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Extension spring - calculation - information - english - Gutekunst Federn

information extension spring calculation

1. pre-setting side	material properties
2. result page	symbols
3. print / inquire / search	loop shapes

1. pre-setting extension spring calculation

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Material, quality category as per DIN 2095, loop shape and a valid combination of diameter, spring forces, spring deflections and lengths must be entered in the parameter pre-settings.

Standard combinations include i.e.:

De or Di, F2, R

De or Di, F2, R, L0

De or Di, F2, s2

De or Di, F2, s2, F1 or s1

De or Di, F2, L2, L0

De or Di, F2, L2, F1 or L1

You have 3 possibilities for entry:

all calculation pre-settings

Here, all entry windows for the calculation are available.

Di = inner coil diameter (mm)

De = outer coil diameter (mm)

F0 = initial tension (N)

F1 = prestressed spring force (N)

F2 = loaded spring force (N)

s1 = prestressed spring deflection (mm)

s2 = loaded spring deflection (mm)

R = spring rate (N/mm)

L0 = unstressed spring length (mm)

L1 = prestressed spring length (mm)

L2 = loaded spring length (mm)

calculation according to paths and forces

In this case for a better overview, only the windows for the calculation according to paths and forces are available.

Di = inner coil diameter (mm)

De = outer coil diameter (mm)

F0 = initial tension (N)

L0 = unstressed spring length (mm)

s1 = prestressed spring deflection (mm)

F1 = prestressed spring force (N)

s2 = loaded spring deflection (mm)

F2 = loaded spring force (N)

calculation according to lengths and forces

In this case for a better overview, only the windows for the calculation according to lengths and forces are available.

Di = inner coil diameter (mm)

De = outer coil diameter (mm)

F0 = initial tension (N)

L0 = unstressed spring length (mm)

L1 = prestressed spring length (mm)

F1 = prestressed spring force (N)

L2 = loaded spring length (mm)

F2 = loaded spring force (N)

2. result page compression spring calculation

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Once the computation has been started from the "Pre-settings", switch automatically to the "results" computing page which displays all the computed spring sizes.

To complete the calculation you are requested here to select the wire diameter < d > according to DIN 2076 and adapt the number of coils < n > and loops accordingly if required. The selection of wire diameter is compulsory. The nearest five values are available for selection in the drop-down lists. In the case of extension springs, the loop position (angle of rotation between the two loops) is changed by adapting the number of coils < n >.

The values entered from the "pre-setting" and the wire diameter < d > can be altered; they are displayed in white highlighted input fields. All other values are purely output values. The spring is recalculated on the basis of the modified values using the calculate button.

Invalid or faulty calculation results are displayed for you in the text box. Solution possibilities will be presented to you if you click on the individual fault messages.

Important

The tension coefficient "k" is incorporated as standard for the extension spring computation. The tension coefficient "k" takes approximate account of the maximum computed tension of the spring body.

Further functions of extension spring calculation

Loop adjustment
The "loop adjustment" shows all properties and values of the selected loops; it is automatically displayed in the current Extension spring design.

Adjustments are carried out as follows:

For computations in which the unstressed spring length < L0 > and the loop heights < LH1, LH2 > are not predefined, the loops heights are computed using a defined factor for the corresponding loop shape. Aou can adjust these predefined values as required, the correction is applied along the unstressed spring length < L0 >. However, when making the alteration please note the structural limitation of certain loop shapes (e.g. 1/1 german loop: Lh = 0,8 to 1,1 Di).

For computations in which the unstressed spring length < L0 > and the loop heights < LH1, LH2 > or just < L0 > are predefined, an "actual value" and a "nominal value" is computed in the loop adjustment. The function < centralise LH1, LH2 > enables you to align the "actual value" to the "nominal value". Here again please note the structural limitation of certain loop shapes. If necessary alter the loop shape.

Diagrams
The diagrams function provides you with the path-force diagram and the Goodmann diagram in the case of dynamic calculation.

3. print / inquire / search

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You can print the calculation or send it as an inquiry direct to Gutekunst Federn. When you have sent your inquiry you will receive a copy of your inquiry back directly by e-mail.

You can search our catalogue range directly for a suitable spring using the "Search" function. As a standard, the search program works with a tolerance value of 10%. Please note that our catalogue springs are only supplied in the materials EN 10270-1 and EN 10270-3-1.4310.

Gutekunst Federn · Carl-Zeiss-Strasse 15 · D-72555 Metzingen
Phone 0049 71 23 9 60-0 · Fax 0049 71 23 9 60-195
service@gutekunst-co.com

Extension springs - metal springs - formula - english - Gutekunst Federn - 2005

formula extension springs

formula	specification	unit
BstNr	order number
Mat	type of material
Oefo	loop shape
Oest	loop position	degrees
Oesttol	+/- tolerance of loop position	degrees
d	wire diameter	mm
D	mean coil diameter	mm
De	outer coil diameter	mm
Detol	+/- tolerance of outer coil diameter	mm
Dh	minimum bush diameter	mm
F0	initial tension	N
F1	prestressed spring force	N
F1tol	+/- tolerance of prestressed spring force	N
F2	loaded spring force	N
F2tol	+/- tolerance of loaded spring force	N
Fn	maximum spring force	N
Fntol	+/- tolerance of maximum spring force	N
Lk	length of relaxed spring body	mm
L0	length of unstressed spring, measured from inner edge of loop to inner edge of loop	mm
L0tol	+/- tolerance of unstressed length	mm
L1	prestressed spring length, inner loop to inner loop	mm
L2	loaded spring length, inner loop to inner loop	mm
Ln	maximum spring length, inner loop to inner loop	mm
s1	prestressed spring deflection	mm
s2	loaded spring deflection	mm
sh	maximum stroke	mm
sn	maximum spring deflection	mm
Lh	distance of inner edge of loop from the spring body	mm
m	loop opening width	mm
R	spring rate	N/mm
nt	total number of coils	pc.
Gew	weight of one spring	g
PG	price group

formula extension springs (spring calculation)

formula	specification	unit
General
Material	Material
G	Shearing modulus	N/mm²
E	Elasticity modulus	N/mm²
Rm min	Minimum tensile strength	N/mm²
tau zul	Permitted shearing strength	N/mm²
k	Stress coefficient
Quality grade	Production quality grade
Wire length	Wire length for producing a spring	mm
Wire weight	Wire weight for producing a spring	g

Loops
Loop position	Angle between loops	degrees
Loop shape 1	Loop shape 1
Lh 1	Loop height of eye shape 1	mm
Loop shape 2	Loop shape 2
Lh 2	Loop height of eye shape 2	mm

Diameter
d	Wire diameter	mm
Di	Inner coil diameter	mm
D	Mean coil diameter	mm
De	Outer coil diameter	mm
Dh min	Minimum bush diameter	mm

Lengths
L0	Length of unstressed spring, measured from inner edge of loop to inner edge of loop	mm
L1	Prestressed spring length, inner loop to inner loop	mm
L2	Loaded spring length, inner loop to inner loop	mm
Ln	Maximum spring length, inner loop to inner loop	mm
Lk	Length of relaxed spring body	mm

Deflections
s1	Prestressed spring deflection	mm
s2	Loaded spring deflection	mm
sn	Maximum spring deflection	mm

Forces
F0	Initial tension	N
F1	Prestressed spring force	N
F2	Loaded spring force	N
Fn	Maximum spring force	N
F0 winding bench	Alignment force for F0 for manufacture on winding bench	N
F0 automatic	Alignment force for F0 for manufacture on automatic unit	N

Spring rate
R	Spring rate	N/mm

Coils
n	Number of active coils	pc.
nt	Total number of coils	pc.
nt-n	Number of non-elastic coils	pc.

Pitch
St.	Spring pitch (coil centre to coil centre)	mm
St.W	Pitch angle	degrees

Ratios
w	Winding ratio
Lk/D	Degree of slimness

Statics load
tau k0	Corrected shearing stress at F0	N/mm²
tau k1	Corrected shearing stress at F1	N/mm²
tau k2	Corrected shearing stress at F2	N/mm²
tau kn	Corrected shearing stress at Fn	N/mm²
tau k2 / tau zul	Ratio
tau kn / tau zul	Ratio

Gutekunst Federn · Carl-Zeiss-Strasse 15 · D-72555 Metzingen
Phone 0049 71 23 9 60-0 · Fax 0049 71 23 9 60-195
service@gutekunst-co.com

Extension Springs