JPH0225162Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvement of glass electrodes, and the object thereof is to provide an electrode that is easy and inexpensive to manufacture and does not cause insulation deterioration even when used at high temperatures.

FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a support tube for a glass electrode, and a glass membrane 2 is provided at the bottom thereof. 3 is internal fluid,
4 is a silver chloride electrode immersed in the internal liquid 3.
5 is a sealing piece. This sealing piece 5 is made up of a conductive silicone rubber 51 having a T-shaped cross section and a non-conductive silicone rubber 52 surrounding the enlarged portion.
Consists of colored molds. The outer periphery of the rubber 52 is corrugated so that the outer diameter is slightly larger than the inner diameter to ensure tight contact with the support tube 1.
61 is an internal lead wire connected to silver chloride 4;
62 is an external lead wire. The lead wires 61 and 62 are mechanically non-contact and are connected to the conductive rubber 5.
They are electrically connected via 1. 7 is a silicone rubber adhesive injected into the support tube 1 above the sealing piece 5.

A glass electrode having such a configuration is manufactured as follows. A glass membrane 2 is attached to the tip of the support tube 1. On the other hand, a two-color molded sealing piece 5 made of conductive silicone rubber 51 and non-conductive silicone rubber 52 is molded, and a lead wire 61 made of, for example, silver is connected to silver chloride 4 . Then, the lead wire 61 is inserted from the rubber 52 side of the sealing piece 5 until it reaches the rubber 51. In addition, the lead wire 62 is inserted into the rubber 51 from the opposite side. Then, the internal liquid 3 is injected into the support tube 1, and the sealing piece 5 to which the lead wires 61 and 62 are attached as described above is attached to the support tube. 1 to a predetermined position and seal the internal liquid 3. Then, silicone 7 is injected and bonded into the gap above the sealing piece 5 in the support tube 1 so that the lead wire 62 is exposed. Finally, the glass electrode is completed by inserting and adhering it into an outer tube 8 made of corrosion-resistant PBS resin as shown in FIG. In addition, the second
In the figure, 9 is a terminal, and 10 is an O-ring.

Conventional electrodes of this type are shown in Figure 3 A and B. In the device shown in Fig. A, a silicone gasket 11 with a through hole for sealing the internal liquid is press-fitted into the support tube 1.
It has a structure in which it is adhered with a silicone adhesive 7. In addition, the electrode shown in FIG. 2 has a lead platinum wire 63 sealed in glass to the upper part of the support tube 1 to seal the internal liquid 3. The inside of the platinum wire 63 is connected to the silver chloride 4 with a lead wire 64, and the lead wire 65 is connected to the outside.

However, according to the electrode shown in FIG. 1, the lead wire 6 connected to the silver chloride 4 passes through the sealing gasket 11 and the adhesive 7 and extends to the terminal 10. Therefore, the internal liquid 3 oozes out through the penetrating portion. In particular, lead wire 6
The adhesive interface between the adhesive 7 and the adhesive 7 peels off at high temperatures due to the difference in expansion coefficients between the two, and the above phenomenon becomes even more remarkable. As a result, insulation deterioration occurs in glass electrodes that require high insulation, and contact failures and disconnection failures occur due to corrosion of lead wires and terminals.

Further, in the apparatus shown in FIG. 2, the internal liquid 3 is sealed by attaching the platinum wire 63 to a glass envelope, but unavoidable processing distortion occurs when the platinum wire 3 is sealed. For this reason, the yield of good products is low, glass processing requires skill, and the cost of the product is high. Furthermore, there is also the problem that the glass portion breaks due to the above-mentioned strain due to temperature cycling, and the internal liquid 3 leaks as shown in FIG.

In contrast, in the present invention, a sealing piece is constructed in which conductive silicone rubber is surrounded by non-conductive silicone rubber. The outer silicone rubber seals the internal liquid, and the inner conductive silicone rubber connects the internal and external lead wires mechanically and electrically without contact. As a result, it is possible to provide an electrode that can withstand continuous use at high temperatures without deterioration of insulation or corrosion of the lead system due to leakage of internal liquid. In addition, not only is the skilled processing technology required for glass processing unnecessary, but
Anyone can assemble it. It is possible to realize an inexpensive electrode that can be manufactured.

In the embodiment, the rubber 51 of the sealing piece 5 is T-shaped, but it may be cylindrical or the like, and may be entirely surrounded by non-insulating rubber 52.

Therefore, according to the present invention, an extremely practical glass electrode can be provided.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams of the configuration of an apparatus according to an embodiment of the present invention, and FIGS. 3A and 3B are explanatory diagrams of the configuration of a conventional electrode. 1...Support tube, 3...Internal liquid, 5...Sealing piece,
51... Conductive rubber, 52... Non-conductive rubber, 6
1,62...Lead wire.

Claims (1)

[Scope of utility model registration request] In an apparatus configured such that a lead wire of a silver chloride electrode immersed in an internal liquid of a glass electrode support tube is led out from the upper part, a sealing piece made of conductive and nonconductive silicone rubber is placed in the support tube and the sealing piece is sealed. The internal liquid is sealed with the piece of non-conductive silicone rubber, and the lead wire connected to the silver chloride electrode and the lead wire outside the support tube are mechanically non-contacted through the conductive silicone rubber. glass electrodes that are electrically connected.