The equipment for bend-forging of crankshaft used for large boat crank throw and forging method
The invention belongs to the forging field, specifically be exactly a kind of equipment for bend-forging and forging and molding method of crankshaft used for large boat crank throw, this technology is obtained by the computer modeling technique of passing through the practical proof accuracy, and it is applicable to the bend-forging process of crankshaft used for large boat crank throw.
Shipping industry is a technology-intensive industries, is again labor-intensive production, and through construction accumulation for many years, Chinese shipbuilding industry has possessed the condition of rapid development.The shipbuilding industry of China has diesel engine production capacity from parts to the complete machine, but the critical component bent axle of high-power low-speed diesel engine dependence on import always.Diesel engine is the heart of large ship, and bent axle is the heart of engine.Only there are a few countries such as Japan, Korea S and Czech to produce in the world.Global supply falls short of demand situation has appearred in the bent axle product in recent years, brings very big pressure to domestic ships with Diesel Engine Plant, influences shipyard simultaneously and connects ship.The import crank axle for vessel not only costs an arm and a leg, and bad delivery, the passive situation of axles such as machine, machine such as " " ships has appearred, seriously restricted the development of China's shipbuilding industry, the supply of bent axle has become the bottleneck problem of restriction China shipping industry development, realizes that the production domesticization of bent axle is extremely urgent.Country is from economic security and build up the angle of world shipbuilding big country as early as possible, expects to solve as early as possible this key issue.
Common large-sized low-speed crankshaft of diesel engine (singly turns weight more than 5 tons, bearing weight is more than 50 tons) structure is semi-built-up, half built-up crank shaft is made up of free end axle journal, output axle journal, middle trunnion and crank throw hot jacket, output axle journal wherein, free end axle journal, middle trunnion blank shape are simple, and size is little, and crank throw is complex-shaped, size is big, it is the key of producing bent axle, in fact, the core technology of manufacturing semi-built-up crankshaft blank is exactly the forging and molding technology of crank throw blank.
Produce crank throw in the past and generally adopt the cut staple manufacturing, be about to steel ingot and be pressed into flat square with crank throw part appearance similar, process crank throw with the method for cutting and open shelves and crank-pin axle journal, this method not only allowance is very big, and cut off the forging fiber of crank-pin axle journal with the junction of cranking arm, reduced the ability of bent axle bearing load.The axle center defective of steel ingot (as loose, segregation etc.) is exposed to journal surface after the cutting, cause that stress concentrates, and influences fatigue strength.
Along with development according to the international shipping transport service, to the demand of boats and ships to maximize, the specialized direction development, the requirement of bent axle also turns to directions such as maximization, high strength, long-life to develop gradually.So the bent axle that adopts the cut staple manufactured can not satisfy the demand for development of boats and ships, bend-forging and two kinds of methods that prepare full fiber crank throw forging of die forging are arranged at present in the world, though die forging makes the forging forming situation good, allowance is little, the production efficiency height, but since every kind of mould can only the production specific model the crank throw forging, and the manufacture difficulty height of mould, all need before each forging and pressing mould is carried out preheating, change Mould operation flow process complexity, therefore in actual production, seldom adopt.The bend-forging method is easy and simple to handle comparatively speaking, and the product type scope is wide, and is less demanding to forging equipment, therefore is widely adopted in big production.
In the bend-forging technological process of existing crank throw, defectives such as horn mouth, fold cracks appear in crank throw internal arm easily, and defectives such as attenuate, waisting appear in the side of cranking arm easily, will cause the crank throw forging to scrap when serious.The preformed blank shape before crooked crank throw and the shape of mould are the main factors that after crank quality quality is forged in decision.
In order to study the deformation mechanism of crank bend forging process, some hammered work persons attempt adopting and actual crank throw has a certain proportion of plumbous original mold plan technology dimensionally, because plumbous and steel difference to some extent after all, be difficult to reflect that the plasticity of metal in the true blank deformation process flows and stressing conditions, the effect that plumbous original mold is intended playing is limited.
Along with the development of numerical simulation technology and modern forging theory, the especially three-dimensional temperature field simulation of forging numerical simulation technology, ess-strain field stimulation enter the practical stage.Develop a lot of simulation softwards (as: ABAQUS, ANSYS, MARC, DEFORM etc.) in the world and simulate the plastic deformation of metal process.According to analog result, can obtain the net shape and the size of forging, situation of change of the stress and strain that flow direction, the diverse location of the metal material that is obtained by simulation is suffered etc. can be predicted the type of forging defect and the position of generation.Utilize these analog results to carry out technological design and optimize the cycle to shorten trial production, save raw material, the rate of reducing the number of rejects and seconds, and then reduce production costs.
Summary of the invention
The object of the present invention is to provide a kind of equipment for bend-forging and forging method of crankshaft used for large boat crank throw, this technological operation is easy, can eliminate defectives such as the frequent horn mouth that occurs of crank bend forging process, fold cracks, waisting, attenuate, and reduce the allowance of crank throw blank forging greatly, guarantee the quality of crank throw forging, promote the performance and the service life of bent axle product.
Technical scheme of the present invention is:
The equipment for bend-forging of crankshaft used for large boat crank throw has patrix, crooked counterdie, last flat anvil, following flat anvil, plate, and patrix, plate lower end (working end that contacts with blank) are arcuate structure, and crooked counterdie inside cavity partly is a wedge structure.
Described crooked counterdie is the outward-dipping wedge-shaped groove structure in side, its laterally inclined angle [alpha]
Described plate both sides are provided with the baffle plate of blank landing in the switching process that can avoid finishing.
The bend-forging method of crankshaft used for large boat crank throw, whole forging and pressing process is totally four fire: first fire, steel ingot jumping-up, pulling are flat square billet, reach the forging ratio of appointment, fully eliminate as-cast structure, improve the compactness of material; Second fire, at blank middle part assigned address number seal, with blank along preformed blank shape that number the band boss is pulled out in the seal position; The 3rd fire adopts the V-arrangement mould blank middle part to be extruded the V-shaped groove of two symmetries; The 4th fire, be placed on the hydraulic press platen crooked counterdie is parallel with following flat anvil, last flat anvil direction is parallel with hydraulic press platen direction, treat with clamp blank to be placed on the crooked counterdie after blank is come out of the stove, adopt the robotic manipulation patrix, and assurance patrix, blank, counterdie centering, use flat anvil then and slowly press mould, blank is bent along following mold cavity, be bent to when the blank boss surface overlaps bottom the counterdie die cavity and stop bending, blank is broken away from counterdie, the rotation patrix drives blank and rotates 90 °, mobile platen makes flat anvil, following flat anvil and blank are in the hydraulic press operating space, flat anvil in the employing, following flat anvil is pressed the blank opening little, then along the crank-pin end to crank arm end with blank gradually upwards mold pressing lean on, and note upset, and make two to crank arm parallelly, and guarantee the length unanimity; Take out patrix, insert the plate finishing, blank two is cranked arm press to specified altitude assignment to plate, the finishing touch profile is taken out the plate completion.
Various forging defects such as the horn mouth that the present invention adopts computer modeling technique to predict crank throw blank forging process may to produce, fold cracks, waisting, attenuate, thus when formulating technology, avoided;
The present invention adopts the preformed blank of computer modeling technique design near-net-shape, the inside of crank throw forging that the crank throw processing parts is placed into final shaping is to determine the allowance of diverse location, the distortion forging that adopts the reversible deformation method will remove unnecessary allowance returns to not deformation state, thereby obtains having the preformed blank of optimum shape;
The present invention adopts computer modeling technique to design the shape of V-arrangement mould, upper die and lower die, plate.
The invention has the beneficial effects as follows:
1, adopt numerical simulation technology to simulate the curved forging process of crank throw, forecast the deficiency that traditional handicraft is forged the crank throw blank, predict defective locations such as horn mouth, fold cracks, waisting, attenuate, set up a kind of computer model that can accurately simulate the crank throw forging forming.
2, adopt computer modeling technique to obtain a kind of new-type crank throw forging and forming technology, this technology can alleviate various defectives such as the normal horn mouth that occurs of crank throw forging process, fold cracks, waisting, attenuate, and make operating process more easy, reduce the forging and pressing fire, improved the yield rate of forging.
3, adopt computer modeling technique to formulate the Forging Technology of crank throw, reduced test number (TN), reduced research expenditure.Can predict the net shape and the size of forging according to the analog computation result exactly, make the allowance of forging reduce 15～20% than traditional handicraft.
4, the computer model set up of the present invention and optimize the technology thinking and can be and forge that similar forging is provided fundamental basis and technology instructs.
5, adopt the inventive method, can produce MAN B ﹠amp; Whole type crankshaft crank parts of W (Man Enbiwei) and WNSD (Wa Xilan) diesel engine patents company.
6, the present invention can save material for the manufacturing of crankshaft used for large boat crank throw provides a kind of, shortens the production cycle, reduce the technology of allowance.The crank throw blank forming quality that adopts the present invention to make is good, the profile symmetry, and streamline is even, and allowance is even, and inside and outside quality and mechanical performance all meet international standards.
Description of drawings
Fig. 1 a-h is the crank throw curved forging process flow diagram.
Fig. 2 is the BENDING PROCESS simulation drawing.
Fig. 3 is for adopting patrix finishing process simulation figure.
Fig. 4 is for adopting plate finishing schematic diagram.
Fig. 5 a-b is that blank and the processing parts after being shaped compares; Fig. 5 a is a vertical view, and Fig. 5 b is a front view.
Fig. 6 is the crank throw blank photo after final the shaping.
Fig. 7 is a traditional handicraft BENDING PROCESS simulation drawing.
Fig. 8 is traditional handicraft finishing process simulation figure.
Fig. 9 a-b is that blank and the processing parts after traditional handicraft is shaped compares; Fig. 9 a is a vertical view, and Fig. 9 b is a front view.
Figure 10 is the crank throw blank photo of traditional handicraft forging and molding.
Figure 11 a-b is a crank throw processing parts schematic diagram; Figure 11 a is a front view, and Figure 11 b is the A-A cutaway view of Figure 11 a.
Figure 12 a-c is a crank throw preformed blank structural representation; Figure 12 a is a front view, and Figure 12 b is a vertical view, and Figure 12 c is a side view.
Figure 13 a-c is the patrix structural representation; Figure 13 a is a front view, and Figure 13 b is a vertical view, and Figure 13 c is a side view.
Figure 14 a-b is crooked counterdie structural representation; Figure 14 a is a front view, and Figure 14 b is a side view.
Figure 15 a-b is the plate structural representation; Figure 15 a is a front view, and Figure 15 b is a vertical view.
Figure 16 a-c is a V-arrangement mode structure schematic diagram; Figure 16 a is a front view, and Figure 16 b is a vertical view, and Figure 16 c is a side view.
Among the figure, the 1-patrix; The 2-blank; The 3-counterdie; The last flat anvil of 4-; Flat anvil under the 5-; The 6-plate; 7-manipulator (or sleeve); The 8-processing parts; Blank after 9-is shaped; 10-V shape groove; 11-patrix deep-slotted chip breaker; 12-plate deep-slotted chip breaker; 13-V shape mould; The 14-crank-pin.
The specific embodiment
Below in conjunction with drawings and Examples in detail the present invention is described in detail.
The technical process of the bend-forging method of crank throw (forging and pressing flow process) is: first fire, steel ingot jumping-up, pulling are flat square billet, and reach the forging ratio of appointment, purpose is fully to eliminate as-cast structure, improves the compactness of material; Second fire, at blank middle part assigned address number seal (promptly employings seal cutter is at the assigned address del groove that to cut two degree of depth be 150～200mm), with blank along number printing the preformed blank shape that the band boss is pulled out in the position; The 3rd fire adopts the V-arrangement mould blank middle part to be extruded the V-shaped groove of two symmetries; The 4th fire (referring to Fig. 1), with crooked counterdie 3 and following flat anvil 5 parallel being placed on the hydraulic press platen, last flat anvil 4 directions are parallel with hydraulic press platen direction, treat with clamp blank to be placed on the crooked counterdie 3 after blank is come out of the stove, adopt manipulator 7 to handle patrix 1, and assurance patrix 1, blank 2, counterdie 3 centerings (referring to Fig. 1 a), use flat anvil 4 then and slowly press mould 1, blank 2 is bent along counterdie 3 inner chambers, be bent to that (crooked counterdie was the outward-dipping wedge-shaped groove structure in side when blank boss surface and counterdie die cavity bottom overlapped, its laterally inclined angle [alpha] counterdie=7-13 °) stop bending (referring to Fig. 1 b), then blank 2 is broken away from counterdie 3, rotation patrix 1 drives blank 2 and rotates 90 °, mobile platen, make flat anvil 4, following flat anvil 5 and blank 2 are in (referring to Fig. 1 c) in the hydraulic press operating space, flat anvil 4 in the employing, following flat anvil 5 is pressed the blank opening little, (referring to Fig. 1 d) presses (referring to Fig. 1 e) to patrix 1 along crank-pin 14 ends to the end of cranking arm with blank 2 then gradually, and note overturning, make two to crank arm parallelly, and guarantee the length unanimity.Take out patrix 1, insert plate 6 finishing (referring to Fig. 1 f), 2 liang of blanks are cranked arm press to specified altitude assignment (referring to Fig. 1 g) to plate 6, the finishing touch profile is taken out plate 6 completions (referring to Fig. 1 h).
The present invention has developed the technology of crankshaft used for large boat crank throw blank bend-forging process, and its main contents comprise:
(1) adopt computer modeling technique to predict common forging defect: because crank throw blank volume is big, the deformation technique complexity, whole forging process needs 4～6 fire, and is unpredictable to the shaping situation of blank in whole forging flow process only according to the forging experience.And the employing computer modeling technique, not only can observe the flow of metal situation of diverse location, obtain the evolution in stress field, strain field and the temperature field of whole forging process, understand the compacting mechanism of forging better, and can dope various forging defects such as horn mouth that crank throw blank forging process may produce, fold cracks, waisting, attenuate, thereby avoided when formulating technology, therefore, computer simulation can be the actual process design theoretical direction is provided.By the repetition test on computer platform, can determine a kind of help guaranteeing forging forming quality, Forging Technology easy and simple to handle.The defective schematic diagram that Fig. 7～10 produce for the traditional Forging Technology that adopts computer simulation to obtain.
(2) adopt computer modeling technique to design the preformed blank of near-net-shape: in the computer simulation process, at first the crank throw processing parts to be placed into the inside of the crank throw forging of final shaping, to adopt the technology of quantizing to determine the allowance of diverse location; Then allowance unnecessary on the crank throw forging is removed, the distortion forging that adopts the reversible deformation method will remove unnecessary allowance returns to not deformation state, just obtain having the preformed blank of optimum shape, the characteristics of this preformed blank are the allowance minimums that can make whole forging; At last, design a kind of practicable blank-making method, make practical operation to prepare the preformed blank 2 of approaching this shape under low-cost, the simple and efficient prerequisite satisfying, shown in Figure 12 a-c, adopt the V-arrangement mould blank middle part to be extruded the V-shaped groove 10 of two symmetries, can make crank throw blank internal arm in BENDING PROCESS that material does not take place like this and pile up, avoid producing horn mouth and crack defect.
(3) design of crank bend forging and finishing mold: metal flow rule when crank throw curved has been determined the shape (Figure 15 a-b) of V-arrangement mould 13 (Figure 16 a-c), patrix 1 (Figure 13 a-c), counterdie 3 (Figure 14 a-b), plate 6, after the computer simulation check, obtain various Mould design sizes.Wherein patrix 1, plate 6 lower ends are arcuate structure, patrix 1 lower end (working end that contacts with blank) is a patrix deep-slotted chip breaker 11, plate 6 lower ends (working end that contacts with blank) are plate deep-slotted chip breaker 12, can make the crank throw blank behind the forging and molding be easy to processing at the internal arm position like this; Counterdie 3 inside cavity partly are wedge shape, can make the blank outer surface of cranking arm when bending paste mould like this, reduce the waisting and the attenuate of side, and the blank crooked inner surface is born against to patrix, thereby improve blank internal arm quality; Designs baffle plate in plate both sides can be avoided blank landing in the switching process of finishing.
(4) definite principle of key process parameter: whole Forging Technology has been designed the technological operation flow process, reduced the forging and pressing fire as far as possible, made operation more easy, and saved the energy, improved production efficiency.
The forging parts of present embodiment is MAN B ﹠amp; The 6S60MC-C model crankshaft crank of W patents company, the blank material is S34MnV, the heavy 16t of blank, blank heating temperature is 1250 ℃, mold material is 35CrMo, whole forging process carries out on ton water hydraulic press, when crooked on the hydraulic press anvil depress speed and be about 20mm/s, whole bending, finishing process are gone through about 40min.Analog result crooked, the finishing process is seen Fig. 2-4, and Fig. 5 a-b compares for blank 9 (grid lines part) after being shaped and processing parts 8 (outline line part), and as seen from the figure, whole forging allowance is more even, has eliminated the horn mouth defective of blank.Fig. 6 is the crank throw blank photo after final the shaping, and as seen from the figure, the crank throw blank forming quality that adopts the present invention to make is good, the profile symmetry, and streamline is even, and allowance is even, and inside and outside quality and mechanical performance all meet international standards.Be depicted as the structural representation of crank throw processing parts 8 as Figure 11 a-b.
Fig. 7 is for adopting the simulation drawing of traditional handicraft BENDING PROCESS, Fig. 8 is traditional handicraft finishing process simulation figure, Fig. 9 a-b is that the blank 9 (grid lines part) after traditional handicraft is shaped compares with processing parts 8 (outline line part), Figure 10 forges the crank throw blank photo that obtains for traditional handicraft, and the design shortcoming of this technology is:
(1) the preformed blank design is unreasonable, and crank throw internal arm material is piled up in BENDING PROCESS, and to the both sides expansion, causes crank throw curved inner surface folding serious, occurs defectives such as horn mouth, fold cracks easily at this position blank.
(2) mold shape design is unreasonable, and mould can not effectively be pasted in the blank side in the BENDING PROCESS, and it is little to contact area between blank and mould, and defectives such as attenuate, waisting appear in the side of cranking arm easily, cause the allowance deficiency.