RU2411100C1 - Embracing spinning ring-shaped tool - Google Patents

Abstract

FIELD: process engineering. ^ SUBSTANCE: invention relates to metal forming, particularly, to devices intended for shell rotary burnishing and spinning. Proposed tool comprises ring-shaped spinning element arranged in the casing to embrace machined billet and provided with inner rounded working surface. Note here that ring outer peripheral surface seats on antifriction bearing fitted in the casing to run free therein. Note also that spinning ring face accommodates needle ring made up of metal wire frieze bundles to allow stiffness adjustment and ID smaller than that of spinning ring working surface by double fit amount. ^ EFFECT: expanded process performances, higher quality and efficiency. ^ 4 dwg

Description

The invention relates to the processing of metals by pressure, in particular to a tool for molding relief on hollow products, as well as for rotational drawing of shells and pressure processing.

A known 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 tool design has 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.

Known designs of pressure rollers, the nature of the processing process which depends on the radius of rounding and the width of the girdle [2]. However, the disadvantage of 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 the grinding radii to maintain the mating radius. 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 using the proposed pressing female tool for rolling hollow products containing a pressure element mounted in the housing, made in the form of a ring that covers the workpiece, with an inner rounded working surface, and the ring with the outer peripheral surface mounted on a rolling bearing in the housing bore with the possibility of free rotation, and at the end of the pressing ring is attached a needle ring drawn from tufts of pile made of metal Coy wire, with the possibility of regulating the rigidity and an inner diameter smaller than the inner diameter of the working surface davilnjami ring double the amount of interference N.

The essence of the design of the proposed pressing female tool - rings and its operation is illustrated by drawings.

Figure 1 shows a diagram of the pressure smoothing treatment of a hollow billet with a cylindrical surface mounted on a mandrel, the proposed pressing female tool - a ring, a longitudinal section; figure 2 - the proposed pressing covering tool is a ring, an end view of A in figure 1; figure 3 - the proposed pressing covering tool - ring, General side view; figure 4 - element B in figure 1.

The proposed pressing female tool - the ring is used to break in and smooth the hollow products. The pressing female tool - the ring contains a pressure member 2 installed in the housing 1, made in the form of a ring that covers the workpiece 3. The tool - the ring 2 has a working surface 4 rounded with a radius R, which is located inside the ring 2. On the outer peripheral surface of the tool - of the ring 2, a rolling bearing 5 is installed, with which the tool - the ring 2 is mounted in the hole of the housing 1 with the possibility of free rotation, transmitted to the pressure element 2 from forcibly rotation billet 3 with a speed of V _W due to friction.

At the end of the tool - ring 2 is attached a needle ring 6, drawn from tufts of pile from a metal wire, with the possibility of regulating stiffness and with an inner diameter smaller than the inner diameter of the working surface 4 of the pressing ring by the amount of double interference N. The needle ring 6 can be installed both from the left and right ends of the tool - ring 2, however, preference should be given to the installation on the left side (see figure 1), when the needle ring 6 moves in front of the pressure ring 2 on an untreated turn NOSTA workpiece 3 at longitudinal feed direction S _OL right to left. This is due to the fact that the diameter of the raw surface of the workpiece is larger than the diameter of the processed surface, so the needles of the needle ring will bend more and the adhesion of the tool to the workpiece will be more and more reliable. In addition, the needle of the needle ring when it runs onto the treated surface of the workpiece will be embedded in it and leave unwanted traces, increasing the height of the microroughness.

The rigidity of the needle ring 6 is controlled by tightening or loosening the screws 7 through the washer 8.

The proposed crushing tool covering the ring works as follows. A tool mounted, for example, on a lathe support is brought to a workpiece mounted on a mandrel on a machine spindle, a workpiece is inserted into the central hole of the tool - rings and the workpiece is pressed by pressing the tailstock of the machine. After that, the transverse feed S _{POP of the} caliper on which the pressing tool is installed is a ring. When approaching the workpiece 3, the pressing tool touches the needle ring 6 of the surface of the forcibly rotating workpiece and the tool - the ring begins to rotate. With further transverse movement of the pressing tool - the ring, the contact area of the needle ring 6 increases and the rotation from the workpiece is transferred to the pressing tool - the ring, as a result, the peripheral rotational speeds V _{З of the} workpiece and the pressing tool - the ring V _{And are} aligned and when cutting it does not slip relative to the workpiece. The pile bundles located in the needle ring and installed with an interference fit N relative to the pressure working surface 4 will bend and, due to elastic forces, improve the adhesion of the tool - the ring to the workpiece, preventing it from slipping relative to the workpiece. After cutting the pressure working surface 4 to the required depth, turn on the longitudinal feed S _PR and run the product in and out, the pressure ring is rotated due to friction and adhesion forces arising on the contact surface of the tool with the workpiece.

To ensure reliable contact of the pressing tool with the elastic needle ring 6 with the workpiece and to prevent the needle of the needle ring from getting under the pressure working surface 4, the cross section of the elastic needle ring 6 is adjusted by screws 7 and the washer 8, the tightening torque of which is determined experimentally. As a pile, a steel spring wire is used, for example, with a diameter of 0.5 ... 1.5 mm from steel 65G, while the tightness is set to N = 1.2 ... 1.5 mm.

The pressing force of the pressing tool - the ring to the workpiece is 200 ... 300 N and depends on the depth of penetration of the pressing element 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 N.

To obtain a high class of roughness on the inner working surface 4 of the pressing ring, a calibrating cylindrical girdle with a width of K = 1.5 ... 3 mm is provided. With a large section K, the deformation forces increase significantly.

The longitudinal feed during rolling and ironing is determined by the formula:

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

where K is the width of the cylindrical girdle on the deforming element.

When applying S _PR = (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 with the proposed tool, the ring improves the roughness by one class, the force of pressing the tool to the workpiece’s work surface is 200 ... 300 N per 10 mm of the length of the working surface of the tool.

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

The diameter of the tool - the rings are taken from design considerations. With a decrease in the inner diameter of the tool - the ring, the area of contact with the workpiece increases, deformation forces and bending moments acting on the support of the machine increase. It is necessary to strive for each machine to use a tool - a ring of one diameter. 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 running and smoothing with the proposed female tool - a ring on the surface to be machined, the probability of the appearance of longitudinal and transverse undulations sharply decreased due to an increase in the contact area and the use of an elastic needle ring, while the fluctuations of the technological system are minimized.

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. are quenched by the proposed enveloping tool with an elastic needle ring, 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 pressing female tool allows you to expand the technological capabilities of rolling in and smoothing by grasping the workpiece with a deforming tool, to improve the quality and productivity of processing, to improve the deformation conditions and metal flow, to reduce the likelihood of expansion, expansion of metal and the occurrence of scoring on the treated surface, as well as to predict roughness and quality of the processed surface; increase the wear resistance of the material of the pressing tool.

Information sources

1. USSR Copyright Certificate, No. 1558534, MKI B21D 22/16. Zubarev V.V., Khmelev S.V., Smooth F.F. 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 .: Mechanical Engineering, 1983. P.147, Fig. 9.6.

Claims (1)

A female press tool for running in hollow articles, comprising a pressure element installed in the housing, characterized in that the pressure element is made in the form of a ring for embracing the workpiece with an inner rounded working surface, and the ring with the outer peripheral surface mounted on a rolling bearing in the housing bore free rotation, and at the end of the ring is attached a needle ring drawn from tufts of pile from a metal wire, with the possibility of adjustment Hovhan hardness having an inner diameter smaller than the inner diameter of the working surface of the ring by the amount of double-tightness.

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