quickly absorb changes in case internal pressure due to temperature changes and external pressure, thereby preventing electrolysis. It can be used to prevent liquid leakage and to replenish liquid contact surfaces when the liquid decreases.

Further, by simply adjusting the size of the missing portion, the amount of electrolyte to be injected into the case can be easily and highly accurately managed, making it possible to simplify the assembly work.

[Brief explanation of the drawing]

Figures 1 and 2 are a sectional view and an assembled perspective view of the device showing an embodiment of the present invention, Figure 3 is an explanatory diagram showing the action of the electrolyte holding member in the same device, and Figures 4, 5, and 6 are FIG. 3 is a sectional view and a perspective view, respectively, showing other embodiments of the electrolyte holding member used in the present invention. 1... Electrolyte holding member, 1a... Base material, 1b...
... Missing part, 2 ... Case, 6, 9 ... Electrode, 1
0,10a...electrolyte solution.

Claims (1)

[Scope of utility model registration request] In a gas detector in which an electrode is arranged at the open end of a case so as to be in contact with an electrolyte, there is a missing part in a base material made of a water-absorbing material that can be accommodated in the case and is formed so as to be in contact with the electrode surface. 1. A cell structure of an electrochemical gas detector, characterized in that an electrolyte holding member provided with an electrolyte is impregnated with an electrolyte and housed in a case.