RU2413587C1 - Device for rotational extrusion of hollow articles - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to extruding hollow articles. Proposed device comprises revolving mandrel, appliance to clamp billet on said mandrel and hold-down tool with flexible ring secured thereon aligned with said mandrel to adjust its cross section, and spinning roll. Flexible ring is made from bundles of metal wire frieze arranged lengthwise and jointed together by flexible component. Said ring is arranged to provide interference relative end face of said spinning roll. Axis of the latter is arranged at crossing angle to billet axis. Aforesaid billet allows selecting its rotational direction to allow contact between end face of spinning roll on the side of the billet lengthwise axis and spinning roll end face.

EFFECT: expanded process performances, higher quality of products.

5 dwg

Description

The invention relates to the processing of metals by pressure, in particular to devices for rotational drawing of cylindrical shells, hollow products and pressure processing.

Known mandrel containing a housing, an element for fixing the workpiece to the mandrel with screws, while on the clip coaxially with the mandrel an elastic element is installed in the form of a ring, for example, polyurethane, and the ring is fixed to the clip with screws, by which it is possible to adjust the cross section of the elastic element [1] .

The known mandrel has in its design a rapidly wearing elastic ring that does not provide reliable contact of the pressure roller with the workpiece, while the design does not preclude the elastic ring from flowing under the pressure roller, and this entails metal grooves during the cutting of the pressure roller into the workpiece, which leads to to reduce the productivity and service life of the mandrel and the rapid wear of the working surface of the tool, while to obtain high quality it is necessary to create large elastic forces lementa on the roller, and this requires the use of rollers with a large radius of the profile, which has a negative effect on the weight and size parameters and is not always feasible.

The objective of the invention is the expansion of technological capabilities, improving the quality and productivity during processing, improving the conditions of deformation and flow of metal, as well as reducing the likelihood of expansion, expansion of metal and the occurrence of scoring on the treated surface, ensuring reliable contact of the pressure roller with an elastic ring, eliminating the flow of the ring under the pressure the roller and the exclusion of tearing of the metal in the process of cutting the pressure roller into the workpiece

The problem is solved using the proposed device for the rotational drawing of hollow articles containing a mandrel made with rotation, a workpiece mounting element on a mandrel and a clamp with an elastic ring mounted and fixed on it coaxially with the mandrel and configured to adjust its cross-sectional size, and a pressure roller, while the elastic ring is made of tufts of pile of metal wire arranged longitudinally and connected to each other by an elastic mass, and it has been established providing an interference with respect to the end of the pressure roller, the axis of the pressure roller is located at a crossing angle α = 2 ... 5 ° relative to the axis of the workpiece, and the mandrel is made with the possibility of choosing the direction of its rotation from the condition of touching and contacting the end of the pressure roller with the elastic ring from the angle (90 ° -α) between the longitudinal axis of the workpiece and the end of the pressure roller.

The essence of the design of the proposed device and its operation are illustrated by drawings.

Figure 1 shows the proposed device, a longitudinal section, a pressure roller outside the processing zone; figure 2 is a top view along A in figure 1, on the left is a pressure roller in the final operating position; figure 3 - the proposed device, a longitudinal section, a pressure roller at the time of implementation in the workpiece, left - pressure roller in the final operating position; figure 4 is a right view along B in figure 1; figure 5 is a cross-section along BB in figure 3, which shows the movement of the elastic ring and the tool in one direction, eliminating slipping and flowing of the ring under the pressure roller.

The device is designed for rotational drawing of hollow articles 1 and contains a mandrel 2 and an element 3 for fixing the workpiece 1 on the mandrel. On the side of the front end of the mandrel 2, a clamp 4 is arranged coaxially with it, on which an elastic ring 8 is installed between the ring segments 6 and the ring 7 using screws 5.

The elastic ring 8 is made of tufts of pile 8 ′ of metal wire located longitudinally relative to the axis of the ring and connected to each other by an 8 ”elastic mass, for example, SKU-7L polyurethane or rubber, which is firmly connected to the metal wire during vulcanization.

In the manufacture of the elastic ring 8, the density of the metal wire should include gaps that are filled with an elastic mass.

In order to avoid flowing elastic ring 8, under the juicer roller 9 is deployed with its axis crossing at an angle α = 2 ... 5 ° relative to the axis of the workpiece 1. The direction of rotation of the mandrel _zag V 2 is selected so that the touch input and the elastic ring in contact with the end face 8 davilnjami roller 9 would be from the angle side (90 ° -α) between the longitudinal axis of the workpiece and the end of the roller (see Fig.2, 5). According to figure 4, the rotation V _{zag of the} workpiece with the mandrel should be counterclockwise, and the roller clockwise.

The device operates as follows.

The workpiece 1 is mounted on the mandrel 2, and using the element 3 and the clamp 4, the workpiece is _mounted on the mandrel with a force P _clamp . The spindle of the press machine (not shown), on which the mandrel 2 is mounted, is turned on. After this, the transverse feed S _{pop of the} support, on which the pressure roller 9 is mounted. When approaching the workpiece 1, the pressure roller 9 touches the rear angle of the elastic ring 8, which rotates from the mandrel 2 through the clamp 4. With further transverse movement of the pressure roller 9, the area of contact with the ring 8 due to the elastic forces of the latter increases and rotation from the ring 8 is transmitted to the pressure roller 9, as a result, the circumferential orosti _zag workpiece rotation V and V davilnjami roller for insertion _in and it does not occur slippage relative to the workpiece. The pile bundles located in the ring and installed with an interference fit i relative to the end of the roller will bend and improve adhesion to the roller, preventing it from slipping relative to the workpiece.

After cutting the pressure roller 9 to the required depth, the longitudinal feed S _{pr is} turned on and the product is rotationally drawn, the pressure roller 9 is rotated due to friction forces arising on the contact surface of the latter with the workpiece.

To ensure reliable contact of the pressure roller 9 with the elastic ring 8 and to avoid leakage of the ring under the pressure roller, the cross section of the elastic ring is adjusted by screws 5, the tightening torque of which is determined experimentally.

Rotational extraction of blanks of hollow products by the proposed crossing pressure roller is performed on lathes with a longitudinal feed drive, the necessary spindle speed and sufficient rigidity of the technological system: machine, tool, tool, workpiece. In this case, the general requirements for the shape and geometry of the pressure rollers are the large width (10 ... 30 mm) of the abutment of the roller to the work surface, the minimum roughness Ra = 0.32 ... 0.080 μm of the hardened and polished working surface of the roller and the high rigidity of the technological system.

However, as the width K of the cylindrical girdle on the roller increases, the smoothing pressure decreases and the roughness increases; as a result, to achieve the required roughness, it is necessary to carry out processing with great efforts, which is not always possible due to insufficient rigidity of the technological system. The proposed cross rollers with a cylindrical belt require careful installation relative to the longitudinal axis of the workpiece.

The longitudinal feed during the rotation hood by the proposed crossing roller is determined by the formula

S _ave = (0,2 ... 0,5) K / cosα,

where K is the width of the cylindrical belt on the roller, mm;

α is the angle of intersection of the longitudinal axes of the workpiece and the roller, deg.

With proper installation, such rollers can work with longitudinal feeds within 3 ... 10 mm / rev, which makes the process of rotational drawing very productive.

As a pile, a steel spring wire is used, for example, with a diameter of 0.5 ... 1.0 mm from steel 65G, while the tightness is set i = 1.2 ... 1.5 mm.

The force of pressing the elastic needle ring to the end of the roller is 200 ... 300 N and depends on the depth of penetration of the roller into the workpiece.

The choice of the appropriate pressure depends on the physicomechanical properties of the material of the wire pile, on the rigidity and density of the latter, as well as on the interference fit i.

Using the proposed device allows you to expand the technological capabilities of rotary hoods, improve the quality and productivity of processing, improve the deformation conditions and metal flow, while reducing the likelihood of expansion, expansion of metal and the occurrence of scoring on the treated surface, to ensure reliable contact of the pressure roller with an elastic ring, and to prevent the ring from flowing under the pressure roller and tearing of the metal during the process of cutting the pressure roller into the workpiece, and also predict ohovatost and surface quality.

Sources of information taken into account

1. Copyright certificate SU No. 1593737, MKI B21D 22/16. Nazarov V.I., Zubarev V.V., Sorokin Yu.G., Khmelev S.V., Gladkikh A.A., Malkov V.P. Mandrel for rotational extraction of hollow products. Application No. 4466461 / 25-27. 07/26/88; 09/23/90. Bull. Number 35.

Claims (1)

A device for rotational drawing of hollow articles containing a mandrel made with the possibility of rotation, an element for attaching a workpiece to a mandrel and a clamp with an elastic ring mounted and fixed to it coaxially with the mandrel and configured to control its cross-sectional size, as well as a pressure roller, characterized in that the elastic ring is made of tufts of pile of metal wire located longitudinally and connected to each other by an elastic mass, and is installed with an interference fit relative to the end face d of the support roller, the axis of the pressure roller is located at a crossing angle α = 2 ... 5 ° relative to the axis of the workpiece, and the mandrel is made with the possibility of choosing the direction of its rotation from the condition of touching and entering into contact of the end of the pressure roller with an elastic ring from the angle side (90 ° - α) between the longitudinal axis of the workpiece and the end of the pressure roller.

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