RU2449847C2 - Method of thermal-power local forming of metal panels - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and may be used in fabricating modular metal panels consisting of sheets and ribs or sections, moulded or welded panels. First, lengthwise forces are applied along stiffness rubs to curve the panel along said ribs. Then, crosswise forces are applied, along with heating, to wedge-like panel sections located across stiffness ribs. Note here that wedge base width and spacing between said sections are selected in proportion to preset radii of curvature, while billet is heated through its height.

EFFECT: reduced labor input, higher efficiency.

2 cl, 5 dwg

Description

The invention relates to the field of metal forming and can be used in the manufacture of metal structures of the module-panel type, consisting of sheets and ribs or profiles, as well as extruded or welded panels.

Known methods of bending and dressing of metal parts using elastoplastic bending in the cold state, as well as using local heating (Kuklin OS, Shabarshin VP "Means of technological equipment of case-processing workshops." - L .: "Shipbuilding", 1985 , Kuklin OS, Mikhailov BC “Problems of improving the quality of dressing and bending of hull parts.” - “Shipbuilding”, 1988, Gorbach VD, Vasiliev A.A. et al. “Technological design of hull processing workshops of shipbuilding enterprises”. - St. Petersburg: FSUE TsNIITS, 2005).

A technical solution is known according to the patent of the Russian Federation No. 927372, in which, when forming metal blanks, the combined effect of local bending forces and local heating along bending lines is proposed.

The objective of the present invention is to provide resource saving when bending and dressing metal parts and structures of the module-panel type. The technical result that provides a solution to the problem is to reduce the duration and complexity of the technological process of forming these parts and structures.

The problem is solved as follows.

In the proposed method, first, longitudinal forces are applied along the axis of the stiffeners until the panel is curved along these ribs, and then transverse forces are simultaneously heated from the concave side of the panel of plots in the form of wedges located across the stiffeners. In this case, the width of the base of the wedges and the step between the sections are chosen inversely proportional to the specified radii of curvature, and the heating depth is carried out to the height of the workpiece.

In the particular case of the proposed method, transverse forces are applied taking into account the subsequent thermal shrinkage of the heated metal and its springing, and in places with a given double curvature, the transverse force is directly proportional to the sum of the specified longitudinal and transverse curvatures of the panel.

The essence of the proposal is illustrated by the diagrams in figure 1-5.

Figure 1 shows the bending of sheet metal by rotational-local deformation (RLD) using local (local) heatings.

Figure 2 shows the same operation using sequentially local deformation.

Figure 3 shows a method of bending (editing) a typical welded construction of the module-panel type (top view), consisting of sheets and profiles.

Figure 4 shows a cross section of a bendable sheet part of a panel or sheets of a welded structure (section AA in Figs. 1-3).

Figure 5 shows a cross section BB of the welded construction module-panel (Figure 3) in the place of welding profile.

The sheet part 1 (Fig. 1) is subjected to a rotational-local deformation (RLD) along the bending line by a roller 3 with a radius of curvature R _{p of the} working surface by a force P along section 5 (AA) along a preheated section 6 of the bending line with a width of b _n in increments bending and heating lines b _i . The specified radii of curvature of the part - longitudinal R _CR and transverse R _pop (figure 4).

The sheet part 1 (FIG. 2), which, for example, is part of the module panel, can be bent sequentially by local deformation (PLD) along the bend line 2 by the punch 3 with a curve Rp of its working surface with force P at points 4, indicated by crosses with preliminary by heating at these points, as shown in cross section AA in FIG. The pitch of the bending lines and heating points b _i .

The welded construction of the module-panel type, consisting of sheets 1 and stiffeners (profiles) 7 (Fig. 3), is subjected to local heating along the bending lines on the sheets 2, as shown in section AA in Fig. 4. Moreover, heating is carried out in the left part with the concave front side from the top, and in the right part of the structure from the bottom (Fig. 5), since the bending direction changes in this place.

Local heating of sheet parts (FIGS. 1-2) and designs (FIG. 3) are made in cross section in the form of a wedge along the thickness (height) of the workpiece) (FIGS. 4 and 5) with a wedge base width b _n . The value of b _n is selected depending on the radius of the specified bending curvature R of the part with which it is connected by the ratio, based on the generally accepted hypothesis of flat sections during bending (figure 4)

.

.

The pitch of the bending lines b _i and the heating width b _n increase with a decrease in the required radius of the part, depending on the tolerance on the given shape of its surface and taking into account the subsequent thermal shrinkage of the heated metal, as is customary for thermal bending of sheets, which is determined by the literature sources .

The application of bending forces P (Figs. 1, 2, 3) is carried out by a roller or punch that is moved along the bending lines 2, and bending moments are created using support dies 8 or stacking weights, as is done when bending sheets and sections of ship hulls.

When bending sheet structural parts (module-panel), double curvature is obtained by thinning the workpiece Δh (Fig. 4), the value of which is determined depending on the required radii of the longitudinal R _pr and transverse R _pop bending according to the generally accepted condition of solid incompressibility

Local heating during bending and dressing can be carried out by HDTV installations, gas or plasma burners, a laser, and the first three of these methods are most effective for creating wedge heating.

Testing of the proposed method was carried out under the production conditions of Severnaya Verf Shipbuilding Plant OJSC, where sheets of the outer skin of the hulls were bent at the pilot plant using local strip heating with gas burners. To intensify the shaping, bending moments were created by crimping the workpiece by wedges along the edges. Local heating was also used It was tested on the MGPS-25 machine under the conditions of OAO Almaz SF. In this case, the heating was carried out by welding electrodes.

The application of the proposed method of forming (bending and straightening) sheet parts of the module-panel type using, for example, the automated bending and correcting complex AGPK-25 will allow, in comparison with the RLD method currently used, increase the thickness of the processed sheets up to 4 times during zone heating HDTV devices, for example, the Norwegian company "ELCA". Compared with hydraulic presses and rollers, the reduction in the required bending effort reaches 20–40 times, the weight of bending equipment by 12–60 times, the mass of equipment by 3.5–6 times, and the installed capacity by 2–4 times.

Claims (2)

1. The method of thermoset forming of metal panels of double curvature, consisting of sheets with stiffeners or profiles, characterized in that first they apply longitudinal forces along the axis of the stiffeners until they are curved with a longitudinal radius of curvature of the panel along these ribs, and then to obtain a transverse radius the curvatures apply lateral forces while heating from the concave side of the panel sections in the form of wedges located across the stiffeners, and the width of the base of the wedge and a step between the portions are selected inversely proportional to specify the radius of curvature, and depth of heating is carried out at the height of the workpiece. 2. The method according to claim 1, characterized in that the transverse forces are applied taking into account the subsequent thermal shrinkage of the heated metal and its springing, and in places with a given double curvature, the transverse force is chosen directly proportional to the sum of the specified longitudinal and transverse curvature of the panel.

Images