CN117862318A - Longitudinal pulling method for large single-double curvature composite surface skin - Google Patents
Longitudinal pulling method for large single-double curvature composite surface skin Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 94
- 239000002131 composite material Substances 0.000 title claims abstract description 14
- 238000003466 welding Methods 0.000 claims abstract description 48
- 238000003825 pressing Methods 0.000 claims abstract description 12
- 238000005520 cutting process Methods 0.000 claims abstract description 8
- 229910000838 Al alloy Inorganic materials 0.000 claims description 35
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 30
- 229910052782 aluminium Inorganic materials 0.000 claims description 30
- 229910000831 Steel Inorganic materials 0.000 claims description 22
- 239000010959 steel Substances 0.000 claims description 22
- 238000003754 machining Methods 0.000 claims description 19
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 238000005553 drilling Methods 0.000 claims description 10
- 238000004364 calculation method Methods 0.000 claims description 5
- 239000013585 weight reducing agent Substances 0.000 claims description 5
- 238000009434 installation Methods 0.000 claims description 4
- 210000001503 joint Anatomy 0.000 claims description 4
- 239000003550 marker Substances 0.000 claims description 4
- 238000010276 construction Methods 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 3
- 229910001172 neodymium magnet Inorganic materials 0.000 claims description 3
- 239000000725 suspension Substances 0.000 claims description 3
- 230000006835 compression Effects 0.000 claims description 2
- 238000007906 compression Methods 0.000 claims description 2
- 238000003780 insertion Methods 0.000 claims 1
- 230000037431 insertion Effects 0.000 claims 1
- 238000013461 design Methods 0.000 abstract description 6
- 238000005056 compaction Methods 0.000 abstract description 3
- 238000004080 punching Methods 0.000 abstract description 2
- 239000002994 raw material Substances 0.000 abstract description 2
- 239000000463 material Substances 0.000 description 17
- 238000012545 processing Methods 0.000 description 10
- 229910001208 Crucible steel Inorganic materials 0.000 description 6
- 239000004411 aluminium Substances 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 230000000712 assembly Effects 0.000 description 5
- 238000000429 assembly Methods 0.000 description 5
- 230000009977 dual effect Effects 0.000 description 4
- 238000005493 welding type Methods 0.000 description 4
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- 238000003801 milling Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- FGRBYDKOBBBPOI-UHFFFAOYSA-N 10,10-dioxo-2-[4-(N-phenylanilino)phenyl]thioxanthen-9-one Chemical compound O=C1c2ccccc2S(=O)(=O)c2ccc(cc12)-c1ccc(cc1)N(c1ccccc1)c1ccccc1 FGRBYDKOBBBPOI-UHFFFAOYSA-N 0.000 description 1
- 230000001174 ascending effect Effects 0.000 description 1
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- 229910052796 boron Inorganic materials 0.000 description 1
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- 238000009827 uniform distribution Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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Abstract
The invention relates to a longitudinal drawing method of a large single-double curvature composite surface skin, belonging to the technical scheme and equipment design field. The invention realizes the longitudinal drawing forming of the single-double curvature composite surface skin by adopting the tightening belt to realize the compaction, and an upper pressing die is not adopted any more, thereby not only reducing the process flow, but also reducing the cost. By adopting the working molded surface and the supporting structure formed by splicing and welding, a new design structure of the skin punching and cutting clamp is developed on the premise of not affecting the use requirement. The final weight of the welded structure skin stretching die is lighter than that of the traditional cast structure, and the utilization rate of raw materials is also improved. Meanwhile, a process hole locator, a skin locating scriber and a multifunctional base are additionally arranged at the proper position of the die, and the multifunctional base comprises a die locating function, a die pitching adjusting function and a skin binding function. The skin locating hole device is used for locating the device as a side surface of the die, and does not occupy the working molded surface of the die.
Description
Technical Field
The invention relates to a large single-double curvature composite surface skin longitudinal drawing method, in particular to a large single-double curvature complex working surface skin longitudinal drawing method and a matched device, belonging to the technical scheme and equipment design field.
Background
The aluminum alloy skin stretching forming is a mainstream manufacturing mode of aircraft skin parts, and is a process method for stretching an aluminum alloy sheet to two sides by adopting skin stretching equipment and simultaneously attaching the aluminum alloy sheet to a die. In the skin stretching process, the skin needs to be stretched along the die surface in the whole process until the skin is completely attached to the die surface. For the longitudinal drawing process of the large single-double curvature composite surface skin, the traditional method adopts a casting die and a pressing device to assist in drawing and forming, the manufacturing method of the single traditional die has high cost, complex process, heavy weight of the pressing device, complex structure and cost waste, and if the pressing device is omitted, the process flow is saved, and the cost is saved.
The invention adopts a special skin stretching method, and realizes the stretching forming by matching with a special mold, a bottom plate device, a tightening belt and other devices.
Disclosure of Invention
The invention provides a longitudinal drawing process method and a matched device for a large single-double-curvature composite surface skin. The matching device comprises a die body, a die bottom plate, a skin scribing device and a skin process hole locator. The mold is divided into three sections, the steel thick plate material is spliced and welded to form the skin stretching mold, the inclined supporting bottom plate is used for controlling the working surface of the mold, and the hinge structure is used for forming the skin scribing device.
Referring to fig. 1, 2 and 3, a large splice welding aluminum alloy skin stretching die and a matched device thereof have the overall length of about 5-10 meters, the width of 1-2 meters and the height of about 400-1000mm, and comprise a die body, a die bottom plate, a skin scribing device and a skin process hole locator, wherein the die bottom plate falls on a skin stretching equipment workbench, and when in longitudinal stretching, the die bottom plate needs to fall on the upper surfaces of two skin stretching equipment workbench. The large splicing and welding type aluminum alloy skin stretching die 1 consists of three sections along the length direction, namely a single-curvature die split, a middle double-curvature die split and an end double-curvature die split which are sequentially connected. The whole body is of an asymmetric structure, and the single-curvature die is also of an asymmetric structure in order to meet the whole weight reduction requirement. The three split structures comprise a supporting frame formed by splicing and welding longitudinal plugboards and transverse plugboards and a molded surface spliced board covered on the supporting frame.
Referring to fig. 2 and 3, when the skin stretching die is used, the skin material is aluminum alloy, the die is stressed mainly by compressive stress, so that the skin stretching die needs to have higher strength, a middle-high strength thick steel plate is used as a forming surface, a cast steel plate is used as a support, an integral structure is built through splicing and inserting at certain intervals, and the strength requirement of the skin stretching die can be met by adopting a local welding mode. In the example, the molded surface jointed board material is 45 # steel, and the supporting plate material is Q235 cast steel.
Referring to fig. 4, taking the split of the middle double-curvature mold as an example, the double-curvature molded surface jointed boards form a working surface of the skin stretching mold, the curvature of the longitudinal cross section of the working surface is equal to the curvature of the joint surface of the skin part, a plurality of longitudinal pinboards and transverse pinboards are positioned below the double-curvature molded surface jointed boards, the construction of a mold supporting frame is completed by adopting a longitudinal and transverse splicing welding mode, and the working surface formed by the double-curvature molded surface jointed boards is supported.
Referring to fig. 5 and 6, the strength of the mold is determined by the longitudinal and transverse plugging plates, the thickness and the spacing of the mold support frame, in order to meet the requirement of compressive stress strength, the longitudinal support plate a inside the middle section of the mold, the longitudinal support plate B inside the middle section of the mold, the longitudinal support plate C inside the middle section of the mold, the longitudinal frame a of the middle section of the mold and the longitudinal frame B of the middle section of the mold are spaced by about 500mm, the transverse support plate a inside the middle section of the mold, the transverse support plate B inside the middle section of the mold, the transverse frame a of the middle section of the mold and the transverse frame B of the middle section of the mold are spaced by about 800mm, and the middle double-curvature mold is split to realize the plugging connection of the support frame by adopting 5 longitudinal plugging plates and 4 transverse plugging plate uniform distribution patterns, and the thickness of the support plate is about 30mm. The longitudinal support plates A, B, C and A, B of the middle section of the mould support frame are inserted in a cross shape, the longitudinal frames A, B and B of the middle section of the four-side frame mould are in L-shaped butt joint to form a square outer frame, the support splice plates 11-15 in the frame and the frame support plates 16-19 are inserted in a T shape, the T-shaped transverse edges are frame plates 16-19, and the vertical edges are the inner splice plates 11-15. Each longitudinal plugboard and each transverse plugboard are correspondingly provided with a butting notch, the width of each notch is about 0.5mm wider than that of each butting board, the depth of each notch is about half of the height of each jointed board at the position, and the notch is flexibly controlled according to practical conditions. The weight reducing holes are formed in the inner transverse supporting plate A of the middle section of the transverse supporting plate die, the inner transverse supporting plate B of the middle section of the die, the transverse frame A of the middle section of the die and the transverse frame B of the middle section of the die, so that the weight is reduced, and the longitudinal supporting plate is provided with the weight reducing holes: the longitudinal support plate A in the middle section of the die, the longitudinal support plate B in the middle section of the die, the longitudinal support plate C in the middle section of the die, the longitudinal frame A in the middle section of the die and the longitudinal frame B in the middle section of the die are taken into consideration, and no lightening hole is formed. After the supporting frame is inserted, a vertical square is adopted to determine a vertical supporting plate A inside a middle section of a vertical plugboard die, a vertical supporting plate B inside a middle section of the die, a vertical supporting plate C inside the middle section of the die, a vertical frame A of the middle section of the die and a vertical frame B of the middle section of the die are vertical to a horizontal supporting plate A inside the middle section of the horizontal plugboard die, a horizontal supporting plate B inside the middle section of the die, a horizontal frame A of the middle section of the die and a horizontal frame B of the middle section of the die are vertical to each other, the supporting frame is fixed through partial welding, the whole frame is moved to a machining table after the fixing, the machining of the connecting part of the supporting frame and a working double-curvature molded surface jointed board is completed, namely, the lap joint surfaces of all the tops of the vertical supporting plates and the working double-curvature molded surface jointed board are machined to the final size according to design contours before the supporting frame is inserted, and a welding process structure is reserved.
Referring to fig. 5, 6 and 7, the dual curvature working profile structure is formed by splicing and welding dual curvature profile panels, and the working profile is dual curvature, so that the profile panel combination is complex, namely, transverse splicing and longitudinal splicing are needed. The surface rough machining of all working surface jointed boards and reserving allowance, the other five surfaces are all machined to the final size, all supporting surfaces of the double-curvature surface jointed boards and all longitudinal and transverse supporting plates are planes, the double-curvature surface jointed boards are convenient to lap on a supporting frame, the longitudinal two end surfaces of the supporting frame and the supporting surface of the frame are used as positioning references, and the surface jointed boards are placed on the supporting frame one by one. Since the compressive stress requirement must be met, the minimum thickness of the double-curvature molded surface jointed board after processing cannot be lower than a certain fixed value, and in the example, the thickness cannot be determined to be lower than 30mm according to the magnitude of the compressive stress and the strength of the used materials. The number of the double-curvature molded surface jointed boards is larger according to the curvature of the molded surface and the thickness of the woolen board, and the larger the curvature of the molded surface is, the larger the number of the molded surface jointed boards is, and conversely, the smaller the number of the molded surface jointed boards is; the curvature of the surface is certain, the thicker the woolen is, the less the needed splicing quantity is, and conversely, the more the woolen is, the thicker the woolen is, and the more the material is removed by the surface processing. In the example, the machining cutting amount and the welding workload are comprehensively considered, and the number of the transverse spliced 7 blocks and the number of the longitudinal spliced blocks are finally determined to be 1-3. When the double-curvature molded surface jointed boards are spliced longitudinally, if one transverse supporting plate in the supporting frame bears the molded surface jointed boards with two different molded surfaces longitudinally, the transverse supporting plate is designed to be of a double-layer structure along the longitudinal direction, such as 11 and 12, and the middle section transverse frame A and the middle section transverse frame B of the two end transverse supporting plate die only support one group of molded surface jointed boards longitudinally, and are not designed to be of a double-layer structure. When the double-curvature molded surface jointed boards are transversely spliced, the two molded surface jointed boards are placed and clamped one by one from the middle to the two sides according to the supporting plate structure, the two molded surface jointed boards at the edge in the transverse direction transversely extend out of the supporting frame to form a tiny eave shape, the extending amount is determined according to the allowance of the skin stretching process, generally 5-50mm, the molded surface jointed boards are finally processed into round corners, and the radius of the round corners is controlled to be R20mm. After the splicing of the jointed boards of the working molded surface is completed, local welding is carried out, local joints of the molded surface are filled by welding, and the finish machining of the working molded surface is completed by integral machining after the three parts of the split single-curvature mold, the split middle double-curvature mold and the split end double-curvature mold are connected.
The whole thickness of the end double curvature die split body is thinner and thinner along with the longitudinal and transverse curvature extension of the shape surface, especially the corner position of the end double curvature die, if the corner position is thickened, the whole height of the die 1 is increased, the die is overweight, and the manufacturing and carrying economy is poor. The width of the large-scale skin is gradually reduced in the double curvature section, the corner position of the end double curvature mould is generally outside the contour of the skin, and in order to ensure the manufacturability of stretching the skin and meet the weight reduction requirement of the mould, the mould part outside the contour of the skin is cut off, and the longitudinal edge area of the working profile is smoothly transited. The supporting frames are properly adjusted, the longitudinal edge supporting plates corresponding to the corners are arranged into one piece, two pieces or more pieces, and are spliced into a fold line shape, and the longitudinal edge supporting plates are directly positioned and clamped for welding due to the fact that the height is low without inserting connection.
The single-curvature die split structure is relatively simple, the supporting frame is spliced and welded by the longitudinal and transverse supporting plates, the curvature change of the molded surface spliced plate exists in a single direction, namely, the molded surface spliced plate is in a straight line direction in the longitudinal direction, and a certain curvature exists only in the transverse direction. The steel plate with the length slightly larger than the longitudinal length of the single curvature section can be utilized to splice the cambered surface similar to the skin mold from the center to the two sides side by side section by section along the transverse direction, the steel plate is built on a supporting structure which utilizes the cast steel plate to splice and weld the skin stretching mold, then the welding work is completed, wherein the transverse supporting plate is only lapped with one group of molded surface jointed plates, and the molded surface structure is relatively simple.
After the splicing and welding of each supporting frame are completed, the three parts are required to be subjected to heat treatment to eliminate welding stress, then the three parts are moved to a machining platform to finish the surface which is overlapped with the molded surface spliced plate, and after the welding of the three parts and the molded surface spliced plate is completed, the welding stress is eliminated by heat treatment.
After each part is completed, three parts of connection work needs to be realized. The connection of the three parts is realized by two connection technologies, and the three sections of die connecting bolt assemblies are adopted for connection. According to the method, through strength calculation, bolt assemblies with the diameter of 20mm are uniformly distributed on the opposite interfaces, and 16 sets of three-section die connecting bolt assemblies are arranged on each two pairs of connecting interfaces. And after the bolts are connected, a groove welding process is adopted to realize three-section connection, the whole heat treatment is carried out after welding to eliminate stress, and finally, the accurate processing of the skin stretching molded surface is realized after the bolts are moved to a machining platform.
To ensure the integrity and accuracy of the working profile of the milling fixture, the working profile must be finished after welding. Therefore, the long beam, the rough supporting plate and the end bevel angle of the welded jointed board should be processed first. And then, a supporting structure is welded by using a large welding platform, the supporting structure comprises a reinforcing plate, and the supporting end face is finished. And then welding the working molded surface jointed boards, taking the middle jointed board as a reference, and welding the jointed boards on two sides. And finally, integrally processing the working profile, and cutting the cambered surface by adopting a numerical control punch and drilling.
Two mould middle section locating notches are formed in the longitudinal frame plate bottom through direction of the split longitudinal frame plate bottom of the middle double-curvature mould, are used for locating a matched mould bottom plate and carrying fork openings of a forklift, and a single-curvature section end frame locating notch is formed in the frame plate bottom of the split end part of the split double-curvature mould in the integral mould 1 and is used for locating the matched mould bottom plate.
The bottom plate comprises two rectangular aluminum alloy bottom plates, four aluminum inclined support plates, three aluminum mold positioning blocks and a plurality of steel hanging rings, wherein the four aluminum inclined support plates are used for bridging the two rectangular aluminum alloy bottom plates. Four aluminium inclined support plates are arranged above two rectangular aluminium alloy bottom plates according to reasonable positions, the upper surfaces of the four aluminium inclined support plates form an integral plane to support the die 1, and the inclined angle of the aluminium inclined support plates is formulated according to a skin stretching process to meet process requirements. Each aluminum inclined support plate is connected by 8 bolts 29 with the diameter of M24mm, countersunk sockets are formed in the upper parts of the bolt holes of the inclined support plates, and the bolts penetrate through the bolt holes of the aluminum inclined support plates and are screwed into threaded holes of the rectangular aluminum alloy bottom plate. The three positioning blocks comprise two transverse long positioning blocks and a longitudinal short positioning block, wherein the long positioning blocks are connected with the aluminum inclined support plate through six M20 bolts 30, countersunk sockets are formed in the upper parts of the long positioning block bolt holes, and the bolts penetrate through the long positioning block bolt holes and are screwed into threaded holes of the aluminum inclined support plate. One short positioning block adopts two M20 bolts to realize countersunk head threaded connection, and the connection mode is the same as the above. The mold positioning groove is sleeved with the long positioning block and the short positioning block of the bottom plate to position the mold on the bottom plate. The lifting rings are uniformly distributed on the end faces of two longitudinal sides of the bottom plate and are used for applying a binding belt to tighten the skin above the mold in the skin stretching process, so that the process requirement is met, the lifting rings are of stainless steel M24 specifications, the lifting rings are used as binding belt fixing tools for a single-curvature section compacting method in the large skin stretching process for the first time, and as the lifting rings are symmetrical along a longitudinal center axis, the binding belt is tightly fixed in an embodiment mode that one end of a wagon binding belt with the specification of 5T is hung on a lifting ring in a hanging mode, the other end of the binding belt is hung on the lifting ring at the symmetrical position or nearby, and binding and compacting of the skin and the mold are completed by manpower.
Referring to fig. 11, four skin marking devices are arranged at four corners of a die, and the four skin marking devices comprise a die fixing block, a hinge fixing plate, a skin marking plate and a hinge shaft, wherein the die fixing block is fixedly arranged on a side plate surface of the die through two screw connections, the hinge fixing plate is fixedly arranged on the outer surface of the die fixing block through two screw connections, the skin marking plate is connected with the hinge fixing plate through the hinge shaft, the other end of the skin marking plate can freely rotate along the hinge shaft, can be attached to the skin surface and can also rotate to be detached. When the marking pen is attached to the surface of the skin, marking lines can be drawn on the skin along the edge outline of the marking pen, a set of skin marking device is respectively arranged at four corners of the mold, and the edge of the mold-shaped surface jointed board extends out of the edge of the side plate of the mold, so that the marking board is arranged to be curved so as to avoid the edge of the skin. In this example, three sets of skin scoring devices are arranged due to the die corner cut.
Referring to fig. 12, the skin process hole locator is a process hole locator for skin during process circulation, generally two skin process hole locators are arranged, high-point flat areas at two longitudinal ends of a mold surface are pressed on the skin, and a conventional process hole locator is arranged on the mold surface and is close to the longitudinal edge. However, the invention is arranged on the support plates at the two longitudinal end surfaces of the die 1, so that the die length can be effectively reduced. The skin process hole positioner comprises a process hole positioning driller, two positioning pins, a drill bushing and a positioning auxiliary block, wherein the two positioning pins and the drill bushing are embedded on the process hole positioning driller and are connected in interference fit, the positioning auxiliary block is connected with the side surface of a frame plate of a die 1 through screws, two positioning holes are formed in the positioning auxiliary block, the skin process hole positioner can be positioned, installed and detached with the positioning auxiliary block through the two positioning pins at any time, and the position of the process hole is determined according to the requirements of skin manufacturing process. The two sets of positioners are not identical, and are characterized in that the contact surface of the two sets of positioners is completely and optimally attached to the contact surface of the skin according to the shape surface of the skin, if the process hole positioning driller and the contact surface of the skin are arranged to be planar, the two sets of positioners are parallel to the longitudinal ridge line of the skin as far as possible, the positioning pins are parallel to the drill bushing, and all the positioning pins of the two sets of process hole positioners of the skin longitudinally front and back are parallel to the drill bushing, in the embodiment, are not only parallel, but also perpendicular to the bottom surface of the die.
Referring to fig. 13, 14, 15 and 16, in order to freely adjust the pitching angle of the die, the invention adopts two sets of hinge structures, namely a hinge structure A and a hinge structure B, which are not completely identical in structure and comprise a hinge shaft, a hinge lower platform and a hinge upper platform, wherein the hinge shaft is a steel material optical axis with the diameter of 80mm, and two ends are threaded, and the hinge shaft is connected through an internal thread sleeve to realize axial limit. The hinge structure A upper platform is of an integrated structure, aluminum materials, the hinge shaft hole is inlaid with a coaxial steel bushing, the bushing is in interference connection, the thickness of the bushing is 10mm, the hinge upper platform is totally four inserting lugs, four connecting holes are formed in the hinge upper platform, the hinge lower platform is of the same material, the coaxial steel bushing is also in interference installation, the total number of the inserting lugs is six, the hole shaft is in clearance fit, and the clearance is 0.5mm on one side. The difference between the hinge structure A and the hinge structure B is that the through hole of the upper platform insert lug of the hinge structure B is set into a slotted hole, a long round steel bushing is installed in an interference mode, and the thickness of the bushing is 10mm. Two sets of hinge structures are installed on two skin stretching equipment work tables of skin stretching equipment through a hinge lower platform, are fixed through T-shaped bolts, are installed on the lower plane of a die base through a hinge upper platform and an upper platform of a hinge structure B, are connected with a rectangular aluminum alloy bottom plate through bolts, pass through countersunk holes of the rectangular aluminum alloy bottom plate and are screwed into threads of the platform, installation is achieved, the rectangular aluminum alloy bottom plate drives pitching of the die 1 to be achieved through independent lifting of the two skin stretching equipment work tables, and when the bottom plate mechanism is adopted, a die positioning block is directly connected to the upper surface of the rectangular aluminum alloy bottom plate and is connected through bolts, and the bolts are screwed into threads of the rectangular aluminum alloy bottom plate from the positioning block countersunk holes Kong Shenru. Because the upper platform or the lower platform of the hinge structure is difficult to integrally manufacture, the hinge structure can be manufactured in a segmented mode, and each segment is provided with 1 lug, 2 lugs or three lugs, and the coaxiality of lug holes is ensured through the integral assembly of the lug holes on the bottom plate of the die.
The skin stretching concrete implementation method comprises the following steps: see fig. 1, 11, 12, 17. When the skin is longitudinally pulled, the lifting of the two skin stretching equipment work tables is respectively adjusted, the pitching angle of the die is controlled, a proper angle is found, the skin is placed on the surface of the die, and the skin is clamped in a skin stretching machine. When stretching, the two skin stretching equipment work tables are controlled to lift respectively, the pitching of the die 1 is adjusted, and along with stretching operation, the pitching angle of the die 1 reaches a preset value, and the lifting of the skin stretching equipment work tables is stopped. The compaction of the skin and the mould 1 is realized through the binding bands above the skin, hooks at two ends of the binding bands are respectively hung in the hanging rings of the bottom plate 2, the hanging rings are matched in pairs for use, the symmetrical positions of the hanging rings and the skin are respectively crossed, 1 binding band can be hung on each pair of hanging rings according to actual stretching working conditions, binding can also be realized by spacing a pair of hanging rings, the distance between the hanging rings is 200mm in the example, in order to ensure the accuracy of the stretching surface of the skin, the binding area is mainly a single curvature section of the skin, binding is not needed for double curvature parts, the stretching risk of the skin is considered, the double curvature sections can be properly bound, and the skin is still protected to be attached to the mould 1 after the end part is broken. Along with the stretch of the skin, the skin is gradually and completely attached to the die 1, the binding belt is tightened again, the skin and the die 1 are pressurized, a tension tester can be added at the suspension section of the binding belt, namely the section between the binding belt and the contact skin, tension monitoring of the binding belt is achieved, the tension tester adopts a conventional two-end hook tester meeting JJG455-2000 standard in the market, the lower limit of the measuring range is not lower than 500Kg, the maximum measuring range is about 10T, one end of the hook is connected with the hook of the binding belt during measurement, and the other end of the hook is directly hung on the hanging ring. When the skin is stretched, the skin scribing plate is turned over to be attached to the skin, and when the skin scribing plate is attached to the surface of the skin, marking lines are drawn on the skin along the rectangular edge outline of the skin by using a marker pen, and a set of skin scribing devices are respectively arranged at four corners of the die, so that corresponding marking lines are respectively drawn. In this example, since one corner of the mold is cut off, three sets of skin scribing devices are arranged, and thus 3 corresponding mark lines are drawn. And after the skin is unloaded, removing each binding belt, removing the skin and cutting off redundant parts of the edges, so that the edges of the skin are all in the contour of the shape surface of the die 1. The positioning of the skin on the die is realized by combining the marking lines on the corners with data calculation, more than 4 strong magnet pressing blocks are arranged above the skin, the clamping of the skin and the die is realized, the strong magnet pressing blocks adopt the strong magnets of neodymium iron boron magnet Dan Dalao on the market, the attraction force is not less than 200Kg, and the lifting hook is contained. And (3) drilling a skin positioning hole by using the process hole driller 4, positioning the process hole positioning driller on the positioning auxiliary block through a positioning pin, fully contacting the process hole positioning driller with the skin, finishing drilling processing, and finishing manufacturing of the skin primary blank.
The beneficial effects of the invention are as follows:
the invention realizes the longitudinal drawing forming of the single-double curvature composite surface skin by adopting the tightening belt to realize the compaction, and an upper pressing die is not adopted any more, thereby not only reducing the process flow, but also reducing the cost. By adopting the working molded surface and the supporting structure formed by splicing and welding, a new design structure of the skin punching and cutting clamp is developed on the premise of not affecting the use requirement. The final weight of the welded structure skin stretching die is lighter than that of the traditional cast structure, and the utilization rate of raw materials is also improved. Meanwhile, a process hole locator, a skin locating scriber and a multifunctional base are additionally arranged at the proper position of the die, and the multifunctional base comprises a die locating function, a die pitching adjusting function and a skin binding function. The skin locating hole device is used for locating the device as a side surface of the die, and does not occupy the working molded surface of the die.
Drawings
FIG. 1 is a schematic view of the overall mold and associated apparatus of the present invention;
FIG. 2 (a) is a front view of the inventive die;
FIG. 2 (b) is a top view of the inventive die;
FIG. 2 (c) is a right side view of the inventive die;
FIG. 3 is a split view of the mold of the present invention;
FIG. 4 is a split view of a middle double curvature mold of the present invention;
FIG. 5 is a diagram of the structure of the middle double curvature mold of the present invention;
FIG. 6 is a split view of a middle double curvature mold structure of the present invention with a cross frame plate;
FIG. 7 is a schematic cross-sectional view of a middle double-curvature mold of the present invention;
FIG. 8 is a split schematic view of an end double curvature mold of the present invention;
FIG. 9 is a bottom view of the mold assembly of the present invention;
FIG. 10 (a) is a top plan view of the floor of the present invention;
FIG. 10 (b) is a front view of the floor of the present invention;
FIG. 11 (a) is a schematic view of the overall skin score line location apparatus of the present invention;
FIG. 11 (b) is an enlarged schematic view of the skin score line location device of the present invention;
FIG. 11 (c) is a side view of the skin score line location device of the present invention;
FIG. 12 is a schematic view of a pilot reamer of the process orifice of the present invention;
FIG. 13 is a schematic view of a mold pitch function floor;
FIG. 14 is a front view of a pitch function chassis;
FIG. 15 is a side view of a hinge structure;
FIG. 16 is a cross-sectional view of a hinge structure;
figure 17 is a skin stretching schematic.
In the figure: 1. a die body; 2. a mold bottom plate; 3. a skin scribing device; 4. skin process hole locator; 5. a skin stretching equipment workbench; 6. the single curvature mould is split; 7. the middle double-curvature die is split; 8. the end double-curvature mold is split; 9 supporting a frame; 10 double curvature molded surface jointed boards; 11. a transverse supporting plate A is arranged in the middle section of the die; 12. a transverse supporting plate B is arranged in the middle section of the die; 13. a longitudinal support plate A is arranged in the middle section of the die; 14. a longitudinal support plate B is arranged in the middle section of the die; 15. a longitudinal support plate C is arranged in the middle section of the die; 16. a transverse frame A at the middle section of the die; 17. a transverse frame B at the middle section of the die; 18. a longitudinal frame A at the middle section of the die; 19. a longitudinal frame B at the middle section of the die; 20. corner position of the end double-curvature mould; 21. the three-section die is connected with the bolt component; 22. a notch is positioned at the middle section of the die; 23. a single curvature section end frame positioning notch; 24. a rectangular aluminum alloy bottom plate; 25. an aluminum inclined support plate 26 and a long positioning block; 27. a short positioning block; 28. a hanging ring; 29. a bolt with the diameter of M24mm is connected; 30. an M20 bolt; 31. a die fixing block; 32. a hinge fixing plate; 33. a skin scribing plate; 34. a hinge shaft; 35. a skin; 36. positioning a drilling device for a process hole; 37. a positioning pin; 38. a drill sleeve; 39. a positioning auxiliary block; 40. a hinge structure A; 41. a hinge structure B; 42. a hinge shaft; 43. a hinged lower platform; 44, a hinged upper platform; 45 internal thread sleeve; 46. a steel bushing; 47 upper platform of hinge structure B; 48. a long round steel bushing; 49. a bolt; 50. a strap; 51. a strong magnet pressing block; 52 tensile tester.
Detailed Description
The following describes embodiments of the present invention in detail with reference to the accompanying drawings, and this embodiment is implemented on the premise of the technical solution of the present invention, and a detailed embodiment and a specific implementation procedure are given, but the scope of protection of the present invention is not limited to the following embodiment examples.
Referring to fig. 1, 2 and 3, a large splice welding type aluminum alloy skin stretching die and a matched device are provided, the whole length is about 5-10 m, the width is 1-2 m, the height is about 400-1000mm, the large splice welding type aluminum alloy skin stretching die comprises a die body 1, a die bottom plate 2, a skin scribing device 3 and a skin process hole locator 4, the die bottom plate 2 falls on a skin stretching equipment workbench 5, and during longitudinal stretching, the die bottom plate 2 needs to fall on the upper surfaces of the two skin stretching equipment workbench 5. The large splicing and welding type aluminum alloy skin stretching die 1 consists of three sections along the length direction, namely a single-curvature die split 6, a middle double-curvature die split 7 and an end double-curvature die split 8 which are sequentially connected. The whole body is of an asymmetric structure, and the single-curvature die is also of an asymmetric structure in order to meet the whole weight reduction requirement. The three split structures comprise a supporting frame formed by splicing and welding longitudinal plugboards and transverse plugboards and a molded surface spliced board covered on the supporting frame.
Referring to fig. 2 and 3, when the skin stretching die is used, the skin material is aluminum alloy, the die is stressed mainly by compressive stress, so that the skin stretching die needs to have higher strength, a middle-high strength thick steel plate is used as a forming surface, a cast steel plate is used as a support, an integral structure is built through splicing and inserting at certain intervals, and the strength requirement of the skin stretching die can be met by adopting a local welding mode. In the example, the molded surface jointed board material is 45 # steel, and the supporting plate material is Q235 cast steel.
Referring to fig. 4, taking a middle double-curvature mold split 7 as an example, a double-curvature molded surface jointed board 10 forms a skin stretching mold working surface, the curvature of the longitudinal cross section of the working surface is equal to the curvature of a skin part joint surface, a plurality of longitudinal pinboards and transverse pinboards are positioned below the double-curvature molded surface jointed board, the construction of a mold supporting frame 9 is completed by adopting a longitudinal and transverse splicing welding mode, and the working surface formed by the double-curvature molded surface jointed board 10 is supported.
Referring to fig. 5 and 6, the longitudinal and transverse spiles, thickness and spacing constituting the mold support frame 9 determine the strength of the mold, in order to meet the requirement of compressive stress strength, in this example, the longitudinal support plate a13 inside the middle section of the mold, the longitudinal support plate B14 inside the middle section of the mold, the longitudinal support plate C15 inside the middle section of the mold, the longitudinal frame a18 inside the middle section of the mold and the longitudinal frame B19 inside the middle section of the mold are spaced by about 500mm, the transverse support plate a11 inside the middle section of the mold, the transverse support plate B12 inside the middle section of the mold, the transverse frame a16 inside the middle section of the mold, and the transverse frame B17 inside the middle section of the mold are spaced by about 800mm, and the middle double-curvature mold split 7 adopts 5 longitudinal spiles and 4 transverse spiles uniformly distributed to achieve the splicing connection of the support frame, and the thickness of the support plate is about 30mm. The longitudinal support plate A13 in the middle section of the mould, the longitudinal support plate B14 in the middle section of the mould, the longitudinal support plate C15 in the middle section of the mould, the transverse support plate A11 in the middle section of the mould and the transverse support plate B12 in the middle section of the mould are spliced in a cross shape, the longitudinal frame A18 in the middle section of the mould, the longitudinal frame B19 in the middle section of the mould, the transverse frame A16 in the middle section of the mould and the transverse frame B17 in the middle section of the mould are spliced in an L shape to form a square outer frame, the support splice plates 11-15 in the frame and the frame support plates 16-19 are spliced in a T shape, the transverse edges of the T shape are frame plates 16-19, and the vertical edges are the inner splice plates 11-15. Each longitudinal plugboard and each transverse plugboard are correspondingly provided with a butting notch, the width of each notch is about 0.5mm wider than that of each butting board, the depth of each notch is about half of the height of each jointed board at the position, and the notch is flexibly controlled according to practical conditions. The weight reducing holes are formed in the inner transverse supporting plate A11 of the middle section of the transverse supporting plate die, the inner transverse supporting plate B12 of the middle section of the die, the transverse frame A16 of the middle section of the die and the transverse frame B17 of the middle section of the die, so that the weight is reduced, and the longitudinal supporting plate is formed: the longitudinal support plate A13 in the middle section of the die, the longitudinal support plate B14 in the middle section of the die, the longitudinal support plate C15 in the middle section of the die, the longitudinal frame A18 in the middle section of the die and the longitudinal frame B19 in the middle section of the die are taken into consideration, and the lightening holes are not formed. After the supporting frame 9 is inserted, a vertical square is adopted to determine a longitudinal supporting plate A13 in the middle section of the longitudinal plugboard die, a longitudinal supporting plate B14 in the middle section of the die, a longitudinal supporting plate C15 in the middle section of the die, a longitudinal side frame A18 in the middle section of the die and a longitudinal side frame B19 in the middle section of the die are perpendicular to a transverse supporting plate A11 in the middle section of the transverse plugboard die, a transverse supporting plate B12 in the middle section of the die, a transverse side frame A16 in the middle section of the die and a transverse side frame B17 in the middle section of the die, the supporting frame 9 is fixed through partial welding, the whole frame is moved to a machining table after the fixing, the mechanical machining of the connecting part of the supporting frame 9 and the working double-curvature molded surface jointed board 10 is completed, namely, all the lap joint surfaces of the tops of the longitudinal and transverse supporting plates and the working double-curvature molded surface jointed board 10 are machined to the final size according to the design outline before the supporting frame is inserted, and a welding process structure is reserved.
Referring to fig. 5, 6 and 7, the double curvature working profile structure is formed by welding double curvature profile panels 10, and the working profile is double curvature, so that the combination of the profile panels is complex, namely, transverse splicing and longitudinal splicing are required. The surface rough machining of all working surface jointed boards and the reserved allowance are more than 5mm, the other five surfaces are all machined to the final size, all supporting surfaces of the double-curvature surface jointed boards 10 and all longitudinal and transverse supporting plates are planes, the double-curvature surface jointed boards are convenient to be lapped on a supporting frame, the longitudinal two end surfaces of the supporting frame 9 and the supporting surface of the frame are used as positioning references, and the surface jointed boards are placed on the supporting frame 9 one by one. Since the compressive stress requirement must be met, the minimum thickness of the dual curvature profile panel 10 after processing cannot be below a certain fixed value, in this example, the thickness cannot be below 30mm depending on the magnitude of the compressive stress and the strength of the materials used. The number of the double-curvature molded surface jointed boards 10 is based on the curvature of the molded surface and the thickness of the blank plate, the larger the curvature of the molded surface is, the more the number of the molded surface jointed boards is needed, and the smaller the number of the molded surface jointed boards is on the contrary; the curvature of the surface is certain, the thicker the woolen is, the less the needed splicing quantity is, and conversely, the more the woolen is, the thicker the woolen is, and the more the material is removed by the surface processing. In the example, the machining cutting amount and the welding workload are comprehensively considered, and the number of the transverse spliced 7 blocks and the number of the longitudinal spliced blocks are finally determined to be 1-3. When the double-curvature molded surface jointed board 10 is spliced along the longitudinal direction, if one transverse supporting board in the supporting frame bears the molded surface jointed boards with two different molded surfaces along the longitudinal direction, the transverse supporting board is designed to be a double-layer structure along the longitudinal direction, such as 11 and 12, and the middle section transverse frame A16 and the middle section transverse frame B17 of the two end transverse supporting boards are only used for supporting one group of the longitudinal molded surface jointed boards, and are not designed to be the double-layer structure. When the double-curvature molded surface jointed boards 10 are transversely spliced, the molded surface jointed boards are placed and clamped one by one from the middle to the two sides according to the supporting plate structure, the two molded surface jointed boards at the edge in the transverse direction transversely extend out of the supporting frame to form a tiny eave shape, the extending amount is determined according to the allowance of the skin stretching process, the extending amount is generally 5-50mm, the molded surface jointed boards are finally processed into round corners, and the radius of the round corners is controlled to be R20mm. After the splicing of the jointed boards of the working molded surface is completed, local welding is carried out, local joints of the molded surface are filled by welding, and the finish machining of the working molded surface is completed by integral machining after the three parts of the single-curvature mold split 6, the middle double-curvature mold split 7 and the end double-curvature mold split 8 are connected.
The whole thickness of the end double curvature die split 8 is gradually thinner along with the longitudinal and transverse curvature extension of the forming surface, in particular, if the end double curvature die corner position 20 is thickened, the whole height of the die 1 is increased, the die is overweight, and the manufacturing and carrying economy is poor. The width of the large skin is gradually reduced in the double curvature section, the corner position 20 of the end double curvature mould is generally outside the contour of the skin, and in order to ensure the manufacturability of stretching the skin and meet the requirement of weight reduction of the mould, the mould part outside the contour of the skin is cut off, and the longitudinal edge area of the working profile is smoothly transited. The supporting frames are properly adjusted, the longitudinal edge supporting plates corresponding to the corners are arranged into one piece, two pieces or more pieces, and are spliced into a fold line shape, and the longitudinal edge supporting plates are directly positioned and clamped for welding due to the fact that the height is low without inserting connection.
The single-curvature die split 6 has a relatively simple structure, the supporting frame is spliced and welded by the longitudinal and transverse supporting plates, the curvature change of the molded surface spliced plate exists in a single direction, namely, the molded surface spliced plate is in a straight line direction in the longitudinal direction, and a certain curvature exists only in the transverse direction. The steel plate with the length slightly larger than the longitudinal length of the single curvature section can be utilized to splice the cambered surface similar to the skin mold from the center to the two sides side by side section by section along the transverse direction, the steel plate is built on a supporting structure which utilizes the cast steel plate to splice and weld the skin stretching mold, then the welding work is completed, wherein the transverse supporting plate is only lapped with one group of molded surface jointed plates, and the molded surface structure is relatively simple.
After the splicing and welding of each supporting frame are completed, the three parts are required to be subjected to heat treatment to eliminate welding stress, then the three parts are moved to a machining platform to finish the surface which is overlapped with the molded surface spliced plate, and after the welding of the three parts and the molded surface spliced plate is completed, the welding stress is eliminated by heat treatment.
After each part is completed, three parts of connection work needs to be realized. The three parts are connected by two connecting technologies, and the three-section die connecting bolt assembly 21 is adopted for connection. In the example, through strength calculation, bolt assemblies with the diameter of 20mm are uniformly distributed on the opposite interfaces, and 16 sets of three-section die connecting bolt assemblies 21 are arranged on each two pairs of connecting interfaces. And after the bolts are connected, a groove welding process is adopted to realize three-section connection, the whole heat treatment is carried out after welding to eliminate stress, and finally, the accurate processing of the skin stretching molded surface is realized after the bolts are moved to a machining platform.
To ensure the integrity and accuracy of the working profile of the milling fixture, the working profile must be finished after welding. Therefore, the long beam, the rough supporting plate and the end bevel angle of the welded jointed board should be processed first. And then, a supporting structure is welded by using a large welding platform, the supporting structure comprises a reinforcing plate, and the supporting end face is finished. And then welding the working molded surface jointed boards, taking the middle jointed board as a reference, and welding the jointed boards on two sides. And finally, integrally processing the working profile, and cutting the cambered surface by adopting a numerical control punch and drilling.
Two mould middle section locating notches 22 are formed in the longitudinal frame plate bottom of the middle double-curvature mould split 7 in a longitudinal direction and are used for locating a matched mould bottom plate and forklift carrying fork openings, and a single-curvature section end frame locating notch 23 is formed in the end double-curvature mould split 8 end frame plate bottom of the integral mould 1 and is used for locating a matched mould bottom plate 2.
The bottom plate comprises two rectangular aluminum alloy bottom plates 24, four aluminum inclined support plates 25, three aluminum mold positioning blocks and a plurality of steel hanging rings 28, wherein the four aluminum inclined support plates 25 are used for bridging the two rectangular aluminum alloy bottom plates 24. Four aluminium inclined support plates 25 are arranged above two rectangular aluminium alloy bottom plates 24 according to reasonable positions, the upper surfaces of the four aluminium inclined support plates 25 form an integral plane to support the mould 1, and the inclined angles of the aluminium inclined support plates 25 are formulated according to skin stretching technology, so that the technological requirements are met. Each aluminum inclined support plate 25 is connected by 8 bolts 29 with the diameter of M24mm, countersunk sockets are formed in the upper parts of the bolt holes of the inclined support plates, and the bolts penetrate through the bolt holes of the aluminum inclined support plates 25 and are screwed into threaded holes of the rectangular aluminum alloy bottom plates 24. The three positioning blocks comprise two transverse long positioning blocks 26 and a longitudinal short positioning block 27, wherein the long positioning blocks 26 are connected with the aluminum inclined support plate 25 through six M20 bolts 30, countersunk sockets are formed in the upper parts of the bolt holes of the long positioning blocks 26, and the bolts penetrate through the bolt holes of the long positioning blocks 26 and are screwed into threaded holes of the aluminum inclined support plate 25. One short positioning block 27 adopts two M20 bolts to realize countersunk head threaded connection in the same way. The positioning groove of the die is sleeved with the long positioning block 26 and the short positioning block 27 of the bottom plate to position the die on the bottom plate. The lifting rings 28 are uniformly distributed on the end faces of two longitudinal sides of the bottom plate and are used for applying a binding belt to tighten the skin above a mold in the skin stretching process, so that the process requirement is met, the lifting rings adopt stainless steel M24 specifications, the lifting rings 28 are used as binding belt fixing tools for a single-curvature section compacting method in the large skin stretching process for the first time, and as the lifting rings are symmetrical along a longitudinal center axis, the binding belt is tightly hung on one lifting ring at one end of a wagon binding belt EN12195-2:2000 with the specification of 5T, the other end of the binding belt is hung on the lifting ring at the symmetrical position or nearby, and the binding and compacting for the skin and the mold are completed by manpower.
Referring to fig. 11, four skin scribing devices 3 are disposed at four corners of the mold, including a mold fixing block 31, a hinge fixing plate 32, a skin scribing plate 33, and a hinge shaft 34, wherein the mold fixing block 31 is fixed on a side plate surface of the mold through two screw connections, the hinge fixing plate 32 is fixed on an outer surface of the mold fixing block 31 through two screw connections, the skin scribing plate 33 and the hinge fixing plate 32 are connected through the hinge shaft 34, and the other end of the skin scribing plate 33 can freely rotate along the hinge shaft 34, can be attached to a surface of the skin 35, and can also rotate to be detached. The skin scribing plate 33 is attached to the surface of the skin and has a rectangular outline at one end, when attached to the surface of the skin 35, a marker pen can be used to draw mark lines on the skin along the outline of the edge, and a set of skin scribing device 3 is arranged at each of four corners of the mold. In this example, three sets of skin scoring devices 3 are arranged due to the die corner cut.
Referring to fig. 12, the skin tooling hole locator 4 is a tooling hole locator for the skin during the process circulation, and is generally provided with two high-point flat areas at two longitudinal ends of the mold surface, and is pressed on the skin 35, and the conventional tooling hole locator is arranged on the mold surface near the longitudinal edge position. However, the invention is arranged on the support plates at the two longitudinal end surfaces of the die 1, so that the die length can be effectively reduced. The skin process hole positioner 4 comprises a process hole positioning driller 36, two positioning pins 37, a drill bushing 38 and a positioning auxiliary block 39, wherein the two positioning pins 37 and the drill bushing 38 are embedded on the process hole positioning driller 36 and are connected in interference fit, the positioning auxiliary block 39 is connected with the side surface of a frame plate of the mold 1 through screws, two positioning holes are formed in the positioning auxiliary block 39, the skin process hole positioner 4 can be positioned and installed and detached with the positioning auxiliary block 39 through the two positioning pins 37 at any time, and the position of the process hole is determined according to the manufacturing process requirements of the skin 35. The two sets of positioners are not identical, and are characterized in that the contact surface with the skin is completely and optimally attached to the skin-shaped surface, if the contact surface of the process hole positioning driller 36 and the skin 35 is set to be planar, the process hole positioning driller is parallel to the longitudinal ridge line of the skin 35 as much as possible, the positioning pins 37 are parallel to the drill bushing 38, and all the positioning pins 37 of the two sets of skin process hole positioners 4 longitudinally front and back are parallel to the drill bushing 38, in this example, are not only parallel, but also perpendicular to the bottom surface of the die.
Referring to fig. 13, 14, 15 and 16, in order to freely adjust the pitching angle of the die, the invention adopts two sets of hinge structures, namely a hinge structure A40 and a hinge structure B41, which are not completely identical in structure and comprise a hinge shaft 42, a hinge lower platform 43 and a hinge upper platform 44, wherein the hinge shaft is a steel material optical axis with the diameter of 80mm, and two ends are threaded, and the hinge shaft 42 is connected through an internal thread sleeve 45 to realize axial limit. The upper platform of the hinge structure A40 is of an integrated structure, aluminum materials are embedded in the hinge shaft holes, the coaxial steel bushings 46 are connected in an interference mode, the thickness of the bushings is 10mm, the total of four inserting lugs of the upper hinge platform 44 is equal to that of the lower hinge platform 43, the four connecting holes are formed in the same material, the coaxial steel bushings are installed in an interference mode, the total of six inserting lugs is equal to that of the six connecting holes, the hole shafts are in clearance fit, and the single side of the clearance is 0.5mm. The difference between the hinge structure A40 and the hinge structure B41 is that the through hole of the upper platform insert lug of the hinge structure B41 is set into a slotted hole, a long round steel bushing 48 is installed in an interference mode, and the thickness of the bushing is 10mm. The two sets of hinge structures are installed on two skin stretching equipment work tables 5 of skin stretching equipment through a hinge lower platform 43, are fixed through T-shaped bolts, are installed on the lower plane of a die base through a hinge upper platform 44 and an upper platform 47 of a hinge structure B, are connected with a rectangular aluminum alloy bottom plate 24 through bolts, bolts 49 penetrate through countersunk holes of the rectangular aluminum alloy bottom plate 24 to be screwed into threads of the platforms, installation is achieved, pitching of the rectangular aluminum alloy bottom plate 24 driving a die 1 is achieved through independent lifting of the two skin stretching equipment work tables 5, and when the bottom plate mechanism is adopted, die positioning blocks are directly connected to the upper surface of the rectangular aluminum alloy bottom plate 24 and are screwed into threads of the rectangular aluminum alloy bottom plate 24 from positioning block countersunk heads Kong Shenru through bolts. Because the upper platform or the lower platform of the hinge structure is difficult to integrally manufacture, the hinge structure can be manufactured in a segmented mode, and each segment is provided with 1 lug, 2 lugs or three lugs, and the coaxiality of lug holes is ensured through the integral assembly of the lug holes on the bottom plate of the die.
The skin stretching concrete implementation method comprises the following steps: see fig. 1, 11, 12, 17. When the skin is longitudinally pulled, the lifting of the two skin stretching equipment work tables 5 is adjusted respectively, the pitching angle of the die is controlled, a proper angle is found, the skin 35 is placed on the surface of the die, and the skin is clamped in a skin stretching machine. When stretching, the two skin stretching equipment working tables 5 are controlled to ascend and descend respectively, the pitching of the die 1 is adjusted, and along with stretching operation, the pitching angle of the die 1 reaches a preset value, and the ascending and descending of the skin stretching equipment working tables 5 are stopped. The compression of the skin 35 and the mold 1 is realized through the binding bands 50 above the skin 35, the binding bands 50EN12195-2:2000 or the like, the hooks at the two ends of the binding bands are respectively hung in the hanging rings 28 of the bottom plate 2, the hanging rings 28 are matched in pairs for use and respectively span the symmetrical positions of the mold 1 and the skin 35, 1 binding band 50 can be hung on each pair of hanging rings 28 according to the actual stretching working condition, and binding can also be carried out by spacing a pair of hanging rings 28, in the example, the space between the hanging rings is 200mm, in order to ensure the accuracy of the stretching shape surface of the skin, the binding area is mainly a single curvature section of the skin 35, the double curvature section can be not bound, but the stretching risk of the skin is considered, the double curvature section can be properly bound, and the skin is still attached to the mold 1 after the end part is broken. Along with the stretch of the skin, the skin 35 is gradually and completely attached to the mold 1, the binding band 50 is tightened again, the skin 35 and the mold 1 are pressurized, a tension tester can be added at the suspension section of the binding band 50, namely the section between the binding band 50 and the contact skin 35 from the hanging ring 28, tension monitoring of the binding band 50 is realized, the tension tester adopts a conventional two-end hook tester meeting JJG455-2000 standard in the market, the lower limit of the measuring range is not lower than 500Kg, the maximum measuring range is about 10T, one end of the hook is connected with the hook of the binding band 50 during measurement, and the other end of the hook is directly hung on the hanging ring 28. When the skin is stretched, the skin scribing plate 33 is turned over to be attached to the skin 35, and when the skin scribing plate is attached to the surface of the skin 35, marking lines are drawn on the skin along the rectangular edge outline of the skin by using a marker pen, and a set of skin scribing devices 3 are respectively arranged at four corners of the die, so that corresponding marking lines are respectively drawn. In this example, since one corner of the mold is cut off, three sets of skin scribing devices 3 are arranged, and thus 3 corresponding mark lines are drawn. After the skin 35 is unloaded, the straps 50 are removed, the skin 35 is removed and the excess edges are cut away so that the edges of the skin 35 are all within the contour of the mold 1. The positioning of the skin on the mold is realized by combining the marking lines on the corners with data calculation, more than 4 powerful magnet pressing blocks 51 are arranged above the skin, the clamping of the skin and the mold is realized, the powerful magnet pressing blocks 51 adopt the strong magnets of neodymium iron boron magnet Dan Dalao on the market, the attraction force is not less than 200Kg, and the lifting hook is contained. And the skin locating holes are drilled by using the process hole driller 4, the locating of the process hole locating driller 36 in the locating auxiliary block 39 is realized by using the locating pin 37, the process hole locating driller 36 is fully contacted with the skin 35, the drilling processing is finished, and the manufacture of the skin blank is finished.
Claims (6)
1. The large single-double curvature composite surface skin longitudinal drawing device is characterized by comprising a die body (1), a die bottom plate (2), skin scribing devices (3) and skin process hole positioners (4), wherein the skin drawing die 1, the die bottom plate (2) falls on a skin drawing equipment workbench (5), and when in longitudinal drawing, the die bottom plate (2) needs to fall on the upper surfaces of the two skin drawing equipment workbench (5); the stretching die 1 consists of three sections along the length direction, namely a single-curvature die split (6), a middle double-curvature die split (7) and an end double-curvature die split (8) which are sequentially connected; the whole body is of an asymmetric structure, and in order to meet the whole weight reduction requirement, the single-curvature die split body (6) is of an asymmetric structure; the three split structures comprise a supporting frame formed by splicing and welding longitudinal plugboards and transverse plugboards and profile spliced boards covered on the supporting frame;
taking a middle double-curvature mold split (7) as an example, a double-curvature molded surface jointed board (10) forms a skin stretching mold working surface, the longitudinal cross section curvature of the working surface is equal to the curvature of a skin part joint surface, a plurality of longitudinal pinboards and transverse pinboards are positioned below the double-curvature molded surface jointed board, the construction of a mold supporting frame (9) is completed in a longitudinal and transverse splicing welding mode, and the working surface formed by the double-curvature molded surface jointed board (10) is supported;
The mold middle section inner longitudinal support plate A (13), the mold middle section inner longitudinal support plate B (14), the mold middle section inner longitudinal support plate C (15) and the mold middle section inner transverse support plate A (11) of the support frame (9) are in cross-shaped insertion connection, and the four-side frame mold middle section longitudinal frame A (18) is in L-shaped butt joint with the mold middle section longitudinal frame B (19) and the mold middle section transverse frame A (16) and the mold middle section transverse frame B (17) to form an L-shaped opening outer frame;
two mould middle section positioning notches (22) are formed in the longitudinal frame plate bottom of the middle double-curvature mould split (7) in a longitudinal direction and are used for positioning a matched mould bottom plate and carrying fork openings of a forklift, and a single-curvature section end frame positioning notch (23) is formed in the end part frame plate bottom of the end double-curvature mould split (8) in the integral stretching mould 1 and is used for positioning a matched mould bottom plate (2);
the die bottom plate (2) comprises two rectangular aluminum alloy bottom plates (24), four aluminum inclined support plates (25), three aluminum die positioning blocks and a plurality of steel hanging rings (28), wherein the four aluminum inclined support plates (25) are used for bridging the two rectangular aluminum alloy bottom plates (24); the four aluminum inclined support plates (25) are arranged above the two rectangular aluminum alloy bottom plates (24) according to reasonable positions, the upper surfaces of the four aluminum inclined support plates (25) form an integral plane, the die 1 is supported, the three positioning blocks comprise two transverse long positioning blocks (26) and one longitudinal short positioning block (27), the long positioning blocks (26) are connected with the aluminum inclined support plates (25), countersunk holes are formed in the upper parts of bolt holes of the long positioning blocks (26), and bolts penetrate through the bolt holes of the long positioning blocks (26) and are screwed into threaded holes of the aluminum inclined support plates (25); a short positioning block (27) adopts two M20 bolts to realize countersunk head threaded connection in the same way; the mould positioning groove is sleeved with the long positioning block (26) and the short positioning block (27) of the bottom plate to realize the positioning of the mould on the bottom plate; hanging rings (28) are uniformly distributed on the end surfaces of the two longitudinal side edges of the bottom plate.
Four skin marking devices (3) are arranged at four corners of the stretching die 1 and comprise a die fixing block (31), a hinge fixing plate (32), a skin marking plate (33) and a hinge shaft (34), wherein the die fixing block (31) is fixedly connected to a side plate surface of the die through two screws, the hinge fixing plate (32) is fixedly connected to the outer surface of the die fixing block (31) through two screws, the skin marking plate (33) is connected with the hinge fixing plate (32) through the hinge shaft (34), the other end of the skin marking plate (33) can freely rotate along the hinge shaft (34), can be attached to the surface of a skin (35) and can also rotate to be detached;
the invention adopts two sets of hinge structures, namely a hinge structure A (40) and a hinge structure B (41), which are not completely identical in structure and comprise a hinge shaft (42), a hinge lower platform (43) and a hinge upper platform (44), wherein the two sets of hinge structures are arranged on two skin stretching equipment work tables (5) of skin stretching equipment through the hinge lower platform (43), are fixed through T-shaped bolts, are arranged on the lower plane of a die base through the hinge upper platform (44) and an upper platform (47) of the hinge structure B, are connected with a rectangular aluminum alloy bottom plate (24) through bolts, and are screwed into threads of the platforms through countersunk holes of the rectangular aluminum alloy bottom plate (24) to realize the installation, and the rectangular aluminum alloy bottom plate (24) drives the pitching of the die 1 to be realized through the independent lifting of the two skin stretching equipment work tables (5).
2. The large single-double curvature composite surface skin longitudinal pulling device according to claim 1, wherein the weight reducing holes are formed in the inner transverse support plate a (11), the inner transverse support plate B (12), the transverse side frame a (16) and the transverse side frame B (17) of the middle section of the mold of the transverse support plate, and the weight is reduced, and the longitudinal support plate is formed by: the longitudinal support plate A (13) in the middle section of the die, the longitudinal support plate B (14) in the middle section of the die, the longitudinal support plate C (15) in the middle section of the die, the longitudinal frame A (18) in the middle section of the die and the longitudinal frame B (19) in the middle section of the die are taken into consideration, and no lightening hole is formed.
3. The large single-double curvature composite surface skin longitudinal pulling device as defined in claim 1 or 2, wherein after the supporting frame (9) is inserted, a square is adopted to determine a longitudinal supporting plate A (13) inside a middle section of a longitudinal plugboard die, a longitudinal supporting plate B (14) inside the middle section of the die, a longitudinal supporting plate C (15) inside the middle section of the die, a longitudinal frame A (18) of the middle section of the die and a longitudinal frame B (19) of the middle section of the die are perpendicular to a transverse supporting plate A (11) inside the middle section of the transverse plugboard die, a transverse supporting plate B (12) inside the middle section of the die, a transverse frame A (16) of the middle section of the die and a transverse frame B (17) of the middle section of the die, the supporting frame (9) is fixed by local welding, and the whole frame after the fixing is moved to a machining table to finish machining the connecting part of the supporting frame (9) and the working double curvature surface jointed board (10), namely machining all joint surfaces between the tops of the longitudinal supporting plates and the middle section and the working double curvature surface jointed board (10).
4. The large single-double curvature composite surface skin longitudinal pulling device as claimed in claim 1 or 2, wherein the skin process hole positioner (4) is a drilling positioner for process holes of the skin during process circulation, high-point flat areas at two longitudinal ends of a mold surface are pressed on the skin (35), the skin process hole positioner (4) comprises a process hole positioning drill (36), two positioning pins (37), a drill bushing (38) and a positioning auxiliary block (39), the two positioning pins (37) and the drill bushing (38) are embedded on the process hole positioning drill (36), the positioning auxiliary block (39) is connected with the side surface of a frame plate of the stretching mold 1 through screws, two positioning holes are formed in the positioning auxiliary block, the skin process hole positioner (4) can be positioned and detached with the positioning auxiliary block (39) through the two positioning pins (37) at any time, and the process hole position is determined according to the manufacturing process requirements of the skin (35).
5. A large single-double curvature composite surface skin longitudinal pulling device as claimed in claim 3, characterized in that the skin process hole positioner (4) is a drilling positioner for process holes of the skin during process circulation, high-point flat areas at two longitudinal ends of a mold surface are pressed on the skin (35), the skin process hole positioner (4) comprises a process hole positioning driller (36), two positioning pins (37), a drill bushing (38) and a positioning auxiliary block (39), the two positioning pins (37) and the drill bushing (38) are embedded on the process hole positioning driller (36), the positioning auxiliary block (39) is connected with the side surface of a frame plate of the stretching mold 1 through screws, two positioning holes are formed in the positioning auxiliary block, the skin process hole positioner (4) can be positioned and detached with the positioning auxiliary block (39) through the two positioning pins (37) at any time, and the process hole position is determined according to the manufacturing process requirements of the skin (35).
6. The method of a large single double curvature composite skin longitudinal pulling device according to any one of claims 1 to 5, characterized by the steps of:
the first step: when the skin is longitudinally pulled, the lifting of the two skin stretching equipment work tables (5) is respectively adjusted, the pitching angle of the mould is controlled, a proper angle is found, the skin (35) is placed on the surface of the mould, and the skin is clamped in a skin stretching machine; when stretching, respectively controlling the lifting of the two skin stretching equipment working tables (5), adjusting the pitching of the stretching die 1, and stopping the lifting of the skin stretching equipment working tables (5) when the pitching angle of the die 1 reaches a preset value along with stretching operation;
and a second step of: the compression of the skin (35) and the mould (1) is realized through the binding bands (50), hooks at two ends of the binding bands (50) are respectively hung in the hanging rings (28) of the bottom plate, the hanging rings (28) are matched in pairs for use, the symmetrical positions of the skin (35) and the mould (1) are respectively crossed, 1 binding band (50) can be hung on each pair of hanging rings (28) according to the actual stretching working condition, and binding can be carried out at intervals between a pair of hanging rings (28), wherein the distance between the hanging rings in the example is 200mm;
and a third step of: along with the stretching of the skin, the skin (35) is gradually and completely attached to the stretching die 1, the binding belt (50) is tightened again, the skin (35) and the stretching die 1 are pressurized, a tension tester (52) can be added at the suspension section of the binding belt (50), namely the section between the hanging ring (28) and the contact skin (35) of the binding belt (50), tension monitoring of the binding belt (50) is realized, one end of the hook is connected with the hook of the binding belt (50) during measurement, and the other end of the hook is directly hung on the hanging ring (28); when the skin is stretched, the skin scribing plate (33) is turned over to be attached to the skin (35), and when the skin is attached to the surface of the skin (35), marking lines are drawn on the skin along the rectangular edge outline of the skin by using a marker pen, and a set of skin scribing devices (3) are respectively arranged at four corners of the die, so that corresponding marking lines are respectively drawn;
Fourth step: after the skin (35) is unloaded, removing each binding belt (50), removing the skin (35) and cutting off redundant parts of the edges, so that the edges of the skin (35) are all in the contour of the shape surface of the die 1; the positioning of the skin on the mold is realized by combining the marking lines on the corners with data calculation, more than 4 strong magnet pressing blocks (51) are arranged above the skin to clamp the skin and the mold, the strong magnet pressing blocks (51) adopt the strong magnets of the neodymium iron boron magnet Dan Dalao on the market, and the attraction force is not less than 200Kg and comprises a lifting hook; and (3) drilling a skin positioning hole by using the process hole driller (4), positioning the process hole positioning driller (36) on the positioning auxiliary block (39) through the positioning pin (37), and fully contacting the process hole positioning driller (36) with the skin (35), so as to finish drilling and finishing the manufacture of the skin blank.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311434642.8A CN117862318A (en) | 2023-11-01 | 2023-11-01 | Longitudinal pulling method for large single-double curvature composite surface skin |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311434642.8A CN117862318A (en) | 2023-11-01 | 2023-11-01 | Longitudinal pulling method for large single-double curvature composite surface skin |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117862318A true CN117862318A (en) | 2024-04-12 |
Family
ID=90588897
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311434642.8A Pending CN117862318A (en) | 2023-11-01 | 2023-11-01 | Longitudinal pulling method for large single-double curvature composite surface skin |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117862318A (en) |
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2023
- 2023-11-01 CN CN202311434642.8A patent/CN117862318A/en active Pending
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