RU1782693C - Method of manufacturing bent h-section parts - Google Patents

Abstract

Usage: in the manufacture of brake pads of a drum brake. SUMMARY OF THE INVENTION: the method consists in 2 producing billets of a T-profile from two strips by welding and bending it to the rib by a predetermined curvature. In this case, before welding, transverse and longitudinal depressions are formed on the strips, moreover, on the strip intended for the flange, depressions are made on the side of the welds, and on the strip intended for the rib, longitudinal depressions are performed only on the stretched section. Then the shelf and the edge are mounted to each other with surfaces having a similar relief, and they are welded, the resulting workpiece is subjected to bending. 1 s.p. f-ly, 10 ill.

Description

The invention relates to the processing of metals by pressure, in particular to bending of a profiled metal, and can be used in the manufacture of drum brake shoes.

A known eb layer for producing curved T-section parts, including producing T-section blanks and bending them on the rib to a predetermined curvature in a stamp.

During bending, from the viewpoint of crack formation, the most dangerous zone is the tension zone, since considerable contact friction arises there.

The latter limits the amount of back pressure on the wedge inserts in the bending die, which adversely affects the quality of the product.

The purpose of the invention is to improve product quality by reducing contact friction and reducing metal consumption.

This goal is achieved in that in a method of manufacturing curved parts of a T-section, including obtaining

billets of T-section and bending them on the rib, the billet is obtained by welding from a strip intended for a shelf and a strip intended for a rib, and before welding, transverse and longitudinal hollows are formed on one side of the strips, and hollows are made on a strip intended for a shelf from the side of the welded NEC, and in the strip intended for the rib, longitudinal depressions are made only in the stretched section.

A design variant is also possible in which similar longitudinal and transverse depressions are formed on the strip intended for the rib on its other side.

Figure 1 shows a cross section of a strip for a T-section shelf after surface treatment; Fig. 2 is a cross-sectional view of a strip for an edge of a T-profile after surface treatment; Fig. 3 is a tee profile formed by welding of two strips with machined surfaces; figure 4 is a section

with

N) Oh

Yu

Cj

AA in FIG. 3; figure 5 is a section bB in figure 3; Fig. 6 is a cross-sectional view of a strip for an edge of a T-profile with a relief on both sides; Fig. 7 is a tee profile formed by welding of two strips with machined surfaces; on Fig - section bb in Fig.7; in Fig.9 is a section GG in Fig.7; in FIG. 10 - brake pad.

Figure 1 shows the strip thickness for flange 1 before surface treatment t, the difference between the strip thickness at the protrusions after surface treatment and the original strip thickness At, the thickness of the strip at the troughs after surface treatment ti.

Figure 2 shows the strip thickness for rib 2 before surface treatment ta, the difference between the strip thickness at the protrusions after surface treatment and the original strip thickness At2, the thickness of the strip at the troughs after surface treatment Chz.

Figures 2, 3, 4, 6, 7, 8, 10 also show a neutral bending line of NLG, dividing the tensile zone that arises during bending into a rib from the compression zone.

The method is carried out as follows.

On a strip intended for a T-shelf flange 1 and having a thickness t, a relief is formed in two stages. Initially formed by rolling on one of its surfaces transverse to the longitudinal axis of the strip of the cavity. In this case, the strip elongates. And then form longitudinal depressions with the simultaneous formation of protrusions. As a result, a regular pattern is formed. Moreover, due to the redistribution of the metal, the height of the protrusions increases by At.

The resulting protrusion of the protrusions represents additional islands of increased strength in comparison with the base metal of the strip.

On the strip intended for the T-bar rib 2, at least on one of the side surfaces, rolls are formed transverse with respect to the longitudinal axis of the strip with elongation of the workpiece. And then, in that portion of the strip that will undergo tension during bending (i.e. below NL), longitudinal depressions are formed to form a protrusion of a relief similar to the above-described relief of a shelf.

A design variant is also possible (see Fig. 6) in which similar longitudinal and transverse depressions are formed on the strip intended for the rib on its other side.

Then, said strips intended respectively for shelves and ribs are mounted to each other with surfaces having a similar relief and welding of the T-profile. It is flexible a t-shaped profile on an edge

0 to a predetermined curvature is carried out in a stamp. Moreover, due to the presence of a relief on the inner surface of the shelf 1 and on the lateral surface of the rib 2, it became possible to apply more force

5 back pressure on the wedge inserts of the stamp during the bending operation, since the contact distance between the rib and the wedge inserts will be lower than when bending the T-profile without a relief.

At the same time, in the compression zones (on an edge higher than NLG), metal redistributes into the depressions of the relief. As a result, the thickening of the t-rib

5 profiles and shelves, i.e. their geometric dimensions are maintained.

In the stretch zone due to its hardening due to the relief and a decrease in contact friction between the workpiece and

With a punch tool, the likelihood of cracking is also reduced.

This generally has a positive effect on product quality.

It is known that as a result of hardening, a slight decrease in the ductility of the metal occurs.

However, in the inventive method, this disadvantage is compensated by the predominance of fluid friction.

0 Thus, the presence of a relief on the surfaces of the strips reduces the contact friction during bending, improves the lubrication of the contacting surfaces, which generally increases the formability

5 blanks and product quality.

In this case, the relief formation occurs with elongation of the strips and with hardening of the surfaces, which makes it possible to reduce the metal consumption of the product by 10%.

0

Claims (2)

SUMMARY OF THE INVENTION 1. A method for manufacturing curved T-section parts, comprising making T-section blanks and bending 5 of them per rib, characterized in that, in order to improve the quality of products by reducing contact friction and reducing metal consumption, the workpiece is obtained by welding from a strip intended for a shelf and a strip intended for the rib, and before welding, transverse and longitudinal depressions are formed on one side of the strips, and on the strip intended for the flange, depressions are made on the side of the welds, and on the strip intended for the rib, longitudinal depressions are performed only in the area subjected to expansion to burning. 2. The method according to claim 1, characterized the fact that in the strip intended for ribs, form similar longitudinal and transverse hollows on its other side. Srig. 1 Figure 1 l shz figure 5 cg and with cm with g m bu l b ) Gg /. 9, ,