JPS6195922A - Manufacturing device of composite pipe of metal and plastic - Google Patents

Abstract

PURPOSE:To perform smoothly molding of a metallic sheet into a continuous round pipe without hurting the surface, by constituting the surface of an inner mold, which is in a sphere whose deformation resistance to be generated while the metallic sheet is being molded into the round pipe is large, with a component over which the metallic sheet is apt to slide. CONSTITUTION:A free-sliding layer 413 is provided on the outside of a sphere 412 wherein the surface of an inner mold 41 of a round pipe molding tool is varying into a round cross section from an eliptic state cross section along an advancing direction of a U-shaped metallic sheet 11. The free-sliding layer 413 possesses function moving smoothly the outside of the inner mold 41 over the metallic sheet 11, which is formed, for example, of plastics or ceramics which is superior in sliding properties and heat-resisting properties. As for arrangement of the free-sliding layer 413, it is performed by a method wherein either an outer mold is set in a predetermined part of the outside of the inner mold by making the outer mold into a split mold or the outer mold is set in the same by a coating method or by making use of a heat-shrinkable tube.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides an apparatus for manufacturing a composite pipe of metal and plastic, and a method for smoothly and continuously forming a metal sheet into a circular pipe, and for forming at least the inner surface of the metal sheet into a circular pipe. The present invention relates to a device for coating plastic layers.

(Prior Art) An apparatus for manufacturing a composite pipe of metal and plastic is disclosed, for example, in Buddhist Patent No. 2463673. This device forms a U-shaped metal sheet into a circular tube by passing it through the gap between the inner and outer molds of a circular tube forming machine, and extrudes molten resin onto the inner surface of the resulting circular tube. It has a structure in which the inner surface is covered with a resin layer. This device is
Since the shape of the metal sheet is pressed between the inner and outer molds of a circular tube forming machine to form it into a circular tube, there is a large amount of friction between the metal sheet and the mold surface due to the resistance to deformation of the metal sheet during forming. happen. If the mold is made of hard metal.

Scratches occur on the surface of the metal sheet, and in extreme cases, the metal sheet may break.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and its purpose is to smoothly and continuously form a metal sheet into a circular tube, and to An object of the present invention is to provide an apparatus for manufacturing a composite pipe of metal and plastic that covers a plastic material. Another object of the present invention is to provide an apparatus for manufacturing a composite pipe of metal and plastic, which can smoothly form a two-circular pipe with a significantly simple mold structure.

(Means for Solving the Problems) The present invention is particularly characterized in that the mold surface in the area where the deformation resistance that occurs while the metal sheet is being formed into a circular tube is large is made of a slippery member of the metal sheet. be.

The apparatus for manufacturing a composite pipe of metal and plastic of the present invention includes:
(1) A circular tube forming mold consisting of an outer mold and an inner mold for continuously forming a continuous metal sheet into a circular tube; (2)
(3) a welding means disposed in a downstream region of the inner mold for welding the closed portion of the circular pipe; (3) an annular molten resin passage provided inside the inner mold; and one end of the passage. a plastic layer extrusion means for covering the inner surface of the circular tube with a plastic layer, the tube having an annular molten resin inlet and an annular molten resin outlet opening in the traveling direction of the metal sheet at the other end; (4) The outer surface of the upstream region of the inner mold has a cross section perpendicular to the longitudinal direction thereof, which has a circular shape in the lower part, and gradually changes from an elliptical shape to a circular shape in the upper part toward the lower part, (5 ) A slippery layer is provided in the outer surface region of the inner mold, the cross section of which is perpendicular to the longitudinal direction of the upper part of the inner mold outer surface changes from an elliptical shape to a circular shape along the traveling direction of the metal sheet; The above objective is achieved.

(Example) The present invention will be described below with reference to Examples.

As shown in FIG. 1, the apparatus of the present invention includes a U-shaped forming machine 2 for forming a metal sheet 10 drawn out from a coiler 1 into a U-shape, and a preheater 3 for forming this U-shaped metal sheet 11 into a U-shape. It has a circular tube forming die 4 for forming a circular tube 12 through the process, and a welding means 5 for welding the closed portion of one circular tube 12. The circular tube mold 4 consists of an inner mold 41 and an outer mold 42. Inner mold 4
1, as described later.

It is equipped with a plastic layer extrusion means for coating the inner surface of the circular tube with a plastic material. The device of the present invention further comprises:
An extrusion die 6 for coating the outer surface of the circular tube 12 with a plastic material as necessary, a cooling tank 7 for cooling the circular tube (composite tube) 13 whose inner and outer surfaces are coated with a plastic layer, and this composite tube 13 It has a collection machine 8 that collects.

The outer surface of the upstream region of the inner mold 41 of the cylindrical mold 4 is shown in FIGS.
As shown in FIG. 4, the cross section perpendicular to the longitudinal direction is circular at the lower part 410, and gradually changes from an elliptical shape toward the lower part 410 at the upper part 411. The outer surface of the downstream region of the inner mold 41 is the second
As shown in FIGS. 3, 3, and 5, the cross section perpendicular to the longitudinal direction is circular. As shown in FIG. 6, in a region 412 where the outer surface of the inner mold 41 changes from an elliptical cross-sectional shape to a circular shape along the traveling direction of the U-shaped metal sheet 1, a slippery layer 413 is provided on the outer surface. It is being This easy-sliding layer 413 has a function of allowing the metal sheet 11 to move smoothly on the outer surface of the inner mold 41, and has sliding properties and heat resistance (
For example, it is made of plastic or ceramic, which has excellent resistance (for example, 200° C. or higher). Fluorine-based resins such as polytetrafluoroethylene, polytrifluorochloroethylene, and polyvinylidene fluoride have a low coefficient of friction and are excellent in heat resistance, chemical resistance, weather resistance, non-water absorption, and non-adhesion. , is suitable as a material for the slippery layer 413. Fluorine-containing polyimide and the like are also suitable from the same point of view. The arrangement of the slippery layer 413 made of such a material is not particularly limited, and may be done by splitting the outer mold 42 and fitting it into a predetermined part of the outer surface of the inner mold, by a coating method, or by fitting it using a heat shrink tube. It can be done. As another example of the slippery layer 413,
As shown in FIGS. 7 and 8, the ring can also be formed by fitting the ring into the outer surface of the inner mold. Insert a sphere instead of a ring.

It is also possible to wrap a thin wire around it. Each of these has a small contact area with the metal sheet 11, so that the frictional force generated between the two is minimized, and smooth advancement of the metal sheet 11 is achieved. The arrangement is continuous (Fig. 7(a)
, (b)) or discontinuously ((Fig. 8(a)
l, (bl) may also be used. These rings etc. are metal 1'
The outer side that contacts the sea H1 has a hemispherical cross section.

The inner side in contact with the inner mold is formed into a planar shape. This makes it easy to install these rings and the like on the outer surface of the inner mold. For example, these rings etc.

Metals such as iron, copper, brass, and aluminum rough, or plastics such as the above-mentioned fluororesin are used.

Such a slippery layer 413 may be disposed not only in the inner mold region 412 but also in a downstream region, either continuously or at an appropriate distance. By doing this, metal sheet 1
The progress and molding of 1 can be made smoother. It is preferable to arrange this slippery layer 413 also on the inner surface of the outer mold 42 in order to further smoothen the progress and shaping of the metal sheet 11.

In order to achieve smooth advancement and shaping of the metal sheath 11, in addition to arranging the smooth layer 413 in a predetermined area 412 of the inner mold 41, it is necessary to arrange The outer diameter A of the mold (an area whose entire cross section is circular) is the outer diameter of the inner mold provided with the slippery layer 413 (the slippery layer 413
It is preferable that the outer diameter (including the outer diameter) is set smaller than B.

The melting means 5 is arranged in the downstream region of the inner mold 41.

The closed portion 120 of the circular tube I2 obtained with the circular tube mold 4 is welded. This welding means 5 does not need to be special.

For example, an ultrasonic welding machine is used.

The inner mold 41 is equipped with plastic extrusion means 43, as shown in FIG. This plastic extrusion means 4
3 has an inner mold main body 431 and a core 432.

An annular molten resin passage 433 is formed between the two.

One end of this annular passage 433 constitutes one or more molten resin inlets 434, and the other end constitutes an annular molten resin outlet 435 that opens along the circular pipe traveling direction. The molten resin passes through this annular passage 433 and the annular outlet 4
It is extruded from 35 along the inner surface of the circular tube 12 and coats the inner surface of the circular tube.

A composite pipe is manufactured by the apparatus of the present invention as follows; A metal sheet 10 drawn from a coiler 1 is formed into a predetermined U-shaped metal sheet 11 by a U-shaped forming machine 2. Next, after being heated in a preheater 3, a circular tube mold 4 is heated.
carried to. Here, the U-shaped metal seam 1 is formed into a circular tube by an inner mold 41 and an outer mold 42. Since the slippery layer 413 is provided on the outer surface of the inner mold, the metal sheet 11 can advance smoothly and can be formed into a tubular shape. Next, the inner mold 41
The circular pipe 12 is closed by the welding means 5 located downstream of the welding means 5 . Next, the molten resin is extruded from the annular molten resin outlet 435 of the plastic extrusion means 43 provided in the inner mold 41, and the inner surface of the circular tube 12 is coated with a resin layer. The thus obtained circular tube 12 with a coated inner surface shows no scratches on the surface. This circular tube 12 is further

If necessary, the outer surface is coated with a plastic material using an extrusion die 6 by a known method, and then cooled in a cooling tank 7 and collected by a take-off machine 8. In this way, the desired composite tube 13 is obtained.

The mold shown in Figure 6 above was used. An inner mold 41 made of 345C is made of a Teflon sheet with a thickness of 1 m as a slippery layer 413.
It was placed on the outer surface of a region 412 that changes from an elliptical shape to a circular shape. The outer diameter A in the downstream region of the inner mold 41 is 14.
6111. The inner mold outer diameter B including the easy sliding N413 in the upstream area was 15 mm. The inner diameter of the outer mold 42 is 16 m, the gap between the inner mold 41 and the outer mold 42 is set to Q, 511, and an aluminum sheet 11 with a thickness of 0.25 m is inserted into this gap.
passed. The temperature of the inner and outer molds was set at 180°C. The aluminum sheet 11 is smoothly formed.

No abrasions were observed on the obtained circular tube 12.

Everything was the same as in Experimental Example 1 except that the inner mold 41 without the sliding layer 413 was used. Scratches occurred on the surface of the aluminum sheet 11 that passed between the inner mold 41 and the outer mold 42, and when it was formed into a circular tube over a length of 10 meters, the scratches on the surface progressed and the sheet 11 finally broke. have done.

! A mold shown in Figure 7 was used. The slippery layer 413 was formed by tightly winding W4vA having an outer diameter of 1 square around the outer surface of the inner mold. All other conditions were the same as in Experimental Example 1. The aluminum sheet 11 that passed through the gap between the inner mold 41 and the outer mold 42 was molded smoothly, and no scratches were observed on the surface.

(Effects of the Invention) As described above, the composite pipe manufacturing apparatus of the present invention comprises a slippery member of the metal sheet on the inner mold surface in the area where the deformation resistance that occurs while the metal sheet is being formed into a circular pipe is large. Therefore, continuous circular tube forming of the metal sheet can be smoothly performed without damaging the surface. The formation and construction of the slippery layer is also extremely easy.

Figure 1 is a flow diagram illustrating the production of a composite pipe using the apparatus of the present invention, and Figures 2 and 3 each show an example of the circular tube mold 4 of the apparatus of the present invention. The front sectional view and main part plan view shown in FIGS. 4 and 5 are the AA sectional view and BB sectional view in FIGS. 2 and 3, and FIGS. FIG. 8(a) is a partially cutaway front view showing an example of the easy-slip layer 413 provided on the outer surface of the inner mold, FIG. 7(b) and FIG. It is a diagram.

4... Circular tube forming mold, 5... Welding means, 10... Metal sheet, 11... U-shaped metal sheet 12... Circular tube, 13... Composite tube, 41... Inside Mold, 42...Outer mold, 43...Plastic extrusion means, 120...Circular tube closing part, 41O...Lower part of the outer surface of the inner mold, 411...
Upper part of the outer surface of the inner mold, 413... Easy sliding layer, 433...
Annular passageway, 434... Molten resin inlet, 435...
Annular molten resin outlet.

that's all

Claims (1)

[Scope of Claims] 1. (1) A circular tube forming die consisting of an outer die and an inner die for continuously forming a continuous metal sheet into a circular tube; (2) the inner die; (3) a welding means disposed in the downstream region of the cylinder for welding the closed portion of the circular pipe; (3) a molten resin comprising an annular molten resin passage provided inside the inner mold and one end of the passage; and a plastic layer extrusion means for covering the inner surface of the circular tube with a plastic layer, the tube having an inlet and an annular molten resin outlet opening in the traveling direction of the metal sheet at the other end; (4) The outer surface of the upstream area of the inner mold has a circular cross section at the lower part at a right angle to the longitudinal direction, and gradually changes from an elliptical shape to a circular shape in the upper part toward the lower part; A metal characterized in that a cross section perpendicular to the longitudinal direction of the upper part of the outer surface of the mold changes from an elliptical shape to a circular shape along the traveling direction of the metal sheet, and an easy-slip layer is provided on the outer surface region of the inner mold. Equipment for manufacturing composite pipes with plastic. 2. The manufacturing apparatus according to claim 1, wherein the outer diameter of the inner mold corresponding to the welded region of the circular tube is smaller than the outer diameter of the inner mold including the slip layer. 3. The manufacturing apparatus according to claim 1, wherein the slippery layer is also provided in a downstream region. 4. The manufacturing apparatus according to claim 1, wherein the slippery layer is made of plastic or ceramic having excellent sliding properties and heat resistance. 5. The manufacturing apparatus according to claim 4, wherein the slipping layer is a ring, a ball, or a thin wire arranged on the outer surface of the inner mold.