JPH03162255A - Lifetime assessment of liquid leakage prevention material and the same material - Google Patents

Abstract

PURPOSE:To permit the deterioration of a packing or the like to be detected before it happens by detecting changes in the physical characteristics of the material having a high magnetic permeability provided in a liquid-impermeable member to discover the corrosion of such material due to water. CONSTITUTION:A liquid-impermeable member 10 is provided with the material 14 having a high magnetic permability nd changes in the physical characteristics of the material 14 are detected to discover its corrosion due to water, whereby the lifetime of the liquid-impermeable member can be assessed. More specifically, this method makes use of the changes made in the physical characteristics of the material 14 provided in the member 10 such as magnetic permeability, the speed of sound and Young's modulus due to the corrosion thereof taking place easily, when the liquid-impermeable member 10 is deteriorated to cause crackings through which the liquid such as water and the oil mixed with water is penetrated into the member 10 or when water in a gas is intruded therein. In this manner the deterioration of the liquid-impermeable member 10 can be detected before it happens.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for determining the lifespan of a liquid leakage prevention material used for packing, liquid containers, etc., and to the liquid leakage prevention material. [Conventional technology] If water leaks in hydraulic machinery such as bombs or hydraulic cylinders, the efficiency will be significantly reduced. Therefore, water leakage prevention devices made of non-water-permeable materials such as silicone rubber and synthetic resin are used to prevent water leakage. Packing etc. are used. In addition, in construction machinery, automobiles, and many other machines and devices, if rainwater enters the engine system or power distribution part, it may cause malfunctions, so seals are made using non-permeable materials to prevent rainwater from entering. are being applied. These things are the same for various machines and devices that use other liquids such as oil, and if the sealing material deteriorates and leaks, or if water gets inside, problems similar to those described above can occur. arise. For this reason, in order to maintain these machines and devices in good condition and ensure safe operation, check whether the packing or sealing material has deteriorated or not, and replace the deteriorated packing and sealing material. There is. [Problem to be solved by the invention] However, conventionally, when determining whether or not the packing or sealing material has deteriorated, a water leak sensor, an oil leak sensor, etc. are used to detect liquid leaks such as water leaks and oil leaks. Monitor for liquid leakage,
It was assumed that the packing and sealing material had reached the end of their service life when this occurred. Therefore, in the past, there was a drawback in that it was not possible to know the deterioration and lifespan of liquid leakage prevention materials such as packing until a certain amount of liquid leakage occurred. In areas where leakage is a problem, packing and other parts are replaced while they are still usable, resulting in waste. An object of the present invention is to provide a method for determining the lifespan of a liquid leakage prevention material that can detect deterioration of packing etc. before liquid leakage occurs, and also allows easy detection of deterioration. The purpose is to provide a material that prevents liquid leakage. [Means for solving the problem] High magnetic permeability materials such as iron-based alloys generally have the property of being easily oxidized and easily corroded by water. Therefore, the inventors developed the present invention by paying attention to such properties of high magnetic permeability materials, and the method for determining the lifespan of liquid leakage prevention materials according to the present invention is based on the i! ! A high permeability material is placed in an impermeable member, and corrosion of the high permeability material by water is detected by detecting changes in the physical properties of the high permeability material, and the lifespan of the member that does not allow liquid to permeate is determined. It is characterized by

Furthermore, the liquid leakage prevention material according to the present invention is characterized in that a high magnetic permeability material is embedded in a base material that does not allow liquid to penetrate.

[Effect]

When high magnetic permeability materials are corroded by contact with water, their physical properties change, such as a decrease in magnetic permeability, a decrease in the speed of sound propagating through high magnetic permeability materials, and a decrease in Young's modulus. For this reason,
In the method for determining the lifespan of a liquid leakage prevention material of the present invention constructed as described above, a member that does not allow liquid to permeate deteriorates and cracks occur, and water or a liquid such as oil mixed with water permeates into this member. When water or moisture in the air enters, the high magnetic permeability material placed inside this member is easily corroded by the water, changing its physical properties such as magnetic permeability, sound velocity, and Young's modulus.
Therefore, by detecting the physical properties of a high magnetic permeability material placed in a member that does not allow liquid to permeate and monitoring changes in the physical properties, corrosion of the high magnetic permeability material can be detected and liquid leakage can be detected. It can be determined that a component that does not allow liquid to permeate has deteriorated, that is, has reached the end of its lifespan, before water leaks into the interior from the outside. Moreover, the liquid leakage prevention material of the present invention has a high i! Since the iiff coefficient material is embedded, when the base material deteriorates, liquid such as water or water-containing oil seeps into the base material, and the high magnetic permeability material is corroded by the water. Therefore, as described above, by detecting the physical characteristics of this high magnetic permeability material, it is possible to easily know that the liquid leakage prevention material has reached the end of its lifespan before liquid leakage occurs. As a result, it is possible to avoid waste such as replacing usable packings to avoid liquid leakage, and the intervals at which maintenance is required are lengthened, improving the operating rate of machines and equipment. [Example] FIG. 1 is an explanatory diagram of an example of the present invention. In FIG. 1, a stopper piece 10 which is a liquid leakage prevention material is a so-called O
It has the shape of a ring. That is, the water stop forest 10 has a base material 12 made of a non-water-permeable elastic material such as vulcanized rubber, silicone rubber, butadiene-based synthetic rubber, etc., which is shaped like an annular ring. A high magnetic permeability material 14 is buried in the center of the base material 12 over almost the entire circumference. The high magnetic permeability material 14 is made of an amorphous or iron-based single crystal material, and is in the form of a thin wire with a diameter of, for example, several μm to several tens of μm, and one end of which is drawn out from the base material I2 and is connected to the detection coil. 16 can be inserted through it. Note that the number of thin wires of the high magnetic permeability material l4 buried in the base material 12 may be one or more.

The detection coil 16 is connected to an AC power source l8 via a resistor R. Further, a reactance detection circuit 19 is connected in parallel to the detection coil 16, so that the reactance of the detection coil l6 can be detected. In the embodiment constructed in this manner, a current of a predetermined frequency is supplied from the AC power supply 18 to the detection coil l6, the reactance of the detection coil 16 is detected by the reactance detection circuit 19, and changes in reactance are monitored. It is possible to detect the deterioration of the base material 12 and the lifespan of the water stop material 10. In other words, high i! The magnetic material 14 has a property of being easily corroded by water, and when the base material 12 deteriorates and cracks occur, and water permeates into the base material 12, it gradually corrodes and its magnetic permeability decreases. ．． Therefore, as the corrosion of the detection coil 164L high magnetic permeability material 14 through which the high i3 magnetic material 14 is inserted progresses, the inductance L decreases and the reactance decreases. In other words, the detection coil 16 before the high magnetic permeability material 14 buried in the base material 12 corrodes.
Let ωL be the reactance (initial reactance) of
As the magnetic permeability deteriorates, water seeps into the base material 12, and the high magnetic permeability material 14 corrodes, it decreases as shown in FIG. Therefore,
The glue actance ωL of the detection coil 16 is detected and monitored by the reactance detection circuit 19, and for example, when the relative reactance ωL/ωL0 becomes smaller than X, the water-stopping material 10 is replaced, assuming that the water-stopping material 1O has reached its lifespan. ．． In this way, in the embodiment, it is possible to determine that the life of the waterproof material 10 has come to an end before water leakage occurs, and it is possible to completely eliminate water leakage and water intrusion into machines and equipment. Furthermore, since the lifespan of the water stop material IO can be accurately determined, it is possible to eliminate waste such as replacing packing etc. while they are still usable, and it is possible to perform accurate maintenance. In addition, in the embodiment, since a high magnetic permeability material is used, when detecting a change in the magnetic permeability of the high magnetic permeability material 14, there is no need to attach the detection coil l6 directly to the corroded part, and the high magnetic permeability A detection coil l6 that separates the end of the material 14 from the base material l2
can be extended to a place where it is easy to attach, magnetic permeability can be easily detected, and the lifespan of the water stop forest 10 can be determined while it is in use. Moreover, since the high magnetic permeability material 14 is shaped like a thin wire, the high magnetic permeability material 14
Even if the material 4 is slightly corroded, the magnetic permeability changes greatly, and corrosion of the high permeability material 14 can be detected early, and the lifespan of the water-stopping material 10 can be accurately determined. By changing the heat treatment, surface treatment, alloy composition, etc. of the high magnetic permeability material 14J, the susceptibility to corrosion (corrosion resistance) can be arbitrarily changed, and the base material High permeability material l4 suitable for determining the life of l2 can be easily obtained. In the above embodiment, a case has been described in which the lifespan of the water stop material 10 is determined by monitoring the reactance ωL. However, by connecting the detection coil 16 to an AC bridge circuit and determining the inductance L of the detection coil 16, Also, by using an oscillation circuit to determine the change in magnetic permeability of the high magnetic permeability material 14 depending on the oscillation frequency and amplitude of the oscillation circuit,
The service life of the water stop material 10 may be determined by detecting corrosion of the high magnetic permeability material 14 due to water. Also, high i! ! It is desirable that the portion of the magnetic material l4 exposed from the base material 12 be subjected to surface treatment to prevent oxidation and corrosion. Further, in the above embodiments, the case where the high magnetic permeability material 14 is in the form of an AT line has been described, but it may be in the form of a plate or a thin film. In the above embodiment, the case where only the thin wire-shaped high magnetic permeability material 14 was buried in the base material 12 was explained, but in addition to arranging the high magnetic permeability material 14, other magnetic materials were buried in the base material 12. For example, the deterioration of this magnetic material may also be detected by mixing it in powder form. FIG. 3 is a front view of the main parts of another embodiment. In FIG. 3, the water stop material 10 forming an O-ring has both ends of a high magnetic permeability material 14 buried in a base material 12 drawn out to the outside. Then, in the part of the base material 12 from which the high magnetic permeability material 14 is pulled out, the base material l2
Connectors 20, 22 made of the same or different material
There is a high i! The coils 24 and 26 through which the fit rate material 14 is inserted can be easily attached and detached. In the embodiment of FIG. 3 constructed in this manner, Let. For example, by connecting the coil 24 to an AC power source and detecting the electromotive force generated in the coil 26 or checking the inductance of the coil 26, it is possible to detect a decrease in magnetic permeability due to corrosion of the high permeability material 14 due to deterioration of the base material l2. can be detected, and the same effect as in the above embodiment can be obtained. Moreover, in this embodiment, by providing the connectors 20 and 22, the coils 24 and 26 can be easily and reliably attached and detached. In addition, in FIG. 3, the connectors 20 and 22 are connected to the base material 1.
Force connector 20 explained for the case where it is directly installed on 2
, 22 may be provided at a position away from the base material l2. In each of the embodiments described above, the high magnetic permeability material 14 is buried over almost the entire circumference of the base material 12, but it may be buried only in a portion of the base material 12. Furthermore, in each of the above embodiments, a case has been described in which the lifespan of the water stop material 10 is determined by measuring AC 1t magnetic characteristics such as reactance ωL of the high magnetic permeability material l4, but the DC electromagnetic properties of the high magnetic permeability material l4 are Corrosion of the high magnetic permeability material 14 may be detected by measuring the properties or other physical properties such as sound velocity and Young's modulus to determine the lifespan of the water stop material IO. Further, in the above embodiments, the case where the waterproof material 10 is an O-ring has been described, but it can also be applied to gaskets, plugs, container walls, partition walls, etc. In addition, in the above embodiments, the water stop material lO that prevents water leakage has been described, but it can also be applied to sealing materials that prevent the leakage of other liquids such as oil, and can be applied to airtight sealing materials. Good too. [Effects of the Invention] As explained above, according to the method for determining the lifespan of a liquid leakage prevention material of the present invention, a member that does not permeate liquid deteriorates and cracks occur, and water or water-containing liquid or air When the moisture inside permeates into the member, the high magnetic permeability material placed inside the member is easily corroded by the water, and the physical properties of the high i3 magnetic material, such as magnetic permeability, sound velocity, and Young's modulus, change. Therefore, by detecting the physical properties of high magnetic permeability material placed in a material that does not allow liquid to permeate, and monitoring changes in the physical properties, it is possible to detect corrosion of high magnetic permeability material due to water, and to prevent liquid leakage. It can be determined that a component that does not allow liquid to penetrate has deteriorated, that is, has reached the end of its lifespan, before water infiltrates from the outside into the inside. Moreover, the liquid leakage prevention material of the present invention is
Since the high magnetic permeability material is embedded in a base material that does not permeate liquid, if the base material deteriorates, the high magnetic permeability material embedded in the base material will corrode as described above. Therefore, by detecting the physical characteristics of this high magnetic permeability material, it is possible to easily know when the liquid leakage prevention material has reached the end of its lifespan before liquid leakage occurs.

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) A high magnetic permeability material is placed in a member that does not allow liquid to seep through,
Lifespan determination of a liquid leakage prevention material characterized by detecting changes in the physical properties of the high magnetic permeability material, detecting corrosion of the high magnetic permeability material due to water, and determining the lifespan of the member through which the liquid does not permeate. Method. (2) A liquid leakage prevention material characterized by having a high magnetic permeability material embedded in a base material that does not allow liquid to penetrate.