DE1533997A1 - Process for the production of helical compression springs from hardened steel - Google Patents

Description

Vladimir Niko ^ jevic äalin June 15, 1967

Leningrad / USSR ^{L / Hu}

P 16 979

Process for the production of helical compression springs from hardened steels

The invention relates to helical compression springs and relates to methods of manufacturing helical compression springs made of hardened steels,

There are known methods for producing helical compression springs from hardened steels, in which the springs are hardened and tempered. The springs produced by the known method have a hardness of at most 52 HR ₀ , and the calculated shear stresses in the event of torsion are approximately 60 kp / mm.

The known springs have dynamic impact loads with high stress speeds that lead to collisions of the windings lead to large permanent deformations that affect the functionality of the mechanisms. In addition, these springs break easily.

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The present invention aims at the above-mentioned Disadvantages are eliminated.

The invention is based on the object of specifying a method for the production of helical compression springs, which allows the brittleness of the material from which the springs are manufactured, len by increasing the hardness and to correct an increased resistance of the springs to erzie- W and by increasing of the calculated shear stresses in the event of torsion to withstand increased stress velocities.

According to the invention, this object is achieved in that the tempering is carried out at a temperature which allows a spring hardness in the range of 55-58 HR _{0 to be} achieved, whereupon the surface of the spring is solidified to eliminate the wire brittleness. This consolidation is expediently carried out by shot peening.

To better understand the invention, a Embodiment described with reference to the accompanying drawings. It shows

1 shows a spring calculated according to customary standards for dynamic shock operation;

2 shows a spring according to the invention;

3 shows a spring according to the invention in the relaxed state.

909887/0617

_3_ 1533397

The process for producing helical compression springs from hardened steels consists essentially in hardening the spring, but tempering it at a lower temperature, which allows a spring hardness in the range of 3-58 HR _{0 to be} achieved. This is followed by a ball blast treatment to remove the wire brittleness that occurs when hardening to a high degree of hardness. The hardness achieved increases the elastic properties of the wire and allows the calculated shear stress at a torsion L of up to 150 kp / mm compared to the existing one

_ ΙΠ SlX.

L max ~ 60 kp / mm to be increased.

This tension is nar.h the formula

i = i 2 ⁺ V y 2 G P calculated, where:

L - ^ "ü ⁶ maximum calculated shear stress at gate

p
sion in kp / mm;

'2 -

Shear stress under compressive stress in operation

in kp / mm;

Y _Q - the rate of stress on the spring in mm / sj

G - the shear modulus in kp / mm;

p / I

- the material density in kp s / mm.

With an increased value L , the surface pressures caused by the collision of the windings decrease.

..Λ 909 887/0 61 /

_4-1533937

The above process is used to produce springs that have significantly reduced dimensions for the same hardness have compared to the known springs (see Fig. 1 and 2). In Figs. 1 and 2, two are by the same force P. preloaded springs shown.

The spring has turns of support 1 and effective turns (Fig. 3) · Between the Stützwindung 1 and the effective next one 2 $ a game is formed, whose size fd half the deflection value does not exceed r ^ active coil. The ends of the support turns 1 have a thickness h which is not greater than half the diameter d of the wire.

This spring design ensures increased resistance of the end coils when the coils collide during the spring work.

The wire can also have a different profile, for example in the form of a square or a rectangle. In this Case, the thickness h of the ends of the support turns 1 does not exceed half the profile thickness, measured along the spring axis 3 *

As different grades of spring steels depending on their chemical Composition after hardening, certain tempering temperatures are required to achieve the hardness range of 53-58 HEL specified in the process, for example for

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a tempering temperature of 360-380 ° 0 for steel grade 60 C2A (see table) and a tempering temperature of 380-40O ⁰ O for steel grade 6502BA.

Tabel :

ι ι ι ι ι Γ Ohem, together- coal- | SiIi-, Man- | Wolf- Chrom ι Nik- At most Setting fabric | ζium I gan I ram 'kel

I ι '

Steel grade

Schwe- Phos · fei phor

02A

0.56 0.64

1.60-2.00

0.60-0.90

-0.30 0.40 0.03 0.035

6502BA

0.61-0.69

1.50-2.00

0.70-1.00

0.80-1.20

-0.30 -0.40 0.03 0.035

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Claims (2)

15. Jimi 1967 L / Hu P 16,979 claims 1. Process for the manufacture of helical compression springs
made of hardened steels, "in which the springs are hardened and tempered, characterized in that the tempering is carried out at a temperature which allows a spring hardness in the range of 53-58 HR _{0 to be} achieved and that the surface of the spring is then used to eliminate the wire brittleness is solidified. 2. The method according to claim 1, characterized in that the solidification is generated by shot peening . 909087/0617