RU2627082C2 - Method of manufacturing complex large-sized fully moulded part from welded workpiece - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: welded workpiece is produced from sheets, the weld is dressed, chipped, bent, drawn, cut, straightened, punched and flanged. In this case, sheets of the same nominal thickness and different material grades in at least two sheets corresponding to the least and the most stressed areas of the part are used. The sheets are welded along three lines (in one, two or three straight lines), where the sheet, strength, plasticity, fatigue and impact resistance of which exceed the said parameters of the sheets, corresponding to the least stressed part areas, correspond to the most stressed area.

EFFECT: increased strength and rigidity of individual areas of the part.

7 cl, 6 dwg

Description

The invention relates to sheet stamping and can be used in press production in various sectors of the national economy for the manufacture of complex large-sized whole-stamped parts from sheet materials (metals and non-metals), mainly for the manufacture of complex large-sized whole-stamped body parts of cars, tractors, agricultural machines, household and other equipment automated lines.

Typical technological processes for stamping complex large-sized body parts of automobiles and other equipment are known. These processes are widely used in automobile and other factories and are described in detail in numerous literature, for example:

1. Romanovsky V.P. Handbook of cold stamping. - S.-Pb .: Engineering, 1979, p. 165.

2. Nefedov A.P. Design and manufacture of dies. M.: Mechanical Engineering, 1973, p. 32, tab. 5.

3. The technology of manufacturing automobile bodies / Under the general. ed. D.V. Hot. - 2nd ed. M .: Mechanical Engineering, 1990, p. 41, tab. one.

Traditional stamping processes for complex large body parts include the following basic stamping operations:

felling of a flat billet from a single source sheet material (sheet, strip, tape or roll), which has the same thickness on the surface, in the procurement department of the press production;

bending the workpiece in order to obtain a semi-finished product with a surface approaching the surface of the elongated part on a separate press of simple action;

semi-finished product extraction on a double-acting head press in the press line or in the first position of a powerful sheet-stamping multiposition automatic machine;

preliminary cutting of technological allowance and punching holes on the semi-finished product on the next simple-action press in the line;

editing the entire form of the semi-finished product;

final trimming of technological allowance, punching holes;

flanging flanges at the edges of the semi-finished product, dressing of individual sections and obtaining the finished part.

A disadvantage of the known technological processes for manufacturing sheet-stamped parts from a single billet of the same thickness on the surface is the overestimated mass of such parts and, accordingly, the overestimated consumption of sheet metal and the cost of manufacturing such parts, since it is technologically impossible to change the thickness, strength and stiffness of individual parts of the part in accordance with the requirements of the functionality of this part in the machine assembly. Therefore, for such well-known technological processes, designers choose an overestimated thickness and brand of the most durable sheet material in order to provide the necessary strength and rigidity of the part in its most stressed areas, while in all other parts of the surface of the part, overestimated sheet thickness and strength are not needed.

In production, for example, in the manufacture of roofs for heavy-duty cabs and similar equipment, due to the absence of large-sized cold-rolled sheets, a technological process is known when large-sized billets are butt-welded from two, three or more sheets of the same thickness and material grade. Then the weld is cleaned, and the thus obtained weldment is stamped in traditional dies.

The disadvantage of stamping a part from a workpiece welded from several sheets of the same thickness and grade of material is the inability to change the strength and stiffness of individual parts of the part in accordance with the requirements of the functionality of this part in the product assembly, which leads to an overestimation of the mass of such a part.

The objective of the invention is to develop a method of manufacturing a complex all-stamped part from a sheet blank, which makes it possible to change the strength and stiffness of individual parts of the part in accordance with the requirements of the functionality of this part in the product assembly and thereby improve accuracy and quality, as well as reduce the mass of the part and the consumption rate material on this item.

The problem is achieved in that in a method for manufacturing a complex large-sized whole-stamped part, including obtaining a welded billet from sheets, cleaning the weld, cutting, bending, drawing, trimming, straightening, punching and flanging to obtain parts with strained sections, characterized in that the workpiece obtained from sheets of one nominal thickness and different, for at least two sheets, grades of material corresponding to the least and most stressed parts of the part, which are welded in three lines, from otory in one, two or three straight lines, while the most stressed section corresponds to a sheet whose strength, ductility, resistance to fatigue and shock loads exceed the specified parameters of the sheets corresponding to less stressed sections of the part.

In special cases, a closed sheet blank is obtained: 1) from four sheets with one central hole with cutouts in the welded edges forming this hole; 2) from four sheets with two central holes with cutouts in the welded edges, forming holes in the workpiece, and the welding lines are interrupted by these cutouts; 3) from four sheets with the formation of a workpiece with two holes, one of the holes of the aforementioned cuts, and the second is formed by a cut inside one sheet, and the welding lines are interrupted by cuts in the welded edges of the workpiece; 4) of four sheets with two holes with two cutouts inside one sheet, forming holes in the workpiece. Also receive: unclosed sheet blank of four sheets with cutouts in the welded edges, and the welding lines are interrupted by cutouts of the above sheets; an open welded sheet blank of five sheets with cutouts in the edges to be welded, while the welding lines are interrupted by cutouts of the above sheets. As sheets, use steel or aluminum sheets of the same nominal thickness, but different, at least for two of four or five sheets, grades with parameters such as strength, ductility, resistance to fatigue and impact loads of one sheet from which the most stressed part of the part is stamped . Moreover, these parameter values exceed the values of the same parameters of the remaining sheets, from which less stressed sections of the part are stamped, and the exact ratio of the parameters of all sheets, the configuration and location of the three welding lines must correspond to the calculated and experimentally obtained requirements for strength, stiffness and the possibility of drawing to a given depth without destruction of all parts of the surface of the part that are stamped from these welded sheets.

The invention is illustrated in FIG. 1-6.

In FIG. 1 shows a workpiece welded along three lines, in particular cases from these three lines along one, two or three straight lines, which can be interrupted by cuts in the welded edges of the sheets, from four sheets of the same nominal thicknesses t ₁ , t ₂ , t ₃ and t ₄ , but different, at least for two of the four sheets, grades of material sheets. Since the grades of the material of the sheets are different, then, in the general case, the tolerances on the thickness of these sheets are also different, which must be taken into account when designing the manufacturing process for manufacturing parts according to this method. Such a welded blank in the form of a closed ring (Fig. 1) is used for manufacturing, for example, a side panel of a passenger car using this method. The hole in the center of the workpiece is designed to facilitate deep drawing in the stamp of the opening for the car door.

The method is implemented as follows.

First, calculations are performed on the strength and rigidity of a given sheet-stamped part in its service position in a node of a working machine. Then calculate the shape, dimensions in plan and the nominal thickness t ₁ , t ₂ , t ₃ and t _{4 of} four sheets of a flat workpiece, as well as the location of the three lines of welding of these sheets (Fig. 1), so as to allow the semi-finished product to be drawn from this workpiece to a given the depth and performance of this part after all stamping operations. Of the four calculated nominal thicknesses t ₁ , t ₂ , t ₃ and t ₄ for four sheets of various grades, for the implementation of this method, one nominal thickness is selected for these four sheets, providing the requirements for the part.

For example, in the first particular case of the method in production, before stamping, the workpiece is welded along three lines of four steel or aluminum sheets 1, 2, 3 and 4 (Fig. 1) of the same nominal thickness t ₁ (equal, for example, 1.8 mm), but different, at least for two of the four sheets, stamps. The welded sheets form a closed blank with one central hole. Such parameters as strength, ductility, resistance to fatigue and shock loads of the first sheet 1, from which the most stressed part of the part is stamped, are larger than the corresponding parameters of the second 2, third 3 and fourth 4 sheets, from which the less stressed parts of the part are stamped, and the exact ratio of the parameters four sheets and the location of the three welding lines 1, 2 and 3 must correspond to the calculated and experimentally obtained requirements for strength, rigidity and the possibility of drawing to a given depth without breaking h Four parts of the surface of the part, which are stamped from these four welded sheets.

Next, the welds are cleaned up taking into account different tolerances for the same nominal thickness, but different grades of material of the four welded sheets, and then traditional operations of stamping a given part are performed.

In the second special case, before stamping, the workpiece is assembled along three welding lines 1, 2 and 3 (Fig. 2), from these three lines along one, two or three straight lines, which can be interrupted by cuts in the welded edges of the sheets, from four sheets 1, 2, 3 and 4 of the same nominal thickness, but different, at least for two of the four sheets, the grades of the material of these sheets, forming a closed blank with two central holes, the contours of which form from the contours of several sheets. Such a welded blank in the form of a closed ring (Fig. 2) is used for manufacturing, for example, a side panel of a passenger car using this method. Two holes in the center of the workpiece are designed to facilitate deep drawing in the stamp of the openings for two car doors.

In the third special case, before stamping, the workpiece is assembled along three welding lines 1, 2 and 3 (Fig. 3), of these three lines along one, two or three straight lines, which can be interrupted by cuts in the welded edges of the sheets, from four sheets 1, 2, 3 and 4 of the same nominal thickness, but different, at least for two of the four sheets, grades of material of these sheets, forming a closed blank with two holes of four sheets with cuts in the welded edges, with one hole formed by the aforementioned cuts, and the second formed by a cut in inside one sheet 2.

In the fourth particular case, before stamping, the workpiece is assembled along three welding lines 1, 2 and 3 (Fig. 4), of these three lines along one, two or three straight lines, which can be interrupted by cuts in the welded edges of the sheets, from four sheets 1, 2, 3 and 4 of the same nominal thickness, but different, at least for two of the four sheets, grades of material of these sheets, forming a closed blank with two holes of four sheets with two cutouts inside one sheet 2.

In the fifth special case, before stamping, the workpiece is assembled along three welding lines 1, 2 and 3 (Fig. 5), of these three lines along one, two or three straight lines, which can be interrupted by cuts in the welded edges of the sheets, from four sheets 1, 2, 3 and 4 of the same nominal thickness, but different, at least for two of the four sheets, grades of material of these sheets, forming an open sheet blank.

In the sixth particular case, before stamping, the workpiece is assembled along three welding lines 1, 2 and 3 (Fig. 6), of these three lines along one, two or three straight lines, which can be interrupted by cuts in the welded edges of the sheets, from five sheets 1, 2, 3, 4 and 5 of the same nominal thickness, but different, at least for two of the five sheets, grades of material of these sheets, forming an open sheet blank.

A method of manufacturing a whole-stamped part from a workpiece welded from sheets of the same nominal thickness, but different grades of material of these sheets, in comparison with the manufacture of a part welded from sheets of the same thickness and grade, can increase the strength and stiffness of certain sections of the part, taking into account its functionality in the product assembly , in the drawing operation, obtain the specified depth of the semi-finished product section without destroying the workpiece (due to the use of high plasticity sheet in this section), reduce the mass of the part (for through the use of sheets of smaller thickness, but greater strength), reduce the cost of manufacturing the part (by reducing the mass of the part and saving sheet metal), reduce the mass of the car (or other similar equipment) on which this part is installed of less weight, and, accordingly, reduce specific fuel consumption for moving this car and the emission of harmful exhaust gases into the atmosphere. Also, through the use of one of the sheets with increased ductility in the drawing operation, it becomes possible to obtain greater depth in certain sections of the elongated semi-finished product without destroying the workpiece.

This method can be applied for the manufacture of the following nomenclature of parts for automotive and other equipment:

inner panels of the front doors of cars;

inner panels of the rear doors, in which the welding line is shorter than that of the inner panels of the front doors;

roof and floor panels of automobiles and the like, and roof and floor panel amplifiers;

longitudinal side members and beams (for example, an automobile frame), grooves, guides, door and window trim, etc .;

transverse spars and beams;

the most diverse racks of car bodies and similar equipment and other nodes (front, rear, door, window, rotary racks, etc.);

the most diverse amplifiers of car body parts and similar equipment and other components.

Claims (7)

1. A method of manufacturing a complex large-sized whole-stamped part, including obtaining a welded billet from sheets, stripping a weld, cutting, bending, drawing, trimming, straightening, punching and flanging to obtain parts with strained sections, characterized in that the billet is obtained from sheets of the same nominal thickness and different, for at least two sheets, grades of material corresponding to the least and most stressed parts of the part that are welded along three lines, at least one of which is straight, while m of the most stressed section corresponds to a sheet whose strength, ductility and resistance to fatigue and impact loads exceed the specified parameters of the sheets corresponding to less stressed sections of the part. 2. The method according to p. 1, characterized in that receive a closed welded billet with one Central hole of four sheets with cutouts in the welded edges, forming a Central hole in the workpiece. 3. The method according to p. 1, characterized in that a closed welded billet is obtained with two central holes of four sheets with cuts in the welded edges forming holes in the workpiece, while the welding lines are interrupted by the said cutouts. 4. The method according to p. 1, characterized in that a closed welded billet with two holes of four sheets with cuts in the welded edges is obtained, one of the holes in the workpiece is formed by the said cuts, and the second hole is cut out inside one sheet, welding lines are interrupted by cutouts in the welded edges of the sheets. 5. The method according to p. 1, characterized in that receive a closed welded billet with two holes of four sheets with two cutouts inside one sheet, forming holes in the workpiece. 6. The method according to p. 1, characterized in that they receive an open welded sheet of four sheets with cutouts in the edges to be welded, while the welding lines are interrupted by cutouts of said sheets. 7. The method according to p. 1, characterized in that they receive an open welded sheet of five sheets with cuts in the edges to be welded, while the welding lines are interrupted by cuts of said sheets.

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