RU2414981C1 - Method of circular spinning by ring tool - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to spinning hollow articles. Deforming tool comprising spinning element arranged in the body is fed crosswise and lengthwise relative to tool lengthwise axis, and workpiece is revolved. Spinning tool is made up of ring with inner rounded working surface surrounding processed workpiece. 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 and methods of forming a relief on hollow 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 course 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 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 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 pressing embracing the processing of hollow products, including a message to the deforming tool containing a pressure element installed in the housing, a transverse feed for cutting and longitudinal feed relative to its own longitudinal axis, and the workpiece rotational movement, and the pressure element is made in the form of a ring with an inner rounded the working surface that covers the workpiece, while the ring outer peripheral surface is installed about on the rolling bearing in the bore of the housing with the possibility of free rotation, and on the end of the pressure ring is fixed a needle ring drawn from tufts of pile of metal wire arranged radially, with the possibility of regulating stiffness and with an inner diameter smaller than the inner diameter of the working surface above said pressure rings by the value of double interference N.

The essence of the proposed method, implemented by a pressing female tool - a ring, 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, a pressing female tool - a ring, a longitudinal section; figure 2 is a pressure covering tool - a ring, an end view of A in figure 1; figure 3 - pressure covering tool - ring, General side view; figure 4 - element B in figure 1.

The proposed method, implemented by a pressing female tool - a ring, serves to run and smooth hollow products and includes a message to the deforming tool containing a pressing female tool installed in the housing 1 - ring 2, the transverse feed S _POP for cutting into the workpiece 3 and the longitudinal feed S _PR relative own longitudinal axis, and the workpiece 3 rotational motion V _Z.

The pressing female tool - ring 2 contains a pressure member installed in the housing 1, made in the form of a ring that covers the workpiece 3. The female pressing tool - the ring has a working surface 4 rounded by a radius R, which is located inside the ring. A rolling bearing 5 is installed on the outer peripheral surface of the pressing female tool - the ring, with which the pressing female tool - the ring is mounted in the hole of the housing 1 with the possibility of free rotation V _And transmitted to the pressing female tool - the ring from the forcibly rotating workpiece 3 with a speed of V _З account of friction forces.

A needle ring 6 is mounted on the end face of the pressing female tool - the ring, drawn from tufts of pile of metal wire arranged radially, with the possibility of regulating stiffness and with an inner diameter smaller than the inner diameter of the working surface of the pressing female tool - rings by the double interference value N. Needle ring 6 can be installed both on the left and on the right ends of the tool - the ring, however, preference should be given to the installation on the left side (see figure 1) when the needle chatoe ring 6 moves ahead davilnjami female tool - ring on the untreated surface of the workpiece 3, with the 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 needles of the needle ring when running onto the treated surface of the workpiece will be embedded in it and leave unwanted traces, worsening the quality of the treated surface and 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.

Work on the proposed method, implemented by a pressing female tool - the ring is as follows.

A tool mounted on a lathe support, for example, is brought to a workpiece mounted on a mandrel on a machine spindle, a workpiece is inserted into the central hole of a pressing female tool - rings, and the workpiece is pressed by pressing the tailstock of the machine. After that, the transverse feed S _{POP of the} caliper is turned on, on which the pressing covering tool, the ring, is installed. When approaching the workpiece 3, the pressing tool touches the surface of the forcibly rotating workpiece with a needle ring, and the pressing female tool, the ring, begins to rotate. With further transverse movement of the pressing female tool - the ring, the contact area of the needle ring increases, and the rotation from the workpiece is transferred to the pressing female tool - the ring, as a result, the peripheral rotational speeds V _{3 of the} workpiece and the pressing female tool - the ring V _{I are} aligned, and when it is inserted, it does not happen slippage relative to the workpiece. The tufts of pile, located and located radially in the needle ring, installed with an interference fit N relative to the pressure working surface, will bend and, due to elastic forces, improve the adhesion of the pressing female 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, and the rotation of the pressing female tool - the ring is carried out from rotation of the workpiece due to friction and adhesion forces arising on the contact surface of the tool with the workpiece.

To ensure reliable contact of the pressing female tool - the ring with the elastic needle ring with the workpiece and to prevent the needle of the needle ring from falling under the pressure working surface, the cross section of the elastic needle ring is adjusted by screws 7 and 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 female tool - the ring to the workpiece is 200 ... 300 N and depends on the depth of penetration of the pressing female tool - the ring 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 of the pressing female tool, the rings 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 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 covering tool - the ring.

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 a tight covering tool - a ring, the roughness by one class is improved.

The proposed method, implemented by a pressing female tool - a 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 female tool - the ring 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 pressing female tool - the rings are taken from design considerations. With a decrease in the inner diameter of the pressing female 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 tool to use a pressing covering 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 rolling in and smoothing the proposed method using a gripping pressing tool - a ring on the surface to be treated, the probability of the appearance of longitudinal and transverse undulations has 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. quenched by the proposed method, used covering tool with an elastic needle ring, however, self-oscillations may occur due to phenomena inherent in the processing process itself.

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, carried out by a pressing female tool - a ring, expands the technological capabilities of rolling in and smoothing by grasping the workpiece with a deforming tool, improves the quality and productivity of processing, improves the conditions of deformation and metal flow, reduces the likelihood of expansion, expansion of metal and the occurrence of scoring on the treated surface and also predict the surface roughness and quality ty; increase the wear resistance of the material of the pressing tool.

Claims (1)

A method of pressing embracing treatment of hollow products, comprising communicating to a deforming tool comprising a pressure element installed in the housing, a lateral feed for cutting and longitudinal feed relative to its own longitudinal axis, and a rotary movement blank, characterized in that the pressure element is made in the form of a ring with an inner a rounded working surface to cover the workpiece, while the ring with the outer peripheral surface is mounted on a rolling bearing in the housing opening with the possibility of free rotation, and on the end of the pressure ring, a needle ring is fixed, drawn from tufts of pile of metal wire arranged radially, with the possibility of regulating stiffness and with an inner diameter smaller than the inner diameter of the working surface of the said pressure ring by double interference.

Images