JPS5853339A - Manufacture of pipe provided with groove on inside surface - Google Patents

Abstract

PURPOSE:To manufacture a metallic pipe having plural continuous grooves on its inside surface, by constituting so that a rolling tool always holds a position for pressing the metallic pipe, and an inside surface working plug is moved to the pressing part of the metallic pipe. CONSTITUTION:A rolling tool 4 always holds a position for pressing a metallic pipe 1, and an inside surface working plug 5 is in a position deviated to the left from the pressing part of the rolling roll 4 when its inside surface grooving work is not executed. When working the inside surface, a die 2 is moved and a plug 3 is moved, and since the inside surface working plug 5 is connected to the plug 3 by a shaft 7, it is moved to the pressing part of the rolling tool 4 simultaneously, and a groove 6 is formed on the inside surface of the pipe 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the method of manufacturing a metal tube having a plurality of continuous grooves on its inner surface.

Conventionally, as shown in Fig. 1, the method for manufacturing internally grooved pipes is as follows:
The metal tube 1 is drawn between the die 2 and the plug 8, and then, as shown in FIG. 6 is known. In this case, the rolling tool 4 is the metal tube 1
For example, eight pieces are installed at equal intervals around the metal tube 1, and initially they are open and are spaced apart from the surface of the metal tube 1 as shown in Figure 1, but when the inner surface is grooved, as shown in Figure 2. A method is adopted in which the metal tube 1 is closed and the metal tube 1 is compressed between it and the inner surface processing plug 5.

Further, the inner surface machining plug 5 is connected and supported by the plug 3 and the shaft 7.

In this conventional method, since it is necessary to open and close the rolling tool 4 at the start and end of the internal grooving process, a complicated mechanism for opening and closing the rotating rolls is required, which increases the size of the device and makes it difficult to balance the rotating parts. However, there are problems such as unbalanced rotation is likely to occur, and the number of rotations cannot be increased very much.

The present invention was made to improve this point, and when forming an inner groove by pressing a metal tube from the outside through a plug for inner surface processing with a rolling tool, the rolling tool constantly presses the metal tube. This method of manufacturing an internally grooved tube is characterized in that the internal groove is processed by holding the metal tube in position and moving the plug for internal processing to the compression part of the metal tube.

To explain this with reference to the drawings, in FIG. 3, the rolling tool 4 (same name as in FIGS. 1 and 2, the same reference numerals are used) always maintains a position where it presses the metal tube 1.
The inner surface machining plug 5 is located at a position retracted to the left of the pressing portion of the rolling tool when the inner surface is not grooved.

When processing the inner surface, as shown in FIG. 4, the plug 5 for inner surface processing is moved to the compression part of the rolling tool 4 to form a groove 6 on the inner surface of the pipe 1.

This movement of the inner surface processing plug 5 is performed as follows. In other words, when the plug 3 is moved by moving the die 2, the inner surface processing plug 5 is moved by this plug 8.
Since the rolling tool 4 is connected to the shaft 7 by the shaft 7, the pressing part 1 of the rolling tool 4 moves at the same time. The movement of the die 2 can be accomplished using ordinary techniques such as hydraulic cylinders and gears (rack and pinion), and the apparatus can be simplified because it does not require a special complicated mechanism unlike the conventional one.

Further, since the rolling tool 4 is always rotating at a fixed position, the rotation can be easily balanced, and therefore it can rotate at a higher speed than conventionally. For example, a product with high precision can be obtained even if the rotation rate is -10,000 rotations per minute or more, whereas the conventional rotation rate was about several thousand rotations per minute.

Therefore, according to the present invention, a product having a smooth surface and grooves on the inner surface can be manufactured with high precision and high efficiency, and its industrial value is extremely large.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams of a conventional example, and FIGS. 3 and 4 are detailed explanatory diagrams of the present invention.0 1... Metal tube 2... Dice 3... Plug 4. ...Rolling tool 5...Plug for internal processing 6...
Groove 7...Shaft Patent applicant Sumitomo Light Metal Industries Co., Ltd. Agent Patent attorney Hide Komatsu

Claims (1)

[Claims] 1. When pressing the metal tube from the outside with a rolling tool through the inner surface processing plug to form an inner groove, the rolling tool always maintains the position where it presses the metal tube, and the inner surface processing plug is pressed against the metal tube. A method for producing an internally grooved tube, characterized in that the internal groove is processed by moving the tube to a compression section.