RU2008117C1 - Tube bending device - Google Patents

Abstract

FIELD: plastic working of metal. SUBSTANCE: bending device has drive for advancing tube along expander and bending unit with power cylinder effectuating rocking motions. Power cylinder rod is connected with actuating unit through lever. Device is characterized in that actuating unit of bending device is formed as cartridge, which is connected with power cylinder through paired pivotal parallelograms. Tube advancement drive has speed change box. Rotational speed of bending cartridge is controlled by power cylinder throttle to provide for required radius of tube bending. EFFECT: increased efficiency and simplified construction. 2 dwg

Description

 The invention relates to a device for bending pipes in a cold state due to local elastic-plastic deformation of the wall material and can be used for the manufacture of steeply bent measured bends for connecting pipes.

 Known devices for bending pipes containing a rolling head with expandable rollers, an oval-shaped stand and a bending unit with a movable roller [1].

 The disadvantage of this device is its limited scope: only for thick-walled pipes due to the possible loss of strength in the bending section and deformation in the power lines.

 A device is selected for the prototype, where in addition to the cage of an oval caliber on the supply side of the pipe there is a calibrating cage with drive rolls that are mutually perpendicular to the rolls of the cage of an oval caliber, and the bending unit is made in the form of a two-shouldered lever connected to a power swinging cylinder, carrying an executive body - bending roller and placed in a groove freely mounted on the axis of the drum [2].

 The bending stand allows you to increase the force required for a stable flow of the bending process, and to calibrate. The installation of rolls in mutually perpendicular planes increases the accuracy of the geometric shape of the bent pipe.

 When moving the workpiece relative to the bending roller, the bending plane rotates, which causes the rotation of the drum. Thus, the tracking system can reduce the load.

 The device provides bending of large-sized thin-walled pipes and improving their quality due to the total deformation from the compression of the pipes previously ovalized in the perpendicular plane, from the distribution by the rolling head and bending force. Thin-walled pipes bend without loss of shape and bearing capacity.

 However, the design of the known device is complex, energy-intensive and, most importantly, is made according to the scheme of deformation by the transverse forces created by the pipe bend assembly fixed in the support rollers. The latter circumstance limits the bending radius of the pipe, since when the curvature increases, geometric defects again arise: ovalization, corrugations, folds, etc.

 In addition, the creation of a bending moment in the area of the plastic hinge by means of the support and bending rollers structurally does not allow the device to produce connecting bends from a measured tube billet.

 The purpose of the invention is the expansion of the technological capabilities of the device for bending pipes both by type and type of product (various diameters and wall thicknesses of pipes, connecting bends of exact sizes), and by the range of bending radii.

 This is achieved in a pipe bending device comprising a pipe feed drive along with a rotating rotating roller equipped with a spacer mechanism, behind which a bending unit is mounted having a swinging power cylinder, the rod of which is connected to the actuator by a lever, the pipe feed actuator is equipped with a gearbox and the actuator the bending unit is made in the form of a rotary cartridge connected through paired parallelograms with a power cylinder, which is mainly connected to the hydraulic system by means of a throttle choke.

 In FIG. 1 shows the proposed device; in FIG. 2 - rolling.

 The device structurally comprises a unit for creating a plastic hinge mounted in a bending pipe mounted on a common bed 1, a longitudinal feed mechanism for the pipe, and a bending unit.

Roller 2 of the first of these nodes is installed on the shaft 3, rotated by the engine M ₁ , which has a variator. Roller 2 (Fig. 2) contains pivotally mounted in bearings 4 rollers 5, which are connected by means of rods 6 to pressure cup 7 (drive not shown), coaxially mounted on shaft 3.

The shaft 3 is placed inside the cartridge 8 of the mechanism of the longitudinal feed of the pipe, which is mounted on the guide 9 and is made in the form of a nut 10 of the lead screw 11 connected to the engine M ₂ through the gearbox 12.

 The Executive body of the bending unit contains a rotary cartridge 13, which is paired with hinged parallelograms 14, 15 connected to the rod of the actuator 16 by means of a lever 17, pivotally mounted on the beam 18, carrying a pantograph 14-15. The master cylinder 16 is connected to the hydraulic system through an adjustable throttle 19.

 In the TGPSh-161 experimental setup, the angular velocity of rotation of the rocker arm 18 by throttling is provided in the range from 0 to 0.131 rad / s, the longitudinal feed rate of the cartridge due to the switched gears of box 12 is set discretely: 10, 40, 70 and 100 mm / s, rotation speed Roller size varies in a row: 30, 120, 210 and 300 rpm depending on the diameter of the bent pipes from 108 to 168 mm with a maximum wall thickness of 10 mm.

 The device operates as follows.

Depending on the specified bending radius and the size of the processed pipe, using the calibration table compiled on the basis of the unambiguous dependence (R = V _t / ω _n ), by switching gears in the box 12 and the degree of throttling of the fluid flow in the cylinder 16, establish the necessary speed ratio longitudinal feed pipe V _t and its rotation ω _n, respectively.

 The tube stock is installed in the cartridge 8 and the supply of the pressure cup 7 through the rotation of the rods 6, the rollers 5 move in the radial direction and create a certain interference with the inner surface of the pipe wall. Then the cartridge 13 is fixed on the free end of the pipe.

At the same time, the rotation drives of the rolling unit 2, the lead screw 11 and the bending unit are turned on, respectively, the engines M ₁ and M ₂ , cylinder 16.

Depending on the pipe material and wall thickness, as well as the required performance, the rotation frequency of the rolling mill 2 and the magnitude of the working interference are set with interchangeable rollers 5 to create a stable plastic hinge. So, for example, for a pipe with a diameter of D _n = 159 mm with a wall of 8 mm from 09G2S steel with a rolling speed of 120 to 300 rpm, an angular velocity of rotation of the cartridge 13 ω _n = 0,030. . . 0.125 rad / s and pipe feed rate: V _t = 40.. . 100 mm / s bending radii were obtained from 2 dN to 21 D _n .

When setting up the machine, for example, at a bending radius of 800 mm, the angular velocity of rotation of the rocker arm 18 ω _n = 0.125 rad / s was set using a throttle 19, and using the gearbox 12, the pipe feed speed V _t = 100 mm / s.

 In the annular contact zone of the rollers 5 of the rolling mill 2 with the pipe, a complex stress state of the material occurs outside the elastic deformations — a plastic hinge that moves along the entire length of the bend. In this case, the pipe is bent under the action of a bending moment, insignificant in magnitude with the pipe being fed to the right (according to the drawing), the rod of the cylinder 16 moves to the left and turns the rocker 18 through the lever 17. The uniform movement of the beam through the parallelograms 14, 15 transfers the bending moment to the cartridge 13 - it is carried out bending the billet almost throughout the entire length between chucks 13 and 8. Then, after stopping the drives, the finished bend is released from the reduced rollers 5 of the rolling mill 2 and the reverse is turned on to return the mechanisms to the original position.

The proposed device is simple in design, reliable in operation, mobile for use in the field of pipeline construction. The exceptional advantage over the prior art devices using the method of plastic hinge, is that the manufacturer may krutozagnutyh (90 ^a) of tap-dimensional preform (waste) with minimal straight ends that are comparable with the pipe diameter and substantially constant wall thickness after bending.

 In a pilot plant of pipe billets with a diameter of 108.. . 168 mm sharp bent bends with radii in the range of 0.49 were obtained. . . 1.52 m, the geometry of which complies with the requirements of GOST 17380-83. (56) 1. Belkin N.M. et al. Bending of pipes by the method of plastic hinge. - Construction of pipelines. N 8, 1989, p. 37-39.

 2. USSR author's certificate N 1516179, cl. In 21 D 9/14, 1991.

Claims (1)

 DEVICE FOR PIPE BENDING, comprising an axial pipe feed mechanism with a drive, a rolling roller with a spacer mechanism mounted for rotation, and a bending assembly including a power cylinder, the rod of which is connected via a lever to an actuator, characterized in that the drive of the axial pipe supply mechanism equipped with a gearbox, the executive body of the bending unit is made in the form of a rotary cartridge connected through paired parallelograms and a lever with a power cylinder, which is connected to the hydraulic system mainly Essentially through an adjustable throttle.

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