The method of fixing tubes
The invention relates to the processing of metals by pressure and can be used when attaching the tubes of heat exchangers using the effect of localized directional plastic deformation of the pipe material. The ends of the tube profiles with the formation of the tip containing the loaded and supporting sectors as well as the transition area between them. One of the ends is installed in the pipe hole, combined with an annular groove, combining groove of rectangular and triangular cross-sections. While the small base ring of the transition section ends have a front edge of the ring grooves with a rectangular cross-section. Then the pipe is fixed on the possible move and fix in the pipe bore by application of compressive efforts on the inner surface of the loaded area. The result is obtaining permanent connection with high utility features. 5 Il. The invention relates to the field of metal forming, and in particular to the process of fixing the tubes of heat exchangers using the effect is the accumulation of tubes, including installation one end of the tubes in the tube hole, fixing it from possible move, welded pipe end to the face of the tube with the subsequent fastening of the pipe in the hole in the tube by the application of compressive efforts on its inner surface (see P. Doroshenko A. manufacturing Technology marine steam generators and heat exchangers. Leningrad: Sudostroenie, 1972, 143).To the main disadvantage of this method of fixing tubes should be attributed to the increased cost of production of the combined compounds. In addition, the latter have a certain restriction on the use, as not all of the material, forming a pair of connected elements are welded., There is also known a method of fixing tubes, including the profiling of the pipe ends with the formation of the tip containing the load bearing sections and conical transition sections between them, one of the ends in the tube hole having an annular groove with a triangular cross-section, fixing the pipes from the possible movement and its subsequent consolidation in the tube hole by application of compressive gain is a remnant of the known method is that, what if its implementation is not ensured transverse shift of the transitional conical section with respect to the outer edge of the annular groove. The latter is a provision in the formation of elevated service characteristics of the longitudinally-pressing fixing tubes.Object of the invention is to provide such a method of fixing tubes, which would allow permanent connection, providing a transverse shift of the transitional conical section with respect to the outer edge of the annular groove.The technical result is achieved in that in the method of fixing tubes, including the profiling of the pipe ends with the formation of edge lines containing loaded, the reference sections and conical transition section between them, one of the ends in the tube hole having an annular groove with a triangular cross-section, fixing the pipes from the possible movement and its subsequent consolidation in the tube hole by application of compressive efforts on the inner surface of the loading plot ending, according to the invention in a tube hole perform a combined annular groove, combining the ditch annular transition section ends have a front edge of the ring grooves with a rectangular cross-section.Implementation of the proposed method of fixing tubes allows permanent connection with high utility features.This is because fixing the pipe in the pipe hole is longitudinally-pressing method, when performing the conical distributing pipes, produce transverse shear blade relative to the edges of the tube holes with fixing the pipe on the front surface of the tube and the simultaneous filling of the volume of the annular groove non-contact deformation of the pipe material. The median surface of the tapered transition section is in contact with the outer edge of the annular groove. Then move the conical mandrel relative to the tube causes the deformation of the conical transition section transverse shift of the material with respect to the outer edge of the annular groove.Smoothing action of the tool on the pipe surface allows you to build in the inner surface layers of the pipe favorable compressive residual stresses of the first kind.The invention is illustrated by drawings, where Fig.1 shows a heat exchanger tube with a profiled tip located is; is a of Fig.2 - stage operation has finished hand loading section ending in a cone in terms of the realization of non-contact deformation of the pipe material when filling the annular groove before fixing the pipes on the walls of the tube holes; Fig.3 - the stage of fixing the pipe on the pipe walls of the hole, followed by radial deformation of the length of the conical transition section located before the outer edge of the annular groove; Fig. 4 - stage fixing the pipe in the hole in the tube, followed by axial irreversible deformation of the blade ends and the transverse shift of the transitional conical section with respect to the outer edge of the annular groove; Fig.5 is a high - quality one-piece connection of the tubes and tube sheets.Variant implementation of the invention consists in the following.Heat transfer pipe 1 (Fig.1) perform operations with the aim of preparing the outer surface of its ends to the profile: edit pipe, cut it length and Stripping the outer surface of the ends to the metal layer.Then on each of the ends of the pipes form a known distribution operations and crimping profiled ends, containing a reference plot with wny the diameter of the hole, and conical transition section between them (marked by dots).The pipe is placed in the hole of the tube 2, having a combined annular groove of rectangular cross-section, transitioning into a triangular cross-section, and fix it from the possible movement (represented by arrows).In this case, the small base of the conical transition section ends are placed in front of the annular groove, for example, by dividing the height of the conical transition section into two equal parts (Fig.1).Check for correct installation of the pipe is carried out by measuring its rearward end on the front surface of the tube.In the hole ending set conical mandrel 3.Applying the mandrel axial force (represented by arrows) to the inner surface of the loading plot ending, reach pressures, causing cone distributing ending, followed by non-contact deformation of the supporting pipe section with a partial filling of the volume of the annular groove and the formation of a plastic hinge at the inner edge of the ring groove (Fig.2).Thus, to produce restriction hearth plastic deformation in the axial direction.the material of the ends of the length from its end surface to the front surface of the tube with the formation of the influx and the formation of the first ring density between the joined elements.Further axial movement of the mandrel causes the fixing pipe on the pipe walls of the hole by a transverse displacement of the blade relative to the edges of the tube holes and the simultaneous deformation of the length of the conical transition area in front of the edge of the groove in the radial direction (Fig.3).At one point during this movement of the mandrel in the axial direction will be full contact length of the conical transition section with the surface of the pipe hole (outside ring grooves).Further axial movement of the mandrel causes the original to axial movement of the transition section in the direction of the ring grooves with subsequent cross his shift with respect to the outer edge of the ring groove (Fig. 4). Thus, the second ring is formed on account of the density between the joined elements.The process of fastening the pipe in the pipe hole ends with a stop tapered mandrel in position, when will pan across the canvas of the pipe relative to the back surface (the third ring density between the joined elements).The removal of deforming the connecting elements of the effort makes practical the internal stresses in the inner layer of the pipe, what determines the obtaining permanent connections specified corrosion characteristics.Pilot, validation of the developed method was pinned steel (20) of the pipe-shaped outer ends in the tube sheets of steel 16GS. Initial geometrical dimensions of the tube were: outer diameter - 25 mm, wall thickness - 2.5 mm Outer surface of the pipe ends have been calibrated for a length of 33 mm up to a diameter equal to 25.7 mm ends of the pipe profiled radial crimping technology to snap diameters: minimum of 24.3 mm and a maximum of 25.3 mmProfiling the ends of the pipes was carried out in the technological snap-on horizontal hydraulic press, double action with the effort of not more than 0.2 MN.Pipe holes were produced with diameters equal to 25,35+0,05mm Combined annular groove had: in a rectangular part of cross section depth of 0.3 mm, width of 1 mm; in the triangular part of the cross sectional length - 4 mmAnnular projections on the fixed tubes in the tube holes had a cross-section with dimensions corresponding to the dimensions of the combined ring grooves.When installation is relatively outer edge of the ring groove.Technological equipment for production of pipes with outer circular edge lines and its fastening in the tube holes were made from tool steel WA with hardness after quenching HRC of not less than 56 units and precision of the Executive sizes 9-th degree of accuracy.The fixing of the tubes was carried out on a special stand with pump station firm "Indresco" and through the conical mandrel, using the extractor.It is established that the profile of the external surface of the pipe end in combination with fixing pipes on the walls of the pipe openings through the transverse displacement of the blade relative to the front surface of the tube and the outer edges of the annular grooves allow you to perform high-quality permanent connection with high utility features.Tests for pulling tubes from the tube confirmed enhanced mechanical strength of the obtained compounds.The density of connections (hydraulic test) provided 100% of their suitability to the requirements of production.The invention is applicable in the manufacture of the tube bundles of heat exchangers oil refining, Neftchi the property securing tubes, includes profiling of the pipe ends with the formation of the tip containing the loaded and supporting sectors as well as conical transition section between them, one of the ends into the tube hole is made with an annular groove, fixing the pipes from the possible movement and its subsequent consolidation in the tube hole by application of compressive efforts on the inner surface of the loading plot ends, characterized in that an annular groove in the tube hole perform combined in the combination of annular grooves of rectangular and triangular cross-sections, and when you install the tail pipe in the pipe hole of the small base of the conical transition section ends have a front edge of the ring grooves with a rectangular cross-section.
FIELD: machine-assembly equipment for producing nuclear reactor fuel assemblies.
SUBSTANCE: proposed machine has pneumatic cylinder rod provided with its motion limiter and contactless sensor at drifting mechanism on through slit of bottom end part of fuel element; cone angle of drift-rod is 30 deg. and annular drilling diameter in each hole of auxiliary spacer grid equals nominal flare of fuel element end part sections internally drifted inside each annular drilling within upper nominal-size tolerance D = Hk, where D is annular drilling diameter; H is nominal flare; k is upper nominal-size tolerance.
EFFECT: enhanced quality of fuel assembly.
1 cl, 5 dwg
FIELD: plastic working of metals, namely by means of energy of electric explosion of metallic connector in condensed media.
SUBSTANCE: apparatus includes dielectric sleeve with transfer medium hydraulically insulated by means of rubber plugs. In cavity of said sleeve are arranged: rigid carcass in the form of two end walls mutually joined by means of metallic studs; and exploded metallic conductor. The last is divided by two parts connected one with other through electrode. Electrode rests upon dielectric sprockets and it is in the form of body of revolution whose shape is described by function defining length and diameters of electrode according to linear dimensions of deformed portion of tube. Relation of maximum diameter of central part of electrode to inner diameter of dielectric sleeve is in range 0.5 - 0.8. Curvilinear surfaces of end walls of exploded conductors are in the form of paraboloid. Boundary ends of exploded conductor are arranged in focal point of paraboloid.
EFFECT: more effective usage of energy of electric explosion of metallic conductor, enhanced quality and reliability of tube pressing-in, improved efficiency of apparatus.
4 dwg, 1 ex
FIELD: plastic working of metals, possibly tube expanding.
SUBSTANCE: tool includes clamp mechanism having clamp cylinder and spacing rod arranged in it. Tool includes housing in which compression spring is arranged in such a way that its one end rests upon housing and other end rests upon end of clamp cylinder; force working member mounted inside compression spring and made of shape memory alloy. One end of working member is secured to housing; its other end is secured to spacing rod. Spring and working member are made with possibility of creation in common system of forces in which direction of summed vector acting upon spacing rod depends upon temperature of working member. Increase of working member temperature till value exceeding that of reverse martensite conversion causes generation of efforts transmitted to spacing rod due to shortened length of working member.
EFFECT: lowered cost price of labor, enhanced efficiency of tool.
FIELD: plastic working of metals, possibly tube securing to tube walls of heat exchange apparatuses by means of directed plastic deforming of tube material.
SUBSTANCE: method comprises steps of placing tube in tube wall opening with annular recess at providing protrusion of tube end over front surface of tube wall; fixing tube against axial motion due to placing on part of its protruded end locking ring with threaded holes for screwing-in bolts and for forming local bulged portions on tube; profiling protruded end of tube; shaping annular thickened portion on tube arranged in annular recess of tube wall and shaping annular protrusion on front side of tube wall. After securing profiled end of tube circular welding of tube to tube wall is realized. Then tube is broached for expanding it in range of tube wall thickness value in zone of bulged portions and for creating plastic yielding of tube material relative to edge of opening at back side of tube wall.
EFFECT: improved quality of non-detachable tube-to-tube wall joint.
2 cl, 9 dwg
FIELD: plastic working of metals, possibly securing thin-wall small-diameter tubes to tube walls of heat exchange apparatuses with use of directed plastic deforming of tube material.
SUBSTANCE: method is realized for tube whose length exceeds desired one. Method comprises steps of subjecting tube material on tube end portions to heat treatment in order to enhance its plastic properties; placing tube in opening of tube walls and preliminarily fastening it due to placing ring on protruded tube end and expanding tube protruded end till diameter of annular recess of tube wall for receiving calibrated zone; applying axial compression effort to end of calibrated zone for forming thickened portion. Then tube is finally fastened in tube wall opening due to broaching its thickened portion and providing plastic yielding of tube material from thickened portion towards rear edge of tube opening. Diameter of opening formed in thickened portion is equal to initial diameter of tube. Tube material embraces rear edge of tube opening.
EFFECT: improved quality of formed joint.
FIELD: plastic working of metals, possibly expanding tubes in tube walls.
SUBSTANCE: rolling unit includes separating housing; cone expanding rollers having rolling bands, head end portion and tail end portion; windows for mounting them; spindle passing along axis of housing. Said windows are formed on separating housing uniformly along its perimeter with central angle 120° between adjacent windows whose axes are turned by predetermined angle relative to generatrix of housing. Said windows are arranged in lengthwise rows, three different-length windows in each row. Boundary windows of lengthwise rows of housing in each row and rollers mounted in them also have different length values. Length values of rolling bands of rollers and distance between rolling bands are determined according to relations given in specification. Total length of rolling band used for expanding is equal to summed length value of rolling bands of all three rollers in window of any lengthwise row and doubled distance between rolling bands of rollers in adjacent windows of each row.
EFFECT: enhanced effectiveness of works for making heat exchange equipment.
FIELD: power machine engineering, possibly manufacture of heat exchange apparatuses.
SUBSTANCE: method comprises steps of placing tube having annular shoulder on outer surface in flanged opening of tube wall till tube resting upon inner surface of said opening; forming surface of shoulder and inner surface of opening in such a way that to provide their matched joining; fixing tube against possible movement and fastening it in opening of tube wall due to performing zone-to-zone deformation of tube and flanging opening by means of pressure pad. Shoulder on outer surface of tube may be in the form of tore-like zigzag or fixed ring.
EFFECT: improved manufacturability of method, enhanced operational reliability and fluid-tightness of formed joint.
3 cl, 4 dwg
FIELD: plastic working of metal.
SUBSTANCE: method comprises assembling the heat exchanging pipes into a pipe bank with the use of intermediate cooling plates and interconnecting the pipes. The device comprises rod and rings provided with projections shifted with respect to the adjacent ring. The projections of each subsequent ring are shifted with respect to these of the previous one by means of rotation around the axis of the rod by a value of the space between the capillary passages.
EFFECT: enhanced strength.
7 cl, 5 dwg, 1 ex
SUBSTANCE: disclosed method consists in forming work-pieces of panels with running channels out of band by means of rolling in coils; in punching mouth and in separating work-pieces of panels in press. Prior to separating work-pieces of panels a window is punched out; the window is symmetrical relative to the line of separation of the work-pieces of the panels. Upon separating work-pieces in one punch the mouth of the panel is flanged in another punch, thereby forming a collar parallel in plane to side walls of the panel.
EFFECT: increased efficiency and upgraded quality of panels.
SUBSTANCE: there are implemented set-up labors on pipes - dressing, cutting sufficiently, finishing of external surface of ends, expansion - calibration of pipe end by rigid punch, cascading radial breaking-down of calibrated section by segments of split die. Herewith it is used matrix, containing finishing, preliminary etchings and working between them. Then it is reshaped calibrated section for maximal and minimal cogged sections and conic transition point between them, with following shaping compensation volume by means of burnishing of cavity of maximal cogged section. Additionally shaped edge line is formed by two compensation volumes in the form of doughnut and thickened section of cloth. Additionally collar is formed successively: at stage of cascade radial breaking-down - its external tapered surface, and at burnishing - intermediate compensatory volume in the form of thickened section of cloth of calibrated section with following giving to it of final shape of collar in finishing etching of matrix by means of shear lateral deformation in cloth of calibrated section at its radial annular overclamping. Thickened section of cloth in final form is formed by repeated burnishing of edge line cavity after receiving of collar with extrusion of pipe material into prliminary etching.
EFFECT: upgraded quality.