JP2007146996A - Wear resistant hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wear resistant hose where a degree of wear on an inner face layer can be easily and accurately found. <P>SOLUTION: The wear resistant hose 10 comprises the inner face layer 11 of a rubber elastic material, a wear adjusting layer 12 formed on the outer peripheral face at one end side thereof, and a wear detecting layer 13 of a white rubber elastic material formed on the outer peripheral face. On upper faces of the inner face layer 11 and the wear detecting layer 13, a fiber reinforcing layer 14 is spirally wound. On the outer peripheral face of the reinforcing layer 14, a reinforcing wire 15 is spirally wound at predetermined pitches. A reinforcing layer 17 is wound on the reinforcing wire 15, and an outer face layer 18 of a rubber elastic material is applied to the outside of the reinforcing layer 17. A portion of the inner face layer 11 including the wear adjusting layer 12 covered with the wear detecting layer 13 is adjusted in thickness so that it wears earlier than other portions of the inner face layer 11 and the wear detecting layer 13 is exposed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wear-resistant hose having a tubular shape composed of an inner surface layer and an outer surface layer made of a rubber elastic body, and a reinforcing layer sandwiched therebetween, which are used for placing ready-mixed concrete at a construction site or the like. In particular, the present invention relates to a wear resistant hose capable of knowing the degree of wear of the inner surface layer.

  This type of wear-resistant hose pumps ready-mixed concrete such as cement mixed with solids such as earth and sand, and the inner surface layer made of rubber elastic body gradually wears under a large internal pressure. The vicinity of the metal outlet is easily worn. Since the hose is suddenly damaged due to such accumulation of wear on the inner surface layer, it is necessary to accurately grasp the degree of wear and replace the hose before it is damaged. Conventionally, the degree of wear of the inner surface layer has been determined empirically based on subtle changes in the appearance of the hose, etc., but due to variations in judgment, the hose may be overused for a long time, or the hose may be damaged. There was a problem that the hose was wasted and the hose was wasted because the replacement was too early.

On the other hand, for example, Patent Document 1 provides a cylindrical protrusion of the same material as the connection fitting protruding in the axial direction from the insertion-side end of the rubber hose for the connection fitting fixed to the end of the rubber hose. Is shown. The cylindrical protrusion is thinner than the effective thickness of the connection fitting body, and wears along with the inner rubber layer when the inner rubber layer is worn by the fluid pumped through the hose and approaches the life of the hose pressure limit. Then, it is formed to a thickness that disappears. However, with regard to the method of judging the life of the hose based on the wear of the metal fitting in this way, the hose may be cut at the metal fitting position due to the wear of the metal fitting. For example, when the hose is hung at a high position from the ground, Since there is a great risk that the cut portion of the material will fall, it is not preferable for ensuring work safety.
Japanese Utility Model Publication No. 7-28476

For example, Patent Document 2 discloses a breakage detection hose in which a conductive sensing wire covered with an insulating material is spirally and integrally embedded between an inner surface layer and a reinforcing layer of a hose. According to this breakage detection hose, the wear state of the inner surface layer is grasped by using the fact that the sense wire breaks with the wear of the inner surface layer and checking the conduction state between both ends of the sense wire. It was. However, if the spiral pitch of the sensing lines is widened, the sensing lines cannot sufficiently determine this when the wear of the inner surface layer between the sensing lines is large. For this purpose, the spiral pitch of the sensing wires can be reduced, but if the pitch is too narrow, the hose weight increases and the hose cost increases, and the hose flexibility decreases and the hose routing work is reduced. There is a problem that the performance is lowered. Further, the sensing line may be disconnected due to a large stress such as bending applied to the hose. In this case, it is erroneously determined that the hose is worn. Further, a labor for checking the conduction state of the sensing line and a dedicated device for that purpose are also required. A similar technique is also described in Patent Document 3.
Japanese Patent Laid-Open No. 5-272469 JP-A-8-270844

  An object of the present invention is to provide a wear-resistant hose capable of easily and accurately knowing the degree of wear of an inner surface layer.

  In order to achieve the above-mentioned object, the structural feature of the present invention is that it is formed in a tubular shape by an inner surface layer and an outer surface layer made of a rubber elastic body, and a reinforcing layer sandwiched between the inner surface layer and the outer surface layer. In a wear-resistant hose that is inserted into a side opening and is used for pressure-feeding fluid containing solid matter supplied through the connection fitting, a part near the outlet of the connection fitting is provided between the inner surface layer and the reinforcing layer. When a wear detection layer having a color different from that of the inner surface layer is provided, and the portion covered with the wear detection layer of the inner surface layer is thicker than the other portions of the inner surface layer and the fluid is pumped The thickness is adjusted so that the wear detection layer is exposed by wearing earlier than other portions of the inner surface layer.

  In the present invention configured as described above, a fluid is supplied to the wear-resistant hose with the connection fitting inserted into the one end side opening, so that a large pressure is applied to the inner surface of the hose, particularly in the vicinity of the outlet of the connection fitting. Wear is accelerated. However, in the wear-resistant hose, the portion of the inner surface layer covered with the wear detection layer is thicker than the other portions of the inner surface layer, and wears earlier than the other portions of the inner surface layer, so that the wear detection layer is exposed. The thickness is adjusted to do. For this reason, the inner surface layer wears out sooner than the other portions in the vicinity of the outlet of the connection fitting, and the wear detection layer having a distinct color from the inner surface layer provided outside the inner surface layer is exposed.

  In the present invention, a wear detection layer that is clearly different in color from the inner surface layer is provided between the inner surface layer and the reinforcing layer in the vicinity of the outlet of the connection fitting inserted into the opening on the one end side of the wear resistant hose. Whether or not the wear detection layer appeared without depending on the judgment of the unstable worker's experience, because the thickness of the portion covered with the wear detection layer of the layer was appropriately adjusted. By visually recognizing this, the life of the hose can be judged easily and accurately, and furthermore, damage to the wear resistant hose due to wear of the inner surface layer other than the portion covered with the wear detection layer can be avoided. A wear-resistant hose can be used without waste. Further, since the wear detection layer is only provided in a part near the outlet of the connection fitting, the weight of the hose is not increased, and the bending rigidity is increased, so that the work is not adversely affected.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 schematically show the upper half of the wear-resistant hose used for concrete placing according to the embodiment in a cross-sectional view and a schematic view, and FIG. 3 shows that the fitting is attached to the wear-resistant hose. The upper half of the state is schematically shown by a sectional view.

  As shown in FIGS. 1 and 2, the wear-resistant hose 10 has a cylindrical inner surface layer 11 made of a wear-resistant rubber elastic body (for example, NR / BR) having a length of 7000 mm and an outer diameter of 96 mmφ. Further, a wear adjusting layer 12 that is a part of the inner surface layer 11 is provided with the same material as the inner surface layer 11 on the outer peripheral surface of a region having a length of approximately 1000 mm on one end side (the left end side in the drawing). A white rubber elastic body (NR) wear detection layer 13 is provided on the outer peripheral surface of the layer 12. In addition, about the area | region which provides the abrasion detection layer 13, it is desirable that it is the range of 500 mm or more from the exit of the connection metal fitting 21 mentioned later, and 1000 mm or less from the exit of the connection metal fitting 21. If the area is less than 500 mm, the portion where the wear detection layer 13 is not provided may be worn first and wear detection may not be performed reliably. If the area exceeds 1000 mm, the hose weight increases and bending rigidity increases. It becomes high and it will have a bad influence on the concrete placement work. Since the wear detection layer 13 is white, it is clearly distinguished from the black inner layer 11. A fitting 21 is inserted into one end opening 10 a of the wear-resistant hose 10, and a large pressure is applied when the ready-mixed concrete is pumped through the fitting 21, and the outlet of the fitting 21 provided with the wear detection layer 13. The vicinity is a portion where the inner surface layer 11 is most worn. On the other hand, the thickness of the wear adjusting layer 12 is such that the portion of the inner surface layer 11 including the wear adjusting layer 12 covered with the wear detecting layer 13 is made thicker than other portions of the inner surface layer 11 and finishes wearing slightly earlier. Has been adjusted.

  A reinforcing layer 14 made of a fiber such as polyester or nylon is spirally wound around the upper surface of the inner surface layer 11 and the wear detection layer 13, and is further wound around the wear detection layer 13. Yes. On the outer peripheral surface of the reinforcing layer 14, a steel reinforcing wire 15 is spirally wound at a predetermined pitch, and an intermediate rubber layer 16 (for example, SBR) serving as an adhesive rubber is filled therebetween. A reinforcing layer 17 is wound on the reinforcing wire 15, and a cylindrical outer surface layer 18 made of a weather resistant rubber elastic body (for example, NB / BR) is covered on the outside of the reinforcing layer 17. Yes. A ring-shaped fastening fitting 19 is wound around the outer peripheral surface on one end side of the wear-resistant hose 10.

  The manufacturing method of the wear-resistant hose 10 is to form an inner surface layer 11 by winding a belt-like rubber elastic body around a mandrel, which is a straight long round bar, and having an approximate length of 1 m on one end side (the left end side in the drawing). A rubber elastic body made of the same material as that of the inner surface layer 11 is wound around the outer peripheral surface of the region, and a wear adjusting layer 12 is formed. Further, a belt-shaped white rubber elastic body is wound around the outer peripheral surface of the wear adjusting layer 12. The wear detection layer 13 is formed. Further, the reinforcing layer 14 is spirally wound around the outer peripheral surfaces of the inner surface layer 11 and the wear detection layer 13 and further wound around the wear detection layer 13. A reinforcing wire 15 is spirally wound around the outer peripheral surface of the reinforcing layer 14 at a predetermined pitch, and the intermediate rubber layer 16 is filled therebetween. A reinforcing layer 17 is wound around the reinforcing wire 15, and a belt-like rubber elastic body is wound around the reinforcing layer 17 to form an outer surface layer 18. In this state, rubber vulcanization molding is performed, and the wear resistant hose 10 is obtained.

  A connection fitting 21, which is a thin-walled tubular fitting, is inserted into one end side opening 10 a of the wear-resistant hose 10. The connection fitting 21 integrally includes a large-diameter coupling portion 22 on the inlet side, a small-diameter insertion portion 24 on the outlet side, and an inclined portion 23 that is inclined in a conical surface shape connecting the both. The inclined portion 23 and the insertion portion 24 are approximately the same length of about 100 mm, the connection portion 22 is approximately half the length of the insertion portion 24, and one end of the connection portion 22 has a radially outer side. An annular engagement convex portion 22a slightly extending in the direction is provided. The outer peripheral surface of the insertion portion 24 has a convex shape with an axial cross-section in a sawtooth shape, the inner diameter thereof is substantially the same as the inner diameter of the inner surface layer 11, and the outer diameter is the inner surface layer 11 excluding the wear adjustment layer 12. The outer diameter is substantially the same. As shown in FIG. 3, the connection fitting 21 is inserted into the inside of the one end side opening 10 a of the wear-resistant hose 10 by press-fitting, and an outer surface layer is formed at a position outside the insertion portion 24. It is tightened from the 18 side by a tightening bracket 19. In this state, the inner peripheral surface of the connecting portion 22 of the connection fitting 21 and the inner peripheral surface of the inner surface layer 11 are connected to be flush with each other, so that the flow of the ready-mixed concrete between them is performed smoothly. . The wear resistant hose 10 is adapted to be supplied with ready-mixed concrete by being attached to the boom tip of the ready-mixed concrete pump car at the connecting portion 22 of the connection fitting 21.

  In the embodiment having the above-described configuration, a large pressure is applied to the inner surface of the hose 10, particularly in the vicinity of the outlet of the connection fitting 21, by supplying the fluid into the wear resistant hose 10 in which the connection fitting 21 is inserted into the one end side opening 10 a. In addition, wear of the inner surface layer 11 is accelerated. However, as described above, in the wear-resistant hose 10, the portion covered with the wear detection layer 13 of the inner surface layer 11 including the wear adjustment layer 12 on one end side is thicker than the other portions of the inner surface layer 11. At the same time, the thickness is adjusted so that the wear detection layer 13 is exposed by wearing faster than other portions of the inner surface layer 11. Therefore, the inner surface layer 11 portion including the wear adjustment layer 12 near the outlet of the connection fitting 21 wears faster than the inner surface layer 11 portion, and is clearly different from the black inner surface layer 11 provided outside the wear adjustment layer 12. A different white wear detection layer 13 is exposed.

  As a result, in the present embodiment, the wear of the wear resistant hose 10 due to wear of the inner surface layer 11 is caused by white wear that is clearly different from the black inner surface layer 11 in the vicinity of the outlet of the connection fitting 21 on one end side of the wear resistant hose 10. By visually recognizing whether or not the detection layer 13 has appeared, it is possible to easily and accurately determine without depending on the judgment based on the experience of an unstable operator. In the present embodiment, the thickness of the inner surface layer 11 covered with the wear detection layer 13 is adjusted so that the portion is worn faster than the other portions of the inner surface layer 11. Before it appears and the failure of the wear resistant hose 10 is judged, damage to the hose 10 due to wear on other parts of the inner surface layer 11 can be avoided. On the other hand, since the portion covered with the wear detection layer 13 of the inner surface layer 11 including the wear adjustment layer 12 is thicker than the other portions of the inner surface layer 11, the wear detection layer 13 against wear of the inner surface layer 11. The exposure is not too early. For this reason, the wear-resistant hose 10 can be used without waste.

  In each of the above-described embodiments, the types of rubber elastic bodies of the inner surface layer, the wear detection layer, the intermediate layer, and the outer surface layer are exemplifications, and rubber materials having similar characteristics can be used. In addition, the wear resistant hose shown in each of the above embodiments is an example, and various modifications can be made without departing from the gist of the present invention.

  In the wear resistant hose of the present invention, a wear detection layer having a color different from that of the inner surface layer is provided between the inner surface layer and the reinforcing layer in the vicinity of the outlet of the connection fitting inserted into the opening at one end of the wear resistant hose. At the same time, the thickness of the portion covered with the wear detection layer of the inner surface layer is adjusted appropriately, so that the hose failure due to wear of the inner surface layer does not depend on the judgment of the unstable operator's experience, It is useful because the wear detection layers having different colors can be easily and accurately determined, and further, the hose can be prevented from being damaged and the wear resistant hose can be used without waste.

It is sectional drawing which shows schematically the cross section of the upper half of the abrasion-resistant hose for concrete placement which is the Example of this invention. It is a schematic diagram which shows roughly the cross section of the upper half of the wear-resistant hose. It is sectional drawing which shows roughly the upper half of the state which attached the connection metal fitting to the wear-resistant hose.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Abrasion resistant hose, 11 ... Inner surface layer, 12 ... Wear adjustment layer, 13 ... Wear detection layer, 14 ... Reinforcement layer, 15 ... Reinforcement wire, 16 ... Intermediate rubber layer, 17 ... Reinforcement layer, 18 ... Outer surface layer, 19 ... fastening brackets, 21 ... connection fittings, 24 ... insertion parts.

Claims (3)

Constructed in a tubular shape by an inner surface layer and an outer surface layer made of a rubber elastic body, and a reinforcing layer sandwiched between the inner surface layer and the outer surface layer, and a connection fitting is inserted into one end side opening and supplied through the connection fitting In a wear resistant hose used for pumping fluid containing solids
A portion in the vicinity of the outlet of the connection fitting is provided with a wear detection layer having a clearly different color from the inner surface layer between the inner surface layer and the reinforcing layer, and the inner surface layer is covered with the wear detection layer However, the thickness is thicker than other portions of the inner surface layer, and when the fluid is pumped, the thickness is increased so that the wear detection layer is exposed by wearing faster than the other portions of the inner surface layer. Wear-resistant hose characterized by being adjusted. The wear-resistant hose according to claim 1, wherein the fluid containing the solid matter is ready-mixed concrete. The wear-resistant hose according to claim 1 or 2, wherein the wear detection layer is provided in a range of 500 mm or more from the vicinity of the outlet of the connection fitting and 1000 mm or less from the vicinity of the outlet of the connection fitting.

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