JPS58188510A - Drawing method of pipe - Google Patents

Abstract

PURPOSE:To draw a pipe into a small diametrical one in a short time without requiring complicated operations, by screwing a carriage to a screwed rod fixed to the tip of a pipe to join them together, and drawing the pipe through a die hole of a drawbench. CONSTITUTION:A rear part of a screwed rod 2 is inserted into the tip of a pipe 1 and is fixed to the pipe. A small diametrical carriage 7 is screwed to a screwed part 5 at the front side of the rod 2 to join together, and is inserted into a hole die 9 of a drawbench 8. The pipe 1 is drawn continuously from the other side of the die 9 by a driving device. By this method, the cutoff part of a product is made short, and the useless part of the product is also reduced. Further, the carriage 7 after drawing is used again.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe drawing method for drawing a pipe through a hole die and processing the pipe into a pipe having a smaller diameter.

Conventionally, this type of method heats the tip of the pipe, forges it to the desired diameter, connects the gripper carriage of the draw bench to the tip, passes it through a hole die, and then pulls it out using a drive device. It is something to be processed. In this processing method, the tip of the pipe must be heated and forged to gradually reduce the diameter, which requires too much time and effort, and the processed portion will eventually be cut out. Therefore, there is a problem that a lot of product is wasted.

Kono's invention solves these problems, and after inserting the threaded part into the tip of the pipe, the tip of the vibrator is machined to a smaller diameter using a hole die or press, and the threaded part is fixed, and then the threaded part is removed. The carriage of a draw bench is screwed onto the threaded part of the part, and the pipe is inserted into a hole die and pulled out by the drive device of the draw bench to process a small diameter pipe.

In addition, D below is the pipe diameter before processing, and d is the pipe diameter after processing.

1st step As shown in Figure 1, insert the rear part of the screw frame with a diameter slightly smaller than the inner diameter of the pipe into the tip of the pipe, then insert it into the die 3 with a diameter smaller than d, and insert the vibrator. Extrusion processing is performed using hydraulic pressure, pneumatic pressure, etc.

In this case, when the pipe/ is advanced further after the tip of the pipe/ comes into contact with the die 3, the diameter is narrowed down by the die/, and the inner circumferential surface of the pipe/ is brought into contact with the rear thread part of the screw frame. It bites in and becomes fixed.

Due to this biting, the pipe/ and the screw frame are partially fixed, and the pipe/ is further pressed, so that the pipe/
and the screw frame unit move at the same speed, and the entire rear screw part is fixed to the pipe.

Step a As shown in FIG. 2, after the screw frame is completely fixed to the tip of the pipe, it is pulled out.

3rd step As shown in FIG. 3, a carriage 7 having a diameter smaller than said d and having a female threaded part B formed on the rear side is screwed onto the front threaded part S of the screw frame fixed to the pipe. The carriage 7 is inserted into a hole in the draw bench g having an inner diameter of d, and the carriage 7 is continuously pulled out from the other hole die 9 by the drive device of the draw bench g.

In this case, since the diameter of the carriage 7 and the tip end of the pipe is smaller than the diameter d, the machining with the hole die starts slightly behind the position of the screw rod of the pipe. Cold drawing is performed on the diameter d. .

As shown in Fig. 9 in the mite stage, after the drawing is completed, the vibrator/portion with a smaller diameter than d is cut, the draw bench g and the carriage 7 are removed, the calisin is removed from the screw rod, and the carriage is removed. 7 is for reuse.

In addition, as a method for fixing the screw frame and the pipe/
As shown in the figure, the pipe into which the threaded body is inserted may be pressed several times using the press 10 to reduce its diameter and the threaded body may be fixed, or the rear threaded part may be replaced by multiple protrusions. A cylindrical member with a diameter smaller than the inner diameter of the pipe may be formed on the rear left side of the front thread part, and the first, It may be fixed to a threaded body having a front threaded portion S on the pipe as in the second step.

Furthermore, although the front screw portion S is shown as a male screw in the accompanying drawings, it may be a female screw.

As described above, the present invention has the following features.

/ A screw body is fixed to the tip of the pipe, and the carriage 7 is screwed onto the screw body, and it is pulled out by the drive device of the draw bench g. This eliminated the extremely complicated work of forging into small pieces, and made it possible to reduce the drawing force υ of pipes in a short time.

Y In this invention, after being pulled out by the hole guide,
The only part to be removed is the part that is slightly longer than the screw rod, but
In the conventional method, it was necessary to cut the entire part whose diameter was gradually reduced, resulting in a lot of loss, but this invention eliminates this irrationality.

3. After screwing the threaded rod fixed to the pipe into the carriage 7 having the female threaded part 6 or the male threaded part and cutting the diameter using a hole die, the carriage 7 can be removed and reused. 7 is reasonable because it can be used many times and is common to all sizes.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIGS. 1 to 3 are cross-sectional views showing the steps of the present invention, and FIG. S is a cross-sectional view showing press working. /6. Hyfuco 0. Screw rod 30. Hole dice 100. press

Claims (1)

[Claims] / A carriage of a draw bench is connected to the tip of the pipe,
1. A method for drawing a pipe, which involves fixing a screw part to the tip of the pipe and screwing a carriage into the thread part, in the process of drawing a pipe to a small diameter using a hole die. (U) The pipe drawing method according to claim 1, wherein the fixing method is a method of inserting a threaded part with a threaded part formed on the rear side into the tip of the pipe and extruding it through a hole die. . 3. The pipe drawing method according to claim 1, wherein the method of fixing is a method of inserting a screw portion into the pipe and then crimping it with a press.