Application of the hottest UG three-dimensional te

2022-10-13
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In recent years, with the rapid development of 3D CAD technology, its application in the field of mechanical engineering has become more and more extensive. Especially in mold design and manufacturing, 3D CAD software is a powerful help for designers, which effectively improves work efficiency and reduces labor intensity. Among many 3D CAD software, UG has occupied a leading position in the industry for a long time with its powerful functions

ug is a feature-based, fully parametric aided design software, which can realize CAD, CAE, cam and other functions, covering all fields of mechanical design. It has many features that are very suitable for mold design and Transformation:

for example, direct modeling can quickly model on existing features, which is conducive to mold structure changes

parametric design can quickly change the design size, without avoiding cumbersome size calculation

geometric connection can quickly establish the corresponding relationship between assembly parts, make some parts change with the changes of key parts, and realize the effect of "pulling a hair, but moving the whole body"

accurate interference inspection and dimension measurement can enable designers to know the assembly relationship between parts at the first time, understand the effect of design, and avoid interference in actual assembly

the simple three-dimensional and two-dimensional conversion and drawing function can quickly complete the drawing of part drawings, reduce repeated labor and shorten the design cycle

there are also many features, which will not be described one by one here. Next, with an example, I will share with you the application of the powerful functions of UG in the rapid transformation of molds

our company originally produced a casing with a diameter of 96mm, which is rolled by Φ 96 shell rounding die is completed. See Figure 1 for the outline of the roll round die. Due to the need of new product development, our company will change the original 96mm diameter casing to 105mm, so it needs to be redesigned Φ 105 shell rounding die

2. Analysis of transformation ideas

in order to maintain the original function, structure and accuracy of production equipment, save costs and reduce the difficulty of transformation, the original parts and components should be changed as little as possible. The changes can be concentrated on some key parts. Here, the key parts refer to those mold parts affected by the size change of machined parts, as well as some parts that can concentrate the changes of other parts on their own. This idea can be realized through the functional characteristics of UG. Based on this idea, we change the size according to the machined parts (here, the casing diameter is determined by Φ 96mm becomes Φ 105mm) find the mold parts associated with it, discharge the corresponding dimension chain, and determine the key parts. In the transformation of this pair of winding round die, because the shell only increases the diameter size, that is, the length of the processed plate becomes longer. As for the width direction, because the original winding round die can adjust the spacing in this direction, there is no need to consider the change here. The lengthening of processing sheet metal leads to the change of the winding mechanism, feeding and unloading mechanism of the die. We will transform the mold from these parts

3. Application of UG in the process of mold transformation

(1) rounding mechanism: Figure 2 shows the schematic diagram of casing rounding. The diameter of the casing increases, which directly affects the diameter of the mold core. At the bottom of the figure are three ways to change the mold core. 1. II the two methods will lead to more parts involved, including the middle die part, and the stroke of the punch must be recalculated. If the method of III is adopted, the position of the middle mold does not need to be changed, and the dimensions of other parts are changed based on the center of the original mold core; After changing the upper and lower dies, it is not necessary to adjust the setting parameters of the punch. Finally, we adopted mode III. If the change method is determined, the relevant dimension chain can be discharged. We use UG software to integrate the original Φ 96 3D modeling and virtual assembly of the parts of the shell rounding die. With the powerful parameterization function of UG, the Φ If the size of the shell rounding die is assigned to UG, the original part size and the assembly dimension chain can be easily and quickly changed. With mode III, the position of the mold core remains unchanged, so that the datum of the upper and lower molds and side molds also remains unchanged. Just enlarge the size of the original mold core to 105mm. At the same time, the shape of the upper and lower molds and side molds are matched into a circle with the mold core, and the dimensional relationship is established in UG. The dimensions of the upper and lower molds and side molds are automatically changed to match the modified dimensions of the mold core. The change effect can be seen quickly on UG. After UG interference and dimension measurement, if interference is found, the original data will be corrected in time

with the same method, the positioning of the wedge baffle in the rounding mechanism can be completed. Using this method, the transformation can be completed quickly and is not easy to make mistakes

(2) feeding mechanism: in mode III, the sheet metal rises by a distance of ()/2=4.5mm, resulting in the height adjustment of the feeding mechanism. As mentioned above, if the size changes of parts are concentrated on key parts, the amount of changes of parts can be reduced, the difficulty of transformation can be reduced, and the efficiency can be improved. Coincidentally, all parts of the feeding mechanism are installed on the feeding mounting base, so as long as the thickness of the feeding mounting base is changed, the effect can be achieved

the die adopts the air cylinder to push the sheet feeding, and the four sheets are fed in turn with their heads and tails connected. As the length of the sheet is longer, the feeding mechanism should also be longer. For this reason, it is necessary to recalculate the length of the feeding plate. In order to simplify the design and reduce the error at the same time, according to the previous basic idea, we focus all the size changes on the last feeding plate, as shown in Figure 3 according to the above standards and the requirements for the experimental machine. Other dimensions including installation relationship remain unchanged. In this way, the length of the last feeding plate can be extended outward on one side. This part of the change is the best embodiment of our change ideas. The connection form of the four sheets is shown in Figure 4. The plates are staggered and meshed, and they can be easily meshed together by using UG interference inspection, so as to calculate the total length, with high accuracy. Based on the first plate, its position remains unchanged (the center of the modified plate is aligned with the center of the mold core before and after the modification), and the other plates move outward in turn. In terms of size determination, the function of wave geometric relationship connector of UG can be used. It can design new parts based on an established part. Using this function, first establish the position of the sheet metal, and then design the last feeding plate whose size needs to be changed according to the geometric surface, line and point of the sheet metal. For example, to calculate the length of the last feeding plate, you can select the outermost side of the fourth plate, and then the designed feeding plate length can only exceed this side. In this way, it greatly facilitates the design. In traditional design, we have to calculate the size ourselves and then draw the drawing; In UG, the calculation process in traditional design has been completed in the process of drawing

the lengthening of the sheet metal will inevitably lead to the lengthening of the pusher plate driven by the cylinder. The amount that needs to be changed can be measured in UG through the length of the sheet metal and the length of the last feeding plate, and then the original parts can be changed with the direct modeling function of UG

(3) unloading mechanism: the mechanism as shown in Figure 5 is used in the mold for unloading. When the casing diameter becomes larger, the diameter of the ejector ring and the length of the ejector bar will change. These changes are closely related to the size change of the mold core. Using UG parametric design to establish the expression, the diameter of the mold core can be associated with the diameter of the ejector ring. As long as the size of the mold core is changed, the ejector ring will automatically adjust. Similarly, the support frame for fixing the jacking cylinder should also be changed with the change of the jacking ring. We use the wave geometric connector of UG to make the positioning screw hole on the support frame automatically change with the change of the support frame. In UG modeling, it is very necessary to establish a perfect dimension and assembly Association, which will effectively improve work efficiency

in addition to the transformation of the main mechanism of the above mold, some structural improvements can also be aided by UG. For example: 1. The feeding side plate becomes thick because of its longer size. For this purpose, remove the screw countersink on the side plate, so that the side plate becomes light and thin. The shape of the side plate and the position of the screw hole on the side plate can be directly generated with the geometric relationship connector of UG. 2. Protect the cover plate of the feeding cylinder. In order to facilitate disassembly and maintenance, the installation form is changed from the original screw connection to the plug-in extraction plate, and the screws are omitted. Use UG to directly generate the slot of the support plate by using the drawing plate shape. 3. The stroke of the feeding cylinder increases due to the lengthening of the sheet metal. With the gap detection and measurement function of UG, the required stroke of the feeding cylinder can be quickly calculated. The feeding cylinder was originally a fixed flexible packaging, which increasingly highlights the importance of light packaging attributes on the mounting base, but the last section of the feeding plate extends outward for a distance. In order to ensure the installation position, we added a support frame without changing other parts. The size of the support frame is related to the mounting base, and the part can be quickly generated with the geometric relationship connector of UG. Another reason for adding this support is to improve the structure. Originally, the cylinder is fixed on a plate connecting the last feeding plate and the feeding mounting base respectively, so that there are many parts in contact, which is easy to be affected by the processing errors of multiple parts, causing installation errors and causing the feeding mechanism to jam. Therefore, the support frame is used to fix the cylinder separately to avoid the above problems. 4. There are many adjusting mechanisms in the die that use nut sliders that slide along dovetail grooves. For these sliders, it is necessary to ensure that the dovetail groove is symmetrically arranged and the screw installation position is centered. The length of some sliders affects the layout of dovetail grooves. Using the feature modeling of UG, it becomes simple and rapid to change their positions

with the help of UG, the transformation task was completed quickly. Then UG can be used for structure and motion analysis. A rough understanding of those parts is not strong enough and the structure is unreasonable; Those movements may interfere. For example, the stress-strain analysis of the cantilever beam of the mold core under pressure can, in turn, redefine the structure and size of the parts. The motion simulation of the rolling process can help us further consider the optimization of the mechanism and determine the best motion parameters. The two-dimensional plotting of UG can easily transform three-dimensional graphics into two-dimensional plans. UG provides sectional views, local views, rotation views, cross sections and other views, which can be quickly generated both part drawings and assembly drawings, greatly improving the efficiency compared with traditional methods

4. Conclusion

using UG for transformation design can intuitively display various structures and understand the rationality of the structure. Its geometric relationship connector function can establish new parts based on the designed parts, without considering the size first, and focus on the structure, and the size is determined by the feature parameters of the existing parts. The assembly relationship is established by expression, and the size is quickly changed by parameterization. In addition to the functions of preheating the machine for 20 ~ 30min, UG has many other functions, which need further practice and learning. When transforming the mold, try to focus the changes on the key parts, and try to use the size of the pressure plate (mm): φ 150. Maintain the original function and structure to save costs and improve efficiency. With the help of UG, technicians can devote more energy to the design itself rather than the tedious work such as calculation and drawing. It brings us a new design concept and is a powerful tool for mold design. (end)

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