JP2006250298A - Curved hose and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curved hose manufacturing method capable of simply manufacturing a curved hose having a specified shape of curvature. <P>SOLUTION: A straight hose 15 of laminate structure is composed of an outer rubber layer 3, an inner rubber layer 5, and a reinforcing layer 7 laid between the outer rubber layer 3 and the inner rubber layer 5. The wall thickness of the hose 15 is greatest in a position 9 along the circumferential direction and varies reducing gradually from this position 9 toward the opposite side in the radial direction to become smallest in a position 11 opposite the position 9. The hose 15 is pulled so that a residual displacement is generated in the outer rubber layer 3 and the inner rubber layer 5, followed by releasing the tensile load, and then the hose 15 is bent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hose used, for example, in a fuel pipe of an automobile, and more particularly to a curved hose having a bent portion and a method of manufacturing such a curved hose.

  In a fuel pipe of an automobile, a rubber hose that can be bent relatively freely is used. For example, piping connection is performed by connecting a straight rubber hose in a circular arc shape between a pipe body projecting in the horizontal direction and a pipe body projecting upward. However, in parts where the arrangement of parts is complicated, if a straight rubber hose is bent and used, the elastic hose often causes the rubber hose to come into contact with surrounding parts. There is a risk that the rubber hose and the parts will be worn early due to the rubbing generated between the two.

  Therefore, a method of previously bending the hose into a predetermined shape is used. In order to bend the hose in advance, first, an unvulcanized or semi-cured rubber hose straightly preformed is prepared, and a flexible mandrel is inserted into the rubber hose. Next, the preformed hose is bent into a predetermined shape together with the mandrel, fitted into the mold, and heated to vulcanize the preformed hose. And if a vulcanization hose is removed from a formwork and a mandrel is pulled out, the curved hose curved to the predetermined shape can be obtained (for example, refer patent document 1).

JP-A-5-57814

  By the way, in such a manufacturing method of a curved hose, a troublesome operation of inserting a mandrel into an unvulcanized or semi-cured preformed hose is required. In particular, when a mandrel that is not flexible and is bent into a predetermined curved shape is used, the mandrel insertion operation becomes more complicated.

  Then, an object of this invention is to provide the manufacturing method of the curved hose which can manufacture easily the curved hose which can be manufactured easily, and the curved hose which has a predetermined | prescribed curved shape.

  A curved hose of the present invention for achieving this object is a curved hose with a curved shape brazed, and has a first layer made of a first material and a residual displacement when a tensile load is applied. A bent portion having a second layer made of a second material smaller than the first material, the first layer and the second layer being bonded to each other and having a thickness in the radial direction The first layer and the second layer are formed so as to be different on both sides, and the thickness of the first layer and the second layer is thicker inside the bent portion than outside the bent portion. The curved hose may be formed substantially only at the bent portion. The curved hose may also have an unbent or straight portion on one or both sides of the bend. The first layer and the second layer can be directly bonded (for example, vulcanized bonding), but can also be bonded (for example, vulcanized bonding) through another layer, for example, a reinforcing layer. For example, the first layer can be bonded to one side surface of the reinforcing layer, and the second layer can be bonded to the other side surface of the reinforcing layer. Such a curved hose can be easily manufactured, for example, by the method for manufacturing a curved hose of the present invention. The method of manufacturing a curved hose according to the present invention is a method of manufacturing a curved hose in which a curved shape is brazed to the hose, and is made of a first material at least partially, for example, at least partially in the axial direction or length direction. And a second layer made of a second material whose residual displacement is smaller than that of the first material when a tensile load is applied. The first layer and the second layer And a hose formed so that the thickness of the first layer and the second layer is different on both sides in the radial direction, a tensile load is applied to the hose, and the hose is The hose is bent by extending in the length direction, releasing the tensile load applied to the hose, and forming a bent portion so that the thick side is the inside. The hose is stretched in the longitudinal direction so that residual displacement occurs in the first layer and the second layer within the elastic deformation limit of the first layer and the second layer. Therefore, when the tensile load applied to the hose is released, the elastic return length differs between the first layer and the second layer. Then, when viewed partially, the layer with the longer elastic return length, that is, the layer with the larger residual displacement, covers the layer with the shorter elastic return length, that is, the layer with the smaller residual displacement. As such, the hose tends to deform. Here, if the thickness of the hose is uniform over the entire circumference, or if the thickness of the first layer and the second layer is uniform over the entire circumference, the deformation force of the hose is biased in one direction. The hose does not bend or is difficult to bend and deform.

  In the present invention, the hose or the curved hose has a laminated structure configured such that the thicknesses of the first layer and the second layer are different on both sides in the radial direction. For example, the thickness of the first layer and the thickness of the second layer are each configured to be different on both sides in the radial direction, and the thickness of the first layer and the thickness of the second layer are each in the radial direction. Thin on one side and thick on the other radial side. Since the deforming force is large at the thick part and the deforming force is small at the thin part, the hose or the curved hose bends according to the deformation tendency or the deformation behavior at the thick part. .

  In the present invention, as the second material, a material having a physical property that has a smaller residual displacement when a tensile load is applied than the first material is used. For example, the first layer is made of the second layer. It is arranged on the inner circumference side. By configuring in this way, when the tensile load is released, a bending deformation force that becomes concave outwards in all parts acts on the hose or the bending hose, but the thin side becomes the thick side. Since it bulges outward as it is pushed out, the curved deformation of the hose or the curved hose can be performed smoothly or without hindrance.

  In the present invention, a curved hose with a suitable curved shape brazed can be obtained at low cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a curved hose according to the present invention manufactured by the method for manufacturing a curved hose according to the present invention, and FIG. 2 is a sectional view of the curved hose.

  The curved hose 1 is used for fuel piping in an engine room of an automobile, and includes an outer rubber layer 3 (second layer), an inner rubber layer 5 (first layer), and the outer rubber layer 3. And a reinforcing layer 7 disposed between the inner rubber layer 5 and the outer rubber layer 3 and the inner rubber layer 5 are vulcanized and bonded via the reinforcing layer 7. . The curved hose 1 has an outer peripheral surface 9 having a circular cross section (the outer peripheral surface of the outer rubber layer 3), but the inner rubber layer 5 and the reinforcing layer 7 are formed eccentrically, and the curved hose 1 has a circumferential direction. It is thickest at one location 9, and gradually changes from the circumferential location 9 toward the opposite side in the radial direction, and is thinnest at the circumferential location 9 and the location 11 on the opposite side in the radial direction. Each of the outer rubber layer 3 and the inner rubber layer 5 is also thickest at one place 9 in the circumferential direction, like the entire curved hose 1, and gradually changes from the circumferential place 9 toward the opposite side in the radial direction. It is the thinnest at the directional part 9 and the diametrically opposite part 11.

  The curved hose 1 is formed to have an outer diameter of 22.6 mm and an inner diameter of 15 mm, and has a thickness of 5.3 mm at the circumferential location 9 and a thickness of 2.3 mm at the circumferential location 11. The outer rubber layer 3 has a thickness of 1.8 mm at the circumferential location 9 and a thickness of 0.5 mm at the circumferential location 11, and the inner rubber layer 5 has a thickness of 1 at the circumferential location 9. It has a thickness of 2 mm and a thickness of 0.8 mm at the circumferential location 11. The reinforcing layer 7 can also be formed to have a uniform thickness over the entire circumference.

  For the outer rubber layer 3 (material of the outer rubber layer 3: second material), for example, ethylene-propylene-diene rubber (EPDM) or ethylene-propylene rubber (EPM) having excellent weather resistance can be used. For the inner rubber layer 5 (the material of the inner rubber layer 5: the first material), for example, low-permeability butyl rubber (IIR) or halogenated butyl rubber (H-IIR) can be used. As the reinforcing layer 7, for example, a braided reinforcing fiber, a wound reinforcing fiber or metal wire, for example, a spiral wound one can be used. The reinforcing layer 7 is formed so as to be able to extend somewhat in the length direction.

  The outer rubber layer 3 and the inner rubber layer 5 are configured to have different residual displacement amounts when a tensile load is applied. More specifically, the outer rubber layer 3 is configured to have a smaller residual displacement than the inner rubber layer 5. That is, the material of the outer rubber layer 3 has a physical property with a smaller residual displacement than the material of the inner rubber layer 5.

  The curved hose 1 includes a bent portion 13 that is curved by approximately 60 degrees so that the circumferential portion 9 is on the inner side.

  FIG. 3 is a view for explaining the manufacturing process of the curved hose 1.

  First, a straight hose 15 having the cross-sectional shape shown in FIG. 2 is prepared (FIG. 3a). Then, a tensile load is applied to the hose 15 between appropriate two points in the length direction of the hose 15 to extend the hose 15 (FIG. 3b). The tensile load is applied so that residual displacement occurs in the outer rubber layer 3 and the inner rubber layer 5 of the hose 15. After a predetermined time has elapsed, the tensile load is released and the hose 15 is elastically restored (FIG. 3c). Then, since the outer rubber layer 3 returns to be shorter than the inner rubber layer 5, the hose 15 tends to be deformed so as to be concave outward. Since the deformation force increases as the wall thickness increases, the hose 15 is bent to form the bent portion 13 so that the circumferential portion 9 is on the inner side, and the curved hose 1 is manufactured.

  The bending hose and the manufacturing method of the bending hose of the present invention are useful for reducing the manufacturing cost of the bending hose and constructing automobile piping and the like at low cost.

It is a perspective view of the curved hose which concerns on this invention manufactured by the manufacturing method of the curved hose which concerns on this invention. It is sectional drawing of a curved hose. It is a figure for demonstrating the manufacturing process of a curved hose.

Explanation of symbols

1 Curved hose 3 Outer rubber layer (second layer)
5 Inner rubber layer (first layer)
13 Bending part

Claims (5)

A curved hose with a curved shape,
A bent portion having a first layer made of a first material and a second layer made of a second material having a residual displacement smaller than the first material when a tensile load is applied;
The first layer and the second layer are bonded to each other, and are formed so that the thickness is different on both sides in the radial direction,
The curved hose characterized in that the first layer and the second layer are thicker on the inside of the bent portion than on the outside of the bent portion.   The curved hose according to claim 1, wherein the first layer and the second layer are bonded to each other through a reinforcing layer.   The curved hose according to claim 1, wherein the first layer is disposed on an inner peripheral side of the second layer. A method of manufacturing a curved hose that brazes a curved shape on a hose,
At least in part, a first layer made of a first material, and a second layer made of a second material whose residual displacement when a tensile load is applied is smaller than the first material. Preparing a hose in which the first layer and the second layer are bonded and the thicknesses of the first layer and the second layer are different on both radial sides;
Apply a tensile load to the hose and stretch the hose in the length direction,
A method for producing a curved hose, comprising: releasing a tensile load applied to the hose, and bending the hose by forming a bent portion so that the thicker side is on the inner side. The method of manufacturing a curved hose according to claim 4, wherein the first layer is disposed on an inner peripheral side of the second layer.

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