JPS6222246Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an apparatus for manufacturing a metal tube having a smooth outer surface and a plurality of continuous grooves or projections on the inner surface.

When attempting to form grooves or protrusions of various shapes on the inner surface of a metal tube, various methods such as extrusion, drawing, and rolling are generally used. When trying to form grooves or protrusions, conventional methods have their own problems. That is, the drawing method is difficult to manufacture due to the magnitude of stress applied to the pipe to be processed, the state of metal flow, tool life, and economic efficiency, and the same is true for the extrusion method.

Recently, a processing method using warm hydraulic extrusion has been proposed, but it requires large-scale equipment. In addition, in the rolling method using a swageer, etc., the material is processed by compressive force that is applied intermittently, so the material is fed in the axial direction intermittently, and at the same time, the material is forcibly rotated as the die rotates. , it is difficult to process long products.

The purpose of this invention is to eliminate the drawbacks of the prior art and to provide an apparatus that can economically produce a long metal tube having a large number of continuous grooves or protrusions on the inner surface in a single process. There is a particular thing.

In order to achieve the above object, this invention arranges two sets of pipe shrinking heads equipped with a plurality of planetary rolls in series in front of a die in a metal pipe drawing device such as a draw bench. While guiding the metal tube through a set of tube shrinking heads to a drawing die, a grooved plug is positioned inside the metal tube at a portion corresponding to the planetary rolls of the two sets of tube shrinking heads, and in this state, the metal tube is While moving the pipe, the two sets of pipe shrinking heads are rotated in opposite directions to compress the metal pipe with the planetary rolls of the two sets of pipe shrinking heads and the grooved plug, thereby removing the metal pipe. It is characterized by providing grooves or protrusions on the inner surface of the tube.

With such a device, the twist that occurs as the planetary roll rotates is canceled out, so it is extremely small, and a high cross-section reduction rate can be easily obtained, making it possible to produce metal with a smooth outer surface and an accurate outer diameter. You can easily get the tube.

FIG. 1 schematically shows the overall configuration of the device according to this invention, which mainly consists of a draw bench 1 and a mandrel holder 2. A tube shrinking device 3 is arranged in series in front of a die holder 11 on the draw bench 1. ing.

As shown in FIG. 2, the tube shrinking device 3 consists of a tube shrinking head 4 and a casing 6 that rotatably supports this via a bearing 5. The tube shrinking head 4 is connected to a belt connected to a drive source. 7. The head 4 is composed of a three-claw type scroll chuck, and a roll 42 is rotatably attached to each claw 41, so that the position of each roll 42 can be adjusted. This means that it is possible to process tubes of arbitrary outer diameters, and there is no need to prepare a large number of tools such as tube shrinking dies for each outer diameter, which is a great economic advantage.

Each roll 42 has an arcuate surface on the upstream side in the moving direction of the tube to be processed 9 so as to make smooth contact with the tube to be processed 9, and a parallel surface on the downstream side to keep the outer surface of the tube to be processed 9 smooth. It is showing. A grooved plug 8, which determines the internal shape of the pipe to be processed 9, is rotatably held at the tip of a mandrel 81 fixed to the holder 2, and inserted into the inside of the pipe to be processed 9 at a portion corresponding to the roll 42. . Each roll 42 is evenly pressed in the axial direction, as shown in FIG. 3, in order to give a predetermined reduction to the tube 9 to be processed. A plurality of protrusions or grooves are provided on the outer circumferential surface of the rotatable grooved plug 8 in order to form grooves or protrusions of predetermined dimensions on the inner circumferential surface of the pipe to be processed 9.

Therefore, when the tube to be processed 9 is passed through the tube shrinking head 4, the grooved plug 8 is positioned inside the tube shrinking head 4, and the tube shrinking head 4 is rotated in the direction of arrow A, each roll 42 is rotated.
The tube to be processed 9 is rotated planetarily around the pipe to be processed 9 to contract the pipe to be processed 9, and this is pressed onto the grooved plug 8 to form its inner surface into a shape corresponding to the shape of the outer peripheral surface of the plug 8. can.

A predetermined number of protrusions or grooves on the outer peripheral surface of the rotatable grooved plug 8, for example 36 protrusions or grooves, are arranged spirally or linearly at equal intervals on the circumference.

The pipe 9 to be processed that has passed through the pipe shrinking device 3 is then passed through the drawing die 1 fixed to the die holder 11.
It is extracted after 2.

Therefore, by continuously rotating the tube shrinking head 4 and moving the carriage 13 to the right, the tube 9 to be processed is continuously processed, and has a smooth outer surface and a predetermined groove or protrusion on the inner surface. A processed tube 91 with an accurate outer diameter can be easily obtained.

In this invention, as shown in FIG. 4, in the vicinity of the tube contraction head 4 shown in FIGS. 1 and 2,
Another set of tube shrinking heads 4A are arranged in series and rotated in opposite directions to shrink the tube 9 to be processed.

In this case, the grooved plug 8A is connected to the tube contraction head 4A.
Although the length is increased in accordance with the position of the side rolls 42, the twisting forces acting on the tube to be processed 9 are mutually canceled out, so twisting of the tube can be prevented.

Reduction can be selected arbitrarily by adjusting the ratio between the number of rotations of the head and the drawing speed even when there is only one condensing head, but high reduction can be achieved by using multiple heads. can be obtained easily. Of course, the same can be said about processing difficult-to-process materials.

As is clear from the above description, the device according to this invention applies axial feed to a metal tube through drawing, and prior to drawing, a tube shrinking head equipped with a plurality of planetary rotating rolls. Since the method uses two sets to shrink the metal tube and provide grooves or protrusions on the inner surface of the metal tube, the tube to be processed hardly rotates, and with a simple device, it can be processed with high degree of processing and has a highly smooth outer surface. This has the effect that it is possible to easily obtain a processed pipe with accurate outer diameter dimensions, and that efficiency can be expected to be improved.

[Brief explanation of the drawing]

1 to 4 are explanatory views of the apparatus according to this invention, and FIG. 4 is an explanatory view of the main parts of the apparatus implementing the present invention. 1: Draw bench, 11: Dice holder, 1
2: Drawing die, 13: Carriage, 2: Mandrel holder, 3: Tube shrinking device, 4 and 4A: Tube shrinking head, 41: Claw, 42: Roll, 8 and 8
A: Grooved plug, 81: Mandrel, 9: Processed pipe, 91: Processed pipe.

Claims (1)

[Scope of utility model registration request] A drawing die for drawing metal tubes, and a plurality of planetary rolls that are sequentially arranged in front of the drawing die in series with the drawing die and press the outer periphery of the metal tube passing through, and rotate in opposite directions. and a grooved plug rotatably held at the tip of a mandrel and located inside the metal tube at a portion corresponding to the planetary rolls of the two sets of tube shrinking heads. A manufacturing device for a metal tube having a plurality of grooves or protrusions on the inner surface, characterized by: