Seized a car design What are the steps? Auto parts seized a small series to promote small series one by one to tell you it.
1、the workpiece and seized a car design modeling - seized a car first reference part drawings analysis artifacts, tentatively fixture design program to determine the reference plane, convex case, the detection section and the positioning surface gages, etc., and simply draw its two-dimensional schematic.
Seized a car in the design, seized a car standard parts and maintenance methods and what? Subject specific design modeling is the key, it directly affects the ability to accurately detect the seizure of the workpiece quality.
Since the body panels to the free surface of the main characteristics of "in-kind reverse" is the common method currently modeling. Reverse workpiece or physical prototype that is based on already existing data acquisition using a laser scanner and after data processing, 3D reconstruction and other processes, construction method Prototype models have specific shape of the structure. We use the laser scanner to the standard workpiece surface sweeping, collected point cloud-based surface feature information, the point coordinates are transformed into the body coordinate with surfacer software processing point letter, to obtain characteristic curves curved surface thereby generating a final free-form surface model; while the maximum and minimum distance to the surface through the point cloud to detect prototype model generates. It should be noted that at this time the resulting model is not the thickness of the sheet body model, the model is to distinguish between the inner or outer surface of the workpiece according to the scanner sweeping surface, which is particularly important for detecting specific design.
Achieve seizure freedom with the detection of the workpiece surface, so that the general subject of specific surface and the inner surface of the workpiece to maintain a constant 3 or 5mm gap, CNC machine tools can achieve high accuracy requirements in accordance with the design of digital-analog-type surface, through the actual testing gage profile with a dedicated measuring reciprocate to measure the deviation of the workpiece surface. The outer contour of the workpiece detection methods are mainly two design corresponding to gage when: ① specific subject workpiece surface contour cut along the outer outwardly extending about 20mm; ② extending about 20mm along the outer contour of the workpiece normal direction downwards. In general CAD software (such as UG), the surface inward offset3 or distance of 5mm (part model is generated if the outer surface, in making offset plus the thickness of the workpiece), then put along the surface its outline tangential or normal extension 20mm, to give the subject of specific detection surface, again drawing plane at a distance that is the subject of specific models. Since the body panels is more complicated, particularly when generating the detection surface of the subject combination of these two methods is often required, and for some special type of surface, it is still difficult to achieve. Figure 2 shows a schematic diagram of the processing of complex surfaces. FIG engine bearing surface within 1,2 two significant interference generated from the intersection and, in order to ensure that the main contour of the workpiece to be detected at the expense of having to detect vertical height difference at the corners to form the subject shown in FIG. specific surface, and finally check the specific interval along the surface of the workpiece contour and 3mm double-crossed, in order to facilitate detection of the workpiece contour. Of course, in the seizure (especially check specific) design will encounter many similar problems, we need to understand and experience penetration gages principles for post-processing.
2、sectional design modeling template for key-shaped surface of the workpiece is detected by the general cross-sectional model to achieve, model gage section is divided into rotary and insert two, when the cross section template over a span of 300mm, in order to ensure the vertical direction detection accuracy will usually be designed to be inserted into the formula. Check specific surface inspection is the inner surface of the workpiece, the model section across the outer surface of the workpiece to detect critical sections of the outer surface, generally from the working surface of the workpiece outer surface of 2-3mm, and the seizure of its modeling approach similar surface. Section template plate material is generally a metal such as steel or aluminum, the surface of the work portion may be made of aluminum or resin. Complex-shaped cross-sectional surface of the template while rotating or inserting cause interference, the actual design of its segments can be processed, as shown in FIG.
If set to plug-sectional model, the interference with the workpiece positioning pin occurs; if set into a single rotary, multi-fold due to the nature of the work itself, and check the specific cause or workpiece interferes be designed into two independent rotary section template, you can meet comprehensive test requirements.
3、workpiece positioning and clamping - seized a car right and proper positioning of the workpiece is accurately measured basis. Body panels in the seizure of the main methods of positioning by the positioning hole and the positioning or clamping collet clamping with the completion of the permanent magnet. With Gage widely used in body construction, the lever-type activities and a permanent magnet chucks series products are optional, movable chuck is also equipped with different types and sizes stand or rack. Most of the body panels have main and auxiliary two positioning hole, the main positioning pin is generally cylindrical pin (hole) or a diamond pin (back hole) to limit the degree of freedom in two directions X. Y; vice positioning pin conical pin or diamond peg to limit ZXYZ four-way freedom. Design of the seizure, the seizure in particular by positioning hole punch (to put positioning pin bushing date), and gives the positioning hole of the vehicle coordinate. At the same time, the workpiece good rigidity and a reasonable distribution of location and activities arranged positioning spacer chuck to ensure secure positioning of the workpiece design should minimize the number of clamping points, to ensure that no interference with other components when the movable chuck work, taking into account the convenient operation of the workers, given the final body positioning coordinates of the center of the gasket surface.
4、backplane assembly design in specific subject on the surface along the plane direction stretch a certain distance, so that the lowest point greater than the thickness of 150mm, to ensure that the specific subject of sufficient strength, while trying to make the bottom surface of the specific subject, namely the base plate assembly the upper surface (base) in the vehicle coordinate system integer position. Concrete floor by the general assembly of the subject substrate channel (if necessary, add beam in the middle), and positioning block caster composition, particularly when the substrate is fixed by the prosecution, the other member can choose the standard model based on the actual situation.
5、hole detecting body stamping in many important holes and cuffs, etc. require separate testing. In the seizure of the design on the surface of specific subject generally add about 1mm thick bosses, and the workpiece center hole center boss on the same axis, the diameter of the aperture is larger than 5mm, and bosses with double crossed when measured hole detection accuracy is relatively high, the use of positioning holes manner as plug and bushing testing. In the large body panels, since this type of seizure of the complex shape, bulky, high production costs, a single detection target, poor flexibility, difficult to quickly get a lot of accurate information it has gradually been advanced automated detection methods (such as online detection systems) are replaced, but for the detection of small stampings mass production, automobile manufacturers present, China is still mainly rely on this type of gage.
