JPH05272469A - Damage sensing hose - Google Patents

Abstract

PURPOSE:To provide a damage sensing hose capable of positively sensing the rupture of a sensitive wire embedded therein and prevented from the generation of dislocation, wear, and the like of the sensitive wire. CONSTITUTION:In a cylindrical hose formed of an inner surface layer 5, a reinforcing layer 7 and an outer surface layer 8, a conductive sensing wire 6 covered with insulating material is integrally embedded between the inner surface layer 5 and the reinforcing layer 7 through insulating covering material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber hose or a resin hose having an inner surface layer, a reinforcing layer and an outer surface layer, which can detect a damage hose when the inner surface layer is worn and worn by a fluid. , For example, in a slurry hose whose inner surface layer is made of elastomer, the inner surface layer may be worn and worn by the fluid, and if the reinforcing layer is damaged, the hose may be destroyed, but the wear life of the inner surface layer should be sensed. The present invention relates to a breakage detection hose that prevents damage to the reinforcing layer.

[0002]

2. Description of the Related Art In a use where the inner surface layer of a hose is worn like a slurry fluid in which solid particles are mixed in a liquid, the life cannot be predicted by observing it from the outer surface. The service life was predicted, a certain amount of pumping amount or time was set, and it was replaced periodically. However, the wear rate of the inner surface layer of the hose fluctuates greatly depending on the pumping method and fluid conditions, and the periodic replacement of the hose must be set to a time much shorter than the expected life, resulting in high cost. Met.

Therefore, the following hose breakage sensing means are provided for the hose used for the pumping of fresh concrete among the slurry fluids.

That is, Japanese Patent Publication No. 58-21118, "Squeezing-out type concrete pump" (conventional example 1) discloses a structure in which a sensing wire having conductivity is arranged over the entire circumference of the hose. Also, Japanese Patent Publication No. 58-21117 “Squeezing-out type concrete pump” (conventional example 2) discloses a configuration in which the sensing lines are partially arranged. Furthermore, the actual Kaihei 2-543
No. 95 "Squeeze Pumping Tube" (Conventional Example 3)
Discloses a structure in which the main reinforcing layer of the hose is a conductive steel cord, and the steel cord itself is a sensing wire. All of them are intended to detect the breakage of the hose itself in advance by cutting the sensing wire by wear and tear.

[0005]

By the way, the above-mentioned conventional example 1
2 and 3 have the following drawbacks because they have a conductive sensing wire embedded directly inside the hose.

(1) Since the inner surface layer and the sensing wire are not adhered to each other, the sensing wire itself may be displaced due to bending of the hose, or the sensing wire may be pulled out from the inner surface layer and broken when it comes into contact with fluid. I don't.

(2) Since the sensing wire is in direct contact with the inner surface layer or the reinforcing layer, the inner surface layer or the reinforcing layer rubs against the sensing wire when the hose is bent, so that the sensing wire itself is worn out, or the reinforcing layer or the inner surface is damaged. It could damage the layers and both.

(3) When a rubber hose is used, it is general to add a large amount of carbon for the purpose of improving abrasion resistance. However, since carbon has good conductivity, even if a part of the sensing wire is in direct contact with the inner rubber layer or the covering rubber layer of the reinforcing layer, when the sensing wire itself is damaged, it is smaller than the resistance value through the fluid. Since only the resistance value is shown, even if the sensing line is cut by the slurry fluid, the conductivity from other parts is superior, and it may not be useful for sensing.

This is remarkable in the method of Conventional Example 3 in which the steel cord is used as the reinforcing layer and the steel cord itself is used as the sensing line. In order to accurately detect damage, the inner rubber layer and the reinforcing rubber layer of the reinforcing layer should not be used. It is required that the slurry which is composed of a conductive material or which is a fluid is a non-conductive material.

Therefore, the object of the present invention is to
In a broken sensing hose with embedded sensing wire, the sensing wire is firmly adhered to the inner surface layer or the reinforcing coating layer, which causes misalignment due to bending, etc., or wears itself off or wears against other members. The resistance value when the sensing wire is worn, worn or cut by the slurry fluid is increased, and it is a material with relatively good conductivity than the resistance value through the fluid and carbon blending. The difference is larger than the resistance value between the fluid and the fluid so that the sensing wire is surely broken.

[0011]

In order to achieve the above object, a breakage detecting hose according to the present invention is a cylindrical hose composed of an inner surface layer, a reinforcing layer, and an outer surface layer, and is made of a conductive material coated with an insulating material. The wisdom wire is integrally embedded in the hose between the inner surface layer and the reinforcing layer via an insulating material.

That is, the damage detection hose of the present invention is
Instead of burying the sensing wire directly in the hose, the sensing wire is covered and integrated with a non-conductive insulating material, and is strongly bonded and integrated with the covering rubber layer of the inner surface layer or the reinforcing layer through this insulating material. It is what

The sensing line disposed between the inner surface layer and the reinforcing layer, that is, the outermost layer of the inner surface layer has a better bending fatigue resistance than the reinforcing member used for the reinforcing layer of the hose, and other than wear and abrasion due to slurry fluid. It is preferable to use a conductive material that is not worn and damaged, for example, a material composed of a wire material that is thinner than the reinforcing member.

FIG. 1 shows an axial cross-sectional view of a breakage sensing hose composed of an inner surface layer 1, a reinforcing layer 2 and an outer surface layer 3 and a sensing wire 4 buried in the outermost portion of the inner surface layer 1. In such a hose, the sensing function when the insulating coating sensing wire according to the present invention is used as the sensing wire 4 and the sensing function when the sensing wire without insulating coating is used are compared.

FIG. 2 is a sectional view of a hose according to the present invention which uses an insulating coating sensing wire as the sensing wire 4, and FIG. 3 is a sectional view of a hose when a bare sensing wire having no insulating coating is used, FIG. 4 and FIG. 5 shows a sectional view when the inner surface layer 1 of the hose of FIGS. 2 and 3 is worn and the sensing wire 4 is cut, and the broken portion is in contact with the fluid.

2 and 3, a to d respectively indicate the following resistances.

A: resistance between the reinforcement and the sensing line b: resistance between the fluid and the sensing line c: resistance between the inner surface layer and the sensing line d: resistance between the sensing line distances In FIGS. 4 and 5, d ′ Indicates the resistance between the sensing line distances when the inner surface layer is worn and the sensing line is cut.

The measured resistance values are shown in the following table.

[Table 1] * D1: Distance 10 mm d2: Distance 100 m * A: When using a general-purpose carbon compound rubber for both the inner surface layer and the reinforcing layer, and embedding a steel cord in the reinforcing layer. * B: When the inner surface layer and the reinforcing layer are made of a rubber compounding carbon compound rubber (compounding tables 1 and 2), and the steel cord is embedded in the reinforcing layer. * Inner layer is 5.0mm thick * Reinforcing layer is 1.5mm thick * Fluid: Water and Portland cement are mixed 1: 1 * Sensing line: S70C 3x3 (0.15) * Insulation coating sensing line: Natural Rubber white compounding (composition table 4)
0.5mm all around the sensing line * The rubber composition of the outer layer is as shown in compounding table 3.

[0019]

[Table 2]

[Table 3] As is clear from the measured resistance values shown in Table 1, the resistance value of the sensing line over the entire circumference of the hose is 16 to 60 Ω in both the insulating coating sensing line and the non-insulating coating sensing line. When it breaks, it shows a large resistance value of 1500Ω, so that the occurrence of break can be detected.

However, in the vicinity of the location where the sensing line is embedded,
When the resistance value with the inner surface layer or the reinforcing layer may show a value close to 16 to 60 Ω, a current flows through these materials, so that even if the sensing wire is cut, it cannot be accurately sensed.

In the case of a slurry hose whose inner surface layer is worn away, when the material of the inner surface layer is rubber, carbon is often added to improve wear resistance, but when the sensing wire comes into direct contact with it. , The resistance value decreases, and the sensing ability as described above is lost. That is, as shown in Table 1, in the case of a sensing wire not having an insulating coating, the resistance values of the sensing wire and the reinforcing layer (a) and between the sensing wire and the inner surface layer (c) are 20 to 240.
Since it is Ω, it is close to the insulation resistance 16 to 60 Ω of the sensing line itself, and in some cases, it falls below that, so that it is impossible or extremely difficult to detect even if the sensing line is cut. On the other hand, when the insulating coated sensing wire according to the present invention is used, the resistance values of the sensing wire, the reinforcing layer (a) and the inner surface layer (c) also show high values of 1200Ω and 2400Ω, respectively. It is a value close to the resistance at the time of disconnection, and it can be seen that when the sensing line is disconnected, the change in resistance value can be easily sensed, and reliable sensing is possible.

In many slurry hoses, metal fibers such as steel cords are used as a reinforcing member for the reinforcing layer for pressure reinforcement, but they are in close proximity to the sensing line and the sensing line is in direct contact. There is a risk of losing its perceptibility. Therefore, in such a case, it is difficult to adopt the method of predicting the damage of the hose itself due to the change in the current value due to the disconnection of the sensing wire. It can be achieved.

[0023]

As described above, when the insulating coated sensing wire of the present invention is used, when carbon-containing rubber is used in the neighboring member, or when the steel cord is buried, it does not interfere with the neighboring member under any circumstances. Since the resistance value of is high, when the sensing line is cut, the change in the resistance value can be reliably sensed, and the hose can be predicted in advance.

Further, since the insulating coating material and the sensing wire, and the insulating coating material and the inner surface layer and the reinforcing layer are firmly adhered and integrated, the problems of contact wear and abrasion with each layer when the hose is bent are solved, and the sensing wire There is no problem of position fluctuation, and even if the sensing lines are arranged at a high density, all are fixed by adhesion, so there are no instability factors, and the initial purpose and function can be fully achieved.

[0025]

EXAMPLE FIG. 6 shows an example in which the insulating coating sensing wire according to the present invention is used in the slurry hose H. FIG. 7 shows an example in which this hose H is used in a squeezing type concrete pump.

In FIG. 6, 5 is an inner surface layer, 6 is an insulating coated sensing wire embedded in the outermost surface of the inner surface layer, 7 is a reinforcing layer, and 8 is an outer surface layer. Inner surface layer 5 has an inner diameter of 100 mm and an outer diameter of 120 mm
Therefore, the abrasion-resistant rubber compound of the compounding table 1 was adopted. Reinforcing layer 7
Uses two 2mm thick steel cord plies. The composition of the coated rubber for the steel cord is shown in Formulation Table 2. The outer surface layer 8 had an inner diameter of 128 mm, an outer diameter of 132 mm, and the rubber compound used was a general-purpose rubber compound shown in Compound Table 3.

The sensing wire is made of S70C high carbon steel, and 3 ×
A 3 (0.12 mm) Zn plated strand was used. An adhesive (for example, Toyo Kagaku Kenkyu Metalloc A
After S) was applied, the rubber of Formulation Table 4 was coated. This coated rubber can be semi-vulcanized or vulcanized in advance and firmly adhered to the sensing wire main body, but after being wrapped around the unvulcanized inner surface layer 5 in an unvulcanized state. It is also possible to vulcanize the entire hose to integrate it. Of course, even if it is vulcanized in advance, it can be sufficiently vulcanized and integrally bonded with other members. The embedding pitch of the sensing wire was 50 mm with respect to the total hose length of 3300 mm.

FIG. 7 shows a state in which the hose H is mounted in the pump. 9 is a pump case, 10 is a hopper, 11 is a discharge side pipe, 12 is a rotor, 13 is a roller, and 14 is a discharge side exposed. A sensing line 15 is an inhalation side exposure sensing line.

When a fresh concrete was put into the hopper 10 of such a pump device and a pressure-feeding test was conducted, when a hose having no sensing line was pressure-fed with 4050 m ³ of the fresh concrete, the hose became its reinforcing layer. Co-ruptured. For a hose with a sensing line, the resistance between the sensing lines at both ends of the hose when not in use (about 30 m) is 6Ω, and the resistance 150 when the sensing line is cut off due to the worn state shown by the diagonal lines in FIG.
With 0Ω, the amount of fresh concrete pumped at this time is 4000 m
^{Was 3} . Therefore, it was possible to pass a current between the sensing lines in advance and sense that the current value fluctuates greatly, and stop the pumping before the hose breaks.

[0030]

As described above, the breakage detecting hose of the present invention is capable of accurately detecting the breakage of the sensing line and accurately detecting the breakage of the hose regardless of the presence of the rubber compound in the inner surface layer and the reinforcing layer and the presence or absence of the steel cord. Can be foreseen. Therefore, since the hose can be replaced before it breaks, it is extremely easy to restore the work. In some cases, it is also possible to replace the part that has not been worn out with the maximum wear part and reuse it, and predict the hose life surely to maximize the hose life and improve the hose life. It can be greatly improved.

Further, since the sensing wire is integrally buried via the insulating coating material, the problem of contact wear and abrasion with each layer when the hose is bent is solved, and there is no problem of position fluctuation of the sensing wire. Even if the sensing lines are arranged at a high density, all are fixed by adhesion, so there are no instability factors, so there is also an advantage that a stable sensing function can be guaranteed for a long period of time, and a highly reliable damage sensing hose is provided. I was able to provide it.

[Brief description of drawings]

FIG. 1 is an axial cross-sectional view showing a general structure of a breakage sensing hose including an inner surface layer, a reinforcing layer, and an outer surface layer, in which a sensing wire is embedded.

FIG. 2 is a cross-sectional view showing a resistance value measuring portion when an insulating coating sensing wire according to the present invention is used for the sensing wire,

FIG. 3 is a cross-sectional view showing a resistance value measuring portion when a non-insulating sensing wire is used as the sensing wire;

4 is a cross-sectional view showing a state in which a sensing line is cut in the example of FIG.

5 is a cross-sectional view showing a state in which a sensing line is cut in the example of FIG.

FIG. 6 is a cross-sectional view showing an example of a damage detection hose according to the present invention,

FIG. 7 is a partially cutaway side view showing an example in which the hose is used in a squeezing type concrete pump,

FIG. 8 is a cross-sectional view showing a state when the inner surface layer of the same hose is worn and the sensing wire is cut.

[Explanation of symbols]

1 ... Inner layer 2 ... Reinforcing layer 3 ... Outer layer
4 ... Sensing line 5 ... Inner surface layer 6 ... Insulating coating sensing wire 7 ... Reinforcing layer 8 ... Outer surface layer H ... Slurry hose

Front page continuation (72) Inventor Kenzo Miyamoto 1183, Sugaya, Inami-cho, Kako-gun, Hyogo Prefecture Toyo Tire & Rubber Co., Ltd. Hyogo Office Akashi Plant (72) Inventor Katsushi Tanaka Bepsho, Miki City, Hyogo Prefecture Tomoe Machi 2 Far East Development Co., Ltd. Miki Factory Park

Claims (1)

[Claims] 1. A cylindrical hose composed of an inner surface layer, a reinforcing layer, and an outer surface layer, in which a conductive sensing wire covered with an insulating material is integrally embedded between the inner surface layer and the reinforcing layer. Sensing hose.