JP2009041607A - Rubber hose and manufacturing method of rubber hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber hose whose reinforcement cord layer can be formed easily and whose dimensional accuracy can be improved. <P>SOLUTION: A small diameter part 9 having a diameter smaller than other parts is formed to be recessed on an end outer surface of an inner rubber 4. The reinforcement cord layers 6a, 6b, 6c and 6d are constituted by spirally winding a band-shaped ply 8 on an outer side of the inner rubber 4. On the outer side of the end of the inner rubber 4, the ply 8 is folded back in such a manner of hooking a fold 10 on the small diameter part 9. By folding back the ply 8, a plurality of the reinforcement cord layers 6a, 6b, 6c and 6d are continuously formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rubber hose used as a pumping tube equipped in, for example, a squeeze pump.

  In general, a rubber hose, such as a pumping tube equipped in a squeeze type pump, that operates at a high pressure when used is a plurality of rubber hoses arranged between an inner rubber and an outer rubber in the circumferential direction while inclining a reinforcing cord with respect to the central axis of the hose. The reinforcing cord layers are provided, and the inclination directions of the reinforcing cords of adjacent reinforcing cord layers are set to intersect each other (for example, Patent Document 1).

  Such a reinforcing cord layer of the rubber hose is often formed by spirally winding a belt-like ply having a plurality of reinforcing cords outside the inner rubber. Further, for each reinforcing cord layer, a plurality of reinforcing cord layers are formed by an intermittent process of cutting the end portion of the ply constituting the reinforcing cord layer and sequentially winding another ply by alternately changing the inclination direction. As the number of code layers increases, the time and man-hours required for the formation increase.

In contrast, by adopting a method in which a long rubber hose is once formed and cut into a desired length to obtain a plurality of rubber hoses, the time and man-hour required for manufacturing one rubber hose can be reduced. There may be reduction.
Japanese Utility Model Publication No. 6-73580

  However, the rubber hose formed by cutting to a desired length exposes the end portion of the reinforcing cord at the cut surface, and rusting or synthetic fiber in the steel cord is caused by intrusion of moisture from the exposed portion. There is a concern that the cord may deteriorate or peel off.

  Further, it is conceivable that a plurality of reinforcing cord layers are continuously formed without cutting the ply by folding the belt-like ply at the end of the rubber hose. In this case, the reinforcing cord has high strength and high rigidity. The position of the fold is likely to become unstable, and in particular, when the formation of the reinforcing cord layer is automated, the accuracy of the size and shape in the vicinity of the fold is likely to decrease.

  It is an object of the present invention to provide a rubber hose and a method for manufacturing the rubber hose which can easily form a reinforcing cord layer and can improve the dimensional accuracy.

  In order to achieve the above object, the rubber hose provided by the present invention is provided with a plurality of reinforcing cord layers that are arranged in the circumferential direction while inclining the reinforcing cord with respect to the central axis of the hose between the inner rubber and the outer rubber. The reinforcement cords of adjacent reinforcement cord layers are set so that the inclination directions of the reinforcement cords cross each other, and the reinforcement cord layer is formed by arranging a belt-like ply having a plurality of reinforcement cords in a spiral shape on the outer side of the inner rubber. A plurality of reinforcing cord layers are continuously provided by folding the ply outside the end portion of the inner surface rubber while inverting the inclination direction of the reinforcing cord with respect to the central axis of the hose. Further, a small-diameter portion having a smaller diameter than that of the other portion is recessed on the outer surface of the end portion of the inner rubber, and the ply is folded back so that a crease is hooked on the small-diameter portion.

  According to the above configuration, since the plurality of reinforcing cord layers are continuously formed without cutting the ply by folding the belt-like ply at the end of the rubber hose, each reinforcing cord layer is intermittently separated by another ply. The reinforcing cord layer can be formed more easily than the formed one. In addition, since the ply is folded back so that the crease is hooked on the small-diameter portion recessed in the outer surface of the end portion of the inner rubber, the crease is creased at the small-diameter portion. This makes it possible to stabilize the position of the crease and increase the accuracy of the dimensions and shape near the crease, and to automate the formation of the reinforcement cord layer, even if the reinforcement cord has high strength and high rigidity. it can. Further, since the time and man-hour required for forming the reinforcing cord layer can be reduced without cutting the rubber hose, the end portion of the reinforcing cord is not exposed, and moisture can be prevented from entering the reinforcing cord layer. .

  If the depth of the small diameter part is set larger than the diameter of the reinforcing cord, the small diameter part absorbs the increase in thickness due to the formation of the crease in the ply. A uniform rubber hose can be obtained.

  When four or more reinforcing cord layers are provided, a plurality of ply folds are formed at one end of the rubber hose, but a plurality of ply folds are formed at different positions in the hose central axis direction outside the small diameter portion. By doing so, it is possible to prevent the rubber hose from being thickened and to obtain a rubber hose having a uniform outer diameter.

  When a metal fitting is attached to the end of the rubber hose according to the configuration of the present invention, a plurality of reinforcing cord layers are continuous, whereby the force for tightening the fitting can be evenly transmitted to each reinforcing cord layer, and is continuous. Since the portion is prevented from coming off, the force for fastening the metal fitting can be increased.

  The rubber hose of the present invention is not particularly limited as long as it is a rubber hose having a plurality of reinforcing cord layers that are arranged while tilting reinforcing cords, for example, for pressure resistance, but as its use, pumping equipped in a squeeze pump A tube can be illustrated.

  Further, according to the present invention, a plurality of reinforcing cord layers are provided between the inner rubber and the outer rubber so that the reinforcing cords are arranged in the circumferential direction while being inclined with respect to the central axis of the hose, and the reinforcing cords of the adjacent reinforcing cord layers are provided. A method of manufacturing a rubber hose that is set so that the inclination directions of the two cross each other is provided.

  Specifically, an inner surface unvulcanized rubber is formed around the mandrel, and a small diameter portion having a smaller diameter than other portions is recessed on the outer surface of the end portion of the inner surface unvulcanized rubber. Next, a belt-like ply having a plurality of reinforcing cords is spirally wound around the inner surface of the unvulcanized rubber to form a first reinforcing cord layer. Furthermore, outside the end of the inner rubber, the ply is folded back so that the fold of the ply is hooked to the small diameter part while reversing the inclination direction of the reinforcing cord with respect to the central axis of the hose, and the ply is spiraled outside the reinforcing cord layer of the first layer And a second reinforcing cord layer is formed. Thereafter, the outer unvulcanized rubber is formed outside the first and second reinforcing cord layers, and the inner unvulcanized rubber and the outer unvulcanized rubber are vulcanized.

  Furthermore, after forming the second-layer reinforcing cord layer, on the outside of the small-diameter portion, the ply is folded back while reversing the inclination direction of the reinforcing cord with respect to the central axis of the hose to form the third and subsequent reinforcing cord layers, When the ply is folded back, the crease is formed outside the previous crease with the position shifted in the hose central axis direction.

  According to these structures, the same effect as the effect by employ | adopting the structure of said rubber hose can be acquired.

  As described above, according to the present invention, since the plurality of reinforcing cord layers are made continuous by folding the belt-like ply at the end portion of the rubber hose, the time and man-hours required for forming the reinforcing cord layer are reduced, and the reinforcing cord layer Automation of the formation of can be achieved. Moreover, since the ply is folded back so that the crease is hooked on the small-diameter part recessed on the outer surface of the inner rubber end, the position can be stabilized by setting the crease and the dimensional accuracy of the rubber hose end can be improved. Can do.

  Hereinafter, the best mode for carrying out a rubber hose and a method for manufacturing a rubber hose according to the present invention will be described with reference to the drawings. FIG. 1 is a view showing a rubber hose according to the present invention, in which an upper half is a sectional view and a lower half is a side view. In FIG. 1, the central part of the lower half peels off the outer rubber so that the reinforcing cord layer is exposed. FIG. 2 is a cross-sectional view of the reinforcing cord layer. FIG. 3 is a view showing an end portion of a rubber hose with a metal fitting fixed thereto, wherein the upper half is a sectional view and the lower half is a side view.

  The rubber hose 1 has, for example, an inner diameter of 30 mm to 80 mm, and is mounted on a squeeze pump for pumping ready-mixed concrete and the like by fastening a metal fitting 3 inserted into the enlarged diameter portion 2 with a split metal fitting from the outside. The four reinforcing cord layers 6a, 6b, 6c, 6d are provided between the inner rubber 4 and the outer rubber 5 in the order of 6a, 6b, 6c, 6d from the inner side. Structure.

  The reinforcing cord layers 6a, 6b, 6c, 6d are arranged in the circumferential direction while inclining the reinforcing cord 7 with respect to the central axis of the hose at inclination angles (θa, θb, θc, θd), respectively. The inclination directions of the reinforcing cords 7 are set so as to intersect each other. The reinforcing cord layers 6 a, 6 b, 6 c, 6 d are configured by arranging a band-like ply 8 having a plurality of reinforcing cords 7 in a spiral shape outside the inner rubber 4, and reinforcing the outer side of the inner rubber 4. The ply 8 is folded back while reversing the inclination direction of the cord 7 and is reciprocated twice in the hose central axis direction, so that four layers are continuously formed.

  The ply 8 is formed by arranging a plurality of reinforcing cords 7 in parallel and wrapping them with a thin sheet-like rubber, and is set to have an equal width over the entire length thereof. The ply 8 has a larger inclination angle of the reinforcing cord 7 with respect to the central axis of the hose (θa <θb <) as the outer layer becomes larger as the diameter of the reinforcing cord layers 6a, 6b, 6c, and 6d increases. θc <θd), the side edges of the ply 8 are not wrapped and are not provided with a gap.

  A small-diameter portion 9 having a smaller diameter than other portions is recessed in the outer surface of the end portion of the inner rubber 4, and the ply 8 is folded back so that a crease 10 is hooked on the small-diameter portion 9. As a result, the crease 10 of the ply 8 is creased by the small diameter portion 9 and formed at a predetermined stable position, stabilizing the shape of the rubber hose 1 and improving the dimensional accuracy.

  The small-diameter portion 9 is set to have a depth larger than the diameter of the reinforcing cord 7, and the two folds 10 of the ply 8 are formed so as to be displaced in the hose central axis direction outside the small-diameter portion 9. . Thereby, the small diameter part 9 absorbs the thickness increase by the crease | fold 10, and the outer diameter of the rubber hose 1 is made uniform.

  Next, a method for manufacturing a rubber hose will be described. FIG. 4 is a diagram showing a procedure for forming a reinforcing cord layer. FIG. 5 is a diagram showing the folding of the ply, (a) before folding and (b) after folding.

  The rubber hose 1 to be manufactured has, for example, an inner diameter of φ38.1 mm, an overall length of 1200 mm, and an enlarged diameter portion 2 having a diameter of 44 mm and a length of 50 mm at both ends. A metal fitting 3 is inserted into the enlarged diameter portion 2. The rubber hose 1 is fastened and fixed with a split metal fitting from the outside.

  Specifically, first, as shown in FIG. 4A, end collars 12 for forming the enlarged diameter portion 2 are attached to the mandrel 11 at a predetermined interval. Next, as shown in FIG. 4B, by rotating the mandrel 11 while moving it in the direction of its central axis, an unvulcanized rubber ribbon is wound around the end collar 12, and around the mandrel 11, for example, An inner unvulcanized rubber 13 having a thickness of 6.5 mm at the center and a thickness of 3.5 mm at the end forming the enlarged diameter portion 2 is formed. At this time, for example, by reducing the extrusion amount of the unvulcanized rubber ribbon or by increasing the rotation of the mandrel 11, the thickness of the inner surface unvulcanized rubber 13 on the outer surface of the end portion is 2.0 mm, for example. The small-diameter portion 9 having a smaller diameter is formed.

  As shown in FIG. 4C, by rotating the mandrel 11 while moving it in the direction of its central axis, the ply 8 is inclined with respect to the hose central axis outside the inner unvulcanized rubber 13 (θa, For example, the reinforcing cord layer 6a of the first layer is formed by being inclined spirally from the end portion by being inclined by 53 °.

  Here, the ply 8 has a belt-like shape having a uniform width (for example, 98 mm) and a plurality of reinforcing cords 7 along the length direction thereof, for example, 20 reinforcing cords 7 made of nylon cords having a cord diameter of 0.6 mm. It is arranged at a number density of / 25 mm and covered with rubber so as to have a thickness of 1.0 mm. The inclination angle (θa) is an angle at which the ply 8 can be spirally wound around the inner surface of the unvulcanized rubber 13 without wrapping the side edges of the ply 8 and without providing a gap.

  As shown in FIG. 4D, when the winding of the ply 8 reaches the outer end of the inner unvulcanized rubber 13, the movement in the central axis direction is reversed while the mandrel 11 is rotated in the same direction. Thereby, the inclination direction of the reinforcing cord 7 with respect to the central axis of the hose is reversed, and the ply 8 is folded back at a stable position while being creased so that the fold line 10a is hooked on the small diameter portion 9. That is, since the ply 8 wound around the small diameter portion 9 cannot move to the larger diameter side, the fold line 10a of the ply 8 is hooked on the small diameter portion 9 and is set. In addition, the thickness increase by forming the crease 10a is sufficiently absorbed by setting the depth of the small diameter portion 9 to 1.5 mm, for example, exceeding 1 mm which is the thickness of the ply 8.

  Further, by rotating the mandrel 11 while moving it in the direction of its central axis, the ply 8 is inclined by an inclination angle (θb, for example, 54.8 °) with respect to the central axis of the hose outside the reinforcing cord layer 6a of the first layer. The second reinforcing cord layer 6b is formed by being inclined and spirally wound. Here, the inclination angle (θb) is an inclination angle at which the ply 8 can be spirally wound around the outer side of the first reinforcing cord layer 6a without wrapping the side edges of the ply 8 and without providing a gap. Since the winding diameter is larger than that of the first layer, it is set larger than the inclination angle (θa).

  When the ply 8 is folded back, as shown in FIG. 5, by setting the inclination angle (θb) of the second layer to be larger than the inclination angle (θa) of the first layer, the fold line 10a becomes (θb− Tilt by θa) / 2. In FIG. 5, reference numeral 14 denotes a bobbin around which the ply 8 is wound and held.

  After forming the second reinforcing cord layer 6b, the ply 8 is folded back while forming the folds 10b and 10c outside the small-diameter portion 9 in the same procedure as the folding from the first layer to the second layer. The fourth reinforcing cord layers 6c and 6d are formed. Further, when the ply 8 is folded back from the third layer to the fourth layer, the fold line 10c is formed at a position shifted to the outer end side in the hose central axis direction from the fold line 10a from the first layer to the second layer.

  Here, since the winding diameter of the third layer is larger than that of the second layer and the winding diameter of the fourth layer is larger than that of the third layer, the inclination angle (θc, for example, 56.2 °) of the third layer is set to two. The inclination angle (θb) of the layer is set larger, and the inclination angle (θd, for example, 57.5 °) of the fourth layer is set larger than the inclination angle (θc) of the third layer. Thereby, the ply 8 is wound without wrapping the side edge and without providing a gap.

  Thereafter, the outer unvulcanized rubber is formed outside the reinforcing cord layers 6a, 6b, 6c and 6d, and the inner unvulcanized rubber 13 and the outer unvulcanized rubber are vulcanized to obtain the rubber hose 1.

  According to the above configuration, the four layers of reinforcing cord layers 6a, 6b, 6c, and 6d are continuously formed by winding the common ply 8 while turning back, so that the reinforcing cord layers 6a, 6b, Compared with the method of forming 6c and 6d individually, the time required for the formation can be shortened, and automation can be easily achieved.

  Further, by continuing the reinforcing cord layers 6a, 6b, 6c and 6d, the force for pulling out the metal fitting 3 can be uniformly transmitted to the reinforcing cord layers 6a, 6b, 6c and 6d, and the reinforcing cord 7 is folded back. As a result, the folded portion functions as a retainer, and the fastening force of the metal fitting 3 is increased. Furthermore, the material loss due to trimming the ends of the reinforcing cord 7 can be reduced by continuing the reinforcing cord 7.

  When the ply 8 is folded back, the small diameter portion 9 is naturally attached, so that the crease 10 can be formed at a predetermined position, the end shape of the rubber hose 1 can be stabilized, and the dimensional accuracy can be increased. Furthermore, since the small diameter portion 9 absorbs the increase in thickness due to the folding of the ply 8 and the folds 10a and 10c are formed with the positions shifted in the hose central axis direction, the outer diameter of the rubber hose 1 can be made uniform.

  Since the rubber hose 1 is formed to have a desired length without being cut, the reinforcing cord 7 is not exposed from the end portion thereof, and deterioration due to moisture absorption or a decrease in durability can be prevented. It is also suitable for use.

  Since the single rubber hose 1 is formed without being cut, it can be formed into a desired end shape by the end collar 12, and grinding of the end can be made unnecessary. In addition, the length of the mandrel 11 can be shortened compared to the method of once forming and cutting a long rubber hose, and the rubber hose 1 is set to have a relatively small diameter because there is no influence of the bending of the mandrel 11. be able to. Furthermore, it is more suitable for small-scale production than the method of obtaining a large number of rubber hoses by cutting a long rubber hose by the amount of forming a single rubber hose 1.

  Since the inner diameter of the rubber hose is set in the range of 30 mm to 80 mm, sufficient pressure resistance can be obtained while improving the accuracy of the shape of the rubber hose. When the inner diameter of the rubber hose is less than 30 mm, the accuracy of the shape of the rubber hose is likely to decrease because the mandrel used for molding the unvulcanized rubber hose is easily bent. Also, the larger the inner diameter, the greater the force acting on the reinforcing cord layer due to the internal pressure received by the rubber hose, and if the inclination angle of the reinforcing cord differs for each reinforcing cord layer, the pressure resistance tends to be slightly reduced, If the inner diameter of the rubber hose exceeds 80 mm, it is difficult to withstand the internal pressure.

  In addition, this invention is not limited to said embodiment, A change can be suitably added within the scope of the present invention. For example, the rubber hose 1 can be used for applications other than the pumping tube, and a form in which the diameter-expanded portion 2 and the metal fitting 3 are not provided at the end can also be adopted. Moreover, the hard steel wire which surrounds a hose central axis spirally and prevents buckling can also be added. The number of reinforcing cord layers is not limited to four as long as it is a plurality of layers. In particular, an even number of reinforcing cord layers are used so that the reinforcing cord layers intersecting with each other in the inclined direction of the reinforcing cord 7 form a pair. It is preferable to provide it.

The figure which shows the rubber hose which concerns on this invention, an upper half is sectional drawing, a lower half is a side view Cross section of reinforcing cord layer It is a figure showing the end of the rubber hose with the metal fittings fastened. The upper half is a sectional view and the lower half is a side view. The figure which shows the procedure of forming a reinforcement cord layer Figures showing the folding of the ply, (a) before folding, (b) after folding

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rubber hose 2 Wide diameter part 3 Metal fitting 4 Inner surface rubber 5 Outer surface rubber 6a, 6b, 6c, 6d Reinforcement cord layer 7 Reinforcement cord 8 Ply 9 Small diameter portion 10 Fold 11 Mandrel 12 End collar 13 Inner surface unvulcanized rubber

Claims (5)

Between the inner rubber and outer rubber, a plurality of reinforcing cord layers are provided that are arranged in the circumferential direction while inclining the reinforcing cords with respect to the central axis of the hose, and the inclination directions of the reinforcing cords of adjacent reinforcing cord layers intersect each other A rubber hose set to
The reinforcing cord layer is formed by arranging a belt-like ply having a plurality of reinforcing cords in a spiral shape on the outer side of the inner rubber, and by inverting the inclination direction of the reinforcing cord with respect to the hose central axis outside the end of the inner rubber. While folding the ply, a plurality of reinforcing cord layers are provided continuously,
A rubber hose characterized in that a small-diameter portion having a smaller diameter than other portions is recessed on the outer surface of the end portion of the inner rubber, and the ply is folded back so as to catch a crease.   The rubber hose according to claim 1, wherein a depth of the small diameter portion is set larger than a diameter of the reinforcing cord.   The reinforcing cord layer of four or more layers is provided, and a plurality of folds of the ply are formed at a position shifted in the hose central axis direction outside the small-diameter portion. Rubber hose. Between the inner rubber and outer rubber, a plurality of reinforcing cord layers are provided that are arranged in the circumferential direction while inclining the reinforcing cords with respect to the central axis of the hose, and the inclination directions of the reinforcing cords of adjacent reinforcing cord layers intersect each other A rubber hose manufacturing method set to be,
An inner surface unvulcanized rubber is formed around the mandrel, and a small-diameter portion having a smaller diameter than the other part is recessed on the outer surface of the end portion of the inner surface unvulcanized rubber, and then on the outer side of the inner surface unvulcanized rubber, A belt-like ply having a plurality of reinforcing cords is spirally wound to form a first reinforcing cord layer, and the inclination direction of the reinforcing cord with respect to the hose central axis is reversed outside the end portion of the inner rubber. The ply is folded back so that the fold is hooked on the small-diameter portion, and the ply is spirally wound around the outer side of the first-layer reinforcing cord layer to form a second-layer reinforcing cord layer. An outer surface unvulcanized rubber is formed on the outer side of the reinforcing cord layer of the layer, and an inner surface unvulcanized rubber and an outer surface unvulcanized rubber are vulcanized and molded.   After forming the second-layer reinforcing cord layer, outside the small-diameter portion, the ply is folded while reversing the inclination direction of the reinforcing cord with respect to the central axis of the hose to form the third-layer and subsequent reinforcing cord layers, 5. The method of manufacturing a rubber hose according to claim 4, wherein when the ply is folded back, the fold is formed by shifting the position of the fold of the ply from the position of the hose central axis direction.

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