RU2415727C1 - Spinner for static-dynamic breaching - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to rotary drawing and shell spinning. Spinner comprises waveguide and striker acting thereon and coupled with mechanical pulse generator. Note here that said waveguide is made up of spinning ring embracing the billet and having inner rounded working surface and needled part made up of metal wire frieze bundles that allows adjusting stiffness, and with ID smaller than that of said rounded working surface by double interference. Note also that spinning ring moves inside the case in radial bearings arranged on ring periphery to transmit to said ring straining force with static and dynamic components.

EFFECT: expanded process performances, higher quality and efficiency.

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Description

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

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 the expansion of technological capabilities, increasing the contact surface interacting with the workpiece, and providing a high roughness of the finish of the processed surface, resulting in high surface quality and not requiring a large number of technological transitions, which dramatically increases productivity, improves deformation conditions and metal flow, as well as reduction the likelihood of expansion, expansion of the metal and the occurrence of scoring on the treated surface, increasing resistance of the pressing tool.

The problem is solved using the proposed pressing tool for static-pulse smoothing and rolling of hollow products, which contains a waveguide and a firing pin acting on it, connected with a mechanical pulse generator, the waveguide being made in the form of a pressure ring covering a workpiece with an inner rounded working surface and a needle part recruited from tufts of pile from a metal wire, with the ability to control rigidity and with an inner diameter smaller than the inner diameter with ruglennoy work surface by an amount of interference double movably mounted in the housing at the expense of radial bearings located at the periphery of the ring, said ring message with static and dynamic components of the deforming force.

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

Figure 1 shows a diagram of the pressure static-pulse smoothing treatment of a hollow billet with a cylindrical surface mounted on a mandrel, the proposed pressing tool is a ring, a longitudinal section; figure 2 - the proposed pressing tool is a ring, an end view of A in figure 1; figure 3 - the proposed pressing tool is a ring, a General side view, showing a design option of the needle part of the pressure ring, characterized by the presence of a chamfer.

The proposed pressing tool is designed for static-pulse smoothing and running of hollow products with a deforming element in the form of a female ring.

A pressing female tool for statically pulsed smoothing and rolling in of hollow products contains a waveguide 1, with the help of which the static P _article and dynamic P _imp components of the deforming force from the mechanical pulse generator (not shown) are communicated to the tool [3, 4]. A pressure ring 4 is mounted inside the housing 2 on radial bearings 3. The waveguide 1 is rigidly connected to the housing 2.

The tool - ring 4 has a working surface 5 rounded with a radius R _d , which is located inside the ring 4. The pressure ring 4 is mounted in the opening of the housing 2 with the possibility of free rotation, transmitted to it from a forcibly rotating workpiece 6 with a speed of V _s due to friction forces. In addition to the working surface 5, a needle ring 7 is located in the opening of the pressure ring 4, drawn from tufts of pile from a metal wire, with the possibility of regulating stiffness and with an inner diameter less than the inner diameter of the working surface 5 of the pressure ring by the double interference N. The needle ring 7 can be installed both on the left and on the right of the work surface 5, however, preference should be given to the installation on the left side (see figures 1, 3), when the needle ring 7 moves ahead of the pressure working turn 5 on the raw surface of the workpiece 6, with the direction of the longitudinal feed S _PR from 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 7 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 7 when running onto the treated surface of the workpiece will be embedded in it and leave unwanted traces, increasing the height of the microroughness. In order to smoothly enter the needle ring 7 into contact with the workpiece 6, when bringing the tool to the workpiece from the free end side, a bevel 7 ^f can be made (see figure 3).

The rigidity of the needle ring 7 is controlled by tightening or loosening the screws 8 through the washer 9.

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. Include the main rotational movement V _{s of the} workpiece. After this, the transverse feed S _{pop of the} caliper, on which the pressing tool is installed, is a ring. When approaching the workpiece 6, the pressing tool touches the needle ring 7 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 adhesion of the needle ring 7 to the workpiece increases and the rotation from the workpiece is transmitted to the pressing tool - the ring, as a result of this, the peripheral rotational velocities V _{s of the} workpiece and the pressing tool - ring V 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 5 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.

The enveloping pressing tool for static-pulse shaping receives the feed movement S _pr and acts on the workpiece with a force of P _st + P _imp (figure 1). Through the waveguide 1, the pulses from the mechanical pulse generator (not shown) are transmitted to the pressure ring 4, with which the workpiece 6 is smoothed [3, 4].

To ensure reliable contact of the pressing tool and the elastic needle ring 7 with the workpiece and to prevent the needle of the needle ring from getting under the pressure working surface 5, the cross section of the elastic needle ring 7 is adjusted, for example, by screws 8 and the washer 9, 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.

To obtain a high class of roughness on the inner pressure working surface 5 of the pressure ring 4, a calibrating cylindrical belt 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 _ol = (0.2 ... 0.5) K.

where K is the width of the cylindrical girdle 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 static-pulse rolling and smoothing with the proposed tool, the ring improves the roughness by one class, the static force of pressing the tool against the workpiece’s work surface is 200 ... 300 N per 10 mm of the tool’s working surface length and depends on the depth of penetration of the pressure element into the workpiece. The choice of the corresponding static-pulse pressure depends on the physicomechanical properties of the workpiece material, the material of the wire pile, the stiffness and density of the latter, as well as the interference fit N.

The proposed squeezing tool - the ring is used on powerful squeezing machines operating by the method of reverse rotation drawing of thick-walled blanks [2]. The radius R _{d of the} presser element depends on the thickness t _{о of the} ironed shell and is taken equal to R _d = (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 static-pulse rolling and smoothing is determined by the following main factors: process kinematics (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.

With static-pulse rolling and smoothing of parts made of steel, brass and aluminum alloys, good results are obtained by using industrial oil I-20A or sulfofresol as a lubricant.

With static-pulse rolling and smoothing with the proposed female tool - a ring on the treated surface, 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.

When static-pulse rolling in the shells, the maximum speed is selected within 10 ... 130 m / min, taking into account the power of the machine and the vibration resistance of the technological system.

The microroughness height obtained by static-pulse smoothing with this tool is within the permissible maximum microroughness height value. Setting the latter according to well-known formulas [4], the pulse frequency, the internal diameter of the tool and the rotation frequency of the workpiece are determined.

During industrial tests, a workpiece with outer and inner diameters of 126 mm and 122 mm, respectively, 250 mm long — an oil filter cap made of tape 08YU-OSV-A-II-2.2 GOST 19851-74, was mounted on a mandrel and pressed focus of the tailstock on the machine 16K20, and a hydraulic generator of mechanical impulses with a female tool with an inner ring diameter of 180 mm - in the tool holder. The workpiece was informed of the rotational movement V _s = 12 m / min, and the tool - a longitudinal feed S _CR = 1.0 mm / rev. The pulse frequency was 30 Hz (AO Auto Unit, Livny city).

Tests have established that the productivity of the process increases by 1.8 ... 2.3 times compared to static-pulse smoothing by cylindrical rollers [2], the dimensions of the machined parts are stable and correspond to the required accuracy level, the roughness of the machined surface corresponds to Ra 1.6 μm, there was no undulation.

The proposed covering tool for static-pulse smoothing is easy to implement, not complicated in design and reliable in operation, it allows to increase the accuracy of manufacturing hollow products, reduce the height of microroughnesses, increase the performance of static-pulse processing, improve the deformation conditions and metal flow, and also reduce the likelihood of expansion, swelling of the metal and the occurrence of scoring on the surface to be treated, to increase the resistance of the pressing tool.

The hardened layer obtained on the surface of the workpiece has increased hardness, wear resistance and resistance to fatigue failure, a large depth of hardening.

Using the proposed pressing tool allows you to expand the technological capabilities of static-pulse rolling and smoothing by covering the workpiece with a deforming tool and applying vibrational movements to the tool, improve the quality and productivity of processing, improve the deformation conditions and metal flow, reduce the likelihood of expansion, expansion of metal and the occurrence of scoring on the surface to be treated, as well as predict the roughness and quality of the sample abutable 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., 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.

3. Lazutkin A.G., Kirichek A.V., Soloviev D.L. The method of static-pulse treatment by surface plastic deformation. RF patent №2098259, В24В 39/00, bull. No. 34, 1997

4. Stepanov Yu.S., Kirichek A.V., Afonin A.N. et al. Covering tool for static-pulse thread rolling. RF patent No. 2280526, B21H 3/02. Bull. No. 21, 2006

Claims (1)

A pressing tool for statically pulsed smoothing and running-in of hollow products, containing a waveguide and a striker acting on it, connected to a mechanical pulse generator, characterized in that the waveguide is made in the form of a pressure ring covering a workpiece with an internal rounded working surface and a needle part drawn from bundles a pile of metal wire with the ability to control stiffness and with an inner diameter less than the inner diameter of a rounded working surface by an amount of two tension, and the pressure ring is movably mounted in the housing by means of radial bearings located on the periphery of the ring, and is configured to communicate to it a deforming force with static and dynamic components.

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