JP2008068575A - Manufacturing method of rubber hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a rubber hose to obtain one superior in thickness precision and having an uneven-walled structure even if the outside shape of the hose varies in the outside diameter in the longitudinal direction like a truncated cone. <P>SOLUTION: The manufacturing method of the rubber hose comprises spirally winding the unvulcanized rubber tape 5 sent out from the rubber supplying means 6 round the outer periphery of the rotating mandrel body 3 to form into a cylindrical shape and vulcanizing the cylindrical formed body. The mandrel 1 is equipped with the mandrel body 3 whose outer peripheral face is formed into the shape of rotational symmetry around the center axis 2 and the rotary shaft 4 which is formed in the eccentric position to the center axis 2 of the mandrel body 3. The rotary shaft 4 is rotated to allow the peripheral speed in the outer peripheral face of the mandrel 1 to be varied periodically, the sending speed of the unvulcanized rubber tape 5 is set to a speed at the lowest speed S1 or slower of the above peripheral speed, and while stretching it according to the difference of the peripheral speed and the sending speed the unvulcanized rubber tape 5 is spirally wound round the mandrel body 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a rubber hose having an eccentric structure in which the center of the inner diameter is eccentric with respect to the center of the outer diameter and the thickness continuously changes in the circumferential direction.

Conventionally, as a manufacturing method of a rubber hose having an uneven thickness structure, as described in Patent Document 1, when a mandrel is used to pass the extrusion die of a crosshead type extruder formed in a circle, the center of the mandrel is extruded. A method is known in which a rubber layer having an uneven thickness structure is formed on the outer periphery of a mandrel by decentering from the center of the die.
Japanese Patent Application Laid-Open No. 2000-110739

  However, in the above method, it is not possible to manufacture a rubber hose having a shape whose outer diameter changes in the length direction of the hose, such as a truncated cone shape. Further, in the crosshead method, since melted unvulcanized rubber is applied to the outer periphery of the mandrel, the rubber fluidity fluctuates, so that the thickness accuracy of the hose becomes worse as the thickness of the hose increases.

  Therefore, in the present invention, manufacturing a rubber hose that is excellent in thickness accuracy and that can obtain a rubber hose having an uneven thickness structure even when the outer surface shape is a truncated cone shape whose outer diameter changes in the hose length direction. The purpose is to provide a method.

  In order to solve the above problems, in the present invention, an unvulcanized rubber tape fed from a rubber supply means is spirally wound around the outer peripheral surface of a rotating mandrel body and formed into a cylindrical shape. A method of manufacturing a rubber hose to be vulcanized, wherein the mandrel includes a mandrel main body having an outer peripheral surface formed in a rotationally symmetric shape around a central axis, and a rotation formed in an eccentric position with respect to the central axis of the mandrel main body. And rotating the rotating shaft to periodically vary the peripheral speed on the outer peripheral surface of the mandrel, and setting the feed speed of the unvulcanized rubber tape to a speed equal to or lower than the minimum speed of the peripheral speed. The unvulcanized rubber tape (hereinafter sometimes abbreviated as a tape) is stretched around the mandrel body in a spiral manner according to the difference from the speed.

  According to the said structure, unvulcanized rubber is wound around the outer peripheral surface of a mandrel main body in the state of a tape, without fuse | melting. At this time, the tape is wound around the outer peripheral surface of the mandrel body while being stretched by setting the tape feed speed to a speed equal to or lower than the minimum speed of the peripheral speed.

  Further, when the mandrel body is rotated, the peripheral speed of the outer surface of the mandrel changes periodically, so the difference between the peripheral speed of the outer surface of the mandrel and the feeding speed of the tape also changes periodically. The amount of tape stretching also varies. Therefore, the thickness of the unvulcanized rubber layer formed on the outer peripheral surface of the mandrel main body periodically varies with each rotation of the mandrel main body, so that a rubber hose having an uneven thickness structure with excellent thickness accuracy can be finally obtained. .

  In the present invention, a rubber hose having an uneven thickness structure has a circular cross section of the hose inner surface and hose outer surface in the cross section of the rubber hose, and the hose inner diameter center is eccentric with respect to the hose outer diameter center. It means a rubber hose having a structure whose thickness changes continuously. That is, in the rubber hose, the thinnest thin part and the thickest thick part are formed at positions facing each other, and the thin part, the thick part, and the central axis of the rubber hose are included in the same plane. Will be formed.

  In order to wrap the unvulcanized rubber tape around the mandrel body in a spiral manner, a rubber supply means for sending the tape in a direction substantially perpendicular to the rotation axis direction of the mandrel is installed, and the rubber supply means and the mandrel are rotated. What is necessary is just to make it relatively movable to an axial direction. Then, the unvulcanized rubber tape is wound around the mandrel body while rotating the rotating shaft of the mandrel as the unvulcanized rubber tape is sent out from the rubber supplying device, and the rubber supplying device and the mandrel are relatively moved in the rotating shaft direction. Move it.

  The thickness of the unvulcanized rubber layer formed by winding the unvulcanized rubber tape around the outer peripheral surface of the mandrel main body becomes thinner as the distance from the rotating shaft to the outer peripheral surface of the mandrel main body becomes longer. This is because the peripheral speed at that portion is increased and the tape is greatly stretched. Conversely, the unvulcanized rubber layer becomes thicker as the distance from the rotating shaft to the outer peripheral surface becomes shorter.

  As a shape of the unvulcanized rubber tape sent out from the extrusion device, one having a width wider than the thickness direction can be used. When this tape is wound around the outer peripheral surface of the mandrel body, the tape is turned sideways, that is, one side of the tape contacts the outer peripheral surface of the mandrel main body to form the inner surface of the rubber hose, and the other side surface is the outer surface of the rubber hose. The tape is preferably wound around the outer peripheral surface of the mandrel body. Thereby, it becomes possible to control the thickness of the unvulcanized rubber layer with high accuracy.

  In the rubber hose manufacturing method according to the present invention, by adjusting the feed speed of the unvulcanized rubber tape, the rotation speed of the mandrel body or the relative movement speed of the rubber supply means and the mandrel (hereinafter referred to as movement speed), etc. Further, the outer surface of the rubber hose can be formed into a shape in which the outer diameter changes in the hose length direction, such as a truncated cone shape.

  Specifically, when the outer peripheral surface of the mandrel body is cylindrical, a cylindrical rubber hose can be obtained on both the inner surface and the outer surface if the tape feed speed, the rotational speed of the rotating shaft, and the moving speed are constant. In this case, if the tape feeding speed is made constant and the rotational speed or moving speed of the rotating shaft is gradually increased, a rubber hose having an inner surface of a cylindrical shape and an outer surface of a truncated cone shape can be obtained.

Further, when the outer peripheral surface of the mandrel body has a truncated cone shape, the inner surface and the outer surface can be formed into a truncated cone shape by appropriately adjusting the tape feeding speed, the rotational speed of the rotating shaft, and the moving speed. It is also possible to form the inner surface in a truncated cone shape and the outer surface in a cylindrical shape.
That is, in the manufacture of the eccentric rubber hose by the conventional crosshead method, only the cylindrical shape of the outer surface could be manufactured. However, according to the present invention, the outer surface can be formed in various shapes. .

  As for the shape of the outer peripheral surface of the mandrel body, the present invention can be applied as long as it is formed in a rotationally symmetric shape around the central axis. For example, a cylindrical shape, a truncated cone shape, a drum shape, a drum shape Or a bellows shape etc. are mentioned. In particular, if the outer peripheral surface of the mandrel body is formed in a cylindrical shape or a truncated cone shape, the inner surface of the rubber hose becomes a cylindrical shape or a truncated cone shape, and a rubber hose suitable for transporting fluid can be obtained. Specifically, it can be suitably used as a pumping tube of a squeeze pump.

  In the present invention, a mandrel having a rotation axis formed at a position eccentric with respect to the central axis of the mandrel body is rotated around the rotation axis to periodically vary the peripheral speed on the outer surface of the mandrel, and the unvulcanized rubber tape The feeding speed is set to a speed equal to or lower than the minimum circumferential speed, and the unvulcanized rubber tape is wound around the mandrel body according to the difference between the circumferential speed and the feeding speed. It is possible to manufacture a rubber hose having

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a mandrel used in the method for manufacturing a rubber hose according to the present invention. FIG. 2 is a schematic diagram showing a state in which unvulcanized rubber is extruded and wound around the mandrel in FIG. 1 from an extruder, and FIG. 3 is a schematic diagram showing a state in which the mandrel in FIG.

  As shown in FIG. 1, the mandrel 1 used in the present invention has a mandrel body 3 whose outer peripheral surface is formed in a truncated cone shape that is rotationally symmetric about the center axis 2, and a central axis on the end surface in the central axis direction of the mandrel body 3. 2 and a rotating shaft 4 formed at a position eccentric with respect to 2.

  In order to spirally wind the unvulcanized rubber tape around the mandrel 1, as shown in FIG. 2, extrusion as a rubber supply means for extruding the unvulcanized rubber tape 5 in a direction perpendicular to the direction of the rotation axis 4 of the mandrel 1 is performed. The apparatus 6 is installed. Then, the unvulcanized rubber tape 5 is extruded from the extrusion device 6 in the circumferential direction of the mandrel 1 while rotating the rotating shaft 4. The rubber supply means is not limited to the extrusion device 6, and for example, the tape can be supplied from a take-up roll obtained by winding an unvulcanized rubber tape.

  When the tape 5 is extruded, the mandrel 1 and the extrusion device 6 are moved relative to each other in the direction of the rotating shaft 4. In the present embodiment, the mandrel 1 is movable in the direction of the rotation axis 4. As a result, the tape 5 is spirally wound around the outer peripheral surface of the mandrel body 3.

  At this time, since the rotating shaft 4 is eccentric with respect to the mandrel body 3, the distance L from the center of the rotating shaft 4 to the outer surface of the mandrel is L1 at the shortest and L2 at the longest. Then, when the rotating shaft 4 is rotated at a constant rotational angular velocity, the peripheral speed of the mandrel outer peripheral surface when the mandrel 1 rotates is the highest when the distance L is L2, as shown in FIG. (S2). Then, as shown in FIG. 3, the peripheral speed of the mandrel is the slowest when the distance L is L1 (S1).

  The unvulcanized rubber tape 5 is set so that the feed speed of the unvulcanized rubber tape 5 is equal to or less than the minimum speed S1 of the peripheral speed of the outer peripheral surface of the mandrel body 3 in order to prevent the slack between the extrusion device 6 and the mandrel body 3. As a result, the tape 5 is held in a tensioned state between the extrusion device 6 and the mandrel body 3 and is stretched according to the difference between the peripheral speed of the outer peripheral surface of the mandrel body 3 and the feed speed of the tape 5. The mandrel body 3 is wound around.

  When the delivery speed of the tape 5 delivered from the extrusion device 6 is constant, the thickness of the unvulcanized rubber layer 7 formed by winding the unvulcanized rubber tape 5 around the outer peripheral surface of the mandrel 1 is as shown in FIG. The outer peripheral surface on the L1 side (L1 outer peripheral surface) is the thickest, and the outer peripheral surface on the L2 side (L2 outer peripheral surface) is the thinnest. The shape of the unvulcanized rubber layer 7 formed in a cylindrical shape on the outer peripheral surface of the mandrel body 3 in this way is such that the outer surface and the inner surface of the rubber layer 7 are circular in cross section, and the center of the inner diameter of the rubber layer 7 is The rubber layer 7 is eccentric with respect to the center of the outer diameter, and the thickness of the rubber layer 7 is an uneven thickness structure that continuously changes in the circumferential direction.

  5 is a cross-sectional view taken along line AA in FIG. 4, FIG. 6 is an enlarged view of a portion B in FIG. 5, and FIG. 7 is an enlarged view of a portion C in FIG. As shown in the figure, the unvulcanized rubber tape 5 is wound so that the tape side surface 5 a contacts the outer peripheral surface of the mandrel body 3.

  As shown in FIGS. 6 and 7, the unvulcanized rubber tape 5 is stretched more on the outer peripheral surface of the L2 than on the outer peripheral surface of the L1, so that both the thickness and the width are reduced. Thus, since the thickness t of the unvulcanized rubber tape 5 is different between the L1 outer peripheral surface and the L2 outer peripheral surface, the inclination angle α of the tape 5 (the angle between the outer peripheral surface of the mandrel body 3 and the tape plane 5b) changes. By doing so, the length in the axial direction of the unvulcanized rubber layer 7 on the L1 outer peripheral surface and the L2 outer peripheral surface after winding the tape 5 is adjusted to be the same. Specifically, the inclination angle α1 on the outer peripheral surface of L2 is automatically adjusted so as to be smaller than the inclination angle α2 on the outer peripheral surface of L1.

  As described above, according to the rubber hose manufacturing method according to the present invention, it is possible to accurately manufacture a rubber hose having an uneven thickness structure. The rubber hose manufactured according to the present invention can have not only a single layer structure but also a multilayer structure. In addition to the rubber layer, a reinforcing layer using a reinforcing cord or the like may be formed.

  Specifically, the manufacturing process of the rubber hose having a multilayer structure in which a reinforcing layer is interposed between the inner rubber layer and the outer rubber layer will be described with reference to FIGS. FIG. 8 is a sectional view showing a rubber hose having a multilayer structure.

  FIG. 8 is a cross-sectional view schematically showing a multi-layer rubber hose 8 used as a pumping tube of a squeeze pump. FIG. 8A is a cross-sectional view in the length direction of the rubber hose, and FIG. A sectional view in the radial direction of a rubber hose is shown.

  As shown in FIG. 8 (a), the rubber hose 8 has an inner surface and an outer surface formed in a truncated cone shape, and as shown in FIG. 8 (b), the hose inner diameter center 8a becomes the hose outer diameter center 8b. It is eccentric. Thereby, the thick part 12 and the thin part 13 are formed in the position which opposes 180 degrees in the hose circumferential direction. The thick portion 12, the thin portion 13, and the central axis X are formed so as to be included in the same plane.

  The rubber hose 8 includes an inner rubber layer 9, a reinforcing layer 10 disposed on the outer peripheral side of the inner rubber layer 9, and an outer rubber layer 11 disposed on the outer peripheral side of the reinforcing layer 10. The reinforcing layer 10 includes a reinforcing cord and a covering rubber that covers the reinforcing cord.

  The inner rubber layer 9 can be formed according to the steps shown in FIGS. That is, as shown in FIG. 1, the outer periphery of the mandrel body 3 is formed using a mandrel 1 in which the outer peripheral surface of the mandrel body 3 is formed in a truncated cone shape around the center axis 2 and the rotation shaft 4 is eccentric with respect to the center axis 2. By winding the unvulcanized rubber tape 5 from the small diameter side to the large diameter side on the surface, the inner surface rubber layer 9 having an uneven thickness structure can be formed.

  After the inner rubber layer 9 is formed on the mandrel outer peripheral surface, the reinforcing layer 10 is formed on the outer periphery of the mandrel 1 as shown in FIG. The reinforcing layer 10 is formed by winding a rubber-coated cord around the outer periphery of the inner rubber layer 9. The rubber-coated cords are alternately wound around a plurality of layers so that the cord directions intersect at a predetermined forming angle with respect to the axis of the rubber hose 8. In this embodiment, the reinforcing layer 10 has a two-layer structure in which two rubber-coated cords are wound.

  After forming the reinforcing layer 10, the outer rubber layer 11 is formed as shown in FIG. 10 by winding the unvulcanized rubber tape 5 fed from the extrusion device 6 around the outer periphery thereof. In addition, the mandrel 1 shown in FIGS. 1 to 4, 9, and 10 schematically shows that the rotating shaft 4 is eccentric with respect to the central axis 2 of the mandrel body 3. The rotation axis 4 is set at a position closer to the central axis 2. Specifically, for example, when the thickness ratio of the thick part / thin part is 1.2, the rotation shaft 4 is set at a position where the value of L2 / L1 in FIG. .

  Accordingly, in FIGS. 9 and 10, the center of the outer diameter of the inner rubber layer 9 in the state in which the inner rubber layer 9 is formed substantially coincides with the rotation axis 4, and the peripheral speed of the mandrel becomes constant. The outer rubber layer 11 formed on the outer peripheral side of the inner rubber layer 9 while rotating the mandrel 1 has a substantially constant thickness in the circumferential direction.

  When the rubber hose 8 obtained in this way is bent and attached to the casing of the squeeze pump, the small diameter side of the truncated cone-shaped rubber hose is set to the discharge port side of the pump, and the bending radius direction of the curved rubber hose is set. The thick part 12 is positioned on the innermost side of the plate. This makes it easier to bend the rubber hose, and even if the rubber hose is pressed by the roller of the squeeze pump and the part deforms and extends, it prevents the hose thickness from becoming thinner than other hose parts, and the squeeze type The durability of the pump can be improved.

The perspective view which shows typically the mandrel used for this invention FIG. 1 is a schematic view showing a state in which rubber is extruded from an extrusion device and wound around the mandrel of FIG. FIG. 2 is a schematic diagram showing a state when the mandrel of FIG. 2 is rotated 180 °. Side view of the mandrel schematically showing the state of forming an unvulcanized rubber layer AA sectional view in FIG. Enlarged view of part B in FIG. Enlarged view of part C in FIG. It is sectional drawing which shows the outline of a multilayer structure rubber hose, FIG. 8 (a) shows sectional drawing of hose length direction, FIG.2 (b) shows sectional drawing of radial direction of a hose. 4 is a side view of a mandrel schematically showing a state in which a reinforcing layer is further formed in FIG. FIG. 9 is a side view of a mandrel schematically showing a state in which an outer rubber layer is further formed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mandrel 2 Center shaft 3 Mandrel main body 4 Rotating shaft 5 Unvulcanized rubber tape 6 Extruder 7 Unvulcanized rubber layer 8 Multilayer rubber hose 9 Inner rubber layer 10 Reinforcement layer 11 Outer rubber layer 12 Thick part 13 Thin part

Claims (6)

An unvulcanized rubber tape fed from a rubber supply means is spirally wound around the outer peripheral surface of a rotating mandrel to form a cylinder, and a method for producing a rubber hose for vulcanizing the cylindrical molded body, The mandrel includes a mandrel body whose outer peripheral surface is formed in a rotationally symmetric shape around the center axis, and a rotation shaft formed in an eccentric position with respect to the center axis of the mandrel body. The peripheral speed on the outer surface of the mandrel is periodically changed, the unvulcanized rubber tape feed speed is set to a speed equal to or lower than the minimum speed of the peripheral speed, and the unvulcanized rubber tape is set according to the difference between the peripheral speed and the feed speed. A method for producing a rubber hose having an uneven thickness structure, characterized in that the mandrel body is spirally wound while being stretched. 2. The rubber hose according to claim 1, wherein the thickness of the unvulcanized rubber layer formed by winding an unvulcanized rubber tape around the outer peripheral surface of the mandrel main body becomes thinner as the distance from the rotating shaft to the outer peripheral surface becomes longer. Manufacturing method. Wrap the unvulcanized rubber tape around the outer surface of the mandrel body so that one side of the unvulcanized rubber tape contacts the outer surface of the mandrel body to form the inner surface of the rubber hose and the other side forms the outer surface of the rubber hose. The method for producing a rubber hose according to claim 1 or 2, characterized in that 4. The method of manufacturing a rubber hose according to claim 1, wherein an outer surface of the rubber hose has a truncated cone shape. The method for manufacturing a rubber hose according to any one of claims 1 to 4, wherein an outer peripheral surface of the mandrel body is formed in a cylindrical shape or a truncated cone shape. 6. The method for producing a rubber hose according to claim 5, wherein the rubber hose is used as a pumping tube of a squeeze pump.

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