CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of Chinese Patent Application No. 201310030267.0 filed on January 25, 2013 in the State Intellectual Property Office of China, the whole disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a silicon oil sensor, more particularly, relates to a silicon oil sensor for detecting silicon oil leaked out of an outdoor electric power terminal filled with the silicon oil.

Description of the Related Art

An outdoor electric power terminal filled with silicon oil may be applied to a high voltage cable, for example, 170kV. However, there is a risk that the silicon oil may be leaked out of the outdoor electric power terminal and cause a power failure. Furthermore, the outdoor electric power terminal is often mounted high above the ground, therefore it is difficult to find the leaked silicon oil in time.

In prior arts, a silicon oil sensor generally comprises a conductive layer directly formed by conductive particles or a porous material (for example, polytetrafluoroethylene) filled by the conductive particles. When the silicon oil is flowed to the conductive layer of the silicon oil sensor, the conductive particles directly contact the silicon oil and are wrapped by the silicon oil, and it changes the electric resistance of the conductive layer. Thereby, it is possible to detect whether the silicon oil is leaked out of the outdoor electric power terminal based on the change of the electric resistance of the conductive layer of the silicon oil sensor.

However, the conventional silicon oil sensor has the following disadvantages:

1) When the conductive particles are wrapped by the leaked silicon oil, the change of the electric resistance of the conductive layer is very slow and not significant, that is, the conventional silicon oil sensor has poor detection sensitivity and cannot detect the leaked silicon oil in time. As a result, it cannot reliably prevent the power failure due to the leaked silicon oil.

2) The electric resistance of the conductive layer of the conventional silicon oil sensor is also affected by rain water or other liquid in addition to the silicon oil. Thereby, when conventional silicon oil sensor is applied in an outdoor environment, it is necessary to provide a special film on the conductive layer to protect it from the rain water but permit the silicon oil to penetrate therethrough, complicating the structure of the silicon oil sensor and increasing the cost.

SUMMARY OF THE INVENTION

The present invention has been made to overcome or alleviate at least one aspect of the above mentioned disadvantages.

Accordingly, it is an object of the present invention to provide a silicon oil sensor that has high detection sensitivity and can detect leaked silicon oil in time.

Accordingly, it is another object of the present invention to provide a silicon oil sensor that has a simple structure and is not affected by rain water.

According to an aspect of the present invention, there is provided a silicon oil sensor, comprising: a conductive layer made of an organic silicone polymer doped with conductive particles, when the conductive layer contacts silicon oil, the organic silicone polymer swells and causes an electric resistance of the conductive layer to increase.

In an exemplary embodiment of the present invention, the organic silicone polymer comprises at least one of silicone rubber, organic silicone adhesive, and organic silicone paint.

In another exemplary embodiment of the present invention, the conductive particle comprises at least one of carbon black powder, graphite powder, silver powder, copper powder, sliver-coated nickel powder, nickel powder, iron powder, aluminum powder, titanium carbide powder, silver-coated copper powder, silver-coated aluminum powder, and silver-coated glass powder.

In another exemplary embodiment of the present invention, the silicon oil sensor further comprising: a first electrode electrically connected to the conductive layer; and a second electrode electrically connected to the conductive layer.

In another exemplary embodiment of the present invention, the silicon oil sensor further comprising: an insulation body on which the first and second electrodes are disposed.

In another exemplary embodiment of the present invention, the conductive layer is coated on a surface of the insulation body on which the first and second electrodes have been disposed.

According to another aspect of the present invention, there is provided an electric power terminal assembly, comprising: an electric power terminal; and the above mentioned silicon oil sensor provided for the electric power terminal.

According to another aspect of the present invention, there is provided an electric power terminal assembly, comprising: an electric power terminal; a funnel disposed below the electric power terminal; and the above mentioned silicon oil sensor disposed below the funnel, wherein the funnel has a flared inlet facing the electric power terminal to receive silicon oil leaked from the electric power terminal and a contracted outlet facing the silicon oil sensor to discharge the silicon oil to the silicon oil sensor.

According to another aspect of the present invention, there is provided a method of using the above mentioned silicon oil sensor, comprising: disposing the silicon oil sensor below an outdoor electric power terminal filled with silicon oil; and determining whether the silicon oil is leaked out of the outdoor electric power terminal according to the change of the electric resistance of the conductive layer of the silicon oil sensor.

In an exemplary embodiment of the present invention, the conductive layer of the silicon oil sensor is directly exposed in an outdoor environment without any water-proof film thereon.

In an exemplary embodiment of the present invention, the conductive layer of the silicon oil sensor of the present invention may be made of an organic silicone composite material formed by mixing an organic silicone polymer with a conductive carbon powder or a conductive metal powder. Such organic silicone composite material can rapidly swell immediately after contacting the silicon oil and the electric resistance thereof can be quickly changed, therefore, it can reliably detect the silicon oil leakage according to the change of the electric resistance.

In the various embodiments of the present invention, since the organic silicone polymer rapidly swells and causes the electric resistance of the conductive layer to occur a jump change once the organic silicone polymer contacts silicon oil, the silicon oil sensor of the present invention can quickly detect the silicon oil leaked from the electric power terminal according to the change of the electric resistance and give an alarm in time, so that an operator is noticed to deal with the electric power terminal that has occurred oil leakage. Accordingly, it can reliably ensure the electric power system to operate normally. Furthermore, the silicon oil sensor of the present invention is adapted to be applied in an outdoor environment because rain water has no effect on the electric resistance of the conductive layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the accompanying drawings, in which:

Fig.1 is an illustrative cross section view of a silicon oil sensor according to an exemplary embodiment of the present invention;

Fig.2 is an illustrative view of an electric power terminal assembly according to an exemplary embodiment of the present invention, in which the silicon oil sensor of Fig.1 is disposed below a horizontal outdoor electric power terminal;

Fig.3 is an illustrative view of an electric power terminal assembly according to another exemplary embodiment of the present invention, in which the silicon oil sensor of Fig.1 is disposed on a vertical outdoor electric power terminal; and

Fig.4 is an illustrative view of an electric power terminal assembly according to another exemplary embodiment of the present invention, in which a funnel is disposed below the outdoor electric power terminal to collect the leaked silicon oil from the outdoor electric power terminal to the silicon oil sensor of Fig.1. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE

IVENTION

Exemplary embodiments of the present disclosure will be described hereinafter in detail with reference to the attached drawings, wherein the like reference numerals refer to the like elements. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art.

Fig. l is an illustrative cross section view of a silicon oil sensor 10 according to an exemplary embodiment of the present invention.

As shown in Fig. l, the silicon oil sensor mainly comprises an insulation body 100, a pair of electrodes 301, 302 disposed on a surface of the insulation body 100, and a conductive layer 200 disposed on the surface of the insulation body 100 and electrically contacting the pair of electrodes 301, 302.

In an exemplary embodiment, as shown in Fig. l, the insulation body 100 and the pair of electrodes 301, 302 may be configured as a Printed Circuit Board (PCB). That is, the insulation body 100 may be configured as a substrate, and the pair of electrodes 301, 302 may be configured as a pair of metal terminals formed on the insulation body 100 by a patterning process.

Please be noted that the silicon oil sensor of the present invention is not limited to the illustrated structure, for example, the insulation body 100 may be formed into a container having an opening, and the conductive layer 200 may be disposed in the container.

In an exemplary embodiment of the present invention, the conductive layer 200 is made of an organic silicone composite material, for example, an organic silicone polymer doped with conductive particles. The organic silicone polymer can rapidly swell

immediately after contacting the silicon oil and cause the electric resistance of the conductive layer 200 to occur a jump change. In this way, the silicon oil sensor of the present invention can quickly detect the silicon oil leaked from the electric power terminal according to the jump change of the electric resistance and give an alarm in time, so that an operator may be noticed to deal with the electric power terminal that has occurred oil leakage. Accordingly, it can reliably ensure an electric power system to operate normally.

Furthermore, when the organic silicone polymer contacts rain water, the organic silicone polymer does not swell at all, and the electric resistance of the conductive layer 200 substantively remains unchanged. Accordingly, the silicon oil sensor of the present invention can be applied in an outdoor environment, and the conductive layer 200 or the entire silicon oil sensor 10 can be directly exposed in the atmosphere environment without providing any water-proof film thereon. For example, the silicon oil sensor 10 of the present invention may be simply disposed below an outdoor electric power terminal filled with silicon oil. In this case, when the silicon oil is leaked out of the outdoor electric power terminal, the leaked silicon oil is dropped onto the conductive layer 200 of the silicon oil sensor 10. As a result, the silicon oil sensor 10 of the present invention can simply and reliably detect the leaked silicon oil from the outdoor electric power terminal.

In an exemplary embodiment of the present invention, the organic silicone composite material may be formed by mixing an organic silicone polymer with a conductive carbon powder or a conductive metal powder.

In an exemplary embodiment of the present invention, the organic silicone polymer may comprise at least one of silicone rubber, organic silicone adhesive, and organic silicone paint.

In an exemplary embodiment of the present invention, the conductive particle may comprise at least one of carbon black powder, graphite powder, silver powder, copper powder, sliver-coated nickel powder, nickel powder, iron powder, aluminum powder, titanium carbide powder, silver-coated copper powder, silver-coated aluminum powder, and silver-coated glass powder or combination of at least two of the same.

In an exemplary embodiment of the present invention, as shown in Fig.1, the

conductive layer 200 may be coated on a surface of the insulation body 100 on which the first and second electrodes 301, 302 have been disposed.

Hereafter, it will describe in detail an outdoor electric power terminal assembly having the silicon oil sensor 10 according to various embodiments of the present invention with reference to Figs.2-4.

Fig.2 is an illustrative view of an electric power terminal assembly according to an exemplary embodiment of the present invention, in which the silicon oil sensor 10 of Fig.1 is disposed below a horizontal outdoor electric power terminal 20.

As shown in Fig.2, the outdoor electric power terminal 20 is arranged in a horizontal direction, and the silicon oil sensor 10 is mounted on a lower surface of the horizontal outdoor electric power terminal 20. With this configuration, once the silicon oil is leaked out of the outdoor electric power terminal 20, the leaked silicon oil flows to the conductive layer 200 of the silicon oil sensor 10, and the organic silicone polymer of the conductive layer 200 swells and causes the electric resistance of the conductive layer 200 to occur a jump increase. In this way, the leaked silicon oil can be reliably detected by the silicon oil sensor 10 in time.

Fig.3 is an illustrative view of an electric power terminal assembly according to another exemplary embodiment of the present invention, in which the silicon oil sensor 10 of Fig.1 is disposed on a vertical outdoor electric power terminal 20.

As shown in Fig.3, the outdoor electric power terminal 20 is arranged in a vertical direction, and the silicon oil sensor 10 is attached on a lower side surface of the vertical outdoor electric power terminal 20. With this configuration, once the silicon oil is leaked out of the outdoor electric power terminal 20, the leaked silicon oil flows to the conductive layer 200 of the silicon oil sensor 10, and the organic silicone polymer of the conductive layer 200 swells and causes the electric resistance of the conductive layer 200 to occur a jump increase. In this way, the leaked silicon oil can be reliably detected by the silicon oil sensor 10 in time.

Fig.4 is an illustrative view of an electric power terminal assembly according to another exemplary embodiment of the present invention, in which a funnel 30 is disposed below the outdoor electric power terminal 20 to collect the leaked silicon oil from the outdoor electric power terminal 20 to the silicon oil sensor 10 of Fig.1.

As shown in Fig.4, the funnel 30 is disposed below the electric power terminal 20, and the silicon oil sensor 10 is disposed below the funnel 30. The funnel 30 has a flared inlet upward facing the electric power terminal 20 to receive the silicon oil leaked out of the electric power terminal 20, and a contracted outlet downward facing the silicon oil sensor 10 to discharge the leaked silicon oil to the silicon oil sensor 10. With this configuration, the leaked silicon oil can be collected and converged by the funnel 30 and discharged onto the conductive layer 200 of the silicon oil sensor 10. Thereby, even if the amount of oil leakage is very small, it also can be reliably detected by the silicon oil sensor 10 in time.

The organic silicone polymer doped with conductive particles is often used as conductive material or electromagnetic shielding material for making, for example, key, case, cabinet or shelter of an electronic product, a microwave waveguide system, a connector bonding pad, etc.. In the present invention, the organic silicone polymer doped with conductive particles is used as the conductive material for making the conductive layer of the silicon oil sensor.

In an exemplary embodiment of the present invention, the conductive layer of the silicon oil sensor may be formed by a conductive silicone rubber coating layer. Furthermore, by adjusting the thickness of the conductive silicone rubber coating layer, the type and the content of conductive particles in the conductive silicone rubber, a silicon oil sensor having a predetermined resistance can be obtained. When the leaked silicon oil flows to the silicon oil sensor, the silicone rubber of the conductive silicone rubber coating layer swells, and the resistance of the silicon oil sensor rapidly increases in a very short time.

The conductive organic silicone polymer for the silicon oil sensor of the present invention has a specific characteristic, that is, the silicon oil can cause the conductive organic silicone polymer to rapidly swell and quickly change the resistance of the conductive organic silicone polymer. Please be noted that other types of polymers are not adapted to the silicon oil sensor of the present invention because they do not have the above specific characteristic of the conductive organic silicone polymer.

Hereafter, it will describe in detail various examples of producing the organic silicone polymer based silicon oil sensor of the present invention.

Example 1

Coating a liquid silicone rubber doped with conductive carbon black powder on a pair of electrodes and between the pair of electrodes to form a thin film; and

Placing the thin film in an oven to dry and cure the thin film at a temperature of about 160 ^° C for a time period of about 2 hours, and then cooling the thin film to a room temperature to obtain a silicone rubber coating layer containing 11.9wt% conductive carbon black powder.

The silicone rubber coating layer has a stable resistance of 7.98k Ω between the pair of electrodes at the room temperature. When a droplet of silicon oil is dropped to the silicone rubber coating layer, the resistance of the silicone rubber coating layer is increased from 7.98k Ω to 12.45k Ω within half an hour, that is, the resistance of the silicone rubber coating layer is increased by 56.0%.

Example 2

Coating a liquid silicone rubber doped with conductive carbon black powder on a pair of electrodes and between the pair of electrodes to form a thin film; and

Placing the thin film in an oven to dry and cure the thin film at a temperature of about 160 ^° C for a time period of about 2 hours, and then cooling the thin film to a room temperature to obtain a silicone rubber coating layer containing 20.6wt% conductive carbon black powder.

The silicone rubber coating layer has a stable resistance of 1.75k Ω between the pair of electrodes at the room temperature. When a droplet of silicon oil is dropped to the silicone rubber coating layer, the resistance of the silicone rubber coating layer is increased from

1.75k Ω to 2.86k Ω within half an hour, that is, the resistance of the silicone rubber coating layer is increased by 63.4%.

Example 3

Coating a liquid silicone rubber doped with silver powder on a pair of electrodes and between the pair of electrodes to form a thin film; and

Placing the thin film in an oven to dry and cure the thin film at a temperature of about 160 ^° C for a time period of about 2 hours, and then cooling the thin film to a room temperature to obtain a silicone rubber coating layer containing 80.2wt% silver powder. The silicone rubber coating layer has a stable resistance of 0.21k Ω between the pair of electrodes at the room temperature. When a droplet of silicon oil is dropped to the silicone rubber coating layer, the resistance of the silicone rubber coating layer is increased from 0.21k Ω to 0.41k Ω within half an hour, that is, the resistance of the silicone rubber coating layer is increased by 95.2%.

Example 4

Coating a liquid silicone rubber doped with sliver-coated nickel powder on a pair of electrodes and between the pair of electrodes to form a thin film; and

Placing the thin film in an oven to dry and cure the thin film at a temperature of about

160 ^° C for a time period of about 2 hours, and then cooling the thin film to a room temperature to obtain a silicone rubber coating layer containing 74.3wt% sliver-coated nickel powder.

The silicone rubber coating layer has a stable resistance of 0.48k Ω between the pair of electrodes at the room temperature. When a droplet of silicon oil is dropped to the silicone rubber coating layer, the resistance of the silicone rubber coating layer is increased from 0.48k Ω to 0.85k Ω within half an hour, that is, the resistance of the silicone rubber coating layer is increased by 77.1%. Example 5

Coating a liquid silicone rubber doped with copper powder on a pair of electrodes and between the pair of electrodes to form a thin film; and

Placing the thin film in an oven to dry and cure the thin film at a temperature of about 160 ^° C for a time period of about 2 hours, and then cooling the thin film to a room temperature to obtain a silicone rubber coating layer containing 72.3wt% copper powder.

The silicone rubber coating layer has a stable resistance of 0.68k Ω between the pair of electrodes at the room temperature. When a droplet of silicon oil is dropped to the silicone rubber coating layer, the resistance of the silicone rubber coating layer is increased from 0.68k Ω to 1.16k Ω within half an hour, that is, the resistance of the silicone rubber coating layer is increased by 70.6%.

It should be appreciated for those skilled in this art that the above embodiments are intended to be illustrated, and not restrictive. For example, many modifications may be made to the above embodiments by those skilled in this art, and various features described in different embodiments may be freely combined with each other without conflicting in configuration or principle, so that more kinds of silicon oil sensor can be achieved with overcoming the technical problem of the present invention.

Although several exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that various changes or modifications may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

As used herein, an element recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments "comprising" or "having" an element or a plurality of elements having a particular property may include additional such elements not having that property.