SU1548221A1 - Method of producing resilient elements - Google Patents

Abstract

The invention relates to mechanical engineering technology and can be used in the production of elastic elements, mainly large springs from hardened steel grades. The purpose of the invention is to increase the operational reliability and durability of elastic elements. Tubes of steel 60C 2 is heated to 980-1000 ° C, deformed by screw compression with tightening, quenched, heated to 620 ° C and wound. The degree of torsional deformation increases 1.3-1.5 times from both ends of the rod over a length corresponding to 1-2 turns of the spring, which allows increasing their durability. 1 tab.

Description

The invention relates to mechanical engineering technology and can be used in the production of elastic elements, mainly large springs from hardened steel grades.

The aim of the invention is to increase the operational reliability and durability of elastic elements -

FIG. 1 shows the initial-stage deformation scheme at HTMT, corresponding to the achievement of the greatest deformation by twisting on the front part of the rod; in fig. 2 - the same, final, stage, corresponding to the achievement of the greatest deformation by twisting on the back of the bar, equal to the value of the deformation on the front.

Driving rollers 1 using an inductor 2 rod 3 is fed into the deforming unit 4, where it is deformed for a given degree of deformation by compression and twisted to a degree of deformation by torsion, specified by the turning angle of the deforming rollers, and then cooled with a sprayer 5. along the length of the rod, namely, an increase in its degree from both ends of the rod over the length L, corresponding to 1-2 turns of the spring, is ensured by the successive release of each of the ends of the rod, over the distance L o T of the deforming unit 4. At the task of the bar 3 with the setting rollers 1 into the deforming unit 4, the front part of the bar is free and has a torque required to deform to the specified degree

compression formations (Fig. 1). In this case, the twisting deformation corresponds to the largest value. Further, when the bar passes through the deforming unit to the distance L, the rod is clamped by the gripper 6. In this case, the effective torque is distributed between the gripper 6 and the driving rollers 1, respectively, the deformation by twisting is reduced to the smallest. After passing the bar at a distance L from the rear part of the bar (Fig. 2), the bar 3 is released from the setting rollers 1 and at the core L of the bar length L the deformation increases by twisting to the highest value s corresponding to the value on the front of the bar.

Example, as an object, the spring of the LAZ bus with parameters was selected; Dc.7 95 mm, a „p 19 mm, n 7.25, t 22 mm, H0 179 mm. The bar length is 2320 mm. To produce an equal-strength spring according to the indicated technology, hot-rolled steel bar with a diameter of 22 m and a length of 1940 cc-i is subjected to TZTMO

from

pilot plant with high-frequency heating to 980-1000 ° С and water spray cooling. Screw crimped-off deformation with twisting is carried out with a degree of compression of 22% and a variable for the length of the deformation by torsion 18-28%, by the NPG 1em at the ends of the rod with a length of 500 mm deformation by torsion is 25-23%, in the middle part of the rod 18-20 %, which is ensured by the corresponding distances from the deforming to the capture and to the setting rollers. The rotation angle of the deforming rollers b, which provide the specified defoliation values to torsion, are calculated from

(5 arctg J-,

where s is the feed rate of the rod,

  mm / rev;

d K - diameter of the rod after; deformation ,, them „

The value of | 5 is 5.5; Coil of proetinum is applied from electrocontact heating 1PCH up to L20%, + 10 ° C at a rate of f-heating.

Cyclical testing of the springs, imitating the conditions of their operation, revealed an increase in the durability of wounds, which were obtained by the proposed method. So, for springs made by

known method of fishing, and

N

Wed 200 -10 cycles proposed - Ncp 235 xy cycles, with breakdowns occurring in different parts of the springs in length, and breakdowns of springs manufactured by a known method (as well as serial ones) occurring near the lugs 5

Torsional deformations with a degree of less than 18% are not enough to form a mechanical texture favorable for torsion (geometric directivity of grains, subgrains, structural components of inclusions), which, taking into account the actual conditions of the springs, should be arranged in a spiral along the direction of maximum tensile stresses. zheniy. From the results of static torsion tests, it follows that, starting with a deformation of 20%,

five

0

five

0

five

0

five

The strength properties of the torsion tests increase and correspond to elevated values with deformations of 25-28% or 1.3-1.5 times larger, which indicates that the texture coincides with the direction of maximum tensile stresses along the length of the rod. An increase in the degree of deformation of more than 28% or more than 1.5 times does not lead to a significant change in the mechanical properties, and the quality of the bar surface deteriorates.

The application of the proposed method allows to increase the operational reliability and durability of large springs with a high production culture. i

These changes in the mechanical properties of steel as a function of torsional deformation (Tzap 980 ° C, Tstp 200 ° CS / A06 20%) are given in the table.

Claims (1)

Invention Formula A method of manufacturing elastic elements, mainly large springs, including heating to temperatures above Ac5, plastic deformation by screw crimping with twisting, quenching, high-speed heating to temperatures below Ac, and winding, characterized in that, in order to increase operational reliability and durability, deformation by twisting 515482216 along the length of the rod, the variables of the rod are carried out, over the length, respectively, increasing 1.3-1.5 times to the end of 1-2 turns of the spring. Mechanical properties Data properties with respect to the degree of twisting ann of the ends of the rod and the middle part 0.7 Direct torsion Ј „, MPa 1735 Reverse torsion Spts, MPa 1700 Wi   J ji 1900 1795 1920 1800 1925 1800 s 1  L, s