RU2190530C1 - Butt welder for polyethylene pipes - Google Patents

Abstract

FIELD: pipeline making. SUBSTANCE: invention relates to making of members of pipelines, particularly to preparation for and welding of shells of polyethylene pipes. Welder frame has upper and lower guides along which heater and facing tool move. Cross guides and stops limiting displacement of working tables are arranged in frame working zone. Pipe alignment and fastening device on working tables is furnished with changeable grips and adapters. Working tables are provided also with pneumatic cylinders. Value of travel under manual control is from 0.09 to 0.12 of pneumatic cylinder rod travel. Welder control system is provided with device setting heater temperature. Program- and-time control devices provide automatic operation of welder. EFFECT: improved quality of welding at reduced time taken for operation. 5 dwg

Description

 The invention relates to the manufacture of pipeline elements, and in particular for the preparation and welding of shells of polyethylene pipes.

 A known installation for the assembly and welding of bulk hollow products / a.s. 1544542, В 23 К 37/04, 1985 /, in which the means providing the preparation and conduct of welding operations are combined in one installation, which helps to increase their mechanization.

 Known mobile and mobile units for butt welding of polyethylene pipes / UDC 621.643.07, Design, construction and operation of pipelines from polymeric materials, ed. A.N. Shestopala and B.C. Romeyko, M.: Stroyizdat, 1985, p. 210-211 /, including trimmer, electric heater, clamping and centering devices.

 Known installations are not mechanized enough, require a large share of manual labor and cannot be automated.

 In the invention, these disadvantages are eliminated.

 The technical result is achieved by the fact that the installation for butt welding of polyethylene pipes contains a frame and a trimmer, a heater, two working tables symmetrically located relative to the frame, a device for centering and fixing the pipes to be welded and a control system mounted on it, the frame is equipped with upper and lower guides, along which the heater and the miter cutter move, with transverse guides located in the working area of the frame, and stops that limit the movement of the work tables, the device centers and the fastenings of the pipes to be welded on the working tables are equipped with interchangeable grippers and adapters, the working tables are equipped with pneumatic cylinders associated with them, and the displacement from manual control is 0.09-0.12 of the stroke of the pneumatic cylinder rod under pressure, and the operation control system the unit is equipped with a device that sets the temperature mode of the heater, as well as for visual temperature control and program-time devices that ensure the operation of the unit in automatic mode.

 Figure 1 presents a structural diagram of the installation; figure 2 - feed mechanism of the desktops; figure 3 - trimming; figure 4 - heater; figure 5 - pneumatic diagram of the installation.

 The installation design diagram / Fig. 1, front view and top view / includes a frame 1, lower and upper guides 2 and 3, a crosscutter 4, interchangeable grips 5, adapters 6, a heater 7 with a handle 8, two pneumatic cylinders 9 and work tables 10.

 Working tables 10 are located symmetrically relative to the frame 1.

 Frame 1 is a welded structure made of channels, it has longitudinal lower and upper guides 2 and 3, along which the crosscutter 4 and the heater 7 move.

 The movement of the working tables 10 occurs with the help of pneumatic cylinders 9, mounted on the frame 1 and limited by the stops / not shown /.

 On the working tables, removable grips 5 are installed, in which welded pipes are fixed using adapters 6.

 Depending on the assortment of pipes, the installation is equipped with replaceable pneumatic cylinders 9.

 The table movement mechanism / Fig. 2/ includes transverse guides 11, a manual control wheel 12 for moving the table 10 and a worm gear 13.

 The steering wheel 12 provides movement of the table, the magnitude of which is 0.09 to 0.12 movement of the stroke of the rod of the pneumatic cylinder, which is under pressure at the stop.

 Cross guides 11 are located in the working area of the frame 1.

 Trimming / Fig. 3 / is equipped with a housing 14, an end double-sided cutter 15, a belt drive 16, an electric motor 17 and a steering wheel 18 with a gear wheel 19.

 Cross-cutter 4 is used for machining the ends of the shells of pipes before welding.

 Double-sided mill 15 and belt drive 16 are located in the housing 14, the motor 17 is mounted on this housing. In the non-working zone of the frame 1, the miter 4 is protected by steel plates attached to the frame.

 Using the steering wheel 18 and the gear wheel 19, the miter 4 moves along the upper and lower guides 2 and 3.

 The heater / Fig. 4/ includes a stove 20, an electric coil 21, a thermocouple 22 and an arm 23.

 The heater 7 is designed to heat the ends of the welded shells of the pipes. The plate 20 consists of copper plates, which are coated on the outside with a special glass enamel having release properties.

 In the non-working zone, the heater is protected by asbestos-cement protective plates attached to the frame 1. The bracket 23 is attached to the frame 1 and is connected to the handle 8. The thermocouple 22 is used to control the heating temperature of the plate 20. The thermocouple 22 and the power cables 21 are attached to the bracket 23.

 The electrical control circuit of the installation has a standard solution and is not shown in the drawing, it includes a device that sets the temperature mode of the heater, and provides visual temperature control, as well as two program-time devices that provide the necessary time for the units to operate in automatic mode.

 The pneumatic circuit / Fig. 5/ includes a pneumatic valve 24, pressure reducing valves 25 and 26, electrically operated valves 27 and 28, pressure gauges 29 and 30, pneumatically controlled valves 31 and 32 and pneumatic cylinders 9.

 A pneumatic valve 24 provides air to the system. Pressure reducing valves 25 and 26 provide air reduction to the specified pressure level. The distributors electrically controlled 27 and 28 and pneumatically controlled 31 and 32 provide the supply of command air at the command of the electric control in the corresponding cavity of the pneumatic cylinders 9 or its bleeding.

 Visual control of the pressure in the pneumatic cylinders is provided by pressure gauges 31 and 32.

 Preparation for work and welding is as follows.

 In the grippers 5 are installed and with the help of adapters 6 the workpieces of the pipes to be welded are fixed, a fixed air pressure is set in the system. Power is supplied to the heater 7, the temperature of which is automatically maintained at a predetermined level.

 The crosscutter 4 is introduced into the working area by rotating the steering wheel 18 and is fastened to the frame by means of a bolted connection.

 Pressure is applied to the pneumatic cylinders 9, the steering wheel 12 carries out the finishing movement of the working tables 10. Then the pipes are trimmed and the miter 4 is returned to its original position.

 When welding pipes in manual mode, the heater 7 is introduced into the working area of the frame 1 using the handle 8. Then, the ends of the pipes are melted in the first clamping stage at a given pressure.

 The duration of the first stage of reflow is determined by the moment of appearance along the entire perimeter of the melted edges of a uniform burr of the specified parameters.

 After the appearance of the burr, the pipe joints are again clamped with the specified force and duration.

 After the fusion process is completed, the pipe joints are bred, the heater 7 is returned to its original position, and then pipes are upset with a given force.

 The technological pause between the end of the reflow and the pipe sludge should be no more than three seconds.

 The duration of pipe cooling is made under pressure for 8-12 minutes.

 In the automatic welding mode, the pipes are melted, fused, sludged and cooled automatically, but after the second reflow mode is completed, when the pipe joints are parted, it is necessary to manually bring the heater plate 7 from its working position to its original position.

 Tests of the prototype of the installation for butt welding of polyethylene pipes, which implements the proposed design features, have shown the possibility of improving the quality of welding while reducing its time.

Claims (1)

 Installation for butt welding of polyethylene pipes, comprising a frame and a trimmer mounted on it, a heater, two working tables symmetrically located relative to the frame, a device for centering and fastening the pipes to be welded and a control system, characterized in that the frame is equipped with upper and lower guides along which they move heater and miter, transverse guides located in the working area of the frame, and stops that limit the movement of the work tables, the device for alignment and mounting of welded t rubles on the working tables is equipped with interchangeable grippers and adapters, the working tables are equipped with pneumatic cylinders associated with them, and the displacement from manual control is 0.09 - 0.12 of the stroke of the pneumatic cylinder rod under pressure, and the control system of the installation is equipped with a device, setting the temperature mode of the heater, as well as for visual temperature control, and program-time devices that ensure the operation of the installation in automatic mode.

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