JP2862371B2 - Equipment for manufacturing metal pipes for composite pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) In the present invention, for example, a synthetic resin layer is coated on the inner peripheral surface of a relatively thin metal tube such as an aluminum tube, or on both the inner and outer peripheral surfaces. The present invention relates to an apparatus for manufacturing a metal tube when manufacturing a composite tube.

(Prior Art) A composite tube in which the inner peripheral surface of an aluminum tube, or both the inner peripheral surface and the outer peripheral surface are coated with a synthetic resin, is usually made of a strip-shaped aluminum sheet such that the respective side edges thereof overlap each other. After the aluminum pipe is continuously manufactured by ultrasonic welding the superposed side edges of the aluminum pipe, the inner peripheral surface or the inner peripheral surface and the outer peripheral surface of the aluminum pipe are formed. It is manufactured by coating both sides with a synthetic resin layer.

In producing such a composite tube, the aluminum sheet is usually formed into a circular tube by a liner type circular tube forming machine shown in FIG. The liner type circular tube molding machine is
It has a resin flow pipe 71 through which the welding resin flows, and an outer mold 72 whose inner peripheral surface is fitted to the resin flow pipe 71 at an appropriate interval. An inner peripheral surface of the outer mold 72 is provided with a cylindrical liner 73 which is fitted to the resin flow tube 71 in a state where a predetermined annular gap is provided with the outer peripheral surface of the resin flow tube 71. I have. Then, an aluminum sheet 74 having a U-shaped cross section is passed through an annular gap formed between the resin flow pipe 71 and the liner 73. When the aluminum sheet 74 passes through the gap, the aluminum sheet 74 comes into sliding contact with the liner 73, and is formed into a tubular shape with its side edges overlapped with each other. A horn of an ultrasonic welding machine is provided on the outer peripheral side edge of the aluminum sheet 74 formed into a tubular shape.
75 is rolled and the side edges are ultrasonically welded together to form an aluminum tube.

The resin flow pipe 71 is inserted into the outer mold 72 from between the respective side edges of the aluminum sheet 74 immediately before being formed into a tubular shape, and the distal end thereof is welded to the aluminum sheet 74 by welding the respective side edges of the aluminum sheet 74. Has reached the inside of the tube. Then, the welding resin is extruded from the tip of the resin flow pipe 71 to the inner peripheral surface of the aluminum pipe.

The material of the liner 73 used in such a tube forming machine is excellent in heat resistance and abrasion resistance of fluorine resin, aromatic polyester resin and the like, and further excellent in sliding property with a metal sheet such as an aluminum sheet. Synthetic resin is used.

(Problem to be Solved by the Invention) In such a liner-type circular tube molding machine, since the liner 73 made of synthetic resin is used, there is no possibility that the outer peripheral surface of the manufactured aluminum tube is damaged. However, the liner 73 made of synthetic resin is
Wears very easily due to sliding contact with Therefore, the liner 73 may be gradually worn while the aluminum sheet 73 is in sliding contact, and the outer diameter of the continuously formed aluminum pipe may be gradually increased.

Also, in the manufactured aluminum pipe, the side edges of the aluminum sheet are overlapped and welded, so that the welded portion is slightly raised. In addition, when the aluminum sheet is formed into a tubular shape, there is a possibility that irregularities may occur on the outer peripheral surface.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide an apparatus for manufacturing a metal pipe for a composite pipe in which a manufactured metal pipe is stably manufactured with a predetermined outer diameter.

(Means for Solving the Problems) An apparatus for manufacturing a metal pipe for a composite pipe according to the present invention is characterized in that when manufacturing a composite pipe in which at least the inner peripheral face of the metal pipe is coated with a synthetic resin layer, the inner peripheral surface is made of synthetic resin In order to be covered with a layer, the respective side edges of the band-shaped metal sheet are overlapped and formed into a circular tube, and the respective side edges are welded to each other to manufacture a metal tube for a composite pipe. There is a cylindrical space formed therein, and when the band-shaped metal sheet is passed through the space, the metal sheet is slid in contact with the inner peripheral surface, and each side edge of the metal sheet is connected to each other. An outer mold for forming a superposed circular tube, a welding machine for welding each side edge of the metal sheets superposed by the outer mold, and a welding machine downstream of the welding machine in the metal sheet conveying direction. So that an annular space having an outer diameter substantially equal to the outer diameter of the metal tube to be manufactured is formed. And a shaping machine having a plurality of hourglass rollers each having a curved surface depressed in an arc shape along the axial direction, thereby achieving the above object.

(Operation) In the apparatus for manufacturing a metal pipe for a composite pipe of the present invention, the metal sheet is formed into a circular tube by slidingly contacting the inner peripheral surface of the outer mold, and the side edges are welded by a welding machine. After that, it passes through the space formed by each hourglass roller in the shaping machine. When the outer diameter of the metal tube formed into a tubular shape is larger than the outer diameter of the metal tube to be manufactured, each of the hourglass rollers reduces the conveyed metal tube on the outer peripheral surface of each hourglass roller. The diameter is adjusted to a predetermined outer diameter.

(Examples) Hereinafter, the present invention will be described with reference to examples.

The apparatus for manufacturing a metal pipe for a composite pipe of the present invention is used, for example, to manufacture an aluminum pipe when manufacturing a composite pipe in which the inner peripheral surface of an aluminum pipe, or both the inner peripheral face and the outer peripheral face are coated with a synthetic resin layer. Used for

As shown in FIG. 2, the metal tube manufacturing apparatus 50 manufactures a strip-shaped aluminum sheet 10 drawn from the uncoiler 20 into an aluminum tube. The aluminum sheet 10 pulled out from the uncoiler 20 is horizontally supported by support rollers 31 and 32. The aluminum sheet 10 fed from the downstream support roller 32 is sequentially deformed from a U-shaped cross section to a circular shape as the distance from the support roller 32 is increased, and is conveyed to the position where the inner die 40 is disposed.

The inner die 40 has a support portion 41 whose lower end is located between the side edges of the aluminum sheet 10 deformed into a U-shaped cross section, and a downstream side in the transport direction of the aluminum sheet 10 from the lower end of the support portion 41. And a cylindrical resin flow pipe 42 extending to the outside. A core (not shown) is inserted concentrically inside the resin flow pipe 42, and the molten resin flows through the gap between the two.

An outer mold 51 is provided in the middle of the resin flow section 42 of the inner mold 40. The outer mold 51 has a cylindrical space formed therein, and a cylindrical liner (not shown) is fitted in the space. Then, the aluminum sheet 10 is inserted into the space formed by the liner. When the aluminum sheet 10 passes through the cylindrical space of the liner, by slidingly contacting the inner peripheral surface of the liner,
The aluminum sheet 10 is formed in a tubular shape in which the respective side edges overlap.

On the downstream side in the transport direction of the aluminum sheet 10 of the outer mold 51,
A horn 52 of an ultrasonic welding machine is provided.
Thereby, the mutually overlapping side edges of the aluminum sheet 10 formed into a tubular shape are ultrasonically welded.

From the tip of the resin flow tube 42 in the inner die 40, the molten resin is radially extruded, and the respective side edges of the aluminum sheet 10 are welded by the horn 52 of the ultrasonic welding machine. The peripheral surface is covered with the resin.

The shaping machine 20 is provided downstream of the horn 52 of the ultrasonic welding machine. The shaping machine 20, as shown in FIG.
It has a pair of hourglass rollers 21 and 21 disposed on the upper side and the lower side in a state orthogonal to the traveling direction of the aluminum sheet 10. Each hourglass roller 21 has on its outer peripheral surface a curved surface 21a that is depressed in a semicircular shape in the axial direction so as to be in rolling contact with almost half of the outer peripheral surface of the manufactured aluminum tube. An annular space is formed by each curved surface 21a of each of the hourglass rollers 21 facing each other, and the diameter of the space is equal to the outer diameter of the composite pipe to be manufactured. The outer peripheral surface of each end of each hourglass roller 21 is a straight cylindrical portion 21b having a constant outer diameter in the axial direction.
It has become. Then, a pair of hourglass rollers 21 and 21
Are rotatably attached to the frame 22, respectively.

When the aluminum sheet 10 conveyed from the outer die 51 passes between the hourglass rolls 21 and 21, the frame 22 supports the support member 23 (not shown) so as not to move following the conveyance of the aluminum sheet 10. (See FIG. 2).
As a material of each hourglass roller 21, metal or hard synthetic resin or the like is used.

On the downstream side of the circular tube shaping machine 20, as shown in FIG.
Take-up machines 60 and 60 are provided, and both take-up machines 60 transport the composite pipe manufactured through the shaping machine 20.

In the composite pipe manufacturing apparatus having such a configuration, the composite pipe is manufactured as follows.

The aluminum sheet 10 enters between the outer peripheral surface of the resin flow pipe 42 in the inner die 40 and the inner peripheral surface of the liner in the outer die 51 in a state where the aluminum sheet 10 is sequentially deformed from a U-shaped cross section to a circular shape. . When the aluminum sheet 10 passes through the cylindrical space in the liner, it slides on the inner peripheral surface thereof, is forcibly curved by the inner peripheral surface, and the cross section where each side edge overlaps is a perfect circle. It is formed into a tubular shape.

The tubular aluminum sheet 10 that has passed through the outer mold 51 is
The outer peripheral side portion of each side edge overlapped with each other is rolled into contact with the horn 52 of the ultrasonic welding machine, and the respective side edges are welded to each other. Thus, a circular aluminum tube is manufactured.

At this time, the molten resin is extruded from the distal end of the resin flow pipe 42, the distal end of which is located in the manufactured aluminum pipe, and the inner peripheral surface of the aluminum pipe is lined with the molten resin.

The liner of the outer mold 51 is usually made of a synthetic resin, and is worn when the aluminum sheet 10 comes into sliding contact. Therefore, when the aluminum sheet 10 is shaped into a tubular shape with the liner worn, the outer diameter of the formed tubular aluminum sheet increases. Aluminum sheet formed into a tubular shape with a large outer diameter
In the case of 10, the overlapped side edges are welded by the horn 52 of the ultrasonic welding machine, so that an aluminum tube having a large outer diameter is formed.

The aluminum tube conveyed from the outer mold 51 and having the overlapped side edges welded to each other passes between the curved surfaces 21a and 21a of the hourglass rollers 21 and 21 in the shaping machine 20.
The curved surfaces 21a and 21a are configured to be in rolling contact with the outer peripheral surface of a circular pipe to be manufactured over substantially the entire circumference. For this reason, the aluminum tube with the larger outer diameter is
When passing between 21 and 21, the aluminum tube 12
Is reduced in diameter so as to be equal to the outer diameter of the aluminum tube to be manufactured. Therefore, even when the aluminum tube 12 having an outer diameter larger than the predetermined outer diameter is manufactured by the outer mold 51, the outer diameter is finally reduced to the outer diameter of the aluminum tube to be manufactured. In addition, the outer peripheral surface of the welded portion of the aluminum tube 12 welded to each overlapped side edge portion is raised, but the aluminum tube 12 extends between the curved surfaces 21a and 21a of the hourglass rollers 21 and 21. By passing through, the swelling is also removed, and the unevenness generated on the outer peripheral surface of the aluminum tube 12 due to other causes is also eliminated.

Further, since the hourglass rollers 21 and 21 are in rolling contact with the outer peripheral surface of the aluminum tube 12 when passing through the aluminum tube 12, there is no possibility of damaging the outer peripheral surface of the aluminum tube 12. In addition, the outer peripheral surfaces of the hourglass rollers 21 and 21 have less wear, and the aluminum tube 12 can be shaped stably.

(Effect of the Invention) The apparatus for manufacturing a metal pipe for a composite pipe according to the present invention has the following features.
Even when a metal sheet is formed into a circular tube having a large outer diameter by the outer die, the diameter is reduced to a predetermined outer diameter by a shaping machine having a plurality of hourglass rollers. Therefore, even when the welded portion is raised by welding the side edges of the metal sheet shaped into a tubular shape, the raised portion is eliminated, and
The unevenness of the outer peripheral surface is also eliminated, so that a metal pipe having a predetermined outer diameter can be manufactured stably.

[Brief description of the drawings]

FIG. 1 is a front view showing a main part of an embodiment of a circular pipe manufacturing apparatus according to the present invention, FIG. 2 is a side view schematically showing the entire apparatus, and FIG. 3 is a conventional apparatus for manufacturing a metal pipe for a composite pipe. It is a block diagram which shows schematically. 10 …… Aluminum sheet, 12 …… Aluminum tube, 20
…… Shaping machine, 21… Drum roller, 40… Inner type, 51… Outer type, 52… Horn.

Claims (1)

(57) [Claims] When manufacturing a composite tube in which at least the inner peripheral surface of a metal tube is covered with a synthetic resin layer, each side of a strip-shaped metal sheet is so coated that the inner peripheral surface is covered with the synthetic resin layer. An apparatus for manufacturing a metal pipe for a composite pipe in which the edges are overlapped and formed into a tubular shape, and the respective side edges are welded to each other to manufacture a metal pipe, wherein a cylindrical space is formed therein, An outer die that slides the metal sheet on the inner peripheral surface when the band-shaped metal sheet passes through the space, and forms a tubular shape in which the respective side edges of the metal sheet are overlapped with each other; A welding machine for welding the side edges of the superposed metal sheets to each other; an annular ring having an outer diameter substantially equal to the outer diameter of the metal pipe to be manufactured, which is disposed downstream of the welding machine in the metal sheet conveying direction. Each having a curved surface depressed in an arc shape along the axial direction so that a space is formed. Apparatus for manufacturing a composite pipe the metal tube having a, a shaping machine having a drum-type roller number.