Characteristics and design principles of die spring

发布日期：2018-8-14 点击数：288 次 新闻来源：

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

近年来随着模具工业发展，模具弹簧尤其是异形截面钢丝模具弹簧的应用数量和品种日益增大。异形截面模具弹簧具有刚度大、寿命长、体积小等特点。但其设计理论发展比较迟缓。目前，除正方形截面强力弹簧的设计方法比较成熟外，其它截面强力弹簧的设计方法，基本是根据具体截面通过试验，找出修正系数得出具体截面的经验设计公式，现对该类弹簧特点和设计问题作一简介。

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.

这个问题，是使用这种弹簧者很关心也必须搞清楚的问题。下面以正方形截面与圆截面螺旋弹簧作一比较。

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.

在相同空间内，正方形截面钢丝弹簧承载能力比圆截面簧要高43-48%。显而易见，矩形簧要大于50%以上。

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%.

从使用应力过大是弹簧破坏的主要原因分析，在相同条件下，异形截面钢丝弹簧比圆截面钢丝弹簧的寿命要提高13-14%。

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.

异形截面钢丝弹簧能产生大的变形量。

Profiled wire springs can produce large deformation.

异形钢丝弹簧的重量大。

The weight of profiled wire springs is large.

线性度比圆截面弹簧好，即刚度更趋于常数值。特别是长边平行于轴线绕制的弹簧。

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.

应用范围受到一定的限制：从分析可见，异形截面材料弹簧如不能充分应用其优点，便不会产生经济效益，什么情况下使用好呢？

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)用圆截面材料达不到设计载荷。

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

(2)取代圆截面复合弹簧。

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

(3)用圆材料弹簧达不到所需要变形量的时候。

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

(4)弹簧安装空间小的地方。

(4) spring installation space is small.

(5)要求弹簧特性严格的地方。

(5) strict requirements for spring characteristics.

二、模具弹簧设计原则

Two. Design principle of die spring

1．弹簧材料许用应力[τ]的选择，应以保证弹簧疲劳寿命为主进行考虑。

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

弹簧的动态寿命，一般分为三类：

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

Ⅰ类：承受交变载荷次数为106；

Class I: the number of alternating loads is 106.

Ⅱ类：承受交变载荷次数为103-105；

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

Ⅲ类：承受交变载荷次数小于103；

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

2． 材料宽厚比(a/b)不宜过大，而弹簧的旋绕不宜过小。

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． 设计非矩形的异形截面弹簧时，一定要推导和绘制在不同旋转比、不同宽厚比与变形修正系数(τ)和切应力修正系数(β)的曲线或计算公式。

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． 要根据给定条件和限制条件，选择计算简便和参数选择合理的设计方法。

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

三 尚存问题

Three surviving problems

1．模具设计标准化程度低，限制了标准化模具弹簧的发展速度。

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

2．模具弹簧标准化程度低，目前除我所为汽车工业制定的QC7111-7113标准外在国内尚无正式使用的国标或行业标准，模具设计人员无标准可选是急待解决的问题。

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．设计理论不完善，目前比较成熟的是矩形截面螺旋弹簧，但对其公差选用尚无定论。其异形截面螺旋弹簧均以矩形截面为基础，经试验加以修正。

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．没有异形截面材料生产的定点厂，特别是没有此类材料的油淬火回火钢丝供应厂家。而由弹簧制造厂自己改制的材料，质量不稳定，造价高，影响此类弹簧的推广应用。

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．没有生产此类弹簧的专用卷簧设备。模具用螺旋弹簧旋绕比一般都小于4，而国内卷簧机适用绕制旋绕比在4以上的弹簧。

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.