Swift preset strategy for trapezoidal integrated body plate spring frame
Traditional parabolic blade design calculations are as follows to avoid tipping of the blade ends. The coordinate selection makes the blade section curve contain three-segment function, that is, two-segment straight line and a parabola. The straight-line segment l1 is clamped on the axle and does not participate in the work. The straight-line segment l2 is used to avoid the end tip setting. This is much more complicated than a simple standard parabola. The traditional trapezoidal blade design <1> calculation diagram directly applies the parabola design calculation diagram, for example, the form is consistent, but because the functions contained in the two are different, the derived calculation formula is self-contained. In a set, the calculation process is essentially not related to the parabola. It does not reflect the basic idea that the trapezoidal variable-section blade is a straight line instead of a parabola. In addition, the trapezoidal blade is a non-equal stress beam. The design calculation result is inevitable and the maximum cross-section of the stress is sought, and the parabola is The design is compared. If it is not satisfied, it has to be adjusted repeatedly according to the above process. Therefore, the workload and complexity of the trapezoidal blade design calculation is much larger than that of the parabolic blade, not to mention the standard parabola design. Traditional parabolic blade design calculation sketch Traditional trapezoidal blade design calculation sketch In fact, the author has seen a certain car factory commissioned several leaf spring factory design variable cross-section spring to replace the original ordinary laminated spring, several designs are all Trapezoidal, but all simply makes the new spring stiffness substantially equal to the original spring stiffness. The reason is that in addition to the designer's own factors, the design workload is large and complicated is also one of the reasons. Therefore, it is even more necessary to seek a more convenient trapezoidal blade design method. The basic idea of ​​the convenient design method changes the coordinate setting of the traditional design calculation sketch, and separates the blade clamping part to simplify the calculation. The leaf spring stiffness is divided into clamping stiffness and inspection stiffness. The clamping stiffness is to exclude the length of the non-working part, that is, the clamping length, and only consider the stiffness of the working part. It is closer to the loading state and is one of the basis for the design of the leaf spring. The test stiffness is the stiffness in the non-clamped state, that is, the stiffness obtained including the non-working length. It is mainly used for product inspection, which can reduce the operation time of clamping and disassembly during the inspection process and improve the inspection work efficiency. Press Yes to convert the given clamping stiffness to the test stiffness and then design. According to Figure 6, the design is directly carried out with the clamping stiffness, and then the test stiffness is calculated, which reduces the complexity of the calculation and is more reasonable. The design and calculation of the six convenient design methods is simple. Since the trapezoidal variable-section blade replaces the parabola with a straight line, based on the standard parabola, a tangent is made on the parabola. When the tangent position makes the area of ​​the triangle AEB the largest, the trapezoidal variable-section blade material is the most utilized, and the parabola is the most alternative. Reasonable state. At this time, the stress at the tangent point is equal to the stress at the same position of the standard parabola, and the stress at other places is smaller than the stress at the corresponding section of the parabolic blade, so the maximum cross section of the stress is no longer needed, and the check process is omitted. Based on the above ideas, the simple expressions of OA and EB are derived. Once OA and EB are calculated, the design of trapezoidal variable-section blades is actually completed. The relationship between the trapezoidal blade and the parabolic blade weight and stiffness, and the tangent point of the standard parabolic tangent at several specific points are derived to facilitate design reference and to correctly grasp the design process and results. Corresponding relationship between the weight and stiffness of the two linear blades. Since both linear blades adopt a variable cross section with equal width and thickness, the area ratio enclosed by the two linear shapes is the weight ratio. The stiffness relationship is here to compare the clamping stiffness of the parabolic blade and the trapezoidal blade in the case where the clamping state is completely uniform, so both can be regarded as rigid clamping to simplify the calculation. The conclusion changes the design idea and coordinate setting, and the traditional design method needs to process the three-stage function and segmentation integration. It is improved to simply design the parabola according to the standard, eliminating the design verification process and getting the convenience. Design method. Through design practice, it has greatly improved design efficiency and shortened design time. The improvement of efficiency is mainly reflected in the artificial design. Compared with the traditional design method, the computer design has no advantage in time, but it can simplify the writing of the design program. Far Infrared Sauna room Guangzhou Aijingsi Sanitary Products Co.,Ltd , https://www.inspirationhottub.com