SU1031744A1 - Apparatus for drawing plastic shells for lining metal pipes - Google Patents

Description

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4: 1 The invention relates to metallurgical engineering, namely, drawing equipment and can be used for lining lashes or individual metal pipes with plastic pipes using the cold method of drawing the latter. A mill for lining metal pipes by cold drawing is known, including a carriage with a lined metal pipe and a spinneret on it, a bar at the end of which a plastic pipe C is attached. However, this mill is not used for lining metal pipes lash the mass pipe inside the metal in the process of drawing plastic pipes of standard diameters. This is explained by the fact that, when used for lining plastic pipes of standard diameter, they are subjected to greater deformation than when lining pipes of a specially selected diameter (non-standard). Closest to the proposed technical entity is a device for drawing plastic shells for lining metal pipes, comprising a drawing die, a hook and a pulling mechanism. The device is also equipped with an unloading device, which is made in the form of an elastic element connected at one end with a hook, and the other with a lid mounted on the rear end of the treated pipe C2. A disadvantage of the known devices is low productivity, since to release a lined pipe from a spring, the latter must be moved in the direction away from the pulling device, which takes about a third of the working time. The purpose of the invention is to increase productivity. This goal is achieved by the fact that the device for bridging plastic shells, when lining metal pipes, contains a drawing die, a hook and a pull mechanism, is equipped with a plug for a metal pipe connected to a compressed air source and connected to a pulling mechanism with a hollow piston with radial channels, and the hook is made with a shank mounted in the piston cavity with the possibility of axial movement, and with communicating longitudinal and radial channels. Figure 1 shows the device, General view, section; in fig. 2 - a hook with a piston, a cut; Fig. 3 is a view of the device at the time of drawing a plastic pipe; in fig. - section aa in figure 1. The device contains a nui mechanism, including a winch 1 (Fig. 1) with a pull cable 2, drive roles and 3 that hold and if necessary move the strands of metal and plastic pipes, a groove with a thrust surface 5, a drawing die 6, air supply unit to the metal pipe, made in the form of a plug 7 with spring-loaded dies 8 installed in its inclined grooves 9 (Fig.), with a seal 10 and a tubular pattern 11 (Fig. 1) informing the cavity 12 (Fig. 4) of the flap 7 with a source of compressed air (not shown). Through the cavity 12 of the plugs and the seal 13 passes the cable 2, which is connected to the piston Ik, having a sealing ring 15 (figure 2), radial channels 16, and the piston is made with circular projections - centralizers 17 - at the ends. In the cylindrical cavity 18 of the piston It is installed with the possibility of axial movement of the shank 19 of the conical hook 20, the holes 21 are drilled on the right centralizer 17, and a longitudinal channel 22 connected with the radial channels 23 on its left cylindrical end along the axis of the hook 20. The pin 19 of the hook, moving in the piston cavity, acts as a spool and together with the piston forms a relief valve. To secure the end of the plastic pipe to the hook 20, the latter is provided with a conical ring 2 (FIG. 3). The device works as follows. Driving rollers 3 (Fig. 1), the lash of metal pipes 25 is moved to the right until the end of the pipe touches the thrust surface 5 of the groove. Then, first, a piston 1 with a hook 20 is inserted into the cavity of the pipe 25 from its right end, and then a plug 7. A whip of plastic pipes 26 is installed in front of the die 6. Then

through pipe 11 into the cavity of the pipe 25 serves under excessive pressure, the air under which the plug 7 moves somewhat to the left and its plates 8, which are located in the inclined grooves 9 (fig.), are pressed against the inner wall of the pipe and thereby prevent the plug from the pipe. Under the influence of air, the piston AND moves to the left, the cable 2 is carried along. At the same time, the SHANK 19 of the hook 20 is in the extreme right position, and the channels 16 of the piston And are closed (Fig. 2). After the release of the hook 20 from the left end of the pipe 25, the air supply is stopped. - The piston stops and the hook continues to move to the left by inertia, and the passage through the drawing die 6 stops after the shank 19 takes its leftmost position (FIG. 3).

Then, the end of the plastic pipe 2b cut along in several places with the help of the ring 2k is fixed to the conical hook 20, includes a winch 1, which by a cable 2 pulls the pipe 26 through the spinneret 6 and introduces it into the cavity of the metal pipe 25. Simultaneously with pipe 25 serves cooled to the air that the passage through the holes 21 of the centralizer 17, the channels 16, the piston cavity 18 and through the channel 22, the holes 23 of the hook 20, enters the cavity of the plastic pipe 26, cooling the latter.

The cooled air through the gap between the piston seal and the wall of the pipe 25 also enters the cavity A (fig. 3) between the pipes 25 and 2b and cools the plastic pipe from the outside. The plastic tube is heated due to (Deformation and friction against the wall of the drawing die and partially against the metal tube, and then cooled with supplied air to a temperature of 20-25 ° C, acquires sufficient strength to prevent the tube from breaking when it is pulled through the metal tube. When when the piston approaches the plug over a distance of about 50 cm by means of automation (not shown, the supply of cooled air is stopped. Upon further movement of the piston, the right centralizer 17 hits

The protruding ends of the dies 8, which, moving along the inclined grooves 9, come out of engagement with the pipe and the plug 7 moves to the right under the action of the piston. After exiting

the metal pipe 25 of the end of the plastic pipe 26, the winch 1 is turned off, the end of the pipe 26 is uncoupled from the hook 20, and the lined metal pipe is removed from the drive rollers 3. The next metal pipe is installed in the empty space, and the plastic pipe is in front of the die.

Due to the fact that the finished lined pipe is not moved in the opposite direction (as in the prototype for release from the spring), the productivity of the device is increased by 25%.

on 90

20 g2

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Claims (1)

DEVICE FOR DRAWING PLASTIC CASES FOR LAYING METAL PIPES, containing a drawing die, a hook and a pulling mechanism, characterized in that, in order to increase productivity, it is equipped with a plug for a metal pipe connected to the source of compressed air and connected to the pulling mechanism with a hollow piston channel , · And the hook is made with a shank installed in the piston cavity with the possibility of axial movement, and with communicating longitudinal and radial channels.