The method of flexible hydraulic drawn tube and equipment thereof
Technical field
The invention belongs to the forming tubular product technology of metallurgical machinery, is a kind of employing hydraulic drive, flexible forming, the method and the equipment thereof of production cold-drawn high-precision material.Can be applicable to the field such as lining, printing machinery, air equipment of shock absorber, the hydraulic cylinder of toner cartridge, the automobile and motorcycle of lighting apparatus.
Background technology
In China for the processing such precision tube of gentle moveable cylinder that surges, generally adopt the method for hot seamless tube through machining, and abroad, then adopt the drawn tube technology of no machining, it is the cold working method of seamless pipe being carried out plastic deformation by drawbench.The drawbench of prior art is divided into all kinds such as chain type, rack-and-pinion, screw type, steel cable type, fluid pressure type by the kind of drive.The common drawback of mechanically operated cold-draw equipment is: can produce vibrations in the process of tube plug drawing mill, the crystal grain that can not guarantee workpiece material is along the moulding of cold-drawn direction, chain-drive mechanism particularly, after the chain sprocket wearing and tearing, can produce periodic shock, the discontinuity of this operation is the lethal factor that tube quality can not get reliable control, directly influences the precision of product.In addition, draw tonnage deficiency, energy consumption is big, also is the major defect of machine driving drawbench.
1999 the 5th phases " heavy-duty machinery " magazine, disclose a kind of " novel hydraulic cold drawing tube machine ", it is made up of master cylinder, drawn-car, product rack, draw lathe bed, withdrawing pattern seat, blank stand, pusher lathe bed, pusher dolly, core bar lathe bed, core bar dolly etc.Drawn-car and master cylinder by kink and dolly axon to fixing, dress dual-active plug sleeve cylinder on the dolly, the piston rod front end is equipped with jaw and chock plug, when piston moved relatively, jaw and chock plug can be sent or regain by demand; 2 one-stroke pretension cylinders are equipped with in the car body both sides, are used to promote screw die and clamp by the pipe of draw.Accumulator is equipped with at the rear portion of car body, is used for drawn-car at lathe bed any part clamping pipe.During the draw steel pipe, at first core bar is penetrated in the pipe endoporus, load onto core print then, will put on the steel pipe front end of core print more and release the withdrawing pattern seat.Starting cover cylinder is sent chock plug into the steel pipe front end.Starting pretension cylinder makes screw die clamp steel pipe, and drawn-car is in original position, master cylinder starting beginning draw.When draw finishes, the action of cover cylinder, the finished product pipe that jaw promotes behind the draw breaks away from car body.
The fluid pressure type drawbench of prior art, it has advantages such as loading and unloading are steady, transmission accuracy is high, speed governing is accurate, collisionless, not damaged than mechanically operated drawbench, but still adopts traditional structure at key positions such as withdrawing pattern and core prints.Therefore, the fluid pressure type drawbench of prior art also can only draw the cylinder barrel that general precision requires, and expect machinings such as more high-precision tubing also must grind.In addition, it is low that the fluid pressure type drawbench of prior art also exists production efficiency, and cope print needs shortcomings such as manually auxiliary.
In order to improve the cold drawing steel tube quality, to enhance productivity and reduce energy consumption, prior art discloses some cold-drawn tubing The Study on New Technology achievements.
Prior art constantly is being devoted to the improvement of aspects such as the design of drawn tube drawing-die, processing.As: adopt the material of high strength, high-wearing feature to make mould; Well-designed and attrition process nib; Adopt the floating core head trombone slide; Use rotating mould to change the action direction of frictional force, reducing the component of drawing direction, and make the nib wearing and tearing even or the like.These measures are in the contact problems that fundamentally do not solve between metal (pipe) and the metal (drawing-die), because in the deformation process, the rigidity contact between pipe and the mould can produce bonding and wearing and tearing, thereby just is difficult to obtain the steel pipe of high-precision surface quality.
Prior art adopts the method for enforced lubricating tube drawing, reduces the frictional resistance of distortion, reduces pulling capacity, improves the fineness of workpiece.As 1992. Science Presses, volume such as Ru Zheng, Yu Wang: the typical structure of having introduced " enforced lubricating drawn tube device " in " plastic working tribology ", device is to adopt force pipe or composite die or plus high-pressure infusion to go into the highly pressurised liquid lubricant in the drawing pipe, make it to form hydrodynamic or hydrostatic lubrication, lubricating status in the time of can improving tube drawing, make under oil film thickness increase, the pulling capacity and reduce, workpiece fineness improves.The enforced lubricating drawing method of prior art though reduced frictional resistance to a certain extent, has reduced pulling capacity, will increase the supercharging facility of a kind of pressure height, good airproof performance at the die entrance place.This facility is prone to lubricant and leaks, the defect that pressure reduces, and therefore, it is big to set up stable lubricating oil film difficulty, and pressure inlet Design of length difficulty often when just beginning drawing, tubing can occur and pull off phenomenon.In addition, the tubing enforced lubricating is generally done lubricant with soap, though can set up hydrodynamic lubrication, there is cut on the surface of extracting tubing, and is of poor quality, and will carry out the coating operation before draw; Work as increased pressure, the viscosity of lubricant reduces, the bonding phenomenon of also keeping away unavoidable generation metal sometimes, heavy damage draw carrying out and can damage mould and core print.Above drawbacks limit the application of enforced lubricating on drawn tube.
Summary of the invention
The objective of the invention is to overcome the shortcoming of prior art, a kind of method of flexible hydraulic drawn tube is provided, it is the liquid stress that forced feed lubrication between mould, core print and the pipe is promoted, make and do not contact between mould and deformable metal, formation is by the plastic deformation state of mould-hydraulic oil-pipe-hydraulic oil-core print, thereby the production method of a kind of low cost of manufacture, drawn tube that the product precision is high is provided.
Another object of the present invention is to overcome the shortcoming of existing drawn tube equipment, and the drawn tube equipment of a kind of hydraulic drive, flexible forming is provided, and its mechanism action is coordinated steadily, and is simple to operation, has improved the precision of drawn tube dramatically.
The present invention is achieved through the following technical solutions:
A kind of method of flexible hydraulic drawn tube, be hydraulic oil to be squeezed between withdrawing pattern and the pipe by hydraulic system, form the pressure-bearing oil pocket, withdrawing pattern is not directly contacted with pipe, plastic force transmits by hydraulic oil, pipe produce the plasticity plastic deformation, thereby draw goes out high-precision tubing under the effect of pressure that is subjected to power media and pulling capacity.
In order to go out high-accuracy tubing by draw, mould and plug combination are designed.Design philosophy is exactly according to the fluid bearings theory, establish oil through at the plug center, inwall at withdrawing pattern has oil groove and establishes horizontal oil through, utilize the peripheral hardware high-pressure oil pump that oil pressure is provided, set up hydrostatic pressure carrying operating mode, simultaneously, owing to have relative motion and convergence gap (the withdrawing pattern hole is by curve design in certain) between tubing and mould and the plug, under the certain speed condition, be easy to set up the hydrodynamic effect, both mutual superposition have just formed the dynamic and static pressure bearing mode of mechanism, under the effect of hydraulic oil, and tubing and mould, separated by high-pressure medium between tubing and the core print, plastic force transmits by fluid media (medium), flexible forming mechanism that Here it is.
In process of tube plug drawing mill, there is a large amount of oil leaks to overflow, and possible splash, therefore, principle according to hydraulic cylinder designs a kind of assembly, and whole drawing pipe is sealed, and makes tubing carry out draw under the situation of sealing fully, not only form the pressure-bearing oil pocket, and solved the leakage of oil problem.The hollow piston structure of hydraulic cylinder is adopted in the support of tubing back segment, and piston both can support pipe with the tubing advanced in unison, can middle pass plug again, has increased plug length.
The concrete processing step of described flexible hydraulic drawn tube method is:
(1) startup pushes away the assembly oil cylinder, and the pulling assembly separates with mould;
(2) the stock shelf rising makes pipe in place;
(3) startup pushes away the plug oil cylinder, and plug is inserted pipe, and pipe is shifted onto in the mould, and stock shelf descends;
(4) push away the assembly oil cylinder and promote assembly to die holder, piston servo-actuated simultaneously, cylinder body and die holder port closure are finished sealing;
(5) start the push piston oil cylinder, the piston that promotes assembly supports the afterbody of pipe;
(6) clamping device action clamps pipe;
(7) start the drawing oil cylinder, the beginning drawing;
(8) drawing cylinder oil pressure reaches setting pressure, high-pressure oil pump work, chew to plug and pipe inwall injection hydraulic oil by hydraulic oil, and inject hydraulic oil to mould by pipe joint, form inside and outside pressure-bearing oil pocket, pipe produces the plasticity plastic deformation under the effect of pressure that is subjected to power media and pulling capacity, finish draw, high-pressure oil pump quits work;
(9) blanking rack rises, and holds tubing;
(10) clamping device unclamps, and the blanking rack band production tube decline and put in place;
(11) the drawing oil cylinder promotes clamping device to die holder;
(12) assembly oil cylinder pulling assembly backhaul, the piston servo-actuated;
(13) the push piston oil cylinder, push away the backhaul of plug oil cylinder, make plug and piston reset, whole process of tube plug drawing mill finishes.
Described medium is a kind of special hydraulic oil, can add extreme pressure agent, oiliness improver, oxidation and corrosion inhibitor and polymeric lubricant in base oil according to a certain percentage.
The used equipment of a kind of flexible hydraulic drawn tube method comprises: the push piston oil cylinder, push away the plug oil cylinder, push away the assembly oil cylinder, lathe bed, assembly, track, feed mechanism, mould, cutting agency, clamping device, drawing oil cylinder.Described assembly is made up of cylinder body, end cap, piston, piston rod, plug, core print, adapter sleeve, taper top, cylinder rack, sealing.The push piston oil cylinder is fixed on the side slightly on the lower side of lathe bed, and its piston rod is connected with the travelling carriage that is provided with in orbit, and travelling carriage is connected with the piston rod of assembly; Push away the plug oil cylinder be fixed on the push piston oil cylinder directly over, the piston rod that pushes away the plug oil cylinder is connected with the plug of assembly; Two push away the both sides that the assembly oil cylinder is fixed on track symmetrically, and the piston rod that pushes away the assembly oil cylinder is connected with fixing assembly support in orbit; Assembly is fixed on the support; Feed mechanism, cutting agency are fixed on a side of track symmetrically with mould, and mould is fixed on the lathe bed; On the fixing clamping dolly in orbit of clamping device, dolly is connected with the piston rod of drawing oil cylinder, and the drawing oil cylinder is fixed on the lathe bed.
Described assembly, there is through hole at its piston center, and the piston left end is fixed with adapter sleeve, is sleeved on the assembly piston rod by adapter sleeve, there is through hole at the piston rod center, be slidingly matched with plug, there is oil through at the plug center, and the plug front end is connected with core print, core print center and laterally be provided with oil through, there is the taper top of through hole at the fixing a kind of center of piston right-hand member, is provided with sealing between piston and the cylinder body, is provided with oil returning pipe joint in the bottom of cylinder body.
Described mould, form by die holder, withdrawing pattern, die cap, end cap axial seal, end cap radial direction sealing, withdrawing pattern axial seal, pipe joint, withdrawing pattern places in the die holder, leave the gap between withdrawing pattern and die holder, the die holder termination is provided with die cap, and with end cap axial seal shutoff, die holder and withdrawing pattern are axially arranged with withdrawing pattern axial seal, die holder is provided with the pipe joint that is connected with high-pressure oil pipe, and the inwall of withdrawing pattern has oil groove and establishes horizontal oil through.
Between the travelling carriage of described push piston oil cylinder and the assembly piston rod, employing is threaded.
Being connected between the described piston rod that pushes away the plug oil cylinder and the plug is by a joint sleeve, an end with push away the plug piston rod thread and be connected, the other end is threaded with plug, and is provided with hydraulic oil chews on joint sleeve.
Described two piston rods that push away the assembly oil cylinder are connected with two earrings of assembly support respectively.
Described clamping device is to utilize the sliding the cooperation fast and inclined-plane of hydraulic oil cylinder driving to sting automatically tightly, oil cylinder is fixed on the clamping dolly, oil cylinder piston promotes wedge block and can seesaw, under the prevention on front cover match inclined-plane, produce laterally and move, can clamp the pipe mouth, the clamping dolly is provided with the earrings that is connected with the drawing oil cylinder piston rod.
Described upper and lower material mechanism is different from traditional structure, is to adopt track vertically to place, and hydraulic cylinder promotes to move up and down.
The present invention compared with prior art has the following advantages and useful effect:
(1) drawing is under the state that forms the hydraulic packing bearing ring, carry out plastic deformation, fundamentally solved in the enforced lubricating and be in the deformation state that is interrupted contact friction between the metal die and pipe, it is the liquid stress that forced feed lubrication is promoted, make not produce between mould and deformable metal to contact that draw power relies on hydraulic oil to transmit, and forms the deformation state of mould-hydraulic oil-pipe-hydraulic oil-core print, be real flexible formation, draw goes out the steel pipe of high-precision surface quality.Thereby can make high accuracy alloy sleeve (as toner cartridge) realize production domesticization, reduce manufacturing cost.
(2) adopt the hydraulic piston type composite unit structure, and cooperate hydraulic trolley, guaranteed the concentricity of each mechanism's center line and nib, prevented the off-centre of workpiece draw.
(3) since in the draw pipe to be difficult to form the deformed area of hydraulic pressure bearing ring end to end longer, adopt the form of long mould, not only overcome above-mentioned shortcoming, and can guarantee workpiece accurately to neutralization raising integral rigidity.
(4) deformation process adopts all-hydraulic control, and under low speed draw, the vibration of stopping process takes place; Clamping device has been cancelled common rod-shoving device of nipping, and utilizes the cooperation on slide block and inclined-plane to sting automatically tightly, and drawing under hydraulic cylinder drives has improved precision greatly, reduces error; Whole mechanism action is coordinated steadily, and is simple to operation, improved the precision of drawn tube dramatically.
(5) general precision tube drawing oil requires viscosity bigger, sticking warm nature is good, filtration and settleability are good, in base oil, add extreme pressure agent according to a certain percentage, oiliness improver, oxidation and corrosion inhibitor and polymeric lubricant etc. have the compounded lubricant of antifriction, wear-resistant effect with formation, and as the power media that is subjected between pipe and the withdrawing pattern, thereby improved lubricant effect, improved the precision of tube surfaces.
Below by preferred embodiment, in conjunction with the accompanying drawings, the present invention is further illustrated.
Description of drawings
Fig. 1 is a kind of structural representation of flexible hydraulic drawn tube equipment;
Fig. 2 is the plan structure schematic diagram of flexible hydraulic drawn tube equipment;
Fig. 3 is the structural representation of withdrawing pattern;
Fig. 4 is the side view of Fig. 3;
Fig. 5 is the structural representation of assembly;
Fig. 6 is the vertical view of Fig. 5;
Fig. 7 is the working state schematic representation of assembly and withdrawing pattern;
Fig. 8 is the push piston oil cylinder, push away the structural representation that is connected between plug oil cylinder and the assembly;
Fig. 9 is the structural representation of clamping device;
Figure 10 is the hydraulic system principle figure of flexible hydraulic drawn tube equipment;
Figure 11 is the hydraulic oil systematic schematic diagram.
The specific embodiment
A kind of concrete processing step of flexible hydraulic drawn tube method is:
(1) startup pushes away assembly oil cylinder 3, and pulling assembly 5 separates with mould 8;
(2) stock shelf 7 risings make pipe 12 in place;
(3) startup pushes away plug oil cylinder 2, and plug 5-5 is inserted pipe, and pipe is shifted onto in the mould 8, and stock shelf 7 descends;
(4) push away assembly oil cylinder 3 and promote assembly 5 to die holder, piston 5-3 servo-actuated simultaneously, cylinder body 5-1 and die holder 8-1 port closure are finished sealing;
(5) start push piston oil cylinder 1, the piston 5-3 that promotes assembly 5 supports the afterbody of pipe;
(6) clamping device 10 actions clamp pipe 12;
(7) start drawing oil cylinder 11, the beginning drawing;
(8) drawing cylinder oil pressure reaches setting pressure, high-pressure oil pump work, chew (2-3) by hydraulic oil and inject hydraulic oil to plug (5-5) and pipe (12) inwall, and inject hydraulic oil to mould (8) by pipe joint (8-7), form inside and outside pressure-bearing oil pocket, pipe produces the plasticity plastic deformation under the effect of pressure that is subjected to power media and pulling capacity, finish draw, the high-pressure oil pump work that quits work;
(9) blanking rack 9 rises, and holds tubing;
(10) clamping device 10 unclamps, and the blanking rack band production tube decline and put in place;
(11) drawing oil cylinder 11 promotes clamping device 10 to die holder;
(12) assembly oil cylinder 3 pulling assemblys 5 backhauls, piston 5-3 servo-actuated;
(13) push piston oil cylinder 1, push away 2 backhauls of plug oil cylinder, make plug and piston reset, whole process of tube plug drawing mill finishes.
Shown in Fig. 1,2,5,6,8, a kind of flexible hydraulic drawn tube equipment comprises: push piston oil cylinder 1, push away plug oil cylinder 2, push away assembly oil cylinder 3, lathe bed 4, assembly 5, track 6, feed mechanism 7, mould 8, cutting agency 9, clamping device 10, drawing oil cylinder 11.Push piston oil cylinder 1 is fixed on the side slightly on the lower side of lathe bed 4, and push piston oil cylinder piston bar 1-1 is connected with travelling carriage 1-2 on being arranged on track 6, and travelling carriage is connected with assembly piston rod 5-4; Push away plug oil cylinder 2 be fixed on push piston oil cylinder 1 directly over, push away plug cylinder piston rod 2-1 and be connected with the plug 5-5 of assembly 5; Two push away assembly oil cylinder 3 and are fixed on track 6 both sides symmetrically, push away assembly oil cylinder piston bar 3-1 and are connected with fixing assembly support 5-9 in orbit; Assembly 5 is fixed on the support 5-9; Feed mechanism 7, cutting agency 9 are fixed on a side of track 6 symmetrically with mould 8, and mould 8 is fixed on the lathe bed 4; Clamping device 10 is fixed on the clamping dolly 10-1 on the track 6, and dolly is connected with drawing oil cylinder piston rod 11-1, and the drawing oil cylinder is fixed on the lathe bed 4.
As Fig. 5,6, shown in 7, described assembly is by cylinder body 5-1, end cap 5-2, piston 5-3, assembly piston rod 5-4, plug 5-5, core print 5-6, adapter sleeve 5-7, taper top 5-8, cylinder rack 5-9, sealing 5-10 forms, there is through hole at its piston 5-3 center, the piston left end is fixed with adapter sleeve 5-7, be installed together by adapter sleeve and assembly piston rod 5-4, assembly piston rod 5-4 is a hollow tube, be slidingly matched with the plug 5-5 in it, there is oil through at plug 5-5 center, the plug front end is connected with core print 5-6, core print center and laterally be provided with oil through, there is the taper top 5-8 of through hole at the fixing a kind of center of piston 5-3 right-hand member, be provided with sealing 5-10 between piston 5-3 and the cylinder body 5-1, be provided with oil returning pipe joint 5-11 in the bottom of cylinder body.Described two push away assembly oil cylinder piston bar 3-1 be connected with two earrings of assembly support 5-9 respectively (referring to Fig. 2).
Shown in Fig. 3,4,7, described mould 8, form by die holder 8-1, withdrawing pattern 8-2, die cap 8-3, end cap axial seal 8-4, end cap radial direction sealing 8-5, withdrawing pattern axial seal 8-6, pipe joint 8-7, withdrawing pattern 8-2 places in the die holder 8-1, leave the gap between withdrawing pattern and die holder, the die holder termination is provided with die cap 8-3, and with end cap axial seal 8-4, end cap radial direction sealing 8-5 shutoff, be provided with withdrawing pattern axial seal 8-6 between die holder and the withdrawing pattern, die holder is provided with the pipe joint 8-7 that is connected with high-pressure oil pipe, and the inwall of withdrawing pattern has oil groove and establishes horizontal oil through.
As shown in Figure 8, between the travelling carriage 1-2 of described push piston oil cylinder 1 and the assembly piston rod 5-4, employing is threaded.Being connected between the described piston rod 2-1 that pushes away plug oil cylinder 2 and the assembly plug 5-5 is by a joint sleeve 2-2, and an end is threaded with piston rod 2-1, and the other end is threaded with plug 5-5, and is provided with hydraulic oil chews 2-3 on joint sleeve.
As shown in Figure 9, described clamping device 10 is to utilize the sliding the cooperation fast and inclined-plane of hydraulic oil cylinder driving to sting automatically tightly, oil cylinder 10-2 is fixed on the clamping dolly 10-1, oil cylinder piston promotes wedge block 10-3 and can seesaw, under the prevention of front cover match inclined-plane 10-4, produce laterally and move, can clamp pipe mouth 12, clamping dolly 10-1 is provided with the earrings 10-5 (referring to Fig. 2) that is connected with drawing oil cylinder piston rod 11-1.
Described upper and lower material mechanism is different from traditional structure, is to adopt track vertically to place, and hydraulic cylinder promotes to move up and down.
Shown in Figure 10,11, hydraulic system principle figure of the present invention, wherein: cylinder 1: stock shelf slides into and withdraws from, cylinder 2,3: stock shelf rises and descends cylinder 4: plug inserts and returns, cylinder 5: assembly advances, returns and pressurize, cylinder 6: piston advances and returns cylinder 7: clamp supplied materials, pressurize and unclamp cylinder 8: drawing, cylinder 9: blanking rack slides into and withdraws from, cylinder 10,11: blanking rack rises and descends.
System specialization:
1, drawing loop: the drawing stroke is bigger, drawing speed will be aspired for stability, the axiality of each parts is had relatively high expectations, adopt the single action piston cylinder, throttle grverning, pulling capacity require control accurately, so adopt pressure-reducing valve, oil return process speed does not require, for ease of control and systems linking adopt travel switch and pressure switch automatically
2, plug cylinder loop: drawing process keeps certain pressure, the travel switch and the pressure switch that adopt reversal valve and hydraulic control one-way valve and control to require.
3, assembly loop: be convenient to make assembly stressed all at the uniform velocity even, adopt two shunting synchronized cylinders, and keep constant voltage and sealing in the drawing process, adopt the accumulation of energy pressurize; Travel switch and pressure switch are adopted in control.
4, piston following loop: seat withstands the pipe tail before and after the drawing, and synchronous with tubing in drawing process, adopts decompression, overflow valve to form the loop.
5, Clamping Circuit: clamping force is provided, adopts accumulation of energy pressurize, check valve and pressure switch loop.
6, material loading, blanking rack loop: adopt the synchronized cylinder loop, adopt travel switch and optoelectronic position determinator; What stock shelf adopted is import one-way distributing valve, and what adopted in the blanking rack loop is outlet one-way distributing valve.
7, high-pressure system requires to have higher pressure, so adopt the multi-stage pressure regulating loop.
The course of work of apparatus of the present invention is:
Push away 3 actions of assembly oil cylinder, pulling assembly 5 separates with mould 8; Stock shelf 7 rises and makes pipe 12 in place; Push away 2 actions of plug oil cylinder plug 5-5 is inserted pipe, pipe is shifted onto in the mould 8, stock shelf 7 descends; Push away assembly oil cylinder 3 and promote assembly 5 to die holder 8-1, piston 5-3 servo-actuated simultaneously, cylinder body 5-1 and die holder 8-1 port closure are finished sealing; 1 action of push piston oil cylinder, the piston 5-3 in the promotion assembly 5 supports the afterbody of pipe; Clamping device 10 actions clamp pipe; Start drawing oil cylinder 11, the beginning drawing; Drawing cylinder oil pressure reaches setting pressure, and high-pressure oil pump work is chewed 2-3 by hydraulic oil and injected hydraulic oil through the oil through of plug 5-5 to plug and pipe material inner wall, inject hydraulic oil by pipe joint 8-7 to mould 8, form inside and outside pressure-bearing oil pocket, draw is finished in the pipe plastic deformation; Blanking rack 9 rises, and holds tubing; Clamping device 10 unclamps, and the blanking rack band production tube decline and put in place; Drawing oil cylinder 11 promotes clamping device 10 to die holder; 5 backhauls of assembly oil cylinder 3 pulling assemblys, piston 5-3 servo-actuated; Push piston oil cylinder 1, push away 2 backhauls of plug oil cylinder, make plug and piston reset, whole process of tube plug drawing mill finishes.