A kind of harmless mapping method of double shrouded wheel
Technical field
?the present invention relates to a kind of mapping method of impeller, relate in particular to a kind of harmless mapping method of double shrouded wheel, belong to measurement technique field.
Background technique
?impeller is the important composition member of pump, in the using process of pump, and impeller High Rotation Speed and directly contacting with liquid, its surface is very easily worn and corrodes, and need to often change.Because impeller shape, the size of various pumps are all different, cannot be general, conventionally can only buy new impeller from producer and change, but its cost is higher, especially the cost of import pump is higher.Therefore many times need existing impeller to survey and draw, the spatial form of the impeller blade obtaining according to mapping again, processes voluntarily new impeller and changes, and can significantly save like this and use and maintenance cost, and shorten engineering time, particularly solve a maintenance difficult problem for import pump.Meanwhile, in the production domesticization and other scientific research activity of pump, also need the hydraulic component of pump to survey and draw, and the mapping of impeller, be wherein most important be also a part for difficulty maximum.
?impeller is generally divided into open type, semi-open type and three kinds of forms of double shrouded wheel, and wherein double shrouded wheel is mainly made up of front shroud, back shroud, wheel hub and some blades, and the front and rear cover plate of impeller is clipped in the middle blade and wheel hub, forms an overall structure.Blade generally has two kinds of cylindrical and twisted shape, and wherein hydrodynamic performance excellence, the efficiency of twisted shape blade are high, cavitation performance good, are the main shapes of blade, but the shape of the impeller blade of spatial warping mapping difficulty is larger.While mapping closing impeller, wheel hub generally has respectively consistent thickness with cover plate, by common three-coordinates measuring machine mapping cover plate outer surface, can obtain the threedimensional model of cover plate and wheel hub, but blade is positioned in the middle of front and rear cover plate, general three-coordinates measuring machine can only record blade and import and export a fraction of shape in two ends, and imports and exports with interior interior shape because cavity is narrow and small, bending, distortion, even if adopt universal 3-d laser measurement instrument, also may directly record hardly.
?the mapping method of existing double shrouded wheel is generally divided into mapping and the two kinds of methods of harmless mapping of damaging.Damaging mapping method need fall (or rear) cover plate turning before impeller, carries out direct three-dimensional coordinates measurement to being exposed to outer blade.Damage mapping method simple, directly, validity is high, shortcoming is must destroy by mapping impeller, have and use or impeller that scientific research is worth, should not destroys can not adopt, and tool for turning cover is subject to the restriction of turning processing conditions for some, can not generally apply.
?the harmless mapping of double shrouded wheel, the harmless mapping of general employing adds matching design method.The method only need record some important parameters of impeller blade, as: inlet diameter, external diameter, exit width, exit angle etc., then calculate the comparative analysis of knowing parameter with oneself by waterpower, design the 3D shape of whole blade.The method surveying-drawing work amount is little, mapping difficulty is low, but need to there is the professional workforce of certain design level to design matching, calculate with analytical work amount greatly, and impeller and former impeller that matching completes cannot carry out size contrast, and workload and process are closer to redesign.
?the harmless mapping of double shrouded wheel can also adopt mold method, for the double shrouded wheel of large flow low-head, because wheel chamber's exit width is large, flow channel length is short, can fill pattern-making material to wheel chamber, after its solidifying, take out, obtain impeller internal chamber model, can directly utilize 3 D measuring instrument to survey and draw.This method can be surveyed and drawn impeller inner flow passage curve form easily, need not destroy blade wheel structure, does not also need to carry out matching designing and calculating, simple to operate, precision is high.But, for convenience of the indoor taking-up model of blade cavity from spatial warping, selected mold material must be elastomeric material, but the mould hardness that highly resilient material is made is low, in the time measuring, because self gravitation effect very easily produces distortion, thereby cause measuring accuracy to reduce, particularly, for the impeller of long and narrow runner, because amount of deformation is excessive, can not adopt the method at all.
Summary of the invention
?what the object of the invention is to exist for the mapping method of existing double shrouded wheel damages mapping and need destroy blade wheel structure, the design matching difficulty of harmless mapping is large, calculation analysis work amount is large, the model deformation of mold method mapping is excessive and affect the shortcomings and deficiencies of mapping precision, a kind of harmless mapping method of new double shrouded wheel is provided, solidify to filling from wheel chamber the punch making, the liquid of putting into equal densities again solidifying obtains die, thereby substantially eliminate the resiliently deformable of the model that self gravitation causes, significantly improve mapping precision, it is simple to operate, technical difficulty is low, degree of accuracy is high.
?for realizing above object, technical solution of the present invention is:
A harmless mapping method for double shrouded wheel, comprises the following steps:
A. chamber is imported and exported mapping, and selected any one impeller blade chamber is is also surveyed and drawn its import and export, obtains the ingress-egress point cloud curved surface of described blade chamber, and described some cloud curved surface comprises impeller central point;
B. fill and solidify, by one end sealing of described blade chamber, fill the liquid molding agent of high elasticity from the other end, after the liquid molding agent of described high elasticity solidifying, take out, obtain blade chamber punch;
C. curved surface reproduction, the surface of the blade chamber punch that step B is obtained applies isolating agent, puts into liquid pool, and the liquid in described liquid pool is identical with the density of material of described high elasticity liquid state molding agent, and percussion vibration punch all enters in pond in liquid it;
D. subdivision mapping, after the liquid curing in liquid pool, cuts solidified liquid in pond open along the maximum cross section of punch, and take out blade chamber punch, obtain the blade chamber die in liquid pool, then the blade chamber die of gained is surveyed and drawn, obtain blade chamber point cloud curved surface;
E. point cloud registration and integration, the some cloud curved surface that the blade chamber that some cloud curved surface and the steps A of the blade chamber that step D is obtained obtains is imported and exported splices mutually, forms complete twisted blade internal chamber curved surface, completes survey on impeller.
?a mapping method for double shrouded wheel, the liquid molding agent in described step B is liquid rubber.
?a mapping method for double shrouded wheel, the liquid molding agent in described step B is liquid room temperature vulcanized silicone rubber.
?a mapping method for double shrouded wheel, the liquid in the liquid pool described in step C is identical with the material of the liquid molding agent of the high elasticity described in step B.
?a mapping method for double shrouded wheel, the isolating agent in described step C is molybdenum sulfide isolating agent.
?a mapping method for double shrouded wheel, in described step C, the time of vibration punch is 2~10 minutes.
?a mapping method for double shrouded wheel, also comprises step B1 in described step B:
B1. after the indoor one end of described blade cavity seals, first insert filler rod from the other end, then filling liquid molding agent, after liquid molding agent solidifying, first extracts filler rod out, then takes out the blade chamber punch of moulding.
?a mapping method for double shrouded wheel, the diameter of described filler rod is 1/3~1/2 of blade chamber exit diameter, length is greater than the length of blade chamber.
?compared with prior art, beneficial effect of the present invention is:
1. mold mapping method of the present invention, for the chamber punch in the indoor filling molding of blade cavity, be positioned in the liquid pool of equal densities, according to the law of buoyancy, punch is subject to the buoyancy equating with self gravitation, thereby the buoyancy that punch is subject to has offseted its gravity, also eliminated the resiliently deformable that gravity produces, thereby made the die forming in punch and liquid pool accurately reappear the curve form of wheel chamber, the mapping carried out on this basis, its mapping precision is high, can meet usage requirement.
?2. mold mapping method of the present invention, be not directly used in mapping from the punch of blade chamber filling molding, but as model again solidifying with fluid-like state molding agent, obtain the die of blade chamber, then die is surveyed and drawn, because Action of Gravity Field causes the resiliently deformable of die much smaller than the resiliently deformable of punch, thereby adopt die to survey and draw, can effectively improve mapping precision.
?3. before the indoor filling elasticity of blade cavity film former, first insert filler rod, taking out before blade chamber punch, first extract filler rod out, thereby blade chamber punch is shunk to inner hollow space appropriateness, to facilitate taking-up punch.
?4. the harmless mapping method of impeller mold of the present invention, owing to having eliminated the resiliently deformable that model gravity causes, thereby can be applicable to the impeller of the long and narrow runner that common mold method can not survey and draw, thereby the harmless mapping of the mold that can extensively be suitable for all kinds of impellers, and simple to operate, technical difficulty is low, mapping precision is high.
Embodiment
Below in conjunction with specific embodiment, the present invention is further detailed explanation.
?the harmless mapping method of double shrouded wheel provided by the invention, belongs to the harmless mapping method of mold, comprises the step by A to E:
A. chamber is imported and exported mapping.Selected any one impeller blade chamber is surveyed and drawn its import and export, obtains this blade chamber ingress-egress point cloud curved surface, and this cloud curved surface comprises impeller central point.
?in steps A, the mapping that the import and export of blade chamber are carried out, can adopt common three-coordinates measuring machine, when measurement, should go deep into chamber as far as possible, the impeller central point that the mapped point cloud curved surface obtaining contains, the locating point splicing as the blade chamber point cloud curved surface obtaining with subsequent step.
?b. fill and solidify.By one end sealing of described blade chamber, fill the liquid molding agent of high elasticity from the other end, after described high elasticity liquid agent solidifying, take out, obtain blade chamber punch.
In step B, the liquid molding agent of high elasticity requires there is higher elasticity, so that take out from the blade chamber of spatial warping, for ensureing molding effect, the liquid molding agent of high elasticity can be selected liquid rubber, preferred liquid room temperature vulcanized silicone rubber.
?in step B, the sealing of blade cavity can be used little plank, wood particle and adhesive to carry out shutoff, and block-up position is controlled at and can directly surveys and draws in region; When sealing, impeller is stood up, the outlet of shutoff chamber upward; Pour into for convenience molding agent, can also near blade exit, surround one with cardboard and leak the draught animals.
?in step B, take out punch for further facilitating from the blade chamber of spatial warping, can also be after the indoor one end sealing of blade cavity, first insert filler rod from the other end, and then filling liquid molding agent, after liquid molding agent solidifying, first extract filler rod out, then take out the blade chamber punch of moulding.Liquid molding agent solidifying is extracted out after filler rod, and punch can shrink to internal modification, can from blade chamber, take out easily.The diameter of filler rod can be 1/3~1/2 of blade cavity chamber exit diameter, and length should be greater than the length of blade chamber.Take out when punch, can catch the silica gel at draught animals place by its whole extracting with Louing, clean out the foreign material that bond it on, cut away Lou draught animals silica gel, retain some impeller outer edge rib traces, facilitate follow-up amalgamation to locate, make it only show internal chamber shape.
?c. curved surface reproduction, the surface of the blade chamber punch that step B is obtained applies isolating agent, puts into liquid pool, and the liquid in described liquid pool is identical with the density of material of described high elasticity liquid state molding agent, and percussion vibration punch all enters in pond in liquid it.
?the object of step C is to overcome the distortion producing due to gravity after silica gel punch takes out.For convenience of the indoor taking-up model of blade cavity from spatial warping, selected mold material must be elastomeric material, but the mould hardness that highly resilient material is made is low, in the time measuring, because self gravitation effect very easily produces distortion, thereby cause measuring accuracy to reduce.Mold mapping method of the present invention, for the chamber punch in the indoor filling molding of blade cavity, be positioned in the liquid pool of equal densities, according to the law of buoyancy, punch is subject to the buoyancy equating with self gravitation, thereby the buoyancy that punch is subject to has offseted its gravity, also eliminated the resiliently deformable that gravity produces, thereby made the die forming in punch and liquid pool accurately reappear the curve form of wheel chamber, the mapping carried out on this basis, its mapping precision is high, can meet usage requirement.
?in step C, the liquid in liquid pool can also be selected the material identical with the liquid molding agent of high elasticity in step B, has both ensured that its density was identical, facilitates again it to select.
?in step C, the preferred molybdenum disulfide isolating agent of isolating agent that convex mould surface applies, its lubricated isolation effect is good.
?in step C, punch is put into behind liquid-state silicon gel pond, should be carried out at once percussion vibration, so that punch silica gel overcomes the viscous force of liquid-state silicon gel, and in complete free state.The time of vibration punch can be 2~10 minutes.
?d. subdivision mapping, after the liquid curing in liquid pool, cuts solidified liquid in pond open along the maximum cross section of punch, and take out blade chamber punch, obtain the blade chamber die in liquid pool, then the blade chamber die of gained is surveyed and drawn, obtain blade chamber point cloud curved surface.
?in step D, while cutting the solidified liquid in liquid pool, should enter cutter from punch maximum cross-section direction and position, try not to destroy the inside punch colloidal silica below maximum cross-section.
?in step D, when mapping, the subdivision body inside of die silica gel can be placed on upward on three-coordinate mapper and survey and draw, when mapping, tackle outer rim rib trace and get a little, as radial location benchmark.
?e. point cloud registration and integration, the some cloud curved surface that the blade chamber that some cloud curved surface and the steps A of the blade chamber that step D is obtained obtains is imported and exported splices mutually, forms complete twisted blade internal chamber curved surface, completes survey on impeller.
By reference to the accompanying drawings embodiments of the invention are illustrated above, but the present invention is not limited to above-described embodiment, in the ken possessing those of ordinary skill in the art, can also make a variety of changes not departing under aim prerequisite of the present invention, as for plain vane impeller, water from impeller suction inlet solid etc.