RU2411098C1 - Method of embracing spinning - Google Patents

Abstract

FIELD: process engineering. ^ SUBSTANCE: invention relates to metal forming, particularly, to burnishing hollow articles. Billet is rotated about its axis while spinning device is fed in lengthwise direction. Proposed spinning device comprises spinning tool fitted on axle in holder and consisting of plate-like body accommodating two working rolls running on axles in antifriction bearings and one tensioning roll. Periphery of sais rolls has groove to support ring-like spinning element made from round metal wire with high spring properties. Note here that force is transmitted to the billet by two working rolls and section of spinning ring arranged between working rolls to partially embrace the billet. Note also that support on one working roll is fixed in aforesaid body while that on another roll is arranged to allow adjustment of embrace angle. ^ EFFECT: expanded process performances, higher quality and efficiency. ^ 2 dwg

Description

The invention relates to the processing of metals by pressure, in particular to methods and tools for forming relief on hollow thin-walled products, as well as for rotational drawing of shells and pressure processing.

A known method and design of a tool for running thin-walled hollow products, containing a roller made in the form of disks located on the axis of the roller holder, while the disk is rigidly fixed to the axis by bolts and mounted with the possibility of adjusting axial movement [1]. Disks are interconnected by a key. A pressure member made of a polymer material is placed concentrically to the axis between the disks.

The known method and tool design have significant drawbacks: narrow technological capabilities, low quality of processed products, low productivity, short life of the pressing tool due to the rapid wear of the working surface and a small range of regulation of the stiffness of the polymer pressing material.

A known method and design of pressure rollers, the nature of the processing process which depends on the radius of rounding and the width of the belt [2]. However, the disadvantage of the method and the known pressure rollers is the difficulty of restoring the shape as a result of wear, since for this it is necessary to grind all external surfaces with a change in grinding radii to maintain a mate of radii. At the same time, adjustments are required in the technological modes. In addition, the disadvantage is their small contact surface interacting with the part, which does not provide a high roughness of the finish of the processed surface, which results in low surface quality and requires a large number of technological transitions, which sharply reduces productivity.

The objective of the invention is to expand technological capabilities, increase the contact surface that interacts with the workpiece and provides a high roughness of the finish of the processed surface, which determines the high surface quality and does not require a large number of technological transitions, which dramatically increases productivity, improves deformation conditions and metal flow, as well as reduces the likelihood expansion, expansion of metal and the occurrence of scoring on the treated surface, increasing resistance of winepress tool.

The problem is solved by the proposed method of embracing pressure machining, including a message to the workpiece of rotational movement around its own axis and longitudinal feeding to the pressure gripping device, comprising a pressure tool installed in the holder by means of an axis, which consists of a plate in the form of a plate, where two workers are mounted on axles on rolling bearings a roller and one tension, on the periphery of which grooves are made, bearing a pressure element in the form of a ring made of metal round cross-sectional and spring-loaded properties, so that the pressing force is transmitted to the workpiece by two working rollers and a part of the pressing ring located between the working rollers, partially covering the workpiece with a coverage angle α, and the support of one working roller is fixed in the housing and the other - with the ability to control the angle of coverage α.

The essence of the proposed method and the design of the pressing female device that implements it, and the operation is illustrated by the drawings.

Figure 1 shows a diagram of the pressure smoothing treatment of a hollow thin-walled billet with a cylindrical surface mounted on a mandrel, the proposed pressing covering method, a partial longitudinal section along BB in figure 2; figure 2 is a pressure covering device that implements the proposed method, a partial cross section along aa in figure 1.

The proposed method and the squeezing female implement that implements it serve to run in and smooth out thin-walled hollow products with a cylindrical, conical and complex generatrix. The pressure device comprises a pressure tool installed in the holder 1 by means of the axis 2, which consists of a plate 3 made in the form of a plate, and two working rollers 8, 9 and one tension roller 10 installed on the axles 4, 5 and 6 on the rolling bearings 7. At the periphery rollers made a groove in which the pressure element 11 is located in the form of a ring made of a metal wire of circular cross section and having spring properties.

The pressure force on the workpiece 12 is transmitted by two working rollers 8, 9 and a section of the pressure ring 11 located between the working rollers, partially covering the workpiece with a coverage angle α.

The support axis 4 of the working roller 8 is mounted in the housing 3 motionless. The support of the axis 5 of the working roller 9 is mounted in the housing 3 with the possibility of adjusting the angle of coverage α and allows you to zoom in or remove the working rollers from each other. The support of the axis 6 of the tension roller 10 is mounted in the housing 3 with the ability to move and tension the pressure element - the ring 11 and allows you to zoom in or remove the tension roller relative to the working rollers.

Axes 4, 5 and 6 are pressed into the holes of the rollers 8, 9 and 10, respectively, and are installed in the housing 3 on bearings 7 with the possibility of independent free rotation transmitted to the pressing element 11 from the rotating workpiece 12 at a speed V ₃ due to friction forces.

A pressure covering device that implements the proposed method works as follows. The assembled pressure device, depending on the material being processed, is adjusted and adjusted to a predetermined angle of coverage α by removing or approaching the roller 9 relative to the working roller 8, then the tension of the pressing element - the ring 11 is adjusted by removing the tension roller 10 relative to the working rollers 8 and 9.

Ready for use, the device is run-in and smoothing the workpiece 12, worn and fixed on the mandrel 13, two working rollers 8, 9 through the pressure element - ring 11.

Before processing, the female device is set to a certain depth of rolling in and smoothing by lateral movement of it manually. Run-in and smoothing of the cylindrical surface is carried out during rotation of the workpiece with a speed of V ₃ , while the device is given a longitudinal feed S _pr (see figure 1). This is done, for example, on a lathe manually or according to a program on a CNC machine.

The pressing female tool is made of class 1 steel spring wire, of increased accuracy, for example, with a diameter of 2 ... 10 mm, from steel 65G (GOST 14959-79) according to GOST 9389-75.

To obtain a high class of roughness on the deforming element 11 provide a calibrating cylindrical band with a width of K = 1.5 ... 3 mm With a large section K, the deformation forces increase significantly.

The longitudinal feed when ironing is determined by the formula

S _ol = (0.2 ... 0.5) K,

where K is the width of the belt on the deforming element.

When applying S _CR = (0.2 ... 0.3) K, the roughness of the treated surface is achieved from Ra = 40 μm to Ra = 1.25 μm.

As a result of rolling in and smoothing by the proposed method and the developed tool, the roughness by one class is improved, the force of pressing the tool against the workpiece’s surface is 200 ... 300 N per 10 mm of the length of the tool’s working surface.

The proposed method and the pressing covering tool are used on powerful pressing machines operating by the method of reverse rotation drawing of thick-walled workpieces. The radius R of the pressing element - the wire depends on the thickness t _{o of the} ironed shell, and it is taken equal to R = (1 ... 1,5) t _o .

The diameters of the rollers are taken from design considerations. With an increase in the diameter of the roller, deforming forces and bending moments acting on the support of the machine increase. It is necessary to strive to use rollers of the same diameter for each machine. This is especially important for CNC machines.

The surface microrelief formed as a result of rolling in and smoothing is determined by the following main factors: the kinematics of the process (the direction of mutual movement of the tool and the workpiece being machined); initial roughness; shape and size of the initial part and the rolling tool; feed rate; plastic flow of metal, causing the appearance of secondary roughness; roughness of the working part of the tool; the value of the elastic recovery of the surface after smoothing; vibration of the technological system machine - tool - tool - workpiece.

When rolling in and ironing parts made of steel, brass and aluminum alloys, good results are obtained when industrial oil I-20A or sulfofresol is used as a lubricant.

When rolling and smoothing by the proposed method, implemented by a female device, on the surface to be treated, the probability of the appearance of longitudinal and transverse undulations due to an increase in the contact area has sharply decreased, while the fluctuations of the technological system are minimized due to the elasticity of the deforming element.

In traditional machining at high speeds, intense vibrations begin, leading to a sharp deterioration in the surface being machined.

Forced vibrations caused by the beating of the machine spindle, beating of the workpiece, waviness, etc. quenched by the proposed method and this deforming covering tool, however, self-oscillations due to phenomena inherent in the processing process itself may occur.

When running the shells, the maximum speed is selected within 60 ... 130 m / min, taking into account the power of the machine and the vibration resistance of the technological system.

Using the proposed method and a pressing covering device allows expanding the technological capabilities of rolling in and smoothing due to the gripping by the deforming tool of the workpiece and the elasticity of the pressing element, improving the quality and productivity of processing, improving the deformation conditions and metal flow, reducing the likelihood of expansion, expansion of metal and the occurrence of scoring on the treated surface , as well as to predict the roughness and quality of processed by tops; increase the wear resistance of the pressing material.

Information sources

1. USSR Copyright Certificate, No. 1558534, MKI B21D 22/16. Zubarev V.V., Khmelev S.V., Gladkikh A.A. and other tools for running thin-walled hollow products. Application 4443728 / 25-27, 06/20/88; 04/23/90. Bull. No. 15.

2. Mogilny N.I. Rotational extraction of shell parts on machines. M .: Engineering, 1983, p. 147, Fig. 9.6.

Claims (1)

A method of embracing pressing processing, comprising communicating to a workpiece rotational motion around its own axis and longitudinally supplying a pressing enclosing device comprising a pressing tool installed in the holder by means of an axis, characterized in that a pressing tool is used, consisting of a body in the form of a plate in which axles are mounted on rolling bearings two working rollers and one idler, on the periphery of which a groove is made, bearing a pressure element in the form of a ring made of metal round wire and having springing properties, the pressure exerted on the workpiece is transmitted by two working rollers and a part of the pressing ring located between the working rollers, with a partial coverage of the workpiece with a coverage angle α, and the support of one working roller is mounted in the housing motionless, and the other - with the ability to control the angle of coverage α.

Images