中文版   ENGLISH
 
   
 
 
 
 
 
News
 
Characteristics and design principles of die spring
Release Date:2018-9-28 Hits:1282 From:


Characteristics and design principles of die spring

Release date: 2018-8-14 hits: 288 news sources:

In recent years, with the development of die industry, the number and variety of die springs, especially the special-shaped section steel wire die springs, are increasing. The special-shaped section die spring has the characteristics of large rigidity, long life and small volume. But the development of its design theory is rather slow. At present, except the design method of square section spring is more mature, the design method of other section spring is basically based on the specific section through the test, find out the correction coefficient to get the empirical design formula of specific section. This paper briefly introduces the characteristics and design problems of this kind of spring.


This problem is a matter which the spring owner is very concerned about and must be clear about. The following is a comparison between the square section and the helical spring with circular section.


In the same space, the load capacity of the square section steel wire spring is higher than that of the circular section spring 43-48%. It is obvious that the rectangle spring is greater than 50%.


According to the analysis of the main cause of spring failure, the service life of the special section steel wire spring is 13-14% longer than that of the circular section steel wire spring under the same conditions.


Profiled wire springs can produce large deformation.


The weight of profiled wire springs is large.


The linearity is better than that of the circular section spring, that is, the stiffness tends to be constant. Especially the spring with long sides parallel to the axis.


The scope of application is limited to a certain extent: it can be seen from the analysis that if the special-shaped section material spring can not fully apply its advantages, it will not produce economic benefits. Under what circumstances can it be used well?


(1) the design load can not be achieved by using circular cross section materials.


(2) replace the composite spring with circular cross section.


(3) when a circular material spring does not meet the required amount of deformation.


(4) spring installation space is small.


(5) strict requirements for spring characteristics.


Two. Design principle of die spring


1. the selection of allowable stress [Ti] of spring material should be considered mainly by ensuring the fatigue life of springs.


The dynamic life of springs is generally divided into three categories.


Class I: the number of alternating loads is 106.


Class II: the number of alternating loads is 103-105.


Class III: the number of times of alternating load is less than 103;


2. the material width to thickness ratio (a/b) should not be too large, and the winding of the spring should not be too small.


3. When designing non-rectangular spring with special section, it is necessary to deduce and draw curves or calculation formulas with different rotation ratio, different width-thickness ratio, deformation correction coefficient (_) and shear stress correction coefficient (_).


4. According to the given conditions and constraints, we should choose a design method which is simple in calculation and reasonable in parameter selection.


Three surviving problems


1. the low degree of standardization of mold design limits the development speed of standardized die springs.


2. The standardization degree of die spring is low. At present, there is no official national standard or industry standard in China except QC7111-7113 standard for automobile industry. It is an urgent problem for die designers to choose standard.


3. The design theory is imperfect. At present, the rectangular section spiral spring is more mature, but the tolerance selection is still uncertain. The helical spring of the special-shaped section is modified on the basis of rectangular section.


4. There are no fixed-point factories for the production of profiled cross-section materials, especially for oil quenched and tempered steel wire suppliers without such materials. The materials made by the spring manufacturer themselves are unstable in quality and high in cost, which affects the popularization and application of this kind of spring.


5. there is no dedicated coil spring equipment for producing such springs. The spiral spring winding ratio for die is generally less than 4, while the domestic coiling machine is suitable for making the spring with the ratio above 4.


Previous:Spring machine classification   Next:How does the leaf spring break and how to deal with it urgently?
 

Copyright ©2023 Zhejiang Yinfeng Automation Technology Co., Ltd. All Rights Reserved.
Add: A3, Yinfeng spring equipment, Yangshan industrial area, Xinjian Town, Jinyun
Contact: General Manager 134-5432-8188
              Manager Huang 188-6782-3279