JPH0349924A - Molding method of tube having spiral rib outside and its molding device - Google Patents

Abstract

PURPOSE:To enable the rib made of hard synthetic resin to be integrally molded spirally outside of an inner tube when the tube is extruded from an extrusion molding machine by a method in which only the outermost hard synthetic resin layer having been extruded in concentric condition is sheared in a prescribed width and is pressure bonded onto an inside tube body, and then said shearing and pressure bonding are moved in order along its peripheral direction. CONSTITUTION:The outer layer A1 and the inner layer A2 composing a tube body A and the hard synthetic resin layer B1 composing ribs B are extruded in concentric condition with an extruding mold 1. Since on one hand, the shearing die 8 moved inwardly in radial direction by the pushing force of a pushing roller 16, 16', is moved along circumferential direction in order, the hard synthetic resin layer B1 is sheared by the action of its movement to the inward from the outward in the radial direction of the shearing die 8. Since the shearing die 8 is moved in order in circumferential direction with the rotation of the pushing roller 16, 16', the ribs cut out by the shearing with the linear pushing of the hard synthetic resin layer B1 became spiral continuously. Moreover said ribs are embossed in a prescribed shape with the embossing part 14 of the shearing die 8, and are integrally pressure bonded onto the outer peripheral surface of the tube body A.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for continuously and seamlessly molding synthetic resin drainage pipes, suction hoses, etc. having spiral ribs on the outside.

(Prior art) As a method of forming synthetic resin pipes or hoses that are integrally provided with hard synthetic resin ribs in a spiral shape on the outer circumferential surface, there is a wrapping method using a ribbed tape. .

In this method, ribs made of hard synthetic resin are laid integrally along the length of one side of a flexible tape-shaped soft resin strip, and then the ribs are laid integrally with the ribs, which are then extruded into metal strips arranged at right angles to the extrusion direction. While being wound around a tube, the metal tube is rotated and moved in one direction, whereby the ribbed tape is overlapped and spirally wound and fused to form a tube body.

(Problems to be Solved by the Invention) The conventional method described above consists of two steps: extrusion of the ribbed tape and winding of the ribbed tape, which requires time and effort for forming, and The body tends to twist along the winding direction, and since the tape is wound and fused, there is a possibility of peeling at the overlapped part. The transparency is poor. In addition, the entire device becomes larger due to the metal tube supply means, etc., and the formed tube is rotated and fed out, so the devices for cooling winding, cutting, etc. in the next process are inevitably complicated and large. There are problems with formalization.

(Object of the Invention) The present invention has been made in view of the problems of the prior art as described above, and its purpose is to provide a rigid synthetic material to the outside of the inner tube at the time of extrusion from an extrusion molding machine. It is an object of the present invention to provide a molding method and a molding device in which resin ribs are integrated into a spiral shape.

(Means for Solving the Problems) In order to achieve the above object, the molding method of the present invention comprises concentrically forming a soft synthetic resin layer constituting the tube body and a hard synthetic resin layer constituting ribs on the outside thereof. At the outlet of the extrusion mold, ribs of a predetermined width are separated by shearing action and crimping action that moves only the outer hard synthetic resin layer from radially outside to the inside, and are crimped and integrated onto the tube body. It is characterized in that the crimping action is sequentially moved in the circumferential direction so that the continuously formed ribs are helically crimped and integrated with the outer peripheral surface of the tube body.

In the above-mentioned molding method, the tube body is not limited to a single soft synthetic resin layer, but it is of course possible to use a composite layer, and in that case, the material for the innermost layer is selected depending on the purpose. In addition, the molding device used to carry out the above molding method is a multilayer extrusion molding machine with a rotating outer ring rotated by an appropriate power source attached to the outside of the outlet of the extrusion mold, and a rotating outer ring and a fixed extrusion mold. During this period, a shearing die is swingably mounted so that its axial movement is restricted and it slides on the front end surface of the extrusion die. The press in which pressure is applied is characterized by pressing in the center direction with a roller, shearing the extruded outermost synthetic resin layer to a predetermined width, and fixing the press on the inner tube body.

In order to press and fix the sheared rib material against the outer circumferential surface of the tube body, the inner circumferential end surface of the shearing die is stamped into the shape of the inner circumferential end surface, and the shape can be arbitrary, such as approximately semicircular or rectangular. can be selected.

(Function) According to the above method, only the outermost hard synthetic resin layer extruded concentrically is sheared to a predetermined width and crimped onto the inner tube body, and the shearing and crimping are performed along the circumferential direction. By sequentially moving the ribs of a predetermined width cut out from the hard synthetic resin layer, the ribs of a predetermined width are helically compressed and integrated with the outer peripheral surface of the tube body, and the tube body is seamlessly molded.

In addition, in this molding device, the shear press placed around a fixed extrusion die is pressed by the rotation of a rotating outer ring installed at the extruder outlet, and the contact position is moved along the circumferential direction by the pressing force of a roller. , the outermost extruded resin layer is sheared and the press is fixed on the inner resin layer. Thereby, upon exiting the extruder, the ribs are formed in a continuous helical manner.

(Example) Embodiments of the present invention will be described below based on the drawings.

In the figure, 1 is an extrusion mold, which includes an inner cylinder 1a, an outer cylinder 11b, and an inner cylinder 1.
The outside 1jJA+ of the tube body A is connected to the gap between the inner cylinder 1a and the spider die 1C, the inner layer A2 of the tube body A is connected to the inner cylinder 1a and the outer cylinder 1b through the spider die 1C, and the inner layer A2 of the tube body A is connected to the inner cylinder 1a and the outer cylinder 1b. The hard synthetic resin layer B1 constituting the rib B is concentrically extruded from the gap.

The spider die 1C installed inside the inner cylinder 1a has an inner r8
The mandrel 2 of the spider die 1C is arranged so as to protrude slightly forward from the front end of the spider die 1A, and the mandrel 2 of the spider die 1C has an adjustment shaft 3 having a tapered surface, and a container such as a bottle or a ball that moves in and out in the radial direction by the back and forth movement of the adjustment shaft 3. Lock member 4
In combination with this, it is possible to freely adjust the movement in the axial direction.

A rotating outer ring 5 is rotatably supported on the outside of the extrusion die 1 via a radial ball bearing 4.4.
The rotating outer ring 5 is driven and rotated by winding a V-belt 6. Further, the rotating outer ring 5 has its front half expanded outward so as to form a wide gap 7 with the outer peripheral surface of the outer n1b of the extrusion mold 1, and the wide gap 7
A shearing die 8 is housed therein.

The shearing die 8 is composed of a guide ring 9 having an inner diameter larger than the outer diameter of the outer cylinder 1b in the extrusion die 1, and a shearing ring 10 joined to the front end surface of the guide ring 9. The ring 9 has an annularly protruding engagement protrusion 11 on its inner circumferential surface and is fitted into an engagement @12 formed on the outer circumferential surface of the outer cylinder 1b to prevent rattling in the axial direction and prevent the outer circumference of the outer cylinder 1b. This allows them to move together on the surface.

The shearing ring 10, which is fixed to the guide ring 9 with a set screw 13, has an embossed part 14 with a substantially semicircular cross section on its inner circumferential surface, and the width of the ring body is equal to the outer circumferential surface of the outer cylinder 1b. When the inner peripheral surface of the guide ring 9 contacts, the shear ring 10 is placed on the inner diameter line of the inner cylinder 1a.
The length reached by the inner circumferential surface of

Further, the shearing ring 10 is arranged so as to slide from the outside in the radial direction to the inside while being in contact with the front end surface of the extrusion die 1.
This makes it possible to shear the hard synthetic resin layer B1 extruded from the gap between the inner cylinder 1a and the outer cylinder 1b.

The means for sliding the shearing die 8 from the outside in the radial direction to the inside is provided by an actuating arm 15 in the form of a swingable front abbreviation located symmetrically between the rotating outer ring 5 and the shearing die 8.
15', and pressing rollers 16 and 16' rotatably attached to the inner ends of the left and right operating arms 15 and 15', respectively.
The pressing is performed by pressing the rollers 16, 16' against the outer peripheral surface of the shearing die 8 and pressing the shearing die 8 inward in the radial direction by means of the outer end of the actuating arm 15, 15' and the spring on the circumferential surface of the rotating outer ring 5. The hook is constituted by a coil spring 18.18° stretched across the pin 17.17'.

The left and right operating arms 15 and 15' mentioned above are attached to a mounting plate 19 fixed to the front end surface of the rotating outer ring 5 at a bent portion 15a thereof.

15a' is pivotally supported by shafts 20 and 20' so as to be swingable.

Next, to explain the molding of a tube having spiral ribs using the above-mentioned molding device, the outer layer A1 and the inner layer A forming the tube body A made of soft synthetic resin are formed by the extrusion die 1.
2, and the hard synthetic resin layer B1 constituting the ribs B are extruded concentrically.

On the other hand, at the exit of the extrusion die 1, the rotation of the rotating outer ring 5 and the symmetrically arranged presses provided on the rotating outer ring 5 are moved radially inward by the pressing force of the rollers 16 and 16'. Since the shearing die 8 is sequentially moved along the circumferential direction, the hard synthetic resin layer B1 is sheared by the movement of the shearing die 8 from the outside in the radial direction to the inside.

Then, shearing is done by rollers 16°16' as described above, and pressing is done by rollers 16°16'.
As the shearing die 8 sequentially moves in the circumferential direction as it rotates, the ribs cut out by shearing together with the linear extrusion of the hard synthetic resin layer B1 become continuously spiral. Furthermore, the ribs are stamped into a predetermined shape by the stamping part 14 of the shearing die 8 and are crimped and integrated with the outer circumferential surface of the tube body A.

That is, ribs of a predetermined width are continuously cut out by shearing the hard synthetic resin layer B1 extruded on the outermost side by a shearing die 8 that moves from radially outward to inward, and the ribs 1 are made into a tube that moves straight inward. It is crimped and integrally fused to the outer peripheral surface of main body A,
A tube with spiral ribs on the outside will be continuously molded.

Note that the width (thickness) of the rib B is determined by the extrusion speed of the hard synthetic resin layer B+ and the moving speed of the shearing die 8 in the circumferential direction.

In the tube formed as described above, the tube body is continuously extruded while still being tubular, and the ribs are successively cut out and crimped together on the outer circumferential surface of the tube, so the shape of the ribs is stable and neat. .

Although the tube body described above has a laminated structure of two layers, an inner layer and an outer layer, it is of course possible to arrange warp threads between the inner and outer layers, or to incorporate a braid into the structure as desired.

(Effects of the invention) By using the molding method of the present invention as described above,
The ribs can be spirally attached and integrated at the same time as the extrusion molding of the tube body, and there are no joints or bonded parts on the tube body, allowing for continuous molding of products with stable quality.

In addition, the spiral rib attached to the outer peripheral surface of the tube body is
The tubular body, which is extruded concentrically on the outside of the tube body, is cut out by a shearing action that moves from the outside in the radial direction to the inside, and is pressed against the outer circumferential surface of the tube body to integrate it, so the shape of the rib can also be changed. It is stable, and the width (thickness) of the rib can be adjusted as appropriate by adjusting the extrusion speed of the tube and the circumferential movement speed of the shearing action.

On the other hand, the molding device has a simple structure in which a rotating outer ring and a shearing die are placed at the outlet of the extrusion mold, and the shearing die is pressed radially inward, making it easy and inexpensive to manufacture. Moreover, since it is only installed around the extrusion mold, the overall size of the device does not need to be increased, and therefore the installation space can be approximately the same as that of a conventional extrusion molding machine, making it very convenient.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional front view, and FIG. 2 is a side view of the same. In the figure, 1: Extrusion mold 5: Rotating outer ring 8: fA cut-off mold 16.16': Pressing roll ram: Tube body B: Rib Patent applicant Toyox Co., Ltd. Figure Figure

Claims (2)

[Claims] (1) Extrude the soft synthetic resin layer constituting the tube body and the hard synthetic resin layer constituting the ribs on the outside in a concentric manner, and extrude only the outer hard synthetic resin layer radially outward at the exit of the extrusion mold. Ribs of a predetermined width are cut off and crimped and integrated onto the tube body using shearing and crimping actions that move inward from the tube, and the shearing and crimping actions are sequentially moved in the circumferential direction to create a continuous rib on the tube body. A method for forming a tube having spiral ribs on the outside, characterized by integrally crimp-bonding the outer peripheral surface in a spiral shape. (2) A rotating outer ring rotated by an appropriate power source is attached to the outside of the exit of the extrusion mold in a multilayer extrusion molding machine, and movement in the axial direction is restricted between the rotating outer ring and the fixed extrusion mold. A shearing die that slides on the front end surface of the extrusion die is swingably mounted, and the shearing die is pressed toward the center by a pressing roller provided on the rotating outer ring that applies a pressing force inward in the radial direction. An apparatus for forming a tube having spiral ribs on the outside, characterized in that the outermost layer of an extruded multilayer tube is sheared into rib shapes and pressed and fixed onto the tube.