Shaped springs, flat springs and leaf springs are among the oldest spring applications. Today they are indispensable construction elements in products in many branches of industry. They are mainly used in mechanical engineering, vehicle construction as well as precision engineering and electrical engineering. Their following property in particular has always been used: to store mechanical work as potential energy by absorbing or transmitting forces with relatively large deformation and to be able to release it again at a freely selectable point in time. The property to save and Converting energy enables their use for energy, force and travel compensation. Relevant prerequisites for the extraordinarily diverse use of flat, shaped and leaf springs in the named areas of application are:
- Development of suitable Materials which, in addition to the high strength and deformability that are important for springs, have additional technical properties (e.g. heat resistance, defined thermal expansion, Conducting electricity , antimagnetic etc.)
- Basics for calculation the dimensions of springs that meet the requirements of specified technical tasks; development of Manufacturing process and manufacturing facilities for effective and accurate manufacturing
- Measurement methods and devices for the determination of spring parameters and for checking the spring function during or after completion of production, but also during experimental testing in the product.
For a long time, the design of assemblies in which springs are used involved a relatively high level of experimental effort. This is currently still partially the case, the reasons for this are complex. On the one hand, there are design-related reasons, for example the late inclusion of the springs in the assembly design. On the other hand, the real operating conditions are often only inadequately captured by the available calculation methods. In addition to sufficient experience in the Design of flat, shaped and leaf springs with classic calculation methods, the Finite element method used as a calculation option.
Table of Contents
Applications for shaped springs, flat springs and leaf springs
The uses of flat spring shapes are innumerable and unmanageable. They range from simple leaf springs to complex ones that are precisely adapted to the geometry of the surrounding components Flat springs and flat spring systems. Despite this diversity, a classification can be found in terms of function / purpose as well as spring shape and spring arrangement. The classification shows the function and purpose of these spring applications more clearly.
Classification according to intended use
- Storage elements, the main task of which is to store and convert energy (e.g. drive springs in watches, drives and weapons)
- Measuring elements in which the linear relationship between force and displacement, which is characteristic of many springs, is used (“spring balance”, force and torque sensors)
- Vibration and damping elements in which the vibration property is used as well as the property of cushioning shocks and causing vibrations to subside relatively quickly through internal friction or in connection with damping elements (frequency meter, balance spring, vehicle suspension springs)
- Rest elements with tasks of force distribution, force and path compensation, the generation of preload forces and the implementation of return movements (backlash compensation, making contacts, seals, securing elements)
- Bearing elements in which the flexural or torsional elasticity of the material is used for movements within a limited range (spring and cross-spring joint, tension band bearing)
The spring shape is divided into straight, curved, coiled and disc-shaped springs.
Just Flat springs are often used for contact systems of electrical switching devices, for example in relays. The contact springs made of flat material can be installed preloaded in this way. This shortens the switching travel and the required contact forces can be generated without major deformation of the supported contact leaf spring.
Curved flat springs one differentiates in curved leaf springs and shaped springs . In the case of the curved leaf spring, the spring is composed of straight and circular arcs. Any spring shape adapted to the task at hand is possible for shaped springs. the calculation is mostly problematic. The long-term experience of the technician is required, who often determines the dimensions by means of rough approximations and experiments. Generally valid calculation models are not known. In any case, the design guidelines are important, and in particular the Minimum bending radii must be adhered to.
Under coiled leaf springs will Coil springs with and without space between coils and scroll springs combined. Disc-shaped flat springs , to which disc springs and Spring washers can be used as a single spring or in a combination of springs.
Design and construction
There are many decisions to be made when designing shaped springs, flat springs or leaf springs. These relate to specifications for the type of spring, the spring shape and the dimensions, the spring fastening, the spring material and the manufacturing and testing options. Decision-making aids are mainly calculations on the deformation behavior and the load-bearing capacity (service life) of the springs. The basis for this are the applicable deformation and stress relationships. The two spring-dependent equations must take into account the numerous requirements for the spring and the existing influences. More than two spring parameters must be specified, so an iterative approach is necessary when designing the spring. Function and strength verification must always be carried out for the designed spring. During the proof of function, compliance with the required spring rate, the forces and distances within specified tolerances, the vibration behavior and other requirements placed on the spring must be checked. This can be done in the form of a voltage, safety, load capacity or service life verification. When determining the shape of the spring, in addition to the geometric conditions resulting from functional requirements, it is above all manufacturing and material-technical concerns that must be taken into account in order to achieve minimum manufacturing costs. The design of Metal springs requires in particular knowledge and experience of cold forming and Heat treatment . However, not only the reliability of the spring function depends on the shape of the spring, but mostly that of the entire product in which the spring is used.
Manufacturing
Flat springs, shaped springs and leaf springs Depending on the requirements, shape and number of pieces, they are simply bent or Stamping and bending process manufactured or by Laser cutting with the following Reshaping by bending, embossing, edging and deep drawing. Especially when it comes to deep drawing, there are no limits to the shaping of flat or shaped springs. There will be final Surface treatments such as vibratory grinding, barrel finishing, phosphating, burnishing, galvanizing, painting etc. are offered. Furthermore, the springs can be installed directly in the assemblies provided. The choice of Spring materials is extensive, in addition to normal spring steels, stainless steels, non-ferrous metals and non-ferrous metals are offered in strip form or plate form.
Material thickness: 0.1 to 3.0 mm
Band widths: 1.0 mm – 150 mm
Panel sizes: 1500 x 2500 mm
Production technology: lasers, embossing, punching, bending, grinding, assembling
Surface technology : Tumbling, phosphating, burnishing, galvanizing and painting … other surfaces on request
Well-founded and long experience is necessary for the optimal production of individual shaped, leaf and flat springs. Due to the individual and complex shape, a standardized interpretation and calculation not always possible according to scheme F. Profound practice in the manufacture of flat and shaped springs is required. Therefore Gutekunst Formfedern documents every production in detail and can therefore provide information for subsequent designs.
Gutekunst Formfedern works out the optimal solution for the current tasks directly with the customer. Using a drawing, CAD data , Installation situation and function, the desired requirements are checked and calculated. If necessary, please use our Inquiry form or send your details directly to info@gutekunst-formfedern.de .
Spring request
For more information: