JPH01269041A - Method for detecting deterioration of flexible composite tube - Google Patents

Abstract

PURPOSE:To detect the deterioration of a flexible composite tube caused by fatigue by connecting an interlocking tube with metallic reinforcing layers at the terminal fittings on one side of the composite tube and connecting a detector between the interlocking tube and layers at the terminal fittings on the other side of the composite tube. CONSTITUTION:Terminal fittings A and B are fitted to both ends of a flexible composite tube 1 and an interlocking tube 2 is electrically connected with the ends of metallic reinforcing layers 4 and 5 by the fittings B. In addition, a detector 25 is connected between the tube 2 and layers 4 and 5 by the fittings A, and thus, a closed circuit which uses the tube 2 and layers 4 and 5 as forward and backward electric paths is formed. Therefore, when an external scar or deterioration by fatigue is produced at some place of the tube or reinforcing layer 4 or 5, the electric resistance of the electric paths changes and the circuit current also changes. Thus the abnormality of the flexible composite tube caused by fatigue can be detected by measuring a change in the circuit current by means of the detector 25.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting deterioration of a visible composite pipe.

[Prior art] Interlock tubes, plastic tubes, etc. are used as visible composite tubes.
A type of flexible composite tube with a composite reinforcing layer is known, but such a flexible composite tube is made by layering a plastic tube on the outer periphery of a metal interlock tube a, as shown in the second figure. The metal reinforcing layers c and d are stacked, and the outer sheath e is stacked on the outer periphery to form a visible composite tube f, and at its terminal, an interlock tube a and a plastic 9b are formed.
Place insulating rings g and h on the edges of the end body j, press the seal m with the inner gauging ring fixed to the fixing bolt to hold the outer periphery of the interlock tube a and the plastic tube, and then insert the inner The casing stand, the metal reinforcing layer C1d, and the outer periphery of the terminal end of the outer sheath e are surrounded by an epoxy resin insulator n, and an outer gauging p is fitted around the outer periphery of the end body j and the epoxy resin insulator n.
A terminal portion was formed by pressing the outer periphery of the terminal of the outer sheath e with a gasket q.

When such flexible composite pipes are used for a long period of time, the interlock pipes and metal reinforcing layers may become fatigued and damaged, and may also be damaged due to external trauma. It is being replaced with a new visible composite tube.

[Problem to be solved by the invention] As mentioned above, if the interlock tube or metal reinforcing layer of the flexible composite tube is damaged, there is a risk of an accident, so it is necessary to replace the tube with a new one before an accident occurs. To achieve this, it is necessary to immediately detect even the slightest deformation, crack, or break before the interlock tube or metal reinforcing layer is damaged, but conventionally there was no such detection means.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for detecting deterioration of a visible composite tube that can immediately detect damage or fatigue deterioration of the metal interlock tube or metal reinforcing layer of the visible composite tube.

[Means for Solving the Problems] In order to achieve the above object, the method for detecting deterioration of a visible composite pipe of the present invention includes
．． 5, terminal fittings A and B are attached to both ends of the flexible composite tube 1, and the ends of the interlock tube 2 and the metal reinforcing layer 4.5 are electrically connected at one terminal fitting B, and At A, a detector 25 is connected between the end of the interlock tube 2 and the end of the metal reinforcement layer 4.5, and the resistance change of the interlock tube 2 and the metal reinforcement layer 4.5 is measured. The deterioration of the metal reinforcing layer 4.5 is detected.

[Operation] By electrically connecting the terminal of the metal interlock tube and the terminal of the metal reinforcing layer in one terminal fitting B, the interlock tube and the metal can be connected from the detector on the other terminal fitting A side. A closed circuit is formed using the reinforcing layer as a reciprocating electrical path.

Any part of the interlock tube and metal reinforcing layer that make up the flexible composite tube 1 may be deformed or damaged due to external trauma or fatigue deterioration.
When an abnormality such as a break occurs, the electrical resistance of the reciprocating circuit changes and increases compared to the normal state, and the circuit current also changes.

Therefore, on the terminal fitting A side, a detector measures the current due to the change in resistance value of the circuit between the interlock tube and the metal reinforcing layer, and if the measured value changes from normal, the interlock tube and the metal reinforcing layer This means that an abnormality has occurred in one of the above, and it is possible to detect an abnormality due to fatigue deterioration of the interlock tube or metal reinforcing layer based on the instructions from this detector.

[Examples] Examples of the present invention will be described below with reference to the drawings. FIG. 1 shows one embodiment of the present invention, where 1 is a visible composite tube. In FIG. 1, the cross section of the visible composite tube 1 shows only a cylindrical section 174, and the other 3/4 sections are symmetrical and are therefore omitted from illustration. 2 is the innermost metal interlock tube,
It is formed by spirally wrapping thin metal tape into a flexible hollow tube. 3 is a plastic tube made of epoxy tit resin on its outer periphery. 4.5 is a double metal reinforcing layer on the outer periphery, for example, an inner reinforcing layer made visible by wrapping a metal tape with a U-shaped cross section so that the opening of the U-shaped cross section is on the outside; The outer reinforcing layer is formed by wrapping a U-shaped metal tape so that the opening of the U-shaped cross section is on the inside and meshing with the metal tape of the inner reinforcing layer. 6 is an outer sheath on its outer periphery, which includes an interlock tube 2, a plastic tube 3, and a metal reinforcing layer 4.5.
, an outer sheath 6 forms a flexible composite tube 1.

A cylindrical insulating side end fitting A and a conducting side end fitting B are attached to both ends of the visible composite tube 1. In addition, in Figure 1,
The upper half of the cylindrical shape and the lower half of the symmetrical shape of the terminal fitting A are omitted and only the upper half is shown in cross section, and the upper half of the terminal fitting B is shown in cross section. The visible composite tube 1 that is continuous between B is shown schematically by a chain line.

At one end 1a of the flexible composite tube 1, the end 2a of the interlock tube 2 and the ends 4a, 5 of the metal reinforcing layer 4.5 are connected.
A detector is connected between both terminals 2a, 4a, and 5a, and the terminal fitting A is attached to the insulated terminal 1a, and is referred to as an insulated terminal fitting. Further, at the other end 1b of the flexible composite tube 1, the end 2b of the interlock tube 2 and the ends 4b, 5b of the metal reinforcing layer 4.5 are electrically connected to each other to establish continuity, and this conductive side end The terminal fitting B attached to 1b is referred to as the conductive side terminal fitting.

The insulating end fitting A attached to the insulating end 1a of one end of the visible composite tube 1 is constructed as follows.

Interlock tube 2 at one end of flexible composite tube 1
An insulating ring 8.9 is placed on the end edge 7 of the end 2a of the plastic pipe 3 and the end 3a of the plastic pipe 3, a metal end body 10 is fitted, and an annular packing 11 is fitted on the outer periphery of the end of the plastic pipe 3.

This end body 10 has the same inner diameter as the interlock tube 2, and has an end 2a of the interlock tube 2, an end 3a of the plastic tube 3, and an insulating ring 8.
A recess 12 into which the annular gasket 9 is inserted and a recess 13 into which the annular gasket 11 is inserted and pressed are provided. Press down the outer circumferences of the ends 2a and 3a of the lock tube 2 and plastic tube 3.

The inner casing 16 and the terminals 4a, 5a of the metal reinforcing layer 4.5 are connected with a bond wire 17 to form the metal reinforcing layer 4.5.
The terminals 4a, 5a of 5 and the end body 10 are electrically connected, and the inner gauging 16 and the metal reinforcing layer 4.5 are electrically connected to each other.
An epoxy resin insulator 18 is placed on the outer circumference of the terminals 4a and 5a of the outer sheath 6 and the outer circumferential surface of the outer sheath 6, and An annular packing 21 is provided between them to hold them down. 22 is a flange portion at the tip of the end body 10.

A lead wire 23 is connected to the terminal 2a of the interlock tube 2 and pulled out to the outside, a lead wire 24 is connected to the end body 10, and a detector 25 such as an ammeter is connected to both lead wires 23 and 24. and the terminal 4a of the metal reinforcing layer 4.5,
A detector 25 is connected between the interlock tube 5a and the end 2a of the interlock tube 2 via a bond wire 17, an end body 10, and lead wires 23 and 24.

The conduction side terminal fitting B attached to the conduction side terminal 1b of the other end of the visible composite pipe 1 is constructed as follows.

The conductive side terminal fitting B connects the terminals 2b and 3 of the interlock tube 2 and the plastic tube 3 to a recess 27 deep inside the metal end body 26 whose inner diameter is the same as that of the interlock tube 2.
b, place the annular packing 29 in the packing holding recess 28 of the inner part, and press the inner end surface 3 of the end body 26.
The ends 2b and 3b of the interlock tube 2 and the plastic tube 3 are pressed by pressing the annular packing 29 with the tip of a metal inner gauging 32 fixed with a fixing bolt 31.

The inner gauging 32 and the terminals 4b, 5b of the metal reinforcing layer 4.5 are connected with a bond wire 33 to form the metal reinforcing layer 4.5.
The terminals 4b, 5b of 5 and the end body 26 are electrically connected, and the inner gauging 32 and the metal reinforcing layer 4.5 are electrically connected to each other.
The outer periphery of the terminals 4b and 5b of the outer sheath 6 and the outer periphery of the terminal 6b of the outer sheath 6 is covered with an epoxy resin insulator 34, and the outer periphery of the rear end 36 of the outer casing 35 screwed onto the outer periphery of the end body 26 and the outer periphery of the terminal 6b of the outer sheath 6. Annular packing 37 between the surfaces
Place and press. 38 is a flange portion at the tip of the end body 26.

A metal sleeve 3 is attached to the end 2b of the interlock tube 2.
By welding 40 one end of the sleeve 39 to the end body 26 and welding 41 the other end of the sleeve 39 to the end body 26 to connect the end 2b of the interlock tube 2 and the end body 26, the end 4b of the metal reinforcing layer 4.5 , 5b and the end 2b of the interlock tube 2 are electrically connected via the bond wire 33, the end body 26, and the sleeve 39.

By attaching the insulating side terminal fitting A and the conductive side terminal fitting B to both ends of the flexible composite tube 1 as described above and connecting the detector 25, the interlock tube 2 and the metal reinforcing layer 4 of the visible composite tube 1 are connected. A circuit is formed in which . 4.5 All terminal fittings! The circuit is formed by the bond wire 17 of l, the bond body 10, the lead wire 24, and the detector 25.

The resistance value of the interlock tube 2 in a normal state with the entire length of the visible composite tube 1 intact is R1, the resistance value of the metal reinforcing layer 4.5 is 82, the resistance value at the insulating side terminal fitting A is R3, the conductive side terminal If the resistance value at metal fitting B is R4, the normal resistance value RO of the above circuit in this normal state is RO
= old + R2 + R3 + 84.

Therefore, this normal interlock tube 2, metal reinforcing layer 4.
When the circuit No. 5 is energized, the detector 25 will indicate a predetermined current value in this normal state.

Interlock tube 2 and metal reinforcement layer 4 of this visible composite tube 1
．． When any of the parts 5 deteriorates due to fatigue or is subjected to external trauma, the cross-sectional area decreases due to deformation, or damage or breakage occurs, but when abnormalities such as deformation, damage, or breakage occur, the electrical resistance value of that part becomes normal. When the interlock tube 2 or the metal reinforcing layer 4.5 is completely cut off, the resistance value becomes infinite.

In this way, the interlock tube 2 or the metal reinforcing layer 4.
If an abnormality occurs in any one of the resistors 5 and its resistance value changes from the normal value R1 or R2, the detector 25 such as an ammeter will give a different indication from the indication in normal times. Therefore, fatigue deterioration of the interlock tube 2 and the metal reinforcing layer 4.5 can be detected by the instruction from the detector 25.

If fatigue deterioration is detected in either the interlock tube 2 or the metal reinforcing layer 4.5, the flexible composite tube 1 is immediately replaced with a new visible composite tube to maintain safety. It is.

[Effects of the Invention] As described above, the present invention forms a closed circuit for abnormality detection with the terminal of the interlock tube, the metal reinforcing layer, and the detector, and detects the interlock tube or the metal reinforcement by changing the circuit resistance at the time of abnormality. Since abnormalities in the layers are detected, if fatigue deterioration or the like occurs in the visible composite pipe, it can be immediately detected and safety can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view of a conventional example. 1: Flexible composite tube 2: Interlock tube 4.5:
Metal reinforcing layer 25: Detector A, B: Terminal fitting Patent applicant Furukawa Electric Co., Ltd. agent Patent attorney Oka 1) Kikuji No. 11! l 21st m

Claims (1)

[Claims] Attach terminal fittings to both ends of a flexible composite tube having a metal interlock tube and a metal reinforcement layer, electrically connect the end of the interlock tube and the end of the metal reinforcement layer at one terminal fitting, and connect the end of the interlock tube and the end of the metal reinforcement layer at one terminal fitting, and A flexible composite tube characterized in that a detector is connected between each terminal of the interlock tube and the metal reinforcing layer in the metal fitting, and deterioration is detected by detecting a change in resistance between the interlock tube and the metal reinforcing layer. Deterioration detection method.