JP2022115139A - Rubber hose and manufacturing method for rubber hose - Google Patents

Abstract

To provide a rubber hose that can be reliably replaced before the rubber hose is damaged by accurately grasping a wear state of an inner surface rubber layer, and a manufacturing method for a rubber hose.SOLUTION: Reinforcing layers 3, 4 are laminated on the outer peripheral side of an inner rubber layer 2. A chemical fiber cord 6 is embedded in the inner rubber layer 2. The chemical fiber cord 6 is spirally arranged to form a wear indicator. The spiral pattern of the chemical fiber cord 6 is exposed on the inner surface of a rubber hose 1 due to wear of the inner rubber layer 2. A pure gap (a1) is provided between the chemical fiber cord 6 and the reinforcing layers 3, 4, and even when the chemical fiber cord 6 is exposed, the inner rubber layer 2 has a necessary and sufficient thickness.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a rubber hose used, for example, for pumping ready-mixed concrete, and a method for manufacturing the rubber hose.

In general, a rubber hose used for pouring ready-mixed concrete at a construction site or the like is constructed in a tubular shape with an inner layer and an outer layer made of a rubber-like elastic material and a reinforcing layer sandwiched therebetween.

Such rubber hoses are used to pump ready-mixed concrete, which is a mixture of cement and solids such as earth and sand. Since the rubber hose will suddenly break when it reaches , it is necessary to accurately grasp the degree of wear and replace the rubber hose before it breaks.

On the other hand, Patent Document 1, for example, discloses a rubber hose (abrasion resistant hose) in which a wear detection layer having a color clearly different from that of the inner layer is provided between the inner layer and the reinforcing layer.

Japanese Patent Application Laid-Open No. 2007-146996 (Claim 1)

However, in the rubber hose of Patent Document 1, the wear detection layer is provided between the inner layer and the reinforcing layer, and the wear detection layer appears only when the inner layer at a certain portion is lost due to wear. Wear can be detected.

Therefore, for example, when using a rubber hose that has been worn to the point where the inner surface layer is lost, for long hours of pouring ready-mixed concrete, at the stage of confirmation before use, the remaining thickness of the inner surface layer up to the reinforcing layer can not be confirmed, the inner surface layer is lost during the single use, and the use is continued without the inner surface layer, which may lead to sudden breakage of the rubber hose.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rubber hose and a method for manufacturing a rubber hose that can accurately grasp the state of wear of the inner rubber layer and reliably replace the rubber hose before it is damaged.

In order to achieve the above object, the rubber hose according to the present invention has a reinforcing layer laminated on the outer peripheral side of the inner rubber layer, and a wear indicating portion exposed on the inner surface due to wear of the inner rubber layer. The display section is configured by spirally arranging a different material from the rubber forming the inner rubber layer, and is embedded in the inner rubber layer with a gap between it and the reinforcing layer.

According to the above configuration, since the wear indicator is embedded in the inner rubber layer while leaving a gap between it and the reinforcing layer, when the inner rubber layer is worn, the inner rubber layer is left with a necessary and sufficient thickness. By exposing the wear indicating portion made of a different material, it is possible to notify that the time for replacement of the rubber hose has come. As a result, even when the rubber hose is used continuously for a long period of time, the inner surface rubber layer wears until the reinforcing layer is exposed during one use, and the rubber hose suddenly becomes unusable. Damage can be prevented.

Moreover, since the wear indicator is formed by spirally arranging a different material from the rubber forming the inner rubber layer, the visibility of the wear indicator can be enhanced by the spiral pattern formed by the different material. . Furthermore, by configuring the wear indicating portion in a spiral shape, the ratio of the portion occupied by the wear indicating portion can be reduced, and the inner surface rubber inside and outside the wear indicating portion can be integrated, so that the wear indicating portion can be made of a separate material. It is possible to suppress the influence on the inner surface rubber layer by arranging the .

Further, a synthetic fiber cord may be spirally arranged as the wear indicator. Here, as the synthetic fiber cord used for the wear indicator, for example, a nylon cord or a polyester cord can be adopted, and it is preferable to set the structure to 940 dtex/2 to 1670 dtex/2.

According to this configuration, since the synthetic fiber cords are spirally arranged to form the wear indicator, the ratio of the portion occupied by the wear indicator is extremely small, and the influence on the inner rubber layer can be sufficiently suppressed. Moreover, the synthetic fiber cord can be worn in the same manner as the inner rubber, and it is possible to prevent the abrasion resistance of the rubber hose from deteriorating due to the separation of the wear indicating portion, which is a separate material, from the inner rubber.

In addition, the other material that constitutes the wear indicator is not limited to the synthetic fiber cord, but may be any material such as steel cord, colored rubber, granules, powder, etc., but it is composed of granules and powder. A wear indicator made of colored rubber tends to have a relatively large proportion of its occupied area, and a wear indicator made of colored rubber tends to reduce the wear resistance and pressure resistance of that part relatively easily, and is made of steel cord. Synthetic fiber cords are particularly suitable for the wear indicator, since they are less likely to be worn in the same manner as the inner surface rubber.

The present invention also provides a method of integrally molding a cylindrical unvulcanized rubber molding with another material. That is, in the present invention, a rubber ribbon made of unvulcanized rubber in the form of a ribbon is overlaid with another material, and the width direction of the rubber ribbon is inclined with respect to the length direction of the mandrel. To provide a method for molding an unvulcanized rubber molded body by winding it spirally and without gaps and molding it into a cylindrical shape.

According to the above configuration, the rubber ribbon is spirally wound around the mandrel without gaps while the width direction thereof is inclined with respect to the length direction of the mandrel. The rubber ribbon can be formed into a thick tubular shape because the rubber ribbon is wound with a slight shift in the longitudinal direction. In this case, by appropriately adjusting the width and inclination angle of the rubber ribbon, a cylindrical unvulcanized rubber molding having a desired thickness can be formed. At that time, by winding a different material on the rubber ribbon in a stacked state, it is possible to integrate the different material with the unvulcanized rubber molded body while configuring it in a helical shape, so that the different material and the unvulcanized rubber molded body can be integrated. A special step for converting can be omitted.

Also, another material may be superimposed at a position away from the side edges of the rubber ribbon toward the center.

According to this configuration, the different material can be embedded in the unvulcanized rubber molded body with a gap between it and the outer peripheral surface of the unvulcanized rubber molded body while forming the spiral shape, and the different material can be embedded in the unvulcanized rubber molded body. can reduce the number of steps required to In other words, in order to embed another material using a generally conceivable method, there is a process of molding the inner unvulcanized rubber, a process of placing a spiral different material on the outside, and an outer unvulcanized rubber on the outside. However, by adopting the configuration of the present invention, an unvulcanized rubber molded body can be obtained by one step of overlapping and winding another material at a position away from the side edge of the rubber ribbon toward the center. Another material can be embedded in the

Also, a cord as a separate material may be superimposed on the rubber ribbon.

According to this configuration, the cord, which is a separate material, can be applied with an appropriate tension and placed on the rubber ribbon at an accurate position, so that the unvulcanized rubber molding can be formed with high accuracy. The other material is not limited to cords such as synthetic fiber cords and steel cords, and may be colored rubber, granules, powder, paint, or any other material.

In addition, the present invention provides a cylindrical unvulcanized rubber molded body formed by the above method as an inner unvulcanized rubber layer, and a reinforcing layer and an outer unvulcanized rubber layer laminated on the outer peripheral side thereof. Provided is a method for producing a rubber hose in which a body is molded, and this laminated body is heated and pressurized to vulcanize and mold the rubber hose.

According to this configuration, the same effects as those obtained by adopting the configuration of the method for molding an unvulcanized rubber molded article can be obtained.

The present invention also provides a molding apparatus for molding a cylindrical unvulcanized rubber molding. That is, the present invention includes a mandrel that is rotatable around a central axis and movable in the longitudinal direction, and an extruder that extrudes a rubber ribbon made of unvulcanized rubber in the form of a ribbon, and the rubber ribbon is supplied from the extruder. A molding device for molding a cylindrical unvulcanized rubber molding by moving a mandrel in the longitudinal direction while rotating it, and winding a rubber ribbon around the mandrel in a helical shape without any gaps. Provided is an apparatus for molding an unvulcanized rubber molded body having a supply passage for supplying a different material to a discharge port for discharging a rubber ribbon so as to integrally mold the unvulcanized rubber molded body with another material.

According to this configuration, the method for molding an unvulcanized rubber molded article can be carried out using the apparatus for molding an unvulcanized rubber molded article.

As described above, according to the present invention, the wear indicator is embedded in the inner rubber layer of the rubber hose while leaving a gap between it and the reinforcing layer on the outer peripheral side thereof. As a result, when the inner rubber layer is worn, the wear indicator can be exposed while the inner rubber layer remains sufficiently thick. can be reliably replaced before it is damaged.

In addition, while the width direction of the rubber ribbon is inclined with respect to the length direction of the mandrel, another material is superimposed, and the rubber ribbon is spirally wound around the mandrel without gaps to form a cylindrical unvulcanized rubber molding. I have to. As a result, the width and inclination angle of the rubber ribbon can be appropriately adjusted to form an unvulcanized rubber molded article having a desired thickness. It can be integrated with the unvulcanized rubber molding while being constructed.

FIG. 1 is a cross-sectional view of a main part of a rubber hose according to the present invention; Side view of molding equipment for unvulcanized rubber molding Plan view of molding equipment for unvulcanized rubber molding Front view of molding equipment for unvulcanized rubber molding Enlarged view of main part of Fig. 4 Enlarged view of main part of Fig. 3

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the manufacturing method of the rubber hose which concerns on this invention, and a rubber hose is described using drawing. First, the structure of the rubber hose will be explained.

As shown in FIG. 1, a rubber hose 1 is used, for example, for pumping ready-mixed concrete. Reinforcement layers 3 and 4 and an outer rubber layer 5 are laminated in this order on the outer peripheral side of an inner rubber layer 2. A synthetic fiber cord 6 serving as a wear display portion exposed on the inner surface due to wear of the inner rubber layer 2 is formed, for example, in a helical shape with an equal pitch. A pure interval (a1) of, for example, about 1 to 2 mm is provided between them as an interval from the cord surface. Here, the synthetic fiber cord 6 is, for example, a nylon cord or polyester cord of 940 dtex/2 to 1670 dtex/2.

The reinforcing layers 3 and 4 are formed by arranging the main reinforcing cords 3a and 4a made of synthetic fiber cords, steel cords, or the like in an even-numbered layer with the main reinforcing cords 3a and 4a being inclined with respect to the length direction of the rubber hose 1, and the inclination of the main reinforcing cords 3a and 4a. The directions are set so as to intersect with each other, and the internal pressure of the rubber hose 1 due to ready-mixed concrete is taken care of while allowing expansion, contraction, diameter expansion, diameter reduction and bending deformation of the rubber hose 1 by so-called pantograph action.

When the rubber hose 1 is used, for example, for pumping ready-mixed concrete, the inner rubber layer 2 receives a large internal pressure and is gradually worn out. Eventually, a spiral pattern due to the synthetic fiber cord 6 appears, indicating that the rubber hose 1 has reached the end of its life. can do. At the time when the spiral pattern of the synthetic fiber cord 6 appears, the remaining thickness of the inner rubber layer 2 has a margin equal to or larger than the net spacing (a1) between the reinforcing layers 3 and 4, and the synthetic fiber cord 6 can be used during use of the rubber hose 1. After the appearance of the helical pattern, the rubber hose 1 is prevented from being suddenly damaged due to the abrasion reaching the reinforcing layers 3 and 4. - 特許庁

The synthetic fiber cord 6 as a wear indicator may be arranged over the entire length of the rubber hose 1, or may be arranged only at a portion of the rubber hose 1 that is particularly likely to be worn.

Next, a method for manufacturing a rubber hose will be described. First, a method of forming the inner surface unvulcanized rubber layer 2a using the forming apparatus 7 for the unvulcanized rubber molded article will be described.

As shown in FIGS. 2 to 6, the molding device 7 includes a mandrel 8 rotatable about a central axis and movable in the longitudinal direction, and an extruder for extruding synthetic fiber cords 6 overlaid on a rubber ribbon 9 made of unvulcanized rubber. 10 and. The extruder 10 has an extrusion head 12 having an extrusion passage 11 with a tapered and flattened cross section, and a thin parallelogram discharge port 14 is formed in a nozzle 13 attached to the tip of the extrusion head 12 . A bobbin 15 for supplying the synthetic fiber cords 6 is provided above the extrusion head 12 , and a supply path 16 for guiding the synthetic fiber cords 6 supplied from the bobbin 15 to the ejection port 14 is formed in the extrusion head 12 .

As shown in FIGS. 5 and 6, by operating the forming device 7, a thin rubber ribbon 9 having a parallelogram cross-sectional shape is discharged from the discharge port 14 at a constant discharge rate, and the side of the rubber ribbon 9 is discharged. A synthetic fiber cord 6 led to a discharge port 14 through a supply path 16 is superimposed at a position spaced apart by a width (b) from the edge toward the center.

The width direction of the rubber ribbon 9 discharged from the discharge port 14 is inclined with respect to the length direction of the mandrel 8 so that the oblique side of the cross-sectional shape of the parallelogram runs along the outer peripheral surface of the mandrel 8 . supplied to the surroundings.

While the rubber ribbon 9 is supplied from the extruder 10, the mandrel 8 rotates and moves in the length direction, so that the inclined rubber ribbon 9 is spirally wound around the mandrel 8 without gaps. That is, the rubber ribbon 9 is wrapped around the mandrel 8 so as to gradually shift in the longitudinal direction while overlapping the previously wound portion, forming a thick cylindrical inner surface unvulcanized rubber layer 2a. In the inner surface unvulcanized rubber layer 2a, synthetic fiber cords 6 are embedded in a helical shape with an equal pitch at a position separated by a pure interval (a2) from the outer peripheral surface thereof as a wear indicator.

The thickness of the inner surface unvulcanized rubber layer 2 can be set to a desired thickness by adjusting the width and inclination angle of the rubber ribbon 9, and the position (a2) of the synthetic fiber cord 6 is positioned on the rubber ribbon 9 side. A desired position can be set by adjusting the width (b) from the edge and the angle of inclination. Also, the pitch of the synthetic fiber cords 6 can be set to a desired pitch by adjusting the thickness of the rubber ribbon 9 by adjusting the rotation speed and movement speed of the mandrel 8 . In addition, the rotational speed and moving speed of the mandrel 8 are adjusted according to the ejection speed of the rubber ribbon 9 .

Thereafter, the reinforcing layers 3 and 4 and the outer unvulcanized rubber layer are laminated on the outer peripheral side of the inner unvulcanized rubber layer 2a to form a laminate. By heating and pressurizing this laminate, the inner surface unvulcanized rubber layer 2a and the outer surface unvulcanized rubber layer are vulcanized while changing the position (a2) of the synthetic fiber cord 6 to the position (a1), A rubber hose 1 is obtained.

According to the above configuration, the synthetic fiber cord 6 is embedded in the inner rubber layer 2 of the rubber hose 1 as a wear indicator. A helical pattern of the synthetic fiber cord 6 appears at , indicating that the rubber hose 1 should be replaced. Furthermore, since a pure gap (a1) is provided between the synthetic fiber cord 6 and the reinforcing layers 3 and 4, it is possible to inform the user that the rubber hose 1 should be replaced with a margin while leaving the inner rubber layer 2. It is possible to prevent the reinforcement layers 3 and 4 from being damaged suddenly during use of the rubber hose 1. - 特許庁

Also, the synthetic fiber cord 6 is superimposed at a position away from the side edge of the rubber ribbon 9 toward the central side, and the rubber ribbon 9 is spirally and tightly wound around the mandrel 8 to form the inner surface unvulcanized rubber layer 2a. As a result, the inner unvulcanized rubber layer 2a with the synthetic fiber cords 6 embedded therein can be molded in one step without separately molding the inner unvulcanized rubber layer 2a into the inside and the outside of the synthetic fiber cords 6.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications can be made as appropriate within the scope of the present invention. For example, as the wear indicator, it is sufficient that a material different from the rubber constituting the inner surface rubber layer 2 is embedded in a spiral shape. , powder, paint, etc., can be used.

1 rubber hose 2 inner rubber layer 2a inner unvulcanized rubber layers 3, 4 reinforcing layers 3a, 4a main reinforcing cord 5 outer rubber layer 6 synthetic fiber cord 7 molding device 8 mandrel 9 rubber ribbon 10 extruder 11 extrusion path 12 extrusion head 13 mouthpiece 14 Discharge port 15 Bobbin 16 Supply passages a1, a2 Pure interval b Width

Claims (7)

A rubber hose having a reinforcing layer laminated on the outer peripheral side of an inner rubber layer and provided with a wear indicating portion exposed on the inner surface due to wear of the inner rubber layer, wherein the wear indicating portion is formed from the rubber constituting the inner rubber layer. A rubber hose characterized in that it is formed by arranging different materials in a spiral shape, and is embedded in the inner surface rubber layer while leaving a gap between it and the reinforcing layer. 2. The rubber hose according to claim 1, wherein a synthetic fiber cord is spirally arranged as said wear indicator. A method of integrally molding a cylindrical unvulcanized rubber molded body with another material,
The other material is superposed on a rubber ribbon made of unvulcanized rubber in the form of a ribbon, and the width direction of the rubber ribbon is inclined with respect to the length direction of the mandrel. A method for forming an unvulcanized rubber molding, characterized in that the unvulcanized rubber molded body is formed into a cylindrical shape by winding the rubber without gaps. 4. The method of forming an unvulcanized rubber molded article according to claim 3, wherein the different material is superimposed at a position away from the side edge of the rubber ribbon toward the center. 5. The method for molding an unvulcanized rubber molded article according to claim 3, wherein a cord as said different material is layered on said rubber ribbon. A cylindrical unvulcanized rubber molded body formed by the method according to claim 3, 4 or 5 is used as an inner unvulcanized rubber layer, and a reinforcing layer and an outer unvulcanized rubber layer are laminated on the outer peripheral side thereof. A method of manufacturing a rubber hose, characterized by forming a laminate by heating and pressurizing the laminate, and vulcanizing and molding the laminate into a rubber hose. A mandrel rotatable around a central axis and movable in a longitudinal direction, and an extruder for extruding a rubber ribbon made of unvulcanized rubber in the form of a ribbon, wherein the mandrel is rotated while supplying the rubber ribbon from the extruder. A molding device for molding a cylindrical unvulcanized rubber molded body by moving the rubber ribbon in a helical shape and without gaps around the mandrel by moving it in the length direction while moving the mandrel,
An unvulcanized rubber molded article characterized in that the extruder is provided with a supply passage for supplying a different material to a discharge port for discharging a rubber ribbon so as to integrally mold the unvulcanized rubber molded article with another material. molding equipment.

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