CS217102B1 - Method of shaping the pipes particularly for making the elbows and device for executing the same - Google Patents

Abstract

A method of forming tubes, particularly for manufacturing knee, consisting in having a pipe it is filled with liquid and a liquid charge app is pushed forward during counter-pressure curved track until it curves. The tube forming apparatus includes press tool provided with a cavity in shape an incomplete circular ring whose one the orifice is movably inserted at · the press tool holder is arranged supporting plunger to abut the front boar tubes in the insertion retainer, and the second the mouth of the pressing tool cavity is provided pressure fluid connection.

Description

A method of forming tubes, in particular for the production of elbows, is to fill the tube with liquid and to push the liquid filled appellate forwardly under a curved path until it curves accordingly.

The tube forming apparatus comprises a press tool provided with an incomplete circular ring cavity, one of which is provided with a movable insertion device, and a support plunger is provided for the press tool holder to abut the front tube of the tube in the insertion retainer. pressure fluids.

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BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming tubes, in particular for the production of elbows, and to apparatus for carrying out this method.

Known methods of forming tubes for the production of elbows utilize the technology of bending the starting tubular blank onto aa-rigid stencil and punch tools. This method is disadvantageous in terms of the complexity and frequency of the tooling as well as the unfavorable stress conditions present therein in the pipe material. Another technological procedure used is to push the tubular blanks onto a curved mandrel, which is called a shepherd's stick ”. In addition to the above-mentioned complexity of tooling for each pipe dimension, this procedure is only suitable for all-wall blanks.

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Another known method of tube shaping is that the tube is blinded at one end and inserted through this end into a curved opening in the tool cavity. Thereafter, a pressurized fluid is introduced into the tube which acts on its blind end as if it were a hollow piston. By the pressure of the liquid, the tube is forced through a curved orifice to form it.

The disadvantage is that each pipe must be blinded at one end before removing it and later removed. Also, the increase in pressure in the liquid at the end of the tube shaping causes difficulties.

Knees of low wall thickness and also produced by sheet metal forming into the shape of a half wall of torus, weld ae and are further divided into required segments. This method of manufacture is complex and laborious.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the disadvantages of the known methods for the production of elbows from tubes, which consists in filling the tube with pressurized liquid and scaled liquid and pushing it forwardly behind the forehead.

The effect of the invention is that the production of thin-walled tubular elbows is also ensured, with considerable savings in operating equipment, since it is possible for one external pipe diameter and different wall thicknesses to be sufficient with one device.

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Further effects of the invention of the brightness can be seen from the following description of the longitudinal undulating method up to the drawing, wherein FIG. 1 shows a cross section of a split die in the etave before forward extrusion of the tubes; FIG. FIG. 4 shows an alternative solution of the device for exerting a back pressure when the pipe is pushed forward by a curved path in the pressing tool.

Method for producing bends of the tubes and using forward extrusion should be performed using a device which consists essentially of lieovacíhb tool 1, which has mills? I formed cavity 2 to the ^square, and has a circular cross-section, corresponding to an diameter of the pipe 7 and the curvature of its aces it forms part of the annular ring corresponding to the desired bending radius of the tube.

A support plunger 6 is mounted in the cavity 2 in a sliding but pressure-tight manner. The end face 4 'of the liner 1 is provided with grooves and gasket g arranged around the circular opening of the cavity 2 into the end face 4 intended to abut the insertion retainer 6 of the tube 7. The insertion retainer 6 comprises a cylindrical cavity for receiving the tube 7 and The second orifice of the cavity 2 is a pressure fluid connection 11 connected to a hydraulic circuit (not shown) to control the pressure and amount of liquid in the adjacent part of the cavity 2 in front of the support plunger g.

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FIG. 2

The pressing tool 1 can also be adapted so that the Se (Fig. 4) cavity 2 is formed by a semicircular groove in the die 2 * by a semicircular recess 14 on the pin 12, which is rotatable about an axis identical to the axis of the cavity 2. 15. resp. The support plunger 2t, which with its play end abuts the plinth of the tube 7. The pin 12 is connected outside the tool to a braking device (not shown) which balances the necessary support pressure of the plunger 2.

The actual method of making elbows 13 from liquid-filled tubes by extrusion through a curved path using a descriptive device is as follows:

The tube 7 is inserted into the inserted insertion retainer 6 and is positioned at the face of the plunger 2. The plunger 8 is abutted, the tube 7 is filled with liquid 10 via the channel 2 ^{in the} punch 8, and vented.

Further downward movement of the liner 8 causes the tube 2 to be pushed forward into the cavity 2 while forcing the plunger 2 backed up by the liquid discharged via the connection 11 de of the hydraulic circuit (not shown).

When the punch 8 reaches the level of the front plate 4 of the punch 1, the process of producing the knees 12 is completed. This is followed by lifting of the mold holder 8 and the insertion retainer 6 de. upper position. By moving the plunger 2 from its initial position due to the supply of pressurized fluid to the connection 11, the finished elbow 13 is forced out of the functional cavity of the die. The extrusion of the finished elbow 13 ae in the case of the variant of the device according to FIG. 4 is carried out by means of a projection 15 on the pin 12.

Claims (5)

Method for shaping tubes, in particular for the production of elbows, characterized in that the tube is filled with liquid and, together with the liquid filling, is pressed through a curved path by a pre-pressure. Pipe-forming device according to claim 1, characterized in that it comprises a pressing tool (1) provided with a cavity (2) in the form of an incomplete circular ring at one mouth of which a movable insertion retainer (6) of the tube (7) is provided. a punch (8) penetrates the tube (7) and a support plunger (3) is provided in the cavity (2) of the punching tool (1) to abut the front end of the tube (7) in the insertion retainer! (6), and the second orifice of the cavity (2) in the die (1) is provided with a pressurized fluid connection (11). 3. Regulation according to claim 2, characterized in that the punch (6) is provided with a channel (9) for supplying liquid Device according to claim 2, characterized in that the cavity (2) in the form of an incomplete circular ring. describes an angle of at least 180 ° in the tool body (1), the support plunger (3) occupying a maximum of half of this range. Device according to Claims 1 and 2, characterized in that a pin (12) and an axis of rotation coincident with the axis of the cavity (2) are arranged in the cavity (2) in the form of an incomplete annular ring of the die (1). provided with a protrusion (15) covering the profile of the cavity (2), and the rest of the circumference of the spigot (12) is provided with a semicircular recess (14) corresponding to the diameter of the pipe (7); 7) in a retractable feed-in shredder (6) with a guide (8).