JPH05340488A - Reinforced rubber hose - Google Patents

Abstract

PURPOSE:To provide a reinforced rubber hose which is prevented from leakage of internal fluid even in a state that an external flaw is produced, capable of detecting a main reinforcing layer, and wide in application and economical by forming a specified cord-contained tubular main reinforcing layer, an auxiliary reinforcing layer, and a buckling resisting layer. CONSTITUTION:A reinforced rubber hose A is formed such that a buckling resisting layer 2, an auxiliary reinforcing layer 3, and a main reinforcing layer 5 are formed, in the order, from the inner peripheral side between inner and outer peripheral rubber layers 1 and 7. The cord angle of the polyester fiber codes C of the main reinforcing layer 5 is 35-45 deg., the cord angle of the auxiliary reinforcing layer 3 is 35-50 deg. and higher than that of the main reinforcing layer 5. The cord angle of the steel fiber cords B of the buckling resisting layer 2 is 80-90 deg.. Since the auxiliary reinforcing layer is radially expanded when the main reinforcing layer is broken, breakage of the main reinforcing layer is detectable. Since, even when an external flaw is produced, the auxiliary reinforcing layer is not broken before the main reinforcing layer, is broken, the breakage thereof can be reliably detected by means of an auxiliary reinforcing layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforced rubber hose used for dredging, transporting oil and other fluids.

[0002]

2. Description of the Related Art Conventionally, the above-mentioned reinforced rubber hose has a sectional structure as shown in FIG. That is, the reinforced rubber hose includes the inner rubber layer 91 and the reinforced layer 9 from the inner peripheral side.
2. Buckling resistant layer 93 including a rigid member 93a composed of a spiral wire, a ring, etc., a breaker layer 94, and an outer rubber layer 9
5 are sequentially laminated.

As the inner rubber layer 91, one having excellent corrosion resistance against the fluid to be transported is used. The reinforcing layer 92 is
It is configured to include a fiber cord arranged so as to form a predetermined angle (hereinafter, referred to as a cord angle) with respect to the hose axis direction, and mainly contributes as a pressure resistant layer. The rigid member 93a such as a spiral wire prevents the reinforcing rubber hose from being crushed or buckled by bending, and particularly restricts the radial expansion (extension in the circumferential direction) of the reinforcing layer 92.
The breaker layer 94 prevents the rigid member 93a such as a spiral wire from being exposed to the outside, and also prevents cut damage due to external damage to the reinforcing rubber hose. As the outer rubber layer 95, one having excellent weather resistance and the like is used.

By the way, in the above-mentioned reinforced rubber hose, if the reinforcing layer 92 is cracked or ruptured for some reason, the internal fluid leaks out through the reinforcing layer 92 to the outside. If the leaked fluid is oil or chemicals, problems such as environmental pollution occur. In particular, when such a leak occurs at sea, the pollution becomes a very serious problem.

Therefore, as disclosed in Japanese Utility Model Laid-Open No. 2-41786, the reinforcing layer is composed of a main reinforcing layer on the inner peripheral side and a sub-reinforcing layer on the outer peripheral side, or as disclosed in Japanese Patent Publication No. 57-15756. As described above, by providing the flexible bag body, a reinforced rubber hose is provided in which the fluid to be transported is retained by the flexible bag body and the sub-reinforcing layer when the main reinforcing layer is damaged. ..

[0006]

By the way, the following 1) to 3) are conceivable as modes of breaking the reinforcing rubber hose. 1) The internal pressure rises above the strength of the reinforcing cord and it breaks (fatigue of the reinforcing cord also becomes a factor). 2) For some reason, cracks from inside reach the main reinforcement layer and break.

3) For some reason, external cracks reach the main reinforcing layer and break. In general, the damage due to the cause 2) is extremely small, and the damage due to 1) or 3) is large. The damage caused by 3) is often caused by the cut by the screw of the ship or the collision by the driftwood. On the other hand, in the reinforced rubber hose disclosed in the above publication, a sub-reinforcing layer and a flexible bag body for retaining an internal fluid when the main reinforced layer is broken are arranged on the outer peripheral side of the main reinforced layer. Therefore, in the case of being damaged, the sub-reinforcing layer and the flexible bag will be damaged before the main reinforcing layer. Since damage to the sub-reinforcement layer, etc. cannot be detected, such a damaged rubber hose is used as it is.If the main reinforcement layer breaks during use, it cannot be detected and the internal fluid is It will leak.

Further, in the conventional reinforced rubber hose in which the auxiliary reinforcing layer is arranged on the outer peripheral side of the main reinforcing layer and the internal fluid is retained by the auxiliary reinforcing layer when the main reinforcing layer is broken, the inner rubber layer which normally contacts the internal fluid is It was uneconomical to use a rubber layer having excellent corrosion resistance against the internal fluid for the two layers of the sub-reinforcing layer that come into contact with the internal fluid in an emergency. On the other hand, Japanese Patent Publication No. 59-47188 and Japanese Patent Laid-Open No. 26978.
There is also provided a structure in which a buoyant material is provided on the outer peripheral side of a sub-reinforcing layer, as shown in Japanese Patent Publication No. 5, which is a buoyant material that functions to prevent external damage, but in such a structure, It is limited to hoses used at sea.

The object of the present invention is to solve the above technical problems, to reliably prevent the leakage of the internal fluid even in the state of being damaged, and to detect the breakage of the main reinforcing layer and to use the same. Is to provide a wide and economical reinforced rubber hose.

[0010]

As a reinforcing rubber hose of the present invention for achieving the above object, a tubular main reinforcing layer containing a fiber cord between a tubular inner surface rubber layer and an outer surface rubber layer, and a sub-reinforcing layer are provided. In a reinforced rubber hose provided with a layer and a buckling resistant layer, a sub reinforcing layer is provided on the inner peripheral side of the main reinforcing layer and a buckling resistant layer is provided on the inner peripheral side of the sub reinforcing layer. The fiber cords of the buckling resistant layer are arranged so as to form an angle of 80 to 90 degrees with respect to the hose axis direction, and the fiber cords of the main reinforcing layer are 35 degrees to with respect to the hose axis direction.
The fiber cord of the sub-reinforcing layer is arranged at an angle of 45 degrees, the fiber cord of the sub-reinforcing layer is at an angle of 35 to 50 degrees with respect to the hose axis direction, and the fiber cord of the main reinforcing layer is with respect to the hose axis direction. It is characterized in that it is arranged so as to form an angle larger than the angle formed.

[0011]

According to the above construction, the cord angle of the fiber cord of the sub-reinforcing layer is smaller than the static angle of 54 degrees and 44 minutes.
Since the main reinforcing layer is broken, the sub-reinforcing layer expands in the radial direction (extends in the circumferential direction) so that its cord angle approaches the static angle. Therefore, due to this expansion, breakage of the main reinforcing layer can be detected.

Further, in the conventional structure in which the sub-reinforcing layer is arranged on the outer peripheral side of the main reinforcing layer, only the sub-reinforcing layer may be damaged due to external damage. If the main reinforcing layer is damaged in this state, this can be detected. Although the internal fluid leaks without any problem, in the present invention, since the sub-reinforcing layer is arranged on the inner peripheral side of the main reinforcing layer, the sub-reinforcing layer is not damaged before the main reinforcing layer, The breakage of the main reinforcement layer can be reliably detected, and the leakage of the internal fluid can be prevented by the sub reinforcement layer.

Furthermore, since the cord angle of the fiber cord of the sub-reinforcing layer is larger than the cord angle of the fiber cord of the main reinforcing layer, the impact received by the sub-reinforcing layer when the main reinforcing layer is broken is reduced. You can

[0014]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a schematic vertical sectional view of a reinforced rubber hose showing an embodiment of the present invention. With reference to FIG. 1, the reinforced rubber hose A has, from the inner peripheral side thereof, an inner rubber layer 1 made of rubber having excellent corrosion resistance to an internal fluid, a buckling resistant layer 2 including a steel fiber cord B, and a fiber cord as a fiber cord. From the sub-reinforcing layer 3 containing the polyester fiber cord C, the intermediate rubber layer 4, the main reinforcing layer 5 containing the polyester fiber cord C, the breaker layer 6 for preventing cut scratches due to external damage, and the rubber having excellent weather resistance. The outer rubber layer 7 is formed in this order.

The main reinforcing layer 5 is a polyester fiber cord C.
And a rubber layer containing at least two plies. Polyester fiber cord C between adjacent plies
Are arranged in opposite directions. The number of laminated plies of the main reinforcing layer 5 is selected so that a predetermined breaking strength can be obtained. Referring to FIG. 2, the cord angle θ of the main reinforcing layer 5 with respect to the hose axis direction P is preferably set in the range of 35 degrees to 45 degrees.

The sub-reinforcing layer 3 is composed of a rubber layer containing at least two plies of polyester fiber cord C made of the same material as the fiber cord on the main reinforcing layer 5 side. The number of laminated plies of the auxiliary reinforcing layer 3 is selected so that a predetermined breaking strength can be obtained. The cord angle of the cord of the sub-reinforcing layer 3 is more than the rest angle so that the sub-reinforcing layer 3 can extend in the hose circumferential direction (expand in the radial direction) when the main reinforcing layer 5 is broken. Small 3
It is preferably set in the range of 5 degrees to 50 degrees, and more preferably set in the range of 45 degrees to 50 degrees.

The buckling resistant layer 2 is made of a rubber layer containing a steel fiber cord B, and is laminated by at least two plies. The cord angle of the steel fiber cord B is 80 degrees to 9 degrees.
It is preferable to set in the range of 0 degree. Instead of the steel fiber cord B, a chemical fiber cord can be used. According to this example, the cord angle of the polyester fiber cord C of the sub-reinforcing layer 3 is set to 35 degrees to 50 degrees, which is smaller than the resting angle of 54 degrees and 44 minutes, and when the main reinforcing layer 5 breaks, The reinforcing layer 3 expands in the radial direction (extends in the circumferential direction) as the cord angle approaches the stationary angle, and thus the breakage of the main reinforcing layer 5 can be detected by this expansion.

Further, in the conventional structure in which the sub-reinforcing layer is arranged on the outer peripheral side of the main reinforcing layer, only the sub-reinforcing layer may be damaged due to external damage. If the main reinforcing layer is damaged in this state, this can be detected. There is a problem that the internal fluid leaks out, but in the present embodiment, since the sub-reinforcing layer 3 is arranged on the inner peripheral side of the main reinforcing layer 5, the sub-reinforcing layer 3 is arranged before the main reinforcing layer 5. Even if the main reinforcing layer 5 is damaged due to external damage due to the damage of the layer 3 as shown in FIG. 3, this can be reliably detected by the expansion of the auxiliary reinforcing layer 3. At the same time, the strength of the sub-reinforcing layer 3 is maintained, so that leakage of the internal fluid can be reliably prevented.

Further, since the cord angle of the polyester fiber cord C of the sub-reinforcing layer 3 is larger than the cord angle of the polyester fiber cord C of the main reinforcing layer 5, the sub-reinforcing layer when the main reinforcing layer 5 is broken. It is possible to reduce the impact that the 3 receives. In addition, since only one inner rubber layer is required as the rubber layer having corrosion resistance against the internal fluid, it is economical.

Furthermore, since the intermediate rubber layer 4 is arranged between the main reinforcing layer 5 and the sub reinforcing layer 3, the impact applied to the sub reinforcing layer 3 when the main reinforcing layer 5 is broken can be alleviated. The present invention is not limited to the above-mentioned embodiments, and for example, the buckling resistant layer 2, the main reinforcing layer 5 and the sub reinforcing layer 3 are included.
The fiber cord contained in each may be either a chemical fiber cord or a steel fiber cord, and as the chemical fiber cord, other than polyester fiber,
Nylon fibers, Kevlar fibers (DuPont) and the like can also be used. In addition, various design changes can be made without changing the gist of the present invention. Test In the reinforced rubber hose according to the example of FIG. 1, the buckling resistant layer 2, the sub reinforced layer 3, the main reinforced layer 5, etc. were set to the following specifications. Buckling resistant layer 2: Steel fiber cord B with a cord angle of 90 degrees
Was laminated for 2 plies. Sub-reinforcing layer 3: Two plies of polyester fiber cord C having a cord angle of 45 degrees are laminated to have a design breaking pressure of 2.94M.
It was Pa. Main reinforcing layer 5: Two plies of polyester fiber cord C having a cord angle of 35 degrees are laminated, and the designed breaking pressure is 7.84M.
It was Pa.

The inner diameter of the hose was 125 mm, and the thickness of the intermediate rubber layer 4 was 10 mm. Then, one end of this reinforcing rubber hose was covered and hermetically closed, and a predetermined amount of water was poured from the other end every unit time to increase the internal pressure until the reinforcing rubber hose was broken, and the results shown in FIG. 4 were obtained. That is, when the main reinforcing layer 5 breaks at 8.33 MPa (indicated by a in the figure), the pressure inside the hose sharply drops, but the hose strength is maintained by the auxiliary reinforcing layer 3,
There is no leakage of internal fluid. Then, when the water injection is further continued, the space between the steel fiber cords B of the buckling resistant layer 2 having a cord angle of 90 degrees with respect to the hose axis direction is expanded, and the internal pressure is applied to the sub-reinforcing layer 3. Become. The reinforcing rubber hose expanded in the radial direction in an attempt to bring the cord angle of the polyester fiber cord C of the sub-reinforcing layer 3 closer to the stationary angle. Due to this expansion, the breakage of the main reinforcing layer 5 could be detected. After that, the sub-reinforcing layer 3 broke at 3.53 MPa (indicated by b in the figure).

[0022]

As described above, according to the reinforced rubber hose of the present invention, when the main reinforcing layer is broken, the sub reinforcing layer expands in the radial direction, whereby the break of the main reinforcing layer can be detected. In addition, even when the external reinforcement is damaged, the sub-reinforcement layer is not damaged before the main reinforcement layer, so that when the main reinforcement layer is broken, it can be reliably detected by the sub-reinforcement layer. Leakage of the internal fluid can be prevented by maintaining the strength of the sub-reinforcing layer.

Further, since the cord angle of the fiber cord of the sub-reinforcing layer is larger than the cord angle of the fiber cord of the main reinforcing layer, the impact received by the sub-reinforcing layer when the main reinforcing layer is broken is reduced. You can In addition, since only one inner rubber layer is required as the rubber layer having corrosion resistance against the internal fluid, various unique effects of being economical are exhibited.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a reinforced rubber hose according to an embodiment of the present invention.

FIG. 2 is a schematic view showing an arrangement direction of polyester fiber cords.

FIG. 3 is a schematic vertical sectional view showing a state in which a main reinforcing layer of a reinforced rubber hose is broken.

FIG. 4 is a diagram showing a change over time in the internal pressure of the hose when a predetermined amount of water is poured.

FIG. 5 is a schematic vertical sectional view of a conventional reinforced rubber hose.

[Explanation of symbols]

 1 Inner surface rubber layer 2 Buckling resistant layer 3 Secondary reinforcement layer 5 Main reinforcement layer 7 Outer surface rubber layer C Polyester fiber cord D Steel fiber cord P Hose axial direction

Claims (1)

[Claims] 1. Between a tubular inner surface rubber layer and an outer surface rubber layer,
In a reinforced rubber hose in which a tubular main reinforcing layer including a fiber cord, a sub-reinforcing layer and a buckling resistant layer are provided, the sub-reinforcing layer is provided on the inner peripheral side of the main reinforcing layer and the sub-reinforcing layer is provided. A buckling resistant layer is provided on the inner peripheral side of the hose, and the fiber cord of the buckling resistant layer is 80
The fiber cords of the main reinforcing layer are arranged so as to form an angle of 90 degrees to 90 degrees.
The fiber cord of the sub-reinforcing layer is arranged at an angle of 45 degrees with respect to the hose axis direction.
A reinforcing rubber hose, characterized in that the reinforcing cord hose is arranged at an angle of 50 degrees to 50 degrees and is larger than the angle formed by the fiber cord of the main reinforcing layer with respect to the axial direction of the hose.