The necking down device of the thin walled welds cylinder of dynamic mold
Technical field
The utility model relates to a kind of necking down device of thin walled welds cylinder of dynamic mold.
Background technology
The necking down of thin walled welds cylinder refers to the one or both ends reduced of thin walled welds cylinder.Thin walled welds cylinder be by a rectangular sheet through become circle be shaped, and by both sides trace overlap after with big current make it melt, cool after be combined into.
The necking down device of thin walled welds cylinder, to carry out the necking down device of two ends necking operation: have a frame, frame has column, column is each up and down installs necking down head bracket through cantilever, and upper and lower necking down working head is identical.The concrete structure of necking down working head has interior axle and is arranged on the outer shaft outside interior axle through linear bearing, and internal mold and external mold are arranged on interior axle and outer shaft through interior die holder and outer mould base respectively.Interior outer shaft is connected with frame through cylindrical cam respectively, and when cantilever rotates according to column, upper lower cantalever does relative open and close movement.Like this, when necking down up and down in outer shaft move toward one another, first make external mold be clipped by cylinder, then make that thin walled welds cylinder end oppressed by external mold and internal mold support makes it unduly be out of shape, thus make cylinder two ends reduced become neck.
Because thin walled welds cylinder has overlap in sheet metal limit when welding, therefore this place can be thicker than other place, and the wall thickness at this place is approximately 1.6-2 times of other positions.And traditional necking down device, for solving the slightly thick problem in soldered place, be interior mode diameter is suitably reduced to hold thicken caused barrel dliameter change.The interior external mold of the program is coaxial and fixing, and be the crimped effect of barrel for make internal mold play preventing from necking down, gap value between two moulds is not very large but close to steel-sheet thickness, but this gap value is not sufficient to accommodation tube wall thickening segment thickness, and namely the thickness at soldered place is still greater than this gap value.Therefore in actual necking operation, the scratch of the inside and outside surface of thin walled welds cylinder between interior external mold in extrusion process can often be caused.
From in fact, as profile cropping Cheng Yuan increase thick for thin walled welds cylinder welding slotted wall formed afterwards, then two eccentric circles being formed of inside and outside contour, therefore, fixing and coaxial interior external mold does not meet this actual conditions.Have new design to be by external mold by making recessed bond ing with outer mould base for this reason, and external mold can bias be moved, thus external mold can elimination abrades to external mold in the side skew formation having barrel to thicken is eccentric when necking down.But be in fact because the structure of external mold itself and the mounting structure reason with outer mould base, force its skew also to need larger power, this power be reaction by the barrel of necking down, therefore abrade and can only alleviate and not easily eliminate, existing for still having.
Summary of the invention
For above-mentioned deficiency, the utility model is exactly the necking down device of the thin walled welds cylinder that will provide a kind of dynamic mold by allowing internal mold offset.
The necking down device of the thin walled welds cylinder of the dynamic mold that the utility model provides, has internal mold to be arranged on interior axle through interior die holder, and have external mold to be arranged on outer shaft through outer mould base, interior outer shaft is coaxially nested; Described inner mold center has circular hole and there is recessed step formation coaxial reducing two rank cylindrical cavity on top, the circular hole on the two cylindrical limit plug in rank of coaxial reducing and internal mold and step is had to make matched in clearance and are fixedly installed on interior die holder with bolt, the aperture of described inner mold center circular hole and the gap between step perisporium diameter and limit plug cylinder are 0.2-0.6 thin walled welds wall thickness of cylinder, and internal mold bottom surface and bench floor and interior die holder end face and limit plug end face make matched in clearance.
Described interior die tip refers to internal mold one end towards thin walled welds cylinder stack shell, then internal mold bottom is the one end connected with interior die holder.Described coaxial reducing is two, and rank are cylindrical refers to the shape formed coaxially to connect by the cylinder of two different-diameters.
The necking down device of the thin walled welds cylinder of the dynamic mold that the utility model provides, interior die holder top secures a limit plug to install internal mold, and between internal mold inner cylinder and limit plug outer cylinder, having the gap of 0.2-0.6 thin walled welds wall thickness of cylinder, matched in clearance is made with interior die holder and limit plug again in internal mold two ends.So, internal mold can relatively be done radial displacement and make the gap value maximum between interior external mold can reach 1.4-2.2 thin walled welds wall thickness of cylinder in axle center.Compared with prior art, internal mold of the present utility model can do enough moving radially, during operation, dodging of internal mold not only overcomes soldered and thickens the disalignment of the circularity gabarit caused and can reduce or eliminate scratch, simultaneously because internal mold quality is little, mounting structure is simple, it is made to offset required thrust less, thus reaction force suffered by barrel is also little, greatly reduce than the power required for external mold skew, scraping that thus barrel may be subject to is also much smaller.In addition, secure external mold coaxial with thin walled welds cylinder, and internal mold skew, then the wall thickness change produced because of soldered is reflected in cylinder, and thin walled welds cylindrical configuration circularity is improved.
The necking down device of the thin walled welds cylinder of the dynamic mold that the utility model provides, described limit plug cylinder has cannelure, one O shape circle is installed in groove, inner edge diameter during O shape circle free state and annular groover rot diameter make matched in clearance, outer most edge diameter during O shape circle free state is less than internal mold inner cylinder diameter, and gap value is less than the gap between internal mold inner cylinder and limit plug cylinder.O shape circle is arranged between internal mold and limit plug with free state, and the gap value between its outer rim and limit plug is less than the gap value between internal mold and limit plug, can produce pressure, thus make it produce elastic force to internal mold when internal mold offsets to O type circle.This elastic force necking operation terminates the rear internal mold to losing thrust provides the power placed in the middle that resets, thus thrust when further mitigating next operation required for internal mold skew.
Accompanying drawing explanation
Fig. 1 is the structure chart of the utility model one embodiment, in figure: axle in 1-, 2-linear bearing, 3-outer shaft, die holder in 4-, 5-outer mould base, 6-external mold, 7-internal mold, the gap after the skew of 7a-internal mold and between limit plug, 8-thin walled welds cylinder, 8a-thin walled welds cylinder welding seam thickening, 9-limit plug, 10-O shape is enclosed, 11-bolt.
Detailed description of the invention
,the necking down device of the thin walled welds cylinder of one double end dynamic mold, the structure of one of them necking down working head as shown in Figure 1.Necking down working head, by interior axle 1 and the outer shaft 3 that is arranged on through linear bearing 2 outside interior axle, is arranged on the internal mold 7 on interior axle through interior die holder 4 and forms through the external mold 6 that outer mould base 5 is arranged on outer shaft.Wherein outer mould base and external mold are all the co-axially fixed shaped object having cylindrical cavity with outer shaft, and its effect oppresses thin walled welds cylinder when necking down to inside contracting change.Interior die holder center is porose and there is recessed step at two ends.Separately have a limit plug 9, its end Duan Weiyi path cylinder and top is a large footpath cylinder, limit plug path cylinder height is greater than interior die holder top and tops bar height and diameter and stepped diameters make interference fits.Interior axle top center screw, step on interior die holder bottom and interior axle are done excessively to coordinate, separately have the bolt 11 coordinated with above-mentioned screw, be fastened on the screw at center, interior axle top through limit plug, outer mould base, have between at the bottom of interior axle top and internal mold seat stand rank pad regulate in die holder axial location.Inner mold center is porose and there is recessed step on top, thus forms a coaxial reducing two rank cylindrical cavity be connected with section large footpath, top cavity by end section path cylindrical cavity.Internal mold upper base section is highly less than height between cylinder bottom, section large footpath, limit plug top and interior die holder top, and internal mold is not fixed by limit plug compressing.And the difference at the bottom of section diameter at the bottom of internal mold and limit plug between section diameter, between internal mold top section diameter and limit plug top section diameter is 0.2-0.6 thin walled welds wall thickness of cylinder.
During operation, when thin walled welds cylinder welding seam thickening 8a is in certain side (in Fig. 1 left side), owing to there is enough displacements between internal mold and interior die holder, make this gap value existed between internal mold inwall and limit plug at opposite side (in Fig. 1 right side) expand as larger internal mold and offset gap 7a afterwards and between limit plug.
Section at the bottom of limit plug has a cannelure, install O shape circle 10, an O shape circle in groove is free state in groove, and namely, outer rim is not oppressed with other parts mutually.The gap within 0.2-0.6 thin walled welds wall thickness of cylinder is had between O shape circle outer most edge and internal mold inwall, depending on the gap between internal mold and limit plug, to can produce certain pressure to O type circle when internal mold offsets, not only to internal mold produce elastic force but also the reaction force of this pressure unlikely to cross ambassador impaired with wall.The effect of O shape circle provides to internal mold the elastic force placed in the middle of resetting when internal mold offset, during to alleviate next operation further internal mold offset required for thrust.