CN1141643C - Digital white car body sample making method - Google Patents
Digital white car body sample making method Download PDFInfo
- Publication number
- CN1141643C CN1141643C CNB021114617A CN02111461A CN1141643C CN 1141643 C CN1141643 C CN 1141643C CN B021114617 A CNB021114617 A CN B021114617A CN 02111461 A CN02111461 A CN 02111461A CN 1141643 C CN1141643 C CN 1141643C
- Authority
- CN
- China
- Prior art keywords
- simulation
- welding
- assembling
- model
- subsystem
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Management, Administration, Business Operations System, And Electronic Commerce (AREA)
Abstract
The present invention relates to a digital sample sealing method for white vehicle bodies, which comprises the processes of press-forming simulation, welding-assembling simulation and matching optimization, wherein the process of press-forming simulation analyzes the press-forming properties of products; then the process of welding-assembling simulation calculates the assembly deviation of a structural body in the process of welding and assembling according to models of body parts after the process of press-forming simulation; finally, the assembly quality of the structural body is matched in an optimal matching mode, and a central control computer feeds back data exchange and adjusts the data among the three processes. The present invention provides a set of high-efficient methods for the development of digital sample vehicles with white bodies, and compared with a traditional manufacture method for physical sample machines, the present invention can greatly shorten the manufacture cycles of sample machines and can realize a prioritization scheme in a system stage. Compared with the existing method for developing virtual sample machines, the present invention has the advantages of high control efficiency of data flow and obviously enhanced accuracy.
Description
Technical field:
The present invention relates to the virtual manufacture method in a kind of commercial production or the industrial test process, relate in particular to a kind of digital white car body sample making method, be used for the car trial production.
Background technology:
The aggravation of market competition is had higher requirement to the vehicle upgrading period of product, design level and the product quality of sedan-making plant, model machine is as the test stone of product design scheme and the evaluation criterion of workmanship, and sample making method directly influences the length of new model construction cycle.The tradition sample making method be by design proposal, engineering drawing are revised repeatedly and repeatedly making again of physical prototyping determine final physical prototyping, increased the cycle and the cost of new product development greatly, be difficult to the real prioritization scheme of acquisition.Digitizing sample making method (claiming Virtual Prototype Technique again) strong means and the instrument of providing that address these problems be provided.The people such as A.Roessler of Germany utilize the space constraint algorithm development one help the deviser in virtual environment, part to be assembled (the Stefan M ü nker of system with disassembling section, Alexander Roessler (Hrsg.) .VirtuelleGeschlechterordnung, In:IM NETZ.Kulturpraktiken des Internet.Frankfurt (Main), Suhrkamp).This method is based on the VirtualWorkbench of parallel company (Courrent Technologies Corporation)
TMAnd data glove, on the SGI workstation, use WorldToolKit
TMDeveloping instrument has been developed the virtual assembly system of a semi-immersion.Virtual Workbench
TMIt is a kind of horizontal real world devices, the user puts on the object observed behind the anaglyph spectacles just as floating on the desktop, be fit to assembling more, this system adopts the bimanual input of simulation staff natural interaction mutual, makes such as more directly perceived to operations such as grasping body, translation, rotations.Because the digital white car body sample making technology relates to the process engineering of a series of complexity such as optimization evaluation of part punching process, assembling process and assembling, said system only obviously can't realize the exploitation of digital white car body model machine to the emulation of assembling process.
Summary of the invention:
The objective of the invention is at the above-mentioned deficiency of prior art and the needs of practical application, a kind of digital white car body sample making method is provided, can directly utilize the physical message and the geological information of the technological parameter that CAD software provided, the dialogue bodywork parts carries out virtual manufacturing and assembling on computers, thereby obtain the digital white car body model machine, make the process of designer's actual manufacturing of real simulated in virtual environment, the multiple design proposal of express-analysis is until obtaining system-level optimization design scheme.
For achieving the above object, predict the workmanship of bodywork parts in the technical scheme of the present invention by the cladding element punching process stimulating technology, set up the spot welding thermal effect and can ignore criterion, application is based on the size quality of the finite element simulation calculation assembly structure of the bodywork parts assembling process of contact analysis.Set up the objective function and the constraint function of partial assembled coupling, realize matching optimization, thereby obtain system-level optimization design scheme.And realize the FEEDBACK CONTROL of data by central computer.
Method of the present invention data transmission Network Based, set up stamping forming simulation, welding simulation and three subsystems of matching optimization the model machine manufacture process is carried out simulation analysis, by exchanges data and the feedback between three technological process submodules of center-controlling computer realization, the optimum digital mockup of manufacturing system level, last result exports by printing, plotting equipment.
Concrete operations step of the present invention is as follows:
1, stamping forming simulation
The stamping forming simulation process is finished on an independent computing machine.(for example LS-Dyna3D, AUTOFROM) analyzes the press formability of product in the power explicit system, predict the springback capacity that the body outer skin punching press is later exactly, be the shaping deviation of product, thereby the realistic model of product is provided for welding process emulation.
The present invention at first adopts the modeling technique of vector quantization to generate geometric model, the original design drawing is scanned, form raster pattern, carry out the processing of vector quantization, in the Cartia system, carry out three-dimensional modeling, finally form the geometric model of an actual 3 D deformation situation of complete reflection.
Next carry out the pre-treatment of simulation analysis, the present invention adopts Belytschko-Tsay shell unit (BT shell unit) that geometric model is dispersed, and each parts is provided with material model and parameter.The software that this step adopts has: HYPERMESH etc.
Consider that elastic deformation occupies very important ratio in the plate total deformation, and the geometric configuration of sheet material changes greatly before and after being shaped, so the present invention adopts the large deformation elasto-plastic finite element method that it is analyzed.The software of this part employing has: LS-DYNA3D, AUTOFORM, LS-NIKE3D etc.
After the finite element analysis computation process finishes, at first dynamically show the motion conditions of each parts (drift, blank holder, sheet material, die etc.), to check rationality of calculations.Each parameter in the stamping process that obtains and the situation of change of physical quantity can with etc. chromatic graph or isogram dynamically show, comprise each sheet deformation constantly, stress, Strain Distribution situation, sheet metal thickness variation etc.Result of calculation input center-controlling computer.
2, cooperative module is handled
Center-controlling computer is by the flow direction of control module judgment data.If result of calculation meets the requirements, based on the cooperative module of the technology of surface reconstruction part finite element model constructing curve according to the punching course generation, foundation can reflect the solid model of part true form.Realize the rapid data conversion between stamping simulation subsystem and welding and assembling technics simulation subsystem.If result of calculation is undesirable, will revise then that data feed back to product model or mold former is made amendment.
3, the process simulation that is welded
Pass the model of the bodywork parts of coming according to the center-controlling computer control module, the location feature and the welding and assembling technics information such as clutch features and bond pad locations that provide in the consideration fixture model, calculate the structure assembling deviation that causes owing to the welding assembling process by the pinpoint welding procedure analog module with based on contact analysis assembling deviation analog module, as the input of matching optimization subsystem.The process simulation that is welded is finished on an independent computing machine, and links to each other with a center-controlling computer, realizes the exchange of data.
Gordian technique is:
1) boundary condition
The boundary condition of spot welding simulation can mainly be divided into 3 kinds of electric border, thermal boundary and mechanical boundaries: electric border: having voltage drop and piece surface voltage between electrode end surface is zero; At electrode and part outside surface
Electric current is zero, and electric current only passes through in part and part surface of contact.Thermal boundary: convection current is arranged at electrode and part outside surface and ambient air; Electrode and part, part and part
Surface of contact has heat conduction, and the contact region does not then produce convection current with outside air; The thermal-radiating quilt that influences
Ignore.Mechanical boundary: electrode force is acted on electrode end surface as even distributed force; Because the rotational symmetry transversal displacement is restrained;
Part and part not contact area do not transmit power.
2) selection of key point
In order to estimate the assembling deviation after bodywork parts welds, the present invention defines the key point notion, in order to weigh the part assembly quality.The following factor of main consideration of choosing of key point:
1. in the measuring point set of body in white three coordinate measuring engine measurement, about waiting to study the measuring point of part;
2. when part enters next assembling after an assembling process, can guarantee function point with other parts coupling;
3. in the entire car manufacture process, guarantee the function point that these parts mate with the vehicle body gadget in total process of assembling.
The criterion ignored of 3) spot welding thermal process
Set up the simulated technological process of structure analysis and electric heating coupling analysis.By pinpoint welding procedure of several circulating analogs, direct method is found the solution the coupling that electric heating is coupled, indirect method is found the solution structure and temperature.
The present invention has compared the analog result and the experimental result of assembling deviation.The no hot calculated value of ignoring pinpoint welding procedure thermal effect influence in bond pad locations has bigger difference with the corresponding average value measured and the hot calculated value that has of consideration pinpoint welding procedure thermal effect; Yet, far away more apart from solder joint, do not have hot calculated value, have hot calculated value and average value measured approaching more, and three groups of data are very approaching when distance solder joint 10mm.Therefore, in the automotive bobdy sheet metal part assembling deviation analytic process under having typical solder joint arrangement condition, can ignore the influence of spot welding thermal process, directly replace through the part deformation behind the whole pinpoint welding procedure, thereby simplified the analytic process of deviation propagation law in the bodywork parts assembling to overcome the part deformation that the part tolerance clearance causes because of the electrode force effect in the pinpoint welding procedure precompressed stage.
4) based on the finite element analogy of the bodywork parts assembling process of contact analysis
Deviation is as unique input, anchor clamps " 3-2-1 location ", and with displacement formal constraint part, clamping force and spot-wedling electrode power realize overcoming the part deformation in part deviation and the process.Foundation is based on the finite element analogy model of the bodywork parts assembling process of contact analysis, by finite element softwares such as ANSYS with shell unit divide complicated automotive bobdy sheet metal part, node coupling scheme simulation spot welding connection, osculating element simulation part arrives nominal rigging position, the deviation of simulation key point in assembling process changes, the welding quality of computation structure body, the input central computer.
4, body structure matching optimization
The size quality of the assembly that obtains according to the welding simulation subsystem is an objective function with the gap and the flatness of vehicle body assembling, realizes the optimization of matching of whole assembly structure by optimal combination.
The present invention has outstanding feature and beneficial effect, realize the stamping forming simulation subsystem by center-controlling computer, the exchanges data feedback between welding simulation subsystem and the matching optimization subsystem and the mediation of data, can directly utilize the physical message and the geological information of the technological parameter that CAD software provided, the dialogue bodywork parts carries out virtual manufacturing and assembling on computers, thereby obtain the digital white car body model machine, make the process of designer's actual manufacturing of real simulated in virtual environment, the multiple design proposal of express-analysis is until obtaining system-level optimization design scheme.The present invention provides a cover high-efficiency method for the exploitation of digital white car body sample car, compares with the manufacture method of traditional physical prototyping and can shorten the cycle that model machine is made greatly, and can realize system-level prioritization scheme; Compare with existing virtual prototype development approach, the control efficiency of data stream is higher, and precision is significantly improved.
Description of drawings:
Fig. 1 is a system construction drawing of the present invention.
Fig. 2 is that the key point and the bond pad locations of instrument panel welding simulation in the embodiment of the invention arranged synoptic diagram.
Wherein, Fig. 2 (a) chooses (y=0 symmetry) for key point, and Fig. 2 (b) distributes for solder joint.
Fig. 3 is an instrument panel matching optimization result schematic diagram in the embodiment of the invention.
Wherein, Fig. 3 (a) is for choosing gap and face difference index, and Fig. 3 (b) is the matching optimization result.
Embodiment:
For understanding technical scheme of the present invention better, below be described further by the drawings and specific embodiments.
As shown in Figure 1, method of the present invention data transmission Network Based, three technological processs are independently finished on the computing machine at three respectively.Center-controlling computer is connected with the matching optimization subsystem with stamping forming simulation subsystem, the process simulation that is welded subsystem respectively, and is connected with the output memory device with intranet.By exchanges data and feedback between three technological processs of center-controlling computer realization, last result exports by printing, plotting equipment.
The stamping forming simulation subsystem carries out emulation to punching course, calculates the forming quality of covering.The deviation of the process simulation that is welded subsystem calculating welding process is calculated the assembly quality of assembling back structure, and passes through center-controlling computer, the exchanges data between realization and the stamping forming simulation subsystem.The matching optimization subsystem carries out matching optimization to assembly structure.Center-controlling computer is connected to intranet and output memory device, and the digitizing body in white result of generation is by output memory device, stores or printout.
Input parameter is diel model, vehicle body product model and soldering cramping apparatus model among the figure, and the stamping forming simulation subsystem is analyzed the diel model, obtains the stampability of covering, calculates the size quality of stamping parts.The control module of result of calculation input center-controlling computer is judged forming quality, if result of calculation does not meet the demands, will revise information feedback to product model or mold former, carries out corresponding modification, up to satisfying forming requirements.If satisfy forming requirements, then result of calculation is imported cooperative module.The finite element model that cooperative module reads in stamping parts generates the data cloud atlas, according to the extraction accuracy requirement of setting, the singular point that rejecting causes owing to the reason of calculating or change, and whole part is cut apart the face unit of several regular shape, each face unit is reconstructed, promptly be linked to be line, line is linked to be face, final formation can reflect the three-dimensional model of part true form, input welding simulation subsystem.Pinpoint welding procedure analog module in the welding simulation subsystem is based on structure analysis and electric heating coupling analysis, by pinpoint welding procedure of several circulating analogs, and direct method is found the solution the coupling that structure and temperature are found the solution in electric heating coupling, indirect method., divide complicated automotive bobdy sheet metal part, node coupling scheme simulation spot welding connection, osculating element simulation part with shell unit and arrive nominal rigging position, the simulation welding procedure by finite element software ANSYS5.5 based on contact analysis assembling deviation analog module.Result after the calculating delivers to center-controlling computer, control module is analyzed result of calculation, if the size quality of assembling surpasses setting value, then center-controlling computer turns back to stamping forming simulation subsystem or vehicle body product model and diel model with modification information, again revise correlation parameter, formability to covering is carried out simulation analysis again, analyzes to import the welding process simulation subsystem into as input.If the size quality of assembling meets setting value, then the result of calculation of welding process simulation subsystem is imported the matching optimization subsystem.According to requirement to the product matching feature, set up objective function with gap and flatness minimum value, the coupling face location parameter of assembly structure is optimized calculating.Obtain the digital virtual model machine of body in white at last.The result is still delivered to the other parts of intranet by the control module decision of center-controlling computer by the terminal device printing stored.
Embodiment:
1, stamping forming simulation
Initial instrument panel design drawing is scanned, the drawing information after the scanning is carried out vectorized process, and generate the three-dimensional entity model of instrument panel.
Utilization finite element pre-processing software DYNAFORM on the basis of the product model of instrument panel, generates the cad model of diel each several part and blank, and divides finite element grid.
The actual stamping process of utilization LS-DYNA3D software simulation instrument panel obtains back, " shaping " back to Strain Distribution and forming limit diagram.
2, the processing of cooperative module
The stamping parts finite element model that stamping forming simulation is generated is sent to center-controlling computer, calls cooperative module and handles.The accuracy class that is provided with is 3 grades, through the actual three-dimensional model of punching press folder after the surface reconstruction generation punching press.
3, the process simulation that is welded
Boundary condition is: spot-wedling electrode power is 200
Kgf, the voltage between top electrode and the bottom electrode reduces to 1.0
V, welding current 8000
A, be 10 cycles weld interval, and welding current is 50Hz, and environment temperature is 20 ℃.
The selection of key point: the structure behind spot welding assembling steering box crossbeam and the cowl upper will form the support slot that front windshield is installed.Therefore, in order to estimate the assembly quality of steering box crossbeam and cowl upper, choose point relevant with supporting front windshield on the cowl upper part as key point, requiring with the assembling function that guarantees the installation front windshield is foundation, estimates its assembly quality.Key point is shown in Fig. 2-a.
Path of welding is (Fig. 2-b): clamp part, order spot welding tie point 1-2-25-26, anchor clamps discharge then, positive and negative along vehicle body y axle to while pad 3-4,5-6,7-8,9-10,11-12,13-14,15-16,17-18,19-20,21-22 and 23-24, the order of formation 3-5-7-9-11-13-15-17-19-21-23 and 4-6-8-10-12-14-16-18-20-22-24.Obtain part gap, electrode force and part welding deformation.With the deformation result of part input center-controlling computer, meet the requirements, the result is input to the optimization of matching submodule, carries out the matching optimization of face difference and gap between these parts and other parts.
4, body structure matching optimization
(Fig. 3-a) is the optimization aim function and the constraint condition of optimal value: f=Min (ω with gap and flatness in foundation
1g
1 u+ ω
2g
1 v+ ω
3g
2 u+ ω
4g
2 v+ ω
5g
3 u+ ω
6g
3 v+ ω
7d
1 5+ ω
8d
2 5)
| d
1 5|≤1|d
2 5|≤1 ω
1ω
8For considering the heavy and normalized combined influence coefficient of target of full powers.After assembling is optimized (Fig. 3-b): minimum slit is 2.8mm, is 3.3mm to the maximum, and the face difference is less than 0.5mm.
The present invention designs the model machine of front panel, compares with traditional physical prototyping trial-production method, and the construction cycle has shortened 50%.
Claims (3)
1, a kind of digital white car body sample making method, it is characterized in that the model machine manufacture process being carried out simulation analysis by setting up stamping simulation subsystem, welding simulation subsystem and matching optimization subsystem, realize exchanges data and feedback between each submodule by center-controlling computer, the optimum digital mockup of manufacturing system level specifically comprises the steps:
1) stamping forming simulation
At first the original design drawing is scanned, form raster pattern, carry out the processing of vector quantization, in the Cartia system, carry out three-dimensional modeling, form the geometric model of an actual 3 D deformation situation of complete reflection; Adopt the Belytschko-Tsay shell unit to carry out the pre-treatment of simulation analysis again, with the large deformation elasto-plastic finite element method analytical calculation is carried out in the geometric configuration variation of sheet material before and after being shaped, obtain each parameter in the stamping process and the situation of change of physical quantity, the result imports central computer;
2) cooperative module is handled
The flow direction by the control module judgment data in the center-controlling computer.If result of calculation meets the requirements, based on the cooperative module of the technology of surface reconstruction part finite element model constructing curve according to the punching course generation, foundation can reflect the solid model of part true form; Realize the rapid data conversion between stamping simulation subsystem and welding and assembling technics simulation subsystem; If result of calculation is undesirable, will revise then that data feed back to product model or mold former is made amendment;
3) process simulation that is welded
Pass the model of the bodywork parts of coming according to center-controlling computer, calculate because the structure assembling deviation that the welding assembling process causes, input as the matching optimization subsystem, set the boundary condition of spot welding simulation and select key point, replace through the part deformation behind the whole pinpoint welding procedure to overcome the part deformation that the part tolerance clearance causes because of the electrode force effect in the pinpoint welding procedure precompressed stage, by finite element softwares such as ANSYS, the deviation of simulation key point in assembling process changes, the welding quality of computation structure body, the input central computer;
4) body structure matching optimization
The size quality of the assembly that obtains according to the process simulation subsystem that is welded is an objective function with the gap and the flatness of vehicle body assembling, realizes the optimization of matching of whole assembly structure.
2, as the said digital white car body sample making method of claim 1, it is characterized in that when being welded process simulation, make up the criterion ignored of spot welding thermal process, promptly ignore at distance solder joint 10mm with interior heat affecting.
3, as the said digital white car body sample making method of claim 1, it is characterized in that when being welded process simulation, foundation is based on the finite element analogy model of the bodywork parts assembling process of contact analysis, with shell unit divide complicated automotive bobdy sheet metal part, node coupling scheme simulation spot welding connection, osculating element simulation part arrives nominal rigging position, simulation points is welded and joins process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB021114617A CN1141643C (en) | 2002-04-23 | 2002-04-23 | Digital white car body sample making method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB021114617A CN1141643C (en) | 2002-04-23 | 2002-04-23 | Digital white car body sample making method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1375770A CN1375770A (en) | 2002-10-23 |
| CN1141643C true CN1141643C (en) | 2004-03-10 |
Family
ID=4741579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB021114617A Expired - Fee Related CN1141643C (en) | 2002-04-23 | 2002-04-23 | Digital white car body sample making method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1141643C (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100401257C (en) * | 2005-02-25 | 2008-07-09 | 浙江大学 | Method for fast simulating tension diameter-reducing procedure of seamless steel tube |
| CN102380521A (en) * | 2010-08-30 | 2012-03-21 | 上海世科嘉车辆技术研发有限公司 | Size verification method of modified vehicle on basis of platform vehicle type with large size deviation |
| CN105788408A (en) * | 2013-03-11 | 2016-07-20 | 林肯环球股份有限公司 | Importing and analyzing external data using a virtual reality welding system |
| CN103440388B (en) * | 2013-09-06 | 2017-03-01 | 上海大众汽车有限公司 | The method that Virtual assemble is evaluated to car quality of match |
| CA2948103A1 (en) | 2014-05-09 | 2015-11-12 | Bombardier Inc. | A method and system for quantifying the impact of features on composite components |
| CN107844630A (en) * | 2017-09-28 | 2018-03-27 | 柯马(上海)工程有限公司 | A kind of method for building up of white body welding dummy emulation system |
| CN108465964B (en) * | 2018-03-19 | 2021-06-01 | 武汉天喻软件股份有限公司 | Three-dimensional white car body welding process card compiling method based on welding spot structured data |
| CN109985952A (en) * | 2019-04-02 | 2019-07-09 | 郭鸿波 | A kind of slab punch forming process for automobile panel |
| CN112097673B (en) * | 2019-06-18 | 2022-11-15 | 上汽通用汽车有限公司 | Virtual matching method and system for vehicle body parts |
-
2002
- 2002-04-23 CN CNB021114617A patent/CN1141643C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1375770A (en) | 2002-10-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109284515B (en) | Sheet material plastic forming limit determining method based on finite element calculation and analysis | |
| CN1141643C (en) | Digital white car body sample making method | |
| CN101339574B (en) | Concrete stirring vane die face design system and method based on springback compensation | |
| CN100465580C (en) | Analogue method for punching mould structure analysis value | |
| CN106269998B (en) | Weld integral panel online adaptive laser peening straightening method and device | |
| CN106407567B (en) | A kind of RV Parametric Design of Reducer modeling method | |
| CN108520119A (en) | The analysis method of automobile accessory frame installation point intensity | |
| CN111460710B (en) | Composite material solidification deformation simulation modeling method based on wire laying track | |
| CN105689560A (en) | Automobile covering part mold manufacturing method | |
| CN102096748A (en) | Body optimization design method of light-weight large-stiffness fine blanking press machine | |
| CN111950080A (en) | Vehicle body lightweight design method | |
| CN105893661A (en) | Multiple-station-progressive mold base-body structure topology optimization method | |
| CN107900255A (en) | Fender cold stamping Springback Analysis and the compensation method of holotype face | |
| CN101567092A (en) | Method for optimizing and simulating machining process of crankshaft lathe of large boat | |
| CN101559511A (en) | Method for analog calculation of welding value by taking temperature as control variable | |
| CN1169638C (en) | Quick shape-rgulating multi-point sheet material formation device | |
| CN101992582B (en) | Cooperative machining method for large sandwich component | |
| Wu et al. | Study on simulation of stamping process and optimization of process parameters of fender | |
| CN103400000B (en) | The deformation of a kind of CAD digital-to-analogue generates method and system | |
| CN110765647A (en) | Rapid design method for front bumper checking fixture | |
| CN109255141A (en) | A kind of body of a motor car forward direction conceptual design cross sectional shape optimization method | |
| CN106980742A (en) | A kind of load projection mapping method that punch forming information is introduced to limit element artificial module | |
| CN109214100B (en) | Sheet material rapid forming prediction method | |
| CN111125879A (en) | Digital twinning method and device for numerical control skin stretch-forming machine | |
| CN202803857U (en) | Multifunction three-machine-linkage bending machine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20040310 Termination date: 20160423 |